电针预处理对脑缺血再灌注大鼠皮质神经元TRPC6表达的影响

目的观察电针预处理对脑缺血再灌注大鼠皮质神经元TRPC6表达的影响,探讨其对神经元可能的保护机制。方法将SD大鼠随机分为假手术组、模型组和电针预处理组,每组8只。采用大脑中动脉栓塞法制备脑缺血再灌注模型。电针预处理组在造模前取"百会"和"大椎"穴给予电针刺激。造模后24h进行神经功能评分并急性分离大鼠皮质神经元,通过蛋白免疫印迹(western blot)检测神经元TRPC6和Caspase-3蛋白表达,钙影像检测细胞内相对钙离子浓度。结果与假手术组比较,模型组大鼠的神经功能评分明显增高(P0.05),大脑皮质神经细胞TRPC6和Caspase-3蛋白表达明显增高(P0.05),神经元内钙离子浓度升高(P0.01);与模型组比较,电针预处理组能明显改善脑缺血再灌注后大鼠的神经功能症状(P0.05),抑制大脑皮质神经细胞TRPC6和Caspase-3蛋白表达(P0.05),并降低细胞内钙离子浓度(P0.01)。结论电针预处理对脑缺血再灌注大鼠脑损伤有保护作用,其机制可能与TRPC6下调,减少细胞钙离子内流从而抑制神经凋亡。

Effects of Electroacupuncture Preconditioning on the Expression of TRPC6 in Cortical Neuron of CI/R Rats

Objective To observe the effect of electroacupuncture preconditioning on the expression of TRPC6 in cortical neuron of cerebral ischemia-reperfusion (CI/R) rats,and explore the underlying mechanism in protection of cortical neuron.Methods 24 Sprague-Dawley rats were randomly divided into groups of sham operation (sham),model and EA preconditioning (n =8).The ischemia model was created by right middle cerebral artery occlusion (MCAO).In the EA preconditioning group,Baihui and Dazhui points were needling with electro acupuncturing before creating models,continuous needle acupuncture was given once a day,totally 7 days.The neurological behavior scores were evaluated post operation after creating models for 24h.A primary cortical neuron was separated and cultured.The protein expressions of TRPC6 and Caspase-3 were detected by western blot,intracellular calcium ion concentration was measured through calcium imaging.Results Compared with sham group,neurological behavior scores of model group significantly increased (P ＜ 0.05),TRPC6 and Caspase-3 expression also increased (P ＜ 0.05),meanwhile,intracellular calcium ion concentration was higher than sham group(P ＜ 0.01).Compared with model group,neurological behavior scores of EA preconditioning group significantly decreased (P ＜ 0.05),TRPC6 and Caspase-3 expression also reduced (P ＜ 0.05),meanwhile,intracellular calcium ion concentration was lower than sham group (P ＜ 0.01).Conclusion Electroacupuncture preconditioning has the protective effects for the brain injury of ischemia reperfusion rats.The mechanism may be related to down regulation of TRPC6 and reduction of calcium influx to inhibit neuron apoptosis.