心房颤动患者离子通道蛋白基因mRNA组学改变及其意义

mRNA genomics change and significance of important ion channel proteins in patients with atrial fibrillation

目的探讨房颤患者重要离子通道蛋白的mRNA组学改变及意义。方法选择2012年1月至2015年1月北京世纪坛医院90例行房颤射频消融术患者，90名健康体检者作为健康对照组，房颤射频消融术中分别取冠状窦血和外周静脉血，使用mRNA芯片进行全基因组mRNA表达谱微阵列分析，Real-time PCR对血液和人心房组织主要离子通道基因mRNA表达差异结果进行验证。结果房颤患者与健康对照组外周血全基因组mRNA表达比较，离子通道蛋白12种mRNA表达升高≥2.0倍，10种表达下降≥2.0倍。其中，K＋通道基因KCNE4、KCND2、KCNN4明显下降，KCNA5下降11.54倍（P〈0.01）；KCNS3、KCNS1、KCNG1、KCNG7，以及Ca2＋通道基因CACNA2D3明显升高。患者冠状窦血与自身外周血mRNA比较，12种离子通道蛋白mRNA表达差异≥2.0倍；与对照组外周血比较，7种离子通道蛋白mRNA表达差异≥2.0倍，其中KCNA5基因表达下调8.13倍。RT－PCR验证，其差异表达的趋势和程度与芯片结果一致。心肌组织RT－PCR结果发现，CACNA1C、KCNC3、KCNG1和KCNK7 mRNA在房颤患者较无房颤组表达上调（P〈0.05），其他离子通道mRNA表达均明显下调（P〈0.05），KCNA5下调最为明显。结论房颤患者IKur通道KCNA5基因表达下调最为明显，更多的K＋通道表达差异较为显著，所以K＋通道重构可能在房颤电重构中起着主导或更为重要的作用。其他涉及神经内分泌调节、兴奋收缩偶联和基因表达等的离子通道与房颤的关系有待深入研究。

ObjectiveTo investigate the mRNA genomics changes and significance of important ion channel proteins in patients with atrial fibrillation （AF）, to reveal the mechanism of electrical remodeling in AF.MethodsNinety patients with AF were chosen to receive the radiofrequency ablation （AF-RFA）, 90 healthy subjects were included as the normal control group.The coronary sinus blood and peripheral venous blood were taken from each AF patient during the operation of AF-RFA.The genome-wide mRNA expression profile was analyzed with mRNA microarray chip, and the mRNA expression difference results for the major ion channel gene was further validated using Real-time PCR test.ResultsThe expression of twelve ion channel protein mRNA increased ≥2.0-fold, expression of 10 mRNA decreased ≥2.0-fold, among which K＋ channel gene KCNE4, KCND2, KCNN4 declined obviously, KCNA5 dropped 11.54-fold （P〈 0.01）; KCNS3, KCNS1, KCNG1, KCNG7 and Ca＋ ＋ channel gene CACNA2D3 increased significantly.Compared with autologous peripheral blood, 12 mRNAs of ion channel protein in coronary sinus blood of AF patients was differentially expressed ≥2.0-fold.Compared with control group in peripheral blood, 7 ion channel protein mRNA expression differences was ≥2.0-fold, and the KCNA5 gene expression was down by 8.13-fold.RT-PCR confirmed that the trend and extent of differential expression were consistent with the chip results.The results of myocardial tissue RT-PCR showed that CACNA1C, KCNC3, KCNG1 and KCNK7 mRNA were up-regulated in AF （P〈0.05）, and other ion channel mRNA expressions were down-regulated （P〈0.05）. KCNA5 was down-regulated most obvious.ConclusionThe down-regulation of KCNA5 gene expression in AF patients is most obvious, and more potassium ion channel expression differences are also significant, so that the potassium ion channel reconstruction may play a dominant or much more important role in AF electrical remodeling.