Neural cell differentiation in vitro from adult human bone marrow mesenchymal stem cells.

Bone marrow (BM) mesenchymal stem cells (MSCs) are cells capable of expanding and differentiating in vitro into nonhematopoietic cells. Neurotrophic cytokines, such as human epidermal growth factor (hEGF) and bovine fibroblast growth factor (bFGF) can induce differentiation into neural cells (NCs). When BM MSCs were cultured with hEGF and bFGF, RNA expression of neuronal specific markers Nestin, MAP-2, and tyrosine hydroxylase (TH) were observed. We tested a new cytokine combination to generate mature NCs. The plastic-adherent cells were collected and then split when they were 90% confluent from an enriched mononuclear cell layer. At passage 3, MSCs were cultured in neural differentiation media (dbcAMP, IBMX, FGF-8, BDNF, hEGF, and bFGF in NEUROBASAL media plus B27). Cells were counted on day 6. Immunofluorescent staining and reverse transcriptase (RT)-PCR were performed to evaluate the expression of neural markers. On day 6, 66% of cells developed dendrites and presented typical neural cell morphology. Some cells were positive for early neural markers Nestin and beta-tubulin III. Cells expressing mature neuronal markers (NF, NeuN, Tau, Nurr1, GABA, oligodendryte GalC, and glial GFAP) were also seen. By adding hEGF, bFGF, dbcAMP, IBMX, BDNF, and bFGF-8 into NEUROBASAL media plus B27, BM MSCs were directed toward becoming early and mature NCs.