微小RNA-26b-5p对缺血性心律失常大鼠心房肌细胞L型钙通道的影响  

Effects of miR-26b-5p on L-type calcium channel in atrial cardiomyocytes of ischemic arrhythmia rats

作　　者：丁莹[1] 王晶予 汤天凤 郑丹丹 Ding Ying;Wang Jingyu;Tang Tianfeng;Zheng Dandan(Department of Electrocardiogra phy and Heart Function,Xiangyang Central Hospital·Affiliated Hospital of Hubei University of Arts and Sciences,Xiangyang 441000,Hubei Province,China)

机构地区：[1]襄阳市中心医院(湖北文理学院附属医院)心电功能科,441000 [2]襄阳市中心医院(湖北文理学院附属医院)心内科,441000

出　　处：《中华老年心脑血管病杂志》2023年第10期1088-1092,共5页Chinese Journal of Geriatric Heart,Brain and Vessel Diseases

基　　金：湖北省卫生健康委科研立项项目(WJ2019M021)。

摘　　要：目的探讨微小RNA(miR)-26b-5p对磷脂酰肌醇3-激酶(PI3K)/磷脂酰肌醇3,4,5-三磷酸(PIP3)信号通路的调控作用以及对缺血性心律失常大鼠心房肌细胞L型钙通道的影响。方法选择SD大鼠72只,按照随机数表法分为假手术组、模型组、LY294002组、阴性对照组、过表达组、联合组,每组12只。各组给予相应干预24h,除假手术组外的其余各组大鼠建立缺血性心律失常模型,假手术组大鼠仅开胸不结扎。建模过程中检测各组大鼠心律失常指标,采用Curtis-Walker评分法进行心律失常评分;荧光定量PCR法检测心房肌细胞中miR-26b-5p表达;全细胞膜片钳技术记录心房肌细胞L型钙通道电流(ICa-L);蛋白印迹法检测L型钙通道α1C亚基(CACNA1C)、钙调蛋白及PI3K/PIP3通路相关蛋白表达。结果与模型组比较,LY294002组大鼠左心室室性期前收缩次数、室性心动过速持续时间、心室颤动持续时间、心律失常评分、心房肌细胞ICa-L峰值密度绝对值、CACNA1C、钙调蛋白表达显著升高,磷酸化PI3K、PIP3、磷酸化蛋白激酶B(Akt)表达显著降低,过表达组大鼠左心室室性期前收缩次数、室性心动过速持续时间、心室颤动持续时间、心律失常评分、心房肌细胞ICa-L峰值密度绝对值、CACNA1C、钙调蛋白表达显著降低,miR-26b-5p、磷酸化PI3K、PIP3、磷酸化Akt表达显著升高(P<0.05)。与过表达组比较,联合组大鼠左心室室性期前收缩次数、室性心动过速持续时间、心室颤动持续时间、心律失常评分、心房肌细胞ICa-L峰值密度绝对值、CACNA1C、钙调蛋白表达显著升高,磷酸化PI3K、PIP3、磷酸化Akt表达显著降低(0.82±0.08vs1.09±0.11,0.91±0.09vs1.17±0.11,0.94±0.09vs1.20±0.12,P<0.05)。结论miR-26b-5p过表达可能通过激活PI3K/PIP3相关信号通路,阻滞缺血性心律失常大鼠心房肌细胞L型钙通道,改善心律失常表现。Objective To explore the regulatory effect of miR-26b-5p on PI3K/PIP3 signaling pathway and its effect on L-type calcium channel of atrial cardiomyocytes in rats with ischemic arrhythmia.Methods A total of 72 SD rats were randomly divided into sham operation group,model group,LY294002 group,negative control group,overexpression group and combination group,with 12 rats in each group.In 24 h after corresponding intervention,rat model of ischemic arrhythmia was established in the other groups except the sham operation group(only thoracotomy but without ligation).During the modeling process,arrhythmia indexes were detected in each group,and Curtis-Walker scoring was used for arrhythmia score.Fluorescence quantitative PCR was employed to detect the expression of miR-26b-5p in atrial myocardiocytes,whole-cell patch-clamp technique was used to record the ICa-L of atrial myocardiocytes,and Western blotting was applied to measure the expression of CACNA1C,calmodulin and PI3K/PIP3 pathway related proteins.Results Compared with the model group,the number of left ventricular preventricular contractions,duration of ventricular tachycardia,duration of ventricular fibrillation,arrhythmia score,absolute value of ICa-L peak density of atrial myocardiocytes,and expression levels of CACNA1C and calmodulin were significantly increased,and the levels of miR-26b-5p,p-PI3K,PIP3 and p-Akt were obviously decreased in the LY294002 group(P<0.05).While the overexpression group had decreased number of left ventricular preventricular contractions,shorter duration of ventricular tachycardia,shorter duration of ventricular fibrillation,lower arrhythmia score,reduced absolute value of ICa-L peak density,and lower expression levels of CACNA1C and calmodulin,and increased levels of miR-26b-5p,p-PI3K,PIP3 and p-Akt than the model group(P<0.05).The number of left ventricular preventricular contractions,duration of ventricular tachycardia,duration of ventricular fibrillation,arrhythmia score,absolute value of ICa-L peak density and expression levels

关 键 词：心律失常 心性 钙通道 L型 磷酸肌醇3-激酶类 微小RNA26b-5p 

分 类 号：R541.7[医药卫生—心血管疾病]