Open AccessGene Transfer of Engineered Calmodulin Alleviates Ventricular Arrhythmias in a Calsequestrin‐Associated Mouse Model of Catecholaminergic Polymorphic Ventricular Tachycardia
Author(s) -
Liu Bin,
Walton Shane D.,
Ho HsiangTing,
Belevych Andriy E.,
Tikunova Svetlana B.,
Bonilla Ingrid,
Shettigar Vikram,
Knollmann Bjorn C.,
Priori Silvia G.,
Volpe Pompeo,
Radwański Przemysław B.,
Davis Jonathan P.,
Györke Sándor
Publication year - 2018
Publication title -
journal of the american heart association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.494
H-Index - 85
ISSN - 2047-9980
DOI - 10.1161/jaha.117.008155
Subject(s) - catecholaminergic polymorphic ventricular tachycardia , calsequestrin , ryanodine receptor 2 , medicine , ryanodine receptor , ventricular tachycardia , myocyte , refractory period , diastole , cardiology , calmodulin , adeno associated virus , endocrinology , calcium , gene , biology , recombinant dna , vector (molecular biology) , genetics , blood pressure
Background Catecholaminergic polymorphic ventricular tachycardia ( CPVT ) is a familial arrhythmogenic syndrome characterized by sudden death. There are several genetic forms of CPVT associated with mutations in genes encoding the cardiac ryanodine receptor (RyR2) and its auxiliary proteins including calsequestrin ( CASQ 2) and calmodulin (CaM). It has been suggested that impairment of the ability of RyR2 to stay closed (ie, refractory) during diastole may be a common mechanism for these diseases. Here, we explore the possibility of engineering CaM variants that normalize abbreviated RyR2 refractoriness for subsequent viral‐mediated delivery to alleviate arrhythmias in non–CaM‐related CPVT . Methods and Results To that end, we have designed a CaM protein ( GSH ‐M37Q; dubbed as therapeutic CaM or T‐CaM) that exhibited a slowed N‐terminal Ca dissociation rate and prolonged RyR2 refractoriness in permeabilized myocytes derived from CPVT mice carrying the CASQ 2 mutation R33Q. This T‐CaM was introduced to the heart of R33Q mice through recombinant adeno‐associated viral vector serotype 9. Eight weeks postinfection, we performed confocal microscopy to assess Ca handling and recorded surface ECGs to assess susceptibility to arrhythmias in vivo. During catecholamine stimulation with isoproterenol, T‐CaM reduced isoproterenol‐promoted diastolic Ca waves in isolated CPVT cardiomyocytes. Importantly, T‐CaM exposure abolished ventricular tachycardia in CPVT mice challenged with catecholamines. Conclusions Our results suggest that gene transfer of T‐CaM by adeno‐associated viral vector serotype 9 improves myocyte Ca handling and alleviates arrhythmias in a calsequestrin‐associated CPVT model, thus supporting the potential of a CaM‐based antiarrhythmic approach as a therapeutic avenue for genetically distinct forms of CPVT .