胰岛素对人心肌细胞QT间期及诱发心律失常的影响

Effects of insulin on the QT interval and induced arrhythmias of human cardiomycytes

目的探讨胰岛素对人诱导多潜能干细胞来源的心肌细胞(hiPSC-CMs)QT间期及诱发心律失常的影响。方法免疫荧光染色及流式细胞术分析hiPSC-CMs纯度,微电极阵列(MEA)检测胰岛素干预hiPSC-CMs前后的电生理改变,包括心率(HR)、阈电位时程(FPD,类似心电图QT间期)、FPDc(经HR校正的FPD)、锋电位与传导速率(CV);观察E4031干预hiPSC-CMs诱发FPDc延长及心律失常的情况;在胰岛素干预hiPSC-CMs基础上,再给予E4031处理,观察胰岛素对E4031诱发FPDc延长及心律失常的改善情况。结果hiPSC-CMs高表达心肌特异性标志物cTnT,hiPSC-CMs纯度为97.1%;胰岛素干预hiPSC-CMs 5 d后,与未干预组比较,干预组HR增快(11.9±3.3)%,FPD缩短(22.7±2.8)%,FPDc缩短(15.6±1.6)%,锋电位增加了(39.1±7.9)%,CV无明显变化;10 nmol/L的E4031可使hiPSC-CMs的FPDc延长(37.8±9.0)%,30 nmol/L的E4031可诱发心律失常;经胰岛素预处理后,10 nmol/L的E4031使hiPSC-CMs的FPDc延长(21.8±3.1)%(与胰岛素未处理组相比,FPDc缩短,P<0.05),30 nmol/L的E4031未诱发出心律失常。结论胰岛素可缩短hiPSC-CMs的QT间期,并显著降低药物诱发hiPSCCMs的QT间期延长及心律失常风险。

Objective To explore the effects of insulin on the QT interval and induced arrhythmias of cardiomyocytes derived from human induced pluripotent stem cells(hiPSC-CMs).Methods Immunofluorescence staining and flow cytometry were used to analyze the purity of hiPSC-CMs.Microelectrode array(MEA)was utilized to detect the electrophysiological changes including heart rate(HR),field potential duration(FPD,which is similar to QT interval in ECG),FPDc(FPD corrected by HR),conduction velocity(CV),and spike amplitude before and after insulin treatment.The effects of E4031 on QT interval prolongation and induced arrhythmias of hiPSC-CMs were evaluated before and after treatment with insulin.Results hiPSC-CMs highly expressed myocardial specific marker cTnT.The purity of hiPSC-CMs was 97.1%.After 5-day insulin treatment of hiPSC-CMs,HR increased by(11.9±3.3)%,FPD shortened by(22.7±2.8)%,FPDc shortened by(15.6±1.6)%,and spike amplitude increased by(39.1±7.9)%when compared with untreated group,but CV remained unchanged.10 nmol/L of E4031 could prolong the FPDc of hiPSC-CMs by(37.8±9.0)%,and 30 nmol/L of E4031 could induce arrhythmias.After insulin treatment,10 nmol/L of E4031 prolonged the FPDc of hiPSC-CMs by(21.8±3.1)%(compared with the untreated group,insulin decreased FPDc prolongation by E4031,37.8%±9.0%vs.21.8%±3.1%,P<0.05),while 30 nmol/L of E4031 did not induce arrhythmias.Conclusion Insulin can shorten the QT interval of hiPSC-CMs and significantly reduce the QT interval prolongation and the risk of arrhythmias induced by drugs.