He Fei, Zhao Jing, Li Ling, Guo Rong
Department of Cardiology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province.
Department of Hematology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan Province, China
Ann Clin Lab Sci. 2015 Winter;45(1):58-63.
The acetylcholine-sensitive potassium channel (IK(ACh)) expresses only in the atrium, not in the ventricle. The main component of the rat IK(ACh) channel is the Kir3.4 protein, and its encoding gene is the KCNJ5 gene. IK(ACh) inhibitors provide a promising treatment for atrial fibrillation without side effects on the ventricle. At present, however, there is no specific IK(ACh) inhibitor. Small interference RNA (siRNA) has the advantages of high specificity and high efficiency. Our aim is to use siRNA to inhibit the IK(ACh) channel on H9c2 cells derived from rat cardiomyocytes.
Three pairs of siRNAs targeting the rat IK(ACh) channel were synthesized. H9c2 cells were divided into six groups: control, negative siRNA control, siRNA sequence 1, siRNA sequence 2, siRNA sequence 3, and amiodarone. The KCNJ5 gene and Kir3.4 protein were measured, and IK(ACh) currents were recorded by patch-clamp.
The negative siRNA control and siRNA sequence 1 had no inhibitory effects on the IK(ACh) channel. siRNA sequences 2 and 3 could cause a significant decrease in KCNJ5 gene expression, Kir3.4 protein, and IK(ACh) currents (p<0.05). Amiodarone could inhibit the IK(ACh) currents but had no effect on KCNJ5 gene expression and Kir3.4 protein.
siRNA could effectively inhibit the IK(ACh) channel and is a potential therapy for atrial fibrillation.
乙酰胆碱敏感性钾通道（IK(ACh)）仅在心房表达，而不在心室表达。大鼠IK(ACh)通道的主要成分是Kir3.4蛋白，其编码基因是KCNJ5基因。IK(ACh)抑制剂为心房颤动提供了一种有前景的治疗方法，且对心室无副作用。然而，目前尚无特异性的IK(ACh)抑制剂。小干扰RNA（siRNA）具有高特异性和高效性的优点。我们的目的是利用siRNA抑制源自大鼠心肌细胞的H9c2细胞上的IK(ACh)通道。
合成了三对靶向大鼠IK(ACh)通道的siRNA。将H9c2细胞分为六组：对照组、阴性siRNA对照组、siRNA序列1组、siRNA序列2组、siRNA序列3组和胺碘酮组。检测KCNJ5基因和Kir3.4蛋白，并通过膜片钳记录IK(ACh)电流。
阴性siRNA对照组和siRNA序列1组对IK(ACh)通道无抑制作用。siRNA序列2组和3组可导致KCNJ5基因表达、Kir3.4蛋白和IK(ACh)电流显著降低（p<0.05）。胺碘酮可抑制IK(ACh)电流，但对KCNJ5基因表达和Kir3.4蛋白无影响。
siRNA可有效抑制IK(ACh)通道，是心房颤动的一种潜在治疗方法。
