Distinct phenotype and proteomic signature of peripheral blood-endothelial colony-forming cells of subjects with varied cardiovascular disease risks

Endothelial progenitor cells (EPCs) are circulating endothelial precursors shown to incorporate into foci of neovascularisation. Herein, we describe phenotypic characteristics of an EPC sub-type called endothelial colony-forming cells (ECFCs). Peripheral blood-isolated ECFCs expressed endothelial and progenitor surface antigens and displayed cobblestone-patterned colonies with clonal proliferative and angiogenic capacities in vitro. ECFCs demonstrated endothelial cell-like shear stress responses including cell alignment and PECAM-1 expression. Proteomic comparison with an endothelial reference population (human umbilical vein endothelial cells) confirmed a similar proteomic profile. Hierarchical clustering revealed two distinct ECFC clusters with differences in cell growth, proliferation and angiogenesis capacities. The cluster with compromised functionality was also associated with elevated blood pressure and impaired lipid profile. Our findings described an endothelial-like phenotype of blood-derived ECFCs with distinctive proteomic signatures based on cellular and clinical characteristics. ECFCs may aid in identifying novel mechanisms associated with cardiovascular disease risk and new targets to enhance angiogenesis.