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.