Autophagy is induced by resistance exercise in young men, but unfolded protein response is induced regardless of age

作者：Hentila J^*; Ahtiainen J P; Paulsen G; Raastad T; Hakkinen K; Mero A A; Hulmi J J^*

来源：Acta Physiologica, 2018, 224(1): UNSP e13069.

DOI：10.1111/apha.13069

• autophagy
• resistance training
• unfolded protein response

AimAutophagy and unfolded protein response (UPR) appear to be important for skeletal muscle homoeostasis and may be altered by exercise. Our aim was to investigate the effects of resistance exercise and training on indicators of UPR and autophagy in healthy untrained young men (n=12, 274years) and older men (n=8, 616years) as well as in resistance-trained individuals (n=15, 255years).
MethodsIndicators of autophagy and UPR were investigated from the muscle biopsies after a single resistance exercise bout and after 21weeks of resistance training.
ResultsLipidated LC3II as an indicator of autophagosome content increased at 48hours post-resistance exercise (P<.05) and after a resistance training period (P<.01) in untrained young men but not in older men. Several UPRER markers, typically induced by protein misfolding in endoplasmic reticulum, were increased at 48hours post-resistance exercise in untrained young and older men (P<.05) but were unaltered after the 21-week resistance training period regardless of age. UPR was unchanged within the first few hours after the resistance exercise bout regardless of the training status. Changes in autophagy and UPRER indicators did not correlate with a resistance training-induced increase in muscle strength and size.
ConclusionAutophagosome content is increased by resistance training in young previously untrained men, but this response may be blunted by ageing. However, unfolded protein response is induced by an unaccustomed resistance exercise bout in a delayed manner regardless of age.

• 出版日期2018-9