Genome Wide Analysis of DNA Methylation and Fine Particulate Matter Air Pollution in Three Study Populations: KORA F3, KORA F4, and the Normative Aging Study
Background: Epidemiological studies have reported associations between particulate matter (PM) concentrations and cancer and respiratory and cardiovascular diseases. DNA methylation has been identified as a possible link but so far it has only been analyzed in candidate sites. Objectives: We studied the association between DNA methylation and short and mid term air pollution exposure using genome wide data and identified potential biological pathways for additional investigation. Methods: We collected whole blood samples from three independent studies KORA F3 (2004 2005) and F4 (2006 2008) in Germany, and the Normative Aging Study (1999 2007) in the United States and measured genome wide DNA methylation proportions with the Illumina 450k BeadChip. PM concentration was measured daily at fixed monitoring stations and three different trailing averages were considered and regressed against DNA methylation: 2 day, 7 day and 28 day. Meta analysis was performed to pool the study specific results. Results: Random effect meta analysis revealed 12 CpG (cytosine guanine dinucleotide) sites as associated with PM concentration (1 for 2 day average, 1 for 7 day, and 10 for 28 day) at a genome wide Bonferroni significance level (p 7.5E 8) 9 out of these 12 sites expressed increased methylation. Through estimation of I2 for homogeneity assessment across the studies, 4 of these sites (annotated in NSMAF, C1orf212, MSGN1, NXN) showed p 0.05 and I2 0.5: the site from the 7 day average results and 3 for the 28 day average. Applying false discovery rate, p value 0.05 was observed in 8 and 1,819 additional CpGs at 7 and 28 day average PM2.5 exposure respectively. Conclusion: The PM related CpG sites found in our study suggest novel plausible systemic pathways linking ambient PM exposure to adverse health effect through variations in DNA methylation. Citation: Panni T, Mehta AJ, Schwartz JD, Baccarelli AA, Just AC, Wolf K, Wahl S, Cyrys J, Kunze S, Strauch K, Waldenberger M, Peters A. 2016. A genome wide analysis of DNA methylation and fine particulate matter air pollution in three study populations: KORA F3, KORA F4, and the Normative Aging Study. Environ Health Perspect 124:983 990; http:/dx.doi.org/10.1289/ehp.1509966
Environmental health perspectives