PEAR1 Promotes Myoblast Proliferation Through Notch Signaling Pathway.

PEAR1, also known as platelet endothelial aggregation receptor 1, is known to play a crucial role in the migration and differentiation of muscle satellite cells (MuSCs). However, its specific effects on skeletal muscle development and regeneration require further exploration. In this study, the expression of PEAR1; the proliferation marker proteins of Pax7, CCNB1, and PCNA; and the key molecules of N1-ICD, N2-ICD, and Hes1 were all increased gradually during the process of C2C12 cell proliferation. Furthermore, Western blotting and EdU results showed that when PEAR1 was over-expressed or inhibited, the proliferation status of C2C12 cell was increased or reduced respectively. This implied that PEAR1 could regulate myoblast proliferation and might be relate to Notch cell signaling pathway. A subsequent immunoprecipitation experiment result showed that the interaction between PEAR1 and Notch1 or Notch2, respectively. Then Western blotting and EdU results showed that the proliferation of C2C12 cell was inhibited under the treatment of Notch signaling pathway inhibitor RIN1. Meanwhile, the proliferation capacity of C2C12 cell could not be improved by treatment with RIN1 even though PEAR1 was over-expressed. These results showed that PEAR1 may regulated C2C12 cell proliferation though Notch signaling pathway. Additionally, a mouse model of muscle injury repair injected with bupivacaine hydrochloride was established in this study. Immunohistochemistry results exhibited that PEAR1 may regulate skeletal muscle post-injury regeneration relevant to Notch1 and Notch2 in different patterns. These findings provide valuable insights into the potential involvement of PEAR1 in skeletal muscle development and post-injury regeneration.