Role of chemokine CXC ligand 13 in spinal cord in neuropathic pain in rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the role of chemokine CXC ligand 13 (CXCL13) in spinal cord in neuropathic pain (NP) in rats.Methods One hundred and eight male Sprague-Dawley rats,weighing 150-200 g,were randomly divided into 4 groups (n =27 each)sham operation group (group S),group NP,small interference RNA (siRNA) negative control group (group NS) and CXCL13-siRNA group (group CS).The animals were anesthetized with intraperitoneal ketamine 50 mg/kg.NP was induced by ligation of L5 spinal nerve (SNL) in groups NP,NS and CS.L5 spinal nerve was only exposed but not occluded in group S.CXCL13-siRNA lentivirus and siRNA negative control lentivirus were injected intrathecally in groups CS and NS,respectively.Mechanical pain threshold was measured at 3,7 and 14 days after SNL.Then the rats were sacrificed and L4-6 segments of the spinal cord were obtained for determination of coexpression of CXCL13 and Neun (by immunofluorescence),activation of astrocytes,and expression of CXCL13 and glial fibrillary acidic protein (GFAP) protein (by Western blot) and mRNA (by RT-PCR) in spinal cord tissues.Results Compared with group S,mechanical pain threshold was significantly decreased and the expression of CXCL13 and GFAP protein and mRNA was up-regulated at each time point after operation in groups NP,NS and CS (P ＜ 0.05).Compared with group NP,mechanical pain threshold was significantly increased and the expression of CXCL13 and GFAP protein and mRNA was down-regulated at each time point after operation in group CS (P ＜ 0.05).There was no significant difference in the indexes mentioned above at each time point after operation between groups NP and NS (P ＞ 0.05).Conclusion CXCL13 is involved in the development and maintenance of NP in rats via activation of astrocytes.