房颤心房肌L型钙通道α1c亚单位mRNA的差异表达改变及意义

Gene expression of L-type Ca^(2+)-channel alpha 1c subunit in atrial myocardium of chronic AF patients

目的研究房颤心房肌L型钙通道结构重塑的分子基础。方法心脏手术中采集慢性房颤及窦性心律患者右心房肌,提取总RNA行逆转录,应用PCR技术检测L型钙通道α1c亚单位不同位置的mRNA片段表达。结果α1c亚单位Ⅰ、Ⅱ跨膜区连接对应的mRNA丰度,慢性房颤心房肌较窦性心律心房肌差异无显著性;α1c亚单位Ⅳ跨膜区对应的mRNA丰度,慢性房颤心房肌较窦性心律心房肌明显降低。结论房颤心房肌L型钙通道结构重塑与α1c亚单位的亚型表达改变有关。

[Objective] To furtherly investigate the molecular mechanisms of atrial electrical remodeling in chronic AF patients, The gene expression of L--type Ca^2＋-chtmnel α1c subunits was investigated in atrial myocardiurn of AF patients, [Methods] Right atrial myocardium were obtained from 24 patients with chronic AF and 19 controls in sinus rhythm. All patients underwent valve replacement surgery. Total RNA was isolated and reversely transcribed into eDNA. In a semi-quantitative polymcrase chain reaction the eDNA of interest and of glyceraldehyde-3- phosphate dehydrogenase were amplified and separated by ethidium hromide-stained gel eleetrophoresis. [Results] The mRNA expression corresponding to the Ⅱ,Ⅲ link of α1c subunits was not altered in patients with chronic AF compared to the controls, while that corresponding to the IV trans-membrane of α1c subunits was reduced. [Conclusion] The reduced ICa.L may due to downregulated expression of the isoform of ale subtmits.