Cardiorespiratory Fitness And Obesity: Oxidative Stress Responses In Circulating Exosomes Following Maximal Aerobic Exercise

Extracellular vesicles (exosomes) represent a mechanism that skeletal muscle communicates with nearby organs and tissue types to possibly attenuate obesity-related disease pathology. Exercise is effective at improving the health-mediating capacity of plasma exosomes as mediators of intercellular crosstalk. PURPOSE: To determine the impact of cardiorespiratory fitness and obesity on the plasma exosome responses to acute maximal treadmill running. METHODS: Normal-weight and aerobically trained (NW-Tr; n = 15), normal-weight and aerobically untrained (NW-UTr; n = 18), and aerobically untrained individuals with obesity (Ob-Utr; n = 10) participated in the study. Plasma exosomes were isolated prior to and in response to acute maximal treadmill exercise. RESULTS: Following maximal aerobic exercise, Ob-UTr subjects exhibited a significantly greater reduction in plasma protein carbonyls from pre-to-post maximal exercise compared to both the NW-Tr and NW-UTr groups (p < 0.001), while NW-UTr subjects exhibited a significantly greater increase in plasma total antioxidant capacity (TAC) compared to the NW-Tr and Ob-UTr groups (p = 0.010). Furthermore, NW-UTr subjects exhibited a significantly greater increase in circulating exosomes flotillin-1 (Flot-1) expression compared to both the NW-Tr and Ob-UTr groups (p = 0.008). Additionally, NW-Tr subjects exhibited a significantly greater reduction in circulating exosomes glutathione (GSH) concentrations from pre-to-post maximal exercise compared to both the NW-UTr and Ob-UTr groups (p = 0.009). Lastly, Ob-UTr subjects had a greater increase in exosome lipid peroxidation from pre-to-post maximal exercise compared to both the NW-Tr and NW-UTr groups (p = 0.003). CONCLUSIONS: We demonstrated that obesity differentially regulates Flot-1 exosome expression and indices of oxidative stress in plasma and circulating exosomes to maximal aerobic exercise, while aerobic capacity as evidenced by VO2max might also influence the release of oxidative stress markers in plasma and circulating exosomes.