Satellite cell-specific deletion of Cipc alleviates myopathy in mdx mice
Jiqing Zheng1, Jing Lou1, Yanfang Li1
1Cyrus Tang Hematology Center, Collaborative Innovation Center of Hematology, Soochow University, 199 Ren Ai Road, Suzhou 215123, P.R. China; National Clinical Research Center for Hematologic Diseases, The First Affiliated Hospital of Soochow University, Suzhou, P.R. China; State Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123, P.R. China.
Abstract:
Skeletal muscle regeneration relies on satellite cells that can proliferate, differentiate, and form new myofibers upon injury. Emerging evidence suggests that misregulation of satellite cell fate and function influences the severity of Duchenne muscular dystrophy (DMD). The transcription factor Pax7 determines the myogenic identity and maintenance of the pool of satellite cells. The circadian clock regulates satellite cell proliferation and self-renewal. Here, we show that the CLOCK-interacting protein Circadian (CIPC) a negative-feedback regulator of the circadian clock, is up-regulated during myoblast differentiation. Specific deletion of Cipc in satellite cells alleviates myopathy, improves muscle function, and reduces fibrosis in mdx mice. Cipc deficiency leads to activation of the ERK1/2 and JNK1/2 signaling pathways, which activates the transcription factor SP1 to trigger the transcription of Pax7 and MyoD. Therefore, CIPC is a negative regulator of satellite cell function, and loss of Cipc in satellite cells promotes muscle regeneration.
