Expression of Caveolin-3 in the Muscle Cell and Tissue

ABSTRACT

OBJECTIVE: Caveolae are the microdomain of the plasma membrane that have been implicated in signal transduction and caveolin is a principal component of the caveolae. Caveolin-3, a family of caveolin related protein, is expressed only in muscle tissue. Here we examined the expression of caveolin-3 in the course of myobalst differentiation and within the muscle tissue. METHOD: L6 cell, rat skeletal myoblast, was cultured in the low mitogen medium and caveolin-3 expression was observed both by immunocytochemistry and western blot analysis. Localization of caveolin-3 within the muscle tissue was investigated and compared to that of dystrophin. RESULTS: While caveolin-3 was not expressed in the proliferating myolast, caveolin-3 was expressed in the differentiated myoblast. Caveolin-3 and dystrophin were co-expressed in the membrane of muscle tissue and integrated density of caveolin-3 was elevated in the area of muscle injury. In the Duchenne muscular dystrophy, caveolin-3 was expressed in the membrane of muscle tissue, but dystrophin was not. CONCLUSION: Caveolin-3 was induced during the myobalst differentiation and its expression was increased during the muscle regeneration. Caveolin-3 was physically associated with dystrophin as a complex, but not absolutely required for the biogenesis of dystrophin complex.