Patient-Specific and Genome-Edited Induced Pluripotent Stem Cell–Derived Cardiomyocytes Elucidate Single-Cell Phenotype of Brugada Syndrome

• Published in: Journal of the American College of Cardiology Vol. 68; no. 19; pp. 2086 - 2096
• Main Authors: Liang, Ping, Sallam, Karim, Wu, Haodi, Li, Yingxin, Itzhaki, Ilanit, Garg, Priyanka, Zhang, Ying, Termglichan, Vittavat, Lan, Feng, Gu, Mingxia, Gong, Tingyu, Zhuge, Yan, He, Chunjiang, Ebert, Antje D., Sanchez-Freire, Veronica, Churko, Jared, Hu, Shijun, Sharma, Arun, Lam, Chi Keung, Scheinman, Melvin M., Bers, Donald M., Wu, Joseph C.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 08.11.2016; Elsevier Limited
• Subjects: action potential; Adolescent; Adult; arrhythmia; Brugada Syndrome - genetics; Brugada Syndrome - metabolism; Brugada Syndrome - pathology; Ca2+ transient; Cardiology; Cardiomyocytes; Cardiomyopathy; Cardiovascular; Cell adhesion & migration; Cell Differentiation; Editing; Electrocardiography; Family medical history; Fibroblasts; Gene expression; Gene Expression Regulation; Genetic engineering; genome editing; Genomes; Genotype; Genotype & phenotype; Heart Conduction System - pathology; Heart Conduction System - physiopathology; Humans; Hypotheses; Induced Pluripotent Stem Cells - cytology; Induced Pluripotent Stem Cells - metabolism; Male; Methods; Middle Aged; Mutation; Myocytes, Cardiac - cytology; Myocytes, Cardiac - metabolism; NAV1.5 Voltage-Gated Sodium Channel - biosynthesis; NAV1.5 Voltage-Gated Sodium Channel - genetics; Patients; Pedigree; Phenotype; Polymerase Chain Reaction; RNA - genetics; SCN5A; Sendai virus; Sodium; Stem cells; Studies; Young Adult; genome editing; BrS; iPSC-CM; Vmax; iPSC; ECG; action potential; AP; hNav1.5; arrhythmia; Ca2+ transient; SCN5A; INa; gene expression; human sodium channel protein type 5 subunit alpha; Ca 2+ transient; I Na; sodium voltage-gated channel alpha subunit 5; electrocardiogram; type 1 Brugada syndrome; induced pluripotent stem cell; maximal upstroke velocity; V max; hNa v1.5; sodium current; induced pluripotent stem cell–derived cardiomyocyte; Ca(2+) transient
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/j.jacc.2016.07.779

Brugada syndrome (BrS), a disorder associated with characteristic electrocardiogram precordial ST-segment elevation, predisposes afflicted patients to ventricular fibrillation and sudden cardiac death. Despite marked achievements in outlining the organ level pathophysiology of the disorder, the understanding of human cellular phenotype has lagged due to a lack of adequate human cellular models of the disorder. The objective of this study was to examine single cell mechanism of Brugada syndrome using induced pluripotent stem cell–derived cardiomyocytes (iPSC-CMs). This study recruited 2 patients with type 1 BrS carrying 2 different sodium voltage-gated channel alpha subunit 5 variants as well as 2 healthy control subjects. We generated iPSCs from their skin fibroblasts by using integration-free Sendai virus. We used directed differentiation to create purified populations of iPSC-CMs. BrS iPSC-CMs showed reductions in inward sodium current density and reduced maximal upstroke velocity of action potential compared with healthy control iPSC-CMs. Furthermore, BrS iPSC-CMs demonstrated increased burden of triggered activity, abnormal calcium (Ca2+) transients, and beating interval variation. Correction of the causative variant by genome editing was performed, and resultant iPSC-CMs showed resolution of triggered activity and abnormal Ca2+ transients. Gene expression profiling of iPSC-CMs showed clustering of BrS compared with control subjects. Furthermore, BrS iPSC-CM gene expression correlated with gene expression from BrS human cardiac tissue gene expression. Patient-specific iPSC-CMs were able to recapitulate single-cell phenotype features of BrS, including blunted inward sodium current, increased triggered activity, and abnormal Ca2+ handling. This novel human cellular model creates future opportunities to further elucidate the cellular disease mechanism and identify novel therapeutic targets. [Display omitted]