The Response of Human Umbilical Vein Endothelial Cells Under Complicated Flow Conditions

ABSTRACT

PURPOSE: Endothelial cells (ECs) are exposed to continuous shear stress from their birth and also respond to the hemodynamic environmental changes which may be localizing factor in vascular diseases, such as atherosclerosis. The hemodynamic shear stress is implicated in the pathogenesis of atherosclerosis, thrombosis, and also restenosis. The objective of this study is to investigate the morphological and molecular biological changes of vein ECs under complicated flow flield which could occur in the anastomosis site of the autogenous vein bypass graft. METHOD: We developed a laminar flow chamber for the normal vessel and a sudden expansion flow chamber to simulate the recirculation or the stagnation zone of vascular graft. RESULT: Normal flow shear stress transformed ECs from random oriented polygonal, cobblestone shape to elongated shape aligned along the flow direction. However the stagnation and flow separation zone could not show the morphologic change of ECs and could be the region of low shear stress prone for intimal hyperplasia and atherosclerosis initiation. CONCLUSION: It also represents that the ECs can sense the magnitude and the direction of the flow shear stress and change their phenotype through the remodeling of the actin microfilaments.