Lipid and Apoprotein Composition of HDL in Partial or Complete CETP Deficiency

High-density lipoprotein (HDL) is a lipid and protein complex that consists of apolipoproteins and lower level HDL-associated enzymes. HDL dysfunction is a factor in atherosclerosis and decreases patient survival. Mass spectrometry- (MS-) based proteomics provides a high throughput approach for analyzing the composition and modifications of complex HDL proteins in diseases. HDL can be separated according to size, surface charge, electronegativity, or apoprotein composition. MS-based proteomics on subfractionated HDL then allows investigation of lipoprotein roles in diseases. Herein, we review recent developments in MS-based quantitative proteomic techniques, HDL proteomics and lipoprotein modifications in diseases, and HDL subfractionation studies. We also discuss future directions and perspectives in MS-based proteomics on HDL.

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Apoprotein composition of very low density lipoproteins of human serum.

Journal of Clinical Investigation ◽

10.1172/jci108245 ◽

1975 ◽

Vol 56 (6) ◽

pp. 1622-1634 ◽

Cited By ~ 291

Author(s):

J P Kane ◽

T Sata ◽

R L Hamilton ◽

R J Havel

Keyword(s):

Human Serum ◽

Low Density Lipoproteins ◽

Low Density ◽

Very Low Density Lipoproteins ◽

Apoprotein Composition

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LDL and HDL enriched in triglyceride promote abnormal cholesterol transport

The Journal of Lipid Research ◽

10.1194/jlr.m100431-jlr200 ◽

2002 ◽

Vol 43 (8) ◽

pp. 1264-1274 ◽

Cited By ~ 42

Author(s):

Josephine W. Skeggs ◽

Richard E. Morton

Keyword(s):

Protein Concentration ◽

Cholesterol Biosynthesis ◽

Fold Increase ◽

Cholesterol Transport ◽

Polar Components ◽

Transfer Protein ◽

Protease Digestion ◽

J774 Cells ◽

Apoprotein Composition ◽

Lipoprotein Composition

Hypertriglyceridemia induces multiple changes in lipoprotein composition. Here we investigate how one of these modifications, triglyceride (TG) enrichment, affects HDL and LDL function when this alteration occurs under conditions in which more polar components can naturally re-equilibrate. TG-enriched lipoproteins were produced by co-incubating VLDL, LDL, and HDL with cholesteryl ester (CE) transfer protein. The resulting 2.5-fold increase in TG/CE ratio did not measurably alter the apoprotein composition of LDL or HDL, or modify LDL size. HDL mean diameter increased slightly from 9.1 to 9.4 nm. Modified LDL was internalized by fibroblasts normally, but its protein was degraded much less efficiently. This likely reflects an aberrant apolipoprotein B (apoB) conformation, as suggested by its resistance to V8 protease digestion and altered LDL electrophoretic mobility. TG-enriched LDL ineffectively down-regulated cholesterol biosynthesis compared with control LDL at the same protein concentration, but was equivalent in sterol regulation when compared on a cholesterol basis. TG-enriched HDL promoted greater net cholesterol efflux from cholesterol-loaded J774 cells. However, cholesterol associated with TG-enriched HDL was inefficiently esterified by lecithin:cholesterol acyltransferase, and TG-enriched HDLs were poor donors of CE to HepG2 hepatocytes by selective uptake.We conclude that TG-enrichment, in the absence of other significant alterations in lipoprotein composition, is sufficient to alter both cholesterol delivery and removal mechanisms. Some of these abnormalities may contribute to increased coronary disease in hypertriglyceridemia.

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High-density lipoprotein subpopulations as substrates for the transfer of cholesteryl esters to very-low-density lipoproteins

Biochemical Journal ◽

10.1042/bj2700441 ◽

1990 ◽

Vol 270 (2) ◽

pp. 441-449 ◽

Cited By ~ 16

Author(s):

M A Lasunción ◽

A Iglesias ◽

N Skottová ◽

E Orozco ◽

E Herrera

Keyword(s):

High Density Lipoprotein ◽

Low Density Lipoprotein ◽

Specific Radioactivity ◽

Density Lipoprotein ◽

Cholesteryl Oleate ◽

High Density ◽

Low Density ◽

Very Low Density Lipoproteins ◽

Apoprotein Composition

1. Human total HDL (high-density lipoprotein), HDL2 and HDL3 were labelled in vitro by incubation with lipoprotein-deficient serum (LPDS) which contained either [3H]cholesteryl oleate or [14C]cholesterol under different conditions. The lipoproteins were then subfractionated by heparin-Sepharose column chromatography, and three subfractions (A, B and C) were successively eluted from each preparation of HDL, HDL2 and HDL3. When the labelling was done at 37 degrees C for 17 h, the subfractions were homogeneously labelled with [3H]cholesteryl oleate. However, when it was performed for only 30 min at 4 degrees C, the subfractions showed marked differences in the 3H specific radioactivity, which was much higher in the C fractions than in the others. 2. 3H-labelled HDL2 and HDL3 subfractions behaved differently under the precipitant action of heparin-Mn2+; fraction C (the richest in apolipoprotein E) produced the largest amount of radioactive and chemical precipitate. More 3H radioactivity, but not the cholesterol, was precipitated from HDL2 or HDL3 by the reagent, demonstrating that 3H-labelled HDL2 and HDL3 behave like their fraction C, which becomes labelled to the highest specific radioactivity despite having the smallest mass. 3. The incubation of 3H-labelled HDL subfractions with human LPDS and very-low-density lipoprotein (VLDL) at 37 degrees C increased the quantity of 3H radioactivity that was precipitated, in proportion to the amount of VLDL present in the media. These changes were attributable to the action of cholesterol ester transfer protein, since they did not occur at 4 degrees C or when human LPDS was replaced with rat LPDS. 4. Kinetics of the transfer of HDL [3H]cholesteryl oleate to VLDL showed a greater apparent Vmax for fractions A than for fractions B from either HDL2 or HDL3, whereas the apparent Km values were very similar, which suggest that this transfer process is influenced by the apoprotein composition of the donor lipoprotein.

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Replacement of endogenous phospholipids in rat plasma lipoproteins during intravenous infusion of an artificial lipid emulsion

Canadian Journal of Biochemistry ◽

10.1139/o78-095 ◽

1978 ◽

Vol 56 (6) ◽

pp. 630-639 ◽

Cited By ~ 41

Author(s):

A. Kuksis ◽

W. C. Breckenridge ◽

J. J. Myher ◽

G. Kakis

Keyword(s):

Intravenous Infusion ◽

Egg Yolk ◽

Rat Plasma ◽

Plasma Lipoproteins ◽

Complete Analysis ◽

Cholesteryl Esters ◽

Apparent Clearance ◽

Male Wistar Rats ◽

Gradual Accumulation ◽

Apoprotein Composition

Male Wistar rats, weighing 250–300 g, were intravenously infused (0.33 ml/h per 100 g body weight) with an artificial emulsion of soybean triacylglycerols and egg yolk phospholipids (Intralipid) for various periods of time ranging from a few hours to a few days. About 0.5 h after the infusion, the animals were sacrificed, various classes of plasma lipoproteins were isolated by centrifugation, and the total lipid profiles of the fractions were determined by high temperature gas chromatography. The lipoproteins collected after 24 h of infusion were subjected to a complete analysis of the molecular species of the various lipid classes. It was shown that continuous intravenous infusion of Intralipid, despite rapid apparent clearance of the visible lipid particles, resulted in a gradual accumulation of exogenous phosphatidylcholine and sphingomyelin, free cholesterol, and plant sterols in the plasma, which displaced the endogenous phospholipids and sterols from the various lipoproteins. At 24 h, about 70% of the endogenous phospholipid of all the plasma lipoproteins was replaced by egg yolk phospholipids of the Intralipid. Under the same conditions, no displacement nor exchange was observed of endogenous cholesteryl esters for exogenous triacylglycerols in any of the lipoprotein classes. Intralipid infusion for periods up to 3 days results in a limited further displacement of endogenous phospholipids by exogenous lipids in the plasma lipoproteins, but a complete substitution was not achieved because of a continued secretion of lipoproteins containing endogenous phospholipids. The infusion of Intralipid led to a significant increase in the proportion of the phospholipid and free sterol in all lipoproteins, which decreased the calculated diameter of the particles by about one-half. Only minor changes were seen in the lipid to protein ratios of the lipoproteins and in their apoprotein composition.

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Concentrations of high-density lipoprotein subfraction HDL2 and lipoprotein A-I in a random population of healthy subjects

Clinical Chemistry ◽

10.1093/clinchem/37.12.2111 ◽

1991 ◽

Vol 37 (12) ◽

pp. 2111-2113 ◽

Cited By ~ 4

Author(s):

D Roche ◽

M L Migueres ◽

N T Lequang ◽

M Burstein ◽

O G Ekindjian ◽

...

Keyword(s):

Low Cost ◽

Density Lipoprotein ◽

High Density ◽

High Density Lipoproteins ◽

Strongly Correlated ◽

Lipoprotein A ◽

The Difference ◽

Apoprotein Composition ◽

Hdl2 Cholesterol

Abstract High-density lipoproteins (HDL) are now currently subdivided according either to density and size—HDL2 and HDL3—or to surface apoprotein composition—lipoprotein A-I (LpA-I) without A-II, and LpA-I:A-II. In samples from blood bank donors (60 women, 47 men), we evaluated HDL subclasses, LpA-I particles, and other classic risk factors for atherosclerosis and compared them with each other. We found a good correlation between HDL2 and LpA-I (r = 0.74, P < 0.001), the correlation being more marked in women (r = 0.74) than in men (r = 0.67). LpA-I was also strongly correlated with total apolipoprotein A-I (apoA-I) (r = 0.61), which suggests that LpA-I represents a significant portion of the variable pool of apoA-I. By contrast, LpA-I:A-II but not LpA-I was correlated with HDL3, confirming the preferential association of LpA-I with HDL2. The difference between the sexes was more marked for HDL2 (+66% in women) than for LpA-I (+25%). We conclude that in normolipemic subjects the size of the HDL2 pool depends on that of LpA-I. Considering the speed and low cost of the assay, determination of HDL2 cholesterol might be a useful tool for assessing cardiovascular risk.

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