Hsp90β interacts with MDM2 to suppress p53‐dependent senescence during skeletal muscle regeneration

• Published in: Aging cell Vol. 18; no. 5; pp. e13003 - n/a
• Main Authors: He, Min Yi, Xu, Shui Bo, Qu, Zi Hao, Guo, Yue Mei, Liu, Xiao Ceng, Cong, Xiao Xia, Wang, Jian Feng, Low, Boon Chuan, Li, Li, Wu, Qiang, Lin, Peng, Yan, Shi Gui, Bao, Zhang, Zhou, Yi Ting, Zheng, Li Ling
• Format: Journal Article
• Language: English
• Published: England John Wiley & Sons, Inc 01.10.2019; John Wiley and Sons Inc
• Subjects: Analysis; Animals; Cell Line; Cellular Senescence; Cyclin-dependent kinase inhibitor p21; Embryogenesis; Embryonic development; Genetic transcription; Heat shock proteins; heat‐shock protein; Homeostasis; HSP90 Heat-Shock Proteins - chemistry; HSP90 Heat-Shock Proteins - metabolism; Hsp90 protein; Hsp90β; MDM2; MDM2 protein; Mice; muscle regeneration; Muscle, Skeletal - metabolism; Muscles; Myoblasts; Original; p53; p53 Protein; Proteasomes; Proto-Oncogene Proteins c-mdm2 - chemistry; Proto-Oncogene Proteins c-mdm2 - metabolism; Ribonucleic acid; RNA; Senescence; Skeletal muscle; Transcription; Tumor proteins; Tumor Suppressor Protein p53 - metabolism; Ubiquitin-protein ligase; senescence; Hsp90β; cellular senescence; MDM2; heat-shock protein; muscle regeneration; skeletal muscle; p53
• ISSN: 1474-9718; 1474-9726
• DOI: 10.1111/acel.13003

Cellular senescence plays both beneficial and detrimental roles in embryonic development and tissue regeneration, while the underlying mechanism remains elusive. Recent studies disclosed the emerging roles of heat‐shock proteins in regulating muscle regeneration and homeostasis. Here, we found that Hsp90β, but not Hsp90α isoform, was significantly upregulated during muscle regeneration. RNA‐seq analysis disclosed a transcriptional elevation of p21 in Hsp90β‐depleted myoblasts, which is due to the upregulation of p53. Moreover, knockdown of Hsp90β in myoblasts resulted in p53‐dependent cellular senescence. In contrast to the notion that Hsp90 interacts with and protects mutant p53 in cancer, Hsp90β preferentially bound to wild‐type p53 and modulated its degradation via a proteasome‐dependent manner. Moreover, Hsp90β interacted with MDM2, the chief E3 ligase of p53, to regulate the stability of p53. In line with these in vitro studies, the expression level of p53‐p21 axis was negatively correlated with Hsp90β in aged mice muscle. Consistently, administration of 17‐AAG, a Hsp90 inhibitor under clinical trial, impaired muscle regeneration by enhancing injury‐induced senescence in vivo. Taken together, our finding revealed a previously unappreciated role of Hsp90β in regulating p53 stability to suppress senescence both in vitro and in vivo. Injury induces p53‐dependent cellular senescence in muscle. During muscle regeneration, elevated Hsp90β inhibits injury‐induced senescence by enhancing wild‐type p53 degradation via a MDM2‐dependent manner. Administration of 17‐AAG, a Hsp90 inhibitor under clinical trial, impaired muscle regeneration by enhancing injury‐induced senescence in vivo.