细胞程序性坏死抑制剂Nec-1可减轻神经病理性痛大鼠的痛觉过敏

Necrostatin-1 ameliorates hyperalgesia in rats with neuropathic pain

目的观察RIP1和RIP3在坐骨神经慢性压迫性损伤(chronic constriction injury, CCI)痛大鼠脊髓水平的表达变化,探讨程序性坏死特异性抑制剂Necrostatin-1(Nec-1)在神经病理性痛中的保护作用。方法雄性8周龄SD大鼠60只,随机分为三组:假手术组(Sham组)、坐骨神经CCI组(CCI组)、坐骨神经CCI+Nec-1组(CN组),每组20只。在术前1周、术后1、3、5、7、10和14 d分别测定大鼠机械缩足反射阈值(mechanical withdrawal threshold, MWT)和热刺激缩足反射潜伏期(thermal withdrawal latency, TWL)。每组取10只大鼠于术后7 d处死,采用Western blot法检测脊髓中RIP1、RIP3蛋白含量,采用透射电镜观察脊髓组织超微结构的变化。结果与Sham组比较,术后1、3、5、7、10和14 d CCI组MWT明显降低(P<0.05),术后3、5、7、10和14 d TWL明显缩短(P<0.05),术后7 d脊髓RIP1和RIP3蛋白含量明显升高(P<0.05),脊髓中可见多处细胞核膜崩解,线粒体肿胀、嵴断裂,神经髓鞘出现明显的分离。与CCI组比较,术后7、10和14 d CN组MWT明显升高(P<0.05)、TWL明显延长(P<0.05),术后7 d脊髓RIP1和RIP3蛋白含量明显降低(P<0.05),脊髓细胞核膜完整,线粒体稍有肿胀、嵴清晰,神经髓鞘分离不明显。结论 RIP1和RIP3介导的信号通路参与大鼠神经病理性痛的发生,给予Nec-1治疗可以减轻神经病理性痛大鼠的痛觉过敏症状。

Objective To observe whether the RIP1 and RIP3 are involved in the pathogenesis of chronic constriction injury(CCI) rats, and to investigate whether necrostatin-1(Nec-1) would ameliorates hyperalgesia in rat models of neuropathic pain. Methods Sixty male Sprague-Dawley rats were randomly divided into three groups, sham operated(group Sham), chronic constriction injury(group CCI), and CCI+Necrostatin-1(group CN), 20 rats in each group. Mechanical withdrawal threshold(MWT) and thermal withdrawal latency(TWL) were measured at one week before surgery and 1, 3, 5, 7, 10, 14 days after surgery. At 7 days after surgery, ten animals were sacrificed in each group, western blot was used to analyze the expression of RIP1 and RIP3 protein, the ultrastructural cells of spinal cord tissue were observed by transmission electron microscopy(TEM). Results Compared with group Sham, MWT was decreased in group CCI 1 to 14 days after surgery(P < 0.05), TWL was decreased in group CCI 3 to 14 days after surgery(P < 0.05), the expression of RIP1 and RIP3 protein in spinal cord of group CCI were increased 7 days after surgery(P < 0.05), nuclear membrane disintegrated, mitochondria swelled and their cristae fragmented, nerve medullary sheath structure separated in group CCI 7 days after surgery. Compared with group CCI, MWT and TWL were decreased in group CN 7 to 14 days after surgery(P < 0.05), the expression of RIP1 and RIP3 protein in spinal cord of group CN were decreased 7 days after surgery(P < 0.05), nuclear membrane integrated, mitochondria slightly swelled, cristae cleared, nerve medullary sheath slightly separated in group CN 7 days after surgery. Conclusion Taken together, necrostatin-1 could alleviate the rats against hyperalgesia induced by CCI, which might be relevant to the inhibition of RIP1 and RIP3 signaling pathway.