人心房肌蛋白激酶C表达下调参与心房颤动发病机制

Downregulation of human atrial protein kinase C in pathogenesis of atrial fibrillation

目的:研究心房颤动(atrial fibrillation,AF)时心房肌组织中PKCα、δ、ε、θ4种亚型mRNA和PKC总蛋白的表达变化,探讨PKC与AF发生发展的相关性。方法:泸州医学院附属医院行体外循环手术患者常规切除的右心耳组织作为研究对象。①实时定量PCR实验:提取人右心耳组织总RNA,β-actin为内参照基因,采用SYBR GreenⅠ法实时荧光定量PCR技术检测SR和AF患者PKCα、δ、ε、θ基因mRNA水平。②western blotting实验:有心耳组织提取总蛋白,测定蛋白浓度,GAPDH作为内参照,SDS-PAGE电泳检测SR和AF患者PKC的蛋白表达变化。结果:①AF患者心房肌细胞PKCα和PKCδ亚基mRNA水平下调;PKCε和PKCθ亚基mRNA水平明显上调。②SR组与AF组PKC总蛋白相对表达量分别为1.37±0.09(n=23)、1.00±0.10(n=18),(P<0.05)有统计学意义。结论:与SR患者相比,AF患者心肌细胞中PKCα、δ亚基mRNA明显下调,PKCε、θ亚基mRNA上调,PKC总蛋白表达降低。PKC亚型mRNA和总蛋白的表达变化可能是参与AF发生发展的分子基础之一。

Objective：To study the changes of mRNA expression of subtype α、δ、ε、θ and total protein of protein kinese C （PKC） during atrial fibrillation （AF）,and the relarionship between PKC and AF. Methods：Right atrial appendage samples from heart disease patients were obtained during cardiac surgery.Total RNA was extracted from the atrial tissues and the PKC α、δ、ε、θ mRNA were detected by SYBR Green I real-time PCR with β-actin as the reference gene.18 patients with chronic atrial fibrillation （AF group）and 23 patients with sinus rhythm （SR,as control group） were used to assess the protein expression of PKC by Western blo.t. Results：Compared with SR group,the left atrial diameters increased significantly in AF group.There were significant differences in mRNA expression of PKC α、δ、ε、θ between two groups;the expression of PKC ε and PKC θmRNA was up-regula-ted and the expression of PKC ε and PKC θ mRNA was down-regulated significantly in AF group （P〈0.05）. PKC protein was significantly decreased in AF group compared with SR group （P 〈 0.05）. Conclusion：The changes of PKC isoform mRNA and protein expression might be one of the molecular bases for the development of AF.