Synergistic effect of neural stem cells and olfactory ensheathing cells on repair of adult rat spinal cord injury.

Spinal cord injury (SCI) is a common clinical disease that places a heavy burden on families and society. Cellular therapy provides a method of giving a supplement of cells lost in the injury and promoting functional recovery after SCI. Neural stem cells (NSCs) and olfactory ensheathing cells (OECs) are two most promising cell types. NSCs have the potential of differentiating into neurons and glial cells, and OECs could help the axons of neurons pass through the glial scar to promote functional recovery. NSCs were isolated from the cortices of fetal rats on days 12-14 of embryonic development and OECs were isolated from the olfactory bulbs of adult rats. In vitro coculture studies demonstrated OECs could promote NSCs to differentiate into neurons. Four groups of rats that had been 3/4 spinal cord transectioned at T9 were injected with DMEM/F12 solution, NSCs, OECs, and NSCs + OECs, respectively, 7 days post-SCI. Twelve weeks postoperation, the hindlimb locomotor function of rats in the cotransplantation group was significantly improved compared with that in the other three groups. Histological observation and immunohistochemical staining of NF-200 both showed new nerve fibers across the injured region. Cotransplantation of NSCs and OECs might have a synergistic effect on promoting neural regeneration and improving the recovery of locomotion function. Cotransplantation of NSCs and OECs was better than a single graft of either NSCs or OECs. These findings have provided a new way of thinking in the treatment of SCI.