Deep phenotyping of testosterone-prompted fibrosis in arrhythmogenic right ventricular cardiomyopathy using iPSC-derived engineered cardiac spheroids

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a progressive disease characterized by adipose and fibrous replacement of the myocardium. While elevated testosterone levels have been implicated in the pathological process of ARVC, its exact contribution to cardiac fibrosis in ARVC remains unclear. In this study, we analyzed the potential contribution of gender-based differences on the distribution of the low-voltage area in an ARVC cohort undergoing an electrophysiological study, which was indicated by feature selection. Additionally, we established engineered cardiac spheroid models in vitro using patient-specific induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iPSC-CMs) and iPSC-derived cardiac fibroblasts (icFBs). We elucidated the pathogenicity of abnormal splicing in the plakophilin-2 (PKP2) gene caused by an intronic mutation. Additionally, pathogenic validation of the desmoglein-2 (DSG2) point mutation further confirms the reliability of the models. Moreover, testosterone exacerbated the DNA damage in the mutated cardiomyocytes and further activated myofibroblasts in a chain reaction. In conclusion, we designed and constructed an in vitro three-dimensionally-engineered cardiac spheroid model of ARVC based on clinical findings and provided direct evidence of the fibrotic role of testosterone in ARVC.