Physical exercise induces rapid release of small extracellular vesicles into the circulation

Abstract

Cells secrete extracellular vesicles (EVs) by default and in response to diverse stimuli for the purpose of cell communication and tissue homeostasis. EVs are present in all body fluids including peripheral blood, and their appearance correlates with specific physiological and pathological conditions. Here, we show that physical activity is associated with the release of nano-sized EVs into the circulation. Healthy individuals were subjected to an incremental exercise protocol of cycling or running until exhaustion, and EVs were isolated from blood plasma samples taken before, immediately after and 90 min after exercise. Small EVs with the size of 100–130 nm, that carried proteins characteristic of exosomes, were significantly increased immediately after cycling exercise and declined again within 90 min at rest. In response to treadmill running, elevation of small EVs was moderate but appeared more sustained. To delineate EV release kinetics, plasma samples were additionally taken at the end of each increment of the cycling exercise protocol. Release of small EVs into the circulation was initiated in an early phase of exercise, before the individual anaerobic threshold, which is marked by the rise of lactate. Taken together, our study revealed that exercise triggers a rapid release of EVs with the characteristic size of exosomes into the circulation, initiated in the aerobic phase of exercise. We hypothesize that EVs released during physical activity may participate in cell communication during exercise-mediated adaptation processes that involve signalling across tissues and organs.

• extracellular vesicles
• exosomes
• exercise
• ergometer cycling
• treadmill running
• plasma
• Hsp70
• Flotillin

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To access the supplementary material to this article, please see Supplementary files under ‘Article Tools’.

Authors’ contributions

CF, PS and EMKA conceived and designed experiments. CF and SH performed experiments. CF, EMKA, SH and PS collected and analyzed data. ST wrote ethical approval and recruited subjects. EMKA and CF wrote the manuscript.

Acknowledgements

The authors are grateful to the volunteers participated in the study. Wen Ping Kuo is thanked for critical comments on the manuscript. EMKA and CF thank Jacqueline Trotter for general support.

Conflict of interest and funding

The authors declare no conflict of interest. This study was supported by a DFG grant to EMKA (KR3668/1-1).

Notes

To access the supplementary material to this article, please see Supplementary files under ‘Article Tools’.