Abstract 482: Modeling PKP2 Mutation Associated Arrhythmogenic Cardiomyopathy With CRISPR-edited iPSC-derived Cardiomyocytes in Engineered Cardiac Tissues

Abstract

Arrhythmogenic cardiomyopathy (ACM), also known as arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), is a leading cause of sudden death among young adults. Over half of ACM cases are associated with inherited desmosome gene mutations, most commonly in the gene PKP2 which encodes plakophilin-2. One of the obstacles to better understanding ACM pathogenesis is the lack of appropriate models which encompass the early stages of disease development; this imposes significant constraints on the advancement of clinical therapies. The recent advent of human induced pluripotent stem cells derived cardiomyocytes (hiPSC-CMs) has enabled the development of models for studying human cardiac cell biology and pathology. In this work, we combine hiPSC-CMs, CRISPR/Cas9 genome editing, and engineered cardiac tissue platforms to develop human in vitro systems for investigating the molecular mechanisms of ACM pathogenesis. Isogenic control and mutant cell lines of hiPSC-CMs harboring ACM-associated PKP2 mutations were generated using CRISPR/Cas9 technology. Specifically, the PKP2tv cell line has an early truncation in plakophilin-2 that mimics PKP2 c.235C>T found in multiple family lineages. The effects of the PKP2tv mutation on cardiac tissue contractility were characterized using a 3D cardiac micro-tissue (CMT) platform. CMTs composed of PKP2tv cardiomyocytes were shown to have significantly decreased contractile forces compared to the control, which recapitulates the reduced ventricular systolic function seen in ACM patients. This result demonstrated the feasibility of using the hiPSC-derived tissue-engineering model to recapitulate ACM disease phenotype and allow for future investigation into the disease mechanisms.