CSF-1自背根节向脊髓转运对长春新碱诱导神经病理性痛大鼠小胶质细胞活化及其炎症的影响

Effects of CSF-1 Transport from Dorsal Root Ganglion to Spinal Cord on Activation of Microglia and Inflammation in Rats with Neuropathic Pain Induced by Vincristine

【目的】探讨CSF-1自背根节向脊髓转运对长春新碱诱导神经病理性痛大鼠小胶质细胞活化的影响。【方法】鞘内置管成功雄性SD大鼠54只,体质量200~230 g,10~12周龄,采用随机数字表法分为3组(每组18只):对照组(Control)、化疗诱发神经病理痛+鞘内注射正常IgG组(CINP)、化疗诱发神经病理痛+鞘内注射CSF1中和抗体(CINP+anti)。隔日腹腔注射长春新碱125μg/kg(共计4次)建立CINP动物模型。分别采用机械缩足反射阈值(MWT)和热缩足反射潜伏期(TWL)评价大鼠机械痛敏和热痛敏;Western blotting法和免疫荧光化学检测CSF-1以及小胶质细胞标志物Iba1表达;RT-PCR法检测CSF-1 mRNA和Iba1 mRNA表达;ELISA法检测TNF-α、IL-6和IL-1β。【结果】与Control组比较,CINP组大鼠在长春新碱首次注射后第3、5、7天MWT和TWL明显降低(P<0.001);与CINP组比较,CINP+anti组MWT和TWL在第5、7天明显升高(P<0.001);与Control组比较,CINP组背根节CSF-1蛋白及mRNA表达、脊髓Iba1mRNA表达、脊髓CSF-1和Iba1蛋白表达、脊髓Iba1和背根节CSF-1荧光强度、脊髓TNF-α、IL-6和IL-1β表达明显上调(P<0.01,P<0.001);与CINP组比较,CINP+anti组背根节和脊髓CSF-1蛋白表达、脊髓Iba1蛋白及mRNA表达、脊髓Iba1和背根节CSF-1荧光强度、脊髓TNF-α、IL-6和IL-1β表达明显下调(P<0.05,P<0.01,P<0.001)。【结论】CSF-1自背根节向脊髓转运参与长春新碱诱导神经病理性疼痛发生过程,其机制可能与大鼠脊髓小胶质细胞活化及其炎症反应有关。

【Objective】To investigate the effects of CSF-1 transport from dorsal root ganglion to spinal cord on activation of microglia in rats with neuropathic pain induced by vincristine.【Methods】A total of 54 male 10-12-week old SD rats with successful intrathecal catheterization,weighing 200-230 g,were divided into three groups according to the random number table method(n=18):Control group(Control),Chemotherapy-induced Neuropathic Pain+intrathecal injection of IgG group(CINP),Chemotherapy-induced neuropathic pain+intrathecal injection of CSF-1 neutralizing antibody(CINP+anti).The animal model of CINP was established by intraperitoneal injection of vincristine 125μg/kg on four alternate days.Mechanical allodynia and heat hyperalgesia were evaluated by MWT and TWL,respectively.The expression of CSF-1 and microglial marker Iba1 were detected by immunofluorescence chemistry and Western blotting.The mRNA expression of CSF-1 and Iba1 was measured by RT-PCR.The expression TNF-α,IL-6 and IL-1βwere determined by ELISA.【Results】Compared with Control group,MWT and TWL in CINP group decreased significantly on the 3rd,5th and 7th day after the first injection of vincristine(P<0.01),MWT and TWL in CINP+anti group increased significantly on the 5th and 7th day compared with CINP group(P<0.01).Compared with Control group,the protein and mRNA expression of CSF-1 in DRG,the mRNA expression of Iba1 in spinal cord,the protein expression of CSF-1 and Iba1 in spinal cord,the immunofluorescence intensity of CSF-1 in DRG and Iba1 in spinal cord,and the expression of TNF-α,IL-6 and IL-1βin spinal cord were significantly up-regulated in CINP group(P<0.01,P<0.001).Compared with CINP group,the protein expression of CSF-1 in DRG and spinal cord,the protein and mRNA expression of Iba1 in spinal cord,the immunofluorescence intensity of spinal Iba1 and CSF-1 in DRG,and the expression of TNF-α,IL-6 and IL-1βwere obviously downregulated in CINP+anti group(P<0.05,P<0.01,P<0.001).【Conclusion】The transport of CSF-1 from dorsal root ganglion to spinal cord is involved in the process of neuropathic pain induced by vincristine,and its mechanism may be related to the activation of microglia and inflammatory reaction in rat spinal cord.