title: Autophagic Adaptations to Long-term Habitual Exercise in Cardiac Muscle.
abstract: Autophagy has been shown to be responsive to physical exercise. However, the effects of prolonged habitual exercise on autophagy in cardiac muscle remain unknown. The present study aimed to examine whether long-term habitual exercise alters the basal autophagic signalling in cardiac muscle. Female Sprague-Dawley rats aged 2 months were randomly assigned to control and exercise groups. Animals in exercise group were kept in cages with free access exercise wheels to perform habitual exercise for 5 months. Animals in the control group were placed in cages without exercise wheels. Ventricular muscle tissues were harvested for analysis after 5 months. Phosphorylation statuses of upstream autophagic regulatory proteins and protein expressions of downstream autophagic facts remained unchanged in the cardiac muscle of exercise animals when compared to control animals. Intriguingly, the protein abundance of microtubule-associated protein-1 light chain -3 II (LC3-II), heat shock protein 72 (HSP72) and peroxisome proliferator-activated receptor-gamma coactivator (PGC-1α) were significantly increased in cardiac muscle of exercise rats relative to control rats. 5 months of habitual exercise causes the adaptive increase in LC3-II reserve without altering autophagic flux, which probably contributes to the elevation of cellular autophagic capacity and efficiency of cardiac muscle.
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciene, Hong Kong Polytechnic University, Hong Kong, Hong Kong.
authors.forename: B T
authors.initials: BT
authors.lastname: Tam
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciene, Hong Kong Polytechnic University, Hong Kong, Hong Kong.
authors.forename: X M
authors.initials: XM
authors.lastname: Pei
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciene, Hong Kong Polytechnic University, Hong Kong, Hong Kong.
authors.forename: B Y
authors.initials: BY
authors.lastname: Yung
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciene, Hong Kong Polytechnic University, Hong Kong, Hong Kong.
authors.forename: S P
authors.initials: SP
authors.lastname: Yip
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciene, Hong Kong Polytechnic University, Hong Kong, Hong Kong.
authors.forename: L W
authors.initials: LW
authors.lastname: Chan
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciene, Hong Kong Polytechnic University, Hong Kong, Hong Kong.
authors.forename: C S
authors.initials: CS
authors.lastname: Wong
authors.affiliation: Department of Health Technology and Informatics, Faculty of Health and Social Sciene, Hong Kong Polytechnic University, Hong Kong, Hong Kong.
authors.forename: P M
authors.initials: PM
authors.lastname: Siu
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology*; D000818:Animals; D001343:Autophagy / Q000502:physiology*; D005260:Female; D050884:HSP72 Heat-Shock Proteins / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D010766:Phosphorylation / Q000502:physiology; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D050884:HSP72 Heat-Shock Proteins; D008869:Microtubule-Associated Proteins; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D014157:Transcription Factors; C526109:Anxa3 protein, rat; C501429:Ppargc1a protein, rat