Abstract 1071: Amniotic Fluid Derived Stem Cells for Cardiac Therapeutics
Cell therapy has been proposed as a means to promote the regeneration of injured heart muscle. We have established lines of broad spectrum multipotent stem cells derived from primitive fetal cells present in human and mouse amniotic fluid (AFS) cells. AFS cells offer several advantages: They are easy to isolate and grow (no feeder layers needed), are highly expansive including clonal growth and they can differentiate into all germ layers. In this study, we hypothesize that AFS cells can differentiate into cardiac muscle cells and be used for cardiac tissue regeneration. AFS cells were treated with 5-aza-2-deoxycytidine to induced cardiogenic differentiation. The cells were analyzed for expression of myogenic and cardiogenic markers. AFS-derived cardiomyocytes were seeded on collagen scaffolds and preconditioned in a bioreactor system with cyclic strain stimulation, mimicking the wall motion of the native heart muscle. Lastly, we used an ischemic injury model in mice to test the ability of the Lac Z+ AFS cells to survive and integrate after direct injection into the myocardium. We analyzed integration by histology and function by measuring infarct size, echocardiography, and Magnetic Resonance Imaging (MRI). We observed that by 10 to 20 days after induction, AFS cells stained positively for cardiomyocyte markers including troponin I, troponin T, α-actinin. RT-PCR analysis revealed expression of cardiomyocyte markers including GATA-4 and MEF2C. AFS-derived cardiomyocytes preconditioned in the bioreactor showed muscle tissue organization and contraction. Histological assessment of AFS cells injected into injured mouse hearts indicated that these cells survived and integrated into the myocardium. Functional studies were performed in controls, ligated and cell treated groups. Data showed a functional improvement in the cell treated group compared to ligated group. These results demonstrate that multipotent stem cells derived from amniotic fluid may aid cardiac regeneration. These cells represent a promising novel source of cells for therapy of a verity of cardiac diseases.