Lipopolysaccharide impaired the functional activity of endothelial colony-forming cells.

Background: Recent studies have shown that endothelial progenitor cells (EPCs) contribute to lung repair after lipopolysaccharide (LPS)-induced lung injury and infusion of LPS decreased early EPCs in human peripheral blood. However, the effects of LPS on endothelial colony-forming cells (ECFCs) remain to be determined.

Objective: To investigate possible effects of LPS on the functional activity of ECFCs.

Methods: ECFCs were isolated from human umbilical cord blood and characterized. ECFCs at passages 3-5 were treated for 24 h with either LPS or vehicle control. Their viability, migration and in vitro vasculogenesis activity were assayed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, modified Boyden chamber and in vitro angiogenesis assays, respectively. ECFC adhesion was assessed by replating cells on fibronectin-coated dishes and subsequent counting of adherent cells.

Results: Incubation with LPS dose-dependently inhibited the viable, migratory, adhesive and in vitro vasculogenesis capacity of ECFCs.

Conclusion: LPS impaired the functional activity of ECFCs.