心房颤动电重构机制中相关microRNA的表达差异

Differential expression of miRNA in the electric remodeling of atrial fibrillation

目的通过体外培养原代心房肌细胞，快速电刺激模拟心房颤动（房颤）模型，筛选、分析与房颤电重构机制中相关的microRNA（miRNA）表达。方法采用胰酶与I型胶原酶双酶法及差速贴壁法分离培养乳鼠心房肌细胞，OL-横纹肌肌动蛋白抗体免疫荧光鉴定。乳鼠心房肌细胞在频率为4Hz、电压为15V、脉冲为5ms的快速电场刺激中培养24h模拟心房肌细胞房颤模型。心房肌细胞随机分为对照组、房颤组，提取各组RNA，运用实时荧光定量PCR（qPCR）TaqMan探针法检测房颤电重构机制中相关miRNA的差异性表达。结果与对照组相比，房颤组miR-101a、miR-101b、miR-26a、miR-26b表达显著下调（P〈0．01），miR-21、miR-328、miR-499表达显著上调（P〈0．01），而miR-1表达略有下调，但与对照组相比差异无统计学意义（P〉0．05）。结论房颤电重构机制相关miRNA存在表达性差异，其中miR-101a、miR-101b、miR-26a、miR-26b低表达，miR-21、miR-328、miR-499高表达，它们有可能成为早期预警诊断房颤的生物学标志物，并有可能成为未来治疗房颤的干预靶点。

Objective To detect the differential expression of microRNA （miRNA） associated with electric remodeling in an atrial fibrillation （AF） model simulating rapid electrical stimulation using primarily cultured rat atrial myocardiocytes. Methods The atrial myocardiocytes of neonatal rats were isolated by the double enzyme digestion and differential adhesion methods and identified with α- sarcomeric actin antibody through immunofluorescent staining. The atrial myocardiocytes were cultured under rapid electrical stimulation （4 Hz, 15 V, 5 ms） for 24 h to simulate a model of AF. The atrial myocardiocytes were randomly divided into a control group and an AF group. Then, the total RNA was extracted and the qPCR TaqMan probe method was applied to detect the expression of miRNAs associated with electric remodeling in AF. Results Compared with the control group, the AF group produced significant reduced amounts of miR - 101 a, miR - 101 b, miR - 26a and miR - 26b （P 〈 0.01 each） but remarkably increased levels of miR - 21, miR - 328 and miR - 499 （P 〈 0.01 ）. The quantity of MiR - 1 was slightly down - regulated, through no statistical significance was seen compared with the control group （P 〉 0.05）. Conclusions Different expression of miRNA associated with electric remodeling exist in the AF model, where miR- 101a, miR- 101b, miR- 26a and miR- 26b are down -regula- ted in comparison with up -regulation of miR -21, miR -328 and miR -499. They may be useful as biomarkers in early diagnosis of AF, and may be served as potential targets for AF treatment in the future.