电针对鱼藤酮诱导的帕金森病大鼠神经炎性反应及Toll样受体4/核因子-κB信号通路的影响

Electroacupuncture improves behavioral activities by suppressing neuroinflammation and TLR4/NF-κB signaling in substantia nigra of midbrain in Parkinson’s disease rats

目的:观察电针“风府”“太冲”穴对鱼藤酮诱导的帕金森病(Parkinson’s disease,PD)大鼠中脑黑质酪氨酸羟化酶(TH)、α-突触核蛋白(α-syn),小胶质细胞(MG)以及Toll样受体4(TLR4)/核因子(NF)-κB信号通路相关蛋白的影响,探讨电针治疗PD的可能作用机制。方法:SD大鼠随机分为正常组、模型组、电针组,每组12只。采取颈背部皮下注射鱼藤酮(1mg/kg)制备PD大鼠模型。电针组电针“风府”和“太冲”,30min/次,每日1次,连续治疗14d。采用行为学评分和敞箱实验检测各组大鼠行为学改变,免疫组织化学法检测大鼠中脑黑质TH、α-syn的表达水平,免疫荧光标记法检测中脑黑质激活的MG数量,蛋白免疫印迹法检测大鼠中脑黑质TLR4、NF-κB P65,酶联免疫吸附法检测中脑黑质肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)等炎性因子水平。结果:与正常组比较,模型组大鼠行为学评分升高(P<0.01),自主运动总路程、平均速度、运动持续时间减少(P<0.01);中脑黑质TH表达减少(P<0.01),α-syn表达、激活的MG数量、TLR4及NF-κB P65蛋白表达、TNF-α及IL-6含量增加(P<0.01)。与模型组比较,电针组行为学评分降低,自主运动总路程、平均速度、运动持续时间增加(P<0.01);中脑黑质TH表达增多(P<0.01),α-syn表达、激活的MG数量、TLR4及NF-κB P65蛋白表达、TNF-α及IL-6含量减少(P<0.01,P<0.05)。结论:电针能有效改善PD大鼠运动迟缓等行为学表现,减少α-syn的异常聚集,提高中脑黑质TH表达水平,其相关机制可能与抑制神经炎性反应及TLR4/NF-κB信号通路相关蛋白有关。

Objective To observe the effect of electroacupuncture(EA)at“Fengfu”(GV16)and“Taichong”(LR3)on the expression of tyrosine hydroxylase(TH),α-synuclein(α-syn)and microglial-related microglial(MG),Toll-like receptor 4(TLR4)/nuclear factor kappa B(NF-κB)signaling pathway in the substantia nigra(SN)of midbrain in Rotenone-induced Parkinson’s disease(PD)rats,so as to explore its mechanisms underlying improvement of PD.Methods SD male rats were randomly divided into normal control,PD model and EA groups(n=12in each group).The PD model was established by subcutaneous injection of rotenone(1mg/kg)at the back of neck.EA(2Hz,1mA)was applied to bilateral GV16and LR3,once daily for 2weeks.The rats’behavior(hair color,reaction capacity,locomotion and gait state)scores(0-10points)were given and the autonomic movement state(trajectory of autonomous motion,total distance,average speed and duration of motion in 8min)was detected by using open field tests.The immunoactivity of TH andα-syn in the SN tissue were determined by using immunohistochemistry staining,and the number of Iba-1-labelled microglia(MG)was detected by using immunofluorescence staining.The expression levels of TLR4and NF-κB P65proteins in the SN were detected by Western blot,and the contents of tumor necrosis factor-α(TNF-α)and interleukin-6(IL-6)in the SN were determined by using enzyme-linked immunosorbent assay.Results In comparison with the normal group,the behavioral score,α-syn immunoactivity,number of Iba-1labelled microglia,expression of TLR4and NF-κB P65proteins and the contents of TNF-αand IL-6in the SN were significantly increased(P<0.01),whereas the total distance,average speed,duration of motion of the autonomic movement in 8min,and the TH immunoactivity were remarkably decreased in the model group(P<0.01).After EA intervention,compared with the model group,the increase of the behavioral score,α-syn immunoactivity,number of Iba-1-labelled microglia,expression of TLR4and NF-κB P65proteins,the contents of TNF-αand IL-6in the SN,and the decrease of the total distance,average speed,duration of motion of the autonomic movement in 8min,and the TH immunoactivity were reversed(P<0.05,P<0.01).Conclusion EA can improve the behavioral manifestations of PD rats,which may be associated with its functions in down-regulating the abnormal accumulation of pathologicalα-syn,TLR4/NF-κB signaling,inhibiting activities of microglia and in up-regulating the expression of TH in the SN of midbrain.