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Record Count: 109
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DESCRIPTION (provided by applicant): Cells are constantly exposed to a variety of environmental agents some of which induce DNA damage i.e. genotoxic stress. Cellular responses to genotoxic stress are complex and therefore, more studies are needed to better understand the mechanisms that control such responses. Here we propose to characterize a novel gene, which we have named PIQ (p53-regulated IQ protein) that codes for an IQ motif protein. IQ motifs promote protein interactions with calmodulin (CaM). CaM is a calcium-binding protein that controls several important signaling events. Evidence presented here show that PIQ does indeed bind to CaM. Furthermore, PIQ mRNA is overexpressed in primary colon tumors when compared with matching normal tissues and that PIQ is down-regulated in response to genotoxic stress and p53 activation. PUMA is a key mediator of p53- dependent genotoxic stress-induced apoptosis and our results indicate that PIQ down-regulates PUMA promoter expression. Importantly, PUMA promoter harbors regulatory elements that are predicted to be regulated by CaM-dependent signaling pathways. We, therefore, propose that in unstressed cells, PIQ may negatively regulate PUMA expression by interfering with CaM-dependent signaling events and PIQ downregulation following genotoxic stress serves to promote PUMA upregulation partly via CaM-dependent pathways. Our overall hypothesis is that PIQ is a negative modulator of apoptosis and that higher levels of PIQ expression noted in colon cancer may alter the threshold of apoptosis and consequently contribute in part to colon tumorigenesis. Three specific aims are proposed here to further characterize PIQ in order to elucidate its role in cellular response to genotoxic stress in general and in the development and/or progression of colon cancer in particular. Specific Aim 1 is to investigate the role of PIQ during p53 and genotoxic stress-induced apoptosis. Specific Aim 2 is to investigate the mechanism by which PIQ negatively regulates PUMA promoter expression. Specific Aim 3 is to analyze PIQ expression at the mRNA and protein levels in a larger pool of primary colon tumors and their matching normal tissues and to evaluate a relationship between tumor PIQ-status and the clinicopathologic features.
Crisp Terms/Key Words: small interfering RNA, RNA interference, protein protein interaction, p53 gene /protein, protein binding, green fluorescent protein, gene environment interaction, neoplastic process, apoptosis, SDS polyacrylamide gel electrophoresis, DNA damage, calcineurin, cell adhesion molecule, calmodulin, protein structure function, messenger RNA, colon neoplasm, neoplasm /cancer genetics, environment related neoplasm /cancer, western blotting, human tissue, gene induction /repression, genetic transcription, genetic promoter element, molecular cloning, genetic marker, cell growth regulation, biological signal transduction
DESCRIPTION (provided by applicant): Although cellular responses to genotoxic (DNA damage) or ER stress are complex, they are vital for cellular homeostasis. Aberrations in cellular responses to these stresses can have profound effects giving rise to major abnormalities including cancer, cardiovascular anomalies, diabetes and neurodegenerative disorders. This application is to characterize a novel gene that we have named BBEL1 (Bax and Bak interacting E3 Ligase 1). BBEL1 encodes a novel stress-regulated E3 ubiquitin ligase that localizes to mitochondria. BBEL1 inhibits DNA damage-induced apoptosis and interacts with the pro-apoptotic Bax and Bak. We hypothesize that BBEL1 is a novel mitochondrial anti-apoptotic E3 ubiquitin ligase that mediates its anti-apoptotic effects by inhibiting Bax and Bak and thus, a key component in the cellular stress response pathways. We are proposing three specific aims to further characterize BBEL1. Specific Aim 1 is to determine the topology and localization of BBEL1. Specific Aim 2 is to investigate the molecular basis for Bax and Bak interactions with BBEL1. Specific Aim 3 is to perform structural functional characterization of BBEL1. Proposed studies are critical initial steps to characterize BBEL1 and to lay the groundwork for further in-depth studies aiming to determine the exact function of this novel ubiquitin ligase particularly in context to toxicology and pathobiology of human diseases. PUBLIC HEALTH RELEVANCE: Cellular responses to DNA damage and other types of stresses are complex yet very vital for cellular wellbeing. Defects in cellular responses to these stresses can have profound effects giving rise to major abnormalities including cancer, cardiovascular anomalies, diabetes and neurodegenerative disorders. Here we propose to characterize a novel gene BBEL1 that encodes a novel stress-regulated E3 ubiquitin ligase. BBEL1 appears to be a key component of cellular stress response pathways as it inhibits DNA damage-induced apoptosis and interacts with pro-apoptotic proteins. Proposed studies are critical initial steps to characterize BBEL1 and to lay the groundwork for further in-depth studies aiming to determine the exact function of this novel ubiquitin ligase particularly in context to toxicology and pathobiology of human diseases.
DESCRIPTION (provided by applicant): Cells are constantly exposed to a variety of environmental agents some of which induce DNA damage i.e. genotoxic stress and cellular ability to effectively manage such stresses starts to decline with age. Cellular responses to DNA damage (genotoxic stress) are complex and therefore, more studies are needed to better understand the mechanisms that control such responses. We propose to characterize a novel gene, which we have named PDRG (p53 and DNA damage-regulated gene). PDRG mRNA is differentially regulated by genotoxic stress and p53 and is overexpressed in primary colorectal tumors when compared with matching normal tissues. By yeast two-hybrid screening, we have identified three important proteins including PDCD7, CIZ1 and MAP1S that exhibit interactions with PDRG. These three proteins have been involved in modulating cell cycle and/or apoptosis suggesting that PDRG may also play a role in regulating these processes. We, therefore, hypothesize that PDRG is an important mediator of cellular response to genotoxic stress and alterations in PDRG expression and PDRG-mediated signaling events are part of the mechanisms underlying the development and/or progression of digestive diseases such as colorectal cancer. Here we propose two specific aims to further characterize PDRG. Specific Aim 1 is to investigate the role of PDRG in cellular response to genotoxic stress in p53-positive and -negative cells. Specific Aim 2 is to determine the molecular basis of PDRG interactions with PDCD7, CIZ1 and MAP1S in context to genotoxic stress response. The outcome of these studies will help to determine the potential role of PDRG in digestive diseases such as colorectal malignancies and thereby further improve our understanding of the pathobiology and toxicology of human digestive diseases.
Public Health Relevance Statement: A variety of environmental agents induce DNA damage i.e. genotoxic stress and cellular ability to effectively manage such stresses starts to decline with age and that is why various tumors are more common in the elderly. Here we propose to characterize a novel p53 and DNA damage-regulated gene that exhibits altered expression in human colorectal tumors. The outcome of these studies will help to determine the potential role of PDRG in diseases such as colorectal tumors and thereby further improve our understanding of the pathobiology and toxicology of human digestive diseases.
DESCRIPTION (provided by applicant): Polycyclic aromatic hydrocarbons (PAHs), such as benzo[a]pyrene (B[a]P), are ubiquitous complete carcinogens that are present in tobacco smoke. The majority of work in previous studies has focused on the mutations that are associated with the tumor initiation effect of these compounds. However, the tumor promotion effect of PAHs, which is thought to be mediated through regulation of signal transduction pathways leading to activation of transcription factors, remains unclear. Our preliminary studies suggest that benzo[a]pyrene diol-epoxide (B[a]PDE), an ultimate carcinogenic metabolite of benzo[a]pyrene (B[a]P), is a major compound responsible for activation of the transcription factor activator protein-1 (AP-1) in non-cytotoxic concentrations. Since growing evidence has shown that activation of AP-1 by carcinogens is required for tumor promotion in both cell culture models and animal experiments, the main hypothesis of this proposal is that signal transduction pathways leading to activation of AP-1 play a critical role in the tumor promotion effect induced by B[a]PDE. The overall aim of this proposal is to elucidate the molecular mechanisms by which PAHs induce tumor promotion. Especially, we will establish the signal transduction pathways leading to AP-1 activation by B[a]PDE in a well-characterized tumor promotion cell culture model, mouse epidermal C141 cells. We will then investigate whether the same pathway occurs in an in vivo model using an AP-1-luciferase reporter transgenic mouse model. Furthermore, we will determine the role of AP-1 activation in B[a]PDE-induced tumor promotion in a two-stage carcinogenesis mouse skin model using dominant negative mutant c-jun (TAM67) transgenic mice. We will investigate these issues in accordance with the following testable hypotheses and specific aims: 1) To elucidate early events involved in initiating the signaling pathways leading to AP-1 activation by B[a]PDE in mouse epidermal C141 cells; 2) To test the hypothesis that the PI-3K/Akt/p7086k pathway is required for B[a]PDE-induced AP-1 activation in mouse epidermal C141 cells; 3) To determine whether B[a]PDE is able to induce AP-1 activation in vivo by using AP-1-luciferase reporter transgenic mice and whether this activation is through the same signal transduction pathways as in vitro; 4) To test the hypothesis that AP-1 activation is essential in the tumor promotion effect of B[a]PDE in a two-stage carcinogenesis mouse model. The significance of the research proposed in this application is that the results derived from the proposed studies will greatly facilitate the understanding of the molecular mechanism of cancer development caused by B[a]P and B[a]PDE. A better understanding of signal transduction pathways leading to AP-1 induction may provide valuable information needed for designing more effective agents for prevention and therapy of cancers caused by cigarette smoke. Such agents could interfere with the signaling pathways leading to AP-1 activation.
DESCRIPTION (provided by applicant): Background: We have recently discovered a new toxic effect of the aryl hydrocarbon receptor (AhR) ligand 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD or dioxin). Specifically, exposure during pregnancy impairs mammary gland development and suppresses the coordinated induction of milk proteins, resulting in impaired lactation and neonatal mortality.
Objectives/Hypothesis: The objectives of the proposed studies are (1) to further characterize this novel finding and (2) to identify the lactogenic regulatory pathways adversely affected by exposure to dioxin. The hypothesis for these studies is that AhR activation during pregnancy disrupts the normal signaling that directs pregnancy-associated mammary development and milk protein gene expression, resulting in impaired epithelial cell differentiation and lactation. Specific Aims: 1).To determine whether defects in lactogenesis result from direct effects on mammary tissue, we will cross-transplant mammary tissue from wild-type and AhR-null mice. 2) To identify the mechanism underlying impaired milk production, we will determine whether exposure to TCDD deregulates the activation of NF-kappaB-, STATSa- and C/EBbeta-mediated signalling pathways in mammary epithelial cells. 3) To determine whether stunted glandular development during pregnancy results from deregulation of proliferation, differentiation, apoptosis or defects in multiple pathways, we will further characterize the effects of exposure to TCDD on these processes in mammary cells during pregnancy. 4) To identify additional molecular pathways that are deregulated following exposure to TCDD, we will compare the expression of factors known to regulate to glandular differentiation and lactogenesis in glands derived from vehicle- and TCDD-treated pregnant mice using a combination of gene expression profiling and immunocytochemical methods. Mammary tissue from AhR-null mice will be used to distinguish defects that are directly AhR-mediated from defects that arise due to an upstream lesion. Significance: The proposed studies address an area that is clinically-relevant but has received very little attention. An estimated 3-6 million mothers of live infants annually are either unable to or have significant difficulty initiating breastfeeding. The causes of this problem are not clear, and very little is known about the effects of exposure to environmental contaminants on lactogenesis. Furthermore, since the mechanisms that control lactogenesis also regulate proliferation and differentiation in other organs, and exposure to AhR ligands disrupts the proliferation and differentiation of epithelial cells in other tissues, findings from these studies will have broad biological significance, and will help us better understand the mechanisms by which dioxin-like chemicals adversely affect epithelial cells throughout the body.
DESCRIPTION (provided by applicant): The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor and one of a family of proteins containing the bHLH-PAS domain structure. Members of this family are involved in responding to signals in the tissue environment and serve regulatory roles in development and cellular differentiation. Although the AhR has been conserved throughout evolution and mice lacking the AhR show many defects in several organ systems, its normal function is not known. Recent work has identified an endogenous ligand, 2-(1'H-indole-3'- carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE), from porcine lung and demonstrated this to be a potent AhR agonist. However, unlike toxic AhR ligands like 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), ITE produces no toxicity in mice even at very high doses. It is hypothesized that ITE differentially interacts with the AhR as compared to toxic ligands such that exposure results in different molecular and biological consequences. It is also hypothesized that, based on work indicating a role of the AhR in the regulation of inflammation, that ITE may have a novel role as a regulatory molecule for inflammatory processes in the lung. Using primary mouse and human lung fibroblasts, we will rigorously determine, by microarray analyses, differences and/or similarities in the gene profile induced by ITE and TCDD. Using both isolated lung cells and a pre-clinical mouse model of lung inflammation, we will also determine whether the inflammatory response is similar or different in the presence of ITE, TCDD, or known AhR antagonists, and will begin to characterize the cellular and signaling pathways that may determine these similarities or differences. The goals of these studies are of particular significance given the wealth of data indicating a role of inflammation in the pathogenesis of several diseases including chronic obstructive pulmonary disease, hypertension, cardiovascular disease, allergic diseases such as asthma, and cancer. Understanding the role of ITE and the AhR in modulating inflammatory processes may lead to possible therapeutic interventions.
DESCRIPTION (provided by applicant): The heme moiety of denatured hemoproteins (heme-proteins) is degraded by HO-1 & HO-2, to CO and biliverdin (BV), an HO activity inhibitor; BV is reduced by its reductase (BVR) to the antioxidant, bilirubin. CO has anti-inflammatory and vasodilatory activities. Stimuli that cause oxidative stress and hemoprotein denaturation, such as surgical interventions, inherited and transmitted hemolytic diseases, and certain drugs, industrial and environmental agents, induce ho-1. The kidney tubules are the target of potent pro-oxidant activity of heme-compounds. To date, no effective strategy has been described to counter heme-protein renal toxicity; however, increase in HO-1 activity by activation of stress-activated response elements, e.g., AP-1/CRE, AREs (antioxidant response elements) is considered cytoprotective. The activation involves cell-line independent binding of basic leucine zipper (bZip) transcription factors: c-Jun, ATF- 2/CREB, and Nrf2. The MAPK and PI3-K pathways transduce signals for activation of bZip factors and "cross talk" using PKCs. bZip factor activity is subject to the identity of its dimeric partner. Phosphorylation of the ultimate target gene product, e.g., HO-1, alters its activity and turnover. In vitro and in cultured cells, we have discovered that: the human (h) BVR is one of the rare kinases that control MAPK and PI3-K signaling; is a bZip factor; activated by ho-1 inducers; and, traffics between the cytosol and nucleus. hBVR binds to AP-l/CRE and ARE elements and also enhances ATF-2 and Nrf2 binding to AP-1 and/or ARE; promotes induction and activation of ATF-2, c-Jun and c-Fos; activates kinase mediators of ho-1 response, i.e. PKCs and PKB/Akt; and, causes cell differentiation. BVR regulates ho-1 oxidative stress response and its anti-apoptotic effect. The overall objective of this application is to further investigate regulation of HO-1 activity by BVR at the molecular and cellular levels and to extend the investigation to the intact animal. Specific aims are to examine: i) function of BVR as kinase:kinase in phosphorylation, activity, and turnover of HO-1; 2) the role of hBVR in transcriptional activity of ATF-2 and Nrf2; and, 3) whether increased levels of BVR protect against heme-mediated injury. Mice expressing hBVR in renal tubules and treated with the hemolytic agent, phenylhydrazine, will be analyzed for pathophysiology, antioxidant status, kinase activities and HO-1 levels. Liver will serve as the non-target organ as control for the expression of the transgene.
DESCRIPTION (provided by applicant): The broad, long-term objective of this application is to establish chemical markers of internal exposure and genetic damage through biomonitoring DNA adducts to assess the risk of carcinogens. Human risk assessment has been severely impeded by the paucity of analytical methods that unambiguously identify and quantitate DNA adducts in vivo, and by the inability to easily obtain relevant tissues to assess cancer development. We hypothesize that the recent advances in sensitivity of liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS) instrumentation allow for the identification and quantification of DNA adducts in exfoliated buccal cells of individuals exposed to tobacco smoke and diet-related carcinogens. The successful use of buccal cells as a reliable tissue to measure DNA adducts requires optimization of the analytical MS methods and the establishment of standardized methods to isolate human buccal cell DNA. To address this hypothesis, the specific aims are: 1) To establish ultra-trace LC/ESI-MS methods to measure DNA adducts of suspected human carcinogens found in tobacco smoke that include: 4-methylnitrosamino-1-(3-pyridyl)-1-butanone, benzo(a)pyrene, 2-amino-a-carboline, 2-amino-3-methyl-a-carboline, 4-aminobiphenyl; and abundant heterocyclic aromatic amine (HAAs) carcinogens formed in grilled meats; 2) Cytobrush and mouthwash rinsing techniques will be compared to isolate buccal cells that maximize the recovery of human DNA and minimize contaminating bacterial DNA. The standardization of the buccal cell DNA isolation method will permit reliable assessment of genotoxin exposure and DNA damage; and 3) Recruit volunteers that include: smokers, non-smokers, and meat-eaters and probe for buccal cell DNA adducts by LC/ESI-MS. Adduct formation will be correlated to salivary nicotine levels for tobacco exposure and HAAs in the diet. The results of this research are expected to show that quantitative LC/ESI-MS analysis of buccal cell DNA adducts may be used to assess damage posed by genotoxins, and reduce the invasiveness of risk assessment procedures by validation of exfoliated cell specimens. The impact of this research on public health is the development of new analytical tools that may be used for biomonitoring and risk assessment, which examine exposure to genotoxicants, assess gene-environment interactions and determinants of cancer, or chemopreventive efficacy.
Crisp Terms/Key Words: nitrosamine, biphenyl compound, adduct, mouthwash, tobacco, benzopyrene, tobacco abuse, meat, mutagen, human subject, nutrition related neoplasm /cancer, cancer risk, chemical carcinogen, nutrition related tag, oral mucosa, liquid chromatography, pyridoindole, tissue /cell culture, technology /technique development, DNA damage, electrospray ionization mass spectrometry, smoking, clinical research, nucleic acid quantitation /detection, environmental exposure
DESCRIPTION (provided by applicant): DNA polymerase delta (Pol d) is a key enzyme that is essential for eukaryotic chromosomal DNA replication. Mammalian Pol d consists of four subunits, all of which are required for its full function in vitro. This proposal is based on the novel discovery that levels of the human Pol d p12 subunit are dramatically depleted after DNA damage by UV and other genotoxic agents that activate the ATR/Chk1 mediated S-phase checkpoint. We have shown that this results in the conversion of Pol d from a tetramer into a trimer, Pol d3. The biochemical properties of pol d3 will be compared to those of the parent enzyme. We will examine its kinetic properties, its abilities to bypass template lesions, and its abilities to act as a proof reading enzyme. Our working hypothesis is that the conversion to Pol d3 prevents Pol d from bypassing template lesions, thereby allowing repair processes to take place. The spatiotemporal aspects of the localization of Pol d3 to DNA damage foci will be studied by immunofluorescence microscopy and laser scanning cytometry after UV damage and compared to the recruitment of other DNA damage proteins. The role of ubiquitination in the depletion of pol d will be studied. The identity of the ubiquitination system will be determined using several different approaches, including siRNA knockdown of candidate ubiquitination proteins, identification of p12 binding proteins, and isolation of E3 ligases that act to ubiquitinate p12 using in vitro assays.
DESCRIPTION (provided by applicant): A growing body of epidemiological data suggests that chronic inflammation and infection induce malignant cell transformations and thus play a critical role in the etiology of human cancers. The overproduction of radicals (carbonate, nitrogen dioxide, superoxide radicals) in response to chronic infection and cellular inflammation is accompanied by the reactions of these radicals with polyunsaturated fatty acids (PUFA) in lipid membranes that generate highly reactive, genotoxic oxyl intermediates (peroxyl and alkoxyl radicals). In turn, these radicals contribute to oxidative DNA damage that contributes to the etiology of cancer by poorly defined pathways. Guanine is the most easily oxidizable nucleic acid base in DNA and is therefore a primary target of attack of reactive radical species. The guanine radicals formed undergo a cascade of reactions that culminate in the formation of stable and unstable, genotoxic chemical end-products. However, the reaction pathways, particularly the mechanisms of reaction of peroxyl and alkoxyl radicals with DNA are poorly understood. We have developed new approaches for studying in real time the reactions of unstable nucleobase radicals in DNA with reactive intermediates such as the peroxyl and alkoxyl radicals derived from lipid peroxidation, in aqueous solutions. The analysis of intermediate and final reaction products by a complex of analytical methods including HPLC, MALDI-TOF/MS, and HPLC-ESI-MS/MS, will provide insights into the mechanism of DNA reaction and oxidation pathways. In specific Aim 1, the mechanisms of radical-radical reactions of PUFA peroxyl radicals and guanine radicals in DNA will be investigated. In specific Aim 2, the further oxidation initiated by PUFA peroxyl radicals of 8-oxoguanine, a ubiquitous and well known form of cellular oxidative DNA damage, will be assessed. In specific Aim 3, the detailed mechanisms of the still poorly understood oxidation pathways of PUFA molecules with reactive oxygen species (carbonate radical anion, nitrogen dioxide, superoxide radicals) will be investigated. The development of a variety of cancers including hepatocellular carcinoma, prostate cancer, pancreatic cancer, renal cell carcinoma, and colon cancer, have been correlated with chronic inflammation and infection. A better understanding of the oxidative lipid peroxidation pathways of DNA damage should provide a rational basis for the development of new strategies for the prevention and/or progression of these types of malignancies.
DESCRIPTION (provided by applicant): The long range goal of this research is to gain a detailed understanding of how covalently modified bases in DNA affect RNA polymerase behavior during the elongation phase of transcription, with the ultimate objective of producing detailed structural models that portray RNA polymerase interactions at bulky and small adducts found in DNA. The following four Specific Aims will be targeted toward this: (1) to assess the effects of transcription past site-specific lesions on elongation past the damaged or modified site; (2) to determine the base sequence of full-length transcripts, and to characterize the base composition at the 3'- ends of truncated transcripts; (3) to determine Km, and Vrnax values for base addition at DNA adducts during transcription; and (4) to employ computer-modeling techniques to provide characteristics of transcription complexes stalled at DNA adducts. It is now quite clear that certain DNA lesions can cause RNA polymerase to stall at the modified site, resulting in a truncated transcript, or progress past the altered base, producing full-length RNA. Stalled transcription complexes signal transcription-coupled DNA repair. The importance of transcription-coupled DNA repair is evidenced by the clinical phenotype observed when it is aberrant, as is seen in patients with Cockayne's syndrome, a disease characterized by severe growth and developmental defects. There are broad and significant implications for preferential clearance of DNA damage from discrete, active genetic loci: Biases in mutagenesis can exist; correlations of DNA damage and repair with tumorigenesis might be stronger when preferential clearance rates for a particular adduct are used for making the comparisons, rather than total genomic repair; and the actual removal of adducts from the transcribed strand of an expressed gene might be very dependent on their ability to impede RNA synthesis.
Crisp Terms/Key Words: adduct, stereochemistry, polymerase chain reaction, computer simulation, carbopolycyclic compound, genetic transcription, transposon /insertion element, RNA biosynthesis, DNA repair, nucleic acid sequence, ribonucleotide, DNA directed RNA polymerase, protein structure function, tissue /cell culture, active site, DNA damage, cell line, enzyme activity
DESCRIPTION (provided by applicant):
DNA polymerases are essential for maintaining genomic order during DNA replication and repair and thus for the long-term survival of a species. When DNA damage arising from a variety of exogenous and endogenous sources (e.g. environmental chemicals and radiation, smoking, thermal aberrations) is not accurately repaired, it can lead to human diseases like colon, lung, or skin cancer and premature aging. Thus, understanding polymerase fidelity mechanisms in DNA synthesis represents a fundamental biological and biomedical challenge. The fidelity of DNA polymerases broadly refers to their ability to incorporate correct rather than incorrect nucleotides complementary to the template DNA; such fidelities span a wide range, from 1 to nearly 10(E6) errors per one million nucleotides incorporated. Based on extensive structural and kinetic data as well as theoretical studies for several DNA polymerases, we hypothesize that high fidelity enzymes tightly orchestrate the assembly of the active site prior to nucleotide incorporation, while lower fidelity polymerases have a more flexible active site and thus a distinct assembly process; characteristic differences in the electrostatic environment and plasticity of the binding pocket likely result. Since static crystallographic structures and kinetic experimental studies of DNA polymerases cannot describe complete dynamic and energetic effects of the active site, dynamics simulations are well poised, and critically needed, to complement polymerase experimental results. In our collaborative project between an experimental and theoretical team, we will investigate systematically at atomic resolution how the conformational changes and nucleotide incorporation (chemical) pathways for higher-fidelity (pol beta) and low-fidelity (Dpo4) polymerases dictate different steering mechanisms, and how the template base, incoming nucleotide, key protein residues, and lesion-modified DNA affect the binding pocket electrostatic environment/plasticity and thus fidelity. These aims will be achieved by a combination of long-time molecular dynamics simulations and novel methodologies (transition path sampling, stochastic path approach, principal component analysis, and mixed quantum-classical mechanics methods) and an iterative design between theory and experimentation for testing, validating, and expanding these hypotheses. In particular, by delineating complete reaction profiles (conformational change and chemistry) for correct and incorrect basepairs in pol beta and relating them to experimentally-determined catalytic efficiencies and fidelity values, we will propose the rate-limiting step, orchestration of the active site assembly, and fidelity mechanisms involved and subsequently test them by experiments on mutant systems. Moreover, we will test our hypothesis that subtle conformational changes in Dpo4's thumb and little finger domains are closely associated with Dpo4's low-fidelity and lesion bypassing mechanisms, which are likely distinct than pol beta's. Our long term goals are to bridge macroscopic polymerase structures and kinetic measurements regarding catalytic efficiency, fidelity, and nucleotide binding affinity to better understand fidelity mechanisms of DNA polymerases, including response to oxidative damage and other lesions. Such studies have immediate applications to the diagnostics, and eventually treatment via polymerase inhibitors, of human diseases caused by defective repair of DNA, like various cancers and premature aging.
Crisp Terms/Key Words: interdisciplinary collaboration, enzyme activity, active site, protein structure function, DNA directed DNA polymerase, nucleotide, mutant, enzyme mechanism, computer simulation, thermodynamics, X ray crystallography, molecular dynamics, conformation, catalyst, chemical reaction, chemical kinetics, adduct, protein binding
DESCRIPTION (provided by applicant): Project 1 is concerned with the chemical biology of the aristolochic acids (AAs), a series of naturally-occurring nitrophenanthrene carboxylic acids, and their related lactams. The toxic effects of AAs lead to chronic renal disease and urothelial cancer. Chemical synthesis will provide large quantities of the AAs, their lactams, and related compounds for further chemical modification, metabolic investigations and toxicity studies. The known dA(N6)- and dG(N2)-adducts found in mammalian DNA will be synthesized and incorportated site-specifically into oligodeoxynucleotides with sequences containing known mutagenic "hot spots" in the ras and p53 genes. The goals of the project are to characterize the biological properties of AA-adducts in duplex DNA and to correlate the mechanisms of lesion repair and mutagenesis with the three dimensional structure. Sophisticated 2D NMR experiments coupled with restrained molecular dynamics calculations will provide solution structures for AA-adducts in duplex DNA. Additionally, the stabilities of these lesion-containing duplexes will be determined by UV-melting profiles. Nucleotide excision repair (NER) is the only known mechanism for repair of bulky lesions, and mechanisms for damage in closed circular plasmids containing a single dA(N6)- or dG(N2)-adduct. While AA is known to induce AT to TA transversions, the biochemical mechanisms involved have not been determined. We will examine the efficiency and fidelity of translesion synthesis (TLS) to identify the DNA polymerase(s) responsible for error-free and error-prone synthesis. Correction of the mechanisms of damage recognition, repair of AA-adducts and their miscoding and mutational specificity with three dimensional structure and duplex stability will provide a molecular basis for the nephrotoxic and carcinogenic properties of aristolochic acids.
DESCRIPTION (provided by applicant): The long-range goals of this grant proposal are to study the involvement of the hypoxia signaling pathway upon chromatin remodeling, gene silencing, and cell transformation. Hypoxia or agents that mimic hypoxia cause a global loss of histone acetylation and increase the methylation of H3 lysine 9 which is the chromatin mark of gene silencing for the individual nucleosomes. Methylation of H3 lysine 9 leads to DNA methylation and inherited gene silencing. We will study the ability of hypoxia and agents that activate hypoxia signaling (NiCI2, CoCI2, deferoxamine, and DMOG) to induce cell transformation in wild-type or in HIF-1alpha knockout mouse embryo fibroblast (MEF). We will transfect a normal HIF-1alpha construct into MEF cells with a knockout of this gene to study whether we can restore their ability to be transformed by hypoxia and agents that mimic hypoxia. We will also stably transfect mutated HIF-1alpha constructs that will constitutively express HIF in its stabile and or stable/active form into MEF HIF+/- cells and study the effect of stabilized and/or activated HIF- 1alpha on anchorage-independent growth and tumor formation in nude mice. We will investigate global changes in H3K9 acetylation, H3K9 methylation, G9a activity (enzyme that dimethylates H3K9) and DNA methylation in MEF with intact or knockout of HIF-1alpha following exposure to hypoxia or agents that mimic hypoxia. We will also utilize the expression levels of DHFR and DNA mismatch repair gene Mlh1 which are down-regulated by hypoxia signaling to study gene specific effects of chromatin remodeling induced by hypoxia signaling using CHIP assays targeted to their promoters with antibodies specific to H3K9 dimethylation and/or H3K9 acetylation. We have obtained mouse embryonic stem cell wild-type (WT), G9a knockout (G9a-/-) and G9a-/- stably transfected with wild-type G9a (G9a-/- + G9a WT), and we will utilize these cells to address the role of G9a in mediating histone methylation H3K9 and the effects of hypoxia signaling on DNA methylation and DHFR/MIh expression. We will study the reversibility and stability of MEF cells that have already been transformed via the hypoxia pathway to chromatin remodeling agents and R59949 (HIF inhibitor). These studies will allow us to understand the importance of hypoxia signaling and the HIF-1alpha transcription factor in promoting neoplastic cell transformation.
DESCRIPTION (provided by applicant): Numerous studies have been conducted on the active methylation of the lysines in histone tails as early components of a chromatin remodeling process that leads to alterations in gene expression. The specific methylation of histone H3 lysine 9 (H3K9) in the promoter region of genes is one of the most important chromatin marks and is commonly associated with nucleosomal DNA methylation and gene silencing. Recent studies have shown that demethylation of the histone H3K9 chromatin mark is mediated by iron (Fe)-, oxygen-, ascorbic acid-, and oxoglutarate-dependent oxidative demethylation, which is catalyzed by a family of dioxygenases (JMJD2A-D and JHDM2A) that contain the Jumonji C (JmjC) protein domain. The affinity constant of nickel ions binding to this JmjC facial triad is predicted to be at least 3 orders of magnitude greater than that of Fe. Our goals and hypothesis of this grant are that nickel ions, as well as other hypoxia signaling insults (hypoxia and deferoxamine), inactivate the JmjC-containing dioxygenases that catalyze the demethylation of H3K9, which leads to chromatin remodeling, DNA methylation, silencing of tumor suppressors genes, and, ultimately, carcinogenesis. We will study the alterations of the mono, di- and tri-methylation patterns of H3K9 following a prolonged exposure to nickel, hypoxia and deferoxamine by Western blot. ChIP- on-chip assays will be employed to determine which gene promoters are associated with alterations of H3K9 methylations following nickel exposure. To link the observed changes in the distribution of histone H3K9 methylations to the inactivation of specific H3K9 demethylases, the ChIP-on-chip assays will also be performed in stable transfectants with RNAi-directed knockdown of JHDM2A or JMJD2A. We will study whether the increase of H3K9 methylation at the gene promoters identified will lead to the establishment of DNA methylation, using methylation-specific PCR. We will also study the general effects of altering the expression of histone H3K9 demethylases alone, by overexpression or RNAi knockdown, or in combination with nickel exposure, on cell transformation and proliferation in human BEAS-2B cells. It will also be of interest to study the roles of nickel-induced gene silencing in the transformation of Beas-2B cells by nickel. We will purify the JMJD2A and JHDM2A enzymes that are expressed in insect cells. Using these purified enzymes, we will determine the effects of nickel and other transition metal ions on the enzymatic activity of these recombinant proteins in vitro. We will also examine the ability of isotopic 63Ni ions to become associated with recombinant JMJD2A and JHDM2A in cells transiently transfected with JMJD2A or JHDM2A expression vectors, and correlate nickel ion incorporation with the loss of enzyme activity as measured by an in vitro demethylation assay. We will determine the number of nickel binding sites and metal dissociation constants for iron and nickel in JMJD2A and JHDM2A. XAS will also be utilized to determine the metal binding sites (iron and nickel ions) in these histone demethylases.
DESCRIPTION (provided by applicant):
Some environmental toxicants are alkylating agents that can damage DNA. If left un-repaired, DNA alkylation damage can lead to mutation, cell death, and can promote carcinogenesis. Fortunately, most cells can prevent the detrimental effects of alkylating agents by initiating cell-signaling programs that promote the repair of damaged DNA. Our long-term research goals are to identify and characterize signaling pathways used to respond to DNA alkylation damage, and to understand the role of these damage-signaling pathways in exposure-related diseases. We have computationally identified a novel environmental stress code (ESC) that (1) is a gene-specific codon usage pattern and (2) is predicted to help regulate cellular responses to DNA alkylation damage. We hypothesize that the identified ESC works in conjunction with tRNA modifying enzymes to promote the translation of DNA repair, signaling, and stress tolerance proteins after damage. Further, we hypothesize that one of the enzymes controlling this program of enhanced translation is tRNA methyltransferase 9 (Trm9). In this study, we will test the novel hypothesis that in response to alkylation damage, Trm9 catalyzes the methylation of select tRNA molecules to enhance the translation of a network of damage-response proteins. We will exploit three powerful model systems (based in Saccharomyces cerevisiae, humans, and mice) to test our hypothesis, to increase our understanding of translational regulation after DNA damage, and to correlate our results to humans. Specifically, we will determine the damage-induced substrate specificity of S. cerevisiae Trm9 (Specific Aim 1) in order to define the spectrum of tRNA molecules enzymatically methylated in response to alkylation damage. In addition, we will use codon-specific reporter constructs and a TAP-tagged protein library to determine how the ESC and Trm9 influence the translation of a damage response network. Experiments proposed in Specific Aim 1 exploit the power of systems-based studies in S. cerevisiae to characterize global protein networks. We will use HEK293 cell models to characterize the damage-induced substrate specificity of human Trm9 (Specific Aim 2) and to analyze the role of Trm9 in the translation of codon-specific reporter constructs. Excitingly, we have linked human Trm9 activity to the regulation of specific DNA repair proteins (Rad54, Brca2, Bccip, Ercc8, Tdg, Msh4, Rad51, and DNA Ligase IV), and we will study how Trm9 affects their damage-induced translation. Importantly, Specific Aim 2 will allow us to use a human system to model the activity of a novel damage-response protein. We will use mouse cell systems (Specific Aim 3) to characterize the substrate specificity of mouse Trm9. In addition, we will study the regulation of Trm9 in developing mouse embryos and adult organs, and use organ extracts to determine tRNA methylation patterns in vivo. Finally, we will use available Gene Trap cell lines to generate a knockout model of Trm9, and we will determine the viability of resulting mice. We will use Specific Aim 3 experiments to build an animal model for future studies. Ultimately, we will study the relationship between DNA alkylation damage and protein translation, and determine how RNA based signals coordinate DNA damage response pathways. In the future, we can use RNA modifications as biomarkers for DNA alkylation damage and environmental exposures. Additionally, damage-signaling mechanisms are potential targets for therapies related to cancer treatment.
DESCRIPTION (provided by applicant): The frequent consumption of meats cooked well-done leads to an increased risk for colon and breast cancer; however, the etiological agents responsible for this risk remain to be elucidated. The Report on Carcinogens, Eleventh Edition, National Toxicology Program, concluded that heterocyclic aromatic amines (HAAs), which arise in grilled meats, are reasonably anticipated to be human carcinogens. Many epidemiological studies have implicated HAAs as specific etiological agents in these cancers. However, the reported associations of dietary factors and genetic polymorphism data can not confirm the relationships between specific chemical exposures and carcinogenesis. Moreover, the characterized HAAs account for less than 30% of the mutagenicity attributed to this class of chemicals in well-done grilled meats and other uncharacterized HAAs are present. Recently, we discovered 2-amino-1-7-dimethylimidazo[4,5-g]quinoxaline (7-MeIgQx), an isomer of 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (8-MeIQx), a potent animal carcinogen. 7-MeIgQx, is the most mass-abundant, genotoxic HAA formed in grilled beef; however, its carcinogenic potential is unknown. Our long-term goal is to assess the cancer risk posed by HAAs, by establishing chemical markers that may distinguish individuals at different levels of risk. Given the high concentrations of 7-MeIgQx formed in cooked beef in relationship to 8-MeIQx or 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), two HAAs that are believed to contribute to dietary-related cancers, we hypothesize that 7-MeIgQx is a significant contributor to the overall genotoxic burden and cancer risk posed by HAAs. The objective of this application is to provide preliminary toxicological data on the capacity of 7-MeIgQx to undergo bioactivation in vitro and bind to DNA in vivo in the rat. We will use highly sensitive accelerator mass spectrometry methods to measure DNA adduct yields of 7-MeIgQx in vivo and compare the yields to those of 8-MeIQx. The rationale is that data generated from these pilot studies will provide a preliminary assessment of the carcinogenic potential of 7-MeIgQx in comparison to 8-MeIQx, based on the carcinogen binding index. This proposed research is relevant to NIH's mission on public health: specific aims 1 and 2 will establish toxicological data on the genotoxic potential of 7-MeIgQx in relationship to its carcinogenic isomer, 8-MeIQx. The proposed DNA binding study in vivo of a newly discovered HAA is an innovative approach to provide a rapid, provisional assessment of the carcinogenic potential of 7-MeIgQx, which arises cooked beef in greater quantities than 8-MeIQx and PhIP. This discovery is highly significant since metabolites and DNA adducts of 7- MeIgQx could serve as biomarkers of exposure and risk assessment to this class of dietary carcinogens. PUBLIC HEALTH RELEVANCE: The proposed study will provide a provisional estimate of the carcinogenic potential of a newly discovered heterocyclic aromatic amine (HAA), 2-amino-1,7-dimethylimidazo[4,5-g]quinoxaline (7-MeIgQx). HAAs are believed to be human carcinogens and 7-MeIgQx is the most mass-abundant HAA formed in cooked meat. The research will allow us to determine the health risk of 7-MeIgQx in relationship to other HAAs present in the diet.
DESCRIPTION (provided by applicant): The biological consequences of cytoplasmic damage are largely unknown. The prevailing dogma considered the genotoxic effects of environmental carcinogens such as polycyclic aromatic hydrocarbons and radon alpha particles as being due mostly to direct damage to the nucleus. Using a precision charged particle microbeam and dual fluorochrome dyes to locate nucleus and cellular cytoplasm respectively, thereby avoiding inadvertent traversal of nuclei, the applicant has shown previously that cytoplasmic irradiation is, in fact, mutagenic at the CD59 locus of human-hamster hybrid (AL) cells while inflicting minimal cytotoxicity. Furthermore, preliminary evidence suggests that reactive oxygen species mediate this process. This raised the following questions: What types of oxyradicals are involved and what are their origins? Does this radical generating process involve mitochondrial damage? Do the mutations induced by targeted cytoplasmic irradiation occur in human bronchial epithelial cells (target tissues of environmental radon) as well? And finally, can cytoplasmic irradiation induce bystander mutagenic effect in mammalian cells in a manner similar to what the applicant has recently demonstrated with nuclear traversal of the AL cells. To address these issues, a series of 5 specific aims are proposed to address the 4 testable hypotheses. Mutations will be scored at the CD59 locus of the AL cells and at the HPRT locus in primary human bronchial epithelial cells. The proposed studies will help to address the mechanisms of how cytoplasmic irradiation results in a genetic event in the nucleus. Together with the bystander mutagenic effect, the study will address some of the fundamental issues regarding extranuclear target and how cytoplasmic damages are being processed in mammalian cells.
DESCRIPTION (provided by applicant): The largest known mass exposure to arsenic is presently occurring due to ground water contamination of well water throughout the Ganges-Brahmaputra Delta There is significant inter-individual variability in susceptibility to progression from arsenic exposure to clinical manifestations of arsenic toxicity (e g skin, lung, liver and bladder cancers) Several observational as well as biochemical studies have led to a prevalent hypothesis that nutritional status may account for a substantial portion of this variability, though no controlled clinical studies have addressed this important hypothesis. Methylation of inorganic arsenic (InAs) is generally considered to be a detoxification pathway InAs and DNA are both methylated via one-carbon metabolism, a biochemical pathway which is dependent on folate for de novo generation of one-carbon groups, and also uses vitamins B12 and B6 as cofactors The primary hypothesis of this proposal is that nutritional regulation of one-carbon metabolism, specifically folate availability, contributes substantially to the large inter-individual variability observed in InAs and DNA methylation, and thus progression from arsenic exposure to toxicity This hypothesis will first be tested in cross-sectional studies of adults and children chronically exposed to arsenic-contaminated drinking water in Bangladesh Other nutritional deficiencies, including those of retinol, carotenoids and protein, have also been implicated as possibly influencing progression from arsenic exposure to toxicity, although the mechanistic bases for these interactions are somewhat less clear Exploratory studies will address these possibilities as secondary objectives in children, who are more likely to be deficient in these nutrients A third objective will test whether, in adults or children, arsenic exposure is correlated with lymphocyte DNA hypomethylation, an early event in some cancers. Finally, a 12-week double blind placebo controlled folate supplementation trial of adults with elevated plasma homocysteine concentrations and low plasma folate concentrations will be conducted to determine if folate supplementation results in improved arsenic and/or lymphocyte DNA methylation.
Crisp Terms/Key Words: adult human (21+), lymphocyte, child (0-11), environmental contamination, Bangladesh, human tissue, interview, questionnaire, arsenic, DNA methylation, nutrition, folate deficiency, malnutrition, protein deficiency, high performance liquid chromatography, liquid chromatography, carotenoid, toxin metabolism, detoxification, toxin, folate, retinoid, water pollution, human genetic material tag, human data, clinical research
DESCRIPTION (Provided by applicant): Hepatocellular carcinoma (HCC) has been correlated with specific p53 mutations and exposure to aflatoxin B1 (AFB1). Individual response to liver carcinogens shows great variability. High risk factors include chronic infection with hepatitis B (HBV) and C viruses (HCV), while additional risk factors include exposure to tobacco smoke. Cytochrome P450 genes, such as CYP1A1, CYP1A2, CYP3A4, and CYP3A5 encode proteins that activate potent liver carcinogens into genotoxic epoxides. Heterocyclic aromatic amines (HAs) require additional activation by N,O-acetyltransferase (NAT2). Specific cytochrome P450 polymorphisms and NAT2 polymorphisms
contribute to risk of specific cancers, such as breast, pancreatic and colon. However, determining the risk of P450 and NAT polymorphisms in HCC is complicated by many modifying factors that can lead to detoxification of metabolites. To determine whether P450 polymorphisms per se are sufficient to increase the genotoxicity of carcinogens, we have expressed the P450 genes in Saccharomyces cerevisiae (yeast), which lacks the detoxification enzymes. We previously observed that expression of specific P450 genes in yeast is sufficient to stimulate carcinogen-associated mutation and recombination, the transcriptional induction of DNA repair genes after AFB1 exposure, and AFB1-associated activation of the checkpoint gene Rad53 (CHK2). We propose to further screen CYP1A1, CYP1A2, CYP3A4 and CYP3A5 polymorphisms that are associated with increased cancer risk. In the first specific aim, we will determine whether a subset of CYP1A1 and CYP1A2 polymorphisms affect frequencies of genetic recombination and mutation and the DNA damage response to AFB1 and liver
carcinogens. In the second specific aim, we will determine whether CYP1A2 and NAT2
polymorphisms affect the metabolic activation of HAs in yeast. In the third specific aim, we will
develop an expression system for CYP3A4 and CYP3A5 in yeast that will enable us to detect
metabolic activation of carcinogens mediated by CYP3A3 and CYP3A5 polymorphisms. These
studies will thus provide a new strategy for determining the potential risk of cytochrome P450
polymorphisms in liver cancer. Ultimately, the information will aid public health practitioners and
clinicians to identify which individuals are at highest risk for liver cancer, and guide prevention
and early detection efforts.
DESCRIPTION (provided by applicant): The aim of this proposal is to create a Standardization Program for Bone Lead measurements (BLSP) obtained via reference methods and via in vivo X-Ray Fluorescence (XRF). The BLSP will fulfill current needs of the bone lead methodologies: lack of appropriate certified reference materials (RMs) and lack of traceability. The BLSP will also provide RMs for electrothermal atomic absorption spectrometry (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS) and will conduct an interlaboratory validation study among laboratories using those methods. The program will also provide RMs for XRF, thereby providing traceability to SI units, and will conduct an interlaboratory validation study among laboratories using XRF for in vivo bone lead measurements. There are six goals: first to cross-validate AAS and ICP-MS in the Wadsworth Trace Elements Laboratory of the New York State Department of Health (NYS DOH); second to establish a national repository of RMs for bone lead measurement via AAS and ICP-MS traceable to NIST SRM 1486 Bone Meal and 1400 Bone Ash; third, to conduct an interlaboratory validation of AAS and/or ICP-MS for bone lead measurement. The fourth goal is to assemble a national repository of RMs for bone lead XRF by preparing two sets of well-characterized goat bone samples containing endogenous lead concentrations that encompass those found in human populations; the fifth goal is to conduct an in vitro XRF interlaboratory validation and comparison study using the two sets of goat bone samples. The first set of XRF RMs will be destroyed as part of the process of obtaining reference concentrations via AAS and ICP-MS for both surface and core bone that are traceable to SI units. The reference concentrations thus obtained will form the basis of the assessment of XRF accuracy. The second set of XRF RMs will be created and used for a second interlaboratory comparison and will be preserved for long-term use. The sixth and last goal is to conduct an in vivo XRF validation study using the euthanized members of the NYS DOH goat colony that will provide the RMs. XRF-measured in vivo concentrations will be compared to the reference concentrations obtained from AAS and ICP-MS.
Crisp Terms/Key Words: goat, chemical registry /resource, chemical standardization, analytical method, atomic absorption spectrometry, mass spectrometry, diagnosis quality /standard, statistics /biometry, lead, lead poisoning, radiofluorescent probe, bone, measurement, method development
DESCRIPTION (provided by applicant):
The impact of vehicle exhaust (especially diesel) on respiratory health is a
major concern of community residents of Northern Manhattan and the South
Bronx, New York City. While the existence of adverse impacts appears obvious
both to residents and health scientists, surprisingly little data are
available to firmly establish this linkage. A principal scientific barrier to
further insights is the uncertainty surrounding human exposure to diesel and
other vehicle exhaust at the community and individual levels. The proposed
study will address these uncertainties by 1) measuring ambient concentrations
of black carbon (BC), PM2.5, and trace elements at four high schools in the
NYC metropolitan area, three of which represent a range of diesel impacts in
Harlem and the South Bronx, and one of which is located in an upwind, suburban
community, testing the hypothesis that BC concentrations will show a gradient
across schools as a function of local diesel traffic density; 2) assess
baseline respiratory health status among 300 students at each school, and
follow a subset of 40 students for daily symptoms, testing the hypothesis that
daily symptoms are associated with daily BC concentrations; 3) in a subset of
20 students at each school, characterize personal exposures to BC, PM2.5, and
traffic-related metals, and determine the relative importance of exposures
occurring at home, at school, and while commuting in total personal BC
exposures; 4) assist participating schools to implement a community air
pollution measurement curriculum using materials currently being developed and
tested jointly by West Harlem Environmental Action and NIEHS; 5) working with
community interns, carry out special studies to collect traffic counts and
airborne particle samples associated with high-volume roadways, bus depots,
and alternative commuting patterns. This community-driven study should expand
our understanding of the relationships between urban traffic sources and
personal exposures to vehicle-related particles among young people living and
going to school in urban core neighborhoods of Northern Manhattan and the
South Bronx.
Crisp Terms/Key Words: air pollution, air sampling /monitoring, adolescence (12-20), secondary school, fossil fuel energy, United States, public health, human subject, questionnaire, statistics /biometry, heavy metal, scanning electron microscopy, particle, epidemiology, longitudinal human study, respiratory disorder, respiratory function, community planning, urban area, clinical research, environmental exposure
DESCRIPTION (provided by principal investigator): Project Summary Excessive noise in the urban setting is a topic of increasing public health concern. Mass transit, and aging subway systems, in particular, are prime sources of urban noise. Yet the risk associated with subway noise is understudied and risk assessment data on subway-related noise exposure are exceptionally limited. As an important first step in our research team's trajectory of assessing urban noise associated with mass transit, we conducted environmental noise sampling of the NYC subway system. Noise levels inside subway cars and on subway platforms were in excess of standard recommended levels; for some of the levels measured, the recommended community exposure limits are as little as 1.5min per 24hrs. To estimate the ridership's risk of potential noise exposure, which is a function of both noise level and exposure duration, we recently conducted a feasibility study. Using a modified street intercept recruitment methodology, preliminary data were obtained from nearly 1100 attendees at neighborhood street fairs. The sample was diverse (26 percent were racial/ethnic minorities, mean age was 43yrs, range 18-89yrs) and representative of NYC census data. 27 percent of the sample reported no subway ridership; for participants that did ride the subways, the mean duration (time spent on platforms and inside subway cars) was 1.98 hrs/day, for an average of 5 days/week (max 7.0 hrs/day, median 1.75 hrs/day, mode 1.20 hr/day). When combined with pilot measurements of subway noise, the preliminary mean subway exposure duration of 1.98 hrs yields a 24-hr average exposure level that substantially exceeds the guidelines for community noise exposure published by the U.S. E.P.A. even without considering other sources of exposure. To characterize the contribution of subway noise to total noise exposure in an urban population, we propose a two-year, four-phase, transdisciplinary risk assessment study of NYC community members. The purpose of this R21 exploratory study is fourfold: (1) to characterize subway and other highly variable mass transit environments using time-integrated dosimetry, (2) to estimate current subway-related noise duration among a large (N=5000) sample of diverse NYC community members representing a range of subway ridership (from none to extensive) using a self-administered questionnaire, (3) to determine total (combined) noise exposure from three major sources (subway and other mass transit related, work and leisure-time) and to determine the contribution of subway noise to total noise exposure, and (4) to compare these exposures to recommended allowable community-level exposure levels. Using validated instruments, duration of work and leisure time activities data will be obtained from questionnaires and noise levels for the various work/leisure activities will be obtained from well validated peer reviewed documents. The findings from this study will not only provide important new information but also the context for the design of urban noise studies which will have translational research implications for public health policy and practice. PUBLIC HEALTH RELEVANCE: This study will determine the risk of excessive noise exposure associated with subway and other mass transit- ridership in a population of urban New York City community members. The population at potential risk in NYC alone is in excess of 3 million riders; nationwide, more than 10 million riders use subway systems that are 75 years old or greater. This study has translational implications for public health policy and practice.
The Hudson River (HR) Estuary contains Superfund sites for PCBs, TCDD, and heavy metals. Atlantic
tomcod from the HR bioaccumulate high tissue burdens of these contaminants, sometimes to record levels.
We have used tomcod as a model to evaluate the ecological effects of these pollutants and to study the
mechanistic bases of their toxicities. Tomcod from throughout the HR are highly resistant to environmentally
relevant doses of coplanar PCBs and TCDD, but not PAHs, at a variety of molecular and organismic
endpoints including early life stage toxicities and aryl hydrocarbon receptor (AHR) pathway-mediated gene
expression. The overall objectives of this renewal application are to further describe the extent of resistance
n the HR tomcod population and to characterize its mechanistic basis. Although, at one time, tomcod from
the HR exhibited remarkably elevated prevalences of hepatic tumors, the role of PCBs in this process was
never empirically addressed. In controlled laboratory studies, we will determine if tomcod offspring from the
HR, compared to those from sensitive populations, are resistant to hepatic neoplasia and related preneoplastic
endpoints such as preneoplastic lesions, K-ras activation, ROS modified bases, bulky DMA
adducts after exposure to PCBs and PAHs. Fish from highly contaminated locales, such as Superfund sites,
are usually co-exposed to aromatic hydrocarbon and metal contaminants. Chemical analyses indicate that
this is the case for tomcod from the HR. Yet, little is known of their interactive effects in vivo. We will
investigate the effects of co-exposure to Gr VI on B[a]P-induced mutations, DMA adducts, and nucleotide
excision repair at the K-ras oncogene which is frequently mutated in environmentally-exposed and
chemically-treated fishes. The mechanistic basis of resistance will be addressed. Genetic polymorphisms will
be characterized and their frequencies enumerated at AHR2, AHRR, and ARNT1 in tomcod from the HR and
non-resistant populations. Those which show significant allelic differences will be functionally evaluated in
assays which will quantify ligand binding, nuclear transformation, and transactivation. Multiple AHRs shown
to exist in other fishes will be isolated and their structure and expression compared between the HR and
sensitive populations. Novel proteins associated with AHRs or DREs will be identified using a proteomics
approach and their expression compared between tomcod from the HR and susceptible populations.
This goal of this study is to increase knowledge of the sources, environmental fate and health risks of chemical contaminants and their transformation products that have the potential to disrupt endocrine function in wildlife or humans - alkylphenol ethoxylate metabolites (APEMs), polybrominated diphenyl ethers (PBDEs) and other brominated flame retardants. Specific aims include: (1) To identify the sources of these potentially endocrine disrupting compounds (EDC) in the Hudson basin and changes in those sources overtime. To assess the contribution that municipal wastewater makes to EDC inputs to the Hudson Basin, specific chemical tracers for wastewater will be developed. (2) To determine the distribution and biogeochemical
cycling of hydroxylated metabolites of PCBs (HO-PCBs) and PBDEs (HO-PBDEs) in sediments and food webs in the Hudson watershed. This research will determine whether EDCs persist and accumulate in sediments and whether HO-PCBs and HO-PBDE congeners enter aquatic food webs from exposure to sediments and/or consumption of aquatic invertebrates. (3) To identify through in vitro assay directed fractionation the spatial variation, likely sources, and identity of important estrogen and androgen agonists in sediments from the Hudson Basin. This aim will rely upon discovery-based mass spectrometric identification of putative structures.
Assessment of the ecological and human health risks related to EDCs is a challenge because of the complexity of EDC mixtures and the many possible mechanisms through which EDCs may interact with endocrine systems. Much of the geochemical work to date with EDCs has focused on analysis of wastewater effluents and ambient water testing, rather than on examining sediments that are likely to be larger reservoirs of bioaccumulative and persistent EDCs. There is especially a lack of study of the identification and distributions of EDCs at sites heavily contaminated with Superfund chemicals. This project will seek to fill those gaps in information. It will link closely to basic biological and epidemiological research in the Mount Sinai SBRP that are elucidating mechanisms of toxicity, exploring gene-environment interactions and studying genetically determined, inter-individual differences in susceptibility to EDCs.
DESCRIPTION (provided by applicant)
Questions continue to arise about the role of environmental agents as modulators of disease and dysfunction. The mission of the University of Rochester EHSC is to improve public health by defining the contribution and underlying mechanisms of environmental agents in health dysfunction and disease outcomes. These goals are achieved by a combination of research and community outreach and education. There are four research cores. The Pulmonary Toxicology Research Core focuses on the mechanisms and consequences of oxidative injury, inflammation and repair in the respiratory system using models ranging from genetically engineered mice to humans. Studies within the Neurotoxicology Research Core use molecular, genetic, neurochemical and behavioral approaches to determine the contributions of toxicant exposures to various diseases and dysfunctions of the nervous system and their mechanisms of action. A new Immunomodulators and Immunopathogenesis Research Core focuses on examining mechanisms and consequences of immunomodulation by environmental agents, with particular emphasis on T-cell immunobiology, autoimmune disease, cell cycle progression, and cell lineage commitment. The Osteotoxicology Research Core is examining the extent to which lead exposure serves as a risk factor for disturbances of the skeletal system, particularly osteoporosis. Scientific efforts of the research cores are promoted and assisted through five facility cores: Pathology Morphology Imaging, Biostatistics, University Facilities, Instrumentation, and Inhalation. Collaborations and new directions are significantly enhanced through a Pilot Project Program and an Enrichment Program that includes a Visiting Scientist Program and EHSC-sponsored seminars and conferences. The COEP has grown considerably in scope and impact over the past five years through several community efforts and a range of pre-college science education programs for both teachers and students. The current organization of the EHSC reflects significant growth and development that has included restructuring of research and facility cores, a new research core and facility core, recruitment of new faculty, and substantial enhancement of the COEP. Many of these advancements are directly attributable to the Pilot Project and Enrichment Programs. The transition of EHSC leadership in this renewal application brings new resources to bear, including additional faculty recruitments, space and renovation over the next 5 years.
This is a revised competing renewal application to the National Institute of Environmental Health
Sciences for years 44 through 48 of the P30 Environmental Health Sciences (EHS) Center grant to the NYU
School of Medicine, Department of Environmental Medicine. The primary mission of this broad-based
Center is to focus a diversity of talent on the recognition, evaluation, prevention and control of the adverse
impact of environmental factors on human health. This is achieved through the interactive programs of the
research cores that provide intellectually stimulating foci for studies addressing the Center's goals, and is_
supported by centralized facilities that provide individual researchers with information, expertise and
technical assistance in specific operations (e.g., analytical chemistry, histopathology, animal care and
specialized animal exposure, gene expression and genotyping analyses, proteomics, computational biology,
biostatistics), and state-of-the-art equipment (e.g., DNA sequencers, atomic force microscopy, microarray and
protein chip technology). This Center also has a strong focus on ambient air pollution effects, environmental
exposures to heavy metals, the role of dietary factors in the causation and prevention of environmentally-induced
human cancer, and hormonal, radiation, and occupational exposures in human carcinogenesis and
disease. The Center reaches out to the community (local and regional) providing information and education
on environmental issues to K-12 students, teachers and community groups, in addition to, training graduate
and medical students for productive careers in environmental health research. The Center also guides its
members into new research areas involving modern technology or into research areas that are timely and will
have significant environmental impact (e.g., The World Trade Center disaster). The Center supports both
investigator-initiated pilot projects, as well as encourages initiatives in new areas that the Center deems
important for the future of our environmental health. The Center's coordination and application of broadbased
scientific talents and research techniques will: 1) facilitate research that relates environmental factors
to human disease; 2) identify mechanisms responsible for the adverse health effects produced by
environmental agents; 3) develop methods for the detection, prevention and control of environmental
exposures that cause or exacerbate human diseases; and 4) study the relationship between genes and
environmental factors that activate or deactivate genes that contribute to differences in population and interindividual
susceptibilities to the development and progression of human diseases..
Description (provided by applicant): The Administrative Core functions as the chief administrative unit of the Center. Its primary objectives are to: 1) provide leadership and facilitate interaction and communication among investigators; 2) facilitate interaction between investigators, local government agencies and the community; 3) supervise the utilization of the CEHNM Facility Cores; 4) implement the Internal and External Advisory Committees' reviews of CEHNM activities; 5) coordinate CEHNM activities including seminars, retreats, symposia, preparation of the annual progress report and competing and noncompeting renewals; 6) organize the announcements, receipts and reviews of pilot project grant applications; 7) manage the CEHNM's budget.
DESCRIPTION (provided by applicant)
This proposal is submitted in response to the Request for Applications (RFA)-ES-05-01, entitled "Superfund Basic Research Program". The contamination of groundwater and soils with arsenic (As) and manganese (Mn) are associated with major public health, remedial and environmental policy problems. Both Arsenic and manganese are found at numerous Superfund sites. This competitive renewal proposal seeks to obtain new knowledge, train multidisciplinary pre- and post-doctoral students concerning the health effects, geochemistry, and remediation of As and Mn, with a particular focus on groundwater. The proposed work involves substantial work at the single most seriously As-affected Superfund site in Vineland, NJ. It also involves epidemiologic studies of As- and Mn-exposed adults and children residing in Bangladesh and New Hampshire. As in the past, the Columbia University SBRP includes a unique balance between biomedical and non-biomedical research. The proposal includes four biomedical research projects: 1) Genotoxicity and Cell Signaling Pathways of As in Mammalian Cells; 2) Health Effects of an As Cohort Study; 3) Consequences of As and Mn Exposure on Childhood Intelligence; and 4) One-Carbon Metabolism, Oxidative Stress, and Arsenic Toxicity. The biomedical research is intimately intertwined with three non-biomedical projects: 5) Mobilization of Natural Arsenic in Groundwater; 6) Mobilization of Anthropogenic Arsenic in Groundwater; and 7) Mitigation of Arsenic Mobilization in Groundwater. A Research Translation Core entitled, "Collaborating with government and the public: As & Mn exposure via groundwater" will work with several government agencies to help understand and solve their local groundwater problems. The Projects are supported by four Research Support Cores: 8) Data Management; 9) Trace Metals; 10) Biogeochemistry; and 11) Hydrogeology. Finally, a Training Core coordinates multi-disciplinary education and interaction among pre- and postdoctoral trainees who benefit from participation in the major inter-disciplinary research program.
DESCRIPTION (provided by applicant): It has been well documented that exposure to fine ambient air particulate matter (PM2.5) induces consistent increased risk for cardiovascular disorders (CVD) in humans at the levels currently encountered in the U.S. However, the mechanism(s) and component(s) responsible for PM2.5 associated cardiovascular effects are still unknown. In our recent subchronic inhalation study, we observed that dramatic increases in heart rate and decreases in heart rate variability occurred in the ApoE-/- mouse model on days when PM2.5 contained elevated concentrations of nickel (Ni) as compared to days with typically lower Ni exposure. We further found in humans that Ni and vanadium best explained the variation of the NMMAPS PM10 mortality risk coefficients across cities. Therefore, we hypothesize that Ni is a major component responsible for PM2.5 associated CVD. It has been difficult, however, to test this hypothesis due to lack of appropriate populations with adequate combination of exposures to both PM2.5 and Ni in the U.S. Recently, we identified two large cities in China, which have exposures to similar ambient PM2.5 mass concentrations but very different levels of Ni (~500ng Ni/m3 in Jinchang and ~10 ng Ni/m3 in Zhanye). Therefore, we propose to evaluate the feasibility of using these ideal and unique populations to examine the potential roles of Ni in PM2.5 associated CVD through population- based mortality and morbidity and panel-based biomarker studies. The specific aims of the study are: 1) to examine the feasibility of conducting time-series analyses of CVD mortality and morbidity in the overall populations of the two Chinese cites to identify the potential mechanistic roles of Ni in PM2.5 associated CVD; 2) to determine whether or not the commonly used CVD biomarkers can be employed to evaluate the role of Ni in PM2.5 related CVD in the identified populations. The candidate biomarkers of CVD include proinflammatory markers [IL-6, and C reactive protein (CRP)]; markers of leukocyte recruitment [monocyte chemoattractant protein 1 (MCP-1)]; and endothelial dysfunction biomarkers (ICAM and VCAM). This study will provide insights into the role of, and mechanism for action of a highly likely PM2.5 component in terms of inducing CVD. This study should have significant implications for both research and legislative regulation in controlling the health hazards associated with ambient PM exposure. PUBLIC HEALTH RELEVANCE: Particulate matter (PM) in ambient air is a mixture and a ubiquitous pollutant that induces consistent increase in hospital admission and death of cardiovascular disorders (CVD) in humans at the levels currently encountered in the U.S. However, why PM causes CVD is still unknown. This study was proposed to address the role that nickel may play in PM associated CVD. The study is relevant to the major environmental health issues and should have significant implications for both research and legislative regulation in controlling the health hazards associated with ambient PM exposure.
DESCRIPTION (provided by applicant): Gump, B. B. (PI) A number of studies have found that increasing lead (Pb) exposure is associated with increases in cardiovascular disease (CVD; e.g., hypertension) in humans. A mechanism to explain this association remains unclear. A number of studies have considered increased cardiovascular reactivity (CVR) to acute stress as a potential mechanism for the development of atherosclerosis. Heightened CVR has been shown to prospectively predict higher baseline blood pressure and increased left ventricular mass in children as well as predict future hypertension and carotid atherosclerosis in adults. We have considered whether lead might affect blood pressure and CVD through changes in CVR. For example, studies with animals have shown lead-induced increases in vascular resistance. We recently demonstrated that 9 1/2 year old children with higher early childhood lead levels were associated with greater total peripheral (vascular) resistance (TPR) responses to acute stress (Gump et al., 2005). These effects were significant for lead levels considered low, notably, below the 10 ¿g/dL threshold currently adopted by the CDC for deleterious effects. We replicated this effect in a small pilot study (N = 40) and at blood lead levels below 3.76 ¿g/dL. The mechanism explaining the association between lead and vascular reactivity is not clear, however, it is presumed to involve a number of systems that regulate vasoconstriction and vasodilation, including the kallikrein-kinin system (KKS), oxidative stress, the renin-angiotensin system (RAS), the sympathoadrenal-medullary (SAM) system, and the hypothalamic-pituitary-adrenal (HPA) system. These potential mediators have not been studied in the context of the association in children between blood lead levels and heightened vascular responses to acute stress. In addition to this question of mechanism, some effect modifiers for the association between lead and vascular reactivity may operate. For example, we recently observed a significant interaction between socioeconomic status and blood lead in the prediction of vascular reactivity in children [19]. We observed that blood lead levels were most strongly associated with blood pressure and vascular reactivity for those children with relatively high SES. The goals in the current research application are therefore to: (a) confirm the lead-TPR reactivity association in children, (b) consider potential mechanisms for this important association, using both a targeted assay approach and a more exploratory proteomics approach, and (c) consider SES as an effect modifier for this association. - Gump, B. B. (PI) Cardiovascular disease (CVD) remains the leading cause of death in the United States and disables 10 million Americans each year. Blood lead (Pb) may increase cardiovascular risk factors in children and thereby contribute to the development CVD. These effects of lead on cardiovascular risk factors may occur at very low levels, levels well below the thresholds currently adopted by the CDC for deleterious effects of lead.
DESCRIPTION (provided by applicant):
Exposure to ambient air particulate matter is associated with increased risk for cardiovascular disease. UItrafine particles (UFP) may be important in this regard because of their high surface area, oxidant capacity, and ability to enter the lung interstitium and vascular space. These studies will test the hypothesis that exposure to ambient UFP causes endothelial dysfunction in both the pulmonary and systemic vascular beds, via oxidant mechanisms. The investigators will determine whether people with type 2 diabetes, who have underlying vascular dysfunction related to oxidative stress, will be more susceptible than healthy subjects to the acute vascular effects of UFP exposure. These studies will consist of three human exposure protocols, using the Harvard Ultrafine Ambient Particle Concentrator. The first protocol will examine effects in healthy subjects, the second protocol will examine effects in age-matched subjects with type 2 diabetes, and the third protocol will assess the role of supplementation with antioxidant vitamins C and E in preventing the vascular effects of UFP exposure. Pulmonary vascular effects will be assessed by changes in the diffusing capacity for carbon monoxide, and the pulmonary capillary blood volume. Systemic vascular effects will be measured using forearm flow-mediated dilatation, with and without nitroglycerin. In addition, the investigators will measure the oxidant capacity of the concentrated ultrafine aerosol, and the level of systemic oxidative stress using glutathione redox balance and plasma lipid peroxides. Confirmation of the hypothesis that UFP oxidant capacity mediates vascular effects will have important implications for air pollution regulatory efforts, and will provide new approaches for the prevention of cardiovascular health effects.
DESCRIPTION (provided by applicant): Binding and activation of the Ah receptor (AhR) is required for the environmental toxin 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD, dioxin) to produce its toxic effects. TCDD toxicity includes a lethal wasting syndrome and cardiovascular dysfunction, but it is not known how TCDD activation of the AhR produces those effects. This research seeks to understand how TCDD activation of the AhR leads to suppression of gluconeogenesis, energy failure and death and to identify contributions of cytochrome P450 (CYP) 1A enzymes, the major transcriptional products of AhR activation, to the toxicity. The following hypothesis will be tested: (1) Transcriptional and posttranslational effects of TCDD on signaling pathways converging on PGC1?, i.e. Akt, AMPK, PKA and Sirt1, contribute to suppression of gluconeogensis by TCDD. PGC1? governs transcription of PEPCK and glucose 6-phosphatase, regulators of flux through the gluconeogenic pathway; (2) Suppression of gluconeogenesis forces reliance on lipids for energy but also limits availability of lipids as a fuel source; (3) Effects of TCDD on CYP-dependent metabolism of the membrane lipid arachidonic acid (aa) contribute to energy failure in liver and heart. The research will follow up on discoveries under prior funding periods of the grant that TCDD causes cardiac contractile dysfunction and increases hepatic formation of CYP-dependent aa epoxides, EETs, and decreases formation of 20-HETE, aa products with major physiologic cardiovascular regulatory effects, to examine their involvement in nutrient metabolism. TCDD will be used as a tool to learn how AhR activation and changes in CYP-dependent aa metabolism can lead to physiologic disturbances in glucose and lipid metabolism involved in the wasting syndrome (specific aim (SA) 1) and in ion channel and cardiac muscle function (SA2). Studies in SA2 will also determine whether increased production of EETs in liver affect the heart and are cardioprotective or cardiotoxic. The chick embryo close to hatching will continue to be used as the major model based on its track record in studying TCDD toxicity, its similarity to humans with respect to aa metabolism and its special utility for this research in permitting hepatic metabolic effects to be studied independently of confounding effects of food intake. Findings will be confirmed in mammalian cells. Definitive evidence for or against a role of CYP1A in AhR effects will be sought by silencing or overexpressing CYP1A4 and CYP1A5 in chick embryo hepatocytes and by a novel molecular approach in which sense and antisense CYP1A gene constructs in retroviral vectors will be targeted to liver or heart in chick embryos at early stages of development and the effects examined at a later stages. This research is expected to show that CYP1A enzymes contribute to metabolic and cardiovascular regulatory pathways, to improve understanding about relationships between glucose and lipid metabolism and the role of the AhR in regulating physiologic and pathologic responses to changes in nutrient availability, and to have implications for common related diseases, cardiovascular disease and diabetes. Relevance: Responses to changes in nutrient supply and metabolism contribute to aging and common human diseases including diabetes, cardiovascular disease and cancer. The environmental toxin, TCDD, by the single action of binding to the aryl hydrocarbon receptor (AhR), which is present in all our cells, initiates a lethal wasting syndrome characterized by a failure to synthesize glucose and leading to energy failure and death. By learning how TCDD activation of the AhR produces massive dysregulation of nutrient responses we expect to learn more about how the body normally orchestrates responses to changing levels of nutrients and how normal regulatory processes can spin out of control, with implications for common human diseases as well as normal physiology.
DESCRIPTION (provided by applicant): The goals of this study are 2-fold: 1) to characterize prenatal phthalate exposures among urban minority mothers and newborns using environmental and biologic monitoring; and 2) to examine effects of exposure on placental function, gestational age and fetal growth. The research is timely. Phthalates are widely used in consumer products and exposures are ubiquitous. 75% of the U.S. population is exposed; women receive higher exposures than men. This has implication for pregnancy as a number of phthalates are endocrine disrupters and have been shown experimentally to modulate steroidogenesis in the placenta, downregulate estradiol and testosterone levels and adversely affect fetal growth. Our pilot data in human populations also indicate that prenatal exposures are reducing gestational age. The proposed study is the first to characterize phthalate exposures specific to urban minorities and to assess endocrine disruption in the placenta and its implication for gestational age and fetal growth. The research is cost-effective in that it will be nested within a well-designed prospective cohort study being conducted by the Columbia Center for Children's Environmental Health. Costs of enrollment, collection and storage of environmental and biologic samples, questionnaires and medical record data are covered under the existing funding. Prenatal phthalate exposures will be characterized in 300 mother/newborn pairs using questionnaires, personal and indoor air monitoring and the measurement of phthalates in biologic samples collected from the mothers and newborns. Repeat measures in a subset will enable evaluation of temporal variability in exposure levels. The study will assess associations between prenatal phthalates, expression of genes involved in steroidogenesis, oxidative stress, and xenobiotic metabolism in the placenta, gestational age and infant birth weight, length and head circumference. The research brings together a collaborative team from Columbia and Harvard Universities, the Centers for Disease Control and Southwest Research Institute with expertise in molecular epidemiology, exposure assessment and health effects of phthalates.
DESCRIPTION (provided by applicant): Common endocrine altering (EA) environmental contaminants, including bisphenol A (BPA) and polybrominated diphenyl ethers (PBDEs), are possible human neurotoxins, immune modulators, reproductive toxicants, or may otherwise interfere with growth and development. Although there have been numerous animal studies, to date there have been no epidemiologic studies investigating the relationship between either BPA or PBDEs with reproductive outcomes such as birth weight, length of gestation, and head circumference. We propose to enroll 200 women of advanced maternal age (AMA) in a prospective pregnancy cohort, and to assemble a repository of maternal biological specimens collected in the antenatal period. Women with the indication of AMA, who are referred to Mount Sinai Medical Center for a routine screening amniocentesis, will be recruited. This unique population will allow us to assess fetal exposure to EA chemicals in the amniotic fluid. The study aims are to: 1) Assemble a repository of biological specimens collected in the antenatal period; 2) Evaluate the correlation between amniotic fluid and maternal urine BPA concentration; and the reproducibility of maternal urine BPA concentration over the course of pregnancy; and 3) Assess the relationships between in utero BPA and PBDE exposure and birth outcomes including birth weight, length of gestation, and head circumference. This project will provide needed preliminary data to gauge the reproductive health risks posed by these agents. Moreover, by comparing BPA concentrations in concurrently collected amniotic fluid and maternal urine, we will be able to evaluate the suitability of maternal urine as a surrogate marker of fetal exposure, while also providing a rigorously collected repository of antenatal specimens that can be drawn upon in future studies. Planned future studies include the interaction between EA chemicals and concurrent intra-amniotic cytokine concentrations; the impact of genetic polymorphisms in key metabolizing enzymes on EA chemical body burden; and the association between EA chemical levels and biomarkers of oxidative stress. The investigative team includes experts in reproductive epidemiology and environmental exposure assessment, and the infrastructure to support this study exists in the Department of Community and Preventive Medicine. This project will provide needed preliminary data to determine the level of prenatal exposure to 6/sphenol A and polybrominated diphenyl ethers experienced by women of advanced maternal age, and attempt to identify common consumer sources of this exposure and their effect on birth outcomes.
Crisp Terms/Key Words: endocrine disrupting compound, environmental exposure, clinical research, women's health, tissue resource /registry, female, placental transfer, embryo /fetus toxicology, gestational age, amniocentesis, age at pregnancy, pregnancy, epidemiology, human pregnant subject, human subject, environmental contamination, human birth weight, urinalysis, cephalometry, blood test, aging, human middle age (35-64)
DESCRIPTION (provided by applicant): The overall goal of this project is to assess whether exposure to endocrine disrupting compounds during pregnancy is associated with a) adverse development (cognitive function, height, weight, weight for height, and for females, age at menarche) in the offspring at birth, early childhood, middle childhood, and adolescence, b) mild deficiencies in maternal thyroid function, and c) whether adverse developmental findings, if any, are attributed in part to deficiencies in exposure to maternal thyroid hormone in utero.
The proposed study draws on data from the Child Health and Development Study, a longitudinal follow up of children born between 1959 and 1966 to mothers enrolled in the Oakland, California membership of the Kaiser Foundation Health Plan. Prenatal sera has been appropriately frozen and stored, and are available to assess both exposure to organochlorine compounds and maternal thyroid function during pregnancy. Serial measures of growth are available in the same children from birth to age 17 years, as are standardized developmental examinations at ages 5, 9-11, and 15-17. The proposed measures of organochlorine exposure and exposure to measures of maternal thyroid function (thyroid stimulating hormone, free thyroxine, thyroid peroxidase antibodies and transthyretin - a protein responsible for the transport of thyroid hormone). Statistical analyses will estimate associations taking advantage of the repeated measures structure of the data. The analyses will employ generalized estimating equations (GEE) methods for repeated measures, taking account of potentially confounding variables.
We will distinguish effects of prenatal organochlorine exposures from infancy through adolescence. We will also investigate a specific mechanism: via maternal thyroid function. Results will fully describe the effects of prenatal exposure and will also further knowledge about the relation between subclinical maternal thyroid hormone deficiency and childhood development. This line of research could lead to prenatal interventions.
DESCRIPTION (provided by applicant): Molecular and traditional epidemiology studies have indicated a possible relationship between in utero environmental exposures and increased risk for childhood cancers, especially acute leukemias. We propose to evaluate pre- natal environmental exposures that may increase the risk of childhood ALL. We propose to measure chromosomal aberrations, a validated biomarker of cancer risk, in a subset of newborns from the Columbia Center for Children's Environmental Health (CCCEH) Prospective Cohort Study. The parent study population is comprised of non-smoking mothers and newborns residing in low-income, minority neighborhoods in New York City, who are subject to varying levels of environmental exposures including polycyclic aromatic hydrocarbons (PAH) and organophosphate pesticides such as chlorpyrifos. Prenatal exposures have been assessed by questionnaires, air monitoring, and biomarkers. In a pilot study, we have examined the frequency and range of chromosome aberrations in cord blood in a small subset of
the CCCEH population using fluorescence in situ hybridization (FISH) with whole chromosome painting probes for chromosomes 1-6. After adjustment for whole genome equivalents, we have found that the frequencies of stable and total chromosomal aberrations are significantly associated with exposure to PAH and chlorpyrifos, measured in air samples obtained by personal air monitoring during the third trimester of pregnancy. Contrary to expectation, the number of aberrations observed per painted chromosome in this study population is not proportional to DNA content, suggesting that certain chromosomes are more sensitive to certain chemical agents. In addition, our pilot data suggest that presence of certain metabolizing enzyme polymorphisms (GSTPI/CYPlal) in infants and their mothers predicts response to prenatal exposures in terms of increased chromosomal aberrations in the infants' cord blood. Other studies indicate that polymorphisms in the PON1 gene involved in the detoxification of organophosphates are also likely to affect the development of chromosomal aberrations. Infant DNA repair capacity (XPD/XRCC1) probably also plays a role in the persistence of chromosomal damage. We therefore wish to explore the role of fetal and maternal genotypes on the mediation of environmental exposures and the development of chromosomal aberrations in the fetus. We propose to expand our pilot study to include a total of 300 newborns from the CCCEH cohort in order to better examine the relationship between exposures to PAH and household pesticides and levels of chromosomal aberrations. We have previously shown that chromosomal translocations characteristic of pediatric leukemia often arise pre-natally, probably as initiating events. In order to better understand a possible link to the first step in leukemogenesis, we will examine samples obtained at delivery from 300 cohort members and an additional 100 samples from a subset of the same children at age two, for the presence of chromosomal aberrations. As a pilot initiative, we will also examine the fusion product, TEL-AMLI. We have previously found TEL-AML1, which is thought to be a necessary but not sufficient step for the development of childhood ALL, to be present in healthy newborns at a frequency 100- fold that of the incidence of ALL. The origin of these initial chromosomal translocations is not known but appears to be linked to prenatal environmental exposures. Chromosomal abnormalities, both those involving specific leukemogenic translocations and those in other areas of the genome, may offer useful information on the etiologic agents involved in leukemogenesis and/or the chromosomes susceptible to these toxicants. Moreover, the utility of chromosomal aberrations to measure genetic damage incurred in utero from PAH and pesticide exposures has not been assessed in a minority population with disproportionately high exposure to these pollutants. Increases in chromosomal aberrations are an established risk marker for cancer, particularly hematological cancers. Thus they may be able to provide information on cancer risk in relationship to PAH and pesticides. Thus far, the link between these exposures and cancer risk has not been adequately studied in more susceptible populations such as fetuses or children exposed to high levels of common urban contaminants. Our proposed study also offers a unique opportunity to explore variations in susceptibility to chromosomal aberrations. Such data can help inform us of the full range of carcinogenic risk from environmental exposures and thus contribute to the formation of policies that will protect populations at greatest risk. Thus, the ultimate goal of this research is to contribute to the prevention of future childhood ALL.
Crisp Terms/Key Words: environmental exposure, cord blood, clinical research, gene environment interaction, fluorescent in situ hybridization, enzyme activity, human genetic material tag, low socioeconomic status, embryo /fetus toxicology, longitudinal human study, organophosphorus insecticide, fluorescence microscopy, chemical carcinogenesis, cancer risk, acute lymphocytic leukemia, pediatric neoplasm /cancer, questionnaire, human pregnant subject, chromosome translocation, chromosome deletion, chromosome aberration, genotype, carbopolycyclic compound, newborn human (0-6 weeks), polymerase chain reaction
DESCRIPTION (provided by applicant): Estrogen replacement therapy (ERT) is widely used to decrease symptoms associated with menopause and to protect women against osteoporosis. ERT, composed of estrogens, equilin, and equilenin, is associated with increased risk of breast, ovarian, and endometrial cancers. As the major metabolites of estrogen and equine estrogen generate oxidative DNA damage and, in some cases react with DNA to form covalent adducts, it is possible that DNA damage plays a central role in the initiation of estrogen-associated cancers. The proposed studies are designed to determine the level of covalent DNA adducts and oxidative damage generated in mammary and reproductive tissues of rats treated with equine estrogens or their metabolites, as well as establish the mutagenic and repair potential of equine estrogen-derived DNA adducts. Leukocytes and endometrial tissue will be collected from women receiving ERT and analyzed for DNA adducts using ultrasensitive 32P-postlabeling and HPLC/electrochemical detection techniques developed in our laboratory. If such adducts are not fully repaired, DNA lesions will persist in target tissues where they may initiate breast, ovarian, and/or endometrial cancer. By demonstrating that certain components of ERT are genotoxic and by defining the biochemical mechanism involved, it should be possible to design drugs that retain desirable therapeutic properties of ERT but lack its carcinogenic effects. This research will also provide biomarkers that can be used to identify subgroups of women at high risk of developing ERT-induced cancer.
Arsenic is among the most ubiquitous of environmental contaminants, originating from natural as well as industrial sources. Human exposure to arsenic can induce multiple acute and chronic illnesses including immune-system disorders. This study is directed towards understanding the molecular mechanisms underlying immunotoxic effects of arsenic using an in vitro model system of human germinal center B-lymphocytes (BLs). Induction of apoptosis in BLs is a potential mediator of immunotoxicity following chemical exposure. However, normal regulation of apoptosis is critical in immune system function. Germinal center BLs undergo apoptosis upon activation of the surface IgM/B-cell receptor (IgM/BCR) to eliminate autoreactive BLs in the process of negative selection, and cells are rescued from IgM/BCR-induced apoptosis after co-stimulation by CD40 in the process of positive selection. The anti-apoptotic effect of CD40 is mediated by the nuclear factor kappa-B (NF-kappaB) pathway, resulting in the activation of the Rel/NF-vJ3 family of transcription factors that induce the expression of multiple genes controlling cell survival and essential BL functions. Preliminary data show that arsenic interferes with the ability of CD40 to rescue BLs from IgM/BCR-induced
apoptosis. The current investigation will test the hypothesis that this effect of arsenic is due to inhibition of the NF-kappaB pathway and that key regulatory points within the pathway are differentially sensitive to inhibition by discrete arsenic concentrations. The proposed experiments will utilize a panel of BL cell lines containing defined genetic changes that effect their sensitivity to apoptosis induction or their ability to activate the NF-KappaB pathway. The molecular interactions of arsenic at specific points in the NF-kappaB pathway will be examined, including: the activation of I-kappa B-kinase signaling complexes, the phosphorylation and degradation of the I-kappa B inhibitory protein, and the DNA binding activity of various Rel/NF-kappaB transcription factors. In addition, the relative contribution of reactive oxygen species and
protein sulfhydryl damage to inhibition of the NF-kappaB pathway will be assessed. Finally, the effects of arsenic on the profile of Rel/NF-kappaB transcription factors associated with promoters of specific anti-apoptotic genes such as Bcl-2 and A1, immediately after CD40 ligation and at later time points will be determined. Ultimately, the research is expected to
identify important mechanisms underlying the inhibitory effects of arsenic on key processes in positive selection in in BLs, including protection from apoptosis and induction of antibody class switching.
DESCRIPTION (provided by applicant): 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most potent immunosuppressive agents known. Humans are exposed to low levels of this and related chemicals on a daily basis. Although the effects on the human immune system are not known, in experimental animals TCDD produces biological and toxic effects by binding to a gene regulatory protein, the Ah receptor (AhR), to inappropriately modulate gene expression, The exact mechanisms responsible for induced immunotoxicity are not known. A major obstacle has been the lack of understanding of the actual primary cell targets. It is hypothesized that stem and/or progenitor cells in the bone marrow and thymus are direct targets for TCDD, that developmental arrest contributes to elicited toxicity, and that TCDD, via the AhR, alters signaling events in these cells at critical stages of differentiation. Using flow cytometry, the hematopoietic developmental stage that is affected by TCDD in mice will be precisely determined. The presence and activity of the AhR with these cells will be determined at different stages of hematopoiesis. Analysis of cell cycle and proliferation rates will determine whether TCDD causes arrest development or programmed cell death. Using established culture systems, it will be determined whether TCDD can directly affect these cells under conditions in vitro. There are several candidate genes whose activities are critical at certain stages of stem/progenitor cell development. Once the precise cell targets in bone marrow and thymus have been determined, real time PCR and low-density array approaches will be used to define the gene targets modulated by TCDD and associated with the toxic endpoints elicited. Finally, recent data has suggested a role of the AhR in normal development of the immune system. Further studies examining phenotypic alterations and patterns of stem cell commitment in AhR null allele cells will further define a putative role of the AhR.
DESCRIPTION (provided by applicant): The heme metabolic pathway is exquisitely responsive to environmental agents, including metal and porphyrin complexes. Biliverdin reductase (BVR) catalyzes the final step in the pathway. In the past BVR, its substrate, biliverdin, and its product (bilirubin) were considered solely in context of disposal of heme degradation products. Recent findings have alluded to their relevance to a wide range of functions in the cell. Bilirubin is an intracellular antioxidant; biliverdin, product of HO-1 and HO-2 activity, suppresses gene expression and underlies the frequently morbid "green jaundice." During the past funding period we demonstrated human BVR is a major component of signal transduction pathways: it is a serine/threonine /tyrosine kinase that is activated by phosphorylation in response to oxidative stress and translocates into the nucleus in response to free radicals, cytokines and cAMP, and in tumorigenesis. In the nucleus, BVR functions as a regulator for expression of AP-1 and cAMP target genes that includes HO-1, c-Jun, and ATF-2/CREB.Gene array analysis identifies other genes crucial to signaling and cytoprotection affected by BVR. BVR is a leucine-zipper transcription factor that binds to AP-1 site; biliverdin inhibits its DNA binding. BVR is a substrate for insulin receptor kinase (IRK), is a kinase for IR substrate and, protects against As (III)- mediated apoptosis. Initial studies show: BVR activates PKC, has PKB/Akt activity, binds to PKC and ERK1/2, and promotes cell differentiation; the effects are not cell line specific. Collectively, these findings reveal a previously unrecognized vital component of cell signaling and cytoprotection. The overall objective of this application is to investigate the mechanism and consequences of BVR modulation of cell signaling by the two major arms of insulin receptor/growth factor cascade: the phosphoinositol-3-kinase (PI3-K) and MAPK/ERK pathways, which are linked by PKC. To achieve this objective, 4 aims are proposed: 1) To define role of BVR in the IRK-mediated activation of PI3-K component of insulin/IGF-1 signaling pathway; 2) To examine regulation of MAPK/ERK component of this pathway by BVR; 3) To further define activation of PKC enzymes by BVR; and, 4) To examine in vivo regulation of insulin/IGF signaling by BVR and biliverdin. For this, mice null for BVR gene will be generated to examine effects of phenylhydrazine and As (III), which are diabetogenic and promote cell death, on glucose metabolism and apoptosis.
DESCRIPTION (provided by applicant): Although polychlorinated biphenyls (PCBs) and certain organochlorine pesticides induce liver tumors in animals, there is limited supporting epidemiologic data because of methodological challenges. There has also been little epidemiologic research into the risk associated with exposure to the low levels of aflatoxin, a known liver carcinogen, typically found in developed countries. We propose to investigate these relationships using already-collected serum and data from two large, population-based, prospective cohorts of men and women (total subjects =451,000) who provided blood samples and risk factor information between the mid- 1960s and mid-1970s. Follow-up and case ascertainment in these cohorts, one in Norway and one in Northern California, is very high and data on potential confounders are available. The aims of this study are to determine whether higher serum concentrations of organochlorines are related to increased risk of liver cancer; whether serum aflatoxin biomarkers are related to this risk; and if a synergy exists for these factors with each other or with HBV or HCV infection. We will include all cases of primary liver cancer diagnosed one or more years after blood draw (n=278) and a random sample of controls matched 3:1 to cases by cohort, age at blood draw, date of blood draw, sex, race, and county of residence (n =1,112 subjects total). We will measure serum concentrations of 39 PCB congeners, 11 organochlorine pesticides, and aflatoxin- albumin adducts, and assess HBV and HCV infection status using banked serum. We will also examine a second serum sample collected from a subset of subjects an average of 8 years after the primary sample. We will obtain information on potential confounders via linkage with previously collected health examination data (collected at blood draw), as well as clinical, census, and birth registry data available for each cohort. To our knowledge, this study would be the first to examine liver cancer risk in relation to body burden of PCBs. To be valid, such a study requires prospectively collected biospecimens because liver disease may affect the metabolism and subsequent elimination of organochlorines. The serum samples in this study were collected around the time that these organochlorines were banned in the U.S. and Norway and, thus, should reflect peak or near-peak levels of these chemicals in the general population of these countries. Although the production and use of these chemicals are banned in many countries, human exposure continues because of bioaccumulation in the food chain, ongoing use of organochlorine pesticides in less developed countries, leakage from equipment and landfills, and environmental persistence and redistribution. This study offers not only an efficient opportunity to examine the association of organochlorines and low-level aflatoxin exposure with risk of liver cancer, but also one of the few opportunities to study it in a methodologically rigorous way.
DESCRIPTION (provided by applicant): This project will continue to focus on the identification of environmental and genetic risk factors for development of hepatocellular carcinoma (HCC) in Taiwan. We are carrying out a case-control study nested in a cohort established by our collaborator, Dr. Chien in which 25,611 subjects were recruited between 1990 and 1992. In our ongoing studies, we demonstrated that, in conjunction with hepatitis B or C virus infection, aflatoxin B1 (AFB1), 4-aminobiphenyl, and polycyclic aromatic hydrocarbons (PAH) increased HCC risk. Synergistic interactions between virus and chemical were also observed. Genotyping for polymorphisms in carcinogen metabolism, oxidative stress and DNA repair are ongoing and suggest that genetic susceptibility is also significant. We will continue to analyze blood and urine samples for AFB1, and PAH biomarkers in all new cases and matched controls but also expand to biomarkers of oxidative stress including oxidized plasma proteins and urinary 8-oxodeoxyguanosine and isoprostane. We hypothesize that biomarkers of environmental exposure and oxidative stress will be higher in cases than controls. We will also continue to genotype subjects for polymorphisms in the pathways currently being investigated but expanding the number of genes. We hypothesize that cases will more frequently be carriers of "higher risk" alleles than controls and that there will also be an interaction between environmental exposures and genotype. Finally, our pilot study demonstrated that p16 was frequently methylated in tumor DNA isolated from plasma of HCC cases. We will now carry out a case-control study within the cohort to determine the frequency of methylation of a panel of genes. We hypothesize that methylation will be more frequent in cases than controls. These studies will allow the development of a panel of genes in which the detection of methylation in blood DNA identifies HCC earlier than currently possible. Our collaborative study with Dr. Chen has provided much useful data on environmental and genetic risk factors for cancer development.
DESCRIPTION (provided by applicant): Hepatocellular carcinoma (HCC) is a major malignancy worldwide. Epidemiological studies have suggested that hepatitis B virus infection and dietary aflatoxin B1 (AFB1) are the two major etiological agents for human HCC. However, the underlying mechanisms of how these two agents induce hepatocarcinogenesis remain unclear. In rats HCC can be induced by a choline-deficient diet (CDD). The pathogenesis of CDD-induced HCC in rats mimics the pathogenesis of human HCC: hepatitis at an early stage, followed by steatosis, cirrhosis and finally HCC. Rats on CDD therefore provide an excellent model for studying HCC. It has been found that the lipid peroxidation (LPO) level and LPO product-induced DNA damage are significantly increased in liver cells of rats on CDD; LPO has thus been suspected of playing an important role in hepatocarcinogenesis. LPO is a cellular process that commonly takes place under normal physiological conditions, and this process becomes significant when cells are under oxidative stress. LPO generates a variety of aldehydes, such as acrolein (Acr), crotonaldehyde, malondialdehyde (MDA), and trans-4-hydroxy- 2-nonenal (4-HNE), that are able to interact with DNA; these adducts induce mainly G to T transversion. Aldehydes are also able to interact with proteins with a thiol group. We have recently found that 4-HNE and MDA are able to significantly inhibit cellular nucleotide excision repair (NER). Based on these results we hypothesize that these aldehydes may play important roles in carcinogenesis through two effects: induction of mutations by their interactions with DNA and inhibition of DNA repair by their interactions with repair proteins. By mapping the 4-HNE-DNA adduct distribution at the sequence level in human p53 gene fragments and genomic DNA we have found that 4-HNE preferentially binds to -GAGGC/A- sequences, including codon 249 of the p53 gene, the sole mutational hotspot in liver cancer. Our results raise the strong possibility that 4-HNE may play a particularly important role in hepatocarcinogenesis in both rats and humans. We propose to test these hypotheses using both the rat and cultured human hepatocyte model. We will determine how 4-HNE-DNA adducts in the p53 gene are processed, and the role of the p53 gene in aldehyde-mediated inhibition of DNA repair in human cells. We will also determine the effect of CDD on the repair capacity in rat liver cells, the formation of 4-HNE- and other aldehyde-induced DNA adducts formed in the p53 gene and the p53 mutational spectrum in CDD-induced HCC in rats. In addition, we will determine the effect of stereostructure of 4-HNE-dG at GAGGC sites on repair and mutagenicity. Results from these studies should greatly enhance our understanding of the role of LPO in hepatocarcinogenesis.
DESCRIPTION (provided by applicant): Lead (Pb2+) produces toxic effects in bone of humans and experimental animals. The exact mechanism of action is unknown. At the molecular level lead has been shown to bind with high affinity to osteocalcin, an abundant noncollagenous bone protein. Since osteocalcin has been shown to play a significant role in bone formation and remodeling, we hypothesize that it is a likely target for lead. We have shown that Pb2+ alters the structure of osteocalcin at a stoichiometry of only 1:1 where as a stoichiometry of 3:1 is needed for Ca2+. In addition, low Pb2+ levels in addition to physiological Ca2+ levels (1 mM) caused a significant (40%) increase in the amount of mineral bound osteocalcin as compared to 1 mM Ca2+ alone. We propose that the molecular mechanism of lead toxicity is an increase in mineral bound osteocalcin. This increase in mineral bound osteocalcin might play a role in perturbed bone remodeling and abnormal bone crystal size, perfection and biomechanical properties. The following specific aims have been designed to test this hypothesis: 1) Determine the high resolution structure of the 3 g-carboxyglutamic acid (Gla) form Pb2+- osteocalcin using X-ray crystallography and that of Ca2+- and Mg2+-osteocalcin for comparison. A mechanism for mineral binding will be proposed. 2) Measure serum and mineral bound osteocalcin and investigate detailed mineral properties (crystal size and perfection) using Fourier Transform Infrared Microspectroscopy (FTIRM), in bones from mice with various levels of Pb2+ exposure. 3) Measure osteocalcin levels and collect FTIRM mineral data in mice on lower Mg2+ diets for comparison to Pb2+ data and 4) Investigate functional effects of these treatments on the bone mineral by measuring biomechanical properties (density, strength, and fragility) in the bones from these mice. Comparisons of all mineral data will help determine the toxic effect of lead at the molecular level, increase our understanding of the physiology of osteocalcin and aid in developing effective pharmacotherapeutic strategies for lead exposed children and the elderly.
DESCRIPTION (provided by applicant): The purpose of this exploratory-developmental (R21) research grant proposal is to investigate whether loss of E-cadherin in basal keratinocytes and their progeny is facilitative in the development of ultraviolet (UV) lightinduced skin squamous cell carcinomas (SCCs) and examine the mechanism(s) by which UV radiation induces E-cadherin down-regulation. Our preliminary data demonstrate that chronic UV-irradiation in SKH-1 hairless mice results in a statistically significant reduction of E-cadherin expression as lesions progress from early in situ carcinomas with isolated areas of dysplasia, through small and large invasive SCCs. Therefore we hypothesize that loss of E-cadherin expression in basal keratinocytes is critical in the early development and subsequent progression of UV-induced skin cancers. In this proposal, we will first employ loss of function studies to determine in a temporally regulated and epidermal-specific fashion whether E-cadherin down-regulation facilitates SCC development. This will be done using our well established model of photocarcinogenesis that has previously been shown to mimic the development of skin carcinogenesis in humans. Second, we will explore whether ¿-catenin mobilization, resulting from targeted E-cadherin deletion, induces alterations in keratinocytes by activating the TCF-LEF1 signaling pathway. Moreover, since we recently demonstrated that inhibition of PGE2 synthesis by indomethacin in vitro, targeted deletion of EP2 in primary mouse keratinocyte (PMK) cultures or deletion of the EP2 receptor in vivo or in vitro abrogated this UV-induced E-cadherin downregulation, we will also examine the mechanism by which PGE2-EP2 signaling induces this loss of cell surface E-cadherin. Since epithelial cancers comprise 80% of all human cancers, research that dissects how loss of cell surface E-cadherin facilitates neoplastic transformation in one epithelial system would likely be important in others. Moreover, in depth knowledge of how specific degradative pathways contribute to UV-induced E-cadherin downregulation might also provide new targets for anti-invasive therapy. Finally, the discovery of 'crosstalk' between the EP2 signaling pathway and these proteolytic pathways might yield new targets for validation in cancer diagnosis and therapy. PUBLIC HEALTH RELEVANCE: Since epithelial cancers comprise 80% of all human cancers, development of mouse model systems in which E-cadherin is selectively deleted in epithelium, may enhance our understanding of how early in situ lesions form and progress to SCCs after a repetitive UV injury. Moreover, in depth knowledge of how specific degradative pathways, via PGE2-EP2 signaling, contribute to UV-induced E-cadherin downregulation might yield new targets for validation in cancer diagnosis and therapy.
DESCRIPTION (provided by applicant): Less than 5% of all cancers result from the action of a single tumor suppressor gene or dominantly acting oncogenes. Instead, for all of the common cancers, it is the cumulative effect of many 'low penetrance' genetic mutations which confer the majority of the risk. Identifying these low penetrance genes has been a challenge which has been greatly assisted by the development of mouse cancer models between resistant and susceptible strains. In these inter-specific crosses the resistant phenotype is dominant and backcrossing to the sensitive strain has been used to perform linkage analyses to identify the chromosomal location of the tumor susceptibility genes. Over the past several years we have used a skin carcinogenesis model to identify 13 susceptibility loci and, in one case, have identified a gene, AURORA2, which confers increased risk in mice and human populations. At present the remaining 12 susceptibility loci are too large for positional cloning strategies. In this proposal, therefore, we will use a combination of strategies to define the positions of the susceptibility genes more precisely as a prelude to identifying the critical gene. In the first aim we use heavy ion beam irradiation to create microdeletions in the testes of resistant mice, which if they affect susceptibility genes, will make the F1 animals susceptible and simultaneously define the critical locus. In the second aim we will use inbred and outbred backcrosses together with linkage disequilibrium haplotype analysis to define the susceptibility loci. The third aim will exploit our previous observation that tumor-specific genetic changes (deletions and amplifications), when they occur in regions known to contain susceptibility genes, can be used to define their location more accurately. These genetic changes will be identified with high-resolution custom BAC arrays available at RPCI. It is anticipated that this combination of approaches will identify candidate suppressor genes which can then be analyzed in more detail for their involvement in cancer risk in mice and human populations. In the long term, understanding the genetic load which leads to cancer susceptibility in the human population will provide rational alternatives to cancer prevention, screening and risk assessment.
DESCRIPTION (provided by applicant): 2,5-Hexanedione (HD), the neurotoxic diketone metabolite of the industrial solvents methyl n-butyl ketone and n-hexane, causes a toxic neuropathy in occupationally exposed humans. Although axonal swellings have been considered the morphological hallmark, recent quantitative morphometric studies show that axon atrophy is a specific, prevalent effect that is temoporally correlated to the development of neurological defects. These findings suggest that atrophy is an essential pathophysiological component of diketone- induced neurotoxicity. The long-term objectives of this research project are to determine the molecular mechanism of axon atrophy. Studies conducted during the current funding period (yrs 04-07) indicated that HD intoxication of rats was associated with a depletion of mobile neurofilament (NF) proteins. This effect did not involve changes in NF phosphorylation or subunit gene expression. Since HD forms pyrrole adducts with NFs, we hypothesize that adduction interferes with the ability of mobile NFs to interact with the stationary cytoskeleton polymer. As a result, the subunit remains attached to the transport vector kinesin, which in the absence of compensatory changes in protein synthesis, promotes anterograde loss of NF subunits. Atrophy occurs due to depletion of the mobile NF pool and to the ensuing impairment of cytoskeletal turnover. This hypothesis will be tested by the following Specific Aims: 1) Mass spectrometry will be used to characterize HD-induced pyrrole formation in the stationary and mobile NF pools. 2) The effects of pyrrole formation on NF subunit kinesin-based transport, assembly and cytoskeletal incorportation will be determined. 3) The content and spatial relationships among cytoskeletal elements (NFs, microtubules) will be quantified in peripheral myelinated axons of HD-intoxicated rats and age-matched controls. 4) The ability of HD structural analogs (e.g., 3,4-dimethyl 2,5-HD) to predictably alter proteomic, morphological and biochemical parameters will be evaluated. Understanding the role and mechanism of axon atrophy in solvent neurotoxicity has broad-based implications for human occupational health and risk assessment.
DESCRIPTION (provided by applicant): The long-term objective is to determine the impact of environmental toxicants on the olfactory system and the role of chemical exposure in the etiology of anosmia and other diseases concerning the nasal cavity, such as nasal polyps, chronic nasal inflammation, microbial infection, and asthma. Our focus has been on the mechanisms of tissue-specific toxicity and molecular approaches to risk assessment. Previous in vitro studies have suggested that olfactory mucosa (OM)-predominant cytochrome P450 (CYP) enzymes may be important in the OM-selective toxicity of many chemicals. In the current funding period, we have succeeded in the preparation and initial characterization of two knockout mouse models, one with germ-line disruption of the OM-specific Cyp2gl gene (Cyp2gl-null mouse), the other with liver-specific deletion of the NADPH-cytochrome P450 reductase (Cpr) gene (liver-Cpr-null mouse). Using these models, we have obtained important preliminary data concerning the role of hepatic metabolism in nasal toxicity of acetaminophen (as a model toxicant), and the role of CYP2A5 and/or CYP2G1 in the toxicity of acetaminophen in the lateral nasal gland (LNG). In the proposed studies, we will test a general hypothesis that target tissue metabolic activation is critical for extrahepatic chemical toxicity; however, the sensitivity of a particular tissue to a given compound will depend on many factors (in addition to the rate of systemic clearance of the parent compound), such as the level and reactivity of circulating hepatic metabolites, and homeostasis of endogenous substrates in the target tissue. The specific aims are: 1) To determine the impact of hepatic metabolism and target tissue metabolic activation on OM toxicity of nasal toxicants; 2) To determine the mechanisms of the increased resistance to AP toxicity in the LNG of the Cyp2gl-null mouse; and 3) To generate additional mouse models that can be used for determining the specific roles of CYP2A5 and CYP2G1 in target tissue metabolic activation and chemical toxicity in the OM and LNG. These studies will have broad implications for risk assessment of potential nasal toxicants, and may serve as a model for studying mechanisms of chemical toxicity in other extrahepatic tissues.
DESCRIPTION (provided by applicant): Synthetic pyrethroids, an important class of neurotoxic insecticides used worldwide in agriculture and public health, cause toxic effects in animals by modifying the normal function of voltage-sensitive sodium channels. Sodium channels in mammalian tissues exist as multiple isoforms that exhibit differential tissue distribution and developmental regulation and are encoded by members of a multigene family. Previous studies of pyrethroid action have not considered the differential sensitivity of sodium channel isoforms as a determining factor in the toxicity of these compounds. The proposed research will test the hypothesis that differences in the pyrethroid sensitivity of mammalian sodium channel isoforms are important determinants of the nature and severity of pyrethroid intoxication. Specific experimental aims are: (1) to define the actions of pyrethroid insecticides on cloned rat sodium channel isoforms expressed in frog (Xenopus laevis) oocytes or transfected mammalian cells; (2) to compare the actions of pyrethroids on orthologous rat and human sodium channel isoforms expressed in Xenopus oocytes or trnasfected mammalian cells; and (3) to map the the structural determinants of pyrethroid action by the construction, functional expression and pharmacological characterization of specifically mutated sodium channels. Cloned sodium channel isoforms will be expressed in Xenopus oocytes or transiently transfected mammalian cells (e.g., HEK-293) and the actions of pyrethroid insecticides on expressed channels will be assessed using electrophysiological recordings of macroscopic sodium currents under two-electrode voltage-clamp or whole cell patch-clamp conditions. Structural determinants of pyrethroid sensitivity will be identified by site-directed mutagenesis, expression, and pharmacological comparison of native a mutated sodium channel isoforms. Results of these studies will define the role of different sodium channel isoforms in pyrethroid toxicity, establish whether rat sodium channels are valid toxicological models for the sensitivity of human sodium channels to pyrethroids, and identify sodium channel domains that determine pyrethroid sensitivity.
Crisp Terms/Key Words: neurotoxicology, protein isoform, animal tissue, environmental toxicology, voltage gated channel, sodium channel, protein structure function, protein sequence, pyrethroid, insecticide, human tissue, gene mutation, gene expression, molecular cloning, transfection, site directed mutagenesis, chemical binding, Xenopus, aminoacid
DESCRIPTION (provided by applicant): Abstract Exposure of humans and laboratory animals to acrylamide (ACR) produces cumulative neurotoxicity characterized by gait abnormalities, muscle weakness and a central-peripheral neuropathy. ACR is an 1,2-unsaturated carbonyl derivative and is classified as a type-2 alkene. This is a large class of electrophilic chemicals that have broad industrial, agricultural and pharmaceutical uses. These chemicals are also well-recognized dietary contaminants and environmental pollutants. Data collected during yrs. 17-20 have provided evidence that ACR impairs nerve terminal function by forming irreversible covalent adducts with nucleophilic sulfhydryl groups on functionally important proteins. Proteomic analyses indicate that the protein targets of ACR and the type-2 alkenes are also acceptors for nitric oxide (NO) signaling. NO is a biological electrophile and has been classically thought to influence cell processes through guanylyl cyclase activation. However, NO can also modulate cell physiology by forming reversible adducts with cysteine thiolates in protein catalytic triads. At the nerve terminal, NO signaling is critically involved in neurotransmission through modulation of the synaptic vesicle cycle and other presynaptic processes. Thus, NO and ACR interact at common cysteine sulfhydryl sites and, therefore, we hypothesize that irreversible adduction of these receptors by ACR blocks reversible NO binding. The disruption of NO signaling and ensuing loss of neuromodulatory control produces presynaptic toxicity. Therefore, Specific Aim #1 research will define the interactions of ACR with the S-nitrosylated (SNO) proteome of CNS nerve terminals. SNOSID (S-nitrosylated site identification) proteomic analysis will be used to demonstrate ACR adduction of SNO-cysteine sites on nerve terminal proteins. Specific Aim #2 studies will evaluate the specificity of the ACR-NO interaction by considering alternative mechanisms of action; i.e., we will determine the effects of ACR on soluble quanylyl cyclase and nitric oxide synthase (NOS) activity/gene expression. Because NO modulates physiological processes in most cells, it is unclear why nerve terminal NO signaling might be selectively targeted by ACR. Therefore, Specific Aim #3 studies will consider several anatomical and molecular features that might predispose nerve terminals to electrophilic attack. Identifying the mechanism of ACR neurotoxicity could offer global insight regarding the toxicological processes of other type-2 alkenes. Results of the proposed research could also help us understand the pathogenesis of Alzheimer's disease (AD) and other chronic neurodegenerative conditions that presumably involve cellular oxidative stress and endogenous generation of acrolein and other type-2 alkenes. PUBLIC HEALTH RELEVANCE Human exposure to conjugated type-2 alkenes (e.g., acrylamide, methyl acrylate, methylvinyl ketone) occurs through pervasive environmental sources (e.g., industrial exposure, cigarette smoking, car exhaust, combustion, pharmaceuticals) and can result in significant toxicity in nervous tissue and other organ systems (liver, kidney). There is also evidence that endogenous production of type-2 alkenes (e.g., acrolein, 2-hydryoxy-4-nonenal) is critically involved in mediating nerve cell injury associated with accidental neurotrauma and certain human neurodegenerative conditions such as Alzheimer's disease. Therefore, the proposed studies of type-2 alkene neurotoxicity could lead to a better understanding of brain injuries caused by environmental toxicant exposure or disease processes, which would ultimately help in the development of effective therapeutic approaches.
DESCRIPTION (provided by applicant): Fetal exposure of man and mice to mercury (Hg) induces long-term behavioral and neuronal dysfunctions, but the mechanistic involvement of neuroendocrine immune network activities, e.g., hypothalamo-pituitary- adrenal (HPA) axis, centrally located immune cells (microglia and mast cells), and autoantibodies to central nervous system (CNS) antigens, have not been adequately addressed. In addition, based on their genetic differences, certain mouse strains develop Hg-induced immunopathologies (autoimmune disease), which are posited to include autoantibody-induced neuroinflammation, leading to neuronal damage and dysfunction. Hg induces enhancement of type-2 immunity, which includes heightened levels of Th2 cytokines IL-4, IL-5 and IL-6 as well as IgE and elevated release of factors from mast cells, eosinophils and basophils. Some mouse strains (e.g., BALB/c mice) develop immune complexes which can localize in certain organs eliciting inflammation whereas mice with the H-2s haplotype (e.g., A.SW mice) develop autoantibodies that bind to select antigens directly initiating targeted damage. We hypothesize that based on the genetics and environmental exposures, some strains have CNS inflammation due to antibodies inducing activation of microgia and mast cells, which leads to behavioral aberrance and neuropathological outcomes that occur in adults following developmental exposures to Hg. The sequence of events that culminate in adult neuroimmune-induced pathologies are posited to be: i) altered neuroendocrine regulation, which enhances type-2 immunity; ii) increased autoimmune responses to CNS antigens; iii) modulation of immune cell (microglia and mast cells) distribution and function in the brain; and iv) elevated neuroinflammation which disrupts neuronal functions. We will first demonstrate that Hg enhances generation of autoantibodies to CNS antigens, dependent on haplotype, and then identify the autoantigens. Aim 2 will investigate the specific brain regions with autoantibodies and the phenotype of the cells present. Aim 3 will evaluate whether autoantibodies in the absence of Hg can cause similar neuroinflammation in Hg-susceptible (H-2s and Th2-prone strains) and Hg-non-susceptible strains. We suggest that certain environmental agents can initiate heightened immunity to self-antigens, including brain antigens, based on the genetics of the host. We will compare the ability of inorganic and organic Hg to initiate the described consequences.
DESCRIPTION (provided by applicant): Pyrazoline-type insecticides (PTIs) are a new class of insecticides exemplified by indoxacarb, the first compound of the class registered for commercial use in the United States. PTIs exert their neurotoxic effects in insects by selectively blocking sodium channels in depolarized cells. PTIs also selectively block mammalian sodium channels at membrane potentials that promote slow sodium channel inactivation. This effect is similar in many respects to the state-dependent sodium channel block caused by several classes of therapeutic drugs (e.g., local anesthetics, antiarrhythmics, anticonvulsants, neuroprotectants and analgesics) that bind to the "local anesthetic receptor" site of sodium channels. As a result, the local anesthetic receptor has been implicated indirectly as the site of PTI action. The proposed research will test the hypothesis that PTIs block sodium channels by binding to the local anesthetic receptor site of slow-inactivated sodium channels. Specific experimental aims for the proposed funding period are: (1) to define the actions of PTIs on cloned rat sodium channel isoforms and subunit combinations expressed in Xenopus oocytes; (2) to elucidate the mechanism of voltage-dependent sodium channel block by PTIs; and (3) to map the structural determinants of PTI binding to sodium channels by site-directed mutagenesis. Cloned sodium channel isoforms will be expressed in Xenopus oocytes and the actions of PTIs on expressed channels will be assessed using electrophysiological recordings of sodium currents under voltage-clamp conditions. Results of these studies will define the differential sensitivity of sodium channel isoforms to PTIs, elucidate the mechanism of state-dependent sodium channel block by these compounds, and identify the molecular determinants of PTI binding to sodium channels. This research will provide new insight into the structure of the local anesthetic receptor and its role in the neurotoxic actions of PTIs.
Crisp Terms/Key Words: binding site, neurotoxicology, gene environment interaction, protein isoform, Xenopus oocyte, environmental toxicology, pyrazole, sodium channel, membrane channel, protein structure function, insecticide, neurotoxin, anesthetic, site directed mutagenesis, chemical structure function, laboratory rat
DESCRIPTION (provided by applicant): Organophosphate (OP) toxicity has acute and chronic components. Although the acute toxicity is through the known mechanism of action of OP's, the inhibition of cholinesterases, the chronic apparently is not. Recent research has suggested that the chronic toxicity is through the production of free radicals, and that this may be particularly damaging during fetal brain development. One way in which the brain responds to an increase in free radicals is through an astrogliotic reaction, which includes release of S100B. S100B is a trophic factor promoting both serotonin terminal outgrowth and synaptogenesis. Thus, in fetal OP toxicity, there will be an increase in serotonin terminals and synaptic density at a young age, but as the animal ages, both will be prematurely lost. In tests of learning and memory, therefore, the young animal may show no deficits, but the older animals, with loss of synapses, will show deficits. The proposal uses a model of OP toxicity previously found to increase serotonin and synaptic markers at a young age- injection of 1 mg/kg of chlorpyrifos (CPF) to rats on gestational days 17-20. The hypothesis will be tested as follows: Specific Aim 1: Using immunochemistry, gestational day (GD) 20 rat pups or mice will be examined for S100B content. Heat shock protein (HSP) -27 and clusterin will be used as markers of oxidative stress and microglial activation as a marker of neuroinflammation. Findings will be compared with litters given a Vitamin E-enriched diet, as an antioxidant Specific Aim 2: Using immunocytochemistry, the hippocampus will be examined for serotonin terminal density, S100B content and changes in astroglial and microglial morphology. Animals will be tested at three ages: postnatal days (PND), PND 35 (adolescence), PND 60 (adult) and PND 365 (aged). Specific Aim 3: Synaptic density will be determined at the same ages, first using immunocytochemistry of microtubule-associated protein (MAP)-2 and synaptophysin. Any changes observed will be confirmed with electronmicroscopy. Specific Aim 4: Animals will be tested for changes in learning and memory at PND 35, 60 and 365.
DESCRIPTION (provided by applicant): Mercury (Hg) vapor and monomethylmercury (MeHg) are separately potent neurotoxins. Dental amalgam restorations, which are composed of approximately 50% metallic Hg, are the principal source of human exposure to Hg vapor, while most exposure to MeHg comes from fish consumption. Both forms of Hg cross the placental and blood-brain barriers, exposing the developing fetus. Of significant concern, the human fetus appears especially vulnerable to MeHg. There is a paucity of data on the developmental effects of prenatal Hg vapor exposure, and no data on the combined exposure to Hg vapor and MeHg exposure, despite concerns that combined exposure may elevate risk via additive or synergistic mechanisms. The proposed study will build on the strength of the Seychelles Child Development Nutrition Study (SCDNS), a longitudinal cohort study examining the association between prenatal exposure to MeHg, nutritional status, and development. Residents of the Seychelles have free dental care using amalgams and consume large quantities of ocean fish. SCDNS children have been evaluated eight times and their nutritional and developmental status to date has been well characterized. Prenatal and postnatal exposure to MeHg to date has been determined by periodic sampling of the mother's/child's hair and maternal dental status during pregnancy was established by oral examinations following delivery. In the proposed study, we will conduct routine dental exams in children recording amalgam restorations placed/present/lost as a measure of postnatal Hg vapor exposure and hair analysis as a measure of postnatal MeHg exposure. Neurodevelopmental testing will occur at 72 and 96 months. Preliminary data from a prior Seychelles cohort suggests an adverse association when Hg vapor exposure (as measured by maternal amalgams present during gestation) is included in analyses. The aim of the proposed project is to capitalize on the availability of the already well-characterized SCDNS cohort to quantify the level of risk for adverse neurodevelopmental outcomes attributable to prenatal and postnatal co-exposure to Hg vapor and MeHg. Three hypotheses will be tested: 1) The level of risk for adverse neurodevelopmental outcomes will be accentuated by combined exposure to Hg vapor and MeHg; 2) Effects of prenatal exposure will be accentuated by postnatal exposure; and 3) Overall exposure effects will be modulated by prenatal nutritional factors.
DESCRIPTION (provided by applicant): Public anxieties about mercury exposure have been aroused by reports about the hazards of fish consumption, dental amalgams, and preservatives in vaccines. Although scientific support for such concerns may be tenuous, it is also true that sizable gaps remain in our understanding of mercury neurotoxicity, especially with respect to combined exposures to different species, a commonplace condition. The two forms that present the greatest health risks are methylmercury, found in fish and marine mammals, and metallic mercury vapor, found in industry, cosmetics, and dental amalgams. Mechanistic analyses and limited experimental data indicate that co-exposure to the two forms may enhance the neurotoxicity of either alone, an especially worrisome outcome for the developing brain. Because joint exposure is such a common occurrence, with assays in pregnant women indicating that the inorganic form accounts for more than 25% of mercury in blood, this project is designed to more clearly define the associated risks to brain development. Pregnant rats will be exposed concurrently to mercury vapor by inhalation and to methylmercury in drinking water. Neurobehavioral measures in the offspring will include schedule-controlled operant behavior to assess cognitive behavior, motivation, and memory; hindlimb splay as an assay for motor function; and locomotor activity, a common assay for neurobehavioral status. Mercury concentrations in offspring brains will also be measured. The research will proceed in stages. (1) Exposure levels will produce mild to moderate degrees of neurotoxicity and reliable dose-effect functions for each form by itself. (2 and 3) Here we determine if a specified concentration of vapor changes the dose-effect function for methylmercury and if a specified dose of methylmercury alters the concentration-effect function of mercury vapor. These results will be used to calculate, by Benchmark Dose modeling, vapor and methyl exposures inducing a 10% and 25% change in the neurotoxic indices. (4) The combined effects of these levels will be determined. The acquisition of these data offers a firm foundation for determining the risks to neurobehavioral development of concurrent exposures to both mercury species.
DESCRIPTION (provided by applicant): Adults and children living in the Great Lakes region are exposed to complex environmental contaminants including RGBs, DDE and mercury. PCBs in particular have been implicated in cognitive impairments in children. The major goal of this proposal is to determine whether low level, prenatal PCBs compromise cognitive development in the teen years. An established database of intrauterine (cord blood and placenta) PCBs, DDE, Mirex, HCB, lead, EP and hair mercury which were collected when each child from the Oswego Project was born are on file for the proposed projects existing 202 participants. In addition, the project also contains data regarding a host of behavioral measures, demographics, substance use, as well as 50+ potentially confounding variables within the analytic database. These data, along with low project attrition, enable us to assess cognitive development and impulse control as the children enter early teenage years. The current proposal is the continuation of the research from the Oswego Project and is bolstered by published and yet-to-be published data that suggest that prenatal exposure to PCBs impairs global skills, cognitive skills and behavioral impulsivity in children.
Specific Aim 1) To investigate the different components of response inhibition that underlies the sustained PCB-related deficits on continuous performance and operant tasks seen at 4, 8 and 10
years of age.
Specific Aim 2) To study (via MRI assessment) the fronto-striatal structures that mediate and the posterior structures that modify PCB-related impulsive responding.
Specific Aim 3) To assess the stability of the association between prenatal PCB exposure and Global
Intelligence (IQ) through re-assessment of IQ at 15 years of age
DESCRIPTION (provided by applicant): This proposal is a competing renewal of Project #5-R01ES08442, entitled Developmental Toxicity of Methyl Mercury, testing the hypothesis that adverse developmental outcomes in children are associated with exposure to methyl mercury (MeHg) from consumption of a diet high in fish. Since 1989, the Seychelles Child Development Study (SCDS) has been following a cohort of 711 children born to mothers who consumed an average of 12 fishmeals per week during pregnancy. The children are now adolescents. The question of whether exposure to MeHg from fish consumption adversely affects child and adolescent development has aroused deepening public concern. The emphasis on prenatal exposures has left several important scientific questions unresolved. Exposure does not cease at birth, yet we know little about the long-term effects of postnatal dietary exposure to MeHg from fish consumption. Also, almost nothing is known about the contributions to long-term outcomes of combined prenatal and postnatal exposure to MeHg. The current proposal aims to determine the consequences of combined prenatal and postnatal exposure especially for long-term or delayed effects that might appear as the children mature. We will examine functions within three major developmental domains: complex cognition, sensory and neuromotor functions, and social behavioral outcomes in adolescence. The SCDS cohort will be examine once when they are 15 years old and the second when they are 17 years using a combination of psychological and neurological tests and surveys. Prenatal exposure to MeHg was determined by cold vapor atomic absorption from maternal hair collected at enrollment. We will continue to collect child hair at each visit (as has occurred for each of the past five visits) to estimate both average postnatal exposure across ages, and recent exposure. Multiple regression analyses will be used to assess associations between prenatal and postnatal exposure and each endpoint. If we find delayed neurotoxic effects of MeHg in adolescence, substantial or even radical modifications would be required in how we interpret associations between prenatal and postnatal exposure to MeHg and the trajectory of later health consequences.
DESCRIPTION (provided by applicant): This research is focused on understanding how non-catastrophic toxicant exposure disrupts normal development and function of the CNS. The continuing determination that concentrations of toxicants once thought to be safe are associated with a variety of maladies, combined with the large numbers of toxicants and potential toxicants found in our environment, make it of great importance to increase our understanding of how normal cellular function may be disrupted by such substances. A central goal of this effort is to identify general principles applicable to the understanding of large numbers of toxicants. The general principle/hypothesis that underlies this application, which emerges directly from our ongoing research, is that, regardless of its other activities, any toxicant that has pro-oxidant activity will have a highly predictable set of effects on both precursor cells and differentiated cells. These effects include inhibition of precursor cell division and enhancement of responsiveness to inducers of differentiation and cell death. This hypothesis, with its clear mechanistic predictions, allows the formulation of a general theory of developmental neurotoxicology applicable to exposure to a wide range of toxicants at concentrations that frequently occur in the environment. Moreover, the predictions of our hypothesis regarding the effects of low dose toxicant exposure on vulnerability to other potentially harmful agents may provide a new understanding of the reasons underlying the enormous variability seen in responsiveness of different individuals to putatively identical physiological stressors. Our in preliminary vitro experimentation provides strong support for the correctness of the hypothesis underlying this proposal, and has demonstrated marked effects of a variety of toxicants on neural cell function, including a striking enhancement of vulnerability to a variety of other physiological stressors. Biochemical analysis demonstrates that despite their different chemistries, all of the toxicants examined converge on Fyn and Cbl activation, leading to enhanced degradation of the PDGFRa. In sum, this research program will define the actions of sublethal concentrations of single toxicants on a variety of neural precursor cells, define the interactions of toxicants with other physiological stressors (including other toxicants) particularly in regards to synergistic toxicity reactions, will define cellular regulatory systems that are modulated by toxicant exposure, and will study clinically relevant situations in which toxicant load can enhance response to injury and in which follow on studies in human populations are both particularly important and comparatively straightforward to carry out.
DESCRIPTION (provided by applicant): This R21 proposal is based on the hypothesis that prenatal exposure to phthalate esters will alter normal brain development and associated behavioral outcomes. Phthalates are ubiquitous environmental contaminants found in cosmetics, household furnishings, medical devices, toys, and numerous other products. Human exposures are universal. Recent human data, showing a significant relationship between levels of phthalate metabolites in maternal urine during pregnancy and shortened anogenital distance in male children, provoke concerns that phthalates may pose significant threats to neurobehavioral development. In rats, exposure during gestation to certain phthalates induces malformations in the reproductive tract of male offspring as well as markers of feminization such as shortened anogenital distance. This syndrome signifies a disturbance in androgen-mediated development attributable to a decrease in fetal testicular production of testosterone. Because testosterone governs sexual differentiation of the brain, reductions in fetal output would be expected to engender demasculinization of brain anatomy and its expression in behavior. To test this hypothesis, pregnant rats will be administered selected phthalate esters (diethylhexyl phthalate, or DEHP, and dibutyl phthalate, or DBP), or a combination of the two, during gestational days 12-20, which encompass the testosterone surge in fetal males. Both male and female offspring will be evaluated behaviorally and morphologically, with an emphasis on behaviors and structures recognized as sexually dimorphic. Behavioral measures include play behavior, exploratory behavior, saccharin preference, sex partner preference, and schedule-controlled operant behavior. Morphological assessments are based on the volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA). This research addresses an urgent question arising from the human data. It will enable us to use the rat as a laboratory model for human phthalate exposures during fetal development, to carefully control exposure dose and timing, and to to amplify and extend the epidemiological findings by subjecting certain of their implications to laboratory investigation. Phthalate esters are chemicals used as plasticizers in personal care items such as shampoos, medical tubing, plastic toys, food packaging, and many other products. They impair male reproductive system development in animal models, and recent studies show similar effects in humans. Because phthalates act as anti-androgens, they have the potential to interfere with human brain and behavioral development. The proposed research will examine this question in rats, and translate its implications into human relevance.
Genetic and endocrine factors are implicated in the etiology of attention deficit disorder with hyperactivity
(ADHD). Polychlorinated biphenyls (PCBs) and, we suggest, polybrominated diphenyl ethers (PBDEs)
induce similar deficits in attention and impulse control in developmentally exposed children, as well as
reducing central catecholamine and thyroid hormone levels in experimental animals?physiological changes
also seen in ADHD. We hypothesize that developmental exposure to PCBs and PBDEs, due to their ability
to alter central catecholamines and/or thyroid hormones during critical periods of development, are etiologic
factors responsible for the contaminant induced behavioral changes that are reminiscent of those seen in
ADHD. To better understand the physiological bases for these behavioral alterations and to gain insights to
the etiology of ADHD we will determine: (i) the effects of these contaminants, alone and in combination, on
central catecholamines and maternal and offspring circulating thyroid hormone levels; (ii) whether
experimental reductions in maternal and fetal circulating thyroid hormones (induced with methimazole) mimic
the changes seen in central catecholamines with PCBs and/or PBDEs; (iii) whether contaminant-induced
reductions in central catecholamines can be ameliorated following either maternal T4 supplementation or
adult methylphenidate exposure and (iv) the effects of these manipulations on mRNA expression and
proteins that regulate catecholamine function in prefrontal cortex, striatum and hippocampus. These studies,
when combined with behavioral data from similarly exposed animals, will begin to determine the
mechanisms by which these contaminants alter behaviors reminiscent of ADHD in developmentally exposed
children, including the relative contributions that contaminant induced reductions in central catecholamines
and thyroid hormone levels play in altering nervous system development and ultimately behavior.
DESCRIPTION (provided by applicant): This proposal is for a two-year project that expands the Seychelles Child Development Study a longitudinal cohort study following children and adolescents in the Republic of Seychelles who were exposed prenatally to MeHg through maternal consumption of a diet high in fish. It provides a unique opportunity to examine the controversial issue of whether ASD is related to MeHg exposure-an issue that has major public health implications in the United States. Recent pilot data from 445 adolescents participating in the SCDS suggested an adverse association between scores on the Social Reciprocity Scale (a teacher questionnaire used to screen for ASD symptoms) and prenatal MeHg exposure. The expected prevalence of ASD is 1:166, hence a very large cohort would be necessary to compare rates in the Seychelles and elsewhere. There are three adolescent cohorts available for study. The first, called the Main Cohort is being examined currently with funding from Grant 2-R01ES08442-05. The proposed project would expand the assessment of this cohort to include administration of the Social Communication Questionnaire (SCQ) a parental screening for ASD. The current assessment battery does not include measures of ASD. We would also screen parents of children from the two other cohorts using the SCQ (called the Pilot Cohort and the Third Cohort) who have not been examined in order to increase statistical power to detect ASD. The prenatal exposure to MeHg is known already for the Main Cohort (N=739) and Pilot Cohort (N=789) subjects. We expect to recall an additional 3,150 parents of Third Cohort children whose maternal hair samples have not yet been analyzed for Hg. The proposed project would permit expansion of the subject pool with known prenatal MeHg exposure to approximately 4,678 subjects. At the conclusion of the proposed project, we will estimate the association between prenatal MeHg exposure and SCQ scores. If warranted by the outcome, this newly characterized cohort could then be used for further study using standard diagnostic procedures to clarify the association between MeHg and ASD and to determine the prevalence of ASD in a population with known high exposure to MeHg from fish consumption during pregnancy. Public Health Significance Concern is growing among scientists and policy makers that there may be a link between exposure to methylmercury and ASD phenotype. There are no published human studies where prenatal exposure to methylmercury has been ascertained and offspring have been tested for ASD. The Seychelles Child Development Study provides a rare opportunity to test the hypothesis that there is an association between ASD and methylmercury exposure from fish consumption.
DESCRIPTION (provided by applicant): The major objective of the proposed research is to study the impact of early-life exposures to common urban pollutants on neurobehavioral development and asthma in a sample of children living in three low-income, minority communities of New York City (Central Harlem, Washington Heights and the South Bronx). Using a molecular epidemiologic approach with monitoring, biomarkers, and clinical assessments at serial time points, we will extend our study of African-American and Latina urban mothers and children in order to follow the cohort through child age 11 years to assess the longer-term impact of exposures on child health and developmental outcomes. The exposures of concern include airborne polycyclic aromatic hydrocarbons (PAHs) and orgnaophosphate pesticides such as chlorpyrifos (CPF). The first Specific Aim (Neurodevelopmental) builds on our prior findings and proposes to evaluate relationships between early exposures (PAHs and CPF) and longer-term neurodevelopment, in order to assess the persistence of neurotoxic effects into the school years, identify effects that may emerge over time, and delve more deeply into the behavioral domains to better understand the significance of behavior problems observed in the preschool years. The second aim (Asthma) also builds on our previous findings with respect to risk factors for asthma. We will repeat the assessment of immunoglobulin (lg)E at ages 5, 7, and 9 and obtain measures of lung function and airway inflammation, and a physician-diagnosis of asthma between ages 5 and 7 years. We will also assess the association between becoming overweight in the first 5 years of life and the development of IgE, airway inflammation, and asthma in childhood. The research will consider the effect of known determinants of disease and potential confounders, including other toxic exposures and demographic factors. By using a multidisciplinary approach to understand the complex pathogenesis of developmental disorders and asthma that impose such a heavy burden on inner-city children, we anticipate that the proposed research will have important implications for prevention.
DESCRIPTION (provided by applicant): Significant neuroanatomical and neuromaturation changes take place during adolescence and are reflected n the maturation of abstract reasoning, affect, and cognition. Hence, exposure of millions of adolescent working children in developing countries to solvents might affect their cognitive and behavioral development, in a previous original study in Lebanon, we reported that male working children exposed to solvents performed worse on neurobehavioral assessment than non-exposed working children. The study had several imitations. The exposed children were recruited from 4 kinds of workplaces with variable solvent exposure. Exposure was assessed only once (4-hour passive monitoring) and a follow up study was not planned. This R21 application, a collaborative between the American University of Beirut (AUB) and the Oregon Health & Science University (OHSU), aims at building capacity at AUB and replicating the previous work towards ubmitting an R01 follow-up study. OHSU will bring in 30 years of experience in neurobehavioral research and their Behavioral Assessment and Research System (BARS) which was applied in different occupations, anguages, and age groups. A cohort of 100 male children (10-17 years) working in mechanics (exposed mainly to Methyl Ethyl Ketone and Toluene) and 100 male non-exposed working children will be recruited from a poor neighborhood in north Lebanon, in collaboration with the Center for Working Children in that neighborhood. The program has enrolled 68 working children in the past 18 months. The study will adapt BARS to the Lebanese context, pilot test it, train local researchers, and then use it to compare the performance of exposed to non-exposed children. The study will also develop a strategy to assess exposure of children to solvents using a combination of direct observation at work, passive air monitoring, and biological monitoring. The long-term goal is to submit an R01 application in which these children are followed-up for 3 years, whereby their exposure to solvents is carefully assessed, their neurobehavioral performance is retested in addition to a set of neurophysiological tests, and a functional MRI is performed on those with the worst exposure or performance. The R01 will address the controversial issues of long-term solvent neurotoxicity and the use of neurobehavioral testing as an early indicator of adverse neurotoxic effects. The findings will inform policy on child labor and solvent exposure.
DESCRIPTION (provided by applicant): Lower socioeconomic status (SES) children in the U.S. are now the primary target of elevated lead (Pb) exposure. Low SES is already a risk factor for disease and behavioral dysfunctions, including learning disorders in children, an effect believed due to greater environmental stress in low SES populations and associated prolonged cortisol elevation. Even higher SES populations experience chronic life stress. Pb and stress both affect brain mesocorticolimbic (MES) systems and produce similar behavioral deficits. An obvious question is whether Pb and stress interact, and, if so, how does it change our understanding of mechanisms of Pb neurotoxicity and associated human health risks? Our current studies demonstrate Pb/ stress interactions from preweaning or postweaning Pb and permanently elevated corticosterone levels in offspring after maternal Pb alone. This application examines the hypothesis that Pb and stress interact by altering corticosterone which then modulates MES function and associated behavioral and neurochemical effects of Pb. Using preweaning or continuous Pb with maternal stress or maternal plus offspring stress, the proposed experiments will examine how Pb exposure level, stress and gender influence the expression and nature of Pb-stress interactions for behavioral function using 2 baselines with demonstrated Pb sensitivity and mediated by MES systems (Fixed Interval, repeated learning). Time course profiles of associated changes in neurochemical function, corticosterone binding and plasma corticosterone will be related to behavior. Corticosteroid antagonists and maternal adrenalectomy wjll be used to provide a mechanistic understanding of corticosterone's role in Pb or Pb+stress effects. Brain Pb alterations as a potential mechanism will also be evaluated. Pb+stress interactions pose questions about our current understanding of mechanisms of Pb neurotoxicity and of the adequacy of current risk assessment. If Pb alters corticosterone and stress responsiveness, it could also modulate susceptibility to disease and dysfunction.
DESCRIPTION (provided by applicant): Our long term goal is to study the mechanism of neurodegeneration induced by environmental neurotoxicants. This proposal is submitted to investigate the active role of astrocytes in regulating the levels of environmental neurotoxic cations and hence, in modulating neurodegeneration. Based on our preliminary data we hypothesize that cations such as MPP+ (1-methyl-4-phenylpyridinium) and paraquat (PQ) are bi- directionally transported across the astrocytic plasma membrane by the organic cation transporter 3 (OCT3) and, through this mechanism, OCT3 modulates neurotoxicity. Thus, the tissue and cellular distribution of OCT3 should be critical in defining the differential regional susceptibility to cationic neurotoxins. Cations representing two different categories of environmental neurotoxicants with different toxicokinetics will be used. 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a lipophillic compound that will be used to generate MPP+ inside of astrocytes. The goal is to assess how the release of MPP+ from astrocytes (v/a OCT3) into the extracellular space would subsequently induce selective death in the nigral dopaminergic neurons. PQ, a widely used cationic herbicide that has been linked to parkinsonism, will be used to assess how astrocytes affect neurodegeneration by taking up (via OCT3) and thus removing toxic cations from the extracellular space. Of note, both MPP+ and PQ also increase the outflow of the endogenous cation dopamine (DA), which is neurotoxic upon oxidation To test our hypotheses, mutant mice deficient in OCT3 and an OCT3 inhibitor will be used. In the first specific aim, we will assess how OCT3 regulates the levels of MPP+, PQ and DA by determining its uptake and reverse transport kinetics for these cations using both cell culture and animal models. In the second specific aim, we will evaluate how OCT3 modulates neurotoxicity through its bi-directional transport of MPP+ and PQ. We hypothesize that OCT3 ablation, by sequestrating MPP+ in astrocytes, attenuates dopaminergic neuronal death after MPTP treatment. Conversely, OCT3 ablation, by preventing the uptake of MPP+, PQ, and DA into astrocytes, enhances dopaminergic neuronal death after MPP+ and PQ treatments. Thus, our plan is to assess the magnitude of dopaminergic neurotoxicity in OCT3 mutant mice as well as co-culture models of astrocytes and dopaminergic neurons, treated with MPTP, MPP+ or PQ. We will also assess whether re-expression of OCT3 in astrocytes deficient in this transporter would reverse the neurotoxic effects. The proposed studies have potential to unravel a still unrecognized pathway by which different cell types in the brain interact with each other to modulate neurodegeneration induced by environmental toxicants. In addition, these studies may provide significant insights into a novel mechanism that contributes to the pattern of cell death as seen in neurodegenerative disorders such as sporadic Parkinson's disease.
DESCRIPTION (provided by applicant): Polychlorinated biphenyls (PCBs) decrease basal ganglia dopamine (DA) function, including reductions in DA content and the number of tyrosine hydroxylase positive (TH+) neurons in the substantia nigra (SN) as well as inhibiting monoamine transporters. This data, however, has been gathered only in males and hence the effects of PCBs on DA function in the female are largely unknown. The need for this data becomes even more relevant because former capacitor workers exposed to extraordinarily high levels of PCBs show increased risk for mortality due to Parkinson's disease and a negative relationship between serum PCB concentrations and DA terminal densities only in women. Because of these epidemiological findings we hypothesize that ovarian hormones, including reductions induced by PCBs or following either menopause or ovariectomy (OVX), events known to reduce basal ganglia monoamine transporters and the number of TH+ neurons, will interact with, and exacerbate, similar PCB-induced changes in basal ganglia DA function, resulting in greater DA dysfunctions in hormonally-depleted females than in comparably-exposed males. These hypotheses will be tested in a series of experiments that will characterize the effects of PCB exposure in male and female rats and the consequences of PCB-induced changes in estrus cyclicity, OVX and ovarian hormone replacement on DA function, including inhibition of monoamine transporters, alterations in cytosolic and extra-neuronal DA and its metabolites, the number of TH+ SN neurons, and measures of oxidative stress and mitochondrial function. We will also measure serum and brain concentrations of PCBs to determine the role of gender in modifying PCB body burdens. The proposed experiments will provide information on the effects of PCB exposure on DA function in the female, a population that has been largely ignored in neurotoxicological studies and will determine the consequences and mechanisms by which ovarian hormones, including their withdrawal, influence PCB-induced changes in DA function, oxidative stress and mitochondrial function. These experiments will set the stage for further study of the role of gender and ovarian hormones modifying the toxicity of other environmental and occupational dopamine neurotoxicants.
DESCRIPTION (provided by applicant): Manganese (Mn) intoxication, a syndrome known as manganism, is most often associated with prolonged occupational exposure, although individuals with cirrhosis of the liver and related hepatic dysfunction display many of the behavioral and neurological symptoms associated with this disorder. The most prominent symptom from overexposure comprises an irreversible extrapyramidal dysfunction resembling that of Parkinson's disease. Manganism, however, is associated with the preferential degeneration of GABAminergic neurons within the globus pallidus and not the dopaminergic neurons in the substantia nigra. Although the neurotoxic mechanisms provoking increased susceptibility of pallidal neurons to the toxic actions of Mn is not fully understood, there is increasing evidence that the excitatory neurotransmitter, glutamate, as playing a role in the degenerative actions of Mn since neurons within the globus pallidus normally receive glutaminergic input from cells within the subthalamic nuclei. This is supported by studies demonstrating that blocking of the glutamate receptors with the NMDA receptor antagonist, MK-801, prevents lesions produced by intrastriatal injections of Mn. This raises the issue that the selective neurotoxic actions of Mn on pallidal neurons may not be caused by any one factor but are likely an amalgamation of several processes occurring simultaneously which include 1) accumulation of Mn in the globus pallidus, 2) similarity between the cytotoxic actions of glutamate and Mn involving mitochondrial dysfunction leading to oxidative stress, 3) Mn inhibition of astrocytic glutamate transport and metabolism leading to increase synaptic levels of glutamate and 4) increased uptake of Mn in pallidal neurons by activated glutamate channels. Thus, it is reasonable to hypothesize that treatment of Mn overdoses with a drug which inhibits both glutamate release and oxidative stress may prove useful in the initial stages of manganism. Interestingly, there is a drug on the market, riluzole, currently approved for treatment of amyotrophic lateral sclerosis (ALS), which mechanistically behaves in this fashion. Riluzole functions by inhibiting glutamate release as well as its actions as both an antioxidant and an antagonist of the ionotropic glutamate receptor. Thus, the combined pharmacological actions of riluzole as both an antioxidant and inhibitor of glutamate activity may make it an ideal drug for the treatment of manganism. As will be described in more detail in this proposal, our preliminary studies, in fact, support this hypothesis. Accordingly, the studies proposed in this grant are designed to 1) examine the mechanism by which glutamate facilitates Mn toxicity, 2) characterize the biochemical mechanisms responsible for the neuroprotective actions of riluzole and 3) demonstrate the neuroprotective actions of riluzole in Mn exposed mice. PUBLIC HEALTH RELEVANCE Overexposure to high atmospheric levels of manganese can lead to a syndrome characterized by an irreversible extrapyramidal dysfunction resembling that of Parkinson's disease. Although it is known that manganism is associated with the preferential degeneration of GABAminergic neurons, the mechanism for this selective toxicity is not fully understood. Thus, the studies proposed in this grant is relevant to human health in that it will investigate new mechanisms to explain the selective toxic actions of manganese in human brain and provide the necessary preliminary evidence to demonstrate the application of the drug, riluzole, for treatment of this debilitating and irreversible disorder.
DESCRIPTION (provided by applicant): Occupational and environmental exposures to manganese (Mn) have long been known to lead to neurological symptoms somewhat similar to those of Parkinson's disease (PD). Furthermore, Mn exposure is recognized as a risk factor for idiopathic PD. With the use of Mn as a gasoline additive, increased use in pesticides, and potential clinical use of a Mn superoxide dismutase mimetic, EUK-8, exposures of the general population to Mn will increase. It is vital that we determine the causes for its neurotoxic effects. In the cells of its target brain tissue, primarily neurons of the globus pallidus and striatum, Mn is sequestered by the mitochondria. The leading hypothesis for Mn-induced damage was through oxidation of important cell and mitochondrial components by the powerful oxidizing agent, Mn3+. However, using XANES spectroscopy, we have shown that Mn3+ does not accumulate in mitochondria or neuron-like cells (PC12 or NT2 cells) because of oxidation of Mn2+. Therefore, either Mn3+ is transported into target cells by a specialized transport system, such as transferrin, or the neuronal damage is caused by Mn2+. Intramito-chondrial Ca2+ is known to activate and control ATP production through binding to a set of intramitochon-drial binding sites involved with oxidative phosphorylation. Since Mn2+ generally binds more strongly to Ca2+ binding sites than Ca2+, we have identified Mn2+ interference with Ca2+ activation of ATP production as a potential cause of Mn- induced damage, particularly to active neurons like those of the basal ganglia. Since this Ca2+-activated ATP production can increase the rate of ATP production several fold, its loss could seriously impact upon the function and vitality of active neurons. Therefore, we have proposed to determine whether Mn3+ can be transported into neuron-like cells or astrocytes via transferrin, using the XANES techniques that we have developed during the past five years, and to determine whether Mn2+ interferes with Ca2+ activation and control of ATP production. We propose to study the effects of Mn2+ at each relevant site of intramitochondrial Ca2+ binding, and at the transporter believed to be responsible for the transport of activating Ca2+ into the mitochondria using specially developed optical techniques.
DESCRIPTION (provided by applicant): NKX3.1 is a prostate-specific homeobox gene that maps to a region of chromosome 8p21 that is lost in up to 85% of prostate cancer cases. Although NKX3.1 does not undergo somatic mutations in prostate cancer, expression of the protein is lost with tumor progression, suggesting a role for NKX3.1 in prostate cancer pathogenesis. In Nkx3.1 mice haploinsufficiency is dominant, resulting in prostatic epithelial hyperplasia and dysplasia that worsens with age. Moreover, Nkx3.1 haploinsufficiency cooperates with loss of other suppressor genes such as Pten to enhance prostate carcinogenesis. These data suggest that loss of NKX3.1 expression may be important in pathogenesis of a large fraction of human prostate cancers and that NKX3.1 is a candidate gatekeeper gene. We described an NKX3.1 polymorphism, C154T, that resulted in an arginine to cysteine alteration of codon 52 (NKX3.1 R52C). In the initial grant period we showed that a single NKX3.1 C154T allele, present in 11% of the population, conferred an increased risk for aggressive prostate cancer. We also showed that the R52C variant altered phosphorylation at the adjacent serine 48 (S48) and that S48 phosphorylation regulated DNA binding in vitro. But NKX3.1 influences gene expression not only by DNA binding, but also by complexing with transcription factors and regulating their activity as a coactivator. Preliminary data shows that the region of amino acids 44-64 is critical for autoregulation of NKX3.1 coactivation activity, presumably by mediating binding to the C-terminus. We now will determine biochemical properties of NKX3.1 critical for its action. In Aim 1 we will perform genetic analysis of NKX3.1 to identify critical elements that regulate protein activity. In Aim 2 we will perform affinity chromatography with NKX3.1 to isolate and identify proteins that bind to NKX3.1. In Aim 3 we will identify and characterize genes whose expression is regulated by NKX3.1. In Aim 4, we will analyze tumor specimens from patients with high-grade prostate cancer to determine whether in those with the C154T polymorphic allele it is preferentially retained after loss of chromosome 8p heterozygosity.
Crisp Terms/Key Words: microarray technology, protein protein interaction, binding site, protein binding, protein structure function, affinity chromatography, cancer risk, prostate neoplasm, neoplasm /cancer genetics, immunoprecipitation, western blotting, immunocytochemistry, human tissue, genetic polymorphism, transcription factor, genetic transcription, genetic regulation, homeobox gene, gene expression, site directed mutagenesis, polymerase chain reaction
DESCRIPTION (provided by applicant): The phthalate ester, diethylhexylphthalate (DEHP), is a constituent chemical of many plastics, conferring their flexibility. Plastics are used ubiquitously in the United States and most industrialized countries and DEHP, which is not chemically bound to the plastic matrix, leaches out over time: human exposure is therefore widespread. Exposure to DEHP is associated with disruption of male sexual development and decreased fertility. Studies by Earl Gray and colleagues have shown that DEHP is anti-androgenic, and that its mechanism of male reproductive toxicity is not through direct interference at the level of the androgen receptor. The P.I. and others have shown that androgen secretion by rat Leydig cells is compromised after in vivo exposures to DEHP. This leads to the hypothesis providing the overall theme to the present application, that the endocrine disrupting properties of DEHP result from adverse effects on Leydig cell development with consequent decreases in androgen secretion. Consistent with this hypothesis, recent data from the P.l.'s lab demonstrate the existence of a critical window of sensitivity for impairment of Leydig cell steroidogenesis in younger animals. In the experiments described for this renewal application, we will analyze the potential for DEHP exposures: I. to suppress expression levels of steroidogenic factor-I, a key nuclear transcription factor that regulates differentiation of Leydig cells and pituitary gonadotropes, and decrease the action of Mullerian inhibiting substance, an SF-1 regulated growth factor that limits Leydig cell division; II. to inhibit proliferation of progenitor Leydig cells; and III. to delay acquisition of steroidogenic enzyme gene expression and steroidogenic capacity. Chronic postnatal exposures to DEHP induced increased levels of gonadotropic secretion by the pituitary and elevated serum testosterone and estradiol levels, which were associated with Leydig cell hyperplasia, a precursor to tumorigenesis. Formation of Leydig cell tumors is commonly observed in DEHP-treated rats. We will describe the time course of DEHP induced Leydig cell hyperplasia and analyze the role of LH, testosterone, and estradiol in the development of tumorigenesis. These studies will be the first to define the involvement of Leydig cells in the endocrine disrupting effects of DEHP. Our data will facilitate identification of biomarkers of exposure to environmental pollutants, and provide information to regulatory agencies in setting limits for the use of DEHP and phthalates in consumer products
Crisp Terms/Key Words: environmental exposure, environmental toxicology, cytotoxicity, steroid biosynthesis, Leydig cell, sex development disorder, early experience, diethylhexylphthalate, chemical carcinogen, chemical carcinogenesis, chemical related neoplasm /cancer, transcription factor, consumer product, cell differentiation, secretion, laboratory rat, androgen inhibitor, animal puberty, newborn animal
DESCRIPTION (provided by applicant): Despite recent concern over the purported decline in sperm counts, there is little, if any, epidemiologic evidence regarding associations with environmental exposures or the timing of such exposures. Disruption of male reproductive function, and in particular decreased semen quality, is thought to be associated with exposure to endocrine active chemicals. To date, no direct evidence in humans either supports or refutes this conjecture. It is possible that exposure to such chemicals in utero and/or during early childhood may disrupt testicular development or development of related endocrine pathways, resulting in subtle disruption of male reproductive function. We propose to examine associations between prenatal exposures to one class of endocrine disruptors, the organochlorine compounds, and testicular and endocrine function in adult men including semen quality, fertility potential, current hormone concentrations and time to pregnancy. We also propose to examine whether such associations, if any, are mediated by disruptions of maternal thyroid function. From a follow up of the now adult members of the Columbia-Presbyterian cohort of the National Collaborative Perinatal Project and the Child Health and Development Study, we will obtain questionnaire data on fertility history, current lifestyle, socioeconomic status, and medical history, request a blood sample and request that the subject come to the clinic for two semen samples, approximately 3 weeks apart. Semen samples will be analyzed using a standard protocol at the University of California, Davis. Serum will be assayed for testosterone, estradiol, follicle stimulating hormone, luteinizing hormone and inhibin B. Stored, frozen prenatal sera will be assayed for organochlorine compounds, and for free thyroxine, thyroid stimulating hormone, and thyroid peroxidase antibodies. Statistical analysis will assess the associations between organochlorine compounds (total and in secondary analyses as specific congeners or groups of congeners) and each outcome variable. Other analyses will assess whether maternal thyroid function during pregnancy mitigates these associations. This study represents the first large systematic evaluation of prenatal exposures to organochlorine compounds and male reproduction and has important implications for basic science, public health and public policy.
Crisp Terms/Key Words: sperm analysis, clinical research, male, male reproductive system disorder, sex development disorder, lifestyle, early experience, embryo /fetus toxicology, longitudinal human study, chlorohydrocarbon insecticide, statistics /biometry, questionnaire, human subject, fertility, hormone inhibitor, hormone regulation /control mechanism, adult human (21+)
DESCRIPTION (provided by applicant): Prostate cancer (CaP) is the most common malignancy of men in America, with no curative treatment for metastatic disease. It is estimated that over 230,000 American men will be diagnosed with CaP in the year 2004 and 29,900 deaths will be attributed to the disease. In addition to the aging process, CaP is thought to result from the interplay of genetic, hormonal, dietary and environmental factors. Further, in utero exposure to elevated levels of hormones, fats and other environmental and biological "carcinogens" are thought to predispose or imprint the prostate to an elevated level of risk for the development of cancer later in life. Recently, the method of food preparation has come under scrutiny as a significant variable in the etiology of cancer. Heterocyclic amines produced during the grilling of meats have emerged as major food carcinogens and important etiologic factors in CaP. PhIP (2-amino-1-methyl-6-phenylimidazol[4,5-b]pyridine) is the predominant heterocyclic amine in cooked meat and fish, wine, beer and cigarette smoke. The ACI rat is an established rat model for spontaneous, naturally occurring, age-associated CaP. PhIP induces CaP in ACI rats at a higher incidence, and earlier in life, than control rats. In utero and perinatal exposure of rats to PhIP has been demonstrated to increase the lifelong risk of breast and colon cancer, but has not been investigated for CaP. We propose to feed pregnant and lactating ACI rats a diet containing PhIP and perform structural, histological and gene expression (microarray) analyses on prostates of male pups to detect effects of PhIP on the developing prostate. Structural studies will include 3-D reconstruction analyses will be performed on day 21 fetuses. We will also determine the lifelong risk of CaP due to fetal/perinatal exposure to PhIP as well as alterations in gene expression. The completion of these experiments will contribute to our understanding of the role of fetal/perinatal exposure to PhIP in the etiology of CaP enable us to identify target molecules for intervention and design rational strategies for the prevention of CaP.
Crisp Terms/Key Words: three dimensional imaging /topography, environmental exposure, microarray technology, disease /disorder onset, disease /disorder etiology, prostate, reproductive development, aminopyridine, embryo /fetus toxicology, nutrition related tag, nitrogenous heterocyclic compound, carcinogen testing, chemical carcinogenesis, cancer risk, prostate neoplasm, nutrition related neoplasm /cancer, chemical related neoplasm /cancer, disease /disorder model, immunocytochemistry, imidazole, gene expression, food processing /preparation, polymerase chain reaction, laboratory rat
DESCRIPTION (provided by applicant): The proposed study will determine whether early childhood exposures to phthalates are associated with the development of current asthma and proallergic immunoglobulin (Ig) E production at ages five to seven and whether current exposures to phthalates are associated with augmented airway inflammation and diminished lung function at ages five to seven. The research will confirm or refute recent epidemiologic findings of associations between phthalate exposures and childhood asthma, atopy and reduced lung function. This prior research is limited by incomplete exposure and outcome measures. However, results from a pilot undertaken for the proposed study also support the hypothesis that phthalate exposures are risk factors in the development of asthma. The proposed study will be conducted among a cohort of 400 children who reside in minority communities in New York City. These communities experience some of the highest childhood asthma rates in the world. Phthalate exposures are also widespread. The research will be performed within the ongoing longitudinal birth cohort study being conducted by the Columbia Center for Children's Environmental Health (CCCEH). The CCCEH is evaluating the contribution of prenatal and postnatal exposures in the development of asthma and other health outcomes. Children are followed from pregnancy through age seven years. The proposed research is cost effective in that many of the required exposure and outcome measurements are already being gathered within the CCCEH cohort. These include detailed history of respiratory and allergic symptoms, asthma treatment and emergency room visits; lung function testing at age six; allergen levels in house dust samples collected from pregnancy through age five; and measurement of allergic sensitization (total and specific IgE measured at ages two, three, and five years). The phthalates will be measured in stored urine samples collected from the mother during pregnancy and from children at ages three and five years and in newly collected indoor air and urine samples at ages five to seven. Also at age five to seven years, exhaled nitric oxide will be measured as an indicator of airway inflammation and total and allergen-specific IgE levels will be determined. The case ascertainment of current asthma at ages five to seven will be made by a designated board- certified pediatric pulmonologist at the Morgan Stanley Children's Hospital of New York Presbyterian Hospital. Hypotheses to be tested are: (1) that early childhood exposures to the phthalates, as measured by metabolite levels in urine samples collected during pregnancy and at ages three and five years, predict current asthma at ages five to seven and production of IgE antibodies at age seven; and (2) after correcting for early phthalate exposure, current exposure as measured by levels of the parent compounds in indoor air samples and metabolites in urine samples collected at ages five to seven years, will be associated inversely with lung function and positively with airway inflammation at ages five to seven years.
DESCRIPTION: (provided by applicant) Asbestos is an important environmental
hazard in the U.S. and remains the primary occupational concern in many
developing countries. Although asbestos is carcinogenic and induces both
bronchogenic carcinomas and pleura and peritoneal mesotheliomas in humans, the
underlying mechanisms of fiber carcinogenesis are not known. With the funding
support of this grant, the applicant has shown, and for the first time, that
asbestos is a potent gene and chromosomal mutagen in mammalian cells and
induces mostly large multilocus deletions. These findings provide the first
direct link between chromosomal abnormalities that have frequently been
demonstrated in vitro and carcinogenicity in vivo. Furthermore, phagocytosis of
asbestos by target cells and the resultant oxyradical production are important
mechanistic factors in fiber mutagenesis. To extend these findings and to
examine how asbestos induces mutations, particularly the origin and types of
free radicals involved, the applicant proposed a series of nine specific aims
to address four testable hypotheses using the human-hamster hybrid (AL) cell
model. The first objective is to determine if nucleus is the direct and
immediate target in fiber mutagenesis by the use of enucleated cells followed
by rescue fusion with karyoplasts to ascertain the incidence and type of CD59
mutations induced. To show that mitochondrial damage plays an essential role in
mediating fiber mutagenesis, we will use mitochondrial deficient cells followed
by rescue fusion with cytoplasts to determine both the quantitative induction
of oxyradicals as well as mutagenesis. The third and fourth objectives are to
determine the role of lipid peroxidation and peroxynitnte anions in fiber
mutagenesis. The AL cell line contains only one copy of human chromosome 11 and
mutations at the CD59 locus coded by the M1C1 gene located on 1 lpl3 can be
readily scored using an antibody complement lysis assay. By using specific DNA
probes of other genes that have been regionally mapped to various sites on
chromosome 11, the molecular spectrum of mutations induced by either asbestos
or glass fiber control will be compared.
DESCRIPTION (provided by applicant): In urban settings, allergic asthma is often associated with a Th2 polarized T cell response to "harmless" allergens. However, despite sensitization and exposure to allergens, only a subset of individuals expresses respiratory manifestations of allergy and respiratory manifestations are variable within an individual. These clinical characteristics of asthma suggest the importance of localized immune responses that control respiratory expression of allergy and suggest that respiratory expression of allergy may be associated with a perturbation in a local suppressive milieu. In the urban environment, inhaled particulate matter (PM) including diesel exhaust particles (DEP) may serve to disrupt immune responses. Bronchial epithelial cells (BECs), the first targets for ambient PM, release a myriad of cytokines in response to exposure. In the airway, dendritic cells (DC) are adjacent to BECs and transit rapidly to regional lymph nodes. As such, the microenvironment provided by BECs has the potential to influence DC. Immune responses are regulated by DCs that have the ability to evoke localized T cell responses including mucosal tolerance or polarized T cell responses. The close association between BECs and DC suggests that the microenvironment provided by BECs has the potential to influence DC subset trafficking, maturation and polarization, and thus subsequent T cell responses. This proposal will focus on the epithelial cell-DC interface and will address the overall hypothesis that DEP stimulation of bronchial epithelial cells results in the loss of normal DC-derived T cell tolerance and promotes DC mediated Th2 responses to common allergens. We will address the hypothesis with three specific aims 1) To test the hypothesis that DEP treatment of human BECs induces selective recruitment of myeloid DC as opposed to plasmacytoid DC using monocyte-derived DC, blood-derived DC and lung-derived DC; 2) To test the hypothesis that DEP treatment of HBECs induces effector DC maturation and polarization with a loss of tolerizing DC with a focus on regulation of epithelial cell-derived GM-CSF, TSLP, IL-10, and TGF-beta using FACs analysis, quantitative RT-PCR, and siRNA and 3) To test the hypothesis that inhalation of DEP disrupts mucosal tolerance to harmless allergens using in vivo murine models of ovalbumin and cockroach tolerance and sensitization. These studies will provide biologic plausibility to explain the increase in allergic asthma associated with pollution exposures.
DESCRIPTION (provided by applicant): The prevalence of asthma varies among communities in the United States. Within New York City (NYC), the reported prevalence of pediatric asthma and hospitalization rates for asthma vary markedly between adjacent neighborhoods. We hypothesize that the difference in the prevalence of asthma observed between neighborhoods in NYC is due to differences in exposure to asthma/allergy environmental triggers (indoor cockroach and mouse allergens, and local sources of diesel particulates), physical activity levels and high body mass index for age. To test this hypothesis, we propose to recruit 800 children age 7 years who reside in NYC and have been enrolled in the HIP health plan through a parent or guardian's employment since birth. The children will be recruited from two types of neighborhoods of approximately equal HIP population size, 1) high asthma prevalence (~16%) neighborhoods [HAPN] 2) lower asthma prevalence (~9%) neighborhoods [LAPN]. Children will be classified as asthmatic or non-asthmatic by telephone administration of the ISAAC survey plus report of asthma controller medication. Employing stratified quota sampling we will recruit an equal number of asthmatics (n=400) and randomly selected non-asthmatics (n=400) enrolled from the combined population of HAPN and LAPN children. The HIP sampling frame will yield a multi-ethnic sample of children from low- middle and middle income homes, all of whom have similar access to health care. We will include measures on SES, ethnicity and built environment in multivariate analyses to control for these potential confounders. This study will use the same measures that are being employed in three other asthma studies being conducted on children the same age who live neighborhoods of high asthma prevalence in NYC. Aim 1. We hypothesize that, compared to children living in LAPN; children living in HAPN will be 1a.) More exposed to cockroach and mouse allergens in the dust and to diesel particulate matter in the air, 1b.) More likely to be sensitized to cockroach and mouse allergens, and 1c.) More sedentary and have a higher body mass index for age. Aim 2. We hypothesize that among children with asthma in LAPN, children with asthma in HAPN will have 2a.) More severe asthma (as classified by symptoms and spirometry), 2b.) higher levels of exhaled nitric oxide, a measure of airway inflammation. Aim 3. We hypothesize that among children sensitized to at least one allergen (i.e., atopic), those who live in a HAPN will be more likely to have asthma than those who live in an LAPN.
DESCRIPTION (provided by applicant): Living in areas with high volumes of motorized traffic has been associated with respiratory symptoms and deceased lung function in children. Based on both these epidemiological findings and supporting experimental data, exposure to diesel-related air pollution has potential for health concerns that include asthma and allergy. However, despite substantial gains in our recognition of likely diesel-induced asthmatic or allergic symptoms, direct associations between exposure to diesel-related air pollution and the onset of atopy and asthma in young children have not yet been demonstrated. The interaction of diesel exposure with other urban exposures on respiratory health also is not clear. We hypothesize that exposure to diesel emissions in Northern Manhattan and the South Bronx is associated with allergen-specific sensitization, decreased lung function, and the onset of asthma in children at age 5 through 6 years. Our strategy is to take advantage of an established inner city birth cohort in which multiple environmental exposures and health outcomes already are being measured to evaluate whether exposure to diesel-related air pollution independently, or jointly with other prevalent urban environmental exposures (allergens, environmental tobacco smoke [ETS]), increase the risk for the onset of atopy or asthma. Specifically, we propose to use our established cohort to:
Aim 1. Determine whether exposure to diesel-related air pollution is associated with the onset of allergen-specific sensitization, decreased lung function and/or asthma at age 5 through 6 years, and
Aim 2. Determine whether exposure to diesel-related air pollution interacts with a) allergen, and/or b) ETS exposure, on the onset of allergen-specific sensitization, decreased lung function and/or asthma at age 5-6 years.
300 Dominican and African American children residing in Northern Manhattan that are being followed prospectively since birth as part of Columbia Center for Children's Environmental Health will be recruited at age 5 through 6 years. Two-week air monitoring at home for PAHs, black carbon, mass, and trace metals will be performed. Repeat measures of PM25 and carbon will be repeated 6 months later. Outcomes include sera IgE, antigen-specific T cell proliferation, allergy skin tests, lung function, and asthma diagnosis. The primary goals are to determine whether diesel-related exposure can induce the development of allergy and/or asthma, and to identify its contribution relative to other urban exposures.
DESCRIPTION (adapted from application):
Assessing spatial and temporal variations in individual exposures to airborne particulate matter components that are representative of key local sources like diesel traffic is critical for advancing our understanding of the health effects of urban air pollution. Current methods of exposure assessment are too cumbersome, noisy and labor-intensive, and do not provide near-real time measurements of key analytes. the investigators propose to develop and test a miniature (palm size), quiet, rechargeable personal sampler that will (1) log in near real-time, time and space-resolved concentrations of black carbon (BC), (2) collect and archive time- and space-resolved PM samples for later laboratory analysis, (3) have one additional channel for use in chemo-optical analysis of a relevant gas or vapor, such as ozone, and (4) log location and activity data. The design goals for size, power, cost and quietness will permit wide use on most individuals, including young children, without disruption of normal activities. BC will be measured via an internal subminiature optical adsorption analysis of deposited particles. Spatial information will be provided by a miniature global position sensor (GPS) for outdoor locations and small home-/work-/car- placed radio beacons for key indoor locations. The unit will archive multiple time- and space-resolved particulate samples, for laboratory analysis via mass spectrometric and single particle techniques, to identify temporal-spatial patterns of exposure to particle sources and to a wide range of trace metals. The programmable miniature "smart" personal monitoring system will have the flexibility to be used in a wide range of sampling designs to assess spatial and temporal patterns of exposure. Development milestones will include designing, building and testing three progressively more advanced versions of the sampler. Version 1 will integrate a GPS sensor, but will lack real-time BC capabilities. Version 2 will incorporate a sampling wheel and optics to allow near real-time measurements of BC and will include development of a base unit that will operate as a battery re-charger and wireless data teleport, permitting continuous monitoring for up to a month without maintenance. To assess subject compliance, a button-size compliance/location sensor will also be built and tested at this stage. In Version 3 we will test the concept of incorporating ozone detection in near real-time on the third channel. Solar powered and/or large-battery-powered base units will also be designed for use in settings where access to the power grid is limited, such as in developing countries or for use at fixed-site outdoor locations lacking power. Laboratory and field experiments will be carried out iteratively during development to generate sensor algorithms, find improvements as well as estimate precision and accuracy via comparison to traditional real-time and integrative sampling methods of PM. The final smart air pollution monitor will incorporate upgrades suggested by the latest field-testing.
DESCRIPTION (provided by applicant):
The proposed effort combines air sampling devices and highly-integrated protein microarrays to permit estimation of multiple protein allergen exposures in a time efficient manner. Portable air sampling devices that fit inside the nostrils and have been used in Australian and European asthma studies will be used for collection of samples in an ongoing study of inner-city New York homes of children (n=200) with increased risk for developing allergy and asthma. Highly multiplexed protein microarrays, allowing parallel assessment of many allergens, integrated onto active complementary metal-oxide-semiconductor (CMOS) substrates will be employed. The use of CMOS allows highly integrated and sensitive devices to be developed because of the immediate proximity of the detector to the sensing electronics. As the commodity technology for microelectronics, such active substrates can be produced at very low cost. An established fluorescence based sensor substrate will be employed for initial studies, augmented by simple microfluidic delivery. Biosensor technology development will include efforts toward real-time measurement capabilities including more complex microfluidic delivery (including pressure activated valves), real-time fluorescence sensing through lifetime-sensitive FRET, and CMOS-integrated mass-based biosensors. The same principles for assessment of allergens in air can be applied to assessment of bacterial and fungal pathogens and their constitutive toxins. These studies have far-reaching implications for acute and chronic measures of public health.
DESCRIPTION (provided by applicant): Mutation to DNA is a primary mechanism by which cancers arise. These events have also been implicated in diseases such as atherosclerosis, and processes such as aging. Therefore, there is an important need for sensitive analytical methods which facilitate the study of mutagenesis, as well as the identification of chemical or physical agents that can mutate DNA. Methods for measuring in vivo mutation currently exist, each with their own advantages and limitations. While some are based on colony formation and require tissue culture work, others rely on expensive, proprietary trangenic rodents. The in vivo mutation assay that is proposed herein is based on the Pig-a locus. The Pig-a gene product is essential for the biosynthesis of glycosyl-phosphatidylinositol (GPI) anchors. Mutations giving rise to nonfunctional GPI anchors prevent certain proteins from being expressed on the cell surface, and this represents a phenotype which can be measured by flow cytometry. Importantly, harvested cells are not cultured before analysis, thus the need for costly- and labor-intensive tissue culture work is eliminated. Furthermore, since Pig-a is an endogenous gene located on the X-chromosome, it is likely that this mutation scoring system will be applicable to any mammalian species of toxicologic interest, including humans. As was the case for Phase I, the proposed Phase II experiments will focus on two readily obtained cell populations for the determination of GPI-anchor deficiency: peripheral blood erythrocytes (total) and an immature fraction of erythrocytes (reticulocytes). Whereas Phase I feasibility studies were conducted strictly with mice, these experiments will consider exposures of both mice and rats to each of six prototypical mutagens. The treatment schedule and the blood harvest times will be varied in order to determine the most appropriate experimental designs. Other experiments will involve isolation and DNA sequencing of GPI-anchor deficient erythroid progenitors from mutagen-treated mice. The presumptive Pig-a mutant colonies will be sequenced to provide mutation spectra data that helps validate the system as an effective mutagenesis assay. Upon successful completion of these proposed experiments, society will benefit as pharmaceutical and chemical companies eliminate genotoxicants from their new product development processes more efficiently. Furthermore, if the system proves compatible with human blood specimens, myriad other research activities will benefit as data generated in laboratory animal models are easily extended to include real-world human exposure scenarios, including: 1) clinical trials, 2) post-market survallience of drugs, 3) environmental exposures, and 4) occupational exposures. PUBLIC HEALTH RELEVANCE: It is well known that DNA damage is a precursor to the development of cancer and other significant diseases. It is, therefore, in the interest of public health to reduce the occurrence of mutagenic chemicals in the environment, in our drugs, and from our workplaces. This research project will refine and validate a powerful new method for detecting mutagenic agents, thereby enhancing the nation's ability to effectively reduce exposure to these toxic compounds.
DESCRIPTION (provided by applicant): Solidus Biosciences, Inc. is developing a proprietary Metabolizing Enzyme Toxicology Assay Chip (MetaChip), along with a xenobiotic metabolism and toxicity screening device that uses these chips (the MetaReader), for high- throughput analysis of drug metabolism and toxicity. The MetaChip integrates the high-throughput metabolite- generating capability of P450 catalysis with human cell-based screening on a single microscale platform. As a result, P450-generated drug-candidate metabolites can be generated and screened against human cell lines even if the metabolites are unstable. The MetaChip platform along with the MetaReader provides Solidus Biosciences with an enabling technology that will have myriad applications in both early stage and preclinical toxicology testing. Solidus is therefore developing the first technology and associated products that can rapidly replicate human metabolism and perform in vitro toxicity testing in a single, automated, high-throughput manner. Consequently, Solidus' products have significant commercial potential and the promise to greatly benefit human health. The proposed Phase II program will focus on the full optimization of the MetaChip and on the design, preparation, and operation of the MetaReader, both of which can be readily combined with other in vitro toxicology and metabolite profiling approaches that deal with ADME (adsorption, distribution, metabolism, and excretion) of xenobiotics. The specific aims and milestones for the Phase II STTR are to: 1. Optimize P450 loading, activity, and stability within sol-gel matrices and generate sol-gels with physicochemical properties that accurately and reproducibly mimic the human liver; 2. Perform rapid P450 inhibition assays on the MetaChip using well-known inhibitors of the different human P450 isoforms; 3. Complete development of the collagen gel and other 3D cell culture techniques for growth inhibition assays on the MetaChip; 4. Expand the repertoire of metabolic enzymes to include phase II drug metabolism enzymes. This also includes addition of glutathione for conjugation to metabolites generated in the MetaChip; 5. Co-develop (with an industrial collaborator) the MetaReader to streamline the application of sample, the enzymatic reaction and assay steps, and image analysis in a simple operating scheme; 6. Use the fully operational MetaChip platform to correlate in vitro toxicity results to in vivo toxicity results. This aim involves components of the ICCVAM validation process. The end result of the Phase II study will be a fully operational and integrated device, the MetaReader, that will become an important tool in early-stage testing of drug and drug-candidate toxicity, and in the development of in vitro models that mimic human metabolism.
Crisp Terms/Key Words: high throughput technology, microarray technology, genetic screening, combinatorial chemistry, cell line, technology /technique development, cytotoxicity, cytochrome P450, growth inhibitor, enzyme inhibitor, drug screening /evaluation, drug metabolism, biotechnology
DESCRIPTION (provided by applicant)
Airborne particulate matter (PM) derived from a variety of natural sources (volcanic activity, forest fires) is omnipresent. However, human activity since the industrial revolution and the advent of the internal combustion engine has substantially increased the concentration of PM, particularly in urban areas. Human derived PM tends to be of smaller size, facilitating entry into the body through the respiratory and digestive tracts, as well as through the skin. It also tends to have adsorbed chemical species with greater toxicity than its natural counterparts. The explosive growth of nanotechnology in research and consumer products (sunscreens, cosmetics, paint) is also creating an array of ultrafine materials with largely unknown health effects. Despite numerous studies implicating PM in various disorders including acute respiratory infections, lung cancer, and chronic respiratory and cardiovascular diseases, the specific biological mechanisms involved are not fully understood. Pathologics seeks to leverage its proprietary Arrayed Imaging Reflectometery (AIR) biosensing platform to build a device capable of capturing the detailed physiological response to PM exposure by profiling key marker proteins in conveniently available biosamples such as a finger pick of blood, urine, mucous, saliva, etc. Currently, such testing takes hours and is often done with individual tests. AIR is capable of sensitive and simultaneous protein detection with a device that is currently the size of a laptop computer. The low complexity of the testing platform will also enable the development of handheld units that would be particularly useful for profiling exposure response in the field. In addition to saving time and offering greater convenience these multiplex sensors will allow far more molecular data to be collected than is currently feasible.
Crisp Terms/Key Words: environmental exposure, protein protein interaction, portable biomedical equipment, technology /technique development, immunologic assay /test, reflection spectrometry, monitoring device, biomarker, air pollution
DESCRIPTION (provided by applicant): The mission of the National Institutes of Health (NIH) is "science in pursuit of fundamental knowledge about the nature and behavior of living systems and the application of that knowledge to extend healthy life and reduce the burdens of illness and disability." Pursuant to that mission, the National Institute of Environmental Health Sciences (NIEHS) released the RFP topic stating their objective and mission that "human health and human disease result from three interactive elements: environmental exposure, genetic susceptibility, and age. The mission of NIEHS is to reduce the burden of human disease and dysfunction from environmental causes by understanding each of these components and how they interrelate." The proposed project from X-ray Optical Systems (XOS) will make a significant contribution for both the NIH and NIEHS Missions, as well as meet the needs of the NIEHS research objective. This project involves development and application of a low-power, compact, reliable, easy-to-operate instrument for measurement of trace elements in any liquid, gel, or solid that can be homogenized for individual environmental exposure assessment. The analyzer can be used in the home, place of employment, and recreational settings for patients undergoing study and treatment for major diseases or for individual and occupational health risk assessment. Abnormal levels of bio-essential metals (iron, copper, and zinc) as well as toxic trace elements (mercury, lead, cadmium, and arsenic) are known to be associated with many health disorders such as cancer, cognitive impairment, and neurological symptoms. The presence of metals is well-known in most neurodegenerative pathologies, such as excess serum copper or brain iron accumulation, which are associated with Wilson's, Alzheimer's, and Parkinson's disease. In spite of their recognized importance, personal exposure to these metals is not routinely measured or monitored in body fluids and tissues or in materials in personal environments. This is due in large part to the difficulty and expense of trace metal measurements in the field or clinic. The proposed analyzer is based on new, powerful, proprietary, monochromatic doubly curved crystal (DCC) and polychromatic polycapillary x-ray optics technology that greatly increases the efficiency and sensitivity for elemental analysis. This new analyzer has the potential to offer an inexpensive, portable, robust, safe, easy-to-operate elemental analyzer for measurements taken on-site, with little or no sample preparation. Furthermore, this will reduce costs for large scale studies such as the Genes, Environment and Health Initiative (GEI), and the National Children's Study (NCS). The proposed analyzer will facilitate much needed links between genetics & exposure research leading to improvements in quality of life while reducing healthcare costs related to a variety of chronic conditions.
Public Health Relevance: The proposed new, trace-element, portable, personal environmental exposure analyzer will enable researchers to examine individual exposure to toxic and bioessential trace elements in the home or place of employment without having to collect, store, track, ship, dispose, or transfer samples through central laboratories. The fluids and materials analyzer can be used to detect and quantify, in minutes, trace elements in any liquid, gel or solid that can be homogenized by using an inexpensive, compact, safe, reliable, simple-to-use instrument for on-site measurements. This instrument will have a broad, positive impact on public health by accelerating research capabilities, enabling new studies to more rapidly gather information, (i.e. to link the genetic and environmental correlations), reducing study costs by testing onsite without delays, improving research data available for studies of specific patient populations (such as Alzheimer's or Asthma), and facilitating individual exposure measurements for family or occupational health assessment.
DESCRIPTION (provided by applicant): This Phase II SBIR proposal describes the development of a prototype device for monitoring the presence of a number of hazardous chemicals in the air. This device is fundamentally different than typical spectroscopic instruments in that it uses enzyme-based plastics as sensing elements. Phase I showed that enzymatic plastics can be employed to continuously monitor the environment when properly adapted to a simple device. Agentase will adapt its proven enzyme-based chemistries for nerve, blood, and blister agent detection into forms that are compatible with continuous monitoring in the proposed Phase II effort. After optimizing individual sensors for sensitivity to agents and response time, a battery of experiments will be conducted to ensure that sensors have sufficient shelf life, operational lifetimes, and resistance to environmental interference. Custom built hardware will also be constructed to house the sensors and ensure their proper implementation. The work plan concludes with a series of operational assessments that serve as a true test of product feasibility prior to use in studies with warfare grade chemical agents. Successful completion of the effort will provide an inexpensive tool for monitoring air quality for the presence of hazardous chemicals. Once hardened and validated, such a device can be used to warn against an event of chemical terrorism. Early detection of released chemicals is the key to minimizing the impact of a chemical event on site and ensuring the best possible medical and emergency responses.
DESCRIPTION (provided by applicant)
The purpose of this proposal is to facilitate the transition of Dr. Michael Laiosa from a mentored postdoctoral research position to an independent academic research scientist. In pursuit of the goal of establishing independence, Dr. Laiosa has proposed to translate findings from human epidemiological studies to a murine model of dioxin-induced T-cell leukemia. This murine model will be used to determine the underlying mechanism(s) of the environmental basis for T-cell acute lymphoblastic leukemia (T-ALL) formation and progression. The relevance to public health is that this model will be employed for a pre-clinical evaluation of the dietary and chemopreventative agent resveratrol, which has the potential to prevent the initiation and/or recurrence of T-cell leukemia in individuals with elevated cancer risk. Moreover, approximately 208,000 people in the United States are currently living with leukemia and approximately 22,000 people a year will die from the disease. Dozens of genetic risk factors for leukemic diseases have been identified, and a number of environmental agents have been shown to increase cancer risk, including 2,3,7,8 -tetrachlordibenzo-pdioxin (TCDD) and dioxin-like compounds, which humans are exposed to at low levels on a daily basis. Understanding, how environmental factors affect the development and progression of leukemia not only represents a significant gap in our knowledge but will also provide Dr. Laiosa with additional training in a new field for him (leukemia) using his extensive experience in the field of thymocyte development and developmental immunotoxicology as a framework. Specifically, this proposal will attempt to define how TCDD interacts with mutations in the Notch protein potentially leading to T-ALL. Mutations in Notch have been identified in more than 70% of patients with T-ALL. This proposal will determine how TCDD activation of the Aryl hydrocarbon receptor (AHR) potentially modulates Notch activity by testing the following three specific aims: 1) test the hypothesis that during thymocyte development, ligand activation of the AHR synergizes with the Notch protein, modulating gene expression, cell cycle regulation, and apoptotic regulation; 2) test the hypothesis that AHR expression and/or activation by environmental agents interacts with activated Notch" 1 promoting T-leukemeogenesis; 3) test the hypothesis that the chemo-preventative agent resveratrol antagonizes AHR dependent toxicity and inhibits T-ALL leukemeogenesis.
DESCRIPTION (provided by applicant)
The Mentored Research Scientist Development Award In Molecular Epidemiology is requested to support the career development of Dr. Susan Teitelbaum, who is a classically trained cancer epidemiologist. The primary aim of the K01 grant is to position Dr. Teitelbaum as an independent research scientist specializing in the environmental and molecular epidemiology of combined effects of multiple exposures. The research aims, relating multiple xenoestrogen exposure to breast cancer risk, will be examined in the Long Island Breast Cancer Study Project, a large population-based case-control study of breast cancer and the environment. Traditional chronic disease epidemiology focuses on single risk factor-disease associations at the individual level with little consideration of the combined effect of multiple exposures, particularly those of similar biological action. Dr. Teitelbaum's career goal is to advance beyond the investigation of single exposure-disease relationships by incorporating advanced data analytic approaches not yet commonly used in epidemiology. Her training program will enable her to acquire in-depth knowledge of advanced statistical methods for examining the combined effect of multiple exposures and gene-environment interactions, a better understanding of the laboratory methods used to assess biomarkers of xenoestrogen exposure, and experience in working with genetic polymorphisms. The training program includes obtaining a Master's degree in biostatistics, laboratory rotations, and attendance at carefully chosen symposia and national meetings. Dr. Teitelbaum's proposal is sponsored by Dr. Mary Wolff (environmental/molecular epidemiology), Dr. Gertrud Berkowitz (epidemiology), and Dr. Sylvan Wallenstein (biostatistics). Additional advisors will be Drs. James Wetmur (environmental genetics) and Avrom Caplan (nuclear receptors). Breast cancer is an estrogen-related disease and xenoestrogens are strongly suspected to be environmental risk factors for breast cancer. With the exception of organochlorine compounds (including DDT, DDE and PCBs), little research has been directed at these environmental chemicals and even less has been focused on the combined effect of these hormonally active agents. Results of the proposed research project will be of enormous public health relevance since they may advance our knowledge of modifiable breast cancer risk factors, thereby providing information that is essential for primary prevention. Furthermore, data analysis approaches applied in this research project will be applicable to a wide range of environmentally associated diseases.
DESCRIPTION (provided by applicant)
Control of intracellular calcium (Ca2+) and reactive oxygen species (ROS) homeostasis is essential for cell survival and function. Elevation of intracellular free Ca2+ and ROS levels play a central role in lymphocyte activation in response to antigenic stimulation. ROS and Ca2+ exert a reciprocal regulation on each other: exogenous application of ROS leads to intracellular Ca2+ mobilization while increased cytoplasmic Ca2+ concentration induces ROS production by lymphocytes. In polycyclic aromatic hydrocarbons (PAH)-induced lymphocyte immune suppression, enhanced ROS production is associated with increased basal levels of intracellular Ca2+. Furthermore, these high basal levels of intracellular Ca2+ do not increase further in response to stimulation of the antigen receptor. Thus, the candidate hypothesizes that the crosstalk between Ca2+ and ROS is vital for lymphocyte activation and that the disruption of this crosstalk contributes to abnormal antigen receptor signaling pathways observed in immune suppression by PAH. Therefore, the candidate plans to investigate the crosstalk between Ca2+ and ROS signaling during normal B-cell receptor stimulation as well as the disruption of this crosstalk during immune suppression by PAH. Specifically, three specific aims will be pursued: (1) to define, using electrophysiology and Ca2+ imaging, the pharmacological and biophysical properties of the Ca2+ channels in B-cells that are activated by exogenous application of ROS, and determine whether members of the transient receptor potential channel proteins (TRPC) family of cation channels are involved. Based on preliminary experiments, TRPC3 and TRPC5 form ROS-sensitive cation channels when expressed in HEK293 cells; (2) to determine the role of intracellular Ca2+ rise in ROS production in B lymphocytes and which membrane-bound NADPH oxidase is necessary for mitogen-induced ROS production in B-cells; (3) to test if the chronic increase of intracellular Ca2+ induced by PAH is maintained by a ROS-dependent mechanism and/or by membrane depolarization. Preliminary data shows that both PAH and ROS induce Ca2+ entry in B-cells. A strong relationship between ROS and Ca2+ signaling defects in PAH-induced immune failure is expected. This effort will contribute to both a better understanding of normal and pathological lymphocyte immunity as well as to the discovery of new therapies for diseases such as immunodeficiency and cancer.
DESCRIPTION (provided by applicant)
The purpose of this proposal is to provide Dr. B. Paige Lawrence with release time from teaching, service and administrative duties, enabling her to devote at least 75% of her professional efforts to her research and career development. Dr. Lawrence is an Assistant Professor in the Department of Pharmaceutical Sciences, College of Pharmacy, Washington State University. She has obtained funding from NIEHS and the March of Dimes Birth Defects Foundation for her research program, studying the immunotoxicity of the pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).
Dr. Lawrence's career development plan includes: 1) devoting additional time to defining the molecular mechanisms that underlie the immunotoxicity of TCDD, 2) expanding the breadth of her program in terms of immunological endpoints, experimental system and methodology, and toxicant studied; and 3) obtaining further training in immunology so that cutting-edge technology and information can be applied to her immunotoxicology research program. To accomplish these goals, she has proposed a project that will direct her research program into an area that is new to her (immunology memory). She will receive training and mentoring from Dr. David L. Woodland, a senior immunologist with expertise in immune memory to respiratory viral infections. This award will allow her to travel to Dr. Woodland's laboratory at the Trudeau Institute in Saranac Lake, NY, where she will receive hands-on training at a state-of-the-art immunology research facility. Given that there is essentially no information on the long-term effect of exposure to AhR ligands on the establishment, maintenance, and recall of T cell memory, the proposed studies will not only expand Dr. Lawrence's training, but will fill a very large gap in knowledge about the immunotoxicity of TCDD and related AhR ligands. Dr. Lawrence's long-term career objectives include an academic career with research focused on understanding how exposure to Ah receptor ligands impacts human health. She hopes to contribute to knowledge that will ultimately diminish the burden of environmentally-related diseases. In summary, Dr. Lawrence plans continuous devotion to research in immunotoxicology throughout her career. This award will help to establish her career by providing her with the training and resources to expand the breadth and depth of her immunotoxicology research program.
DESCRIPTION (provided by applicant)
The primary goal of the research training program is to continue to immerse highly competent and motivated minority predoctoral students in a rich research setting pertaining to environmental and occupational health sciences for the purpose of attracting them into pursuing research careers in these and related disciplines. To achieve this goal, a number of specific objectives permeate the structure and function of the Short-Term Research Training Program. These objectives include: 1) Identifying and enlisting bright minority college students with academic potential, into a short-term research experience in the environmental and occupational health sciences; 2) Creating a set of meaningful research experiences in which the students engage in critical thinking and assume responsibility in environmental health research projects in order to expose them to possible future careers in environmental health research; 3) Providing a broad learning experience for participating students to enable them to draw links between the environment in which they live and the health outcomes in their communities and be able to relate these issues to the disciplines of occupational health, toxicology, epidemiology and public policy; 4) Exposing students to the issues of Environmental Justice and Health Disparities and encourage their involvement; 5) Encouraging contact between the students and their mentors, who serve as career role models; and 6) Tracking students in the years following their participation in the training program to assess their career choices as a measure of the success of the program. These objectives are consistent with Mount Sinai's existing efforts to increase the number of underrepresented minority individuals in health sciences careers. These efforts are essential to identify and recruit potential applicants to the areas of environmental health science. Programs that socialize the target population towards these areas at a time when they are making career choices are critical in training the students in the language, skills and knowledge of the scientific enterprise and can eventually draw them to these research careers.
DESCRIPTION (provided by applicant)
Since 1943, the University of Rochester has distinguished itself as an internationally recognized center for research and training in toxicology. This recognition has been achieved in part by the successes of this training grant, which is now in its 30th year of funding. The present renewal application requests funding for 12 pre-doctoral and 6 postdoctoral trainees to continue a program that is highly interdisciplinary, has a focus on clinical and translational approaches, and a strong emphasis on the basic principles that define the field of toxicology. The overall objective of this broad-based toxicology training program is to provide contemporary pre- and postdoctoral training in the environmental health sciences, such that our graduates can assume significant leadership positions in academia, government, industry and other occupations related to environmental health and public policy. This program is housed within the Department of Environmental Medicine, but its focus is multidisciplinary and interdisciplinary. The 37 training faculty come from a total of 13 different departments within the School of Medicine and Dentistry. As such, this training program takes advantage of the great diversity of specialties and resources available at a major academic medical center by reaching beyond the immediate confines of a single basic science group to draw in exceptional faculty from other basic science and clinical departments. Faculty research programs span the entire spectrum of toxicology, from molecular mechanisms to cellular processes to whole animals and human populations. There are seven major training areas: Neurotoxicology, Pulmonary Toxicology, Osteotoxicology, Molecular Modifiers of Toxicity, Carcinogenesis, Immunotoxicology, and Reproductive and Developmental Toxicology. This Training Program is distinguished by a long history of outstanding, cutting-edge research and training in toxicology, the many accomplishments of its former and current students, fellows, and faculty, the remarkable collegiality and extensive research collaborations among its faculty members and trainees, an extensive base of research support, and by a strong institutional commitment to research and training in the environmental health sciences. The program is further enhanced by the presence of an NIEHS Environmental Health Sciences Center, an EPA Center, and a Division of Occupational Medicine within the Department of Environmental Medicine, and an integrated Biomedical Sciences Graduate structure at the School of Medicine and Dentistry. The Medical Center is also the recipient of a Clinical and Translational Sciences Award from the NIH. There are presently 31 Toxicology Ph.D. students in residence, with six new Toxicology Ph.D. trainees starting in July-August, 2007, and 20 postdoctoral fellows currently in training. Our overall goal is to educate the next generation of talented environmental health investigators who are able to generate novel research findings, and then convert these findings into information, resources, or tools that can be used by public health and medical professionals, as well as the public, to improve overall health. This is a large training program with a long history that goes back to 1943. It has funding support through several federally funded grants. Program leadership has been stable, with Dr. Ned Ballatori taking over the role of Training Program Director in 1999. He continues to function in that capacity.
DESCRIPTION (provided by applicant): Small molecule toxins have been found to be epidemiologically linked to a number of protein misfolding diseases. Using arsenite (As(lll)) as a model system, the potential role of environmental toxins on altering the global protein fold in vivo will be analyzed. The mechanism of As(lll)-induced protein misfolding will be evaluated by comparing the proteins found to be misfolded in As(lll)-treated cells and proteins that are found to bind As(lll) in situ. As(lll)-induced misfolding will be further characterized by comparisons between the misfolded proteins in As(lll) treated cells and misfolded proteins in cells treated with other stress- inducing agents, allowing the mechanism of As(lll)-induced misfolding to be elucidated. Using the methods outlined in this proposal, the role of the Integrated Stress Response and AIRAP in protecting cells against As(lll) toxicity will be also be examined. This work will not only identify potential therapeutic targets for the numerous human populations predisposed to human disease by As(lll) exposure, but it will also allow for a better understanding of the role environmental toxins play in predisposing populations to protein misfolding diseases of aging and neurodegeneration.
Crisp Terms/Key Words: small molecule, postdoctoral investigator, cytoprotection, matrix assisted laser desorption ionization, molecular chaperone, SDS polyacrylamide gel electrophoresis, toxin, environmental toxicology, cytotoxicity, radiotracer, binding protein, protein structure function, protein folding, neural degeneration, nervous system disorder, environment related neoplasm /cancer, intermolecular interaction, arsenic, molecular pathology, diabetes mellitus, teratogen, cytoplasm, biophysics
DESCRIPTION (provided by applicant):
Goal: The program goal is to train predoctoral and postdoctoral biostatisticians in statistical theory and methods as applied to environmental health sciences (EHS). This aim is addressed by an integrated collaboration between biostatisticians and toxicologists to provide: supervision by biostatistician with extensive experience in the development of statistical methodology; interaction with researchers with extensive experience in human and animal studies; practical experience in the applications of statistical methodology to problems in toxicology by participating in consulting projects and attending colloquia; mentoring of trainees to assist in developing independent academic careers. Training: This training program is a collaboration between the Department of Biostatistics and Computational Biology and the Environmental Health Sciences Center. The Department of Biostatistics & Computational Biology offers a Ph.D. degree in Statistics with an option in Biostatistics. The Department, created to foster biostatistical research and collaboration with researchers in the Medical Center, provides the administrative leadership and the critical link with the toxicologists. Trainees will be matched with a biostatistician as primary preceptor and a toxicologist as a secondary cosponsor. The EHS Biostatistics Training Grant Committee will review the progress of the trainees and the program. Trainees: Predoctoral trainees will have completed a baccalaureate degree with a major in mathematics, statistics or a science major with a strong minor in mathematics or statistics. Selection is based on academic record, GRE scores, and recommendations. Predoctoral trainees must fulfill the standard requirements for the Ph.D. degree in statistics plus additional courses in biostatistics, epidemiology and toxicology. Two predoctoral four-year awards will be granted. Postdoctoral trainees must have completed a Ph.D. in statistics, mathematics or a related discipline, or a Ph.D. in toxicology. Each postdoctoral trainee will enroll in appropriate courses, attend seminars, and work with faculty mentors on biostatistical research and specific toxicology related projects. Two postdoctoral traineeships are awarded to establish an alternating two-year program.
DESCRIPTION (provided by applicant)
This proposal seeks to continue a summer research training program for medical students to learn about the environmental and occupational health sciences. The Division of Environmental and Occupational Medicine of Mount Sinai School of Medicine has sponsored such a program for the past fifteen years with funding from NIEHS and is submitting this proposal for continued funding for the next 5 years.
The primary goal of the research training program is to immerse highly competent medical students in a rich research setting pertaining to environmental and occupational health sciences to introduce them to the field, with the ultimate goal of increasing interest in the field among medical students. Specific objectives to achieve this broad goal, include: a) the identification and enrollment of qualified medical students with significant academic potential, especially students of minority groups, into a summer research experience in the environmental and occupational health sciences; b) the creation of a set of meaningful research experiences in which the students engage in critical thinking and assume responsibility in research projects; c) the provision of a broad learning context for participating medical students to enable the students to draw links between their specific research projects and related issues in clinical occupational medicine, toxicology, epidemiology, preventive medicine and public policy; and d) the assessment of the short-term and long-term impact of the program by assessing student satisfaction and changes in their knowledge and skills relevant to the environment health sciences, and by tracking students in the years following their participation in the training program to assess their choices of careers.
To achieve these objectives, medical students will work on individual research projects under the close supervision of faculty mentors at Mt. Sinai School of Medicine. The mentors and research projects will be drawn from a spectrum of disciplines in the environmental health sciences, including epidemiology, clinical occupational medicine, toxicology, and molecular biology. In addition, the students will attend a research seminar series, observe patient sessions at the Irving J. Selikoff Occupational Health Clinic Center, and visit a variety of worksites with potential environmental hazards. At the end of the program, all students are required to present their findings at a department-wide seminar.
DESCRIPTION (provided by applicant)
New York University (NYU) School of Medicine is a national leader in educating future academic physicians. NYU/Bellevue provides opportunities for translational research: 250,000 ambulatory and 25,000 inpatients/year, access to cohorts of working poor and underserved minorities, and an inquisitive faculty interested in gene-environment interactions. Three interdisciplinary programs intersect in this Environmental Pulmonary Medicine Training Program: the Division of Pulmonary and Critical Care Medicine with 60 faculty and 18 fellows, the Nelson Institute/Department of Environmental Medicine with 44 faculty members, and the Sackler Institute of Graduate Biomedical Sciences with 155 faculty in the basic-science departments. The investigators have 30 mentors collaborating on this training grant: 6 pulmonary, 8 environmental medicine and 16 Sackler. All are molecular/computational biologists pursuing genomic/proteomic approaches to evaluating gene-environment queries in human cohorts. They have assembled cohorts with exposures to World Trade Center dust, allergens, asbestos, and tobacco, with environmental pulmonary diseases (asthma, fibrosis, lung cancer, mesothelioma) and intriguing disease-precursor lesions. The investigators are building an Environmental Lung Health Center for translational research with 8 offices and laboratories. They have developed an MS in Translational Research and an MPH in Global Public Health that will add to the didactic components of their environmental medicine training. They have trained 37 postdoctoral fellows, including 8 minorities and 32 in academics. In the past 5 years, the investigators supported 14 trainees (11 in academics, 3 on NIH grants, and one underrepresented minority). They propose a two-year research fellowship for pulmonary fellows to obtain an MS degree and PhD degree to receive didactic instruction in translational research in environmental medicine, emphasizing genomic/proteomic approaches. The principal investigator and co-investigator utilize a Research Training Committee to assist selecting, advising, and monitoring the progress of the trainees. Research fellows develop their own projects and practically all have presented their research at national meetings with publications appearing in peer-reviewed journals. The goal of the program is to train academicians to provide Environmental Pulmonary Medicine leadership into the 21st century.
BACKGROUND
This renewal application proposed a two year fellowship training program with a shift in direction toward translational research with application of modern molecular approaches including proteomics and genomics. The previous focus was on basic science training in cell and molecular biology, but with the building of an Environmental Lung Health Center for translational research, an MS program in Translational Research and an MPH in Global Public Health the objective has shifted in this direction. Another change is the request now for a total of eight fellows compared to six in the current granting period. There are also a few changes in the participating faculty but the net number remains essentially unchanged at thirty.
DESCRIPTION (provided by applicant)
This is a revision of the first competitive renewal application for this Program in Interdisciplinary Training in Environmental Health. To date, there have been 13 trainees in this pre-doctoral program leading to the Ph.D. degree in Environmental Health Sciences that includes two years of course work and three years of dissertation research. In addition, the program has incorporated several educational enrichment activities to enhance the training experience, including: seminars; workshops; field trips; teaching experience; retreats; grant writing experience; and informal activities. The training program is also integrated with the numerous other environmental health activities of the department, school and university, including: the Center for Environmental Health in Northern Manhattan; the Center for Children's Environmental Health; the Superfund Basic Science Research Program; and the Columbia Earth Institute. This program has focused on interdisciplinary training combining public health and basic biomedical science skills in solving complex problems in environmental health related to four areas: environmental cancer; environmental respiratory disease; environmental neuro-degenerative disease; and environmental reproductive/developmental disease. The training faculty for the program consists of 16 well-funded investigators with research programs related to one or more of these focus areas, all of whom have experience in mentoring trainees in collaborative interdisciplinary research. The current grant has provided support for three pre-doctoral slots per year, but, through leveraging of funding, the investigators have been able to considerably increase the number of slots in the program. Thus, the program currently has 10 trainees (including three under-represented minorities) and has had two recent graduates who have gone on to environmental health research positions in government and academia.
DESCRIPTION (provided by applicant)
Environmental factors play a significant role in the causation of human disease. Thus, such disease is preventable to the extent that such factors can be identified and either removed from the environment or counteracted. Recognition of this possibility requires intensified efforts to identify the causal factors, to elucidate their mechanisms of action and to formulate appropriate measures for blocking or reversing their effects. The purpose of this Program is to provide training to prepare scientists for active and productive careers in environmental toxicology, with emphases on respiratory, molecular and genetic toxicology. The objective is to prepare the trainees to plan, conduct and interpret toxicological studies which are appropriate to specific scientific issues in question. The scope is broad, and trainees may, for example, be provided with backgrounds enabling them to examine mechanisms of environmentally-related disease as well as to improve exposure technology and methods of assessing biological responses. The Program provides for four predoctoral and two postdoctoral (Ph.D.) positions.
DESCRIPTION (provided by applicant) Despite federal policies that are designed to protect human subjects involved in scientific research studies, serious ethical challenges continue to occur in environmental health research that appear to negatively impact the safety and welfare of communities of color and low-income communities. This problem will be addressed by an interdisciplinary research team drawn from an existing collaboration between West Harlem Environmental Action, Inc. (WE ACT), the NIEHS Center For Environmental Health in Northern Manhattan, and the Columbia Center for Children's Environmental Health (the latter organizations are both part of Columbia's Mailman School of Public Health) who will implement an educational and demonstration project, "Developing an Effective Community Ethical Review Model." The project will educate researchers (specifically, principal investigators and co-investigators of NIEHS-funded studies) and community members (specifically, community-based organization advisors and research partners on NIEHS- or CDC-funded studies and others who are working on environmental health issues in communities of color (most of whom are women of color) on the best practices for bolstering human subject protection. This will be accomplished through the development, implementation, and evaluation of a replicable model for ensuring effective community review of gene-environment and non-therapeutic environmental health research. Specifically, the project will focus on ethical issues regarding research on the etiology and exacerbation of asthma [including genetic factors] and home-based interventions on asthma and lead. These research studies have been chosen because the project team has broad experience with these studies and because such studies are of nationwide interest. The demonstration model will be based upon, 1) an assessment of community members', researchers', and health funders' knowledge of environmental health hazards and research ethics; 2) case studies of existing community ethical review models; 3) linguistically and culturally appropriate educational materials and trainings on environmental health and research ethics; 4) local and national dialogues regarding research ethics; and 5) evaluation of all project activities.
Crisp Terms/Key Words: cooperative study, health education, education evaluation /planning, environmental health, ethics, human subject, interview, model design /development, health care model, health survey, low socioeconomic status, community, gene environment interaction, clinical research, behavioral /social science research tag, genetic susceptibility, educational resource design /development, medically underserved population, environmental exposure
DESCRIPTION (provided by applicant)
Nutrition has been studied almost exclusively as a matter of individual choice, and control of nutrition-related heath problems has been considered a matter of health education, however it is incontrovertible that what people eat depends on what is available given our agricultural and food distribution systems, including pricing and advertising by retailers. The goal of this project is to address food justice in East New York (ENY). This initiative is based on a partnership between community members of ENY; a local health care provider, Wyckoff Heights Medical Center and an epidemiologist at Mount Sinai School of Medicine. It will characterize the extent of inequitable access to healthy food in ENY, introduce community driven solutions (a sustainable food co-op, health education/ screenings and a student internship program), and evaluate the process and outcomes associated with these interventions on residents and program participants. A series of undertakings are proposed that will address food justice in ENY by incorporating: a) interactions with the existing ENY Food Policy Council to develop a community advisory board and subcommittees, to actively guide the assessment, implementation, communication and evaluation of the project; b) a community assessment to measure the local food environment (food store/restaurant location, cost and quality of foods) and the attitudes, perceptions, knowledge and behaviors of ENY residents with regard to nutrition and health; c) modifications to the local food environment by: opening a food co-op in ENY, initiating nutrition/ cooking classes as well as a health screening services and training programs for students; d) policy makers to develop new policies towards food justice. The process involved in implementing these efforts will be evaluated by an external evaluator where results will be used to improve the implementation and finally, outcomes associated with these changes to the local food environment will be monitored. The study will be the first to evaluated community impact of a year round modification to a local food environment, at a neighborhood level, and will be the first to accomplish these goals as a community driven response to what local residents have identified as an environmental justice issue.
DESCRIPTION (provided by applicant)
The overall goal of the South Bronx Environmental Justice Partnership (SBEJP) is to improve the health of the people who live in the South Bronx. The partnership is an on-going collaboration between For a Better Bronx (FABB), Lehman College (CUNY), Montefiore Medical Center (MMC), and the Albert Einstein College of Medicine (AECOM). The Partnership was established in 2000 with funding from the NIEHS Environmental Justice program. Lehman College formally joins the Partnership with this proposal. In this proposal SBEJP seeks to accomplish the following Specific Aims: 1. Strengthen the Partnership and collaboration between AECOM, FABB, Lehman, and Montefiore and promote environmental health education and research at each, by a) expansion of websites, environmental health library, and information center in the South Bronx; b) not-for-profit incorporation, 501c3 status, and additional administrative, accounting, and research capacity for FABB; c) assistance for development of MPH program at Lehman College; d) strengthening and integrating SBEJP and enhancing Partners mutual learning; and e) recruitment of additional Community Advisory Board members of AECOM's Institute for Community & Collaborative Health. 2. Conduct Geographical Information Systems (CIS) environmental health research on cardiovascular disease (CVD) and diabetes related air pollution and land use in the Bronx, informed by on-going dialogue with its community, by a) mapping of CVD hospitalizations against local stationary and mobile sources of air pollution and other noxious land use; b) conduct preliminary CIS studies on diabetes mellitus hospitalizations and their geographic relationship with potential sources of endocrine disrupters, air pollution; and noxious land use and mitigating features of the built environment; and c) develop culturally and linguistically-appropriate risk communication materials for community dialogue about these GIS findings. 3. Develop community-driven, health-promoting improvements in the social and built environments in collaboration with other organizations in the South Bronx, by a) an equity analysis of Bronx parks using GIS; b) conduct focus groups, town meetings, and community surveys to learn community priorities; c) develop community-prioritized demonstration projects; d) develop model code enforcement and mitigation initiatives; and e) develop community-based, culturally-appropriate approaches to improved nutrition and exercise.
We propose to investigate the impact of the built environment characteristics on body size, physical activity and diet in residents of New York City (NYC). We will use data from three large human health studies. The first data set will be from 1000 Black and Hispanic children enrolled in prospective cohort study of Head Start families. From all of the children we will have complete demographic data, and mother's reports on the height and weight and physical activity of the child. From 500 of the children data will be available on skin fold thickness, body mass index (BMI) and 6 days of physical activity monitoring. Data will be available at baseline and from two annual follow-ups of the cohort. The second data set will be from 18,000 adult New Yorkers from whom we will have demographic data and objectively measured BMI. The third will be from 2,400 healthy Black and Caucasian. From these women we will have demographic data,
questionniare data on diet and physical activity and objective measures of BMI, waist and hip circumference and body fat by bio-impedence. From all of these subjects we will have a home address which we will geocode into a CIS model of New York City. Multi-level modeling approaches will be used to determine whether neighborhoods characterisitcs (for example; land use, street design, availability and quality of parks and retail food stores, zoning, public transport, farmers markets) predict body size, physical activity and diet.
Because of the very large immigrant population in NYC we will conduct qualitative research on how acculturation to the built environment of NYC impacts body size. Prior work suggests that acculturation to main stream American norms leads to weight increases in immigrants and their children. We do not see this effect in our data and propose that NYC is not "main stream America". We propose to conduct qualitative research on Hispanic mothers and children in the Head Start study and investigate how they relate to the built environment of NYC. Our goal is to develop a new measure of acculturation that includes adaption to the built environment of NYC and will be useful in studies of obesity. The quantitative research will also be used to develop new GIS based measures of aspects of the City that are important to the mothers.
This research on the phsyical environment and adaption to it, will identify strategies for building and organizing communites that increase physical activity, improve diets and reduce obesity.
DESCRIPTION (provided by applicant)
Two classes of industrial chemicals with endocrine-disrupting capability-the phthalates and the alkylphenols-have become widely dispersed in the urban built environment, and significant levels of phthalates are now nearly ubiquitous in the bodies of Americans. Highest exposures occur in children and in minorities. Infants and children appear especially susceptible to disruptors, because of their disproportionately heavy exposures and the vulnerability of their still forming organs to any disruption of the hormonal signaling that irreversibly shapes early development. Yet little is known, either of children's pathways of exposure, or of the human developmental toxicity of EDs. To address these gaps, the Mount Sinai Center for Children's Environmental Health and Disease Prevention Research proposes, 1) to characterize the levels and sources of children's exposures to contemporary-use EDs in the urban built environment; 2) to study relationships between EDs and neurobehavioral development; 3) to study relationships among ED exposures, diet, physical activity, and somatic growth; 4) to characterize previously unexplored enzymatic polymorphisms that may modulate individual susceptibility to EDs; and 5) to develop and deploy culturally appropriate, evidence-based strategies in East Harlem to improve children's diets, increase physical activity, reduce obesity, reduce ED exposures, and promote good health. Project 1, the Community-based Prevention Research Project (CBPR), Growing Up Healthy in East Harlem, is built on a long-standing partnership with the East Harlem community. It will study levels and sources of urban children's exposures to EDs and assess relationships among ED exposures, diet, physical activity, obesity, and use of personal care products. Project 2, an ongoing prospective epidemiological study, will analyze new and previously banked biological samples to examine associations between pre- and postnatal exposures to EDs and growth and development in a cohort study of urban children. This project will also continue to assess the developmental effects in this cohort of early exposures to neurotoxicants-organophosphates, pyrethroids, PCBs, and lead-that have been its focus for the past 5 years. Project 3, a molecular genetic study, will assess gene-environment interactions that may influence individual susceptibility to EDs by identifying and characterizing polymorphisms and variations in expression levels of PON1, lipase, and UGT-glucuronyltransferase enzymes involved in ED metabolism. A new Community Outreach and Translation Core (COTC) will use scientific information from the Center to educate and empower community leaders in East Harlem and to inform policy makers and health professionals regionally and nationally about links between the urban environment and children's health. The Center will contain an Exposure Assessment Core that collaborates with the laboratories of the Center for Disease Control and Prevention (CDC) National Center for Environmental Health, a Biostatistics and Data Management Core and an Administration Core. The Center will support two new investigators in children's environmental research.
DESCRIPTION (provided by applicant)
The overall theme of the Columbia Center for Children's Environmental Health (CCCEH) is the identification and prevention of risks of neurodevelopmental impairment and childhood asthma from prenatal and postnatal exposure to urban pollutants. Since it was established in 1998, the Center has forged a successful partnership with West Harlem Environmental Action, Inc. (WE ACT), and nine other community organizations to identify and prevent environmental causes of childhood disease in Northern Manhattan and the South Bronx. The Center has enrolled and retained a unique cohort of mothers and children of color who belong to one of the most at-risk urban populations in this country with respect to environmental exposures, social adversity, and childhood health problems. Using molecular epidemiologic approaches, Center investigators have developed a rich body of knowledge about this vulnerable and disadvantaged urban population. They have documented substantial prenatal exposure to indoor and outdoor urban pollutants, including the combustion byproduct polycyclic aromatic hydrocarbons (PAH), environmental tobacco smoke (ETS), pesticides, and pest allergens. The research has demonstrated significant associations between prenatal exposures to those pollutants and adverse birth outcomes and/or neurodevelopmental, immunological, and respiratory health outcomes in children studied through age two. Building on its achievements of the past five years, the Center proposes several important new initiatives. These include follow-up of the mother and child cohort through ages five to seven, as the children enter school, with links to school performance data at age eight. Additional exposure, biomarker, and outcome assessments will allow testing of new etiologic hypotheses in the community based participatory research (CBPR) projects on asthma and growth and development. A new laboratory-based mechanistic research project will elucidate possible mechanisms of in utero sensitization by co-exposure to PAH/diesel exhaust particles and allergens, directly complementing the CBPR asthma project. A CBPR Intervention project on integrated pest management and health-related housing improvements will be conducted in partnership with the New York City Departments of Health and Mental Health and the New York City Housing Authority. A new Community Outreach, Translation, and Application Core (COTAC) will ensure that the Center's findings have local and national public health impact. COTAC initiatives will include: education of medical students, medical residents, and pediatricians about children's environmental health; a new community campaign to improve air and housing quality in New York City, co-led by WE ACT; and risk assessment, cost, and risk prevention analyses on the Center's findings regarding the health effects of environmental exposures and the cost-effectiveness of IPM. In summary, it is important that the Center as an institution be continued as an established and valued resource to the community, scientific researchers, and policymakers.
Crisp Terms/Key Words: environmental exposure, clinical research, developmental neurobiology, human subject, environmental health
DESCRIPTION (provided by applicant):
The objective of this study is to determine the long-term cardiovascular effects of inhaled nanoparticles. The hypothesize that long-term inhalation of nanoparticles can enhance the development and progression of vascular dysfunction leading to atherosclerosis in a sensitive animal model, and that the vascular dysfunction process is mediated by oxidative stress through the disruption of nitric oxide (NO) regulation. Preliminary studies have demonstrated that 6 months of 6-hr weekday exposures of mice lacking apolipoprotein E (ApoE-/-) to fine ambient concentrated particles enhanced atherosclerosis, and altered vasoconstrictor responses to phenylephrine and serotonin challenge in the thoracic aorta. These changes were accompanied by marked increases in macrophage infiltration, the inducible isoform of nitric oxide synthase (iNOS), increased generation of reactive oxygen species (ROS) and greater immunostaining for the protein nitration product 3-nitrotyrosine. Since nanoparticles have been shown to be able to penetrate into the systemic circulation after inhalation, and are capable of affecting endothelial cell function, it is likely that manufactured nanoparticles could produce cardiovascular effects similar to those seen in preliminary studies. While a tremendous amount of research has addressed the greater pulmonary toxicity associated with ultrafine particles (< 100nm) compared to fine or coarse sized particles, little research has examined the cardiovascular effects of ultrafine or nanoparticles (< 50nm). Furthermore, the few studies that have investigated the cardiovascular effects of inhaled particles were short-term exposure in.nature. To date, there is no study that has investigated the chronic cardiovascular effects of inhaled nanoparticles.
Three different nanoparticles will be used to test the hypothesis, nickel, titanium, and carbon. Nanoparticles (count median diameter = 20 nm) will be produced using a spark generator with pure electrodes of nickel, titanium, and carbon. ApoE (-/-) mice will be exposed to 0 (filtered air control), 25, 50, or 100 ng/m3 nanoparticles for 6 hr/d, 5 d/wk, for up to 6 months. The development and progression of atherosclerosis will be assessed using non-invasive ultrasound biomicroscopy (UBM) as well as serial morphometric measurements. Serial endpoints such as vasoconstriction response, macrophage infiltration, NOS expression level (both inducible and endothelial isoforms), ROS, and 3-nitrotyrosine production will also be investigated as the major mechanisms involved in vascular dysfunction leading to nanoparticle enhanced atherosclerosis.
It is expected that nanoparticle toxicity will be influenced by a variety of exposure conditions including concentration, duration of exposure, and composition. This study will allow us to begin to understand the long-term exposure effects of nanoparticles on the cardiovascular system. The data obtained in the proposed animal studies can readily be used for extrapolation to occupational and ambient settings. In summary, the results from this proposal address a number of the research needs identified in this solicitation, including toxicity and exposure assessment. Ultimately, a systems approach will be developed to the understanding of nanomaterials toxicology sufficiently complete to allow predictions about health effects.
DESCRIPTION (provided by applicant): Protein malfolding plays an important role neurodegenerative conditions, such as Parkinson's Disease, Alzheimer's Disease and Motor Neuron Disease. Accumulating evidence suggests that environmental agents may contribute to the pathophysiology of these common disorders by perturbing protein folding, either directly or indirectly through their effects on cell metabolism. However, little is known about how cells adapt to the threat of environmentally-induced proteotoxicity. This study will exploit arsenic as a model for an environmental toxin that adversely affects protein folding and one that represents an important public health hazard affecting multiple organ systems. Two recently-identified adaptations to arsenic exposure will serve as this study's point of departure: (1) Regulated attenuation of new protein synthesis. (2) Modification of the cell's protein degradation apparatus to better accommodate it to arsenic-induced proteotoxicity. Stress-induced phosphorylation of translation initiation factor 2a (elF2a) attenuates protein synthesis and activates a salubrious gene expression program known as the Integrated Stress Response (ISR), which reduces the stress caused by arsenic-induced protein malfolding. Therefore, elF2a phosphorylation has emerged as an important component of cellular unfolded protein responses (UPR). Phosphatases that dephosphorylate elF2a will be characterized in an effort to identify specific biochemical steps whose inhibition activates the ISR. The physiological significance of inhibiting elF2a phosphatases will be tested in mouse models of neurodegenerative diseases. These studies will uncover the promise and potential limitations of therapeutic strategies to protect against proteotoxicity by inhibiting elF2a phosphatases. AIRAP, a novel arsenite induced protein, adapts the proteasome's regulatory cap to the conditions in cells experiencing arsenite-induced proteotoxicity and thereby promotes the cell's ability to deal with malfolded proteins. In an effort to understand how the intracellular protein degradation machinery adapts to proteotoxicity, arsenite-induced and AIRAP-dependent changes in the composition of the proteasome will be characterized by proteomic approaches. Gene knock out experiments in mouse and worms will be used to create experimental systems lacking AIRAP, and these will be applied as tools to identify arsenite-modified proteins whose degradation depends on AIRAP induction and AIRAP integration into the 19S proteasome regulatory particle. In vitro biochemical assays of purified proteasomes containing AIRAP will be used to characterize functionally proteasomal adaptation to environmentally-induced protein malfolding. The goal of this research program is to reduce the cellular adaptations to protein malfolding induced by environmental toxins to their molecular constituents. This will lay the groundwork for identifying relevant bio- markers of exposure and for future preventive and therapeutic interventions against neurodegeneration.
DESCRIPTION (provided by applicant):
It is hypothesized that human exposures to environmental stresses (biological, chemical, physical and psychological) result in alterations to the neuro-endocrine-immune axis. These changes provoke shifts in molecular components of the blood that reflect changes in biomarker levels. Septic patients and rheumatoid arthritis patients will be used as prototype stressed individuals to identify and quantify the presence of serum proteins that have increased, decreased, or which display epitope-modified expression. These molecular features will form the basis of specific biomarker signatures that are characteristic of stressed human individuals. Preliminary experiments document that biological, chemical, and psychological stress alters plasma protein expression levels, which in part, are due to inflammation and/or oxidative processes. Since we suggest the different forms of stressors modulate the interactive pathways between the endocrine, immune, and nervous systems, we anticipate that immune, endocrine, and nervous system factors will be predictors of stress and that the profiles of these factors will provide prognosis for the degree of stress and the severity of the exposure. Individual biomarkers, which are predicted to relate to regulatory pathways associated with inflammation: anti-inflammation, oxidants: anti-oxidants, and innate immune processes, will then be quantified in humanized mice after exposure to three prototype stressors: cadmium, cold-restraint, and listerial infection. The plan is to delineate and quantify the normal basal and responsive plasma concentrations of relevant biomarkers and to validate their analysis with a new biosensor employing grating- coupled surface plasmon resonance imaging (GCSPRI). GCSPRI is a microarray platform that will enable the multiplexed detection of these biomarker signatures with an automated diagnostic system in near real time. In addition to stressor-induced changes in plasma constituents, we will evaluate changes to blood leukocyte antigens; lymphocytes are especially sensitive to inflammatory products and oxidants. Blood products are obtained with minimal invasiveness, and they represent the best composite of the systemic response to a stressor. The GCSPRI technology will be parallel tested against the Luminex technology. The biomarkers to be evaluated include blood clotting factors, cytokines, stress proteins, neuropeptides, antioxidant enzymes, and normal plasma proteins with thiol-related modifications. Finally, we will evaluate the consequences of different stress response capabilities on the character of the biomarker signatures that have been identified in this work. At the conclusion of this work we will have identified specific biomarker signatures that are both diagnostic of specific signatures, and which will be invaluable in both the diagnosis of stress, and the characterization of therapeutic management of stressed individuals.
DESCRIPTION (provided by applicant)
This proposal is submitted in response to the RFA-ES-06-001 DISCOVER initiative. The fetus and young child have physiologic, developmental, metabolic, and behavioral patterns that make them uniquely vulnerable to hazards in their environments. Ambient air pollution has been implicated as a major risk factor for asthma and asthma exacerbation, however epidemiological studies have been hampered by uncertainties in exposures and the nature of airway responses. The Columbia Center for Children's Environmental Health (CCCEH) Disease Investigation through Specialized Clinically-Oriented Ventures in Environmental Research (DISCOVER) seeks to understand when and how airborne polycyclic aromatic hydrocarbons (PAHs) and diesel exhaust particles (DEP) increase the risk for childhood asthma and airway inflammation, develop new biomarkers to identify children at risk and improve clinical treatment, evaluate the success of a public policy intervention, and implement physician education initiatives as a mode of intervention. This proposal includes four closely linked projects and Administrative and Data Management and Biostatistics Cores each ensuring the seamless coordination of the multiple research activities involved in this proposal. The cores play vital roles in the quality of research information and statistical analyses and the administrative/financial oversight and translational components of the four main DISCOVER research project initiatives. The four project aims are: 1) Take advantage of repeat PAH measurements pre- and post-natally to distinguish between the biological effects of prenatal PAH exposure versus postnatal exposure during early childhood and pre-adolescence; 2) To advance the understanding of the influence of diesel exhaust exposures, which include PAHs, in acute asthma exacerbations by linking innovative exposure and outcome measures; 3) To determine whether epigenetic changes related to PAH exposure are involved in the pathogenesis of childhood asthma; 4) To ascertain if traffic related PAHs affect ?2AR function in airway smooth muscle cells in vitro, alter (?2AR function following in utero and early life exposures, affect (?2AR expression and function in airway epithelial cells in vitro. The research is translational to asthma prevention, clinical treatment, physician education, and policy.
INTEGRATED (clinical and basic) and INTERDISCIPLINARY NATURE OF PROGRAM
Description: The goal of the DISCOVER Center submitted by Dr. Perera, Columbia University, is to expand the work of the existing Columbia Center for Children's Environmental Health (CCCEH) to understand how and when airborne polycyclic aromatic hydrocarbons (PAHs) and diesel exhaust particles (DEP) increase the risk for childhood inflammation and asthma. The Center will also develop new biomarkers to identify children at risk and improve clinical treatment, evaluate the success of a public policy intervention and implement physician education initiative as a mode of intervention.
DESCRIPTION (provided by the applicant)
The Seventh International Conference on Urban Health will gather scientists, practitioners, policy makers and community organizations from different disciplines and countries to exchange progress on work in improving the health of urban populations and to foster cooperation among urban health stakeholders. The conference will take place in Vancouver, BC, Canada. Through environmental health sessions at the conference, it is proposed to showcase current research on how the built and social environment affects the health of urban populations. As such, approximately $8,000 of the total cost of the conference ($600,000) is requested to fund the following environmental health research components of the program: 1) Plenary speakers on urban environmental health research; 2) Concurrent sessions on environmental health research as applies to cities; 3) Poster sessions focused on urban environmental health research; and 4) Publication of a supplement of the Journal of Urban Health that will include featured articles and poster abstracts on environmental health research. By holding this conference in one of the leading cities in the world, it is intended to foster an international research group to collectively improve the understanding of the common health risks faced by urban residents and to influence the development of effective public health interventions across the globe. Perspectives and lessons from different countries can be valuable to share. Six prior conferences have been held that have been well attended, and to continue this series is anticipated. The track on environmental health has been present in earlier meetings and is a critical part of this effort. These tracks will help to foster interdisciplinary collaborations among researchers in each area who are interested in how urban environments play a role in physical and mental health, as well as how features of urban settings may lend themselves to interventions. Dissemination of information will come in the form of published abstracts and papers in the Journal of Urban Health; press conferences with radio, newspaper, and television; and press interviews with key speakers. Urbanization presents one of the major public health challenges for the 21st Century. In 2007, half of the world's population lives in urban environments and by 2030, two-thirds will be urban dwellers. The complexity of health challenges will require interdisciplinary perspectives from public health, urban design and policy to address problems of infectious and chronic diseases, and mental health and substance abuse problems. The International Conferences on Urban Health will provide a forum for scientists and public health practitioners to exchange information and forward the science needed to address urban health challenges. In particular, the environmental health impacts urbanization and urban areas affect a growing proportion of the world's population.
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