Differentiation potential of bone marrow stromal cells to enteric neurons in vitro

OBJECTIVE: To investigate whether bone marrow stromal cells (BMSC) can be induced to differentiate into enteric neurons and to produce more nerve growth factor (NGF) and glial cell line-derived neurotrophic factor (GDNF). METHODS: Bone marrow stromal cells were harvested from male Sprague-Dawley rats and cultured in Dulbecco's modified eagle medium supplemented with 20% fetal bovine serum. The BMSC were passaged six times and characterized by flow cytometry. The BMSC were pre-induced by basic fibroblast growth factor (10 ng/mL) for 24 h, then induced with GDNF in fetal gut condition medium (FGCM) for 10 days. The expressions of neuronal markers neural specific enolase (NSE), neurofilament (NF), glial cell marker, glial fibrillary acedic protein (GFAP), and enteric neuronal marker protein gene product 9.5 (PGP9.5), neural nitric oxide synthase (nNOS), and enteric neural transmitter vasoactive intestinal polypeptide (VIP) were detected by fluorescent immunohistochemistry. Expression levels of GDNF and NGF mRNA were determined by RT-PCR. RESULTS: The cultured BMSC were CD90 (99.7%) positive and CD45 negative on flow cytometry. At day 10 of induction, 58.5 +/- 10.8% cells adopted neuron-like morphological changes and showed expression of NSE (47.6 +/- 7.5%), NF (75.6 +/- 8.4%), GFAP (negative), PGP9.5 (57.7 +/- 6.5%), nNOS (46.6 +/- 5.4%) and VIP (72.3 +/- 6.7%) by immunofluorescence. The BMSC expressed low levels of NGF and GDNF mRNA; however, after induction of GDNF in FGCM, the expression levels of NGF and GDNF mRNA were significantly increased. CONCLUSION: Bone marrow stromal cells have the potential to be induced to differentiate into enteric neurons, express enteric neural transmitters, and produce more NGF and GDNF. Therefore, BMSC could be used as new method to treat gastrointestinal motility disorders associated with enteric neural lesions.