[Activin A and BMP-4 induce cardiomyocyte-like cells differentiation of human amniotic epithelial cells]

Amniotic epithelial cells (AECs) have been expected to be a good cell source for stem cell-based cardiac repair. Activin A signaling is required for cardiac differentiation in human embryonic stem cells (ESCs), and bone morphogenetic protein-4 (BMP-4) is an important regulator that controls stem cell fates. Previous study has established an efficient protocol to generate cardiomyocytes from human ESCs via induction with Activin A and BMP-4. The aim of present study was to test the hypothesis that Activin A and BMP-4 could also induce AECs to differentiate into cardiomyocytes in vitro. Human AECs (hAECs) were isolated from human term placenta by trypsin digestion according to the previous reports. Freshly isolated hAECs were examined to detect the expression of cytokeratin 19 by immunocytochemistry. High-density undifferentiated hAECs at passage 1 were sequential treated with 100 ng/ ml human recombinant Actvin A and 10 ng/ml BMP-4. The expression of cardiac-specific genes was examined before and after in vitro induction of cellular differentiation. Freshly isolated hAEC could express cytokeratin 19, the specific marker of epithelial cells. The data showed that hAECs treated with Activin A and BMP-4 were able to express cardiac-specific genes, including Nkx2.5 and alpha-actinin. Our results demonstrated that Activin A and BMP-4 could induce cardiomyocyte differentiation of hAECs, which might be a novel approach to induce differentiation of AECs into cardiomyocytes-like cells.