A leaky voltage sensor domain of cardiac sodium channels causes arrhythmias associated with dilated cardiomyopathy.

TitleA leaky voltage sensor domain of cardiac sodium channels causes arrhythmias associated with dilated cardiomyopathy.
Publication TypeJournal Article
Year of Publication2018
AuteursMoreau, A, Gosselin-Badaroudine, P, Mercier, A, Burger, B, Keller, DI, Chahine, M
JournalSci Rep
Volume8
Issue1
Pagination13804
Date Published2018 Sep 14
ISSN2045-2322
Abstract

Dilated cardiomyopathy (DCM) is a structural heart disease that causes dilatation of cardiac chambers and impairs cardiac contractility. The SCN5A gene encodes Na1.5, the predominant cardiac sodium channel alpha subunit. SCN5A mutations have been identified in patients with arrhythmic disorders associated with DCM. The characterization of Na1.5 mutations located in the voltage sensor domain (VSD) and associated with DCM revealed divergent biophysical defects that do not fully explain the pathologies observed in these patients. The purpose of this study was to characterize the pathological consequences of a gating pore in the heart arising from the Na1.5/R219H mutation in a patient with complex cardiac arrhythmias and DCM. We report its properties using cardiomyocytes derived from patient-specific human induced pluripotent stem cells. We showed that this mutation generates a proton leak (called gating pore current). We also described disrupted ionic homeostasis, altered cellular morphology, electrical properties, and contractile function, most probably linked to the proton leak. We thus propose a novel link between SCN5A mutation and the complex pathogenesis of cardiac arrhythmias and DCM. Furthermore, we suggest that leaky channels would constitute a common pathological mechanism underlying several neuronal, neuromuscular, and cardiac pathologies.

DOI10.1038/s41598-018-31772-0
Alternate JournalSci Rep
PubMed ID30218094
PubMed Central IDPMC6138662
Grant ListMOP-111072 / / Gouvernement du Canada | Canadian Institutes of Health Research (Instituts de Recherche en Santé du Canada) /
MOP-130373 / / Gouvernement du Canada | Canadian Institutes of Health Research (Instituts de Recherche en Santé du Canada) /
AFM19962 / / Association Française contre les Myopathies (AFM) /