电针对心肌缺血细胞G蛋白信号通路的影响

Effect of Electroacupuncture on Signal Transduction of G-protein in Rat Ischemic Myocardial Cells

目的:分析电针对缺血心肌细胞G蛋白信号通路的影响,揭示电针抗心肌缺血的分子作用途径。方法:健康SD雄性大鼠20只,随机分为正常组、模型组、电针正常“神门”组、电针模型“神门”组,每组5只。采用冠状动脉结扎法复制心肌缺血模型,然后电针“神门”穴,予以1.3 mA、2 Hz方波刺激,每日1次,3 d后动物麻醉状态下活体取材,用基因芯片技术筛选各组G蛋白及其相关基因。结果:筛选到表达G蛋白15个,通过cAMP或Ca2+途径影响下游基因表达,调节细胞转录和应答。电针“神门”特异性G蛋白2个,主要是G蛋白γ亚型通过cAMP影响下游蛋白激酶Aβ2调节细胞转录。结论:电针抗心肌缺血可以通过调节多种G蛋白影响缺血心肌细胞内的基因表达,从而发挥保护心肌的作用,以Gi和Gq最为重要;心经与心脏间具有相对特异的分子联系途径,可能主要是Gγ和PKAβ2途径。

Objective： To analyze the effect of electroacupuncture （EA） on myocardial cellular signal transduction of G- protein in myocardial ischemia （MI） rats so as to explore the molecular pathway of EA against MI injury. Methods： Twenty male SD rats were randomized into normal, model, EA-normal and EA-model groups, 5 rats in each group. MI model was established by occlusion of the descending anterior branch of the left coronary artery under anesthesia with 10 % chloral hydrate （0.36 mL/ 100 g）. EA （ 1.3 mA, 2 Hz, 300 μs in the duration of pulse） was applied to ＂Shenmen＂ （HT 7） for 20 min, once daily continuously for 3 days. Three days later, the myocardial tissue sample was taken for shifting out related G-proteins and corresponding genes by using gene chip technology. Results： In comparison with model group, after EA of ＂Shenmen＂ （HT 7）, 782 differentially expressed genes were found, of which, 328 were upregulated and 454 downgrelated; compared with normal group, 426 differentially expressed genes were found in EA-normal group, among them, 217 genes were upregulated and the other 209 downregulated in the expression. Further analysis showed that, 21 genes were associated with G-protein signal transduction pathway, 15 genes （L01115.1, Gng11, Adcy2, Calm3, Ppp3ca, Adcy5, Gnao, Prkoc, Arhgef1, RGD：619921, Pccb, Prkcd, Ppp3cb, Gng5, Gnai1 ） had an apparent expression in the 4 groups, 4 genes （Gnaz, Prkcb1, Adcy3 and Adcy5） had no marked changes, and the rest 2 （Gng8 and Prkar2b） were differentially expressed genes. Of the 2 differentially expressed genes, Gng8 displayed weaker and stronger expression in EA-normal and EA-model groups respectively, and had no expression in normal and model groups, suggesting being closely related to EA-HT 7 ; while Prkar2b showed no expression in normal and EA-normal groups, and had a detectable expression in model and EA-model groups, suggesting being related to MI. Conclusion： EA-HT 7 can affect gene expression of ischemic myocardiocytes; among the differentially expressed genes being closely associated with G-protein signaling pathway, Gng8 and Prkar2b may play an important role in EA-induced protective action on myocardial ischemia.