title: [The changes of p-Akt/MuRF1/FoxO1 proteins expressions in the conditions of training and immobilization in rats' gastrocnemius muscle].
abstract: This study was aimed to investigate the changes of muscle protein synthesis and degradation under different movement conditions, so as to provide theoretical basis for muscle atrophy mechanism. Sprague Dawley (SD) rats were randomly divided into control, endurance training (treadmill training), hind limb overhanging and eccentric training (treadmill training, angle -16º) groups. The gastrocnemius muscles of rats were taken and weighed. The muscle was sectioned, and HE staining was employed to determine the cell's cross-sectional area. Protein expression of p-Akt was measured by immunohistochemistry; and the expressions of MuRF1 and FoxO1 were determined by Western blot. The results showed that, compared with control group, hind limb overhanging and eccentric training groups exhibited decreased muscle weight and cross-sectional area, but endurance training group did not show any changes. The expressions of p-Akt in endurance and eccentric training groups, not in hind limb overhanging group, were significantly higher than that in control group. Compared with that of control, MuRF1 protein remained unchanged in endurance training groups, but was increased in eccentric training and hind limb overhanging groups; FoxO1 protein was decreased in endurance training group, but was increased in eccentric training and hind limb overhanging groups. These results indicate that movement (endurance and eccentric training) can activate Akt expression, but does not increase muscle weight, whereas eccentric training and hind limb overhanging can increase the expressions of MuRF1 and FoxO1, and induce amyotrophy, suggesting MuRF1 and FoxO1 are major determinant factors in muscle atrophy.
authors.affiliation: Physical Education College of Liaoning Normal University, Dalian 116029, China; Molecular Biology Lab, the Second Hospital of Dalian Medical University, Dalian 116029, China; College of Life Science of Liaoning Normal University, Dalian 116029, China. weizou60@hotmail.com.
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Su
authors.forename: Zhe
authors.initials: Z
authors.lastname: Su
authors.forename: Kai
authors.initials: K
authors.lastname: Zhang
authors.forename: Qian-Kun
authors.initials: QK
authors.lastname: Yuan
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
authors.forename: Shen
authors.initials: S
authors.lastname: Lv
authors.forename: Zhao-Hui
authors.initials: ZH
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Zou
mesh_terms: D000818:Animals; D051858:Forkhead Transcription Factors / Q000502:physiology*; D019417:Hindlimb Suspension; D009124:Muscle Proteins / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D009133:Muscular Atrophy / Q000503:physiopathology; D009419:Nerve Tissue Proteins / Q000502:physiology*; D010805:Physical Conditioning, Animal; D051057:Proto-Oncogene Proteins c-akt / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases / Q000502:physiology*; D000071161:Forkhead Box Protein O1
chemical_list: D051858:Forkhead Transcription Factors; D009124:Muscle Proteins; D009419:Nerve Tissue Proteins; D051057:Proto-Oncogene Proteins c-akt; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases; C074639:Foxo1 protein, rat; D000071161:Forkhead Box Protein O1; C499086:Trim63 protein, rat