title: Autophagy is essential to support skeletal muscle plasticity in response to endurance exercise.
abstract: Physical exercise is a stress that can substantially modulate cellular signaling mechanisms to promote morphological and metabolic adaptations. Skeletal muscle protein and organelle turnover is dependent on two major cellular pathways: Forkhead box class O proteins (FOXO) transcription factors that regulate two main proteolytic systems, the ubiquitin-proteasome, and the autophagy-lysosome systems, including mitochondrial autophagy, and the MTORC1 signaling associated with protein translation and autophagy inhibition. In recent years, it has been well documented that both acute and chronic endurance exercise can affect the autophagy pathway. Importantly, substantial efforts have been made to better understand discrepancies in the literature on its modulation during exercise. A single bout of endurance exercise increases autophagic flux when the duration is long enough, and this response is dependent on nutritional status, since autophagic flux markers and mRNA coding for actors involved in mitophagy are more abundant in the fasted state. In contrast, strength and resistance exercises preferentially raise ubiquitin-proteasome system activity and involve several protein synthesis factors, such as the recently characterized DAGK for mechanistic target of rapamycin activation. In this review, we discuss recent progress on the impact of acute and chronic exercise on cell component turnover systems, with particular focus on autophagy, which until now has been relatively overlooked in skeletal muscle. We especially highlight the most recent studies on the factors that can impact its modulation, including the mode of exercise and the nutritional status, and also discuss the current limitations in the literature to encourage further works on this topic.
authors.affiliation: Department of Critical Care, McGill University Health Centre and Meakins-Christie Laboratories, Department of Medicine, McGill University, Montreal, Quebec, Canada; University of Perpignan Via Domitia, Laboratoire Performance Santé Altitude, EA 4604, Font-Romeu, France; anthony.sanchez@univ-perp.fr.
authors.forename: Anthony M J
authors.initials: AM
authors.lastname: Sanchez
authors.affiliation: Institut National de la Recherche Agronomique, UMR 866 Dynamique Musculaire et Métabolisme, Montpellier, France; and.
authors.forename: Henri
authors.initials: H
authors.lastname: Bernardi
authors.affiliation: Faculty of Sport Sciences, University of Montpellier 1, Montpellier, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Py
authors.affiliation: Faculty of Sport Sciences, University of Montpellier 1, Montpellier, France.
authors.forename: Robin B
authors.initials: RB
authors.lastname: Candau
mesh_terms: D000818:Animals; D001343:Autophagy / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors / Q000502:physiology; D006801:Humans; D000076222:Mechanistic Target of Rapamycin Complex 1; D008928:Mitochondria / Q000502:physiology; D046912:Multiprotein Complexes / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology; D058570:TOR Serine-Threonine Kinases / Q000502:physiology
chemical_list: C085126:FOXO1 protein, human; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D046912:Multiprotein Complexes; D000076222:Mechanistic Target of Rapamycin Complex 1; D058570:TOR Serine-Threonine Kinases
keywords: MTOR; amino acids; endurance exercise; mitophagy; protein turnover