Modeling incomplete penetrance in arrhythmogenic cardiomyopathy by human induced pluripotent stem cell derived cardiomyocytes

Marzia De Bortoli; Viviana Meraviglia; Katarina Mackova; Laura S Frommelt; Eva König; Johannes Rainer; Chiara Volani; Patrizia Benzoni; Maja Schlittler; Giada Cattelan; Benedetta M Motta; Claudia Volpato; Werner Rauhe; Andrea Barbuti; Serena Zacchigna; Peter P Pramstaller; Alessandra Rossini

doi:10.1016/j.csbj.2023.02.029

Modeling incomplete penetrance in arrhythmogenic cardiomyopathy by human induced pluripotent stem cell derived cardiomyocytes

Comput Struct Biotechnol J. 2023 Feb 17:21:1759-1773. doi: 10.1016/j.csbj.2023.02.029. eCollection 2023.

Authors

Marzia De Bortoli¹, Viviana Meraviglia^{1

2}, Katarina Mackova¹, Laura S Frommelt¹, Eva König¹, Johannes Rainer¹, Chiara Volani^{1

3}, Patrizia Benzoni³, Maja Schlittler¹, Giada Cattelan¹, Benedetta M Motta¹, Claudia Volpato¹, Werner Rauhe⁴, Andrea Barbuti³, Serena Zacchigna⁵, Peter P Pramstaller¹, Alessandra Rossini¹

Affiliations

¹ Institute for Biomedicine (Affiliated to the University of Lübeck), Eurac Research, Bolzano, Italy.
² Department of Anatomy and Embryology, Leiden University Medical Center, 2316 Leiden, the Netherlands.
³ Universita` degli Studi di Milano, The Cell Physiology MiLab, Department of Biosciences, Milano, Italy.
⁴ San Maurizio Hospital, Department of Cardiology, Bolzano, Italy.
⁵ International Centre for Genetic Engineering and Biotechnology (ICGEB), Cardiovascular Biology Laboratory, Trieste, Italy.

Abstract

Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) are commonly used to model arrhythmogenic cardiomyopathy (ACM), a heritable cardiac disease characterized by severe ventricular arrhythmias, fibrofatty myocardial replacement and progressive ventricular dysfunction. Although ACM is inherited as an autosomal dominant disease, incomplete penetrance and variable expressivity are extremely common, resulting in different clinical manifestations. Here, we propose hiPSC-CMs as a powerful in vitro model to study incomplete penetrance in ACM. Six hiPSC lines were generated from blood samples of three ACM patients carrying a heterozygous deletion of exon 4 in the PKP2 gene, two asymptomatic (ASY) carriers of the same mutation and one healthy control (CTR), all belonging to the same family. Whole exome sequencing was performed in all family members and hiPSC-CMs were examined by ddPCR, western blot, Wes™ immunoassay system, patch clamp, immunofluorescence and RNASeq. Our results show molecular and functional differences between ACM and ASY hiPSC-CMs, including a higher amount of mutated PKP2 mRNA, a lower expression of the connexin-43 protein, a lower overall density of sodium current, a higher intracellular lipid accumulation and sarcomere disorganization in ACM compared to ASY hiPSC-CMs. Differentially expressed genes were also found, supporting a predisposition for a fatty phenotype in ACM hiPSC-CMs. These data indicate that hiPSC-CMs are a suitable model to study incomplete penetrance in ACM.

Keywords: ABC, active ß-catenin; ACM, arrhythmogenic cardiomyopathy; ASY, asymptomatic; Arrhythmogenic cardiomyopathy; BBB, bundle-branch block; CMs, cardiomyocytes; CTR, control; Cx43, connexin-43; DEGs, differentially expressed genes; GATK, Genome Analysis Toolkit; Human induced pluripotent stem cell derived cardiomyocytes; ICD, implantable cardioverter-defibrillator; ID, intercalated disk; Incomplete penetrance; LBB, left bundle-branch block; MRI, magnetic resonance imagingmut, mutated; NSVT, non-sustained ventricular tachycardia; RV, right ventricle; hiPSC, human induced pluripotent stem cell; wt, wild type.