Duchenne muscular dystrophy (DMD), characterized by the absence of the dystrophin protein, has been considered a disease caused by muscle fiber fragility. However, new research shows that impaired muscle stem cells also have an important role in muscle degeneration (Dumont NA et al. Nat Med. doi:10.1038/nm.3990 [published online November 16, 2015]).
Through experiments conducted in mice, investigators from the University of Ottawa and their colleagues discovered that, like muscle fiber cells, muscle stem cells express the dystrophin protein. Without dystrophin, muscle stem cells lost their ability to establish cellular polarity, which impaired cell division and reduced the production of muscle progenitor cells needed to form functional muscle fibers. These stem cell defects prevented the repair of damaged muscle tissue, contributing to muscle wasting in DMD.
Hampton T. Stem Cell Dysfunction Exacerbates Muscular Dystrophy. JAMA. 2016;315(1):19. doi:10.1001/jama.2015.17486