Abstract
We have shown that stem cell populations residing in the interstitial spaces of skeletal muscle can give rise to myogenic-endothelial cell lineages, and were designated Sk-34 (CD34+/45-) and Sk-DN (CD34-/45-) cells. Potential therapeutic use of these cells, such as the functional significance of the transplanted tissue, and vasculogenesis, myogenesis was investigated in detail. For this purpose, we developed a severe-damage model of mouse tibialis anterior muscle with a large deficit of nerve fibers, muscle fibers, and blood vessels. Freshly isolated and cultured Sk-34 and Sk-DN cells were transplanted directly into damaged portion of the muscle. Results showed that, after transplantation, implanted cells give rise to myogenic, vascular (pericytes, vascular smooth muscle and endothelial cells), and neural (Schwann cells) cells, as well as contributed to the synchronized reconstitution of blood vessels, muscle fibers, and peripheral nerves, with significant recovery of both mass and contractile function after transplantation. Intrinsic plasticity of these cells was also revealed by fluorescence in situ hybridization (FISH) analysis for the transplanted muscle detecting the Y chromosome. As well, there were no donor-derived Sk-34 and Sk-DN cells in the muscle of lethally irradiated bone marrow-transplanted animals, indicating that the Sk-34 cells were not derived from bone marrow. [J Physiol Sci. 2006;56 Suppl:S145]
