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Induced Pluripotent Stem Cell-Derived Cardiomyocytes with SCN5A R1623Q Mutation Associated with Severe Long QT Syndrome in Fetuses and Neonates Recapitulates Pathophysiological Phenotypes

Authors :
Emiko Hayama
Yoshiyuki Furutani
Nanako Kawaguchi
Akiko Seki
Yoji Nagashima
Keisuke Okita
Daiji Takeuchi
Rumiko Matsuoka
Kei Inai
Nobuhisa Hagiwara
Toshio Nakanishi
Source :
Biology, Vol 10, Iss 10, p 1062 (2021)
Publication Year :
2021
Publisher :
MDPI AG, 2021.

Abstract

The SCN5A R1623Q mutation is one of the most common genetic variants associated with severe congenital long QT syndrome 3 (LQT3) in fetal and neonatal patients. To investigate the properties of the R1623Q mutation, we established an induced pluripotent stem cell (iPSC) cardiomyocyte (CM) model from a patient with LQTS harboring a heterozygous R1623Q mutation. The properties and pharmacological responses of iPSC-CMs were characterized using a multi-electrode array system. The biophysical characteristic analysis revealed that R1623Q increased open probability and persistent currents of sodium channel, indicating a gain-of-function mutation. In the pharmacological study, mexiletine shortened FPDcF in R1623Q-iPSC-CMs, which exhibited prolonged field potential duration corrected by Fridericia’s formula (FPDcF, analogous to QTcF). Meanwhile, E4031, a specific inhibitor of human ether-a-go-go-related gene (hERG) channel, significantly increased the frequency of arrhythmia-like early after depolarization (EAD) events. These characteristics partly reflect the patient phenotypes. To further analyze the effect of neonatal isoform, which is predominantly expressed in the fetal period, on the R1623Q mutant properties, we transfected adult form and neonatal isoform SCN5A of control and R1623Q mutant SCN5A genes to 293T cells. Whole-cell automated patch-clamp recordings revealed that R1623Q increased persistent Na+ currents, indicating a gain-of-function mutation. Our findings demonstrate the utility of LQT3-associated R1623Q mutation-harboring iPSC-CMs for assessing pharmacological responses to therapeutic drugs and improving treatment efficacy. Furthermore, developmental switching of neonatal/adult Nav1.5 isoforms may be involved in the pathological mechanisms underlying severe long QT syndrome in fetuses and neonates.

Details

Language :
English
ISSN :
20797737
Volume :
10
Issue :
10
Database :
Directory of Open Access Journals
Journal :
Biology
Publication Type :
Academic Journal
Accession number :
edsdoj.2e11d85f1306437cb6a6f913b53ccac6
Document Type :
article
Full Text :
https://doi.org/10.3390/biology10101062