Air pollution exposure and histone 3 methylation and acetylation in highly exposed individuals in Beijing, China: A repeated-measures study

Background: Particulate matter (PM) induces epigenetic changes including histone modifications which influence chromatin structure and gene expression. We evaluated whether ambient PM exposure is associated with modifications of histone 3 (H3) in individuals exposed to high levels of air pollution in Beijing, China. Methods: The Beijing Truck Driver Air Pollution Study included 60 truck drivers and 60 office workers examined 1-2 weeks apart in 2008. Our study examined three measures of PM exposure: personal PM exposure, including PM2.5 and black carbon (BC), measured during eight work hours using portable monitors; acute ambient PM10 exposures using examination-day data averaged from 27 monitoring stations; and recent (14-day moving average) ambient PM10 exposure, also based on the monitoring station data. For histone modifications we measured global levels of H3 lysine 9 acetylation (H3K9ac), H3 lysine 9 tri-methylation (H3K9me3), H3 lysine 27 tri-methylation (H3K27me3), and H3 lysine 36 tri-methylation ...