Amniotic fluid-derived stems isolation, characterization and differentiation

Amniotic fluid-derived stems (AFS) are widely accepted as a new powerful tool for basic research as well for the establishment of new stem-cell-based therapy concepts. Here we induced AFS cells to differentiate into cardiomyocytes and endothelial cells through the administration of mixture of hyaluronan with butyric and retinoic acids (HA+BU+RA). First the cells, isolated from amniotic fluid, have been immusnoselected using an anti-c-kit antibody, expanded in vitro and characterized by flow cytometry. The data obtained show that the antigenic profile of AFS cells is analogous to mesenchymal stem cells (MSCs). AFS cells were trated with HA+BU+RA to induce cardiac differentiation. The molecule demonstrated to be able to induce the cardiomyogenic process in these cells activating the expression pattern typical of the cardiac lineage commitment (GATA4, Nkx2.5 and prodynorphin genes). Moreover AFS cells (under the HA+BU+RA induction) are able to form fully differentiated cardiomyocytes. In fact immunofluorescence and flow cytometry analysis show the expression of α-sarcomeric actinin and MYH (intracellular cardiospecific marker proteins). Interestingly, exposure to HA+BU+RA induces the expression of von Willebrand factor (vWF) a gene tightly involved in vasculogenesis and angiogenesis and led to the development of vWF-expressing endothelial cells