Changes in calpain and caspase gene expression at the mRNA level during bovine muscle satellite cell myogenesis and the correlation between the cell model and the muscle tissue

The calpain proteolytic system plays a central role in cell death and cell signaling. Caspases are a family of proteases implicated in apoptosis. The objective of this study was to explore the regulation and change trend of calpains (CAPN1 and CAPN3) and caspases (caspase-3, caspase-7, and caspase-9) expression at the mRNA level in Luxi cattle skeletal muscle satellite cells during proliferation and differentiation into myotubes. We also sought to assess whether there is a relationship between the muscle satellite cell model and skeletal muscle tissue. Satellite cells were isolated from longissimus dorsi muscle from Luxi cattle and cultured in vitro. Immunofluorescence was used to characterize satellite cells. Our study was divided into three groups: stage one, satellite cells proliferated at 50- and 80-% confluence; stage two, satellite cells differentiated at days 1, 3, 5, 7, and 15; stage three, not the satellite cells but the skeletal muscle tissue. Real-time PCR was used to quantify expression of calpains and the caspases at the mRNA level. These data demonstrated that CAPN1, CAPN3, CASP7, Myf5, and MyoG gene expression significantly increased from satellite cell proliferation to differentiation phases (P < 0.05). In contrast, CASP3 and CASP9 gene expression was significantly down-regulated during myogenesis (P < 0.05). Moreover, we put the CAPN1, CAPN3, CASP3, CASP7, CASP9, Myf5, and MyoG together to say that these genes expression had no significant correlation between the satellite cell model and the skeletal muscle tissue (P > 0.05). Here, we conclude that calpains (CAPN1 and CAPN3), caspases (caspase-3, caspase-7, and caspase-9), and Myf5 and MyoG all have important roles in satellite cell myogenesis. However, there is no relationship between the cell model and muscle tissue.