Abstract 12906: Generation of Induced Pluripotent Stem Cells and Cardiomyocytes as a Cellular Model of Arrhythmogenic Right Ventricular Cardiomyopathy
Introduction: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic disorder primarily affecting heart muscle and is associated with a high risk of ventricular arrhythmias and sudden cardiac death. Diagnosis is currently based upon clinical criteria and can be easily missed in the early stages. The pathophysiological studies of ARVC are being hampered by a lack of human models.
Hypotheses: Functional cardiomyocytes can be derived from ARVC patient-specific induced pluripotent stem cells (iPSC) and used as a cellular disease model.
Methods: Several iPSC lines were reprogrammed from dermal fibroblasts of an ARVC patient via retroviral transduction of 4 Yamanaka factors. These iPSC lines were characterized by immuno-staining, Real-time PCR, DNA methylation, and telomerase activity studies. Moreover, contracting embryoid bodies (EBs) were generated from iPSC and cardiomyocytes were characterized by immuno-staining, Real-time PCR, patch-clamp and confocal Ca2+ imaging.
Results: Four ARVC iPSC lines were generated from a patient with ARVC (PKP2 mutation); iPSCs shared similar characteristics with H9 human embryonic stem cells (hESCs), including high expression of pluripotency markers (Oct-4, SSEA-4, TRA1-60 and TRA1-81), high telomerase activity, and overall demethylation status of the promoter of Oct-4 and Nanog. In addition, contracting cardiomyocytes differentiated from ARVC-iPSCs expressed typical cardiac markers (alpha-Actinin and beta-MHC) and a ventricular action potential profile was observed in the majority of cardiomyocytes (>70%). Normal patterns of action potentials were observed. Interestingly, compared to H9 hESC-derived cardiomyocytes, higher Ca2+ transient amplitudes were noted with ARVC patient derived cardiomyocytes.
Conclusion: we have successfully generated iPSC lines from an ARVC patient and differentiated them into cardiomyocytes. Our preliminary results suggest that abnormal Ca2+ handling can be observed at an early stage in iPSC-derived cardiomyocytes from patients with ARVC.
- © 2011 by American Heart Association, Inc.