自噬调节在脉冲射频治疗神经病理性疼痛中的作用

目的：观察腰5(L5)脊神经结扎(spinal nerve ligation，SNL)致慢性疼痛大鼠接受背根神经节脉冲射频(pulse radiofrequency，PRF)治疗后痛觉行为学的变化，检测脊髓背角自噬相关基因LC3和自噬受体蛋白P62的表达情况，研 究PRF是否能通过调节脊髓背角神经元自噬水平发挥镇痛作用。方法：36只SD大鼠随机分为假手术组(Sham组)、SNL 组(行左侧L5脊神经的暴露和结扎)和SNL+PRF组(建立SNL模型后即刻给予1次同侧背根神经节PRF治疗)。分别于手 术前1 d及术后1，3，7，14，28 d观察各组大鼠机械刺激缩足反应阈值(paw withdrawal mechanical threshold，PWMT)改 变，Western印迹检测自噬相关基因LC3和细胞自噬受体蛋白P62在大鼠损伤侧相应节段脊髓背角的表达改变。结果： 与Sham组相比，SNL组大鼠在术后各时点PWMT均明显下降(P<0.05)；与SNL组相比，SNL+PRF组大鼠在PRF治疗术 后第1天即出现PWMT的升高，并持续28 d(P<0.05)；与Sham组相比，SNL组大鼠在术后7 d脊髓背角LC3-II和P62蛋白 表达明显升高(P<0.05)；与SNL组相比，SNL+PRF组大鼠在术后7 d脊髓背角LC3-II和P62蛋白表达明显下调(P<0.05)。 结论：SNL慢性疼痛大鼠接受背根神经节PRF治疗后出现疼痛行为学改善，PRF治疗可能通过上调脊髓背角神经元自 噬水平发挥镇痛作用。

Role of the autophagy in the treatment of neuropathic pain with pulsed radiofrequency

Objective: To detect the eff ect of pulse radiofrequency (PRF) treatment on the neuropathic pain established by L5-spinal nerve ligation (SNL) on rats, and to investigate if PRF treatment would aff ect the expression of autophagy related protein LC3 and autophagy related receptor P62 at the dorsal horn. Methods: A total of 36 male Sprague-Dawley rats were randomly divided into 3 groups: a Sham group, a SNL group, and a SNL+PRF group. The 50% paw withdrawal mechanical threshold (PWMT) was detected at 1 day before and 1, 3, 7, 14 and 28 days post-operation by using Von-Frey filaments. The autophagy related protein LC3 and autophagy related receptor P62 were investigated by Western blot. Results: Compared with the Sham group, the PWMT significantly decreased in the SNL group at each time points (P<0.05); in SNL+PRF group, PRF treatment could elevate the PWMT at the 1st day post-operation and lasted for 28 days (P<0.05). What’s more, SNL could elevate the LC3-II and P62 levels at the 7th day post-operation (P<0.05), which were decreased by the PRF treatment (P<0.05). Conclusion: PRF treatment could improve SNL-induced the neuropathic pain, which might be partly due to the regulatory effects on the autophagy levels at the spinal dorsal horn.