Marion Pierre, Mohammed Djemai, Valérie Pouliot, Hugo Poulin, Michael H Gollob, Mohamed Chahine
{"title":"Exploring SCN5A Variants Associated with Atrial Fibrillation in Atrial Cardiomyocytes Derived from hiPSCs: A Characterization Study.","authors":"Marion Pierre, Mohammed Djemai, Valérie Pouliot, Hugo Poulin, Michael H Gollob, Mohamed Chahine","doi":"10.1016/j.hrthm.2024.09.013","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Atrial fibrillation (AF) poses a major risk for heart failure, myocardial infarction, and stroke. Several studies have linked SCN5A variants to AF, but their precise mechanistic contribution remains unclear. Human induced pluripotent stem cells (hiPSCs) provide a promising platform for modeling SCN5A-linked AF variants and their functional alterations.</p><p><strong>Objective: </strong>The purpose of this study was to assess the electrophysiological impact of three AF-linked SCN5A variants, K1493R, M1875T and N1986K identified in three unrelated individuals.</p><p><strong>Methods: </strong>CRISPR-Cas9 was used to generate a new hiPSC line in which Na<sub>V</sub>1.5 was knocked-out. Following differentiation into specific atrial cardiomyocyte by using retinoic acid, the adult WT and SCN5A variants were introduced into the Na<sub>V</sub>1.5 KO line through transfection. Subsequent analysis including molecular biology, optical mapping, and electrophysiology were performed.</p><p><strong>Results: </strong>The absence of Na<sub>V</sub>1.5 channels altered the expression of key cardiac genes. Na<sub>V</sub>1.5 KO hiPSC-aCMs displayed slower conduction velocities, altered action potential (AP) parameters, and impaired calcium transient propagation. The transfection of the WT channel restored sodium current density and AP characteristics. Among the AF variants, one induced a loss-of-function (N1986K) while the other two induced a gain-of-function in Na<sub>V</sub>1.5 channel activity. Cellular excitability alterations, and early afterdepolarizations were observed in AF variants.</p><p><strong>Conclusion: </strong>Our findings suggest that distinct alterations in Na<sub>V</sub>1.5 channel properties may trigger atrial hyperexcitability and arrhythmogenic activity in AF. Our KO model offers an innovative approach for investigating SCN5A variants in a human cardiac environment.</p>","PeriodicalId":12886,"journal":{"name":"Heart rhythm","volume":null,"pages":null},"PeriodicalIF":5.6000,"publicationDate":"2024-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Heart rhythm","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1016/j.hrthm.2024.09.013","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CARDIAC & CARDIOVASCULAR SYSTEMS","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Atrial fibrillation (AF) poses a major risk for heart failure, myocardial infarction, and stroke. Several studies have linked SCN5A variants to AF, but their precise mechanistic contribution remains unclear. Human induced pluripotent stem cells (hiPSCs) provide a promising platform for modeling SCN5A-linked AF variants and their functional alterations.
Objective: The purpose of this study was to assess the electrophysiological impact of three AF-linked SCN5A variants, K1493R, M1875T and N1986K identified in three unrelated individuals.
Methods: CRISPR-Cas9 was used to generate a new hiPSC line in which NaV1.5 was knocked-out. Following differentiation into specific atrial cardiomyocyte by using retinoic acid, the adult WT and SCN5A variants were introduced into the NaV1.5 KO line through transfection. Subsequent analysis including molecular biology, optical mapping, and electrophysiology were performed.
Results: The absence of NaV1.5 channels altered the expression of key cardiac genes. NaV1.5 KO hiPSC-aCMs displayed slower conduction velocities, altered action potential (AP) parameters, and impaired calcium transient propagation. The transfection of the WT channel restored sodium current density and AP characteristics. Among the AF variants, one induced a loss-of-function (N1986K) while the other two induced a gain-of-function in NaV1.5 channel activity. Cellular excitability alterations, and early afterdepolarizations were observed in AF variants.
Conclusion: Our findings suggest that distinct alterations in NaV1.5 channel properties may trigger atrial hyperexcitability and arrhythmogenic activity in AF. Our KO model offers an innovative approach for investigating SCN5A variants in a human cardiac environment.
期刊介绍:
HeartRhythm, the official Journal of the Heart Rhythm Society and the Cardiac Electrophysiology Society, is a unique journal for fundamental discovery and clinical applicability.
HeartRhythm integrates the entire cardiac electrophysiology (EP) community from basic and clinical academic researchers, private practitioners, engineers, allied professionals, industry, and trainees, all of whom are vital and interdependent members of our EP community.
The Heart Rhythm Society is the international leader in science, education, and advocacy for cardiac arrhythmia professionals and patients, and the primary information resource on heart rhythm disorders. Its mission is to improve the care of patients by promoting research, education, and optimal health care policies and standards.