Endothelial cells cultured on engineered vascular grafts are able to transduce shear stress

In vitro endothelialization of small-diameter vascular prostheses confluently lined with cultured autologous endothelial cells (ECs) before clinical implantation improves their patency. Many authors have studied the effects of shear stress on ECs seeded on various substrates showing activation of mitogen-activated protein (MAP) kinases. Very few studies have reported any functional EC response to shear stress when they are seeded on vascular grafts. The purpose of this in vitro study was to investigate whether ECs were able to transduce shear stress. Human saphenous vein ECs were seeded on 6 mm fibrin-glue-coated grafts, then submitted to 15 dyn/cm(2) for 10, 30, and 120 min. Cell lysates were submitted to Western blot analysis to detect phosphorylated ERK 1/2 and p38. ERK 1/2 activation was observed at 10 min (1.6 fold) followed by a lower activation than under static conditions at 30 and 120 min. Shear stress induced a significant increase in p38 phosphorylation (2.5 fold) at 10 and 30 min, decreasing at 120 min. Thus, ECs are able to transduce shear stress in an in vitro model in closed clinical conditions, but the ERK 1/2 and p38 temporal activation profile is different. We provide new insights into the validity of the vascular tissue engineering approach.