A study on the effect of olfactory ensheathing cells on the proliferation of neural stem cells

Objective: To research the effects of olfactory ensheathing cells (OECs) on the proliferation of neural stem cells (NSCs). Methods: OECs and NSCs were separated and cultured in vitro. The proliferation of NSCs was observed by means of co-culture and two-chamber shared medium culture with OECs. For investigating the mechanism of the proliferation of NSCs, the cytokines and their receptors of OECs were tested by immunocytochemistry and RT-PCR. Results: After 4 days in co-culture and two-chamber shared medium culture, the population of NSCs were increased significantly (P < 0.05), and some of them were differentiated. The result of RT-PCR showed that OECs could express mRNA of β-NGF, BDNF, NT-3, PDGF-B, trkA and trkB, but not NT-4. Moreover, positive staining of NGF, BDNF and p75 was observed in the cytoplasm of OECs by immunocytochemistry. Conclusions: OECs can express or secrete a large amount of cytokines, for example β-NGF, BDNF, NT-3 and PDGF-B and promote the proliferation of NSCs by paracrine secretion and retrograde transport from target.