Effects of ambient ozone exposure on circulating extracellular vehicle microRNA levels in coronary artery disease patients
Abstract
Exposure to ambient air pollutants such as ozone and particulate matter (PM) is associated with increased cardiovascular morbidity and mortality, but the underlying biological mechanisms have yet to be described. Emerging evidence shows that gene regulation by microRNAs (miRNAs) may play a role in air pollution-induced cardiovascular risk. This study aims to explore the association between exposure to ambient air pollutants and extracellular vehicle (EV) miRNA changes related cardiovascular disease. Fourteen participants with coronary artery diseases (CAD) were enrolled in this panel study. Each participant had up to 10 clinical visits and their plasma samples were collected and measured for expression of miRNA-21 (miR-21), miR-126, miR-146, miR-150, and miR-155. Mixed effects models adjusted for temperature, humidity, and season were used to examine the association between miRNA levels and exposure to 8-hour ozone or 24-hour PM2.5 up to 4 days prior. Results showed that miR-150 expression was positively associated with ozone exposure at 1 – 4 days lag and 5d moving average while miR-155 expression tracked with ozone exposure at lag 0. No significant association was found between miRNA expression and ambient PM2.5 at any time point. β-blocker and diabetic medication usage significantly modified the association between ozone exposure and miR-150 expression where the link was more prominent among non-users. In conclusion, we observed an association between exposure to ambient ozone and circulating levels of EV miR-150 and miR-155. The findings shed light on the mechanisms of ozone-induced cardiovascular effects and the role of miRNA targets.