Epigenetics and Mercury Exposure in the Michigan Dental Association (MDA) Cohort

Research Trainee: Jaclyn Goodrich, PhD, Postdoctoral Fellow, Dept. of Environmental Health Sciences, University of Michigan

Faculty Researcher: Niladri Basu, PhD, Assistant Professor of Environmental Health Sciences at the University of Michigan

Mercury is a potent toxic substance of concern to occupationally exposed workers and the general public. While the adverse health effects of mercury are well characterized at high dose, little is known about mercury’s effects following chronic exposure levels relevant to workers and the general population. Epigenetic modifications (e.g., DNA methylation) have the ability to influence gene expression and have recently emerged as potential mechanisms of toxicity for various substances. Recent animal studies suggest that organic mercury may alter DNA methylation patterns at both global and gene-specific levels, though the influence of inorganic or organic mercury on DNA methylation in humans remains unknown. We hypothesize that inorganic mercury (via dental amalgams) and organic mercury (via fish consumption) are associated with altered DNA methylation patterns in human DNA purified from buccal cells. We propose to carry out our studies with the Michigan Dental Association (MDA), an organization with which we have an ongoing, strong relationship. From this pilot project announcement, we are seeking funds to analyze global percent DNA methylation and methylation patterns at four genic regions of interest, selected based on known sensitivity to methylation changes or previously documented mercury-induced dysregulation, using archived DNA samples from MDA members who participated in a prior study with our research group (n=200). Mercury biomarker levels (hair, urine) were previously measured for these subjects. To our knowledge, this proposed scientific study will be the first epidemiological trial to relate mercury exposure to epigenetic effects. The outcome of this work is expected to enhance our ability to assess the human health risks of mercury for occupationally exposed workers and the general public.

Publications resulting from this project:
Basu N, Goodrich JM, Head J. Ecogenetics of mercury: from genetic polymorphisms and epigenetics to risk assessment and decision-making. Environ Toxicol Chem. 2014;33(6):1248-1258. doi: 10.1002/etc.2375.

Wang Y, Goodrich JM, Werner R, Gillespie B, Basu N, Franzblau A. Relationship of estimated dietary intake of n-3 polyunsaturated fatty acids from fish with peripheral nerve function after adjusting for mercury exposure. Sci Total Environ. 2013;454-455:73-78. doi: 10.1016/j.scitotenv.2013.02.075. PMC3640748

Goodrich JM, Wang Y, Gillespie B, Werner R, Franzblau A, Basu N. Methylmercury and elemental mercury differentially associate with blood pressure among dental professionals. Int J Hyg Environ Health 2013;216(2):195-201. doi: 10.1016/j.ijheh.2012.03.001. PMCID: 372742

Goodrich JM, Basu N, Franzblau A, Dolinoy DC. Mercury biomarkers and DNA methylation among Michigan dental professionals. Environ Mol Mutagen 2013;54(3):195-203. doi: 10.1002/em.21763. PMCID: 375096.

 

Research trainee’s current position:
Jaclyn Goodrich is currently a Research Assistant Professor in Environmental Health Sciences at the University of Michigan