Overexpression of eNOS decrease tissue factor (TF) level in CD34+ cells exhibit increased antithrombogenic property in small caliber vascular graft.

Endothelial progenitor cells (EPCs) have reduced expression of eNOS, this may decrease their antithrombogenic property when used as seeding cells for small caliber vascular graft. The aim of this study is to investigate whether overexpression of eNOS in EPCs can increase its antithrombogenic property and regulate tissue factor (TF) level. CD34+ cells were isolated from canine bone marrow. Differentiation of CD34 cells into endothelial cells was inducted by VEGF. Overexpression of eNOS in CD34+ cells were obtained by transfection with eNOS plasmid. TF expression was examined by western blot after TNFα stimulation. Platelets adhesion assay was performed to determine antiplatelet adhesion property of the cells in vitro. The cells were seeded onto the lumimal surface of small caliber vascular graft and implanted in vivo. The thrombopoiesis in vivo were examined by SEM. Transfection with eNOS gene decreased the level of TF in CD34+ cells. The expression of TF increased after stimulation with TNFα in time dependent manner, this effect was abrogated by eNOS gene transfection. Overexpression of eNOS significantly inhibited the platelet adhesion on EPCs in vitro. Over expression of eNOS in CD34+ cells also decreased thrombopoiesis and fibrin adhesion onto the lumimal surface of small caliber vascular graft in vivo. Overexpression of eNOS decrease TF level in CD34+ cells, and increase antithrombogenic property of small caliber vascular graft.