集落刺激因子-1自背根节向脊髓转运在长春新碱诱导神经病理性疼痛中的作用

Role of trafficking colony stimulating factor-1 from dorsal root ganglion to spinal cord in neuropathic pain induced by vincristine

摘要:

目的 探讨集落刺激因子-1(CSF-1)自背根节向脊髓转运在长春新碱诱导神经病理性疼痛中的作用及其机制。方法 健康雄性SD大鼠30只,采用随机数表法分为3组:正常对照组、化疗所致神经病理性疼痛(CINP)组(隔日腹腔注射长春新碱建立CINP模型)和背根切断(DRR)组(切断腰4~6背根后,建立CINP模型),每组10只。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检测背根节和脊髓CSF-1、以及离子钙结合适配器分子1(Iba1)表达；免疫荧光化学法检测脊髓Iba1表达；逆转录-聚合酶链反应法检测背根节和脊髓CSF-1 mRNA表达。采用SPSS 19.0软件进行数据处理。组间比较采用单因素方差分析。结果 与对照组比较,腹腔注射长春新碱3、5、7d后,CINP组和DRR组大鼠的MWT和TWL均显著降低(P<0.01)；与CINP组比较,DRR组大鼠在给药3、5、7d后的MWT和TWL均显著升高(P<0.01)。与对照组相比,CINP组大鼠背根节[(0.21±0.04)和(1.08±0.15)]和脊髓CSF-1蛋白表达[(0.22±0.05)和(1.17±0.14)]、脊髓Iba1蛋白表达[(100±0)%和(250±19)%]、背根节CSF-1 mRNA表达[(0.20±0.05)和(1.02±0.10)]均显著升高(P<0.05)；与CINP组相比,DRR组大鼠脊髓CSF-1蛋白表达[(1.17±0.14)和(0.45±0.06)]、脊髓Iba1蛋白表达[(250±19)%和(130±16)%]均显著降低(P<0.05)。结论 长春新碱诱导CINP的机制可能与CSF-1自背根节向脊髓转运激活小胶质细胞有关。

Abstract:

Objective To investigate the role of trafficking colony stimulating factor-1 (CSF-1) from dorsal root ganglion to spinal cord in neuropathic pain induced by vincristine and its mechanism. Methods A total of 30 healthy male SD rats were randomly divided into 3 groups (10 in each):control group, chemotherapy-induced neuropathic pain (CINP) group (modeled by intraperitoneal injection of vincristine every other day), DRR group (modeled after dorsal root transection). Mechanical allodynia was evaluated with mechanical withdrawal threshold (MWT), and heat hyperalgesia with thermal withdrawal latency (TWL). Western blotting was used to detect the expression of CSF-1 in dorsal root ganglion and spinal cord, immunofluorescence assay to detect the expression of Iba1 in spinal cord, and reverse transcription-polymerase chain reaction to detect the expression of CSF-1mRNA in dorsal root ganglion and spinal cord. Data were analyzed with SPSS statistics 19.0, and one-way analysis of variance was used for comparison between groups. Results MWT and TWL in CINP and DRR groups were significantly lower than those in the control group at 3,5 and 7 days after the first injection of vincristine (P<0.01). MWT and TWL in the DRR group were significantly higher than those in the CINP group. Significant up-regulation was found in the CINP group as compared with the control group in the expression of CSF-1 in dorsal root ganglion [(0.21±0.04) vs (1.08±0.15)] and spinal cord [(0.22±0.05) vs (1.17±0.14)], the expression of Iba1 in the spinal cord [(100±0)% vs (250±19)%], and the expression of CSF-1mRNA in dorsal root ganglion [(0.20±0.05) vs (1.02±0.10)] (P<0.01). Significant down-regulation was observed in the DRR group as compared with the CINP group in the protein expression of CSF-1 [(1.17±0.14) vs (0.45±0.06)] and Iba1 [(250±19)% vs (130±16)%] in the spinal cord. Conclusion The mechanism of neuropathic pain induced by vincristine may be related to the trafficking of CSF-1 from dorsal root ganglion to spinal cord and activation of spinal microglia.