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

Abstract

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 <.05). 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.