In vitro neural differentiation of bone marrow stromal cells induced by cocultured olfactory ensheathing cells

Bone marrow stromal cells (BMSCs) could be induced to differentiate into neural cells under certain conditions, nevertheless, optimal protocols that could be reproducible and reliable in generating transplantable BMSCs in vitro are still not available. We studied for the first time the neural differentiation of BMSCs induced by coculturing with olfactory ensheathing cells (OECs). BMSCs and OECs were isolated from bone marrow and nasal olfactory lamina propria of adult SD rats respectively, then brought to coculture with transwell culture dishes. At various time points (0 h, 6 h, 12 h, 24 h, 72 h, 1 week and 2 weeks post-coculture), BMSCs were morphologically observed and processed for immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). The number of cells assuming neural morphology dramatically increased at 1- and 2-week-post-coculture, so as the number of immunoreactive cells labeled by neural markers NSE, β-III-tubulin, MAP2, GFAP and p75NTR. Our findings demonstrate that BMSCs can efficiently differentiate into neural cells when coculturing with OECs, and the present protocol provides an alternative neurogenesis pathway for generating sufficient numbers of neural cells from BMSCs.