Modeling Arrhythmogenic Right Ventricular Cardiomyopathy(ARVC) By Human IPSC-derived Cardiomyocytes With Desmoplakin(DSP) Mutations

Induced pluripotent stem cell(iPSC)is a reprogrammed cell from mature somatic cell by overexpressing key transcriptional factors.Compared with embryonic stem cells,iPSC avoids the ethical issue of "destroying blastocyst" while maintaining its self-renewal and muti-lineage differentiation potential.Reprogramming methods for iPSC are developing from the virusmediated transgene to genetic material free manners,such as protein import,and even small molecule chemical induction.iPSC could be induced to cardiomyocytes in vitro by a chemical defined method.And the metabolic enrichment and highly efficient differentiation make the cardiomyocytes production in a large scale possible.The iPSC derived cardiomyocytes are the perfect cell source in regenerative medicine and hereditary cardiomyopathy’s disease modeling.Arrhythmia right ventricular cardiomyopathy(ARVC)is a type of hereditary cardiomyopathy,with the clinical phenotype as ventricular fibrosis,adiposis infiltration,and ventricular arrhythmia,leading to an increased risk of sudden cardiac death.Due to the limitations of the ARVC mouse model,ARVC patient iPSC derived cardiomyocytes can be used to build the disease model for study the ARVC pathogenesis.In this study,we reprogrammed monocytes from one pair of identical twins containing double mutations of desmoplakin(DSP)to obtain DSP double-mutated iPSC cell lines HUBU5 and HUBU5-B(DSP,c.104G>T,c.5617C>T).At the same time,using the patient’s parents’ iPSC,HUBU5-M(DSP,c.104G>T)and HUBU5-F(DSP,c.5617C>T)were obtained as single point mutation controls;Normal iPSC(WTC)was used as control.By in vitro differentiation into cardiomyocytes with all these groups,we found: 1)DSP double mutation will not affect iPSC pluripotency and ability to differentiate into cardiomyocytes;2)Compared with the wildtype group,DSP double mutation iPSC upregulated genes related to fat formation,increased levels of cardiomyocyte apoptosis,and altered protein localization of DSP in cardiomyocytes.This study established and optimized the human monocytes’ reprogramming method and modified cardiomyocytes differentiation protocol.By evaluating the ARVP-iPSC derived cardiomyocytes,we are trying to establish the DSP mutated ARVC disease model.This work will help to study the molecular mechanisms of fibrosis and lipogenesis in the heart and provide a basis for the research on the pathogenesis of ARVC.