Differentiation of Human Embryonic Stem Cells to Endothelial Progenitor Cells on Laminins in Defined and Xeno-free Systems

A major hurdle for in vitro culturing of primary endothelial cells (ECs) is that they readily de-differentiate, hampering their use for therapeutic applications. Human embryonic stem cells (hESCs) may provide an unlimited cell source; however, most current protocols deriving endothelial progenitor cells (EPCs) from hESCs use direct differentiation approaches albeit on undefined matrices, yet final yields are insufficient. We developed a method to culture monolayer hESCs on stem-cell niche laminin (LN) LN511 or LN521 matrix. Here, we report a chemically defined, xeno-free protocol for differentiation of hESCs to EPCs using LN521 as the main culture substrate. We could generate ~95% functional EPCs defined as VEGFR2+CD34+CD31+VE-Cadherin+. RNA sequencing analyses of hESCs, EPCs and primary HUVECs showed differentiation-related ECs expression signatures, regarding basement membrane composition, cell-matrix interactions, and changes in endothelial lineage markers. Our results may facilitate production of stable ECs for treatment of vascular diseases and in vitro cell modeling.