Defective myoblasts identified in Duchenne muscular dystrophy.

Publisher Website
Google Scholar
Abstract
A defect in the proliferative capacity of satellite cells, mononucleated precursors of mature muscle fibers, was found in clonal analyses of cells cultured from Duchenne muscular dystrophy (DMD) patients. The total yield of myoblasts per g of muscle biopsy was decreased to 5% of normal. Of the DMD myoblast clones obtained, a large proportion contained a morphological class of flat distended cells that had an increased generation time and ceased to proliferate beyond 100-1000 cells but could be induced to fuse and form myotubes. The altered muscle phenotype was detected in all cultures from DMD patients but was rarely found among myoblasts of controls. By age 14 yr, it comprised as many as 90% of DMD myoblasts. The remaining DMD myoblast clones, which initially grew well, had severely impaired proliferative capacity upon passage and further cultivation. Eventually all myoblasts from DMD muscle tissue exhibited defective growth potential. The fibroblast yield and proliferative capacity from DMD samples did not differ from normal. A hypothesis for the etiology of DMD was proposed. Dividing myoblasts are required for muscle growth and maintenance, and the limited capacity of DMD myoblasts to grow is directly related to the progressive muscle degeneration characteristic of the disease.