Venular and Arterial Endothelial Cells Differ in their Expression of Adhesion Molecules and in their Ability to Degrade the Subendothelial Basement Membrane

Abstract

Endothelial cells (EC) play a central role in inflammation by expressing adhesion molecules and also may prepare the subendothelial basement membrane (BM) for invasion by leukocytes. Usually the majority of adhering and extravasating leukocytes in inflammatory responses are found in postcapillary venules. In an attempt to explain this selectivity, human umbilical cord venular and arterial EC were examined for their expression of adhesion molecules, and their ability to degrade the subendothelial BM in response to proinflammatory cytokines.The cytokine induced expression of the adhesion molecules E-selectin, VCAM-1 and ICAM-1 was shown to be similar between early passage venular and arterial EC. However, a number of striking differences between venular and arterial EC were demonstrated. First, arterial EC expressed significant constitutive levels of VCAM-1 whereas venular EC expressed low constitutive levels of VCAM-1. Second, TNFα and IL-lα were virtually unable to induce adhesion molecule expression on l...