Functional Heterogeneity of Endothelial Cells Derived from Human Pluripotent Stem Cells

Specification of endothelial cells (ECs) into arterial, venous, and lymphatic cells is a crucial process of vascular development, and expanding our knowledge about EC specification from human pluripotent stem cells (hPSCs) will aid the design of optimal strategies for producing desired types of ECs for therapies. In our prior studies, we revealed that hPSC-derived VE-cadherin(V)⁺CD31⁺CD34⁺ ECs are heterogeneous and include at least three major subsets with distinct hemogenic properties: V⁺CD43/235a^-CD73^- hemogenic endothelial progenitors (HEPs), V⁺CD43^loCD235a⁺73^- angiogenic hematopoietic progenitors (AHPs), and V⁺CD43/235a^-73⁺ non-HEPs. In this study, using angiogenesis assays, we demonstrated that ECs within these subsets have distinct endothelial colony- and tube-forming properties, proliferative and migratory properties, and endothelial nitric oxide synthase and inflammatory cytokine production potentials. Culture of isolated subsets in arterial, venous, and lymphatic conditions revealed that AHPs are skewed toward lymphatic, HEPs toward arterial, and non-HEPs toward venous differentiation in vitro. These findings suggest that selection and enhancement of production of a particular EC subset may aid in generating desirable EC populations with arterial, venous, or lymphatic properties from hPSCs.