To explore the mechanisms of the profound plasma cholesterol elevations in familial homozygous hypercholesterolemia (type IIa), cholesterol turnover, sterol balance, cholesterol absorption, and low density lipoprotein studies were carried out under controlled dietary conditions in two sisters (aged 13 and 16). Cholesterol turnover was prolonged. The half-life of the first exponential of the pla...

OBJECTIVE The mechanisms by which apolipoprotein E (apoE) can promote the regression of atherosclerosis are not well understood. This study examined whether apoE can promote atherosclerosis regression independently of lowering plasma cholesterol levels. METHODS AND RESULTS We studied hypomorphic apoE mice (Apoe(h/h)), which express an apoE4-like form of mouse apoE at approximately 2% to 5% of...

Using albumin and crystalloid as the only replacement fluids, the effect of partial plasma exchange on the removal and recovery of normal plasma constituents was studied. The results of 30 procedures on 10 individuals were evaluated. Four patterns of removal are described: reduction in the concentration of fibrinogen and C3 were greater than would be expected based upon the extent of the exchan...

We investigated the effects of moderate hypercholesterolemia and endothelial regrowth on the function of vascular endothelium. Groups of rabbits were fed either a high or low cholesterol diet and subjected to removal of the aortic endothelium or sham-operated. Endothelial removal caused diffuse thickening of the myointima. The high cholesterol diet did not affect the extent of endothelial regen...

A 72-hour incubation of cultured cells with blood sera or plasma of patients suffering from coronary heart disease (CHD) with angiographically assessed coronary atherosclerosis caused a threefold to fourfold elevation of intracellular cholesterol. An elevated cholesterol level in the cells precultured with patients' sera was retained several days after the removal of the examined serum from cul...

Changes in the concentration and composition of serum VLDL, LDL, and HDL were studied in rabbits transferred from Chow diets to cholesterol-free, semipurified diets containing casein or isolated soy protein. During the first week on the casein diet, there was a marked increase in LDL-cholesterol and these higher levels were maintained during the subsequent 3 weeks of the study. Similar but less...

Measurements of cholesterol turnover in man have been reported previously (1-3), but a relationship between turnover and cholesterol concentration has not been demonstrated (3). This may be due, in part, to the complex distribution of cholesterol in the body that renders the interpretation of isotopic data difficult. Cholesterol exists in the body in a number of separate pools that appear to tu...

Oocyte-derived bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) are key regulators of follicular development. Here we show that these factors control cumulus cell metabolism, particularly glycolysis and cholesterol biosynthesis before the preovulatory surge of luteinizing hormone. Transcripts encoding enzymes for cholesterol biosynthesis were downregulated in bot...

Knowledge concerning the formation and transport of esterified cholesterol in plasma is fundamental to an understanding of the mechanisms by which cholesterol is delivered to peripheral tissues from the liver and removed from these tissues for recycling or excretion through the liver. Hepatic cholesterol enters the plasma in man predominantly in the unesterified, or free, form as a component of...

We have previously shown that GFP-tagged human ABCG1 on the plasma membrane (PM) and in late endosomes (LE) mobilizes sterol on both sides of the membrane lipid bilayer, thereby increasing cellular cholesterol efflux to lipid surfaces. In the present study, we examined ABCG1-induced changes in membrane cholesterol distribution, organization, and mobility. ABCG1-GFP expression increased the amou...