Autophagic response to a single bout of moderate exercise in murine skeletal muscle.
The effect of a single bout of exercise on autopahgy in murine gastrocnemius muscle was investigated. Autophagy is a process for the degradation system of cytoplasmic components, which may help maintain intracellular quality control of cell survival and turnover under normal conditions. The present study investigated the changes of autophagy-related proteins including microtubule-associated protein 1b light chain 3 (LC3), Beclin-1, Atg7 (autophagy-related gene 7), conjugation form of Atg12 to Atg5, lysosome-associated membrane protein (LAMP2a), and muscle-specific RING finger protein-1 (MURF-1) protein level in gastrocnemius muscle after a single bout of treadmill exercise. Mice exercised on a treadmill for 50 min at a speed of 12.3 m/min with a slope of 5°. The animals were sacrificed by cervical dislocation 0, 3, 6, or 12 h after exercise, and muscle samples were collected immediately. Western blot analysis demonstrated that the autophagy marker LC3-II was significantly decreased during the recovery period (3, 6, and 12 h) whereas there was no decrease immediately after exercise (0 h). To identify factors related to this decrease, autophagosome component proteins were examined in murine gastrocnemius muscle. A decrease in Beclin-1, Atg7, and LAMP2a during recovery period was concomitant with the decreased level of LC3-II. Additionally, MuRF-1 expression was significantly increased after a single bout of exercise. This study is the first to demonstrate autophasic related protein expression after a single bout of treadmill exercise and our results suggest that a single bout of treadmill exercise attenuates the autophagic response in murine skeletal muscle.
Institute of Biotechnology, Chungnam National University, Daejeon, South Korea.
Yong An
YA
Kim
Young Sang
YS
Kim
Wook
W
Song
D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D001343:Autophagy; D000071192:Autophagy-Related Protein 12; D000071187:Autophagy-Related Protein 5; D000071193:Autophagy-Related Protein 7; D000071186:Beclin-1; D052119:Lysosomal-Associated Membrane Protein 2 / Q000378:metabolism; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009043:Motor Activity; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D005082:Physical Exertion; D020033:Protein Isoforms / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
D051017:Apoptosis Regulatory Proteins; C491971:Atg12 protein, mouse; C495773:Atg5 protein, mouse; C502661:Atg7 protein, mouse; D000071192:Autophagy-Related Protein 12; D000071187:Autophagy-Related Protein 5; D000071186:Beclin-1; C115010:Becn1 protein, mouse; D052119:Lysosomal-Associated Membrane Protein 2; C480860:Map1lc3b protein, mouse; D008869:Microtubule-Associated Proteins; D009124:Muscle Proteins; D020033:Protein Isoforms; D011506:Proteins; D000070584:Tripartite Motif Proteins; C499084:Trim63 protein, mouse; D044767:Ubiquitin-Protein Ligases; D000071193:Autophagy-Related Protein 7