丹参酮ⅡA对神经病理性疼痛大鼠的影响

Effection of Tanshinone ⅡA on Neuropathic Pain Model of Rats

目的观察丹参酮ⅡA(TanⅡA)对神经病理性疼痛模型(SNL)大鼠脊髓组织高迁移率族蛋白B1(HMGB1)、Toll样受体4(TLR4)和肿瘤坏死因子-α(TNF-α)、白细胞介素1β(IL-lβ)和白细胞介素10(IL-10)表达的影响,探讨TanⅡA对神经病理性疼痛的作用及其机制。方法成年雄性SD大鼠54只,随机分为3组:假手术组、模型对照组和TanⅡA组(术后腹腔注射TanⅡA 30 mg·kg^(-1)·d^(-1)),分别于术前1 d,术后第3,7,14天测试机械痛阈和热痛阈后,取L_4～L_(6 )脊髓,置于液氮中迅速冷冻。实时荧光定量PCR和Western blotting检测脊髓HMGB1、TLR4 mRNA和蛋白的表达,酶联免疫吸附测定(ELISA)法检测脊髓TNF-α、IL-lβ和IL-10蛋白的表达情况。结果与假手术组比较,模型对照组、TanⅡA组在术后第3,7,14天机械痛阈和热痛阈降低,脊髓HMGB1,TLR4 mRNA和蛋白表达上调(P<0.05)。与模型对照组比较,TanⅡA组在术后第3,7,14天机械痛阈和热痛阈升高,脊髓HMGB1、TLR4 mRNA和蛋白表达下调(P<0.05)。与假手术组比较,模型对照组、TanⅡA组在术后第3,7,14天脊髓TNF-α、IL-1β表达上调(P<0.05),而IL-10表达下调(P<0.05)。与模型对照组比较,TanⅡA组在术后第3,7,14天脊髓TNF-α、IL-1β表达下调(P<0.05),IL-10表达上调,行为学指标改善(P<0.05)。结论丹参酮ⅡA能减轻大鼠神经病理性疼痛,可能机制是在分子水平抑制HMGB1-TLR4信号通路及其下游的细胞因子,HMGB1-TLR4信号通路可能与神经病理性疼痛有关,是治疗神经病理性疼痛的靶点。

Objective Detect the expression level of HMGB1,TLR4, TNF-α,IL-1β and IL-10 in spinal cord tissue of neuropathic pain model rat after tanshinone ⅡA treated to explore its effect on neuropathic pain and the mechanisms. Methods A total of 54 males Sprague-Dawley (SD) rats were randomly divided into three groups: sham-operated group,model control group, and Tan ⅡA group.Tan ⅡA was administered intraperitoneally to rats in Tan ⅡA group at a dose of30 mg·kg^-1 daily for14 days after surgery.The pain threshold was measured1 day before SNL (baseline) and3, 7, and14 days after surgery.The expressions of HMGB1, TLR4 mRNA and protein in lumbar spinal cord4-6(L4 -L 6 ) were assessed by RT-PCR and Western blotting, respectively.The levels of TNF-α, IL-1β and IL-10 in the spinal cord were detected by ELISA. Results The paw withdrawl threshold (PWT) and paw withdrawl latency (PWL) were significantly decreased after SNL ( P <0.05).The expressions of TLR4, HMGB1 mRNA and protein were significantly increased ( P <0.05),and the levels of TNF-α, IL-1β were significantly increased after SNL compared with those in the sham-operated group ( P <0.05).After Tan ⅡA treatment, HMGB1 and TLR4 mRNA and protein levels were reduced significantly ( P <0.05).TNF-α and IL-1β were downregulated, but IL-10 was upregulated in the spinal cords of SNL-induced rats ( P < 0.05),which was accompanied by improvement of pain behaviours in the Tan ⅡA group ( P <0.05). Conclusion These results indicate Tanshinone ⅡA inhibited SNL-induced neuropathic pain via multiple effects, the possible mechanism is that HMGB1-TLR4 signal transduction pathway and its downstream cytokines are inhibited at the molecular level.It also suggesting that HMGB1-TLR4 signal transduction pathway may be related to neuropathic pain and is a target for the treatment of neuropathic pain.