Recycle, Repair, Recover: The Role of Autophagy in Modulating Skeletal Muscle Repair and Post-Exercise Recovery.

Abstract

Skeletal muscle is a highly plastic tissue which can adapt relatively rapidly to a range of stimuli. In response to novel mechanical loading, e.g. unaccustomed resistance exercise, myofibers are disrupted and undergo a period of ultrastructural remodelling to regain full physiological function, normally within 7 days. The mechanisms which underpin this remodelling are believed to be a combination of cellular processes including UPS/Calpain-mediated degradation, immune cell infiltration and satellite cell proliferation/differentiation. A relatively understudied cellular system which has the potential to be a significant contributing mechanism to repair and recovery is autophagolysosomal system, a cellular process which degrades damaged and dysfunctional cellular components to provide constituent components for the resynthesis of new organelles and cellular structures. This review summarises our current understanding of the autophagolysosomal system in the context of skeletal muscle repair and recovery. In addition, we also provide hypothetical models of how this system may interact with other processes involved in skeletal muscle remodelling and provide avenues for future research to improve our understanding of autophagy in human skeletal muscle.