Inability of plasma high-density lipoproteins to inhibit cell adhesion molecule expression inhuman coronary artery endothelial cells.
31 - 38.
High-density lipoproteins (HDL) have several antiatherogenic actions, including the ability to sequester cellular cholesterol, to protect low-density lipoproteins from oxidation and to inhibit platelet aggregation. An early event in atherogenesis is the adhesion and recruitment of blood monocytes, a process mediated by cell adhesion molecules (CAMs), including vascular cell adhesion molecule-1 (VCAM-1) which is rapidly synthesized by endothelial cells in response to cytokines. It has been reported that HDL limits CAM expression in cultured human umbilical vein endothelial cells (HUVECs), implying that HDL also protects at an early stage in lesion development. Here, we have studied HDL suppression of CAM induction in human coronary artery endothelial cells (HCAECs), a model directly relevant to blood vessels susceptible to atherosclerosis. Arterial endothelial cells were preincubated with increasing amounts of total HDL, or different subfractions, and then activated with the inflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha). Flow cytometric analysis failed to detect any downregulation of VCAM-1 or E-selectin expression by HDL in this model of vascular endothelium. Moreover, we were unable to confirm that HDL could suppress CAM induction in well-characterized, low-passage HUVECs, even though positive controls, 17 beta -estradiol or a nitric oxide donor, did cause downregulation and factors such as variability in donors and HDL preparation, or culture conditions, were excluded. We tentatively conclude that, as isolated HDL. did not downregulate CAM expression in cultured HCAECs or HUVECs, attenuation of CAM induction in arterial endothelium is unlikely to contribute to HDL antiatherogenic actions in vivo. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.
|Title:||Inability of plasma high-density lipoproteins to inhibit cell adhesion molecule expression inhuman coronary artery endothelial cells|
|Keywords:||atherosclerosis, E-selectin, human umbilical vein endothelial cells, inflammatory cytokines, vascular cell adhesion molecule-1, APOLIPOPROTEIN-A-I, INDUCED PLATELET-AGGREGATION, CYTOKINE-INDUCED EXPRESSION, HUMAN UMBILICAL VEIN, VCAM-1 EXPRESSION, ATHEROSCLEROTIC LESIONS, DEFICIENT MOUSE, GENE-EXPRESSION, TRANSGENIC MICE, LIVER-DISEASE|
|UCL classification:||UCL > School of Life and Medical Sciences
UCL > School of Life and Medical Sciences > Faculty of Medical Sciences
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