New Stem Cells Restore Function of Dystrophic Muscles
Milan - Italian researchers have identified human muscle stem cells that may be used as future treatment of incureable inherited muscular dystrophies, caused by the loss of the ability to regenerate muscles. The clinicans from Milan University isolated a new human stem cell population from normal blood which expresses AC133, a marker required for muscle precursor cells to differentiate into mature muscle (J. Clin. Invest. 114(2): 182-195). After growth in culture, the cells were subsequently injected into the skeletal muscle tissue of scid/mdx mice that are a model for human Duchenne dystrophy. The human stem cells invaded the damaged muscle fibers, expressed characteristic muscle fiber and stem cell (M-cadherin and MYF5) markers, and formed functional myofibers that restored muscle function. The injected mice also experienced amelioration of the clinical symptoms of muscular dystrophy and a restoration of the so-called satellite stem cell pool required for muscle regeneration. The research opens up a treatment for Duchenne muscular dystrophy (DMD), a common X-linked disease characterized by wide-spread muscle damage that invariably leads to paralysis and death.