Circulating extracellular vesicles in the aging process: impact of aerobic exercise.

Our aim was to investigate transitory and delayed exercise effects on serum extracellular vesicles (EVs) in aging process. Male Wistar rats of 3-, 21-, and 26-month old were allocated into exercised and sedentary groups. The exercise protocol consisted in a daily moderate treadmill exercise (20 min daily during 2 weeks). Trunk blood was collected 1 and 18 h after the last exercise session, and circulating EVs were obtained. CD63 levels and acetylcholinesterase (AChE) activity were used as markers of exosome, a subtype of EVs. In addition, the quantification of amyloid-β (Aβ) levels and the oxidative status parameters, specifically reactive species content, superoxide dismutase (SOD) activity, and SOD1 content were evaluated. Aged rats showed reduced CD63 levels and increased AChE activity in circulating exosomes compared to young ones. Moreover, higher reactive species levels were found in circulating EVs of aged rats. Delayed exercise effects were observed on peripheral EVs, since CD63, reactive species content, and AChE activity were altered 18 h after the last exercise session. Our results suggest that the healthy aging process can modify circulating EVs profile, and exercise-induced beneficial effects may be related to its modulation on EVs.