Departments of Cardiovascular Medicine (Division of Heart Rhythm Services), Pediatric and Adolescent Medicine (Division of Pediatric Cardiology), and Molecular Pharmacology and Experimental Therapeutics (Windland Smith Rice Sudden Death Genomics Laboratory), Mayo Clinic, Rochester, MN (M.K., D.Y., C.S.J.K., W.Z., D.J.T., J.R.G., M.J.A.).
Departments of Cardiovascular Medicine (Clinician-Investigator Training Program), Mayo Clinic, Rochester, MN (J.R.G.).
Circ Genom Precis Med. 2021 Jun;14(3):e003234. doi: 10.1161/CIRCGEN.120.003234. Epub 2021 May 18.
Prior epidemiological studies demonstrated that the p.D85N-Potassium voltage-gated channel subfamily E member 1 (KCNE1) common variant reduces repolarization reserve and predisposes to drug-induced QT prolongation/torsades de pointes. We sought to develop a cellular model for drug-induced long QT syndrome using a patient-specific induced pluripotent stem cell-derived cardiomyocyte (iPSC-CM).
p.D85N-KCNE1 iPSCs were generated from a 23-year-old female with an exaggerated heart rate-corrected QT interval response to metoclopramide (ΔQTc of 160 ms). Clustered regularly interspaced short palindromic repeats-associated 9 technology was used to generate gene-corrected isogenic iPSCs. Field potential duration and action potential duration (APD) were measured from iPSC-CMs.
At baseline, p.D85N-KCNE1 iPSC-CMs displayed significantly longer field potential duration (281±15 ms, n=13 versus 223±8.6 ms, n=14, <0.01) and action potential duration at 90% repolarization (APD90; 579±22 ms, n=24 versus 465±33 ms, n=26, <0.01) than isogenic-control iPSC-CMs. Dofetilide at a concentration of 2 nM increased significantly field potential duration (379±20 ms, n=13, <0.01) and APD90 (666±11 ms, n=46, <0.01) in p.D85N-KCNE1 iPSC-CMs but not in isogenic-control. The effect of dofetilide on APD90 (616±54 ms, n=7 versus 526±54 ms, n=10, <0.05) was confirmed by Patch-clamp. Interestingly, treatment of p.D85N-KCNE1 iPSC-CMs with estrogen at a concentration of 1 nM exaggerated further dofetilide-induced APD90 prolongation (696±9 ms, n=81, <0.01) and caused more early afterdepolarizations (11.7%) compared with isogenic control (APD90: 618±8 ms, n=115 and early afterdepolarizations: 2.6%, <0.05).
This iPSC-CM study provides further evidence that the p.D85N-KCNE1 common variant in combination with environmental factors such as QT prolonging drugs and female sex is proarrhythmic.
先前的流行病学研究表明，钾电压门控通道亚家族 E 成员 1（KCNE1）的 p.D85N 常见变体可降低复极储备并易引发药物引起的 QT 延长/尖端扭转型室性心动过速。我们试图使用患者特异性诱导多能干细胞衍生的心肌细胞（iPSC-CM）建立药物引起长 QT 综合征的细胞模型。
从一名 23 岁女性中产生 p.D85N-KCNE1 iPSC，该女性对甲氧氯普胺的心率校正 QT 间期反应明显（ΔQTc 为 160 ms）。使用簇状规律间隔的短回文重复相关 9 技术生成基因校正的同基因 iPSC。从 iPSC-CM 中测量场电位持续时间和动作电位持续时间（APD）。
在基线时，p.D85N-KCNE1 iPSC-CM 显示出明显更长的场电位持续时间（281±15 ms，n=13 与 223±8.6 ms，n=14，<0.01）和动作电位 90%复极时的持续时间（APD90；579±22 ms，n=24 与 465±33 ms，n=26，<0.01）比同基因对照 iPSC-CM 更长。在 p.D85N-KCNE1 iPSC-CM 中，浓度为 2 nM 的多非利特显着增加了场电位持续时间（379±20 ms，n=13，<0.01）和 APD90（666±11 ms，n=46，<0.01），但在同基因对照中没有增加。多非利特对 APD90 的作用（616±54 ms，n=7 与 526±54 ms，n=10，<0.05）通过 Patch-clamp 得到了证实。有趣的是，用浓度为 1 nM 的雌激素处理 p.D85N-KCNE1 iPSC-CM 进一步加重了多非利特诱导的 APD90 延长（696±9 ms，n=81，<0.01）并引起更多的早期后除极（11.7％）与同基因对照相比（APD90：618±8 ms，n=115 和早期后除极：2.6％，<0.05）。
这项 iPSC-CM 研究进一步证明，p.D85N-KCNE1 常见变体与 QT 延长药物和女性等环境因素结合是致心律失常的。
