Cav1.3-C-terminus Restores Electrical and Contractile Functions in hiPSC-derived Cardiomyocytes Model of Heart Failure

Objective: Heart failure (HF) is a major global health concern characterized by impaired excitation-contraction coupling and extensive structural remodeling of the myocardium, often modeled using a potent vasoactive and neurohumoral mediator, endothelin-1 (ET-1). This study investigates whether AAV6-mediated delivery of the Cav1.3-C-terminus, acting as an auto-trans-regulator of gene transcription, can restore electrophysiological and contractile functions in an ET-1-induced HF model using hiPSC-CMs. Methods: hiPSC-CM monolayers were treated with 10 nM ET-1 for 48 hours to induce HF-like phenotype and then co-treated with an AAV6-Cav1.3-C-terminus. We subsequently evaluated gene expression via RT-qPCR, single-cell electrophysiological properties via patch-clamp, and contractile function using custom video analysis software. Results: ET-1 treatment induced a HF-associated remodeling phenotype, characterized by significant upregulation of hypertrophic (NPPA, NPPB, and ACTA1) and extracellular matrix-associated (COL1A1) genes, along with increased cell membrane capacitance. This structural remodeling was accompanied by marked electrophysiological alterations, including downregulation of KCNH2, CACNA1D, CACNA1C, and SCN5A, reduced potassium, calcium, and sodium current densities, and prolonged action potential duration. ET-1 impaired both the spontaneous beating rate and contraction amplitude of the monolayers. Co-treatment with the Cav1.3-C-terminus successfully restored CACNA1D and KCNH2 gene expression to baseline levels, accompanied by normalized L-type calcium and potassium current densities, normalized APD prolongation, and completely restored the chronotropic and inotropic functions to control levels. Conclusions: ET-1-treated hiPSC-CMs model effectively recapitulates the electrophysiological and contractile dysregulations of HF. Gene therapy by Cav1.3-C-terminus provides robust functional rescue myocardial contractility, highlighting its potential as a novel therapeutic strategy for HF.