Abstract 10706: Directed Differentiation of Patient-specific Induced Pluripotent Stem Cells Identifies The Cardiac Transcriptional Repression During Myocardial Growth and Patterning in Hypoplastic Left Heart Syndrome
Background: The pathogenesis of hypoplastic left heart syndrome (HLHS) originate as a primary defect in the left ventricular outflow tract (LVOT) mainly at a level of aortic valve, that leads to secondary left ventricle hypoplasia. The genetic basis of patients with HLHS remains unknown and the lack of animal models to reconstitute the cardiac maldevelopment has hampered the study of this disease. The purpose of this study was to investigate the altered control of transcriptional regulatory programs which may affect the development of HLHS by using disease-specific induced pluripotent stem (iPS) cells.
Methods and Results: Cardiac tissue specimens were obtained from patients with congenital heart diseases during operation, and cardiac progenitor cells (CPCs) were isolated and infected with retroviruses encoding human transcription factors, Oct4, Sox2, Klf4, and c-myc to generate patient-specific iPS cells. Comparative gene expression of HLHS- and biventricle (BV) heart-derived iPS cells was analyzed to dissect the complex genetic circuits that may promote disease phenotype. Both HLHS and BV heart-derived CPCs were reprogrammed to generate disease-specific iPS cells and those showed characteristic human embryonic stem cell signatures, expressed pluripotent markers and alkaline phosphatase, and established iPS cells formed teratoma and could give rise to cardiomyocytes. However, HLHS-iPS cells produced lower cardiomyogenic differentiation potential compared with that from BV-iPS cells. Quantitative gene expression analysis was performed by using 201B7 and BV-derived iPS cells as control cells. HLHS-derived iPS cells showed that a transcriptional repression in Nkx2.5 that acts on the progenitor cell expansion and differentiation in primary heart field, reduced levels of Tbx2 and Notch/Hey signaling for atrioventricular canal and valve formation, repressed expressions of Notch/Hey signaling for LVOT formation, and inhibited Hand1/2 transcripts prerequisite for chamber morphogenesis.
Conclusions: These findings suggest that patient-specific iPS cells may provide potential molecular insights into complex transcriptional regulation that coordinately contribute to cardiac malformations in HLHS.
- Hypoplastic left heart
- Regenerative medicine stem cells
- Single ventricle
- Congenital heart disease
- Gene expression
- © 2013 by American Heart Association, Inc.