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Record Count: 122
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DESCRIPTION (provided by applicant): Many environmental toxins are oxidants. Proteins, which are major targets of oxidative modification, loose function/activity and must be proteolyticaly degraded or they will aggregate, and form cross-linked cellular inclusion bodies. In previous cycles of this grant, we have shown a major role for the proteasome in detoxifying oxidized proteins. Now we find proteasome is under dynamic control, exchanging regulators, and catalytic subunits in mild, acute stress. Understanding dynamic and inducible mechanisms of detoxification by proteasome is our immediate priority. Our broad, long-term objective is to define the mechanism(s) by which oxidized proteins undergo selective proteasomal proteolysis, the contributions of this detoxification system to health, and the impairment of proteasome under chronic or repeated stress. Our specific aims are to test the following hypotheses: 1) During acute oxidative stress, 20S proteasome undergoes activation by 11 S(PA28) or PA200 regulators, or by PARP or HSP90; whereas 26S proteasome undergoes disassembly and reassembly facilitated by HSP70; 2) Expression of proteasome, immunoproteasome, and proteasome regulators, is transiently induced by acute oxidative stress, allowing more efficient degradation of oxidized proteins; and 3) While acute (mild) oxidative stress transiently improves the ability of the proteasomal system to protect against oxidatively modified proteins, chronic or repeated stress actually impairs such adaptation and increases long-term susceptibility to environmental toxins. Hydrogen peroxide will be the major oxidant studied. Limited comparative studies will be conducted with peroxynitrite, hypochlorous acid/hypochlorite, hydroxyl radical, redox cycling quinones, and a hyperoxic cultivation environment. The importance of proteasome regulators and subunit exchanges will be tested with a combination of knockout mutants, siRNA (or antisense), antibody precipitation, and biochemical techniques. Direct activation versus increased subunit/regulator expression will be tested with transcriptional and translational inhibitors. Direct regulation by phosphorylation or glutathionylation will also be tested. Constitutively overexpressing cells and tet-off conditional transgenic cells, for proteasome subunits and regulators, will be used to model mechanisms of stress-adaptation, and to test our conclusions. Our studies will contribute to public health through improved understanding of mechanisms of toxicity, especially acute exposure versus chronic or repeated insults.
DESCRIPTION (provided by applicant): Our new ecologic evidence from Northern Chile suggests that arsenic exposure in childhood or in utero could cause up to a 10-fold increase in lung cancer in young adults. This may be the first time that early-life exposure to a common environmental agent has been linked to such high risks of an adult cancer in humans. Although supported by intriguing animal data, these findings are preliminary and need to be confirmed. The highly unique arsenic exposure scenario in Northern Chile offers an excellent and rare opportunity to do this. Because almost everyone in Northern Chile obtains their water from large municipal sources, and past arsenic levels in all of these sources are well documented over the past 50 years or more, arsenic carcinogenicity can be studied using data on past exposure that are much more accurate than can be obtained anywhere else in the world. In addition, a very distinct 14-year period of high exposure in this area has created a population where tens of thousands of people were highly exposed only in utero and early childhood. As such, this area provides a unique opportunity to study the long-term impacts of an early-life carcinogen with excellent data on past exposure. We propose a case-control study of 675 lung and bladder cancer cases obtained over a three-year period using a rapid case ascertainment system involving all local pathologists. Controls will be obtained from the Chile electoral register which includes 94% of the Chile population. We will obtain dose-response information with data on past exposure that is more accurate than found in any previous study and that can be directly applied to US regulatory and public health decisions. Biological samples will be collected and susceptibility related to metabolism, diet, genetics, and other factors will also be investigated. We have found evidence that people producing high levels of monomethylated arsenic (MMA) may have 2-5 times higher cancer risks than others. Whether this is due to the rarely studied but highly toxic trivalent form (MMA3) will be explored and could provide new information on the primary toxic species of arsenic carcinogenesis. Millions of people in the US are exposed to drinking water arsenic. Current US arsenic regulations do not incorporate information on potentially susceptible subgroups despite the fact that cancer risks in these groups could be exceedingly high. The information gained from this project may help to determine if some people, such as children, pregnant women, those who metabolize arsenic poorly, or those with poor nutrition, may need special consideration in regulatory standard setting. Information on early-life exposure, MMA3, diet, and the future genetic and proteomic studies we will plan as part of this project could add further insight into the important co-factors and mechanisms of environmental carcinogenesis.
DESCRIPTION (provided by applicant): We propose that pattern recognition receptors, whose normal function is in innate immune responses, are also activated by stress-generated ligands, such as molecules released by dying cells, normal and oxidized lipids and a variety of so called "danger" signals in addition to environmental toxins and pathogen associated molecular patterns. Activation of such receptors either by endogenous- (i.e. host-generated) or pathogen- generated ligands turns on stress-activated protein kinases, such as JNK, p38 MAPK and IKK, that serve as molecular transducers that contribute to development of chronic inflammatory diseases. Importantly, these pathogenic mechanisms allow the integration of environmental factors and genetic susceptibility loci that together contribute to the development of some of the most common chronic diseases, including type 2 diabetes, asthma, inflammatory bowel disease and chronic liver disease. In the previous grant period we have generated strong evidence in support of this hypothesis by focusing on the pathogenic functions of the JNK and IKK signaling pathways. We also generated a mouse model expressing the equivalent of the most common susceptibility allele for Crohn's disease, an inflammatory bowl disease whose pathogenesis is affected by genetic and environmental factors. In the present period we will focus our main effort on the pathogenic function of different classes of pattern recognition receptors as targets for stress - and injury- generated stimuli, as well as continue with our studies on the role of p38 MAPK in liver inflammation and toxicity. More specifically we will examine: 1) the role of protein kinase C isozymes and Toll like receptors (TLRs) in obesity-induced JNK activation and insulin resistance; 2) the role of TLRs in toxin-induced liver injury, liver inflammation and liver cancer; 3) examine the role of p38 MAPK in toxin-induced liver injury, liver inflammation and liver cancer; 4) examine the mechanism by which the intracellular NOD-like receptor NOD2 leads to activation of caspase 1 and IL-lbeta secretion; 5) construct a conditional mouse mutant that allows constitutive NOD2 activation and use it along with our previously generated Nod2delta33 knockin mutant to examine effects of tobacco smoke, microparticles and bacterial products on development of NOD2- modulated colonic and airway inflammation. To accomplish these aims we will use a combination of cellular biochemistry, molecular genetics and experimental pathology, an approach that has been proven effective during the previous project period.
DESCRIPTION (provided by applicant): Dioxins, generated both commercially and naturally, are chlorinated polycyclic aromatic hydrocarbons that are highly toxic environmental contaminants. These agents are known to be potent rodent carcinogens and suspected human carcinogens. The best known prototype of this group of agents is 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD). It has been well-documented that most, if not all, of the TCDD effects are mediated through the Ah receptor (AhR). In an effort to better understand the mechanism of TCDD action, we will investigate the molecular mechanism of the AhR signaling pathway. The working hypothesis is as follows: Upon TCDD binding, nuclear translocation of the receptor occurs and the AhR forms the AhR/Arnt/DRE complex in the nucleus, leading to activation of gene transcription. We discovered that p23 and CyP40 potentiate the formation of this AhR ternary complex in vitro (Refs: 1. Shetty, P. V., Wang, X., and Chan, W. K. (2004) Arch. Biochem. Biophys. 429, 42-9; 2. Shetty, P. V., Bhagwat, B. Y., and Chan, W. K. (2003) Biochem. Pharmacol. 65, 941-8) and these proteins appear to affect the AhR signaling in cell culture studies. This proposal focuses on the endogenous roles of p23 and CyP40 in the AhR signaling. Four specific aims have been proposed as follows: We will use p23 and CyP40 knockdown and overexpressed cells to determine whether (1) the heterodimerization of AhR and Arnt and the binding of the heterodimer to the DRE are affected by p23 and CyP40 in intact cells (Aim 1); the assembly of the AhR complex to the enhancer region prior to activation of gene transcription is affected by p23 and CyP40 in intact cells (Aim 2) and (3) the fate of the nuclear AhR is affected by p23 and CyP40. We will also examine the requirements of p23 and CyP40 in the AhR signaling (Aim 4). Deletion and mutation studies will be performed to map out the minimal structural requirement of p23 and CyP40 for the AhR function. Interactions between CyP40 and AhR will be examined and characterized. CyP40-interacting proteins that are essential for the full CyP40 effect on the AhR function will be identified and characterized.
The overall goal of our research is to understand the molecular mechanism by which halogenated aromatic hydrocarbons (HAHs), polycyclic aromatic hydrocarbons (PAHs) and related chemicals interact with the Ah receptor (AhR) to alter gene expression and responses of cells and animals to these inducers. The AhR is a ligand-dependent transcription factor that mediates the majority of the biological and toxicological actions of HAHs and PAHs. Significant species, tissue- and ligand-specific differences have been reported in the spectrum of toxic and biological responses observed following exposure to HAHs and PAHs but also in the concentration of chemicals needed to produce these responses, with HAHs being significantly more potent than PAHs. Although differential responsiveness to HAHs and PAHs can result from a variety of biochemical and physiological characteristics in target cells, it is generally accepted that the greater toxicological and biological potency of HAHs results from their significantly higher AhR binding affinity and resistance to metabolism. Recent evidence has demonstrated that differences exist in the potency and efficacy of HAHs and PAHs as activators of AhR-dependent gene expression that are separate from those directly related to their persistence and metabolic stability in the cell. We hypothesize that some of the differences in the potency and biological responses produced by PAHs and HAHs are directly related to ligand-specific differences in the structure of the AhR protein and/or AhR protein complex that alters the functionality of the AhR and its relative affinity/specificity for DNA/chromatin. Accordingly, here we propose to conduct detailed comparative studies to characterize the similarities and differences in the activation and persistence of ligand and DNA/chromatin binding of mouse AhR occupied by selected HAHs and PAHs in vitro and in cells in culture and to identify and characterize ligand-dependent changes in AhR structure. The DREnucleotide
specificity for transcriptional activation of gene expression by AhR complexes bound by HAHs
and PAHs and similarities and differences in HAH- and PAH-induction of gene expression assessed in cells culture and CYP null mice using microarrays. Finally, transgenic animals expressing a consitutively active (e.g., ligand-independent) AhR complex will be generated to examine contributions of the AhR and the ligand to the adverse effects associated with this persistent AhR activation. Overall, these studies will provide insights into the species- and ligand-specific differences in the ability of HAHs and PAHs to activate the AhR, the mechanisms responsible for the persistence of this activation and the role that it plays in the toxic and biological effects of HAHs and PAHs.
DESCRIPTION (PROVIDED BY APPLICANT): The Ah receptor (AhR) is a ligand-dependent transcription factor that mediates the toxic and biological effects of a variety of chemicals and it is believed that these effects result from receptor-dependent alterations in gene expression in susceptible cells. While the best characterized and highest affinity ligands for the AhR include a variety of toxic halogenated aromatic hydrocarbons, recent studies have revealed that the AhR can be activated by a wide variety of structurally dissimilar chemicals. This observation strongly suggest that the AhR has a promiscuous ligand binding domain (LED) and raises questions regarding the actual spectrum of chemicals which can bind to and/or activate the AhR. Although it's clear that that the AhR plays the key pivotal role in mediating the response of a cell to AhR ligands, there is little information with respect to the specific binding interactions of these ligands within the AhR LED or how these interactions lead to ligand-dependent activation of the AhR and AhR signal transduction. We hypothesize that specific binding interactions between AhR ligands and key amino acids contained within the AhR LBD are responsible for differential ligand affinity and specificity as well as ligand-induced changes in the AhR LBD structure that leads to AhR activation. Testing of this hypothesis has not been previously possible due to the lack of a 3- dimensional model of the AhR LBD. However, our recent development of a homology model of the PAS domain of the AhR LBD provides an avenue by which to carry out a mechanistically-directed structural analysis of these hitherto undefined events. Accordingly, we propose to develop, optimize and validate of homology model of the structure of the AhR LBD based on existing crystal structures for PAS domains from related proteins. Validation of the model will be confirmed using site-directed mutagenesis and characterization of AhR functional activities of mutant AhRs. QSAR and molecular docking approaches will be used to model the specific binding of ligands within the modeled AhR LBDs and will utilize binding data obtained by functional analysis of a library of novel flavonoids and indirubins. Site-directed mutagenesis and AhR functional studies will also be used in combination with modeling approaches to identify and characterize the regions of the AhR and AhR LBD responsible for interactions with hsp90 and the effect of ligand binding on these interactions. Overall, the studies proposed here will not only allow provide the first detailed analysis of the mechanisms by which ligands bind to and activate the AhR, but they will provide new insights into observed differences in species- and ligand-specific binding and activation of the AhR.
Crisp Terms/Key Words: aromatic hydrocarbon receptor, animal genetic material tag, toxicant screening, environmental toxicology, tissue /cell culture, receptor expression, receptor binding, DNA binding protein, protein structure function, gene expression, transfection, eicosanoid, species difference, indole
DESCRIPTION: (Adapted from the Investigator's Abstract) This is a
continuation application for a long-term project on effects of trace metal
ions on gene expression in human cells. During the last period, we began to
investigate the effects of toxic metal ions on signal transduction pathways
used for global regulation of gene expression, cell proliferation and
survival. The tumor promoter arsenite (As+3) was found to be a potent
activator of two mitogen activated protein kinase (MAPK) cascades that
stimulate the activity of transcription factor AP-1. This effect of As+3 is
due to inhibition of a dual-specificity protein phosphatase, JNK
phosphatase, whose normal function is to keep the MAPKs, JNK and p38 in a
low activity state. As induction of AP-1 activity is closely linked to
tumor promotion, the JNK phosphatase is probably an important mediator of
As+3 cocarcinogenesis. It may also be involved in As+3 induced inflammatory
disease. To examine the physiological role of the JNK phosphatase we will
characterize and molecularly identify it using a combination of biochemical
and molecular biological approaches. Dominant-negative mutants will be
transfected into cultured cell lines to inhibit endogenous JNK phosphatase
activity and thus assess its function in cell physiology. We will also
examine the susceptibility of mouse strains and cell lines deficient in JNK
or JNK phosphatase to As+3 induced cocarcinogenesis and toxicity. As+3 and
other trace metals were also proposed to act through non-specific induction
of oxidant stress. We therefore started to investigate the regulation of
transcription factor NF-KB, which was proposed to be a major sensor of
oxidant stress. We recently purified and cloned a key component in the
pathway leading to NF-KB activation, the protein kinase responsible for
phosphorylation and eventual degradation of the inhibitors of NF-KB, the
IKBs. We now propose to study the molecular mechanism by which oxidants
lead to activation of this IKB kinase (IKK). As NF-KB plays a key role in
inflammation, understanding the regulation of IKK activity by oxidants, such
as ozone, will provide a molecular basis for oxidant induced inflammatory
disease.
Crisp Terms/Key Words: mitogen activated protein kinase, nuclear factor kappa beta, oxidative stress, enzyme activity, phosphoprotein phosphatase, human genetic material tag, environmental toxicology, tissue /cell culture, protein tyrosine kinase, tumor promoter, cocarcinogen, molecular oncology, metal poisoning, heavy metal, metal complex, gene mutation, gene induction /repression, transcription factor, protooncogene, gene expression
DESCRIPTION (provided by applicant): The ability of the cell to maintain the stability of its genome is critical for survival, and eukaryotic cells are constantly challenged by both exogenous and endogenous sources of DNA damage. Cells are particularly susceptible to DNA damage during replication, when replication-blocking lesions can lead to collapse of a replication fork and formation of a double-strand break. As a result, cells have finely tuned processes to repair DNA damage during replication and to stabilize and restart forks that have stalled during DNA replication. Importantly, defects in these processes have been linked to a growing number of human diseases, among which are a number of syndromes associated with congenital and developmental defects as well as a predisposition to cancer. The overall objective of the studies proposed here is to identify and characterize new pathways and proteins involved in maintaining genomic integrity and replication fork stability. We recently conducted an unbiased genome-wide siRNA screen in human cells to identify candidate genes involved in these processes. Amongst our screening hits are many genes with no previously known connections to genome stability pathways. Here, we propose a series of additional assays to identify novel effectors of replication fork stability among our candidates. The unbiased approach we have taken has the potential to reveal unexpected connections between genome stability and other cellular processes, and to define new mechanisms by which cells maintain genome stability. Thus, we anticipate that these experiments will open novel avenues of investigation. PUBLIC HEALTH RELEVANCE: Defects in DNA damage response pathways have been linked to a growing number of human diseases, among which are a number of syndromes associated with a predisposition to cancer as well as congenital and developmental defects. Thus, the proteins and processes that we may link to replication fork stability could be responsible for some of these disease, and the knowledge gained from understanding the signaling pathways linked to these syndromes could provide critical insights relevant to their diagnosis, treatment and etiology.
DESCRIPTION (provided by applicant): Eukaryotic cells face constant challenges to the integrity of their genome, and sophisticated processes have evolved to respond to DMA damage. Cells arrest cell division, repair damage, and in some cases undergo apoptosis, and failure to carry out these processes can lead to genomic instability and cancer. In fact, defects in these processes form the molecular basis for many cancer-prone disorders. DMA damage tolerance mechanisms are another aspect of the DMA damage response that allow the cell to continue replication in the presence of polymerase-blocking lesions, leaving repair of the damage for a later time. The overall goal of this proposal is to understand the molecular mechanisms that regulate DMA damage tolerance. One form of tolerance involves switching from high-fidelity replicative polymerases to translesion synthesis (TLS) polymerases at the site of damage. This switch is thought to involve monoubiquitination of the replicative sliding clamp PCNA at the stalled replication fork. This form of tolerance is error prone because the TLS polymerases are of lower fidelity than the replicative polymerases. A second, error-free form of DMA damage tolerance also involves the ubiquitination of PCNA. In order to understand the mechanisms regulating DMA damage tolerance and TLS, we will: (1) Determine the mechanism by which single-stranded DMA regulates the ubiquitination of PCNA; (2) Investigate the relationship between PCNA ubiquitination and the switch between replicative and TLS polymerases at the replication fork; and (3) Determine the role of the ATR-mediated checkpoint in TLS and DNA-damage induced mutagenesis. We will explore these questions using a cell free system derived from the eggs of Xenopus laevis that recapitulates many aspects of DNA damage tolerance. These extracts provide a tractable system for analyzing the complex pathways regulating TLS and damage repair. The experiments described in this proposal should help us understand the mechanisms used by cells to regulate DNA damage tolerance process. Because defects in these processes lead to loss of genomic integrity, cancer and cell death, these studies will provide valuable insight into how cancer develops and may ultimately point the way to new approaches for the treatment or detection of cancer.
DESCRIPTION (provided by applicant): The damage of DNA by ultraviolet (UV) light from the sun is assumed to be responsible for the induction of mutations and the development of skin cancer in humans. To understand UV carcinogenesis, a more detailed knowledge of the molecular mechanisms of UV damage, repair and mutagenesis is necessary. In this competing continuation application, we will address the following issues: In Specific Aim I, we will characterize the DNA damaging and mutagenic properties of UVA irradiation, a component of the solar spectrum that has been linked to melanoma. In Specific Aim II, we will try to demonstrate a molecular link between sunlight exposure and melanoma. We will attempt to identify a UVB signature in the human p16 gene of melanoma patients and a UVA signature in the BRAF gene. In Specific Aim III, we will test the hypothesis that specific lesion-tolerant DNA polymerases and additional factors are involved in UV mutagenesis. We will determine the in vivo roles of DNA polymerases eta, iota, kappa, beta, RAD3/RAD7 and REV1, as well as other proteins in UV mutagenesis. These studies will employ siRNA technology to knock down specific proteins involved in UV mutagenesis. The experiments will use supF plasmids containing CPDs or (6-4) photoproducts, which are replicated in cells treated with siRNA against the same polymerases. These studies will be complemented by ones using mouse embryonic fibroblasts carrying mutation reporter transgenes and derivatives of these cells expressing photoproduct-specific photolyases and specific siRNAs. In Specific Aim IV we will test the hypothesis that 5-methylcytosine plays a crucial role in UV mutagenesis in mammalian cells. We will study the effects of 5-methylcytosine and 5-methylcytosinebinding proteins (mCpG-binding proteins, MeCP2, MBD2, MBD1) on UV damage induction and repair in vitro, on the deamination of 5-methylcytosine within cyclobutane pyrimidine dimers, and on mutagenesis in a CpG-methylated mutation reporter gene. Altogether, these studies should increase our understanding of the mechanisms of UV-induced DNA damage, its repair and the mechanisms of mutagenesis that lead to alterations in genes that are implicated in nonmelanoma and melanoma skin cancers.
DESCRIPTION (provided by applicant):
Most complex diseases have genetic causes, but observations from families and especially from twins indicate that other factors are almost always necessary for the actual appearance of disease. One such factor appears to be the proportion of DNA units that have methyl groups attached to them, or more accurately the methylation status at important specific loci. The level of methylation is known to vary between individuals and has been linked to several chronic diseases. The level has been shown to change with increasing age, even within the members of identical twin pairs. Some of these changes are probably the result of endogenous forces and therefore are likely to have appeared at random. Others, however, are likely to be the result of the environmental exposures that cause disease or the risk factors that precede its appearance. This study seeks to evaluate the linkage between the DNA methylation status and environmental factors known to predict disease occurrence. Methylation will be assayed using the more accurate pyrosequencing method, and studied both in blood cells, upon which much of the current understanding is based, and squamous epithelial cells from the mouth, likely to be more heavily exposed to high levels of environmental agents. The level of methylation will be compared in twins who give a history of pertinent environmental exposure, to that in their relatively unexposed identical co-twins. The list of such exposures includes smoking, alcohol usage, obesity, consumption of foods known to contain folic acid and food known to contain carcinogens, and occupational and residential exposure to various environmental chemicals and toxins. The plan is to also select those sets of identical twins least likely to have been exposed to environmental toxins, based on residence, occupational exposure, and diet, in order to measure the age-specific levels of DNA methylation, and the degree to which those levels vary in relation to sex and twin pair. These levels and indices of variation will be compared to the same findings from pairs selected on the basis of sex, educational status, and maternal educational status (a measure of childhood social class). Finally, any evidence of a heritable propensity to change methylation status, based on identical and like sex fraternal twins having the least evidence of cumulative toxic exposure, will be investigated.
DESCRIPTION (provided by applicant):
Epigenetic mechanisms act at the interface between genetics and environment and are an important determinant in disease risk to complex human diseases such as cancer or autism. This proposal employs a combination of systems and approaches that focus on the central question of the impact of persistent environmental pollutants (POPs) on precise epigenetic changes that occur in neurodevelopmental disorders. The widespread prevalence of POPs such as polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in the environment and their detection in human milk has prompted concern about in utero and early infant exposure to these compounds. Perinatal exposure to PCBs and PBDEs in rats results in long-lasting defects in learning, memory, behavior, and seizure susceptibility in adulthood. Epigenetic changes to the genome as a result of PCB and PBDE exposures have not been previously explored but are a plausible explanation for the long-lasting effects on neuropsychological function. This proposal will focus specifically on two compounds, PCB 95 and PBDE 47, with high levels in humans and known effects on neurodevelopment. The genetically controlled component of the proposed studies will be to use a genetically engineered Mecp2 mutant mouse model of Rett syndrome and autism. In additional to animal studies, human blood and post-mortem brain samples from individuals with autism, mental retardation, and controls will be tested for precise epigenetic changes in three neurodevelopmentally important genes (MECP2, GABRB3, UBE3A). Since PCB and PBDE levels will be determined in these human samples, correlations of exposures to epigenetic changes can be performed. Several public health relevant questions will be addressed by these studies: What specific epigenetic changes to neurodevelopmentally important genes occur as a result of POP exposure? What is the compounding effect of known genetic and environmental factors in the etiology of autism and mental retardation? Can specific epigenetic changes be diagnostic for autism and mental retardation of unknown genetic etiology? Are epigenetic changes affecting neurodevelopment heritable?
DESCRIPTION (provided by applicant): We propose to work cooperatively with other Mapping Centers and the Data Coordination Center (EDACC) funded by this Roadmap mechanism to comprehensively map epigenomes of select human cells with significant relevance to complex human disease. Our group, consisting of scientists at UCSF, UC Davis, UCSC and the British Columbia Genome Sciences Centre has the broad expertise that this project requires. We will focus on cells relevant to human health and complex disease including cells from the blood, brain, breast and U.S. Government-approved lines of human embryonic stem cells (aim 1). We will incorporate high quality, homogeneous cells from males and females, and two predominant racial groups, and biological replicates of each cell type. Production of comprehensive maps will include 6 histone modifications selected for their opposing roles in regulating active and inactive chromatin (aim 2), DNA methylation (aim 3) and miRNA and gene expression (aim 4). This epigenetic data, along with genetic and expression data will be integrated using advanced informatics (aim 5) to address fundamental roles of epigenetics in differentiation, maintenance of cell-type identity and gene expression. Our cell and data production pipeline will incorporate verification and data validation with independent methods, and will operate under a model motivated by increased data production and decrease cost. We summarize the analysis capacity of our instruments and our explicit strategy for data sharing of our proposed REMC-generated resources including biological specimens, protocols, data, software tools and intellectual resources. We envision that our group in conjunction with the other REMC teams, the EDACC, ENCODE, future EHHD (Epigenetics of Human Health and Disease) centers and the NIH Roadmap program will develop methods, tools and reference epigenome maps for the research community that will make the promise of epigenetics in understand and treating human complex disease a reality. Our reference epigenomes will enable new disciplines including human population epigenetics, comparative epigenomics, neuroepigenetics, and therapeutic epigenetics for tissue regeneration and reversal of disease. PUBLIC HEALTH RELEVANCE: The epigenome is the dynamic interface between our changing environment and the static genome, and understanding it is a goal of immense importance to human health. We will map reference cell epigenomes of the brain, breast, blood and approved embryonic stem cells, inclusive of males and females and different racial groups. This cooperative work will transform our understanding of the short and long-lasting consequences of environment impact on human health and disease.
DESCRIPTION (provided by applicant): This proposal aims to develop a method to screen for chemical agents that disrupt epigenetic processes in mammalian cells. Epigenetics deals with heritable changes to the function of DNA that does not involve altered DNA sequence. In mammals and other multicellular organisms, most of the genome is kept in a silent transcriptional state by epigenetic mechanisms. Disruption of this silent state can have drastic effects, including developmental anomalies and cancer. Some chemicals are known to disrupt epigenetic silencing, but we have no comprehensive picture of the environmental agents that can act as "epimutagens". We hypothesize that there are many chemical epimutagens. In order to facilitate the discovery and study of these agents, we propose to develop a mammalian cell-based system that can screen for epimutagenic activity in mammalian cells. We will adapt a system that we have used extensively to study epigenetic silencing of transgenes in cultured cells. By selecting for cell clones that are sensitive to the disruption of epigenetic silencing by known epimutagens, we will derive a panel of cell lines that can be used to screen for epimutagenic activity in a manner analogous to the Ames test for mutagenicity. PUBLIC HEALTH RELEVANCE: Human development and disease are pervasively affected by epigenetic processes. There may be many environmental agents that are capable of disrupting epigenetic silencing and causing health effects, but we lack the means to readily identify them. We propose to develop a system that will permit screening of large numbers of chemicals for epigenetic effects. PUBLIC HEALTH RELEVANCE: The protection of humans from harmful environmental chemicals requires the existence of means to identify such compounds from among the millions of dietary and industrial chemicals to which people are exposed. Tests for mutagenic compounds-those that cause errors in the sequence of DNA and are therefore carcinogenic-have existed since the 1970s. Another class of potential carcinogen, however, the class of epimutagenic compounds, is currently undetectable; research into and regulation of such compounds is not a routine part of environmental health monitoring. We propose to develop tools for the detection and measurement of epimutagens, ultimately enabling environmental protections to be put in place.
DESCRIPTION (provided by applicant):
Some non-genotoxic agents cause epigenetic changes, including aberrant DNA methylation. A subset of these drug, called endocrine disrupters -synthetic chemicals resembling natural hormones-, have profound effects on development and fertility. The central hypothesis of the proposal is that developing germ cells, which undergo genome-wide epigenetic reprogramming, are especially vulnerable to the epigenetic effects of endocrine disrupters. Fetal germ cells provide an excellent study system to reveal the origin of transgenerational epigenetic effects. This proposal seeks to identify epigenetic changes in fetal germ cells after intrauterine exposure to selected endocrine disrupters. To address the central hypothesis, the specific aims are to: 1) Determine the methylation status of the H19/lgf2 imprinting control region (ICR) in perinatal germ cells after fetal exposure to endocrine disrupting chemicals; 2) Assess global transcription changes caused by endocrine disrupters in fetal germ cells and gonadal somatic cells; and 3) Identify targets for aberrant hypermethylation by endocrine disrupters, in mouse female and male germ cells.
DESCRIPTION (provided by applicant): The human embryonic stem cells (hESCs) are a unique model system for investigating the mechanisms of human development due to their ability to replicate indefinitely while retaining the capacity to differentiate into a host of functionally distinct cell types. In addition, these cells could be potentially used as therapeutic agents in regenerative medicine. Differentiation of hESCs involves selective activation or silencing of genes, a process controlled in part by the epigenetic state of the cell. In order to gain a better understanding of the epigenetic mechanisms regulating differentiation of hESCs, and produce general reference epigenome maps of the human cells, we propose to establish an Epigenome Center in San Diego. Our center will be focused on both undifferentiated hESC and four hESC-derived early embryonic cell lineages including extraembryonic endoderm, trophoblast, mesendoderm (a common precursor to mesodermal and endodermal lineages), and mesenchymal cells (a specific mesoderm derivative). We have developed and validated high throughput technologies for mapping the state of DNA methylation and chromatin modifications throughout the genome, and will use these methods to generate high-resolution maps of the reference epigenomes. Specifically, we will grow and differentiate hESCs into multiple lineages, and map DNA methylation sites using a newly developed technology that combines bisulfite conversion and whole genome shotgun sequencing. We will also determine the histone modification status in the genome by performing both ChlP-chip and ChlP-Seq analysis. We will develop advanced statistical and algorithmic solutions to facilitate high-throughput sequencing data analysis, and establish an informatics pipeline for collecting, storage, and distribution of epigenome maps. Finally, we will perform integrated data analysis to identify new epigenetic patterns in the genome that could provide insights in mechanisms of epigenetic regulation.
DESCRIPTION (provided by applicant): A major function of telomeres is to protect the ends of chromosomes and prevent chromosome fusion. Chromosome fusion can result in chromosome instability through breakage/fusion/bridge (B/F/B) cycles, which occur when chromosomes repeatedly break and fuse with each cell division. B/F/B cycles can be prevented or terminated by the addition of telomeres to the ends of broken chromosomes, which results in the formation of terminal deletions. In Tetrahymena and yeast, telomeres are added on to the ends of broken chromosomes by telomerase, termed chromosome healing. Chromosome rearrangements associated with telomere loss and B/F/B cycles have been found in a variety of human genetic diseases, and are thought to play an important role in the chromosome instability associated with cancer. We have established an assay that utilizes selectable marker genes located adjacent to a telomere to monitor the consequences of telomere loss in mammalian cells. Telomere loss is induced through the introduction of a double-strand break at an I-Scel site adjacent to the telomere following the expression of the I-Scel endonuclease. Most mouse embryonic stem cells that lose a telomere have telomeres added directly on at the I-Scel site; however, sister chromatid fusion and chromosome instability involving B/F/B cycles is observed in cells that do not add a telomere on to the end of the broken chromosome. The present proposal will use this system to address the consequences of telomere loss in mammalian cells. Specific Aim 1 will investigate the role of telomerase and the Pif1 helicase in chromosome healing. Pif1 mutants in yeast have a 600-fold higher incidence of chromosome healing, and as a result, Pif1 has been proposed to negatively regulate chromosome healing to prevent terminal deletions. These experiments will test the hypotheses that telomerase and Pifl are important in chromosome healing in mammalian cells and that chromosome healing prevents B/F/B cycles. Specific Aim 2 will utilize cell lines containing mutations in DNA-PKcs or NBS1, to address the role of nonhomologous end joining and the Mre11/Rad50/Nbs1 complex in telomere maintenance, chromosome healing and chromosome fusion. Specific Aim 3 will test the hypothesis that chromosome instability due to telomere loss promotes carcinogenesis by expressing I-Scel in vivo and monitoring preneoplastic changes resulting from the amplification/rearrangement of the c-Myc gene on the chromosome 15 containing a telomeric I-Scel site.
DESCRIPTION (provided by applicant): The long term goal of this research program is to uncover and understand mutational pathways, the DNA repair processes or avoidance mechanisms that counteract these pathways and the consequences of defects in these systems. Our basic approach has often involved characterizing "mutator strains" that have higher mutation rates than wild-type, and then determining the affected pathway or repair system. We have developed new approaches for the detection of mutators, and this has allowed us to define several new mutational pathways, including one that results from the overexpression of the EmrR repressor of a multi-drug resistance efflux pump. Overexpressing a common repressor is one way to detect mutational pathways that back each other up and thus require two knockouts to produce a mutator phenotype. We hypothesize that this system acts to pump out mutagenic products of metabolism and represents the cell's first line of defense against mutagenesis. This proposal seeks to test this idea by further charactering this novel system, and also to characterize other new mutational pathways we have discovered. For instance, the use of metagenomic libraries has revealed that multiple copies of extensively repeated sequences results in global genomic instability. This will be further investigated. We will also utilize the recently completed E. coli knockout collection, consisting of close to 4,000 strains, each carrying an in-frame deletion of one of the orfs in the E. coli genome, together with our own tools to screen for new mutational pathways. We will use gene fusions to study the regulation of different repair genes and to characterize the action of new mutators, and will use several pathogen or extremophile genomes (Bordetella pertussis, Campylobacterjejeuni, and Deinococcus radiodurans) as a source for genes that might provoke mutator phenotypes in E. coli, and also that would complement different E. coli repair defects. We will also construct a system for studying mutagenesis in a pathogen such as B. pertussis.
DESCRIPTION (provided by applicant): The broad objectives of this grant are to investigate biochemical mechanisms by which damaged DNA is copied by the cell's replication and repair enzymes, focusing on proteins that are induced in response to DNA damage. Damage-induced DNA repair occurs in both procaryotic and eucaryotic organisms. In Escherichia coli, response to DNA damage is orchestrated by an operon, the "SOS regulon", containing more than 40 different proteins under negative control of a repressor protein, LexA, and a multifunctional protein, RecA. In E. coli, and in animal cells, damage-induced DNA repair can often be aberrant. There is a reduction in fidelity that enables replication to continue past blocking DNA damage sites. The primary goal of this proposal is to elucidate the biochemical basis for SOS-induced error-prone repair in E. coli. Such repair depends on RecA protein interacting with a mutagenic UmuD'2C protein complex, which we showed to be a new DNA polymerase, E. coli pol V. The discovery of this new polymerase provided the impetus for the "explosive" growth based on subsequent discoveries of fundamentally important error- prone eukaryotic DNA repair polymerases involved, for example, in avoiding skin cancer and in generating antibody diversity. There are numerous types of damage occurring in DNA when cells are exposed to chemicals, drugs or radiation. To study the biochemical basis of error-prone repair in vitro, we have chosen to focus primarily on copying site-directed biologically relevant lesions that occur spontaneously or from exogenous DNA damage. DNA template lesions often present a strong block to DNA replication. When replication past a lesion does occur, it can generally cause a mutation targeted to the DNA damage site. In this proposal, we will focus on the key biochemical interactions responsible for error-prone translesion DNA synthesis, involving E. coli DNA polymerase V, RecA protein, and polymerase processivity clamp proteins. We intend to determine the mechanisms governing targeting of repair polymerases to damaged DNA and mechanisms of trafficking between polymerases, to exchange high fidelity replication polymerase blocked at a site of DNA damage with low fidelity repair polymerases that can relieve the blockage at the expense of generating mutations. During the previous grant period, we discovered an unprecedented mechanism in DNA replication by which E. coli DNA polymerase V is unable to copy damaged or undamaged DNA unless activated in trans by RecA bound to ssDNA not being copied by pol V. A central theme of this proposal is to establish the mechanistic basis for RecA- ssDNA transactivation of pol V. The data generated in the proposed experiments will have major biological impact in exploring the principles of how damaged DNA is copied.
Project Narrative: In organisms ranging from bacteria to humans, almost all mutations are deleterious, serving as a root cause of numerous diseases including cancer. Ironically, however, it has recently been found that there are error-prone DNA repair pathways that are beneficial, indeed essential, in providing immunological diversity, general fitness and avoidance of cell death, and even protecting against some human diseases, for example skin cancer. The proposed research explores the biochemical basis governing the ability of error-prone DNA polymerases to copy damaged DNA that would otherwise cause a cessation of chromosome replication leading to cell death.
DESCRIPTION (provided by applicant):
Both genes and environmental toxins may act as risk factors for Parkinson's disease (PD), but their potential interplay remains poorly understood. This proposal seeks to investigate gene-environment interactions that are potentially relevant to PD using the model organism Drosophila melanogaster. Attention will be directed on genes and toxins associated with PD that affect mitochondrial dysfunction, protein ubiquitination and dopamine homeostasis. Over-expression of the Drosophila vesicular monoamine transporter (DVMAT) has been shown to protect against the neurotoxic effects of at least one mutant gene associated with PD (parkin), and at least one pesticide (rotenone) that selectively kills dopaminergic neurons. This study will therefore test the hypothesis that the neuroprotective effects of VMAT will extend to a different toxin, paraquat, thought to act by a different mechanism than rotenone, and whether this requires its localization to synaptic vesicles and if it is required at a specific time relative to neurotoxic insults. Studies here have shown that over-expression of mutant forms of parkin can cause dopaminergic cell degeneration in flies. If mutations in parkin function as a risk factor for PD, then additional environmental agents may enhance this risk. This study will test this hypothesis using rotenone, paraquat and other agents. Parallel experiments for gene-environment interactions will be performed with the PD related gene, pink1. Finally, already established pink mutant phenotypes will be used to screen for agents that rescue the neurotoxic effects of mitochondrial dysfunction.
DESCRIPTION (provided by applicant): ATM (ataxia telangiectasia mutated) heterozygosity seems to be a risk factor for cancer. Even though the penetrance seems to be low, because of the high prevalence of 1-5% in the human population, the population risk is higher than for BRCA1 and BRCA2 together. We hypothesize that the reason why only some people heterozygous for ATM develop cancer may in part be due to the fact that the human population is extremely varied with regard to additional genetic cancer predisposing or protecting factors as well as nutrition factors and that only certain gene-gene and/or gene-nutrition interactions may lead to the highest risk for cancer. Genetic instability, in particular DNA deletions are involved in the etiology of cancer. ATM deficient homozygous patients and mice show a high incidence of cancer, signs of oxidative stress and an elevated frequency of DNA deletions which we found using an in vivo pigmentation assay. This assay is based on the quantification of black spots on fur and eyes resulting from reversion of the pun mutation. This reversion occurs by deletion of 70 kb of an internal duplication within the p gene. We have also shown that ATMASRI missense mutation homozygous as well as heterozygous mice show elevated frequencies of DNA deletions. In addition, we have shown that the elevated frequency of DNA deletions in ATM homozygous disruption mutant mice is completely reverted to wildtype levels by nutritional supplementation with the radical scavenger N-acetyl cysteine (NAC). GGT deficient mice have lower levels of glutathione and show signs of oxidative stress. In aim 1 we propose to investigate whether ATMASRI heterozygous or homozygous mice together with GGT deficiency show synergistically elevated frequencies of DNA deletions (gene-gene interactions), In aim 2 we propose to test whether ATMASRI homo and heterozygous mice nutritionally supplemented with NAC show reduced frequencies of DNA deletions and whether mice supplemented with the prooxidant BSO show an increased frequency of deletions (gene-nutrition interactions). It will be tested in the third aim whether the elevated frequency of cancer in ATMASRI homozygous mice can be reduced by chemoprevention with the antioxidant NAC (gene-nutrition interaction). Implications for human health may include that ATM patients as well as heterozygous people (1-5% of the human population) in combination with genetic or nutritional factors predisposing to a higher sensitivity to oxidative stress may show an increased risk for cancer, and that chemoprevention with antioxidants may reduce the cancer risk in such genetically predisposed people.
DESCRIPTION (provided by applicant): CYP2S1 is a recently identified human cytochrome P450, expressed extensively in epithelial tissues. We propose that CYP2S1 plays a significant role in the metabolic activation of environmental procarcinogens, and the metabolism of pharmaceuticals and endogenous compounds. The proposal will address this hypothesis and characterize regulation of the enzyme. There are three specific aims: (i) We have expressed human CYP2S1 in bacteria, and demonstrated that it metabolizes several compounds that are toxic and/or carcinogenic to epithelial tissues. We will also over-express the enzyme in mammalian cells. Using these expression systems, we will screen for additional substrates, and also for procarcinogens that are activated to mutagenic (and therefore probably carcinogenic) derivatives by CYP2S1. The Km and Vmax values will be determined for representative compounds, and the metabolites that are formed will be identified. The degree to which CYP2S1 contributes towards the total metabolism of particular substrates in human epithelial tissues will be determined using an inhibitory antibody to the enzyme, (ii) We have shown that CYP2S1 is inducible by dioxin, carcinogenic polycyclic aromatic hydrocarbons (PAHs), and hypoxia. We will investigate whether the potential Xenobiotic Responsive Elements (XREs), or the potential Antioxidant Response Element (ARE) in the 5' flanking region of the human CYP2S1 gene mediate induction by dioxin and/or PAHs, and address the hypothesis that due to the particular nucleotide sequences of the above XREs, the gene responds better to PAHs than to dioxin in certain cells. We will also analyze the mechanism of hypoxic induction of the gene, (iii) We will generate a knockout mouse for Cyp2s1, and then generate a derivative of this mouse containing the human CYP2S1 gene, including its flanking regulatory regions. This "CYP2S1-humanized" mouse will be used to study the metabolism of substrates of human CYP2S1, the biological consequences of this metabolism, and the regulation of the human CYP2S1 gene by xenobiotics and hypoxia, thus complementing and extending specific aims 1 and 2. Our studies may demonstrate important roles for CYP2S1 in the metabolism of carcinogens, Pharmaceuticals and endogenous compounds, and may ultimately provide opportunities for reducing the deleterious effects of environmental carcinogens and the adverse effects of certain Pharmaceuticals in the human population.
DESCRIPTION (provided by applicant): In this project, we will investigate the effects of neighborhood social context on biomarkers of stress and health for children and adults of all ages. We will use new data from the Los Angeles Family and Neighborhood Survey (L.A.FANS), whose design remedies many of the problems that have limited previous research on neighborhood effects, by collecting longitudinal data on neighborhoods, families, adults, and children, and on residential choice and neighborhood change. The first wave (L.A.FANS-1), completed in January 2002, interviewed adults and children living in 3,090 households in a diverse stratified probability sample of 65 neighborhoods throughout Los Angeles County. The second wave (L.A.FANS-2), planned for 2005-2006, is being funded by NICHD and NIA and includes the collection of biomarkers of stress and health for adults in the sample, data on adults and on children and their caregivers, as well as information on neighborhood social and physical conditions. As part of this project (L.A.FANS-2/Health), fieldwork will be undertaken to collect similar biomarkers of stress and health for all children in the sample. Data collection will be conducted simultaneously with the main L.A.FANS-2 survey, which will promote efficiency and reduce costs.
The specific aims of this project are to: (1) collect physiological markers of stress, disease, and health, including obesity, cortisol (a stress hormone), blood pressure, C-reactive protein (a marker of acute inflammation), Epstein-Barr virus antibodies (a marker of immune function), cholesterol, diabetes, and pulmonary function for all children in L.A.FANS-2; and (2) investigate the effects of social context and family environment on health status for adults and children, focusing on physiological markers of stress and health across the life course.
Extensive information will be available from the L.A.FANS database on respondents' social environment as well as confounding factors such as neighborhood choice, residential mobility, migration, and neighborhood change. We will use multilevel statistical models to control for unobserved heterogeneity at the individual, family, and neighborhood levels and will employ extensions of these models, as well as fixed effects models, to tackle issues of endogeneity using longitudinal data and data on matched respondents from the same family.
DESCRIPTION (provided by applicant): This proposal describes a research program directed towards resolving a stereochemical controversy over the structure of the marine neurotoxin maitotoxin through chemical synthesis, the total synthesis of a truncated version of maitotoxin lacking the side chains, the total synthesis of maitotoxin, and the development of antibodies of suitable maitotoxin-like structures for analytical and biological studies. The escalating challenges of this chemical synthesis program will be met by a convergent strategy involving methods developed in this and other laboratories. Featured in the synthetic plans are olefin metathesis- based carbon-carbon bond forming reactions, novel asymmetric processes and ring closures. Synthetic truncated maitotoxin-like molecules will be tested for biological activity and developed antibodies will become available for the detection and measurement of maitotoxin and further biological studies. The proposed program is also expected to yield significant new synthetic strategies and technologies for broader applications in the drug discovery and development process, particularly for the synthesis of small enantiomerically pure building blocks suitable for pharmaceutical research. Overall the significance of the proposed work lies in improving and assuring environmental health, detecting and measuring marine neurotoxins and cleaning the oceans, as well as to prevent human poisoning through seafood consumption. The project is also expected to significantly advance our knowledge in chemical synthesis, chemical biology, and medicine
DESCRIPTION (provided by applicant): In 2002, our group was asked by NAS/NRC to review all evidence linking water quality indicators to human health. We published these results as a meta-analysis (Wade et al. 2003). Traditional indicators (total coliform, fecal coliform, and Enterococcus) are problematic because prolonged analysis times (18-96 hours) make timely warnings difficult. Advances in microbiologic techniques are now pronounced and justify a comparison of current indicators with more rapidly measured new indicators. Additionally, important advances in statistical methods (such as the estimation of multivariate dose-response functions using inverse-probability of exposure weighting) have not been used to investigate the possibility of important multivariate relationships of these indicators to health and prediction. As preparation, we conducted a study at 6 San Diego beaches in 2003. We enrolled 12,458 beach users, recorded detailed swimming histories and collected illness data for 14 days. We collected hourly water samples at sites linked to the swimmer locations. We present analyses of this pilot data showing our ability to detect risk from swimming and a strong association with health outcomes of 1 novel indicator (F+ coliphage) used in the pilot. We present newly released EPA data showing a strong correlation between gastrointestinal (Gl) illness and Enterococcus measured by rapid QPCR (same method we use) in a freshwater site. We propose, over 4 summers, to enroll at least 17,600 beach users at Doheny Beach (one of California's most contaminated public beaches) using the same design and expanding our indicator testing to include rapid methods and viral agents from water samples spatially linked to each swimmer. Our 2003 pilot study research team is entirely intact (UC Berkeley, SCCWRP, Harvard, UNO, OHSU) and now has been joined by the NOAA Hollings Marine Lab. Decisions about beach closures have enormous economic implications. If successful, we will quantify the relationship between health and novel rapid methods for traditional indicators as well as viral indicators.
Crisp Terms/Key Words: transportation /recreation safety, nucleic acid quantitation /detection, clinical research, water sampling /testing, water pollution, coliphage, Adenoviridae, virus disease, longitudinal human study, epidemiology, fluorimetry, statistics /biometry, interview, human subject, health related legal, gastroenteritis, environmental health, disease /disorder proneness /risk, cooperative study, communicable disease control, biomarker, bacterial disease, Enterococcus, environmental exposure
DESCRIPTION (provided by applicant): Hydrogen sulfide (H2S) gas has high acute toxicity, but little is known about the effects of long-term, low-level exposures. Current evidence indicates the nervous system, the respiratory system and the eye are the most sensitive organs to effects of H2S. Substantial chronic occupational and community exposures to H2S occur in the United States. Sources include concentrated animal feeding operations, pulp mills, and gas refineries. However, small exposed population sizes, fears caused by the "rotten eggs" odor of H2S, potential reporting biases from litigation and compensation issues, and potential confounding by other exposures have made very difficult investigations into whether health effects are caused by chronic H2S exposures. Rotorua city (population >50,000), situated on a geothermal field in New Zealand, presents a unique opportunity to investigate whether chronic H2S exposure causes health effects. No other large population exists where chronic low-level exposures to H2S, in the absence of other potentially toxic gases, coincide with acceptance of the odor as a fact of daily life (avoiding possible biases from fear-induced symptoms or pending litigation). This cross-sectional study of a sample of the Rotorua population follows earlier research suggesting possible health effects associated with H2S exposure in the city. The study sample will consist of 1,800 adults, aged 18 to 65, living in Rotorua areas with high, medium and low exposures to H2S. We will obtain: (1) responses to a questionnaire, including questions on demographic factors, symptomatology, and residential and occupational histories; (2) the results of a battery of tests of neurobehavioral function; (3) the results of an examination of peripheral nerve function; (4) the results of lung function testing by spirometry; and (5) the results of ocular and vision testing including examination for cataract and color vision impairment. Exposure data will be based on extensive Rotorua monitoring data for H2S, with spatial modeling of exposures across the city. For each participant, the information from the questionnaire on residential and work histories and daily movement patterns will be combined with the H2S modeling results to construct individual cumulative exposure indices. To validate exposure estimates, a sample of participants will wear personal H2S samplers for three weeks. Statistical analysis will seek associations between the exposure indices and each of the measures of health effect - neurobehavioral, peripheral neuropathy, respiratory and ocular function/vision. Study results will either confirm the adequacy of current U.S. occupational and environmental exposure standards for H2S or provide evidence that they are insufficiently health protective.
DESCRIPTION (provided by applicant): The long-term objective of the proposed research is to elucidate the structural basis for the substrate specificities of cytochromes P450 2B. For decades, these hepatic enzymes have served as a prototype for investigation of the mechanism by which drugs such as phenobarbital and environmental contaminants such as polychlorinated biphenyls activate gene expression. P450 2B enzymes are also very versatile catalysts with a broad range of substrates, including drugs, environmental carcinogens, and steroids. Through extensive prior studies supported by ES03619 more is known at present about the structural determinants of P450 2B specificity than about any other mammalian subfamily. The major accomplishments during the most recent grant period were: solving four X-ray crystal structures of rabbit P450 2B4, pioneering the use of isothermal titration calorimetry (ITC) to study the thermodynamics of P450-ligand interactions in solution and the ensuing conformational changes, and incorporating directed evolution approaches for generating enzymes with enhanced catalytic activity and stability. The P450 2B4 structures represent the greatest diversity of conformations of a single mammalian P450 reported to date, provide a ready explanation for how substrates can gain access to the active site, indicate how ligand binding may facilitate redox partner binding, and are utilized by many other groups to model their results. Above all, the results suggest that P450 2B, and other mammalian P450s, exhibit considerable plasticity and operate by more of an induced fit than the classical lock and key mechanism inferred from the earlier bacterial P450 structures. This concept creates new challenges in predicting cytochrome P450-mediated metabolism but also provides new modalities for engineering novel activities and/or physical properties. Despite the importance of human P450 2B6 in the metabolism of numerous clinically used drugs, insecticides, herbicides, industrial chemicals, and environmental contaminants, structure-function studies have lagged significantly behind those of P450 2B enzymes in rats, rabbits, and dogs. Fortunately, recent advances in heterologous expression and protein engineering now enable a concerted effort to elucidate the structural basis for P450 2B6 function using rigorous biochemical, biophysical, and structural approaches. The central hypothesis is that P450 2B ligand binding affinity and specificity are determined by enzyme plasticity as well as ligand access and binding. The specific aims are: 1) To elucidate the determinants of affinity and selectivity of 1-aryl- and arylalkylimidazole binding to cytochrome P450 2B4 using X-ray crystallography, isothermal titration calorimetry, time-resolved fluorescence, site-directed mutagenesis, and virtual screening with multiple structures; 2) To engineer more functionally diverse or thermostable P450 2B enzymes by site-directed mutagenesis and directed evolution; 3) To investigate structure-function relationships of human P450 2B6 wild type and genetic variants. Understanding how hepatic cytochromes P450 recognize different ligands should have important implications for safety assessment of chemicals and drug discovery. PUBLIC HEALTH RELEVANCE: Cytochromes P450 are crucial enzymes found predominantly in the liver that are responsible for breaking down a wide variety of compounds to which humans are exposed, including drugs, environmental contaminants, and industrial chemicals. The proposed research will enable us to understand in detail how P450s bind and metabolize compounds of widely different chemical structure. The results should have important implications for predicting individual response to medications and individual susceptibility to toxic chemicals, and for choosing appropriate animal models for safety evaluation of new compounds.
DESCRIPTION (provided by applicant):
We propose basic research into the use of reactive amendments as an alternative remediation technology for hazardous metal and metalloid contaminants (namely, As, Hg, Se, Pb, Cu) of high priority in sediments at Superfund and other contaminated sites. These inorganic contaminants are particularly problematic because they do not degrade, they pose chronic health hazards to humans and organisms at low concentrations, they can be widely dispersed, they may be remobilized by changing environmental conditions, and many can bioaccumulate. Our approach is aimed at developing a molecular-chemical understanding of element sequestration mechanisms as a result of in situ reaction between the amendment and contaminated sediments. Using laboratory experiments with sediments from contaminated sites, we will investigate contaminant sequestration reactions and aging of the amendment products, with the aim of optimizing novel treatments to maintain or increase their stability as sedimentary environments change from oxidized to reduced. We will employ advanced spectroscopic and microscopic characterizations, including synchrotron X-ray methods, to determine contaminant element speciation, mechanism(s) of sequestration, and host phases at the molecular-to-microscopic scale in complex sediment mixtures. Our proposed work will also evaluate the feasibility of adapting existing engineering technologies for the delivery of reactive amendments to field systems. Because few remediation alternatives exist presently for contaminated sediments, this research will fill gaps in basic knowledge about the long-term fate of sediment amendments and their sequestered contaminants in subsurface environments, which presently contributes to a lack of acceptance and use of this approach. New methods for the sequestration and immobilization of inorganic contaminants in the environment will have positive impacts on public health by reducing their ability to enter the food chain and thus their potential bioaccumulation and biomagnification.
DESCRIPTION (provided by applicant):
The goal of this project is to develop activated carbon (AC) amendment as a multifunctional, in-situ sediment remediation technique to reduce the bioavailability of both mercury (Hg) and polychlorinated biphenyls (PCBs) at contaminated sediment sites. Activated carbon particles will be impregnated with nanoscale zero-valent iron (nZVI) to induce Hg reduction and sequestration, and PCB dechlorination. Successful application of this innovative technology may significantly reduce the human health risks posed by Hg and PCBs at many hazardous waste sites, while minimizing negative impact to sensitive habitats. The project will accomplish its main goal through a combination of spectroscopic, physicochemical, and biological tests. State-of-the-art microspectroscopy will be used to understand contaminant binding to AC at the particle scale. Physicochemical tests will probe the partitioning of Hg and PCBs to AC particles, and provide insight into sequestration and dechlorination rates, including mechanistic understanding of the role of nZVI on these processes. Finally, biological tests with a relevant clam species will document the effectiveness of AC amendment in reducing Hg and PCB bioavailability to sediment-dwelling macro- invertebrates. Sediment from Stege Marsh (San Francisco Bay, CA), a toxic "hot spot" contaminated with both Hg and PCBs, will be used in these tests. In-situ treatment with (nZVI-) AC may protect sensitive habitats and endangered species, such as the California clapper rail in the case of Stege Marsh. Combined, Hg and PCB contamination are responsible for the vast majority of fish consumption advisories currently in effect in the US. In addition, public use of Hg- and PCB-contaminated sites is limited due to human health risks associated with these often co-occurring contaminants. This research advances AC amendment as a remediation strategy that will lower both types of human health risks by (1) reducing the level of Hg and PCBs entering the food chain, and (2) decreasing the availability of Hg and PCBs to the local environment.
DESCRIPTION (OVERALL) (provided by applicant) Breast cancer remains the most common cancer for women and perhaps their most feared medical diagnosis. Although much is known about the etiology of breast cancer, questions remain about environmental factors that initiate breast cancer carcinogenesis and when they act during the lifespan. The Bay Area Breast Cancer and the Environment Research Center (BABCERC), based at the University of California San Francisco Comprehensive Cancer Center under the leadership of Dr. Robert A. Hiatt, Director of Population Sciences, will address the on-going concerns about the environmental etiology of breast cancer by focusing on mammary gland development during puberty when the breast may be especially vulnerable to environmental influences. At the same time it will create a unique organizational infrastructure for enhancing the existing partnership of scientists with local community and advocacy groups following the principles of community-based participatory research. The Bay Area is well suited for such a Center because rates of breast cancer there have been reported as the highest in the nation and there is high interest and cooperation from involved community members, government leaders, health departments, academic institutions and advocacy groups. Project 1 will study mammary cells and the mammary microenvironment in normal and cancer prone mice during all stages of development to determine the effects of exposure to prototypical environmental stressors in this model and develop in vitro mechanism-based screens to detect agents with possible mammary gland carcinogenicity. Project 2 proposes to recruit a cohort of approximately 400 7-8 year old girls from the Kaiser Foundation Health Plan and follow them through the pubertal transition. Data will be collected during a 6 year follow-up period from questionnaires, physical examination, and biospecimens that will allow analyses of links between environmental factors and mammary development, including the possible importance of susceptibility associated with selected gene-environment interactions. The Community Outreach and Translational Core will be directed and comprised of leaders in the local breast cancer advocacy movements in Marin and San Francisco Counties, who are highly experienced working with their respective communities on the topic of this research. The COTC activities are both highly integrated and interactive with the research projects and well connected to the community and its concerns. By incorporating the skills of a broad spectrum of expertise in fields such as developmental biology, epidemiology, and community advocacy, the BABCERC will provide an exciting opportunity for transdisciplinary research on a significant societal and biomedical challenge...understanding the relationship of breast cancer to the environment.
Neighborhoods impact a host of health outcomes, including infant mortality, the development of asthma and heart disease and life expectancy, independent of personal characteristics. The pathways through which neighborhoods 'get under the skin', are only partly understood. This center will study neighborhood influences on health, focusing on those characteristics of neighborhoods that are potentially amenable to change through changes in public policy. The Center has the following goals:
1) To conduct research to explain how neighborhoods contribute to health throughout the life cycle, including through biological pathways and health behaviors
2) To develop a rich data resource that can be used to advance the understanding of how neighborhoods influence health, and the biological pathways through which such influences work.
3) To develop robust community-based participatory research (CBPR) partnerships within each of the 3 cities in which RAND is located, involving both community-based organizations and academic institutions.
4) To develop and foster a community of interdisciplinary researchers (including social and basic scientists) focused on the social determinants of health, specifically the role of neighborhoods in health.
5) To contribute to improving public policies that can improve population health through a set of policy recommendations that are developed from the results of the Center's research.
The Center, which places a high priority on community-based participatory research, will be composed of 4 projects, 2 pilots, and 2 cores. Projects span 3 levels of analysis: biological, social/environmental, and behavioral/psychological. Project 1 will examine the impact of a large natural experiment involving the development and renovation of recreational facilities on physical activity and other health outcomes. Project 2 will study neighborhood factors that impact the functional and cognitive aspects of the disabling process in the elderly. Project 3 examines the relationships between neighborhoods and biological markers of allostatic load. Project 4 studies the impact of the built environment on mental health. An administrative core will support the entire project. A data and methods core provides data and computing support, and serves as a focus for intellectual activity around measurement and statistical issues.
Crisp Terms/Key Words: health disparity, geographic difference, health services research tag, behavioral /social science research tag, clinical research, socioenvironment, human morbidity
DESCRIPTION (provided by applicant)
This application is to continue our Southern California Environmental Health Sciences Center whose main purposes are: 1) to study the effects of environmental exposures on humans; 2) to determine host factors (genetic and other) influencing response to these exposures; and 3) to inform the public. To accomplish these goals the investigators bring together an interdisciplinary team of investigators from two major Southern California universities: the University of Southern California (USC) and the University of California, Los Angeles (UCLA). The research of the Center features several interdisciplinary cornerstones: detailed exposure assessment, including toxicokinetics and biomarkers; cutting edge study design, including the most powerful statistical and epidemiologic approaches; and the basic sciences, including physiology, molecular biology, genetics, chemistry and engineering. The foci of the Center cover a wide range of problems and address environmental exposures of public health importance including indoor and outdoor air pollution, pesticides, aflatoxins, radiation and passive smoking. The four Research Cores consist of: the Respiratory Effects Research Core (Director: Peters); the Exposure Assessment Research Core (Director: Froines); the Cancer Research Core (Director: Ross); and the Study Design and Statistical Methodology Research Core (Director: Thomas). The three Facility Cores consist of: the Molecular Biology, Sample Processing and Storage Facility Core (Director: Dubeau); the Exposure Assessment and GIS Facility Core (Director: Hinds); and the Biostatistics Facility Core (Director: Gauderman). The Center also features an integrative Core for Community Outreach and Education (COEP; Director: Hricko). The Center is structured to promote interdisciplinary research and linkage between the research and the COEP. Processes creating these interactions include research initiatives, seminar series, pilot projects, research focus groups, workshops and retreats. The previous nine years of support for this Center have resulted in the recruitment of new investigators, more investigators working on environmental health problems, increasing funding support, more interaction between researchers from different disciplines and a greater production of research findings relevant to answering critical public health questions. The Center also has developed research initiatives for the next five years that focus the interdisciplinary team of investigators on important environmental health problems and is poised to build on its success in facilitating cutting edge environmental health sciences research.
DESCRIPTION (provided by applicant):
The major goal of the NIEHS Center for Environmental Health Sciences at UCD is
to maintain a strong program in the toxicology of agrochemicals and related
xenobiotics, particularly relating to human health and the mechanistic aspects
of toxicology.
A team of 20 Center investigators whose interests are specifically aligned
with Center goals has been assembled. Collectively these investigators are in
charge of almost $12 million per year (direct costs) in research grants. The
Center members include new and experienced scientists, many fields of
interest, and strong histories of collaboration. To build an infrastructure
which facilitates relationships within and between groups, the Center has been
reorganized to form seven facility/service cores: (1) Administrative, (2)
Analytical Biochemistry, (3) Cell/Tissue Culture, (4) Cellular and Molecular
Imaging, (5) Field Studies (6) Functional Genomics and Molecular Biology, and
(7) Primate/Animal Models. In addition, to promote focused research efforts,
intellectual stimulation and synergistic interactions, five research cores
have been formed: (1) Epidemiology, (2) Molecular Neurotoxicology, (3)
Reproductive and Developmental Toxicology, (4) Respiratory Toxicology, and our
newest core, (5) Toxicogenomics. The composition of these cores changed to
provide flexibility to the Center?s research directions. The Pilot Projects
Program is used to bring in new investigators and research ideas. An
Affiliate Scientist category was developed to recognize interactions with UCD
faculty through a less formal mechanism than full membership, and 11 new
Affiliate members were appointed. The new COEP has been carefully guided by
the Center Director, and under the leadership of the new coordinator, Rebecca
Morrison, the COEP Mini-Grants Program has been an effective program to
identify new ideas. From those ideas came a successful long-term program that
currently supports four outreach programs for agricultural workers, three K-12
programs, and an alumni/corporate outreach program. In addition, during the
current project period, the COEP conducted a national symposium on aging and a
town-hall meeting, and sponsored the International Congress on Ecosystem
Health in 1999 and the Dioxin 2000 Twentieth International Symposium on
Halogenated Environmental Organic Pollutants and POPS. The COEP also serves
as an Environmental Health Information Center for the public, answering
questions via phone and e-mail, and disseminating information via websites,
list servers, newsletters, and annual community events attended by
approximately 1,000 people/year. The CEHS program is reviewed annually by the
External Advisory Committee consisting of experts in this area of science, the
Internal Advisory Committee consisting of eminent scientists with
administrative experience at UCD, and the Executive Committee composed of CEHS
faculty. The UCD has made a strong commitment of support (approximately
40%/year) by providing salaries and benefits for all Center investigators,
providing space, and purchasing equipment for the CEHS.
DESCRIPTION (provided by applicant):
Understanding the cellular and molecular mechanisms of hazardous chemicals in our environment is a critical national objective. The Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) was established to gain knowledge on the public health risks associated with exposure to Superfund site hazardous waste. Thus, a greater understanding of the exposure pathway and the health consequences resulting from human exposure to uncontrolled hazardous waste from Superfund sites are high priorities. The goals of the UCSD SBRP are to implement modern scientific approaches to identify and characterize mechanisms responsible for genomic stress elicited by water born pollutants found at Superfund sites. Findings from the researchers have shown that chemical exposure leads to alterations in patterns of gene expression which are controlled and regulated by underlying signal transduction pathways. The UCSD SBRP will test the hypothesis that 'Alterations in cellular signaling and gene expression by Superfund site chemicals can be exploited to develop biological models for the detection and bioremediation of chemical toxicants'. Experimental strategies will rely heavily upon recombinant DNA and the development of new technologies to yield new perspectives on monitoring, remediation and mechanisms of toxicity mediated through altered gene expression and aberrant cellular signaling. To meet these goals, the UCSD SBRP will develop a multidisciplinary effort consisting of 6 biomedical research projects, 2 non-biomedical research projects and 3 research support cores. The research will be supported in part by a Ph.D. training program. The environmental problems resulting from the investigators' location in a coastal environment and our proximity to a populated border creates unique environmental US/Mexico border issues that are of special relevance to water born pollutants. Through the Research Translation and Outreach Core, partnerships have been formed with local industry and community groups to utilize developing technologies as applied biological tools for assessment of exposure levels and to predict health risk. Investigators with complimentary expertise from 10 UCSD Departments, Organized Research Units and Centers are participating in this project. The combined efforts are anticipated to provide new insights into the molecular mechanisms that lead to environmental illness and to improve our understanding of the consequences of exposure to Superfund site contaminants.
DESCRIPTION (provided by applicant)
Although our ability to analyze hazardous material in waste sites has improved dramatically in recent years, we are very limited in our ability to trace the movement of hazardous materials from Superfund sites through various media or to prioritize and mitigate the hazards involved. Our ability to predict exposure or effect of these materials on humans and their environment is still more limited. This Program consists of 8 integrated projects, 3 research support cores, a training core, a research translation core and an administrative core to address these problems. The investigators will determine the fate and transport of hazardous materials in ground water, surface water, and air as they move from toxic waste sites using classical and innovative methodologies. They will examine the effect of some of these materials using an epidemiological approach. Concurrently, they will develop sensitive systems for evaluating the exposure and effect of populations to these materials. Immunochemical, cell based and other systems will be used to detect biomarkers. Development of these biomarkers will be based on a fundamental understanding of the toxicological processes involved. The project will emphasize multiple organ systems with an in vivo emphasis on pulmonary and reproductive effects. New technologies for thermal and bioremediation of toxic waste will also be explored, and possible health risks associated with these technologies will be addressed. Rapid immunochemical and cell based analysis will supplement classical technologies for the evaluation of sites, validating models of transport from these sites, as well as determining human susceptibility, exposure and effect. Modern mass spectral technology will be evaluated for monitoring parent hazardous chemicals as well as biomarkers of exposure and effect. The investigators are expanding the use of transcriptomics, proteomics, metabolomics and integrated bioinformatic technologies to discover new mechanisms of action of hazardous materials and biomarkers for their action. The biomarkers developed in this project will serve as biological dosimeters in epidemiological and ecological studies in this and sister projects. The technologies developed in the project will be tested at field sites and transferred to end users through a research translation core.
DESCRIPTION (provided by applicant)
The goal of the Superfund Basic Research Program at the University of California, Berkeley is "to improve understanding of the relationship between exposure and disease; provide better human and ecological risk assessments; lower cleanup costs; and develop a range of prevention strategies to improve and protect public health, ecosystems and the environment." The Program builds on the strengths of UC Berkeley and Lawrence Berkeley National Laboratory in engineering, chemistry and molecular epidemiology, and consists of six interrelated basic and applied research projects. The overall theme of the program is "The application of functional genomics, proteomics, transcriptomics, and nanotechnology to better detect arsenic, mercury, benzene, polycyclic aromatic hydrocarbons, trichloroethylene and other Superfund priority chemicals in the environment; evaluate their effects on human health, especially the health of susceptible populations such as children; and remediate their presence and reduce their toxicity. Themes of the individual projects include using proteomics and transcriptomics to study the role of chemical exposure in causing childhood leukemia; taking a functional genomic approach to finding susceptibility genes; applying novel biomarkers to study the health effects of arsenic; improving bioremediation of toxic chemicals through the application of -omic technologies and nanotechnology, and developing nano-scale sensors of chemical species in the environment. A toxicogenomic laboratory core and a computational biology core will assist researchers in creating tools for use in epidemiological and risk research. The new research translation core will facilitate intensive discussions between investigators and government audiences, and generate new initiatives to increase understanding of the significance and applicability of emerging areas of research to public health protection through policy, interventions, and individual actions. The training core will prepare graduate and post-doctoral students to conduct multidisciplinary research into the effects of environmental factors on health, and to develop technological solutions to prevent or mitigate the harm resulting from Superfund priority chemicals.
DESCRIPTION (provided by applicant): The goal of this application is to engage a multidisciplinary team of leading environmental, cardiovascular and proteomics researchers in the study of the pro-oxidative and pro-inflammatory pathways by which ambient pariculate matter (PM) enhance atherogenesis in apolipoprotein (apoE) and LDL receptor (LDL-R) deficient mice. The principal hypothesis is that PM-induced oxidative stress synergizes with oxidized lipid components to enhance inflammation and apoptosis in atherosclerotic lesions. There are three specific aims. Aim 1 will determine whether ambient PM exposures exacerbate atherosclerosis in these genetically susceptible strains. Animals will be exposed to ambient ultrafine (aerodynamic diameter < 0.1 mu m) and fine (< 2.5 mu m) particulates collected by particle concentrators in the Los Angeles basin. The endpoints will be a quantitative assessment of early and late atherosclerotic lesion development. These studies will be supplemented by in vivo and in vitro studies looking at the pro-oxidative, pro-inflammatory, and pro-apoptotic effects of concentrated ambient particulates (CAPs) on vascular endothelial, smooth muscle and phagocytic cells. Aim 2 will determine the role of PM-induced oxidative stress in inflammation and apoptosis. Aortic vascular tissue from CAPs exposed animals will be examined for lipid peroxidation and for heme oxygenase 1 (HO-1) expression, MAP kinase activation, and apoptosis. Blood will be used to study CAPs effects on acute phase proteins, fibrinogen and oxidative modification of protective HDL activity. Transgenic HO-1 promoter-luciferase mice will be used for in vivo imaging of the kinetics and vascular sites of oxidative stress generation. In vitro studies will include proteome analysis of the oxidative stress response in endothelial cells. All oxidative stress effects will be correlated with the PAH and quinone content of the CAPs, as well as their in vitro redox cycle capacity, determined by the DTT assay. Aim 3 will determine whether modified antioxidant defense mechanisms affect the induction of atherosclerotic lesions by CAPs in apoE deficient mice, which have been crossed with HO-1 transgenic as well as paraoxonase knockout animals. The investigators will also determine whether a deficiency of the Nrf-2 transcription factor, which regulates antioxidant enzyme expression, will affect lesion development in apoE t/- animals. These mice will be exposed to CAPs as discussed in Aims 1 and 2, and select endpoints used to demonstrate the effect on atherosclerotic inflammation and apoptosis.
Crisp Terms/Key Words: proteomics, environmental exposure, terminal nick end labeling, heme oxygenase, disease /disorder etiology, apolipoprotein E, mitogen activated protein kinase, low density lipoprotein receptor, oxidative stress, enzyme activity, apoptosis, high performance liquid chromatography, particle, pollutant interaction, oxidized lipid, enzyme linked immunosorbent assay, transcription factor, inflammation, pathologic process, gas chromatography mass spectrometry, polymerase chain reaction, atherosclerosis, genetically modified animal, laboratory mouse, air pollution
DESCRIPTION (provided by applicant): Epidemiological studies show significant associations between exposure to particulate matter with particles of aerodynamic diameter of <_2.5 ¿m (PM2.5) and cardiovascular-related morbidity including ventricular arrhythmias and sudden cardiac death. While there appears to be little doubt that PM2.5 exposure poses a significant cardiovascular health risk, the underlying causes are poorly understood. The decreased heart rate variability (HRV) associated with PM2.5 exposure is particularly important since decreased HRV has been shown to be an index of cardiac vagal regulation and is associated with increased susceptibility to ventricular arrhythmias and risk for cardiovascular-related sudden death. Even less understood is the mechanism(s) mediating the reduced HRV and hence the cardiovascular-related morbidity. Using the mouse we propose to use state-of-the-art inhalation facilities to deliver environmentally relevant particulate pollutants (iron/soot) from a true combustion source that captures the carbon-based particles and a transition metal ubiquitous in the environment to test the Hypothesis that short-term (3-day) exposure to PM2.5 results in a reduced HRV due to decreases in the intrinsic membrane properties and/or synaptic excitability of anatomically- and functionally-identified CNS cardiac vagal neurons in the nucleus ambiguous (NA) that regulate HRV. We will test the hypothesis in mice exposed to two concentrations of iron/soot particles and filtered air (FA) as a control by the following Specific Aims. 1. To determine whether short-term (3-day) exposure to PM2.5 in the form of iron/soot particles produces the phenotype of a reduced cardiac vagal regulation of heart rate, by quantifying overall 24-h HRV, diurnal changes in HRV, and heart rate recovery following an acute stressor (exercise). 2. To determine whether the PM2.5 exposure-induced decrease in HRV is mediated by decreased intrinsic excitability of the NA cardiac vagal neurons by measuring resting membrane potential, membrane conductance and spiking responses to depolarizing current injections. 3. To determine whether the PM2.5 exposure-induced decreased intrinsic excitability of NA cardiac vagal neurons is mediated by increased potassium currents, left shift in activation kinetics, and/or right shift in inactivation kinetics of three major potassium channels present in NA neurons. 4. To determine whether the PM2.5 exposure-induced decrease in HRV is mediated by decreased synaptic excitability by enhanced inhibitory ;?-aminobutyric acid (GABA) mechanisms at the NA cardiac vagal neurons, by measuring the frequency and amplitude of tonic GABA-mediated inhibitory postsynaptic currents (GABA IPSCs). 5. To determine whether the PM2.5 exposure-induced decrease in HRV is mediated by decreased synaptic excitability by depressed glutamatergic (GLU) excitatory mechanisms at the NA cardiac vagal neurons, by measuring the frequency and amplitude of tonic excitatory postsynaptic currents (GLU EPSCs) and the amplitude of evoked GLU EPSCs.
DESCRIPTION (provided by applicant): Ambient air pollution correlates with cardiovascular mortality and morbidity and is a cause of systemic inflammation. Inflammation is the hallmark of atherosclerosis, which is the primary underlying pathophysiology of cardiovascular diseases (CVD). Significant associations between air pollution and subclinical atherosclerosis have been reported in adults, using sonographically measured thickness of the carotid artery wall. Carotid intima-media thickness (CIMT) is an established marker of subclinical atherosclerosis. CIMT gradually increases from birth, is associated with subclinical inflammation in early life, and is a strong determinant of CVD. This project pursues the hypothesis that long-term exposure to local and regional air pollutants from outdoor origin promotes atherogenesis in early life, leading to differences in CIMT in 10-12yr old children. CIMT and covariates will be assessed among 650 children followed up from 13 Southern California communities. Lifetime residents from non-smoking households will be selected from an ongoing cohort study on air pollution and health. On average, children spend more than 80% of their time indoors at home and in school. Thus, exposure assessment will be based on fine particulate matter (PM2.5) from outdoor origin measured indoors in the home and school of each child and in selected outdoor locations. A Harvard long-term sampler will collect PM2.s in each location over a period of nine months. Light reflectance of PM2.s serves as a marker of local mobile source emissions and sulfur mass indicates regional PM2.s. Time spent indoors at home and school, in commuting, and in outdoor activities will be assessed by questionnaire. The microenvironmental concentrations and time-activity information will provide the input to derive exposure to local and regional pollution for each child. Associations between CIMT and personal lifetime exposure to local and regional outdoor pollution will be analyzed in multilevel spatial regression models. Relevance: The American Heart Association recommends focusing on prevention of atherosclerosis in children. Inflammatory air pollutants represent ubiquitous exposures, and millions of American children live in areas that exceed current government standards. It is biologically plausible that exposure to local and regional ambient pollutants effects CIMT in children. Small differences in CIMT at a young age translate into clinically relevant CVD later in life - the leading cause of morbidity and mortality in the U.S.
DESCRIPTION (provided by applicant): This project pursues the hypothesis that lifetime cumulative exposure to ambient air pollution is associated with sonographically measured carotid intima-media thickness (CIMT) at age 18-20. CIMT is an established marker of subclinical atherosclerosis - the primary pathogenic process of cardiovascular diseases (CVD). CIMT gradually increases from birth to death and is associated with subclinical inflammation at all ages, and is a strong determinant of CVD. Ambient air pollution is associated with cardiovascular mortality and morbidity and is a cause of pulmonary and systemic inflammation - a hallmark of atherosclerosis. Significant associations between air pollution and CIMT have been reported in adults. Long-term exposure to air pollution also adversely affects lung function (LF) which is a strong predictor of CVD mortality. Both pulmonary and systemic inflammation is an important correlate of poor LF. Poor LF also modifies the distribution and uptake of pollutants in the respiratory tract, leading to higher tissue dose. Given systemic inflammation affecting CIMT, LF and dyslipidemia, low LF, high C-reactive protein (CRP) and high lipids (LDL) these markers will be used to those most susceptible to atherogenic effects of air pollution. CIMT, lifetime residential history, cardio-respiratory covariates, LF, LDL and CRP will be assessed among 800 non-smoking USC College students with lifetime California residencies. Statewide air pollution monitoring information will be assembled to interpolate monthly fine particulate matter (PM2.5), nitrogen- dioxide (NO2) and ozone (O3) concentrations to each residence across lifetime. Concentrations will be weighted by activity levels and time spent indoors and outdoors to individually derive estimates of lifetime exposure. The association between exposure and CIMT and the interaction with LF, CRP and LDL will be investigated with multivariate regressions, tests for interactions, and structural equation modeling. The American Heart Association recommends focusing on prevention of atherosclerosis in early life. Air pollutants represent ubiquitous inflammatory exposures, and millions of young Americans live in areas that exceed current government standards. Small differences in CIMT and LF at a young age translate into clinically relevant diseases, including CVD - the leading cause of mortality in the U.S.
DESCRIPTION: (provided by applicant) Heart disease is the leading cause of death and hospitalization among the elderly population, which makes the identification of preventable causes for heart disease morbidity and mortality a major goal of epidemiologic research. Numerous studies have shown associations of outdoor particulate matter (PM) air pollution with cardiovascular hospital admissions and mortality. The causal pollutant components and physiologic mechanisms for these associations are not fully understood. There is evidence that airway inflammation resulting from airway deposition of ultrafine particles (< 0.1 mu/m in diameter) could lead to an increase in thrombogenic and inflammatory activity in the blood, and to a disturbance in cardiovascular function, resulting from oxidant stress responses at extra-pulmonary sites, including the vascular endothelium of the heart. This is expected to increase the risk of adverse cardiovascular outcomes, particularly in people with underlying coronary heart disease (CHD). We propose to conduct a panel study with repeated measurements to evaluate acute cardiovascular and respiratory health effects of ultrafine PM personal, indoor and outdoor exposures. Over seven month periods, we will follow 72 nonsmoking elderly individuals with CHD living in areas with high air pollution levels in the Los Angeles Air Basin of California. The design will maximize the utility of intensive exposure assessments by measuring multiple interrelated clinical, physiological and biochemical outcomes. The specific aims will address the following hypotheses: 1) Exposure to ultrafine particles will be associated with increased circulating biomarkers of inflammation and thrombosis, increased blood pressure, adverse cardiac clinical outcomes, and increases in a biomarker of airway inflammation, exhaled nitric oxide; and 2) These associations will be stronger for measurements of particle components and certain ambient sources thought to influence inflammatory processes through oxidant damage. We will also evaluate relationships of outcomes with accumulation mode PM (0.18-2.5 mu/m) and coarse mode PM (2.5-10 fm). We will assess whether estimates of association for predicted (adjusted) personal or indoor exposure to ultrafine or accumulation mode PM of outdoor origin are stronger than estimates of association for unadjusted (raw) personal or indoor exposures. Results of this study will advance knowledge on the cardiovascular and respiratory effects of ultrafine particles. Our results are expected to clarify findings in the literature of associations between ambient particulate air pollution (PM10 and PM2.5) and severe cardiovascular outcomes, including mortality and hospital admissions.
Crisp Terms/Key Words: patient oriented research, outcomes research, clinical research, comorbidity, nitric oxide, pollution related respiratory disorder, longitudinal human study, particle, oxidizing agent, tumor necrosis factor alpha, interleukin 6, interleukin 1, human subject, electrocardiography, coronary disorder, inflammation, blood pressure, thrombosis, blood test, biomarker, air sampling /monitoring, air pollution, human old age (65+)
DESCRIPTION (provided by applicant): This proposal is designed to identify etiologic associations between environmental exposures and childhood leukemia. The proposal expands an ongoing case control study of children ages 0 to 14 years that has been successfully implemented in 35 Northern and Central California counties. Notably, a high percentage of the subjects (about 40%) are children of Hispanic origin, which is unique in a study of childhood leukemia. Using a design that approximates population based ascertainment, the proposed study will expand the sample size (from 400 to 1148 newly diagnosed incident cases) and refine design and analytical procedures developed during the first five years of "Childhood Leukemia and Environmental Exposures" (R01 ES 09137, 1998-2003). Two matched control subjects for each case will be randomly selected from the statewide birth registry. Increased awareness of the molecular and cytogenetic diversity of leukemia within major subtypes (acute lymphoblastic leukemia and acute myeloid leukemia), and the significance of this diversity for clinical and epidemiologic research, underscore the need to uncover the etiologies of molecularly distinct subgroups of leukemia. We will use molecular-biologic techniques to differentiate leukemia subgroups and to identify the association of environment exposures with each molecular subgroup. For disease classification, biological specimens from case subjects will include pretreatment bone marrow and peripheral blood (collected at the time of diagnosis) and archived newborn blood specimens (collected at birth). To study genetic susceptibility, buccal cell specimens will be collected from cases, controls, and their biological mothers. To measure micronutrients and biomarkers of environmental chemical exposures, peripheral blood specimens will be collected from biological mothers of cases under age 7 and their matched controls. Data on a wide spectrum of environmental exposures (including parental occupational exposures, parental tobacco smoke, pesticides and other chemicals, maternal and child diet, and child immunological factors) will be collected through a detailed in-person interview with a biological parent. This comprehensive information on environmental exposures and genetic characteristics, in conjunction with improved disease classification and stratification by Hispanic status, will provide significant insights into the etiology of childhood leukemia.
DESCRIPTION (provided by applicant): The shape of the dose-response curve for benzene-induced leukemia at exposures below 10 ppm is a key public policy and risk assessment issue involving potentially billions of dollars. During the previous grant period, biological samples were collected from 250 workers exposed to a wide range of benzene concentrations (0.2 to 50 ppm as a time-weighted average, with 88% of the workers being exposed to <10 ppm) and 140 matched controls. These biological samples will be analyzed using a biomarker approach to (a) shed light on the dose-response curve for benzene's hematotoxic and genotoxic effects between 0.2 and 50 ppm in air and its mechanisms of toxicity; and, (b) develop new biomarkers of exposure, early effect and susceptibility for benzene. Leukemia-specific chromosome aberrations will be measured by fluorescence in situ hybridization in the metaphase spreads of lymphocytes of all 390 study subjects and the dose-response relationship evaluated. Further, using a new technique called OctoChrome FISH the effects of benzene on all chromosomes will be investigated to determine if it has selective effects. In a sub-group of 53 subjects hematopoietic progenitor cells circulating in the blood were cultured in colony forming assays, allowing us to evaluate the dose-dependent effects of benzene on these target cells. The level of genetic damage in progenitor cells will also be compared with that found in lymphocytes to determine if the latter are good surrogates. More than 40 genetic polymorphisms and folate and vitamin B status have been determined in all study subjects. This data will be correlated with data on chromosome damage and hematotoxicity to determine the role these effect-modifiers play in susceptibility to benzene. Finally, emerging technologies, such as microarrays and proteomics, offer a significant opportunity to develop new biomarkers and provide key mechanistic information. The use of Affymetrix microarrays is proposed and will reveal changes in gene expression related to benzene exposure. Further, application of a Ciphergen ProteinChip mass spectrometer will allow for differentially expressed proteins and protein modifications related to benzene exposure to be identified and a protein profile for benzene exposure to be established in serum and lymphocytes. The overall goal is to develop new biomarkers of exposure and early effect for benzene and provide new insights into the mechanisms of benzene toxicity.
Crisp Terms/Key Words: proteomics, environmental exposure, microarray technology, genetic susceptibility, clinical research, gene environment interaction, fluorescent in situ hybridization, human genetic material tag, DNA damage, vitamin B12, environmental toxicology, Chinese, occupational hazard, chemical carcinogenesis, neoplasm /cancer epidemiology, leukemia, chemical related neoplasm /cancer, human subject, genetic polymorphism, chromosome translocation, chromosome aberration, polymerase chain reaction, biomarker, benzene
DESCRIPTION (provided by investigator): We will address two major weaknesses in previous studies examining the association of air pollution with perinatal outcomes. The first weakness, exposure error, will be addressed by linking a comprehensive and large birth database with spatially and temporally resolved exposure estimates from an advanced exposure modeling system. The second weakness, namely, minimal knowledge concerning time-activity and behavior changes that affect women's personal exposures during pregnancy, will be addressed by following a prospective cohort using questionnaires and GPS time-activity sampling. Outcomes include low birth weight (LBW) and preterm delivery (PTD). Exploratory analysis will be conducted for ultrasound outcomes in the prospective cohort. The long-term goal will be to develop methods that can be applied to a large population- based study of births that will include more intensive outcome and exposure assessments, as well as assessments of maternal-fetal genetic variation. The specific aims are as follows: 1) To determine the association of mothers' residential exposure to traffic-related air pollutants with LBW and PTD in a large retrospective cohort. We will study this birth cohort (N=97,500) with detailed clinical data for the mother during pregnancy. Outdoor concentrations of polycyclic aromatic hydrocarbons (PAH), nitric oxide (NO), and nitrogen dioxide (NO2) at each residence will be estimated and summarized by month and trimester for each subject. Logistic regression will be performed adjusting for known or suspected confounding factors not generally available in birth registries. In utero windows of vulnerability to air pollutants will be examined. 2) To test prospective recruiting methods and develop data collection instruments that can be used in a planned larger study using ultrasound data. We will prospectively recruit 100 subjects during their first prenatal visit. The subjects will be followed by an environmental and behavior questionnaire coupled with one-week GPS sampling three times during their pregnancy. Changes in time-activity and air pollution exposures during pregnancy will be assessed. In addition, methods will be developed to examine the association of air pollution with ultrasound outcomes (e.g. head circumference), which may serve as biomarkers of in utero growth restrictions. 3) To test measurement and modeling methods. We will conduct extensive exposure measurements for 40 of the prospective subjects, and models will be developed and validated to estimate outdoor, in-transit and personal exposures. Model performance will form the basis for the design of a larger study. PUBLIC HEALTH RELEVANCE The knowledge that will emerge from this study will be of benefit to public health by identifying and describing environmental factors affecting adverse birth outcomes. This research is expected to have an impact on decisions regarding the protection of health in pregnant women who are susceptible to the adverse effects of air pollution.
DESCRIPTION (provided by applicant): High breast density is associated with increased risk of breast cancer. This epidemiological study will test the hypothesis that in-utero exposure to environmental endocrine-active compounds (organochlorine compounds, p,p'-DDT, p,p'-DDE, o,p'-DDT and individual PCB congeners) alters breast density in women measured at 40-44 years of age. The study population (N=601) is a subset of the Child Health and Development Studies (CHDS), a California cohort that has been followed for more than 40 years, beginning before birth. We have already shown that in-utero exposures to organochlorine compounds are 1) high and variable in the CHDS cohort and 2) are associated with reproduction (time to pregnancy) in adult daughters. The proposed study will use existing data on breast density and health status in CHDS daughters at age 40-44 years of age, which are currently being collected in two NIH funded projects (P01 AG023028-01, Ezra Susser, PI and RO1 CA104842-01, Mary Beth Terry, PI). The proposed project would fund assays of maternal prenatal serum for organochlorines and related new data analysis. In addition, existing data in the CHDS provide an opportunity to examine important confounding or mediating factors, which include 1) Prospective data on maternal estrogen and androgen levels during the daughter's gestation, maternal reproductive and menstrual history, maternal body mass, and pregnancy weight gain, maternal smoking and alcohol use, whether daughter was breastfed, daughter's growth in-utero, infancy, early and and middle childhood; and 2) Retrospective and cross-sectional data on daughter's menstrual and reproductive history, adult body size, health and health behaviors. This would be the first longitudinal study of human breast density that can measure exposure to organochlorines in-utero, when the fetus may be highly vulnerable. Findings will be relevant to understanding and predicting the breast cancer risk of women born in the 1960's, who were exposed to high levels of DDT in-utero. These women have not yet achieved the age of high breast cancer risk. The proposed project is an efficient use of existing resources for a unique 40-year follow-up study.
DESCRIPTION (provided by applicant): One of the most important human health-related scientific challenges is to understand how the immune system is able to protect against a wide variety of infectious agents. The broad objective of this grant is to investigate the biochemical basis of human immunodiversity. Two key events are required to produce high affinity antibodies from lower specificity antibodies, somatic hypermutation (SHM) and class switch recombination (CSR). Both antibody diversification events require the action of a recently discovered enzyme, activation induced cytidine deaminase (AID). Within the past year it has been shown that AID catalyzes deamination of cytosine to uracil on single-stranded DNA substrates. The deaminations observed in vitro occur most frequently in specific trinucleotide sequences corresponding to SHM hot spot sequences in vivo. Our specific goal, encompassed in four specific aims, is to understand the biochemical basis of SHM. We propose to address this problem first by characterizing the deamination specificity of purified AID in hotspot and coldspot sequences. We will carry out a kinetic analysis to determine binding and catalytic preferences for human wild type AID. We will then investigate AID mutants with altered C deamination specificity that no longer favor hotspot motifs. We will test the hypothesis that wild type AID properties are determined by its ability to scan DNA processively, in contrast to less processive AID mutants exhibiting reduced deamination specificity. Only actively transcribed immunoglobulin variable genes undergo SHM. In the third specific aim, we will investigate AID-catalyzed deamination using a eukaryotic transcription system, including RNA polymerase II and transcription factors. Using "classical" biochemical add-back experiments, we will perform a systematic search for transcription components that function to target AID to the transcription apparatus. The first three specific aims are intended to clarify the role of AID in initiating C to T transition mutations in the non-transcribed stand, at an important class of hotspot motifs in SHM. A longer-term goal, embodied in specific aim four, is to investigate mutational strand specificity, including mutations at A and T sequences. This aim will investigate AID in conjunction with base excision repair, mismatch repair and recently discovered error-prone DNA polymerases.
DESCRIPTION (provided by applicant): Decay accelerating factor (DAF, CD55) is a member of the complement-regulatory protein family that protects cells from attack by autologous complement proteins. Recently DAF was identified as a negative regulator of adaptive immune responses. Furthermore, Daf1 deficiency was shown to exacerbate lupus, myasthenia gravis and experimental autoimmune encephalomyelitis (EAE) in animal models. We found that DBA/2 mice, which are resistant to induction of systemic autoimmunity, have higher expression of Daf1 compared with lupus-prone strains (NZB, NZW, MRL). Induction of mercury-induced autoimmunity (HgIA) in B10.S mice decreases Daf1 mRNA levels and cell surface expression on CD4 T cells. Cell sorting identified CD4 CD44hi T cells from HgIA mice as having the lowest level of Daf1, and this was associated with elevated IL- 4; a marker of active disease in this model. Although primary control of Daf1 protein expression appears to be at the level of transcription, we found that the differential expression between NZB and DBA/2 mice was not from Daf1 gene and promoter polymorphisms. Further characterization of the Daf1 promoter revealed positive and negative regulatory regions, and basal transcriptional activity that requires functional cooperation of Sp1-binding sites. We hypothesize that Daf1 plays a critical role in the adaptive immune response, particularly of CD4 T cells, and that low endogenous expression of Daf1 predisposes to autoimmunity. The specific aims of this application will address the following:- 1) We will use spontaneous models of systemic autoimmunity to define the relationship between reduced Daf1 expression and the development of systemic autoimmunity, 2) We will use viral and non-viral gene delivery systems to ask if manipulation of the level of Daf1 influences expression of systemic autoimmunity, 3) We will examine what regulates expression of Daf1, and test the hypothesis that regulation of Daf1 expression in autoimmunity is due to mechanisms regulating the transcriptional activity of Sp1. Experimental confirmation of a role for Daf1 in regulating lymphoid cell activity, and development of systemic autoimmunity, will contribute significantly to our understanding of the autoimmune disease process and aid in the development of novel therapeutic interventions. Project Narrative:
The complement regulatory protein decay accelerating factor (DAF) is hypothesized to play a protective role in regulating lymphoid cell activity and development of systemic autoimmunity. This project will use gene therapy to determine if increasing the level of expression of Daf1 in autoimmune prone mice offers a defense against autoimmunity.
DESCRIPTION (provided by applicant): Exposure to xenobiotics can produce aberrant immune reactions, including autoimmunity. Exposure of mice to the heavy metal mercury leads to systemic autoimmunity with characteristic lymphadenopathy, hypergammaglobulinemia, autoantibodies and immune complex disease. In both idiopathic and mercury-induced autoimmunity (mHglA) reductions in IFN-gamma levels are associated with reductions in both autoantibody levels and immune-complex mediated pathology. Prior studies have revealed that genes, which control IFN-gamma expression, such as IL-4, IL-12, STAT4 and ICE, do not significantly influence the development of mHglA. However absence of genes involved in IFN-gamma function (IFN-gamma, IFN-gamma receptor, IRF-1) suppresses development of mHglA, suggesting that specific defects in signaling pathways and gene expression subsequent to IFN-gamma/IFN-gamma receptor interaction control disease expression. These observations underlie the hypothesis that mHgIA is dependent upon IFN-gamma and that the severity of disease is regulated by molecular and cellular events downstream of IFN-gamma expression. This hypothesis will be addressed by four specific aims:- 1) Determination of the Site and Kinetics of IFN-gamma Production in mHglA, 2) Determination of the Cellular Requirements Leading to IFN-gamma Dependent mHglA, 3) Determination of the Genetic Requirements Leading to lFN-gamma Dependent mHglA, and 4) Examination of the Suppression of the IFN-gamma Response as a Therapy for IFN-gamma Dependent mHglA. Identification of the role that IFN-gamma plays in the development of induced murine systemic autoimmunity should prove applicable to murine models of idiopathic systemic autoimmunity and to human lupus.
DESCRIPTION (provided by applicant): Trichloroethylene (TCE) and other industrial solvents cause acute renal failure in mammals by inducing selective necrosis of S2 and S3 segments of the proximal tubule (S2- and S3-PT) in contrast to significantly less affected S1 segment of the PT (S1-PT). The mechanism(s) by which these solvents cause acute renal failure is incompletely understood. It is known that the metabolism of TCE and other solvents results in the generation of mercapturic acids (N-acetyl-cysteine S-conjugates), which are absorbed by the PT. In the PT, mercapturic acids are either secreted, or deacetylated and further metabolized into nephrotoxic sulfur-containing reactive fragments. The key renal enzyme responsible for deacetylating mercapturic acids derived from TCE thereby mediating their nephrotoxicity was only partially purified from rat kidney and was not completely characterized. We have now cloned and characterized this enzyme, which we named aminoacylase III (AAIII). AAIII deacetylated N-acetyl-(1,2-dichlorovinyl)- and N-acetyl-(2,2-dichlorovinyl)-L-cysteine (N-acetyl-2,2-DCVC) derived from TCE, and some other toxic mercapturates. In mouse kidney, AAIII was localized to the apical membrane of the S1-PT and to the cytoplasm of the S2- and S3-PT. We hypothesized that the cytoplasmic localization of AAIII is responsible for the greater toxicity of the TCE-derived mercapturates for S2- and S3-PT than for S1-PT. The difference in the localization of AAIII between the S1-, S2- and S3-PT was due to a novel protein that was named AAIII binding protein (AAIIIBP) which was specifically expressed on the apical membrane of S1-PT and was not expressed in S2-, S3-PT and other nephron segments. In the mouse PT cell line (mPCT) used as a model system, AAIII was localized to the cytoplasm as in the S2- and S3-PT. When AAIIIBP was expressed exogenously in these cells, AAIII was targeted to the apical membrane, which resulted in significantly reduced mercapturic acid-mediated nephrotoxicity as in the S1-PT. Furthermore, the preliminary experiments indicated that the complex of AAIII and AAIIIBP formed a transport metabolon with the multi-drug resistance associated protein 2 (Mrp2) thereby increasing the transport of mercapturates via Mrp2. In this proposal, the hypothesis of AAIII is involved in TCE-derived mercapturate-mediated toxicity will be studied. Successful completion of this project will enhance our understanding of the mechanism of mercapturic acid-mediated nephrotoxicity.
DESCRIPTION (provided by applicant): Sun exposure has been consistently implicated in the development of non-melanoma skin cancers, but its role in melanoma etiology remains controversial, and is complicated by poorly understood genetic and behavioral factors. Melanoma incidence continues to increase (it is now the 4th most common cancer among males in California). Efforts to reduce melanoma incidence through sun exposure avoidance have had limited success, underscoring our lack of understanding of the true mechanisms of melanogenesis. Melanoma epidemiology is based on retrospective studies: recall bias probably explains associations between sunburn (almost always self-reported) and melanoma. Moreover, sun burn represents only excessive exposure to solar radiation, while sun-induced DNA damage potentially occurs across all levels of intensity: there is no accepted method for directly measuring sun exposure in epidemiological studies. In order to better understand the etiology of melanoma (particularly the role of sun exposure), valid methods of assessing both current and historical sun exposure are needed. While genetic factors probably play some role in melanogenesis, no study has yet managed to distinguish genetic from sun exposure-related risks. We will address both these issues in a case-control study of identical twins (nested in an established population-based cohort of 52,000 twins in California) assessing the role of sun exposure in melanoma etiology in the absence of genetic effects. Historical sun exposure will be assessed by combining residential history with novel fine-layer interpolated solar radiation level using GIS: we have already shown this method significantly reduces misclassification and recall bias. We will measure the actual impact of solar radiation on the skin, measuring UV- induced epidermal damage in tumor specimens noting differences in risk with varying UV intensity and wavelength. These results have the potential to improve primary prevention of melanoma and other skin cancers, and to direct the research team's future work on gene-environment interactions relevant to melanogenesis. We will measure the actual impact of solar radiation on the skin, measuring ultra-violet (UV)-induced epidermal damage in tumor specimens noting differences in risk with varying UV intensity and wavelength, and estimating the risk of melanoma with lifetime and age- specific exposures to specific wavelengths of UV. These results have the potential to improve primary prevention of melanoma and other skin cancers by indicating the appropriate means of avoiding harmful UV exposure, and to direct the research team's future work on gene-environment interactions relevant to melanogenesis.
DESCRIPTION (provided by applicant)
Lead (Pb2+) poisoning remains the most common disease of environmental origin in the United States today. The long-term goal is to investigate age-specific and cell type-specific mechanisms by which lead causes its neurotoxicity. Lead is known to cause myelin defects, although the mechanism is unclear. Myelin in the central nervous system is formed by oligodendrocytes, making these cells a possible target for lead. The investigators have previously demonstrated that environmentally relevant, low-level lead can disturb the survival, proliferation, and differentiation of oligodendrocytes at critical windows of development. The investigators have also demonstrated that developing oligodendrocytes are highly vulnerable to excitotoxicity mediated by Ca2+-permeable glutamate receptors (GluRs). Lead is a divalent metal ion that can mimic Ca2+ and interferes with Ca2+-sensitive targets. Mitochondria play a major role in buffering intracellular Ca2+, and are a known Pb2+ target. Here we propose to examine the hypothesis that a critical factor in lead neurotoxicity is the impairment of Ca2+-permeable GluR function and alteration of developmental GluR expression, concurrently with deficits in signaling mechanisms involving altered mitochondrial dynamics and redox potential in developing oligodendrocytes, resulting in aberrant neuron-glia connectivity and functional impairments. Aim 1 of this proposal will examine whether Pb2+ inhibits Ca2*-permeable GluR function in developing oligodendrocytes, and determine the relative roles of GluR subtypes in Pb2+ toxicity. Aim 2 will determine whether lead exposure modifies GluR subunit expression and phosphorylation state, and downstream signaling molecules that regulate GluR function. Aim 3 will determine whether Pb2+ causes alterations in mitochondrial function, maturation, dynamics effusion and fission, and redox state in developing oligodendrocytes. Overall, the Principal Investigator proposes to use a combination of cellular and molecular techniques applied to both in vitro and in vivo models of lead exposure, to provide overlapping approaches to unravel novel mechanisms of lead-induced toxicity to the developing brain. This project is the first to study the role of GluRs and mitochondria of developing oligodendroglia in lead toxicity. Elucidating these previously unrecognized mechanisms of Pb2+ action will provide insights into understanding the risks associated with lead exposure and the development of intervention strategies of targeting Ca2+-permeable GluRs and associated signaling pathways for dealing with lead toxicity.
DESCRIPTION (provided by applicant): N-hexane was a component of many degreasing products used by auto mechanics from 1990-2002; its use ceased when several mechanics were identified as having peripheral neuropathy. Exposure data suggested that these workers were exposed to levels of n-hexane less than half the Threshold Limit Value (TLV). Acetone, which has been shown in animal studies to potentiate the effects of n-hexane and increase persistence, was added to these products in 1997. This retrospective cohort study aims to investigate possible persistent neurologic, reproductive and ocular effects of n-hexane and acetone after cessation of exposure. The sample will be drawn from the cohort of mechanics employed in the Bay Area during 1990- 2002. The cohort of potentially exposed workers will be identified through union records (District 190 of the International Association of Machinists and Aerospace Workers). Data will be abstracted from the union records for all potentially eligible participants in the study. Based on knowledge of which employers used hexane-containing products, we will recruit a sample of 600 mechanics who had worked at automotive repair shops that had once used hexane-containing products and another 600 will be recruited from such shops that never used hexane-containing products. Participants will be administered a questionnaire to obtain histories of symptoms experienced and solvent use, as well as demographic data and potential confounder exposures. They will also be administered batteries of tests to assess peripheral nerve function and cognitive function, as well as a test of blue-yellow color discrimination. Urine samples will be collected for measurement of the gonadotropins FSH and LH. Animal evidence indicates that n-hexane may cause testicular atrophy, which would be reflected by raised urinary metabolite levels of the FSH. The questionnaire will also inquire about any fertility problems subjects may have experienced. Individual n- hexane and other solvent exposure profiles will be created on the basis of solvent use and employment histories combined with existing exposure measurements and historical product composition information. Statistical analysis of the data will investigate associations of exposure histories with symptomatology, clinical and laboratory test results, and time-to-pregnancy. These results may provide a basis for reassessment of the current TLV for n-hexane, particularly when it is used in conjunction with acetone. PUBLIC HEALTH RELEVANCE: Hexane is a very widely used chemical in industry, consumer products and gasoline that has known toxic effects, particularly on the nervous system. As hexane exposure is widespread, it is important to understand whether current permitted exposure levels are protective. This study will assess this by investigating possible effects on the nervous system, the reproductive system and the eye in a large group of auto mechanics, many of whom have been exposed to hexane in their work.
DESCRIPTION (provided by applicant): In 2001, more than 90 countries signed the Stockholm Convention on Persistent Organic Pollutants (POPs), committing to eliminate the use of 12 POPs of greatest concern to the health of the global community. POPs are lipophilic chemicals that persist in the environment, accumulate in the food chain and human adipose tissues, and are likely endocrine disrupters. Dichlorodiphenyltrichloroethane (DDT) was used as recently as 2000 in some countries, such as Mexico, and continues to be used in others for malaria control. Some are advocating their increased use. Animal studies indicate that DDT is a neurodevelopmental toxicant and we have recently shown that DDT is associated with mental deficits in two-year old children. As some of these POPs are being discontinued, new chemicals with endocrine disrupting properties are increasing in use. Polybrominated diphenyl ethers (PBDEs) are flame retardants used in textiles, furniture, and electronic products with increasing use and human exposure. Animal studies suggest that pre- and post-natal PBDE exposure causes decrements in learning and memory, and hyperactivity. Mechanisms for these effects may include thyroid hormone disruption. Recent studies have documented widespread PBDE exposure to humans, with higher levels in the United States (U.S.) compared to Europe. Only one small study (n=9) in humans has examined the relationship of pre- or post-natal PBDE exposure and thyroid function, and no studies have examined the relationship with human neurodevelopment or whether populations with higher levels of both DDT and PBDE are more adversely affected. We propose to examine the relationship of PBDE exposure, DDT exposure, and their interaction on neurodevelopment of children, and whether PBDE exposure is associated with maternal and neonatal thyroid function. We will utilize the rich data and biorepository already collected as part of the CHAMACOS project, the keystone project of the NIEHS/EPA-funded Center for Children's Environmental Health Research at UC Berkeley. This longitudinal birth cohort study is a community-based participatory project investigating in utero and postnatal exposure to pesticides and other environmental toxicants and children's health. The CHAMACOS children, whose mothers primarily immigrated from Mexico to the agricultural Salinas Valley in California, received relatively high exposure to DDT and DDE (DDT/E) in utero and are likely exposed to high levels of PBDE as they grow up in the U.S. By comparison with children living in areas of Mexico where the CHAMACOS mothers originated, we will determine the role of migration in exposure to PBDEs and DDT. The proposed study will address US EPA's data gaps in the regulation of PBDEs and the goals of NIEHS strategic plan to focus on underserved populations exposed to high concentrations of environmental agents within a broader global perspective.
DESCRIPTION (provided by applicant): Autism is a severe developmental disorder characterized by deficits in social interaction and communication and by stereotypic or repetitive behaviors or restricted interests. Despite a strong influence of genetics, environmental factors are likely to play a causal role for many children. The disorder is defined purely by behavioral phenotype, with research only now burgeoning on biologic mechanisms and biochemical markers of pathogenesis. The proposed project will continue an epidemiologic study of the environmental and genetic causes of autism that was initiated under the UC Davis Center for Children's Environmental Health (CCEH) funded in the fall of 2001 by the NIEHS (1 P01 ES11269), U.S. EPA, and M.I.N.D. (Medical Investigations of Neurodevelopmental Disorders) Institute. This project, known as the CHARGE (Childhood Autism Risks from Genetics and Environment) Study, is a comprehensive, population-based case-control investigation of underlying causes for autism and triggers of regression. Cases are children with autism, and two other groups are included: children with developmental delay and children selected at random from the general population. Close to 700 participants will have been enrolled in CHARGE by the end of the first funding period of the CCEH. The proposed continuation of the CHARGE study will use the R01 mechanism due to the high cost of recruitment and data collection, which is too expensive to maintain within the CCEH, and will extend the sample size to 1600. The larger sample size will permit the examination of exposures of relatively low prevalence, of gene- environment interactions, and of etiologic specificity for subtypes of autism defined by phenotypic characteristics. The proposed study will address the possible role of exposures during the peri-conceptional, gestational, perinatal, and early childhood periods, including infections, assisted reproductive technology, medications, pesticides, brominated flame retardants, and metals. It will also evaluate these environmental factors in conjunction with genes involved in xenobiotic metabolism or suggested by our current microarray results or by SNP arrays. Finally, because autism manifests in heterogeneous phenotypes, we will examine all exposures in relation to specific subtypes of autism defined by developmental patterns such as regression versus early onset, high versus. low adaptive/cognitive function, and by immunologic profiles. This project addresses a critical and growing public health concern, namely, autism; this disorder affects as many as one in 166 children. Our project will evaluate risk factors that may play a causal role.
Crisp Terms/Key Words: immune response, single nucleotide polymorphism, developmental disease /disorder, environmental exposure, microarray technology, genetic susceptibility, disease /disorder etiology, clinical research, gene environment interaction, family genetics, autism, early experience, cognition, epidemiology, pesticide, heavy metal, questionnaire, interview, data collection, language, human tissue, human subject, medical record, medical outreach /case finding, halogenation, population genetics, disease /disorder proneness /risk, preschool child (1-5)
DESCRIPTION (provided by applicant): There is considerable public and regulatory concern that developmental exposures to polychlorinated biphenyls (PCBs) cause significant cognitive and behavioral deficits in children, but assessing the risks posed by these compounds has been difficult because the biological mechanisms underlying PCB effects on the developing nervous system have yet to be identified. We have recently demonstrated that developmental exposure of rodents to a commercial PCB mixture impairs dendritic growth and plasticity in vivo coincident with deficits in spatial learning. These effects on neurodevelopment and cognitive function correlate with altered expression and function of ryanodine receptors (RyR) within the central nervous system. RyR regulate calcium-dependent signaling pathways that have been implicated in activity-dependent dendritic growth, which is a critical determinant of neuronal connectivity in the developing brain. The goal of our study is to characterize the mechanisms and structure-activity relationship (SAR) of PCB developmental neurotoxicity by testing the hypothesis that non-coplanar PCBs alter dendritic growth and plasticity by disrupting RyR function. The specific aims are to: 1. Test the relative contributions of RyR perturbation and thyroid hormone deficits in PCB effects on dendritic growth and plasticity in vivo; 2. Use primary cultures of hippocampal neurons to identify the molecular mechanisms mediating PCB effects on dendritic growth; 3. Determine how non-coplanar PCBs alter the function and expression of proteins that comprise calcium release units in cultured hippocampal neurons; 4. Determine whether heritable mutations in ryr1 and ryr2 that increase sensitivity to halogenated compounds in the human population increase susceptibility to PCB developmental neurotoxicity in mice expressing these mutations. These studies address the critical need to better understand mechanisms underlying PCB developmental neurotoxicity. Results will provide a rational basis for characterizing exposure risks and developing biomarkers of exposure and effect. Since RyR genes exhibit a significant number of expressed mutations and polymorphisms in the human population, data supporting RyR as a molecular target of PCBs in the developing nervous system will provide insights into genetic susceptibilities that magnify environmentally induced neurodevelopmental disorders. Polychlorinated biphenyls (PCBs) are persistent, widespread environmental contaminants, and there is compelling evidence that exposure of the developing brain to PCBs can cause learning and memory problems in children. But how PCBs cause these effects is not well understood. The goal of the proposed studies is to link known molecular effects of PCBs (activation of ryanodine receptors) to specific changes in brain development (disruption of dendritic growth). Establishing this link will provide a powerful means for predicting which of the 209 possible PCBs present the greatest risk to the developing brain and may provide novel insights into genetic susceptibilities that magnify environmentally induced neurodevelopmental disorders.
DESCRIPTION (provided by applicant): Gene-environment interactions may be major contributors to Parkinson's disease (PD) etiology, however this area of research has been severely hampered by the relatively small sample size of most population-based PD studies and/or a lack of valid and standardized exposure assessment across studies. We will take advantage of a worldwide unique resource available in Denmark to conduct the largest population-based case-control study ever to examine gene-environment interactions in PD: the National Parkinson's Patient Register in Denmark. We propose to recruit actively and prospectively approximately 2500 recently registered incident PD patients and 2,500 age-gender matched controls from the Danish population to collect risk factor information per interview and biological materials for genetic analyses. All patients will be examined and characterized clinically and phenotypically by a trained movement disorder fellow. We will examine 1) which lifetime occupations and occupational exposures are associated with PD; specifically, we will evaluate farming and greenhouse occupations (pesticides), metal related industries (metals and solvents), and night shift work (melatonin levels); 2) whether certain drugs and medical conditions are positively or inversely associated with PD (e.g. NSAIDS, aspirin, and cortisone use, or M. Crohn and colitis and rheumatoid arthritis) through their potential to induce chronically low iron levels and induce/reduce systemic inflammation; and 3) previously identified factors including smoking, alcohol use, dietary nutrients and contaminants (such as pesticides and metals from fish consumption), and physical activity. Most importantly, we will examine whether functional polymorphisms of metabolic and PD specific candidate genes differentially influence risks associated with environmental factors. As a secondary aim we will also employ passive record linkage by unique ID to link data from the National Patient Register, Pharmacy Database, and National Pension fund to identify risk factor information contained in these records (e.g. occupations, medication use, and diseases prior to PD onset) for approximately 13,000 PD cases diagnosed since 1983 and age-gender matched controls from the Danish population. The proposed research cannot be performed in the US due to a lack of population PD registries that would provide access to such a large number of cases and valid methods for control recruitment from the general population.
DESCRIPTION (provided by applicant): Over the last few decades, concern has heightened over the potential hormone-like effects of environmental chemicals on the reproductive health of fish, wildlife, and humans. The compound 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD) is a widespread environmental contaminant, produced by various chemical reactions and combustion processes, and in animals is a potent endocrine disrupter. On July 10, 1976, a chemical explosion near Seveso,Italy exposed the residents to the highest levels of TCDD exposure in a human population. We followed up the women 20 years after the accident to determine whether they were at higher risk for reproductive disease. Women aged 0 to 40 years at the time of the explosion, and who lived in Zones A or B were interviewed and examined, and serum specimens stored from the time of the explosion were analyzed to determine individual levels of TCDD exposure. The Seveso Women's Health Study, originally funded in 1996 (R01 ES07171) aimed to examine the relationship of serum TCDD levels and endometriosis. Continued funding in 1999 and 2001 allowed the analysis of additional serum specimens for TCDD and examination of the relation to other reproductive endpoints: menstrual cycle characteristics, age of menarche, fetal loss and birth weight, age at menopause, breast cancer incidence, length of lactation, ovarian disease and fibroids. We found that the youngest women (<10 years in 1976) were the highest exposed, but they were also the least likely to have experienced reproduction at follow-up (25 percent nulliparous in 1996). Among other findings, we observed a significant increased risk for breast cancer, but the cohort averaged only 40 years old in 1996. In this proposal, we aim to follow-up this unique cohort approximately 30 years after the explosion, when the women have aged and longer-term sequelae of exposure to TCDD may emerge. We expand our health assessment to include non-reproductive health outcomes likely affected by endocrine disruption. Specifically, we aim to study the relation of serum TCDD to breast cancer, diabetes and metabolic syndrome, bone density, and women and neonatal thyroid hormone. The proposed study takes advantage of previously collected data and specimens, including the 1976 serum TCDD levels and 1996 archived bloods. We propose to interview the women about their health and obtain medical records, and on a subsample, perform a bone density evaluation, and measure thyroid hormone and TCDD/TEQ in archived 1996 blood. We will acquire from registry records the neonatal TSH levels of all children born after 1994. The Seveso Women's Health Study is the only comprehensive study to date of the health of women exposed to TCDD. This study has the benefit of being a large cohort study with a wide range of TCDD exposure, documented by individual-level TCDD measured in sera collected soon after the explosion.
DESCRIPTION (provided by applicant): Reports of deleterious reproductive effects ascribed to the actions of endocrine disrupting chemicals are steadily increasing. One chemical in particular, bisphenol A (BPA), has been the focus of considerable attention and controversy. . BPA is one of the highest volume chemicals in production and humans are exposed to low levels on a daily basis. Recent studies in the mouse indicate that exposure to low levels of BPA during three distinct developmental stages in utero can adversely affect the genetic quality of the egg. Thus, these findings, and those from a host of other rodent studies, raise grave concerns about human fetal exposures. Directly assessing the effects of this chemical in humans, however, is neither ethically nor experimentally feasible. The proposed studies represent the first attempt to use a more relevant animal model, the rhesus monkey, to answer questions about the pharmacokinetics of BPA and to directly assess its effects on the early events of oogenesis in the fetal ovary. The oral dose of BPA used in these studies will be carefully monitored so that the resulting blood levels will be within the range currently found in humans. Aim 1 will test the hypothesis that BPA clearance rates differ in pregnant and non-pregnant female monkeys and that BPA levels accumulate in fetal tissues. Aim 2 will test the effect of BPA exposure on the earliest events of oogenesis in the fetal ovary. The BPA dose will be carefully timed during the pregnancy to coincide with the time of meiotic entry of the fetal oocytes to determine if BPA disrupts the processes of synapsis and recombination between homologous chromosomes. Aim 3 will test the hypothesis that perinatal BPA exposure disrupts follicle formation in the female rhesus monkey. Although BPA exposure has been suggested to induce a variety of effects in experimental animals, to date, no study has measured blood or urine levels of BPA in relation to any health outcome in any species. The combined data from these studies will provide the first direct analysis of the effects of BPA exposure on the developing primate fetus and, as such, will have important implications for humans. PUBLIC HEALTH RELEVANCE: Bisphenol A (BPA) is a widely used compound found in plastics and the lining of cans used for food that has been shown to have deleterious effects on offspring of mice when the pregnant dams are exposed to low doses. This project will measure BPA metabolism in non-pregnant and pregnant monkeys and determine if effects on eggs or ovaries are seen in developing offspring in primates as they are in mice. Because the dose used will be similar to current human blood levels of BPA, the results should have direct relevance to human health.
DESCRIPTION (provided by applicant): Hypospadias, a congenital malformation in which the urethral opening is on the ventral side of the penis, is one of the most common congenital malformations. The main mechanisms believed to underlie hypospadias are environmental and genetic factors that impair maternal, fetal, or placental androgen and estrogen metabolism. However, the contribution of such factors to hypospadias risk has either not been evaluated or has largely been investigated with epidemiologic studies that have numerous limitations. We propose to address these shortcomings with a population-based nested case-control study of pesticides and candidate genes. This study will test the hypothesis that pesticides and candidate genes which interfere with maternal, fetal, or placental sex steroid metabolism affect hypospadias risk through the following specific aims: Aim 1 - Pesticides and hypospadias. We will determine whether maternal residential proximity to applications of agricultural pesticides around the time of urethral development is associated with increased hypospadias risk. We will examine individual pesticides as well as groupings of pesticides that have common physicochemical or functional properties. Aim 2 - Candidate genes and hypospadias. We will decipher the association between hypospadias risk and variants in 47 genes from the following mechanistic pathways important to urethral development: fetal and placental biosynthesis and biotransformation of sex steroid hormones, regulation of sex steroid hormone biosynthesis and action, and regulation of genital tubercle outgrowth and differentiation. These aims will be achieved by linking several sources of existing information: 1) detailed phenotypic data collected as part of a population-based, actively ascertained birth defects registry; 2) data from California pesticide-use reports; 3) newborn bloodspots collected as part of routine newborn screening; and 4) maternal and newborn descriptive characteristics from vital statistics. Thus, a critical strength of this proposal is that it will utilize epidemiologic data that were collected using rigorous case ascertainment and classification criteria and highly detailed data on exposures and covariates. The proposed research represents the first large-scale epidemiologic study to explore genetic and environmental exposures and hypospadias risk. This work will fill an important gap in our knowledge regarding the highly discussed but minimally studied association of endocrine-related exposures with hypospadias risk. Ultimately this research will provide valuable information about the causes of hypospadias and give avenues for preventive measures against this common congenital malformation. PUBLIC HEALTH RELEVANCE: The proposed research will improve our understanding of the causes of hypospadias. Its findings will contribute to the development of effective interventions or prevention messages, so that hypospadias can be prevented. While this malformation can be treated with surgery, it has a significant impact both on an individual's-and the overall public's-health, with long-term consequences such as impaired sexual function and psychosocial difficulties related to sexuality and sexual activity.
DESCRIPTION (provided by applicant): Evidence for male-mediated developmental toxicity derives from strong animal data and epidemiological studies, in which exposures of fathers to toxicants are associated with adverse consequences for the fetus and offspring. There is a strong paternal contribution for de novo gene mutations, sex chromosomal aneuploidies and structural aberrations in offspring. The purposes of this study are to examine the effects of benzene, a well-recognized mutagen, on DNA and chromosomal damage in human sperm and to determine the association between chromosomal damage in sperm and blood cells within the same individuals. Although there are a few previous sperm studies on benzene-exposed workers, they are small, have not controlled for potential confounders, and have included highly-exposed workers. In 2004, we conducted the China Benzene and Sperm Study (C-BASS) under the auspices of a prior Superfund grant. We have collected all biologic and environmental samples, including urine, blood, and semen samples and personal air badge monitors, and questionnaire data on 78 workers. Additionally, all sperm and blood genetic assays, including FISH for aneuploidy (X-Y-21), ACM, sperm Comet, Sperm Chromatin Structure Assay (SCSA), and OctoChrome FISH will be completed by June 2006. Delays due to the SARS epidemic in China prevented the earlier initiation and hence, the completion of the data analyses. The specific aims of this project are:1) to determine whether benzene-exposed Chinese workers (n=34) have higher frequencies of sperm with numerical and structural chromosomal defects compared to unexposed Chinese workers (n=34), and to determine if this relationship is dose-related to benzene exposure; 2) to determine whether the same benzene-exposed Chinese workers have more sperm with DNA fragmentation and DNA breaks compared to unexposed workers and to determine if this relationship is dose- related to benzene exposure; and 3) to determine whether benzene-exposed workers compared to unexposed workers have higher frequencies of aneuploidy and aberrations in lymphocytes and whether these chromosomal abnormalities are associated with similar defects in sperm. This project will contribute towards understanding the reproductive health of men exposed to benzene, by understanding whether benzene exposure is associated with production of a higher frequency of genetically- defective sperm and, indirectly, with the potential for an increased risk for paternally-mediated developmental effects in offspring. We will also add to the body of information necessary for risk assessment by determining whether benzene exposures represent a risk at doses nearer to those that are permissible in US workers than examined in previous studies. Lastly, this study is one of the first to investigate the relative sensitivities of sperm and blood cells to chromosomal defects induced by benzene.
Crisp Terms/Key Words: environmental exposure, clinical research, fluorescent in situ hybridization, DNA damage, environmental toxicology, questionnaire, human subject, China, aneuploidy, gene deletion mutation, gene mutation, diploidy, sperm, lymphocyte, benzene, hazardous substance, male reproductive system disorder, mutagen, waste disposal
DESCRIPTION (provided by applicant): Epidemiological and experimental studies suggest that disruption of embryonic programming and gonadal development during human fetal life can result in testicular dysgenesis, manifested as undescended testis, hypospadias, poor semen quality, and testicular cancer. Preliminary data indicates that exposure of Leydig cells to low and environmentally relevant concentrations of di-(2-ethylhexyl) phthalate (DEHP) in vivo and mono-ethylhexyl phthalate (MEHP) in vitro altered the genomic and proteomic profile of the cells in a manner that parallels the inhibition of hormone-dependent steroid formation and the induction of Leydig cell hyperplasia. The central objective of this proposal is to gain greater understanding of the fetal basis of male reproductive disorders by elucidating the mechanisms by which exposure of the fetus to the environmental antiandrogen DEHP suppresses fetal testosterone production and later, testosterone and estradiol production by the adult. Our major goals are to identify the cellular targets and the molecular mechanisms underlying the responses of the fetus to DEHP, and to reveal the mechanisms by which effects on the fetus lead to pathologies of the male reproductive tract in the adult. The overarching hypothesis is that in utero exposures to DEHP suppress fetal testosterone production by direct effects on fetal Leydig cells and/or on the mesenchymal cells that are the precursors of adult Leydig cells, and by doing so, suppresses postnatal development and function of the adult Leydig cell population. We will test this hypothesis with the following specific aims: (1) identify the cellular and molecular targets of gestational DEHP in the fetal testis; (2) identify the mechanism(s) by which gestational exposure to DEHP results in reduced testosterone production by the fetal testis; and (3) determine the effects of fetal exposure to DEHP on the formation and function of the adult population of Leydig cells and its impact on testicular function in the immature and adult testis. We believe that these Aims will identify the molecular signaling pathways and characterize their role in mediating the hyperplasic and antiandrogenic effect of phthalates leading to testicular dysgenesis in the adult. Taken together the proposed studies will unveil the endocrine disruptor-sensitive steps in the steroidogenic pathway that are affected by this antiandrogen, and the mechanisms and consequences of endocrine disruption on the endocrine milieu of the adult.
DESCRIPTION (provided by investigator): There is growing evidence that some air pollution constituents perturb fetal development. Some studies point to motor vehicle exhaust pollutants specifically as causative agents of interest. However, to date almost all existing studies have focused on criteria air pollutants (CO, NOx, particles, SO2) rather than specific air toxics and have used data from existing government air monitors to assess exposure. These air monitoring data are unlikely to adequately capture the effects of primary motor vehicle exhaust pollutants whose concentrations vary based on proximity to sources. Land use-based regression (LUR) models are an attractive alternative to assess exhaust toxin exposures, since they can be applied to large populations and account for neighborhood- scale variations in pollutant concentrations. Thus, the specific aims of this study are to: (1) examine associations between prenatal exposure to motor vehicle air toxics and low birth weight (LBW) and preterm birth in women residing in Los Angeles County, California between 1994-2006 using both ambient measurement data and LUR models; and (2) gain information about how LUR models built on NOx measurements reflect exposures to specific toxins thought to have biological relevance for these outcomes. Specifically, using existing data sources, we will examine associations between the exhaust toxins polycyclic aromatic hydrocarbons (PAHs), benzene, and metals and adverse birth outcomes in an epidemiologic cohort study. We will assess pregnancy-specific exposures to these compounds using a unique resource of air toxics monitoring data from existing government networks coupled with special measurement studies recently conducted in LA. We will also apply LUR models we are currently developing for the LA Basin based on NOx measurements (as a tracer for vehicle exhaust) to obtain more spatially refined exposure metrics. Using data from a nested case-control sample of LA County births we previously collected in 2003, we will also examine confounding of air pollution effect estimates by a large number of risk factors for which information is not available on birth certificates. These data will also allow us to examine exposure misclassification due to mobility during pregnancy. The proposed study will contribute significantly to understanding the spatial patterns of motor vehicle toxin exposure among pregnant women in LA County, a region heavily polluted by vehicular emissions. Information will be generated on the association between NOx-based traffic pollutant models, increasingly used in health effects assessment, and measured air toxics concentrations. Most important, we expect the findings to enhance our understanding of whether motor vehicle air toxics are the primary drivers of associations between fetal development and criteria air pollutants (CO and particles) observed in previous studies. If the proposed pilot study is able to pinpoint specific toxins of greater relevance to birth outcomes, future research using personal and biomonitoring would be able to target these compounds. PUBLIC HEALTH RELEVANCE Perturbations of fetal development, including preterm and low weight birth, elevate the risk of mortality and morbidity in childhood, and may also impact health in adulthood increasing the risk for cardiovascular disease and diabetes. The expected growth in motor vehicle usage in both developed and developing countries underscore the public health relevance of traffic sources of air pollution and their impact on fetal development.
DESCRIPTION (provided by applicant): Long-term Objective: To establish contribution of nicotinic acetylcholine receptors (nAChRs) expressed in respiratory cells to mediating the oncogenic action of the nicotine-derived nitrosamines and identify antidotes to the tobacco-related carcinogenesis. Rationale: Nicotine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and N'-nitrosonornicotine (NNN) can specifically bind to nAChRs and alter growth of pulmonary cells. Our preliminary studies indicate that nicotinic antagonists can block binding of NNK and NNN to pulmonary cells and abolish effects of these nitrosamines on cell proliferation, apoptosis and anchorage-independent growth. Working Hypotheses: functional inactivation of nAChRs can: 1) abolish the oncogenic effects of NNK and NNN in in vitro and in vivo models of lung tumorigenesis; and 2) prevent alterations in the cholinergic receptor structure and function in respiratory cells. Specific Aims: to determine: 1) the roles for lung nAChRs in mediating oncogenic effects of NNK and NNN in cultures of human bronchial epithelial BEP2D cells and A/J mice; and 2) alterations in the gene expression and ligand-binding abilities of cholinergic receptors in the exposed respiratory cells, and tumors in mice. Methodology: To assure accurate "assignment" of the specific nAChR subtypes to a particular carcinogen, we will use overlapping approaches to abolish the effects of NNK and NNN. We will identify the nAChR- selective drug, small interfering RNA, or antisense oligonucleotides, that can abolish tumor-inducing activities of test nitrosamines. Significance: The results will provide crucial information for identifying the focus of future research toward elucidation of the role of specific nAChR subtypes in tobacco-related carcinogenesis and lung cancer chemoprevention. Description: The proposed research elaborates a novel paradigm of receptor-mediated action of tobacco carcinogens on target cells, and a well-substantiated hypothesis that an increased frequency of lung cancer in former smokers results from nicotine-induced alterations of binding to and signaling within the lung cells of the local hormone acetylcholine. The proposed studies will establish the role for each nAChR subtype involved in the process of malignant transformation of respiratory in response to the tobacco-specific nitrosamines. These findings will open a door for future mechanistic studies of the intracellular signaling pathways mediating the carcinogenic and tumor-promoting actions of tobacco nitrosamines.
Crisp Terms/Key Words: environmental exposure, smoking cessation, respiratory epithelium, nicotinic receptor, receptor expression, receptor binding, protein structure function, chemical carcinogen, chemical carcinogenesis, neoplastic transformation, cancer risk, neoplasm /cancer epidemiology, lung neoplasm, chemical related neoplasm /cancer, immunofluorescence technique, tobacco abuse, acetylcholine, biological signal transduction, laboratory mouse, athymic mouse, nitrosamine
DESCRIPTION (provided by applicant): Asthma is the most common chronic disease of children. The etiology is not clear, but recent studies suggest that traffic-related particulate air pollution may contribute to the occurrence of childhood asthma and asthma- related bronchitic symptoms. Respirable particulate matter (PM) produces oxidative stress and acute inflammatory and allergic affects characteristic of asthma, but there has been little study of how these effects may lead chronically to the development of disease. A better understanding of which specific PM-induced biological effects result in asthma could lead to targeted clinical interventions and to new prevention strategies focused on the biological activity of PM. We propose a new approach to population studies of complex mixtures of air pollution that will assess exposure based on the in vitro effects of PM on key biological pathways and examine the relationship to the development of chronic disease. These pathways include inflammation, characterized by PM-induced cytokines (IL-8, GM-CSF, and IL-12), allergy (IgE response and release of histamine) and oxidative stress (reactive oxygen species production, GST activity and Phase II enzyme induction). We will also investigate genetic susceptibility based on the change in PM-induced biological activity in cells expressing GSTM1 and in cells with GSTM1 expression reduced using siRNA. We selected this gene as a prototype for our research approach because it has a common null genotype that increases the risk of asthma associated with oxidant PM exposure. We will use the in vitro toxicological assays to predict the risk of asthma and assess susceptibility associated with GSTM1 genotype. Our ongoing prospective cohort study of air pollution, genetics and respiratory disease among 3372 children in the southern California Children's Health Study provides an opportunity to use the new approach to evaluate whether: 1) asthma incidence and bronchitic exacerbation are associated with the in vitro ability of PM to induce pro- oxidant, inflammatory and allergic effects; and 2) susceptibility to health effects of PM-induced biological activity is influenced by in vitro GSTM1 expression and by participants' GSTM1 genotype. The in vitro biological responses to PM less than 2.5 5m in aerodynamic diameter will be measured along with gaseous oxidant co-pollutants (NOx and ozone) at community monitors, schools and a sample of homes in each of the eight study communities. Results will be integrated in the analyses using an innovative hierarchical modeling strategy to predict variation in particle biological activity related to traffic within communities and across study communities representing the range of ambient PM exposure in southern California. Each biological exposure index, which will be specific for study participants' GSTM1 genotype, will be assigned to the entire cohort and will be used to predict asthma and bronchitic symptoms. The study has the potential to fill important gaps in our understanding of the
role of particulate air pollution in the development of childhood respiratory disease. PUBLIC HEALTH RELEVANCE This new approach to exposure assessment has the potential to provide better estimates of asthma risk and susceptibility due to exposure to particulate air pollution. This information will be useful for risk assessment and could lead to new regulatory and monitoring approaches for controlling the health hazards of air pollution.
DESCRIPTION (provided by applicant): The overall goal of this program since its inception has been to define the pathobiological response of the mammalian respiratory system to the inhalation of ambient concentrations of oxidant air pollutants. The focus of this renewal application will be on mechanisms of environmentally induced asthma in young children, using the model of environmental asthma in infant rhesus monkeys that the investigators have developed through the support of this program. Using this model over the previous five years of funding, the investigators have made a number of startling discoveries regarding the effect of chronic ozone exposure on lung development and growth during infancy, including: stunting of airway growth, postnatal loss of airway generations, impaired establishment of the fibroblast growth factor (FGF)-2 ternary signaling complex by basal cells, the failure of epithelial surfaces to innervate, impaired central nervous control, enhancement of the allergic response, airway hyperreactivity, disrupted alveolarization, and airway remodeling. The analytical framework in which all of the studies proposed for this renewal will be conducted is the epithelial/mesenchymal trophic unit (EMTU), whose cellular components establish trophic interactions via an extracellular signaling complex modulated by the basement membrane zone (BMZ). The overall hypothesis is that environmental exposure to oxidant air pollutants promotes the development of allergic asthma in the developing lungs of young children and exacerbates its severity by: 1) disrupting the homeostasis within the EMTU and 2) fundamentally compromising the establishment and differentiation of the trophic interactions that promote normal airway growth and development. These changes result from the superimposition of continual cycles of acute injury, inflammation, and repair on the immune response to allergen exposure. Each of the four projects within the program will focus on different components of the EMTU: Project 1, epithelial and mesenchymal cells (fibroblasts, smooth muscle) and the BMZ; Project 2, mucosal immune system; Project 3, innervation and neural control; and Project 4, vasculature.
DESCRIPTION (provided by applicant): The major physiologic actions of inhaled toxic chemicals on the lung are bronchoconstriction and pulmonary edema. Although these effects are well understood, the absence of specific antidotes has limited the effectiveness of prior therapeutic interventions. As surfactant inactivation and the formation of free radicals are important pathways in acute lung injury and edema, we propose testing synthetic surfactant in rats exposed to highly toxic chemicals. Synthetic surfactant has the advantage of large-scale production and a long shelf-life, and may be readily adapted to optimize resistance against inactivation. Our laboratory has designed, synthesized and characterized several highly-active surfactant protein B (SP-B) and C (SP-C) mimics (mini-B, super-mini-B, maxi-B, and SP-Cff) as a synthetic alternative for the natural lung surfactant preparations currently used in neonatal respiratory distress syndrome (RDS). These synthetic surfactant protein mimics formulated in synthetic lung lavage lipids and phospholipase-resistant phosphatidylcholine (phosphonolipids, e.g. DEPN-8) are under investigation for usefulness in acute RDS (ARDS), which shares many characteristics of lung injury secondary to inhaled highly toxic chemicals. The specific aims of this application are to: i) synthesize and characterize novel synthetic surfactant mimic proteins and phospholipase-resistant phosphonolipids designed to have high lipid binding, surface activity and inhibition resistance; and ii) to test the in vivo efficacy of an optimized surfactant preparation in rats with acute lung injury induced by exposure to highly toxic gases (e.g., chlorine) or liquids (e.g., hydrochloric acid). These specific aims will be accomplished using an integrated suite of techniques, including the synthesis of peptide constructs of SP-B and C; solution structure of the SP-B and C peptides by 2D-NMR; monolayer and multilayer FTIR residue-specific structural studies of SP-B and C peptides and proteins; characterization of the surface activity of these constructs in synthetic surfactant lipids by captive bubble surfactometry; and the use of the chlorine/ hydrochloric acid rat model to estimate in vivo efficacy of experimental surfactant on lung function under conditions of surfactant inactivation. These studies should facilitate the development of a synthetic surfactant mixture for treatment of ARDS induced by inhaled toxic chemicals. PROJECT NARRATIVE: Inhalation of toxic chemicals leads to airway damage, bronchoconstriction and severe lung edema secondary to surfactant inhibition and free radical formation. Exogenous surfactant therapy can function as an antidote for lung edema and we propose to develop new synthetic surfactants resistant against inhibition and oxidative stress and test these in rats with life-threatening respiratory disease after exposure to chlorine gas or hydrochloric acid.
DESCRIPTION (provided by applicant): Metabolism is a key step in eliminating xenobiotics from the body. Despite the fundamental importance of metabolism in determining the potency of contaminants and carcinogens, little is known about sex-specific differences in critical metabolic pathways. Differences between the sexes can be due to steroid hormone (gonadal) interactions or to differences in gene content (genomic interactions). We propose to investigate the effect of gonadal vs. genomic interactions on metabolism of a class of ubiquitous environmental contaminants (polycyclic aromatic hydrocarbons, PAHs) in a primary target organ for chemical carcinogenesis, the lung. The model compound will be naphthalene, the predominant PAH in environmental tobacco smoke and a byproduct of fossil fuel combustion. Human exposure to naphthalene is a concern as naphthalene was recently declared a likely human carcinogen. Naphthalene toxicity is of interest in the female population for 3 reasons: 1) women develop lung cancer earlier and after less cigarette exposure than men, 2) naphthalene causes lung tumors in female (but not male) mice and 3) data shows that female mice are more sensitive than male mice to naphthalene pulmonary toxicity. Sex-specific effects on metabolism and detoxification of naphthalene in the lung will be investigated in this proposal. Alterations in these systems may pre-dispose the lungs of females to increased airway epithelial injury and subsequent remodeling dependent on the stage of the reproductive cycle at which exposure occurs. The central hypothesis is that elevated susceptibility of females to metabolically activated compounds, such as naphthalene, is influenced primarily by gonadal hormones. The central hypothesis is addressed through two specific aims. These will determine if: 1) Female gonadal hormones regulate pulmonary metabolism of naphthalene and 2) Female-specific gene expression regulates pulmonary metabolism of naphthalene. We will use a multidisciplinary approach that combines morphology, site-specific quantitative gene expression, enzyme activity measures and proteomic approaches to define the effect of sex and steroid hormones on bioactivation of naphthalene. The proposed studies are relevant to diseases associated with pulmonary remodeling and PAH activation, such as lung cancer.
DESCRIPTION (provided by applicant): Accumulating evidence suggests that chronic exposure to particulate matter (PM) negatively affects growth of lung function in children and can lead to COPD in adults, but there is a dearth of information on the long-term effects of early life exposure to PM. In the proposed research we address the effects of exposure during infancy to biomass smoke PM on respiratory health later in childhood. Our mechanistic hypothesis is that the combustion-generated organic compounds present on fine particles in biomass smoke induce oxidative stress, upregulation of inflammatory cytokine production, and subsequent airway inflammation. Variation in the genotypes of key antioxidant enzymes (e.g., GSTM1 and GSTP1) may help to identify which children are more susceptible to the effects of inhaled PM on respiratory health. We propose to conduct a longitudinal follow-up study of a birth cohort of infants currently enrolled in a NIH-funded, randomized stove intervention trial to reduce acute lower respiratory illness (ALRI) in rural Guatemala. The improved cookstove markedly reduces biomass smoke exposure. After the participating child is 18 months old all families are offered the improved stove. Our proposed longitudinal follow-up study is designed to a) determine whether exposure to higher levels of PM during the first 18 months of life is associated with increased respiratory symptoms, bronchodilator responsiveness, sensitization to aeroallergens, and decreased rate of growth of lung function and somatic growth; and b) determine whether the GSTM1 null genotype renders children more susceptible and the GSTP1val105 variant less susceptible to the development of PM-induced oxidative stress and chronic respiratory effects. The effects of biomass smoke exposure have never been studied in a longitudinal design with quantitative exposure assessment. The current randomized intervention trial provides a unique opportunity to study the long-term effects of high exposure to biomass smoke/PM during the critical time window of lung development if follow-up is extended until later in childhood.
DESCRIPTION (provided by applicant): Genetics and ambient air pollutants are contributors to childhood respiratory diseases; however, gaps in the
scientific knowledge base concerning the roles of specific sources, components and characteristics of air
pollution and the role of inter-individual variation in susceptibility to air pollution's adverse effects impede
effective intervention. The overall objective of the proposed program of research is to address these key
gaps by investigating the contribution of genetics and exposure to air pollutants during childhood to the
occurrence of asthma and deficits in lung function growth. Accordingly, the overall theme of the program
project remains "Genetics, air pollution and children's respiratory health." The program of research proposed
in this application builds on the rich health, exposure and genetic data resources of the Children's Health
Study (CHS), an ongoing cohort study investigating both genetic and environmental factors related to
children's respiratory disease in over 11,000 southern California children. The research hypotheses are
based on mounting evidence that oxidant gases, traffic-related exposures and specific combustion-exhaust
particle-bound constituents activate oxidative/nitrosative stress and inflammatory pathways and contribute to
respiratory morbidity. Our research questions target the following health issues: (1) Are chronic respiratory
health effects associated with exposure to near source combustion particles from vehicular exhaust? (2) Do
PM mass in specific size fractions (PM[0.25], PM[0.25-2.5], and PM[2.5.-10]) or specific size-fractionated constituents
(e.g., water-soluble or total organic carbon, elemental carbon, or selected transition metals) affect health? (3)
Do genetic variants involved in innate or adaptive immune responses or nitrosative/oxidative stress
pathways contribute to respiratory disease, deficits in lung development, or differences in susceptibility to the
adverse effects of near source combustion products or regional gaseous or particulate pollutants? These
questions will be investigated in three inter-related projects with support from three cores (Exposure
Assessment, Integrative Health Sciences, and Biostatistics and Data Management). The projects will
evaluate the relationship between respiratory health (asthma, lung function growth, exhaled NO) and
combustion particulate and gaseous pollutants; examine genetic variation in key pathways that modulate
response to air pollution and disease occurrence; and develop new biostatistical methods for GxE studies
and integrated analysis across multiple outcomes and exposures. Building upon our large and wellcharacterized
children's cohorts, rich exposure data, and substantial genetic resources, our collaborative
multidisciplinary team will apply an integrative approach to efficiently address key gaps in the knowledge
base needed for timely and effective disease prevention and treatment.
DESCRIPTION (provided by applicant):
Southern California experienced catastrophic wildfires in October 2007 that burned more than 500,000 acres and over 2,000 homes. Particulate matter (PM) concentrations were elevated for nearly two weeks, with 24- hour average PM10 and PM2.5 outdoor concentrations approaching 10 times the levels typically observed in some locations. During this wildfire period the Children's Health Study (CHS) field team was measuring lung function and exhaled NO (eNO), both objective measures of respiratory health, as part of previously scheduled activities. These concurrent events provide a unique opportunity to substantively improve current health risk assessment technology. By combining satellite imagery and remote sensing data with fixed-site monitoring data to produce local estimates of PM2.5 and PM10 exposure, our current health and exposure information can be used to improve wildfire event exposure assessment. For each day that the Southern California was impacted by recent wildfire smoke, the impact of smoke exposure on children's respiratory health can be assessed. Measurements of aerosol optical depth (AOD) made from MODIS (Moderate Resolution Imaging Spectroradiometer) will be integrated with satellite imagery, meteorological data, and fixed-site air pollution monitoring data to estimate PM concentrations for each one- to two-kilometer square grid cell in the air basin during the hours of elevated air pollution associated with the wildfire. We will examine whether estimated PM concentrations correlate with reported smoke exposures from a sample of over 500 CHS participants and by reports obtained from community public schools. Our unique cohort resource will be used to examine whether temporally- and spatially-resolved estimates of PM2.5 and PM10 concentrations during wildfires have short- (days) or longer-term (weeks or months) effects on children's lung function and eNO. The tools developed during this study will fill critical gaps in existing exposure assessment methods during future wildfire events, which are expected to recur and increase if potential global warming scenarios develop. Improved assessment of smoke exposures and a greater understanding of wildfire health effects will be important elements in making recommendations to protect public health during future wildfire events.
DESCRIPTION (provided by applicant): The proposed project will prospectively investigate physical and social environmental exposures as determinants of Health-Related Quality of Life (HRQOL) in adult asthma and rhinitis, focusing on the role of severity of disease as a principal mediator between the physical and social environment and HRQOL. The proposed study, a competitive renewal of an R01 near completion, builds upon our current research elucidating multifactorial models of physical and social environmental risks. The specific study aims are: 1.] Delineate the specific pathways linking physical and social environmental exposures to disease-specific and general HRQOL in adult asthma and rhinitis, including mediation by changing disease status overtime; 2.] Identify specific risk factors, such as personal socioeconomic status, that modify the impact of these environmental factors on disease severity or the effect of severity on HRQOL in adult asthma and rhinitis. To accomplish these goals, we will assemble a prospective cohort of 636 adults, merging our ongoing asthma-rhinitis cohort (the basis of the current R01) with a second cohort of adults with severe asthma established as part of a methodologically similar study. Subjects will undergo 3 waves of structured telephone interviews over the study period to ascertain environmental exposures, disease severity, and HRQOL. Two home visits will be conducted in a subset of subjects (n=380) to assess the home environment (including measurements of dust antigen, airborne particulate, and dampness), measure pulmonary function and exhaled fraction of nitric oxide, and collect biological samples to measure secondhand smoke exposure. We will also carry out geocoding for linkage to external data sets for U.S. Census information, traffic density, and levels of ambient air pollutants. We will test predictive models of physical and social environmental factors, including measures of indoor air quality, ambient pollution, and neighborhood and community status, estimating the longitudinal effect of these factors on HRQOL. We will assess the role of disease severity as a mediating factor in the causal pathway leading from environmental exposures to changes in HRQOL; we will also assess selected individual factors that may be effect modifiers of this relationship, especially personal socioeconomic status (SES). Public Health Importance: In order to understand the complex web of factors influencing airway disease outcomes from the perspective of persons with disease, there is a critical need for an analytic approach that can test the effect of multiple combined environmental risk factors on HRQOL, assess the mediating role of disease severity, and take into account individual effect modifiers. The long- term goal of our study is to identify modifiable factors and subgroups at high risk in order to improve HRQOL among adults with asthma. The proposed project builds upon our success in the current R01 by testing more specific pathways in the context of our accumulated experience to date.
DESCRIPTION (provided by applicant): The respiratory tract is an important target for environmental agents, which require P450 dependent metabolism to ellicit toxicity. Naphthalene (NA) and close structural congeners produce injury to airway Clara cells which is species selective. Human exposure to naphthalenes occurs from a variety of sources including cigarette smoke and polluted air. Nitronaphthalenes (NN)(and structural congeners) are generated in the atmosphere from NA and are a direct byproduct of diesel exhaust but do not show species selective toxicity. The overarching goal of work outlined in this application is to identify biochemical and metabolic mechanisms for the toxicity of these agents in animals with the aim of determining the relevance of these mechanisms in humans. The following hypotheses will be tested: 1) epoxides generated from the parent hydrocarbons are proximate intermediates in both toxicity and protein adduct formation, 2) these electrophiles interact irreversibly with a number of proteins involved in antioxidant protection and protein folding (protein disulfide isomerase, peroxiredoxin, heat shock proteins and glutathione transferase) 3) by depleting glutathione these electrophiles enhance the redox sensitivity of these same proteins, 4) glutathione transferase pi plays a key role in the inactivation of toxic metabolites generated from both compounds and 5) the liver plays a role in generating metabolites which are released to the circulation and enhance the susceptibility of the lung to metabolites generated in situ. These studies will use a number of mouse models in which key enzymes involved in the detoxication of the epoxides (epoxide hydrolase, glutathione transferase pi), a key enzyme in quinone redox cycling (NADPH quinone oxidoreductase) and the redox partner for CYP450 in the liver have been genetically disrupted. Adducts with, and loss of sulfhydryls on individual proteins will be measured using 2D electrophoresis. These studies are expected to identify appropriate biomarker targets and metabolic proteins where polymorphisms could be important in altering individual susceptibility.
DESCRIPTION (provided by investigator): Asthma is caused by the interaction of genetic and environmental factors. In the U.S., asthma prevalence, morbidity and mortality are highest in Puerto Ricans, intermediate in Dominicans and Cubans, and lowest in Mexicans and Central Americans. There are many potential explanations for this observation, including place of birth, acculturation, early life exposures and genetic predisposition. Latinos are admixed and share varying proportions of African, Native American and European ancestry. The mixed ancestry of Latinos provides unique opportunities in epidemiological and genetic studies of complex traits and may be useful in untangling complex gene-environment (G x E) interactions in disease susceptibility. We hypothesize that ancestry will modify the association between environmental risk factors and asthma prevalence and severity. We propose to investigate whether individual ancestry, genetic factors, and environmental risk factors interact to influence asthma and asthma-related traits among several Latino ethnic groups. We will collect a well-characterized sample of Latino asthmatics (n = 2000) and clinic-based controls (n = 2000), age 8-21 years, from the Bronx, NY, Chicago, IL, San Francisco, CA, Houston, TX and Puerto Rico. This application has three specific aims. 1) We will test the hypothesis that genetic ancestry interacts with environmental/demographic risk factors to modify asthma risk and asthma-related phenotypes in Latinos of high risk Puerto Rican, intermediate risk Dominican, and low risk Central American and Mexican ethnicities. 2) We will genotype fifty candidate genes that may be involved in G x E interactions relevant to asthma. We will test whether there are ethnic-specific G x E interactions that differentially affect asthma risk, severity and pharmacologic response among Latino ethnic groups. 3) We will determine whether migration and acculturation are associated with asthma and severe asthma. Place of birth and length of stay in the U.S. are indicators of migration and acculturation. We will test the hypotheses that these indicators are associated with asthma and asthma severity. We will also test the hypothesis that place of birth and length of stay in the U.S. interact with ancestry, environmental, clinical and demographic risk factors to modify their associations with asthma and asthma severity among Latinos. PUBLIC HEALTH RELEVANCE The diversity and similarity among Latinos provide a valuable opportunity to study the interactions of race, genetics, culture, and environment. By taking advantage of such diversity, we may gain a much more thorough understanding of asthma, its causes, and its distribution among Latinos and other ethnic groups.
DESCRIPTION (provided by applicant): The long-term objective of this study is to better understand the fate of inhaled particulate matter (PM) in the human lung. This is important whether PM exposure results from atmospheric pollution, biological warfare, and occupational factors or inhaled drug therapy. More and more evidence links the presence of fine PM in the air with cardiopulmonary diseases. This PM is of great concern because it can penetrate deep into the acinus. To date, the most realistic model of the human acinus consists of a multi-bifurcation structure of two-dimensional alveolated ducts (AD). In the present study we will develop three-dimensional acinar models of children and adult lung with a high degree of anatomical realism. A first type of model will consist of a single bifurcation of AD with rigid walls. A second type of model will address the effects of alveolar wall motions during breathing and will form a realistic structure of up to four successive bifurcations. This will be the most comprehensive acinar models yet developed. PM transport and deposition (DE) will be simulated for particle diameters (dp) ranging 0.005-5 (m and for flow rates ranging from quiet breathing to moderate exercise. For 0.5<5 (m, DE is mainly due to gravitational sedimentation and is mainly affected by the structure orientation with respect to the gravity vector. For dp < 0.5 (m, DE is mainly due to Brownian diffusion and is affected by the alveolar surface available to PM to deposit. The contribution of velocity profiles, rhythmical motions of the alveolar walls and PM intrinsic motions to overall convective mixing will be determined. Convective mixing causes inhaled PM to be irreversibly transferred to the resident air. As a result, some PM remains in suspension in the distal airways at the end of a normal expiration and penetrates deeper in the lung during the next breath where it eventually deposits. The process of stretch and fold where, because of non-reversibility of flow in the lung, air streamlines become folded back on themselves, will also be simulated to determine whether it is responsible for additional mixing in the acinus, and consequently for higher DE than that previously predicted. Finally the numerical predictions will be compared to experimental data obtained in human subjects and in simple physical models. The results of this study will provide a link to the mechanisms by which even seemingly modest PM exposure can cause or exacerbate lung disease and will also help to better design spatial targeting of inhaled drugs.
DESCRIPTION (provided by applicant): The purpose of this application for renewal is to define the impact of exposure to bioactivated environmental contaminants on a special population: children. Lung disease is the leading cause of death in infants under one year of age and a strong relationship exists between human infant exposure to environmental air pollutants, increased respiratory infections in childhood and distal airway disease and asthma in adults. We have asked how exposure to bioactivated environmental lung toxicants affects neonatal lung growth and maturation. We have found 1) lungs of neonates are susceptible to acute injury by bioactivated Clara cell cytotoxicants at doses below the threshold for injury in adults and 2) once the acute cytotoxic injury occurs in neonates, repair is abnormal and incomplete, persisting even when the animals become adults. In this renewal, we propose to 1) characterize the normal pattern of airway growth and development focusing on extracellular signaling molecules known to be involved in injury and repair in the adult, 2) evaluate how repair of acute Clara cell injury conflicts with active airway growth to inhibit repair and the normal pattern of airway growth and development. We will use a comparative approach to discriminate the differences in normal growth and development when neonates are exposed to a P450-mediated toxicant. We have developed methods for quantifying airway growth in very small animals and will use this in combination with genetic and protein analysis to define the role of extracellular signaling molecules in airway growth and repair. This work will further our understanding of the basic molecular mechanisms by which environmental insults are involved in the origins of lung diseases that begin in childhood.
DESCRIPTION (provided by applicant): Our long range goal is to understand how to regulate glutathione (GSH) biosynthesis and thereby protect lungs from oxidative damage. Adaptation to oxidative stress in the lung involves an increase in the ability of cells to remove reactive and toxic molecules. Perhaps the most common mechanism for this is an increase in the ability to synthesize the endogenous antioxidant, GSH, which is essential for adaptation as it is critical in removal of hydroperoxides and toxic lipid peroxidation products, such as 4-hydroxynonenal (HNE). HNE is produced during exposure to any kind of oxidative stress but, interestingly, is one of the strongest inducers of GSH synthesis through increased transcription of both the regulatory and catalytic subunits of glutamate cysteine ligase (GCL). GCL catalyzes the rate limiting and first step in GSH synthesis. There is much evidence supporting roles for TRE and EpRE cis elements in regulation of the two GCL genes. We found that a little explored mode of activation of the EpRE and TRE elements is transcription factor (TF) switching. Our results also indicated that inhibition of the stress activated protein kinase, JNK, results in complete suppression of GCL induction by HNE. Thus, we hypothesize that HNE induced transcription of the two GCL genes involves switching from inactive or suppressing EpRE and TRE TF complexes to transcriptionally active complexes. We also hypothesize that HNE activation of the JNK signaling pathway is critical to both EpRE and AP-1 activation in GCL gene expression. The aims are: 1) to determine how the changes in the transcription factor binding complexes that bind to EpRE and TRE binding complexes in response to HNE cause increased transcription of both GCL genes and 2) to determine the mechanism of JNK activation by HNE. Both normal human bronchial epithelial cells (NHBE) and HBE1 cells will be used in exposures to subtoxic concentrations of HNE. In Aim 1, we will identify potential TFs by DNA affinity chromatography and LC-MS/MS analysis and then use chromatin immunoprecipitation (ChiP) assays to identify the EpRE and TRE TF complexes in the context of the whole GCL genes in situ. "NoShift" and Shift-Western assays will be used to quantify changes in TF binding and TF functionality will be determined by silencing TF genes and measuring EpRE and TRE driven luciferase reporters. In Aim 2, the effect of JNK inhibition on binding and function of TFs bound to EpRE will be examined along with a determination of which protein in the JNK pathway binds HNE. Relevance: Oxidative damage is a major component of lung injury during inflammation, other respiratory diseases and in exposure to air pollutants. The endogenous antioxidant glutathione increases during adaptation to sublethal oxidative stress through induction of the enzyme, GCL. In this investigation, the mechanism through which GCL increases in response to a toxic product of membrane oxidation will be investigated, hopefully leading to understanding of how to increase GSH without the use of toxic agents.
DESCRIPTION (provided by applicant): Lung cancer is the leading cause of cancer mortality in the United States. Ethnic differences in lung cancer occurrence and survival are inadequately understood and may reflect both environmental and genetic influences. Elucidating the interplay of these factors in very high- and very low-risk populations will be crucial in developing novel intervention and prevention strategies. This study focuses on African-Americans who bear a disproportionate burden of lung cancer and Latinos who have very low rates. In this continuation of our ecogenetics study of lung cancer, we propose to expand recruitment of non-Latino Caucasian cases and controls to allow comparisons of smoking related cancer risk in three ethnic groups and test specific findings from the first study in a large population of African-Americans and Latinos in Northern California and will explore gene loci never before studied in minorities. We will collect blood or buccal specimens and interviews to achieve the following approximate sample sizes for the three groups:non-Latino whites (1200 cases, 1200 controls), African Americans (800 cases, 1600 controls), Latinos (450 cases, 900 controls). Cases will be identified through the Northern California Cancer Center (NCCC) Rapid Case Ascertainment program and through the entire Northern California Kaiser Permanente membership. All controls will be age-, race, county of residence and sex-frequency matched and recruited through Kaiser Permanente Northern California. We will establish a DNA bank and estimate the prevalence of genetic polymorphisms in carcinogen metabolism (e.g. CYPIA 1), DNA repair (e.g. XRCC1) and inflammation (MPO) as risk factors for lung cancer. Gene-environment interactions will be explored for smoking, diet and occupational risk factors. Population stratification and genetic admixture will be explored in the Latino and African American populations using both birthplace algorithms and population specific gene markers; these studies will help identify methodologic solutions to genetic studies in this diverse population. Previous associations of polymorphic traits with lung cancer among Caucasians are not readily generalizable to minorities without the further detailed study we propose. An especially unique contribution, our study represents the only broadly-based study of its kind among Latinos and includes a catchment area of 15 counties in Northern California. This will be only the second large genetic epidemiologic study of lung cancer in African-Americans; African-American men in California have an 11% lifetime risk of lung cancer.
DESCRIPTION (provided by applicant):
Diesel and gasoline exhaust, produced when an engine burns fuel, is a complex mixture of gases and fine particles. Recent studies have linked respiratory diseases and cancer to exposure to gasoline and diesel exhaust. These diseases, however, are also attributed to genetic susceptibility. Establishing a direct linkage of these diseases to diesel and/or gasoline exhaust requires reliable and reproducible quantitative measure of exposure. The overall aim of the proposed collaborative research is to create, evaluate and validate an autonomous/self-contained wearable, approximately 4" by 4", sensor array for the real-time monitoring of exposure through inhalation to the gaseous components of internal combustion engine exhaust. The fully integrated light weight sensor that can be worn as badge similar to y-radiation counter will comprise an array of conductometric and amperometric sensors, and low-power fully integrated microelectronics for power management, data collection, and signal processing and wireless communications. Arrays of independent sensors can offer much more analytical information on personal exposure and thus hold a great potential for selective and accurate monitoring of low concentrations of mobile source air toxics and other relevant pollutants in real-time. The conductometric and amperometric platforms have strengths that are complementary to each other and are extremely 1C compatible. Advanced data processing will be used for generating distinct response patterns and detecting the individual compounds in gaseous mixtures. Such judicious integration of two powerful detection schemes along with an intelligent data processing should dramatically increase the gathered information on personal exposure to offer remarkable reliability along with broad scope, while meeting the portability requirements of decentralized detection systems. Our multidisciplinary expertise, extensive preliminary data and successful past collaboration lay the groundwork for the proposed activity. The overall goal will be realized by 1) developing, optimizing, characterizing and testing conductometric nanosensor array, 2) developing, optimizing, characterizing and testing microfabricated amperometric sensor array 3) developing integrated microelectronics for optimal power management, data collection and signal processing and remote communication, 4) integrating conductometric and amperometric sensor arrays in a single platform with incorporated microelectronics and 5) testing and validating the wearable sensor array by monitoring in real-time diesel and gasoline exhausts under realistic exposure conditions.
DESCRIPTION (provided by applicant)
Phoenix Biosystem intends to leverage the in-house expertise in sensors, microfluidics, and microelectronics to design, develop and validate novel, battery powered portable measurement technologies which, by the end of the Phase II funding period, will result in field-deployable tools that would provide accurate internal assessment of internal dose and/or activity of priority environmental exposures in real time. The sensors would have the ability to measure multiple agents within a single class of exposure i.e. pesticides. The Phase I prototype will detect personal exposure to OP conjugates in whole blood samples. Since the resultant OP conjugate typically correlates directly with the OP structure, an antibody-based nanoarray analysis would be superior to the current, end point-based colorimetric method.
DESCRIPTION (provided by applicant)
It is proposed to develop (during phase I and II) a person portable, highly sensitive and selective, broad band, real time data acquisition, GPS enabled and remotely accessible by wireless or by internet a "Personal Exposure Monitor" for the detection of trace amounts of harmful chemical species present in the exhaled breath of a human being. This instrument will employ a novel atmospheric pressure "supersonic pulsed ion beam source, (SPIBS)" recently developed by the principal investigator of this proposal and a miniature focusing time-of-flight mass spectrometer (FTOF-MS), also developed by the principal investigator for NASA in the past (published in the NASA Tech Brief Journal, 2004). Utilizing this combination, mass spectra of exhaled breath, covering the entire mass range of chemicals of present interest, will be obtained by employing the charged particle counting technique that is capable of a large dynamic range permitting sensitive detection of trace species in an air sample where other chemical species may be present in high concentrations. The novelty lies in the fact that the exhaled breath will be introduced into the vacuum system, housing the miniature FTOF-MS and the charged particle detector, in the form of short pulses (~ 100 ms duration) of supersonic beams for mass analysis. This will reduce the load on the vacuum pumps that are normally used in routinely employed mass spectrometers where the sample of air to be mass analyzed is introduced continuously. This continuous introduction of air sample into the vacuum chamber of a mass spectrometer requires large and heavy vacuum pumps employing differential pumping methods. This makes them heavy, bulky and excessively power consuming. On the other hand, pulsed introduction reduces the gas load and permits the use of recently available light weight miniature vacuum pumps requiring low power for their operation. The principal investigator of this proposal has recently developed a vacuum system in which the room air can be introduced in the form of short pulses lasting approximately 100 ms without increasing the vacuum chamber's pressure beyond about 10-6 Torr. A TOF can be operated in this pressure range and several thousands TOF mass spectra can be obtained in this short interval of time. The "personal Exposure Monitor" proposed here for the analysis of exhaled breath will be person portable and can be accommodated in a back pack. It will have the following novel features: 1) Light weight (estimated to be less than 3.6 kg which includes a miniature Alcatel turbo pump, a diaphragm pump and an electronics box), 2) will operate with power provided by a 24 volts power pack consisting of miniature Li batteries put together in the form of a belt (weight of this belt is estimated to be less than 4 Kg), 3) it will be low power consuming ( less than 250 watts), 4) pulsed introduction of the exhaled breath for sensitive detection (ppb range) of chemicals of present interest, 5) real time and fast data acquisition, 6) wireless data transmission, and 7) capable of multiple analyte measurement or the measurement of ozone alone. Such an instrument is not commercially available at the present time to make any comparison. The R & D during the Phase I will utilize our breadboard instrument to prove the concept of pulsed introduction of contaminated air procured from gas companies, measure its sensitivity, and mass selectivity. During Phase II a person portable instrument will be fabricated by utilizing the results of Phase I and limited field tested.
DESCRIPTION (provided by applicant):
Under current regulatory policies, chemicals that are believed to comprise both a significant exposure and health risk in the human population are selected to undergo testing for toxicity and carcinogenic potency. The traditional method for evaluating carcinogenic activity and chronic toxicity of a specific chemical has been the two-year bioassay. Due to relatively large amounts of resources involved, each bioassay costs between 2 million and 4 million dollars and takes several years to complete. According to the National Toxicology Program (NTP), the number of chemicals currently tested stands at 505 in long-term studies and 66 in short-term tests, and only a single sub-chronic study. By comparing the number of completed bioassays with the 70,000 to 85,000 chemicals in commerce today it is impossible to apply the current testing system to all chemicals of concern. Alternative approaches must be developed in the interest of protecting human health and in saving economic resources. To develop an efficient and accurate assessment of the carcinogenic potential of an unknown chemical we propose to: (1) identify a set of genes that is predictive of chemically induced hepatocarcinogenesis in a standard rodent 2-year bioassay using a tissue-engineered rodent liver model; and (2) apply the diagnostic gene expression profile derived from the rodent studies to the equivalent tissue-engineered human liver model to evaluate cross-species scaling of the chemically-induced carcinogenic endpoint. To accomplish this, in vivo exposures and exposures of engineered three-dimensional liver co-cultures will be performed with a training set of compounds that include non-hepatocarcinogens and hepatocarcinogens of the following classes: genotoxic, non-genotoxic, sex-dependent and species-dependent. Microarray analysis will be performed on mRNA derived from the exposed animal and liver cultures and the results used to identify gene sets that are statistically predictive of hepatocarcinogenicity in the two-year animal bioassay. A commercial product derived from this research will enable prioritization of hepatocarcinogenic potential of untested chemicals and allow a significant savings of time, money and animals for both governmental agencies as well as private industry related to chemical manufacturing, food additives and pharmaceuticals.
DESCRIPTION (provided by applicant): Several US agencies and regulators require low-cost chemical sensors for detecting and monitoring environmental clean-up, remediation, and decommissioning processes where groundwater may be contaminated. The sensors must be capable of detecting contaminants in the sub-surface groundwater and must be compatible with use in a range of environments. Most significantly, these customers require a low-cost alternative to its current expensive and labor intensive methods, namely using mobile laboratories. The project will result in the innovative use of low-cost sensor systems that will be capable of detecting and monitoring for dense non-aqueous phase liquids in the subsurface and groundwater, unattended, and in real- time from within a push-probe, using a chemicapacitor array and miniature preconcentrator. Seacoast's Phase I research will focus on developing the sensor array, demonstrating sensitivity to chlorinated hydrocarbons at relevant concentrations, and field tests in actual contaminated sites. The ultimate goal is to provide the DOD, DOE, NIEHS and other agencies with a method to map and track subsurface contamination plumes in real-time without requiring an operator. The systems will have MEMS microcapacitor sensor arrays that can monitor for leaks of toxic chemicals, contaminants from wastes, and changes in groundwater streams. A preconcentrator collects the contaminants and releases them to a microsensor array. The sensor arrays are filled with several chemoselective polymers whose dielectric permittivity changes when exposed to different vapors, creating a fingerprint response for each chemical. An array of differently responding sensors and pattern recognition can thereby compensate for changes in humidity, temperature, and composition. These low-power systems can be left unattended and transmit data wirelessly or through USB to a central location. The most important application to public health and safety is unattended monitoring of drinking water, water treatment processes, and water sources. The potential commercial markets include building chemical process monitoring and control, toxic vapor leak detection, industrial process control, and industrial health and safety. Transitioning the developed prototype to other markets where worker and public health, environmental health and regulatory compliance will be investigated to reduce the financial risks and broaden the acceptance of the technology. PUBLIC HEALTH RELEVANCE: This proposal will describe a potential method to specifically address the need for detecting groundwater contaminants and long-term monitoring of contaminated sites, by providing an unattended sensor system that tracks contamination in real-time and transmits contaminant concentrations. Such a system would be used in tandem with other methods, to provide comprehensive contamination management at DOE, DOD, and Superfund sites where ground and water clean-up projects are already underway. The proposed work will focus on detection of chlorinated hydrocarbons, which are described as among the most common pollutants in groundwater and soils at DOE sites.
DESCRIPTION (provided by applicant)
A field-portable instrument that can determine the blood level of specific toxic metals is vital in establishing the link between toxic exposure and genetic expression in that it aides in identification of genes whose expression is modified by exposure. Such data is critical for both laboratory and epidemiological studies. Standard assay methods require samples be sent to off-site laboratories, increasing costs and errors, and imposing a delay in identifying exposure sources. The overall goal of the proposed work will be to develop a small, easy-to-use, handheld instrument used with disposable silicon microchips to provide rapid, in field simultaneous detection of lead, cadmium, copper and zinc in blood. The microsampling and assay chip, which integrates a microneedle comparable in size to a human hair for painless blood drawing with a microcuvette containing an electrochemical detection structure, can be cost-effectively fabricated using MEMS (microelectromechanical systems) technology. The assay will employ electrochemical-stripping analysis; a proven technique for accurate and precise detection of trace amounts of toxic heavy metals. The assay permits detection of the analytes without requiring sample de-oxygenation, and uses an internal standard to avoid the need for external calibration. It is thus ideal for field use and can be used by untrained personnel. In addition, self-metering of sample volume will provide for accurate determination of levels of the four metals in blood. Phase I will demonstrate feasibility by: developing the assay and validating it with in vitro testing, designing the microchip and fabricating key components, and developing measurement and control instrumentation. In Phase II, a complete prototype system will be fabricated and evaluated via in vitro and animal testing.
DESCRIPTION (provided by applicant): According to the Cincinnati Children's Hospital Medical Center report, carbon monoxide is the leading cause of accidental death by poisoning. More recent estimates reveal 3,500-4,000 people die each year due to accidental CO exposure; and an additional 10,000 seek medical attention. Carbon monoxide exposure is especially dangerous for unborn babies, infants, and children because they have smaller bodies and faster metabolisms -- they absorb carbon monoxide quicker and at lower levels. Toxic levels of carbon monoxide can be up to ten times higher in the fetus than the mother. Possible mitigation requires a reliable, early warning CO detector. High sensitivity and complete reversibility are two desirable characteristics that are lacking severely in CO detectors currently available in the market. During Phase I, InnoSense LLC has demonstrated a thin film-based CO sensor sensitive to 5 ppm CO responding within five seconds. The sensor has also shown reversibility within five seconds. The Phase II project would: (a) Fine-tune the CO indicator for shortening the response/recovery times by 50% or more, (b) Conduct extensive performance studies to evaluate for how long and how effectively this sensor would perform reliably in the presence of contaminants likely to be found in a typical household. PUBLIC HEALTH RELEVANCE: Sensitive to Low PPM and Reversible Sensor for CO Phase II Project Narrative A key goal of the Phase II project is to fine-tune the CO indicator formulation. The Phase II work builds on the thin film formulation developed during Phase I utilizing ormosil matrix. This formulation strategy along with the fiber bundle approach complements the Principal Investigator's earlier patents covering basic ingredients of the CO indicator. Together, the sensing platform is expected to offer devices that would have multi-analyte detection capability. InnoSense LLC has systematically assembled and developed chemical sensor capabilities, materials science expertise, and home-built optoelectronic test and measurement devices. The company has also assembled a competent scientific team having seventy person-years of experience developing commercially viable sensor products. Given these resources and its commitment to the area of medically relevant sensors, InnoSense LLC is uniquely positioned to make effective use of the Phase II funding to study development of this life-saving device especially for a vulnerable portion of our populace - the elderly, infants and pregnant women carrying the unborn.
DESCRIPTION (provided by applicant): Genomic methods simultaneously report both specific and holistic assessments of biological systems an ideal property when assessing the potential impact of chemicals on ecosystems and the environment. To date, however, genomics infrastructures have not been developed for one of the most commonly used and accepted environmental toxicity monitoring organisms Ceriodaphnia dubia. In this Phase II proposal, we expand on our Phase I work by sequencing a large number of C. dubia cDNAs using high-throughput sequencing. After sequence assembly and annotation, we will print a 4x70,000-element oligonucleotide microarray representing at least 10,000 distinct genes. This array will be used to perform toxicity tests on four reference toxins with different chemical properties. Each of the chemicals tested will be assayed at three different concentrations. We will define expression signatures for each of the toxins and attempt to correlate expression results with known toxicity mechanisms. In addition, we will perform one 7-day exposure at a low concentration of a toxin known to have chronic effects and note how the expression profile changes over time. Finally, we will assemble a highly annotated Ceriodaphnia database that has been integrated into a bioinformatics infrastructure that will allow easy interpretation and sharing of hybridization data.This project aims to develop DNA microarrays for the identification and understanding of environmental toxicity in the one of the key organisms used for testing environmental toxicity the water flea Ceriodaphnia dubia. DNA microarrays are a uniquely powerful method of identifying and characterizing environmental toxicity due to their ability to combine many specific tests to achieve a global understanding of toxic effects.
High throughput DNA sequencing and NimbleGen based array synthesis will be used to produce fully annotated and commercial ready microarrays for use both in academic and commercial settings. In addition to commercially available Ceriodaphnia microarrays, Eon Corporation will facilitate use of these arrays through contracted performance of microarray based tests, and distribution of an expression analysis database that incorporates identification, function, and expression information for each element/gene.
Technologies for environmental toxicity testing have fallen 15 years behind those now commonly used in pharmaceutical toxicity testing. Without new technologies for identifying and characterizing environmental toxins, the increasing variety and quantity of chemicals released into the environment will mount untold environmental and human health tolls.
DESCRIPTION (provided by applicant A miniature, battery-powered monitor will be developed for measurement of hourly concentrations of chemical constituents of PM2.5 aerosols that are important to human exposure. The method utilizes a laminar-flow, water condensation method to provide a concentrated, "ready-to-analyze" deposit of ambient particles. Many deposits will be contained on a single collection wafer designed for automatic analysis by common liquid chromatographic methods. The objective is wide-scale, inexpensive time-resolved monitoring of individual constituents of ambient particulate matter for personal exposures assessment. PUBLIC HEALTH RELEVANCE: Proposed is the development of a compact, battery powered monitor to provide time-resolved measurements of personal exposures to many of the toxic chemical components of PM2.5. Short- term exposures to high levels may be important for understand the respiratory and cardiovascular health effects of exposure. This research improves the time-resolution and the range of chemical components that can be measured in personal monitoring studies.
DESCRIPTION (provided by applicant): This project will develop statistical methods relevant to two common forms of environmental epidemiologic studies. The primary goal is to provide methods that extract a concise assessment of health risks associated with environmental exposures, supplemented by appropriate statistical inference. The first topic will evaluate the association between exposure and the risk of a health outcome using diagnosis data on a cohort of individuals supplemented with screening information on undiagnosed participants. The methods will be applied to data from the Seveso Women's Health Study which addresses health risks in women exposed to high levels of dioxin. It is intended that the statistical methods will apply generally to similar studies that include a combination of diagnostic and screening data. The second project concerns statistical techniques to investigate the effects of multiple environmental exposures on health and developmental outcomes. The ideas will be applied to data from the CHAMACOS study of Latino women and their children in California, where information has been collected on environmental (largely pesticide) exposures, in utero and in childhood, for a cohort of women and their infants. Statistical issues involve estimation and ranking-in importance-of suitable causal effects of each exposure, supplemented by a rigorous assessment of which of these represent real effects rather than spurious associations, allowing appropriately for multiple comparisons. Both studies involve the study of vulnerable populations exposed to above average environmental exposures with the potential for elevated risk for poor health outcomes. Statistical and computational algorithms will be developed and provided in an open source user-friendly format allowing their rapid dissemination and use by other investigators. The relevance to public health is two-fold: first, the research will allow environmental epidemiologists to accurately describe the effects of (i) acute dioxin exposure on the reproductive health of women, in particularly on the onset of fibroids, and of (ii) pesticide exposures on birth outcomes and subsequent neurodevelopment of children born to Latino women, in a farmworking community. Second, the proposed research will provide appropriate statistical tools and software to allow other investigators to apply these complex methods to similar studies of the effects of environmental exposures in a wide variety of settings.
Crisp Terms/Key Words: computational biology, Hispanic American, leiomyoma, Italy, children, environmental exposure, women's health, human data, female, embryo /fetus toxicology, pesticide biological effect, dioxin, statistics /biometry, health science research analysis /evaluation, disease /disorder proneness /risk, computer program /software
DESCRIPTION (provided by applicant): Nearly a decade ago, Risch and Merikangas suggested the possibility of conducting genome-wide association scans. Although the cost was prohibitive at the time, they predicted that these technological barriers would eventually be overcome. With the advent of 500K chip-based or bead technologies, at a cost of about 0.2 cents per genotype, that prediction has now become a reality. Nevertheless, these will still be expensive studies to conduct and there remain numerous methodological challenges to efficient and valid design of such studies. To address these issues, we convened a panel of 165 investigators from around the world at USC in April 2005. These discussions highlighted a number of study design and statistical analysis problems that we propose to continue working on as part of this Cooperative Agreement. Our team is also involved in conducting and planning several such studies for such conditions as breast, colon, and prostate cancer and age-related macular degeneration. We anticipate that this research will inform the conduct of these studies and be motivated by the needs of these projects (as well as the many others at other institutions). In particular, we propose to focus on the following methodological issues: (1) tag SNP selection and haplotype-based methods incorporating both case-control association and case-case sharing comparisons; (2) multiple testing procedures for multistage sampling designs, including hierarchical models for prioritizing SNPs for further consideration using external genomic data; (3) family- vs. population-based studies and allowance for population stratification and admixture; and (4) gene-gene and gene-environment interactions. To investigate these problems, we will apply the methods to real data from our own studies (the Multiethnic Cohort and the Los Angeles Latino Eye Study of age-related macular degeneration), as well as data available in public databases such as the HapMap Project. Since most genome-wide datasets are limited to relatively small samples and are not connected to any phenotype information, we will develop ways for using these real data to generate large populations that would contain realistic degrees of genetic diversity that would look like those seen in these small samples. We will then sample from these populations to simulate replicate case-control data sets under known phenotype models to investigate the statistical performance of alternative study designs and analysis methods.
DESCRIPTION (provided by applicant):
The primary objective of this research is to determine the importance of thioredoxin in neutrophil-airway epithelial cell interactions after oxidant injury. Neutrophils play a beneficial role by removing oxidant-injured airway epithelial cells and enhancing subsequent epithelial repair after ambient ozone exposure. The central hypothesis is that neutrophil-dependent removal of oxidant-injured airway epithelial cells requires thioredoxin production by the injured cells that then enhances neutrophil co-localization, removal of injured cells and subsequent epithelial repair. The objectives of this proposal will be addressed in four parts. First, the investigators will determine the molecular interaction between thioredoxin and the cell membrane of oxidant-injured airway epithelial cells. Secondly, they will investigate the importance of thioredoxin in neutrophil co-localization to airway epithelial cells, their removal after injury and enhancing subsequent epithelial repair. Immortalized human bronchial epithelial cells will be stably transfected with a thioredoxin expression construct and the investigators will quantify neutrophil co-localization to these cells, neutrophil-dependent removal of oxidant injured cells and epithelial repair using BrdU. To assess the importance of thioredoxin structure in these functions, the investigators will repeat the experiments using monolayers transfected with thioredoxin expression constructs mutated in key cysteine amino acids. Third, they will show thioredoxin is chemotactic for mouse neutrophils. This will lead to the fourth aim of developing a transgenic mouse over-expressing wild type and mutant thioredoxin in airway epithelium and demonstrating the role of thioredoxin in neutrophil emigration and removal of injured cells in vivo. The primary candidate's long-term research goals are to investigate mechanisms of pulmonary inflammation and repair with special emphasis on the interaction between neutrophils and airway epithelial cells. She hopes to use a career research award to gain additional knowledge and training in molecular biology while transitioning to an independent researcher who will be competitive for R01 funding.
DESCRIPTION (provided by applicant): The proposed research addresses a fundamental question in biology: how do the environment and genotype interact to produce the phenotype? The pea aphid, an emerging genomic model system, exhibits dramatically different adult phenotypes of winged or unwinged morphs that are induced by environmental conditions in asexual females (a polyphenism) and by a single unidentified genetic locus in males (a polymorphism). Further, genetic variation for the female wing polyphenism segregates with the male wing polymorphism suggesting that the developmental networks underlying the polyphenism and polymorphism are not independent. I propose to (1) map and identify the male polymorphism gene to determine the developmental genetic basis of the male polymorphism, (2) characterize the transcriptional and metabolomic response to wing-inducing stimuli in the asexual females to determine the developmental genetic basis of the female polyphenism and (3) use a systems biology approach to link the results from (1) and (2) to provide a cohesive picture of how environmental signals and genetic signals interact to produce fundamentally similar adult alternative morphologies. The year-long mentored stage of this award focuses on developing a holistic view of the biological systems involved in a training environment that excels in systems and network biology: the laboratory of Dr. Sergey Nuzhdin in the Molecular and Computational Biology section at the University of Southern California. Following the mentored period, I will transition to a tenure-track position at an academic research institution. Relevance: All phenotypes, from our height and weight to our disease susceptibility, result from a complex interplay between our genes and our environment. This project aims to illuminate basic rules acting to integrate environmental and genetic signals in the production of the phenotype.
DESCRIPTION (provided by applicant):
This application is based in large measure on the candidate's prior experience in treating children with asthma in a small developing island-nation where the incidence of asthma is rapidly increasing. This experience deeply motivated the candidate to obtain in-depth knowledge into both the epidemiology and pathophysiology of pedjatric asthma. The candidate's goal is to pursue independent investigation into the mechanisms responsible for this burgeoning pediatric illness. At the University of California, Irvine, the candidate selected as co-mentors two physician scientists whose research in: 1) air pollution and pediatric asthma; and 2) immune responses to exercise in children complemented one another. The rationale for this collaboration is that both air pollution and exercise exacerbate asthma in children, but the mechanisms that link these two phenomena are not clear. It is known that exercise even in healthy children leads to a robust activation of innate immunity with increases in neutrophils, neutrophil adhesion molecules, and neutrophit oxidative stress mechanisms that play a role in bronchoconstriction. Air pollution sensitizes neutrophils rendering them more prone to release these factors when environment factors, similar to exercise, stimulate innate immunity. Intriguingly, both exercise and pollution also affect lymphocyte TH1/TH2 polarization, now known to influence neutrophil function. Despite these compelling observations, little is known about neutrophil responses to exercise in the child with asthma, or the association to lymphocyte TH1/TH2 balance, and this is the focus of the proposed research. A major stumbling block in research in pediatric asthma has been the difficulty in truly characterizing disease severity. This study proposes to identify a cohort of children with persistent asthma whose clinical severity and air pollution exposure will be measured comprehensively under field conditions using nephelometry and spirometry to investigate new disease mechanisms using laboratory based, precisely controlled exercise challenges focused on neutrophil function and the association to lymphocyte TH1/TH2 balance. Neutrophil function will be assessed from the level of neutrophil genomic expression to systemic manifestations of neutrophil oxidative stress responses. The lymphocyte TH1/TH2 balance will be assessed by intracellular cytokine profiles. To complement the research project, the candidate has developed a robust didactic program including formal courses in statistics, molecular biology, and epidemiology; and ongoing postgraduate seminar series in exercise physiology and immunology. Finally, the candidate's career development will be overseen by the project co-mentors and a distinguished advisory committee consisting of immunologists, exercise physiologists, and biostatisticians.
DESCRIPTION (provided by applicant)
The Environmental Pathology Program at the University of California-Davis (UC-Davis), currently entering its 29th year, supports a subspecialty group of veterinary pathology trainees whose research and career interests are in health effects of environmental agents. This program is a part of a larger research Training Program in Pathogenesis of Diseases administered by the Department of Pathology, Microbiology and Immunology (PMI) and the Graduate Group in Comparative Pathology. This is a 6 year overall program leading to American College of Veterinary Pathologists (ACVP) board eligibility and the Ph.D. trainees are supported during their graduate and research program after completing their clinical training in anatomic pathology. Partcipants receive training in comparative pathology, basic cell biology, the cell and molecular basis of disease, and biochemical toxicology and do research activity in faculty laboratories sufficient to qualify for the Ph.D. degree. Training faculty are selected by the applicability of their research program on human environmental health issues.
This request is for 3, three year postdoctoral positions which, when combined with students supported by other resources, forms a core of postdoctoral professionals who exists in a self-teaching hierarchy of experience under the mentorship of an interdisciplinary and well funded training faculty. Also requested is one pre-doctoral position to be used for minority recruitment in the DVM Ph.D. program. The foundation of the training program is the established interaction at UC-Davis between the academic discipline of pathology and strong environmentally-orientated research centers, principally in the California Primate Research Center, the Center for Health and Environment, the Departments of PMI, Molecular Biosciences and Anatomy, Physiology and Cell Biology (Veterinary School), Environmental Toxicology (College of Agriculture and Environmental Sciences), and Internal Medicine (School of Medicine). The training uses the format of a specially-tailored Ph.D. degree program in Comparative Pathology. The first 12 months of the 3 to 4-year research program are spent primarily in advanced coursework appropriate to pathology and an introduction to the environmental research programs through seminars and rotations in research laboratories. Trainees next perform a thesis project under the direction of one of the training faculty. Currently active areas include reproductive toxicants, hazards posed by air pollutants and environmental cardiology.
BACKGROUND
This is a competing continuation application for a training program in Environmental Pathology that has been funded for 29 years. Funds are requested to support 3 postdoctoral positions and one pre-doctoral position. The program is somewhat unique in that the majority of participants have veterinary medical degrees and it provides training in clinical veterinary pathology in addition to research experience as part of the program. At the end of the postdoctoral program trainees are expected to have completed requirements for the Ph.D. degree and are board eligible for ACVP certification. Support is requested for the three-year research portion of the six-year postdoctoral training curriculum. New to this application is the addition of one pre-doctoral training slot within the three-year research portion of the combined Ph.D./D.V.M veterinary scientist training program. The addition of the pre-doctoral slot is requested to facilitate recruitment of trainees from underrepresented minorities. Also new to this application are the addition of components to provide training in presentation skills, literature reviews, increased seminar participation and the availability of new research facilities including microarray and microimaging equipment.
DESCRIPTION (provided by applicant)
This is a request for an award to support a summer research program for outstanding undergraduate students and a summer program of organized educational experiences for undergraduate and high school students. Training in the environmental health sciences is crucial to fill the needs of both society and academia. Heightened public awareness and concern about chemicals in the environment elicit a continuing strong demand for toxicologists and other environmental scientists, for effective governmental regulators and for scientists who understand how chemical interactions with biological systems can precipitate or modulate disease states. This program will recruit and train the most talented students with a goal of increasing the pool of environmental health scientists who can have the greatest impact on improving human health and preventing disease. The investigators view this program as a mechanism to provide the most gifted undergraduates recruited at the University of California, Davis with the opportunity for 1) an intensive summer research experience in the area of environmental health combined with 2) educational experiences that will support informed career decisions in the environmental health sciences and provide a framework for understanding major issues in this arena. These experiences will undoubtedly encourage students to pursue graduate research in the environmental health sciences and increase the pool of graduate applicants in environmental health sciences at a national as well as local level.
DESCRIPTION (provided by applicant)
This pre-doctoral and postdoctoral program will train environmental health scientists through interdisciplinary research and courses in mission areas of the NIEHS. Training faculty consist of 29 active researchers in the Schools of Medicine and Veterinary Medicine and the College of Agricultural and Environmental Science. Areas of emphasis include neuro-, respiratory and reproductive toxicology, intracellular signaling and oxidative stress. Faculty interests overlap in these areas, leading to interaction among laboratories and to interdisciplinary approaches to human biology and disease. A large pool of excellent pre-doctoral applicants is available through the Pharmacology and Toxicology Graduate Group and other graduate groups (covering such disciplines as molecular biology, genetics, cell biology, neuroscience, pathology, epidemiology) to which the training faculty belong, a strength of graduate education at the University of California, Davis. Postdoctoral applicants will be solicited among those attracted to the laboratories of the training faculty and by advertisements in widely read journals. In addition, trainees will be solicited among new graduates of the campus Masters in Public Health Program. Trainees will have access to advanced technologies, including proteomics, genomics and use of genetically modified mice. A second strength of training at the University of California, Davis is the vertical integration of studies of environmentally induced disease. Molecular, cellular, tissue and whole laboratory animal (including knockout mouse) approaches complement use of nonhuman primates and human clinical samples obtained through the funded Clinical and Translational Science Center (CTSC). Integration of research with ongoing activities in the various campus research centers (children's health, air pollution, agrochemical exposures and effects, etc.) and with the developing School of Public Health will provide synergy and promote connections to disease prevention and public health. Trainees will receive enrichment in responsible conduct of research and obtain instruction and practice in scientific writing, including proposals for extramural funding. They will also participate in activities communicating scientific findings (seminars, retreats, national meetings) and in workshops organized by the CTSC. This proposed training builds on an established program with a strong track record of meeting the NIEHS mission to protect public health by connecting scientific advances to environmental exposures and the consequent disease processes.
BACKGROUND
This is a competing continuation application for a Training Program in environmental health sciences at the University of California, Davis that has been in existence for over 30 years and is administered by the Department of Environmental Toxicology. In the past the award has provided support for approximately 120 trainees. The previous funded cycle supported 10 pre-doctoral trainees. In this competing renewal application support is requested for 6 pre-doctoral and 3 postdoctoral trainees each year. Of those completing the program more than 10 years ago, nearly half are in industry, one quarter function as managers and regulators in federal and state governments, approximately 15% are in academia and 5% have left the environmental health sciences field. There are a total of 29 mentors listed with three of them physician-scientists. Over the past 10 years 75% of the students have come out of the Pharmacology and Toxicology (PTX) Graduate Group and this is expected to continue.
DESCRIPTION (provided by applicant)
This training grant will support pre-doctoral and postdoctoral students in the Molecular Toxicology Interdepartmental Program (IDP) at the University of California, Los Angeles (UCLA). Prior to the establishment of the IDP in 2000, toxicological research and training was scattered through many departments at UCLA, and lacked cohesion and coordination. Establishment of the IDP focused training in one program and stimulated interactions and collaborations among the participating faculty and their students and postdoctoral fellows. The training grant will help further consolidate, improve and expand the Molecular Toxicology Program, and signal the "arrival" of toxicology as an important player in the biomedical sciences at UCLA. The nine faculty of the training grant have their primary appointments in seven different departments in three different schools. Nevertheless their laboratories/offices are in close proximity to one another. The faculty members have substantial NIEHS funding. Most importantly, they have a common interest in the mechanisms whereby toxicants induce disease. Several of the faculty members investigate the role of air pollution particulates in the exacerbation of asthma. Others investigate the carcinogenic/mutagenic effects of these and other environmental pollutants. A new area for the program is the role of pesticides in the etiology of Parkinson's disease. Capitalizing on their experience with ambient air particles, some of the faculty have begun research on the emerging field of the toxicity of manufactured nanoparticles (nanotoxicology).
One pre- and one postdoctoral position is requested in the first year. These numbers will progressively increase to four and two, respectively, in the fifth year. Pre-doctoral students will be supported for up to three years after they have completed their first year of course work. Postdoctoral fellows will receive two years of support. Five of the nine mentoring faculty are physician-scientists. These faculty members will provide an avenue for the recruitment of physicians to postdoctoral positions in the training grant. The grant is highly relevant to public health. A better understanding of the processes whereby air pollution, pesticides and other environmental pollutants cause diseases, including asthma, cancer, and/or Parkinson's disease, will lead to improved risk assessment as well as methodologies for reducing or eliminating the deleterious effects of these environmental agents.
BACKGROUND
This is a resubmission of an application for a training grant in Molecular Toxicology at UCLA. This revised application has undergone substantial revision to address concerns of the previous review. Training grant preceptors without R01 type funding have been omitted and the number of preceptors has decreased from fifteen to nine. Course requirements have been changed to reflect the addition of more toxicology courses. Previous incomplete sections/tables are now generally complete. Dr. Hankinson, the Program Director, presented that among the 9 faculty members included in this current training grant, 7 now have substantial NIEHS funding. In response to the concern that none of the mentors is affiliated with environmental health sciences, Dr. Hankinson points out that one of the new members of the faculty (Dr. Froines) is a Professor in the Department of Environmental Health Sciences, while two other members of the faculty (Drs. Ritz and Schiestl) have secondary appointments in that Department. He also points out that it should be noted that the Molecular Toxicology Program is an interdepartmental program, and believes that the resulting broad perspective represents one of the strengths of the program.
DESCRIPTION (provided by applicant)
The Environmental Health Sciences Division, in the School of Public Health at the University of California, Berkeley, proposes to provide a summer research internship for undergraduate and high school students to introduce them to the field of environmental health with the long-term aim of increasing the number of talented students who pursue graduate degrees and careers in this field. Students will be recruited from the University of California, Berkeley, other San Francisco Bay Area colleges and universities, and local high schools. Students admitted to the program will be matched to faculty conducting environmental health research of interest to the intern. Student interns will conduct research with the designated faculty member and members of the research team, including staff scientists, graduate students and postdoctoral scholars, when appropriate and in accordance with the learning objectives. The interns will also attend seminars including ones on Environmental Health Sciences, the Responsible Conduct of Science, and a Research Discussion Group. They will meet weekly with their faculty mentor. The faculty mentors will define projects suitable for the intern, monitor the interns' progress on a weekly basis, and provide written feedback on the performance of the intern and the structure and administration of the program. Likewise, the interns will provide written and verbal feedback about their mentor and the STEER program as a whole. Research projects may include direct data collection, patient interaction, laboratory experiments, computer-based modeling, and data analysis, among others. Grant management will establish a Campus Advisory Committee to ensure that the summer internship program benefits from the experience and services available on the campus. It will also establish an Internal Advisory Committee made up of project management, faculty and students. It will develop an effective recruitment process and an evaluation process to ensure the program continuously improves over the five-year period of the grant.
DESCRIPTION (provided by applicant)
The main objective of the proposed Program is to introduce selected and highly qualified undergraduate students from traditionally underrepresented ethnic groups to laboratory research in experimental toxicology. The ultimate goal will be to motivate and to prepare such students for graduate school and careers in environmental health sciences. This Program is affiliated with the presently funded NIEHS graduate training grant "Advanced Training in Environmental Toxicology" (2 T32 ES07059) and incorporates its highly qualified faculty and much of its administrative structure. Using the available University network, students will be recruited from the relatively large pool of excellent minority undergraduates at the University of California, Davis, the California State University system, and the California community college system. In addition, contacts will be made to solicit applications from across the USA. To accomplish the stated objectives, trainees will be assigned a specific laboratory project that will yield some tangible results within a two-to-three month time frame. The students will be introduced to laboratory techniques in toxicology and applications of the scientific method. Research areas represented by the faculty include respiratory toxicology, pharmacokinetics, epithelial targets, genetic damage, developmental and reproductive effects, neurotoxicity and environmental fate of toxicants. By being associated closely with faculty members, graduate students and undergraduate peers, trainees will become acquainted with academic goals and aspirations of their coworkers. In addition, the students will be provided with general overviews of issues in environmental toxicology and with current active research programs of University of California-Davis faculty. They will receive information on the process of applying to graduate school and taking the Graduate Record Examination. They will be registered for credit in summer session undergraduate research, permitting them to utilize University library and recreational facilities. The intent is to give the students a favorable and realistic picture of graduate school and careers in science and thereby encourage their pursuit of higher education. Ideally, this Program will eventually increase the pool of qualified undergraduate minority students who will enter graduate school at institutions such as University of California-Davis to pursue environmental health research and who can be supported by NIEHS graduate training grants.
DESCRIPTION: My career goal is to be a leader in evolutionary ecology as a faculty member at a first-tier research university. To reach this goal, I envision building upon my background in field-based ecological research by pairing it with the pursuit of detailed mechanistic and genetic-network based approaches. The NRSA fellowship could provide me with the opportunity to build upon my ecological skills by developing genetic and genomic tools for an emerging ecological model organism. As a NRSA postdoctoral fellow and eventually as an independent researcher, I want to understand how genotypes vary in their sensitivity to heavy metal toxicity. Heavy metal toxicity has clear medical implications, but is also important for understanding patterns of plant diversity and speciation that track soil chemistry, and is increasingly important for agricultural production in polluted soils. I see this as an area with great research potential and importance.
Crisp Terms/Key Words: postdoctoral investigator, environmental exposure, high throughput technology, microarray technology, matrix assisted laser desorption ionization, gene environment interaction, Arabidopsis, SDS polyacrylamide gel electrophoresis, environmental toxicology, soil sampling, soil pollution, plant growth /development, heavy metal, metal metabolism, genetic polymorphism, plant genetics, genotype, genetic mapping, mass spectrometry, biochemical evolution
DESCRIPTION (provide by applicant)
Two trends have dramatically altered the landscape of training in biomedical research. The first is increasing emphasis on multidisciplinary research, requiring investigators to have both depth in their own particular area of expertise, as well as the breadth of skills required to form new liaisons and collaborations with other scientists in diverse fields. The second is the increasing use of sophisticated statistical and computational data analyses, especially of genomic data. Mathematical and computational scientists must be thoroughly engaged in the biological issues of the problems they are working on if they are to be able to communicate with their colleagues and make important contributions.
The proposed program will offer new pre-and postdoctoral training in environmental genetics that spans the disciplines of genetic, molecular and environmental epidemiology, statistical genetics, bioinformatics and computational molecular biology. The investigators propose to build upon the historical strength of the (University of Southern California) USC Department of Preventive Medicine in cancer and environmental epidemiology to focus their training on dissecting complex biological pathways involving gene-environment and gene-gene interactions, issues that are central to the NIEHS Environmental Genome Project. The investigators also propose to integrate these training programs based at the Keck School of Medicine more closely with those in the Program in Molecular and Computational Biology located at the University Park Campus, in order to provide training in modern genomics and bioinformatics techniques that are relevant to the NHGRI Human Genome Project and International Haplotype Mapping ("HapMap") Project.
The specific aims of this proposal are to provide multidisciplinary training for three pre-doctoral scientists and two postdoctoral scientists in specialized training at the interface between environmental health and genomics. Extensive research resources are available in support of studying gene-environment and gene/gene interactions in cancer and other diseases.
DESCRIPTION (provided by applicant)
The California-Arizona Consortium (CAC) proposes to train 17,848 hazardous waste/materials workers in EPA Regions IX and X under the HWWT program. The CAC consists of UCLA-LOSH as the lead agency, UC Davis Extension, UC Berkeley LOHP, Arizona State University College of Technology & Applied Sciences and the University of Washington NW Center for Occupational Health & Safety. With over 3,145 active cleanup sites in the 8 states and 4 U.S.-affiliated Pacific Islands, there continues to be great need for training. A full range of courses will be provided for workers and supervisors involved in CERCLA cleanup, hazmat emergency response, and hazmat transport. Weapons of mass destruction (WMD) courses will be provided as needed. Train-the-Trainer courses will be offered for environmental justice organizations, maquiladora workers along the U.S./Mexico border, and other NIEHS awardees. The CAC will assist with the National Trainers' Exchanges. Access to target populations has been established over the past 17 years of NIEHS funding. The CAC emphasizes outreach to underserved, non-English-speaking workers, those with limited literacy skills, and those who are low income or workers of color. Curricula will be updated, e-learning and WMD modules introduced, and materials translated into Spanish. The Impact Evaluation addresses 2 NORA priority areas.
The proposed HDPT program will expand the scope and target population of the CAC to a new frontline high-risk workforce at West Coast ports. The CAC will develop a model program and train 3,040 workers to identify and respond appropriately in the event of hazmat emergencies or security threats. The CAC will partner with the International Longshore and Warehouse Union and coordinate with the Area Maritime Security Committees at the Ports of Los Angeles/Long Beach, Oakland/San Francisco and Seattle/Tacoma. The CAC will also convene a Community Forum to address occupational or environmental health and security issues related to the transport of global goods from the ports throughout the Southern California region.
DESCRIPTION (provided by applicant)
The social and built environments affect food consumption patterns that influence disease occurrence and public health. Health disparities arise when environmental factors make it difficult to access healthy food choices. Access factors that influence dietary choices include the cost, availability and physical accessibility of healthy foods. Residents of neighborhoods that lack affordable sources of healthy food may experience higher rates of overweight and diabetes, resulting from differences in the consumption of fresh fruits and vegetables and whole grains versus foods that are high in calories, added fat, and sugars, and low in other nutrients. The local nutrition environments created by such factors can, however, be changed if community members are actively involved in shaping community nutrition norms and influencing policies that increase the availability of affordable healthy foods. Such proactive intervention has the potential to reduce the health disparities for overweight and diabetes that plague low-income communities and communities of color.
The goal of the project is to facilitate positive community-driven changes in local nutrition environments in schools and communities that suffer disproportionately from diet-related poor health conditions. The project will evaluate access factors in those schools and communities; raise nutrition, environmental and food access awareness; develop and implement intervention strategies; and assess the environmental and policy impact of those strategies. Activities include the training of low-income African-American and Latino students, parents, and residents to undertake community and school food assessments; the development of appropriate and feasible action plans to address poor nutrition environments and policies; and the creation of local community nutrition advisory councils to mobilize efforts to move intervention strategies forward. The project hypotheses are: 1) through participation in community and school food assessments and the development of community nutrition councils, school and community members will have increased awareness and knowledge of the health disparities related to lack of access to health-promoting foods; and 2) increased awareness and the development of community-driven strategies for environmental and policy change will in turn lead to improved nutrition environments that reduce risk factors for overweight and diabetes.
Crisp Terms/Key Words: curriculum, health education, nutrition education, school, education evaluation /planning, diet, dietary constituent, nutrition related tag, dietary excess, African American, Hispanic American, community, clinical research, health disparity
DESCRIPTION (provided by applicant)
There is growing optimism that adjusting the built environment can reverse the obesity trend through increased opportunities for physical activity and the reduced reliance on automobiles for basic transportation. The majority of research, however, on the influence of the built environment on health related outcomes have used cross-section designs. As a result, there is a limited amount of information on the causal impact of changes in the built environment on obesity levels. The proposed 24-month pilot study would provide a foundation for assessing the short-term causal influence of light rail mass transit on physical activity and obesity. The proposed study will consist of a natural experiment that examines the before and after effects of the introduction of a new light rail system in Charlotte, NC on obesity related factors.
The specific aims of the proposed pilot study are: (a) to test the impact of light rail on the daily physical activity levels and BMI of riders; and (b) to assess whether the use of light rail transit leads to significant increases in physical activity and reductions in BMI of study participants who use light rail compared to similarly situated participants who do not use light rail transit. Through a two-wave longitudinal panel design of interviews with 1,000 household residents living within a mile radius of the soon-to-open light rail transit system the study will assess pre and post-levels of daily physical activity and BMI. A propensity score matching approach will be used to match light rail riders and non-riders on all relevant health, social, and economic factors. The results from the propensity score matching will be used to compare the physical activity and BMI levels over time of participants who use the light rail system with participants who do not use light rail transit. Results from the research will provide a causal test of the impact of light rail on obesity and the potential positive economic impacts of integrating public health objectives in transportation decision-making.
Crisp Terms/Key Words: outcomes research, behavioral /social science research tag, clinical research, weight loss, travel, urban area, socioenvironment, socioeconomics, chordate locomotion, human population dynamics, longitudinal human study, data collection methodology /evaluation, interview, human subject, public health, physical fitness, body physical activity, exercise, environmental engineering, obesity, body composition
DESCRIPTION (provided by applicant)
Over the past 5 years, the Center for Children's Environmental Health Research at the University of California, Berkeley has successfully created a fully coordinated research program that addresses the unique environmental health needs of primarily Latino farmworker children living in an agricultural community. The investigators have focused their research on pesticide exposures, their potential health consequences, and community-based exposure prevention strategies. A strong community partnership and infrastructure has been developed with extensive outreach to constituent groups, service providers, and policy makers, and the investigators have received awards from both the University and the community. In addition, the investigators have leveraged Center resources to obtain additional funding for numerous other community and scientific projects. The core of the Center has been the CHAMACOS (Center for the Health Assessment of Mothers and Children of Salinas) project, conducted in collaboration with a coalition of community health care providers and agencies. CHAMACOS, which means 'small child' in Mexican Spanish, is a longitudinal birth cohort study of pregnant women and children living in the agricultural community of the Salinas Valley, Monterey County, California. The CHAMACOS cohort includes primarily low-income Mexican immigrant farmworkers and their families, and thus, provides a unique opportunity to examine prospectively the influence of prenatal and early childhood exposures encountered in an agricultural environment, such as to pesticides and bioaerosols, on the health of children. Over the next 5 year, the investigators propose to follow the CHAMACOS cohort into the school years and to determine whether prenatal and childhood exposure have impacted their neurodevelopment, respiratory health, and somatic growth. Moreover, they propose to expand the scope of the Center in three related and complementary directions: first, laboratory investigations will be conducted to understand the mechanisms of immuno- and neuro-toxicity of pesticides; second, exposure-related studies will be conducted to better understand the routes and pathways of pesticide exposure to children; and third, outreach will be extended to constituent groups within the immediate Salinas community and to similar populations in Monterey County, the state of California, and throughout the nation. These activities are aimed at accomplishing the Center's ultimate goal: to translate research findings into sustainable strategies to reduce pesticide and other environmental exposures to children, and thus reduce the incidence of environmentally related childhood disease.
DESCRIPTION (provided by applicant)
The mission of the University of California-Davis Center for Children's Environmental Health (CCEH) is to promote daily interactions among a multidisciplinary team of scientists whose main research interest is to understand the complex web of etiologic factors that contribute to autism. The shared philosophy among Center participants is that a better understanding of the immunological and neurobiological mechanisms associated with this neurodevelopmental disorder can not only lead to a better understanding of the mechanisms that influence it but can also accelerate the discovery of effective intervention strategies. The goals of the CCEH in the next five years are to: (1) better understand the mechanisms by which environmental, immunologic, and molecular factors interact to influence the risk and severity of autism; (2) identify early immunologic, environmental, and genomic markers of susceptibility to autism; (3) develop mouse models of immunologic susceptibility to environmental triggers and define the impact of these triggers on the development of complex behaviors, key brain structures and neurotransmitter receptors relevant to autism; (4) translate the research findings into diagnostic tools that can be used in clinical practice to predict early autism risk; and (5) supply the community with accurate and timely information about autism risk factors. The CCEH has organized three interrelated hypothesis-based Research Projects that are supported by five Facility Cores (Administrative, Community Outreach and Translation, Analytical Chemistry, Molecular Genomics, and Statistics).
The projects are: Project 1, Environmental Epidemiology of Autism, will build upon the investigators' discovery of immunologic and molecular biomarkers specific to children with autism found in 2-5 year olds enrolled in the CHARGE (Childhood Autism Risks from Genetics and Environment) study. Working closely with the Community Outreach and Translation Core and Project 2, newborn bloodspots and a second set of blood samples (CHARGE-BACK study) from CHARGE children will examine the stability over time of these biomarkers. CHARGE-BACK blood samples will also provide peripheral immune cells to study how autism alters properties of cell activation, and susceptibility to known immunotoxicants. The investigators will launch a new cohort study called Markers of Autism Risk in Babies-Learning Early Signs (MARBLES) that tracks 200 women at high risk of giving birth to an autistic child, starting from early pregnancy and following the pregnancies and the babies to the age of three years.
Project 2, Immunological Susceptibilities in Autism, will work closely with Project 1 to test the overall hypothesis that autistic children have fundamental defects in cellular immunity that ultimately lead to abnormalities in immune dysfunction and heightened susceptibility to environmental triggers. Project 3, Models of Neurodevelopmental Susceptibility, will develop and use mouse models to understand the relationships between immune system dysfunction and perinatal exposure to environmental toxicants in the development of neurobehavioral disorders in sociability and seizure susceptibility. Working closely with Project 2, the investigators will test mouse strains with low (C57BL/6J) or high (SJL mice) susceptibility to autoimmunity to determine how perinatal exposures to methylmercury, noncoplanar PCB, or polybrominated diphenyl ether 47 (BDE 47) influence brain development, complex social behaviors, and immune system function.
DESCRIPTION (provided by applicant)
During its first five years, the Children's Environmental Health Center (CEHC) supported investigations of the roles of the environment and susceptibility in children's respiratory health. Important contributions were made supporting the growing consensus that current levels of ambient air pollutants and tobacco smoke have substantial adverse effects on children's respiratory health, especially among susceptible groups. The overall scientific and translational theme of the CEHC renewal application is air pollution, susceptibility, and childhood airway disease. The objectives proposed for the Center's next five years are: 1) to investigate the role of ambient air pollutants and genetic susceptibility in airway inflammation and in asthma occurrence during childhood; 2) to investigate the mechanism for the modulating effects of ambient air pollutants on allergic inflammation in children; 3) to implement a community-based participatory research program to respond to community concerns about the effects of regional ambient air pollutants and locally emitted fresh vehicle exhaust on early life asthma; 4) to provide a scientific resource for the broader community involved in protecting children's environmental health. In this application, the CEHC offers an innovative program of community-based participatory research, mechanistic and epidemiologic research to fill some pressing research and public health needs. The investigators propose a vigorous outreach and translation effort to ensure that communities, legislators, regulatory agencies, and other groups interested in children's environmental health are well informed about the evolving science and health impacts on children and communities. The proposed research program is integrated scientifically by a biological model that hypothesizes that chronic oxidative and nitrosative stress mediate the chronic effects of air pollution on asthma and allergic rhinitis. The investigators have identified six key research and translation questions about the adverse effects of ambient air pollution on children's airway diseases: 1) Do regional ambient air pollutants such as 03 or locally emitted fresh vehicle exhaust increase the risk of early life asthma? 2) Is chronic airway inflammation a risk factor for new onset asthma? 3) Do ambient air pollutants or locally emitted fresh vehicle exhaust produce chronic airway inflammation? 4) Do levels of expression or polymorphic variants of genes in antioxidant pathways such as GSTM1 confer special airway sensitivity to air pollution? 5) Which pollutants are responsible for the effects we see? 6) Can scientific approaches and translation to the broader community involved in protecting children's environmental health be enhanced by community-based participatory research approaches? Because the burden of airway disease and the numbers of children exposed to unhealthful air are large and growing, answers to these questions are urgently needed. The CEHC research program offers a timely opportunity to efficiently answer these key questions using an integrated approach and unique population and exposure assessment resources. Our collaborative multidisciplinary investigative team and strong working relationships with the community research partners, enhance the CEHC's ability to continue to contribute to understanding the effects of environmental exposures on childhood airway disease and to strengthen public health efforts to protect children.
The long-term goal of our research is to identify the cause(s) of Parkinson's disease. This proposal features an integrative approach to the investigation of (1) cellular mechanisms involved in neurodegeneration, (2) environmental determinants that affect disease risk, and (3) genetic factors that may affect susceptibility. It is composed of four different integrative research projects, and three cores (administrative, research development, and information
outreach), which together make up a Coordinated Center for Parkinson's Disease Environment Research. The broad theme underlying this proposal is that Parkinson's disease results from the interaction between environmental toxicants (such as pesticides or metals), protective factors in the environment (such as nicotine, caffeine) and genetic susceptibility factors. Project 1 (entitled "Genes, Environment & PD: Studies in 4 Unique Cohorts") investigates the separate and combined roles of occupational toxicant exposure (pesticides, metals), genetic variants of membrane transporters of these toxicants and putative neuroprotective behaviors (tobacco & caffeine use) in more than 1000 PD cases and over 1500 controls. Shared diagnostic and exposure assessment in 4 cohorts facilitates combined analyses, while the diverse
characteristics of each cohort maximize generalizability. The goal of Project 2 (entitled "Neurotoxicants, Oxidative Stress and Alpha-synuclein") is to investigate the role of oxidative stress as a key contributor to the development of alpha-synuclein aggregation, inclusion body formation and ultimately neuronal injury at the experimental level. The effects of metals/pesticides on these pathological processes will also be assessed. Our third project (entitled "Iron, Oxidative Stress, and Pesticides)," will examine (i) the agerelated susceptibility of the mouse nigrostriatal system to combined damage from iron and pesticide exposure, (ii) the effects of oxidative stress in the context of such exposures, and (iii) ways to protect against these effects. Both Projects 2 and 3 will utilize well-established and novel transgenic models to achieve their scientific goals. Our fourth project (entitled," Nicotine and neuroprotection in nonhuman primates") will explore the effects of nicotine as a potential neuroprotective agent against nigrostriatal injury in a primate model of Parkinson's disease. The hypothesis that this action may be achieved through a receptor mediated stimulation of growth factors will also be examined. These integrative research projects should provide important new insights in the environmental, genetic and cellular factors contributing to Parkinson's disease, and could bring us closer to finding the cause of the disease. Success in these endeavors could lead to new strategies for treatment and even disease prevention.
DESCRIPTION (provided by applicant): Obesity and associated metabolic syndrome diseases have become an epidemic of global proportions. Excessive consumption of calorie-dense food and diminished physical activity are generally accepted causal factors for obesity. But can environmental factors expose preexisting genetic differences or exacerbate the root causes of diet and exercise? The "obesogen hypothesis" proposes that environmental chemicals can perturb lipid homeostasis, adipocyte development and adipose tissue function. Exposure during sensitive developmental windows can induce imbalances resulting in permanent changes that result in increased fat storage. New work from our laboratory has identified organotins as a novel class of obesogen candidates. Organotins are a well-studied group of environmental endocrine disrupting agents demonstrated to cause pleiotropic effects on development, hormonal physiology and sex determination in vertebrates and invertebrates. We found that the ligand dependent retinoid X receptors (RXR) and peroxisome proliferator activated receptor gamma (PPARg) are novel high-affinity molecular targets of the organotins such as tributyltin (TBT). RXR-PPARg signaling is a critical component in vertebrate adipogenesis. RXR also serves a broader role as the common heterodimeric partner to many additional nuclear receptors involved in lipid, metabolic and developmental signaling pathways. We have proposed that the potent effects by TBT on these receptors occurs via a novel covalent modification and that inappropriate activation has the potential to strike at the heart of adipose tissue homeostasis. Initial results show that TBT promotes adipocyte differentiation in the murine 3T3-L1 adipogenic model, modulates known adipogenic genes in vivo, and increases adiposity in mice after in utero exposure, consistent with an obesogen model. We hypothesize that TBT acts as an environmental obesogen and that prenatal exposure can lead to long-term effects on metabolism, predisposing exposed individuals to obesity and related disorders. We propose three specific aims to test this hypothesis: 1) How does prenatal TBT exposure perturb adipose homeostasis, in vivo? 2) Which molecular interactions are critical for the organotin elicited adipogenic phenotype? 3) What are the molecular interactions between organotins and RXRs-PPARg? Validation of this hypothesis will provide a paradigm shift in our evaluation of obesity related gene-environment interactions from the molecular to the whole animal level. Since central adiposity plays a pivotal role in increasing the risk of metabolic syndrome diseases in human populations, the proposed research studying a novel contributing mechanism is highly relevant to current public health concerns.
DESCRIPTION (provided by applicant): The goal of this proposal is to elucidate the eukaryotic DNA damage response through an integrated experimental/computational approach leading to in-silico models of signaling and regulatory networks. Comparative modeling of the networks induced by different damaging agents is likely to reveal rich new insights into cellular toxicity and, ultimately, cancer progression. Experimentally, we will focus on how the yeast DNA damage control network is reprogrammed by exposure to methyl methanesulfonate (MMS; years 1-2) or methyl-N'-nitro-N-nitrosoguanidine (MNNG; years 3-4), two different types of alkylating agent. The network will be characterized using high-throughput genomic technologies including chromatin immunoprecipitation in conjunction with promoter microarrays to identify protein-DNA interactions (chlP- chip); coimmunopreciptation followed by mass spectrometry to identify protein-protein interactions; and DNA microarrays to monitor genome-wide expression profiles resulting from systematic single and double gene knockouts. Computationally, we will integrate and model these data using tools for comparison of networks across multiple conditions (PathBLAST), statistical identification of expression-activated network regions (ActiveModules), and a specialized visualization platform and database we have developed for operating on network models (Cytoscape). A systems approach will be crucial for revealing the complex web of interactions between diverse cellular damage responses ranging from base-excision repair and homologous recombination to cell-cycle arrest, apoptosis, general stress response, protein metabolism, and those yet to be discovered.
DESCRIPTION (provided by applicant)
This proposal describes a tightly unified effort between metabolomic specialists and environmental health researchers who will collaboratively characterize the development of asthmatic-type respiratory malfunctions in newborn and young adult rats, caused by model airborne particles using (a) soot particles and (b) secondhand smoke or environmental tobacco smoke (ETS). First, the investigators will compare the effects of soot and ETS at a concentration of 1 mg/m3 on the development of respiratory malfunctions in newborn and young adult rats. These effects will be correlated by comparing these model particles with respect to physical parameters and particulate matter composition. Second, the investigators will establish routes of primary metabolization and transport of organic pollutants from pregnant mothers' lungs to blood plasma. Third, the investigators will study metabolic aberrations in fetal, newborn and young adult rat's lungs. By this, links will be established between the type of particulate matter, its organic composition, the timing of metabolic changes in lung development, and the onset and progression of airways dysfunction. This unique combination of biomedical designs with metabolomic assessments will test the hypotheses that (a) perinatal exposure to organic constituents of airborne matter cause alterations in maturation as well as cellular structure and function in the lungs of young adult rats, (b) organic components deposited in the mother 's lung are directly involved in the development of pulmonary diseases such as airway hyper-reactivity, in addition to secondary alterations in immune response or release of bronchoconstrictive mediators by neuroendocrine cells, and (c) the development of respiratory malfunctions are associated with characteristic metabolic changes and can be distinguished from non-specific stress-related changes. Testing of these hypotheses will be enabled by a combination of cutting-edge analytical and metabolomic techniques at a high throughput level. Primary analytical tools will be gas chromatograph (GC)xGC-time of flight (TOF) mass spectrometry (MS) in combination with automatic peak annotation, enabling multivariate statistical comparisons of metabolic changes as well as compositional analysis of airborne model particles. Data will be complemented by full scan liquid chromatography (LC)-ion trap mass spectrometry and unbiased biomarker detection, and multi-target characterization of metabolites as a result of organic pollutants in lung tissues by LC-triple quadrupole MS/MS.
DESCRIPTION (provided by applicant)
This work proposes to study two lung toxicants, ozone (O3) and 1-nitronaphthalene (1-NN) using a metabolomics approach. Specifically, mechanisms causing lung tolerance to repeated O3 exposure and the synergistic effects on 1-NN toxicity will be investigated. It is hypothesized that a metabolomics approach will detect changes in the metabolome corresponding to modulation of lung susceptibility to repeated O3 exposure with and without 1-NN. Analysis of these changes in metabolic phenotype will contribute to the understanding of underlying mechanisms leading to ozone tolerance and the corresponding higher lung susceptibility to 1-NN. In specific aim (SA) 1, a time course study of O3 exposure using rats will be performed to analyze metabolic changes associated with acute O3 toxicity, repair and tolerance development. In SA 2, changes in metabolic phenotype caused by co-exposure to 1-NN will be studied at the three stages of O3 exposure; acute inflammation, resolution of initial inflammation and O3 tolerance. It is hypothesized that metabolic changes will be reflected in bronchiolar alveolar lavage fluid (BALF), as well as circulating and excreted biofluids. It is further hypothesized that metabolic markers detected in the rodent model will be indicative for O3 toxicity in non-human primates, providing a basis for a biomarker approach extendable to humans. In SA 3, BALF and plasma from O3 exposure experiments with non-human primates, obtained from a collaborator, will be analyzed and compared to the rodent model. SA 4 focuses on data analysis, interpretation and integration. The metabolomics approach includes both metabolic fingerprinting to identify novel biomarkers of toxin exposure as well as a hypothesis-driven metabolic profiling. This includes profiling of oxylipins and antioxidant levels to investigate inflammatory response and oxidative stress, phospholipid speciation in BALF to reflect compositional changes in epithelial lining fluid, and screening for common Phase II metabolites to investigate metabolite excretion.
DESCRIPTION (provided by applicant): We will engage a multidisciplinary team from the University of California Lead Campus Program for Nanotoxicology in studying how the physicochemical characteristics of metal oxide (NP) influence biocompatibility and toxicity in vivo and in vitro. The long-term goal is to develop a rapid screening procedure that classifies NP into potentially safe or dangerous categories. Outline: Titanium dioxide (TiO2), zinc oxide (ZnO) and Ceria (CeO2/Ce2O3) metal oxide NP were chosen based on high volume of production, potential for airborne spread and ability to induce airway inflammation through the generation of reactive oxygen species (ROS). We are particularly interested in how a variation in the physicochemical characteristics of engineered NP influences their biocompatibility or toxicity in portal-of- entry (e.g., macrophages, epithelial, endothelial cells) cellular targets in the lung. In particular, we would like to determine whether our predictive hierarchical oxidative stress model, which is comprised of compensatory as well as injurious cellular responses, could be used for generating a high throughput screening procedure in tissue culture cells that can be used to predict the toxic potential of NP in vivo. To achieve this goal, we will determine how controlled design of the physicochemical characteristics (chemical composition, particle size, state of agglomeration, encapsulation, surface charge) of metal oxide influence ROS production in cells. Metal oxide NP will be synthesized by flame pyrollysis, followed by studying the NP characteristics under dry and wet conditions. We will determine how the variation in the design properties influences: (i) induction of incremental levels of oxidative stress that culminate in adaptive, pro-inflammatory and cytotoxic responses (Aim 1). (2) cellular uptake, subcellular localization and mitochondrial targeting as a prelude to cellular toxicity or biological adaptation (Aim 2); These in vitro cellular studies will involve the use of flow cytometry, real-time PCR, Western blotting, ELISA assays electron microscopy, and confocal microscopy. Once toxicity profiling has been accomplished, the different readouts will be combined into a high-throughput epifluorescence screening procedure that compares several particle types and design modifications simultaneously (Aim 3). Finally, we will determine how the variation in NP physicochemical characteristics influences the induction of airway inflammation in a murine intratracheal instillation model (Aim 4). We will also attempt to relate the vitro oxidant stress effects to the induction of in vivo oxidative stress by using a transgenic mouse that expresses the heme oxygenase 1 promoter linked to a luciferase reporter. We will determine whether the knockout of a key antioxidant defense regulator (Nrf2) renders these animals more susceptible to NP-induced oxidative stress injury.
PUBLIC HEALTH RELEVANCE: This application will develop a novel testing strategy to screen for the safety of a large number of new nanomaterials that are coming onto the market. We will use the design of metal oxide nanoparticle as a screening tool to develop our toxicity screening method that will assess how these particles lead to cell death by different uptake mechanisms and ability to produce toxic oxygen radicals.
DESCRIPTION (provided by applicant):
Data for performing a preliminary risk assessment of manufactured nanomaterials are just beginning to emerge. However, early studies of nanomaterial toxicity in aqueous media have tended to be more observational than mechanistic, and have often focused on a single, advanced stage of toxicity that could yield contradictory results. Moreover, the ability to generalize findings to other nanomaterials is limited by the lack of a rational basis for categorizing nanomaterials. Elucidating the mechanisms of toxicity for a given nanomaterial will provide a basis for classifying materials for regulatory purposes, postulating dose-response curves, screening potential risks, and prescribing strategies for risk management. The primary objective of this work is to elucidate the mechanism(s) by which manufactured nanoparticles may induce toxicity in vitro and in vivo. Specifically, this study will consider fullerene-based materials, comparing them with, (i) reference standards (TiO2 and carbon black); (ii) ultrafine particles obtained from an urban airshed (well characterized by in vitro toxicology studies); We will explore a methodology for rapidly screening potentially toxic nanoparticles based on their propensity to generate ROS. The principal hypothesis is that certain classes of nanoparticles such as fullerenes induce ROS production, cellular oxidative stress and cytotoxicity. Fullerenes are selected based on the relatively novel properties (e.g. strength.arid electron affinity) that make them attractive for commercialization. The investigators propose that oxidative stress induced by fullerene derivatives occurs in several stages (tiers), beginning with the induction of phase II antioxidant defenses at the lowest tier of oxidative stress (tier 1), followed by pro-inflammatory (tier 2) and mitochondrion-mediated cytotoxic effects (tier 3) as the level of oxidative stress increases. Particle size, shape, surface area, charge, and chemical composition are important physical variables that could determine their ROS-generating or scavenging properties. Rapid physicochemical determination of ROS production might provide a paradigm to assess the possible toxicity of nanomaterials that act via these mechanisms.
Specific Aim 1 will characterize commercial nanoparticles and their derivatives in terms of particle size, shape, surface area, charge, aqueous solubility, propensity to aggregate, and their ability to catalyze or quench ROS production in vitro. Materials will also be characterized in model solutions containing naturally occurring organic matter, proteins and ions at levels similar to those present in natural waters. Aim 2 will determine whether various fullerenes can generate a hierarchical oxidative stress response in macrophages, bronchial epithelial cells, endothelial cells, neural cells and hepatocytes. This will be accomplished by comparing the effects of fullerenes and reference nanoparticles on, (i) phase II enzyme expression and activation of the heme oxygenase 1 (HO-1) promoter (tier 1); (ii) cytokine and chernokine expression as well as assays for MAP kinase activation (tier 2); (iii) mitochondria! perturbation and induction of cellular apoptosis (tier 3). These biological responses will be compared to the physicochemieal properties of nanomaterials elucidated in Aim 1. Aim 3 will perform in vivo imaging of the oxidative stress-sensitive HO-1 promoter linked to a luciferase reporter in transgenic mice. Organs and tissues showing increased luciferase activity will be investigated for histological evidence of inflammation and cytotoxicity. Aim 4 will compare the biologic responses elicited by each of the nano-scale particles with their ability to generate ROS abiotically, and test the hypothesis that ROS generation can be used to screen toxicity.
By focusing on mechanisms of toxicity rather than outcomes alone, this work will provide the basis for classifying nanomaterials for regulatory purposes. Based on preliminary results presented in this proposal, we anticipate that ROS generation in solution and under UV radiation will be good predictors of nanoparticle toxicity and that ROS measurements can be adapted to screen nanomaterials. A broader assessment of nanomaterial toxicity in the context of the hierarchical oxidative stress response is likely to yield a more sensitive paradigm for toxicity testing, perhaps resolving inconsistencies reported in the literature.
DESCRIPTION (provided by applicant): Aromatase is the enzyme that converts androgen to estrogen. The applicant has hypothesized and demonstrated that aromatase is an important target of endocrine disrupting chemicals. These compounds have been found to inhibit aromatase activity, which results in both a decrease in the level of estrogen and an increase in the level of androgen in treated cells. Animal experiments have been performed that demonstrated the in vivo action of anti-aromatase chemicals. Additionally, environmental chemicals (both phytochemicals and xenochemicals) were found to modify the expression of aromatase in various tissues, which results in a change in the conversion ratio of androgen to estrogen. The compounds that inhibit aromatase or suppress aromatase expression behave as antiestrogens or androgen-like compounds in vivo. Conversely, compounds that either increase aromatase expression or enhance aromatase activity (or stability) may actually function as anti-androgens or estrogen-like compounds. Research conducted in the applicant's laboratory during the last four years demonstrated that estrogen-related receptor alpha (ERR-alpha) and estrogen receptor alpha (ER-alpha) can regulate the expression of aromatase. It has also been shown that endocrine disrupting chemicals, by acting as the ligands of these two receptors, can modify the expression of aromatase in treated cells.
Aromatase, ER-alpha, and ERR-alpha are all important players in maintaining our endocrine function. To continue with and expand on the current efforts in the applicant's laboratory to identify endocrine disrupting chemicals, it is proposed in this competitive renewal application that they utilize their newly established high throughput computer-assisted virtual screening approach to search endocrine disrupting chemicals which serve as ligands/inhibitors of these proteins. It is also further proposed that they determine the structural characteristics of these chemicals by evaluating their structure activity relationship. Such structural information will be valuable for the identification of unanticipated endocrine disrupting chemicals. The proposed studies will focus on 1014 phytochemicals (including chalcones, chromones, coumarins, flavanones, flavones and isoflavones) that would be purchased from Indofine Co (Somerville, New Jersey). In addition, it is proposed that the endocrine disrupting actions of compounds (which have been identified by the high throughput screening method) be confirmed through both in vitro and in vivo experiments.
DESCRIPTION (provided by applicant): The vicinal haloalkenes are toxicants commonly found at many Superfund sites. Of the 30 most common toxicants detected at Superfund sites, five are nephrotoxic vicinal haloalkenes. Unlike other halogenated hydrocarbons, vicinal haloalkenes uniquely damage the kidney by destroying proximal tubule cells and induce renal carcinomas. It is believed that the nephrotoxic and nephrocarcinogenic effects of vicinal haloalkenes stems from their conversion in hepatic microsomes by the enzyme microsomal glutathione transferase-1 (MGST1) to GSH S-conjugates, which are transported to intestine and then converted to the corresponding cysteine S-conjugates. These cysteine S-conjugates are then transported to the kidney and cleaved by renal cysteine beta-lyases to form toxic haloalkylthiols that damage mitochondria in renal proximal tubular cells. This hypothesis is controversial as there are competing theories that do not include a role for either the liver or for MGST1. Confirmation (or disproof) of this hypothesis has been difficult due to the complex interaction between multiple organ systems and a lack of in vitro models. Complicating the issue is the recent finding that there are multiple human microsomal glutathione transferases capable of conjugating halogenated hydrocarbons. Our objectives are [1] To definitively determine the role of MGST1 in modulating the toxicity of these Superfund vicinal haloalkene contaminates. This will be accomplished by producing both MGST1 overexpressing animals and two types of MGST1 -deficient animals (complete MGST1 nulls versus liver-deficient only) and determining their sensitivity/resistance to the prototype vicinal haloalkenes trichloroethylene (TCE) and hexachlorobutadiene (HCBD). Our studies will confirm the tissue and subcellular distribution of MGST1, which is also controversial, and also determine if deletion of MGST1 results in compensatory changes in other cytosolic and microsomal GST isoforms and in select antioxidant systems. We will also investigate the stress-induced regulation of MGST1 by examining variation in mRNA transcripts that are produced by alternative start sites, and monitoring changes in MGST1 protein content in various organs. [2] To determine if other members of the MGST family are capable of conjugating vicinal haloalkenes and thereby have a potential role in bioactivation of these toxins. [3] To determine whether recombinant MGST proteins could assist in bioremediation of HCBD. [4] To determine the relative contribution of MGST1 and MGST2 to cellular antioxidant capacity through studies utilizing human MGST1 and MGST2 null cells.
DESCRIPTION (provided by applicant): Recent studies demonstrate widespread organophosphate pesticide (OP) exposures to pregnant women and children. However, given the same exposure, some individuals may be more susceptible to the adverse effects of OPs depending on their genetic makeup and expression of genes encoding key metabolic enzymes. For example, the human enzyme paraoxonase (PON1) detoxifies various OPs with different efficiency depending on the main polymorphism at position 192 and others along promoter and coding regions. As part of the CHAMACOS longitudinal birth cohort study, we have investigated OP exposures and health effects in -500 pregnant Latina women and their children living in the agricultural community of the Salinas Valley, CA. Initial data suggest that OP exposure in this cohort exceed national reference levels, and that maternal OP urinary metabolite levels were associated with shortened gestation and abnormal reflexes in neonates. Preliminary data from 130 maternal and cord blood samples show that newborns had lower PON1 activity than their mothers, suggesting they may be more susceptible to the adverse effects of OPs. Thus, differences in genotype, enzyme activity, and age may contribute to differential sensitivity to OP exposures. In the proposed study, we will take advantage of an extensive biorepository and data on growth and neurodevelopment from the CHAMACOS cohort. Our objectives are: 1) to create a PON1 gene haplotype map for this Latino population; 2) to examine the ontogeny of PON1 enzyme activity in infants from birth through 24 months; 3) to establish whether PON1 genotype is associated with OP pesticides in maternal and cord blood; and 4) to determine whether PON1 modifies the relationship of OP exposure and fetal growth, length of gestation and neurodevelopment. To address these aims, we will genotype CHAMACOS mothers and children for five PON1 polymorphisms (192, 55, -108, -909, -162); measure four substrate-specific PON1 enzyme activities (arylesterase, paraoxonase, diazoxonase, chlorpyrifos oxonase) in maternal, cord and child blood at 12 and 24 months; and measure OPs in cord and maternal bloods. This study will help identify human subpopulations more susceptible to the health impact of OP exposure. These data will support planning for the National Children's Study, identify subpopulations susceptible to chemical warfare agents, and inform policy decisions for implementation of the Food Quality Protection Act.
DESCRIPTION (provided by applicant): The proposed work focuses on three molybdenum-containing enzymes of environmental relevance: DMSO reductase, arsenite oxidase and sulfite oxidase. The first of these catalyzes the reduction of DMSO to the anti-greenhouse gas DIMS, and as such plays an important role not simply in the global sulfur cycle but in modulating climate as well. The second enzyme catalyzes the oxidation of arsenite to arsenate, an important step in the biotransformation of arsenic in the environment that represents a detoxification mechanism for those microorganisms in which it is found. It is a member of the same family of molybdenum-containing enzymes as DMSO reductase, but has an active site structure that represents a variation on that seen in DMSO reductase. Sulfite oxidase from higher eukaryotes (both vertebrates and plants) catalyzes the final step in sulfur catabolism, the oxidation of sulfite to sulfate, and prevents the deleterioius accumulation of the highly reactive sulfite in vivo. The overall goal of the proposed work is to gain a more complete understanding of the mechanism of action of these enzymes in the context of their structures, comparing and contrasting their behavior. The guiding hypothesis behind the approach is that enzyme function and catalytic power are dictated by the physical and electronic structure of the active site. The Specific Aims include rapid kinetic studies as well as spectroscopic and computational work aimed at determining the electronic structures of the enzyme active sites. In the cases of DMSO reductase and sulfite oxidase, site-directed mutants targeting specific active site amino acid residues will also be examined to evaluate their roles in catalysis.
Crisp Terms/Key Words: protein protein interaction, enzyme activity, Arabidopsis, iron sulfur protein, active site, plant protein, oxidoreductase, circular magnetic dichroism, molybdenum, site directed mutagenesis, enzyme structure, enzyme mechanism, Raman spectrometry, electron spin resonance spectroscopy, chemical kinetics
DESCRIPTION (provided by applicant): Project Summary: Hypotheses and Objectives: This two part study will (a) use refined air pollution data to examine the influence of air pollution on adverse birth outcomes such as low birth weight and premature birth, and (b) evaluate the feasibility of assembling a birth-cohort to provide saliva samples for the analysis of genetic susceptibility to the effects of air pollution on birth outcomes. The study will make use of several existing data sources from Fresno and Bakersfield, CA, two areas with some of the highest ozone and particulate concentrations in the U.S. This project will lay the groundwork for the analysis of genetic polymorphisms that may modify the influence of air pollution on adverse birth outcomes, and ultimately, influence the development of asthma. Methods: Part A involves linking exposure data from the California Regional PM10/PM2.5 Air Quality Study (CRPAQS) to California birth certificate data to evaluate the impact on adverse birth outcomes such as premature birth and low birth weight. The data will be limited to Fresno and Bakersfield, California, for the years 2000-2004, providing an estimated 68,000 births. We will also examine the role of traffic exposure, as measured by the California Department of Transportation on birth outcomes. Part B involves a case-control design where 500 low birth weight and/or preterm infants will be counter-matched with 500 normal infants. The mothers of these 1000 infants will be sent a short health survey and be asked to provide a maternal and child saliva sample via the mail. The saliva samples will be used for future analysis of gene-environment interactions. Additional survey data will be collected to address confounding and effect-modification of the pollution/birth outcomes association. Expected Benefits: This proposal directly addresses NIEHS's research priorities regarding early life exposures and subsequent environmentally induced health effects such as adverse birth outcomes. It will make use of the most detailed and highly refined air pollution data ever collected. It will lay the groundwork to examine the impact of genetic polymorphisms that may identify susceptible children and pregnant women. It will allow for the extrapolation of small data sets to obtain population based estimates of disease burden, while establishing a birth cohort and specimen bank for future analyses of both maternal and child gene-environment interactions. Given that the children who we will target are now up to age 8 years, this may be a last chance opportunity to establish a birth cohort. Study designs that allow for cost-efficient participant recruitment and sample collection would guide future cohort studies of children's environmental health. Project Narrative--Expected Benefits: These research questions directly address NIEHS's research priorities regarding early life exposures and subsequent environmentally induced health effects such as adverse birth outcomes. It will make use of the most detailed and highly refined air pollution data ever collected. It will lay the groundwork to examine the impact of genetic polymorphisms that may identify susceptible children and pregnant women. It will allow for the extrapolation of small data sets to obtain population based estimates of disease burden, while establishing a birth cohort and specimen bank for future analyses of both maternal and child gene-environment interactions. Given that the children who we will target are now up to age 8 years, this may be a last chance opportunity to establish a birth cohort. Study designs that allow for cost-efficient participant recruitment and sample collection would guide future cohort studies of children's environmental health.
DESCRIPTION (provide by applicant)
The goal of the Administration Core is to provide a centralized structure to unify the research program under the Program Director hand and to facilitate the coordination of the research projects to fulfill the research goals of the grant. Specifically, this Core will do the following:
1) Assist the Program Director in planning and coordinating research activities; 2) Integrate cross-disciplinary research; 3) Oversee fiscal and resources management and ensuring that all agency and university guidelines are met; 4) Maintain ongoing communication with NIEHS and other BRIES Centers and Individual Projects; 5) Organize an Annual Meeting of all investigators, NIEHS collaborators and guest scientists; 6) Assist in the organization of meetings related to the BRIES Centers and Individual Projects; 7) Produce all progress reports, manuscripts and other written documents related to the program in a timely manner; 8) Set up and maintain databases of publications, personnel, investigator addresses, and equipment inventory; and, 9) Provide day-to-day administrative assistance to the Program Director.
DESCRIPTION (provided by applicant)
Mutations in the PINK1 gene are linked to an autosomal recessive early onset familial form of Parkinson's disease (PD). The molecular and physiological functions of PINK1 that generate pathological abnormality of PD-associated PINK1 mutants are largely unknown. Therefore, this group has developed a genetic model of PD in Drosophila to study the in vivo role and genetic interactions of PINK1 with known and new potential contributors to this disease. It has been recently shown that inactivation of Drosophila PINK1 (dPINKI) using RNAi results in progressive loss of dopaminergic (DA) neurons and in ommatidial degeneration of the compound eye, which is rescued by expression of human PINK1 (hPINKI). Moreover, expression of human superoxide dismutase 1 (SOD1) suppresses neurodegeneration induced by dPINKI inactivation, and treatment of dPINKI RNAi flies with antioxidants (e.g., vitamin E) significantly inhibits ommatidial degeneration. Thus, PINK1 may normally prevent neurons from undergoing oxidative stress, a potential mechanism by which a reduction in PINK1 function leads to PD-associated neurodegeneration. Therefore, in this proposal it is hypothesized that PINK1 plays a critical role in maintaining survival of dopaminergic neurons via a regulated pathway involving protection against oxidative stress. PD-pathogenic PINK1 mutants impair the functional pathway and therefore lose the ability to protect neurons from oxidative stress. In this study, efforts will focused on utilizing the newly-developed PD fly model (published in PNAS) to first investigate the genetic mechanisms and interactions that influence the severity of the PD pathogenic phenotype produced by PINK1 mutations under different (oxidative) stress conditions. The fact that wild-type human PINK1 but not disease-associated PINK1 mutations can reverse PD-associated pathologies in our fly model provides us with the opportunity to efficiently screen in a whole animal system for genetic and chemical modifiers that are likely relevant to finding therapeutics for this disease. New genetic factors as well as chemical compounds will be screened that function to alter (e.g., ameliorate or aggravate) the neurodegenerative phenotype observed in our PD fly model.
DESCRIPTION (provided by applicant)
The goal of the UCLA-CGEP is to identify novel pathogenic mechanisms of sporadic PD based on understanding the critical cellular pathways disrupted by Putative Environmental Toxicants (PETs). This group found associations between high levels of exposure to PETs with PD, and in parallel experiments discovered PETs alter specific cellular pathways potentially involved in disease pathogenesis, the ubiquitin-proteasome system (UPS), microtubule polymerization, and aldehyde dehydrogenase (ALDH). The goal of this project is to determine the relative importance of UPS disruption (especially E1 activating enzyme), microtubules and ALDH by candidate pesticides in conferring vulnerability to dopamine (DA) neurons using cell-based assays. We will test whether disruption of these cellular mechanisms in isolation or in combination (i.e., multiple hits) leads to nigrostriatal cell death using cell lines and primary mesencephalic neurons in culture. A secondary goal of this project is to determine whether selective vulnerability of nigral neurons is due, at least in part, to alterations in DA homeostasis by measuring the effect of PET exposure on DA and its metabolites and altering cytosolic DA using viral mediated VMAT expression. A third goal is to identify additional agricultural pesticides that are also able to disrupt those same cellular pathways shown to alter the viability of nigrostriatal dopaminergic neurons. These studies will help elucidate the mechanisms of action of agents known to increase PD risks over long periods of exposure. The results will also help determine which genetic polymorphisms associated with Project 4, and the screening results will guide further epidemiological analyses of agricultural risk factors. The hypothesis is that the determination of mechanisms of action of environmental agents that increase the risk of PD will shed light on the pathophysiological processes involved in sporadic PD.
DESCRIPTION (provided by applicant)
The International Society for Environmental Epidemiology (ISEE) is the premier international scientific organization for environmental epidemiology. It was established in 1988 to foster the study of health and the environment. Membership is open to environmental epidemiologists, other scientists, and public health professionals worldwide. The society has more than 850 members. The International Society of Exposure Analysis (ISEA) was established in 1989 to foster and advance the science of exposure analysis related to environmental contaminants, both for human populations and ecosystems. Any person with a professional interest in exposure analysis and environmental research is eligible for membership. ISEE has about 475 members. The ISEE and ISEA each sponsor annual scientific conferences, which draw together members and non-members worldwide from a wide variety of disciplines. The two societies sponsor a joint annual conference approximately every three years.
The ISEE and ISEA will have a Joint Annual Conference in Pasadena, CA, on October 12-16, 2008. The objective is to bring together at least 1,000 scientists and other stakeholders to present and exchange information about recent advances in exposure science, environmental epidemiology, and public health. The conference theme is "Exposure and Health in a Global Environment." The conference will enable participants to exchange ideas about ecological and human health impacts due to industrialization and urban growth; global transport of pollution; worldwide energy demands; and changes in manufacturing, agriculture and land use. Examples of priority related topics that will be addressed include bio-monitoring and exposure biology; air pollution-exposure characterization and health effects; children's environmental health; interaction of environmental and genetic factors in health and development; health effects of global environmental changes; changing patterns of infectious diseases; environmental factors in national and international patterns of health disparities; spatial epidemiology; and ethics and environmental health policy.
The conference has established a Program Planning Committee that is organizing plenary sessions. The Committee is soliciting and will peer-reviews proposals for symposia, individual presentations, and posters. Accepted abstracts will be published in Epidemiology and made available through the societies' websites. The conference will have special programs and provide travel awards to encourage participation of students and scientists from developing countries. The conference quality and impact will be formally evaluated.
The conference will enhance science and research in the fields of exposure science, epidemiology, and environmental health. It will promote the conduct of relevant research that will strongly support the mission of the NIEHS and other institutes of the NIH. The conference will generate and disseminate information to the scientific community, government officials, and the general public who are interested in these fields.
The conference will enhance science and research in the fields of exposure science, epidemiology, and environmental health by generating and disseminating information to the scientific community, government officials, and the general public who are interested in these fields. The meeting will promote the conduct of relevant research and reduce the burden of human health risks from environmental causes by increasing the understanding of these elements and how they relate. The outcomes will include the advancement of knowledge of human exposure analysis, epidemiological methods, linkages between exposures and health responses, environmental health sciences, and public health.
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