心房颤动时人的肺静脉前庭组织中T型钙离子通道的表达改变

目的研究正常窦律（SR）与心房颤动（AF）两组患者肺静脉前庭（PVA）组织中T型钙离子通道（T-type calcium channel,TTCC）α1G、α1H亚基mRNA及蛋白的表达差异。方法术中获取各组患者（SR=34,AF=38）少量肺静脉前庭组织标本,实时荧光定量RT-PCR对各组α1G及α1H亚基的mRNA丰度相对定量（2-ΔΔCt法）;蛋白免疫印迹法比较两种α1亚基蛋白表达水平;HE染色及免疫组化染色比较两种α1亚基蛋白在细胞中的分布表达。结果与SR组相比,AF组患者的肺静脉前庭组织中TTCC的α1H亚基的mRNA表达丰度及亚基蛋白的表达水平均明显升高,但α1G亚基在两组中的表达水平接近,H-E染色及免疫组织化学染色结果与前一结论符合,并证实α1G、α1H亚基蛋白定位于心肌细胞膜表面。结论 AF组对比SR组,其T型钙通道α1H亚基表达显著增加,而α1G亚基的表达水平两组间无明显差异。

Changes of the mRNA and Protein Expression of T-type Calcium Channels in PVA of Human with Chronic Atrial Fibrillation

Objective To investigate whether there are changes in the expression,at mRNA and protein level,of α1 subunits of T-type(α1G andα1H) calcium channels in the human pulmonary vein antrum(PVA) tissue between sinal rhythm(SR) and atrial fibrillation(AF) patients.Methods The PVA tissue was obtained from two distinct groups of patients during the open-chest cardiac surgery,and the numbers of the patient were 34 for SR and 38 for AF,respectively.Real-time quantative RT-PCR was used to measure the abundance of mRNA of two different calcium channel subunits--α1G and α1H,by the 2-ΔΔCt method.Western-Blot was also used to examine the expression of these three channel proteins by a semi-quantative method.H-E and immuno-histochemistrical(IHC) staining are used to evaluate the morphological differences between two groups.Results In comparison with the SR group,the mRNA abundance and protein expression level of α1H subunits was significantly up-regulated in the AF group(P<0.05).However,the level of α1G subunit was not significantly different between two groups.The results of H-E and IHC staining are quit consistent with the data above,and prove that the protein of TTCC is located on the menbrane of myocardial cell.Conclusions The present study demonstrated that the expression of α1H subunits of TTCC,but not α1G subunit,was up-regulated in atrial fibrillation.