In vitro shear stress modulates antithrombogenic potentials of human endothelial progenitor cells

Background Recent study suggested that endothelial progenitor cells (EPCs), a novel therapeutic approach for endothelial dysfunction, present limited antithrombogenic potentials. However, few attempts have been done to improve the antithrombogenic potentials of EPCs. Our previous study proved that in vitro shear stress contributes to the increase in t-PA production by human EPCs. Here, we further investigated whether in vitro shear stress contributes to the secretion of antithrombogenic substances including plasminogen activator inhibitor-1 (PAI-1) and prostaglandin 12 (PGI(2)) by human EPCs. Methods The peripheral blood mononuclear cells of healthy subjects were induced into EPCs. Then the human EPCs were treated with four levels of shear stress including stationary condition low media and high flow shear stress. The production of PAI-1 and 6-keto-prostaglandin Fl(1 alpha)(6-Keto-PGF(1 alpha)) by human EPCs with shear stress treatment were measured. Results In vitro medium and high flow shear stress inhibited PAI-1 secretion by human EPCs, but low flow shear stress had no effect on PAI-1. secretion by human EPCs. All levels of shear stress significantly increased 6-Keto-PGF(1 alpha) production by human EPCs in a dose-dependent manner. Conclusions The present study demonstrates that in vitro shear stress can promote PGI(2) secretion and inhibit PAI-1 secretion by human EPCs, which improves the antithrombogenic potentials of human EPCs.