Differential gene expression pattern of neurotrophins and their receptors during neuronal differentiation of rat bone marrow stromal cells.

Neural-like cells derived from bone marrow stromal cells (BMSC) have potential usefulness in repair of the CNS injuries or diseases. The functional recovery mediated by these cells, however, depends on secretion of specific growth factors and their designated receptors. In the present study, we have investigated the expression profile of neurotrophins NGF, BDNF and NT-3 and their high-affinity (TrkA, TrkB, TrkC) and common low-affinity (p75NTR) receptors before and during neural differentiation of rat BMSCs by RT-PCR. Results indicate that NGF and BDNF but not NT-3 are expressed in both un-differentiated as well as neurally differentiated BMSCs. In contrast, the expression of TrkA and TrkB is restricted to neurally differentiated cells, while TrkC is not expressed in these cells either before or after differentiation. Interestingly, p75NTR expression is absent in un-differentiated cells but is initiated upon the induction of neural differentiation, and then shut off in fully differentiated neuron-like cells.