Transplantation of microencapsulated olfactory ensheathing cells inhibits the P2X2 receptor over-expressionmediated neuropathic pain in the L4-5 spinal cord segment

Objectives: The purpose of this study was to determine the effect of microencapsulated olfactory ensheathing cells (MC-OECs) transplantation on neuropathic pain (NPP) caused by sciatic nerve injury in rats, and its relationship with the expression levels of P2X2 receptor (P2X2R) in the L4-5 spinal cord segment. Methods: Olfactory bulb tissue was removed from a healthy Sprague-Dawley (SD) rat for culturing olfactory ensheathing cells (OECs). Forty-eight SD rats were randomly divided into four groups (12 per group): the sham, chronic constriction injury (CCI), olfactory ensheathing cells (OECs), and MC-OECs groups. On days 7 and 14 after surgery, the mechanical withdrawal thresholds (MWT) were measured by using behavioral method. The expression levels of P2X2R in the L4-5 spinal cord segment were detected by in situ hybridization and Western blotting. Results: On days 7 and 14 post-surgical, the MWT of rats from high to low were the sham, MC-OECs, OECs, and CCI groups, the MWT of rats in the MC-OECs groups were higher than that in OECs groups. The expression levels of P2X2R in the L4-5 spinal cord segment from high to low were the CCI, OECs, MC-OECs, and sham groups, the expression levels of P2X2R were lower than that in OECs groups. All differences between groups were statistically significant (p value ). Conclusions: OECs and MC-OECs transplantation can reduce the expression levels of P2X2R genes in the L4-5 spinal cord segment, and relieve NPP. The therapeutic efficacy of MC-OECs transplantation was better than the transplantation of OECs.