Effect of Oxidative Stress on the Status of Adhesion Molecules, Nuclear Receptors and Cholesterol Flux in Endothelial Cells: Priming of Monocytes

Abstract: Circumstantial evidence suggests that oxidative stress plays a crucial role in the initiation and progression of atherosclerosis, but little is known about the relationship between oxidative stress per se, cholesterol transport and endothe-lial cell integrity. The aim of the present work is to tackle this issue by treating human umbilical vein endothelial cells (HUVEC) with iron/ascorbate for 4 and 8 hours and by subsequently evaluating the cholesterol fl ux, the gene expression status of cho-lesterol transporters, nuclear receptors and adhesion molecules, as well as the cellular adhesion of THP-1 monocytes to HUVEC. The incubation of HUVEC with iron/ascorbate resulted in marked lipid peroxidation as refl ected by high malo-ndialdehyde levels, which were reduced by pre-treatment with the antioxidant Trolox. Our experiments could not reveal any modifi cations in the protein and gene expression of the transporters (ABCA1, SR-BI, LOX-1), the adhesion molecules (VCAM-1, ICAM-1 and E-selectin) and the nuclear receptors (PPARs and LXRs) under the infl uence of iron/ascorbate