ISSN: 2155-9880
Yusunari Mutsuzaka1,2, Kazuo Hashido1*
Duchenne Muscular Dystrophy (DMD) is caused by loss-of-function mutations in the dystrophin gene on chromosome Xp21. Disruption of the Dystrophin–Glycoprotein Complex (DGC) on the cell membrane causes cytosolic Ca2+ influx, resulting in protease activation, mitochondrial dysfunction, progressive myofiber degeneration, leading to muscle wasting, and fragility. In addition to the function of dystrophin in the structural integrity of myofibers, a novel function of asymmetric cell division in muscular stem cell (satellite cell) has been reported. Therefore, it has been suggested that myofiber instability is not the only cause of dystrophic degeneration, but rather that the phenotype might be caused by multiple factors, including stem cell and myofiber functions. Further, it has been focused functional regulation of satellite cell by intracellular communication of microRNAs via exosome in DMD pathology. Recently, novel molecular mechanism of DMD pathogenesis as circulating RNA disease is revealed though study of target pathways modulated by the nSMase2/Smpd3 protein. These findings suggest that circulating exosomal RNAs may be therapeutic targets of DMD.