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Record Count: 63
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DESCRIPTION (provided by applicant): Research in this lab and others has provided evidence for an important role for expression of glutathione S-transferases (GSTs) (Phase II detoxification) in normal cellular defenses against reactive electrophilic metabolites of carcinogens, and as part of the biological response induced by chemopreventive agents. We have employed a transgenic cell modeling approach to examine the specific contributions of GSTs expressed individually and in combination with relevant genes, including members of the cytochrome P450 (Phase I activation) and the multidrug resistance protein (Phase III efflux) multigene families. We have found that protection against cytotoxicity and/or genotoxicity (DNA adducts or mutagenesis) can be quite different, depending in some cases primarily on GST characteristics and expression level, or in other cases on the nature of the carcinogen, whether it requires activation, and the P450 activation enzyme co-expressed with the GST. We propose to continue these investigations with our existing single-and dual-transfected V79 cell lines that stably express human GSTP1, GSTM1, or GSTA1, alone and also in combination with human P450-1A1 or-1B1, with addition of -1A2. We will focus on a limited set of polycyclic aromatic hydrocarbon (PAH) substrates for these P450s and GSTs, Benzo[a]Pyrene (and its two 7,8-dihydrodiol enantiomers); the more potent DiBenzo[a,I]Pyrene (and its intermediate 11,12-diol metabolites); and 5-methylchrysene. We will also examine metabolism and toxicities of estradiol, reportedly activated by these CYP isozymes and detoxified by hGSTP1, in these cell lines. In Aim #1 we will examine the unique metabolic interactions between each P450 and GST combination, with both cytotoxicity/apoptosis, DNA adducts, and mutagenicity as endpoints. Aim # 2 will model cell-cell interactions, asking whether binary mixtures of these cell lines show simple additivity, or synergy or antagonism in the presence of PAHs (e.g. via exchange of stable intermediates), and if GST expression is more effective in concert with one or the other P450 in the two different cell lines co-cultured. Aim #3 will determine the mechanisms that underlie the large differences observed in GST protection against the cytotoxic vs. genotoxic effects of certain carcinogens. In Aim #4 we will determine the mechanism for the intriguing observation that expression of GSTs with high efficiency for 4-nitroquinoline oxide or 4-hydroxynonenal conjugation confer paradoxical sensitivity instead of protection. These studies will enhance our knowledge of the factors that govern chemoprotective functions of GSTs.
DESCRIPTION (provided by applicant): Lung cancer is a major lung disease and accounts for more than one-fourth of all cancer deaths. Therefore, research into causes of the disease, identification of genetic and environmental risk factors, and discovery of better diagnosis and treatment strategies are urgently needed. One strategy to combat lung cancer is to identify genes that normally suppress tumor development. We have developed the first genetically engineered mouse model in which claudin-7 gene is deleted. Knockout of claudin-7 using gene targeting approach resulted in hyperproliferation of lung epithelial cells. Heterozygous claudin-7 mice showed an increased incidence of developing spontaneous lung tumors. Importantly, claudin-7 expression is either disrupted or downregulated at the cell-cell junction in lung cancer cells, and the overexpression of claudin-7 reduced human lung cancer cell growth in culture. These studies prompted the hypothesis that claudin-7 plays important roles in lung cancer progression as a tumor suppressor. To investigate how claudin-7 suppresses cancer growth in cell culture as well as in mouse models in vivo, this project will address two specific aims. Specific Aim 1: To investigate the roles of claudin-7 in lung cancer cell growth and survival in culture. We will use flow cytometry, TUNEL imaging, Matrigel invasion assay and cell- cell dissociation methods to determine if the properties of cell cycle, apoptosis, as well as cell adhesion and invasion, are altered when claudin-7 is stably expressed in a claudin-7-deficient human lung cancer cell line NCI-H1299. These experiments will determine how claudin-7 reduces lung cancer cell growth. Specific Aim 2: To investigate environmental carcinogens on the growth of lung carcinoma in vivo and on tumor-host interactions in Cln7 mice. We will investigate if environmental carcinogens, such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), can induce a greater tumor incidence in Cln7 mice compared to Cln7 mice. We will also investigate whether reduced claudin-7 expression results in altered host cell-cell junction and adhesion, allowing inoculated Lewis lung carcinoma LLC1 cells to interact with the pulmonary microenvironment more favorably and metastasize more easily. This project will allow us to collect preliminary data to determine whether Cln7 mouse strain is a viable model system for studies of claudin-7 function in lung carcinogenesis. These studies will also lay the foundation for a future NIH RO1 project to investigate the molecular mechanisms of how claudin-7 functions as a tumor suppressor. PUBLIC HEALTH RELEVANCE: One strategy to combat lung cancer is to identify genes that normally suppress tumor development. Claudin-7 is important in limiting lung epithelia from uncontrolled cell growth, as revealed by our genetically engineered claudin- 7 knockout mouse model. It is now important to investigate whether mice deficient in claudin-7 are more susceptible for lung cancer formation when exposed to environmental carcinogens and how claudin-7 suppresses cancer growth.
DESCRIPTION (provided by applicant): Peroxisome proliferators are a large group of non-genotoxic carcinogens whose effects are tissue-and species-specific. The mechanism of carcinogenesis in rodents is not completely understood but is thought to involve (i) increased proliferation of hepatocytes; (ii) activation of nuclear receptor PPARa and proliferation of peroxisomes; (iii) production of reactive oxygen species and damage to DNA; and (iv) oxidant-mediated activation of mitogen production by Kupffer cells. This proposal is designed not only to fill in the gaps in specific signaling mechanisms induced by peroxisome proliferators, but also to elucidate how individual cellular and molecular pathways interact to bring about the changes that lead to cancer. Specifically, we hypothesize that peroxisome proliferators activate Kupffer cells to generate oxidants, which increase mitogenic cytokines that require PPARa in parenchymal cells to stimulate cell proliferation maximally. A number of pivotal questions remain unanswered. First, what is the role of oxidant production in long-term effects of peroxisome proliferators? Here we will test the hypothesis that oxidant production by Kupffer cells is critical for the effects on cell proliferation; that WY,14643, but not DEHP, is able to cause a sustained activation of Kupffer cells; and that this phenomenon is important for liver carcinogenesis. Second, which signaling mechanisms are responsible for activation of Kupffer cells by peroxisome proliferators? We will test the hypothesis that peroxisome proliferators, highly lipophilic compounds, form lipid-like particles and bind to the receptors on the Kupffer cell membrane in a non-specific "particle-mediated" manner, leading to increases in intracellular calcium and activation of kinase cascades. This results in activation of NADPH oxidase via phosphorylation of its subunits leading to oxidant production, which stimulates NF-KB. As a result, cytokine production by Kupffer cells is increased and stimulates cell proliferation in parenchymal cells where PPARa-dependent signaling events warrant specificity of peroxisome proliferator-induced responses. Third, what are the molecular events in hepatocytes that are involved in increased cell proliferation in hepatocytes by mitogenic cytokines and PPARa-activators and how do these pathways interact? We will test the hypothesis that maximal stimulation of parenchymal cell proliferation by mitogenic cytokines from Kupffer cells is potentiated by the actions of peroxisome proliferators on PPARa in parenchymal cells. Specifically, activation of PPARa leads to an increase in the pool of prenyl isoprenoids available for post-translational modification of Ras and thereby promotes its translocation to the membrane where it can be activated. This results in a "potentiation" of a non-specific mitogen release from Kupffer cells activated by lipid-like peroxisome proliferator particles, thus accounting for a characteristic burst of proliferation in the liver.
Crisp Terms/Key Words: prenylation, peroxisome proliferator activated receptor, cell proliferation, gel mobility shift assay, biosynthesis, guanine nucleotide binding protein, phthalate, NAD(P)H dehydrogenase, oxidizing agent, chemical carcinogen, chemical carcinogenesis, liver neoplasm, molecular oncology, intermolecular interaction, Kupffer's cell, western blotting, immunogenetics, immunoregulation, cytokine, leukocyte activation /transformation, genetic regulation, electron spin resonance spectroscopy, chemical structure function, cell growth regulation, peroxisome, biological signal transduction
DESCRIPTION (provided by applicant): This project will test the hypothesis that defects in DNA repair are acquired during stages of melanoma development and produce a chromosomal-mutator phenotype in UV-irradiated cells. Focus will be on nucleotide excision repair (NER), post-replication repair (PRR), DNA double-strand break (dsb) repair and intra-S checkpoint responses to the component of sunlight (UV radiation) that is most efficient in inducing DNA damage. In the three specific aims, DNA repair will be quantified in strains of normal human melanocytes, in melanoma cell lines, and in melanocytes expressing mutated genes commonly found in melanoma. Specific Aim 1 will determine whether NER capacity is attenuated or lost during stages of melanomagenesis. PRR capacity (translesions synthesis and gap repair) and the intra-S checkpoint response of inhibition of replicon initiation will be measured in Specific Aim 2. Proposed studies will also investigate the hypothesis that UV-induced DNA damage triggers a signaling pathway that results in trans-inhibition of DNA chain elongation; this novel element of the intra-S checkpoint is postulated to reduce the rate of fork displacement in replicons that have not yet encountered a template lesion. A DNA fiber-spreading and immuno-staining assay will enable visualization of replication dynamics and measurement of individual replication tracks. Knockdown of the Timeless-interacting protein (Tipin), together with ectopic expression of RNAi-resistant Tipin, will test whether this protein regulates the rate of displacement of DNA replication forks through its binding to RPA. Induction of chromosomal aberrations and INK4a allelic deletions in UV-treated cells will be examined in Specific Aim 3. Aberrations and deletions are thought to be associated with DNA dsb generated at collapsed replication forks and other single-strand DNA regions formed during replication of the UV-damaged DNA. Phospho-histone H2AX/phospho-ATM/Mre11-positive nuclear foci will be quantified to monitor the formation and repair of UV-induced DNA dsb. Studies will determine whether genetic alterations associated with melanoma development enhance UV-clastogenesis in cultured melanocytes. The proposed studies will shed light on how an environmental carcinogen, sunlight, induces skin cancer by expanding our knowledge of DNA damage responses in normal human melanocytes and providing insight into the mechanisms of genetic instability in melanoma.
DESCRIPTION (provided by applicant): Single molecule electron microscopy provides a powerful approach to study the way in which damaged DNA is remodeled by proteins. The focus of this application is understanding how a number of central human DNA repair and telomere binding proteins interact at large, complex DNA structures containing damage, and how they carry out repair or signal the presence of lesions. This is a highly interactive program which represents longstanding fruitful collaborations with Dr. Paul Modrich working on human mismatch factors, Dr. Aziz Sancar working on human repair signaling factors, and with Dr. Titia deLange working on telomere binding proteins. Together from our own work on this topic and through these collaborations we have published over 20 papers in the past 5 years. This is a highly propitious time to carry out these studies since we have developed two powerful new EM methods: nano-scale biopointers that provide a means of identifying the location of proteins within multi-protein complexes and glycerol spray/low voltage EM that gives a more gentle means of preparing samples for EM. Further, as substrates for these studies, we have produced large natural DNAs containing replication forks or Holliday junctions with nearby mismatched bases and a model telomere DNA. Work on the mismatch repair proteins will take advantage of the recent in vitro reconstitution of nick directed excision repair by the Modrich laboratory. Work on Claspin and the Rad 9- Husl-Radl complex will focus on learning how these proteins interact with replication forks containing damage. Studies of the remodeling of telomeres will take advantage of the recent discovery of discrete multi protein complexes at telomeres. Finally continuing work from our laboratory will focus on p53 as a facilitator of DNA damage recognition. Each system offers a unique window into basic questions of DNA protein remodeling at sites of damage and telomeres and information garnered from one study is immediately applied to the others.
DESCRIPTION (provided by applicant):
Discordant phenotypes and varying incidences of complex diseases in monozygotic twins as well as genetically identical organisms have long been attributed to differential environmental exposures. Accumulating evidence indicates, however, that epigenetic gene dysregulation by DNA methylation and histone modifications from environmental exposures also play a role in this differential susceptibility to disease. Thus, the overarching hypothesis of this grant application is that early exposure to environmental agents influences adult disease susceptibility by causing stable alterations in critical DNA control elements that regulate metastable epialleles - genes whose epigenome is established probabilistically during development, leading to variable gene expressivity and widely varying individual adult phenotypes. Despite a growing consensus on the importance of epigenetics in the etiology of chronic human diseases, the genes most prone to epigenetic dysregulation are incompletely defined. Moreover, neither the environmental agents most strongly affecting the epigenome nor the critical windows of vulnerability to environmentally induced epigenetic alterations have been characterized. These major deficits in knowledge have severely constrained our ability to systematically define and characterize the metastable epialleles mechanistically involved in the etiology of human diseases. The overall objective of this grant application is to help correct these deficiencies by using the viable yellow Agouti (Avy) mouse model, as well as human samples to identify environmentally responsive, metastable epialleles in the mouse and human genomes. Specifically, the intent is to determine if maternal dietary supplementation of Avy mice with low levels of the plasticizer bisphenol A (BPA) affects adult phenotype of the offspring by altering the fetal epigenome. Gene expression and genome-wide bioinformatic approaches to identify imprinted and non-imprinted metastable epialleles in both mice and humans will be employed. The results of this study should ultimately allow for improved diagnosis, treatment, and prevention of chronic human diseases such as asthma, diabetes, cancer, obesity and neurological disorders by targeting the epigenome rather than the genome. They will also be helpful in determining under what circumstances the mouse is an appropriate toxicological model for assessing human risk from agents that elicit their biological effect primarily by altering the epigenome.
DESCRIPTION (provided by applicant): Genomic imprinting refers to an epigenetic marking of genes that results in parent-of-origin dependent, monoallelic expression. Imprinted genes have critical roles in embryonic growth and behavior; many also function as cancer susceptibility loci in somatic cells because their functionally haploid state makes them vulnerable to inactivation or overexpression. This heightened susceptibility is exacerbated by positional clustering of imprinted genes under the regional control of imprinting centers that, when disrupted genetically or epigenetically, lead to multigenetic phenotypic abnormalities including cancer. Imprinted genes may also mechanistically link nutritional perturbations like methylation deficiency directly to the etiology of cancer because their cis-acting regulatory elements are epigenetically labile. We propose to use phylogenetic comparisons of orthologous sequences from members of the three extant mammalian orders, Prototheria, Metatheria and Eutheria to characterize the evolution of imprinted domain structures and define the fundamental cis-acting imprint regulatory elements that epigenetically distinguish the parental alleles and also constitute targets for epigenetic dysregulation. The overall hypothesis of this grant application is that gene promoter silencing represents the primordial imprint mechanism, and that ongoing interparental genetic conflict has led to increased regulatory complexity for some imprinted domains, as the maternal and paternal genomes evolved counteracting strategies to overcome gene repression. Imprinting mechanisms are therefore postulated to be less complex in more ancestral mammals. To test this novel hypothesis we recently produced bacterial artificial chromosome (BAC) libraries from the imprinted opossum (Didelphus virginiana) and the non-imprinted platypus (Ornithorhynchus anatinus) to examine imprinted domains containing genes involved in cancer that are regulated by three different imprinting mechanisms. Maternal repression of expression will be modeled by NNAT (Neuronatin); paternal repression of expression with antisense transcripts will be modeled by M6P/IGF2R, and reciprocal parental repression of juxtapositioned genes by an intervening imprint center will be modeled by the IGF2/H19 and DLK1/MEG3 imprinted domains. We will test the functional relevance of novel regulatory elements identified in these comparisons by determining if they can direct acquisition of imprinting in transgenic mice. The successful completion of these comparative phylogenetic studies will significantly enhance our understanding of the evolution of this unique mammalian form of gene regulation. These studies will also be critical for identifying novel imprinted genes, and characterizing the less well-defined imprinted domains known to harbor genetic and/or epigenetic mutations mechanistically involved in cancer and neurogenetic disorders, such as schizophrenia, bipolar disease and autism.
DESCRIPTION (provided by applicant): 1,3-butadiene (BD) is a known carcinogen. However, the DNA adducts responsible for mutations remain unknown. The overall goals of the proposed research are to examine the molecular dose of previously unexplored DNA adducts in rodents exposed to BD and 3-butene-1, 2-diol (BD-diol), comparing the data with mutation frequencies and mutational spectra to determine if a particular adduct could be used as a quantitative indicator of mutagenesis, and to evaluate effects of exposure on gene expression. The first hypothesis to be tested is that hydroxymethylvinyl ketone (HMVK) is formed in vivo during exposure to BD and BD-diol in a sex, species, and exposure concentration dependent manner resulting in important differences in mutagenicity. The second hypothesis is that promutagenic N1 adenine adducts convert to the more stable inosine adducts which are poorly repaired and accumulate during chronic exposure to BD. Several specific aims will be accomplished while addressing these hypotheses. Specific Aim 1 is to examine the formation of potentially mutagenic DNA adducts (specifically 1, N2-propanodeoxyguanosine) by HMVK in vivo. The second aim is to determine the utility of the N-terminal valine adduct of HMVK (HMVK-Val) as a biomarker of HMVK formation by BD and BD-diol. Specific Aim 3 is to develop methods for detecting N1- inosine, N1 - and N6 adenine adducts derived from BD metabolites in vivo. Specific Aim 4 is to determine the mutagenic responses induced by BD exposures and characterize the impact of BD-diol derived metabolites on the spectra of mutations induced by BD exposure in the B6C3F1 mouse and F344 rat to identify which adducts studied in Aims 1 and 3 are quantitative indicators of mutagenesis. Specific Aim 5 will examine the effects of exposure to BD and BD-diol on gene expression and DNA repair pathways. Collectively, these experiments have been designed to look at adduct formation, DNA repair, mutagenicity, and genomic alterations in rodents exposed BD and BD-diol, as well as the impact of glutathione depletion and DNA repair deficiency. Finally, HMVK-Val adducts will be measured in samples from BD exposed humans. Our research will identify critical metabolites and adducts that are responsible for BD mutagenicity, as well as develop biomarkers suitable for future molecular epidemiology studies. Ultimately these data will improve our understanding of critical mechanisms of toxicity and ability to accurately assess the risk of BD to humans.
Crisp Terms/Key Words: environmental exposure, clinical research, DNA damage, technology /technique development, inosine, DNA repair, chemical carcinogen, ketone, human tissue, gene mutation, mutagen, environmental contamination, diene, adduct, biomarker, laboratory rat, laboratory mouse
DESCRIPTION (provided by applicant):
Recent expansion of large scale confined animal feeding operations (CAFOs) is
generating a wide variety of health concerns in the USA and other nations.
Air and ground water pollution from swine CAFOs are of particular concern in
North Carolina, where industrial hog production has expanded rapidly since the
1980s. Airborne emissions are composed of hundreds of agents including
hydrogen sulfide, ammonia, volatile organic compounds, and dusts or
particulate matter that contains biological materials including proteins and
endotoxins. Nitrates, pathogens, and antibiotic residues have been documented
in ground water near swine CAFOs. The investigators propose a series of
community-based participatory studies that will (1) quantify community
exposures to hydrogen sulfide, volatile organic compounds, dusts, and
endotoxins; (2) evaluate relationships between air emissions and perceptions
of odor and irritation; (3) measure exposures to airborne emissions from
livestock operations to strengthen the design of an already-funded health
symptom survey; and (4) prospectively quantify relationships between ambient
exposures and respiratory symptoms, lung function, and other health status
measures among persons residing near swine CAFOs in North Carolina. They will
also (5) conduct surveillance for nitrates and antibiotic residues in well
water of study participants. Bacterial flora of any participants who report a
history of drinking water contaminated by veterinary antibiotic residues will
be tested for antibiotic resistance. Due to widespread distrust of biomedical
research in poor and people of color communities where NC swine CAFOs are
concentrated, community-based participatory research approaches are required
for addressing these health issues. The proposed studies build on five years
of community-driven research conducted by Concerned Citizens of Tillery and
the University of North Carolina School of Public Health, as well as on
extensive research on chemical odorants and their effects, and on water
quality, conducted by other project collaborators. This project will provide
new scientific data on exposures and human health effects of swine CAFOs and
increase the capacity of communities in eastern NC to improve public health
conditions in an underdeveloped region of the United States.
Crisp Terms/Key Words: air pollution, air sampling /monitoring, swine, disease /disorder proneness /risk, industrial waste, gastrointestinal disorder, public health, community health service, human subject, interview, questionnaire, statistics /biometry, epidemiology, longitudinal human study, emotion, pollution related respiratory disorder, spirometry, sensory discrimination, water pollution, water sampling /testing, quality of life, clinical research, health services research tag, odor, medically underserved population, environmental exposure
DESCRIPTION (provided by applicant): This competing continuation application builds on over 10 years of community-based participatory research conducted by a partnership of the North Carolina Farmworkers Project and Wake Forest University School of Medicine. This group's past research has developed and tested lay health promoter interventions to increase pesticide safety behaviors among Latino farmworkers (R24 ES08739) and among their families (R01 ES08739). In the course of this research, the partnership has also developed, analyzed, and published effective means to establish and sustain university-community collaboration. Despite efforts by our partnership and others to help farmworkers make their work environments safer and change their behaviors to reduce pesticide exposure, there are remarkably few data to document the actual routine exposure of farmworkers to pesticides in their work and home environments. To address this problem, this proposed project will accomplish 4 specific aims. It will: (1) use community-based participatory processes to design an acceptable and effective strategy for collecting valid and reliable data on routine farmworker pesticide exposure; (2) document pesticide exposure levels and variability in these levels among farmworkers in North Carolina using urinary biomarkers; (3) delineate the predictors of pesticide exposure levels among farmworkers in North Carolina, including farmworker workplace and household behaviors, characteristics of the work and household environments, psychosocial stressors and health beliefs; and (4) develop and implement a communication and dissemination plan for disseminating risk information in culturally and educationally appropriate formats to farmworkers concerning pesticide exposure. The research design for this project is based on a conceptual framework that contrasts proximal and distal determinants of pesticide exposure for farmworkers, and tests hypotheses derived from this conceptual model. The research will be conducted over 4 years. In year 1, data collection procedures will be finalized through collaborative efforts with our community partners. In year 2, data will be collected; this will involve 4 repeated measures at monthly intervals with a sample of 260 farmworkers across the agricultural season. A minimum of 3 data points is necessary to answer research questions about within-person variation in pesticide exposure. Data collection will include 2 components, a structured interview questionnaire and a urine sample. Laboratory analysis will be completed in years 2 and 3. In years 3 and 4, through the collaborative efforts of the community and academic partners, the communication and dissemination plan will be implemented, including returning results to participants, communicating results to the community, and communicating results to policy makers.
Crisp Terms/Key Words: environmental exposure, interdisciplinary collaboration, behavioral /social science research tag, clinical research, work site, environmental toxicology, psychological stressor, community, health behavior, pesticide, agriculture worker, occupational hazard, data collection methodology /evaluation, information dissemination, human subject, disease /disorder prevention /control, education evaluation /planning, health education, urinalysis, biomarker
DESCRIPTION: (provided by applicant) Everyone who works in agriculture is exposed to numerous environmental risk factors (weather, mechanical devices, chemicals, animals, wild plants, organic and inorganic dust, fungi) that can result in occupational injury and illness. Occupational skin disease (OSD) is a widely acknowledged, but poorly documented, occupational illness among all agricultural workers. Environmental risks are especially great for migrant and seasonal farm-workers. Most farm-workers are Latino immigrants, with the vast majority being from Mexico. Due to their lack of workplace control and limited treatment options, OSD among farm-workers must be examined in a health disparities and environmental justice framework. This study will employ in-depth interviews, surveillance, and a clinic-based study to: 1) delineate farm-worker interpretations of OSD symptomatology, etiology, self-care behaviors, and barriers to prevention and treatment seeking; 2) estimate the prevalence of OSD across the work season; 3) determine the risk factors for (a) the presence and severity of OSD symptoms, including work activities and exposures, environmental factors, farm-worker biological and personal characteristics, preventive behaviors, and treatment behaviors, and (b) skin-related quality of life; and 4) determine the predictors of OSD severity and specific diagnoses among farm-workers who present to migrant health clinics. Guided by a biopsychosocial model that acknowledges the multiple factors that determine the presence and severity of skin symptoms, and the impact of symptom severity on quality of life, this project will produce the first prospective data on occupational skin disease and its risk factors among migrant and seasonal farm-workers. The results of this project will be used in subsequent projects to address our long-term goal of reducing environmental risk for OSD among all agricultural workers. The project will be completed in an area of eastern North Carolina in which a large number of farm-workers are employed. There are 3 research components for this 4- year project. First, in-depth interviews will be used to elicit farm-workers' Explanatory Models for OSD. Second, a prospective surveillance study will follow 225 farmworker at 8 points during an agricultural season to delineate farm-worker perceptions of OSD symptoms, dermatological quality of life, and OSD risk factors. Finally, a clinic study will use telemedicine procedures to diagnosis OSD among 150 farm-workers who present at migrant clinics and delineate the risks associated with these diagnoses.
Crisp Terms/Key Words: rural health, health disparity, patient oriented research, disease /disorder etiology, clinical research, quality of life, migrant, Mexican American, Hispanic American, skin disorder diagnosis, skin disorder, perception, high risk behavior /lifestyle, health behavior, epidemiology, agriculture worker, occupational disease /disorder, interview, human subject, health care service availability, community health service, self care, disease /disorder prevention /control, environmental health, sign /symptom, disease /disorder proneness /risk, telemedicine
DESCRIPTION (provided by applicant): Approximately 16,000 municipal waste water treatment plants in the US produce over seven million tons (dry weight) of residual sludge each year; most is applied to agricultural lands as free fertilizer. This sludge, also known as biosolids, consists of sediments resulting from the treatment of waste water from homes, streets, schools, hospitals, and industries. In addition to nutrients useful for agriculture sludges contain pathogens, allergens, metals, industrial chemicals and Pharmaceuticals. As land application of sludges has increased, neighboring rural residents have reported health problems and impaired quality of life. Residents whose concerns have been dismissed by government officials have low trust in authorities and in health research conducted by government agencies and university researchers who have ties with sludge generators and industries that profit from sludge disposal. Many affected communities are in low income, rural areas, making land application of sludge an environmental justice issue. Since the 1990's community members from across the country have organized through conferences and the internet to seek assistance in conducting research into health problems that may be caused by land application of sewage sludge, and to educate citizens and government officials. Using CBPR methods developed in prior research on human exposure to hog waste, and building on community and research partnerships solidified at a recent participatory workshop, we propose to conduct an assessment of off-site migration of sludge constituents linked to an epidemiologic study of neighbors of sites permitted for land application of sludges. We will recruit neighbors of sites permitted for sludge application in North Carolina and Virginia to participate in a one-year longitudinal study of environmental exposures, symptoms, physiological functioning, and health- related quality of life. Neighbors in two types of areas will participate: areas where permits have been issued but no land application has yet occurred; and areas where sludges have been recently applied. Recruitment will be accompanied by environmental health and environmental justice education conducted under the leadership of experienced community based organizations.
DESCRIPTION (provided by applicant)
There is growing evidence that chronic exposure of humans to inorganic arsenic, a potent environmental oxidative stressor, is associated with the incidence of Type 2 diabetes. In contrast to what has been a prevailing beneficial view of antioxidants in preventing pancreatic ?-cell dysfunction in diabetes, this project proposes that in response to arsenic exposure, transcription factor Nrf2-mediated adaptive induction of endogenous antioxidant enzymes plays paradoxical roles in ?-cell function. The investigators hypothesize that, on the one hand, Nrf2-mediated antioxidant response blunts glucose-triggered `ROS signaling' that plays an important role in glucose-stimulated insulin secretion (GSIS); on the other hand, the response protects ?-cells from oxidative damage and subsequent apoptosis/necrosis. The investigators propose three specific aims: (1) Test the hypothesis that induction of antioxidant enzymes in response to arsenic exposure and related oxidative stress impedes glucose-triggered `ROS signaling' and thus GSIS; (2) Test the hypothesis in silico that adaptive induction of antioxidant enzymes in response to chronic oxidative stress impedes `ROS signaling', and explore intervention approaches that can improve `ROS signaling'; (3) Test the hypothesis that Nrf2-mediated antioxidant response is critical for protecting ?-cells from oxidative damage and apoptosis/necrosis induced by arsenic and/or glucose toxicity. The integrated wet-lab and computational approaches will allow to: (1) understand how environmental arsenic exposure impairs ?-cell function; (2) characterize the quantitative nature of the effect of arsenic-induced oxidative stress on `ROS signaling' that is involved in GSIS; (3) distinguish the specific roles of Nrf2 and its target antioxidant enzymes in `ROS signaling' and ?-cell function; and (4) identify novel targets and approaches to modulate insulin secretion and protect ?-cells from oxidative damage. This project will investigate the pathogenic mechanisms of Type 2 Diabetes caused by environmental arsenic exposure. The results may enable new therapeutic managements and preventive strategies for arsenic or other environmental oxidative stress-associated diabetes.
DESCRIPTION (provided by applicant): Millions of people in various geographical regions, including the US, are exposed to unsafe levels of inorganic arsenic (iAs) in drinking water. The research of the effects of chronic exposure to iAs has commonly focused on its carcinogenic potency. However, epidemiologic studies indicate that iAs exerts other adverse effects that do not involve cancer. Several studies in arseniasis-endemic areas of Taiwan, Bangladesh, and Mexico have linked chronic exposures to high or moderate levels of iAs in drinking water to an increased risk for type 2 diabetes mellitus (T2D). Although results of epidemiologic studies in low-exposure areas or occupational settings have been inconclusive, laboratory research shows that exposures to iAs can produce symptoms that are consistent with T2D. In our preliminary studies, mice chronically exposed to iAs in drinking water developed impaired glucose tolerance. The major fraction of arsenic retained in tissues of these mice, including liver, pancreas, adipose and skeletal muscle tissues, was represented by methylated arsenicals, the products of the methylation of iAs by arsenic (3+ oxidation state) methyltransferase (AS3MT). Our in vitro studies showed that methylated trivalent arsenicals are more potent than iAs as inhibitors of insulin signaling and insulin-stimulated glucose uptake in cultured adipocytes. Notably, concentrations of arsenicals that inhibit glucose uptake by adipocytes and arsenic concentrations in tissues of mice that developed impaired glucose tolerance after exposure to iAs in drinking water are similar to arsenic concentrations in livers of residents in the arseniasis areas of Bangladesh. These results suggest that the formation of methylated trivalent arsenicals in the course of iAs metabolism may be a determining factor for development of T2D in individuals exposed to iAs in drinking water and that insulin-activated signal transduction pathway is the key target for these arsenicals. Based on these findings, we propose a translational research project that will examine diabetogenic effects of iAs in cultured cells, laboratory mice, and in humans. The main goals of this project are (i) to further characterize the association between iAs exposure and T2D, (ii) to identify molecular mechanisms for the diabetogenic effects of iAs exposure, (iii) to evaluate the roles specific metabolites of iAs play in these effects, and (iv) to characterize AS3MT polymorphisms that are associated with the increased production of these metabolites. Results of this project will advance knowledge in the area of environmental toxicology of As that has not been systematically studied, providing novel information that will improve the risk assessment of diabetes in arseniasis-endemic areas and the identification of individuals with increased susceptibility to the diabetogenic effects of chronic exposures to iAs. PUBLIC HEALTH RELEVANCE: Millions of people worldwide are exposed to arsenic in drinking water. Previous epidemiologic studies have linked chronic exposures to arsenic to an increased risk for type 2 diabetes mellitus. We propose a translational research project that will examine diabetogenic effects of arsenic in cultured cells, laboratory mice, and in humans. The goals of this project are to identify mechanisms by which exposures to arsenic induce diabetes and to characterize genetic polymorphisms that are associated with increased risk of diabetes for individuals exposed to arsenic in drinking water.
The UNC-Chapel Hill Center for Environmental Health and Susceptibility brings population science,
medical and biomedical researchers together to examine major issues in environmental health resulting from gene environment interactions that affect an individual's susceptibility to disease. The highly complex nature of such interactions demands in-depth expertise in many different disciplines to understand the influence of genetic, metabolic, endocrine, developmental and toxicological issues on disease outcomes. This proposal seeks core support to achieve this goal by fostering enhanced interaction and collaboration among researchers, so that the expertise of experts in diverse fields of environmental health can expand the vision and capabilities of a preeminent cadre of researchers to excel far beyond the norm. Such interaction and collaboration has been demonstrated during the first three years of support and will continue among the five research cores: Genetic Susceptibility, Developmental Susceptibility, Toxicokinetic Susceptibility, Transomics, and Obesity Research. The core support will also make state-of-the-art resources and expertise available to our scientists through the support of four facility cores. Molecular Epidemiology will provide centralized resources for biospecimen
collection, preparation, storage and tracking, and high throughput genetic analysis.
Biostatistical and Epidemiologic Methods will provide consultation on statistical and study design and analysis to help ensure that valid scientific conclusions emerge from our environmental health research. The Biomarkers core makes available training, expertise and sample analysis using expensive and sophisticated instrumentation for mass spectrometry, molecular biology, genomics, proteomics and metabolomics. Finally, the Nutrient Assessment core will supply analysis and dietary assessment of nutrients and biomarkers of nutritional status that may modulate environmental health and disease. The core support also provides funds for a multifaceted Pilot Project Program that promotes interdisciplinary collaboration, encourages young investigators to enter environmental health research, and enhances use of the facility cores. In addition, the requested support will provide a diverse enrichment program that will increase interactions with visiting investigators and broaden the scope of environmental health
research. Support for a Community Outreach and Education Program will facilitate translational
activities that communicate the scientific advances of the Center to the lay community, concerned citizens groups, and government. This NIEHS Center of Excellence will be coordinated by an Administrative core that reports through the School of Public Health at the University of North Carolina.
Despite the tremendous inter-individual variability in the response to environmental toxins, we simply do not understand why certain people develop disease when challenged with environmental agents and others remain healthy. Although an emerging consensus suggests that many of the complex and prevalent diseases that humans develop occur as a result of
multiple biologically unique gene-gene and gene-environment interactions, this conceptual framework is limited. Environmental exposures affect those that are vulnerable temporally (age), spatially (geographically), and by unique circumstance (co-morbid disease, nutritional status, economic status, race, and genetics). Even this paradigm fails to address the complex interaction of endogenous and exogenous risks that ultimately cause disease. While the recent
advances in human and molecular genetics provide an unparalleled opportunity to understand how genes interact with environmental stimuli to either preserve health or cause disease, without accounting for the temporal, spatial, and other unique components of an individual's microenvironment, our understanding of environmental health will remain incomplete. Thus, the theme of our proposed Center is to understand how biological, physiological, and social
aspects of vulnerability alter the effect of environmental toxins on human health. Specific goals of the Center are:
1. To develop and operate an interdisciplinary environmental health sciences research center with a focus on understanding how biological, physiological, and social aspects of vulnerability alter the effect of environmental toxins on human health;
2. To enhance research in environmental health at Duke by promoting research interactions between existing interdisciplinary programs in environmental health, fostering the development of new research loci in environmental health, and establishing an infrastructure to support and extend research in environmental health;
3. To identify new and creative policy approaches that combine advanced understanding of environmental health sciences with the reality of policy application; and
4. To serve as a technical and educational resource to the region, the nation, and to international agencies in the area of environmental health.
DESCRIPTION (provided by applicant)
The major theme of this proposed Superfund Hazardous Substances Basic Research Program is the elucidation of mechanisms of exposure and toxicity in humans and ecosystems to particular Superfund chemicals selected based upon their potential significance with respect to developmental effects. The major goals of the Program are as follows: 1) to elucidate mechanisms of developmental toxicity of selected Superfund chemicals and chemical mixtures; 2) to facilitate the transfer of mechanistic information obtained across selected invertebrate and vertebrate models relevant to human and/or ecological health; 3) to utilize microarray approaches for assessing gene expression during normal and perturbed development in our models, and enhance the genomic database for these models; 4) to develop highly sensitive and efficient markers for developmental toxicities that can be incorporated into human health and ecological assessments; 5) to elucidate microbial and photolytic transformations of selected Superfund chemicals that augment their environmental fate and effects upon development; 6) to use Geographic Information Systems (GIS) spatial analysis to develop and disseminate preventive risk models for environmental health in North Carolina, with an emphasis on children; 7) to effectively deliver the Program's research results to critical members of the scientific, governmental, business and lay communities; and 8) to enhance interdisciplinary research, and graduate and post-graduate training, in the biomedical and environmental sciences.
DESCRIPTION (provided by applicant)
The primary objective of the NIEHS Superfund Basic Research Program (SBRP) is to understand the human health and environmental risks associated with hazardous waste sites, with the goal of more accurately assessing risks and more efficiently remediating hazardous waste sites. Since its inception, the UNC SBRP has focused its multidisciplinary research on addressing scientific issues that underpin the assessment of human risk and the development of improved methods for remediation of hazardous waste sites, in the proposed research, we will further advance this goal through the following objectives: 1) apply new molecular and analytical tools in a systems biology framework to understand critical pathways for environmental disease and bioremediation; 2) develop biomarkers of exposure and effect for humans and experimental models of environmental disease; 3) use this knowledge to elucidate the modes of action for major chlorinated hydrocarbons and polycyclic aromatic hydrocarbons; 4) examine the effects of dose-response on such modes of action; 5) evaluate and understand genetic susceptibility to hazardous chemicals; 6) determine the factors controlling dermal absorption of polycyclic aromatic hydrocarbons and the relationship of internal dose to both skin and systemic exposure; and 7) develop and evaluate remediation methods in complex, field-relevant systems for their potential to reduce overall human exposures and risks. These objectives will be accomplished through six diverse, but highly interdigitated research projects, two research support cores, a research translation core, a training core and an administrative core.
DESCRIPTION (provided by applicant)
Despite the tremendous inter-individual variability in the respond to
environmental toxins, the investigators simply do not understand why certain
people develop disease when challenged with environmental agents and others
remain healthy. Yet, there is emerging consensus that many of the complex
(and prevalent) diseases that humans develop occur as a result of multiple
biologically unique gene-gene and gene-environment interactions. The recent
advances in human and molecular genetics has provided an unparalleled
opportunity to understand how genes and genetic changes interact with
environmental stimuli to either preserve health or cause disease. The theme
of this Center is to use gene expression profiling to understand the effect of
environmental stresses on human health. This will be accomplished by
establishing an interdisciplinary Center that supports the use of
complementary biologic systems (humans, mice, zebrafish and worms) to
investigate the role of genetic susceptibility in the pathogenic response to
specific types of environmental stress (bacteria, malnutrition, and metals).
This approach will enable the investigators to develop and investigate
environmental models of human disease that represent biologically unique gene-environment-
pathophysiological phenotypes. Microarray analyses will be used
to comprehensively evaluate the biological response to environmental stress
and to identify pathogenic mechanisms that are relevant to innate immunity,
neural tube defects, and transition metal toxicity. The end result is a broad
based yet highly integrated program that has the potential to make a number of
novel, related observations. The overall hypothesis unifying this research
program is that gene expression profiling will identify genes and pathogenic
processes that are critical to human environmental health and disease. In
aggregates the coupled scientific findings from the proposed Program will
substantially enhance our understanding of environmental toxicology and
genomics.
Crisp Terms/Key Words: environmental health, gene expression, clinical research
DESCRIPTION (provided by applicant): Air pollution and cardiovascular disease mortality are clearly linked, yet population-based studies of air pollution and arrhythmogenesis have not been conducted in women. Moreover, extant studies have not evaluated whether acute, pro-arrhythmic effects of exposure to ambient air pollutants are modified by three potentially important markers of the environmental, socioeconomic and clinical context within which such exposures ostensibly increase cardiovascular risk in women: chronic exposure status, neighborhood of residence, and disease-specific susceptibility factors for sudden death. We will investigate these issues in an ethnically diverse population of 68,133 post-menopausal women aged 59-70 years from the 40 clinical centers and their satellites participating in the baseline examination of the Women's Health Initiative clinical trial (WHI, 1993-1998). We will estimate exposure to criteria pollutants (PM10; NO2; SO2; CO; 03) in ambient air at geocoded participant addresses using validated, spatial models that rely on pollutant concentrations recorded at adjacent fixed-site monitors in the U.S. Environmental Protection Agency Aerometric Information Retrieval System. Spatially interpolated exposures will take the form of average pollutant concentrations on the day of, and for the 1, 2 & 3 days and 1, 2 & 3 years preceding the baseline examination and year three follow-up. We will reliably evaluate autonomic function, atrioventricular conduction, ventricular depolarization, ventricular repolarization and ectopy from resting, standard 12-lead ECGs recorded at the WHI examinations. After removing seasonal variations and long-term trends, and in addition, adjusting for demographic and meteorological covariates, we will explore the putative association between air pollutants and ECG measures. Then we will determine whether the associations are modified by chronic exposure status, socioeconomic characteristics of geographic regions in which participants live, and clinical risk factors for sudden cardiac death using Bayesian, hierarchical models. Lastly, we will assess sensitivity of our findings to adjustment for exposure measurement error arising from spatial interpolation of personal exposures from ambient concentrations of air pollutants. Our ancillary study will thereby evaluate the biologically relevant proarrhythmic mechanisms and contextual features linking ambient air pollution to cardiovascular disease morbidity and mortality in a large, ethnically and geographically diverse group of postmenopausal women. In doing so, it will improve understanding of associations between airborne pollutants and cardiovascular disease mortality, facilitate assessment of current U.S. air quality standards, and yield insight into the relatively gradual decline of sudden cardiac death rates among U.S. women over the last decade.
Crisp Terms/Key Words: cardiovascular disorder risk, clinical research, gene environment interaction, women's health, human data, socioeconomics, female, human morbidity, longitudinal human study, human population study, mathematical model, electrocardiography, sudden cardiac death, arrhythmia, geographic site, postmenopause, cardiovascular function, cardiovascular disorder epidemiology, air pollution, human old age (65+), human middle age (35-64)
DESCRIPTION (provided by applicant): Hypoplastic left heart (HLH) is a grave congenital condition, uniformly fatal if untreated and requiring multiple surgeries for survival. Recently a cluster of HLH was discovered in children in the Baltimore-Washington area that correlated with accidental release of dioxins and polychlorinated biphenyls (PCBs). In an unrelated incident in Eastern NC during 2004, three migrant workers gave birth to infants with severe congenital defects, including one baby born without limbs, another with severe facial defects and associated heart abnormalities, and a third lacking reproductive structures who died shortly after birth; all birth defects were associated with pesticide overexposure. Strikingly, the PCB- induced HLH and pesticide associated birth defects may be related because PCBs and some pesticides disrupt cells by the same mechanism: activation of the aryl hydrocarbon receptor (AHR) signaling pathway which leads to tissue specific cell cycle arrest. Recently we created a novel model for toxin induced HLH in zebrafish where the AHR agonist PCB-126 induces a stringy heart with a reduced ventricle and out flow tract defects identical to those in HLH; remarkably, PCB-126 up regulates p53 and down regulates a heart specific transcription factor tbx5, implicated in Holt-Oram Syndrome and in HLH. We also found that the common organophosphate pesticide chlorpyrifos, both a developmental neurotoxin and AHR agonist, induces an enlarged atrium and a diminished ventricle reminiscent of that seen in PCB-treated zebrafish. Indeed, the cardiotoxicity common to PCB-126 and chlorpyrifos may reflect the fact that both are AHR agonists. We propose to create fluorescent reporter strains in zebrafish that will signal in living embryos when an AHR agonist disrupts cardiovascular development, and will use this approach to evaluate pesticides for developmental cardiotoxicity, particularly for teratogenic synergy. In Aim 1, we test the hypothesis that PCB-126 or chlorpyrifos activated AHR leads to down regulation of tbx5 followed by p53 mediated cell cycle arrest in the heart by using genetic epistasis and DNA microarray analysis. In Aim 2, fluorescent reporters in living zebrafish hearts will be constructed and then validated for use in signaling cardiotoxicity from exposure to PCB-126 and chlorpyrifos. The reporter strains then will be used to screen pesticides used in agriculture, in combinations and sequence typical of a growing season. We expect that our studies will provide a new testing paradigm to more accurately predict risk to EPA approved toxins as they are encountered routinely in real life. We seek to protect those in our society most vulnerable to toxin exposure those living in poverty, those with inadequate health care and migrant farm workers suffering occupational over exposure to pesticides.Hypoplastic left heart (HLH) is a grave congenital condition, uniformly fatal if untreated and requiring multiple surgeries for survival. Recently a cluster of HLH was discovered in children in the Baltimore-Washington area that correlated with accidental release of banned dioxins and polychlorinated biphenyls (PCBs). We have created a model for HLH in zebrafish where the AHR agonist, PCB-126, induces a stringy heart with a reduced ventricle and out flow tract defects identical to those seen in children with HLH. We propose to create fluorescent reporter strains in zebrafish that will signal in living embryos when an AHR agonist disrupts cardiovascular development and will use this approach to evaluate pesticides for developmental cardiotoxicity; we seek to protect those in our society most vulnerable to toxin exposure those living in poverty, those with inadequate health care and migrant farm workers suffering occupational over exposure to pesticides.
DESCRIPTION (provided by applicant)
Children's Exposure to Flame Retardants: Effects on Thyroid Hormone Regulation. The flame retardant chemicals polybrominated diphenyl ethers (PBDEs) are persistent and ubiquitous pollutants, particularly in indoor environments. Human biomonitoring studies have shown that levels of PBDEs are more than an order of magnitude higher in the United States population relative to any other region measured, including other industrialized countries in Europe. Furthermore, children between the ages of 0-4 are predicted to have the highest exposure and body burdens of PBDEs due to placental transfer, breast milk ingestion and inadvertent dust ingestion. Children's exposure is of concern because laboratory studies using animal models have found that PBDEs exert negative effects on thyroid hormone homeostasis, which is more pronounced in newborn animals relative to adults. The central hypothesis of this proposed study is that children in the United States are receiving greater exposure to PBDEs from inadvertent dust ingestion, leading to adverse effects on thyroid hormone regulation. The objectives of this study are threefold: 1) to measure children's (ages 1-4) exposure to PBDEs from indoor dust, determine ingestion rates from hand to mouth contact, and measure serum levels of PBDEs in these children; 2) to determine the products of hepatic metabolism of PBDEs; and 3) to determine the effects of PBDEs and their metabolites on intra- and extra-cellular thyroid hormone regulation to elucidate the mechanisms of action for thyroid toxicity. Using in vitro assays the following will be investigated: the effects of PBDEs and their metabolites on intracellular thyroid hormone levels, deiodinase (DI) enzyme activity, mRNA expression of thyroid regulating genes, and specific binding to thyroid binding globulin. The principal investigator also plans to develop and validate a new method to measure thyroid hormone levels and DI activity using liquid chromatography tandem mass spectrometry (LC/MS-MS), which will use stable isotopes instead of radio-labeled isotopes used in more traditional methods. This method could then be used as a screening tool for assessing effects of chemicals on intra-cellular thyroid regulation mediated by DI enzymes. Data gathered from this project will increase the understanding of PBDE effects on thyroid hormone regulation and aid in understanding children's developmental health risks from exposure to flame retardant chemicals in indoor environments.
DESCRIPTION (provided by applicant):
Epidemiological data suggest that the incidence of both precocious puberty and impaired fecundity are increasing. It has been hypothesized that exposure to endocrine active compounds (EACs), may play a role in this trend. Advanced puberty and persistent estrus have been documented for many EACs in rodents but very little is known about the mechanisms by which EACs produce these effects. This lack of knowledge makes it difficult to predict how a potential EAC may ultimately affect human health. In females, puberty results from the maturation of the hypothalamic-pituitary-gonadal (HPG) axis and culminates with the onset of cyclic gonadotropin releasing hormone (GnRH) pulses that stimulate ovulation. The anterior ventral periventricular nucleus (AVPV) is the primary regulator of GnRH neuronal activity. The specific hypothesis behind the proposed research is that the disruption of puberty by neonatal exposure to the EACs Bisphenol-A (BPA) and genistein (GEN) results from the improper sexual differentiation of the AVPV and thus the estrogen receptor (ER)-initiated signal transduction pathways that regulate GnRH secretion. This hypothesis is supported by the following preliminary data. First, both compounds advanced pubertal onset. Second, both compounds
defeminized an AVPV neuronal phenotype that contains ER?. Third, GEN disrupted the estrus cycle postpuberty. And finally, both compounds defeminized adult AVPV volume. Using behavioral, anatomical and molecular techniques the investigators will compare the effects of BPA and GEN with agonists specific for the two forms of the estrogen receptor (ER? and ER?) to characterize the signal transduction pathways through which EACs affect the timing and progression of puberty. For all studies, the dose of EAC administered will fall within the range relevant to human exposure. AIM 1: Characterize the effect of neonatal BPA, GEN, the ER? agonist DPN or the ER? agonist PPT exposure on kisspeptin and galanin signaling in the AVPV at puberty onset. AIM 2: Map the expression of ER? and ER? in the prepubertal rat AVPV and determine if this pattern is disrupted by BPA, GEN or DPN or PPT. AIM 3: Examine how estrus cyclicity and sexual behavior post-puberty are affected by neonatal exposure to BPA, GEN, DPN or PPT. AIM 4: Characterize the impact of neonatal BPA, GEN, DPN or PPT on AVPV volume, AVPV ER and kisspeptin content, and hormone-stimulated GnRH neuronal activation post-puberty.
DESCRIPTION (provided by applicant)
This program will use a systems biology approach to investigate the mechanism(s) whereby human melanocytes undergo neoplastic transformation, clonal expansion, and malignant progression to cutaneous melanomas. The proposed studies are based on the premise that an environmental carcinogen, solar radiation, contributes to development of melanoma by inducing chromosomal damage in proliferating melanocytes. Malignant melanomas are of significant public health concern because their incidence is rising and no effective medical intervention is available for reducing morbidity and mortality. The guiding hypothesis of this program is that breakdowns in the systems of defense against DNA damage underlie the acquisition by meianocytes of a mutator phenotype, which reduces the effective dose of solar radiation needed to induce each subsequent step in the multi-stage development of cancer. Functional defects in DNA repair and cell cycle checkpoints, individually and in concert, contribute to genome destabilization, and thus increase the probability of accumulation in a single clone of the genetic alterations required for development of melanoma. Three research projects and three service cores will interact extensively to monitor quantitatively and qualitatively the system of response to DNA damage in UV-damaged human and murine melanocytes. Two research projects will determine how nucleotide excision repair, post-replication repair, double-strand break repair, and cell cycle checkpoint responses to UV-induced DNA damage cooperate to suppress chromosomal aberrations and allelic deletions in the melanoma tumor suppressor locus CDKN2A/INK4A. Functional assays will associate chromosomal instability and defective DNA damage responses in melanoma cell lines and melanocytes with alterations in melanomagenic genes. A third research project uses in vivo models of melanoma in mice and humans to monitor chromosomal destabilization during stages of development of melanoma. program investigations will determine how activating mutations in melanoma oncogenes and inactivating mutations in melanoma suppressor genes contribute to chromsomal instability and malignant progression. New findings will lead to the discovery of biomarkers with potential therapeutic and prognostic value for specific types of melanomas and different stages of melanoma progression. Computational models will be created to predict how DNA repair and checkpoint functions suppress UV-induced chromsomal damage. These studies will establish the degree to which melanoma-associated genetic alterations alone and in combinations contribute to a UV-chromosomalmutator phenotype and enhance environmental carcinogenesis. Lessons learned in this program will also impact on methods of risk assessment by showing that the effective dose of a carcinogen falls during the multi-step development of cancer.
PROGRAM AS AN INTEGRATED EFFORT
DESCRIPTION (provided by applicant):
The basic leucine zipper (bZIP) transcription factor, CCAAT/enhancer binding protein-a/(C/EBPa) is abundantly expressed within keratinocytes of the epidermis, however relatively little is known regarding its function in skin. C/EBPa has been implicated as a human tumor suppressor in acute myeloid leukemia and our results in experimental systems suggest C/EBPa negatively regulates keratinocyte growth and may have a tumor suppressor function in skin tumorigenesis. Sunlight, more specifically the UVB component of sunlight, causes DMA damage and is responsible for the majority of human skin cancers. Keratinocytes can respond to UVB irradiation by undergoing cell cycle arrest, apoptosis and/or altered differentiation. We have discovered that UVB, as well as other DNA damaging agents, are potent inducers of C/EBPa expression in human and mouse keratinocytes and that this induction requires p53, Thus, we have identified C/EBPa as a novel p53-regulated DNA damage-inducible gene in human and mouse keratinocytes. The ability of cells to respond to DNA damage is essential to ensure the integrity of the genome. DNA damage can initiate the activation of cell cycle checkpoints that arrest cell cycle progression preventing replication of damaged DNA and allowing time for DNA repair. We hypothesize that UVB-induced C/EBPa has a DNA damage checkpoint function involving cell cycle arrest and we propose the loss of UVB-induced C/EBPa would enhance UVB carcinogenesis. While p53 is an absolute requirement for UVB-induced C/EBPa, we have observed that catalytically active GSK is also required. We propose that UVB-induction of C/EBPa involves direct binding of p53 to the C/EBPa promoter resulting in increased expression of C/EBPa and that nuclear GSK3 has a regulatory role in this process. Characterization of the biological function of C/EBPa in the UVB-response in keratinocytes as well as how the UVB signal is translated into the transcriptional up-regulation of C/EBPa will provide new insight into mechanisms of UVB-induced gene regulation, cellular responses and skin cancer.
DESCRIPTION (provided by applicant): Nerve gases such as sarin are used in warfare and terrorism. Despite sarin's known role as a neurotoxicant in the mature organism, there is almost no information on the thresholds or mechanisms by which it exerts its effects on the more sensitive developing brain, and the current proposal will establish an avian model for such effects. Chicks, like humans, are vulnerable to organophosphate-induced neuropathies and the ready availability of chick eggs and the absence of confounding maternal toxicity make the chick an ideal model for these studies. Based on our recent findings with organophosphate pesticides, we hypothesize that a defect in the cholinergic-induced translocation/activation of PKCv in the intermedial part of the hyperstriatum ventrale (IMHV) is a major component in the mechanisms of the organophosphate-induced teratogenicity of imprinting behavior in the chick. The relationship between PKC and imprinting will be verified in a pharmacological study. Sarin will be injected into chicken eggs and the IMHV nucleus-related imprinting behavior of the hatching chicks will be evaluated, along with cholinergic-induced PKC function and cholinergic markers related to imprinting and learning. The results will be compared to an additional innervation (serotonin). Special emphasis will be placed on neuroteratogenicity at doses that do not cause malformation so as to model the effects of apparently subtoxic exposures that might otherwise go undetected in a terrorist incident. The findings will provide a model for ascertaining the mechanism of sarin neurobehavioral teratogenicity for future studies on the reversal of the defects using therapies already established in our laboratories, and for extension of the work to mammalian models. The avian model may also be useful for rapid screening of developmental neurotoxicity of other nerve agents. Our specific aims are: 1. To establish an avian (chick) model for sarin neurobehavioral teratogenicity. 2. To test the hypothesis that sarin prehatch administration in doses below the systemic toxicity threshold (established in SA1) impairs behaviors related to cholinergic innervation. 3. To test the hypothesis that abolition of the cholinergic-induced translocation/activation of PKC, mainly the gamma isoform, in the IMHV is a major mechanisms underlying the neurobehavioral teratogenicity of sarin, and to assess the relationship of this defect to presynaptic and postsynaptic cholinergic function upstream from PKC, comparison to serotonin.
DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is a devastating, incurable and rapidly fatal disorder of the motor neurons responsible for voluntary muscle movement. Genes responsible for the familial form of ALS have been identified, but the majority of ALS is sporadic and has a complex etiology with contributions of both genetic and environmental factors. The hypothesis that gene-environment (GxE) interaction may play a substantial role in ALS pathogenesis is supported by studies of high-risk clusters in the Western Pacific Islands. ALS is a disease of high priority for the Department of Veterans Affairs (VA) since an increased incidence of the disease has been reported in deployed compared to non-deployed Gulf War veterans. Recently, the VA has initiated a National Registry of veteran ALS patients, which is expected to recruit approximately 1,500 patients with blood samples over the next three years. Given this unique resource, the explosion of data from the Human Genome Project, and the development of new laboratory and statisticalgenetic analysis tools, the time is ripe for new approaches to dissecting the etiology of ALS, with an emphasis on uncovering complex GxE interactions. The specific aims of the study proposed here are to (1) ascertain 3,000 veteran controls frequency-matched to the ALS Registry patients by age, sex, ethnicity and branch of military service; (2) collect environmental risk factor information from ALS patients and controls, building upon an instrument currently used in other ALS studies, which will be modified and expanded to include military-specific exposure assessment; (3) genotype nuclear DNA of ALS patients and controls for single-nucleotide polymorphisms (SNPs) in a number of putative candidate genes, using an efficient DNA pooling strategy combined with high-throughput individual genotyping; (4) genotype mitochondrial haplogroups of ALS patients and controls; and (5) perform statistical analysis of case-control and case-only data to identify main effects of genetic and non-genetic risk factors for ALS as well as GxE interaction. Both traditional regression-based well as novel computationally intensive methods will be employed. Genetic and environmental effects on disease progression will also be examined. Our study will not only be of great relevance for the veteran population, but is also likely to improve our understanding of ALS in the general population.
DESCRIPTION (provided by applicant): The overall objective of this proposal is to determine the mechanisms by which phthalate esters downregulate testosterone production in the developing fetal rat testes, resulting in antiandrogenic effects on the developing male reproductive tract. Phthalate esters are a class of environmental chemicals to which humans are ubiquitously exposed and which cause antiandrogenic effects on the developing male reproductive tract in rats. The mechanisms by which phthalate esters cause their effects remain to be determined. In preliminary studies, global changes in gene expression in the developing rat testis following in utero exposure to di(n-butyl) phthalate (DBP) were examined. A significant finding was that DBP produced a reduction in key genes in pathways associated with either steroid production or the provision of substrates for this activity. It is therefore hypothesized that phthalates decrease testosterone in the developing testes because of a coordinate disruption in cholesterol transport and steroid biosynthesis. This hypothesis will be tested by investigating the following specific aims: 1) Identify the key steps involved in cholesterol transport and testosterone biosynthesis that are targets for disruption by in utero exposure to DBP in the developing fetal rat testes, 2) Determine the consequences of DBP-induced changes in target gene and protein expression identified in Specific Aim 1 on fetal testicular cell signaling pathways, cholesterol transport, and steroidogenesis, and 3) Establish the molecular mechanism by which DBP downregulates expression of genes involved in cholesterol transport and steroid biosynthesis. Quantitative RT-PCR and protein analysis will be used to identify gene targets in the developing fetal testis following in utero exposure to DBP. The promoter regions of selected gene target will be further examined in vitro to determine the mechanism by which phthalate esters act on cholesterol transport and steroidogenesis. The proposed studies will identify critical genes and pathways associated with cholesterol transport that are targets for DBP in the male rat in utero and will aid in determining potential human risks from exposure to this class of environmental chemicals.
DESCRIPTION (provided by applicant): Ozone (O3) and particulate matter (PM) are the most commonly encountered air pollutants in the United States. Exposure to even low levels of these pollutants has been associated with increased hospitalizations for respiratory disorders, exacerbations of asthma and other respiratory tract diseases. Coarse and fine mode PM is comprised of a number of classes of components, including biologicals, such as endotoxin (or lipopolysaccharide or LPS). Though regulated and considered on an individual basis, people often encounter increased exposure to O3 and LPS simultaneously with low level exposures causing exacerbation of lung disease. A number of observations suggest that LPS and O3 share a number of general mechanistic features, which mediate induction of neutrophilic inflammation. We have observed that expression of CD11b on circulating monocytes (and to lesser extent neutrophils) correlates very well with neutrophil influx to the airway following challenge with either agent. Others have observed that the toll-like receptor 4 (TLR4, which along with CD14 is a primary receptor for LPS) has been implicated in the airway response of rodents to ozone. The inflammatory nature of the response to both O3 and LPS, taken together with the observations outlined above, suggests that common determinants of susceptibility account for increased responsiveness to both stimuli. Animal studies suggest that ozone modifies the response to LPS. In humans, we have found that challenge with low levels of LPS can enhance macrophage responsiveness, and suspect that low level O3 may act similarly. Taken together, these observations lead to the following hypotheses: 1. That inflammatory response to ozone will correlate with response to LPS, suggesting a common airway inflammation response phenotype; 2. That low-level O3 exposure enhances macrophage responsiveness to inflammatory stimuli, and; 3. That low level ozone will enhance response to LPS. Testing these hypotheses will be used to better define the ways that O3 and LPS interact to exacerbate airway disease.
DESCRIPTION (provided by applicant): There are currently no effective strategies for the treatment of chronic airway fibrosis in asthma or interstitial pulmonary fibrosis that result from environmental exposures to a wide variety of inhaled allergens and toxicants. It is generally accepted that current anti-inflammatory therapies fail to improve fibrotic outcomes in the lung. Therefore, the development of translational approaches that target fibrosis are urgently needed. Our work has shown that interleukin (IL)-13, a key mediator of asthma and fibrosis, stimulates the production of platelet-derived growth factor (PDGF). The binding of PDGF to cell-surface PDGF receptors results in the proliferation of fibroblasts, the principal cell type that secretes collagen to form fibrotic scar tissue. IL-13-induced PDGF production by lung cells is tightly regulated by STAT transcription factors; STAT-6 promotes IL-13-induced PDGF production while STAT-1 suppresses PDGF production. The primary objective of this project is to explore innovative strategies aimed at reducing IL-13-induced PDGF signaling and fibrosis. Our hypothesis is that inhibition of PDGF production, PDGF receptor binding, or PDGF receptor phosphorylation will reduce airway or interstitial fibrosis in established mouse models of chronic lung disease. In the first aim we will determine whether the oral administration of bis(maltolato)oxovanadium(IV) (BMOV), a bioavailable form of vanadium that is used for diabetes therapy, decreases PDGF levels and airway fibrosis in vivo in mouse models of asthma and interstitial pulmonary fibrosis. Because vanadium activates STAT-1 to reduce IL-13-induced PDGF production in lung cells in vitro, we will determine if BMOV reduces airway fibrosis in vivo using the ovalbumin mouse model of asthma and in a bleomycin mouse model of interstitial fibrosis. In the second aim we will determine whether administration of a monoclonal neutralizing antibody to selectively block PDGF binding to the PDGF receptor reduces fibrosis in mouse models of asthma and pulmonary fibrosis. In the final aim, we will determine whether blocking PDGF receptor tyrosine kinase activity reduces fibrosis in a mouse model of asthma. This aim will utilize the receptor tyrosine kinase inhibitor, imatinib mesylate, to block PDGFR phosphorylation. If any one of the three proposed strategies for blocking PDGF signaling result in amelioration of fibrosis, then this would provide a breakthrough for future application to clinical trials aimed at the treatment of airway fibrosis in asthma or interstitial pulmonary fibrosis. Asthma and pulmonary fibrosis are chronic lung diseases that result from environmental exposure and genetic susceptibility to a wide variety of inhaled allergens and toxicants. In the United States there are over 200,000 patients with pulmonary fibrosis, and of these over 40,000 expire annually. 20 million people in the United States have been diagnosed with asthma and nearly 9 million of them are children. Therefore, these chronic lung diseases clearly pose a major health problem. Airway fibrosis in asthma is part of a chronic remodeling process that contributes to the obstructive nature of this disease and reduces lung function. Moreover, there are currently no effective treatment strategies to reduce airway fibrosis in chronic asthma, nor are drugs available that significantly reduce interstitial pulmonary fibrosis. We will attempt to develop preclinical strategies aimed at reducing growth factor signaling, fibroblast proliferation, and collagen deposition in mouse models of chronic asthma and interstitial pulmonary fibrosis.
DESCRIPTION (provided by applicant): For both adults and young children acute, and repetitive exposure of the airways to air toxins has had led to both transient, and reversible airway injury, but also to remodeling of the airway with impairment of lung growth and pulmonary function. In the completely normal/healthy airway, exposure to O3, a ubiquitous urban air pollutant, induces an inflammatory response that is characterized by increases in epithelial permeability, neutrophil infiltration, and bronchial hyperreactivity. Inhalation of the pleiotropic pro-inflammatory cytokine tumor necrosis factor (TNF) leads to the development of nearly identical responses: hyperresponsiveness of the bronchial airway (AHR), and neutrophil influx. We have recently found a link between these 2 challenges: whereby in single laboratory exposures of young healthy subjects (n=135), a common single nucleotide polymorphism (SNP) in the TNF gene (-308), confers susceptibility to an ambient concentration of O3. Our preliminary results were highly significant and subjects, homozygotic (A/A) or heterozygotic (G/A) for the mutant allele of the TNFa (-308) polymorphism, were 2-times as likely to develop sensitivity to methacholine after O3 as compared to subjects with the wild-type TNFa (-308) (G/G) haplotype. Previous reports suggest that the TNFa (-308) polymorphism leads to increased TNF gene transcription and increased TNFa cytokine production. However, the functional significance of this common TNF polymorphism remains controversial; and moreover, the functional implications of the TNFa (-308) polymorphism in the lung remain undeveloped. We hypothesize that subjects - homozygotic (AA) or heterozygotic (GA) for the mutant allele of the TNFa (-308) promoter polymorphism, will demonstrate enhancement in phenotypic responses to O3 including: increased cellular inflammation and secretion of pro-inflammatory cytokines, enhanced activation of resident alveolar macrophages, and altered bronchial sensitivity, leading to AHR. The proposed research is focused on understanding the interaction between host factors and exposure to a prototypal urban air pollutant. Results from the research plan will help understand the functional contribution of a common polymorphism of TNFa to the initiation inflammatory airway disease, and assign and validate genetic factors that confer vulnerability to O3. PUBLIC HEALTH RELEVANCE. The research plan proposes to develop translational studies in humans that will identify host susceptibility factors that confer vulnerability to the prototypal air pollutant, ozone. The results will have significant impact upon and aid in understanding mechanisms of pro-oxidant lung injury, airway hyperresponsiveness, and adverse health effects that occur during and following exposure to respirable airborne irritants.
The overall theme of this Program Project Grant (P01) is to understand further the pathogenesis and genetics of asthma by studying environmental airway disease. We chose this theme for our PPG for the following reasons: 1) the symptoms and signs of asthma constitute a broad clinical phenotype; 2) asthma is a complex genetic disease caused by many biologically unique gene-gene and gene-environment interactions; 3) environmental models of airway disease
serve to narrow the biological phenotype of asthma, providing an ideal opportunity to study the pathogenesis and genetics of this complex disease; and 4) this theme builds on existing scientific expertise and ensures a highly interactive program. Since acquired and innate mechanisms of immunity can function independently or interactively to cause or exacerbate asthma, we have chosen to use allergens and/or irritants (endotoxin and ozone) in the proposed
projects to narrow the exposure-response phenotype and investigate the pathogenesis and genetics of environmental airway disease. The end result is a highly integrated and focused program that has the potential to make a number of novel, related observations. The primary hypothesis unifying this research program is that investigating environmental airway disease by modeling biologically unique gene-environment-asthma phenotypes will advance our understanding of the pathogenesis and genetics of asthma. The project-specific hypotheses proposal are: Project 1: Polymorphisms of genes expressed by airway cells in asthmatics following specific subsegmental airway challenges predispose individuals to the development of asthma. Project 2: Integrating the assessment of the environmental risk factors with an enhanced understanding of specific asthma susceptibility genes will lead to a coherent understanding of the relationship between genes, environment, and the development of asthma in an African American population. Project 3: Specific gene polymorphisms/mutations contribute to differential susceptibility to Oa-induced lung injury in asthmatic and normal subjects, and specific acquired host factors regulate injury from exposure to O3. Project 4: Alteration in airway SNO metabolism is important in the pathogenesis of asthma resulting in the dysregulation of airway cell apoptosis that contributes to the acute and chronic inflammatory changes seen in
asthma. In aggregate, the coupled scientific findings in this program will substantially enhance our understanding of the pathogenesis and genetics of asthma.
DESCRIPTION (provided by applicant): This amended Program Project competitive renewal is focused on revealing mechanisms of action following Florida red tide toxin exposure in laboratory models, and at providing relevant information for humans exposed on beaches. Florida red tides caused by Karenia brevis occur annually along the U.S. Gulf of Mexico coastline, and release 12 irritating natural environmental polyether brevetoxins into water and air with toxic results. Toxin antagonists are also released. The investigators have shown during the first 5 years that brevetoxins elicit neurotoxic, immunologic, and pulmonary effects in inhalation-exposed humans and animal models. The investigators shall further characterize inhalation exposure to the complex mixture of materials aerosolized from red tide, depositing in occupational, recreational, and susceptible human and animal populations. Mechanisms of action and prevention, and therapeutics are intensified foci in laboratory and field alike. Elements include: Administrative Core; Facility Core 1 "Toxin Probes & Assays" provides QA/QC toxins, derivatives and antagonists, analytical support and assay development; ; Facility Core 2 "Field Logistics & Deployment" optimizes environmental monitoring of organism and seawater, deploys air samplers and meterologic gear, and provides logistics for Research Project 4. Research Project 1 "Characterization of Red Tide Aerosols" correlates bloom dynamics with the size, composition, and aerosol potency, and adds meteorlogic modeling to data sets. Research Project 2 "Inhaled PbTxs: Health Effects & Mechanisms" explores pulmonary and immunotoxic mechanisms in rodents. Research Project 3 "Mechanism of PbTx-lnduced Responses" explores inhaled effects in a sheep model, including inflammation, mucociliary clearance, therapeutics and prevention. Research Project 4 "Aerosolized Red Tide PbTx on Humans" collects pre/post exposure data (chemical and physiological criteria) for a revised cohort, as well as prevention/intervention trials. Using the Research Projects and Facility Cores synergy optimized over the past 5 years, the investigators will evaluate acute and chronic immune and pulmonary PbTx effects on humans and animals, as well as prevention and intervention.
Lay summary: Florida red tides cause human illness through the airborne release of bioactive chemicals produced during a bloom. Using an interdisciplinary approach, this Program Project employs both laboratory studies and beachside work to understand the human consequences of exposure to aerosolized toxins, to explore therapies for intoxication, and to develop new drugs exploiting red tide bioactive materials.
DESCRIPTION (provided by applicant): Exposure to particulate matter (PM) can significantly affect the susceptibility to infectious agents. Especially in urban environments, diesel exhaust (DE) emissions contribute to ambient PM levels. Despite vaccination efforts and antiviral treatments, respiratory virus infections, such as influenza virus infections, continue to be a significant threat to public health, especially in young children and the elderly. While the effects of DE or influenza virus alone have been studied in vitro and in vivo, the effects of acute or subchronic DE exposures on the susceptibility to subsequent influenza infections are largely unknown. Preliminary evidence suggests that exposure to DE increases influenza virus infections in epithelial cells in vitro and in mice in vivo and that these effects are not caused by suppressed interferon-dependent antiviral defense responses. Oxidative stress mediates many of the adverse effects induced by DE and addition of GSH was able to reverse the effects of DE extract (DEE) on influenza infections in vitro. Therefore, this project will expand our observations made in epithelial cells in vitro and examine the effects of acute and subchronic exposure to DE on influenza infections in mice in vivo and determine the role of oxidative stress in DE-induced modifications of influenza infections in vivo. Similar to our in vitro studies, this project plans to examine potential mechanisms involved in the increased influenza infections following DE exposures by concentrating on the effects of DE on the levels of collectins and the ability of resident macrophages to phagocytize influenza virus. Experiments conducted in vitro indicate that exposure to DEP increases influenza infections by enhancing influenza virus attachment within 2 hours post-infection. The experiments proposed here will examine potential mechansims involved in this response, focusing on oxidative modification and inactivation of collectins, as well as the enhanced ability to proteolytically activate the virus to enter the cell. Recent data suggests that in dendritic cells influenza-induced inflammatory cytokine production may depend on both toll-like receptor (TLR) 3 and TLR7. However, it is not clear whether TLR3, TLR7, or both are involved in influenza-induced responses in respiratory epithelial cells, which will be determined in this proposal. In addition, our in vitro data indicate that exposure to DEP enhances TLR3-dependent signaling by increasing the expression of TLR3 in respiratory epithelial cells. The experiments proposed here will build on this data and examine whether DE exposure enhances TLR3 or TLR7 levels and function in vivo and in vitro and determine the role of oxidative stress in these responses. Data derived from these experiments will provide important insights into the molecular mechanisms by which exposure to DE could enhance the susceptibility to influenza infections.
DESCRIPTION (provided by applicant): Recent epidemiologic studies have re-ignited an old controversy and opinions are forming as to whether mucus hypersecretion is crucial in the etiology of airway disease. For patients with asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis, mucus hypersecretion is now being considered as a risk factor for increased morbidity. The irritant and epithelial membrane effects of O3, a main component of urban smog, upon the airway, and in particular on mucin-type secretory cells and/or interaction with epithelial physiology, have not been investigated vigorously, and at best only superficially, in vivo. We have recently demonstrated in genetically diverse inbred mice that O3-induced pulmonary inflammation and up-regulation of lung mucin secretion and airway mucociliary clearance are host factor dependent. These results match translationally with our evaluations in humans where O3 exposure leads to alterations in mucociliary clearance, and release of a mediator(s) capable of increasing mucin protein synthesis and secretion in vitro. Importantly additional observations by us in a healthy cohort of non-smoking human subjects (n=135) demonstrates that a homozygotic genotype for a single nucleotide polymorphism of the quinone oxido-reductase enzyme, NQO1, protects from the acute irritant effects on air flow that occur with exposure to ambient levels of O3. We have also found that NQO1 can modulate synthesis of mucin proteins by airway epithelial cells in vitro; and in connection with host-factor dependency, that NQO1 is differentially expressed in mouse models susceptible and resistant to O3. As a working global hypothesis we propose that exposure to O3 by susceptible humans activates NQO1, generates reactive oxygen metabolites and leads to an increase in MUC5AC mRNA expression and production of mucins by airway epithelial cells. This cycle is re-initiated when O3-induced airway neutrophilia, leads to re-activation of NQO1 by neutrophil elastase, leading to expression and secretion of mucins, disordered mucociliary clearance, and reduced pulmonary function. Investigations are proposed for mouse models represented by an O3 susceptible strain, a lung mucin hypersecretion model, and a NQO1 deficient model and simultaneous with translational studies in humans that are segregated genetically between wild-type (NQO1 sufficient) and a single nucleotide polymorphism associated with NQO1 deficiency. The research plan is the initial step towards a definitive link between an ubiquitous urban air pollutant, and genetic factors that regulate oxidant-induced airway hypersecretion of mucus. PROJECT NARRATIVE: The research plan proposes translational studies in relevant animal models and human subjects in order to identify host (genetic) susceptibility factors that confer vulnerability to the prototypal air pollutant, ozone. The results will have significant impact upon, and aid in, understanding mechanisms regulating pro-oxidant lung injury, production and secretion of airway mucins, and clearance of respiratory mucus, and adverse health effects, that occur during and following exposure to airborne respiratory irritants.
DESCRIPTION (provided by applicant): Functions common to Clara cells from different mammalian species are their ability to serve as a progenitor for renewal of the airway epithelium and their role in production of airway secretions. Both have potential to impact airway integrity yet surprisingly little is known of physiological roles for Clara cell secretion in airway homeostasis and disease. Goals of this competing renewal application are to investigate roles for Clara cells and their major secretory product, CCSP, in airway defense against oxidant injury. Key findings from our previous studies are that CCSP deficiency severely compromises Clara cell secretory function and elevates susceptibility of the epithelium to oxidative stress. Related findings are that ozone rapidly triggers the release of intracellular stores of CCSP, suggesting that secretion is an immediate cytoprotective response, and that CCSP deficiency is associated with altered post-translational processing of annexin A1 (ANXA1), a potential regulator of ciliary function. Based upon these data, continuing studies will address the hypothesis that CCSP functions directly in the cytoprotection of epithelial cells from the harmful effects of oxidative stress. We propose three specific aims to address this hypothesis. Air-liquid interface culture models will be used in Aim 1 to determine whether functional properties intrinsic to Clara cells and Clara cell secretory protein confer cytoprotection against oxidative stress. Experiments in Aim 2 will use a combination of in vitro and regulated in vivo models to determine contributions made by the highly conserved calcium and lipophilic ligand binding sites of CCSP in regulated secretion and cytoprotection of epithelial cells from oxidant injury. Goals of experiments in Aim 3 are to build upon exciting new data demonstrating that CCSP deficiency results in altered post-translational processing of ANXA1, a calcium and phospholipid binding protein that localizes to the apical membrane and cilia of ciliated cells. These data suggest a previously unappreciated link between secretory and ciliated cell function. We will determine post-translational modifications of ANXA1 in CCSP-/- mice to reveal CCSP-dependent signaling pathways that are compromised with CCSP deficiency. We will also use ANXA1-/- mice to determine contributions made by ANXA1 modifications to oxidant sensitivity of CCSP-/- mice and cultures epithelia. Completion of these aims will provide new insights into pathobiological mechanisms of chronic airway diseases that have the consistent feature of compromised Clara cell secretory function.
DESCRIPTION (provided by applicant): Interstitial pulmonary fibrosis (IPF) has numerous etiologies and afflicts millions of individuals worldwide. Yet, there are no effective preventive agents or therapeutic approaches. This situation is due in large part to a lack of understanding of the fundamental molecular mechanisms that mediate the fibrogenic process. In the work proposed here, we have focused on two peptide factors that have been implicated by numerous researchers as central to the development of IPF. These factors are tumor necrosis factor alpha (TNF-a) and transforming growth factor beta one (TGF-B1). Our previous work and preliminary data show that TNF-a up-regulates the expression of TGF-B1 both in vitro and in vivo, but the basic mechanisms through which TNF-a influences TGF-B1 expression remain undefined. TNF-a has been considered by many to be a "master cytokine" that controls the expression of a number of biologically relevant molecules. In as much as TGF-B1 is considered to be a primary "fibrogenic factor", we have set forth the central hypothesis that TNF-a induces TGF-B1 production by transcriptional regulation through the MEK/ERK pathway in lung cells: and the pathway of fibrogenesis mediated by TNF-a through TGF-B1 can be interrupted by specific siRNAs that mediate the degradation of transcripts that code for TNF-a, MP-1- a key component of MEK/ERK phosphorylation, and TGF-B1. Specific Aim 1 will establish MEK/ERK transduction pathways from TNF-a to TGF-B1 and the transcriptional mechanisms of expression. Aim 2 will focus on other factors that could up-regulate TGF-B1 through this same pathway; and in Aim 3, we will learn if the epithelial and mesenchymal cells in vivo in the lung exhibit the same transduction and transcriptional pathways in health and disease. These studies will provide specific targets for potential therapeutic approaches through the use of small interfering RNAs (siRNA). Thus, in Aim 4, we will show that an siRNA we have designed blocks endogenous TNF-a gene expression. We propose to use this construct as well as an siRNA that degrades MP1 (a key protein in MEK/ERK phosphorylation), and finally an siRNA that will block TGF-B1 expression, and ultimately the development of IPF in our established animal models.
DESCRIPTION (provided by applicant)
Ambient ozone is associated with increased respiratory illness, hospitalizations, and cardiovascular mortality. Because the lung is recurrently exposed to low level ozone, understanding how ozone modifies immune mechanisms is of considerable importance to human health. The investigators have recently demonstrated that ozone enhances both systemic and pulmonary innate immune response to lipopolysaccharide (LPS) including cytokine production, lung injury, and airway hyper-responsiveness. In addition, ozone exposure enhances subsequent LPS-induced inflammatory cell apoptosis, lowering the concentration of inflammatory cells in the alveoli. The investigators have discovered that the mechanism of ozone-priming of innate pulmonary immunity, in part, involves enhanced surface expression of toll-like receptor 4 (tlr4) on alveolar macrophages, which amplifies the biological response to inhaled LPS. The investigators now have evidence that ozone-induced release of short-fragment hyaluronan contributes to the innate immune response, and published work supports the role of NF-?B in both the response to ozone and trafficking of toll-like receptors. It is also clear that ozone inhalation is associated with the formation of reactive oxygen species (ROS), and the investigators observe that activation of NF-?B in the lung after ozone is facilitated by NADPH oxidase (NOX). However, it remains unknown whether either NOX or ROS regulate surface expression of toll-like receptor 4 and the role of surface recognition of hyaluronan in ozone priming innate immunity remain unexplored. Mechanistic understanding of the pathways that regulate trafficking of toll-like receptor 4 after exposure to this common air pollutant is of considerable interest in the pathogenesis of environmental airways disease. Thus, the overall hypothesis of this proposal is that ambient ozone modulates pulmonary innate immunity through enhanced trafficking of tlr4 to the surface of alveolar macrophages resulting in an enhanced functional response to lipopolysaccharide. Furthermore, ozone-induced trafficking of tlr4 is the result of proteolytic release of short-fragment hyaluronan, leading to NF-?B activation and amplification of the airway inflammatory response in a manner dependent on NOX2 and ROS-production. The investigators will address this hypothesis through the following Specific Aims. Specific Aim 1: Determine whether release of soluble hyaluronan contributes to ozone-dependent priming of LPS response in the lung and macrophages. Specific Aim 2: Determine the role of NF-?B activation in ozone priming of pulmonary innate immunity in lung macrophages. Specific Aim 3: Determine the role of NOX2 in regulating tlr4-dependent responses in macrophages after exposure to ozone.
DESCRIPTION (adapted from application):
The long-term objectives of this research include (1) develop a versatile low-burden personal aerosol exposure platform for pulmonary diseases to sample and sense sized and speciated aerosols and link them with selected biological markers of disease severity; (2) add parallel acute and chronic metrics for outcomes where both exposure types apply; (3) plan how to add parallel exposure assessment capabilities to the platform to eventually address known and potential inhalation co-factors, including ozone, ultrafines, volatile organic compounds (VOCs), and carbonyls, as well as the confounder, environmental tobacco smoke (ETS); and (4) develop procedures and components that enable deployment of the personal platform in large-scale exposure biology etiology studies, including the methods for the associated data capture and validation. Focus areas of this proposal include the following: Personal Exposure: (1) develop an extremely small and lightweight real-time aerosol sensor with adequate specificity and sensitivity to characterize sized, breathing zone aerosol for children; (2) modify the design of the current RTI MicroPEM(tm) personal exposure platform to include the new aerosol sensor via a universal sensor interface for acute exposures; (3) include integrated (chronic) collections for aerosol mass and endotoxin while retaining the low-burden design; (4) integrate the aerosol sensor into the platform and allow real-time mass and endotoxin concentration estimates; (5) include global positioning system (GPS), activity level, and wearing compliance sensors; and (6) incorporate parallel integrated collections to assess ozone exposure (as a co-factor) and ETS (as a confounder). Exposure Biology: (1) in a limited-scale effort, demonstrate how urinary LTE4 levels for a pilot cohort of asthmatic children or adults can be related to real-time and integrated aerosol mass and endotoxin personal exposure levels through exposure biology models; (2) for participants in the pilot cohort determined to be passively exposed to ETS, relate urinary cotinine levels to elevated ETS levels in the integrated collection; and (3) include ozone as a potential co-factor in the models. The prevalence of pulmonary diseases, and especially asthma, in the United States for adults and children, combined with the existing uncertainties in linkages between personal exposures to known stressors such as aerosols and the resultant biological exacerbations, fully supports this research.
DESCRIPTION (provided by applicant): This SBIR application is submitted in response to the objectives of the NIEHS Predictive Test Systems for Safety Evaluation Program by developing, standardizing, and validating sensitive and specific new and novel tests or batteries of tests . Primary human CD34+ bone marrow stem cells will be used as a novel biological system to identify predictive biomarkers of altered immune system differentiation, cellular toxicity, and genotoxicity. Human CD34+ bone marrow stem cells are pluripotent cells that possess the potential of self-renewal, proliferation, and differentiation toward different lineages of blood cells. Human CD34+ cells can be directed to differentiate in vitro and expand along specific cell lineages of immune cells. This lineage-specific differentiation of CD34+ cells is a complex biological process that includes the combinatorial and coordinated expression of genetic pathways that drive cellular proliferation and the acquisition of specialized cell functions. A screening assay based on human primary cells would be useful to assess the predictive power, or in vitro in vivo correlation, of high-throughput screens based on tumor cell lines. As cell lines derived from tumors often lack many critical genes that regulate cellular responses to stressors, the results of environmental agents tested in tumor cell line-based assays may have limited relevance to human health and disease, and there is a need for a human primary cell- based screening assay. This Phase I SBIR has three specific aims: Miniaturize human TK6 cell assay as a prototype assay to establish FCM-based measures of cytotoxicity, apoptosis, cell cycle arrest, oxidative DNA damage and DNA double strand breaks, adapt biological endpoints established in human TK6 cells with human CD34+ stem cells, establish cellular and molecular biomarkers of human CD34+ stem cell differentiation along specific lineages, assess impact of toxicants on CD 34+ health status and differentiation. Since bone marrow stem cells play a pivotal role in the function of the hematopoietic and immune systems and are the putative target cell population of concern for a host human cancers and diseases, the results obtained from these systems are biologically relevant to human disease and can be extrapolated to humans. The human CD34+ stem cell multiplex assay proposed here is ideally suited as platform to assess toxicity for environmental agents and pre-clinical drug candidates, as well a follow-up test system for high-throughput testing initiatives. PUBLIC HEALTH RELEVANCE: Stem cells have the unique ability among all of the cells of the human body of self- renewal, that is, they can remain in a primitive unspecialized state. Under the right conditions, they can give rise to specialized cells of the body (differentiation) like the heart, liver, or pancreas. CD34+ stem cells are the stem cell of bone marrow that differentiates into all of the cells in the blood (white and red blood cells). Therefore, these cells present a unique model system to understand and assess the effects of environmental agents and new drug candidates to predict or anticipate toxicity in humans.
DESCRIPTION (provided by applicant)
Conventional environmental exposure monitoring requires bulky instrumentation without providing a personalized history of environmental exposure. Valencell's long-term goal is to provide a noninvasive, low-profile, real-time, affordable personal environmental exposure monitor platform that is virtually unnoticed by the user for maximum performance and convenience. This platform will provide a quantitative, reliable, in-field measurement of personal-level, point-of-contact exposure to a variety of airborne chemical toxins of particular interest to health conscious end-users, sports enthusiasts, the immunocompromised, and medical professionals. Integrated Bluetooth communication protocols will be employed towards sending real-time information wirelessly to a cell phone or PDA. In turn, this information can then be sent wirelessly to online databases for storing and processing information relating personal health with personal environmental factors and user demographics.
The specific goal of this Phase I feasibility study is the development of a novel sensor element providing the flexibility of monitoring volatile organic compounds (VOCs), ozone, carbon monoxide, polycyclic aromatic hydrocarbons (PAHs), and other reactive airborne species in the same compact device. Filament-heated tin oxide VOC sensors, the workhorse of solid-state VOC sensing, are sufficiently compact but require significant operating power and lack vapor specificity. Valencell's innovative approach is the development of a novel wide band gap (WBG) VOC sensor offering enhanced vapor specificity and dramatically reduced power consumption over standard metal oxide sensors. This innovation enables the development of a novel, low-power (<10 mW), real-time (<100 ms sampling), compact (< 10 cm3), wearable VOC monitor capable of long-term battery-powered operation, high specificity, and broad sensitivity (0.1 to 1000 ppm).
In this program, Valencell will fabricate sensor electrodes from novel WBG metal-oxide films deposited by North Carolina State University (NCSU). The functionality of these sensor electrodes will then be validated by evaluating the sensitivity and specificity of each electrode in a bell jar VOC test bed. The sensor electrodes will then be integrated into a self-contained VOC sensor prototype such that the predicted performance specifications can be statistically validated in the VOC test bed.
Crisp Terms/Key Words: air pollution, monitoring device, organic chemical, electrode, case history, information system, metal oxide, technology /technique development, clinical research, portable biomedical equipment, environmental exposure
DESCRIPTION (provided by applicant): Many aspects of the social world bear on important health outcomes, but for most, the exact nature of their impact is still unclear. Although much has been learned through statistical approaches, the literature falls short of a causal understanding of how macro and micro processes interrelate in affecting health. The proposed research uses a spatially explicit agent-based modeling approach, informed by insights from sociology, geography, and economics. Dynamic social networks are included endogenously, an especially innovative element. Through the construction of a model in one setting, a set of modeling tools will be developed that will be applicable across a wide range of settings. These new tools will be made available through a public website. Once the agent-based model is constructed, it will be used to study interconnections among the social, spatial, and biophysical dimensions of the local context, taking into account migration, residential choice, land use, and household wealth, and feedbacks therein. In the process will come a better understanding of the consequences of oversimplification in standard statistical models of community effects. The model will also be used to conduct experiments about the effects of a sudden shift in infant mortality and shifts in economic conditions. The model will be field tested twice, the first time to validate key model assumptions and the second time to explore unexpected results. Indeed, an advantage of the agent-based approach is the possibility of "emergence" at the system or community level (i.e., the integration of macro and micro processes producing new structures not anticipated based on a simple aggregation of individual and household behaviors). Finally, borrowing and extending tools from the fields of meteorology and control theory, new methods for testing model sensitivity that are more computationally efficient than those now in use will be developed, applied, and made broadly available. The proposed project will develop tools to study social processes involving individuals, households, social networks, and communities in relation to health. The application of these tools will help us better understand and interpret the research literature connecting community factors with health outcomes and provide a complement to the standard statistical approaches.
DESCRIPTION (provided by applicant): Environmental epidemiological data need to be collected over time and across different geographic domains. These data need to be analyzed in order to determine important aspects of national environmental policy, aspects that protect the health of citizens and prevent damage to infrastructure and the environment. The purpose of this research is to develop a statistical framework and methodology for integrated analyses of spatial temporal data on air pollution concentrations and other environmental agents, exposure, health outcomes and covariate information. Generally, these various data layers are temporally misaligned and are observed at different spatial scales. The focus of this research is:
[1] the development of new statistical methods and models for the investigation of the spatial and temporal association between environmental stressors, taking into account human activity, and adverse human health outcomes in the context of two case studies: *study of the impact of ozone and PM (fine, course and ultrafine) on cardiovascular mortality across the conterminuous U.S. *study of the impact of ozone and PM (fine, course and ultra fine) on asthma, cardiovascular and cerebrovascular diseases in the state of Wisconsin.
[2] The development of a broad statistical framework to study the association of environmental factors and adverse health outcomes. This general framework incorporates parametric and nonparametric ial dependence structure for environmental processes, taking into account spatial misalignment, spatial and temporal change of support, and lack of stationarity and lack of separability in the space-time covariance function. An exposure simulator model is used to characterize population exposure levels.
[3] The model fitting, estimation and prediction of multivariate space-time environmental epidemiological data.
[4] The statistical assessment of the performance of deterministic and stochastic models, and model diagnostics. In aims 2-4 we establish general statistical frameworks that will be implemented to the case studies introduced in aim 1.
DESCRIPTION (provided by applicant)
Parkinson's disease (PD) is a chronic, progressive neurological disorder characterized by resting tremor, bradykinesia, postural instability and rigidity, resulting from the loss of dopamine (DA) neurons in the substantia nigra pars compacta (SNpc). The most vulnerable neurons affected in Parkinson's disease (PD) have the highest density of the phenotypic marker of DA neurons, the plasma membrane dopamine transporter (DAT). DAT is the major controller of DA neuron homeostasis being critically important not only for clearance of released DA from extracellular space but also for maintenance of intracellular DA stores. Thus by altering expression levels of the DAT it is possible to significantly change both extracellular and intracellular DA levels. The investigators recently developed a novel strain of mice over-expressing 6 copies of the DAT gene (DAT-Tg) specifically in the DA neurons by using BAG vector technology. Their preliminary results show that there is a 35% DA cell loss in the SN of these mice, most probably due to enhanced DA uptake and increased vulnerability of DA neurons to the neurotoxic effects of cytosolic endogenous DA. The investigators propose to use this strain of mutant mice to evaluate the effect of environmental toxicants known to induce DA cell loss and Parkinsonian phenotypes. There is ample evidence of gene/environment interaction resulting in increased susceptibility of individuals to the deleterious effects of toxicant. Here the investigators propose to directly evaluate whether increases in DAT level and intracellular DA may increase the toxicity induced by three model toxicants, namely MPTP, rotenone and paraquat. In parallel, they will also directly address whether augmenting DAT levels will lead to increased vulnerability of DA neurons to physiological concentrations of DA and of MPTP. For this, the investigators will use cultured postnatal SN neurons from transgenic mice with varied expression levels of DAT (DAT-KO, WT and DAT-tg). Using this approach it will be possible to test how DA induced toxicity correlates with DAT levels. This will hopefully allow them to address the specific importance of DAT in DA induced toxicity.
DESCRIPTION (provided by applicant)
The candidate, Cynthia Rider, plans to further her scientific development in an academic setting under the mentorship of Dr. David Hinton and Dr. Richard Di Giulio at Duke University during the post-doctoral phase of the program in order to facilitate her transition to an independent position as a tenure-track researcher during the independent phase of the award. Her short term goals include securing funding for her proposed research and developing the skill set needed to successfully operate an independent research laboratory, including: additional technical training, practical laboratory maintenance, mentoring, and teaching. During the mentored phase of the award, her research will involve characterizing the effects of environmentally-relevant endocrine active compounds on a host of endpoints in the aquarium fish, Japanese medaka (Oryzias latipes). This work will provide the foundation for the proposed research to be completed during the independent phase of the award. Her long-term goal is to maintain an active research program in an academic or government environment focusing on the effects of mixtures of endocrine disrupting chemicals using a small vertebrate animal model. The hypothesis to be tested in the proposed research is that compounds that disrupt endocrine signaling via multiple specific mechanisms (estrogenic and antiandrogenic) act in a concentration additive fashion that can be predicted using mixture modeling approaches. First, she will characterize the concentration-response profiles for a select group of endocrine disrupting chemicals. Next, she will use mathematical models of mixture toxicity to predict the combined effects of the mixtures on male reproductive endpoints in medaka. Lastly, she will compare the predicted responses to observed responses generated by exposure of medaka to mixtures of the endocrine active chemicals. The relevance of the proposed research to public health is clear; the investigators are exposed to multiple toxicants and there is epidemiological evidence of endocrine disruption in humans, however, the combined effects of endocrine active chemicals remains obscure. Establishing principles that describe the action of multiple endocrine active chemicals in a vertebrate system will greatly enhance their ability to determine risk associated with exposures to chemical mixtures and therefore, increase their ability to protect the public from potentially harmful combinations.
DESCRIPTION (provided by applicant): The severity and duration of food-borne diseases are influenced by plasmid-encoded virulence factors and antibiotic resistance genes. Environmental pathogens such as Escherchia coli, Salmonella, and Shigella, which are transmitted to the food chain from polluted irrigation and fertilization systems, have been shown to possess both of these plasmid-encoded elements. Patients infected with either virulent or antibiotic resistant microorganisms from contaminated food face severely limited treatment options or significantly prolonged therapeutic regimens. My long term objectives are to increase our understanding of conjugative plasmid transfer between environmental pathogens as it relates to the spread of antibiotic resistance genes and virulence factors. Conjugative plasmid transfer is the method by which these elements are spread among pathogenic and non-pathogenic microbial strains. Transfer of the prototypical F (fertility) plasmid and the numerous R (resistance) plasmids is mediated by a plasmid-specific Tral enzyme. We have identified potent (EC50 and Ki values in the nanomolar range) inhibitors of F plasmid transfer and Tral-mediated plasmid cleavage. Because F and R plasmid Tral enzymes share up to 98% sequence identity, I hypothesize that similar small molecules will be effective inhibitors of R plasmid transfer. The specific aims of this proposal are to: first, identify potent inhibitors of the F plasmid Tral enzyme; second, compare the structure of the Tral enzyme from the F plasmid to those of R plasmid Tral enzymes; third, identify inhibitors targeting the R plasmid Tral enzymes. I will use a combination of molecular biology and biochemistry to elucidate the structural basis of Tral inhibition and to identify new inhibitors of Tral enzymes encoded on the both F and R plasmids. This is a necessary first step to address the widespread and growing problem of antibiotic resistance.
DESCRIPTION (provided by applicant)
This training grant proposal requests support for 8 pre-doctoral and 4 postdoctoral trainees in environmental toxicology at the University of North Carolina-Chapel Hill (UNC). The proposed Training Program brings together a highly interactive and productive faculty of basic scientists, physician- scientists and public health researchers from the Schools of Medicine, Public Health, and Pharmacy at UNC, plus outstanding researchers and mentors from the EPA, NIEHS and the Hamner Institute in Research Triangle Park. This unique blend of environmental health researchers has worked together for the past 25 years to produce 106 Ph.D. graduates and 63 postdoctoral fellows who have gone on to productive academic, government and private sector positions. To capitalize on this success, this Training Program has undergone extensive critical evaluation that has led to major improvements in administration, faculty-selection, and training approaches. This has resulted in greater cohesiveness, increased co-mentoring, and a focus on interdisciplinary and translational research with critical clinical and public health impact. The proposed training program faculty includes 49 basic researchers, 16 MDs, and 3 epidemiologists with proven research records in environmental health. The faculty conducts research in the areas of molecular carcinogenesis, mechanistic toxicology, cardiopulmonary toxicology, neurotoxicology, hepatotoxicology, computational toxicology, and developmental/-immunotoxicology. The training is focused on interdisciplinary cross-cutting programs in environmental toxicology, systems toxicology, research translation, animal models of human diseases and biomarkers. The program has outstanding didactic instruction, excellent oversight, unparalleled resources, and a superb environment to support the proposed training. Trainees supported by the NIEHS training grant will be engaged in research projects addressing critical environmental health research issues, such as (i) how the environment contributes to toxic injury; (ii) the molecular components of biological systems of protection against cellular damage; (iii) the specific mechanisms involved in response to toxicity and in repair pathways, and (iv) disease outcomes associated with environmental exposures to toxicants. The outstanding new scientists the investigators train will excel at interdisciplinary approaches that improve mechanistic understanding and translate their findings to environmental health.
BACKGROUND
This is a competing continuation application requesting funding for a Training Program that was initially established in 1979. Funding is requested for eight pre-doctoral trainees and four postdoctoral trainees. Several changes have occurred or are proposed for the leadership of this program. Dr. Swenberg will remain as the Program Director. However, four of the other five key leadership positions have changed. Dr. Ivan Rusyn has assumed the duties of Associate Director. Dr. Richard Mailman has assumed the duties of Director of Postdoctoral Studies. Dr. Marila Cordeiro-Stone has assumed the position of Director of Pre-doctoral Training and Dr. Bernard Weissman has assumed the position of Director of Admissions. Changes have also occurred in the training program faculty. Sixteen faculty members are no longer part of the Training Program and thirty-four faculty members have joined the Training Program. There are currently a total of 69 faculty members participating in the program. Of those forty-seven are on-campus and twenty-one are adjunct faculty.
DESCRIPTION (provided by applicant)
This 5-year program is designed to train predoctoral (Ph.D.) students and postdoctoral fellows in three distinct but related areas: Environmental Biostatistics (BIOS), Environmental Epidemiology (EPID), and Environmental Exposure Assessment (ENVR). The interdisciplinary goal of this training program is to prepare scientists to address emerging challenges in environmental health research, with an emphasis on the development of tools for harnessing the rich and high-dimensional information that is now routinely available. The overarching goal is to improve the understanding of effects of environmental and other exposures, such as diet and physical activity, in order to impact public health through prevention and better clinical care. Increasingly, we need scientists with strong skills in statistics, epidemiology and basic science, along with an ability to understand and translate the clinical implications of their findings. A critical component is a better understanding of heterogeneity among individuals in environmental effects through the creative use of emerging technologies for measuring gene expression, levels of metabolites, and single nucleotide polymorphisms across the genome. Along with detailed measures of environmental exposures, these tools allow careful study of gene by environment interaction, which has great clinical importance, as interventions may be increasingly driven by genetic factors in order to optimize efficacy.
The BIOS goal is to train biostatisticians in general statistical methods, including new approaches for analyzing and visualizing very high-dimensional data. In addition, a focus will be on use of methods motivated by the biology, allowing integration of data from multiple sources. The EPID goal is to train scientists in conducting studies of environmental effects, fully utilizing and understanding the statistical and technological tools available, while also addressing the translational goals described above. The ENVR goal is to train environmental scientists to conduct research on biological and statistical methods for assessing environmental exposures as they relate to human health effects.
The typical pre-doctoral trainee will have a Bachelor's or Master's degree with an excellent academic record appropriate for one of the three training areas, and the typical postdoctoral trainee will have highly relevant doctoral training. Funding is requested for the support of 20 pre-doctoral trainees for each of 5 years (8 BIOS, 6 EPID, 6 ENVR) and for 8 postdoctoral trainees (2 BIOS, 3 EPID, 3 ENVR). The Departments of Biostatistics, Epidemiology, and Environmental Sciences and Engineering, the three largest and most recognized departments in the 2nd-ranked UNC School of Public Health, have available all the personnel and facilities sufficient to provide comprehensive pre-doctoral and postdoctoral training.
BACKGROUND
This proposal is a competing continuation of a large, established, and successful training program spanning three different departments and covering three areas: environmental biostatistics, environmental epidemiology, and environmental exposure assessment. The program has been very successful in training and placing successful researchers in academic, government, industry, and consulting positions in each of the three areas. The program has been in place for 35 years and continually funded for the last 29 years. The proposed program reduces the number of pre-doctoral trainees from thirty in 2005-2006 to twenty and increases the number of postdoctoral trainees from four in 2005-2006 to eight.
DESCRIPTION (provided by applicant)
Renewal is requested for a Training Program in Bioinformatics at North Carolina State University, with support for 10 predoctoral trainees and four postdoctoral trainees. The application rests on the success of the bioinformatics graduate program at North Carolina State University. This Program began in the fall of 1999 and has now produced 19 Master of Bioinformatics and 7 Ph.D. in Bioinformatics graduates. The doctoral graduates are in academic or postdoctoral positions, or are working in the pharmaceutical industry. The Graduate Training Program has pre-requisites in mathematics, statistics, computing and genetics. Ph.D. candidates are engaged in coursework in bioinformatics, computer science, genetics or biochemistry, and statistics for two years, and are expected to complete their Program within four or five years. Candidates share some courses and a journal club with candidates in a parallel degree program in functional genomics. The number of applicants to the Program has risen steadily every year. For fall of 2003, there were 143 applicants to the Ph.D. program. Forty were admitted and 17 enrolled. In the spring of 2004, the program has 38 Ph.D. candidates, including 3 African Americans, 1 Asian American, 16 women and 18 international students. Twenty-nine faculty across 10 departments in four Colleges are listed as trainers in this application.
DESCRIPTION (provided by applicant)
The purpose of this Training Program is to develop well-trained environmental pathologists, who have a broad and comprehensive understanding of major human diseases and who are expert in the techniques and strategies that can disclose mechanisms by which environmental pollutants perturb cellular processes to cause disease. The Program focuses on cancer, its etiology and pathogenesis, cytotoxicity and neurodegenerative diseases because this group of diseases and the processes by which they develop continue to be major problem facing environmental risk assessors and are strengths of the faculty of this Program. The Program draws its faculty from the Department of Pathology at the University of North Carolina at Chapel Hill (UNC), from other departments at UNC and from various federal, industrial and independent research laboratories in Research Triangle Park. The Program offers the Ph.D. degree in molecular pathology and postdoctoral training in research. It also participates in a research program for minority undergraduates.
Predoctoral candidates must have completed a B.S./B.A. or M.S. degree in a relevant scientific discipline of biological science or chemistry, or hold an M.D. or DVM degree. Applicants are evaluated based on their undergraduate academic record, GRE test scores, letters of recommendation, and interview. A faculty committee reviews candidates and makes nominations to the Graduate School for formal offers of admission and for traineeships. Applicants for postdoctoral training are evaluated based on their previous academic/research records and their perceived scientific potential for future development. Postdoctoral candidates are selected by a Program Committee. Minority candidates are actively sought for predoctoral and postdoctoral training, and for the undergraduate research program. The Program has an established record in the training of minority scientists.
The training facilities of the faculty consist of more than 40,000 square feet of active research laboratories performing state-of-science research on various aspects of environmental carcinogenesis/ mutagenesis and neuropathology. The Program is centered in a comprehensive human pathology department with active training programs in human and experimental pathology, highly regarded research programs on molecular and cellular pathology, and modern diagnostic services. Faculty members also participate on various risk assessment panels. Excellent facilities, outstanding faculty and research projects characterize this Training Program.
DESCRIPTION (provided by applicant): Somatic mutation of the von Hippel-Lindau (VHL) tumor suppressor gene is associated with sporadic renal cell carcinoma (RCC), and germline VHL mutation results in VHL disease with predisposition to RCC and/or other neoplasms. Despite striking genotype-phenotype correlations in VHL disease, disruption of specific pVHL functions is not directly related to the spectrum of clinical disease. I will examine representative RCC- predisposing VHL mutations in vitro and in vivo to identify mutant pVHL functions important for renal tumorigenesis. I hypothesize that VHL mutations exert their tissue-specific effects by disrupting wild-type or introducing novel pVHL functions and that other genetic events are necessary to cause invasive kidney cancer. I will delineate the key genetic events using chemical and insertional mutagenesis. Potassium bromate, a byproduct of water distillation, causes oxidative damage, mutations, and RCC in the renal tubules of rats. I will use this biologically-relevant, kidney-targeted environmental toxin to perform chemical mutagenesis in wild-type and VHL-mutant mice. I will supplement this approach with insertional mutagenesis using a mammalian transposition system targeted to the renal parenchyma.
DESCRIPTION (provided by applicant)
This application seeks to continue support for a Program to train underrepresented minority undergraduate students in research in environmental health. The Program provides minority undergraduate students with opportunities to be involved in environmental health research at a sufficiently early point in their education so that this experience will convince some of them may choose environmental health research for their careers. There are three NIEHS sponsored research-training programs on this campus. These include ES07017, Environmental Pathology; ES07018, Biostatistics for Research in Environmental Health; and ES07126, Pre-and Postdoctoral training in Toxicology. The training proposed in this application will place minority undergraduate students under the supervision of a faculty mentor from one of these environmental training programs. Ideally, two trainees will be placed with preceptors from each program each year. Trainees will be selected from among applicants to the Summer Pre-Graduate Research Experience (SPGRE) Program at the University of North Carolina at Chapel Hill. This established and effective Program attracts top ranked undergraduate students from underrepresented minorities to this campus for a summer academic experience. Applicants to the SPGRE Program with appropriate background and interest in research on environmental disease will be selected for this Program and paired with a research mentor. Facilitators in this Program match applicants with appropriate faculty mentors engaged in research in the area of the student's interest. The goal of this Program is to motivate these students to pursue graduate education in environmental health fields following completion of their undergraduate education. The extent to which the trainees make such career decisions is the measure of the investigators' success. At best, these trainees will opt to pursue their graduate training in one of the three sponsoring NIEHS training programs on this campus or a similar program at another institution. Through these efforts the investigators hope to contribute to an increase in minority representation among health professionals in environmental health sciences. They believe that they have made very good progress toward this goal during the first ten years of this Program.
DESCRIPTION (provided by applicant):
This is the 2nd revision of the competitive renewal of the training grant ES-07046 "Training in Biochemical and Environmental Toxicology". The training program encompasses three graduate study concentrations; Molecular and Cellular Toxicology, Environmental Toxicology and General Toxicology. Trainees enter the program with a strong background in the biological and physical sciences. A minimum undergraduate grade point average of 3.0 on a 4.0 scale in the biological and physical sciences and combined verbal and quantitative scores on the GRE of at least 1100 are required for admission into the program. All trainees take core courses in toxicology, biochemistry, pharmacology, pathology, statistics, ethics and elective courses are selected based on trainees' research interests and graduate study concentration. Trainees generally receive their Ph.D. in 4-5 years. This training grant is administered through and is an integral part of the Department of Environmental and Molecular Toxicology. There are 10 preceptors participating in this training program and the major research theme is to understand how toxicants/cellular stressors induce cell responses through the alteration of signal transduction pathways and the regulation of gene expression. The elucidation of how toxicants/cellular stressors are translated into alterations in expression and how the gene products are involved in adaptive and toxic cellular responses is crucial to understanding mechanisms of toxicity at the cell, organ and organism level. Trainees receive state-of-the-art research training in areas including: molecular carcinogenesis, cell cycle regulation, endocrine disruption, oxidative stress, signaling pathways involving MAPK, apoptosis, transcriptional regulation, functional toxicogenomics, regulation and expression of xenobiotic metabolizing enzymes, and chemical exposure assessment. The Department of Environmental and Molecular Toxicology's faculty, funding base, student body, training program and facility all have undergone significant and continued growth. To sustain the growth in training opportunity for graduate students in toxicology, funding of this training grant is requested at the level of five predoctoral trainees for year one, six trainees for year two, seven trainees for year three, and eight trainees for years four and five.
DESCRIPTION (provided by applicant)
The long-term objective of Community Health and Environmental Reawakening (CHER) is to improve environmental health in the rural South by supporting grassroots leadership and community empowerment. Isolated rural areas of the South have high levels of poverty and unemployment. Polluting industries may be attracted to these areas because of the decline in family farming, low land prices, low wages, and lack of political influence. This project seeks to make a long-term impact on unjust patterns of environmental contamination by facilitating technical and political capacities of rural African-Americans to be partners in research, to engage in community education, and to organize around environmental health issues. The project is centered on a strong grassroots community organization that was founded in 1978, the Concerned Citizens of Tillery (CCT), in Halifax County, North Carolina (NC). In 2000, the population of Halifax Co. was 52.6% African-American, 33.7% of whom live in poverty; CCT's 300 active local membership is 99% African-American. In 1987 CCT organized the Area Wide Health Committee (AWHC) to provide medical care to predominantly African-American communities in partnership with medical providers from East Carolina Medical School. CHER brings together CCT, AWHC, and environmental health scientists from the University of North Carolina (UNC) School of Public Health to, 1) expand environmental health knowledge of eastern NC citizens and health professionals, 2) increase local participation in prevention and remediation of environmental health problems, 3) provide education and outreach to environmental justice groups throughout NC, 4) increase the capacity of medical care providers to respond to environmental health problems of rural African-Americans, and 5) offer practice-based learning in rural environmental health and environmental justice issues to students in public health, medicine and allied health sciences. These aims will be accomplished through collaboration of the partner organizations in education, outreach and networking; the Tillery People's Clinic; and a graduate-level semester-long course, Community-driven Epidemiology and Environmental Justice.
Crisp Terms/Key Words: rural health, biohazard detection, environmental exposure, repetitive motion injury, health services research tag, behavioral /social science research tag, clinical research, human data, environmental toxicology, rural area, socioeconomics, community planning, African American, early experience, occupational health /safety, lead poisoning, workshop, health related legal, occupational therapy, health care service, waste disposal, environmental contamination, environmental health, education evaluation /planning, health education
DESCRIPTION (provided by applicant): Migrant and seasonal farmworkers and their families are exposed to numerous environmental and occupational health hazards, and they experience high rates of injuries and illnesses. Efforts to document the health hazards and illnesses that farmworkers experience have expanded. However, the involvement of farmworkers in the conduct of research that addresses their health hazards and illnesses, and the communication of research results to farmworkers in forms that they can understand and use remains limited. We propose a partnership between an existing framework of the community-based organizations and agencies that comprise the Farmworker Advocacy Network (FAN) and health scientists at Wake Forest University School of Medicine (WFUSM). The community-based participatory research (CBPR) partnership we propose in this application is based on two principles. The first is that farmworkers and their community-based organizations should collaborate with health scientists in selecting and conducting research that addresses farmworker health. The second principle is that farmworkers should understand the results of biomedical and behavioral science so that they can better use this knowledge to improve their health and quality of life. As a first step toward implementing these principles, this project will achieve three specific aims; we will (1) develop a framework for ongoing collaboration between FAN community-based organizations and agencies and WFUSM; (2) build the capabilities among FAN community-based organizations and agencies to participate in research on the health and quality of life of migrant and seasonal farmworkers, and build the capacity of WFUSM health scientists to effectively communicate with community stakeholders; and (3) identify, implement and evaluate effective approaches to communicate the results of health science to migrant and seasonal farmworkers. At the end of this project, the FAN/WFUSM partnership will be in a position to collaborate effectively in the conduct of research addressing farmworker health and to communicate the results of this research to farmworkers in a form that they can use. The FAN and WFUSM partnership will also be in a position to use their collaboration to translate their research results to inform policy that will improve regulations that affect the health and quality of life of farmworkers. Migrant and seasonal farmworkers and their families are exposed to numerous environmental and occupational health hazards, and they experience high rates of injuries and illnesses. Efforts to document the health hazards and illnesses that farmworkers experience have expanded; however, the involvement of farmworkers in the conduct of research that addresses their health hazards and illnesses, and the communication of research results to farmworkers in forms that they can understand and use remains limited. The results of this research will provide a framework for the Farmworker Advocacy Network / Wake Forest University School of Medicine partnership to collaborate effectively in the conduct of research addressing farmworker health and to communicate the results of this research to farmworkers in a form that they can use.
DESCRIPTION (provided by applicant)
The specific research goal of this study is to identify discriminatory environmental items in preschool play areas to be included in a pilot tool that will rate their potential to produce physical activity when three-to five- year-old children are exposed to them. Currently, no tool exists that links the amount of physical activity and preschool play areas, with the potential of affecting policy. This study will characterize behavior settings, their components and attributes, in terms of the physical activity patterns of understudied population preschool childcare centers. Research has shown that: a) time spent outdoors is an environmental determinant most strongly correlated with greater amounts of physical activity in children and opportunities for whole body exercise; b) children's physical activity is strongly motivated by diversity of outdoor environments; c) preschoolers with higher levels of outdoor physical activity retain higher levels as schoolage children; d) active outdoor childhood tracks into and influences the preference for outdoor experiences in adulthood; and e) the preschool and, more specifically the preschool outdoors is a strong determinant of physical activity. Fifteen childcare centers will be selected from respondents to the Baseline Survey of Environmental Conditions of Outdoor Areas in NC Childcare Centers. Sites range across urban, suburban, and rural contexts and diverse ethnic and socioeconomic groups. Research activities: 1. Behavior mapping (GIS coded) of preschool play areas to identify physical activity patterns in specific behavior settings (spatial location of subjects and physical activity amount); 2. Inventory of environmental components and attributes of behavior settings associated with different amounts of physical activity; 3. Identification of discriminatory environmental items to be included in a draft measuring tool; 4. Develop pilot measuring tool; 5. Preliminary test of reliability and validity. This study responds to the Strategic Plan for NIH Obesity Research, including the goals to "Assess children's environments...to determine barriers to increasing physical activity"; to "Identify...environmental and behavioral factors to obesity...prevention...and assess... environments such as...childcare...for specific barriers to increasing physical activity"; and to "Use prospective observational' studies to identify modifiable behavioral and environmental determinants of weight gain and obesity in children...[related to] critical periods for inappropriate weight gain" i.e., in childcare centers.
Crisp Terms/Key Words: data quality /integrity, weight gain, behavioral /social science research tag, clinical research, method development, play, behavior test, human subject, body physical activity, disease /disorder prevention /control, environmental health, preschool child (1-5), day care center, child care, child behavior, obesity
DESCRIPTION (provided by applicant): Current chemical hazard testing procedures do not take into account the genetic diversity of the population that may be at risk of exposure; however, our recent data show that genetic differences between mouse inbred strains have a profound impact on time-, dose- and organ-specific effects of toxic agents. Thus, we hypothesize that the knowledge on the modes of action of toxic agents can be efficiently combined with advances in tissue engineering, in silico modeling, genetics and genomics to develop novel approaches that improve in vitro and in vivo chemical hazard testing paradigms, prioritize environmental agents for selection and increase throughput of screening in a biologically meaningful and sensible way. This application proposes to establish a partnership between environmental health scientists, biological engineers, chem- informaticians, biostatisticians and geneticists. This multidisciplinary team will apply an integrative, systems approach to: (1) Develop a 3D microscale mouse liver tissue bioreactor that can be applied to high- throughput screening of chemicals. This is a design-directed effort to produce a unique tool that can increase throughput of testing while reducing the number of animals; (2) To build, test and validate Quantitative Structure-Toxicity Relationship (QSTR) models that employ both chemical and biological descriptors of molecular structures and take into account genetic diversity between individuals. This aim is a discovery- driven approach that will produce a computational method for compound-prioritization based on the chemical structure, multi-dimensional toxicity data that includes -omics endpoints, and information on genetic diversity of the population; and (3) Validate a fiscally sensible in vivo and in vitro toxicity screening paradigm for a class of allylbenzene derivatives by producing knowledge anchored on the genetic variability present within the population. This aim will test the hypothesis that genetic variability among individuals is a major determinant in the toxic effects of chemical hazards and that the genetic basis for susceptibility can be successfully elucidated using a panel of mouse inbred strains. The partnership will be directed by Ivan Rusyn, M.D., Ph.D. (UNC Public Health) who is an environmental health scientist with experience in liver toxicology and mouse models of toxicity. Other Lead Investigators are: Linda Griffith, Ph.D. (Massachusetts Institute of Technology), a world-renowned researcher in the field of liver tissue engineering; Alex Tropsha, Ph.D., (UNC Pharmacy), a leader in the field of quantitative structure activity/toxicity relationship modeling; and David Threadgill, Ph.D. (UNC Medicine), a geneticist whose work pioneers the applications of mouse genetics into cancer research and toxicology. Collectively, this effort will lead to significant and timely advances in understanding the relationship between chemical identity and chemical hazard within a genetically diverse population. It will also illustrate how basic science in environmental health, genetics, chem-informatics and bioengineering can be combined to prevent human disease by improving our ability to extrapolate and translate findings from chemical testing to human populations and by informing regulatory decisions that limit exposures to disease-associated environmental agents.
DESCRIPTION (provided by applicant): Although the toxic nature of many chemicals, such as carcinogenic species, which have found their way into the environment is well-known, the mechanisms by which these chemicals exert their toxic effects at the cellular and molecular level are only now beginning to be understood. There is a strong need for developing a molecular tool that is capable of monitoring biochemical processes or detecting specific biomarkers in a living cell following chemical exposure. Minimally invasive analysis of cellular signaling pathways inside single intact cells is becoming increasingly important fundamentally because cells in a population respond asynchronously to external stimuli. The objective of this research is to conduct fundamental research and develop nanobiosensors for probing chemical exposure and health effects of individual living cells. The proposed technique could provide unprecedented insights into intact cell function, allowing studies of molecular functions in the context of the functional cell architecture. This proposed research will contribute to future advancements in biology and medicine, which is directly relevant to the mission of National Institute of Environmental Health Sciences (NIEHS). The specific aims of the project are: 1) Develop a nanosensor for monitoring the carcinogenic compound, benzo[a]pyrene (BaP) and the related biomarker of exposure, benzopyrene tetrol (BPT), 2) Develop dual-target sensing technology for the nanobiosensor to achieve simultaneous detection of BaP and BPT using phase-resolved detection, and 3) Investigation of exposure and metabolism pathways in a single living cell exposed to BaP. The nanoprobes to be developed in this project will open new horizons to a host of applications in biotechnology, molecular biology and environmental health research, and the study of in situ intracellular signaling processes, and investigations of the chemical transport and toxicity.
DESCRIPTION (provided by applicant)
Carbon nanotubes exhibit exceptional structural properties and conductivity, and are being incorporated into diverse manufacturing processes, yet little is known about the risks that these novel molecules pose to human health. Emerging observations indicate that pulmonary exposure to carbon nanotubes induce a fibrotic response in the lungs that is related at least in part due to their size and shape. Preliminary experiments from our group indicate that pulmonary exposure to multiwalled carbon nanotubes (MWCNT) alters hemostasis, vascular reactivity, and myocardial injury resulting from acute coronary occulusion and reperfusion. Furthermore, comparison to other nano-scale particles, including elemental carbon (Printex 90), ceramic nanoparticles and ambient particulate matter, indicates that cardiotoxicity of nano-scale particles is related more to the particle composition and surface characteristics than to its shape.
In this project, we propose to test the hypothesis that respirable MWCNT are cardiotoxic, and how MWCNTtissue interaction impacts their biological activity. MWCNT of uniform length (10 to 20 |am) and well-defined surface characteristics will be generated through a collaboration with the Institute of Regenerative Medicine at Winston-Salem Health Sciences Center and NanoTechLabs, Inc. Investigators at the East Carolina University will deliver the nanotubes by acute inhalation to mice, verify the pulmonary distribution and define the acute and chronic effects of particle exposure on hemostasis, vascular reactivity, and myocardial response to ischemia. The modifications to be compared represent alteration to the pristine MWCNT and surface functionalization paradigms that are common in nanotechnology and will include a) nitrogen-doping, b) surface carboxylation, and c) surface amination.
The effects of these modifications will be tested in each of the following Specific Aims:
Specific Aim 1. Evaluate the fate of inhaled MWCNT,
Specific Aim 2. Demonstrate that aspiration of multiwalled carbon nanotubes alters hemostasis and myocardial response to ischemia and reperfusion.
Specific Aim 3. Test the hypothesis that inhalation of MWCNT alters vascular reactivity via impared adenosine signaling.
Specific Aim 4. Assess the role of endothiela nitric oxide, oxidative stress and vascular function in MWCNT cardiotoxicity.
DESCRIPTION (provided by applicant): Farmworker exposure to pesticides is a widely acknowledged environmental health problem (Arcury et al., 2002; Arcury & Quandt 2003; Reeves & Schafer 2003; Arcury et al., 2006b). Organophosphorus (OP) insecticides are among the most widely used pesticides, and include chlorpyrifos, diazinon, dimethoate, disulfoton, and phosmet. Exposure to OP pesticides is detrimental to human health (Reigart & Roberts 1999), with immediate effects of limited exposure including rash, nausea, and blurry vision, and immediate effects of significant exposure including loss of continence, coma, and death. Delayed effects of exposure may include sterility, birth defects, cancer, and neurodegenerative disease. Sources of pesticide exposure among farmworkers and their families include occupational, para-occupational, residential, and environmental factors (Fenske et al., 2000; Arcury et al., 2006c; Quandt et al., 2006). Farmworkers have little to no control of their exposure (Austin et al., 2001), and have limited access to facilities at work for changing out of work clothes and showering before coming home (United States General Accounting Office (GAO) 2000; Arcury et al., 2001). The housing available to farmworkers is often located near fields to which pesticides are applied (Housing Assistance Council 2001; Early et al., 2006) and is generally substandard, with infestations that lead to residential pesticide application (Quandt et al., 2004; Early et al., 2006). Farmworkers and their spouses are often not provided with the information they need to protect themselves and their families from exposure (Arcury et al., 1999; Rao et al., 2006). The effective dose of pesticide exposure is clearly dependent on the initial environmental exposure, but it is also influenced by an individual's innate ability to metabolize and excrete the toxins. Metabolism of OP pesticides is primarily determined by specific proteins in the cytochrome P450 family and the paraoxonase class of molecules. Several of these genes are clustered in the same chromosomal region, indicating a potential common regulatory mechanism, which may be mediated by genetic variation within or between these genes. Polymorphisms in PON1 have been reported to be correlated with the levels of PON1 enzyme (e.g., (Holland et al., 2006)), suggesting that genetic variation contributes to the level or activity of this enzyme. A comprehensive analysis of the entire PON locus, containing PON1, PON2, and PON3, is necessary to identify the individual single nucleotide polymorphisms (SNPs) or combinations of SNPs that contribute to individual variability in OP metabolism. It has been suggested that lower levels of PON1 activity lead to an increased risk of the damaging effects of OP exposure. The goal of this study is to thoroughly characterize genetic variation of the specific p450 genes involved in OP metabolism and the entire PON locus in an effort to identify those individuals most at risk to the negative health effects of chronic organophosphate exposure. Pesticide exposure is an environmental health problem with both acute and chronic risks to farmworkers. The risk to any given individual can be expressed as an interaction between the quantity of the exposure itself and the rate at which that individual is able to metabolize and detoxify the pesticide. To fully understand the links between pesticide exposure and behavior or environmental factors, analyses must be able to consider genetic variability in pesticide metabolism. The goal of this study is to evaluate the genetic contribution of pesticide metabolism in a population of North Carolina farmworkers, in order to gain a more complete understanding of the potential for long term effects of chronic pesticide exposure.
DESCRIPTION (provided by applicant):
Chlorine gas (CI2) is a readily available chemical warfare agent that causes a dose-dependent toxicity to pulmonary and other mucosal tissues. The major toxicity of CI2 exposure is oxidative damage of lung tissues that is thought to be due to the direct effects of CI2 reaction products combined with inflammatory mediators released by lung-infiltrating leukocytes. This proposed mechanism has not been clearly demonstrated but raises the possibility that inhibition of pulmonary inflammation following CI2 exposure will reduce subsequent morbidity and mortality. Our laboratory has identified the cells and the cell migration events that lead to immune-mediated lung damage, morbidity, and mortality during viral and bacterial infections. Our preliminary studies demonstrate that a similar pattern of inflammation occurs after chlorine exposure. These findings suggest that chlorine-induced lung injury could be substantially lessened using a specific chemokine receptor antagonist. Importantly, a pharmacologic antagonist for the chemokine receptor we have identified has already been developed and proven to be safe and effective in early clinical trials for other indications. This raises the possibility that a drug already exists that would reduce the morbidity and mortality of chlorine exposure in humans. In a series of murine studies, we will determine the extent to which specific pulmonary inflammatory cell types contribute to chlorine-induced lung injury and the consequent epithelial damage, bronchial reactivity, morbidity, and mortality. We will then examine the ability of the chemokine receptor antagonist to reduce these toxicities. These studies will provide a basis for determining if trials of chemokine receptor antagonists should be considered in humans.
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