电针对心肌缺血细胞G蛋白信号通路的影响

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。

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

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,Prkcc,Arhgef1,RGD:619921,Pccb,Prkcd,Ppp3cb,Gng5,Gnai1) had an apparent expression in the 4 groups,4 genes(Gnaz,Prkcb1,Adcy3 and Adcy8) 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.