Regenerative Medicine Institute, School of Medicine University of Galway Galway Ireland.
Department of Pharmacology Northwestern University Feinberg School of Medicine Chicago IL USA.
J Am Heart Assoc. 2024 Oct 15;13(20):e034690. doi: 10.1161/JAHA.124.034690. Epub 2024 Oct 8.
Long-QT syndrome is a primary cardiac ion channelopathy predisposing a patient to ventricular arrhythmia through delayed repolarization on the resting ECG. We aimed to establish a patient-specific, human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes model of long-QT syndrome type 3 (LQT3) using clustered regularly interspaced palindromic repeats (CRISPR/Cas9), for disease modeling and drug challenge.
HiPSCs were generated from a patient with LQT3 harboring an pathogenic variant (c.1231G>A; p.Val411Met), and an unrelated healthy control. The same pathogenic variant was engineered into the background healthy control hiPSCs via CRISPR/Cas9 gene editing to generate a second disease model of LQT3 for comparison with an isogenic control. All 3 hiPSC lines were differentiated into cardiomyocytes. Both the patient-derived LQT3 () and genetically engineered LQT3 () hiPSC-derived cardiomyocytes showed significantly prolonged cardiomyocyte repolarization compared with the healthy control. Mexiletine, a cardiac voltage-gated sodium channel (Na1.5) blocker, shortened repolarization in both patient-derived LQT3 and genetically engineered LQT3 hiPSC-derived cardiomyocytes, but had no effect in the control. Notably, calcium channel blockers nifedipine and verapamil showed a dose-dependent shortening of repolarization, rescuing the phenotype. Additionally, therapeutic drugs known to prolong the corrected QT in humans (ondansetron, clarithromycin, and sotalol) demonstrated this effect in vitro, but the LQT3 clones were not more disproportionately affected compared with the control.
We demonstrated that patient-derived and genetically engineered LQT3 hiPSC-derived cardiomyocytes faithfully recapitulate pathologic characteristics of LQT3. The clinical significance of such an in vitro model is in the exploration of novel therapeutic strategies, stratifying drug adverse reaction risk and potentially facilitating a more targeted, patient-specific approach in high-risk patients with LQT3.
长 QT 综合征是一种原发性心脏离子通道病，通过静息心电图上的延迟复极导致患者发生室性心律失常。我们旨在使用成簇规律间隔短回文重复序列（CRISPR/Cas9）建立一个长 QT 综合征 3 型（LQT3）的患者特异性、人诱导多能干细胞（hiPSC）衍生的心肌细胞模型，用于疾病建模和药物挑战。
从携带致病性变异（c.1231G>A；p.Val411Met）的 LQT3 患者和无关的健康对照中生成 hiPSC。通过 CRISPR/Cas9 基因编辑将相同的致病性变异引入健康对照 hiPSC 的背景中，以生成第二个 LQT3 疾病模型，与同基因对照进行比较。所有 3 种 hiPSC 系均分化为心肌细胞。与健康对照组相比，患者来源的 LQT3（）和基因工程 LQT3（）hiPSC 衍生的心肌细胞均表现出明显的心肌细胞复极化延长。心脏电压门控钠离子通道（Na1.5）阻滞剂美西律缩短了患者来源的 LQT3 和基因工程 LQT3 hiPSC 衍生的心肌细胞的复极，但对对照组没有影响。值得注意的是，钙通道阻滞剂硝苯地平和维拉帕米表现出剂量依赖性复极缩短，可挽救表型。此外，已知在人类中延长校正 QT 的治疗药物（昂丹司琼、克拉霉素和索他洛尔）在体外显示出这种作用，但与对照组相比，LQT3 克隆没有受到不成比例的更大影响。
我们证明了患者来源和基因工程 LQT3 hiPSC 衍生的心肌细胞忠实地再现了 LQT3 的病理特征。这种体外模型的临床意义在于探索新的治疗策略，分层药物不良反应风险，并可能为 LQT3 高危患者提供更有针对性、个体化的方法。
