Microencapsulated olfactory ensheathing cell transplantation reduces P2X4 receptor overexpression and inhibits neuropathic pain in rats

Abstract

ObjectivesThe aim of this study was to determine the role of microencapsulated olfactory ensheathing cells (MC-OECs) transplantation in rats with sciatic nerve injury-induced neuropathic pain, and its relationship with P2X4 receptor expression in the L4-5 spinal cord segment. MethodsOlfactory bulb tissues of healthy Sprague Dawley (SD) rats were collected to culture olfactory ensheathing cells (OECs) using differential attachment methods. Seventy-two healthy SD rats were randomly assigned to four groups: the sham, chronic constriction injury (CCI), OECs, and MC-OECs groups. Mechanical paw withdrawal thresholds were measured on days 7, 14 and 21 after surgery. The expression of P2X4 receptor genes in the L4-5 spinal cord segment was detected by in situ hybridization, western blotting and RT-PCR. ResultsOn post-surgical days 7, 14 and 21. The mechanical paw withdrawal thresholds of rats from low to high were the CCI, OECs, MC-OECs and sham groups. The expression level of P2X4 receptor mRNA and protein from low to high were the sham, MC-OECs, OECs and CCI groups. Compared with the OECs group, the mechanical paw withdrawal thresholds of rats were increased, and the expression level of P2X4 receptor mRNA and protein were decreased in the MC-OECs group. In addition, the mechanical paw withdrawal thresholds of rats were higher and the expression level of P2X4 receptor were lower in the MC-OECs group on post-surgical days 21 than that on days 7 and 14. All differences between groups were statistically significant (P value < 0.05). ConclusionsOECs and MC-OECs transplantation can reduce the expression level of P2X4 receptor and relieve pain. The therapeutic efficacy was better in the MC-OECs group than in the OECs group. MC-OECs transplantation have the better effects of treatment with the increase of MC-OECs transplantation time.