The Effects of Ambient Air Pollution on Mitochondrial Respiration in Circulating Platelets: The Role of Omega-3 Fatty Acids

Abstract

Abstract Objectives Circulating platelets act as “fast responders” to endothelial damages. Dietary long-chain polyunsaturated omega-3 fatty acids have been shown to ameliorate cardiovascular function decrement after exposure to air pollution. This project aimed to explore the role of omega-3 fatty acids in mitochondrial respiratory function in circulating platelets exposed to ambient air pollution. Methods Platelets were isolated from healthy male adult volunteers (n = 20) from the Research Triangle Area (RTP), NC and measured for mitochondrial respiratory rates using an extracellular flux analyzer (Seahorse Mitochondrial Stress Test). Omega-3 indices were measured in total blood by OmegaQuant LLC. Local ambient air pollution data were obtained from the ambient air quality monitoring stations. Results Oxygen consumption rates corresponding to maximum mitochondrial respiration and spare respiration capacity were correlated with PM2.5 levels (r = 0.56 and r = 0.57 respectively, all P < 0.05). Additionally, moderation analysis revealed that the associations between these respiratory parameters and PM2.5 levels were contingent upon the levels of omega-3 indices (all P < 0.05). Specifically, the Johnson-Neyman method indicated that for omega-3 indices of 5.11 or higher, the two associations reached statistically significant: levels of PM2.5 were positively correlated with the two respiratory parameters. Conclusions Taken together, these preliminary findings suggest that exposure to PM2.5 increases platelet mitochondrial respiration and that this effect is potentiated by omega-3 fatty acids. Funding Sources This project was supported by the U.S. EPA Intramural Research Program.