The physiological role of murine scavenger receptor class B type I (SR-BI) was evaluated by in vivo clearances of human HDL3 and LDL in normal and SR-BI knockout (KO) mice. In normal mice, cholesteryl esters (CEs) were removed faster than proteins, indicating a selective uptake process from both HDL3 and LDL. SR-BI KO mice showed 80% losses of HDL-CE selective uptake and the complete loss of LD...

Enhanced oxidative stress is implicated in the development of atherosclerosis in humans and animal models. F(2)-isoprostanes are formed in vivo via free radical peroxidation of arachidonic acid, and their quantification has allowed assessment of oxidative stress in vivo. F(2)-isoprostanes associate with lipids, although their distribution in human plasma lipoproteins is unknown. Our aim was to ...

DETAILED STUDIES OF THE HIGH DENSITY LIPOPROTEINS FROM THREE PATIENTS WITH ABETALIPOPROTEINEMIA HAVE REVEALED THE FOLLOWING PRINCIPAL ABNORMALITIES: 1) High density lipoprotein 3 (HDL3) is reduced in both absolute and relative concentration, although HDL2 is present in normal amounts. 2) The phospholipid distribution of both HDL fractions is abnormal, with low concentrations of lecithin and an ...

Expression of apolipoprotein (apo) E by macrophages is tightly regulated by cellular cholesterol content. We have investigated a potential modulating role for apoE on macrophage cholesterol homeostasis by stably transfecting the J774 macrophage, which does not express its endogenous apoE gene, with a human apoE cDNA expression vector and comparing cholesterol homeostasis in this cell line with ...

Degranulated mast cells are present in human fatty streaks. Chymase in granules released from degranulated rat serosal mast cells, i.e., in granule remnants, proteolyzes human high density lipoprotein3 (HDL3), and so reduces its ability to induce cholesterol efflux from macrophage foam cells in vitro. In this study we found that remnant chymase, by proteolyzing human serum and human aortic inti...

Cholesteryl ester transfer protein (CETP) deficiency causes elevated high-density lipoprotein-cholesterol (HDL-C) levels; its impact on HDL functionality however remains elusive. We compared functional and compositional properties of HDL derived from 9 Caucasian heterozygous CETP mutation carriers (splice-site mutation in intron 7 resulting in premature truncation) with those of 9 age- and sex-...

BACKGROUND We previously showed that low-saturated-fat dietary intervention from infancy until 5 years of age safely and effectively reduced serum cholesterol concentration. We now report how such intervention influenced serum lipids, LDL particle size, and HDL subfractions in children when they reached the age of 7 years. METHODS AND RESULTS Healthy 7-month-old infants (n=1062) were randomiz...

Androgen effects on lipoproteins, mainly high density lipoprotein (HDL), could be exerted by a direct interaction of testosterone (T) or dihydrotestosterone (DHT) with liver androgen receptors. To assess if T needs to be converted into DHT to affect lipid metabolism, 13 patients were studied, affected with benign prostatic hyperplasia (BPH) and treated with an inhibitor of 5 alpha-reductase (fi...

BACKGROUND High density lipoprotein (HDL) particles are heterogeneous in composition, structure, size, and may differ in conferring protection against cardiovascular disease. HDL associated enzyme, paraoxonase-1 (PON1), has an important role in attenuation of atherogenic low density lipoprotein (LDL) oxidation. The aim of this study was to investigate the associations between HDL particle size ...

We investigated high density lipoprotein (HDL) subfractions in abetalipoproteinemia (ABL) using rate zonal ultracentrifugation. In ABL, HDL2 is the major subfraction, 65% of total mass compared to less than 10% in normal subjects with similar HDL levels. HDL2 and HDL3 in ABL (n = 3) are larger and lighter than in normals (n = 3), with mean diameters of 136 +/- 19 A and 100 +/- 12 A, respectivel...