Expression of the gene for large subunit of m-calpain is elevated in skeletal muscle from Duchenne muscular dystrophy patients

[摘要] Calpain is an intracellular nonlysosomal protease involved in essential regulatory or processing functions of the cell, mediated by physiological concentrations of Ca2+. However, in an environment of abnormal intracellular calcium, such as that seen in Duchenne muscular dystrophy (DMD), calpain is suggested to cause degeneration of muscle owing to enhanced activity. To test whether the reported increase in calpain activity in DMD results from de novo synthesis of the protease, we have assessed the quantitative changes in mRNA specific for m-calpain. mRNA isolated from DMD and control muscle was analysed by dot blot hybridization using a cDNA probe for the large subunit of m-calpain. Compared to control a four-fold increase in specific mRNAwas observed in dystrophic muscle. This enhanced expression of the m-calpain gene in dystrophic condition suggests that the reported increase in m-calpain activity results from de novo synthesis of protease and underlines the important role of m-calpain in DMD.

[学科分类] 生物科学（综合）

[关键词] m-calpain;Duchenne muscular dystrophy;muscle tissue;RNA dot blot;calpain genetics.