脊髓NINJ2在大鼠神经病理性痛中的作用:与NF-κB信号通路的关系

Role of spinal NINJ2 in neuropathic pain in rats:the relationship with NF-κB signaling pathway

目的评价脊髓神经损伤诱导蛋白2(NINJ2)在大鼠神经病理性痛中的作用及其与NF-κB信号通路的关系。方法清洁级健康雄性SD大鼠32只,体重230~260 g,7~8周龄,采用随机数字表法分为4组(n=8):假手术组(Sham组)、神经病理性痛组(NP组)、神经病理性痛+NINJ2干扰病毒组(NP+siRNA组)和神经病理性痛+对照病毒组(NP+scrRNA组)。Sham组与NP组鞘内注射生理盐水10μl;NP+siRNA组和NP+scrRNA组鞘内注射相应病毒10μl。1周后采用结扎胫神经和腓总神经的方法制备大鼠神经病理性痛模型,Sham组只暴露坐骨神经及其分支不结扎。分别于术前3、1 d和术后1、3、5、7、10和14 d时测定大鼠术侧机械缩足反应阈(MWT)。术后14 d时处死大鼠取脊髓腰膨大,采用Western blot法测定NINJ2和p-NF-κB p65的表达,采用ELISA法检测TNF-α、IL-1β和IL-6的含量。结果与Sham组比较,其余3组术后3、5、7、10和14 d时术侧MWT降低,脊髓NINJ2和p-NF-κB p65表达上调,TNF-α、IL-1β和IL-6含量升高(P<0.05);与NP组比较,NP+siRNA组术后3、5、7、10和14 d时术侧MWT升高,脊髓NINJ2和p-NF-κB p65表达下调,TNF-α、IL-1β和IL-6含量降低(P<0.05),NP+scrRNA组不同时点各指标差异无统计学意义(P>0.05)。结论脊髓NINJ2参与了大鼠神经病理性痛的过程,与激活NF-κB信号通路有关。

Objective To evaluate the role of spinal ninjurin 2(NINJ2)in the neuropathic pain(NP)and the relationship with nuclear factor kappa B(NF-κB)signaling pathway in rats.Methods Thirty-two clean-grade healthy male Sprague-Dawley rats,weighing 230-260 g,aged 7-8 weeks,were divided into 4 groups(n=8 each)using a random number table method:sham operation group(Sham group),NP group,NP plus NINJ2 interfering virus group(NP+siRNA group)and NP plus control virus group(NP+scrRNA group).After intrathecal catheterization,rats in sham group and NP group received normal saline 10μl,while NP+NINJ2 siRNA group and NP+scrRNA group received NINJ2 siRNA 10μl and scrRNA 10μl,respectively.NP model was developed via ligation of tibial nerve and common peroneal nerve one week later.Sham group only exposed the sciatic nerve and its branches.The mechanical paw withdrawal threshold(MWT)on the operated side was measured on preoperative days 3 and 1 and postoperative days 1,3,5,7,10 and 14.The rats were sacrificed at postoperative day 14,and the lumbar enlargement segments of the spinal cord were harvested for determination of the expression of NINJ2 and phosphorylated NF-κB p65(p-NF-κB p65)(by Western blot)and contents of tumor necrosis factor-alpha(TNF-α),interleukin-1beta(IL-1β)and IL-6(by enzyme-linked immunosorbent assay).Results Compared with Sham group,the MWT on the operated side was significantly decreased,the expression of NINJ2 and p-NF-κB p65 in spinal cord was up-regulated,and contents of TNF-α,IL-1β and IL-6 were increased on the postoperative days 3,5,7,10 and 14 in the other three groups(P<0.05).Compared with NP group,the MWT on the operated side was significantly increased,the expression of NINJ2 and p-NF-κB p65 in spinal cord was down-regulated,and contents of TNF-α,IL-1β and IL-6 were decreased on the postoperative days 3,5,7,10 and 14 in NP+siRNA group(P<0.05),and no significant change was found in each parameter mentioned above at different time points in NP+scrRNA group(P>0.05).Conclusion NINJ2 is involved in NP,which is related to activation of NF-κB signaling pathway in rats.