Stem cell plasticity has created great interest because of its potential therapeutic application in degenerative or inherited diseases. Transplantation of bone marrow-derived stem cells was shown to give rise to cells of muscle, liver, nerve, endothelium, epithelium, and so on. But there are still disputes about stem cell plasticity, especially concerning the contribution of bone marrow-derived cells to skin cells. In this study, CM-DiI fluorescence-labeled Flk-(1+) bone marrow mesenchymal stem cells (bMSCs) of BALB/c mice (H-2Kd, white) were transplanted into lethally irradiated C57BL/6 mice (H-2Kb, black). By fluorescence tracing, we found that donor cells could migrate and take residency at the skin, which was confirmed by Y chromosome-specific PCR and Southern blot. The recipient mice grew white hairs about 40 days later and white hairs could spread over the body. Immunochemistry staining and RT-PCR demonstrated that skin tissue within the white hair regions was largely composed of donor-derived H-2Kd cells, including stem cells and committed cells. Furthermore, most skin cells cultured from white hair skin originated from the donor. Thus, our findings provide direct evidence that bone marrow-derived cells can give rise to functional skin cells and regenerate skin tissue. These may have important scientific implications in stem cell biology and transplantation therapy for skin tissue injury.

Recently stem cell plasticity has arouse great interests in stem cell research for its potential therapeutic application in degenerative or inherited diseases. Transplantation of bone marrow-derived stem cells in vivo has been shown to give rise to cells of muscle,liver,nerve,endothelium,epithelium etc. But there are still disputes as to stem cell plasticity, as is in the case of contribution of bone marrow-derived cell to skin cells. Here we show that cells co-purified from bone marrow mesenchymal stem cells can evidently give rise to skin tissue in vivo. In the present study, we first isolated and expanded bone marrow-derived multipotentianl mesenchymal stem cells from BALB/C mice(H-2K~(d), white hair), then co-transplanted them with certain bone marrow cells from C57BL/6 mice via tail vein into lethally-irradiated 12 weeks old C57BL/6 mice(H-2K~(b),black hair).The recipient mice grew out white hair on the back about forty days later.