NIOSHTIC-2 Publications Search

Mercury biomarkers and DNA methylation among Michigan dental professionals.

Goodrich JM; Basu N; Franzblau A; Dolinoy DC

Environ Mol Mutagen 2013 Apr; 54(3):195-203

https://doi.org/10.1002/em.21763

20042586

Modification of the epigenome may be a mechanism underlying toxicity and disease following chemical exposure. Animal and human data suggest that mercury (Hg) impacts DNA methylation. We hypothesize that methylmercury and inorganic Hg exposures from fish consumption and dental amalgams, respectively, may be associated with altered DNA methylation at global repetitive elements (long interspersed elements, LINE-1) and candidate genes related to epigenetic processes (DNMT1) and protection against Hg toxicity (SEPW1, SEPP1). Dental professionals were recruited at Michigan Dental Association (MDA) meetings in 2009 and 2010. Subjects (n=131) provided survey data (e.g. exposure sources, demographics) and biological samples for Hg measurement and epigenetic analysis. Total Hg was quantified via atomic absorption spectrophotometry in hair and urine, indicative of methylmercury and inorganic Hg exposures, respectively. Global repetitive and candidate gene methylation was quantified via pyrosequencing of bisulfite converted DNA isolated from buccal mucosa. Hair Hg (geometric mean (95% CI): 0.37 (0.31-0.44) µg/g) and urine Hg (0.70 (0.60-0.83) µg/L) were associated with sources of exposure (fish consumption and dental amalgams, respectively). Multivariable linear regression revealed a trend of SEPP1 hypomethylation with increasing hair Hg levels, and this was significant (P<0.05) among males. The trend remained when excluding non-dentists. No significant relationships between urine Hg and DNA methylation were observed. Thus, in a limited cohort, we identified an association between methylmercury exposure and hypomethylation of a potentially labile region of the genome (SEPP1 promoter), and this relationship was gender specific.

Dental-materials; Dentists; Mercury-compounds; Employee-exposure; Environmental-exposure; Humans; Biomarkers; Genes; Methyl-compounds; Urinalysis; Analytical-processes; Genetic-factors; Genotoxic-effects; DNA-damage; Food; Inorganic-mercury; Professional-workers; Atomic-absorption-spectrometry; Men; Women; Chemical-analysis; Sampling; Proteins; Nucleotides; Sex-factors; Sulfites; Author Keywords: epigenetics; environmental exposure; occupational exposure; selenoproteins

Jaclyn M. Goodrich, 1415 Washington Heights, Ann Arbor, MI 48109, USA

EMMUEG

7439-97-6; 22967-92-6

20130401

Journal Article

gaydojac@umich.edu

Grant

2013

Grant-Number-T42-OH-008455; B20130531

3

0893-6692

Environmental and Molecular Mutagenesis

MI

University of Michigan, Ann Arbor