Exercise stimulates the release of molecules into the circulation, supporting the concept that inter-tissue signaling proteins are important mediators of adaptations to exercise. Recognizing that many circulating proteins are packaged in extracellular vesicles (EVs), researchers from the Garvan Institute of Medical Research employed quantitative proteomic techniques to characterize the exercise-induced secretion of EV-contained proteins. Following a 1-hr bout of cycling exercise in healthy humans, they observed an increase in the circulation of over 300 proteins, with a notable enrichment of several classes of proteins that compose exosomes and small vesicles. Pulse-chase and intravital imaging experiments suggested EVs liberated by exercise have a propensity to localize in the liver and can transfer their protein cargo. Moreover, by employing arteriovenous balance studies across the contracting human limb, the researchers identified several novel candidate myokines, released into circulation independently of classical secretion. These data identify a new paradigm by which tissue crosstalk during exercise can exert systemic biological effects.
Tissue crosstalk via extracellular vesicles during exercise can exert systemic biological effects
Whitham M, Parker BL, Friedrichsen M, Hingst JR, Hjorth M, Hughes WE, Egan CL, Cron L, Watt KI, Kuchel RP, Jayasooriah N, Estevez E, Petzold T, Suter CM, Gregorevic P, Kiens B, Richter EA, James DE, Wojtaszewski JFP, Febbraio MA. (2018) Extracellular Vesicles Provide a Means for Tissue Crosstalk during Exercise. Cell Metab 27(1):237-251. [abstract]