Transplantation of NSCs with OECs alleviates neuropathic pain associated with NGF downregulation in rats following spinal cord injury

•Transplantation of NSCs with OECs could improve the sensory function after SCI.•New strategy by transplantation of NSCs to withdraw the side effect.•Available to the cell treatment of SCI in clinical practice.

Spinal cord injury (SCI) is a common and serious disease which often induces catastrophic consequence in patients. Part of them exhibit neuropathic pain which presents unique challenges to clinicians, and there is no effective approach for the treatment up to now. Neural stem cells (NSCs) transplantation, as a promising and an effective method, could be considered for the treatment of SCI, whereas a main problem is the low survival of NSCs in traumatic milieu in host spinal cords, and the effect of NSCs on sensory function remains elusive. In this study, we investigated the effect and underlying molecular mechanism of co-transplantation of NSCs with olfactory ensheathing cells (OECs) on sensory functional improvement. In the measurement of thermal and mechanical stimuli, NSCs grafts recovered sensory function in SCI rats, while OECs led to hyperalgesia, indicated by the tail flick latency (TFL) and paw withdraw latency (PWL) (p < 0.05). Co-transplantation could promote NSCs survival, and reverses the hyperalgesia triggered by OECs. This was corresponding to a significant improvement in sensory function. Moreover, NGF expression was substantial downregulated in the spinal cord of co-transplantation rats. The present findings suggested that co-transplantation of NSCs with OECs could improve sensory function and the possible mechanism is involved in NGF downregulation in rats with SCI. This may give some new indications for the treatment of SCI in future clinic cell therapy trial.