预针刺对AD样大鼠学习记忆能力及TLR4/NF-κB信号通路的影响

Effect of pre acupuncture on learning and memory ability and TLR4/NF-κB signaling pathway in AD like rats

目的观察预针刺对阿尔茨海默病(Alzheimer′s disease,AD)样大鼠空间学习记忆能力、小胶质细胞及TLR4/NF-κB信号通路相关分子的影响,探讨预针刺防治AD的可能作用机制。方法SD大鼠随机分为正常组、模型组、治疗组,每组12只。腹腔注射D-半乳糖[120 mg/(kg·d)]8周制备AD样大鼠模型。治疗组造模方法同模型组,同时予电针刺激,20 min/次,每日1次,共8周,观察体质量变化。治疗结束后Morris水迷宫实验评估大鼠空间学习记忆能力,免疫荧光标记法检测海马区小胶质细胞的阳性表达数,Western blot法测定大鼠海马Toll样受体4(TLR4)、核因子κB(NF-κB)P65蛋白表达水平,酶联免疫吸附测定法检测海马组织炎症因子白细胞介素1β(IL-1β)、白细胞介素IL-6、肿瘤坏死因子-α(TNF-α)含量。结果造模后,模型组体质量低于正常组(P<0.01),治疗组高于模型组(P<0.01);对于平均逃避潜伏期,模型组高于正常组(P<0.01),治疗组低于模型组(P<0.01);平台穿越次数和目标象限探索时间,模型组低于正常组(P<0.01),治疗组高于模型组(P<0.01)。对于活化的小胶质细胞数量以及TLR4、NF-κB P65、IL-1β、IL-6、TNF-α蛋白表达,模型组高于正常组(P<0.01),治疗组低于模型组(P<0.05)。结论预针刺可降低AD样大鼠神经炎症反应,缓解学习记忆功能障碍,其机制可能与抑制TLR4/NF-κB信号通路有关。

Objective To observe the effect of pre-acupuncture on spatial learning and memory ability,microglia and TLR4/NF-κB signaling pathway in Alzheimer′s disease(AD)-like rats so as to explore the mecha-nism of pre-acupuncture on the prevention and treatment of AD.Methods SD rats were randomly divided into nor-mal group,model group and treatment group with 12 rats in each group.D-galactose[120 mg/(kg·d)]was inject-ed intraperitoneally for 8 weeks.Electroacupuncture was given for 20 minutes each time after injection,once a day for 8 weeks,and their weights were meausred on weekly basis After treatment,Morris water maze test was used to evaluate the spatial learning and memory ability.Immunofluorescence was used to detect the activated microglia in the hippocampus.Western blot was used to detect the expression levels of TLR4,NF-κB p65 protein in the hippo-campus.ELISA was used to detect the levels of IL-1β,IL-6 and TNF-α.Results After modeling,the weight of the model group was lower than that of normal group(P<0.01),and that of the treatment group was higher than the model group(P<0.01).The average escape latency of the model group was significantly higher than the normal group(P<0.01),and that of the treatment group was significantly lower than the model group(P<0.01).The times of platform crossing and the time of target quadrant exploration of the model group were both significantly lower than the normal group(P<0.01),and those of the treatment group were significantly higher than the model group(P<0.01).The expressions of TLR4,NF-κB p65,IL-1β,IL-6,TNF-αand the number of activated mi-croglia in the model group were all significantly higher than the normal group(P<0.01),and those of the treatment group were significantly lower than model group(P<0.01 or P<0.05).Conclusion Pre-acupuncture can reduce the neuroinflammatory response and relieve the learning and memory dysfunction in AD-like rats.Its mecha-nism may be related to the its inhibition to TLR4/NF-κB signal pathway.