Patient-Specific and Genome-Edited Induced Pluripotent Stem Cell-Derived Cardiomyocytes Elucidate Single-Cell Phenotype of Brugada Syndrome.
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.
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California; The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute of Translational Medicine, Zhejiang University, Hangzhou, China. Electronic address: pingliang@zju.edu.cn.
Ping
P
Liang
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Karim
K
Sallam
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Haodi
H
Wu
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Yingxin
Y
Li
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Ilanit
I
Itzhaki
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Priyanka
P
Garg
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Ying
Y
Zhang
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Vittavat
V
Vermglinchan
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Feng
F
Lan
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Mingxia
M
Gu
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California; The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China.
Tingyu
T
Gong
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Yan
Y
Zhuge
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Chunjiang
C
He
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Antje D
AD
Ebert
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Veronica
V
Sanchez-Freire
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Jared
J
Churko
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Shijun
S
Hu
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Arun
A
Sharma
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California.
Chi Keung
CK
Lam
Department of Medicine, Division of Cardiology, University of California, San Francisco, California.
Melvin M
MM
Scheinman
Department of Pharmacology, University of California, Davis, California.
Donald M
DM
Bers
Stanford Cardiovascular Institute, Department of Medicine, Division of Cardiovascular Medicine, and Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, California. Electronic address: joewu@stanford.edu.
Joseph C
JC
Wu
D000293:Adolescent; D000328:Adult; D053840:Brugada Syndrome / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation; D004562:Electrocardiography; D005786:Gene Expression Regulation; D005838:Genotype; D006329:Heart Conduction System / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D062554:NAV1.5 Voltage-Gated Sodium Channel / Q000096:biosynthesis / Q000235:genetics*; D010375:Pedigree; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012313:RNA / Q000235:genetics*; D055815:Young Adult
D062554:NAV1.5 Voltage-Gated Sodium Channel; C568320:SCN5A protein, human; D012313:RNA
Ca(2+) transient; SCN5A; action potential; arrhythmia; gene expression; genome editing