Projects

2011 Pilot Project Awards

Project 1
Title: Culturally and literacy Modified Signage for Environmental Safety Awareness
PI: Greg Cope, PhD, Professor, EM Toxicology, CALS, NC State
Co-PI: Catherine LePrevost, PhD student (NC State)

The Community Outreach and Engagement Core (COEC) is partnering with the NC Department of Health and Human Services and community groups to focus on risk communication and human consumption of contaminated fish. An outreach program is being developed to translate recent collaborative research findings in this topic area using culturally and literacy appropriate approaches. This pilot will utilize an engaged scholarship approach for this effort. Community stakeholders obtained through the NC Department of Health and Human Services local contacts identified fish consumption advisories as a pressing human health concern to be addressed by the COEC. According to their and the COEC’s combined group of stakeholders, state and local governments have limited resources to design, evaluate, and implement effective educational materials related to fish advisories to inform the public of potential risks associated with eating certain fish. Although consumption of fish is recommended as part of a healthy, low-fat, protein-rich diet, many fish targeted by commercial, recreational, and subsistence fishers contain contaminants, such as mercury and PCBs that can adversely affect human health. This is of particular concern in sensitive subpopulations like pregnant women, children, and people who depend on fish for a substantial part of their diet. North Carolina currently has fish consumption advisories for mercury in eight freshwater fish species and in 17 marine (ocean) fish species, which include the U.S. Food and Drug Administration’s fish consumption guidelines for mercury in their marine species of concern (shark, swordfish, and tilefish). The North Carolina Department of Health and Human Services rarely evaluates marine fish and shellfish species for human health consumption, particularly as it relates to dietary exposures. As a result, this pilot project will focus on developing new signage types that target populations in NC that may not understand or adequately interpret existing signage and warnings about consumption of specific freshwater fish types and locations.

Project 2
Title: Variance Decompositions of Genetic and Exposure Data Pilot Project
PI: Alison Motsinger-Reif, PhD, Associate Professor, Dept. of Statistics, CALS, NC State
Co-PI: Jane Hoppin, PhD (NIEHS and AHS)

Personnel in the Bioinformatics and Statistics Facility Core (BSFC) will work directly with investigators in the Agricultural Health Study (AHS) to make use of the wealth of data available on rural population risks to synthesize current knowledge into potentially translatable findings. A pilot project will initiate a formal collaboration between the CHHE and AHS investigators, specifically Drs. Jane Hoppin, Michael Alavanja, Laura Beane-Freeman, and David Umbach. The project will take advantage of the wealth of exposure data collected on the cohort, as well as genotyping data available from a nested prostate cancer case-control study. Specifically, data related to current and past industrial exposures, lifestyle and dietary information, current and past person exposures, and person and family health histories are available through the AHS. Additionally, genotypes from a candidate gene study of prostate cancer is available for a large number of participants. This pilot will support exploratory bioinformatics analyses on the data, including: 1) Exposure data analysis. Principle components analysis will be used for dimensionality reduction, to summarize and characterize composite measures of exposure. This analysis will be used to quantify the variation explained by these composite measures of exposure. 2) Genetic data analysis. Genetic data from the prostate cancer study nested within the AHS will be used for analysis. In order to have a dataset that is representative of the overall population, the controls from this casecontrol study will be used for analysis, along with a randomly selected number of cases that is determined by the population prevalence of prostate cancer. This sampling will ensure that prostate cancer patients are neither over- nor under-represented in the data analysis. This genetic data will then be used to estimate relatedness amongst participants in the AHS. Principle components analysis will also be used to summarize and characterize composite genetic information – generating “meta-genes” that describe the genetic information in the population. Analysis of variance analysis will be used to quantify the variation explained by these composite measures of exposure. 3) Combined data analysis. The results of the data reductions in stages 1 and 2 of the analysis will be used to investigate the relationships between and among environmental/exposure data and genetic information. Correlation and clustering analysis will be used to describe the relationships between the composite measures previously derived. These results will provide insight into the correlations between potentially important health risk factors. The results of these analyses will provide information of the information structure in this large dataset. The dimensionality reduction of the above analyses will summarize the correlation structure of the variables in the AHS, identifying redundancies and synergies that could prioritize groups of variables or composite variables for follow-up in associating these different components to important health outcomes.

2012 Pilot Project Awards

Project 1
Title: Proteomic analyses of oxygenase expression in trichloroethylene
(TCE) –degrading Mycobacteria
PI: Michael Hyman, Professor, Department of Microbiology, CALS, NC State University

Trichloroethylene (TCE) is frequently encountered as a contaminant in groundwater in the United States.  There is considerable interest in microbiological processes capable of degrading this human toxicant in groundwater systems.  Several aerobic microorganisms can cometabolically degrade TCE through the activity of non-specific oxygenate enzymes.  However, this activity is often limited by toxicant effects that are most likely caused by reactive metabolites generated by TCE-oxidizing oxygenases.  Mycobacterium vaccae JOB5 is a well-characterized example of acid-fast bacteria that often grow on simple hydrocarbons such as propane.  This model organism is unusual as it can sustain TCE oxidation over extended periods of time and is remarkably resistant to toxic effects normally associated with TCE oxidation.  These characteristics suggest this strain, and similar hydrocarbon-oxidazing mycobacteria, could be particularly useful for bioremediation of TCE.  Our hypothesis is this limited sensitivity of strain JOB5 to TCE-mediated toxicity is primarily due to expression of propane- and TCE-oxidizing cytochrome P450 that produces less toxic metabolites than those generated by other bacterial TCE-oxidizing enzymes.  The research described in this proposal aims to use a shotgum proteomic analysis of whole cell protein expression to identify this TCE-oxidizing oxygenase in two closely related Mycobacterium strains. The results of this study will be used as preliminary data for a proposal the PI will resubmit in 2012 as part of an intercollegiate, multi-investigator application to the NIEHS Superfund Basic Research program.  This proposal will focus on the health effects of TCE exposure and methods for the bioremediation of TCE in groundwater.

Project 2
TITLE: Investigation of Potential Neurotoxicological Impacts Associated with Chronic Ingestion of Manganese in North Carolina Ground Water
PI: Ricky L. Langley, MD, MPH, Adjunct Professor, Dept. EM Toxicology, NC Division of Public Health, DHHS
Co-PI: Sandra L. Mort, MS, NC Division of Public Health, DHHS, PHD student, Dept. of Biology, NCSU
Co-PI(s): Mina Shehee, PhD, CHES, DHHS, Epidemiology Section
Tanya Barros, MPH, CHES, DHHS, Epidemiology Section
Mercedes Hernandez-Pelletier, MPH, CHES, DHHS, Epidemiology Section

The epidemiological evidence of neurotoxic effects for occupational inhalation and food-related over exposure to manganese (Mn) are well documented, with effects to the central nervous system, lung, heart, liver, reproductive system and the fetus reported. The brain is identified as particularly susceptible to accumulation of excess Mn, leading to the development of a neurodegenerative disorder characterized by both central nervous system (CNS) and neurobehaviora disturbances. Evidence of detrimental effects of elevated Mn in drinking water has been limited because it was long assumed that homeostatic regulation of essential nutrients were protective and prevented their accumulation to toxic levels. It is now thought there are differences in the uptake of Mn from water ingestion relative to that from food, and that this may lead to possible neurotoxic effects at water exposure concentrations previously thought safe. Life stage differences in Mn pharmacokinetics are suspected and it has been postulated that early-life Mn exposure may produce later-life and adult disease phenotypes through epigenetic processes. Approximately 30% of N.C.’s population relies on groundwater as their primary source of drinking water. Concentrations of Mn in N.C. groundwaters exceed those identified as inducing neurotoxicity in adults and children. N.C. DPH proposes a retrospective cohort study of residents on private drinking water wells that have elevated Mn concentrations utilizing health surveys to investigate Mn in groundwater dose-response relationships with neurotoxic effects.

Project 3
Title:  Exposure to environmental toxicants, a mechanism of hypermutability of cardiomyopathy – linked genes
PI: Kathryn M. Meurs, DVM, PhD, Professor, Dept. of Clinical Sciences, CVM
Co PI: Jeffrey A. Yoder, PhD, Associate Professor, Dept of Molecular Biosciences,
CVM
Co PI:  Mac Law, DVM, PhD, Professor, Dept of Population Health and Pathobiology, CVM

Hypertrophic cardiomyopathy is the most common cause of sudden cardiac death in young people. Familial hypertrophic cardiomyopathy is linked to over 300 mutations, but mechanisms underlying hypermutability of cardiomyopathy-linked genes are unknown. The inability to identify the mutagenic event resulting in the development of familial hypertrophic cardiomyopathy has limited the focus of research primarily to the identification of new mutations and has made if difficult to develop prevention protocols.
Our long-term goal is to increase understanding of mechanisms of mutagenesis in cardiomyopathy-linked genes. Our central hypothesis is that genetic heterogeneity of familial hypertrophic cardiomyopathy is a consequence of effect of environmental toxicants on cardiomyopathy-linked genes at the germline level.
We will test our central hypothesis with the following:
Specific Aim: Characterize the extent to which environmental toxicants are responsible for hypermutabilityof a cardiomyopathy-linked gene
The working hypothesis is that cardiomyopathy-linked genes are hypermutable in response to benzo[a]pyrene and pentachlorophenol, common environmental toxicants. We anticipate finding a statistically significant increase in development of mutations in a common cardiomyopathy-linked gene in comparison to the skeletal muscle isoform of this gene in offspring of zebrafish exposed to the toxicants. This increase in mutation frequency will support our hypothesis and provide needed support for the work to be expanded in future studies.  The significance lies in its potential to shift the focus of understanding of hypertrophic cardiomyopathy from that of an intra-familial disease to one associated with environmental toxicants and to use that knowledge to develop innovative screening and risk prevention protocols.

Project 4
Title:  REDEFINING THENETWORK OF TRANSCRIPTIONAL RESPONSES TO ENVIRONMENTAL GENOTOXINS
PI:       Michael Sikes, PhD, Associate Professor, Dept of Microbiology, CALS

DNA damage alters the expression of hundreds of genes involved in a variety of processes far beyond the canonical DNA damage response (DDR) pathway. In preliminary studies, we found that DNA damage from either double-strand breaks or nucleotide crosslinking leads to phosphorylation of the pleiotropic transcription factor USF-1 and loss of DNA-binding activity in lymphocytes. USF-1-dependent promoters that regulate both tissue-specific and ubiquitously expressed genes were affected, resulting in altered gene expression. USF-1 is also highly responsive to DNA damage in both differentiated melanocytes and basal keratinocytes of the skin, and indeed is bound to promoters across the genome in all tissues studied. Together, these findings suggest that USF-1 is part of a general cellular mechanism that is induced by a variety of DNA lesions to regulate a wide spectrum of genes. As such, USF-1 is an ideal and untapped candidate to identify new transcriptional programs induced as part of the broader DDR. We are particularly focused on identifying responses specific to basal stem cells, which are exquisitely sensitive to DNA damage. We propose to couple USF-1’s sensitivity to genotoxic stress with an unbiased genome-wide approach to identify genes regulated by USF-1 following exposure of keratinocyte stem cells to UV-light or etoposide. Specifically, we propose to use ChIP-seq and microarray analyses to identify genes in keratinocytes and differentiated dermal fibroblasts for which USF-1 binding is altered in response to genotoxic stress. These experiments will provide critical insights and lay the foundation for a definitive study of the mechanisms by which DNA damage initiates an array of cellular responses.

Project 5
Title: Linking Free Radical Chemistry and Toxicity of Engineered Nanomaterials
PI: Tatyana I. Smirnova, PhD, Associate Professor, Dept. of Chemistry, PAMS
Co-PI: Alex I Smirnova, PhD, Professor, Dept of Chemistry, PAMS

This pilot project will initiate a research program to link interfacial physicochemical characteristics of nanomaterials with catalytic production of reactive oxygen species (ROS) that could lead to oxidative stress and cytotoxicity in vitro. We will investigate whether production of ROS by nanoparticles (NPs) correlates with oxidative stress observed in cells. Iron oxide (Fe2O3, Fe3O4), titanium dioxide (TiO2), zinc oxide (ZnO), silver (Ag), and Ceria (CeO2/Ce2O3) NPs are selected for this project. Although there are is an indication that these mass-produced nanomaterials may be responsible for oxidative stress and/or inflammatory response in cells and tissue, the understanding of the underlying molecular mechanisms is currently lacking. To address this knowledge gap the NP-initiated ROS will be assessed by spin trapping electron paramagnetic resonance (EPR) to identify the radical species (e.g., superoxide and hydroxyl radicals) and quantify the production rate. Relationships between physicochemical characteristics of NPs (particle size, surface area, chemical composition and surface charge) and the ROS production rate in cells will be studied. Effects of NP coating on ROS production will be investigated and correlated with cytotoxicity. Future directions of this project would include molecular-level assessment of biophysical and biochemical interactions of NPs with membranes and proteins and effects of these interactions on ROS and oxidative stress. The main innovations of this project are in comprehensive characterization of unique physicochemical properties of bio-nano interface using an arsenal of biophysical and materials science methods and correlating catalytic production of ROS by NPs in cells with the oxidative stress.