Notch2 deficiency prevents muscle atrophy induced by mechanical unloading and diabetes.

Notch signaling plays essential roles in maintenance of muscle stem cell pool. We found that Notch2, but not Notch1 and Notch3, is expressed in fully differentiated myofibers. To study the specific role of Notch2 in adult myofibers, we generated muscle-specific Notch2-knockout mice. Here, we showed that muscle-specific Notch2 deficiency prevented muscle atrophy induced by hindlimb unloading and diabetes millitus. RNA sequencing analysis revealed that the loss of Notch2 gene in myofibers inhibited gene responses to unloading and diabetes. Especially, several FoxO-target genes and atrogenes were upregulated in wildtype muscles but not in Notch2-deficient muscles by unloading and diabetes. Thus, our characterization of muscle-specific Notch2-knockout mice indicates that Notch2 acts as a regulatory factor of skeletal muscle plasticity and could be a therapeutic target of muscle atrophy. mRNA profiles of gastrocnemius muscle tissues obtained from WT and Notch2-mKO mice under unloading, diabetic, or control condition.