从Notch信号通路探讨长春新碱诱导神经病理性疼痛的发生机制

Explore the role of spinal Notch signaling pathway in the development of chemothrapy-induced neuropathic pain in rats

摘要:

【】 目的 研究Notch信号通路的活化在长春新碱诱导的神经病理性疼痛大鼠中的作用。方法 大鼠鞘内置管并筛选出痛阈值合格的SD大鼠40只,采用随机配伍的方法分为4组：对照组、长春新碱(vincristine, VCR)组、DAPT多次给药+VCR组、DAPT单次给药+VCR组。用隔日腹腔注射长春新碱(125 μg/kg)的方法建立化疗痛动物模型,Notch信号通路抑制剂DAPT从建立化疗痛模型前1日起鞘内注射(50 μg/rat,1 μL),其它各组同步注射生理盐水。用测痛仪测定大鼠机械痛阈值、热痛阈值及冷痛阈值；免疫组化法检测Notch信号通路活化标志物NICD蛋白；Western Blot法检测脊髓NICD蛋白；RT-PCR法检测Hes1 mRNA表达。 结果 与对照组比较,VCR组大鼠机械痛阈值、热痛阈值、冷痛阈值显著降低(P<0.01),脊髓背角NICD、Hes1 mRNA表达显著升高(P<0.01)；与VCR组比较,DAPT多次给药+VCR组、DAPT单次给药+VCR组大鼠机械痛阈值、热痛阈值和冷痛阈值均升高(P<0.05),脊髓背角NICD、Hes1 mRNA表达显著降低(P<0.05或P<0.01)。 结论 Notch信号通路的活化可能参与了长春新碱诱导的神经病理性疼痛的发生、发展,抑制Notch信号通路的活化缓解了化疗诱导大鼠痛觉过敏。

Abstract:

Objective: To explore the role of spinal Notch signaling pathway in the development of chemotherapy-induced neuropathic pain. Methods: 40 Sprague-Dawley rats with intrathecal catheterization were picked out and divided into 4 groups: control group, VCR group, repeated administration of DAPT+VCR group, single administration of DAPT+VCR group. Vincristine (125 μg/kg, i.p.) was administrated on alternate days to establish chemotherapy-induced neuropathic pain model in rats. Intrathecal administration (50 μg, 1 μL, i.t.) of DAPT ( inhibitor of Notch signaling pathway) to DAPT group from D0 to D7 (define the first administration of vincristine as D1). The other groups received the same volume of vehicle. Electronic vonfrey , thermal radiation and cold anesthesiometer were used to measure the mechanical paw withdrawl threshold, thermal withdrawl latency and cold paw withdrawl threshold of rats. The expression of NICD (activation markers of Notch signaling pathway) was detected by immunohistochemistry. The expression of NICD protein in the spinal cord was detected by western-blot. The expression of Hes1 mRNA was detected by RT-PCR. Results: Compared with the control group, the pain threshold decreased and the expression of NICD, Hes1 mRNA increased in VCR group (P<0.01).Compared with the VCR group, the pain threshold increased and the expression of NICD, Hes1 mRNA decreased in DAPT+VCR groups (P<0.05 or P<0.01). Conclusion: Spinal Notch signaling pathway may mediate the development of chemotherapy-induced neuropathic pain in rats.