title: Relationship among IL-6, LDL cholesterol and lipid peroxidation.
abstract: Previous studies evidenced a significant reduction in serum cholesterol levels during an episode of acute inflammation. The aim of the present study was to verify the hypothesis of a regulatory role of cytokines through an in vitro model that simulates a situation of vascular inflammation and high levels of LDL or lipoperoxides. Human microvascular endothelial cells-1 were used in all experiments. The cells were exposed for 24 h to increasing doses of LDL, oxidized lipoprotein, and 8-isoprostane (in the absence or presence of SQ29.548, a TXA2 receptor antagonist). Moreover, LDL receptor and oxidized lipoprotein receptor expression analyzed after endothelial cells' incubation with increasing doses of interleukin-6. The ELISA test and quantitative real-time PCR were performed. Endothelial cells showed a significant increase in interleukin-6 medium levels associated with LDL, oxidized LDL and with the degree of oxidation (absence or presence of SQ29.548), while 8-isoprostane did not. Treatment of human microvascular endothelial cells-1 for 24 h with increasing doses of interleukin-6 significantly enhanced LDL receptor and oxidized lipoprotein receptor-1 mRNA expression. Our data suggest the presence of a compensatory mechanism. The induction of a significant increase of IL-6 does not seem to be caused by the presence of the biological activity of 8-isoprostane.
authors.forename: Valter
authors.initials: V
authors.lastname: Lubrano
authors.forename: Morena
authors.initials: M
authors.lastname: Gabriele
authors.forename: Maria Rita
authors.initials: MR
authors.lastname: Puntoni
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Longo
authors.forename: Laura
authors.initials: L
authors.lastname: Pucci
mesh_terms: D008078:Cholesterol, LDL / Q000494:pharmacology*; D015237:Dinoprost / Q000031:analogs & derivatives / Q000494:pharmacology; D042783:Endothelial Cells / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D015850:Interleukin-6 / Q000502:physiology*; D015227:Lipid Peroxidation; D008077:Lipoproteins, LDL / Q000494:pharmacology; D055806:Microvessels / Q000378:metabolism*; D011973:Receptors, LDL / Q000235:genetics; D051127:Scavenger Receptors, Class E / Q000235:genetics
chemical_list: D008078:Cholesterol, LDL; C508600:IL6 protein, human; D015850:Interleukin-6; D008077:Lipoproteins, LDL; C495137:OLR1 protein, human; D011973:Receptors, LDL; D051127:Scavenger Receptors, Class E; C099252:oxidized low density lipoprotein; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost