Human platelets contain a mitogen, the platelet-derived growth factor (PDGF), that stimulates the proliferation of a variety of cell types in culture and that may play a role in atherogenesis. Studies were conducted to explore the effects of PDGF on low density lipoprotein (LDL) receptor activity of cultured human fibroblasts. The PDGF utilized in these studies was partially purified from human...

Fully oxidized LDL (OxLDL) is believed to contribute to atherogenesis in part by virtue of uptake into macrophages via specific scavenger receptors. This phenomenon results in the formation of cholesterol-loaded foam cells, a major component of atherosclerotic lesions. The present study is directed at examining the effects of OxLDL and minimally oxidized LDL (MM-LDL) on scavenger receptor expre...

Regulation of low density lipoprotein (LDL) receptor activity of cultured human skin fibroblasts was studied by measuring 4 degrees C binding of 125I-LDL after cells were incubated at 37 degrees C with medium containing varying lipoprotein and serum compositions. When cells grown on medium containing 10% human whole serum were exposed to medium containing 10% human lipoprotein-deficient serum, ...

Murine P388D1 macrophages have a receptor pathway that binds human hypertriglyceridemic very low density lipoproteins (HTG-VLDL) that is fundamentally distinct from the LDL receptor pathway. Trypsin-treated HTG-VLDL (tryp-VLDL), devoid of apolipoprotein (apo)-E, fail to bind to the LDL receptor, yet tryp-VLDL and HTG-VLDL cross-compete for binding to P388D1 macrophage receptors, indicating that...

Lovastatin and simvastatin which are very potent cellular cholesterol biosynthesis inhibitors, significantly affect the plasma lipoprotein concentration. After incubation of plasma with 14C-labelled compounds, radioactivity was found in all lipoprotein fractions but mainly (40%) in high density lipoprotein (HDL), and in the lipoprotein-deficient plasma fraction (20-30%). Drug-treated lipoprotei...

Very low density lipoproteins (VLDL), Sf60 to 400, from normolipemic individuals do not suppress 3-hydroxy-3-methylglutaryl-CoA reductase activity in cultured normal human fibroblasts at concentrations 20fold higher than those of low density lipoproteins (LDL) that give total suppression. To determine if these VLDL contain all of the structural elements necessary for receptor-mediated suppressi...

Oxidation of low density lipoprotein (LDL) by cells of the arterial wall or in the presence of copper ions was shown to result in the peroxidation of its fatty acids as well as its cholesterol moiety. LDL incubation with cholesterol oxidase (CO) resulted in the conversion of up to 85% of the lipoprotein unesterified cholesterol (cholest-5-en-3-ol) to cholestenone (cholest-4-en-3-one) in a dose-...

BACKGROUND Oxidation of LDL produces a series of biologically active, oxidized lipids. Among them, isoprostanes, and in particular iPF(2alpha)-III, seem to be crucial in mediating some of the key cellular events seen in myocardial ischemia-reperfusion injury. METHODS AND RESULTS Minimally modified LDL (MM-LDL) triggers a dose-dependent, very rapid neutrophil adhesion to human fibrinogen. Rapi...

Background—Oxidation of LDL produces a series of biologically active, oxidized lipids. Among them, isoprostanes, and in particular iPF2 -III, seem to be crucial in mediating some of the key cellular events seen in myocardial ischemia-reperfusion injury. Methods and Results—Minimally modified LDL (MM-LDL) triggers a dose-dependent, very rapid neutrophil adhesion to human fibrinogen. Rapid adhesi...