Epigenetic changes seen in elderly men after prolonged air pollution exposure.

Epigenetic changes seen in elderly men after prolonged air pollution exposure.
http://www.environmentalhealthnews.org/ehs/newscience/prolonged-air-pollution-alters-methylation-in-elderly-men/  

"New research suggests that long-term exposure to certain air pollutants alters DNA methylation, a mechanism that controls gene expression."

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Madrigano J, A Baccarelli, MA Mittleman, RO Wright, D Sparrow, PS Vokonas, L Tarantini and J Schwartz. 2011. Prolonged exposure to particulate pollution, genes associated with glutathione pathways, and DNA methylation in a cohort of older men. Environmental Health Perspectives http://dx.doi.org/10.1289/ehp.1002773.
Synopsis by Heather Volk

Abstract

Background and Objective: DNA methylation is a potential pathway linking environmental exposures to disease. Exposure to particulate air pollution has been associated with increased cardiovascular morbidity and mortality, and lower blood DNA methylation has been found in processes related to cardiovascular morbidity. We hypothesized that prolonged exposure to particulate pollution would be associated with hypomethylation of repetitive DNA elements and that this association would be modified by genes involved in glutathione metabolism and other host characteristics.

 

Methods: DNA methylation of the Long Interspersed Nucleotide Element-1 (LINE-1) and the short interspersed nucleotide element, Alu, were measured by quantitative PCR-Pyrosequencing in 1406 blood samples from 706 elderly participants in the Normative Aging Study (NAS). We estimated changes in repetitive element DNA methylation associated with ambient particles (PM2.5), black carbon and sulfates, with mixed models. We examined multiple exposure windows (one to six months) prior to DNA methylation measurement. We investigated whether this association was modified by genotype and phenotype.

 

Results: An increase of an interquartile range in black carbon over a 90-day period was associated with a decrease of 0.31% 5-methylcytosine (5-mC) (95% CI: 0.12%, 0.50%) in Alu. An increase in an interquartile range of sulfate over a 90-day period was associated with a decrease of 0.27% 5mC (0.02%, 0.52%) in LINE-1. The GSTM1 null genotype strengthened the association between black carbon and Alu hypomethylation.

 

Conclusion: Prolonged exposure to black carbon and sulfate particles was associated with hypomethylation of two types of repetitive elements.

PMID: 21385671