TY - JOUR T1 - Differential protein metabolism and regeneration in hypertrophic diaphragm and atrophic gastrocnemius muscles in hibernating Daurian ground squirrels JF - bioRxiv DO - 10.1101/793752 SP - 793752 AU - Xia Yan AU - Xuli Gao AU - Xin Peng AU - Jie Zhang AU - Xiufeng Ma AU - Yanhong Wei AU - Huiping Wang AU - Yunfang Gao AU - Hui Chang Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/10/05/793752.abstract N2 - Whether differences in regulation of protein metabolism and regeneration are involved in the different phenotypic adaptation mechanisms of muscle hypertrophy and atrophy in hibernators? Two fast-type muscles (diaphragm and gastrocnemius) in summer active and hibernating Daurian ground squirrels were selected to detect changes in cross-sectional area (CSA), fiber type distribution, and protein expression indicative of protein synthesis metabolism (protein expression of P-Akt, P-mTORC1, P-S6K1, and P-4E-BP1), protein degradation metabolism (MuRF1, atrogin-1, calpain-1, calpain-2, calpastatin, desmin, troponin T, Beclin1, and LC3-II), and muscle regeneration (MyoD, myogenin, and myostatin). Results showed the CSA of the diaphragm muscle increased significantly by 26.1%, whereas the CSA of the gastrocnemius muscle decreased significantly by 20.4% in the hibernation group compared with the summer active group. Both muscles displayed a significant fast-to-slow fiber-type transition in hibernation. Our study further indicated that increased protein synthesis, decreased protein degradation, and increased muscle regeneration potential contributed to diaphragm muscle hypertrophy, whereas decreased protein synthesis, increased protein degradation, and decreased muscle regeneration potential contributed to gastrocnemius muscle atrophy. In conclusion, the differences in muscle regeneration and regulatory pattern of protein metabolism may contribute to the different adaptive changes observed in the diaphragm and gastrocnemius muscles of ground squirrels.Aktprotein kinase BmTORthe mammalian target of rapamycinmTORC1mammalian target of rapamycin in complex 1S6K170 kDa ribosomal protein S6 kinase 14E-BP1eukaryotic initiation factor 4E-binding protein 1CSAcross-sectional areamyoDmyogenic differentiation 1Beclin1B-cell Lymphoma 2 interacting protein 1LC3microtubule-associated protein light chain 3MuRF1Muscle RING finger 1Atrogin-1/MAFbxmuscle atrophy F-box ER -