Dose effect relationship between the number of normal progenitor muscle cells grafted in mdx mouse skeletal striated muscle and the number of dystrophin-positive fibres

Abstract

The transplantation of progenitor muscle cells in striated skeletal muscle of mdx mice, a model of dystrophin deficiency, is well known to induce the formation of mosaic fibres expressing dystrophin near the site of injection. We tried to determine if the number of injected cells is related to the number of dystrophin-positive fibres. The grafted cells provided by 5 day-old C57Bl10 mice are syngenic to mdx mice and were cultured to select undifferentiated progenitors. Dystrophin-positive fibres distinct to ‘revertant’ fibres were detectable 10 days following the graft of as few as 10 3 cells. The number of dystrophin-positive fibres increases logarithmically with the number of grafted cells. The data indicate that the number of dystrophin-positive fibres plateaus above 5×10 5 –10 6 grafted cells and that a greater number of progenitor cells is not required to obtain a better result.