Abstract 13231: Patient-Specific Induced Pluripotent Stem Cell as a Model for Familial Dilated Cardiomyopathy
Introduction: Dilated cardiomyopathy (DCM) is the most common diagnosis leading to heart transplantation and places considerable burdens on healthcare worldwide. The advent of induced pluripotent stem cells (iPSCs) offers an exceptional opportunity for creating disease-specific models, investigating underlying mechanisms, and optimizing therapy. In this study, we generated cardiomyocytes (CMs) from iPSCs derived from patients of a DCM family carrying a point mutation (R173W) in the gene encoding sarcomeric protein cardiac troponin T (cTnT). Functional properties of DCM iPSC-CMs were extensively studied.
Methods: CMs were differentiated from iPSCs generated from both DCM and control healthy individuals in the same family cohort (n=7). Electrophysiological properties of the iPSC derived beating embryoid bodies and single CMs were assayed by multi-electrode arrays and patch clamping recordings respectively. Contractility and calcium handling properties of single iPSC-CMs were analyzed by atomic force microscopy and calcium imaging. Sarcomeric organizations were analyzed by double immnucytochemistry of α-actinin and cTnT.
Results: Compared to the controls, DCM iPSC-CMs exhibited decreased calcium transient amplitude, decreased contractility, and abnormal sarcomeric α-actinin distribution (Figure 1). When stimulated with β-adrenergic agonist, DCM iPSC-CMs showed characteristics of failure such as reduced beating rates, compromised contraction, and significantly more cells with abnormal sarcomeric α-actinin distribution. β-adrenergic blocker treatment and over-expression of sarcoplasmic reticulum Ca2+ ATPase (Serca2a) improved the function of DCM iPSC-CMs.
Conclusion: Our study demonstrated that human DCM iPSC-CMs recapitulated the disease phenotypes morphologically and functionally, and thus can serve as a useful platform for exploring molecular and cellular mechanisms and optimizing treatment of this particular disease.
- © 2011 by American Heart Association, Inc.