The effects of human platelet lysate versus commercial endothelial growth medium on the endothelial differentiation potential of human amniotic fluid mesenchymal stem cells

To differentiate stem cells into endothelial cells, vascular endothelia growth factors (VEGF) serve as the major signal for stimulating the cells. However, there are other cytokines or growth factors associated with endothelial cell development and differentiation. Human platelet lysate (hPL) has been a promising reagent in cell-based therapy since it is considered as a source of bioactive molecules and growth factors. The aim of this study was to investigate the in vitro differentiation of human amniotic fluid mesenchymal stem cells (hAF-MSCs) into endothelial-like cells under hPL together with VEGF or endothelial cell growth medium 2 (EGM-2), a commercially induced medium. In this study, hAF-MSCs were isolated from human amniotic fluid cells (hAFCs) using the direct adherence method. The cells expressed CD44, CD73, CD90, and HLA-ABC at high levels and expressed Oct-4 (octamer-binding transcription factor 4) at low levels. The cells were negative for CD31, CD34, CD45, CD105 and HLA-DR. This study found that hAF-MSCs induced with hPL and VEGF had the ability to differentiate into endothelial-like cells by presenting endothelial specific markers (vWF, VEGFR2 and eNOS), forming a network-like structure on Matrigel, and producing nitric oxide (NO). This outcome was similar to those of experiments involving EGM-2 induced cells. The present findings indicate that hPL + VEGF can induce hAF-MSCs to express endothelial cell characteristics. Our findings represent an important step forward in the development of a clinically compliant process for the production of endothelial cell-derived hAF-MSCs, and their subsequent testing in future clinical trials.