Role of calpastatin in the regulation of mRNA expression of calpain, caspase, and heat shock protein systems in bovine muscle satellite cells.

Calpastatin participates in apoptotic cell death and cell signaling, but its role in skeletal myoblast development and molecular involvements in cell growth still remains unknown. The current study aimed to investigate the role of calpastatin on the expression patterns of calpains, caspases, and heat shock proteins (HSPs). In addition, the cell viability during myoblast growth under calpastatin silence condition was also investigated. Three small interference RNA sequences (siRNAs) were used to silence calpastatin gene and ligated into pSilencer plasmid vector to construct short hairpin RNA (shRNA) expression. The all three siRNAs significantly silence the calpastatin gene. Moreover, suppression of calpastatin significantly reduced the viability of myoblasts during growth phase when compared to control cells. Additionally, knockdown of calpastatin significantly increased the mRNA expression of μ-calpain, caspase-3, caspase-7, and caspase-9, as well as HSP-27, -70, and -90. The present study results suggested that the suppression of calpastatin resulted in the increased expression of μ-calpain, caspases, and HSPs which in turn regulate the apoptotic cell death. The present study throws light on the central role of calpastatin in the control of calpain activity, cell proliferation, cell survival, and apoptotic pathways.