Gene Therapy for Catecholaminergic Polymorphic Ventricular Tachycardia by Inhibition of Ca ²⁺ /Calmodulin-Dependent Kinase II

Abstract

Background: Catecholaminergic polymorphic ventricular tachycardia (CPVT), an inherited cardiac arrhythmia characterized by adrenergically triggered arrhythmias, is inadequately treated by current standard of care. Ca 2+ /calmodulin-dependent protein kinase II (CaMKII), an adrenergically activated kinase that contributes to arrhythmogenesis in heart disease models, is a candidate therapeutic target in CPVT. However, translation of CaMKII inhibition has been limited by the need for selective CaMKII inhibition in cardiomyocytes. Here we tested the hypothesis that CaMKII inhibition using a cardiomyocyte-targeted gene therapy strategy would suppress arrhythmia in CPVT mouse models. Methods:We developed AAV9-GFP-AIP, an adeno-associated viral vector in which a potent CaMKII inhibitory peptide (AIP), is fused to GFP and expressed from a cardiomyocyte selective promoter. The vector was delivered systemically. Arrhythmia burden was evaluated using invasive electrophysiology testing in adult mice. AIP was also tested on induced pluripotent stem cells (iPSC) derived from CPVT patients with different disease-causing mutations to determine the effectiveness of our proposed therapy on human iPSC-derived cardiomyocytes (iPSC-CMs) and different pathogenic genotypes.Results: AAV9-GFP-AIP was robustly expressed in the heart without significant expression in extra-cardiac tissues, including the brain. Administration of AAV9-GFP-AIP to neonatal mice with a known CPVT mutation (RYR2 R176Q/+ ) effectively suppressed ventricular arrhythmias induced by either β-adrenergic stimulation or programmed ventricular pacing, without significant proarrhythmic effect. Intravascular delivery of AAV9-GFP-AIP to adolescent mice transduced ~50% of cardiomyocytes and was effective in suppressing arrhythmia in CPVT mice. iPSC-CMs derived from two different CPVT patients with different pathogenic mutations demonstrated

Molecular and tissue mechanisms of catecholaminergic polymorphic ventricular tachycardia

“…RyR2 phosphorylation by CaMKII increases RyR2 calcium leak. CaMKII inhibition with KN-93 (Liu et al 2011) or with AAV-mediated delivery of a CaMKII peptide inhibitor (Bezzerides et al 2019) was effective in suppressing arrhythmias in a murine model of CPVT. Finally, Kifuensine, an inhibitor of mannosidase-I, was used to successfully rescue expression of calsequestrin and reduce CPVT occurrence in triadin-KO mice by preventing proteasomal degradation of misfolded proteins (Cacheux et al 2019).…”

Targeting Ca2 + Handling Proteins for the Treatment of Heart Failure and Arrhythmias

“…It is worth noting that in relation to CPVT, AAV-mediated delivery of a CaMKII peptide inhibitor (autocamtide-2-related inhibitory peptide, AIP) has been shown to suppress ventricular arrhythmias induced by either β-adrenergic stimulation or programmed ventricular pacing. AAV-GFP-AIP delivery also suppressed abnormal Ca 2+ release events in induced pluripotent stem cells derived from two patients with two distinct CPVT pathogenic mutations (Bezzerides et al, 2019). The advantage of using a gene therapy approach over classic CaMKII blockers, including KN-93, is that it allows for cardiomyocyte-specific CaMKII inhibition with limited extracardiac effects.…”

LncRNAs in cardiac hypertrophy: From basic science to clinical application

“…Moreover, some gene-editing method has also been taken into knock 64,65 which has proved the advantages of applying AAV system in gene therapy within cardiovascular system. 66 Besides, the AAV vector has been approved by FDA to clinical application for gene therapy at 2017.…”