Differentiation of adult human bone marrow mesenchymal stem cells into Schwann-like cells in vitro.

OBJECTIVE: To investigate the differentiative capability of adult human bone marrow mesenchymal stem cells (BMSCs) into Schwann-like cells. METHODS: Bone marrows were aspirated from healthy donors and mononuclear cells were separated by Percoll lymphocytes separation liquid (1.073 g/ml) with centrifugation, cells were cultured in DMEM/F12 (1:1) medium containing 10% fetal bovine serum (FBS), 20 ng/ml epidermal growth factor (EGF) and 20 ng/ml basic fibroblast growth factor (bFGF). Cells of passage 1 were identified with immunocytochemistry. RESULTS: Mononuclear cells separated by Percoll's were passaged 10 times by trypsin/ethylenediaminetetraacetic acid (EDTA) digestion in 40 days, and BMSCs increased about 6x10(7) times in this short period. Immunohistochemistry identified that BMSCs were CD34- and CD31-, but they expressed neuron specific enolase; 0.01%-0.02% of total cells expressed nestin, the marker for neural progenitor cells; 40%-50% cells stained heavily by neurofilament 200; and no glial fibrillary acidic protein (GFAP) positive cells were identified; S100 expression was detected among 0.1%-0.2% cells. CONCLUSIONS: Bone marrow contains the stem cells with the ability of differentiating into Schwann-like cells, which may represent an alternative stem cell sources for neural transplantation.