Neutrophil–lymphocyte ratio is associated with low high-density lipoprotein cholesterol in healthy young men

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Duran Tok

2014-04-01

Full Text Available Objective: It has been reported that the neutrophil–lymphocyte ratio is significantly elevated in patients with low high-density lipoprotein cholesterol (<35 mg/dL. But in this study, some patients had hypertension that may have affected the neutrophil–lymphocyte ratio. This study consisted of 1274 asymptomatic healthy young men. In contrast with the previous study, we investigated the neutrophil–lymphocyte ratio in healthy young men with low high-density lipoprotein cholesterol compared with controls. Methods: We studied 1274 asymptomatic young males (military personnel screening who underwent routine health check-up. Of them, 102 subjects had low high-density lipoprotein cholesterol. Results: The neutrophil–lymphocyte ratio was significantly higher among the men with low high-density lipoprotein cholesterol than that of the control group (P < 0.001. Conclusion: We conclude that the neutrophil–lymphocyte ratio is significantly elevated in asymptomatic healthy young men with low high-density lipoprotein cholesterol compared with control participants.

[Residual risk: The roles of triglycerides and high density lipoproteins].

Science.gov (United States)

Grammer, Tanja; Kleber, Marcus; Silbernagel, Günther; Scharnagl, Hubert; März, Winfried

2016-06-01

In clinical trials, the reduction of LDL-cholesterol (LDL-C) with statins reduces the incidence rate of cardiovascular events by approximately one third. This means, that a sizeable "residual risk" remains. Besides high lipoprotein (a), disorders in the metabolism of triglyceride-rich lipoproteins and high density liproteins have been implicated as effectors of the residual risk. Both lipoprotein parameters correlate inversely with each other. Therefore, the etiological contributions of triglycerides and / or of HDL for developing cardiovascular disease can hardly be estimated from either observational studies or from intervention studies. The largely disappointing results of intervention studies with inhibitors of the cholesteryl ester transfer protein and in particular the available set of genetically-epidemiological studies suggest that in the last decade, the importance of HDL cholesterol has been overvalued, while the importance of triglycerides has been underestimated. High triglycerides not always atherogenic, but only if they are associated with the accumulation relatively cholesterol-enriched, incompletely catabolized remnants of chylomicrons and very low density lipoproteins (familial type III hyperlipidemia, metabolic syndrome, diabetes mellitus). The normalization of the concentration of triglycerides and remnants by inhibiting the expression of apolipoprotein C3 is hence a new, promising therapeutic target. © Georg Thieme Verlag KG Stuttgart · New York.

Interrelationships between postprandial lipoprotein B:CIII particle changes and high-density lipoprotein subpopulation profiles in mixed hyperlipoproteinemia.

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Saïdi, Y; Sich, D; Camproux, A; Egloff, M; Federspiel, M C; Gautier, V; Raisonnier, A; Turpin, G; Beucler, I

1999-01-01

We studied the relationships postprandially between triglyceride-rich lipoprotein (TRL) and high-density lipoprotein (HDL) in 11 mixed hyperlipoproteinemia (MHL) and 11 hypercholesterolemia (HCL) patients. The high and prolonged postprandial triglyceridemia response observed in MHL but not HCL patients was essentially dependent on very-low-density lipoprotein (VLDL) changes. This abnormal response was related to decreased lipoprotein lipase (LPL) activity (-48.7%, P<.01) in MHL compared with HCL subjects. Cholesteryl ester transfer protein (CETP) activity was postprandially enhanced only in MHL patients, and this elevation persisted in the late period (+19% at 12 hours, P<.05), sustaining the delayed enrichment of VLDL with cholesteryl ester (CE). The late postprandial period in MHL patients was also characterized by high levels of apolipoprotein B (apoB)-containing lipoproteins with apoCIII ([LpB:CIII] +36% at 12 hours, P<.01) and decreased levels of apoCIII contained in HDL ([LpCIII-HDL] -34% at 12 hours, P<.01), reflecting probably a defective return of apoCIII from TRL toward HDL. In MHL compared with HCL patients, decreased HDL2 levels were related to both HDL2b and HDL2a subpopulations (-57% and -49%, respectively, P<.01 for both) and decreased apoA-I levels (-53%, P<.01) were equally linked to decreased HDL2 with apoA-I only (LpA-I) and HDL2 with both apoA-I and apoA-II ([LpA-I:A-II] -55% and -52%, respectively, P<.01 for both). The significant inverse correlations between the postprandial magnitude of LpB:CIII and HDL2-LpA-I and HDL2b levels in MHL patients underline the close TRL-HDL interrelationships. Our findings indicate that TRL and HDL abnormalities evidenced at fasting were postprandially amplified, tightly interrelated, and persistent during the late fed period in mixed hyperlipidemia. Thus, these fasting abnormalities are likely postprandially originated and may constitute proatherogenic lipoprotein disorders additional to the HCL in MHL patients.

A high-density lipoprotein-mediated drug delivery system.

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Mo, Zhong-Cheng; Ren, Kun; Liu, Xing; Tang, Zhen-Li; Yi, Guang-Hui

2016-11-15

High-density lipoprotein (HDL) is a comparatively dense and small lipoprotein that can carry lipids as a multifunctional aggregate in plasma. Several studies have shown that increasing the levels or improving the functionality of HDL is a promising target for treating a wide variety of diseases. Among lipoproteins, HDL particles possess unique physicochemical properties, including naturally synthesized physiological components, amphipathic apolipoproteins, lipid-loading and hydrophobic agent-incorporating characteristics, specific protein-protein interactions, heterogeneity, nanoparticles, and smaller size. Recently, the feasibility and superiority of using HDL particles as drug delivery vehicles have been of great interest. In this review, we summarize the structure, constituents, biogenesis, remodeling, and reconstitution of HDL drug delivery systems, focusing on their delivery capability, characteristics, applications, manufacturing, and drug-loading and drug-targeting characteristics. Finally, the future prospects are presented regarding the clinical application and challenges of using HDL as a pharmacodelivery carrier. Copyright © 2016 Elsevier B.V. All rights reserved.

Oxidized low-density lipoprotein in postmenopausal women

DEFF Research Database (Denmark)

Jankowski, Vera; Just, Alexander R; Pfeilschifter, Johannes

2014-01-01

BACKGROUND: Oxidized low-density lipoprotein (oxLDL) leads to atherosclerosis and cardiovascular disease, the most frequent causes of death worldwide. After menopause, lipid and lipoprotein metabolism changes and women are at greater risk of cardiovascular disease compared to fertile women. The aim.......10-0.43). Although intima-media thickness did not differ, postmenopausal women with serous oxLDL had more often atherosclerotic plaques compared to women without oxLDL (6/66 vs. 0/467; P lipoprotein, impaired glucose intolerance, and DBP were independently associated...... with the occurrence of oxLDL. If oxLDL was present, higher high-density lipoprotein and glucose intolerance were associated with higher concentrations of oxLDL. In contrast, higher blood urea concentrations were associated with lower concentrations of oxLDL. CONCLUSION: This study presents the prevalence...

Metabolism of cholesteryl esters of rat very low density lipoproteins.

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Faergeman, O; Havel, R J

1975-06-01

Rat very low density lipoproteins (d smaller than 1.006), biologically labeled in esterified and free cholesterol, were obtained form serum 6 h after intravenous injection of particulate (3-H) cholesterol. When injected into recipient animals, the esterified cholesterol was cleared form plasma with a half-life of 5 min. After 15 min, 71% of the injected esterified (3-H) cholesterol had been taken up by the liver, where it was rapidly hydrolyzed. After 60 min only 3.3% of the amount injected had been transferred, via lipoproteins of intermediate density, to the low density lipoproteins of plasma (d 1.019-1.063). Both uptake in the liver and transfer to low density lipoproteins occurred without change of distribution of 3-H in the various cholesteryl esters. 3-H appearing in esterified cholesterol of high density lipoproteins (d greater than 1.063) was derived from esterification, presumably by lecithin: cholesterol acyltransferase, of simultaneously injected free (3-H) cholesterol. Content of free (3-H) cholesterol in the very low density lipoproteins used for injection could be reduced substantially by incubation with erythrocytes. This procedure, however, increased the rate of clearance of the lipoproteins after injection into recipient rats. These studies show that hepatic removal is the major catabolic pathway for cholesteryl esters of rat very low density lipoproteins and that transfer to low density lipoproteins occurs to only a minor extent.

Role of Lipids in Spheroidal High Density Lipoproteins

NARCIS (Netherlands)

Vuorela, Timo; Catte, Andrea; Niemela, Perttu S.; Hall, Anette; Hyvonen, Marja T.; Marrink, Siewert-Jan; Karttunen, Mikko; Vattulainen, Ilpo

2010-01-01

We study the structure and dynamics of spherical high density lipoprotein (HDL) particles through coarse-grained multi-microsecond molecular dynamics simulations. We simulate both a lipid droplet without the apolipoprotein A-I (apoA-I) and the full HDL particle including two apoA-I molecules

Role of lipids in spheroidal high density lipoproteins

NARCIS (Netherlands)

Vuorela, T.A.; Catte, A.; Niemelä, P.S.; Hall, A.; Hyvönen, M.T.; Marrink, S.J.; Karttunen, M.E.J.; Vattulainen, I.

2010-01-01

We study the structure and dynamics of spherical high density lipoprotein (HDL) particles through coarse-grained multi-microsecond molecular dynamics simulations. We simulate both a lipid droplet without the apolipoprotein A-I (apoA-I) and the full HDL particle including two apoA-I molecules

Hemodynamics alter arterial low-density lipoprotein metabolism

International Nuclear Information System (INIS)

Warty, V.S.; Calvo, W.J.; Berceli, S.A.; Pham, S.M.; Durham, S.J.; Tanksale, S.K.; Klein, E.C.; Herman, I.M.; Borovetz, H.S.

1989-01-01

We have investigated the role of hemodynamic factors on low-density lipoprotein transport and metabolism in the intact arterial wall. Freshly excised canine carotid blood vessels were exposed to well-defined pulsatile flow in vitro for continuous periods up to 20 hours. We chose to impose the following hemodynamic conditions on our test carotid arteries: normotension, hypertension (at physiologic flow conditions), and hypertension coupled with elevated flow of canine serum perfusate. In several experiments the effect of endothelial denudation was examined in carotid arteries exposed to normotensive pulsatile flow. A trapped ligand method was used for quantitating low-density lipoprotein uptake and metabolism in the arterial wall. The distribution of both intact and degraded low-density lipoprotein fractions was determined from measurements of radiolabelled low-density lipoprotein activity within thin radial sections of perfused arteries. Our results suggest that both hypertensive hemodynamic simulations exacerbate the uptake of low-density lipoprotein within the arterial wall (by a factor of three to nine). The percentage of low-density lipoprotein that undergoes irreversible degradation falls from 41% under normotensive conditions to below 30% when hypertensive conditions are imposed, indicating that degradative processes are not proportionally elevated with the accelerated influx. A similar pattern is observed for deendothelialized vessels

Elevated plasma low-density lipoprotein and high-density lipoprotein cholesterol levels in amenorrheic athletes: effects of endogenous hormone status and nutrient intake.

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Friday, K E; Drinkwater, B L; Bruemmer, B; Chesnut, C; Chait, A

1993-12-01

To determine the interactive effects of hormones, exercise, and diet on plasma lipids and lipoproteins, serum estrogen and progesterone levels, nutrient intake, and plasma lipid, lipoprotein, and apolipoprotein concentrations were measured in 24 hypoestrogenic amenorrheic and 44 eumenorrheic female athletes. When compared to eumenorrheic athletes, amenorrheic athletes had higher levels of plasma cholesterol (5.47 +/- 0.17 vs. 4.84 +/- 0.12 mmol/L, P = 0.003), triglyceride (0.75 +/- 0.06 vs. 0.61 +/- 0.03 mmol/L, P = 0.046), low-density lipoprotein (LDL; 3.16 +/- 0.15 vs. 2.81 +/- 0.09 mmol/L, P = 0.037), high-density lipoprotein (HDL; 1.95 +/- 0.07 vs. 1.73 +/- 0.05 mmol/L, P = 0.007), and HDL2 (0.84 +/- 0.06 vs. 0.68 +/- 0.04 mmol/L, P = 0.02) cholesterol. Plasma LDL/HDL cholesterol ratios, very low-density lipoprotein and HDL3 cholesterol, and apolipoprotein A-I and A-II levels were similar in the two groups. Amenorrheic athletes consumed less fat than eumenorrheic subjects (52 +/- 5 vs. 75 +/- 3 g/day, P = 0.02), but similar amounts of calories, cholesterol, protein, carbohydrate, and ethanol. HDL cholesterol levels in amenorrheic subjects correlated positively with the percent of dietary calories from fat (r = 0.42, n = 23, P = 0.045) but negatively with the percent from protein (r = -0.49, n = 23, P = 0.017). Thus, exercise-induced amenorrhea may adversely affect cardiovascular risk by increasing plasma LDL and total cholesterol. However, cardioprotective elevations in plasma HDL and HDL2 cholesterol may neutralize the risk of cardiovascular disease in amenorrheic athletes.

Comparison of soymilk and probiotic soymilk effects on serum high-density lipoprotein cholesterol and low-density lipoprotein cholesterol in diabetic Wistar rats

Directory of Open Access Journals (Sweden)

Mina Babashahi

2015-04-01

Full Text Available BACKGROUND: Soy milk (SM and its fermented products are identified as rich sources of bioactive compounds helping to manage and to reduce the risk of chronic disease. This study aimed to compare the effects of SM and probiotic SM (PSM consumption on serum low-density lipoprotein cholesterol (LDL-C and high-density lipoprotein cholesterol (HDL-C in diabetic Wistar rats. METHODS: Probiotic SM was prepared by fermentation of the plain SM with a native strain of Lactobacillus plantarum. 20 streptozotocin-nicotinamide-induced diabetic Wistar rats were divided into two groups based on the type of administered SM (SM group and PSM group. The animals were fed with 1 ml/day of either soy or PSM for 21 days. The serum lipoprotein levels were analyzed at baseline and the end of the intervention period. RESULTS: HDL-C increased significantly in PSM group. Furthermore, this group showed more percent of change in increased HDL-C in compression with SM group (P < 0.050. Regarding LDL-C level, rats fed with SM was not significantly different from the PSM group (P < 0.050; though, this biomarker was reduced in both group. CONCLUSION: Probiotic SM could modulate blood lipoprotein levels. Thus, it may be considered in managing diabetes complications and atherosclerotic risks. 

Cholesteryl ester transfer activity in plasma measured by using solid-phase-bound high-density lipoprotein

International Nuclear Information System (INIS)

Sparks, D.L.; Frohlich, J.; Cullis, P.; Pritchard, P.H.

1987-01-01

We studied the ability of lipid-transfer factors in plasma to promote transfer, to endogenous lipoproteins, of [ 3 H]cholesteryl ester from high-density lipoprotein (HDL) covalently bound to Sepharose 4B beads. After incubation for 2 h at 37 degrees C, 12 to 14% of the [ 3 H]cholesteryl ester had been transferred to the lipoproteins of the plasma, in the proportions 57% to HDL and 43% to low- and very-low-density lipoproteins. This process was a function of the amount of plasma present and was stimulated by addition of partly purified lipid-transfer protein. Transfer also depended on the concentration of donor HDL but was independent of the amount of acceptor lipoprotein. This simple evaluation of cholesteryl ester transfer does not require removal of lipoproteins from the plasma before incubation

Effect of apolipoprotein M on high density lipoprotein metabolism and atherosclerosis in low density lipoprotein receptor knock-out mice

DEFF Research Database (Denmark)

Christoffersen, Christina; Jauhiainen, Matti; Moser, Markus

2008-01-01

To investigate the role of apoM in high density lipoprotein (HDL) metabolism and atherogenesis, we generated human apoM transgenic (apoM-Tg) and apoM-deficient (apoM(-/-)) mice. Plasma apoM was predominantly associated with 10-12-nm alpha-migrating HDL particles. Human apoM overexpression (11-fol...

Lipoprotein complex formation

International Nuclear Information System (INIS)

Musliner, T.A.; Krauss, R.M.

1987-01-01

Transfers of lipids and proteins between different lipoproteins are known to occur in the course of their metabolism. It is likely that these transfers take place during transient physical associations between lipoprotein particles, but the nature and chemical basis for such interactions are poorly understood. The fact that lipid and apolipoprotein movements are particularly prevalent during the intravascular lipolysis of triglyceride-rich lipoproteins suggested to us that lipolysis products accumulating on these particles might promote physical binding with other lipoproteins. To test this hypothesis, we studied interactions between very low-density, low density, and high-density lipoproteins in the setting of partial lipolysis by bovine milk lipoprotein lipase in the presence of limited unesterified fatty acid acceptor. 2 figs., 1 tab

In vitro incorporation of radiolabeled cholesteryl esters into high and low density lipoproteins

International Nuclear Information System (INIS)

Terpstra, A.H.; Nicolosi, R.J.; Herbert, P.N.

1989-01-01

We have developed and validated a method for in vitro incorporation of radiolabeled cholesteryl esters into low density (LDL) and high density lipoproteins (HDL). Radiolabeled cholesteryl esters dissolved in absolute ethanol were mixed with LDL or HDL in the presence of lipoprotein-deficient serum (LPDS) as a source of core lipid transfer activity. The efficiency of incorporation was dependent on: (a) the core lipid transfer activity and quantity of LPDS, (b) the mass of added radiolabeled cholesteryl esters, (c) the length of incubation, and (d) the amount of acceptor lipoprotein cholesterol. The tracer incorporation was documented by repeat density gradient ultracentrifugation, agarose gel electrophoresis, and precipitation with heparin-MnCl2. The radiolabeling conditions did not affect the following properties of the lipoproteins: (1) chemical composition, (2) electrophoretic mobility on agarose gels, (3) hydrated density, (4) distribution of apoproteins on SDS gels, (5) plasma clearance rates, and (6) immunoprecipitability of HDL apoproteins A-I and A-II. Rat HDL containing radiolabeled cholesteryl esters incorporated in vitro had plasma disappearance rates identical to HDL radiolabeled in vivo

Should we change our lipid management strategies to focus on non-high-density lipoprotein cholesterol?

NARCIS (Netherlands)

Rana, Jamal S.; Boekholdt, S. Matthijs

2010-01-01

Purpose of review Despite aggressive low-density lipoprotein cholesterol lowering, patients continue to be at significant risk of cardiovascular events. Assessment of non-high-density lipoprotein cholesterol (non-HDL-C) provides a measure of cholesterol contained in all atherogenic particles. In the

In vivo transfer of cholesteryl ester from high and low density plasma lipoproteins into human aortic tissue

International Nuclear Information System (INIS)

Stender, S.; Hjelms, E.

1988-01-01

For the study of cholesteryl ester transfer from different plasma lipoproteins into human aortic tissue, patients scheduled for reconstructive aortic surgery were intravenously injected with autologous in vitro labeled lipoproteins 20 to 24 hours before aortic intima-media samples were obtained during the operation. The injectate contained high density lipoproteins (d greater than 1.063) labeled with 3H-cholesteryl ester and lipoproteins of lower density (d less than 1.063) labeled with 14C-cholesteryl ester or lipoproteins with the opposite labeling. In 16 aortic tissue samples (some with visible atherosclerosis) from 11 normocholesterolemic patients, the aortic influx of total cholesteryl ester was 1 to 50 nmol x cm-2 x day-1. Some 39% +/- 3% (mean +/- SEM) of the influx was derived from high density lipoproteins, which in plasma accounted for only 22% +/- 2% (mean +/- SEM) of the esterified cholesterol. The findings suggest that: 1) esterified cholesterol from the two lipoprotein fractions in plasma enter the aortic intima by the same mechanism, and 2) influx of cholesteryl ester from the smaller, high density lipoproteins is greater than influx from the larger, lower density lipoproteins considering their concentrations in plasma. In some patients, the cholesterol content in the intima-media tissue with no visible atherosclerosis corresponded to only a few months of continuous cholesteryl ester influx. This time is short considering the age of the patients and, therefore, indicates that removal of esterified cholesterol from the intima-media is of major importance in preventing cholesterol deposition in the arterial wall

Pharmacologic management of isolated low high-density lipoprotein syndrome.

Science.gov (United States)

Bermúdez, Valmore; Cano, Raquel; Cano, Clímaco; Bermúdez, Fernando; Arraiz, Nailet; Acosta, Luis; Finol, Freddy; Pabón, María Rebeca; Amell, Anilsa; Reyna, Nadia; Hidalgo, Joaquin; Kendall, Paúl; Manuel, Velasco; Hernández, Rafael

2008-01-01

High-density lipoprotein (HDL) cholesterol is a heterogeneous group of lipoproteins exhibiting a variety of properties like prostacyclin production stimulation, decrease in platelet aggregation, endothelial cell apoptosis inhibition, and low-density lipoprotein oxidation blockade. Epidemiologic studies have shown an inverse relation between HDL cholesterol levels and cardiovascular risk. Low HDL cholesterol is associated with increased risk for myocardial infarction, stroke, sudden death, peripheral artery disease, and postangioplasty restenosis. In contrast, high HDL levels are associated with longevity and protection against atherosclerotic disease development. Given the evolving epidemic of obesity, diabetes mellitus, and metabolic syndrome, the prevalence of low HDL will continue to rise. In the United States, low HDL is present in 35% of men, 15% of women, and approximately 63% of patients with coronary artery disease. Data extracted from the Framingham study highlight that 1-mg increase in HDL levels decreases by 2% to 3% the risk of cardiovascular disease. There is no doubt regarding clinical importance about isolated low HDL, but relatively few clinicians consider a direct therapeutic intervention of this dyslipidemia. In this sense, lifestyle measures should be the first-line strategy to manage low HDL levels. On the other hand, pharmacologic options include niacin, fibrates, and statins. Fibrates appear to reduce risk preferentially in patients with low HDL with metabolic syndrome, whereas statins reduce risk across all levels of HDL. Torcetrapib, a cholesteryl esters transfer protein inhibitor, represented a hope to raise this lipoprotein; however, all clinical trials on this drug had ceased after ILLUMINATE, RADIANCE and ERASE trials had recorded an increase in mortality, rates of myocardial infarction, angina, and heart failure. In the near future, drugs as beta-glucans, Apo-A1 mimetic peptides, and ACAT inhibitors, are the new promises to treat this

Antioxidant activity of high-density lipoprotein (HDL) using different ...

African Journals Online (AJOL)

HDL is a potent antioxidant in terms of inhibition of lipid peroxidation, ROS production and LDL oxidation. These may to some extent add to the antiatherogenic beyond reverse-cholesterol transport properties of HDL. Keywords: high-density lipoprotein; reverse cholesterol transport; apolipoprotein A1; antioxidant; in vitro.

Changes in plasma low-density lipoprotein (LDL)- and high-density lipoprotein cholesterol in hypo- and hyperthyroid patients are related to changes in free thyroxine, not to polymorphisms in LDL receptor or cholesterol ester transfer protein genes

NARCIS (Netherlands)

Diekman, M. J.; Anghelescu, N.; Endert, E.; Bakker, O.; Wiersinga, W. M.

2000-01-01

Thyroid function disorders lead to changes in lipoprotein metabolism. Both plasma low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) increase in hypothyroidism and decrease in hyperthyroidism. Changes in LDL-C relate to altered clearance of LDL particles

Lipoprotein profile, lipoprotein-associated phospholipase A2 and cardiovascular risk in hemodialysis patients.

Science.gov (United States)

Rolla, Roberta; De Mauri, Andreana; Valsesia, Ambra; Vidali, Matteo; Chiarinotti, Doriana; Bellomo, Giorgio

2015-12-01

Cardiovascular disease is the leading cause of morbidity and mortality in hemodialysis patients; the increased risk of cardiovascular disease is due to accelerated atherosclerosis, inflammation and impaired lipoprotein metabolism. We aimed to evaluate lipoprotein-associated phospholipase A2 (Lp-PLA2) and some pro-inflammatory aspects of the lipoprotein profile in dialyzed patients in order to evaluate the relationship with the accelerated atherosclerosis and vascular accidents. In 102 dialysis patients and 40 non-uremic controls, we investigated the lipoprotein plasma profile, high sensitivity C-reactive protein (CRP), ceruloplasmin and serum amyloid A protein (SAA), and followed patients for 1 year to analyze the risk of acute cardiovascular events. Total cholesterol, low-density lipoprotein and high-density lipoprotein plasma levels were significantly lower in uremic patients than controls, whereas CRP, SAA, ceruloplasmin, Lp-PLA2 and their ratio with apolipoprotein A1 were significantly higher. Patients with Lp-PLA2 levels >194 nmol/min/ml had more acute cardiovascular events than patients with lower values. Our results show that in dialysis subjects: (1) low-density lipoproteins show a more atherogenic phenotype than in the general population; (2) high-density lipoproteins are less anti-inflammatory; (3) Lp-PLA2 could potentially be used to evaluate cardiovascular risk.

Comparison of gemfibrozil versus simvastatin in familial combined hyperlipidemia and effects on apolipoprotein-B-containing lipoproteins, low-density lipoprotein subfraction profile, and low-density lipoprotein oxidizability

NARCIS (Netherlands)

Bredie, S. J.; de Bruin, T. W.; Demacker, P. N.; Kastelein, J. J.; Stalenhoef, A. F.

1995-01-01

We evaluated in a double-blind, placebo-controlled, randomized trial of 45 well-defined patients with familial combined hyperlipidemia, the effect of gemfibrozil (1,200 mg/day) or simvastatin (20 mg/day) on apolipoprotein-B (apo-B)-containing lipoproteins, low-density lipoprotein (LDL) subfraction

Nanocrystal core high-density lipoproteins: a multimodality contrast agent platform

NARCIS (Netherlands)

Cormode, David P.; Skajaa, Torjus; van Schooneveld, Matti M.; Koole, Rolf; Jarzyna, Peter; Lobatto, Mark E.; Calcagno, Claudia; Barazza, Alessandra; Gordon, Ronald E.; Zanzonico, Pat; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.

2008-01-01

High density lipoprotein (HDL) is an important natural nanoparticle that may be modified for biomedical imaging purposes. Here we developed a novel technique to create unique multimodality HDL mimicking nanoparticles by incorporation of gold, iron oxide, or quantum dot nanocrystals for computed

Metabolism of lipoproteins by human fetal hepatocytes

International Nuclear Information System (INIS)

Carr, B.R.

1987-01-01

The rate of clearance of lipoproteins from plasma appears to play a role in the development of atherogenesis. The liver may account for as much as two thirds of the removal of low-density lipoprotein and one third of the clearance of high-density lipoprotein in certain animal species and humans, mainly by receptor-mediated pathways. The purpose of the present investigation was to determine if human fetal hepatocytes maintained in vitro take up and degrade lipoproteins. We first determined that the maximal binding capacity of iodine 125-iodo-LDL was approximately 300 ng of low-density lipoprotein protein/mg of membrane protein and an apparent dissociation constant of approximately 60 micrograms low-density lipoprotein protein/ml in membranes prepared from human fetal liver. We found that the maximal uptake of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL by fetal hepatocytes occurred after 12 hours of incubation. Low-density lipoprotein uptake preceded the appearance of degradation products by 4 hours, and thereafter the degradation of low-density lipoprotein increased linearly for at least 24 hours. In contrast, high-density lipoprotein was not degraded to any extent by fetal hepatocytes. [ 125 I]Iodo-LDL uptake and degradation were inhibited more than 75% by preincubation with low-density lipoprotein but not significantly by high-density lipoprotein, whereas [ 125 I]iodo-HDL uptake was inhibited 70% by preincubation with high-density lipoprotein but not by low-density lipoprotein. In summary, human fetal hepatocytes take up and degrade low-density lipoprotein by a receptor-mediated process similar to that described for human extrahepatic tissues

Impact of hormonal contraception and weight loss on high-density lipoprotein cholesterol efflux and lipoprotein particles in women with polycystic ovary syndrome.

Science.gov (United States)

Dokras, Anuja; Playford, Martin; Kris-Etherton, Penny M; Kunselman, Allen R; Stetter, Christy M; Williams, Nancy I; Gnatuk, Carol L; Estes, Stephanie J; Sarwer, David B; Allison, Kelly C; Coutifaris, Christos; Mehta, Nehal; Legro, Richard S

2017-05-01

To study the effects of oral contraceptive pills (OCP), the first-line treatment for PCOS, on high-density lipoprotein cholesterol (HDL-C) function (reverse cholesterol efflux capacity) and lipoprotein particles measured using nuclear magnetic resonance spectroscopy in obese women. Secondary analysis of a randomized controlled trial (OWL-PCOS) of OCP or Lifestyle (intensive Lifestyle modification) or Combined (OCP + Lifestyle) treatment groups for 16 weeks. Eighty-seven overweight/obese women with PCOS at two academic centres. Change in HDL-C efflux capacity and lipoprotein particles. High-density lipoprotein cholesterol efflux capacity increased significantly at 16 weeks in the OCP group [0·11; 95% confidence interval (CI) 0·03, 0·18, P = 0·008] but not in the Lifestyle (P = 0·39) or Combined group (P = 0·18). After adjusting for HDL-C and TG levels, there was significant mean change in efflux in the Combined group (0·09; 95% CI 0·01, 0·15; P = 0·01). Change in HDL-C efflux correlated inversely with change in serum testosterone (r s = -0·21; P = 0·05). In contrast, OCP use induced an atherogenic low-density lipoprotein cholesterol (LDL-C) profile with increase in small (P = 0·006) and large LDL-particles (P = 0·002). Change in small LDL-particles correlated with change in serum testosterone (r s = -0·31, P = 0·009) and insulin sensitivity index (ISI; r s = -0·31, P = 0·02). Both Lifestyle and Combined groups did not show significant changes in the atherogenic LDL particles. Oral contraceptive pills use is associated with improved HDL-C function and a concomitant atherogenic LDL-C profile. Combination of a Lifestyle program with OCP use improved HDL-C function and mitigated adverse effects of OCP on lipoproteins. Our study provides evidence for use of OCP in overweight/obese women with PCOS when combined with Lifestyle changes. © 2017 John Wiley & Sons Ltd.

Human plasma phospholipid transfer protein increases the antiatherogenic potential of high density lipoproteins in transgenic mice

NARCIS (Netherlands)

M.J. van Haperen (Rien); A. van Tol (Arie); P. Vermeulen; M. Jauhiainen; T. van Gent (Teus); P.M. van den Berg (Paul); S. Ehnholm (Sonja); A.W.M. van der Kamp (Arthur); M.P.G. de Crom (Rini); F.G. Grosveld (Frank)

2000-01-01

textabstractPlasma phospholipid transfer protein (PLTP) transfers phospholipids between lipoprotein particles and alters high density lipoprotein (HDL) subfraction patterns in vitro, but its physiological function is poorly understood. Transgenic mice that overexpress

One precursor, three apolipoproteins: the relationship between two crustacean lipoproteins, the large discoidal lipoprotein and the high density lipoprotein/β-glucan binding protein.

Science.gov (United States)

Stieb, Stefanie; Roth, Ziv; Dal Magro, Christina; Fischer, Sabine; Butz, Eric; Sagi, Amir; Khalaila, Isam; Lieb, Bernhard; Schenk, Sven; Hoeger, Ulrich

2014-12-01

The novel discoidal lipoprotein (dLp) recently detected in the crayfish, differs from other crustacean lipoproteins in its large size, apoprotein composition and high lipid binding capacity, We identified the dLp sequence by transcriptome analyses of the hepatopancreas and mass spectrometry. Further de novo assembly of the NGS data followed by BLAST searches using the sequence of the high density lipoprotein/1-glucan binding protein (HDL-BGBP) of Astacus leptodactylus as query revealed a putative precursor molecule with an open reading frame of 14.7 kb and a deduced primary structure of 4889 amino acids. The presence of an N-terminal lipid bind- ing domain and a DUF 1943 domain suggests the relationship with the large lipid transfer proteins. Two-putative dibasic furin cleavage sites were identified bordering the sequence of the HDL-BGBP. When subjected to mass spectroscopic analyses, tryptic peptides of the large apoprotein of dLp matched the N-terminal part of the precursor, while the peptides obtained for its small apoprotein matched the C-terminal part. Repeating the analysis in the prawn Macrobrachium rosenbergii revealed a similar protein with identical domain architecture suggesting that our findings do not represent an isolated instance. Our results indicate that the above three apolipoproteins (i.e HDL-BGBP and both the large and the small subunit of dLp) are translated as a large precursor. Cleavage at the furin type sites releases two subunits forming a heterodimeric dLP particle, while the remaining part forms an HDL-BGBP whose relationship with other lipoproteins as well as specific functions are yet to be elucidated.

Genetically elevated apolipoprotein A-I, high-density lipoprotein cholesterol levels, and risk of ischemic heart disease

DEFF Research Database (Denmark)

Lundegaard, Christiane; Tybjærg-Hansen, Anne; Grande, Peer

2010-01-01

Epidemiologically, levels of high-density lipoprotein (HDL) cholesterol and its major protein constituent, apolipoprotein A-I (apoA-I), are inversely related to risk of ischemic heart disease (IHD).......Epidemiologically, levels of high-density lipoprotein (HDL) cholesterol and its major protein constituent, apolipoprotein A-I (apoA-I), are inversely related to risk of ischemic heart disease (IHD)....

Alpha slow-moving high-density-lipoprotein subfraction in serum of a patient with radiation enteritis and peritoneal carcinosis

International Nuclear Information System (INIS)

Peynet, J.; Legrand, A.; Messing, B.; Thuillier, F.; Rousselet, F.

1989-01-01

An alpha slow-moving high-density-lipoprotein (HDL) subfraction was seen in a patient presenting with radiation enteritis and peritoneal carcinosis, who was given long-term cyclic parenteral nutrition. This subfraction, observed in addition to normal HDL, was precipitated with low-density lipoproteins (LDL) and very-low-density lipoproteins (VLDL) by sodium phosphotungstate-magnesium chloride. The patient's serum lipoproteins were analyzed after fractionation by density gradient ultracentrifugation. The alpha slow-moving HDL floated in the ultracentrifugation subfractions with densities ranging from 1.028 to 1.084 kg/L, and their main apolipoproteins included apolipoprotein E in addition to apolipoprotein A-I. These HDL were larger than HDL2. The pathogenesis of this unusual HDL subfraction is hypothesized

High triglycerides and low high-density lipoprotein cholesterol lipid profile in rheumatoid arthritis: A potential link among inflammation, oxidative status, and dysfunctional high-density lipoprotein.

Science.gov (United States)

Rodríguez-Carrio, Javier; Alperi-López, Mercedes; López, Patricia; López-Mejías, Raquel; Alonso-Castro, Sara; Abal, Francisco; Ballina-García, Francisco J; González-Gay, Miguel Á; Suárez, Ana

The interactions between inflammation and lipid profile in rheumatoid arthritis (RA) are poorly understood. The lipid profile study in RA has been biased toward lipoprotein levels, whereas those of triglycerides (TGs) and lipoprotein functionality have been underestimated. Since recent findings suggest a role for TG and TG-rich lipoproteins (TRL) on inflammation, we aimed to evaluate a combined lipid profile characterized by high TG and low high-density lipoprotein cholesterol levels (TG high HDL low ) in RA. Lipid profiles were analyzed in 113 RA patients, 113 healthy controls, and 27 dyslipemic subjects. Levels of inflammatory mediators, paraoxonase-1 (PON1) activity, and total antioxidant capacity were quantified in serum. PON1-rs662 status was evaluated by real-time polymerase chain reaction. The TG high HDL low profile was detected in 29/113 RA patients. Although no differences in prevalence compared with healthy controls or dyslipemic subjects were observed, this profile was associated with increased tumor necrosis factor α (P = .004), monocyte chemotactic protein (P = .004), interferon-gamma-inducible protein-10 (P = .018), and leptin (P < .001) serum levels in RA, where decreased PON1 activity and total antioxidant capacity were found. TG high HDL low prevalence was lower among anti-TNFα-treated patients (P = .004). When RA patients were stratified by PON1-rs662 status, these associations remained in the low-activity genotype (QQ). Finally, a poor clinical response on TNFα blockade was related to an increasing prevalence of the TG high HDL low profile over treatment (P = .021) and higher TRL levels at baseline (P = .042). The TG high HDL low profile is associated with systemic inflammation, decreased PON1 activity, and poor clinical outcome on TNFα blockade in RA, suggesting a role of TRL and HDL dysfunction as the missing link between inflammation and lipid profile. Copyright © 2017 National Lipid Association. Published by Elsevier Inc

High-density lipoprotein-like particle formation of Synuclein variants.

Science.gov (United States)

Eichmann, Cédric; Kumari, Pratibha; Riek, Roland

2017-01-01

α-Synuclein (α-Syn) is an intrinsically disordered protein in solution whose fibrillar aggregates are the hallmark of Parkinson's disease (PD). Although the specific function of α-Syn is still unclear, its high structural plasticity is key for the interactions of α-Syn with biological membranes. Recently, it has been observed that α-Syn is able to form high-density lipoprotein-like (HDL-like) particles that are reminiscent of self-assembling phospholipid bilayer nanodiscs. Here, we extended our preparation method for the production of α-Syn lipoprotein particles to the β- and γ-Syn variants, and the PD-related familial α-Syn mutants. We show that all human Syns can form stable and homogeneous populations of HDL-like particles with distinct morphologies. Our results characterize the impact of the individual Syns on the formation capacity of these particles and indicate that Syn HDL-like particles are neither causing toxicity nor a toxicity-related loss of α-Syn in PD. © 2016 Federation of European Biochemical Societies.

High density lipoprotein as a source of cholesterol for adrenal steroidogenesis: a study in individuals with low plasma HDL-C

NARCIS (Netherlands)

Bochem, Andrea E.; Holleboom, Adriaan G.; Romijn, Johannes A.; Hoekstra, Menno; Dallinga-Thie, Geesje M.; Motazacker, Mahdi M.; Hovingh, G. Kees; Kuivenhoven, Jan A.; Stroes, Erik S. G.

2013-01-01

Few studies have addressed the delivery of lipoprotein-derived cholesterol to the adrenals for steroid production in humans. While there is evidence against a role for low-density lipoprotein (LDL), it is unresolved whether high density lipoprotein (HDL) contributes to adrenal steroidogenesis. To

Comparison of human plasma low- and high-density lipoproteins as substrates for lecithin: cholesterol acyltransferase.

Science.gov (United States)

Barter, P J; Hopkins, G J; Gorjatschko, L

1984-01-17

A recent observation that lecithin: cholesterol acyltransferase (EC 2.3.1.43) interacts with both low-density lipoproteins (LDL) and high-density lipoproteins (HDL) in human plasma is in apparent conflict with an earlier finding that the purified enzyme, while highly reactive with isolated HDL, was only minimally reactive with LDL. There is evidence, however, that lecithin: cholesterol acyltransferase may exist physiologically as a component of a complex with other proteins and that studies with the isolated enzyme may therefore provide misleading results. Consequently, interactions of the enzyme with isolated human lipoproteins have been re-examined in incubations containing lecithin: cholesterol acyltransferase as a component of human lipoprotein-free plasma in which a physiologically active complex of the enzyme with other proteins may have been preserved. In this system there was a ready esterification of the free cholesterol associated with both LDL and HDL-subfraction 3 (HDL3) in reactions that obeyed typical enzyme-saturation kinetics. For a given preparation of lipoprotein-free plasma the Vmax values with LDL and with HDL3 were virtually identical. The apparent Km for free cholesterol associated with HDL3 was 5.6 X 10(-5) M, while for that associated with LDL it was 4.1 X 10(-4) M. This implied that, in terms of free cholesterol concentration, the affinity of HDL3 for lecithin: cholesterol acyltransferase was about 7-times greater than that of LDL. When expressed in terms of lipoprotein particle concentration, however, it was apparent that the affinity of LDL for the enzyme was considerably greater than that of HDL3. When the lipoprotein fractions were equated in terms of lipoprotein surface area, the apparent affinities of the two fractions for the enzyme were found to be comparable.

Novel Therapies Focused on the High-Density Lipoprotein Particle

NARCIS (Netherlands)

van Capelleveen, Julian C.; Brewer, H. Bryan; Kastelein, John J. P.; Hovingh, G. Kees

2014-01-01

Cardiovascular disease (CVD) remains a major burden for morbidity and mortality in the general population, despite current efficacious low-density lipoprotein-cholesterol-lowering therapies. Consequently, novel therapies are required to reduce this residual risk. Prospective epidemiological studies

Comparison of different statin therapy to change low-density lipoprotein cholesterol and high-density lipoprotein cholesterol level in Korean patients with and without diabetes.

Science.gov (United States)

Khang, Ah Reum; Song, Young Shin; Kim, Kyoung Min; Moon, Jae Hoon; Lim, Soo; Park, Kyong Soo; Jang, Hak Chul; Choi, Sung Hee

2016-01-01

It is difficult to apply the proper intensity of statin for new treatment guidelines in clinical settings because of few data about the statin efficacy in Asians. We conducted a retrospective, observational study to estimate the percentage changes in lipid parameters and glucose induced by different statins. We analyzed 3854 patients including those with nondiabetes and diabetes treated at the outpatient clinic between 2003 and 2013 who were statin-naïve and maintained fixed-dose of statin for at least 18 months. Moderate- and low-intensity statin therapy was effective in reducing low-density lipoprotein cholesterol (LDL-C) to statin group. The effects of statins in elevating high-density lipoprotein cholesterol were similar in each statin groups, except the ezetimibe-simvastatin group (4.5 ± 2.1%) and high-dose atorvastatin groups (9.7 ± 3.3% and 8.7 ± 2.4% for 40 mg and 80 mg of atorvastatin/day, respectively). High-density lipoprotein cholesterol increased less and LDL-C decreased more in diabetes than in nondiabetes. There were no significant changes of fasting glucose after statin use in nondiabetic patients. Moderate- or low-intensity statin was effective enough in reaching National Cholesterol Education Program Adult Treatment Panel III LDL-C target goals in Koreans. Low-intensity statin showed around 30% LDL-C reduction from the baseline level in Koreans, which is comparable to moderate-intensity statin in new guideline. Copyright © 2015 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Cholesterol transfer from normal and atherogenic low density lipoproteins to Mycoplasma membranes

International Nuclear Information System (INIS)

Mitschelen, J.J.; St Clair, R.W.; Hester, S.H.

1981-01-01

The purpose of this study was to determine whether the free cholesterol of hypercholesterolemic low density lipoprotein from cholesterol-fed nonhuman primates has a greater potential for surface transfer to cell membranes than does the free cholesterol of normal low density lipoprotein. The low density lipoproteins were isolated from normal and hypercholesterolemic rhesus and cynomolgus monkeys, incubated with membranes from Acholeplasma laidlawii, a mycoplasma species devoid of cholesterol in its membranes, and the mass transfer of free cholesterol determined by measuring membrane cholesterol content. Since these membranes neither synthesize nor esterify cholesterol, nor degrade the protein or cholesterol ester moieties of low density lipoprotein, they are an ideal model with which to study differences in the cholesterol transfer potential of low density lipoprotein independent of the uptake of the intact low density lipoprotein particle. These studies indicate that, even though there are marked differences in the cholesterol composition of normal and hypercholesterolemic low density lipoproteins, this does not result in a greater chemical potential for surface transfer of free cholesterol. Consequently, if a difference in the surface transfer of free cholesterol is responsible for the enhanced ability of hypercholesterolemic low density lipoprotein to promote cellular cholesterol accumulation and, perhaps, also atherosclerosis, it must be the result of differences in the interaction to the hypercholesterolemic low density lipoprotein with the more complicated mammalian cell membranes, rather than differences in the chemical potential for cholesterol transfer

Single-Particle Tracking of Human Lipoproteins.

Science.gov (United States)

de Messieres, Michel; Ng, Abby; Duarte, Cornelio J; Remaley, Alan T; Lee, Jennifer C

2016-01-05

Lipoproteins, such as high-density lipoprotein (HDL), low-density lipoprotein (LDL), and very-low density lipoprotein (VLDL), play a critical role in heart disease. Lipoproteins vary in size and shape as well as in their apolipoprotein content. Here, we developed a new experimental framework to study freely diffusing lipoproteins from human blood, allowing analysis of even the smallest HDL with a radius of 5 nm. In an easily constructed confinement chamber, individual HDL, LDL, and VLDL particles labeled with three distinct fluorophores were simultaneously tracked by wide-field fluorescence microscopy and their sizes were determined by their motion. This technique enables studies of individual lipoproteins in solution and allows characterization of the heterogeneous properties of lipoproteins which affect their biological function but are difficult to discern in bulk studies.

Extract of mangosteen increases high density lipoprotein levels in rats fed high lipid

Directory of Open Access Journals (Sweden)

Dwi Laksono Adiputro

2013-04-01

Full Text Available Background In cardiovascular medicine, Garcinia mangostana has been used as an antioxidant to inhibit oxidation of low density lipoproteins and as an antiobesity agent. The effect of Garcinia mangostana on hyperlipidemia is unknown. The aim of this study was to evaluate the effect of an ethanolic extract of Garcinia mangostana pericarp on lipid profile in rats fed a high lipid diet. Methods A total of 40 rats were divided into five groups control, high lipid diet, and high lipid diet + ethanolic extract of Garcinia mangostana pericarp at dosages of 200, 400, and 800 mg/kg body weight. The control group received a standard diet for 60 days. The high lipid diet group received standard diet plus egg yolk, goat fat, cholic acid, and pig fat for 60 days with or without ethanolic extract of Garcinia mangostana pericarp by the oral route. After 60 days, rats were anesthesized with ether for collection of blood by cardiac puncture. Analysis of blood lipid profile comprised colorimetric determination of cholesterol, triglyceride, low density lipoprotein (LDL, and high density lipoprotein (HDL. Results From the results of one-way ANOVA it was concluded that there were significant between-group differences in cholesterol, trygliceride, LDL, and HDL levels (p=0.000. Ethanolic extract of Garcinia mangostana pericarp significantly decreased cholesterol, trygliceride, and LDL levels, starting at 400 mg/kg body weight (p=0.000. Ethanolic extract of Garcinia mangostana pericarp significantly increased HDL level starting at 200 mg/kg body weight (p=0.000. Conclusion Ethanolic extract of Garcinia mangostana pericarp has a beneficial effect on lipid profile in rats on a high lipid diet.

Extract of mangosteen increases high density lipoprotein levels in rats fed high lipid

Directory of Open Access Journals (Sweden)

Dwi Laksono Adiputro

2015-12-01

Full Text Available BACKGROUND In cardiovascular medicine, Garcinia mangostana has been used as an antioxidant to inhibit oxidation of low density lipoproteins and as an antiobesity agent. The effect of Garcinia mangostana on hyperlipidemia is unknown. The aim of this study was to evaluate the effect of an ethanolic extract of Garcinia mangostana pericarp on lipid profile in rats fed a high lipid diet. METHODS A total of 40 rats were divided into five groups control, high lipid diet, and high lipid diet + ethanolic extract of Garcinia mangostana pericarp at dosages of 200, 400, and 800 mg/kg body weight. The control group received a standard diet for 60 days. The high lipid diet group received standard diet plus egg yolk, goat fat, cholic acid, and pig fat for 60 days with or without ethanolic extract of Garcinia mangostana pericarp by the oral route. After 60 days, rats were anesthesized with ether for collection of blood by cardiac puncture. Analysis of blood lipid profile comprised colorimetric determination of cholesterol, triglyceride, low density lipoprotein (LDL, and high density lipoprotein (HDL. RESULTS From the results of one-way ANOVA it was concluded that there were significant between-group differences in cholesterol, trygliceride, LDL, and HDL levels (p=0.000. Ethanolic extract of Garcinia mangostana pericarp significantly decreased cholesterol, trygliceride, and LDL levels, starting at 400 mg/kg body weight (p=0.000. Ethanolic extract of Garcinia mangostana pericarp significantly increased HDL level starting at 200 mg/kg body weight (p=0.000. CONCLUSION Ethanolic extract of Garcinia mangostana pericarp has a beneficial effect on lipid profile in rats on a high lipid diet.

Lipoprotein distribution and serum concentrations of 7α-hydroxy-4-cholesten-3-one and bile acids: effects of monogenic disturbances in high-density lipoprotein metabolism

DEFF Research Database (Denmark)

Steiner, Carine; Holleboom, Adriaan G; Karuna, Ratna

2012-01-01

BA (bile acid) formation is considered an important final step in RCT (reverse cholesterol transport). HDL (high-density lipoprotein) has been reported to transport BAs. We therefore investigated the effects of monogenic disturbances in human HDL metabolism on serum concentrations and lipoprotein...... concentrations of conjugated and secondary BAs differed between heterozygous carriers of SCARB1 (scavenger receptor class B1) mutations and unaffected individuals (P...

Investigations on the transport and metabolism of high density lipoprotein cholesteryl esters in African green monkeys

International Nuclear Information System (INIS)

Sorci-Thomas, M.G.

1984-01-01

The metabolic fate of circulating high density lipoprotein cholesteryl esters was studied in African green monkeys to determine the significance of the lipid transfer reaction on the catabolism of lipoprotein cholesteryl esters. A method of doubly labeling both moieties of lipoprotein cholesteryl esters with [ 3 He]cholesteryl oleate and cholesteryl [ 14 C]oleate was developed for the purpose of studying plasma cholesteryl ester metabolism in vivo. In these studies the total plasma [ 3 He]cholesterol turnover resulted in production rates, which ranged from 10-17 mg/kg day, similar to previously reported values in African green monkeys and in normal lipoproteinemic humans. In contrast to the production rates calculated from the decay of plasma 3 He-radioactivity, the production rates calculated from lipoproteins labeled with cholesteryl [ 14 C]oleate were approximately 2-3 times greater. In addition to these studies, a plasma cholesteryl ester transacylation activity was demonstrated in vitro when HDL containing doubly labeled cholesteryl esters were incubated with fresh plasma. These results demonstrated that high density lipoprotein cholesteryl esters undergo transacylation in vitro, resulting in release and reesterification of free [ 3 H]cholesterol

Current guidelines for high-density lipoprotein cholesterol in therapy and future directions

Directory of Open Access Journals (Sweden)

Subedi BH

2014-04-01

Full Text Available Bishnu H Subedi,1,2 Parag H Joshi,1 Steven R Jones,1 Seth S Martin,1 Michael J Blaha,1 Erin D Michos1 1Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, 2Greater Baltimore Medical Center, Baltimore, MD, USA Abstract: Many studies have suggested that a significant risk factor for atherosclerotic cardiovascular disease (ASCVD is low high-density lipoprotein cholesterol (HDL-C. Therefore, increasing HDL-C with therapeutic agents has been considered an attractive strategy. In the prestatin era, fibrates and niacin monotherapy, which cause modest increases in HDL-C, reduced ASCVD events. Since their introduction, statins have become the cornerstone of lipoprotein therapy, the benefits of which are primarily attributed to decrease in low-density lipoprotein cholesterol. Findings from several randomized trials involving niacin or cholesteryl ester transfer protein inhibitors have challenged the concept that a quantitative elevation of plasma HDL-C will uniformly translate into ASCVD benefits. Consequently, the HDL, or more correctly, HDL-C hypothesis has become more controversial. There are no clear guidelines thus far for targeting HDL-C or HDL due to lack of solid outcomes data for HDL specific therapies. HDL-C levels are only one marker of HDL out of its several structural or functional properties. Novel approaches are ongoing in developing and assessing agents that closely mimic the structure of natural HDL or replicate its various functions, for example, reverse cholesterol transport, vasodilation, anti-inflammation, or inhibition of platelet aggregation. Potential new approaches like HDL infusions, delipidated HDL, liver X receptor agonists, Apo A-I upregulators, Apo A mimetics, and gene therapy are in early phase trials. This review will outline current therapies and describe future directions for HDL therapeutics. Keywords: high-density lipoprotein, lipids, cholesterol, atherosclerosis, cardiovascular disease, therapy

Early incorporation of cell-derived cholesterol into pre-beta-migrating high-density lipoprotein

International Nuclear Information System (INIS)

Castro, G.R.; Fielding, C.J.

1988-01-01

Cultures of human skin fibroblasts were labeled to high cholesterol specific activity with [ 3 H]cholesterol and incubated briefly (1-3 min) with normal human plasma. The plasma was fractionated by two-dimensional agarose-polyacrylamide gel electrophoresis and the early appearance of cholesterol label among plasma lipoproteins determined. A major part of the label at 1-min incubation was in a pre-beta-migrating apo A-I lipoprotein fraction with a molecular weight of ca. 70,000. Label was enriched about 30-fold in this fraction relative to its content of apo A-I (1-2% of total apo A-I). The proportion of label in this lipoprotein was strongly correlated with its concentration in plasma. Further incubation (2 min) in the presence of unlabeled cells demonstrated transfer of label from this fraction to a higher molecular weight pre-beta apo A-I species, to low-density lipoprotein, and to the alpha-migrating apo A-I that made up the bulk (96%) of total apo A-I in plasma. The data suggest that a significant part of cell-derived cholesterol is transferred specifically to a pre-beta-migrating lipoprotein A-I species as part of a cholesterol transport transfer sequence in plasma

Kinetics of incorporation/redistribution of photosensitizer hypericin to/from high-density lipoproteins

Czech Academy of Sciences Publication Activity Database

Joniova, J.; Buriánková, L.; Búzová, Diana; Miškovský, P.; Jančura, D.

2014-01-01

Roč. 475, 1-2 (2014), s. 578-584 ISSN 0378-5173 Institutional support: RVO:67179843 Keywords : aggregation * drug delivery * fluorescence * high- and low- density lipoproteins * Hypericin Subject RIV: FR - Pharmacology ; Medidal Chemistry Impact factor: 3.650, year: 2014

Membrane receptors for very low density lipoprotein (VLDL) inhibitor of lymphocyte proliferation

International Nuclear Information System (INIS)

Yi, P.I.; Beck, G.; Zucker, S.

1981-01-01

Physiologic concentrations of human plasma very low density lipoproteins inhibit the DNA synthesis of lymphocytes stimulated by allogeneic cells or lectins. In this report reachers have compared the effects of isolated lipoproteins [very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL)] and lipoprotein-depleted plasma (LDP) on DNA synthesis by phytohemagglutinin-stimulated human lymphocytes. The relative potency for the inhibition of lymphocyte proliferation was VLDL greater than LDL greater than HDL greater than LDP. Fifty percent inhibition of DNA synthesis was observed at a VLDL protein concentration of 1.5--2.0 microgram/ml. Researchers have further demonstrated the presence of specific receptors for VLDL on human lymphocytes. Native VLDL was more effective than LDL in competing for 125I-VLDL binding sites. Subsequent to binding to lymphocytes, 125I-VLDL was internalized and degraded to acid-soluble products. Based on a Scatchard analysis of VLDL binding at 4 degrees C, the number of VLDL receptors per lymphocyte was estimated at 28,000 +/- 1300. Based on an estimated mean binding affinity for the VLDL receptor complex at half saturation of approximately 8.8 X 10(7) liter/mole, it is estimated that 91% of lymphocyte VLDL receptors are occupied at physiologic VLDL concentrations in blood. Although the immune regulatory role of plasma lipoproteins is uncertain, researchers suggest tha VLDL and LDL-In may maintain circulating blood lymphocytes in a nonproliferative state via their respective cell receptor mechanisms

Transfer of plasma lipoprotein components and of plasma proteins into aortas of cholesterol-fed rabbits. Molecular size as a determinant of plasma lipoprotein influx

International Nuclear Information System (INIS)

Stender, S.; Zilversmit, D.B.

1981-01-01

The arterial influx of esterified and free cholesterol from low density lipoproteins and very low density lipoproteins in 20 hypercholesterolemic rabbits was measured simultaneously by the use of lipoproteins labeled in vivo with [ 3 H]- and [ 14 C]-cholesterol. The simultaneous arterial influx of either [ 3 H]-leucine-labeled very low density lipoproteins, low density lipoproteins, high density lipoproteins, or plasma proteins was also measured in each rabbit. The arterial influx was calculated as intimal clearance, i.e., the influx of a given fraction divided by its plasma concentration. The intimal clearance of low density lipoprotein esterified cholesterol was equal to that for the apolipoproteins of that fraction, which is compatible with an arterial influx of intact low density lipoprotein molecules. The intimal clearance of very low density apolipoprotein or cholesteryl ester was less than that for low density lipoprotein, whereas high density lipoprotein and albumin clearances exceeded low density lipoprotein clearance by 1.5- to 3-fold. The intimal clearances of plasma proteins, high density, low density, and very low density lipoproteins decreased linearly with the logarithm of the macromolecular diameter. This indicates that the arterial influx of three plasma lipoprotein fractions and of plasma proteins proceeds by similar mechanisms. Apparently the relative intimal clearances of lipoproteins are more dependent on their size relative to pores or vesicular diameters at the plasma-artery interface than on specific interactions between lipoproteins and the arterial intimal surface

Lipoprotein Lipase and PPAR Alpha Gene Polymorphisms, Increased Very-Low-Density Lipoprotein Levels, and Decreased High-Density Lipoprotein Levels as Risk Markers for the Development of Visceral Leishmaniasis by Leishmania infantum

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Márcia Dias Teixeira Carvalho

2014-01-01

Full Text Available In visceral leishmaniasis (VL endemic areas, a minority of infected individuals progress to disease since most of them develop protective immunity. Therefore, we investigated the risk markers of VL within nonimmune sector. Analyzing infected symptomatic and, asymptomatic, and noninfected individuals, VL patients presented with reduced high-density lipoprotein cholesterol (HDL-C, elevated triacylglycerol (TAG, and elevated very-low-density lipoprotein cholesterol (VLDL-C levels. A polymorphism analysis of the lipoprotein lipase (LPL gene using HindIII restriction digestion (N = 156 samples (H+ = the presence and H− = the absence of mutation revealed an increased adjusted odds ratio (OR of VL versus noninfected individuals when the H+/H+ was compared with the H−/H− genotype (OR = 21.3; 95% CI = 2.32–3335.3; P = 0.003. The H+/H+ genotype and the H+ allele were associated with elevated VLDL-C and TAG levels (P < 0.05 and reduced HDL-C levels (P < 0.05. An analysis of the L162V polymorphism in the peroxisome proliferator-activated receptor alpha (PPARα gene (n = 248 revealed an increased adjusted OR when the Leu/Val was compared with the Leu/Leu genotype (OR = 8.77; 95% CI = 1.41–78.70; P = 0.014. High TAG (P = 0.021 and VLDL-C (P = 0.023 levels were associated with susceptibility to VL, whereas low HDL (P = 0.006 levels with resistance to infection. The mutated LPL and the PPARα Leu/Val genotypes may be considered risk markers for the development of VL.

Nanotechnology for Synthetic High Density Lipoproteins

Science.gov (United States)

Luthi, Andrea J.; Patel, Pinal C.; Ko, Caroline H.; Mutharasan, R. Kannan; Mirkin, Chad A.; Thaxton, C. Shad

2014-01-01

Atherosclerosis is the disease mechanism responsible for coronary heart disease (CHD), the leading cause of death worldwide. One strategy to combat atherosclerosis is to increase the amount of circulating high density lipoproteins (HDL), which transport cholesterol from peripheral tissues to the liver for excretion. The process, known as reverse cholesterol transport, is thought to be one of the main reasons for the significant inverse correlation observed between HDL blood levels and the development of CHD. This article highlights the most common strategies for treating atherosclerosis using HDL. We further detail potential treatment opportunities that utilize nanotechnology to increase the amount of HDL in circulation. The synthesis of biomimetic HDL nanostructures that replicate the chemical and physical properties of natural HDL provides novel materials for investigating the structure-function relationships of HDL and for potential new therapeutics to combat CHD. PMID:21087901

UVB-induced photoperoxidation of lipids of human low and high density lipoproteins. A possible role of tryptophan residues

International Nuclear Information System (INIS)

Salmon, S.; Maziere, J.C.; Santus, R.; Bouchemal, N.; Morliere, P.

1990-01-01

Ultraviolet radiation of the UVB region readily destroys tryptophan (Trp) residues of low (LDL) and high (HDL) density lipoproteins. The photooxidation of tryptophan residues is accompanied by peroxidation of low and high density lipoproteins unsaturated fatty acids, as measured by thiobarbituric acid assay. Moreover, low and high density lipoproteins are natural carriers of vitamin E and carotenoids. These two antioxidants are also rapidly bleached by UVB. The UVA radiation promotes neither tryptophan residue destruction nor lipid photoperoxidation. The redox cycling Cu 2+ ions considerably increase lipid photoperoxidation. The synergistic action of photo and auto (Cu 2+ -induced) peroxidation induces marked post-irradiation modifications of apolipoproteins as illustrated by degradation of most tryptophan residues after overnight incubation in the dark of pre-irradiated samples. (author)

Changes in remnant and high-density lipoproteins associated with hormone therapy and progression of coronary artery disease in postmenopausal women

Science.gov (United States)

The effect of hormone therapy (HT) on the plasma concentration of remnant lipoprotein cholesterol (RLP-C) and high density lipoprotein (HDL) subpopulations and the contribution of HT-related changes in these lipoproteins to the progression of coronary heart disease (CHD) were examined in 256 postmen...

Phytosterols, Phytostanols, and Lipoprotein Metabolism

Directory of Open Access Journals (Sweden)

Helena Gylling

2015-09-01

Full Text Available The efficacy of phytosterols and phytostanols added to foods and food supplements to obtain significant non-pharmacologic serum and low density lipoprotein (LDL cholesterol reduction is well documented. Irrespective of age, gender, ethnic background, body weight, background diet, or the cause of hypercholesterolemia and, even added to statin treatment, phytosterols and phytostanols at 2 g/day significantly lower LDL cholesterol concentration by 8%–10%. They do not affect the concentrations of high density lipoprotein cholesterol, lipoprotein (a or serum proprotein convertase subtilisin/kexin type 9. In some studies, phytosterols and phytostanols have modestly reduced serum triglyceride levels especially in subjects with slightly increased baseline concentrations. Phytosterols and phytostanols lower LDL cholesterol by displacing cholesterol from mixed micelles in the small intestine so that cholesterol absorption is partially inhibited. Cholesterol absorption and synthesis have been carefully evaluated during phytosterol and phytostanol supplementation. However, only a few lipoprotein kinetic studies have been performed, and they revealed that LDL apoprotein B-100 transport rate was reduced. LDL particle size was unchanged, but small dense LDL cholesterol concentration was reduced. In subjects with metabolic syndrome and moderate hypertriglyceridemia, phytostanols reduced not only non- high density lipoprotein (HDL cholesterol concentration but also serum triglycerides by 27%, and reduced the large and medium size very low density lipoprotein particle concentrations. In the few postprandial studies, the postprandial lipoproteins were reduced, but detailed studies with apoprotein B-48 are lacking. In conclusion, more kinetic studies are required to obtain a more complete understanding of the fasting and postprandial lipoprotein metabolism caused by phytosterols and phytostanols. It seems obvious, however, that the most atherogenic lipoprotein

Phytosterols, Phytostanols, and Lipoprotein Metabolism.

Science.gov (United States)

Gylling, Helena; Simonen, Piia

2015-09-17

The efficacy of phytosterols and phytostanols added to foods and food supplements to obtain significant non-pharmacologic serum and low density lipoprotein (LDL) cholesterol reduction is well documented. Irrespective of age, gender, ethnic background, body weight, background diet, or the cause of hypercholesterolemia and, even added to statin treatment, phytosterols and phytostanols at 2 g/day significantly lower LDL cholesterol concentration by 8%-10%. They do not affect the concentrations of high density lipoprotein cholesterol, lipoprotein (a) or serum proprotein convertase subtilisin/kexin type 9. In some studies, phytosterols and phytostanols have modestly reduced serum triglyceride levels especially in subjects with slightly increased baseline concentrations. Phytosterols and phytostanols lower LDL cholesterol by displacing cholesterol from mixed micelles in the small intestine so that cholesterol absorption is partially inhibited. Cholesterol absorption and synthesis have been carefully evaluated during phytosterol and phytostanol supplementation. However, only a few lipoprotein kinetic studies have been performed, and they revealed that LDL apoprotein B-100 transport rate was reduced. LDL particle size was unchanged, but small dense LDL cholesterol concentration was reduced. In subjects with metabolic syndrome and moderate hypertriglyceridemia, phytostanols reduced not only non- high density lipoprotein (HDL) cholesterol concentration but also serum triglycerides by 27%, and reduced the large and medium size very low density lipoprotein particle concentrations. In the few postprandial studies, the postprandial lipoproteins were reduced, but detailed studies with apoprotein B-48 are lacking. In conclusion, more kinetic studies are required to obtain a more complete understanding of the fasting and postprandial lipoprotein metabolism caused by phytosterols and phytostanols. It seems obvious, however, that the most atherogenic lipoprotein particles will be

Drugs targeting high-density lipoprotein cholesterol for coronary artery disease management.

Science.gov (United States)

Katz, Pamela M; Leiter, Lawrence A

2012-01-01

Many patients remain at high risk for future cardiovascular events despite levels of low-density lipoprotein cholesterol (LDL-C) at, or below, target while taking statin therapy. Much effort is therefore being focused on strategies to reduce this residual risk. High-density lipoprotein cholesterol (HDL-C) is a strong, independent, inverse predictor of coronary heart disease risk and is therefore an attractive therapeutic target. Currently available agents that raise HDL-C have only modest effects and there is limited evidence of additional cardiovascular risk reduction on top of background statin therapy associated with their use. It was hoped that the use of cholesteryl ester transfer protein (CETP) inhibitors would provide additional benefit, but the results of clinical outcome studies to date have been disappointing. The results of ongoing trials with other CETP inhibitors that raise HDL-C to a greater degree and also lower LDL-C, as well as with other emerging therapies are awaited. Copyright © 2012 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

Experimental hypothyroidism modulates the expression of the low density lipoprotein receptor by the liver

International Nuclear Information System (INIS)

Scarabottolo, Lia; Trezzi, Ermanno; Roma, Paola; Catapano, A.L.

1986-01-01

The effect of exprimental hypothyroidism of the catabolism of plasma lipoproteins and on the expression of low density lipoprotein receptors by the liver was investigated in rats made hypothyroid by surgery. The animals developed mild hypercholesterolemia, mainly due to an increase of plasma low density lipoprotein, while other lipoprotein classes were only marginally affected. Kinetic studies using ( 125 I)LDL indicated that a decreased fractional catabolic rate of the lipoprotein was responsible for this finding in agreement with the in vitro observation of a reduced binding of lipoproteins to liver membranes from hyperthyroid rats and with the demonstrations, by ligand blotting analysis, of a decreasd expression of lipoprotein receptors in liver membranes. These data suggest that hypothyroidism affects lipoprotein distribution also by decreasing the catabolism of low density lipoproteins by the liver (author)

High-density lipoprotein cholesterol: How High

Directory of Open Access Journals (Sweden)

G Rajagopal

2012-01-01

Full Text Available The high-density lipoprotein cholesterol (HDL-C is considered anti-atherogenic good cholesterol. It is involved in reverse transport of lipids. Epidemiological studies have found inverse relationship of HDL-C and coronary heart disease (CHD risk. When grouped according to HDL-C, subjects having HDL-C more than 60 mg/dL had lesser risk of CHD than those having HDL-C of 40-60 mg/dL, who in turn had lesser risk than those who had HDL-C less than 40 mg/dL. No upper limit for beneficial effect of HDL-C on CHD risk has been identified. The goals of treating patients with low HDL-C have not been firmly established. Though many drugs are known to improve HDL-C concentration, statins are proven to improve CHD risk and mortality. Cholesteryl ester transfer protein (CETP is involved in metabolism of HDL-C and its inhibitors are actively being screened for clinical utility. However, final answer is still awaited on CETP-inhibitors.

High density lipoproteins, dyslipidemia, and coronary heart disease

National Research Council Canada - National Science Library

2010-01-01

... with premature coronary heart disease (CHD). These familial disorders include lipoprotein(a) excess, dyslipidemia (high triglycerides and low HDL), combined hyperlipidemia (high cholesterol and high triglycerides often with low HDL), hypoalphalipoproteinemia (low HDL), and hypercholesterolemia. We discuss the management of these disorders. W...

Effects of aerobic exercise on lipids and lipoproteins.

Science.gov (United States)

Wang, Yating; Xu, Danyan

2017-07-05

Dyslipidemia is the risk of cardiovascular disease, and their relationship is clear. Lowering serum cholesterol can reduce the risk of coronary heart disease. At present, the main treatment is taking medicine, however, drug treatment has its limitations. Exercise not only has a positive effect on individuals with dyslipidemia, but can also help improve lipids profile. This review is intending to provide information on the effects of exercise training on both tranditional lipids, for example, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides and new lipids and lipoproteins such as non-high-density lipoprotein cholesterol, and postprandial lipoprotein. The mechanisms of aerobic exercise on lipids and lipoproteins are also briefly described.

Triglyceride-rich lipoproteins and high-density lipoprotein cholesterol in patients at high risk of cardiovascular disease: evidence and guidance for management

Science.gov (United States)

Chapman, M. John; Ginsberg, Henry N.; Amarenco, Pierre; Andreotti, Felicita; Borén, Jan; Catapano, Alberico L.; Descamps, Olivier S.; Fisher, Edward; Kovanen, Petri T.; Kuivenhoven, Jan Albert; Lesnik, Philippe; Masana, Luis; Nordestgaard, Børge G.; Ray, Kausik K.; Reiner, Zeljko; Taskinen, Marja-Riitta; Tokgözoglu, Lale; Tybjærg-Hansen, Anne; Watts, Gerald F.

2011-01-01

Even at low-density lipoprotein cholesterol (LDL-C) goal, patients with cardiometabolic abnormalities remain at high risk of cardiovascular events. This paper aims (i) to critically appraise evidence for elevated levels of triglyceride-rich lipoproteins (TRLs) and low levels of high-density lipoprotein cholesterol (HDL-C) as cardiovascular risk factors, and (ii) to advise on therapeutic strategies for management. Current evidence supports a causal association between elevated TRL and their remnants, low HDL-C, and cardiovascular risk. This interpretation is based on mechanistic and genetic studies for TRL and remnants, together with the epidemiological data suggestive of the association for circulating triglycerides and cardiovascular disease. For HDL, epidemiological, mechanistic, and clinical intervention data are consistent with the view that low HDL-C contributes to elevated cardiovascular risk; genetic evidence is unclear however, potentially reflecting the complexity of HDL metabolism. The Panel believes that therapeutic targeting of elevated triglycerides (≥1.7 mmol/L or 150 mg/dL), a marker of TRL and their remnants, and/or low HDL-C (<1.0 mmol/L or 40 mg/dL) may provide further benefit. The first step should be lifestyle interventions together with consideration of compliance with pharmacotherapy and secondary causes of dyslipidaemia. If inadequately corrected, adding niacin or a fibrate, or intensifying LDL-C lowering therapy may be considered. Treatment decisions regarding statin combination therapy should take into account relevant safety concerns, i.e. the risk of elevation of blood glucose, uric acid or liver enzymes with niacin, and myopathy, increased serum creatinine and cholelithiasis with fibrates. These recommendations will facilitate reduction in the substantial cardiovascular risk that persists in patients with cardiometabolic abnormalities at LDL-C goal. PMID:21531743

Moderate doses of alcoholic beverages with dinner and postprandial high density lipoprotein composition

NARCIS (Netherlands)

Hendriks, H.F.J.; Veenstra, J.; Tol, A. van; Groener, J.E.M.; Schaafsma, G.

1998-01-01

Moderate alcohol consumption is associated with a reduced risk of coronary heart disease. In this study, postprandial changes in plasma lipids, high-density lipoprotein (HDL) composition and cholesteryl ester transfer protein (CETP) and lecithin: cholesterol acyltransferase (LCAT) activity levels

Interfacial Tension and Surface Pressure of High Density Lipoprotein, Low Density Lipoprotein, and Related Lipid Droplets

DEFF Research Database (Denmark)

Ollila, O. H. S.; Lamberg, A.; Lehtivaara, M.

2012-01-01

) are essentially lipid droplets surrounded by specific proteins, their main function being to transport cholesterol. Interfacial tension and surface pressure of these particles are of great interest because they are related to the shape and the stability of the droplets and to protein adsorption at the interface....... Here we use coarse-grained molecular-dynamics simulations to consider a number of related issues by calculating the interfacial tension in protein-free lipid droplets, and in HDL and LDL particles mimicking physiological conditions. First, our results suggest that the curvature dependence......Lipid droplets play a central role in energy storage and metabolism on a cellular scale. Their core is comprised of hydrophobic lipids covered by a surface region consisting of amphiphilic lipids and proteins. For example, high and low density lipoproteins (HDL and LDL, respectively...

High-density lipoprotein modulates glucose metabolism in patients with type 2 diabetes mellitus

DEFF Research Database (Denmark)

Drew, Brian G; Duffy, Stephen J; Formosa, Melissa F

2009-01-01

BACKGROUND: Low plasma high-density lipoprotein (HDL) is associated with elevated cardiovascular risk and aspects of the metabolic syndrome. We hypothesized that HDL modulates glucose metabolism via elevation of plasma insulin and through activation of the key metabolic regulatory enzyme, AMP...

Low density lipoproteins mediated nanoplatforms for cancer targeting

International Nuclear Information System (INIS)

Jain, Anupriya; Jain, Keerti; Kesharwani, Prashant; Jain, Narendra K.

2013-01-01

Chemotherapy is a foremost remedial approach for the treatment of localized and metastasized tumors. In order to explore new treatment modalities for cancer, it is important to identify qualitative or quantitative differences in metabolic processes between normal and malignant cells. One such difference may be that of increased receptor-mediated cellular uptake of low density lipoproteins (LDLs) by cancer cells. Lipoproteins in general and specifically LDL are ideal candidates for loading and delivering cancer therapeutic and diagnostic agents due to their biocompatibility. By mimicking the endogenous shape and structure of lipoproteins, the reconstituted lipoproteins can remain in circulation for an extended period of time, while largely evading the reticuloendothelial cells in the body’s defenses. In this account, we review the field of low density inspired nanoparticles in relation to the delivery of cancer imaging and therapeutic agents. LDL has instinctive cancer targeting potential and has been used to incorporate various lipophillic molecules to transport them to tumors. Nature’s method of rerouting LDL provides a strategy to extend the cancer targeting potential of lipoproteins far off its constricted purview. In this review, we have discussed the various aspects of LDL including its role in cancer imaging and chemotherapy in retrospect and prospect and current efforts aimed to further improve the delivery efficacy of LDL–drug complexes with reduced chances of drug resistance leading to optimal drug delivery. This review provides a strong support for the concept of using LDL as a drug carrier

Low density lipoproteins mediated nanoplatforms for cancer targeting

Energy Technology Data Exchange (ETDEWEB)

Jain, Anupriya; Jain, Keerti; Kesharwani, Prashant, E-mail: prashant_pharmacy04@rediffmail.com; Jain, Narendra K., E-mail: jnarendr@yahoo.co.in [Dr. H. S. Gour University, Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences (India)

2013-09-15

Chemotherapy is a foremost remedial approach for the treatment of localized and metastasized tumors. In order to explore new treatment modalities for cancer, it is important to identify qualitative or quantitative differences in metabolic processes between normal and malignant cells. One such difference may be that of increased receptor-mediated cellular uptake of low density lipoproteins (LDLs) by cancer cells. Lipoproteins in general and specifically LDL are ideal candidates for loading and delivering cancer therapeutic and diagnostic agents due to their biocompatibility. By mimicking the endogenous shape and structure of lipoproteins, the reconstituted lipoproteins can remain in circulation for an extended period of time, while largely evading the reticuloendothelial cells in the body's defenses. In this account, we review the field of low density inspired nanoparticles in relation to the delivery of cancer imaging and therapeutic agents. LDL has instinctive cancer targeting potential and has been used to incorporate various lipophillic molecules to transport them to tumors. Nature's method of rerouting LDL provides a strategy to extend the cancer targeting potential of lipoproteins far off its constricted purview. In this review, we have discussed the various aspects of LDL including its role in cancer imaging and chemotherapy in retrospect and prospect and current efforts aimed to further improve the delivery efficacy of LDL-drug complexes with reduced chances of drug resistance leading to optimal drug delivery. This review provides a strong support for the concept of using LDL as a drug carrier.

Low density lipoproteins mediated nanoplatforms for cancer targeting

Science.gov (United States)

Jain, Anupriya; Jain, Keerti; Kesharwani, Prashant; Jain, Narendra K.

2013-09-01

Chemotherapy is a foremost remedial approach for the treatment of localized and metastasized tumors. In order to explore new treatment modalities for cancer, it is important to identify qualitative or quantitative differences in metabolic processes between normal and malignant cells. One such difference may be that of increased receptor-mediated cellular uptake of low density lipoproteins (LDLs) by cancer cells. Lipoproteins in general and specifically LDL are ideal candidates for loading and delivering cancer therapeutic and diagnostic agents due to their biocompatibility. By mimicking the endogenous shape and structure of lipoproteins, the reconstituted lipoproteins can remain in circulation for an extended period of time, while largely evading the reticuloendothelial cells in the body's defenses. In this account, we review the field of low density inspired nanoparticles in relation to the delivery of cancer imaging and therapeutic agents. LDL has instinctive cancer targeting potential and has been used to incorporate various lipophillic molecules to transport them to tumors. Nature's method of rerouting LDL provides a strategy to extend the cancer targeting potential of lipoproteins far off its constricted purview. In this review, we have discussed the various aspects of LDL including its role in cancer imaging and chemotherapy in retrospect and prospect and current efforts aimed to further improve the delivery efficacy of LDL-drug complexes with reduced chances of drug resistance leading to optimal drug delivery. This review provides a strong support for the concept of using LDL as a drug carrier.

What are lipoproteins doing in the brain?

Science.gov (United States)

Wang, Hong; Eckel, Robert H

2014-01-01

Lipoproteins in plasma transport lipids between tissues, however, only high-density lipoproteins (HDL) appear to traverse the blood-brain barrier (BBB); thus, lipoproteins found in the brain must be produced within the central nervous system. Apolipoproteins E (ApoE) and ApoJ are the most abundant apolipoproteins in the brain, are mostly synthesized by astrocytes, and are found on HDL. In the hippocampus and other brain regions, lipoproteins help to regulate neurobehavioral functions by processes that are lipoprotein receptor-mediated. Moreover, lipoproteins and their receptors also have roles in the regulation of body weight and energy balance, acting through lipoprotein lipase (LPL) and the low-density lipoprotein (LDL) receptor-related protein (LRP). Thus, understanding lipoproteins and their metabolism in the brain provides a new opportunity with potential therapeutic relevance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Alterations of serum cholesterol and serum lipoprotein in breast cancer of women

OpenAIRE

Hasija, Kiran; Bagga, Hardeep K.

2005-01-01

Fasting blood sample of 50 normal subjects (control) and 100 patients of breast cancer were investigated for serum total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, very low density lipoprotein, high density lipoprotein cholesterol:low density lipoprotein cholesterol ratio and total cholesterol:high density lipoprotein cholesterol ratio during breast cancer of women. Five cancer stages, types, age groups, parity and menopausal status were undertaken...

Assessing the functional properties of high-density lipoproteins : an emerging concept in cardiovascular research

NARCIS (Netherlands)

Triolo, Michela; Annema, Wijtske; Dullaart, Robin P. F.; Tietge, Uwe J. F.

Although plasma concentrations of high-density lipoprotein (HDL) cholesterol correlate inversely with the incidence of atherosclerotic cardiovascular disease, results from recent epidemiological, genetic and pharmacological intervention studies resulted in a shift of concept. Rather than HDL

Kandungan kolesterol, High Density Lipoprotein (HDL dan low density lipopro-tein (LDL darah burung puyuh dengan pemberian aditif cair buah naga merah

Directory of Open Access Journals (Sweden)

Khabib Arrosichin

2016-04-01

Full Text Available The study aims to determine, assess and evaluate the content of cholesterol, high density lipoprotein (HDL and Low Density Lipoprotein (LDL blood quail which were treated with liquid additive red dragon fruit. Materials used in the study were 200 female quails aged 14 days with an average weight of 13.61 ± 0.49 g. Ration composed by metabolizable energy content of ± 3000 kcal/kg and ± 20% of crude protein. The study consisted of 4 treatments and 5 replications. The treatments were (T0: without addition of liquid red dragon fruit (control; T1: addition of 5 ml liquid red dragon fruit twice a day; T2: addition of 5 ml liquid red dragon fruit once a day and T3: addition of 5 ml liquid red dragon fruit once in every two days. Blood sampling was performed in EDTA tube at the end of the study. Analysis of samples was carried out in health laboratory Semarang. The results were analyzed using analysis of variance (ANOVA. The study showed that the addition of liquid red dragon fruit additive had no significant effect (P> 0.05 on cholesterol, HDL and LDL of quil’s blood. Keywords: Quail, cholesterol; HDL, LDL, and red dragon fruit

High-density lipoproteins inhibit urate crystal-induced inflammation in mice

OpenAIRE

Scanu Anna; Luisetto Roberto; Oliviero Francesca; Gruaz Lyssia; Sfriso Paolo; Burger Danielle; Punzi Leonardo

2015-01-01

Objectives To investigate the effects and mechanisms of action of high density lipoproteins (HDL) in monosodium urate (MSU) crystal induced inflammation—that is gouty inflammation in vivo. Methods Air pouches raised on the backs of mice were injected with MSU crystals or tumour necrosis factor (TNF) in the presence or absence of HDL and/or interleukin (IL) 1 receptor antagonist (IL 1Ra) for 3 h. Leucocyte count and neutrophil percentage in pouch fluids were measured using a haemocytometer an...

Radiolabelled lipoproteins and method for making same

International Nuclear Information System (INIS)

Lees, R.S.

1987-01-01

A method is described for detecting accumulation of low density lipoproteins in an arterial wall, the method comprising the steps of A. preparing a technetium-99m-labelled low density lipoprotein in a solution having a pH between 8 and 9; B. injecting the labelled low density lipoprotein into the vascular system of a patient; C. subsequently viewing the patient's vascular system with extracorporeally-located detecting means capable of detecting the labelled low density lipoprotein; D. determining from the detecting means the locations of the labelled density lipoproteins; and E. quantifying concentrations of the labelled low density lipoproteins at the locations to determine the accumulation of the lipoproteins

Kinetics of incorporation/redistribution of photosensitizer hypericin to/from high-density lipoproteins.

Science.gov (United States)

Joniova, Jaroslava; Buriankova, Luboslava; Buzova, Diana; Miskovsky, Pavol; Jancura, Daniel

2014-11-20

By means of fluorescence spectroscopy we have studied the kinetics of interaction of a photosensitizer hypericin (Hyp) with high-density lipoproteins (HDL). Hyp is incorporated into HDL molecules as monomer till ratio Hyp/HDL ∼8:1 and above this ratio forms non-fluorescent aggregates. This number is different from that found in the case of Hyp incorporation into low-density lipoprotein (LDL) molecules (8:1 vs 30:1). The difference is mainly attributed to the smaller size of HDL in comparison with LDL molecule. Biphasic kinetics of Hyp association with HDL was observed. The rapid phase of incorporation is completed within seconds, while the slow one lasts several minutes. The kinetics of the association of Hyp molecules with free HDL, Hyp/HDL=10:1 complex and the redistribution of Hyp from Hyp/HDL=70:1 complex to free HDL molecules reveal a qualitative similar characteristics of these processes with those observed for the interaction of Hyp with LDL. However, the incorporation of Hyp into HDL in the "slow" phase is more rapid than to LDL and extend of Hyp penetration into lipoproteins in the fast phase is also much higher in the case of HDL. The lower concentration of cholesterol molecules in outer shell of HDL particles is probably the determining factor for the more rapid kinetics of Hyp incorporation to and redistribution from these molecules when comparing with LDL particles. Copyright © 2014 Elsevier B.V. All rights reserved.

Obtention of scintillography images by low density lipoproteins labelled with technetium 99

International Nuclear Information System (INIS)

Silva, S.; Coelho, I.; Zanardo, E.; Pileggi, F.; Meneguethi, C.; Maranhao, R.C.

1992-01-01

The low density lipoproteins carry the most part of the cholesterol in the blood plasma. These lipoproteins are labelled with technetium-99-m and have been used for obtaining images in nuclear medicine. The introduction of this technique is presented, aiming futures clinical uses. Scintillographic images are obtained 25 minutes and 24 hours after the injection of 3 m Ci of low density lipoproteins - technetium-99 m in rabbits. (C.G.C.)

Accumulation of native and methylated low density lipoproteins by healing rabbit arterial wall

International Nuclear Information System (INIS)

Fischman, A.J.; Lees, A.M.; Lees, R.S.; Barlai-Kovach, M.; Strauss, H.W.

1987-01-01

To determine whether healing arterial wall accumulation of low density lipoproteins (LDL) is mediated by the high affinity LDL receptor, normocholesterolemic rabbits were injected with 125 I-LDL, /sup 99m/Tc-LDL, or the reductively methylated analogs of these compounds ( 125 I-MeLDL, /sup 99m/Tc-MeLDL), 1 month after balloon catheter deendothelialization of the abdominal aorta. If the mechanism of accumulation requires interaction with the LDL receptor, reductively methylated lipoproteins which do not bind to the receptor should not accumulate in healing arterial wall. Twenty-four hours after injection of labelled lipoproteins, each animal was injected with Evans blue dye, in order to distinguish reendothelialized from deendothelialized aorta. One hour after dye injection, the aorta was fixed, removed, divided into abdominal (ballooned) and thoracic (unballooned) regions and counted. For all lipoprotein preparations, there were three to four times as many counts in the abdominal as in the thoracic aorta. En face autoradiographs were made of the aortas that had been exposed to 125 I-labelled lipoproteins. In the autoradiographs, the areas of the lowest activity corresponded to the centers of healing endothelial islands. The most intense radioactivity for both lipoproteins occurred in the region of the leading edge of the endothelial islands where active endothelial regeneration was in progress. The overall distribution of native and MeLDL accumulation was the same. The results suggest that low density lipoproteins are accumulated in areas of active endothelial regeneration by a mechanism that does not involve the high affinity LDL receptor

Release of endothelial cell lipoprotein lipase by plasma lipoproteins and free fatty acids

International Nuclear Information System (INIS)

Saxena, U.; Witte, L.D.; Goldberg, I.J.

1989-01-01

Lipoprotein lipase (LPL) bound to the lumenal surface of vascular endothelial cells is responsible for the hydrolysis of triglycerides in plasma lipoproteins. Studies were performed to investigate whether human plasma lipoproteins and/or free fatty acids would release LPL which was bound to endothelial cells. Purified bovine milk LPL was incubated with cultured porcine aortic endothelial cells resulting in the association of enzyme activity with the cells. When the cells were then incubated with media containing chylomicrons or very low density lipoproteins (VLDL), a concentration-dependent decrease in the cell-associated LPL enzymatic activity was observed. In contrast, incubation with media containing low density lipoproteins or high density lipoproteins produced a much smaller decrease in the cell-associated enzymatic activity. The addition of increasing molar ratios of oleic acid:bovine serum albumin to the media also reduced enzyme activity associated with the endothelial cells. To determine whether the decrease in LPL activity was due to release of the enzyme from the cells or inactivation of the enzyme, studies were performed utilizing radioiodinated bovine LPL. Radiolabeled LPL protein was released from endothelial cells by chylomicrons, VLDL, and by free fatty acids (i.e. oleic acid bound to bovine serum albumin). The release of radiolabeled LPL by VLDL correlated with the generation of free fatty acids from the hydrolysis of VLDL triglyceride by LPL bound to the cells. Inhibition of LPL enzymatic activity by use of a specific monoclonal antibody, reduced the extent of release of 125 I-LPL from the endothelial cells by the added VLDL. These results demonstrated that LPL enzymatic activity and protein were removed from endothelial cells by triglyceride-rich lipoproteins (chylomicrons and VLDL) and oleic acid

Geometrical separation method for lipoproteins using bioformulated-fiber matrix electrophoresis: size of high-density lipoprotein does not reflect its density.

Science.gov (United States)

Tabuchi, Mari; Seo, Makoto; Inoue, Takayuki; Ikeda, Takeshi; Kogure, Akinori; Inoue, Ikuo; Katayama, Shigehiro; Matsunaga, Toshiyuki; Hara, Akira; Komoda, Tsugikazu

2011-02-01

The increasing number of patients with metabolic syndrome is a critical global problem. In this study, we describe a novel geometrical electrophoretic separation method using a bioformulated-fiber matrix to analyze high-density lipoprotein (HDL) particles. HDL particles are generally considered to be a beneficial component of the cholesterol fraction. Conventional electrophoresis is widely used but is not necessarily suitable for analyzing HDL particles. Furthermore, a higher HDL density is generally believed to correlate with a smaller particle size. Here, we use a novel geometrical separation technique incorporating recently developed nanotechnology (Nata de Coco) to contradict this belief. A dyslipidemia patient given a 1-month treatment of fenofibrate showed an inverse relationship between HDL density and size. Direct microscopic observation and morphological observation of fractionated HDL particles confirmed a lack of relationship between particle density and size. This new technique may improve diagnostic accuracy and medical treatment for lipid related diseases.

Genetic analysis of long-lived families reveals novel variants influencing high density-lipoprotein cholesterol

DEFF Research Database (Denmark)

Feitosa, Mary F; Wojczynski, Mary K; Straka, Robert

2014-01-01

The plasma levels of high-density lipoprotein cholesterol (HDL) have an inverse relationship to the risks of atherosclerosis and cardiovascular disease (CVD), and have also been associated with longevity. We sought to identify novel loci for HDL that could potentially provide new insights...

High density lipoproteins as indicators of endothelial dysfunction in children with diadetes type I

Directory of Open Access Journals (Sweden)

Lobanova S.M.

2011-12-01

Full Text Available The aim of the investigation was to study the level of blood high density lipoproteins (HDL in the groups of children with different course of diadetes type I in order to find out the dependence of course and complications of diabetes on that level. Materials and methods: Blood high density lipoprotein (HDL levels were investigated in children and adolescents with diadetes type I, depending on the duration of diadetes type I, age, stage of sexual development, the stage of diabetic nephropathy and levels of plasma endothelin-1 (E-1. Results: Decrease in HDL level with increasing duration of diadetes type I in prepubertate patients, higher indices of HDL cholesterol were determined in girls, especially with impaired puberty. HDL cholesterol was higher in diabetic nephropathy at the stage of proteinuria and high level of blood endothelin-1. Conclusion: The revealed changes were considered to cause deregulation of vascular endothelium as a manifestation of the initial stages of endothelial dysfunction

Acetaldehyde binding increases the catabolism of rat serum low-density lipoproteins

International Nuclear Information System (INIS)

Savolainen, M.J.; Baraona, E.; Lieber, C.S.

1987-01-01

Acetaldehyde was found to form adducts with rat serum lipoproteins. The binding of [ 14 C]acetaldehyde to lipoproteins was studied at low concentrations which are known to exist during ethanol oxidation. The amount of lipoprotein adducts was a linear function of acetaldehyde concentration up to 250 μM. Incubation of rat plasma low-density lipoproteins (LDL) with 200 μM acetaldehyde increased the disappearance rate of the 3 H-label from the cholesterol ester moiety of LDL injected into normal rats. The data show that even low concentrations of acetaldehyde are capable of affecting LDL metabolism. These findings may provide an explanation for the low concentrations of serum LDL in alcoholics. The alcohol-induced hyperlipidemia includes either a lack of increase or a decrease in the low-density lipoprotein (LDL) concentration, but the underlying mechanism is not known. It has been shown previously, that the acetylation of lysine residues of LDL apoprotein (apoB) by acetanhydride leads to rapid uptake of LDL particles by macrophages through a non-LDL receptor pathway. Since acetaldehyde, the first toxic metabolite of ethanol, is a chemically reactive compound capable of binding to proteins, they tested whether acetaldehyde forms adducts with serum lipoproteins and subsequently alters the catabolism of LDL. 19 references, 2 figures, 1 table

Biomimetic High Density Lipoprotein Nanoparticles For Nucleic Acid Delivery

Science.gov (United States)

McMahon, Kaylin M.; Mutharasan, R. Kannan; Tripathy, Sushant; Veliceasa, Dorina; Bobeica, Mariana; Shumaker, Dale K.; Luthi, Andrea J.; Helfand, Brian T.; Ardehali, Hossein; Mirkin, Chad A.; Volpert, Olga; Thaxton, C. Shad

2014-01-01

We report a gold nanoparticle-templated high density lipoprotein (HDL AuNP) platform for gene therapy which combines lipid-based nucleic acid transfection strategies with HDL biomimicry. For proof-of-concept, HDL AuNPs are shown to adsorb antisense cholesterylated DNA. The conjugates are internalized by human cells, can be tracked within cells using transmission electron microscopy (TEM), and regulate target gene expression. Overall, the ability to directly image the AuNP core within cells, the chemical tailorability of the HDL AuNP platform, and the potential for cell-specific targeting afforded by HDL biomimicry make this platform appealing for nucleic acid delivery. PMID:21319839

Rethinking reverse cholesterol transport and dysfunctional high-density lipoproteins.

Science.gov (United States)

Gillard, Baiba K; Rosales, Corina; Xu, Bingqing; Gotto, Antonio M; Pownall, Henry J

2018-04-12

Human plasma high-density lipoprotein cholesterol concentrations are a negative risk factor for atherosclerosis-linked cardiovascular disease. Pharmacological attempts to reduce atherosclerotic cardiovascular disease by increasing plasma high-density lipoprotein cholesterol have been disappointing so that recent research has shifted from HDL quantity to HDL quality, that is, functional vs dysfunctional HDL. HDL has varying degrees of dysfunction reflected in impaired reverse cholesterol transport (RCT). In the context of atheroprotection, RCT occurs by 2 mechanisms: one is the well-known trans-hepatic pathway comprising macrophage free cholesterol (FC) efflux, which produces early forms of FC-rich nascent HDL (nHDL). Lecithin:cholesterol acyltransferase converts HDL-FC to HDL-cholesteryl ester while converting nHDL from a disc to a mature spherical HDL, which transfers its cholesteryl ester to the hepatic HDL receptor, scavenger receptor B1 for uptake, conversion to bile salts, or transfer to the intestine for excretion. Although widely cited, current evidence suggests that this is a minor pathway and that most HDL-FC and nHDL-FC rapidly transfer directly to the liver independent of lecithin:cholesterol acyltransferase activity. A small fraction of plasma HDL-FC enters the trans-intestinal efflux pathway comprising direct FC transfer to the intestine. SR-B1 -/- mice, which have impaired trans-hepatic FC transport, are characterized by high plasma levels of a dysfunctional FC-rich HDL that increases plasma FC bioavailability in a way that produces whole-body hypercholesterolemia and multiple pathologies. The design of future therapeutic strategies to improve RCT will have to be formulated in the context of these dual RCT mechanisms and the role of FC bioavailability. Copyright © 2018 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Gemfibrozil treatment of the high triglyceride-low high-density lipoprotein cholesterol trait in men with established atherosclerosis

NARCIS (Netherlands)

Knipscheer, H. C.; Nurmohamed, M. T.; van den Ende, A.; Plaat, B.; Pruijs, H. J.; Mulder, W. J.; Kastelein, J. J.

1994-01-01

To study the short-term efficacy, tolerability and safety of the treatment with gemfibrozil 600 mg twice daily or placebo in male patients with established atherosclerosis, with a lipid profile matching the 'high triglyceride-low high-density lipoprotein (HDL) cholesterol trait'. Double-blind

Direct effects of fatty meals and adiposity on oxidised low-density lipoprotein.

Science.gov (United States)

Laguna-Camacho, Antonio; Alonso-Barreto, Arely S; Mendieta-Zerón, Hugo

2015-01-01

High-fat intake and high adiposity contribute to hyperlipaemia. In a hyperlipaemic state, lipoproteins infiltrate arterial wall where they are modified and cause an immune response characteristic of atherosclerosis. A small fraction of modified lipoproteins including oxidised low-density lipoprotein (ox-LDL) returns to circulation. The present study tracked high-fat meals during four weeks as to find effects of sustained frequency change on adiposity and ox-LDL. The findings indicated that changes in frequency of consumption of high-fat eating episodes correlated directly with changes in adiposity and ox-LDL. Hence the number of fatty meals consumed by people with overweight or obesity in few weeks could affect the atherogenic process. Copyright © 2015 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.

A 90 minute soccer match decreases triglyceride and low density lipoprotein but not high-density lipoprotein and cholesterol levels

Directory of Open Access Journals (Sweden)

Nader - Rahnama

2009-11-01

Full Text Available

• BACKGROUND: The association between the lipid profiles level and the incidence and severity of coronary heart disease (CHD is very pronounced in epidemiological studies, and an inverse relation between physical fitness and the incidence of coronary heart disease has been observed in many studies. The aim of this study was to investigate the impact of a soccer match on lipid parameters of professional soccer players.
• METHODS: Twenty two professional soccer players participated in the study. Blood (10ml for determination of lipid profiles was obtained at rest and immediately after a 90 minute soccer match. Lipid parameters were measured using Boehringer Mannheim kits and Clinilab and BioMerieux analyser.
• RESULTS: The results of this study showed that the triglyceride was significantly higher before the match than afterwards (159.09 ± 58.2 vs. 88.63 ± 34.1 mg/dl, p < 0.001, whereas the low-density lipoprotein (LDL was lower before the match than after it (98.04 ± 28.9 vs. 112.31 ± 30.5 mg/dl. Moreover, there were no significant differences in cholesterol concentration (171.4 ± 30.28 mg/dl vs. 173.18 ± 32.75 mg/dl and high-density lipoprotein (HDL concentration (34.04 ± 5.58 mg/dl vs. 34.4 ± 4.6 mg/dl between before and after the match.
• CONCLUSIONS: Although the soccer competitive match has no favourable acute effect on lipid

• Effect of chromium chloride supplementation on glucose tolerance and serum lipids including high-density lipoprotein of adult men.

  Science.gov (United States)

  Riales, R; Albrink, M J

  1981-12-01

  Chromium deficiency may cause insulin resistance, hyperinsulinemia, impaired glucose tolerance, and hyperlipidemia, recovered by chromium supplementation. The effect of chromium supplementation on serum lipids and glucose tolerance was tested in a double-blind 12-wk study of 23 healthy adult men aged 31 to 60 yr. Either 200 micrograms trivalent chromium in 5 ml water (Cr) or 5 ml plain water (W) was ingested daily 5 days each week. Half the subjects volunteered for glucose tolerance tests with insulin levels. At 12 wk high-density lipoprotein cholesterol increased in the Cr group from 35 to 39 mg/dl (p less than 0.05) but did not change in the water group (34 mg/dl). The largest increase in high-density lipoprotein cholesterol and decreases in insulin and glucose were found in those subjects having normal glucose levels together with elevated insulin levels at base-line. The data are thus consistent with the hypothesis that Cr supplementation raises high-density lipoprotein cholesterol and improves insulin sensitivity in those with evidence of insulin resistance but normal glucose tolerance.

• In vitro production of beta-very low density lipoproteins and small, dense low density lipoproteins in mildly hypertriglyceridemic plasma: role of activities of lecithin:cholester acyltransferase, cholesterylester transfer proteins and lipoprotein lipase.

  Science.gov (United States)

  Chung, B H; Segrest, J P; Franklin, F

  1998-12-01

  As a model for the formation of beta-very low density lipoproteins (VLDL) and small, dense LDL by the intraplasma metabolic activities in vivo, lipoproteins in fresh plasma were interacted in vitro with endogenous lecithin:cholesterol acyltransferase (LCAT) and cholesterylester transfer proteins (CETP) and subsequently with purified lipoprotein lipase (LpL). The LCAT and CETP reactions in a mildly hypertriglyceridemic (HTG) plasma at 37 degrees C for 18 h resulted in (1) esterification of about 45% plasma unesterified cholesterol (UC), (2) a marked increase in cholesterylester (CE) (+129%) and a decrease in triglyceride (TG) (-45%) in VLDL, and (3) a marked increase of TG (+ 341%) with a small net decrease of CE (-3.6%) in LDL, causing a significant alteration in the TG/CE of VLDL (from 8.0 to 1.9) and of LDL (from 0.20 to 0.93). The LDL in LCAT and CETP-reacted plasma is larger and more buoyant than that in control plasma. In vitro lipolysis of control and LCAT and CETP-reacted plasma by LpL, which hydrolyzed >90% of VLDL-TG and about 50-60% of LDL-TG, converted most of VLDL in control plasma (>85%) but less than half (40%) of VLDL in LCAT and CETP-reacted plasma into the IDL-LDL density fraction and transformed the large, buoyant LDL in the LCAT and CETP-reacted plasma into particles smaller and denser than those in the control plasma. The remnants that accumulated in the VLDL density region of the postlipolysis LCAT and CETP-reacted plasma contained apo B-100 and E but little or no detectable apo Cs and consisted of particles having pre-beta and beta-electrophoretic mobilities. The inhibition of LCAT during incubation of plasma, which lessened the extent of alteration in VLDL and LDL core lipids, increased the extent of lipolytic removal of VLDL from the VLDL density region but lowered the extent of alteration in the size and density of LDL. The LCAT, CETP and/or LpL-mediated alterations in the density of LDL in normolipidemic fasting plasma were less pronounced

• Lipoprotein glomerulopathy treated with LDL-apheresis (Heparin-induced Extracorporeal Lipoprotein Precipitation system: a case report

  Directory of Open Access Journals (Sweden)

  Rivasi Paolo

  2009-12-01

  Full Text Available Abstract Introduction Lipoprotein glomerulopathy is a glomerulonephritis which was described for the first time by Saito in 1989 and is currently acknowledged as a separate nosological entity. It is histologically characterized by a marked dilatation of the glomerular capillaries and the presence of lipoprotein thrombi in the glomerular lumens. The dyslipidemic profile is similar to that of type III dyslipoproteinemia with Apolipoprotein E values that are often high; proteinuria and renal dysfunction are present. Proteinuria often does not respond to steroid and cytostatic treatments. The phenotypic expression of lipoprotein glomerulopathy is most probably correlated to a genetic alteration of the lipoprotein metabolism (mutation of the Apolipoprotein E coding gene. In literature, lipoprotein glomerulopathies have mainly been reported in Japanese and Chinese subjects, except for three cases in the Caucasian race, reported in France and the USA. Case presentation We describe the case of a 60-year-old female, Caucasian patient suffering from lipoprotein glomerulopathy, carrier of a new mutation on the Apolipoprotein E gene (Apolipoprotein EMODENA, and treated successfully with low density lipoprotein-apheresis with the Heparin induced extracorporeal lipoprotein precipitation system. After a first phase of therapeutic protocol with statins, the patient was admitted for nephrotic syndrome, renal failure and hypertension. Since conventional treatment alone was not able to control dyslipidemia, aphaeretic treatment with heparin-induced Extracorporeal Lipoprotein Precipitation - apheresis (HELP-apheresis was started to maintain angiotensin converting enzyme inhibitor therapy for the treatment of hypertension. Treatment with HELP-apheresis led to a complete remission of the proteinuria in a very short time (four months, as well as control of hypercholesterolemia and renal function recovery. Conclusion According to this case of lipoprotein glomerulopathy

• Role of Hepatic Lipase and Endothelial Lipase in High-Density Lipoprotein-Mediated Reverse Cholesterol Transport

  NARCIS (Netherlands)

  Annema, Wijtske; Tietge, Uwe J. F.

  Reverse cholesterol transport (RCT) constitutes a key part of the atheroprotective properties of high-density lipoproteins (HDL). Hepatic lipase (HL) and endothelial lipase (EL) are negative regulators of plasma HDL cholesterol levels. Although overexpression of EL decreases overall

• [A history and review of cholesterol ester transfer protein inhibitors and their contribution to the understanding of the physiology and pathophysiology of high density lipoprotein].

  Science.gov (United States)

  Corral, Pablo; Schreier, Laura

  2014-01-01

  There is irrefutable evidence that statins reduce the risk of cardiovascular events in a magnitude proportional to the intensity of the decrease in cholesterol transport by the low density lipoproteins. Despite this great advance there is still a residual risk of cardiovascular events. For this reason, an increase in the levels of high density lipoprotein is considered in order to boost the main action of this lipoprotein, which is reverse cholesterol transport. Distinct classes of evidence (epidemiological, genetic, and pathophysiological) show that the inhibition and/or modulation of cholesterol ester transfer protein increases plasma high density lipoprotein-cholesterol levels. The main reason for presenting this review is to look at the physiology of cholesterol ester transfer protein, its interrelationship with high density lipoproteins, and to give an update on the development of different cholesterol ester transfer protein inhibitor/modulator molecules. Copyright © 2013 Elsevier España, S.L. y SEA. All rights reserved.

• Uptake of [3H]vitamin D3 from low and high density lipoproteins by cultured human fibroblasts

  International Nuclear Information System (INIS)

  Shireman, R.B.; Williams, D.; Remsen, J.F.

  1986-01-01

  The plasma distribution and cellular uptake of [ 3 H]vitamin D 3 was studied in vitro using cultured human fibroblasts. Incubation of [ 3 H]vitamin D 3 (cholecalciferol) with plasma followed by sequential ultracentrifugal fractionation of the lipoproteins indicated that 2-4% of the radioactivity associated with the very low density lipoprotein (VLDL), 12% with low density lipoprotein (LDL), and approximately 60% with the high density lipoprotein (HDL). The remaining radioactivity, 25%, was associated with the sedimented plasma fractions. By comparison, an average of 86% of the radioactivity from [ 3 H] 1,25-dihydroxycholecalciferol associated with the sedimented plasma fractions. The uptake of [ 3 H]vitamin D 3 from plasma, LDL, or HDL was studied in cultured human cells; uptake by normal fibroblasts was greatest from LDL and least from plasma. The cellular association of vitamin D 3 was time, concentration, and temperature dependent. At a concentration of 50 μg LDL/ml of medium, the uptake of [ 3 H]vitamin D 3 from LDL at 37 0 C was rapid and reached a maximum at approximately 4 hr; it was slower from HDL but continued to increase slowly up to 24 hr. The significance of these in vitro findings is uncertain since much of the vitamin D 3 absorbed from the intestine reportedly associates with chylomicrons and is rapidly taken up by the liver

• Correlation between serum lipoproteins and abdominal fat pad in ...

  African Journals Online (AJOL)

  GREGORY

  2010-08-30

  Aug 30, 2010 ... Triglyceride, cholesterol and VLDL concentrations were positively correlated with ... negative correlation was observed between high-density lipoprotein and ... Abbreviations: HDL, High density lipoprotein; VLDL, very low.

• Effects of 1,2-cyclohexanedione modification on the metabolism of very low density lipoprotein apolipoprotein B: potential role of receptors in intermediate density lipoprotein catabolism

  International Nuclear Information System (INIS)

  Packard, C.J.; Boag, D.E.; Clegg, R.; Bedford, D.; Shepherd, J.

  1985-01-01

  The conversion of very low density (VLDL) to low density lipoproteins (LDL) is a two-step process. The first step is mediated by lipoprotein lipase, but the mechanism responsible for the second is obscure. In this study we examined the possible involvement of receptors at this stage. Apolipoprotein B (apoB)-containing lipoproteins were separated into three fractions, VLDL (Sf 100-400), an intermediate fraction IDL (Sf 12-100), and LDL (Sf 0-12). Autologous 125I-labeled VLDL and 131I-labeled 1,2-cyclohexanedione-modified VLDL were injected into the plasma of four normal subjects and the rate of transfer of apoB radioactivity was followed through IDL to LDL. Modification did not affect VLDL to IDL conversion. Thereafter, however, the catabolism of modified apoB in IDL was retarded and its appearance in LDL was delayed. Hence, functional arginine residues (and by implication, receptors) are required in this process. Confirmation of this was obtained by injecting 125I-labeled IDL and 131I-labeled cyclohexanedione-treated IDL into two additional subjects. Again, IDL metabolism was delayed by approximately 50% as a result of the modification. These data are consistent with the view that receptors are involved in the metabolism of intermediate density lipoprotein

• Cholesterol synthesis by human fetal hepatocytes: effect of lipoproteins

  International Nuclear Information System (INIS)

  Carr, B.R.; Simpson, E.R.

  1984-01-01

  The purpose of the present investigation was to determine the effect of various lipoproteins on the rate of cholesterol synthesis of human fetal liver cells maintained in culture. This was accomplished by measuring the rate of incorporation of tritium from tritiated water or carbon 14-labeled acetate into cholesterol in human fetal liver cells. Optimal conditions for each assay were determined. When human fetal liver cells were maintained in the presence of low-density lipoprotein, cholesterol synthesis was inhibited in a concentration-dependent fashion. Intermediate--density lipoprotein and very-low-density lipoprotein also suppressed cholesterol synthesis in human fetal liver cells. In contrast, high-density lipoprotein stimulated cholesterol synthesis in human fetal liver cells. The results of the present as well as our previous investigations suggest that multiple interrelationships exist between fetal liver cholesterol synthesis and lipoprotein-cholesterol utilization by the human fetal adrenal gland and that these processes serve to regulate the lipoprotein-cholesterol levels in fetal plasma

• Epidemiological reference ranges for low-density lipoprotein ...

  African Journals Online (AJOL)

  Although there is widespread acceptance that total cholesterol (TC) value reference ranges should be based on epidemiological rather than statistical considerations, the epidemiological action limits for Iow-density lipoprotein cholesterol (LDL-C) are still incomplete and only statistical reference ranges for apolipoprotein B ...

• Effects of hormones on lipids and lipoproteins

  Energy Technology Data Exchange (ETDEWEB)

  Krauss, R.M.

  1991-12-01

  Levels of plasma lipids and lipoproteins are strong predictors for the development of atherosclerotic cardiovascular disease in postmenopausal women. In women, as in men, numerous factors contribute to variations in plasma lipoproteins that may affect cardiovascular disease risk. These include age, dietary components, adiposity, genetic traits, and hormonal changes. Each of these factors may operate to varying degrees in determining changes in plasma lipoprotein profiles accompanying menopause- Cross-sectional and longitudinal studies have suggested increases in levels of cholesterol, low density lipoproteins (LDL) and triglyceride-rich lipoproteins associated with menopause. High density lipoproteins (HDL), which are higher in women than men and are thought to contribute to relative protection of premenopausal women from cardiovascular disease, remain relatively constant in the years following menopause, although small, and perhaps transient reductions in the HDL{sub 2} subfraction have been reported in relation to reduced estradiol level following menopause. Despite these associations, it has been difficult to determine the role of endogenous hormones in influencing the plasma lipoproteins of postmenopausal women. In principle, the effects of hormone replacement should act to reverse any alterations in lipoprotein metabolism that are due to postmenopausal hormone changes. While there may be beneficial effects on lipoproteins, hormone treatment does not restore a premenopausal lipoprotein profile. Furthermore, it is not dear to what extent exogenous hormone-induced lipoprotein changes contribute to the reduced incidence of cardiovascular disease with hormone replacement therapy.

• Nonfasting Triglycerides, Low-Density Lipoprotein Cholesterol, and Heart Failure Risk

  DEFF Research Database (Denmark)

  Varbo, Anette; Nordestgaard, Børge G

  2018-01-01

  OBJECTIVE: The prevalence of heart failure is increasing in the aging population, and heart failure is a disease with large morbidity and mortality. There is, therefore, a need for identifying modifiable risk factors for prevention. We tested the hypothesis that high concentrations of nonfasting...... triglycerides and low-density lipoprotein cholesterol are associated with higher risk of heart failure in the general population. APPROACH AND RESULTS: We included 103 860 individuals from the Copenhagen General Population Study and 9694 from the Copenhagen City Heart Study in 2 prospective observational...... association studies. Nonfasting triglycerides and low-density lipoprotein cholesterol were measured at baseline. Individuals were followed for ≤23 years, during which time 3593 were diagnosed with heart failure. Hazard ratios were estimated using Cox proportional hazard regression models. In the Copenhagen...

• Low density lipoprotein uptake by an endothelial-smooth muscle cell bilayer

  International Nuclear Information System (INIS)

  Alexander, J.J.; Miguel, R.; Graham, D.

  1991-01-01

  To study the interaction of endothelial and smooth muscle cells, and the means by which such interaction may affect lipid permeability of the arterial wall, cell bilayers were established by use of a transwell culture system. After confluent growth of both cell types had been achieved, iodine 125 bound to low-density lipoprotein (10 ng protein/ml) was added to the media of the upper well. After a 3-hour incubation period, the iodine 125-bound low-density lipoprotein content of the upper and lower media demonstrated an impedance to lipoprotein movement across the endothelial cell monolayer as compared to the bare porous polycarbonate filter of the transwell (p less than 10(-6)). The presence of smooth muscle cells in the bottom well significantly enhanced the permeability of the endothelial cell layer (p less than 10(-60)). This effect remained unchanged over a 9-day time course. Membrane binding and cellular uptake of low-density lipoprotein by endothelial cells was not altered by smooth muscle cells, indicating that this change in permeability could not be easily attributed to changes in receptor-mediated transport or transcytosis. Membrane binding (p less than 0.02) and cellular uptake (p less than 10(-6)) of low-density lipoprotein by smooth muscle cells in the bilayer, when adjusted for counts available in the smooth muscle cell media, were both reduced in the early incubation period as compared to isolated smooth muscle cells. The disproportionate reduction in uptake as compared to binding would suggest that this was not entirely a receptor-dependent process

• High-density lipoprotein cholesterol and cardiovascular disease. Four prospective American studies.

  Science.gov (United States)

  Gordon, D J; Probstfield, J L; Garrison, R J; Neaton, J D; Castelli, W P; Knoke, J D; Jacobs, D R; Bangdiwala, S; Tyroler, H A

  1989-01-01

  The British Regional Heart Study (BRHS) reported in 1986 that much of the inverse relation of high-density lipoprotein cholesterol (HDLC) and incidence of coronary heart disease was eliminated by covariance adjustment. Using the proportional hazards model and adjusting for age, blood pressure, smoking, body mass index, and low-density lipoprotein cholesterol, we analyzed this relation separately in the Framingham Heart Study (FHS), Lipid Research Clinics Prevalence Mortality Follow-up Study (LRCF) and Coronary Primary Prevention Trial (CPPT), and Multiple Risk Factor Intervention Trial (MRFIT). In CPPT and MRFIT (both randomized trials in middle-age high-risk men), only the control groups were analyzed. A 1-mg/dl (0.026 mM) increment in HDLC was associated with a significant coronary heart disease risk decrement of 2% in men (FHS, CPPT, and MRFIT) and 3% in women (FHS). In LRCF, where only fatal outcomes were documented, a 1-mg/dl increment in HDLC was associated with significant 3.7% (men) and 4.7% (women) decrements in cardiovascular disease mortality rates. The 95% confidence intervals for these decrements in coronary heart and cardiovascular disease risk in the four studies overlapped considerably, and all contained the range 1.9-2.9%. HDLC levels were essentially unrelated to non-cardiovascular disease mortality. When differences in analytic methodology were eliminated, a consistent inverse relation of HDLC levels and coronary heart disease event rates was apparent in BRHS as well as in the four American studies.

• Unique Features of High-Density Lipoproteins in the Japanese: In Population and in Genetic Factors

  Directory of Open Access Journals (Sweden)

  Shinji Yokoyama

  2015-04-01

  Full Text Available Despite its gradual increase in the past several decades, the prevalence of atherosclerotic vascular disease is low in Japan. This is largely attributed to difference in lifestyle, especially food and dietary habits, and it may be reflected in certain clinical parameters. Plasma high-density lipoprotein (HDL levels, a strong counter risk for atherosclerosis, are indeed high among the Japanese. Accordingly, lower HDL seems to contribute more to the development of coronary heart disease (CHD than an increase in non-HDL lipoproteins at a population level in Japan. Interestingly, average HDL levels in Japan have increased further in the past two decades, and are markedly higher than in Western populations. The reasons and consequences for public health of this increase are still unknown. Simulation for the efficacy of raising HDL cholesterol predicts a decrease in CHD of 70% in Japan, greater than the extent by reducing low-density lipoprotein cholesterol predicted by simulation or achieved in a statin trial. On the other hand, a substantial portion of hyperalphalipoproteinemic population in Japan is accounted for by genetic deficiency of cholesteryl ester transfer protein (CETP, which is also commonly unique in East Asian populations. It is still controversial whether CETP mutations are antiatherogenic. Hepatic Schistosomiasis is proposed as a potential screening factor for historic accumulation of CETP deficiency in East Asia.

• Heritability of Biomarkers of Oxidized Lipoproteins: Twin Pair Study.

  Science.gov (United States)

  Rao, Fangwen; Schork, Andrew J; Maihofer, Adam X; Nievergelt, Caroline M; Marcovina, Santica M; Miller, Elizabeth R; Witztum, Joseph L; O'Connor, Daniel T; Tsimikas, Sotirios

  2015-07-01

  To determine whether biomarkers of oxidized lipoproteins are genetically determined. Lipoprotein(a) (Lp[a]) is a heritable risk factor and carrier of oxidized phospholipids (OxPL). We measured oxidized phospholipids on apolipoprotein B-containing lipoproteins (OxPL-apoB), Lp(a), IgG, and IgM autoantibodies to malondialdehyde-modified low-density lipoprotein, copper oxidized low-density lipoprotein, and apoB-immune complexes in 386 monozygotic and dizygotic twins to estimate trait heritability (h(2)) and determine specific genetic effects among traits. A genome-wide linkage study followed by genetic association was performed. The h(2) (scale: 0-1) for Lp(a) was 0.91±0.01 and for OxPL-apoB 0.87±0.02, which were higher than physiological, inflammatory, or lipid traits. h(2) of IgM malondialdehyde-modified low-density lipoprotein, copper oxidized low-density lipoprotein, and apoB-immune complexes were 0.69±0.04, 0.67±0.05, and 0.80±0.03, respectively, and for IgG malondialdehyde-modified low-density lipoprotein, copper oxidized low-density lipoprotein, and apoB-immune complexes 0.62±0.05, 0.52±0.06, and 0.53±0.06, respectively. There was an inverse correlation between the major apo(a) isoform and OxPL-apoB (R=-0.49; Plipoprotein and copper oxidized low-density lipoprotein, and apoB-immune complexes. Sib-pair genetic linkage of the Lp(a) trait revealed that single nucleotide polymorphism rs10455872 was significantly associated with OxPL-apoB after adjusting for Lp(a). OxPL-apoB and other biomarkers of oxidized lipoproteins are highly heritable cardiovascular risk factors that suggest novel genetic origins of atherothrombosis. © 2015 American Heart Association, Inc.

• How Well Does BODIPY-Cholesteryl Ester Mimic Unlabeled Cholesteryl Esters in High Density Lipoprotein Particles?

  DEFF Research Database (Denmark)

  Karilainen, Topi; Vuorela, Timo; Vattulainen, Ilpo

  2015-01-01

  We compare the behavior of unlabeled and BODIPY-labeled cholesteryl ester (CE) in high density lipoprotein by atomistic molecular dynamics simulations. We find through replica exchange umbrella sampling and unbiased molecular dynamics simulations that BODIPY labeling has no significant effect...... on the partitioning of CE between HDL and the water phase. However, BODIPY-CE was observed to diffuse more slowly and locate itself closer to the HDL-water interface than CE due to the BODIPY probe that is constrained to the surface region, and because the CE body in BODIPY-CE prefers to align itself away from...... the HDL surface. The implications as to the suitability of BODIPY to explore lipoprotein properties are discussed....

Metabolism of triglyceride-rich nascent rat hepatic high density lipoproteins

International Nuclear Information System (INIS)

Winkler, K.E.; Marsh, J.B.

1989-01-01

Nascent high density lipoprotein (HDL) and nascent very low density lipoprotein (VLDL) were isolated from rat livers that had been perfused with [3H]glycerol to label the triglyceride. When injected into intact rats, the labeled HDL-triglyceride disappeared as rapidly as the VLDL-triglyceride, with only 10% of the injected label remaining in the plasma after 30 min. The protein moiety of nascent HDL was labeled with [35S]methionine in a similar fashion and the labeled nascent HDL was separated into nonretained (NR) and retained (R) fractions by heparin-Sepharose affinity chromatography. When injected into rats, 55% of the injected label in nascent fraction NR and 72% of that in nascent fraction R was recovered from plasma at 30 min, compared to only 10% of the triglyceride label from unfractionated nascent HDL, indicating dissociation of triglyceride and apolipoprotein clearance. The plasma decay curves for both triglyceride and protein were biexponential. By 5 min, 15% of the 35S label remaining in plasma represented apoE and apoC that had been transferred from nascent HDL fractions NR and R to the d less than 1.063 g/ml fraction of plasma. Plasma HDL was labeled in vivo with [35S]methionine, separated into fractions NR and R, and the clearance of the two plasma HDL fractions was compared with that of the corresponding nascent HDL fractions. Except for a faster rate of removal of the nascent HDL fractions during the first 5 min, the serum decay curves were very similar

Increased Antioxidant Quality Versus Lower Quantity Of High Density Lipoprotein In Benign Prostatic Hyperplasia

Directory of Open Access Journals (Sweden)

Aydin Ozgur

2015-10-01

Full Text Available Background: Oxidative stress may be involved in the pathogenesis of every human disease. To understand its possible role in benign prostatic hyperplasia (BPH, we measured the overall oxidative status of patients with BPH and the serum activity of the high density lipoprotein (HDL-related antioxidant enzymes paraoxonase 1 (PON1 and arylesterase (ARE.

On-treatment non-high-density lipoprotein cholesterol, apolipoprotein B, triglycerides, and lipid ratios in relation to residual vascular risk after treatment with potent statin therapy

DEFF Research Database (Denmark)

Mora, Samia; Glynn, Robert J; Boekholdt, S Matthijs

2012-01-01

The goal of this study was to determine whether residual risk after high-dose statin therapy for primary prevention individuals with reduced levels of low-density lipoprotein cholesterol (LDL-C) is related to on-treatment apolipoprotein B, non-high-density lipoprotein cholesterol (non-HDL-C), tri...

Lipoprotein-associated phospholipase A2 distribution among lipoproteins differs in type 1 diabetes.

Science.gov (United States)

Jarvie, Jennifer L; Wang, Hong; Kinney, Gregory L; Snell-Bergeon, Janet; Hokanson, John E; Eckel, Robert H

2016-01-01

LpPLA2 mass and activity have been variably related to cardiovascular disease risk, and the distribution of LpPLA2 in patients with type 1 diabetes (T1D), wherein cardiovascular disease risk is high despite normal or higher levels of high-density lipoprotein (HDL) cholesterol, is unknown. To determine whether there are differences in the distribution of LpPLA2 mass and activity across lipoproteins and their association with coronary artery calcium (CAC) in patients with T1D. Men with T1D (n = 19) not on statins, with and without CAC progression, and men without diabetes matched for HDL cholesterol (n = 25) had lipoproteins separated by fast protein liquid chromatography. Both LpPLA2 mass and activity were found within low-density lipoprotein (LDL) and HDL pools with more LpPLA2 mass being associated with HDL (54% vs 44%; P-value lipoprotein subfractions was observed between all groups, and there was no relationship between LpPLA2 activity or mass and its distribution and CAC score progression in healthy or T1D men. LpPLA2 is found in both LDL and HDL and is distributed differently in men with T1D without any relationship to CAC score progression. Copyright © 2016 National Lipid Association. Published by Elsevier Inc. All rights reserved.

Novel changes in discoidal high density lipoprotein morphology: a molecular dynamics study.

Science.gov (United States)

Catte, Andrea; Patterson, James C; Jones, Martin K; Jerome, W Gray; Bashtovyy, Denys; Su, Zhengchang; Gu, Feifei; Chen, Jianguo; Aliste, Marcela P; Harvey, Stephen C; Li, Ling; Weinstein, Gilbert; Segrest, Jere P

2006-06-15

ApoA-I is a uniquely flexible lipid-scavenging protein capable of incorporating phospholipids into stable particles. Here we report molecular dynamics simulations on a series of progressively smaller discoidal high density lipoprotein particles produced by incremental removal of palmitoyloleoylphosphatidylcholine via four different pathways. The starting model contained 160 palmitoyloleoylphosphatidylcholines and a belt of two antiparallel amphipathic helical lipid-associating domains of apolipoprotein (apo) A-I. The results are particularly compelling. After a few nanoseconds of molecular dynamics simulation, independent of the starting particle and method of size reduction, all simulated double belts of the four lipidated apoA-I particles have helical domains that impressively approximate the x-ray crystal structure of lipid-free apoA-I, particularly between residues 88 and 186. These results provide atomic resolution models for two of the particles produced by in vitro reconstitution of nascent high density lipoprotein particles. These particles, measuring 95 angstroms and 78 angstroms by nondenaturing gradient gel electrophoresis, correspond in composition and in size/shape (by negative stain electron microscopy) to the simulated particles with molar ratios of 100:2 and 50:2, respectively. The lipids of the 100:2 particle family form minimal surfaces at their monolayer-monolayer interface, whereas the 50:2 particle family displays a lipid pocket capable of binding a dynamic range of phospholipid molecules.

Comparing fluorescence-based cell-free assays for the assessment of antioxidative capacity of high-density lipoproteins

Science.gov (United States)

Background: Population studies have shown an inverse association between high-density lipoprotein (HDL) cholesterol levels and risk of coronary heart disease (CHD). HDL has different functions, including the ability to protect biological molecules from oxidation. Our aim was to evaluate the performa...

Increased oxidizability of low-density lipoproteins in hypothyroidism

NARCIS (Netherlands)

Diekman, T.; Demacker, P. N.; Kastelein, J. J.; Stalenhoef, A. F.; Wiersinga, W. M.

1998-01-01

Hypothyroidism leads to an increase of plasma low-density lipoprotein (LDL) cholesterol levels. Oxidation of LDL particles changes their intrinsic properties, thereby enhancing the development of atherosclerosis. T4 has three specific binding sites on apolipoprotein B; furthermore it inhibits LDL

Lipoprotein particle distribution and skeletal muscle lipoprotein lipase activity after acute exercise.

Science.gov (United States)

Harrison, Michael; Moyna, Niall M; Zderic, Theodore W; O'Gorman, Donal J; McCaffrey, Noel; Carson, Brian P; Hamilton, Marc T

2012-07-10

Many of the metabolic effects of exercise are due to the most recent exercise session. With recent advances in nuclear magnetic resonance spectroscopy (NMRS), it is possible to gain insight about which lipoprotein particles are responsible for mediating exercise effects. Using a randomized cross-over design, very low density lipoprotein (VLDL) responses were evaluated in eight men on the morning after i) an inactive control trial (CON), ii) exercising vigorously on the prior evening for 100 min followed by fasting overnight to maintain an energy and carbohydrate deficit (EX-DEF), and iii) after the same exercise session followed by carbohydrate intake to restore muscle glycogen and carbohydrate balance (EX-BAL). The intermediate, low and high density lipoprotein particle concentrations did not differ between trials. Fasting triglyceride (TG) determined biochemically, and mean VLDL size were lower in EX-DEF but not in EX-BAL compared to CON, primarily due to a reduction in VLDL-TG in the 70-120 nm (large) particle range. In contrast, VLDL-TG was lower in both EX-DEF and EX-BAL compared to CON in the 43-55 nm (medium) particle range. VLDL-TG in smaller particles (29-43 nm) was unaffected by exercise. Because the majority of VLDL particles were in this smallest size range and resistant to change, total VLDL particle concentration was not different between any of these conditions. Skeletal muscle lipoprotein lipase (LPL) activity was also not different across these 3 trials. However, in CON only, the inter-individual differences in LPL activity were inversely correlated with fasting TG, VLDL-TG, total, large and small VLDL particle concentration and VLDL size, indicating a regulatory role for LPL in the non-exercised state. These findings reveal a high level of differential regulation between different sized triglyceride-rich lipoproteins following exercise and feeding, in the absence of changes in LPL activity.

Combined analysis of six lipoprotein lipase genetic variants on triglycerides, high-density lipoprotein, and ischemic heart disease: cross-sectional, prospective, and case-control studies from the Copenhagen City Heart Study

DEFF Research Database (Denmark)

Wittrup, HH; Andersen, RV; Tybjærg-Hansen, A

2006-01-01

CONTEXT: Genetic variants in lipoprotein lipase may affect triglycerides, high-density lipoprotein (HDL), and risk of ischemic heart disease (IHD). OBJECTIVE: The objective of this study was to investigate the influence of T(-93)G, G(-53)C, Asp9Asn, Gly188Glu, Asn291Ser, and Ser447Ter lipoprotein...... lipase genotypes on triglycerides, HDL, and IHD. DESIGN: The cross-sectional study involved 9004 adults. The prospective study consisted of 8817 adults developing 1001 IHD events over 23 yr. The case-control study involved 7818 non-IHD individuals vs. cohorts of 915 and 1062 IHD patients, respectively....... SETTING: The study was performed in the Danish general population (the Copenhagen City Heart Study). PARTICIPANTS: IHD was angina pectoris or myocardial infarction. MAIN OUTCOME MEASURES: Triglycerides, HDL, and IHD were the main outcome measures. RESULTS: Cross-sectionally, triglycerides varied...

Biominetic High Density Lipoproteins for the Delivery of Therapeutic Oligonucleotides

Science.gov (United States)

Tripathy, Sushant

Advances in nanotechnology have brought about novel inorganic and hybrid nanoparticles with unique physico-chemical properties that make them suitable for a broad range of applications---from nano-circuitry to drug delivery. A significant part of those advancements have led to ground-breaking discoveries that have changed the approaches to formulation of therapeutics against diseases, such as cancer. Now-a-days the focus does not lie solely on finding a candidate small-molecule therapeutic with minimal adverse effects, but researchers are looking up to nanoparticles to improve biodistribution and biocompatibility profile of clinically proven therapeutics. The plethora of conjugation chemistries offered by currently extant inorganic nanoparticles have, in recent years, led to great leaps in the field of biomimicry---a modality that promises high biocompatibility. Further, in the pursuit of highly specific therapeutic molecules, researchers have turned to silencing oligonucleotides and some have already brought together the strengths of nanoparticles and silencing oligonucleotides in search of an efficacious therapy for cancer with minimal adverse effects. This dissertation work focuses on such a biomimetic platform---a gold nanoparticle based high density lipoprotein biomimetic (HDL NP), for the delivery of therapeutic oligonucleotides. The first chapter of this body of work introduces the molecular target of the silencing oligonucleotides---VEGFR2, and its role in the progression of solid tumor cancers. The background information also covers important aspects of natural high density lipoproteins (HDL), especially their innate capacity to bind and deliver exogenous and endogenous silencing oligonucleotides to tissues that express their high affinity receptor SRB1. We subsequently describe the synthesis of the biomimetic HDL NP and its oligonucleotide conjugates, and establish their biocompatibility. Further on, experimental data demonstrate the efficacy of silencing

Correlation of structural stability with functional remodeling of high-density lipoproteins: the importance of being disordered.

Science.gov (United States)

Guha, Madhumita; Gao, Xuan; Jayaraman, Shobini; Gursky, Olga

2008-11-04

High-density lipoproteins (HDLs) are protein-lipid assemblies that remove excess cell cholesterol and prevent atherosclerosis. HDLs are stabilized by kinetic barriers that decelerate protein dissociation and lipoprotein fusion. We propose that similar barriers modulate metabolic remodeling of plasma HDLs; hence, changes in particle composition that destabilize HDLs and accelerate their denaturation may accelerate their metabolic remodeling. To test this notion, we correlate existing reports on HDL-mediated cell cholesterol efflux and esterification, which are obligatory early steps in cholesterol removal, with our kinetic studies of HDL stability. The results support our hypothesis and show that factors accelerating cholesterol efflux and esterification in model discoidal lipoproteins (including reduced protein size, reduced fatty acyl chain length, and/or increased level of cis unsaturation) destabilize lipoproteins and accelerate their fusion and apolipoprotein dissociation. Oxidation studies of plasma spherical HDLs show a similar trend: mild oxidation by Cu(2+) or OCl(-) accelerates cell cholesterol efflux, protein dissociation, and HDL fusion, while extensive oxidation inhibits these reactions. Consequently, moderate destabilization may be beneficial for HDL functions by facilitating insertion of cholesterol and lipophilic enzymes, promoting dissociation of lipid-poor apolipoproteins, which are primary acceptors of cell cholesterol, and thereby accelerating HDL metabolism. Therefore, HDL stability must be delicately balanced to maintain the structural integrity of the lipoprotein assembly and ensure structural specificity necessary for interactions of HDL with its metabolic partners, while facilitating rapid HDL remodeling and turnover at key junctures of cholesterol transport. The inverse correlation between HDL stability and remodeling illustrates the functional importance of structural disorder in macromolecular assemblies stabilized by kinetic barriers.

High-Density and Very-Low-Density Lipoprotein Have Opposing Roles in Regulating Tumor-Initiating Cells and Sensitivity to Radiation in Inflammatory Breast Cancer

Energy Technology Data Exchange (ETDEWEB)

Wolfe, Adam R. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Atkinson, Rachel L. [Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Reddy, Jay P. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Debeb, Bisrat G.; Larson, Richard; Li, Li [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Masuda, Hiroko; Brewer, Takae [Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Atkinson, Bradley J. [Department of Clinical Pharmacy Services, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Brewster, Abeena [Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ueno, Naoto T. [Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A., E-mail: wwoodward@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Clinical Cancer Prevention, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

2015-04-01

Purpose: We previously demonstrated that cholesterol-lowering agents regulate radiation sensitivity of inflammatory breast cancer (IBC) cell lines in vitro and are associated with less radiation resistance among IBC patients who undergo postmastectomy radiation. We hypothesized that decreasing IBC cellular cholesterol induced by treatment with lipoproteins would increase radiation sensitivity. Here, we examined the impact of specific transporters of cholesterol (ie lipoproteins) on the responses of IBC cells to self-renewal and to radiation in vitro and on clinical outcomes in IBC patients. Methods and Materials: Two patient-derived IBC cell lines, SUM 149 and KPL4, were incubated with low-density lipoproteins (LDL), very-low-density lipoproteins (VLDL), or high-density lipoproteins (HDL) for 24 hours prior to irradiation (0-6 Gy) and mammosphere formation assay. Cholesterol panels were examined in a cohort of patients with primary IBC diagnosed between 1995 and 2011 at MD Anderson Cancer Center. Lipoprotein levels were then correlated to patient outcome, using the log rank statistical model, and examined in multivariate analysis using Cox regression. Results: VLDL increased and HDL decreased mammosphere formation compared to untreated SUM 149 and KPL4 cells. Survival curves showed enhancement of survival in both of the IBC cell lines when pretreated with VLDL and, conversely, radiation sensitization in all cell lines when pretreated with HDL. In IBC patients, higher VLDL values (>30 mg/dL) predicted a lower 5-year overall survival rate than normal values (hazard ratio [HR] = 1.9 [95% confidence interval [CI]: 1.05-3.45], P=.035). Lower-than-normal patient HDL values (<60 mg/dL) predicted a lower 5-year overall survival rate than values higher than 60 mg/dL (HR = 3.21 [95% CI: 1.25-8.27], P=.015). Conclusions: This study discovered a relationship among the plasma levels of lipoproteins, overall patient response, and radiation resistance in IBC patients

High-Density and Very-Low-Density Lipoprotein Have Opposing Roles in Regulating Tumor-Initiating Cells and Sensitivity to Radiation in Inflammatory Breast Cancer

International Nuclear Information System (INIS)

Wolfe, Adam R.; Atkinson, Rachel L.; Reddy, Jay P.; Debeb, Bisrat G.; Larson, Richard; Li, Li; Masuda, Hiroko; Brewer, Takae; Atkinson, Bradley J.; Brewster, Abeena; Ueno, Naoto T.; Woodward, Wendy A.

2015-01-01

Purpose: We previously demonstrated that cholesterol-lowering agents regulate radiation sensitivity of inflammatory breast cancer (IBC) cell lines in vitro and are associated with less radiation resistance among IBC patients who undergo postmastectomy radiation. We hypothesized that decreasing IBC cellular cholesterol induced by treatment with lipoproteins would increase radiation sensitivity. Here, we examined the impact of specific transporters of cholesterol (ie lipoproteins) on the responses of IBC cells to self-renewal and to radiation in vitro and on clinical outcomes in IBC patients. Methods and Materials: Two patient-derived IBC cell lines, SUM 149 and KPL4, were incubated with low-density lipoproteins (LDL), very-low-density lipoproteins (VLDL), or high-density lipoproteins (HDL) for 24 hours prior to irradiation (0-6 Gy) and mammosphere formation assay. Cholesterol panels were examined in a cohort of patients with primary IBC diagnosed between 1995 and 2011 at MD Anderson Cancer Center. Lipoprotein levels were then correlated to patient outcome, using the log rank statistical model, and examined in multivariate analysis using Cox regression. Results: VLDL increased and HDL decreased mammosphere formation compared to untreated SUM 149 and KPL4 cells. Survival curves showed enhancement of survival in both of the IBC cell lines when pretreated with VLDL and, conversely, radiation sensitization in all cell lines when pretreated with HDL. In IBC patients, higher VLDL values (>30 mg/dL) predicted a lower 5-year overall survival rate than normal values (hazard ratio [HR] = 1.9 [95% confidence interval [CI]: 1.05-3.45], P=.035). Lower-than-normal patient HDL values (<60 mg/dL) predicted a lower 5-year overall survival rate than values higher than 60 mg/dL (HR = 3.21 [95% CI: 1.25-8.27], P=.015). Conclusions: This study discovered a relationship among the plasma levels of lipoproteins, overall patient response, and radiation resistance in IBC patients

Reconstituted high-density lipoprotein infusion modulates fatty acid metabolism in patients with type 2 diabetes mellitus

DEFF Research Database (Denmark)

Drew, BG; Carey, AL; Natoli, AK

2011-01-01

We recently demonstrated that reconstituted high-density lipoprotein (rHDL) modulates glucose metabolism in humans via both AMP-activated protein kinase (AMPK) in muscle and by increasing plasma insulin. Given the key roles of both AMPK and insulin in fatty acid metabolism, the current study inve...

The Application of a Modified d-ROMs Test for Measurement of Oxidative Stress and Oxidized High-Density Lipoprotein

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Fumiaki Ito

2017-02-01

Full Text Available Reactive oxygen species (ROS are involved in the initiation and progression of atherosclerosis. ROS-derived hydroperoxides, as an indicator of ROS production, have been measured by using the diacron reactive oxygen metabolites (d-ROMs test, which requires iron-containing transferrin in the reaction mixture. In this study we developed a modified d-ROMs test, termed the Fe-ROMs test, where iron ions were exogenously added to the reaction mixture. This modification is expected to exclude the assay variation that comes from different blood iron levels in individuals. In addition, this Fe-ROMs test was helpful for determining the class of plasma lipoproteins that are hydroperoxidized. Low-density lipoprotein/very low-density lipoprotein (LDL/VLDL and high-density lipoprotein (HDL were purified by use of an LDL/VLDL purification kit and the dextran sulfate-Mg2+ precipitation method, respectively; their hydroperoxide contents were assessed by performing the Fe-ROMs test. The majority of the hydroperoxides were detected only in the HDL fraction, not in the LDL/VLDL. Further detailed analysis of HDLs by size-exclusion high-performance liquid chromatography revealed that the hydroperoxide-containing molecules were small-sized HDLs. Because HDL was shown to be the principal vehicle for the plasma hydroperoxides, this Fe-ROMs test is a beneficial method for the assessment of oxidized-HDL levels. Indeed, Fe-ROMs levels were strongly associated with the levels of oxidized HDL, which were determined by performing the malondialdehyde-modified HDL enzyme immunoassay. In conclusion, the Fe-ROMs test using plasma itself or the HDL fraction after dextran sulfate-Mg2+ precipitation is useful to assess the functionality of HDL, because the oxidation of HDL impairs its antiatherogenic capacity.

Achieving secondary prevention low-density lipoprotein particle concentration goals using lipoprotein cholesterol-based data.

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Simon C Mathews

Full Text Available BACKGROUND: Epidemiologic studies suggest that LDL particle concentration (LDL-P may remain elevated at guideline recommended LDL cholesterol goals, representing a source of residual risk. We examined the following seven separate lipid parameters in achieving the LDL-P goal of <1000 nmol/L goal for very high risk secondary prevention: total cholesterol to HDL cholesterol ratio, TC/HDL, <3; a composite of ATP-III very high risk targets, LDL-C<70 mg/dL, non-HDL-C<100 mg/dL and TG<150 mg/dL; a composite of standard secondary risk targets, LDL-C<100, non-HDL-C<130, TG<150; LDL phenotype; HDL-C ≥ 40; TG<150; and TG/HDL-C<3. METHODS: We measured ApoB, ApoAI, ultracentrifugation lipoprotein cholesterol and NMR lipoprotein particle concentration in 148 unselected primary and secondary prevention patients. RESULTS: TC/HDL-C<3 effectively discriminated subjects by LDL-P goal (F = 84.1, p<10(-6. The ATP-III very high risk composite target (LDL-C<70, nonHDL-C<100, TG<150 was also effective (F = 42.8, p<10(-5. However, the standard secondary prevention composite (LDL-C<100, non-HDL-C<130, TG<150 was also effective but yielded higher LDL-P than the very high risk composite (F = 42.0, p<10(-5 with upper 95% confidence interval of LDL-P less than 1000 nmol/L. TG<150 and TG/HDL-C<3 cutpoints both significantly discriminated subjects but the LDL-P upper 95% confidence intervals fell above goal of 1000 nmol/L (F = 15.8, p = 0.0001 and F = 9.7, p = 0.002 respectively. LDL density phenotype neared significance (F = 2.85, p = 0.094 and the HDL-C cutpoint of 40 mg/dL did not discriminate (F = 0.53, p = 0.47 alone or add discriminatory power to ATP-III targets. CONCLUSIONS: A simple composite of ATP-III very high risk lipoprotein cholesterol based treatment targets or TC/HDL-C ratio <3 most effectively identified subjects meeting the secondary prevention target level of LDL-P<1000 nmol/L, providing a potential alternative to advanced lipid testing in many clinical

The effect of insulin deficiency on the plasma clearance and exchange of high-density-lipoprotein phosphatidylcholine in rats.

Science.gov (United States)

Martins, I J; Redgrave, T G

1992-01-01

Triolein/cholesteryl oleate/cholesterol/phosphatidylcholine emulsions designed to model the lipid composition of chylomicrons were injected intravenously into control and streptozotocin-treated insulin-deficient rats. As previously described for lymph chylomicrons, the emulsion triolein was hydrolysed and phosphatidylcholine was transferred to the plasma high-density lipoproteins (HDL). This mechanism was used to introduce a phospholipid label into HDL in vivo. The subsequent clearance of phospholipid radioactivity from the plasma of insulin-deficient rats was significantly slower than in controls (P less than 0.025). Plasma clearance was similarly slower in insulin-deficient rats after injection of HDL that was previously labelled with radioactive phospholipids. After injection, the phospholipid label redistributed rapidly between the large-particle fraction of plasma lipoproteins (very-low- and low-density lipoproteins), and the lighter and heavier fractions of HDL. Compared with control rats, in insulin-deficient rats less of the phospholipid label was distributed to the lighter HDL fraction and more to the heavier HDL fraction, and this difference was not due to changes in activity of lecithin: cholesterol acyltransferase or in the apparent activity of phospholipid transfer protein. In insulin-deficient rats the changes in HDL phospholipid clearance and exchange appeared to be secondary to the associated hypertriglyceridaemia and the related changes in distribution of phospholipids between classes of plasma lipoproteins. PMID:1536661

Social Inclusion Predicts Lower Blood Glucose and Low-Density Lipoproteins in Healthy Adults.

Science.gov (United States)

Floyd, Kory; Veksler, Alice E; McEwan, Bree; Hesse, Colin; Boren, Justin P; Dinsmore, Dana R; Pavlich, Corey A

2017-08-01

Loneliness has been shown to have direct effects on one's personal well-being. Specifically, a greater feeling of loneliness is associated with negative mental health outcomes, negative health behaviors, and an increased likelihood of premature mortality. Using the neuroendocrine hypothesis, we expected social inclusion to predict decreases in both blood glucose levels and low-density lipoproteins (LDLs) and increases in high-density lipoproteins (HDLs). Fifty-two healthy adults provided self-report data for social inclusion and blood samples for hematological tests. Results indicated that higher social inclusion predicted lower levels of blood glucose and LDL, but had no effect on HDL. Implications for theory and practice are discussed.

Structural and metabolic heterogeneity of plasma low density lipoproteins in nonhuman primates

International Nuclear Information System (INIS)

Marzetta, C.A.

1986-01-01

To test the hypothesis that a variety of precursor particles secreted by the liver could result in heterogeneity of LDL products in plasma, the metabolic fate of selected radiolabeled hepatic lipoproteins evaluated was determined in vivo. The hepatic lipoproteins evaluated were isolated from liver perfusate and were triglyceride-rich VLDL (d < 1.006 or d < 1.017) and phospholipid-rich LDL (1.017 < d < 1.049 or 1.030 < d < 1.063). Radiolabeled autologous plasma LDL were injected into recipient animals together with the radiolabeled hepatic lipoproteins. Density gradient ultracentrifugation and gel filtration were used to characterize the distribution of radiolabeled lipoproteins in the plasma at selected times after injection. A variety of hepatic lipoproteins were precursors to lipoproteins that resembled plasma LDL. Between 22 to 80% of the injected dose of radiolabeled hepatic lipoprotein apo B-100 was converted to plasma LDL-like particles, regardless of the type of hepatic lipoprotein injected. A kinetic model was generated to describe the metabolic behavior of hepatic VLDL-derived and plasma LDL-derived apo B-100 radioactivity. Both models required multiple metabolic pools to fit the data. Hepatic VLDL-derived apo B-100 radioactivity was metabolized rapidly into various kinds of LDL subfractions. This rapid conversion of hepatic VLDL apo B-100 to LDL apo B-100 may be analogous to the portion of plasma VLDL that gets converted to LDL without passing through the delipidation cascade that has been described in humans and has been termed direct LDL production

Radiochemical and immunohistochemical detection of low density lipoprotein surface binding by lymphocytes

International Nuclear Information System (INIS)

Melzner, I.; Hambitzer, R.; Haferkamp, O.

1983-01-01

Human peripheral blood lymphocytes bind and take up low density lipoprotein (LDL) by receptor-mediated endocytosis. The binding of LDL was determiend by incubation with 125 I-LDL and an immunohistochemical assay. By both techniques a diminished rate of binding was found when cells were freshly isolated from the blood, but increased 5 to 10 fold when lymphocytes were incubated in lipoprotein-deficient medium for 72 hours. In addition, it was shown immunohistochemically that only few ceels showed an LDL-dependent fluorescent labelling: approximately 5 to 10 % of the freshly isolated lymphocytes and 40 to 50 % of the cells incubated for 72 hours under lipoprotein-free conditions. The present data indicate that not only the high affinity LDL receptor described by Goldstein and Braun may be involved in the uptake of cholesterol by lymphocytes, but also other binding sites, which may have immunological function in some lymphocyte subpopulations. (author)

The effect of interaction between Lipoprotein Lipase and ApoVLDL-II ...

African Journals Online (AJOL)

GREGO

2007-04-02

Apr 2, 2007 ... correlation between growth and fitness is not absolute, it ... significant differences are found in the plasma triglyceride ... (VLDL) and high density lipoprotein (HDL) concentration ... High-density lipoprotein cholesterol was.

High hydrostatic pressure specifically affects molecular dynamics and shape of low-density lipoprotein particles

Science.gov (United States)

Golub, M.; Lehofer, B.; Martinez, N.; Ollivier, J.; Kohlbrecher, J.; Prassl, R.; Peters, J.

2017-04-01

Lipid composition of human low-density lipoprotein (LDL) and its physicochemical characteristics are relevant for proper functioning of lipid transport in the blood circulation. To explore dynamical and structural features of LDL particles with either a normal or a triglyceride-rich lipid composition we combined coherent and incoherent neutron scattering methods. The investigations were carried out under high hydrostatic pressure (HHP), which is a versatile tool to study the physicochemical behavior of biomolecules in solution at a molecular level. Within both neutron techniques we applied HHP to probe the shape and degree of freedom of the possible motions (within the time windows of 15 and 100 ps) and consequently the flexibility of LDL particles. We found that HHP does not change the types of motion in LDL, but influences the portion of motions participating. Contrary to our assumption that lipoprotein particles, like membranes, are highly sensitive to pressure we determined that LDL copes surprisingly well with high pressure conditions, although the lipid composition, particularly the triglyceride content of the particles, impacts the molecular dynamics and shape arrangement of LDL under pressure.

Physical inactivity interacts with an endothelial lipase polymorphism to modulate high density lipoprotein cholesterol in the GOLDN study

Science.gov (United States)

BACKGROUND: Plasma high density lipoprotein (HDL) cholesterol (HDL-C) concentration is highly heritable but is also modifiable by environmental factors including physical activity. HDL-C response to exercise varies among individuals, and this variability may be associated with genetic polymorphism...

Loss of Function of GALNT2 Lowers High-Density Lipoproteins in Humans, Nonhuman Primates, and Rodents

DEFF Research Database (Denmark)

Khetarpal, Sumeet A; Schjoldager, Katrine T; Christoffersen, Christina

2016-01-01

Human genetics studies have implicated GALNT2, encoding GalNAc-T2, as a regulator of high-density lipoprotein cholesterol (HDL-C) metabolism, but the mechanisms relating GALNT2 to HDL-C remain unclear. We investigated the impact of homozygous GALNT2 deficiency on HDL-C in humans and mammalian mod...

Genetics of Lipid and Lipoprotein Disorders and Traits.

Science.gov (United States)

Dron, Jacqueline S; Hegele, Robert A

2016-01-01

Plasma lipids, namely cholesterol and triglyceride, and lipoproteins, such as low-density lipoprotein (LDL) and high-density lipoprotein, serve numerous physiological roles. Perturbed levels of these traits underlie monogenic dyslipidemias, a diverse group of multisystem disorders. We are on the verge of having a relatively complete picture of the human dyslipidemias and their components. Recent advances in genetics of plasma lipids and lipoproteins include the following: (1) expanding the range of genes causing monogenic dyslipidemias, particularly elevated LDL cholesterol; (2) appreciating the role of polygenic effects in such traits as familial hypercholesterolemia and combined hyperlipidemia; (3) accumulating a list of common variants that determine plasma lipids and lipoproteins; (4) applying exome sequencing to identify collections of rare variants determining plasma lipids and lipoproteins that via Mendelian randomization have also implicated gene products such as NPC1L1 , APOC3 , LDLR , APOA5 , and ANGPTL4 as causal for atherosclerotic cardiovascular disease; and (5) using naturally occurring genetic variation to identify new drug targets, including inhibitors of apolipoprotein (apo) C-III, apo(a), ANGPTL3, and ANGPTL4. Here, we compile this disparate range of data linking human genetic variation to plasma lipids and lipoproteins, providing a "one stop shop" for the interested reader.

Lipoprotein particle distribution and skeletal muscle lipoprotein lipase activity after acute exercise

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Harrison Michael

2012-07-01

Full Text Available Abstract Background Many of the metabolic effects of exercise are due to the most recent exercise session. With recent advances in nuclear magnetic resonance spectroscopy (NMRS, it is possible to gain insight about which lipoprotein particles are responsible for mediating exercise effects. Methods Using a randomized cross-over design, very low density lipoprotein (VLDL responses were evaluated in eight men on the morning after i an inactive control trial (CON, ii exercising vigorously on the prior evening for 100 min followed by fasting overnight to maintain an energy and carbohydrate deficit (EX-DEF, and iii after the same exercise session followed by carbohydrate intake to restore muscle glycogen and carbohydrate balance (EX-BAL. Results The intermediate, low and high density lipoprotein particle concentrations did not differ between trials. Fasting triglyceride (TG determined biochemically, and mean VLDL size were lower in EX-DEF but not in EX-BAL compared to CON, primarily due to a reduction in VLDL-TG in the 70–120 nm (large particle range. In contrast, VLDL-TG was lower in both EX-DEF and EX-BAL compared to CON in the 43–55 nm (medium particle range. VLDL-TG in smaller particles (29–43 nm was unaffected by exercise. Because the majority of VLDL particles were in this smallest size range and resistant to change, total VLDL particle concentration was not different between any of these conditions. Skeletal muscle lipoprotein lipase (LPL activity was also not different across these 3 trials. However, in CON only, the inter-individual differences in LPL activity were inversely correlated with fasting TG, VLDL-TG, total, large and small VLDL particle concentration and VLDL size, indicating a regulatory role for LPL in the non-exercised state. Conclusions These findings reveal a high level of differential regulation between different sized triglyceride-rich lipoproteins following exercise and feeding, in the absence of changes in

Lipoprotein particle distribution and skeletal muscle lipoprotein lipase activity after acute exercise

LENUS (Irish Health Repository)

Harrison, Michael

2012-06-06

AbstractBackgroundMany of the metabolic effects of exercise are due to the most recent exercise session. With recent advances in nuclear magnetic resonance spectroscopy (NMRS), it is possible to gain insight about which lipoprotein particles are responsible for mediating exercise effects.MethodsUsing a randomized cross-over design, very low density lipoprotein (VLDL) responses were evaluated in eight men on the morning after i) an inactive control trial (CON), ii) exercising vigorously on the prior evening for 100 min followed by fasting overnight to maintain an energy and carbohydrate deficit (EX-DEF), and iii) after the same exercise session followed by carbohydrate intake to restore muscle glycogen and carbohydrate balance (EX-BAL).ResultsThe intermediate, low and high density lipoprotein particle concentrations did not differ between trials. Fasting triglyceride (TG) determined biochemically, and mean VLDL size were lower in EX-DEF but not in EX-BAL compared to CON, primarily due to a reduction in VLDL-TG in the 70–120 nm (large) particle range. In contrast, VLDL-TG was lower in both EX-DEF and EX-BAL compared to CON in the 43–55 nm (medium) particle range. VLDL-TG in smaller particles (29–43 nm) was unaffected by exercise. Because the majority of VLDL particles were in this smallest size range and resistant to change, total VLDL particle concentration was not different between any of these conditions. Skeletal muscle lipoprotein lipase (LPL) activity was also not different across these 3 trials. However, in CON only, the inter-individual differences in LPL activity were inversely correlated with fasting TG, VLDL-TG, total, large and small VLDL particle concentration and VLDL size, indicating a regulatory role for LPL in the non-exercised state.ConclusionsThese findings reveal a high level of differential regulation between different sized triglyceride-rich lipoproteins following exercise and feeding, in the absence of changes in LPL activity.

21 CFR 866.5590 - Lipoprotein X immunolog-ical test system.

Science.gov (United States)

2010-04-01

... device that consists of the reagents used to measure by immunochemical techniques lipoprotein X (a high-density lipoprotein) in serum and other body fluids. Measurement of lipoprotein X aids in the diagnosis of obstructive liver disease. (b) Classification. Class I (general controls). The device is exempt from the...

Aerosol preparation of intact lipoproteins

Science.gov (United States)

Benner, W Henry [Danville, CA; Krauss, Ronald M [Berkeley, CA; Blanche, Patricia J [Berkeley, CA

2012-01-17

A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

Ion mobility analysis of lipoproteins

Science.gov (United States)

Benner, W. Henry; Krauss, Ronald M.; Blanche, Patricia J.

2007-08-21

A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

Trypanosome lytic factor, an antimicrobial high-density lipoprotein, ameliorates Leishmania infection.

Directory of Open Access Journals (Sweden)

Marie Samanovic

2009-01-01

Full Text Available Innate immunity is the first line of defense against invading microorganisms. Trypanosome Lytic Factor (TLF is a minor sub-fraction of human high-density lipoprotein that provides innate immunity by completely protecting humans from infection by most species of African trypanosomes, which belong to the Kinetoplastida order. Herein, we demonstrate the broader protective effects of human TLF, which inhibits intracellular infection by Leishmania, a kinetoplastid that replicates in phagolysosomes of macrophages. We show that TLF accumulates within the parasitophorous vacuole of macrophages in vitro and reduces the number of Leishmania metacyclic promastigotes, but not amastigotes. We do not detect any activation of the macrophages by TLF in the presence or absence of Leishmania, and therefore propose that TLF directly damages the parasite in the acidic parasitophorous vacuole. To investigate the physiological relevance of this observation, we have reconstituted lytic activity in vivo by generating mice that express the two main protein components of TLFs: human apolipoprotein L-I and haptoglobin-related protein. Both proteins are expressed in mice at levels equivalent to those found in humans and circulate within high-density lipoproteins. We find that TLF mice can ameliorate an infection with Leishmania by significantly reducing the pathogen burden. In contrast, TLF mice were not protected against infection by the kinetoplastid Trypanosoma cruzi, which infects many cell types and transiently passes through a phagolysosome. We conclude that TLF not only determines species specificity for African trypanosomes, but can also ameliorate an infection with Leishmania, while having no effect on T. cruzi. We propose that TLFs are a component of the innate immune system that can limit infections by their ability to selectively damage pathogens in phagolysosomes within the reticuloendothelial system.

Degradation of high density lipoprotein in cultured rat luteal cells

International Nuclear Information System (INIS)

Rajan, V.P.; Menon, K.M.J.

1986-01-01

In rat ovary luteal cells, degradation of high density lipoprotein (HDL) to tricholoracetic acid (TCA)-soluble products accounts for only a fraction of the HDL-derived cholesterol used for steroidogenesis. In this study the authors have investigated the fate of 125 I]HDL bound to cultured luteal cells using pulse-chase technique. Luteal cell cultures were pulse labeled with [ 125 I]HDL 3 and reincubated in the absence of HDL. By 24 h about 50% of the initallay bound radioactivity was released into the medium, of which 60-65% could be precipitated with 10% TCA. Gel filtration of the chase incubation medium on 10% agarose showed that the amount of TCA-soluble radioactivity was nearly completely accounted for by a sharp peak in the low molecular weight region which was identified as 96% monoiodotyrosine by paper chromatography. The TCA-precipitable radioactivity was nearly completely accounted for by a sharp peak in the low molecular weight region which was identified as 96% monoiodotyrosine by paper chromatography. The TCA-precipitable radioactivity eluted over a wide range of molecular weights (15,000-80,000), and there was very little intact HDL present. Electrophoresis of the chase medium showed that component of the TCA-precipitable portion had mobility similar to apo AI. Lysosomal inhibitors of receptor-mediated endocytosis had no effect on the composition or quantity of radioactivity released during chase incubation. The results show that HDL 3 binding to luteal cells is followed by complete degradation of the lipoprotein, although the TCA-soluble part does not reflect the extent of degradation

Role of oxidized low-density lipoprotein in renal disease

NARCIS (Netherlands)

Heeringa, P; Tervaert, JWC

Accelerated atherosclerosis is often observed in patients with chronic renal failure. In the present review we summarize and discuss the recent literature on the pathogenic role of low-density lipoproteins modified by oxidative processes in atherosclerosis and the possible role in renal diseases.

Human Low Density Lipoprotein as a Vehicle of Atherosclerosis ...

African Journals Online (AJOL)

Low-density lipoproteins have been sufficiently established as an important precursor of atherosclerosis. The actual mechanism is still unclear, and the current technique of using radioisotopes has clinical limitation. However, the current study techniques or methods excellently elucidate the functional aspects of ...

Lipoproteins and lipoprotein mimetics for imaging and drug delivery.

Science.gov (United States)

Thaxton, C Shad; Rink, Jonathan S; Naha, Pratap C; Cormode, David P

2016-11-15

Lipoproteins are a set of natural nanoparticles whose main role is the transport of fats within the body. While much work has been done to develop synthetic nanocarriers to deliver drugs or contrast media, natural nanoparticles such as lipoproteins represent appealing alternatives. Lipoproteins are biocompatible, biodegradable, non-immunogenic and are naturally targeted to some disease sites. Lipoproteins can be modified to act as contrast agents in many ways, such as by insertion of gold cores to provide contrast for computed tomography. They can be loaded with drugs, nucleic acids, photosensitizers or boron to act as therapeutics. Attachment of ligands can re-route lipoproteins to new targets. These attributes render lipoproteins attractive and versatile delivery vehicles. In this review we will provide background on lipoproteins, then survey their roles as contrast agents, in drug and nucleic acid delivery, as well as in photodynamic therapy and boron neutron capture therapy. Copyright © 2016 Elsevier B.V. All rights reserved.

Low fasting low high-density lipoprotein and postprandial lipemia

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Sorodila Konstandina

2004-07-01

Full Text Available Abstract Background Low levels of high density lipoprotein (HDL cholesterol and disturbed postprandial lipemia are associated with coronary heart disease. In the present study, we evaluated the variation of triglyceride (TG postprandially in respect to serum HDL cholesterol levels. Results Fifty two Greek men were divided into 2 main groups: a the low HDL group (HDL p = 0.002. The low HDL group had significantly higher TG at 4, 6 and 8 h postprandially compared to the controls (p = 0.006, p = 0.002, and p p = 0.017 compared to the matched-control group. ROC analysis showed that fasting TG ≥ 121 mg/dl have 100% sensitivity and 81% specificity for an abnormal TG response (auc = 0.962, p Conclusions The delayed TG clearance postprandially seems to result in low HDL cholesterol even in subjects with low fasting TG. The fasting TG > 121 mg/dl are predictable for abnormal response to fatty meal.

A clustering analysis of lipoprotein diameters in the metabolic syndrome

Science.gov (United States)

The presence of smaller low-density lipoproteins (LDL) has been associated with atherosclerosis risk, and the insulin resistance (IR) underlying the metabolic syndrome (MetS). In addition, some research has supported the association of very low-, low- and high-density lipoprotein (VLDL HDL) particle...

Peri and Postparturient Concentrations of Lipid Lipoprotein Insulin and Glucose in Normal Dairy Cows

OpenAIRE

BAŞOĞLU, Abdullah; SEVİNÇ, Mutlu; OK, Mahmut

1998-01-01

In order to provide uniqe insight into the metabolic disturbences seen after calving cholesterol, triglycerid, high density lipoprotein, low density lipoprotein, very low density lipoprotein, glucose and insulin levels in serum were studied before calving (group I), in aerly (group II) and late (group III) lactation in 24 normal cows. Serum lipoproteins were separeted into various density classes by repeated ultracentrifugation. The results indicate that there was a rise in glucose, trygl...

Plasma Cholesteryl Ester Transfer, But Not Cholesterol Esterification, Is Related to Lipoprotein-Associated Phospholipase A(2) : Possible Contribution to an Atherogenic Lipoprotein Profile

NARCIS (Netherlands)

Dullaart, Robin P. F.; Constantinides, Alexander; Perton, Frank G.; van Leeuwen, Jeroen J. J.; van Pelt, Joost L.; de Vries, Rindert; van Tol, Arie

Context: Plasma lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) predicts incident cardiovascular disease and is associated preferentially with negatively charged apolipoprotein B-containing lipoproteins. The plasma cholesteryl ester transfer (CET) process, which contributes to low high-density

Lipoprotein(a)

DEFF Research Database (Denmark)

Langsted, Anne; Kamstrup, Pia R; Nordestgaard, Børge G

2014-01-01

OBJECTIVE: There are no recommendations in guidelines on measuring lipoprotein(a) in the fasting or nonfasting state, or on the influence of inflammation. We tested the hypotheses that lipoprotein(a) levels change only minimally in response to normal food intake, and to inflammation. Also, we...... tested whether normal food intake or inflammation influenced lipoprotein(a)'s ability to predict ischemic heart disease. METHODS: We studied 34 829 individuals from the Danish general population using the Copenhagen General Population Study and the Copenhagen City Heart Study. RESULTS: Lipoprotein......(a) levels did not change in response to normal food intake: median fasting levels were 17.3 mg/dL, while median levels at 3-4 h since last meal were 19.4 mg/dL(p = 0.38). Lipoprotein(a) levels increased minimally with increasing levels of C-reactive protein(CRP): median lipoprotein(a) levels at CRP

Low-density lipoprotein cholesterol and risk of gallstone disease

DEFF Research Database (Denmark)

Stender, Stefan; Frikke-Schmidt, Ruth; Benn, Marianne

2013-01-01

Drugs which reduce plasma low-density lipoprotein cholesterol (LDL-C) may protect against gallstone disease. Whether plasma levels of LDL-C per se predict risk of gallstone disease remains unclear. We tested the hypothesis that elevated LDL-C is a causal risk factor for symptomatic gallstone...

Changes in lipoprotein kinetics associated with type 2 diabetes affect the distribution of lipopolysaccharides among lipoproteins.

Science.gov (United States)

Vergès, Bruno; Duvillard, Laurence; Lagrost, Laurent; Vachoux, Christelle; Garret, Céline; Bouyer, Karine; Courtney, Michael; Pomié, Céline; Burcelin, Rémy

2014-07-01

Lipopolysaccharides (LPSs) are inflammatory components of the outer membrane of Gram-negative bacteria and, in plasma, are mostly associated with lipoproteins. This association is thought to promote their catabolism while reducing their proinflammatory effects. Our aim was to determine the impact of lipoprotein kinetics on plasma LPS distribution and how it may affect patients with type 2 diabetes mellitus (T2DM). We performed a kinetic study in 30 individuals (16 T2DM patients, 14 controls) and analyzed the impact of changes in lipoprotein kinetics on LPS distribution among lipoproteins. Plasma LPS levels in T2DM patients were not different from those in controls, but LPS distribution in the two groups was different. Patients with T2DM had higher LPS-very low-density lipoprotein (VLDL; 31% ± 7% vs 22% ± 11%, P = .002), LPS-high-density lipoprotein (HDL; 29% ± 9% vs 19% ± 10%, P = .015), free (nonlipoprotein bound) LPS (10% ± 4% vs 7% ± 4%, P = .043) and lower LPS-low-density lipoprotein (LDL; 30% ± 13% vs 52% ± 16%, P = .001). In multivariable analysis, VLDL-LPS was associated with HDL-LPS (P < .0001); LDL-LPS was associated with VLDL-LPS (P = .004), and VLDL apolipoprotein (apo) B100 catabolism (P = .002); HDL-LPS was associated with free LPS (P < .0001) and VLDL-LPS (P = .033); free LPS was associated with HDL-LPS (P < .0001). In a patient featuring a dramatic decrease in VLDL catabolism due to apoA-V mutation, LDL-LPS was severely decreased (0.044 EU/mL vs 0.788 EU/mL in controls). The difference between T2DM patients and controls for LDL-LPS fraction was no longer significant after controlling for VLDL apoB100 total fractional catabolic rate. Our data suggest that in humans, free LPS transfers first to HDL and then to VLDL, whereas the LPS-bound LDL fraction is mainly derived from VLDL catabolism; the latter may hence represent a LPS catabolic pathway. T2DM patients show lower LDL-LPS secondary to reduced VLDL catabolism, which may represent an

INHIBITION OF HUMAN LOW-DENSITY LIPOPROTEINS OXIDATION BY Hibiscus radiatus CUV. CALYCES EXTRACT

Directory of Open Access Journals (Sweden)

Hernawan Hernawan

2010-06-01

Full Text Available Hibiscus radiatus Cuv calyces extracts rich in polyphenols was screened for their potential to inhibit oxidation of human low-density lipoproteins-cholesterol (LDL-C in vitro. The inhibition of LDL-C oxidation (antioxidant activity was determined by measuring the formation of conjugated dienes and thiobarbituric acid reagent substances (TBARS. LDL-C oxidation was carried out in the presence of H. radiatus Cuv calyces extract (20 and 50 μM. CuSO4 (10 μM was used as the oxidation initiator and  butylated hydroxytoluene (BHT at 50 μM was used as standard antioxidant. The protective effect of H. radiatus Cuv. calyces extract toward human low-density lipoproteins, complex lipid system was  demonstrated by significant increase lag time (> 103 min, diminished of the propagation rate (44 %, and diminution of conjugated dienes formation 59.42 % (50 μM compared to control.   Keywords: antioxidant, conjugated dienes, Hibiscus radiatus Cuv, low-density lipoproteins-cholesterol

The Relationship between the Triglyceride to High-Density Lipoprotein Cholesterol Ratio and Metabolic Syndrome.

Science.gov (United States)

Shin, Hyun-Gyu; Kim, Young-Kwang; Kim, Yong-Hwan; Jung, Yo-Han; Kang, Hee-Cheol

2017-11-01

Metabolic syndrome is associated with cardiovascular diseases and is characterized by insulin resistance. Recent studies suggest that the triglyceride/high-density lipoprotein cholesterol (TG/HDLC) ratio predicts insulin resistance better than individual lipid levels, including TG, total cholesterol, low-density lipoprotein cholesterol (LDLC), or HDLC. We aimed to elucidate the relationship between the TG/HDLC ratio and metabolic syndrome in the general Korean population. We evaluated the data of adults ≥20 years old who were enrolled in the Korean National Health and Nutrition Examination Survey in 2013 and 2014. Subjects with angina pectoris, myocardial infarction, stroke, or cancer were excluded. Metabolic syndrome was defined by the harmonized definition. We examined the odds ratios (ORs) of metabolic syndrome according to TG/HDLC ratio quartiles using logistic regression analysis (SAS ver. 9.4; SAS Institute Inc., Cary, NC, USA). Weighted complex sample analysis was also conducted. We found a significant association between the TG/HDLC ratio and metabolic syndrome. The cutoff value of the TG/HDLC ratio for the fourth quartile was ≥3.52. After adjustment, the OR for metabolic syndrome in the fourth quartile compared with that of the first quartile was 29.65 in men and 20.60 in women (Pmetabolic syndrome.

[Alterations in the protein content and dysfunction of high-density lipoproteins from hyperhomocysteinemic mice].

Science.gov (United States)

Julve, Josep; Errico, Teresa Laura; Chen, Xiangyu; Santos, David; Freixa, Júlia; Porcel, Inmaculada; Cubero, Esther; Escolà-Gil, Joan Carles; Blanco-Vaca, Francisco

2013-01-01

The aim of this study was to evaluate the proteic changes in high-density lipoproteins (HDL) induced by methionine-induced hyperhomocysteinemia in mice and its relationship with two of their main antiatherogenic properties. The oral administration of methionine resulted in an elevation (~8 times) in the plasma concentration of homocysteine. Hyperhomocysteinemia was inversely correlated with the plasma concentration of HDL cholesterol and its main protein component of HDL, apolipoprotein (apo) A-I, respectively. The cholesterol efflux in vivo from macrophages to HDL was decreased in hyperhomocysteinemic mice compared with the control mice. However, the reverse cholesterol transport from macrophages to feces remained unchanged. On the other hand, the ability of HDL from hyperhomocysteinemic mice to prevent the oxidative modification of low-density lipoproteins (LDL) was found decreased and associated with a concomitant reduction in the plasma activity of paraoxonase-1 (PON1) and the plasma concentration of apoA-I, and with a relative reduction in the apoA-IV content (~1.5 times) in the hyperhomocysteinemic HDL, respectively. The decrease in the ability of HDL from hyperhomocysteinemic mice to prevent LDL from oxidation was associated with a decrease in the apoA-I, PON1 and apoA-IV. Copyright © 2013 Elsevier España, S.L. and SEA. All rights reserved.

Effects of gemfibrozil or simvastatin on apolipoprotein-B-containing lipoproteins, apolipoprotein-CIII and lipoprotein(a) in familial combined hyperlipidaemia

NARCIS (Netherlands)

Bredie, S. J.; Westerveld, H. T.; Knipscheer, H. C.; de Bruin, T. W.; Kastelein, J. J.; Stalenhoef, A. F.

1996-01-01

Familial combined hyperlipidaemia (FCH), characterized by elevated very-low-density lipoprotein (VLDL) and/or low-density lipoprotein (LDL), is associated with an increased prevalence of premature cardiovascular disease. Therefore, lipid-lowering is frequently indicated. We evaluated in a parallel,

Plasma lipoprotein(a) levels in patients with homozygous autosomal dominant hypercholesterolemia

NARCIS (Netherlands)

Sjouke, B.; Yahya, R.; Tanck, M.W.T.; Defesche, J.C.; Graaf, J. de; Wiegman, A.; Kastelein, J.J.; Mulder, M.T.; Hovingh, G.K.; Roeters van Lennep, J.E.

2017-01-01

BACKGROUND: Patients with autosomal dominant hypercholesterolemia (ADH), caused by mutations in either low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin-kexin type 9 (PCSK9) are characterized by high low-density lipoprotein cholesterol levels and

Novel lipoprotein density profiling in healthy dogs of various breeds, healthy miniature schnauzers, and miniature schnauzers with hyperlipidemia

Science.gov (United States)

2013-01-01

Background Despite the importance of abnormalities in lipoprotein metabolism in clinical canine medicine, the fact that most previously used methods for lipoprotein profiling are rather laborious and time-consuming has been a major obstacle to the wide clinical application and use of lipoprotein profiling in this species. The aim of the present study was to assess the feasibility of a continuous lipoprotein density profile (CLPDP) generated within a bismuth sodium ethylenediaminetetraacetic acid (NaBiEDTA) density gradient to characterize and compare the lipoprotein profiles of healthy dogs of various breeds, healthy Miniature Schnauzers, and Miniature Schnauzers with primary hypertriacylglycerolemia. A total of 35 healthy dogs of various breeds with serum triacylglycerol (TAG) and cholesterol concentrations within their respective reference intervals were selected for use as a reference population. Thirty-one Miniature Schnauzers with serum TAG and cholesterol concentrations within their respective reference intervals and 31 Miniature Schnauzers with hypertriacylglyceridemia were also included in the study. Results The results suggest that CLPDP using NaBiEDTA provides unique diagnostic information in addition to measurements of serum TAG and cholesterol concentrations and that it is a useful screening method for dogs with suspected lipoprotein metabolism disorders. Using the detailed and continuous density distribution information provided by the CLPDP, important differences in lipoprotein profiles can be detected even among dogs that have serum TAG and cholesterol concentrations within the reference interval. Miniature Schnauzers with serum TAG and cholesterol concentrations within the reference interval had significantly different lipoprotein profiles than dogs of various other breeds. In addition, it was further established that specific lipoprotein fractions are associated with hypertriacylglyceridemia in Miniature Schnauzers. Conclusions The results of the

Regulation of low density lipoprotein receptor function in a human hepatoma cell line

International Nuclear Information System (INIS)

Leichtner, A.M.; Krieger, M.; Schwartz, A.L.

1984-01-01

Low density lipoprotein (LDL) processing was investigated in a human hepatoma-derived cell line, Hep G2. Hep G2 cells bound, internalized and degraded LDL via a saturable, high affinity pathway similar to that present in other mammalian cells. Although 80% of the uptake and degradation of 125 I-LDL was inhibited by 40-fold excess native LDL, the same concentration of methylated LDL, which cannot bind to LDL receptors, had virtually no effect on processing. When added at low concentrations, the lysosomotropic agent, chloroquine, inhibited degradation without affecting the rate of lipoprotein internalization. Receptor activity was decreased 60% by preincubation of the cells in medium containing a source of cholesterol (LDL or unesterified cholesterol) and increased 1.7-fold by preincubation with compactin, a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase. The Hep G2 cell line may prove a useful system both for the further study of hepatic lipoprotein metabolism and for the evaluation of new antihypercholesterolemic agents

Use of the TLX ultracentrifuge for the isolation of different density lipoproteins and effects of freeze/thawing of human plasma before ultracentrifugation.

Science.gov (United States)

Charlton-Menys, Valentine; Chobotova, Jelena; Durrington, Paul N

2008-01-01

Isolation of different density lipoproteins by ultracentrifugation can require lengthy centrifugation times and freeze/thawing of plasma may influence recovery. We isolated a range of lipoproteins using a preparative ultracentrifuge and the TLX micro-ultracentrifuge and determined the effect of freeze/thawing of plasma beforehand. In fresh plasma, there was no significant difference in results for small-dense low-density lipoprotein apolipoprotein B (LDL apoB) (density >1.044 g/mL) or cholesterol at density >1.006 g/mL. Freeze/thawing had no effect on closely correlated results for small-dense LDL apoB (r=0.85; pTLX micro-ultracentrifuge is a reliable alternative to the preparative ultracentrifuge and freeze/thawing has only a small effect on small-dense LDL apoB or high-density lipoprotein cholesterol.

Plasma lipoprotein(a) levels in patients with homozygous autosomal dominant hypercholesterolemia

NARCIS (Netherlands)

Sjouke, Barbara; Yahya, Reyhana; Tanck, Michael W. T.; Defesche, Joep C.; de Graaf, Jacqueline; Wiegman, Albert; Kastelein, John J. P.; Mulder, Monique T.; Hovingh, G. Kees; Roeters van Lennep, Jeanine E.

2017-01-01

Patients with autosomal dominant hypercholesterolemia (ADH), caused by mutations in either low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), or proprotein convertase subtilisin-kexin type 9 (PCSK9) are characterized by high low-density lipoprotein cholesterol levels and in some

Remnant lipoproteins

DEFF Research Database (Denmark)

Varbo, Anette; Nordestgaard, Børge G.

2017-01-01

Purpose of review: To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk. Recent findings: In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined...... of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way....

Human Lipoproteins at Model Cell Membranes

DEFF Research Database (Denmark)

Browning, K L; Lind, T K; Maric, S

2017-01-01

High and low density lipoproteins (HDL and LDL) are thought to play vital roles in the onset and development of atherosclerosis; the biggest killer in the western world. Key issues of initial lipoprotein (LP) interactions at cellular membranes need to be addressed including LP deposition and lipid...... exchange. Here we present a protocol for monitoring the in situ kinetics of lipoprotein deposition and lipid exchange/removal at model cellular membranes using the non-invasive, surface sensitive methods of neutron reflection and quartz crystal microbalance with dissipation. For neutron reflection, lipid...... support the notion of HDL acting as the 'good' cholesterol, removing lipid material from lipid-loaded cells, whereas LDL acts as the 'bad' cholesterol, depositing lipid material into the vascular wall....

Analytic ultracentrifugation of lipoproteins: Some current collaborations

International Nuclear Information System (INIS)

Lindgren, F.T.

1987-01-01

This summary briefly reports on three ongoing studies - the heterogeneity of Low Density Lipoproteins (LDL) in the cynomolgus monkey, the domain nature of Apolipoprotein E-3, and the molecular weight of apoB-100 in low density lipoprotein subfractions in normal males. 4 refs

Cholesterol concentrations in lipoprotein fractions separated by anion-exchange-high-performance liquid chromatography in healthy dogs and dogs with hypercholesterolemia.

Science.gov (United States)

Oda, Hitomi; Mori, Akihiro; Hirowatari, Yuji; Takoura, Toshie; Manita, Daisuke; Takahashi, Tomoya; Shono, Saori; Onozawa, Eri; Mizutani, Hisashi; Miki, Yohei; Itabashi, Yukiko; Sako, Toshinori

2017-10-01

Anion-exchange (AEX)-high-performance liquid chromatography (HPLC) for measurement of cholesterol can be used to separate serum lipoproteins (high-density lipoprotein (HDL); low-density lipoprotein (LDL); intermediate-density lipoprotein (IDL); very-low-density lipoprotein (VLDL)) in humans. However, AEX-HPLC has not been applied in veterinary practice. We had three objectives: (i) the validation of AEX-HPLC methods including the correlation of serum cholesterol concentration in lipoprotein fraction measured by AEX-HPLC and gel permeation-HPLC (GP-HPLC) in healthy dogs and those with hypercholesterolemia was investigated; (ii) the reference intervals of lipoprotein fractions measured by AEX-HPLC from healthy dogs (n=40) was established; (iii) lipoprotein fractions from the serum of healthy dogs (n=12) and dogs with hypercholesterolemia (n=23) were compared. Analytic reproducibility and precision of AEX-HPLC were acceptable. Positive correlation between serum concentrations of total cholesterol (Total-Chol), HDL cholesterol (HDL-Chol), LDL cholesterol (LDL-Chol)+IDL cholesterol (IDL-Chol), and VLDL cholesterol (VLDL-Chol) was noted for AEX-HPLC and GP-HPLC in healthy dogs and dogs with hypercholesterolemia. Reference intervals measured by AEX-HPLC for serum concentrations of Total-Chol, HDL-Chol, and LDL-Chol were determined to be 2.97-9.32, 2.79-6.57, 0.16-3.28mmol/L (2.5-97.5% interval), respectively. Furthermore, there was significant difference in lipoprotein profiles between healthy and dogs with hypercholesterolemia. These results suggest that AEX-HPLC can be used to evaluate lipoprotein profiles in dogs and could be a new useful indicator of hyperlipidemia in dogs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Preparation and Characterization of Stable α-Synuclein Lipoprotein Particles.

Science.gov (United States)

Eichmann, Cédric; Campioni, Silvia; Kowal, Julia; Maslennikov, Innokentiy; Gerez, Juan; Liu, Xiaoxia; Verasdonck, Joeri; Nespovitaya, Nadezhda; Choe, Senyon; Meier, Beat H; Picotti, Paola; Rizo, Josep; Stahlberg, Henning; Riek, Roland

2016-04-15

Multiple neurodegenerative diseases are caused by the aggregation of the human α-Synuclein (α-Syn) protein. α-Syn possesses high structural plasticity and the capability of interacting with membranes. Both features are not only essential for its physiological function but also play a role in the aggregation process. Recently it has been proposed that α-Syn is able to form lipid-protein particles reminiscent of high-density lipoproteins. Here, we present a method to obtain a stable and homogeneous population of nanometer-sized particles composed of α-Syn and anionic phospholipids. These particles are called α-Syn lipoprotein (nano)particles to indicate their relationship to high-density lipoproteins formed by human apolipoproteins in vivo and of in vitro self-assembling phospholipid bilayer nanodiscs. Structural investigations of the α-Syn lipoprotein particles by circular dichroism (CD) and magic angle solid-state nuclear magnetic resonance (MAS SS-NMR) spectroscopy establish that α-Syn adopts a helical secondary structure within these particles. Based on cryo-electron microscopy (cryo-EM) and dynamic light scattering (DLS) α-Syn lipoprotein particles have a defined size with a diameter of ∼23 nm. Chemical cross-linking in combination with solution-state NMR and multiangle static light scattering (MALS) of α-Syn particles reveal a high-order protein-lipid entity composed of ∼8-10 α-Syn molecules. The close resemblance in size between cross-linked in vitro-derived α-Syn lipoprotein particles and a cross-linked species of endogenous α-Syn from SH-SY5Y human neuroblastoma cells indicates a potential functional relevance of α-Syn lipoprotein nanoparticles. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Oxidized low-density lipoprotein in children with familial hypercholesterolemia and unaffected siblings: effect of pravastatin

NARCIS (Netherlands)

Rodenburg, Jessica; Vissers, Maud N.; Wiegman, Albert; Miller, Elizabeth R.; Ridker, Paul M.; Witztum, Joseph L.; Kastelein, John J. P.; Tsimikas, Sotirios

2006-01-01

OBJECTIVES: To assess the role of oxidized phospholipids (OxPLs) in children with familial hypercholesterolemia (FH) and the effect of pravastatin. BACKGROUND: Oxidized phospholipids are a major component of oxidized low-density lipoprotein (OxLDL) and are bound to lipoprotein (a) [Lp(a)]. The

PFOS induced lipid metabolism disturbances in BALB/c mice through inhibition of low density lipoproteins excretion

Science.gov (United States)

Wang, Ling; Wang, Yu; Liang, Yong; Li, Jia; Liu, Yuchen; Zhang, Jie; Zhang, Aiqian; Fu, Jianjie; Jiang, Guibin

2014-04-01

Male BALB/c mice fed with either a regular or high fat diet were exposed to 0, 5 or 20 mg/kg perfluorooctane sulfonate (PFOS) for 14 days. Increased body weight, serum glucose, cholesterol and lipoprotein levels were observed in mice given a high fat diet. However, all PFOS-treated mice got reduced levels of serum lipid and lipoprotein. Decreasing liver glycogen content was also observed, accompanied by reduced serum glucose levels. Histological and ultrastructural examination detected more lipid droplets accumulated in hepatocytes after PFOS exposure. Moreover, transcripitonal activity of lipid metabolism related genes suggests that PFOS toxicity is probably unrelevant to PPARα's transcription. The present study demonstrates a lipid disturbance caused by PFOS and thus point to its role in inhibiting the secretion and normal function of low density lipoproteins.

The complex fate in plasma of gadolinium incorporated into high-density lipoproteins used for magnetic imaging of atherosclerotic plaques

NARCIS (Netherlands)

Barazza, Alessandra; Blachford, Courtney; Even-Or, Orli; Joaquin, Victor A.; Briley-Saebo, Karen C.; Chen, Wei; Jiang, Xian-Cheng; Mulder, Willem J. M.; Cormode, David P.; Fayad, Zahi A.; Fisher, Edward A.

2013-01-01

We have previously reported enhancing the imaging of atherosclerotic plaques in mice using reconstituted high density lipoproteins (HDL) as nanocarriers for the MRI contrast agent gadolinium (Gd). This study focuses on the underlying mechanisms of Gd delivery to atherosclerotic plaques. HDL, LDL,

Effects of maximal doses of atorvastatin versus rosuvastatin on small dense low-density lipoprotein cholesterol levels

Science.gov (United States)

Maximal doses of atorvastatin and rosuvastatin are highly effective in lowering low-density lipoprotein (LDL) cholesterol and triglyceride levels; however, rosuvastatin has been shown to be significantly more effective than atorvastatin in lowering LDL cholesterol and in increasing high-density lipo...

The Correlation between the Triglyceride to High Density Lipoprotein Cholesterol Ratio and Computed Tomography-Measured Visceral Fat and Cardiovascular Disease Risk Factors in Local Adult Male Subjects

OpenAIRE

Park, Hye-Rin; Shin, Sae-Ron; Han, A Lum; Jeong, Yong Joon

2015-01-01

Background We studied the association between the triglyceride to high-density lipoprotein cholesterol ratio and computed tomography-measured visceral fat as well as cardiovascular risk factors among Korean male adults. Methods We measured triglycerides, high density lipoprotein cholesterol, body mass, waist circumference, fasting plasma glucose, hemoglobin A1c, systolic blood pressure, diastolic blood pressure, visceral fat, and subcutaneous fat among 372 Korean men. The visceral fat and sub...

Loci of catabolism of beta-very low density lipoprotein in vivo delineated with a residualizing label, 125I-dilactitol tyramine

International Nuclear Information System (INIS)

Daugherty, A.; Thorpe, S.R.; Lange, L.G.; Sobel, B.E.; Schonfeld, G.

1985-01-01

beta-Very low density lipoprotein (beta-VLDL) may be a major atherogenic lipoprotein, and knowledge of the sites of its catabolism should facilitate elucidation of mechanisms important in the regulation of its plasma concentrations. In this study, catabolic sites of beta-VLDL have been delineated in normolipidemic rabbits with a novel, radioiodinated, residualizing label, 125 I-dilactitol tyramine ( 125 I-DLT). Comparative studies of beta-VLDL and low density lipoprotein catabolism were performed with 125 I-DLT conjugated to each lipoprotein and with lipoproteins iodine-labeled conventionally. Conjugation did not alter size distributions or charge characteristics of lipoprotein particles. The overall processing (binding and degradation) of lipoproteins by cultured rabbit skin fibroblasts was not influenced by 125 I-DLT derivatization, suggesting that attachment of the label did not influence cell receptor-lipoprotein interactions. Furthermore, although degradation products of 125 I-lipoproteins leaked out of the cells and into the medium, the degradation products of 125 I-DLT lipoproteins were retained by the cells. The principal catabolic site of beta-VLDL in normolipidemic rabbits was found to be the liver with 54 +/- 4% of injected 125 I retained in this organ 24 h after injection of 125 I-DLT-beta-VLDL. When catabolism was normalized to tissue weight, the liver and adrenals were found to be approximately equally active in the metabolism of beta-VLDL. In agreement with results of other studies with residualizing labels, the principal organ of catabolism of 125 I-DLT-LDL in vivo was the liver. The adrenals were the most highly catabolizing organ when results were normalized for tissue weight

Levels of high-density lipoprotein cholesterol (HDL-C among children with steady-state sickle cell disease

Directory of Open Access Journals (Sweden)

Seixas Magda O

2010-08-01

Full Text Available Abstract Background The search for sickle cell disease (SCD prognosis biomarkers is a challenge. These markers identification can help to establish further therapy, later severe clinical complications and with patients follow-up. We attempted to study a possible involvement of levels of high-density lipoprotein cholesterol (HDL-C in steady-state children with SCD, once that this lipid marker has been correlated with anti-inflammatory, anti-oxidative, anti-aggregation, anti-coagulant and pro-fibrinolytic activities, important aspects to be considered in sickle cell disease pathogenesis. Methods We prospectively analyzed biochemical, inflammatory and hematological biomarkers of 152 steady-state infants with SCD and 132 healthy subjects using immunochemistry, immunoassay and electronic cell counter respectively. Clinical data were collected from patient medical records. Results Of the 152 infants investigated had a significant positive association of high-density lipoprotein cholesterol with hemoglobin (P Conclusions We hypothesize that some SCD patients can have a specific dyslipidemic subphenotype characterized by low HDL-C with hypertriglyceridemia and high VLDL-C in association with other biomarkers, including those related to inflammation. This represents an important step toward a more reliable clinical prognosis. Additional studies are warranted to test this hypothesis and the probably mechanisms involved in this complex network of markers and their role in SCD pathogenesis.

Lipoproteins tethered dendrimeric nanoconstructs for effective targeting to cancer cells

Science.gov (United States)

Jain, Anupriya; Jain, Keerti; Mehra, Neelesh Kumar; Jain, N. K.

2013-10-01

In the present investigation, poly (propylene imine) dendrimers up to fifth generation (PPI G5.0) were synthesized using ethylene diamine and acrylonitrile. Lipoproteins (high-density lipoprotein; HDL and low-density lipoprotein; LDL) were isolated from human plasma by discontinuous density gradient ultracentrifugation, characterized and tethered to G5.0 PPI dendrimers to construct LDL- and HDL-conjugated dendrimeric nanoconstructs for tumor-specific delivery of docetaxel. Developed formulations showed sustained release characteristics in in vitro drug release and in vivo pharmacokinetic studies. The cancer targeting potential of lipoprotein coupled dendrimers was investigated by ex vivo cytotoxicity and cell uptake studies using human hepatocellular carcinoma cell lines (HepG2 cells) and biodistribution studies in albino rats of Sprague-Dawley strain. Lipoprotein anchored dendrimeric nanoconstructs showed significant uptake by cancer cells as well as higher biodistribution of docetaxel to liver and spleen. It is concluded that these precisely synthesized engineered dendrimeric nanoconstructs could serve as promising drug carrier for fighting with the fatal disease, i.e., cancer, attributed to their defined targeting and therapeutic potential.

Lipoproteins tethered dendrimeric nanoconstructs for effective targeting to cancer cells

Energy Technology Data Exchange (ETDEWEB)

Jain, Anupriya; Jain, Keerti, E-mail: keertijain02@gmail.com; Mehra, Neelesh Kumar, E-mail: neelesh81mph@gmail.com; Jain, N. K., E-mail: dr.jnarendr@gmail.com [Dr. H. S. Gour University, Pharmaceutics Research Laboratory, Department of Pharmaceutical Sciences (India)

2013-10-15

In the present investigation, poly (propylene imine) dendrimers up to fifth generation (PPI G5.0) were synthesized using ethylene diamine and acrylonitrile. Lipoproteins (high-density lipoprotein; HDL and low-density lipoprotein; LDL) were isolated from human plasma by discontinuous density gradient ultracentrifugation, characterized and tethered to G5.0 PPI dendrimers to construct LDL- and HDL-conjugated dendrimeric nanoconstructs for tumor-specific delivery of docetaxel. Developed formulations showed sustained release characteristics in in vitro drug release and in vivo pharmacokinetic studies. The cancer targeting potential of lipoprotein coupled dendrimers was investigated by ex vivo cytotoxicity and cell uptake studies using human hepatocellular carcinoma cell lines (HepG2 cells) and biodistribution studies in albino rats of Sprague-Dawley strain. Lipoprotein anchored dendrimeric nanoconstructs showed significant uptake by cancer cells as well as higher biodistribution of docetaxel to liver and spleen. It is concluded that these precisely synthesized engineered dendrimeric nanoconstructs could serve as promising drug carrier for fighting with the fatal disease, i.e., cancer, attributed to their defined targeting and therapeutic potential.

Serum and urinary lipoproteins in the human nephrotic syndrome: evidence for renal catabolism of lipoproteins

Energy Technology Data Exchange (ETDEWEB)

Shore, V.G.; Forte, T.; Licht, H.; Lewis, S.B.

1982-03-01

The urinary excretion of lipoproteins and the possibility of catabolic alterations on glomerular filtration were investigated in four nephrotic subjects difering in etiology, serum lipoprotein profile, and 24 hr urinary output of protein and lipids. The apolipoproteins and lipoproteins of urine were compared with those of serum with respect to distribution profile, physical properties, and composition. As expected from molecular sieving effects during glomerular filtration, the urinary HDL were more abundant than the lower density lipoproteins even when the plasma LDL was elevated markedly. Intact apolipoproteins were not found in the concentrated urinary fraction isolated by ultrafiltration between the limits of 10/sup 4/ and 5 x 10/sup 4/ daltons. On the basis of immunoreactivity, gel electrophoresis, and amino acid composition, apolipoproteins B and AI are the major and minor proteins, respectively, of urinary LDL, and apo B is the major protein of the urinary IDL and VLDL. Apolipoproteins AI, AII, CI, CIII, and possibly AIV were isolated from the urinary HDL. As much as 20% of the protein moiety of the urinary HDL appeared to be large apolipoprotien fragments with molecular weights and isoelectric points similar to those of apo CII and apo CIII. The lower density classes of urinary lipoproteins also appeared to have lost apo E and apo C's and to have undergone partial proteolysis.

Flow-cytometric determination of high-density-lipoprotein binding sites on human leukocytes

International Nuclear Information System (INIS)

Schmitz, G.; Wulf, G.; Bruening, T.A.; Assmann, G.

1987-01-01

In this method, leukocytes were isolated from 6 mL of EDTA-blood by density-gradient centrifugation and subsequently incubated with rhodamine isothiocyanate (RITC)-conjugated high-density lipoproteins (HDL). The receptor-bound conjugate particles were determined by fluorescent flow cytometry and compared with 125 I-labeled HDL binding data for the same cells. Human granulocytes express the highest number of HDL binding sites (9.4 x 10(4)/cell), followed by monocytes (7.3 x 10(4)/cell) and lymphocytes (4.0 x 10(4)/cell). Compared with conventional analysis of binding of 125 I-labeled HDL in tissue-culture dishes, the present determination revealed significantly lower values for nonspecific binding. In competition studies, the conjugate competes for the same binding sites as 125 I-labeled HDL. With the use of tetranitromethane-treated HDL3, which fails to compete for the HDL receptor sites while nonspecific binding is not affected, we could clearly distinguish between 37 degrees C surface binding and specific 37 degrees C uptake of RITC-HDL3, confirming that the HDL receptor leads bound HDL particles into an intracellular pathway rather than acting as a docking type of receptor. Patients with familial dysbetalipoproteinemia showed a significantly higher number of HDL binding sites in the granulocyte population but normal in lymphocytes and monocytes, indicating increased uptake of cholesterol-containing lipoproteins. In patients with familial hypercholesterolemia, HDL binding was increased in all three cell types, indicating increased cholesterol uptake and increased cholesterol synthesis. The present method allows rapid determination of HDL binding sites in leukocytes from patients with various forms of hyper- and dyslipoproteinemias

Low-density lipoprotein cholesterol to high-density lipoprotein cholesterol ratio is the best surrogate marker for insulin resistance in non-obese Japanese adults

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Takayama Shuzo

2010-12-01

Full Text Available Abstract Background The aim of the present study was to examine how lipid profiles are associated with insulin resistance in Japanese community-dwelling adults. Methods This cross-sectional study included 614 men aged 58 ± 14 (mean ± standard deviation; range, 20-89 years and 779 women aged 60 ± 12 (range, 21-88 years. The study sample were 1,042 (74.8% non-obese (BMI 2 and 351 (25.2% overweight (BMI ≥ 25 kg/m2 subjects. Insulin resistance was defined by homeostasis model assessment of insulin resistance (HOMA-IR of at least 2.5. The areas under the curve (AUC of the receiver operating characteristic curves (ROC were used to compare the power of these serum markers. Results In non-obese subjects, the best marker of insulin resistance was low-density lipoprotein cholesterol (LDL-C/high-density lipoprotein cholesterol (HDL-C ratio of 0.74 (95% confidence interval (CI, 0.66-0.80. The HDL-C, triglyceride (TG/HDL-C ratio, and non-HDL-C also discriminated insulin resistance, as the values for AUC were 0.31 (95% CI, 0.24-0.38, 0.69 (95% CI, 0.62-0.75 and 0.69 (95% CI, 0.62-0.75, respectively. In overweight subjects, the AUC for TG and TG/HDL-C ratio were 0.64 (0.58-0.71 and 0.64 (0.57-0.70, respectively. The optimal cut-off point to identifying insulin resistance for these markers yielded the following values: TG/HDL-C ratio of ≥1.50 and LDL-C/HDL-C ratio of ≥2.14 in non-obese subjects, and ≥2.20, ≥2.25 in overweight subjects. In non-obese subjects, the positive likelihood ratio was greatest for LDL-C/HDL-C ratio. Conclusion In non-obese Japanese adults, LDL-C/HDL-C ratio may be the best reliable marker of insulin resistance.

The Impact of Cardiorespiratory Fitness on Age-Related Lipids and Lipoproteins

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Park, Yong-Moon Mark; Sui, Xuemei; Liu, Junxiu; Zhou, Haiming; Kokkinos, Peter F.; Lavie, Carl J.; Hardin, James W.; Blair, Steven N.

2015-01-01

Background Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce. Objectives This study sought to assess the longitudinal, aging trajectory of lipids and lipoproteins for the life course in adults, and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins. Methods Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 (mean 3.5) health examinations between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied. Results Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until the mid-40s to early 50s, with subsequent declines (all p lipoproteins in young to middle-aged men than in older men. Conclusions Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men, and suggests that promoting increased CRF levels may help delay the development of dyslipidemia. PMID:25975472

The effect of cardiorespiratory fitness on age-related lipids and lipoproteins.

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Park, Yong-Moon Mark; Sui, Xuemei; Liu, Junxiu; Zhou, Haiming; Kokkinos, Peter F; Lavie, Carl J; Hardin, James W; Blair, Steven N

2015-05-19

Evidence on the effect of cardiorespiratory fitness (CRF) on age-related longitudinal changes of lipids and lipoproteins is scarce. This study sought to assess the longitudinal aging trajectory of lipids and lipoproteins for the life course in adults and to determine whether CRF modifies the age-associated trajectory of lipids and lipoproteins. Data came from 11,418 men, 20 to 90 years of age, without known high cholesterol, high triglycerides, cardiovascular disease, and cancer at baseline and during follow-up from the Aerobics Center Longitudinal Study. There were 43,821 observations spanning 2 to 25 health examinations (mean 3.5 examinations) between 1970 and 2006. CRF was quantified by a maximal treadmill exercise test. Marginal models using generalized estimating equations were applied. Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides, and non-high-density lipoprotein cholesterol (non-HDL-C) presented similar inverted U-shaped quadratic trajectories with aging: gradual increases were noted until age mid-40s to early 50s, with subsequent declines (all p lipoproteins in young to middle-age men than in older men. Our investigation reveals a differential trajectory of lipids and lipoproteins with aging according to CRF in healthy men and suggests that promoting increased CRF levels may help delay the development of dyslipidemia. Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

EFFECT OF ADIPOSITY ON PLASMA-LIPID TRANSFER PROTEIN ACTIVITIES - A POSSIBLE LINK BETWEEN INSULIN-RESISTANCE AND HIGH-DENSITY-LIPOPROTEIN METABOLISM

NARCIS (Netherlands)

DULLAART, RPF; SLUITER, WJ; DIKKESCHEI, LD; HOOGENBERG, K; VANTOL, A

The mechanisms responsible for the decreased high density lipoprotein (HDL) cholesterol levels associated with obesity and insulin resistance are not well understood. Lecithin: cholesterol acyltransferase (LCAT) and cholesterol ester transfer protein (CETP) are key factors in the esterification of

Postprandial Hyperlipidemia and Remnant Lipoproteins.

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Masuda, Daisaku; Yamashita, Shizuya

2017-02-01

Fasting hypertriglyceridemia is positively associated with the morbidity of coronary heart disease (CHD), and postprandial (non-fasting) hypertriglyceridemia is also correlated with the risk status for CHD, which is related to the increase in chylomicron (CM) remnant lipoproteins produced from the intestine. CM remnant particles, as well as oxidized low density lipoprotein (LDL) or very low density lipoprotein (VLDL) remnants, are highly atherogenic and act by enhancing systemic inflammation, platelet activation, coagulation, thrombus formation, and macrophage foam cell formation. The cholesterol levels of remnant lipoproteins significantly correlate with small, dense LDL; impaired glucose tolerance (IGT) and CHD prevalence. We have developed an assay of apolipoprotein (apo)B-48 levels to evaluate the accumulation of CM remnants. Fasting apoB-48 levels correlate with the morbidity of postprandial hypertriglyceridemia, obesity, type III hyperlipoproteinemia, the metabolic syndrome, hypothyroidism, chronic kidney disease, and IGT. Fasting apoB-48 levels also correlate with carotid intima-media thickening and CHD prevalence, and a high apoB-48 level is a significant predictor of CHD risk, independent of the fasting TG level. Diet interventions, such as dietary fibers, polyphenols, medium-chain fatty acids, diacylglycerol, and long-chain n-3 polyunsaturated fatty acids (PUFA), ameliorate postprandial hypertriglyceridemia, moreover, drugs for dyslipidemia (n-3 PUFA, statins, fibrates or ezetimibe) and diabetes concerning incretins (dipeptidyl-peptidase IV inhibitor or glucagon like peptide-1 analogue) may improve postprandial hypertriglyceridemia. Since the accumulation of CM remnants correlates to impaired lipid and glucose metabolism and atherosclerotic cardiovascular events, further studies are required to investigate the characteristics, physiological activities, and functions of CM remnants for the development of new interventions to reduce atherogenicity.

Remnant cholesterol, low-density lipoprotein cholesterol, and blood pressure as mediators from obesity to ischemic heart disease.

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Varbo, Anette; Benn, Marianne; Smith, George Davey; Timpson, Nicholas J; Tybjaerg-Hansen, Anne; Nordestgaard, Børge G

2015-02-13

Obesity leads to increased ischemic heart disease (IHD) risk, but the risk is thought to be mediated through intermediate variables and may not be caused by increased weight per se. To test the hypothesis that the increased IHD risk because of obesity is mediated through lipoproteins, blood pressure, glucose, and C-reactive protein. Approximately 90 000 participants from Copenhagen were included in a Mendelian randomization design with mediation analyses. Associations were examined using conventional measurements of body mass index and intermediate variables and using genetic variants associated with these. During ≤22 years of follow-up 13 945 participants developed IHD. The increased IHD risk caused by obesity was partly mediated through elevated levels of nonfasting remnant cholesterol and low-density lipoprotein cholesterol, through elevated blood pressure, and possibly also through elevated nonfasting glucose levels; however, reduced high-density lipoprotein cholesterol and elevated C-reactive protein levels were not mediators in genetic analyses. The 3 intermediate variables that explained the highest excess risk of IHD from genetically determined obesity were low-density lipoprotein cholesterol with 8%, systolic blood pressure with 7%, and remnant cholesterol with 7% excess risk of IHD. Corresponding observational excess risks using conventional body mass index were 21%, 11%, and 20%, respectively. The increased IHD risk because of obesity was partly mediated through elevated levels of nonfasting remnant and low-density lipoprotein cholesterol and through elevated blood pressure. Our results suggest that there may be benefit to gain by reducing levels of these risk factors in obese individuals not able to achieve sustained weight loss. © 2014 American Heart Association, Inc.

Modified high-density lipoproteins by artificial sweetener, aspartame, and saccharin, showed loss of anti-atherosclerotic activity and toxicity in zebrafish.

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Kim, Jae-Yong; Park, Ki-Hoon; Kim, Jihoe; Choi, Inho; Cho, Kyung-Hyun

2015-01-01

Safety concerns have been raised regarding the association of chronic consumption of artificial sweeteners (ASs) with metabolic disorders, especially in the heart and brain. There has been no information on the in vivo physiological effects of AS consumption in lipoprotein metabolism. High-dosage treatment (final 25, 50, and 100 mM) with AS (aspartame, acesulfame K, and saccharin) to human high-density lipoprotein (HDL) induced loss of antioxidant ability along with elevated atherogenic effects. Aspartame-treated HDL3 (final 100 mM) almost all disappeared due to putative proteolytic degradation. Aspartame- and saccharin-treated HDL3 showed more enhanced cholesteryl ester transfer activity, while their antioxidant ability was disappeared. Microinjection of the modified HDL3 exacerbated the inflammatory death in zebrafish embryos in the presence of oxLDL. These results show that AS treatment impaired the beneficial functions of HDL, resulting in loss of antioxidant and anti-atherogenic activities. These results suggest that aspartame and saccharin could be toxic to the human circulation system as well as embryonic development via impairment of lipoprotein function.

Effect of I125 on oxidation behavior of lipoprotein subpopulations

International Nuclear Information System (INIS)

Majtenyi, S.

2002-07-01

Lipoproteins play a central role in lipid metabolism. They serve as a transport vehicle for cholesterol and triglycerides keeping them in plasma in solution. Lipoproteins are characterized by the content of specific apoproteins and differences in the hydrated density ranges. Moreover, they are distinguished by electrophoretic mobility and other characteristics as high and low-density lipoproteins, respectively lipoprotein (a). More specifically, HDL is classified into HDL 2 and HDL 3 . In atherogenesis, lipoproteins are considered to play a key-role. Oxidatively modified LDL is selectively taken up via scavenger receptors of the macrophage-monocyte system. These cells are transformed into foam cells promoting atherogenesis in vessels in the subendothelial space. Oxidized HDL essentially appears to loose its protective effects on LDL and its beneficial function in reverse cholesterol transport. Thus, it turns proatherogenic. The effects various species of free radicals exert on lipoproteins are the reason for this oxidative modification. Thyroid function also influences lipoproteins in a complex manner. Based on their hydrated density ranges, lipoprotein subpopulations were fractionated and isolated via isopycnic density gradient ultracentrifugation. After investigation of the general oxidation behavior, initiated by addition of CuSO 4 to the isolated samples of HDL 3 , HDL 2 , LDL and Lp(a), the influence of different activities of radioiodine-125 on the kinetics of the formation of conjugated dienes was assessed. This was achieved by coincubation of plasma with I 125 . The spectrophotometrical measurement of the concentration of conjugated dienes in the course of CuSO 4 -induced lipid peroxidation leads to measurable changes in absorption at 234 nm. These changes in absorption over time result in a characteristically shaped curve graphically plotted. The shape of these curves mirrors different indicators of lipid peroxidation. Therefrom lag time, maximal

Low-density lipoproteins cause atherosclerotic cardiovascular disease

DEFF Research Database (Denmark)

Ference, Brian A.; Ginsberg, Henry N.; Graham, Ian

2017-01-01

Aims To appraise the clinical and genetic evidence that low-density lipoproteins (LDLs) cause atherosclerotic cardiovascular disease (ASCVD). Methods and results We assessed whether the association between LDL and ASCVD fulfils the criteria for causality by evaluating the totality of evidence from...... proportional to the absolute reduction in LDL-C and the cumulative duration of exposure to lower LDL-C, provided that the achieved reduction in LDL-C is concordant with the reduction in LDL particle number and that there are no competing deleterious off-target effects. Conclusion Consistent evidence from...

Serum oxidized low density lipoprotein levels in preeclamptic and normotensive pregnants.

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Kozan, A; Yildirmak, S Turkmen; Mihmanli, V; Ayabakan, H; Cicek, Y G; Kalaslioglu, V; Doean, S; Cebeci, H Cerci

2015-01-01

BACKGROUNDS/AIM: The aim of the study was to determine serum lipids and oxidized low density lipoprotein (ox-LDL) levels in preeclamptic pregnants and compare with those of normotensives. Ox-LDL levels were determined by enzyme linked immunosorbent assay (ELISA); total cholesterol, hight density lipoprotein (HDL)-cholesterol and triglyceride levels were measured by enzymatic colorimetric assay in 26 normotensive and 27 preeclamptic pregnants. LDL and very low density lipoprotein (VLDL) cholesterol was calculated by Friedwald formula. Serum levels of Ox-LDL (U/L), total-cholesterol (mg/dL), HDL-cholesterol (mg/dL), LDL-cholesterol (mg/dL), triglyceride (mg/dL), and VLDL-cholesterol (mg/dL) in normotensive and preeclamptic pregnants were found as 130±60 and 133±69; 248±49 and 248±81; 67±14 and 61±16; 147±61 and 135±59; 207±76 and 256±87; 41±15 and 50±17, respectively. Mean values of Ox-LDL and other lipid parameters were higher than the upper limits of their reference ranges in both of groups. However no significant differences were found in Ox-LDL, total, HDL and LDL-cholesterol levels between two groups. However, the levels of triglyceride and VLDL-cholesterol were significantly higher in preeclampsia group. The present results suggest that the levels of serum Ox-LDL and other lipid parameters rise as a result of pregnancy rather than as a result of preeclampsia.

Serum lipid and lipoprotein concentrations following exposure to ozone

Energy Technology Data Exchange (ETDEWEB)

Vaughan, W J; Adamson, G L; Lindgren, F T; Schooley, J.C.

1984-07-01

The effects of exposure to ozone (O/sub 3/) on concentrations of serum lipids and lipoproteins were investigated. Male and female guinea pigs were exposed to O/sub 3/ at 1 ppm for two weeks. Serum concentrations of cholesterol, triglycerides, low density (LDL) and very low density (VLDL) lipoproteins were elevated after O/sub 3/ exposure, particularly in males. During O/sub 3/ exposure the food intake per day decreased (for a constant body weight), suggesting that metabolic rate and possibly basal metabolic rate was lower. Lung wet weights increased during O/sub 3/ exposure by 87% for males and 45% for females. When individual lung weight/body weight ratios were correlated with cholesterol and LDL values from the same animal, a high correlation is found for males (r . 0.81, P less than 0.05), suggesting that there may be a relationship between lipoprotein elevations and lung damage for males. Because elevated concentrations of lipids and lipoproteins in humans increase the risk of coronary heart disease (CHD), the lipoprotein results suggest that an epidemiological study of the incidence of CHD with metropolitan O/sub 3/ levels may be warranted.

Association between ABCG1 polymorphism rs1893590 and high-density lipoprotein (HDL) in an asymptomatic Brazilian population.

Science.gov (United States)

Zago, V H S; Scherrer, D Z; Parra, E S; Panzoldo, N B; Alexandre, F; Nakandakare, E R; Quintão, E C R; de Faria, E C

2015-03-01

ATP binding cassette transporter G1 (ABCG1) promotes lipidation of nascent high-density lipoprotein (HDL) particles, acting as an intracellular transporter. SNP rs1893590 (c.-204A > C) of ABCG1 gene has been previously studied and reported as functional over plasma HDL-C and lipoprotein lipase activity. This study aimed to investigate the relationships of SNP rs1893590 with plasma lipids and lipoproteins in a large Brazilian population. Were selected 654 asymptomatic and normolipidemic volunteers from both genders. Clinical and anthropometrical data were taken and blood samples were drawn after 12 h fasting. Plasma lipids and lipoproteins, as well as HDL particle size and volume were determined. Genomic DNA was isolated for SNP rs1893590 detection by TaqMan(®) OpenArray(®) Real-Time PCR Plataform (Applied Biosystems). Mann-Whitney U, Chi square and two-way ANOVA were the used statistical tests. No significant differences were found in the comparison analyses between the allele groups for all studied parameters. Conversely, significant interactions were observed between SNP and age over plasma HDL-C, were volunteers under 60 years with AA genotype had increased HDL-C (p = 0.048). Similar results were observed in the group with body mass index (BMI) m(2), where volunteers with AA genotype had higher HDL-C levels (p = 0.0034), plus an increased HDL particle size (p = 0.01). These findings indicate that SNP rs1893590 of ABCG1 has a significant impact over HDL-C under asymptomatic clinical conditions in an age and BMI dependent way.

Lipoprotein-a

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/007262.htm Lipoprotein-a To use the sharing features on this page, please enable JavaScript. Lipoproteins are molecules made of proteins and fat. They ...

The Human Pathogen Streptococcus pyogenes Releases Lipoproteins as Lipoprotein-rich Membrane Vesicles.

Science.gov (United States)

Biagini, Massimiliano; Garibaldi, Manuela; Aprea, Susanna; Pezzicoli, Alfredo; Doro, Francesco; Becherelli, Marco; Taddei, Anna Rita; Tani, Chiara; Tavarini, Simona; Mora, Marirosa; Teti, Giuseppe; D'Oro, Ugo; Nuti, Sandra; Soriani, Marco; Margarit, Immaculada; Rappuoli, Rino; Grandi, Guido; Norais, Nathalie

2015-08-01

Bacterial lipoproteins are attractive vaccine candidates because they represent a major class of cell surface-exposed proteins in many bacteria and are considered as potential pathogen-associated molecular patterns sensed by Toll-like receptors with built-in adjuvanticity. Although Gram-negative lipoproteins have been extensively characterized, little is known about Gram-positive lipoproteins. We isolated from Streptococcus pyogenes a large amount of lipoproteins organized in vesicles. These vesicles were obtained by weakening the bacterial cell wall with a sublethal concentration of penicillin. Lipid and proteomic analysis of the vesicles revealed that they were enriched in phosphatidylglycerol and almost exclusively composed of lipoproteins. In association with lipoproteins, a few hypothetical proteins, penicillin-binding proteins, and several members of the ExPortal, a membrane microdomain responsible for the maturation of secreted proteins, were identified. The typical lipidic moiety was apparently not necessary for lipoprotein insertion in the vesicle bilayer because they were also recovered from the isogenic diacylglyceryl transferase deletion mutant. The vesicles were not able to activate specific Toll-like receptor 2, indicating that lipoproteins organized in these vesicular structures do not act as pathogen-associated molecular patterns. In light of these findings, we propose to name these new structures Lipoprotein-rich Membrane Vesicles. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Mechanism of action of gemfibrozil on lipoprotein metabolism.

OpenAIRE

Saku, K; Gartside, P S; Hynd, B A; Kashyap, M L

1985-01-01

Gemfibrozil is a potent lipid regulating drug whose major effects are to increase plasma high density lipoproteins (HDL) and to decrease plasma triglycerides (TG) in a wide variety of primary and secondary dyslipoproteinemias. Its mechanism of action is not clear. Six patients with primary familial endogenous hypertriglyceridemia with fasting chylomicronemia (type V lipoprotein phenotype) with concurrent subnormal HDL cholesterol levels (HDL deficiency) were treated initially by diet and once...

Lipoprotein Apheresis for Lipoprotein(a)-Associated Cardiovascular Disease

DEFF Research Database (Denmark)

Roeseler, Eberhard; Julius, Ulrich; Heigl, Franz

2016-01-01

OBJECTIVE: Lipoprotein(a)-hyperlipoproteinemia (Lp(a)-HLP) along with progressive cardiovascular disease has been approved as indication for regular lipoprotein apheresis (LA) in Germany since 2008. We aimed to study the long-term preventive effect of LA and to assess hypothetical clinical correl...

To Study the Activity of Paraoxonase-1 and High Density Lipoprotein-Cholesterol in Alcoholic Liver Cirrhosis

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Pooja Nemagoudar

2017-01-01

Full Text Available Background: Alcoholic liver cirrhosis is the most common complication of ethanol abuse. Alcoholic fatty liver progresses to alcoholic hepatitis, cirrhosis and liver failure. Lipoproteins are synthesized by the liver and secreted into the circulation. Alcoholic liver cirrhosis causes alteration in lipoprotein metabolism producing liver steatosis and necrosis. Paraoxonase-1 (PON-1 is an enzyme synthesized in liver and has an esterase activity towards lipid peroxides and circulates in plasma bound to High-Density Lipoproteins-cholesterol (HDL-c. Aim and Objectives: To determine the activity of PON-1 and levels of HDL-c in alcoholic liver disease and to correlate PON-1 activity with HDL-c. Materials and Methods: A Cross sectional study done in Department of Biochemistry and Department of Medicine, Belagavi Institute of Medical Sciences, Belagavi, Karnataka, India, from 1st December 2014 to 31st January 2016 Study included 50 males (age range 25-55 years with alcoholic liver cirrhosis and 50 healthy male participants (age range 25-55 years. PON-1 activity was estimated using spectrophotometric method by the hydrolysis of phenylacetate. HDL-c level was measured by cholesterol oxidase-peroxidase method. Results: The serum PON-1 activity and levels of HDL-c in patients with alcoholic liver cirrhosis were significantly reduced (p<0.001 compared with controls. Conclusion: A significant decrease in PON-1 and HDL-c in alcoholic liver cirrhosis may contribute to the risk of atherosclerosis in alcoholic liver cirrhosis patients.

Apolipoprotein B-containing lipoproteins and atherosclerotic cardiovascular disease [version 1; referees: 2 approved

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Michael D. Shapiro

2017-02-01

Full Text Available Cholesterol-rich, apolipoprotein B (apoB-containing lipoproteins are now widely accepted as the most important causal agents of atherosclerotic cardiovascular disease. Multiple unequivocal and orthogonal lines of evidence all converge on low-density lipoprotein and related particles as being the principal actors in the genesis of atherosclerosis. Here, we review the fundamental role of atherogenic apoB-containing lipoproteins in cardiovascular disease and several other humoral and parietal factors that are required to initiate and maintain arterial degeneration. The biology of foam cells and their interactions with high-density lipoproteins, including cholesterol efflux, are also briefly reviewed.

Acrolein impairs the cholesterol transport functions of high density lipoproteins.

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Chadwick, Alexandra C; Holme, Rebecca L; Chen, Yiliang; Thomas, Michael J; Sorci-Thomas, Mary G; Silverstein, Roy L; Pritchard, Kirkwood A; Sahoo, Daisy

2015-01-01

High density lipoproteins (HDL) are considered athero-protective, primarily due to their role in reverse cholesterol transport, where they transport cholesterol from peripheral tissues to the liver for excretion. The current study was designed to determine the impact of HDL modification by acrolein, a highly reactive aldehyde found in high abundance in cigarette smoke, on the cholesterol transport functions of HDL. HDL was chemically-modified with acrolein and immunoblot and mass spectrometry analyses confirmed apolipoprotein crosslinking, as well as acrolein adducts on apolipoproteins A-I and A-II. The ability of acrolein-modified HDL (acro-HDL) to serve as an acceptor of free cholesterol (FC) from COS-7 cells transiently expressing SR-BI was significantly decreased. Further, in contrast to native HDL, acro-HDL promotes higher neutral lipid accumulation in murine macrophages as judged by Oil Red O staining. The ability of acro-HDL to mediate efficient selective uptake of HDL-cholesteryl esters (CE) into SR-BI-expressing cells was reduced compared to native HDL. Together, the findings from our studies suggest that acrolein modification of HDL produces a dysfunctional particle that may ultimately promote atherogenesis by impairing functions that are critical in the reverse cholesterol transport pathway.

High density lipoprotein cholesterol (HDL) metabolism and its role in ischemic heart disease

International Nuclear Information System (INIS)

Pirzado, Z.A.; Sngi, S.A.; Malik, R.

1999-01-01

Case control and prospective epidemiological studies have found a striking, consistently negative association between High Density Lipoprotein(HDL) levels and coronary vascular events. As a results, the genetic and environmental determinants of HDL levels are being studied intensively. These investigations and their potential clinical applications require a fundamental understanding of the structure, function and metabolism of HDL and its components. Of the special interest are the means by which it exerts its apparently protective effect. In this report we characterize the structure of HLD: and describe its compounds, particularly the protein component. We discuss HDL metabolism in light of the relationship of HDL to other lipoprotein classes and relate what little is known of the functions of HDL. We also review the biochemical mechanism by which HDL may protect against cardiovascular disease and discuss further biochemical research that will be necessary for a better understanding of HDL. Interest in HDL has been greatly intensified in recent years, stimulated largely by the finding that HDL is inversely related in HDL has been greatly intensified in recent years, stimulated largely by the finding that HDL is inversely related to coronary artery disease. Case-control and prospective observations of the striking, consistent and independent negative association between HDL levels and coronary vascular events have in turn generated new interest in the structure, composition and metabolism of these fascinating lipoproteins. Several studies carried out in Pakistan also reveal the inverse relation of HDL to IHD/sup 1,2/. This article contains a tremendous amount of information on HDL and its relationship to genetic and environmental factors which should be useful to investigations and clinicians in their evaluation and use of HDL cholesterol measurements to assess hearth disease risk. A knowledge of the structure, function and metabolism of HDL and its components is

Relationship between low-density lipoprotein cholesterol and severe acute pancreatitis (“the lipid paradox”

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Hong W

2018-05-01

Full Text Available Wandong Hong,1,* Vincent Zimmer,2,3,* Simon Stock,4,* Maddalena Zippi,5 Jones AQ Omoshoro-Jones,6 Mengtao Zhou71Department of Gastroenterology and Hepatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China; 2Department of Medicine II, Saarland University Medical Center, Saarland University, Homburg, Germany; 3Department of Medicine, Marienhausklinik St Josef Kohlhof, Neunkirchen, Germany; 4Department of Surgery, World Mate Emergency Hospital, Battambang, Cambodia; 5Unit of Gastroenterology and Digestive Endoscopy, Sandro Pertini Hospital, Rome, Italy; 6Department of Surgery, Chris Hani-Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa; 7Department of Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, People’s Republic of China*These authors contributed equally to this workBackground and aim: The aim of this study was to investigate the association between low-density lipoprotein cholesterol (LDL-C and the development of severe acute pancreatitis (SAP.Patients and methods: A total of 674 patients with acute pancreatitis were enrolled. Nonlinearity in the relationship between LDL-C and SAP was assessed by restricted cubic spline analysis. Univariable and multivariable regression analyses were used to identify independent risk factors of SAP.Results: The restricted cubic spline analysis suggested a nonlinear association between high-density lipoprotein cholesterol (HDL-C, LDL-C and triglyceride levels and incidence of SAP. The incidence of SAP in patients with low LDL-C (<90 mg/dL, moderate LDL-C (90–150 mg/dL and high LDL-C (>150 mg/dL levels was 15.1%, 3.7% and 9.8%, respectively. Multivariable analysis confirmed that low LDL-C levels (odds ratio [OR] 3.05; 95% confidence interval [CI] 1.35–6.90, high LDL-C levels (OR 4.42; 95% CI 1.41–13.87 and low HDL-C levels (OR 6.90; 95% CI 2.61–18.23 but

A prominent large high-density lipoprotein at birth enriched in apolipoprotein C-I identifies a new group of infancts of lower birth weight and younger gestational age

Energy Technology Data Exchange (ETDEWEB)

Kwiterovich Jr., Peter O.; Cockrill, Steven L.; Virgil, Donna G.; Garrett, Elizabeth; Otvos, James; Knight-Gibson, Carolyn; Alaupovic, Petar; Forte, Trudy; Farwig, Zachlyn N.; Macfarlane, Ronald D.

2003-10-01

Because low birth weight is associated with adverse cardiovascular risk and death in adults, lipoprotein heterogeneity at birth was studied. A prominent, large high-density lipoprotein (HDL) subclass enriched in apolipoprotein C-I (apoC-I) was found in 19 percent of infants, who had significantly lower birth weights and younger gestational ages and distinctly different lipoprotein profiles than infants with undetectable, possible or probable amounts of apoC-I-enriched HDL. An elevated amount of an apoC-I-enriched HDL identifies a new group of low birth weight infants.

Serum Paraoxonase 1 Activity Is Associated with Fatty Acid Composition of High Density Lipoprotein

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Maryam Boshtam

2013-01-01

Full Text Available Introduction. Cardioprotective effect of high density lipoprotein (HDL is, in part, dependent on its related enzyme, paraoxonase 1 (PON1. Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. Methods. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Results. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA. PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω6 fatty acids of HDL. Conclusion. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health.

Serum paraoxonase 1 activity is associated with fatty acid composition of high density lipoprotein.

Science.gov (United States)

Boshtam, Maryam; Razavi, Amirnader Emami; Pourfarzam, Morteza; Ani, Mohsen; Naderi, Gholam Ali; Basati, Gholam; Mansourian, Marjan; Dinani, Narges Jafari; Asgary, Seddigheh; Abdi, Soheila

2013-01-01

Cardioprotective effect of high density lipoprotein (HDL) is, in part, dependent on its related enzyme, paraoxonase 1 (PON1). Fatty acid composition of HDL could affect its size and structure. On the other hand, PON1 activity is directly related to the structure of HDL. This study was designed to investigate the association between serum PON1 activity and fatty acid composition of HDL in healthy men. One hundred and forty healthy men participated in this research. HDL was separated by sequential ultracentrifugation, and its fatty acid composition was analyzed by gas chromatography. PON1 activity was measured spectrophotometrically using paraxon as substrate. Serum PON1 activity was directly correlated with the amount of stearic acid and dihomo-gamma-linolenic acid (DGLA). PON1/HDL-C was directly correlated with the amount of miristic acid, stearic acid, and DGLA and was inversely correlated with total amount of ω 6 fatty acids of HDL. The fatty acid composition of HDL could affect the activity of its associated enzyme, PON1. As dietary fats are the major determinants of serum lipids and lipoprotein composition, consuming some special dietary fatty acids may improve the activity of PON1 and thereby have beneficial effects on health.

Effect of apolipoprotein E-free high density lipoproteins on cholesterol metabolism in cultured pig hepatocytes

International Nuclear Information System (INIS)

Bachorik, P.S.; Virgil, D.G.; Kwiterovich, P.O. Jr.

1987-01-01

We studied cholesterol synthesis from [ 14 C]acetate, cholesterol esterification from [ 14 C]oleate, and cellular cholesterol and cholesteryl ester levels after incubating cells with apoE-free high density lipoproteins (HDL) or low density lipoproteins (LDL). LDL suppressed synthesis by up to 60%, stimulated esterification by up to 280%, and increased cell cholesteryl ester content about 4-fold. Esterification increased within 2 h, but synthesis was not suppressed until after 6 h. ApoE-free HDL suppressed esterification by about 50% within 2 h. Cholesterol synthesis was changed very little within 6 h, unless esterification was maximally suppressed; synthesis was then stimulated about 4-fold. HDL lowered cellular unesterified cholesterol by 13-20% within 2 h and promoted the removal of newly synthesized cholesterol and cholesteryl esters. These changes were transient; by 24 h, both esterification and cellular unesterified cholesterol returned to control levels, and cholesteryl esters increased 2-3-fold. HDL core lipid was taken up selectively from 125 I-labeled [ 3 H]cholesteryl ester- and ether-labeled HDL. LDL core lipid uptake was proportional to LDL apoprotein uptake. The findings suggest that 1) the cells respond initially to HDL or LDL with changes in esterification, and 2) HDL mediates both the removal of free cholesterol from the cell and the delivery of HDL cholesteryl esters to the cell

Expression of human apolipoprotein A-I epitopes in high density lipoproteins and in serum

International Nuclear Information System (INIS)

Marcel, Y.L.; Jewer, D.; Vezina, C.; Milthorp, P.; Weech, P.K.

1987-01-01

The expression and immunoreactivity of apolipoprotein (apo) A-I epitopes in high density lipoproteins (HDL) and serum has been investigated using two series of monoclonal antibodies (Mabs) which have been described elsewhere. Series 1 Mabs, identified as 3D4, 6B8, and 5G6, were obtained by immunization and screening with apoA-I, and series 2 Mabs, identified as 2F1, 4H1, 3G10, 4F7, and 5F6, were obtained by immunization and screening with HDL. These Mabs were characterized with respect to their binding to HDL particles in solution. In series 2 Mabs, 2F1, 3G10, and 4F7, which react with apoA-I CNBr-fragments 1 and 2, could precipitate 100% of 125 I-labeled HDL, while 4H1 and 5F6, which react with CNBr fragments 1 and 3, precipitated 90 and 60% of 125 I-labeled HDL, respectively. Therefore, three distinct epitopes mapped to CNBr fragments 1 and 2 have been identified which are expressed on all HDL particles, indicating that several antigenic do mains exist on apoA-I which have the same conformation on all apoA-I-containing lipoproteins. The Mabs reacting at these sites have significantly higher affinity constants for 125 I-labeled HDL than those that failed to precipitate 100% of HDL. This suggests that the high affinity Mabs react with apoA-I epitopes that are both expressed on all lipoproteins and located in thermo-dynamically stable regions of the molecules. All Mabs from series 1 precipitated 35% or less of 125 I-labeled HDL prepared from freshly collected serum, but the proportion of HDL particles expressing the epitopes for these Mabs doubled or more upon serum storage at 4 degrees C. The time course of the alteration of apoA-I antigen in vitro was measured in three normolipemic donors

Transendothelial lipoprotein exchange and microalbuminuria

DEFF Research Database (Denmark)

Jensen, Jan Skov; Feldt-Rasmussen, Bo; Jensen, Kurt Svarre

2004-01-01

OBJECTIVE: Microalbuminuria associates with increased risk of atherosclerosis in individuals without diabetes. We hypothesized that transendothelial lipoprotein exchange is elevated among such individuals, possibly explaining increased intimal lipoprotein accumulation and thus atherosclerosis....... METHODS: Using an in vivo isotope technique, transendothelial exchange of low density lipoprotein (LDL) was measured in 77 non-diabetic individuals. Autologous 131-iodinated LDL was reinjected intravenously, and the 1-h fractional escape rate was calculated as index of transendothelial exchange. RESULTS......: There was no difference in transendothelial LDL exchange between subjects with microalbuminuria versus normoalbuminuria (mean (95% confidence interval) 3.8%/h (3.3-4.3%/h) versus 4.2%/h (3.7-4.7%/h); P=0.33). In contrast, there was a positive correlation between transendothelial LDL exchange and (logarithmically...

Serum amyloid A is found on ApoB-containing lipoproteins in obese humans with diabetes.

Science.gov (United States)

Jahangiri, Anisa; Wilson, Patricia G; Hou, Tianfei; Brown, Aparna; King, Victoria L; Tannock, Lisa R

2013-05-01

In murine models of obesity/diabetes, there is an increase in plasma serum amyloid A (SAA) levels along with redistribution of SAA from high-density lipoprotein (HDL) to apolipoprotein B (apoB)-containing lipoprotein particles, namely, low-density lipoprotein and very low-density lipoprotein. The goal of this study was to determine if obesity is associated with similar SAA lipoprotein redistribution in humans. Three groups of obese individuals were recruited from a weight loss clinic: healthy obese (n = 14), metabolic syndrome (MetS) obese (n = 8), and obese with type 2 diabetes (n = 6). Plasma was separated into lipoprotein fractions by fast protein liquid chromatography, and SAA was measured in lipid fractions using enzyme-linked immunosorbent assay and Western blotting. Only the obese diabetic group had SAA detectable in apoB-containing lipoproteins, and SAA reverted back to HDL with active weight loss. In human subjects, SAA is found in apoB-containing lipoprotein particles only in obese subjects with type 2 diabetes, but not in healthy obese or obese subjects with MetS. Copyright © 2012 The Obesity Society.

High-Density Lipoprotein Function in Exudative Age-Related Macular Degeneration.

Directory of Open Access Journals (Sweden)

Laura Pertl

Full Text Available High-density lipoproteins (HDL have long been implicated in the pathogenesis of age-related macular degeneration (AMD. However, conflicting results have been reported with regard to the associations of AMD with HDL-cholesterol levels. The present study is the first to assess HDL composition and metrics of HDL function in patients with exudative AMD and control patients.Blood samples were collected from 29 patients with exudative AMD and 26 age-matched control patients. Major HDL associated apolipoproteins were determined in apoB-depleted serum by immunoturbidimetry or ELISA, HDL-associated lipids were quantified enzymatically. To get an integrated measure of HDL quantity and quality, we assessed several metrics of HDL function, including cholesterol efflux capacity, anti-oxidative and anti-inflammatory activities using apoB-depleted serum from study participants.In our study, we observed that the HDL associated acute phase protein serum amyloid A (SAA was significantly increased in AMD patients (p<0.01, whereas all other assessed apolipoproteins including ApoA-I, apoA-II, apoC-II, apoC-III and apoE as well as major HDL associated lipids were not altered. HDL efflux capacity, anti-oxidative capacity and arylesterase activity were not different in AMD patients when compared with the control group. The ability of apoB-depleted serum to inhibit monocyte NF-κB expression was significantly improved in AMD patients (mean difference (MD -5.6, p<0.01. Moreover, lipoprotein-associated phospholipase A2 activity, a marker of vascular inflammation, was decreased in AMD subjects (MD -24.1, p<0.01.The investigated metrics of HDL composition and HDL function were not associated with exudative AMD in this study, despite an increased content of HDL associated SAA in AMD patients. Unexpectedly, anti-inflammatory activity of apoB-depleted serum was even increased in our study. Our data suggest that the investigated parameters of serum HDL function showed no

Metabolism of triglyceride-rich lipoproteins and transfer of lipids to high-density lipoproteins (HDL) in vegan and omnivore subjects.

Science.gov (United States)

Vinagre, J C; Vinagre, C G; Pozzi, F S; Slywitch, E; Maranhão, R C

2013-01-01

Vegan diet excludes all foodstuffs of animal origin and leads to cholesterol lowering and possibly reduction of cardiovascular disease risk. The aim was to investigate whether vegan diet improves the metabolic pathway of triglyceride-rich lipoproteins, consisting in lipoprotein lipolysis and removal from circulation of the resulting remnants and to verify whether the diet alters HDL metabolism by changing lipid transfers to this lipoprotein. 21 vegan and 29 omnivores eutrophic and normolipidemic subjects were intravenously injected triglyceride-rich emulsions labeled with (14)C-cholesterol oleate and (3)H-triolein: fractional clearance rates (FCR, in min(-1)) were calculated from samples collected during 60 min for radioactive counting. Lipid transfer to HDL was assayed by incubating plasma samples with a donor nanoemulsion labeled with radioactive lipids; % lipids transferred to HDL were quantified in supernatant after chemical precipitation of non-HDL fractions and nanoemulsion. Serum LDL cholesterol was lower in vegans than in omnivores (2.1 ± 0.8, 2.7 ± 0.7 mmol/L, respectively, p vegans than in omnivores (0.016 ± 0.012, 0.003 ± 0.003, p vegans than in omnivores (2.7 ± 0.6, 3.5 ± 1.5%, p vegans, but the lipolysis process, estimated by triglyceride FCR was equal. Increased removal of atherogenic remnants and diminution of cholesteryl ester transfer may favor atherosclerosis prevention by vegan diet. Copyright © 2011 Elsevier B.V. All rights reserved.

Contribution of lipoproteins and lipoprotein processing to endocarditis virulence in Streptococcus sanguinis.

Science.gov (United States)

Das, Sankar; Kanamoto, Taisei; Ge, Xiuchun; Xu, Ping; Unoki, Takeshi; Munro, Cindy L; Kitten, Todd

2009-07-01

Streptococcus sanguinis is an important cause of infective endocarditis. Previous studies have identified lipoproteins as virulence determinants in other streptococcal species. Using a bioinformatic approach, we identified 52 putative lipoprotein genes in S. sanguinis strain SK36 as well as genes encoding the lipoprotein-processing enzymes prolipoprotein diacylglyceryl transferase (lgt) and signal peptidase II (lspA). We employed a directed signature-tagged mutagenesis approach to systematically disrupt these genes and screen each mutant for the loss of virulence in an animal model of endocarditis. All mutants were viable. In competitive index assays, mutation of a putative phosphate transporter reduced in vivo competitiveness by 14-fold but also reduced in vitro viability by more than 20-fold. Mutations in lgt, lspA, or an uncharacterized lipoprotein gene reduced competitiveness by two- to threefold in the animal model and in broth culture. Mutation of ssaB, encoding a putative metal transporter, produced a similar effect in culture but reduced in vivo competiveness by >1,000-fold. [(3)H]palmitate labeling and Western blot analysis confirmed that the lgt mutant failed to acylate lipoproteins, that the lspA mutant had a general defect in lipoprotein cleavage, and that SsaB was processed differently in both mutants. These results indicate that the loss of a single lipoprotein, SsaB, dramatically reduces endocarditis virulence, whereas the loss of most other lipoproteins or of normal lipoprotein processing has no more than a minor effect on virulence.

Sphingomyelin in High-Density Lipoproteins: Structural Role and Biological Function

Directory of Open Access Journals (Sweden)

Jesús Osada

2013-04-01

Full Text Available High-density lipoprotein (HDL levels are an inverse risk factor for cardiovascular diseases, and sphingomyelin (SM is the second most abundant phospholipid component and the major sphingolipid in HDL. Considering the marked presence of SM, the present review has focused on the current knowledge about this phospholipid by addressing its variable distribution among HDL lipoparticles, how they acquire this phospholipid, and the important role that SM plays in regulating their fluidity and cholesterol efflux from different cells. In addition, plasma enzymes involved in HDL metabolism such as lecithin–cholesterol acyltransferase or phospholipid transfer protein are inhibited by HDL SM content. Likewise, HDL SM levels are influenced by dietary maneuvers (source of protein or fat, drugs (statins or diuretics and modified in diseases such as diabetes, renal failure or Niemann–Pick disease. Furthermore, increased levels of HDL SM have been shown to be an inverse risk factor for coronary heart disease. The complexity of SM species, described using new lipidomic methodologies, and their distribution in different HDL particles under many experimental conditions are promising avenues for further research in the future.

Androgen and FSH synergistically stimulate lipoprotein degradation and utilization by ovary granulosa cells

International Nuclear Information System (INIS)

Schreiber, J.R.; Nakamura, K.; Schmit, V.; Weinstein, D.B.

1984-01-01

Androgen can directly modulate the induction of steroidogenic enzymes by FSH (follicle stimulating hormone) in ovary granulosa cells. In studies of its mechanism of action, the authors examined the androgen effect on granulosa cell interaction with lipoproteins, the physiologic source of cholesterol. After granulosa cells were cultured for 48 hours with and without androgen and/or FSH, the cells were incubated for 24 hours with 125 I-lipoproteins [human high density lipoprotein (HDL), rat HDL, or human low density lipoprotein (LDL)]. The media were then analyzed for lipoprotein protein coat degradation products (mainly 125 I-monoiodotyrosine) and progestin [mainly 20 alpha-dihydroprogesterone (20 alpha-DHP)]. In the absence of FSH and androgen, 2 X 10(5) granulosa cells degraded basal levels of all three lipoproteins, but produced no measurable 20 alpha-DHP. The addition of 10(-7) M androstenedione (A), testosterone (T), or 5 alpha-dihydrotestosterone (DHT) had no effect on lipoprotein protein degradation or 20 alpha-DHP production. FSH alone stimulated lipoprotein protein degradation by 50 to 300% while the addition of androgen synergistically augmented the FSH-stimulated 20 alpha-DHP production as well as protein coat degradation of all three lipoproteins. DHT and T were both effective, indicating that androgens themselves, and not estrogen products, were responsible for the effect on lipoprotein protein degradation and 20 alpha-DHP production

High-density lipoprotein apolipoproteins in urine: I. Characterization in normal subjects and in patients with proteinuria.

Science.gov (United States)

Gomo, Z A; Henderson, L O; Myrick, J E

1988-09-01

A high-resolution two-dimensional electrophoretic method for protein, with silver staining, has been used to characterize and identify urinary high-density-lipoprotein apolipoproteins (HDL-Apos) and their isoforms in healthy subjects and in patients with kidney disease. Analytical techniques based on both molecular mass and ultracentrifugal flotation properties were used to isolate urinary lipoprotein particles with characteristics identical to those of HDL in plasma. HDL-Apos identified in urine of normal subjects and patients with glomerular proteinuria were Apos A-I, A-II, and C. Five isoforms of Apo A-I were present. Immunostaining of electroblotted proteins further confirmed the presence of HDL-Apos in urine. Creatinine clearance rate was decreased in the patients with proteinuria, and ranged from 32.5 to 40 mL/min. Concentrations of cholesterol and triglycerides in serum were greater in the patients' group, whereas mean HDL-cholesterol (0.68, SD 0.10 mmol/L) and Apo A-I (0.953, SD 0.095 g/L) were significantly (each P less than 0.01) lower. Results of this study suggest that measurement of urinary Apo A-I will reflect excretion of HDL in urine.

A one-step separation of human serum high density lipoproteins 2 and 3 by rate-zonal density gradient ultracentrifugation in a swinging bucket rotor

NARCIS (Netherlands)

Groot, P.H.E.; Scheek, L.M.; Havekes, L.; Noort, W.L. van; Hooft, F.M. van 't

1982-01-01

A method was developed for the separation of the high density lipoprotein subclasses HDL2 and HDL3 from human serum. Six serum samples are fractionated in a single-step ultracentrifugal procedure using the Beckman (SW-40) swinging bucket rotor. The method is based on a difference in flotation rate

Transvascular low-density lipoprotein transport in patients with diabetes mellitus (type 2)

DEFF Research Database (Denmark)

Kornerup, Karen; Nordestgaard, Børge Grønne; Feldt-Rasmussen, Bo

2002-01-01

accumulation and, thus, atherosclerosis. METHODS AND RESULTS: We developed an in vivo method for measurement of transvascular transport of low density lipoprotein (LDL) and applied it in 16 patients with maturity-onset diabetes (type 2) and 29 healthy control subjects. Autologous 131I-labeled LDL...... plasma insulin levels in diabetic patients. CONCLUSIONS: Transvascular LDL transport may be increased in patients with type 2 diabetes. This suggests that lipoprotein flux into the arterial wall is increased in people with diabetes, possibly explaining the accelerated development of atherosclerosis....... in patients with diabetes and control subjects, respectively (P2.5%/h and 5.3+/-1.6%/h (P

The effect of insulin deficiency on the plasma clearance and exchange of high-density-lipoprotein phosphatidylcholine in rats.

OpenAIRE

Martins, I J; Redgrave, T G

1992-01-01

Triolein/cholesteryl oleate/cholesterol/phosphatidylcholine emulsions designed to model the lipid composition of chylomicrons were injected intravenously into control and streptozotocin-treated insulin-deficient rats. As previously described for lymph chylomicrons, the emulsion triolein was hydrolysed and phosphatidylcholine was transferred to the plasma high-density lipoproteins (HDL). This mechanism was used to introduce a phospholipid label into HDL in vivo. The subsequent clearance of pho...

The majority of lipoprotein lipase in plasma is bound to remnant lipoproteins: A new definition of remnant lipoproteins.

Science.gov (United States)

Sato, Koichi; Okajima, Fumikazu; Miyashita, Kazuya; Imamura, Shigeyuki; Kobayashi, Junji; Stanhope, Kimber L; Havel, Peter J; Machida, Tetsuo; Sumino, Hiroyuki; Murakami, Masami; Schaefer, Ernst; Nakajima, Katsuyuki

2016-10-01

Lipoprotein lipase (LPL) is a multifunctional protein and a key enzyme involved in the regulation of lipoprotein metabolism. We determined the lipoproteins to which LPL is bound in the pre-heparin and post-heparin plasma. Tetrahydrolipstatin (THL), a potent inhibitor of serine lipases, was used to block the lipolytic activity of LPL, thereby preventing changes in the plasma lipoproteins due to ex vivo lipolysis. Gel filtration was performed to obtain the LPL elution profiles in plasma and the isolated remnant lipoproteins (RLP). When ex vivo lipolytic activity was inhibited by THL in the post-heparin plasma, majority of the LPL was found in the VLDL elution range, specifically in the RLP as inactive dimers. However, in the absence of THL, most of the LPL was found in the HDL elution range as active dimers. Furthermore, majority of the LPL in the pre-heparin plasma was found in the RLP as inactive form, with broadly diffused lipoprotein profiles in the presence and absence of THL. It is suggested that during lipolysis in vivo, the endothelial bound LPL dimers generates RLP, forming circulating RLP-LPL complexes in an inactive form that subsequently binds and initiates receptor-mediated catabolism. Copyright © 2016 Elsevier B.V. All rights reserved.

The fibrate drug gemfibrozil disrupts lipoprotein metabolism in rainbow trout

International Nuclear Information System (INIS)

Prindiville, John S.; Mennigen, Jan A.; Zamora, Jake M.; Moon, Thomas W.; Weber, Jean-Michel

2011-01-01

Gemfibrozil (GEM) is a fibrate drug consistently found in effluents from sewage treatment plants. This study characterizes the pharmacological effects of GEM on the plasma lipoproteins of rainbow trout (Oncorhynchus mykiss). Our goals were to quantify the impact of the drug on: 1) lipid constituents of lipoproteins (phospholipids (PL), triacylglycerol (TAG), and cholesterol), 2) lipoprotein classes (high, low and very low density lipoproteins), and 3) fatty acid composition of lipoproteins. Potential mechanisms of GEM action were investigated by measuring lipoprotein lipase activity (LPL) and the hepatic gene expression of LPL and of the peroxisome proliferator-activated receptor (PPAR) α, β, and γ isoforms. GEM treatment resulted in decreased plasma lipoprotein levels (- 29%) and a reduced size of all lipoprotein classes (lower PL:TAG ratios). However, the increase in HDL-cholesterol elicited by GEM in humans failed to be observed in trout. Therefore, HDL-cholesterol cannot be used to assess the impact of the drug on fish. GEM also modified lipoprotein composition by reducing the abundance of long-chain n-3 fatty acids, thereby potentially reducing the nutritional quality of exposed fish. The relative gene expression of LPL was increased, but the activity of the enzyme was not, and we found no evidence for the activation of PPAR pathways. The depressing effects of GEM on fish lipoproteins demonstrated here may be a concern in view of the widespread presence of fibrates in aquatic environments. Work is needed to test whether exposure to environmental concentrations of these drugs jeopardizes the capacity of fish for reproduction, temperature acclimation or migratory behaviors.

Low density lipoprotein induces upregulation of vasoconstrictive endothelin type B receptor expression

DEFF Research Database (Denmark)

Xu, Cang-Bao; Zheng, Jian-Pu; Zhang, Wei

2014-01-01

Vasoconstrictive endothelin type B (ET(B)) receptors promote vasospasm and ischemic cerebro- and cardiovascular diseases. The present study was designed to examine if low density lipoprotein (LDL) induces upregulation of vasoconstrictive ET(B) receptor expression and if extracellular signal...

Quantitative studies of transfer in vivo of low density, Sf 12-60, and Sf 60-400 lipoproteins between plasma and arterial intima in humans

International Nuclear Information System (INIS)

Shaikh, M.; Wootton, R.; Nordestgaard, B.G.; Baskerville, P.; Lumley, J.S.; La Ville, A.E.; Quiney, J.; Lewis, B.

1991-01-01

To assess the potential of various plasma lipoprotein classes to contribute to the lipid content of the arterial intima, influx and efflux of these plasma lipoprotein fractions into and from the intima of human carotid arteries were measured in vivo. While low density lipoprotein (LDL) is known to transfer from plasma into the arterial wall, there is less information on the atherogenic potential of lipoproteins of intermediate density (Sf 12-60) or of very low density (Sf 60-400). Aliquots of the same lipoprotein (LDL, Sf 12-60 lipoprotein particles, or Sf 60-400 lipoprotein particles) iodinated with iodine-125 and iodine-131 were injected intravenously 18-29 hours and 3-6 hours, respectively, before elective surgical removal of atheromatous arterial tissue, and the intimal clearance of lipoproteins, lipoprotein influx, and fractional loss of newly entered lipoproteins were calculated. Intimal clearance of Sf 60-400 particles was not detectable (less than 0.3 microliter x hr-1 x cm-2), whereas the average value for both LDL and Sf 12-60 lipoprotein particles was 0.9 microliter x hr-1 x cm-2. Since the fractional loss of newly entered LDL and Sf 12-60 lipoprotein particles was also similar, the results suggest similar modes of entry and exit for these two particles. However, due to lower plasma concentrations of Sf 12-60 lipoproteins as compared with LDL, the mass influx of cholesterol in the Sf 12-60 particles was on the order of one 10th of that in LDL, and that of apolipoprotein B was about one 20th

Sex, plasma lipoproteins, and atherosclerosis: prevailing assumptions and outstanding questions.

Science.gov (United States)

Godsland, I F; Wynn, V; Crook, D; Miller, N E

1987-12-01

We review the hypothesis that the incidence of coronary heart disease (CHD) is higher in men than in women due to differences in plasma lipoprotein risk factors between the sexes. Men and women appear to be equally susceptible to the effects of lipoprotein risk factors for CHD, and the difference between the sexes in lipoprotein risk factors for CHD appears to be consistent with their being, at least in part, responsible for the sex difference in CHD. This is apparent both when men and women of equal age are compared, and when age-related variations in the sex differences in plasma lipoproteins and CHD are considered. Differences between the sexes in lipoprotein concentrations are still present when sex differences in adiposity, cigarette smoking, physical activity, and diet are taken into account. Evidence relating these sex differences in CHD and lipoproteins to the effects of sex hormones is critically examined. It is commonly accepted that androgens induce changes in lipoprotein concentrations that would predispose towards CHD, whereas estrogens are held to have opposite effects. However, much of the evidence for this comes from studies of changes associated with administration of synthetic gonadal steroids or with changes in gonadal function. Studies of differences in lipoprotein metabolism in normal men and women are extremely limited. In males high-density lipoprotein (HDL) cholesterol levels fall at puberty, correlating with the rise in plasma testosterone concentrations. In females, HDL levels do not change at puberty, despite the rise in estrogen concentrations. Evidence for lipoprotein changes during the menopause, when estrogen levels decline, is equivocal. Similarly, the evidence for an increase in CHD incidence at the menopause is inconclusive. National mortality data indicate that the decreasing sex difference in CHD after 50 years of age is due to a declining rate of increase in men rather than to an acceleration in CHD incidence in women. In men

Remnant lipoproteins.

Science.gov (United States)

Varbo, Anette; Nordestgaard, Børge G

2017-08-01

To review recent advances in the field of remnant lipoproteins and remnant cholesterol with a focus on cardiovascular disease risk. In line with previous years' research, current observational, genetic, and mechanistic studies find remnant lipoproteins (defined in different ways) to be involved in atherosclerosis development and cardiovascular disease risk. High concentrations of remnant cholesterol could explain some of the residual risk of cardiovascular disease seen after LDL cholesterol lowering. This will be increasingly important as populations worldwide become more obese and more have diabetes, both of which elevate remnant cholesterol concentrations. Many smaller scale studies and post hoc analyses show that remnant cholesterol can be lowered by different types of drugs; however, results from large scale studies with the primary aim of reducing cardiovascular disease risk through lowering of remnant cholesterol in individuals with elevated concentrations are still missing, although some are under way. Remnant cholesterol is a risk factor for cardiovascular disease, and can be lowered by different types of drugs; however, large scale studies of cardiovascular disease risk reduction through remnant lipoprotein lowering are under way.

Metabolism of high density lipoproteins reconstituted with [3H]cholesteryl ester and [14C]cholesterol in the rat, with special reference to the ovary

International Nuclear Information System (INIS)

Nestler, J.E.; Bamberger, M.; Rothblat, G.H.; Strauss, J.F. III

1985-01-01

In order to study the metabolism of high density lipoprotein (HDL)-carried sterol in the rat, human HDL was reconstituted with [ 14 C]cholesterol and [ 3 H]cholesteryl ester. After iv injection into immature PMSG-human CG primed rats pretreated with 4-aminopyrazolopyrimidine and aminoglutethimide, there was time-dependent accumulation of 3 H and 14 C in various organs which reached a maximum by 15-90 min. On a milligram wet weight basis, uptake of 3 H and 14 C was greatest in the adrenals, next in ovaries, followed by the liver, with little uptake by kidneys and spleen. On an organ basis, accumulation was greatest by the liver. Coadministration of excess unlabeled HDL, but not human low density lipoprotein, reduced accumulation of radioactivity by the ovaries and adrenals by 60%, indicating a specific and saturable uptake process. Granulosa cells cultured in lipoprotein-deficient medium with reconstituted HDL formed 3 H- and 14 C-labeled 20 alpha-hydroxypregn-4-en-3-one. Over a 24-h period, utilization of both [ 14 C]cholesterol and [ 3 H]cholesteryl ester was linear, but rates of utilization of the two sterol moieties were not parallel. Lysosomotropic agents had no effect on utilization of either free or esterified cholesterol for steroidogenesis but reduced degradation of 125 I-labeled low density lipoprotein apoprotein. These findings lend further support to the concept of a distinct HDL pathway in steroidogenic cells of the rat

Triglyceride-rich lipoproteins as a causal factor for cardiovascular disease

Directory of Open Access Journals (Sweden)

Toth PP

2016-05-01

Full Text Available Peter P Toth1,2 1Ciccarone Center for the Prevention of Cardiovascular Disease, Johns Hopkins University School of Medicine, Baltimore, MD, 2Preventive Cardiology, CGH Medical Center, Sterling, IL, USA Abstract: Approximately 25% of US adults are estimated to have hypertriglyceridemia (triglyceride [TG] level ≥150 mg/dL [≥1.7 mmol/L]. Elevated TG levels are associated with increased cardiovascular disease (CVD risk, and severe hypertriglyceridemia (TG levels ≥500 mg/dL [≥5.6 mmol/L] is a well-established risk factor for acute pancreatitis. Plasma TG levels correspond to the sum of the TG content in TG-rich lipoproteins (TRLs; ie, very low-density lipoproteins plus chylomicrons and their remnants. There remains some uncertainty regarding the direct causal role of TRLs in the progression of atherosclerosis and CVD, with cardiovascular outcome studies of TG-lowering agents, to date, having produced inconsistent results. Although low-density lipoprotein cholesterol (LDL-C remains the primary treatment target to reduce CVD risk, a number of large-scale epidemiological studies have shown that elevated TG levels are independently associated with increased incidence of cardiovascular events, even in patients treated effectively with statins. Genetic studies have further clarified the causal association between TRLs and CVD. Variants in several key genes involved in TRL metabolism are strongly associated with CVD risk, with the strength of a variant's effect on TG levels correlating with the magnitude of the variant's effect on CVD. TRLs are thought to contribute to the progression of atherosclerosis and CVD via a number of direct and indirect mechanisms. They directly contribute to intimal cholesterol deposition and are also involved in the activation and enhancement of several proinflammatory, proapoptotic, and procoagulant pathways. Evidence suggests that non-high-density lipoprotein cholesterol, the sum of the total cholesterol carried by

Contribution of Lipoproteins and Lipoprotein Processing to Endocarditis Virulence in Streptococcus sanguinis▿ §

Science.gov (United States)

Das, Sankar; Kanamoto, Taisei; Ge, Xiuchun; Xu, Ping; Unoki, Takeshi; Munro, Cindy L.; Kitten, Todd

2009-01-01

Streptococcus sanguinis is an important cause of infective endocarditis. Previous studies have identified lipoproteins as virulence determinants in other streptococcal species. Using a bioinformatic approach, we identified 52 putative lipoprotein genes in S. sanguinis strain SK36 as well as genes encoding the lipoprotein-processing enzymes prolipoprotein diacylglyceryl transferase (lgt) and signal peptidase II (lspA). We employed a directed signature-tagged mutagenesis approach to systematically disrupt these genes and screen each mutant for the loss of virulence in an animal model of endocarditis. All mutants were viable. In competitive index assays, mutation of a putative phosphate transporter reduced in vivo competitiveness by 14-fold but also reduced in vitro viability by more than 20-fold. Mutations in lgt, lspA, or an uncharacterized lipoprotein gene reduced competitiveness by two- to threefold in the animal model and in broth culture. Mutation of ssaB, encoding a putative metal transporter, produced a similar effect in culture but reduced in vivo competiveness by >1,000-fold. [3H]palmitate labeling and Western blot analysis confirmed that the lgt mutant failed to acylate lipoproteins, that the lspA mutant had a general defect in lipoprotein cleavage, and that SsaB was processed differently in both mutants. These results indicate that the loss of a single lipoprotein, SsaB, dramatically reduces endocarditis virulence, whereas the loss of most other lipoproteins or of normal lipoprotein processing has no more than a minor effect on virulence. PMID:19395487

Oxidized low-density lipoproteins upregulate proline oxidase to initiate ROS-dependent autophagy

OpenAIRE

Zabirnyk, Olga; Liu, Wei; Khalil, Shadi; Sharma, Anit; Phang, James M.

2009-01-01

Epidemiological studies showed that high levels of oxidized low-density lipoproteins (oxLDLs) are associated with increased cancer risk. We examined the direct effect of physiologic concentrations oxLDL on cancer cells. OxLDLs were cytotoxic and activate both apoptosis and autophagy. OxLDLs have ligands for peroxisome proliferator-activated receptor gamma and upregulated proline oxidase (POX) through this nuclear receptor. We identified 7-ketocholesterol (7KC) as a main component responsible ...

A statin-loaded reconstituted high-density lipoprotein nanoparticle inhibits atherosclerotic plaque inflammation

Science.gov (United States)

Duivenvoorden, Raphaël; Tang, Jun; Cormode, David P.; Mieszawska, Aneta J.; Izquierdo-Garcia, David; Ozcan, Canturk; Otten, Maarten J.; Zaidi, Neeha; Lobatto, Mark E.; van Rijs, Sarian M.; Priem, Bram; Kuan, Emma L.; Martel, Catherine; Hewing, Bernd; Sager, Hendrik; Nahrendorf, Matthias; Randolph, Gwendalyn J.; Stroes, Erik S. G.; Fuster, Valentin; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.

2014-01-01

Inflammation is a key feature of atherosclerosis and a target for therapy. Statins have potent anti-inflammatory properties but these cannot be fully exploited with oral statin therapy due to low systemic bioavailability. Here we present an injectable reconstituted high-density lipoprotein (rHDL) nanoparticle carrier vehicle that delivers statins to atherosclerotic plaques. We demonstrate the anti-inflammatory effect of statin-rHDL in vitro and show that this effect is mediated through the inhibition of the mevalonate pathway. We also apply statin-rHDL nanoparticles in vivo in an apolipoprotein E-knockout mouse model of atherosclerosis and show that they accumulate in atherosclerotic lesions in which they directly affect plaque macrophages. Finally, we demonstrate that a 3-month low-dose statin-rHDL treatment regimen inhibits plaque inflammation progression, while a 1-week high-dose regimen markedly decreases inflammation in advanced atherosclerotic plaques. Statin-rHDL represents a novel potent atherosclerosis nanotherapy that directly affects plaque inflammation.

Opposing effects of apolipoprotein m on catabolism of apolipoprotein B-containing lipoproteins and atherosclerosis

DEFF Research Database (Denmark)

Christoffersen, Christina; Pedersen, Tanja Xenia; Gordts, Philip L S M

2010-01-01

Rationale: Plasma apolipoprotein (apo)M is mainly associated with high-density lipoprotein (HDL). HDL-bound apoM is antiatherogenic in vitro. However, plasma apoM is not associated with coronary heart disease in humans, perhaps because of a positive correlation with plasma low-density lipoprotein...

Ultracentrifugal and electrophoretic characteristics of the plasma lipoproteins of miniature schnauzer dogs with idiopathic hyperlipoproteinemia.

Science.gov (United States)

Whitney, M S; Boon, G D; Rebar, A H; Story, J A; Bottoms, G D

1993-01-01

To better characterize the idiopathic hyperlipoproteinemia of Miniature Schnauzer dogs, the plasma lipoproteins of 20 Miniature Schnauzers (MS) and 11 dogs of other breeds (DOB) were evaluated by ultracentrifugation, electrophoresis, and biochemical tests. Seventeen MS were healthy; 3 had diabetes mellitus. Plasma from 6 of 17 healthy and all 3 diabetic MS was visibly lipemic. Lipemia was slight to marked in healthy lipemic MS, and marked in diabetic ones. All DOB had clear plasma; 8 were healthy and 3 had diabetes. All healthy lipemic MS and diabetic lipemic MS had hypertriglyceridemia associated with excess very low density lipoproteins. Chylomicronemia was present in 4 of 6 healthy lipemic MS and all 3 diabetic lipemic MS. Lipoproteins with ultracentrifugal and electrophoretic characteristics of normal low density lipoprotein were lacking in 4 of 6 healthy lipemic MS. The lipoprotein patterns of 4 of 11 healthy nonlipemic MS were characterized by mild hypertriglyceridemia associated with increased very low density lipoproteins and a lack of lipoproteins with characteristics of normal low density lipoproteins. Lipoprotein patterns of diabetic DOB closely resembled those of healthy DOB; those of diabetic lipemic MS resembled those of markedly lipemic healthy lipemic MS. In conclusion, the hyperlipoproteinemia of Miniature Schnauzers is characterized by increased very low density lipoproteins with or without accompanying chylomicronemia; some affected dogs may have decreased low density lipoproteins.

Nonpharmacological lipoprotein apheresis reduces arterial inflammation in familial hypercholesterolemia

NARCIS (Netherlands)

van Wijk, Diederik F.; Sjouke, Barbara; Figueroa, Amparo; Emami, Hamed; van der Valk, Fleur M.; MacNabb, Megan H.; Hemphill, Linda C.; Schulte, Dominik M.; Koopman, Marion G.; Lobatto, Mark E.; Verberne, Hein J.; Fayad, Zahi A.; Kastelein, John J. P.; Mulder, Willem J. M.; Hovingh, G. Kees; Tawakol, Ahmed; Stroes, Erik S. G.

2014-01-01

Patients with familial hypercholesterolemia (FH) are characterized by elevated atherogenic lipoprotein particles, predominantly low-density lipoprotein cholesterol (LDL-C), which is associated with accelerated atherogenesis and increased cardiovascular risk. This study used (18)F-fluorodeoxyglucose

Immune Response to Lipoproteins in Atherosclerosis

Directory of Open Access Journals (Sweden)

Sonia Samson

2012-01-01

Full Text Available Atherosclerosis, the underlying cause of cardiovascular disease, is characterized by chronic inflammation and altered immune response. Cholesterol is a well-known risk factor associated with the development of cardiovascular diseases. Elevated serum cholesterol is unique because it can lead to development of atherosclerosis in animals and humans even in the absence of other risk factors. Modifications of low-density lipoproteins mediated by oxidation, enzymatic degradation, and aggregation result in changes in their function and activate both innate and adaptive immune system. Oxidized low-density lipoprotein (LDL has been identified as one of the most important autoantigens in atherosclerosis. This escape from self-tolerance is dependent on the formation of oxidized phospholipids. The emerging understanding of the importance of immune responses against oxidized LDL in atherosclerosis has focused attention on the possibility of development of novel therapy for atherosclerosis. This review provides an overview of immune response to lipoproteins and the fascinating possibility of developing an immunomodulatory therapy for atherosclerosis.

Controlling for high-density lipoprotein cholesterol does not affect the magnitude of the relationship between alcohol and coronary heart disease.

Science.gov (United States)

Magnus, Per; Bakke, Eirin; Hoff, Dominic A; Høiseth, Gudrun; Graff-Iversen, Sidsel; Knudsen, Gun Peggy; Myhre, Ronny; Normann, Per Trygve; Næss, Øyvind; Tambs, Kristian; Thelle, Dag S; Mørland, Jørg

2011-11-22

This study tested the hypothesis that moderate alcohol intake exerts its cardioprotective effect mainly through an increase in the serum level of high-density lipoprotein cholesterol. In the Cohort of Norway (CONOR) study, 149 729 adult participants, recruited from 1994 to 2003, were followed by linkage to the Cause of Death Registry until 2006. At recruitment, questionnaire data on alcohol intake were collected, and the concentration of high-density lipoprotein cholesterol in serum was measured. Using Cox regression, we found that the adjusted hazard ratio for men for dying from coronary heart disease was 0.52 (95% confidence interval, 0.39-0.69) when consuming alcohol more than once a week compared with never or rarely. The ratio changed only slightly, to 0.55 (0.41-0.73), after the regression model included the serum level of high-density cholesterol. For women, the corresponding hazard ratios were 0.62 (0.32-1.23) and 0.68 (0.34-1.34), respectively. Alcohol intake is related to a reduced risk of death from coronary heart disease in the follow-up of a large, population-based Norwegian cohort study with extensive control for confounding factors. Our findings suggest that the serum level of high-density cholesterol is not an important intermediate variable in the possible causal pathway between moderate alcohol intake and coronary heart disease.

Impaired suppression of plasma free fatty acids and triglycerides by acute hyperglycaemia-induced hyperinsulinaemia and alterations in high density lipoproteins in essential hypertension

NARCIS (Netherlands)

Ligtenberg, JJM; vanTol, A; vanHaeften, TW; Sluiter, WJ; Dullaart, RPF

1996-01-01

Objectives. Essential hypertension may be associated with abnormalities in free fatty acids (FFA) and triglyceride metabolism, which could lead to alterations in high density lipoproteins (HDL). Lecithin: cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP) are key

High Density Lipoprotein: A Therapeutic Target in Type 2 Diabetes

Directory of Open Access Journals (Sweden)

Philip J. Barter

2013-09-01

Full Text Available High density lipoproteins (HDLs have a number of properties that have the potential to inhibit the development of atherosclerosis and thus reduce the risk of having a cardiovascular event. These protective effects of HDLs may be reduced in patients with type 2 diabetes, a condition in which the concentration of HDL cholesterol is frequently low. In addition to their potential cardioprotective properties, HDLs also increase the uptake of glucose by skeletal muscle and stimulate the synthesis and secretion of insulin from pancreatic β cells and may thus have a beneficial effect on glycemic control. This raises the possibility that a low HDL concentration in type 2 diabetes may contribute to a worsening of diabetic control. Thus, there is a double case for targeting HDLs in patients with type 2 diabetes: to reduce cardiovascular risk and also to improve glycemic control. Approaches to raising HDL levels include lifestyle factors such as weight reduction, increased physical activity and stopping smoking. There is an ongoing search for HDL-raising drugs as agents to use in patients with type 2 diabetes in whom the HDL level remains low despite lifestyle interventions.

ApoE and the role of very low density lipoproteins in adipose tissue inflammation

Science.gov (United States)

Our goal was too identify the role of triglyceride-rich lipoproteins and apoE, a major apolipoprotein in triglyceride-rich lipoproteins, in adipose tissue inflammation with high-fat diet induced obesity. Male apoE-/- and C57BL/6J wild-type mice fed high fat diets for 12 weeks were assessed for metab...

Formation of tissue factor activity following incubation of recombinant human tissue factor apoprotein with plasma lipoproteins

International Nuclear Information System (INIS)

Sakai, T.; Kisiel, W.

1990-01-01

Incubation of recombinant human tissue factor apoprotein (Apo-TF) with human plasma decreased the recalcified clotting time of this plasma in a time-and dose-dependent manner suggesting relipidation of the Apo-TF by plasma lipoproteins. Incubation of Apo-TF with purified preparations of human very low density, low density and high density lipoproteins resulted in tissue factor activity in a clotting assay. The order of effectiveness was VLDL greater than LDL much greater than HDL. Tissue factor activity generated by incubation of a fixed amount of Apo-TF with plasma lipoproteins was lipoprotein concentration-dependent and saturable. The association of Apo-TF with lipoprotein particles was supported by gel filtration studies in which 125 I-Apo-TF coeluted with the plasma lipoprotein in the void volume of a Superose 6 column in the presence and absence of calcium ions. In addition, void-volume Apo-TF-lipoprotein fractions exhibited tissue factor activity. These results suggest that the factor VIII-bypassing activity of bovine Apo-TF observed in a canine hemophilic model may be due, in part, to its association with plasma lipoproteins and expression of functional tissue factor activity

High density lipoprotein (HDL)-associated sphingosine 1-phosphate (S1P) inhibits macrophage apoptosis by stimulating STAT3 activity and survivin expression

DEFF Research Database (Denmark)

Feuerborn, Renata; Becker, Susen; Potì, Francesco

2017-01-01

BACKGROUND AND AIMS: Macrophage apoptosis is critically involved in atherosclerosis. We here examined the effect of anti-atherogenic high density lipoprotein (HDL) and its component sphingosine-1-phosphate (S1P) on apoptosis in RAW264.7 murine macrophages. METHODS: Mitochondrial or endoplasmic re...

Characteristics of 2,4,5,2',4',5'-hexachlorobiphenyl distribution among lipoproteins in vitro

International Nuclear Information System (INIS)

Vomachka, M.S.; Vodicnik, M.J.; Lech, J.J.

1983-01-01

The uptake, distribution, and transfer of 2,4,5,2',4',5'-hexachlorobiphenyl (6-CB) were examined in vitro with human and rat whole blood, plasma, and lipoprotein fractions. 6-CB distribution between plasma and erythrocytes as well as among lipoproteins was determined following sedimentation of erythrocytes and ultracentrifugal fractionation of plasma. In both rat and human whole blood, 70 to 75% of 6-CB partitioned into plasma and 25 to 30% into erythrocytes. The uptake of 6-CB into plasma was extremely rapid and the rate of uptake was found to be dependent upon temperature. The distribution of 6-CB among lipoproteins was relatively homogeneous with 20 to 30% being distributed in very low-density lipoproteins (VLDL, d . 0.95-1.006 g/ml), 15 to 20% in low-density lipoproteins (LDL, d . 1.006-1.063 g/ml), and 15 to 25% in high-density lipoproteins (HDL, d . 1.063-1.21 g/ml). Over 25% of 6-CB was found in the remaining bottom fraction. In addition, each isolated fraction when incubated alone with 6-CB was shown capable of uptake. The relative proportion of 6-CB among the lipoproteins was independent of the level taken up by plasma. 6-CB was also found to transfer among lipoproteins. This exchange of 6-CB proved to be dependent upon the concentrations of both protein and triacylglycerol in the incubations. Two proteins in the bottom fraction (Bf), albumin and a steroid binding globulin, were capable of competing with the lipoproteins for 6-CB uptake

A Phospholipidomic Analysis of All Defined Human Plasma Lipoproteins

Science.gov (United States)

Dashti, Monireh; Kulik, Willem; Hoek, Frans; Veerman, Enno C.; Peppelenbosch, Maikel P.; Rezaee, Farhad

2011-01-01

Since plasma lipoproteins contain both protein and phospholipid components, either may be involved in processes such as atherosclerosis. In this study the identification of plasma lipoprotein-associated phospholipids, which is essential for understanding these processes at the molecular level, are performed. LC-ESI/MS, LC-ESI-MS/MS and High Performance Thin Layer Chromatography (HPTLC) analysis of different lipoprotein fractions collected from pooled plasma revealed the presence of phosphatidylethanolamine (PE), phosphatidylinositol (PI), and sphingomyeline (SM) only on lipoproteins and phosphatidylcholine (PC), Lyso-PC on both lipoproteins and plasma lipoprotein free fraction (PLFF). Cardiolipin, phosphatidylglycerol (PG) and Phosphatidylserine (PS) were observed neither in the lipoprotein fractions nor in PLFF. All three approaches led to the same results regarding phospholipids occurrence in plasma lipoproteins and PLFF. A high abundancy of PE and SM was observed in VLDL and LDL fractions respectively. This study provides for the first time the knowledge about the phospholipid composition of all defined plasma lipoproteins. PMID:22355656

High lipoprotein(a) as a possible cause of clinical familial hypercholesterolaemia

DEFF Research Database (Denmark)

Langsted, Anne; Kamstrup, Pia Rørbœk; Benn, Marianne

2016-01-01

, and that individuals with both high lipoprotein(a) concentrations and clinical familial hypercholesterolaemia have the highest risk of myocardial infarction. METHODS: We did a prospective cohort study that included data from 46 200 individuals from the Copenhagen General Population Study who had lipoprotein...... cholesterol, mean lipoprotein(a) concentrations were 23 mg/dL in individuals unlikely to have familial hypercholesterolaemia, 32 mg/dL in those with possible familial hypercholesterolaemia, and 35 mg/dL in those with probable or definite familial hypercholesterolaemia (ptrend... LDL cholesterol for lipoprotein(a) cholesterol content the corresponding values were 24 mg/dL for individuals unlikely to have familial hypercholesterolaemia, 22 mg/dL for those with possible familial hypercholesterolaemia, and 21 mg/dL for those with probable or definite familial...

Low plasma lecithin : cholesterol acyltransferase and lipid transfer protein activities in growth hormone deficient and acromegalic men: role in altered high density lipoproteins

NARCIS (Netherlands)

Beentjes, JAM; van Tol, A; Sluiter, WJ; Dullaart, RPF

2000-01-01

Growth hormone (GH) deficiency and acromegaly may be associated with increased cardiovascular risk. Little is known about alterations in high density lipoproteins (HDL) in these conditions. Lecithin:cholesterol acyl transferase (LCAT) has the ability to esterify free cholesterol (FC) in HDL.

Biogenesis and Membrane Targeting of Lipoproteins.

Science.gov (United States)

Narita, Shin-Ichiro; Tokuda, Hajime

2010-09-01

Bacterial lipoproteins represent a unique class of membrane proteins, which are anchored to membranes through triacyl chains attached to the amino-terminal cysteine. They are involved in various functions localized in cell envelope. Escherichia coli possesses more than 90 species of lipoproteins, most of which are localized in the outer membrane, with others being in the inner membrane. All lipoproteins are synthesized in the cytoplasm with an N-terminal signal peptide, translocated across the inner membrane by the Sec translocon to the periplasmic surface of the inner membrane, and converted to mature lipoproteins through sequential reactions catalyzed by three lipoprotein-processing enzymes: Lgt, LspA, and Lnt. The sorting of lipoproteins to the outer membrane requires a system comprising five Lol proteins. An ATP-binding cassette transporter, LolCDE, initiates the sorting by mediating the detachment of lipoproteins from the inner membrane. Formation of the LolA-lipoprotein complex is coupled to this LolCDE-dependent release reaction. LolA accommodates the amino-terminal acyl chain of lipoproteins in its hydrophobic cavity, thereby generating a hydrophilic complex that can traverse the periplasmic space by diffusion. Lipoproteins are then transferred to LolB on the outer membrane and anchored to the inner leaflet of the outer membrane by the action of LolB. In contrast, since LolCDE does not recognize lipoproteins possessing Asp at position +2, these lipoproteins remain anchored to the inner membrane. Genes for Lol proteins are widely conserved among gram-negative bacteria, and Lol-mediated outer membrane targeting of lipoproteins is considered to be the general lipoprotein localization mechanism.

High-density lipoprotein is a potential growth factor for adrenocortical cells

International Nuclear Information System (INIS)

Murao, Koji; Imachi, Hitomi; Cao, Wenming; Yu, Xiao; Li, Junhua; Yoshida, Kazuya; Ahmed, Rania A.M.; Matsumoto, Kensuke; Nishiuchi, Takamasa; Wong, Norman C.W.; Ishida, Toshihiko

2006-01-01

The entry of cholesterol contained within high-density lipoprotein (HDL) into adrenocortical cells is mediated by a human homologue of SR-BI, CD36, and LIMPII Analogous-1 (CLA-1) and thus augmenting their growth. To address the role of CLA-1, we created a mutant mCLA that lacked the C-terminal tail. HDL CE selective uptake by cells carrying the mCLA-1 receptor was fully active and equivalent to those transfected with full-length CLA-1 (fCLA-1). Expression of mCLA inhibited the proliferation of an adrenocortical cell line and the incorporation of [ 3 H]thymidine into the cells. This effect was sensitive to wortmannin, an inhibitor of phosphoinositide 3-kinase (PI3K). Our transcriptional studies revealed that the inhibitory action of mCLA required the transcriptional factor AP-1 and the effect of HDL on AP-1 activation was also abrogated by wortmannin. These findings raise the possibility that the inhibitors of the effects of HDL may be of therapeutic value for adrenocortical tumor

Pyrene-Labeled Amphiphiles: Dynamic And Structural Probes Of Membranes And Lipoproteins

Science.gov (United States)

Pownall, Henry J.; Homan, Reynold; Massey, John B.

1987-01-01

Lipids and proteins are important functional and structural components of living organisms. Although proteins are frequently found as soluble components of plasma or the cell cytoplasm, many lipids are much less soluble and separate into complex assemblies that usually contain proteins. Cell membranes and plasma lipoproteins' are two important macro-molecular assemblies that contain both lipids and proteins. Cell membranes are composed of a variety of lipids and proteins that form an insoluble bilayer array that has relatively little curvature over distances of several nm. Plasma lipoproteins are different in that they are much smaller, water-soluble, and have highly curved surfaces. A model of a high density lipoprotein (HDL) is shown in Figure 1. This model (d - 10 nm) contains a surface of polar lipids and proteins that surrounds a small core of insoluble lipids, mostly triglycerides and cholesteryl esters. The low density (LDL) (d - 25 nm) and very low density (VLDL) (d 90 nm) lipoproteins have similar architectures, except the former has a cholesteryl ester core and the latter a core that is almost exclusively triglyceride (Figure 1). The surface proteins of HDL are amphiphilic and water soluble; the single protein of LDL is insoluble, whereas VLDL contains both soluble and insoluble proteins. The primary structures of all of these proteins are known.

Ascorbic acid protects lipids in human plasma and low-density lipoprotein against oxidative damage

Energy Technology Data Exchange (ETDEWEB)

Frei, B. (Department of Nutrition, Harvard School of Public Health, Boston, MA (Unites States))

1991-12-01

The authors exposed human blood plasma and low-density lipoprotein (LDL) to many different oxidative challenges and followed the temporal consumption of endogenous antioxidants in relation to the initiation of oxidative damage. Under all types of oxidizing conditions, ascorbic acid completely protects lipids in plasma and LDL against detectable peroxidative damage as assessed by a specific and highly sensitive assay for lipid peroxidation. Ascorbic acid proved to be superior to the other water-soluble plasma antioxidants bilirubin, uric acid, and protein thiols as well as to the lipoprotein-associated antioxidants alpha-tocopherol, ubiquinol-10, lycopene, and beta-carotene. Although these antioxidants can lower the rate of detectable lipid peroxidation, they are not able to prevent its initiation. Only ascorbic acid is reactive enough to effectively intercept oxidants in the aqueous phase before they can attack and cause detectable oxidative damage to lipids.

TRIIODOTHYRONINE RAPIDLY LOWERS PLASMA-LIPOPROTEIN (A) IN HYPOTHYROID SUBJECTS

NARCIS (Netherlands)

DULLAART, RPF; VANDOORMAAL, JJ; HOOGENBERG, K; SLUITER, WJ

Background: Increases in plasma low-density-lipoprotein (LDL) cholesterol and apolipoprotein B (apo-B) are well known in primary hypothyroidism, but it is uncertain whether thyroid dysfunction is associated with elevated levels of the atherogenic lipoprotein (a) (Lp(a)). Methods: The effect of

Macroporous poly(vinyl alcohol) microspheres bearing phosphate groups as a new adsorbent for low-density lipoprotein apheresis

Energy Technology Data Exchange (ETDEWEB)

Wang Weichao; Xie Hui; Ou Lailiang; Wang Lianyong; Yu Yaoting; Kong Deling [Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin 300071 (China); Sun Lisha, E-mail: wly@nankai.edu.c, E-mail: kongdeling@nankai.edu.c [General Hospital, Tianjin Medical University, Tianjin 300052 (China)

2009-12-15

A new low-density lipoprotein (LDL) adsorbent with phosphate groups as the ligand was prepared in this study. Macroporous poly(vinyl acetate-co-triallyl isocyanurate) microspheres were prepared using a free-radical suspension polymerization method. A hydrolysis reaction in sodium hydroxide/methanol changed the materials into poly(vinyl alcohol) (PVA) microspheres. Further reaction with phosphorus oxychloride in anhydrous DMF led to the LDL adsorbent PVA-phosphate microspheres. The preparation conditions such as reaction time, temperature and the amount of phosphorus oxychloride were optimized. The adsorption of plasma lipoproteins was examined by in vitro adsorption assays. The influence of adsorption time, plasma volume and ionic strength on the adsorption capacity was investigated. The circulation adsorption showed that the pathogenic lipoproteins in the plasma such as total cholesterol (TC), LDL and triglyceride (TG) could be removed markedly, in which the removal percentages were 42.9%, 45.0% and 44.74%, respectively. However, the reduction of high-density lipoprotein (HDL) and other normal plasma components was very slight. For in vivo experiment, rabbits were fed with high-cholesterol food to develop a hyperlipidemia model and treated by extracorporeal blood perfusion using the PVA-phosphate columns. Eight hyperlipidemia rabbits were treated with the PVA-phosphate adsorbent, and the removal of TC, LDL and TG was 45.03 +- 6.64%, 48.97 +- 9.92% and 35.42 +- 14.17%, respectively. The sterilization and storage tests showed that the adsorbent was chemically and functionally stable. It could be easily sterilized by a common method and stored for months without loss of adsorption capacity. Therefore, this new PVA-phosphate-based LDL adsorbent may have potential for application in LDL apheresis.

Macroporous poly(vinyl alcohol) microspheres bearing phosphate groups as a new adsorbent for low-density lipoprotein apheresis

International Nuclear Information System (INIS)

Wang Weichao; Xie Hui; Ou Lailiang; Wang Lianyong; Yu Yaoting; Kong Deling; Sun Lisha

2009-01-01

A new low-density lipoprotein (LDL) adsorbent with phosphate groups as the ligand was prepared in this study. Macroporous poly(vinyl acetate-co-triallyl isocyanurate) microspheres were prepared using a free-radical suspension polymerization method. A hydrolysis reaction in sodium hydroxide/methanol changed the materials into poly(vinyl alcohol) (PVA) microspheres. Further reaction with phosphorus oxychloride in anhydrous DMF led to the LDL adsorbent PVA-phosphate microspheres. The preparation conditions such as reaction time, temperature and the amount of phosphorus oxychloride were optimized. The adsorption of plasma lipoproteins was examined by in vitro adsorption assays. The influence of adsorption time, plasma volume and ionic strength on the adsorption capacity was investigated. The circulation adsorption showed that the pathogenic lipoproteins in the plasma such as total cholesterol (TC), LDL and triglyceride (TG) could be removed markedly, in which the removal percentages were 42.9%, 45.0% and 44.74%, respectively. However, the reduction of high-density lipoprotein (HDL) and other normal plasma components was very slight. For in vivo experiment, rabbits were fed with high-cholesterol food to develop a hyperlipidemia model and treated by extracorporeal blood perfusion using the PVA-phosphate columns. Eight hyperlipidemia rabbits were treated with the PVA-phosphate adsorbent, and the removal of TC, LDL and TG was 45.03 ± 6.64%, 48.97 ± 9.92% and 35.42 ± 14.17%, respectively. The sterilization and storage tests showed that the adsorbent was chemically and functionally stable. It could be easily sterilized by a common method and stored for months without loss of adsorption capacity. Therefore, this new PVA-phosphate-based LDL adsorbent may have potential for application in LDL apheresis.

The Role of High-Density Lipoproteins in Diabetes and Its Vascular Complications

Directory of Open Access Journals (Sweden)

Nathan K. P. Wong

2018-06-01

Full Text Available Almost 600 million people are predicted to have diabetes mellitus (DM by 2035. Diabetic patients suffer from increased rates of microvascular and macrovascular complications, associated with dyslipidaemia, impaired angiogenic responses to ischaemia, accelerated atherosclerosis, and inflammation. Despite recent treatment advances, many diabetic patients remain refractory to current approaches, highlighting the need for alternative agents. There is emerging evidence that high-density lipoproteins (HDL are able to rescue diabetes-related vascular complications through diverse mechanisms. Such protective functions of HDL, however, can be rendered dysfunctional within the pathological milieu of DM, triggering the development of vascular complications. HDL-modifying therapies remain controversial as many have had limited benefits on cardiovascular risk, although more recent trials are showing promise. This review will discuss the latest data from epidemiological, clinical, and pre-clinical studies demonstrating various roles for HDL in diabetes and its vascular complications that have the potential to facilitate its successful translation.

Lipoprotein(a) and dietary proteins: casein lowers lipoprotein(a) concentrations as compared with soy protein1-3

DEFF Research Database (Denmark)

Nilausen, Karin Johanne; Meinertz, H.

1999-01-01

Lipoprotein(a), plasma lipoproteins, dietary proteins, soy protein, casein, liquid-formula, coronary artery disease, men, Denmark......Lipoprotein(a), plasma lipoproteins, dietary proteins, soy protein, casein, liquid-formula, coronary artery disease, men, Denmark...

Prevalence of Low High-density Lipoprotein Cholesterol Among Adults, by Physical Activity: United States, 2011-2014.

Science.gov (United States)

Zwald, Marissa L; Akinbami, Lara J; Fakhouri, Tala H I; Fryar, Chryl D

2017-03-01

Data from the National Health and Nutrition Examination Survey •The prevalence of low high-density lipoprotein (HDL) cholesterol was significantly higher among adults who did not meet recommended physical activity guidelines (21.0%) than adults who met the guidelines (17.7%). •Low HDL cholesterol prevalence differed significantly for both men and women by adherence to physical activity guidelines. •Prevalence of low HDL cholesterol declined as age increased for both those who did and did not meet the physical activity guidelines. •Non-Hispanic white and non-Hispanic black adults who did not meet the physical activity guidelines had a higher prevalence than those who met the guidelines. •Low HDL cholesterol prevalence declined with increasing education level regardless of adherence to physical activity guidelines. Regular physical activity can improve cholesterol levels among adults, including increasing high-density lipoprotein (HDL) cholesterol (1). HDL cholesterol is known as "good" cholesterol because high levels can reduce cardiovascular disease risk (2). The 2008 Physical Activity Guidelines for Americans recommend that adults engage in 150 minutes or more of moderate-intensity aerobic activity per week, 75 minutes of vigorous-intensity aerobic activity per week, or an equivalent combination (3). Adherence to these guidelines is expected to decrease the prevalence of low HDL cholesterol levels (4-8). This report presents national data for 2011-2014 on low HDL cholesterol prevalence among U.S. adults aged 20 and over, by whether they met these guidelines. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.

The lipid- and lipoprotein- [LDL-Lp(a)] apheresis techniques. Updating.

Science.gov (United States)

Stefanutti, C; Morozzi, C; Perrone, G; Di Giacomo, S; Vivenzio, A; D'Alessandri, G

2012-01-01

Therapeutic plasmapheresis allows the extracorporeal removal of plasmatic lipoproteins (Lipid-apheresis) (LA). It can be non selective (non specific), semi - selective or selective low density lipoprotein-lipoprotein(a) (specific [LDL- Lp(a)] apheresis) (Lipoprotein apheresis, LDLa). The LDL removal rate is a perfect parameter to assess the system efficiency. Plasma-Exchange (PEX) cannot be considered either specific nor, selective. In PEX the whole blood is separated into plasma and its corpuscular components usually through centrifugation or rather filtration. The corpuscular components mixed with albumin solution plus saline (NaCl 0.9%) solution at 20%-25%, are then reinfused to the patient, to substitute the plasma formerly removed. PEX eliminates atherogenic lipoproteins, but also other essential plasma proteins, such as albumin, immunoglobulins, and hemocoagulatory mediators. Cascade filtration (CF) is a method based on plasma separation and removal of plasma proteins through double filtration. During the CF two hollow-fiber filters with pores of different diameter are used to eliminate the plasma components of different weight and molecular diameter. A CF system uses a first polypropylene filter with 0.55 µm diameter pores and a second one of diacetate of cellulose with 0.02 µm pores. The first filter separates the whole blood, and the plasma is then perfused through a second filter which allows the recovery of molecules with a diameter lower than 0.02 µm, and the removal of molecules larger in diameter as apoB100-containing lipoproteins. Since both albumin and immunoglobulins are not removed, or to a negligible extent, plasma-expanders, substitution fluids, and in particular albumin, as occurs in PEX are not needed. CF however, is characterized by lower selectivity since removes also high density lipoprotein (HDL) particles which have an antiatherogenic activity. In the 80's, a variation of Lipid-apheresis has been developed which allows the LDL

Immunosuppressive activity of human cord-blood lipoproteins

International Nuclear Information System (INIS)

Forte, T.M.; Davis, P.A.; Curtiss, L.K.

1985-01-01

It is now known that the role of plasma lipoproteins is multifunctional. More recently it has been shown that lipoproteins may regulate immune responses as well. Low-density lipoproteins carrying apolipoprotein B (apoB) are known to suppress phytohemagglutinin (PHA) activated lymphocytes by inhibiting DNA synthesis. More recently, an immunoregulatory role has been described for another apolipoprotein, apoE, which is found in low quantities in normal plasma. In these studies with human umbilical-cord blood the authors were intrigued by two factors: the low level of LDL and hence apoB, and the elevated quantity of apoE. This study examines the hypothesis that apoE may regulate lymphocyte function in the human fetus

Heparin induces an accumulation of atherogenic lipoproteins during hemodialysis in normolipidemic end-stage renal disease patients.

Science.gov (United States)

Barbagallo, Carlo M; Noto, Davide; Cefalù, Angelo B; Ganci, Antonia; Giammarresi, Carlo; Panno, Donata; Cusumano, Gaspare; Greco, Massimiliano; Di Gaudio, Francesca; Averna, Maurizio R

2015-07-01

Dyslipidemias may account for the excess of cardiovascular mortality in end-stage renal disease (ESRD). Lipoprotein studies in ESRD patients are usually relative to prehemodialysis samples even if significative changes may occur after dialysis. In this study, we aimed to investigate the effects of ESRD on triglyceride-rich lipoproteins (TRL) subpopulations distribution and acute change following hemodialytic procedures, including the relative contribution of heparin administration. We selected a group of normolipidemic male middle-aged ESRD patients free of any concomitant disease affecting lipoprotein remnant metabolism compared with controls. We separated TRL subfractions according to density and apoE content and evaluated the changes of these particles after hemodialytic procedures with or without heparin. ESRD subjects had higher TRL subfractions, with the exception of apoE-rich particles, lower high-density lipoprotein (HDL) largest subclasses, and a smaller low-density lipoprotein peak particle size than controls. After a hemodialytic standard procedure with heparin, we demonstrated a significant reduction of triglyceride, an increase of HDL-cholesterol levels, and a raise of small very-low-density lipoprotein, intermediate-density lipoproteins (IDL), apoE-rich particles, and non-HDL-cholesterol levels. When hemodialysis was performed without heparin, no significant changes were observed. In the absence of concomitant hyperlipidemic triggers, ESRD patients show significant lipoprotein abnormalities before dialysis, but without any increased remnant particles concentrations. We speculate that hemodialysis, in particular heparin administration during this procedure, leads to a massive atherogenic TRLs production because of the acute stimulation of the dysfunctional lipolytic system not followed by an efficient removal, determining a recurrent lipoprotein remnant accumulation. © 2014 International Society for Hemodialysis.

Purification of a sarcoplasmic reticulum protein that binds Ca2+ and plasma lipoproteins

International Nuclear Information System (INIS)

Hofmann, S.L.; Brown, M.S.; Lee, E.; Pathak, R.K.; Anderson, R.G.; Goldstein, J.L.

1989-01-01

A protein in the sarcoplasmic reticulum of rabbit skeletal and cardiac muscle was identified because of its ability to bind 125I-labeled low density lipoprotein (LDL) with high affinity after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This protein, referred to as the 165-kDa protein, is restricted to striated muscle. It was not detected in 14 other tissues, including several that contain smooth muscle, but it appears in rat L6 myoblasts when they differentiate into myocytes. Immunofluorescence and immunoelectron microscopic studies revealed that the protein is present throughout the sarcoplasmic reticulum and the terminal cisternae. It binds 45Ca2+ on nitrocellulose blots and stains metachromatically with Stains-all, a cationic dye that stains Ca2+-binding proteins. It does not appear to be a glycoprotein, and it appears slightly larger than the 160-kDa glycoprotein previously described in sarcoplasmic reticulum. The 165-kDa protein binds LDL, beta-migrating very low density lipoprotein, and a cholesterol-induced high density lipoprotein particle that contains apoprotein E as its sole apoprotein with much higher affinity than it binds high density lipoprotein. The protein is stable to boiling and to treatment with sodium dodecyl sulfate, but it becomes sensitive to these treatments when its cystine residues are reduced and alkylated. The protein was purified 1300-fold to apparent homogeneity from rabbit skeletal muscle membranes. It differs from the cell surface LDL receptor in that (1) its apparent molecular weight is not changed by reduction and alkylation; (2) it is present in Watanabe-heritable hyperlipidemic rabbits, which lack functional LDL receptors; (3) binding of lipoproteins is not inhibited by EDTA; and (4) it is located within the lumen of the sarcoplasmic reticulum where it has no access to plasma lipoproteins

Identification of the Oxidized Low-Density Lipoprotein Scavenger Receptor CD36 in Plasma

DEFF Research Database (Denmark)

Handberg, Aase; Levin, Klaus; Højlund, Kurt

2006-01-01

BACKGROUND: Macrophage CD36 scavenges oxidized low-density lipoprotein, leading to foam cell formation, and appears to be a key proatherogenic molecule. Increased expression of CD36 has been attributed to hyperglycemia and to defective macrophage insulin signaling in insulin resistance. Premature...

Genetics, Lifestyle, and Low-Density Lipoprotein Cholesterol in Young and Apparently Healthy Women

NARCIS (Netherlands)

Balder, Jan-Willem; Rimbert, Antoine; Zhang, Xiang; Viel, Martijn; Kanninga, Roan; van Dijk, Freerk; Lansberg, Peter; Sinke, Richard; Kuivenhoven, Jan Albert

2018-01-01

BACKGROUND: Atherosclerosis starts in childhood but low-density lipoprotein cholesterol (LDL-C), a causal risk factor, is mostly studied and dealt with when clinical events have occurred. Women are usually affected later in life than men and are underdiagnosed, undertreated, and understudied in

Clinical benefit from pharmacological elevation of high-density lipoprotein cholesterol: meta-regression analysis.

Science.gov (United States)

Hourcade-Potelleret, F; Laporte, S; Lehnert, V; Delmar, P; Benghozi, Renée; Torriani, U; Koch, R; Mismetti, P

2015-06-01

Epidemiological evidence that the risk of coronary heart disease is inversely associated with the level of high-density lipoprotein cholesterol (HDL-C) has motivated several phase III programmes with cholesteryl ester transfer protein (CETP) inhibitors. To assess alternative methods to predict clinical response of CETP inhibitors. Meta-regression analysis on raising HDL-C drugs (statins, fibrates, niacin) in randomised controlled trials. 51 trials in secondary prevention with a total of 167,311 patients for a follow-up >1 year where HDL-C was measured at baseline and during treatment. The meta-regression analysis showed no significant association between change in HDL-C (treatment vs comparator) and log risk ratio (RR) of clinical endpoint (non-fatal myocardial infarction or cardiac death). CETP inhibitors data are consistent with this finding (RR: 1.03; P5-P95: 0.99-1.21). A prespecified sensitivity analysis by drug class suggested that the strength of relationship might differ between pharmacological groups. A significant association for both statins (p<0.02, log RR=-0.169-0.0499*HDL-C change, R(2)=0.21) and niacin (p=0.02, log RR=1.07-0.185*HDL-C change, R(2)=0.61) but not fibrates (p=0.18, log RR=-0.367+0.077*HDL-C change, R(2)=0.40) was shown. However, the association was no longer detectable after adjustment for low-density lipoprotein cholesterol for statins or exclusion of open trials for niacin. Meta-regression suggested that CETP inhibitors might not influence coronary risk. The relation between change in HDL-C level and clinical endpoint may be drug dependent, which limits the use of HDL-C as a surrogate marker of coronary events. Other markers of HDL function may be more relevant. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Lipoprotein lipase gene variants: Association with acute myocardial ...

African Journals Online (AJOL)

Mahyar Bahrami

2015-05-13

May 13, 2015 ... ated with acute myocardial infarction but with triglyceride levels. У 2015 The ... C) and low levels of high-density lipoprotein cholesterol. (HDL-C) are .... relationship between LDL, HDL, cholesterol and TG levels with LPL ...

The Role of High-Density Lipoproteins in Reducing the Risk of Vascular Diseases, Neurogenerative Disorders, and Cancer

Directory of Open Access Journals (Sweden)

Donovan McGrowder

2011-01-01

Full Text Available High-density lipoprotein (HDL is one of the major carriers of cholesterol in the blood. It attracts particular attention because, in contrast with other lipoproteins, as many physiological functions of HDL influence the cardiovascular system in favourable ways unless HDL is modified pathologically. The functions of HDL that have recently attracted attention include anti-inflammatory and anti-oxidant activities. High anti-oxidant and anti-inflammatory activities of HDL are associated with protection from cardiovascular disease. Atheroprotective activities, as well as a functional deficiency of HDL, ultimately depend on the protein and lipid composition of HDL. Further, numerous epidemiological studies have shown a protective association between HDL-cholesterol and cognitive impairment. Oxidative stress, including lipid peroxidation, has been shown to be the mediator of the pathologic effects of numerous risk factors of Alzheimer's disease. Lifestyle interventions proven to increase HDL- cholesterol levels including “healthy” diet, regular exercise, weight control, and smoking cessation have also been shown to provide neuro-protective effects. This review will focus on current knowledge of the beneficial effects of HDL-cholesterol as it relates to cardiovascular diseases, breast and lung cancers, non-Hodgkin's lymphoma, as well as its neuroprotective potential in reducing the risk of Alzheimer's disease and dementia.

Low-Density Lipoprotein Modified by Myeloperoxidase in Inflammatory Pathways and Clinical Studies

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Cédric Delporte

2013-01-01

Full Text Available Oxidation of low-density lipoprotein (LDL has a key role in atherogenesis. Among the different models of oxidation that have been studied, the one using myeloperoxidase (MPO is thought to be more physiopathologically relevant. Apolipoprotein B-100 is the unique protein of LDL and is the major target of MPO. Furthermore, MPO rapidly adsorbs at the surface of LDL, promoting oxidation of amino acid residues and formation of oxidized lipoproteins that are commonly named Mox-LDL. The latter is not recognized by the LDL receptor and is accumulated by macrophages. In the context of atherogenesis, Mox-LDL accumulates in macrophages leading to foam cell formation. Furthermore, Mox-LDL seems to have specific effects and triggers inflammation. Indeed, those oxidized lipoproteins activate endothelial cells and monocytes/macrophages and induce proinflammatory molecules such as TNFα and IL-8. Mox-LDL may also inhibit fibrinolysis mediated via endothelial cells and consecutively increase the risk of thrombus formation. Finally, Mox-LDL has been involved in the physiopathology of several diseases linked to atherosclerosis such as kidney failure and consequent hemodialysis therapy, erectile dysfunction, and sleep restriction. All these issues show that the investigations of MPO-dependent LDL oxidation are of importance to better understand the inflammatory context of atherosclerosis.

Relationship between Serum Lipoprotein Ratios and Insulin Resistance in Polycystic Ovary Syndrome

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Shou-Kui Xiang

2012-01-01

Full Text Available Objective. To investigate the association between serum lipoprotein ratios and insulin resistance in women with polycystic ovarian syndrome (PCOS. Methods. 105 PCOS patients and 109 controls were randomly enrolled in the study. Serum levels of luteinizing hormone (LH, follicle-stimulating hormone (FSH, estradiol (E2, total testosterone (T, fasting glucose (FBG, fasting insulin (FINS, serum triglycerides (TG, total cholesterol (TC, high-density lipoprotein (HDL-C, and low-density lipoprotein (LDL-C levels were checked, and then TG/HDL-C ratio, TC/HDL-C, ratio and LDL-C/HDL-C ratio were calculated. The homeostasis model assessment of insulin resistance (HOMA-IR was used to calculate the insulin resistance. Results. All lipoprotein ratios were significantly higher in PCOS patients as compared to healthy controls (<0.05. TG/HDL-C ratio, TC/HDL-C ratio, and LDL-C/HDL-C ratio were significantly correlated with HOMA-IR (<0.05. The ROC curve demonstrated that TC/HDL-C ratio had higher sensitivity and specificity in diagnosing PCOS with insulin resistance. Conclusion. This study demonstrates that serum lipoprotein ratio significantly correlates with insulin resistance and can be used as the marker of insulin resistance in PCOS patients.

PCSK9 and triglyceride-rich lipoprotein metabolism.

Science.gov (United States)

Druce, I; Abujrad, H; Ooi, T C

2015-07-20

Pro-protein convertase subtilisin-kexin 9 (PCSK9) is known to affect low-density lipoprotein (LDL) metabolism, but there are indications from several lines of research that it may also influence the metabolism of other lipoproteins, especially triglyceride-rich lipoproteins (TRL). This review summarizes the current data on this possible role of PCSK9. A link between PCSK9 and TRL has been suggested through the demonstration of (1) a correlation between plasma PCSK9 and triglyceride (TG) levels in health and disease, (2) a correlation between plasma PCSK9 and markers of carbohydrate metabolism, which is closely related to TG metabolism, (3) an effect of TG-lowering fibrate therapy on plasma PCSK9 levels, (4) an effect of PCSK9 on postprandial lipemia, (5) an effect of PCSK9 on adipose tissue biology, (6) an effect of PCSK9 on apolipoprotein B production from the liver and intestines, (7) an effect of PCSK9 on receptors other than low density lipoprotein receptor (LDLR) that are involved in TRL metabolism, and (8) an effect of anti-PCSK9 therapy on serum TG levels. The underlying mechanisms are unclear but starting to emerge. © 2015 the Journal of Biomedical Research. All rights reserved.

Low density lipoprotein sensor based on surface plasmon resonance

International Nuclear Information System (INIS)

Matharu, Zimple; Sumana, G.; Pandey, M.K.; Gupta, Vinay; Malhotra, B.D.

2009-01-01

Biotinylated heparin has been immobilized onto self-assembled monolayer of 4-aminothiophenol using avidin-biotin specific binding. The modified electrodes have been characterized using surface plasmon resonance technique (SPR), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM) and contact angle (CA) measurements. The interaction of immobilized biotinylated heparin with low density lipoprotein (LDL) has been studied using surface plasmon resonance technique. The biotinylated heparin modified electrode can be used to detect LDL in the range of 20 to 100 mg/dl with the sensitivity of 513.3 m o /μM.

Low density lipoprotein sensor based on surface plasmon resonance

Energy Technology Data Exchange (ETDEWEB)

Matharu, Zimple [Department of Science and Technology Centre on Biomolecular Electronics, National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012 (India); Department of Physics and Astrophysics, University of Delhi, New Delhi-110007 (India); Sumana, G.; Pandey, M.K. [Department of Science and Technology Centre on Biomolecular Electronics, National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012 (India); Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, New Delhi-110007 (India); Malhotra, B.D., E-mail: bansi.malhotra@gmail.co [Department of Science and Technology Centre on Biomolecular Electronics, National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi-110012 (India)

2009-11-30

Biotinylated heparin has been immobilized onto self-assembled monolayer of 4-aminothiophenol using avidin-biotin specific binding. The modified electrodes have been characterized using surface plasmon resonance technique (SPR), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM) and contact angle (CA) measurements. The interaction of immobilized biotinylated heparin with low density lipoprotein (LDL) has been studied using surface plasmon resonance technique. The biotinylated heparin modified electrode can be used to detect LDL in the range of 20 to 100 mg/dl with the sensitivity of 513.3 m{sup o}/{mu}M.

Dietary fatty acids were not independently associated with lipoprotein subclasses in elderly women.

Science.gov (United States)

Alaghehband, Fatemeh Ramezan; Lankinen, Maria; Värri, Miika; Sirola, Joonas; Kröger, Heikki; Erkkilä, Arja T

2017-07-01

Dietary fatty acids are known to affect serum lipoproteins; however, little is known about the associations between consumption of dietary fatty acids and lipoprotein subclasses. In this study, we hypothesized that there is an association between dietary fatty acids and lipoprotein subclasses and investigated the cross-sectional association of dietary fat intake with subclasses of lipoproteins in elderly women. Altogether, 547 women (aged ≥65 years) who were part of OSTPRE cohort participated. Dietary intake was assessed by 3-day food records, lifestyle, and health information obtained through self-administrated questionnaires, and lipoprotein subclasses were determined by nuclear magnetic resonance spectroscopy. To analyze the associations between fatty acids and lipoprotein subclasses, we used Pearson and Spearman correlation coefficients and the analysis of covariance (ANCOVA) test with, adjustment for physical activity, body mass index, age, smoking status, and intake of lipid-lowering drugs. There were significant correlations between saturated fatty acids (SFA; % of energy) and concentrations of large, medium, and small low-density lipoproteins (LDL); total cholesterol in large, medium, and small LDL; and phospholipids in large, medium, and small LDL, after correction for multiple testing. After adjustment for covariates, the higher intake of SFA was associated with smaller size of LDL particles (P = .04, ANCOVA) and lower amount of triglycerides in small very low-density lipoproteins (P = .046, ANCOVA). However, these associations did not remain significant after correction for multiple testing. In conclusion, high intake of SFA may be associated with the size of LDL particles, but the results do not support significant, independent associations between dietary fatty acids and lipoprotein subclasses. Copyright © 2017 Elsevier Inc. All rights reserved.

Increased fluidity and oxidation of malarial lipoproteins: relation with severity and induction of endothelial expression of adhesion molecules

Directory of Open Access Journals (Sweden)

Looareesuwan Sornchai

2004-06-01

Full Text Available Abstract Introduction Oxidative stress has been demonstrated in malaria. The potential oxidative modification of lipoproteins derived from malaria patients was studied. These oxidized lipids may have role in pathogenesis of malaria. Method The plasma lipid profile and existence of oxidized forms of very low density lipoprotein (VLDL, low density lipoprotein (LDL and high density lipoprotein (HDL were investigated in malaria (17 mild and 24 severe patients and 37 control subjects. Thiobarbituric acid reactive substances (TBARs, conjugated dienes, tryptophan fluorescence and fluidity of lipoproteins were determined as markers of oxidation. The biological effect of malarial lipoproteins was assessed by the expression of adhesion molecules on endothelial cells. Results Malarial lipoproteins had decreased cholesterol (except in VLDL and phospholipid. The triglyceride levels were unchanged. The cholesterol/phospholipid ratio of LDL was decreased in malaria, but increased in VLDL and HDL. TBARs and conjugate dienes were increased in malarial lipoproteins, while the tryptophan fluorescence was decreased. The fluidity of lipoproteins was increased in malaria. These indicated the presence of oxidized lipoproteins in malaria by which the degree of oxidation was correlated with severity. Of three lipoproteins from malarial patients, LDL displayed the most pronounced oxidative modification. In addition, oxidized LDL from malaria patients increased endothelial expression of adhesion molecules. Conclusion In malaria, the lipoproteins are oxidatively modified, and the degree of oxidation is related with severity. Oxidized LDL from malarial patients increases the endothelial expression of adhesion molecules. These suggest the role of oxidized lipoproteins, especially LDL, on the pathogenesis of disease.

Serum amyloid A stimulates macrophage foam cell formation via lectin-like oxidized low-density lipoprotein receptor 1 upregulation

International Nuclear Information System (INIS)

Lee, Ha Young; Kim, Sang Doo; Baek, Suk-Hwan; Choi, Joon Hyuk; Cho, Kyung-Hyun; Zabel, Brian A.; Bae, Yoe-Sik

2013-01-01

Highlights: ► SAA induced macrophage foam cell formation. ► SAA stimulated upregulation of lectin-like oxidized low-density lipoprotein receptor 1 (LOX1). ► SAA-induced LOX1 expression and foam cell formation is mediated by JNK/NF-κB signaling. ► HDL-conjugated SAA also stimulates foam cell formation via LOX1 upregulation. ► The finding reveals a novel mechanism of action of SAA in the pathogenesis of atherosclerosis. -- Abstract: Elevated levels of serum amyloid A (SAA) is a risk factor for cardiovascular diseases, however, the role of SAA in the pathophysiology of atherosclerosis remains unclear. Here we show that SAA induced macrophage foam cell formation. SAA-stimulated foam cell formation was mediated by c-jun N-terminal kinase (JNK) signaling. Moreover, both SAA and SAA-conjugated high density lipoprotein stimulated the expression of the important scavenger receptor lectin-like oxidized low-density lipoprotein receptor 1 (LOX1) via nuclear factor-κB (NF-κB). A LOX1 antagonist carrageenan significantly blocked SAA-induced foam cell formation, indicating that SAA promotes foam cell formation via LOX1 expression. Our findings therefore suggest that SAA stimulates foam cell formation via LOX1 induction, and thus likely contributes to atherogenesis

Serum amyloid A stimulates macrophage foam cell formation via lectin-like oxidized low-density lipoprotein receptor 1 upregulation

Energy Technology Data Exchange (ETDEWEB)

Lee, Ha Young, E-mail: hayoung@skku.edu [Department of Biological Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Kim, Sang Doo [Department of Biological Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Baek, Suk-Hwan [Department of Biochemistry and Molecular Biology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Choi, Joon Hyuk [Department of Pathology, College of Medicine, Yeungnam University, Daegu 705-717 (Korea, Republic of); Cho, Kyung-Hyun [School of Biotechnology, Yeungnam University, Gyeongsan 712-749 (Korea, Republic of); Zabel, Brian A. [Palo Alto Institute for Research and Education, Veterans Affairs Hospital, Palo Alto, CA 94304 (United States); Bae, Yoe-Sik, E-mail: yoesik@skku.edu [Department of Biological Science, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Mitochondria Hub Regulation Center, Dong-A University, Busan 602-714 (Korea, Republic of); Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 135-710 (Korea, Republic of)

2013-03-29

Highlights: ► SAA induced macrophage foam cell formation. ► SAA stimulated upregulation of lectin-like oxidized low-density lipoprotein receptor 1 (LOX1). ► SAA-induced LOX1 expression and foam cell formation is mediated by JNK/NF-κB signaling. ► HDL-conjugated SAA also stimulates foam cell formation via LOX1 upregulation. ► The finding reveals a novel mechanism of action of SAA in the pathogenesis of atherosclerosis. -- Abstract: Elevated levels of serum amyloid A (SAA) is a risk factor for cardiovascular diseases, however, the role of SAA in the pathophysiology of atherosclerosis remains unclear. Here we show that SAA induced macrophage foam cell formation. SAA-stimulated foam cell formation was mediated by c-jun N-terminal kinase (JNK) signaling. Moreover, both SAA and SAA-conjugated high density lipoprotein stimulated the expression of the important scavenger receptor lectin-like oxidized low-density lipoprotein receptor 1 (LOX1) via nuclear factor-κB (NF-κB). A LOX1 antagonist carrageenan significantly blocked SAA-induced foam cell formation, indicating that SAA promotes foam cell formation via LOX1 expression. Our findings therefore suggest that SAA stimulates foam cell formation via LOX1 induction, and thus likely contributes to atherogenesis.

Application of directly coupled HPLC MMR to separation and characterization of lipoproteins from human serum

DEFF Research Database (Denmark)

Daykin, C. A.; Corcoran, O.; Hansen, S. H.

2001-01-01

method for the separation of highdensity lipoprotein, low-density lipoprotein, and very low-density lipoprotein from intact serum or plasma. The separation was achieved using a hydroxyapatite column and elution with pH 7.4 phosphate buffer with 100-muL injections of whole plasma. Coelution of HDL...... run time was 90 min with stopped-now 600-MHz NMR spectra of each lipoprotein being collected using 128 scans, in 7 min. The H-1 NMR chemical shifts of lipid signals were identical to conventional NMR spectra of freshly prepared lipoprotein standards, confirming that the lipoproteins were not degraded...

Learning from biology: synthetic lipoproteins for drug delivery.

Science.gov (United States)

Huang, Huang; Cruz, William; Chen, Juan; Zheng, Gang

2015-01-01

Synthetic lipoproteins represent a relevant tool for targeted delivery of biological/chemical agents (chemotherapeutics, siRNAs, photosensitizers, and imaging contrast agents) into various cell types. These nanoparticles offer a number of advantages for drugs delivery over their native counterparts while retaining their natural characteristics and biological functions. Their ultra-small size (lipoprotein receptors, i.e., low-density lipoprotein receptor (LDLR) and Scavenger receptor class B member 1 (SRB1) that are found in a number of pathological conditions (e.g., cancer, atherosclerosis), make them superior delivery strategies when compared with other nanoparticle systems. We review the various approaches that have been developed for the generation of synthetic lipoproteins and their respective applications in vitro and in vivo. More specifically, we summarize the approaches employed to address the limitation on use of reconstituted lipoproteins by means of natural or recombinant apolipoproteins, as well as apolipoprotein mimetic molecules. Finally, we provide an overview of the advantages and disadvantages of these approaches and discuss future perspectives for clinical translation of these nanoparticles. © 2014 Wiley Periodicals, Inc.

Analysis of lipoproteins by capillary zone electrophoresis in microfluidic devices: Assay development and surface roughness measurements

NARCIS (Netherlands)

Weiller, Bruce H.; Ceriotti, Laura; Shibata, Takayuki; Rein, Dietrich; Roberts, Matthew A.; Lichtenberg, Jan; German, J. Bruce; De Rooij, Nico F.; Verpoorte, Elisabeth

2002-01-01

The development of a new assay for lipoproteins by capillary electrophoresis in fused-silica capillaries and in glass microdevices is described in this paper. The separation of low-density (LDL) and high-density (HDL) lipoproteins by capillary zone electrophoresis is demonstrated in fused-silica

Changes of very low-density lipoprotein concentration in hepatic blood from cows with fasting-induced hepatic lipidosis.

Science.gov (United States)

Oikawa, Shin; Mizunuma, Yuko; Iwasaki, Yukari; Tharwat, Mohamed

2010-10-01

The purpose of this study was to evaluate changes of very low-density lipoprotein (VLDL) components in hepatic blood (HB) from 5 nonlactating nonpregnant cows fasted from days 0 to 3 and subsequently refed to day 10 and, in addition, to assess those of other lipoproteins. Increased phospholipid concentrations in each lipoprotein after the start of fasting suggested their availability for the surface lipids of lipoproteins. Although the VLDL-triglyceride (TG) concentration in HB from all cows increased on day 1, the value on day 4 became similar to that on day 0. However, the concentration on day 10 was significantly increased. In all cows, the decreased ratio of the VLDL-TG concentration in HB to the non-esterified fatty acids (NEFA) concentration in portal blood (PB) on day 4 appeared to reflect relatively decreased secretion of TG as VLDL by NEFA excessively mobilized to the liver via PB. The markedly increased ratio on day 10 was considered to contribute to the improvement of hepatic lipidosis.

Low density lipoprotein : structure, dynamics, and interactions of apoB-100 with lipids

NARCIS (Netherlands)

Murtola, T.; Vuorela, T.A.; Hyvönen, M.T.; Marrink, S.J.; Karttunen, M.E.J.; Vattulainen, I.

2011-01-01

Low-density lipoprotein (LDL) transports cholesterol in the bloodstream and plays an important role in the development of cardiovascular diseases, in particular atherosclerosis. Despite its importance to health, the structure of LDL is not known in detail. This is worrying since the lack of LDL's

Enzymatic Modification of Plasma Low Density Lipoproteins in Rabbits: A Potential Treatment for Hypercholesterolemia

Science.gov (United States)

Labeque, Regine; Mullon, Claudy J. P.; Ferreira, Joao Paulo M.; Lees, Robert S.; Langer, Robert

1993-04-01

Phospholipase A_2 (EC 3.1.1.4) hydrolyzes certain phospholipids of low density lipoprotein (LDL). Plasma clearance of phospholipase A_2-modified human LDL is up to 17 times faster than that of native human LDL in hypercholesterolemic rabbits. Modification of blood lipoproteins of hypercholesterolemic rabbits was performed by using an extracorporeal circuit containing immobilized phospholipase A_2. After 90-min treatments, nearly 30% decreases in plasma cholesterol concentrations were observed. Erythrocyte, leukocyte, and platelet counts showed no net change after treatment. This technique does not require any fluid replacement or sorbent regeneration and offers a potential approach for lowering serum cholesterol and LDL levels.

High-density lipoproteins potentiate α1-antitrypsin therapy in elastase-induced pulmonary emphysema.

Science.gov (United States)

Moreno, Juan-Antonio; Ortega-Gomez, Almudena; Rubio-Navarro, Alfonso; Louedec, Liliane; Ho-Tin-Noé, Benoit; Caligiuri, Giuseppina; Nicoletti, Antonino; Levoye, Angelique; Plantier, Laurent; Meilhac, Olivier

2014-10-01

Several studies report that high-density lipoproteins (HDLs) can carry α1-antitrypsin (AAT; an elastase inhibitor). We aimed to determine whether injection of exogenous HDL, enriched or not in AAT, may have protective effects against pulmonary emphysema. After tracheal instillation of saline or elastase, mice were randomly treated intravenously with saline, human plasma HDL (75 mg apolipoprotein A1/kg), HDL-AAT (75 mg apolipoprotein A1-3.75 mg AAT/kg), or AAT alone (3.75 mg/kg) at 2, 24, 48, and 72 hours. We have shown that HDL-AAT reached the lung and prevented the development of pulmonary emphysema by 59.3% at 3 weeks (alveoli mean chord length, 22.9 ± 2.8 μm versus 30.7 ± 4.5 μm; P pulmonary emphysema than AAT alone, and may represent a significant development for the management of emphysema associated with AAT deficiency.

Interaction of estradiol and high density lipoproteins on proliferation of the human breast cancer cell line MCF-7 adapted to grow in serum free conditions

International Nuclear Information System (INIS)

Jozan, S.; Faye, J.C.; Tournier, J.F.; Tauber, J.P.; David, J.F.; Bayard, F.

1985-01-01

The responsiveness of the human mammary carcinoma cell line MCF-7 to estradiol and tamoxifen treatment has been studied in different culture conditions. Cells from exponentially growing cultures were compared with cells in their initial cycles after replating from confluent cultures (''confluent-log'' cells). It has been observed that estradiol stimulation of tritiated thymidine incorporation decreases with cell density and that ''confluent-log'' cells are estrogen unresponsive for a period of four cell cycles in serum-free medium conditions. On the other hand, growth of cells replated from exponentially growing, as well as from confluent cultures, can be inhibited by tamoxifen or a combined treatment with tamoxifen and the progestin levonorgestrel. This growth inhibitory effect can be rescued by estradiol when cells are replated from exponentially growing cultures. The growth inhibitory effect cannot be rescued by estradiol alone (10(-10) to 10(-8) M) when cells are replated from confluent cultures. In this condition, the addition of steroid depleted serum is necessary to reverse the state of estradiol unresponsiveness. Serum can be replaced by high density lipoproteins but not by low density lipoproteins or lipoprotein deficient serum. The present data show that estradiol and HDL interact in the control of MCF-7 cell proliferation

Genetic determinants of LDL, lipoprotein(a), triglyceride-rich lipoproteins and HDL: concordance and discordance with cardiovascular disease risk

DEFF Research Database (Denmark)

Nordestgaard, Børge G; Tybjærg-Hansen, Anne

2011-01-01

To evaluate whether new and known genetic determinants of plasma levels of LDL cholesterol, lipoprotein(a), triglyceride-rich lipoproteins, and HDL cholesterol associate with the risk of cardiovascular disease expected from the effect on lipoprotein levels. Concordance or discordance of such gene......To evaluate whether new and known genetic determinants of plasma levels of LDL cholesterol, lipoprotein(a), triglyceride-rich lipoproteins, and HDL cholesterol associate with the risk of cardiovascular disease expected from the effect on lipoprotein levels. Concordance or discordance...

Onset of lipoprotein-supported steroidogenesis in differentiating granulosa cells of rats: cellular events involved in mediating FSH-enhanced uptake of low-density lipoproteins

International Nuclear Information System (INIS)

Foster, J.D.

1987-01-01

Luteal cells use lipoproteins as the main source of cholesterol in steroidogenesis. However, little is known about the mechanisms underlying hormonal control of lipoprotein uptake. Thus, the authors tested the hypothesis that FSH and androgens regulate low density lipoprotein (LDL)-supported steroidogenesis in maturing granulosa cells by affecting receptor-mediated endocytosis of LDL at a cellular level. For this, immature ovarian granulosa cells were cultured with or without hormones, compactin (de novo synthesis inhibitor), or unlabeled or labeled ( 125 I or gold particles) LDL. Nonhormone-treated cultures produced little progestin; FSH and FSH/androstenedione stimulated steroid secretion. Progestin production by hormone-, but not nonhormone-, treated cultures was decreased by compactin, suggesting that de novo synthesis provided sterol for steroidogenesis. EM quantitation of cells exposed to gold-LDL at 37 0 C revealed that, compared to nonhormone-treated cells, FSH-treated cells (1) bound and internalized more gold-LDL, (2) had a smaller percentage of gold-LDL at their surfaces, (3) displayed a faster apparent rate of LDL internalization and delivery to lysosomes, and (4) contained more gold-labeled lysosomes. Data from biochemical studies in which 125 I-LDL was used supported the morphological findings. In conclusion, this study demonstrates that FSH has important effects at the cellular level on LDL uptake, which seem to underlie the striking increase in progestin production accompanying granulosa cell differentiation

In vivo regulation of scavenger receptor BI and the selective uptake of high density lipoprotein cholesteryl esters in rat liver parenchymal and Kupffer cells

NARCIS (Netherlands)

Fluiter, K.; van der Westhuijzen, D. R.; van Berkel, T. J.

1998-01-01

High density lipoprotein cholesteryl esters (HDL-CE) are selectively taken up by liver parenchymal cells without parallel apolipoprotein uptake. This selective uptake route forms an important step in the so-called reverse cholesterol transport. Scavenger receptor BI (SR-BI) is the only known HDL

Optical coherence tomography in quantifying the permeation of human plasma lipoproteins in vascular tissues

Science.gov (United States)

Ghosn, M. G.; Mashiatulla, M.; Tuchin, V. V.; Morrisett, J. D.; Larin, K. V.

2012-03-01

Atherosclerosis is the most common underlying cause of vascular disease, occurring in multiple arterial beds including the carotid, coronary, and femoral arteries. Atherosclerosis is an inflammatory process occurring in arterial tissue, involving the subintimal accumulation of low-density lipoproteins (LDL). Little is known about the rates at which these accumulations occur. Measurements of the permeability rate of LDL, and other lipoproteins such as high-density lipoprotein (HDL) and very low-density lipoprotein (VLDL), could help gain a better understanding of the mechanisms involved in the development of atherosclerotic lesions. The permeation of VLDL, LDL, HDL, and glucose was monitored and quantified in normal and diseased human carotid endarterectomy tissues at 20°C and 37°C using optical coherence tomography (OCT). The rates for LDL permeation through normal tissue at 20°C was (3.16 +/- 0.37) × 10-5 cm/sec and at 37°C was (4.77 +/- 0.48) × 10-5 cm/sec, significantly greater (plipoproteins.

Overexpression of porcine lipoprotein-associated phospholipase A2 in swine

NARCIS (Netherlands)

Tang, Xiaochun; Wang, Gangqi; Liu, Xingxing; Han, Xiaolei; Li, Zhuang; Ran, Guangyao; Li, Zhanjun; Song, Qi; Ji, Y; Wang, Haijun; Wang, Yuhui; Ouyang, Hongsheng; Pang, Daxin

2015-01-01

Lipoprotein-associated phospholipase A 2 (Lp-PLA2) is associated with the risk of vascular disease. It circulates in human blood predominantly in association with low-density lipoprotein cholesterol (LDL-C) and hydrolyses oxidized phospholipids into pro-inflammatory products. However, in the mouse

Spirochetal Lipoproteins and Immune Evasion

Science.gov (United States)

Christodoulides, Alexei; Boyadjian, Ani; Kelesidis, Theodoros

2017-01-01

Spirochetes are a major threat to public health. However, the exact pathogenesis of spirochetal diseases remains unclear. Spirochetes express lipoproteins that often determine the cross talk between the host and spirochetes. Lipoproteins are pro-inflammatory, modulatory of immune responses, and enable the spirochetes to evade the immune system. In this article, we review the modulatory effects of spirochetal lipoproteins related to immune evasion. Understanding lipoprotein-induced immunomodulation will aid in elucidating innate pathogenesis processes and subsequent adaptive mechanisms potentially relevant to spirochetal disease vaccine development and treatment. PMID:28424696

Elevated Lipoprotein(A Impairs Platelet Radiolabeling Yield

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Susanne Granegger

2015-02-01

Full Text Available Objectives: Platelet radiolabeling in clinical routine usually results in labeling efficiencies (LE above 80%. A variety of risk factors and clinical conditions are known to impair platelet labeling yield, among them elevated triglycerides and low-density lipoproteins. The potential influence of lipoprotein(a (Lp(a, an atherogenic lipoprotein particle containing a kringle subunit, which is widely found in the proteins of fibrinolysis pathway, has never been studied. Normal Lp(a levels range below 30 mg/ dl. The exact prevalence of elevated Lp(a is unknown, most likely ranging below 10%. Even more rare is an isolated elevation despite an otherwise normal lipoprotein profile. Methods: We examined the role of isolated elevated Lp(a (> 50 mg/dl, ranging up to 440 mg/dl compared to patients with normal lipid profile. Platelets were radiolabeled with in-111-oxine at 37 °C for 5 minutes using ISORBE-consensus methodology. Results: The findings indicate that already at levels below 100 mg/dl Lp(a decreases LE. LE assessment after cross-incubation of hyper-Lp(a platelets with normal Lp(a plasma and vice versa reveals that platelets rather than the plasmatic environment are responsible for the deterioration of labeling yield. This behavior already has been reported for elevated low-density lipoproteins. Apparently, the quantitative influence of LDL and Lp(a/mg is comparable. Plotting the sum of LDL and Lp(a versus LE reveals a clear significant negative correlation. Conclusion: As extremely elevated Lp(a, particularly above 150 mg/dl, may significantly impair labeling results. We therefore recommend to include extremely elevated Lp(a into the list of parameters, which should be known before performing radiolabeling of human platelets.

Synthetic high-density lipoprotein nanodisks for targeted withalongolide delivery to adrenocortical carcinoma

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Kuai R

2017-09-01

Full Text Available Rui Kuai,1,2,* Chitra Subramanian,3,* Peter T White,3,* Barbara N Timmermann,4 James J Moon,1,2,5 Mark S Cohen,3,6 Anna Schwendeman1,2 1Department of Pharmaceutical Sciences, College of Pharmacy, 2Biointerfaces Institute, University of Michigan, 3Department of Surgery, University of Michigan, Ann Arbor, MI, 4Department of Medicinal Chemistry, University of Kansas, Lawrence, KS, 5Department of Biomedical Engineering, 6Department of Pharmacology, University of Michigan, Ann Arbor, MI, USA *These authors contributed equally to this work Abstract: Adrenocortical carcinoma (ACC is a rare endocrine malignancy and has a 5-year survival rate of <35%. ACC cells require cholesterol for steroid hormone production, and this requirement is met via expression on the cell surface of a high level of SRB1, responsible for the uptake of high-density lipoproteins (HDLs, which carry and transport cholesterol in vivo. Here, we describe how this natural lipid carrier function of SRB1 can be utilized to improve the tumor-targeted delivery of a novel natural product derivative – withalongolide A 4,19,27-triacetate (WGA-TA – which has shown potent antitumor efficacy, but poor aqueous solubility. Our strategy was to use synthetic HDL (sHDL nanodisks, which are effective in tumor-targeted delivery due to their smallness, long circulation half-life, documented safety, and ability to bind to SRB1. In this study, we prepared sHDL nanodisks using an optimized phospholipid composition combined with ApoA1 mimetic peptide (22A, which has previously been tested in clinical trials, to load WGA-TA. Following optimization, WGA-TA nanodisks showed drug encapsulation efficiency of 78%, a narrow particle size distribution (9.81±0.41 nm, discoid shape, and sustained drug release in phosphate buffered saline. WGA-TA-sHDL nanodisks exhibited higher cytotoxicity in the ACC cell line H295R half maximal inhibitory concentration ([IC50] 0.26±0.045 µM than free WGA-TA (IC50 0.492±0

Lipoprotein receptors in cultured bovine endothelial cells

International Nuclear Information System (INIS)

Struempfer, A.E.M.

1983-07-01

In this study, receptors that may be involved in the uptake of low density lipoproteins (LDL) and low density lipoproteins which have been modified by acetylation (AcLDL), were characterized. Aortic epithelial cells were used and a cell culture system which closely resembled the in vivo monolayer was established. Endothelial cell and lipoprotein interactions were examined by incubating the cells with 125 l-labelled lipoproteins under various conditions. The receptor affinity of bovine aortic endothelial cells was higher for AcLDL than that for LDL. Competition studies demonstrated that there were two distinct receptors for LDL and AcLDL on the endothelial cells. AcLDL did not compete with LDL for the LDL receptor, and conversely LDL did not compete with AcLDL for the AcLDL receptor. The receptor activities for LDL and AcLDL were examined as a function of culture age. Whereas the LDL receptor could be regulated, the AcLDL receptor was not as susceptible to regulation. Upon exposing endothelial cells for 72 h to either LDL or AcLDL, it was found that the total amount of cellular cholesterol increased by about 50%. However, the increase of total cholesterol was largely in the form of free cholesterol. This is in contrast to macrophages, where the increase in total cholesterol upon exposure to AcLDL is largely in the form cholesteryl esters

Lipoprotein Nanoplatform for Targeted Delivery of Diagnostic and Therapeutic Agents

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Jerry D. Glickson

2008-03-01

Full Text Available Low-density lipoprotein (LDL provides a highly versatile natural nanoplatform for delivery of visible or near-infrared fluorescent optical and magnetic resonance imaging (MRI contrast agents and photodynamic therapy and chemotherapeutic agents to normal and neoplastic cells that overexpress low-density lipoprotein receptors (LDLRs. Extension to other lipoproteins ranging in diameter from about 10 nm (high-density lipoprotein [HDL] to over a micron (chylomicrons is feasible. Loading of contrast or therapeutic agents onto or into these particles has been achieved by protein loading (covalent attachment to protein side chains, surface loading (intercalation into the phospholipid monolayer, and core loading (extraction and reconstitution of the triglyceride/cholesterol ester core. Core and surface loading of LDL have been used for delivery of optical imaging agents to tumor cells in vivo and in culture. Surface loading was used for delivery of gadolinium-bis-stearylamide contrast agents for in vivo MRI detection in tumor-bearing mice. Chlorin and phthalocyanine near-infrared photodynamic therapy agents (≤ 400/LDL have been attached by core loading. Protein loading was used to reroute the LDL from its natural receptor (LDLR to folate receptors and could be used to target other receptors. A semisynthetic nanoparticle has been constructed by coating magnetite iron oxide nanoparticles with carboxylated cholesterol and overlaying a monolayer of phospholipid to which apolipoprotein A1 or E was adsorbed for targeting HDL or adsorbing synthetic amphipathic helical peptides ltargeting LDL or folate receptors. These particles can be used for in situ loading of magnetite into cells for MRI-monitored cell tracking or gene expression.

An alternative procedure for incorporating radiolabelled cholesteryl ester into human plasma lipoproteins in vitro

International Nuclear Information System (INIS)

Roberts, D.C.K.; Miller, N.E.; Price, S.G.L.; Crook, D.; Cortese, C.; Ville, A. La; Masana, L.; Lewis, B.

1985-01-01

A simple method has been developed for labelling human plasma lipoproteins to high specific radioactivity with radioactive cholesteryl esters in vitro. After isolation by preparative ultracentrifugation, the selected lipoprotein was incubated for 30 min at 4 0 C in human serum (d > 1.215) that had been prelabelled with [4- 14 C]cholesteryl oleate or [1,2- 3 H]cholesteryl linoleate, and was then re-isolated by ultracentrifugation. All major lipoprotein classes were labelled by the procedure. Specific radioactivities of up to 18 d.p.m. .pmol -1 (46d.p.m. .ng -1 ) were achieved. When radiolabelled high-density lipoprotein was infused intravenously, the radioactive cholesteryl ester behaved in vivo indistinguishably from endogenous cholesteryl esters produced by the lecithin (phosphatidylcholine): cholesterol acyltransferase reaction. (author)

Cellular uptake of lipoproteins and persistent organic compounds-An update and new data

International Nuclear Information System (INIS)

Hjelmborg, Philip Sebastian; Andreassen, Thomas Kjaergaard; Bonefeld-Jorgensen, Eva Cecilie

2008-01-01

There are a number of interactions related to the transport of lipophilic xenobiotic compounds in the blood stream of mammals. This paper will focus on the interactions between lipoproteins and persistent organic pollutants (POPs) and how these particles are taken up by cells. A number of POPs including the pesticide p,p'-dichlorodiphenyltrichloroethane (DDT), and especially its metabolite p,p'-dichlorodiphenyldichloroethene (DDE), interacts with nuclear hormone receptors causing these to malfunction, which in turn results in a range of deleterious health effects in humans. The aim of the present study was to determine the role of lipoprotein receptors in mouse embryonic fibroblast (MEF) cells in conjunction with uptake of DDT-lipoprotein complexes from supplemented media in vitro. Uptake of DDT by MEF cells was investigated using MEF1 cells carrying the receptors low-density lipoprotein receptor-related protein (LRP) and low-density lipoprotein receptor (LDLR) present and MEF4 cells with no LRP and LDLR expression. Cells were incubated together with the complex of low-density lipoproteins (LDL) and [ 14 C]DDT. The receptor function was further evaluated by adding the 40 kDa receptor-associated protein (RAP) which blocks receptor activity. The results showed that [ 14 C]DDT uptake was decreasing when the LDL concentration was increasing. There was no strong evidence for a receptor-mediated uptake of the [ 14 C]DDT-lipoprotein complex. To conclude, DDT travels in the blood stream and can cross cell membranes while being transported as a DDT-lipoprotein complex. The lipoproteins do not need receptors to cross cell membranes since passive diffusion constitutes a major passageway

Impact of Chronic Hepatitis C Virus Genotype 1b Infection on Triglyceride Concentration in Serum Lipoprotein Fractions

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Tomohisa Nagano

2015-08-01

Full Text Available Reduced low-density lipoprotein (LDL cholesterol level is a characteristic feature of dyslipidemia in chronic hepatitis C virus (HCV infection. However, abnormality in serum triglyceride (TG has not been fully investigated. To clarify the impact of HCV genotype 1b (G1b infection and advanced fibrosis on serum TG profiles, TG concentrations in lipoprotein fractions were examined in fasting sera from 185 subjects with active or cleared HCV infection by high-performance liquid chromatography. Serum lipoproteins were fractionated into four classes: chylomicron, very low-density lipoprotein (VLDL, LDL, and high-density lipoprotein (HDL. Then, the significance of HCV G1b infection on TG levels in each lipoprotein fraction was determined using multiple regression models. We found that active HCV G1b infection was positively associated with high HDL-TG levels and low VLDL-TG levels, independent of other factors included in the regression model. In VLDL sub-fractions, active HCV infection was only found to be associated with low levels of large VLDL-TG. Similarly, advanced liver fibrosis in chronic HCV G1b infection was associated with high levels of LDL-TG, HDL-TG, and small VLDL-TG, independent of other clinical factors. These findings indicate that active HCV G1b infection and advanced fibrosis are closely associated with abnormal serum TG profiles.

Recombinant Lipoproteins as Novel Vaccines with Intrinsic Adjuvant.

Science.gov (United States)

Chong, Pele; Huang, Jui-Hsin; Leng, Chih-Hsiang; Liu, Shih-Jen; Chen, Hsin-Wei

2015-01-01

A core platform technology for high production of recombinant lipoproteins with built-in immunostimulator for novel subunit vaccine development has been established. This platform technology has the following advantages: (1) easily convert antigen into lipidated recombinant protein using a fusion sequence containing lipobox and express high level (50-150mg/L) in Escherichia coli; (2) a robust high-yield up- and downstream bioprocess for lipoprotein production is successfully developed to devoid endotoxin contamination; (3) the lipid moiety of recombinant lipoproteins, which is identical to that of bacterial lipoproteins is recognized as danger signals by the immune system (Toll-like receptor 2 agonist), so both innate and adaptive immune responses can be induced by lipoproteins; and (4) successfully demonstrate the feasibility and safety of this core platform technology in meningococcal group B subunit vaccine, dengue subunit vaccine, novel subunit vaccine against Clostridium difficile-associated diseases, and HPV-based immunotherapeutic vaccines in animal model studies. © 2015 Elsevier Inc. All rights reserved.

Comparison of 2 electrophoretic methods and a wet-chemistry method in the analysis of canine lipoproteins.

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Behling-Kelly, Erica

2016-03-01

The evaluation of lipoprotein metabolism in small animal medicine is hindered by the lack of a gold standard method and paucity of validation data to support the use of automated chemistry methods available in the typical veterinary clinical pathology laboratory. The physical and chemical differences between canine and human lipoproteins draw into question whether the transference of some of these human methodologies for the study of canine lipoproteins is valid. Validation of methodology must go hand in hand with exploratory studies into the diagnostic or prognostic utility of measuring specific lipoproteins in veterinary medicine. The goal of this study was to compare one commercially available wet-chemistry method to manual and automated lipoprotein electrophoresis in the analysis of canine lipoproteins. Canine lipoproteins from 50 dogs were prospectively analyzed by 2 electrophoretic methods, one automated and one manual method, and one wet-chemistry method. Electrophoretic methods identified a higher proportion of low-density lipoproteins than the wet-chemistry method. Automated electrophoresis occasionally failed to identify very low-density lipoproteins. Wet-chemistry methods designed for evaluation of human lipoproteins are insensitive to canine low-density lipoproteins and may not be applicable to the study of canine lipoproteins. Automated electrophoretic methods will likely require significant modifications if they are to be used in the analysis of canine lipoproteins. Studies aimed at determining the impact of a disease state on lipoproteins should thoroughly investigate the selected methodology prior to the onset of the study. © 2016 American Society for Veterinary Clinical Pathology.

Treating patients with low high-density lipoprotein cholesterol: choices, issues and opportunities

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Watts Gerald F

2001-05-01

Full Text Available Abstract Three clinical trials have recently focused on the benefits of lipid-regulating therapy in populations with normocholesterolaemia and low high-density lipoprotein (HDL-cholesterol. Two secondary prevention studies (Veterans Affairs HDL-Cholesterol Intervention Trial [VA-HIT] and Bezafibrate Infarction Prevention [BIP] trial testified to the efficacy of fibrates in decreasing cardiovascular events, particularly in patients with coexisting risk factors, including hypertriglyceridaemia. The Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS demonstrated that a statin could decrease acute coronary events in patients with isolated low HDL-cholesterol in a primary prevention setting. The absolute risk reduction in coronary events in the VA-HIT study compares favourably with those reported from the statin-based Cholesterol and Recurrent Events (CARE and Long-term Intervention with Pravastatin in Ischaemic Disease (LIPID trials. The absolute risk reduction in AFCAPS-TexCAPS is similar to that in West of Scotland Coronary Pravastatin Study (WOSCOPS. Recommendations are given concerning lifestyle and pharmacological management of low HDL-cholesterol. Optimal management also requires review of current treatment targets for HDL-cholesterol and triglycerides levels.

Lipoprotein (a) and biochemical parameters in elderly

OpenAIRE

Yuttana Sudjaroen

2016-01-01

Background: Lipoprotein (a) [Lp(a)] is an low-density lipoprotein like particle and is an important independent risk factor for coronary artery diseases (CAD). Few studies on Lp(a) level in Thai elderly to screening risk of CAD may concerned. Aims: To study the relation of Lp(a) level and routine biochemical parameters including lipid profiles and fasting blood glucose in elderly and to determine risk of subclinical symptoms by using Lp(a) levels as early risk predictor. Settings and Design: ...

Native and Reconstituted Plasma Lipoproteins in Nanomedicine: Physicochemical Determinants of Nanoparticle Structure, Stability, and Metabolism.

Science.gov (United States)

Pownall, Henry J; Rosales, Corina; Gillard, Baiba K; Ferrari, Mauro

2016-09-01

Although many acute and chronic diseases are managed via pharmacological means, challenges remain regarding appropriate drug targeting and maintenance of therapeutic levels within target tissues. Advances in nanotechnology will overcome these challenges through the development of lipidic particles, including liposomes, lipoproteins, and reconstituted high-density lipoproteins (rHDL) that are potential carriers of water-soluble, hydrophobic, and amphiphilic molecules. Herein we summarize the properties of human plasma lipoproteins and rHDL, identify the physicochemical determinants of lipid transfer between phospholipid surfaces, and discuss strategies for increasing the plasma half-life of lipoprotein- and liposome-associated molecules.

Anion exchange HPLC isolation of high-density lipoprotein (HDL and on-line estimation of proinflammatory HDL.

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Xiang Ji

Full Text Available Proinflammatory high-density lipoprotein (p-HDL is a biomarker of cardiovascular disease. Sickle cell disease (SCD is characterized by chronic states of oxidative stress that many consider to play a role in forming p-HDL. To measure p-HDL, apolipoprotein (apo B containing lipoproteins are precipitated. Supernatant HDL is incubated with an oxidant/LDL or an oxidant alone and rates of HDL oxidation monitored with dichlorofluorescein (DCFH. Although apoB precipitation is convenient for isolating HDL, the resulting supernatant matrix likely influences HDL oxidation. To determine effects of supernatants on p-HDL measurements we purified HDL from plasma from SCD subjects by anion exchange (AE chromatography, determined its rate of oxidation relative to supernatant HDL. SCD decreased total cholesterol but not triglycerides or HDL and increased cell-free (cf hemoglobin (Hb and xanthine oxidase (XO. HDL isolated by AE-HPLC had lower p-HDL levels than HDL in supernatants after apoB precipitation. XO+xanthine (X and cf Hb accelerated purified HDL oxidation. Although the plate and AE-HPLC assays both showed p-HDL directly correlated with cf-Hb in SCD plasma, the plate assay yielded p-HDL data that was influenced more by cf-Hb than AE-HPLC generated p-HDL data. The AE-HPLC p-HDL assay reduces the influence of the supernatants and shows that SCD increases p-HDL.

Anion exchange HPLC isolation of high-density lipoprotein (HDL) and on-line estimation of proinflammatory HDL.

Science.gov (United States)

Ji, Xiang; Xu, Hao; Zhang, Hao; Hillery, Cheryl A; Gao, Hai-Qing; Pritchard, Kirkwood A

2014-01-01

Proinflammatory high-density lipoprotein (p-HDL) is a biomarker of cardiovascular disease. Sickle cell disease (SCD) is characterized by chronic states of oxidative stress that many consider to play a role in forming p-HDL. To measure p-HDL, apolipoprotein (apo) B containing lipoproteins are precipitated. Supernatant HDL is incubated with an oxidant/LDL or an oxidant alone and rates of HDL oxidation monitored with dichlorofluorescein (DCFH). Although apoB precipitation is convenient for isolating HDL, the resulting supernatant matrix likely influences HDL oxidation. To determine effects of supernatants on p-HDL measurements we purified HDL from plasma from SCD subjects by anion exchange (AE) chromatography, determined its rate of oxidation relative to supernatant HDL. SCD decreased total cholesterol but not triglycerides or HDL and increased cell-free (cf) hemoglobin (Hb) and xanthine oxidase (XO). HDL isolated by AE-HPLC had lower p-HDL levels than HDL in supernatants after apoB precipitation. XO+xanthine (X) and cf Hb accelerated purified HDL oxidation. Although the plate and AE-HPLC assays both showed p-HDL directly correlated with cf-Hb in SCD plasma, the plate assay yielded p-HDL data that was influenced more by cf-Hb than AE-HPLC generated p-HDL data. The AE-HPLC p-HDL assay reduces the influence of the supernatants and shows that SCD increases p-HDL.

Nuclear magnetic resonance studies of lipoproteins

International Nuclear Information System (INIS)

Hamilton, J.A.; Morrisett, J.D.

1986-01-01

Several nuclei in lipoproteins are magnetically active and are thus potential NMR probes of lipoprotein structure. Table I lists the magnetic isotopes preset in the covalent structures of the molecular constituents of lipoproteins: lipids, proteins, and carbohydrates. Every type of nucleus that is part of the endogenous structure of these molecules has at least one magnetic isotope. Each magnetic nucleus represents an intrinsic and completely nonperturbing probe (when at the natural abundance level) of local molecular motion and magnetic environment. The NMR experiment itself is also nonperturbing and nondestructive. Table I also lists for each nucleus its nuclear spin, its natural isotopic abundance, its sensitivity, and its resonance frequency at two commonly employed magnetic in the low field range (21.14 kG or 2.11 Tesla) and the other in the high field range (47.0 kG or 4.70 Tesla). Of the nuclei listed in Table I, /sup 1/H, /sup 13/C, and /sup 31/P have been the primary ones studied in lipoproteins. The general advantages and disadvantages afforded by these and other nuclei as probes of lipoprotein structure are discussed. /sup 13/C NMR spectroscopy, the method which has had the most extensive application (and probably has the greatest future potential) to lipoproteins, is treated in greatest detail, but many of the principles described apply to other nuclei as well

Effect of methylglyoxal on the physico-chemical and biological properties of low-density lipoprotein

NARCIS (Netherlands)

Schalkwijk, C.G.; Vermeer, M.A.; Stehouwer, C.D.A.; Koppele, J. te; Princen, H.M.G.; Hinsbergh, V.W.M. van

1998-01-01

In patients with diabetes, non-enzymatic glycation of low-density lipoprotein (LDL) has been suggested to be involved in the development of atherosclerosis. α-Dicarbonyl compounds were identified as intermediates in the non-enzymatic glycation and increased levels were reported in patients with

[Measurement of sialic acid from lipoproteins and human plasma by liquid chromatography-tandem mass spectrometry].

Science.gov (United States)

Guo, Shoudong; Sang, Hui; Yang, Nana; Kan, Yujie; Li, Fuyu; Li, Yu; Li, Fangyuan; Qin, Shucun

2014-11-01

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established to quantify sialic acid (N-acetylneuraminic acid, NANA) from lipoproteins and human plasma. The method was used to investigate the different contents of NANA from lipoproteins between diabetic with an average age of 51.6 years and healthy participants with an average age of 50.7 years. The NANA from lipoprotein samples was hydrolyzed by acetic acid (pH = 2) at 80 °C for 2 h and analyzed by the optimized LC-MS/MS method after high speed centrifugation and filtration. The limits of detection and quantification of NANA were 7.4 and 24.5 pg, respectively. The linear range was 2.5-80 ng/mL for NANA and the correlation coefficient (R2) was more than 0.998. The levels of NANA in the plasma of type II diabetics and healthy participants were (548.3 ± 88.9) and (415.3 ± 55.5) mg/L, respectively; and the levels of NANA from very low density lipoproteins (VLDL), low density lipoproteins (LDL), and high density lipoproteins (HDL) of the type II diabetics and the healthy participants were (4.91 ± 0.19), (6.95 ± 0.28), (3.61 ± 0.22) μg/mg and (2.90 ± 0.27), (7.03 ± 0.04), (2.40 ± 0.09) μg/mg, respectively. The sialic acid levels of VLDL and HDL from the type II diabetics were markedly higher than those of the corresponding healthy participants with the similar ages (P lipoproteins, and is reproducible and time saving.

Low density lipoprotein receptors: preliminary results on 'in vivo' study

International Nuclear Information System (INIS)

Lupattelli, G.; Virgolini, I.; Li, S.R.; Sinzinger, H.

1991-01-01

Plasmatic levels of low density lipoproteins (LDL) are regulated by the receptor pathway and most LDL receptor are located in the liver. A receptor defect due to genetic mutations of the LDL receptor gene is the cause of familial hypercholesterolemia (F.H.), a disease characterized by high cholesterol levels and premature atherosclerosis. Injections of autologous radiolabelled LDL, followed by hepatic scintiscanning, can be used to obtain 'in vivo' quantification of hepatic receptor activity, both in normal and hypercholesterolemic patients. In this study we observe no hepatic increase of radioactivity in patients affected by F.H., confirming the liver receptor defect. Scintigraphy is a non-invasive technique which can be used to diagnose this disease and to monitor the efficiacy of hypolipidemic therapy. (Authors)

Hepatic apo B-100 lipoproteins and plasma LDL heterogeneity in African green monkeys

International Nuclear Information System (INIS)

Murthy, V.N.; Marzetta, C.A.; Rudel, L.L.; Zech, L.A.; Foster, D.M.

1990-01-01

The contribution of hepatic apolipoprotein (apo) B-100 lipoproteins to plasma low-density lipoprotein (LDL) metabolic heterogeneity was examined in African green monkeys. Hepatic 3H-labeled very low-density lipoproteins (VLDL) (d less than 1.006, where d is density in g/ml) or hepatic 131I-labeled LDL (1.030 less than d less than 1.063) were isolated from perfused livers and injected simultaneously with autologous plasma 125I-LDL into African green monkeys. Serial blood samples were taken, and the distribution of radioactivity among various subfractions of apo B-100 lipoproteins was determined using density-gradient ultracentrifugation. Compartmental models were developed to describe simultaneously the kinetics of hepatic lipoproteins and plasma LDL. In five of seven studies, the metabolic behavior of LDL derived from radiolabeled hepatic lipoprotein precursors differed from the metabolic behavior of radiolabeled autologous plasma LDL. These differences could be described by different models supporting two hypotheses with different physiological interpretations: (1) lipoproteins of donor and recipient animals are kinetically distinct, and/or (2) plasma LDL derived from various potential sources are kinetically distinct. Compartmental modeling was used to test these hypotheses, which were not accessible to testing by conventional experimental methodologies. The kinetic analyses of these studies suggest that plasma LDL may be derived from a variety of precursors, including hepatic VLDL and hepatic LDL, with each source giving rise to metabolically distinct plasma LDL

Improvement of Lipid Profile Is Accompanied by Atheroprotective Alterations in High-Density Lipoprotein Composition Upon Tumor Necrosis Factor Blockade A Prospective Cohort Study in Ankylosing Spondylitis

NARCIS (Netherlands)

Eijk, van I.C.; Vries, de M.K.; Levels, J.H.M.; Peters, M.J.L.; Huizer, E.E.; Dijkmans, B.A.C.; Horst - Bruinsma, van der I.E.; Hazenberg, B.P.C.; Stadt, van de R.J.; Wolbink, G.; Nurmohamed, M.T.

2009-01-01

Objective. Cardiovascular mortality is increased in ankylosing spondylitis (AS), and inflammation plays an important role. Inflammation deteriorates the lipid profile and alters high-density lipoprotein cholesterol (HDL-c) composition, reflected by increased concentrations of serum amyloid A (SAA)

Biomedicinal implications of high-density lipoprotein: its composition, structure, functions, and clinical applications.

Science.gov (United States)

Cho, Kyung-Hyun

2009-07-31

High-density lipoprotein (HDL) is a proven biomarker for the monitoring of changes in antioxidant and anti-inflammation capability of body fluids. The beneficial virtues of HDL are highly dependent on its lipids and protein compositions, and their ratios. In normal state, the HDL particle is enriched with lipids and several HDL-associated enzymes, which are responsible for its antioxidant activity. Lower HDL-cholesterol levels (40 mg/dL) have been recognized as an independent risk factor for coronary artery disease, as well as being a known component of metabolic syndrome. Functional and structural changes of HDL have been recognized as factors pivotal to the evaluation of HDL-quality. In this review, I have elected to focus on the functional and structural correlations of HDL and the roles of HDL-associated apolipoproteins and enzymes. Recent clinical applications of HDL have also been reviewed, particularly the therapeutic targeting of HDL metabolism and reconstituted HDL; these techniques represent promising emerging strategies for the treatment of cardiovascular disease, for drug or gene therapy.

Familial lipoprotein lipase deficiency

Science.gov (United States)

... lack an enzyme called lipoprotein lipase. Without this enzyme, the body cannot break down fat from digested food. Fat particles called chylomicrons build up in the blood. Risk factors include a family history of lipoprotein lipase deficiency. The condition is usually ...

In vitro studies of PBT Nonwoven Fabrics adsorbent for the removal of low density lipoprotein from hyperlipemia plasma

Energy Technology Data Exchange (ETDEWEB)

Cao Ye; Wang Hong [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610052 (China); Yang Chao [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhong Rui [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610052 (China); Lei Yu [Chengdu Blood Center, Chengdu 610041 (China); Sun Kang [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu Jiaxin, E-mail: jxliu8122@vip.sina.com [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610052 (China)

2011-06-15

Polyanion ligands such as acrylic acid (AA) and heparin were grafted on PBT Nonwoven Fabrics (PBTNF) to study their effect on the adsorption of low density lipoprotein (LDL). These modified PBTNFs were characterized by Horizontal Attenuated Total Reflectance Fourier Transform Infrared spectroscopy and X-ray Photoelectron spectroscopy. The blood compatibilities of the modified PBTNFs were examined using in vitro hemolysis rate (HR), platelet adhesion, total protein (TP) and activated partial thromboplastin time. The results showed that direct immobilized heparin could improve PBTNF-PAA's blood compatibility and decrease the adsorption capability of useful high density lipoprotein, but would possess so low bioactivity that could not further improve the absorption of LDL and TC. Since the PBTNF-PAA55-Heparin adsorbent had quite good adsorption selectivity for these proteins, it can be an excellent candidate for depletion of LDL with good blood compatibility.

Synthetic Lipoproteins as Carriers for Drug Delivery.

Science.gov (United States)

Huang, Gangliang; Liu, Yang; Huang, Hualiang

2016-01-01

Synthetic lipoprotein is an effective carrier of targeted delivery for drugs. It has the very small size, good biocompatibility, suitable half-life, and specific lipoprotein receptorbinding capacity. Compared with the traditional natural lipoprotein, synthetic lipoprotein not only retains the original biological characteristics and functions, but also exhibits the excellent characteristics in drug delivery. Herein, the advantages, development, applications, and prospect of synthetic lipoproteins as drug carriers were summarized.

Low density lipoprotein receptor-related protein 1 expression correlates with cholesteryl ester accumulation in the myocardium of ischemic cardiomyopathy patients

Directory of Open Access Journals (Sweden)

Cal Roi

2012-08-01

Full Text Available Abstract Our hypothesis was that overexpression of certain lipoprotein receptors might be related to lipid accumulation in the human ischemic myocardium. Intramyocardial lipid overload contributes to contractile dysfunction and arrhythmias in cardiomyopathy. Thus, the purpose of this study was to assess the effect of hypercholesterolemic LDL and hypertrigliceridemic VLDL dose on LRP1 expression in cardiomyocytes, as well as the potential correlation between LRP1 expression and neutral lipid accumulation in the left ventricle tissue from ischemic cardiomyopathy patients. Cell culture experiments include control and LRP1-deficient cardiomyocytes exposed to lipoproteins under normoxic and hypoxic conditions. Explanted hearts from 18 ICM patients and eight non-diseased hearts (CNT were included. Low density lipoprotein receptor-related protein 1 (LRP1, very low density lipoprotein receptor (VLDLR and low density lipoprotein receptor (LDLR expression was analyzed by real time PCR and Western blotting. Cholesteryl ester (CE, triglyceride (TG and free cholesterol (FC content was assess by thin layer chromatography following lipid extraction. Western blotting experiments showed that protein levels of LRP1, VLDLR and HIF-1α were significantly upregulated in ischemic hearts. Immunohistochemistry and confocal microscopy analysis showed that LRP1 and HIF-1α were upregulated in cardiomyocytes of ICM patients. In vitro studies showed that VLDL, LDL and hypoxia exerted an upregulatory effect on LRP1 expression and that LRP1 played a major role in cholesteryl ester accumulation from lipoproteins in cardiomyocytes. Myocardial CE accumulation strongly correlated with LRP1 levels in ischemic hearts. Taken together, our results suggest that LRP1 upregulation is key for myocardial cholesterol ester accumulation in ischemic human hearts and that LRP1 may be a target to prevent the deleterious effects of myocardial cholesterol accumulation in ischemic cardiomyopathy.

Accumulation of Oxidized Low-Density Lipoprotein in Psoriatic Skin and Changes of Plasma Lipid Levels in Psoriatic Patients

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Nilgun Solak Tekin

2007-01-01

Full Text Available Background. Psoriasis is a chronic inflammatory skin disease characterized by an accelerated turnover of epidermal cells and an incomplete differentiation in epidermis with lesion. However, the exact etiology of psoriasis is unknown. Abnormalities in essential fatty acid metabolism, free radical generation, lipid peroxidation, and release of lymphokines have been proposed. Objective. Our purpose was to evaluate the plasma lipids and oxidized low-density lipoprotein accumulation in psoriatic skin lesion in order to ascertain the possible participation of oxidative stress and oxidative modification of lipids in pathogenesis of psoriasis. Methods. The study group included 84 patients with psoriasis, and 40 sex- and age-matched healthy volunteers. Blood lipid profile was determined. Psoriatic and nonlesional skin samples of psoriatic patients were evaluated for the presence of oxidized low-density lipoprotein by using an immune-fluorescent staining method. Results. The mean levels of lipids (total cholesterol, triglyceride, and LDL cholesterol in patients with psoriasis were found to be significantly higher than those of healthy subjects. Psoriatic skins were shown positive oxidized low-density lipoprotein staining. There was no staining in nonlesional skin samples of the same individuals. Conclusion. Lipid peroxidation mediated by free radicals is believed to be one of the important causes of cell membrane destruction and cell damage. This study shows for the first time the accumulation of oxidized low-density lipoprotein in psoriatic skin lesion. We believe that accumulation of ox-LDL in psoriatic skin may have an important role in the immune-inflammatory events that result in progressive skin damage.

Genetics of non-conventional lipoprotein fractions

Science.gov (United States)

Lipoprotein subclass measures associate with cardiometabolic disease risk. Currently the information that lipoproteins convey on disease risk over that of traditional demographic and lipid measures is minimal, and so their use is clinics is limited. However, lipoprotein subclass perturbations repres...

Improving lipoprotein profiles by liver-directed gene transfer of low ...

Indian Academy of Sciences (India)

cesses, where a myriad of proteins necessary for metabolism and immune .... containing 5% nonfat milk for several hours, the membrane .... high-density lipoprotein cholesterol; mice were fed with a high fat diet (21% fat, 0.15% choles- terol).

Determining the risk of cardiovascular disease using ion mobility of lipoproteins

Science.gov (United States)

Benner, W. Henry; Krauss, Ronald M.; Blanche, Patricia J.

2010-05-11

A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

Preferential enrichment of large-sized very low density lipoprotein populations with transferred cholesteryl esters

International Nuclear Information System (INIS)

Eisenberg, S.

1985-01-01

The effect of lipid transfer proteins on the exchange and transfer of cholesteryl esters from rat plasma HDL2 to human very low (VLDL) and low density (LDL) lipoprotein populations was studied. The use of a combination of radiochemical and chemical methods allowed separate assessment of [ 3 H]cholesteryl ester exchange and of cholesteryl ester transfer. VLDL-I was the preferred acceptor for transferred cholesteryl esters, followed by VLDL-II and VLDL-III. LDL did not acquire cholesteryl esters. The contribution of exchange of [ 3 H]cholesteryl esters to total transfer was highest for LDL and decreased in reverse order along the VLDL density range. Inactivation of lecithin: cholesterol acyltransferase (LCAT) and heating the HDL2 for 60 min at 56 degrees C accelerated transfer and exchange of [ 3 H]cholesteryl esters. Addition of lipid transfer proteins increased cholesterol esterification in all systems. The data demonstrate that large-sized, triglyceride-rich VLDL particles are preferred acceptors for transferred cholesteryl esters. It is suggested that enrichment of very low density lipoproteins with cholesteryl esters reflects the triglyceride content of the particles

Revisiting the gram-negative lipoprotein paradigm

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The processing of lipoproteins (lpps) in Gram-negative bacteria is generally considered to be an essential pathway. Mature lipoproteins in these bacteria are triacylated, with the final fatty acid addition performed by Lnt, an apolipoprotein n-acyltransferase. The mature lipoproteins are then sorted...

Effect of bicarbonate on iron-mediated oxidation of low-density lipoprotein

Science.gov (United States)

Arai, Hirofumi; Berlett, Barbara S.; Chock, P. Boon; Stadtman, Earl R.

2005-07-01

Oxidation of low-density lipoprotein (LDL) may play an important role in atherosclerosis. We studied the effects of bicarbonate/CO2 and phosphate buffer systems on metal ion-catalyzed oxidation of LDL to malondialdehyde (MDA) and to protein carbonyl and MetO derivatives. Our results revealed that LDL oxidation in mixtures containing free iron or heme derivatives was much greater in bicarbonate/CO2 compared with phosphate buffer. However, when copper was substituted for iron in these mixtures, the rate of LDL oxidation in both buffers was similar. Iron-catalyzed oxidation of LDL was highly sensitive to inhibition by phosphate. Presence of 0.3-0.5 mM phosphate, characteristic of human serum, led to 30-40% inhibition of LDL oxidation in bicarbonate/CO2 buffer. Iron-catalyzed oxidation of LDL to MDA in phosphate buffer was inhibited by increasing concentrations of albumin (10-200 μM), whereas MDA formation in bicarbonate/CO2 buffer was stimulated by 10-50 μM albumin but inhibited by higher concentrations. However, albumin stimulated the oxidation of LDL proteins to carbonyl derivatives at all concentrations examined in both buffers. Conversion of LDL to MDA in bicarbonate/CO2 buffer was greatly stimulated by ADP, ATP, and EDTA but only when EDTA was added at a concentration equal to that of iron. At higher than stoichiometric concentrations, EDTA prevented oxidation of LDL. Results of these studies suggest that interactions between bicarbonate and iron or heme derivatives leads to complexes with redox potentials that favor the generation of reactive oxygen species and/or to the generation of highly reactive CO2 anion or bicarbonate radical that facilitates LDL oxidation. Freely available online through the PNAS open access option.Abbreviations: LDL, low-density lipoprotein; MDA, malondialdehyde; MetO, methionine sulfoxide.

Gold nanocrystal labeling allows low-density lipoprotein imaging from the subcellular to macroscopic level

NARCIS (Netherlands)

Allijn, Iris E.; Leong, Wei; Tang, Jun; Gianella, Anita; Mieszawska, Aneta J.; Fay, Francois; Ma, Ge; Russell, Stewart; Callo, Catherine B.; Gordon, Ronald E.; Korkmaz, Emine; Post, Jan Andries; Zhao, Yiming; Gerritsen, Hans C.; Thran, Axel; Proksa, Roland; Daerr, Heiner; Storm, Gert; Fuster, Valentin; Fisher, Edward A.; Fayad, Zahi A.; Mulder, Willem J. M.; Cormode, David P.

2013-01-01

Low-density lipoprotein (LDL) plays a critical role in cholesterol transport and is closely linked to the progression of several diseases. This motivates the development of methods to study LDL behavior from the microscopic to whole-body level. We have developed an approach to efficiently load LDL

Glycated albumin and direct low density lipoprotein cholesterol levels in type 2 diabetes mellitus

Science.gov (United States)

Diabetes mellitus is a major risk factor for coronary heart disease (CHD), renal failure, retinopathy, and neuropathy. Lowering glycosylated hemoglobin (HbA1c) as well as low-density lipoprotein-cholesterol (LDL-C) has been associated with a decreased risk of these complications. We evaluated the ut...

Lipoprotein(a Serum Levels in Diabetic Patients with Retinopathy

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Giulia Malaguarnera

2013-01-01

Full Text Available Background. Atherogenic lipoproteins, such as total cholesterol, LDL cholesterol, oxidized low density lipoprotein, and triglycerides, are associated with progression of retinopathy. Aim. To evaluate the relationship between lipoprotein(a and retinopathy in patients with type 2 diabetes mellitus. Materials and Methods. We enrolled 145 diabetic consecutive patients (82 females, 63 males; mean age 66.8±12 years, mean duration of diabetes 9.4±6.8 years. Presence and severity of retinopathy were evaluated. Serum lipid profile, including Lp(a level, was assessed. Results. High Lp(a levels have been observed in 54 (78.3% subjects and normal levels in 13 (18.85% subjects as regards diabetic patients with retinopathy. Lp(a levels were high in 15 subjects (21.75% and normal in 63 subjects (91.35% as regards patients without retinopathy. Conclusions. Lp(a levels are increased in a significant percentage of patients with retinopathy compared to diabetic patients without retinopathy. The impact of Lp(a levels on diabetic retinopathy needs to be further investigated.

Lipoprotein subclasses in the Monitored Atherosclerosis Regression Study (MARS). Treatment effects and relation to coronary angiographic progression.

Science.gov (United States)

Mack, W J; Krauss, R M; Hodis, H N

1996-05-01

Accumulating evidence suggests that triglyceride-rich lipoproteins contribute to coronary artery disease. Using data from the Monitored Atherosclerosis Regression Study, an angiographic trial of middle-aged men and women randomized to lovastatin or placebo, we investigated relationships between lipoprotein subclasses and progression of coronary artery atherosclerosis. Coronary artery lesion progression was determined by quantitative coronary angiography in low-grade ( or = 50% diameter stenosis), and all coronary artery lesions in 220 baseline/2-year angiogram pairs. Analytical ultracentrifugation was used to measure lipoprotein masses that were statistically evaluated for treatment group differences and relationships to progression of coronary artery atherosclerosis. All low density lipoprotein (LDL), intermediate density lipoprotein (IDL), and very low density lipoprotein (VLDL) masses were significantly lowered and all high density lipoprotein (HDL) masses were significantly raised with lovastatin therapy. The mass of smallest LDL (Svedberg flotation rate [Sf] 0 to 3), IDL (Sf 12 to 20), all VLDL subclasses (Sf 20 to 60, Sf 60 to 100, and Sf 100 to 400), and peak LDL flotation rate were significantly related to the progression of coronary artery lesions, specifically low-grade lesions. Greater baseline levels of HDL3, were related to a lower likelihood of coronary artery lesion progression. In multivariate analyses, small VLDL (Sf 20 to 60) and HDL3 mass were the most important correlates of coronary artery lesion progression. These results provide further evidence for the importance of triglyceride-rich lipoproteins in the progression of coronary artery disease. In addition, these results present new evidence for the possible protective role of HDL3 in the progression of coronary artery lesions. More specific information on coronary artery lesion progression may be obtained through the study of specific apolipoprotein B-containing lipoproteins.

The multiligand α₂-macroglobulin receptor/low density lipoprotein receptor-related protein

DEFF Research Database (Denmark)

Gliemann, Jørgen; Nykjær, Anders; Petersen, Claus Munck

1994-01-01

The fusion of separate lines of research has greatly helped in elucidating the function of the giant members of the low density lipoprotein (LDL) receptor (LDLR) supergene family. The cDNA encoding a large protein structurally closely related to LDLR, and hence named LDLR-related protein (LRP......), was cloned by Herz et al. in 1988.'Evidence was provided demonstrating that LRP can function as a receptor for chylomicron remnants@-migrating very low density lipoproteins (P-VLDL) rich in apolipoprotein E (apoE)?' The a2-macroglobulin (a2M) receptor (a2MR) was purified from rat livep and human p l a~e n t...... from the observation that affinity-purified a2MR/LRP contains a 40-kDa5.8 or 39-kDa6.' protein, designated a2MRAP, in addition to the a2MFULRP a- and P-chains. cDNA cloning" disclosed the 323-residue protein as both the human homologue of mouse heparin binding protein 44 (see reference 11) and...

Classifying lipoproteins based on their polar profiles.

Science.gov (United States)

Polanco, Carlos; Castañón-González, Jorge Alberto; Buhse, Thomas; Uversky, Vladimir N; Amkie, Rafael Zonana

2016-01-01

The lipoproteins are an important group of cargo proteins known for their unique capability to transport lipids. By applying the Polarity index algorithm, which has a metric that only considers the polar profile of the linear sequences of the lipoprotein group, we obtained an analytical and structural differentiation of all the lipoproteins found in UniProt Database. Also, the functional groups of lipoproteins, and particularly of the set of lipoproteins relevant to atherosclerosis, were analyzed with the same method to reveal their structural preference, and the results of Polarity index analysis were verified by an alternate test, the Cumulative Distribution Function algorithm, applied to the same groups of lipoproteins.

Genetic determinants of LDL, lipoprotein(a), triglyceride-rich lipoproteins and HDL: concordance and discordance with cardiovascular disease risk

DEFF Research Database (Denmark)

Nordestgaard, Børge G; Tybjærg-Hansen, Anne

2011-01-01

To evaluate whether new and known genetic determinants of plasma levels of LDL cholesterol, lipoprotein(a), triglyceride-rich lipoproteins, and HDL cholesterol associate with the risk of cardiovascular disease expected from the effect on lipoprotein levels. Concordance or discordance...... of such genetic determinants with cardiovascular disease risk will either favor or disfavor that these lipoproteins are causally related to cardiovascular disease....

Low-density lipoprotein electronegativity is a novel cardiometabolic risk factor.

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Jing-Fang Hsu

Full Text Available BACKGROUND: Low-density lipoprotein (LDL plays a central role in cardiovascular disease (CVD development. In LDL chromatographically resolved according to charge, the most electronegative subfraction-L5-is the only subfraction that induces atherogenic responses in cultured vascular cells. Furthermore, increasing evidence has shown that plasma L5 levels are elevated in individuals with high cardiovascular risk. We hypothesized that LDL electronegativity is a novel index for predicting CVD. METHODS: In 30 asymptomatic individuals with metabolic syndrome (MetS and 27 healthy control subjects, we examined correlations between plasma L5 levels and the number of MetS criteria fulfilled, CVD risk factors, and CVD risk according to the Framingham risk score. RESULTS: L5 levels were significantly higher in MetS subjects than in control subjects (21.9±18.7 mg/dL vs. 11.2±10.7 mg/dL, P:0.01. The Jonckheere trend test revealed that the percent L5 of total LDL (L5% and L5 concentration increased with the number of MetS criteria (P<0.001. L5% correlated with classic CVD risk factors, including waist circumference, body mass index, waist-to-height ratio, smoking status, blood pressure, and levels of fasting plasma glucose, triglyceride, and high-density lipoprotein. Stepwise regression analysis revealed that fasting plasma glucose level and body mass index contributed to 28% of L5% variance. The L5 concentration was associated with CVD risk and contributed to 11% of 30-year general CVD risk variance when controlling the variance of waist circumference. CONCLUSION: Our findings show that LDL electronegativity was associated with multiple CVD risk factors and CVD risk, suggesting that the LDL electronegativity index may have the potential to be a novel index for predicting CVD. Large-scale clinical trials are warranted to test the reliability of this hypothesis and the clinical importance of the LDL electronegativity index.

Use of 3H-colesterol and its kinetics to assess the dynamics of the cholesterol metabolism in human lipoprotein fractions

International Nuclear Information System (INIS)

Grossmann, K.D.; Marek, H.; Fieber, R.S.

1982-01-01

The assessment of the dynamics of 3 H cholesterols in very low, low and high density lipoproteins, resp. lipoproteins after oral administration in normal subjects and in patients with hyperlipoproteinemia type II a and II b is described. Specific activity-time-curves of the lipoprotein fractions isolated by means of discontinuous ultracentrifugation were recorded. In order to optimize the centrifugation activity-electrophoresis-profiles of the separating steps were recorded. The fractions obtained were characterized by the determination of cholesterol, agarose electrophoresis and radioactivity measurement. The turnover of the tracer in the lipoproteins was determined on the basis of the maximum values of the specific activity-time-curves. Hyperlipoproteinemia patients showed time shifts of the maximum values especially with regard to esterized cholesterols and high density lipoprotein cholesterol as compared to healthy persons. (author)

Receptor-mediated uptake of low density lipoprotein stimulates bile acid synthesis by cultured rat hepatocytes

International Nuclear Information System (INIS)

Junker, L.H.; Davis, R.A.

1989-01-01

The cellular mechanisms responsible for the lipoprotein-mediated stimulation of bile acid synthesis in cultured rat hepatocytes were investigated. Adding 280 micrograms/ml of cholesterol in the form of human or rat low density lipoprotein (LDL) to the culture medium increased bile acid synthesis by 1.8- and 1.6-fold, respectively. As a result of the uptake of LDL, the synthesis of [14C]cholesterol from [2-14C]acetate was decreased and cellular cholesteryl ester mass was increased. Further studies demonstrated that rat apoE-free LDL and apoE-rich high density lipoprotein (HDL) both stimulated bile acid synthesis 1.5-fold, as well as inhibited the formation of [14C]cholesterol from [2-14C]acetate. Reductive methylation of LDL blocked the inhibition of cholesterol synthesis, as well as the stimulation of bile acid synthesis, suggesting that these processes require receptor-mediated uptake. To identify the receptors responsible, competitive binding studies using 125I-labeled apoE-free LDL and 125I-labeled apoE-rich HDL were performed. Both apoE-free LDL and apoE-rich HDL displayed an equal ability to compete for binding of the other, suggesting that a receptor or a group of receptors that recognizes both apolipoproteins is involved. Additional studies show that hepatocytes from cholestyramine-treated rats displayed 2.2- and 3.4-fold increases in the binding of apoE-free LDL and apoE-rich HDL, respectively. These data show for the first time that receptor-mediated uptake of LDL by the liver is intimately linked to processes activating bile acid synthesis

Characterization of blood lipoproteins and validation of cholesterol and triacylglycerol assays for free-ranging polar bears (Ursus maritimus).

Science.gov (United States)

Whiteman, John P; Frank, Nicholas; Greller, Katie A; Harlow, Henry J; Ben-David, Merav

2013-05-01

Blood triacylglycerol (TG) and lipoproteins are important variables for evaluating nutritional status of wildlife, but measurements are often expensive and difficult. Performance of a small, portable blood analyzer intended for human medical diagnostics was evaluated in measuring these variables in plasma and serum from free-ranging polar bears (Ursus maritimus), which are experiencing nutritional stress related to sea ice loss. The analyzer accurately tracked changes in concentration of total cholesterol (Ctotal), cholesterol associated with high-density lipoprotein (CHDL), and TG during a validation protocol of diluting samples and spiking them with exogenous cholesterol and glycerol. Values of Ctotal and TG agreed well with values obtained by other methods (ultracentrifugation followed by colorimetric assays); agreement was variable for values of cholesterol associated with specific lipoproteins. Similar to a study of captive polar bears, ultracentrifugation methods revealed greater TG in very low-density lipoproteins than in low-density lipoprotein, which is unusual and merits additional study.

Small high-density lipoprotein (HDL) subclasses are increased with decreased activity of HDL-associated phospholipase A₂ in subjects with prediabetes.

Science.gov (United States)

Filippatos, Theodosios D; Rizos, Evangelos C; Tsimihodimos, Vasilios; Gazi, Irene F; Tselepis, Alexandros D; Elisaf, Moses S

2013-06-01

Alterations in high-density lipoprotein (HDL) subclass distribution, as well as in the activities of HDL-associated enzymes, have been associated with increased cardiovascular disease (CVD) risk. HDL subclass distribution and the activities of HDL-associated enzymes remain unknown in prediabetic patients, a condition also associated with increased CVD risk. The aim of the present study was to assess any differences in HDL subclass distribution (using polyacrylamide gel electrophoresis) and in activities of HDL-associated enzymes between prediabetic (impaired fasting glucose, IFG, n = 80) and non-prediabetic subjects (n = 105). Subjects with prediabetes had significantly increased waist circumference, blood pressure and triacylglycerol (TAG) levels compared with subjects with fasting glucose levels prediabetic subjects compared with their controls (p prediabetes (p prediabetes. In a stepwise linear regression analysis, the proportion of small HDL3 over HDL-C concentration was independently associated with the presence of prediabetes and with total cholesterol and TAG concentration (positively), as well as with HDL-C levels (negatively). We also observed a trend of increased small dense low-density lipoprotein cholesterol levels in prediabetic subjects compared with their controls. Subjects with IFG exhibit increased proportion of small HDL3 particles combined with decreased activity of the anti-atherogenic HDL-LpPLA₂.

Reversible flow of cholesteryl ester between high-density lipoproteins and triacylglycerol-rich particles is modulated by the fatty acid composition and concentration of triacylglycerols

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E.C.R. Quintão

2010-12-01

Full Text Available We determined the influence of fasting (FAST and feeding (FED on cholesteryl ester (CE flow between high-density lipoproteins (HDL and plasma apoB-lipoprotein and triacylglycerol (TG-rich emulsions (EM prepared with TG-fatty acids (FAs. TG-FAs of varying chain lengths and degrees of unsaturation were tested in the presence of a plasma fraction at d > 1.21 g/mL as the source of CE transfer protein. The transfer of CE from HDL to FED was greater than to FAST TG-rich acceptor lipoproteins, 18% and 14%, respectively. However, percent CE transfer from HDL to apoB-containing lipoproteins was similar for FED and FAST HDL. The CE transfer from HDL to EM depended on the EM TG-FA chain length. Furthermore, the chain length of the monounsaturated TG-containing EM showed a significant positive correlation of the CE transfer from HDL to EM (r = 0.81, P < 0.0001 and a negative correlation from EM to HDL (r = -041, P = 0.0088. Regarding the degree of EM TG-FAs unsaturation, among EMs containing C18, the CE transfer was lower from HDL to C18:2 compared to C18:1 and C18:3, 17.7%, 20.7%, and 20%, respectively. However, the CE transfer from EMs to HDL was higher to C18:2 than to C18:1 and C18:3, 83.7%, 51.2%, and 46.3%, respectively. Thus, the EM FA composition was found to be the rate-limiting factor regulating the transfer of CE from HDL. Consequently, the net transfer of CE between HDL and TG-rich particles depends on the specific arrangement of the TG acyl chains in the lipoprotein particle core.

A cross-linking study on the particle species of human plasma high density lipoproteins.

Science.gov (United States)

Yachida, Y; Minari, O

1983-08-01

The present investigation was on the particle species of human plasma high density lipoprotein (HDL) characterized by the stoichiometry of their apoprotein components. HDL2-1, HDL2-2, HDL3-1, and HDL3-2 isolated from normal human plasma by sequential ultracentrifugal flotation were further subfractionated by Bio Gel A-5m gel chromatography or hydroxyapatite column chromatography, and three distinct subfractions were obtained. Subfraction 1 was obtained from all the HDL fractions and it contained mostly apolipoprotein A-I (A-I). Subfraction 2 was obtained from HDL2-2 and HDL3-1 and it contained A-I and apolipoprotein A-II (A-II) in the molar ratio of one to one, and subfraction 3 from HDL2-2 and HDL3-1 contained A-I and apolipoprotein C (C). Each subfraction was treated with bifunctional cross-linking reagents, and the intraparticle cross-linked products of apolipoproteins were examined by SDS-polyacrylamide gel electrophoresis. The results of the cross-linking studies indicated that the HDL2 fraction consisted mainly of lipoprotein particles of the (A-I)4 type and a few of the (A-I)5, (A-I)2(A-II)2, and (A-I)4(C)2 types, and that the HDL3 fraction consisted mainly of (A-I)2(A-II)2 type particles and a few (A-I)4, (A-I)3, (A-I)2, (A-I), and (A-I)3(C)2 type particles. From the results of analyses of the lipid components in the HDL of each type, it was suggested that the function of the particle species of the (A-I)n type (n = 1--5), which contained more cholesteryl ester than the (A-I)2(A-II)2 type, was concerned mainly with cholesterol metabolism.

Serum lipids and lipoproteins in patients with psoriasis.

Science.gov (United States)

Taheri Sarvtin, Mehdi; Hedayati, Mohammad Taghi; Shokohi, Tahereh; HajHeydari, Zohreh

2014-05-01

Psoriasis is a common chronic and recurrent inflammatory skin disorder characterized by hyperproliferation of keratinocytes and infiltration of T cells, monocytes/macrophages and neutrophils into dermal and epidermal layers of the skin. The prevalence of cardiovascular disorders in these patients is remarkably higher compared to normal individuals, which seems to be associated with the hyperlipidemia. This study was designed and conducted to investigate the serum lipid profile in psoriatic patients and its association with the severity of disease. This case-control study was performed on 50 plaque-type psoriasis patients and 50 healthy individuals as control, matched for age and sex. Blood samples were collected after 14 h fasting. Serum triglyceride, cholesterol and lipoproteins were assayed using the standard kit (made by Pars Azmon Co. Iran). Certain parameters, including serum triglyceride, cholesterol, low density lipoprotein (LDL), and very low density lipoprotein (VLDL), were significantly higher in the case group compared to the controls (P lipoprotein (HDL) was significantly lower in the former (P < 0.001). In addition, there was a significant relationship between severity of psoriasis and serum lipid profile. The results have revealed the higher plasma level of lipids in psoriatic patients. This may elevate the risk of atherosclerosis, particularly cardiovascular disorders. Therefore, from the epidemiological point of view, screening psoriatic patients, particularly those with severe psoriasis, is recommended.

Structure and motion of phospholipids in human plasma lipoproteins. A 31P NMR study

International Nuclear Information System (INIS)

Fenske, D.B.; Chana, R.S.; Parmar, Y.I.; Treleaven, W.D.; Cushley, R.J.

1990-01-01

The structure and motion of phospholipids in human plasma lipoproteins have been studied by using 31 P NMR. Lateral diffusion coefficients, D T , obtained from the viscosity dependence of the 31 P NMR line widths, were obtained for very low density lipoprotein (VLDL), low-density lipoprotein (LDL), high-density lipoproteins (HDL 2 , HDL 3 ), and egg PC/TO microemulsions at 25 degree C, for VLDL at 40 degree C, and for LDL at 45 degree C. In order to prove the orientation and/or order of the phospholipid head-group, estimates of the residual chemical shift anistropy, Δσ, have been obtained for all the lipoproteins and the microemulsions from the viscosity and field dependence for the 31 P NMR line widths. These results suggest differences in the orientation and/or ordering of the head-group in the HDLs. The dynamic behavior of the phosphate moiety in LDL and HDL 3 has been obtained from the temperature dependence of the 31 P spin-lattice relaxation rates. Values of the correlation time for phosphate group reorientation and the activation energy for the motion are nearly identical in LDL and HDL 3 and are similar to values obtained for phospholipid bilayers. This argues against long-lived protein-lipid interactions being the source of either the slow diffusion in LDL or the altered head-group orientation in the HDLs

Apolipoprotein(a) phenotypes and lipoprotein(a) concentrations in patients with hyperthyroidism

DEFF Research Database (Denmark)

Klausen, I C; Hegedüs, L; Hansen, P S

1995-01-01

Lipoprotein(a) [Lp(a)] is a low-density lipoprotein (LDL) particle in which apolipoprotein B-100 (apoB) is attached to a glycoprotein called apolipoprotein(a) [apo(a)]. Apo(a) has several genetically determined phenotypes differing in molecular weight, to which Lp(a) concentrations in plasma are ...

Comparative reactivity of the myeloperoxidase-derived oxidants HOCl and HOSCN with low-density lipoprotein (LDL)

DEFF Research Database (Denmark)

Ismael, Fahd O; Proudfoot, Julie M; Brown, Bronwyn E

2015-01-01

Atherosclerosis is characterised by the accumulation of lipids within macrophages in the artery wall. Low-density lipoprotein (LDL) is the source of this lipid, owing to the uptake of oxidised LDL by scavenger receptors. Myeloperoxidase (MPO) released by leukocytes during inflammation produces ox...

Association of triglyceride-rich lipoproteins-related markers and low-density lipoprotein heterogeneity with cardiovascular risk: effectiveness of polyacrylamide-gel electrophoresis as a method of determining low-density lipoprotein particle size.

Science.gov (United States)

Tani, Shigemasa; Matsumoto, Michiaki; Nagao, Ken; Hirayama, Atsushi

2014-01-01

Despite well-controlled low-density lipoprotein cholesterol (LDL-C), hypertriglyceridemia is an independent predictor of coronary events. We investigated the risk of atherosclerotic cardiovascular disease through examining the relation between triglyceride (TG) metabolism and LDL-heterogeneity as assessed by polyacrylamide-gel electrophoresis (PAGE). Estimated LDL-particle size [relative LDL migration (LDL-Rm value)] measured by PAGE with the LipoPhor system (Joko, Tokyo, Japan) was evaluated in 645 consecutive patients with one additional risk factor for atherosclerotic cardiovascular disease.Multivariate regression analysis after adjustments for traditional risk factors revealed an elevated triglyceride-rich lipoproteins (TRLs)-related markers [TG, remnant-like particle cholesterol (RLP-C), very LDL (VLDL) fraction, apolipoprotein (apo) C-II, and apo C-III] level to be an independent predictor of smaller-size LDL-particle size, both in the overall population, and in a subset of patients with serum LDL-C <100 mg/dL. Even among the patients with LDL-C levels <100 mg/dL, the serum levels of atherogenic lipid markers in those with a LDL-Rm value ≥0.40, suggesting the presence of large amounts of small-dense LDL and upper limit (mean+2 standard deviation) in this population, were significantly higher than in those with a LDL-Rm value <0.40. Moreover, the serum levels of TRLs-related markers showed high accurate area under the receiver-operating characteristic curve (TG, 0.896; RLP-C, 0.875; VLDL fraction, 0.803; apo C-II, 0.778; and apo C-III, 0.804, respectively) in terms of evaluation of the indicators of LDL-Rm value ≥0.40. To further reduce the risk of atherosclerotic cardiovascular disease, it may be of particular importance to pay attention not only to the quantitative change in the serum LDL-C, but also TG-metabolism associated with LDL-heterogeneity. Combined evaluation of TRLs-related markers and LDL-Rm value may be useful for assessing the risk of

Experimental atheromatous plaque imaging with 99mTc labelled low density lipoproteins in rabbit

International Nuclear Information System (INIS)

Wang Quanshi; Chen Yu; Wu Chunshan; Zhang Yijin; Liu Dexuan

1996-01-01

Atheromatous plaque imaging with 99m Tc labeled low density lipoproteins ( 99m Tc-LDL) were evaluated in rabbits for its clinical prospect. The 99m Tc-LDL atheromatous plaque imaging were performed in 9 rabbit models of atherosclerosis and 4 controls. The imagings were compared with autoradiographic and pathological results. The rabbit models of atherosclerosis by high cholesterol and high fat diet were successful in 100%. The atheromatous plaques well visualized in 8 of 9 rabbit models 24 hours after injection. The site and density of radioactive accumulation was closely correlated in autoradiography also. There was no radioactive spot in 4 controls. 99m Tc-LDL imaging may have a significant value for the diagnosis of atherosclerosis

Human endothelial progenitor cells internalize high-density lipoprotein.

Directory of Open Access Journals (Sweden)

Kaemisa Srisen

Full Text Available Endothelial progenitor cells (EPCs originate either directly from hematopoietic stem cells or from a subpopulation of monocytes. Controversial views about intracellular lipid traffic prompted us to analyze the uptake of human high density lipoprotein (HDL, and HDL-cholesterol in human monocytic EPCs. Fluorescence and electron microscopy were used to investigate distribution and intracellular trafficking of HDL and its associated cholesterol using fluorescent surrogates (bodipy-cholesterol and bodipy-cholesteryl oleate, cytochemical labels and fluorochromes including horseradish peroxidase and Alexa Fluor® 568. Uptake and intracellular transport of HDL were demonstrated after internalization periods from 0.5 to 4 hours. In case of HDL-Alexa Fluor® 568, bodipy-cholesterol and bodipy-cholesteryl oleate, a photooxidation method was carried out. HDL-specific reaction products were present in invaginations of the plasma membrane at each time of treatment within endocytic vesicles, in multivesicular bodies and at longer periods of uptake, also in lysosomes. Some HDL-positive endosomes were arranged in form of "strings of pearl"- like structures. HDL-positive multivesicular bodies exhibited intensive staining of limiting and vesicular membranes. Multivesicular bodies of HDL-Alexa Fluor® 568-treated EPCs showed multilamellar intra-vacuolar membranes. At all periods of treatment, labeled endocytic vesicles and organelles were apparent close to the cell surface and in perinuclear areas around the Golgi apparatus. No HDL-related particles could be demonstrated close to its cisterns. Electron tomographic reconstructions showed an accumulation of HDL-containing endosomes close to the trans-Golgi-network. HDL-derived bodipy-cholesterol was localized in endosomal vesicles, multivesicular bodies, lysosomes and in many of the stacked Golgi cisternae and the trans-Golgi-network Internalized HDL-derived bodipy-cholesteryl oleate was channeled into the lysosomal

Langmuir-Blodgett films of polyaniline for low density lipoprotein detection

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Matharu, Zimple [Department of Science and Technology Centre on Biomolecular Electronics, Biomedical Instrumentation Section, National Physical Laboratory (CSIR), Dr. K. S. Krishnan Marg, New Delhi-110012 (India); Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India); Sumana, G. [Department of Science and Technology Centre on Biomolecular Electronics, Biomedical Instrumentation Section, National Physical Laboratory (CSIR), Dr. K. S. Krishnan Marg, New Delhi-110012 (India); Gupta, Vinay [Department of Physics and Astrophysics, University of Delhi, Delhi-110007 (India); Malhotra, B.D., E-mail: bansi.malhotra@gmail.co [Department of Science and Technology Centre on Biomolecular Electronics, Biomedical Instrumentation Section, National Physical Laboratory (CSIR), Dr. K. S. Krishnan Marg, New Delhi-110012 (India)

2010-11-30

Langmuir-Blodgett (LB) films of polyaniline (PANI) were utilized for the fabrication of impedimetric immunosensor for detection of human plasma low density lipoprotein (LDL) by immobilizing anti-apolipoprotein B (AAB) via EDC-NHS coupling. The modified electrodes were characterized by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. AAB/PANI-SA LB immunoelectrodes studied by EIS spectroscopy revealed detection of LDL in the wide range of 0.018 {mu}M (6 mg/dl) to 0.39 {mu}M (130 mg/dl), covering the physiological range in blood, with a sensitivity of 11.25 k{Omega} {mu}M{sup -1}.

Langmuir-Blodgett films of polyaniline for low density lipoprotein detection

International Nuclear Information System (INIS)

Matharu, Zimple; Sumana, G.; Gupta, Vinay; Malhotra, B.D.

2010-01-01

Langmuir-Blodgett (LB) films of polyaniline (PANI) were utilized for the fabrication of impedimetric immunosensor for detection of human plasma low density lipoprotein (LDL) by immobilizing anti-apolipoprotein B (AAB) via EDC-NHS coupling. The modified electrodes were characterized by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy. AAB/PANI-SA LB immunoelectrodes studied by EIS spectroscopy revealed detection of LDL in the wide range of 0.018 μM (6 mg/dl) to 0.39 μM (130 mg/dl), covering the physiological range in blood, with a sensitivity of 11.25 kΩ μM -1 .

Effect of theobromine consumption on serum lipoprotein profiles in apparently healthy humans with low HDL-cholesterol concentrations

NARCIS (Netherlands)

Jacobs, Doris M.; Smolders, Lotte; Lin, Yuguang; Roo, de Niels; Trautwein, Elke A.; Duynhoven, van John; Mensink, Ronald P.; Plat, Jogchum; Mihaleva, Velitchka V.

2017-01-01

Scope: Theobromine is a major active compound in cocoa with allegedly beneficial effect on high-density-lipoprotein-cholesterol (HDL-CH). We have investigated the effect of theobromine (TB) consumption on the concentrations of triglyceride (TG) and cholesterol (CH) in various lipoprotein (LP)

Triglyceride-rich lipoproteins as a causal factor for cardiovascular disease

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Toth, Peter P

2016-01-01

Approximately 25% of US adults are estimated to have hypertriglyceridemia (triglyceride [TG] level ≥150 mg/dL [≥1.7 mmol/L]). Elevated TG levels are associated with increased cardiovascular disease (CVD) risk, and severe hypertriglyceridemia (TG levels ≥500 mg/dL [≥5.6 mmol/L]) is a well-established risk factor for acute pancreatitis. Plasma TG levels correspond to the sum of the TG content in TG-rich lipoproteins (TRLs; ie, very low-density lipoproteins plus chylomicrons) and their remnants. There remains some uncertainty regarding the direct causal role of TRLs in the progression of atherosclerosis and CVD, with cardiovascular outcome studies of TG-lowering agents, to date, having produced inconsistent results. Although low-density lipoprotein cholesterol (LDL-C) remains the primary treatment target to reduce CVD risk, a number of large-scale epidemiological studies have shown that elevated TG levels are independently associated with increased incidence of cardiovascular events, even in patients treated effectively with statins. Genetic studies have further clarified the causal association between TRLs and CVD. Variants in several key genes involved in TRL metabolism are strongly associated with CVD risk, with the strength of a variant’s effect on TG levels correlating with the magnitude of the variant’s effect on CVD. TRLs are thought to contribute to the progression of atherosclerosis and CVD via a number of direct and indirect mechanisms. They directly contribute to intimal cholesterol deposition and are also involved in the activation and enhancement of several proinflammatory, proapoptotic, and procoagulant pathways. Evidence suggests that non-high-density lipoprotein cholesterol, the sum of the total cholesterol carried by atherogenic lipoproteins (including LDL, TRL, and TRL remnants), provides a better indication of CVD risk than LDL-C, particularly in patients with hypertriglyceridemia. This article aims to provide an overview of the

Triglyceride-rich lipoproteins as a causal factor for cardiovascular disease.

Science.gov (United States)

Toth, Peter P

2016-01-01

Approximately 25% of US adults are estimated to have hypertriglyceridemia (triglyceride [TG] level ≥150 mg/dL [≥1.7 mmol/L]). Elevated TG levels are associated with increased cardiovascular disease (CVD) risk, and severe hypertriglyceridemia (TG levels ≥500 mg/dL [≥5.6 mmol/L]) is a well-established risk factor for acute pancreatitis. Plasma TG levels correspond to the sum of the TG content in TG-rich lipoproteins (TRLs; ie, very low-density lipoproteins plus chylomicrons) and their remnants. There remains some uncertainty regarding the direct causal role of TRLs in the progression of atherosclerosis and CVD, with cardiovascular outcome studies of TG-lowering agents, to date, having produced inconsistent results. Although low-density lipoprotein cholesterol (LDL-C) remains the primary treatment target to reduce CVD risk, a number of large-scale epidemiological studies have shown that elevated TG levels are independently associated with increased incidence of cardiovascular events, even in patients treated effectively with statins. Genetic studies have further clarified the causal association between TRLs and CVD. Variants in several key genes involved in TRL metabolism are strongly associated with CVD risk, with the strength of a variant's effect on TG levels correlating with the magnitude of the variant's effect on CVD. TRLs are thought to contribute to the progression of atherosclerosis and CVD via a number of direct and indirect mechanisms. They directly contribute to intimal cholesterol deposition and are also involved in the activation and enhancement of several proinflammatory, proapoptotic, and procoagulant pathways. Evidence suggests that non-high-density lipoprotein cholesterol, the sum of the total cholesterol carried by atherogenic lipoproteins (including LDL, TRL, and TRL remnants), provides a better indication of CVD risk than LDL-C, particularly in patients with hypertriglyceridemia. This article aims to provide an overview of the available

[3H]cholesteryl ester labeling and transfer among human and honhuman primate plasma lipoproteins

International Nuclear Information System (INIS)

Thomas, M.S.; Rudel, L.L.

1983-01-01

Aliquots of human and nonhuman primate plasma containing 5,5'-dithiobis (2-nitrobenzoic acid) were incubated at 37 0 C in tubes previously coated with trace amounts of tritium-labeled cholesteryl oleate ([ 3 H]CO). Initially, cholesteryl esters were transferred at a rapid rate into plasma after which the rate slowed. During 24 h of incubation, an average of 55% of the [ 3 H]CO transferred from the side of the tube into African green monkey plasma, 44% into human plasma and 21% into rat plasma. Greater than 98% of the radioactive ester transferred into plasma was found to be associated with plasma lipoproteins that were then rapidly separated using vertical rotor density gradient ultracentrifugation. In very low density lipoprotein (VLDL)-poor plasma after 30 min incubations, high density lipoproteins (HDL) contained most of the [ 3 H]CO while 5- to 24-h incubations resulted in increased labeling of low density proteins (LDL). In VLDL-rich plasma, it was found that in addition to the labeling of HDL, VLDL contained about 25% of the labeled cholesteryl esters after 30-min incubations and, as above, the proportion in LDL subsequently increased. Compositional analyses showed that intermediate-sized LDL (ILDL) were accumulating cholesteryl ester mass while transfer occurred. LDL labeled using this method were injected intravenously into monkeys and their removal from plasma was found to be similar to that found for LDL labeled in vivo. It was concluded that this method of plasma lipoprotein cholesteryl ester labeling, presumably a result of cholesteryl ester transfer protein activity, was efficient, resulted in lipoproteins labeled only in the cholesteryl ester moiety, and induced minimal modification of lipoprotein particles that did not alter their biological activity

EFFECTS OF EXERCISE TRAINING ON BLOOD LIPIDS AND LIPOPROTEINS IN CHILDREN AND ADOLESCENTS

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Kerstin Stoedefalke

2007-09-01

Full Text Available The following review aims to describe what is known about the effects of exercise training in children and adolescents on the following blood lipids and lipoproteins: total cholesterol (TC, high density lipoprotein cholesterol (HDL-C, low density lipoprotein cholesterol (LDL-C, and triglycerides (TG. Only studies that described mode, frequency, duration and intensity of the exercise were included in the review. The results of the studies reviewed were equivocal. Clearly the effects of exercise training on the blood lipid and lipoprotein levels of normolipidemic children and adolescents are equivocal. Of the 14 studies reviewed, six observed a positive alteration in the blood lipid and lipoprotein profile, four of the studies observed no alteration in the blood lipid and lipoprotein profile and one study observed a negative effect on HDL-C but an overall improvement in the lipid and lipoprotein profile due to the decrease in the TC/HDL ratio. It appears that methodological problems present in the majority of the exercise training studies limits the ability to make a conclusive, evidence based statement regarding the effect exercise training has on blood lipid levels in normolipidemic children. Most of the research design flaws can be linked to one or more of the following: small numbers of subjects in each study, low or no representation of girls, inclusion of both boys and girls in the subject pool, inclusion of boys and girls at different maturational stages in the subject pool, exercise training regimes that do not adequately control for exercise intensity, exercise training regimes that do not last longer than 8 weeks and exercise training studies that do not have an adequate exercise volume to elicit a change. Ideally, future research should focus on longitudinal studies which examine the effects of exercise training from the primary school years through adulthood

Thermodynamic and kinetic approaches for evaluation of monoclonal antibody - Lipoprotein interactions.

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Multia, Evgen; Sirén, Heli; Andersson, Karl; Samuelsson, Jörgen; Forssén, Patrik; Fornstedt, Torgny; Öörni, Katariina; Jauhiainen, Matti; Riekkola, Marja-Liisa

2017-02-01

Two complementary instrumental techniques were used, and the data generated was processed with advanced numerical tools to investigate the interactions between anti-human apoB-100 monoclonal antibody (anti-apoB-100 Mab) and apoB-100 containing lipoproteins. Partial Filling Affinity Capillary Electrophoresis (PF-ACE) combined with Adsorption Energy Distribution (AED) calculations provided information on the heterogeneity of the interactions without any a priori model assumptions. The AED calculations evidenced a homogenous binding site distribution for the interactions. Quartz Crystal Microbalance (QCM) studies were used to evaluate thermodynamics and kinetics of the Low-Density Lipoprotein (LDL) and anti-apoB-100 Mab interactions. High affinity and selectivity were observed, and the emerging data sets were analysed with so called Interaction Maps. In thermodynamic studies, the interaction between LDL and anti-apoB-100 Mab was found to be predominantly enthalpy driven. Both techniques were also used to study antibody interactions with Intermediate-Density (IDL) and Very Low-Density (VLDL) Lipoproteins. By screening affinity constants for IDL-VLDL sample in a single injection we were able to distinguish affinity constants for both subpopulations using the numerical Interaction Map tool. Copyright © 2016 Elsevier Inc. All rights reserved.

Are oxidized low-density lipoprotein and C-reactive protein markers of atherosclerosis in nephrotic children?

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Rybi-Szumińska, A.; Wasilewska, A.; Michaluk-Skutnik, J.; Osipiuk-Remża, B.; Fiłonowicz, R.; Zając, M.

2014-01-01

Background Lipid disorders are known to be linked to disturbance in oxidative reactions and play an important role in the progression and complications of idiopathic nephrotic syndrome (INS). Aims The aim of this study was to assess oxidized low-density lipoprotein (oxLDL), high-sensitive C-reactive protein (hs-CRP) serum concentrations and other parameters of lipid metabolism in children with INS during relapse and remission of proteinuria. Methods The examination was performed on 23 childre...

Systemic excretion of benzo(a)pyrene in the control and microsomally induced rat: the influence of plasma lipoproteins and albumin as carrier molecules

International Nuclear Information System (INIS)

Shu, H.P.; Bymun, E.N.

1983-01-01

In vitro studies have previously indicated that benzo(a)pyrene distributes primarily into the plasma lipoprotein fraction when incubated with whole plasma. Hydroxylated metabolites of benzo(a)pyrene distribute increasingly into the albumin fraction as the degree of metabolite hydroxylation increases. This report assesses the influence of plasma lipoproteins and albumin as carriers for benzo(a)pyrene on carcinogen excretion in the control and microsomally induced rat. Male Sprague-Dawley rats cannulated in the bile duct received i.v. injections of radiolabeled benzo(a)pyrene noncovalently bound to the very-low-density, low-density, or high-density lipoproteins in equimolar amounts. Bile was collected and measured for radioactivity. Cumulative biliary excretions of benzo(a)pyrene complexed with rat lipoproteins were 39.6 +/- 9.7 (S.D.), 24.6 +/- 1.3, and 21.2 +/- 8.8% for very low-density, low-density, and high-density lipoprotein, respectively. Values for excretion of benzo(a)pyrene complexed with rat or human lipoproteins were comparable. These data suggest that the transport molecule can effect a 2-fold difference in benzo(a)pyrene excretion under conditions of the present study. Thus, excretion increased as the degree of benzo(a)pyrene hydroxylation increased. The effect of microsomal enzyme induction on excretion of lipoprotein-bound benzo(a)pyrene was also assessed. Contrary to expectation, excretion of benzo(a)pyrene bound to the very-low-density, low-density, or high-density lipoproteins in Aroclor-induced rats was not greater than that of control animals. Hence, under the conditions of the present study, 60 to 80% of the injected benzo(a)pyrene and 50 to 60% of the injected benzo(a)pyrene metabolites were not excreted immediately in control or microsomally induced animals. This benzo(a)pyrene may represent a carcinogen pool that is slowly excreted

Association Between Lipoprotein(A) and Small Apo(A) Phenotypes and Coronary Heart Disease in Sudanese Diabetic Patients

International Nuclear Information System (INIS)

Ahmed, A.M.; Elabid, B.E.H.; Addalla, M.A.

2013-01-01

Background:Recent studies indicate an independent association of apolipoprotein(a) small phenotypes with the diabetes and the onset of coronary heart disease.Apolipoprotein(a)small phenotypes when used together with Lipoprotein(a) levels make powerful markers in assessing the actual risk of developing coronary heart disease in diabetic patients. Objectives: Evaluation of clinical and diagnostic significant of Lipoprotein(a) levels and apolipoprotein(a) small phenotypes and its relation to coronary heart disease in Sudanese diabetic patients. Setting and duration of study: Diabetic patients attending hospitals and medical centers from May 2011-December 2012, in Khartoum, Sudan. Patients and Methods: This was a case control, hospital based study done on 138 Sudanese diabetic patients attending hospitals and medical centers in Khartoum. Patients were divided into 2 groups. One group had diabetic cases with coronary heart disease and the other were diabetic patients without coronary heart disease. Controls were age and gender matched. Blood samples were collected from both groups(patients and controls) and were run for apolipoproteins, lipoproteins and apolipoprotein(a) small phenotype,low-density lipoprotein,high-density lipoprotein and trigeminal ganglia. Results: The levels of Lipoprotein(a) of patients were significantly higher than controls (p<0.05). Apolipoprotein(a)small phenotype distribution showed a significant difference when compared between patients of both groups (diabetics with and without coronary heart disease) and controls (p<0.05). Both low-density lipoprotein and high-density lipoprotein cholesterol showed significant difference in both patient groups and controls (p<0.05). Total cholesterol and triglyceride levels showed no significant difference between patients and controls. Apolipoprotein(a) small phenotypes showed significant distribution in diabetic patients when compared with coronary heart disease patients (more than one low molecular weight

Consumption of nonfat milk results in a less atherogenic lipoprotein profile: a pilot study.

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Hidaka, Hiroya; Takiwaki, Masaki; Yamashita, Mine; Kawasaki, Kenji; Sugano, Mitsutoshi; Honda, Takayuki

2012-01-01

An increase in plasma low-density lipoprotein (LDL) is a well-known risk factor in the development of atherosclerosis. Dairy consumption may lower the risk of atherosclerosis; however, studies on the effects of milk on cardiovascular risk factors are still scarce. We were interested in investigating whether the intake of milk improves the atherogenic lipoprotein profile. We investigated the effects of consuming whole or nonfat milk on plasma lipoprotein composition in healthy Japanese subjects as a pilot study. Normolipidemic subjects consumed 500 ml of whole milk (whole milk group; n=7) or nonfat milk (nonfat milk group; n=7) every day for 2 weeks. The consumption of nonfat milk resulted in a lowering of plasma triglyceride (TG) and phospholipid levels and TG level in high-density lipoprotein (HDL) and increased the plasma apolipoprotein (apo) C-III level. In addition, the TG/cholesterol ratios in HDL and LDL were significantly decreased, and LDL particles became larger. In contrast, the only changes observed following whole milk consumption were increases in the plasma levels of apoC-III and apoE. These findings suggest that consumption of nonfat milk, but not whole milk, may result in a less atherogenic lipoprotein profile, and that the constituents of nonfat milk may improve lipid metabolism.

Receptor-mediated endocytosis of low density lipoproteins in aortic endothelial cells

International Nuclear Information System (INIS)

Sanan, D.A.

1986-04-01

Lipoprotein binding and metabolism in actively-dividing (subconfluent) and quiescent (postconfluent) bovine aortic endothelial cells (ECs) were qualitatively investigated by fluorescence microscopy using dioctadecylindocarbocyanine-labelled lipoproteins and by indirect immunofluorescence microscopy. LDL and acetylated-LDL (AcLDL) were seen bound to the surfaces of subconfluent ECs (at 4 degrees C or at 37 degrees C), as a random distribution of punctate foci. ECs therefore closely resembled fibroblasts in the distribution of LDL receptors on their surfaces. No binding of LDL was seen on postconfluent EC surfaces by either direct or indirect fluorescence microscopy. The patterns of AcLDL binding on postconfluent ECs resembled those on subconfluent ECs. Intracellular LDL and AcLDL occurred as perinuclear accumulations of large fluorescent disc-shaped profiles in subconfluent ECs. These accumulations were shown to arise from surface-bound material by pulse-chase experiments. Intracellular LDL was absent in the majority of postconfluent ECs, while AcLDL accumulation was massive. 'Wounding' of cultures allowed simultaneous assessment of lipoprotein metabolism in quiescent and actively-dividing areas of the same culture. It is concluded that postconfluent quiescent bovine aortic ECs in vitro metabolise virtually no LDL via the LDL-receptor pathway due to a vanishingly low number of LDL receptors. This contrasts with the ability of postconfluent cells to metabolise relatively large amounts of AcLDL via a receptor-mediated mechanism. The significance of these conclusions is discussed with respect to the interaction of plasma lipoproteins with the endothelium in vivo. 301 refs

Evaluation of biodistribution and imaging of atherosclerotic lesions using 111In-labeled low-density lipoprotein

International Nuclear Information System (INIS)

Yamashina, Hisayo

1993-01-01

111 In-labeled low-density lipoprotein (LDL) was administered to Watanabe heritable hyperlipidemic rabbits (WHHL group) and control rabbits (control group) to evaluate its biodistribution and scintigraphic images by γ-camera and radioactivity of each organ. With external imaging, the heart, liver, kidney, bone and spleen of each rabbit were observed. By setting the region of interest, the liver/heart ratio of the WHHL group was significantly lower than that of the control group (p 111 In-labeled-LDL was recognized in the aortic arch, bifurcation of intercostal and celiac artery in the WHHL group. By the use of labeled LDL with the combination of γ-camera, it is capable of detecting the regulation of lipoprotein metabolism and imaging atherosclerotic lesions externally. (author)

Niacin extended-release/simvastatin combination therapy produces larger favorable changes in high-density lipoprotein particles than atorvastatin monotherapy

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Toth PP

2012-01-01

Full Text Available Peter P Toth1, Kamlesh M Thakker2, Ping Jiang2, Robert J Padley21University of Illinois College of Medicine, Peoria, and CGH Medical Center, Sterling, 2Abbott, Abbott Park, IL, USABackground: The purpose of this research was to compare the effects of niacin extended-release in combination with simvastatin (NER/S versus atorvastatin monotherapy on high-density lipoprotein (HDL particle number and size in patients with hyperlipidemia or dyslipidemia from the SUPREME study.Methods: This was a post hoc analysis of patients (n = 137 who completed the SUPREME study and who had lipid particle number and size measurements at both baseline and at week 12 by nuclear magnetic resonance spectroscopy. Following ≥4 weeks without lipid-modifying therapy (washout period, the patients received NER/S 1000/40 mg/day for 4 weeks followed by NER/S 2000/40 mg/day for 8 weeks, or atorvastatin 40 mg/day for 12 weeks. Median percent changes in HDL particle number and size from baseline to week 12 were compared between the NER/S and atorvastatin treatment groups using the Wilcoxon rank-sum test. Distribution of HDL particle subclasses at week 12 was compared between the treatment groups using the Cochran–Mantel–Haenszel test.Results: Treatment with NER/S resulted in a significantly greater percent reduction in small HDL particle number at week 12 compared with atorvastatin monotherapy (-1.8% versus 4.2%, P = 0.014, and a numerically greater percent increase in large HDL particle number (102.4% versus 39.2%, P = 0.078 compared with atorvastatin monotherapy. A significantly greater percent increase in HDL particle size from baseline at week 12 was observed with NER/S compared with atorvastatin (6.0% versus 1.3%, P < 0.001. NER/S treatment also resulted in a significant shift in HDL particle size from small and medium at baseline to large at week 12 (P < 0.0001.Conclusion: Treatment with NER/S resulted in larger favorable changes in number and size of HDL particle

Non-high-density lipoprotein cholesterol on the risks of stroke: a result from the Kailuan study.

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Jianwei Wu

Full Text Available AIMS: To prospectively explore the association between non-high-density lipoprotein cholesterol (non-HDLC and the risks of stroke and its subtypes. METHODS: A total of 95,916 participants (18-98 years old; 76,354 men and 19,562 women from a Chinese urban community who were free of myocardial infarction and stroke at baseline time point (2006-2007 were eligible and enrolled in the study. The serum non-HDLC levels of participants were determined by subtracting the high-density lipoprotein cholesterol (HDLC from total serum cholesterol. The primary outcome was the first occurrence of stroke, which was diagnosed according to the World Health Organization criteria and classified into three subtypes: ischemic stroke, intracerebral hemorrhage, or subarachnoid hemorrhage. The Cox proportional hazards models were used to estimate risk of stroke and its subtypes. RESULTS: During the four-year follow-up, we identified 1614 stroke events (1,156 ischemic, 416 intracerebral hemorrhagic and 42 subarachnoid hemorrhagic. Statistical analyses showed that hazard ratios (HR (95% Confidence Interval: CI of serum Non-HDLC level for total and subtypes of stroke were: 1.08 (1.03-1.12 (total, 1.10 (1.05-1.16 (ischemic, 1.03 (0.96-1.10 (intracerebral hemorrhage and 0.83 (0.66-1.05 (subarachnoid hemorrhage. HR for non-HDLC refers to the increase per each 20 mg/dl. For total and ischemic stroke, the risks were significantly higher in the fourth and fifth quintiles of non-HDLC concentrations compared to the first quintile after adjusting the confounding factors (total stroke: 4(th quintile HR=1.33 (1.12-1.59; 5(th quintile HR = 1.36 (1.15-1.62; ischemic stroke: 4(th quintile HR =1.34 (1.09-1.66; 5(th quintile HR = 1.53 (1.24-1.88. CONCLUSIONS: Our data suggest that serum non-HDLC level is an independent risk factor for total and ischemic stroke, and that higher serum non-HDLC concentrations are associated with increased risks for total stroke and ischemic stroke, but not

Lipoprotein metabolism indicators improve cardiovascular risk prediction.

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Daniël B van Schalkwijk

Full Text Available BACKGROUND: Cardiovascular disease risk increases when lipoprotein metabolism is dysfunctional. We have developed a computational model able to derive indicators of lipoprotein production, lipolysis, and uptake processes from a single lipoprotein profile measurement. This is the first study to investigate whether lipoprotein metabolism indicators can improve cardiovascular risk prediction and therapy management. METHODS AND RESULTS: We calculated lipoprotein metabolism indicators for 1981 subjects (145 cases, 1836 controls from the Framingham Heart Study offspring cohort in which NMR lipoprotein profiles were measured. We applied a statistical learning algorithm using a support vector machine to select conventional risk factors and lipoprotein metabolism indicators that contributed to predicting risk for general cardiovascular disease. Risk prediction was quantified by the change in the Area-Under-the-ROC-Curve (ΔAUC and by risk reclassification (Net Reclassification Improvement (NRI and Integrated Discrimination Improvement (IDI. Two VLDL lipoprotein metabolism indicators (VLDLE and VLDLH improved cardiovascular risk prediction. We added these indicators to a multivariate model with the best performing conventional risk markers. Our method significantly improved both CVD prediction and risk reclassification. CONCLUSIONS: Two calculated VLDL metabolism indicators significantly improved cardiovascular risk prediction. These indicators may help to reduce prescription of unnecessary cholesterol-lowering medication, reducing costs and possible side-effects. For clinical application, further validation is required.

Bacterial lipoproteins; biogenesis, sorting and quality control.

Science.gov (United States)

Narita, Shin-Ichiro; Tokuda, Hajime

2017-11-01

Bacterial lipoproteins are a subset of membrane proteins localized on either leaflet of the lipid bilayer. These proteins are anchored to membranes through their N-terminal lipid moiety attached to a conserved Cys. Since the protein moiety of most lipoproteins is hydrophilic, they are expected to play various roles in a hydrophilic environment outside the cytoplasmic membrane. Gram-negative bacteria such as Escherichia coli possess an outer membrane, to which most lipoproteins are sorted. The Lol pathway plays a central role in the sorting of lipoproteins to the outer membrane after lipoprotein precursors are processed to mature forms in the cytoplasmic membrane. Most lipoproteins are anchored to the inner leaflet of the outer membrane with their protein moiety in the periplasm. However, recent studies indicated that some lipoproteins further undergo topology change in the outer membrane, and play critical roles in the biogenesis and quality control of the outer membrane. This article is part of a Special Issue entitled: Bacterial Lipids edited by Russell E. Bishop. Copyright © 2016 Elsevier B.V. All rights reserved.

Importance of high-density lipoprotein cholesterol levels in elderly diabetic individuals with type IIb dyslipidemia: A 2-year survey of cardiovascular events.

Science.gov (United States)

Ina, Koichiro; Hayashi, Toshio; Araki, Atsushi; Kawashima, Seinosuke; Sone, Hirohito; Watanabe, Hiroshi; Ohrui, Takashi; Yokote, Koutaro; Takemoto, Minoru; Kubota, Kiyoshi; Noda, Mitsuhiko; Noto, Hiroshi; Ding, Qun-Fang; Zhang, Jie; Yu, Ze-Yun; Yoon, Byung-Koo; Nomura, Hideki; Kuzuya, Masafumi

2014-10-01

The risk factors for ischemic heart disease (IHD) or cerebrovascular accident (CVA) in elderly diabetic individuals with type IIb dyslipidemia are not fully known. Therefore, we investigated the relationship between lipid levels and IHD and CVA in diabetic individuals with type IIb dyslipidemia. The Japan Cholesterol and Diabetes Mellitus Study is a prospective cohort study of 4014 type 2 diabetic patients (1936 women; age 67.4 ± 9.5 years). The primary end-points were the onset of IHD or CVA. Lipid and glucose levels, and other factors were investigated in relation to the occurrence of IHD or CVA. A total of 462 participants were included in the group of patients with type IIb dyslipidemia. The 462 diabetic participants with type IIb dyslipidemia were divided into those who were aged 75 years (n=168, 190 and 104, respectively). High-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol/HDL-C were significantly associated with the risk of cardiovascular events in diabetic individuals with type IIb dyslipidemia who were aged dyslipidemia who were aged dyslipidemia who were aged <75 years. © 2013 Japan Geriatrics Society.

Serum prolactin, leptin, lipids and lipoproteins levels during antipsychotics treatment in Parkinson's disease and related psychosis.

Science.gov (United States)

Rustembegovic, Avdo; Sofic, Emin; Wichart, Ildiko

2006-01-01

Weight gain is a common adverse effect associated with the use of most typical and atypical antipsychotic. Aim of this study was to investigate serum prolactin, leptin, cholesterol, triglyceride, lipoproteins, such high density lipoprotein (HDL), and low density lipoprotein (LDL) levels in patients with Parkinson's disease (PD)-related psychosis during long-term medication with atypical antipsychotic. The study population comprised 40 patients, who were divided into 4 groups: olanzapine (n=10), risperidone (n=10), seroquel (n=10) monotherapy, a group of 10 patients receiving only antiparkinson drugs and a control group of 8 healthy persons. The patients were evaluated at baseline and at the sixth and twelfth week according to the Positive and Negative Syndrome Scale (PANSS), body mass index (BMI), and fasting serum prolactin, leptin, lipids and lipoproteins levels. Treatment of patients with olanzapine caused marked increase of serum LDL, cholesterol, triglyceride, and leptin levels (prelationship between serum leptin, lipid levels and BMI. However, treatment of patients with seroquel did not cause changes in serum prolactin, leptin, lipids, and lipoproteins levels. Our results suggest that treatment of patients with PD-related psychosis with seroquel appears to have minimal influence on serum leptin, prolactin, lipids, lipoproteins and BMI compared with olanzapine and risperidone.

Lipoprotein metabolism indicators improve cardiovascular risk prediction

NARCIS (Netherlands)

Schalkwijk, D.B. van; Graaf, A.A. de; Tsivtsivadze, E.; Parnell, L.D.; Werff-van der Vat, B.J.C. van der; Ommen, B. van; Greef, J. van der; Ordovás, J.M.

2014-01-01

Background: Cardiovascular disease risk increases when lipoprotein metabolism is dysfunctional. We have developed a computational model able to derive indicators of lipoprotein production, lipolysis, and uptake processes from a single lipoprotein profile measurement. This is the first study to

Effect of the Probiotic Saccharomyces boulardii on Cholesterol and Lipoprotein Particles in Hypercholesterolemic Adults: A Single-Arm, Open-Label Pilot Study.

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Ryan, Jennifer Joan; Hanes, Douglas Allen; Schafer, Morgan Beth; Mikolai, Jeremy; Zwickey, Heather

2015-05-01

Elevated blood cholesterol levels are a major risk factor for coronary artery disease, the leading cause of death worldwide. Probiotics have been investigated as potential cholesterol-lowering therapies, but no previous studies have assessed the effect of the probiotic yeast Saccharomyces boulardii on cholesterol levels in human volunteers. The objective of this study was to examine the effect of S. boulardii on serum cholesterol and lipoprotein particles in hypercholesterolemic adults. This study was a single-arm, open-label pilot study. Twelve hypercholesterolemic participants were recruited into the study; one dropped out. Participants took 5.6×10(10) colony forming unit (CFU) encapsulated S. boulardii (Saccharomyces cerevisiae var. boulardii CNCM I-1079) twice daily for an 8-week period. Fasting concentrations of cholesterol (total cholesterol, low-density lipoprotein-cholesterol [LDL-C], high-density lipoprotein-cholesterol [HDL-C], and triglycerides), lipoprotein particles (very-low-density lipoprotein-particle [VLDL-P], remnant lipoprotein particle [RLP-P], total LDL-P, LDL III-P, LDL IV-P, total HDL-P, and HDL 2b-P), and additional cardiovascular biomarkers (apo B-100, lipoprotein [a], high-sensitivity C-reactive protein, homocysteine, fibrinogen, and insulin) were measured at baseline, after 4 weeks, and after 8 weeks. Remnant lipoprotein particles decreased by 15.5% (p=0.03) over the 8-week period. The remaining outcome measures were not significantly altered. In this pilot study, 8 weeks of daily supplementation with S. boulardii lowered remnant lipoprotein, a predictive biomarker and potential therapeutic target in the treatment and prevention of coronary artery disease.

Effect of cocoa bran on low-density lipoprotein oxidation and fecal bulking.

Science.gov (United States)

Jenkins, D J; Kendall, C W; Vuksan, V; Vidgen, E; Wong, E; Augustin, L S; Fulgoni, V

Legumes have reported benefits in terms of reduced risk for coronary heart disease and of colonic health. A novel legume fiber, cocoa bran, also may have favorable health effects on serum lipid levels, low-density lipoprotein (LDL) cholesterol oxidation, and fecal bulk. Twenty-five healthy normolipidemic subjects (13 men and 12 women) (mean +/- SEM age, 37 +/- 2 years; mean +/- SEM body mass index [calculated as weight in kilograms divided by the square of height in meters], 24.6 +/- 0.7) ate cocoa-bran and chocolate-flavored low-fiber breakfast cereals for 2-week periods, with 2-week washout, in a double-blind crossover study. The cocoa-bran cereal provided 25.0 g/d of total dietary fiber (TDF). The low-fiber cereal (5.6 g/d TDF) was of similar appearance and energy value. Fasting blood samples were obtained at the start and end of each period, and 4-day fecal collections were made from days 11 through 14. High-density lipoprotein (HDL) cholesterol level was higher (7.6% +/- 2.9%; P =.02) and the LDL/HDL cholesterol ratio was lower (6.7% +/- 2.3%; P =.007) for cocoa-bran compared with low-fiber cereal at 2 weeks. No effect was seen on LDL cholesterol oxidation. Mean fecal output was significantly higher for cocoa-bran than for low-fiber cereal (56 +/- 14 g/d; Pchocolate-flavored cocoa-bran cereal increased fecal bulk similarly to wheat bran and was associated with a reduction in the LDL/HDL cholesterol ratio. In view of the low-fat, high-fiber nature of the material, these results suggest a possible role for this novel fiber source in the diets of normal, hyperlipidemic, and constipated subjects.

Bio F1B hamster: a unique animal model with reduced lipoprotein lipase activity to investigate nutrient mediated regulation of lipoprotein metabolism

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Cornish Marion L

2007-12-01

Full Text Available Abstract Background Bio F1B hamster is an inbred hybrid strain that is highly susceptible to diet-induced atherosclerosis. We previously reported that feeding a high fat fish oil diet to Bio F1B hamster caused severe hyperlipidaemia. In this study we compared the effects of various diets in the Bio F1B hamster and the Golden Syrian hamster, which is an outbred hamster strain to investigate whether genetic background plays an important role in dietary fat mediated regulation of lipoprotein metabolism. We further investigated the mechanisms behind diet-induced hyperlipidaemia in F1B hamster. Methods The Bio F1B and Golden Syrian hamsters, 8 weeks old, were fed high fat diets rich in either monounsaturated fatty acids, an n-6: n-3 ratio of 5 or a fish oil diet for 4 weeks. Animals were fasted overnight and blood and tissue samples were collected. Plasma was fractionated into various lipoprotein fractions and assayed for triacylglycerol and cholesterol concentrations. Plasma lipoprotein lipase activity was measured using radioisotope method. Microsomal triglyceride transfer protein activity was measured in the liver and intestine. Plasma apolipoproteinB48, -B100 and apolipoprotein E was measured using Western blots. Two-way ANOVA was used to determine the effect of diet type and animal strain. Results The fish oil fed F1B hamsters showed milky plasma after a 14-hour fast. Fish oil feeding caused accumulation of apolipoproteinB48 containing lipoprotein particles suggesting hindrance of triglyceride-rich lipoprotein clearance. There was no significant effect of diet or strain on hepatic or intestinal microsomal triglyceride transfer protein activity indicating that hyperlipidaemia is not due to an increase in the assembly or secretion of lipoprotein particles. F1B hamsters showed significantly reduced levels of lipoprotein lipase activity, which was inhibited by fish oil feeding. Conclusion Evidence is presented for the first time that alterations in

The levels of plasma low density lipoprotein are independent of cholesterol ester transfer protein in fish-oil fed F1B hamsters

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Davis Phillip J

2005-03-01

Full Text Available Abstract Background Cholesterol ester transfer protein (CETP plays a major role in regulating the levels of LDL- and HDL-cholesterol. We previously observed a fish-oil-induced elevation of low-density lipoprotein (LDL-and very-low-density lipoprotein (VLDL-cholesterol concentrations and a decrease in high-density lipoprotein (HDL-cholesterol concentration in F1B hamsters. The molecular mechanism/s by which fish oil induces hyperlipidaemic effect was investigated in this study. We examined whether the effects of dietary fish oil on plasma lipoprotein concentrations are due to fish-oil-induced alterations in plasma CETP activity. MIX diet, a diet supplemented with a mixture of lard and safflower oil, was used as the control diet. Results We found that fish oil feeding in hamsters reduced CETP mass as well as CETP activity. Increasing the dietary fat level of fish-oil from 5% to 20% (w/w led to a further decrease in CETP mass. Supplementation with dietary cholesterol increased both CETP mass and CETP activity in fish-oil and MIX-diet fed hamsters. However, there was no correlation between CETP mass as well as CETP activity and LDL-cholesterol concentrations. Conclusion These findings suggest that cholesterol ester transfer between HDL and LDL is not likely to play a major role in determining fish-oil-induced changes in LDL- and HDL-cholesterol concentrations in F1B hamsters. A possible role of reduced clearance of LDL-particles as well as dietary fat level and dietary cholesterol dependent changes in LDL-lipid composition have been discussed.

Recombinant high-density lipoprotein nanoparticles containing gadolinium-labeled cholesterol for morphologic and functional magnetic resonance imaging of the liver

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Rui M

2012-07-01

Full Text Available Mengjie Rui,1 Wei Guo,2 Qian Ding,2 Xiaohui Wei,2 Jianrong Xu,3 Yuhong Xu21School of Life Science and Biotechnology, 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People's Republic of China; 3Department of Radiology, Renji Hospital Affiliation with Medical School of Shanghai Jiao Tong University, Shanghai, People's Republic of ChinaBackground: Natural high-density lipoproteins (HDL possess important physiological functions to the transport of cholesterol from the peripheral tissues to the liver for metabolic degradation and excretion in the bile.Methods and results: In this work, we took advantage of this pathway and prepared two different gadolinium (Gd-DTPA-labeled cholesterol-containing recombinant HDL nanoparticles (Gd-chol-HDL and Gd-(chol2-HDL as liver-specific magnetic resonance imaging (MRI contrast agents. The reconstituted HDL nanoparticles had structural similarity to native HDL, and could be taken up by HepG2 cells via interaction with HDL receptors in vitro. In vivo MRI studies in rats after intravenous injections of 10 µmol gadolinium per kg of recombinant HDL nanoparticles indicated that both nanoparticles could provide signal enhancement in the liver and related organs. However, different T1-weighted image details suggested that they participated in different cholesterol metabolism and excretion pathways in the liver.Conclusion: Such information could be highly useful to differentiate functional changes as well as anatomic differences in the liver. These cholesterol-derived contrast agents and their recombinant HDL preparations may warrant further development as a new class of contrast agents for MRI of the liver and related organs.Keywords: magnetic resonance imaging, apolipoprotein, high-density lipoprotein, contrast agent, gadolinium, liver

Structural studies on lipoprotein lipase

International Nuclear Information System (INIS)

Socorro, L.

1985-01-01

The structure of lipoprotein lipase is not known. The lack of information on its primary sequence has been due to the inability of preparing it in homogeneous and stable form. This research has focused on the structural characterization of lipoprotein lipase. The first approach taken was to develop a purification method using bovine milk and affinity chromatography on heparin-Sepharose. The protein obtained was a heterogeneous peak with the activity shifted towards the trailing edge fractions. These fractions only presented a 55 Kdalton band on polyacrylamide gel electrophoresis. Monoclonal antibodies against this band detected an endogenous, phenyl methane sulfonyl fluoride-sensitive protease responsible for the presence of lower molecular weight fragments. The second approach was to label the lipoprotein lipase with a radioactive, active site, directed probe. After incubation and affinity chromatography a complex [ 3 H]inhibitor enzyme was isolated with a stoichiometry of 1.00 +/- 0.2. The complex was digested with CNBr and the insoluble peptides at low ionic strength (>90% [ 3 H]dpm) were used for further purification. Differential extraction of the [ 3 H]-peptide, digestion with S. aureus V8 protease, and high performance liquid chromatography yielded a hexapeptide with a composition consistent with the consensus sequence of the active site peptides of many serine-esterase. This and the kinetic data imply this being the mechanism of action for lipoprotein lipase

Identification and Localization of Myxococcus xanthus Porins and Lipoproteins

Science.gov (United States)

Bhat, Swapna; Zhu, Xiang; Patel, Ricky P.; Orlando, Ron; Shimkets, Lawrence J.

2011-01-01

Myxococcus xanthus DK1622 contains inner (IM) and outer membranes (OM) separated by a peptidoglycan layer. Integral membrane, β-barrel proteins are found exclusively in the OM where they form pores allowing the passage of nutrients, waste products and signals. One porin, Oar, is required for intercellular communication of the C-signal. An oar mutant produces CsgA but is unable to ripple or stimulate csgA mutants to develop suggesting that it is the channel for C-signaling. Six prediction programs were evaluated for their ability to identify β-barrel proteins. No program was reliable unless the predicted proteins were first parsed using Signal P, Lipo P and TMHMM, after which TMBETA-SVM and TMBETADISC-RBF identified β-barrel proteins most accurately. 228 β-barrel proteins were predicted from among 7331 protein coding regions, representing 3.1% of total genes. Sucrose density gradients were used to separate vegetative cell IM and OM fractions, and LC-MS/MS of OM proteins identified 54 β-barrel proteins. Another class of membrane proteins, the lipoproteins, are anchored in the membrane via a lipid moiety at the N-terminus. 44 OM proteins identified by LC-MS/MS were predicted lipoproteins. Lipoproteins are distributed between the IM, OM and ECM according to an N-terminal sorting sequence that varies among species. Sequence analysis revealed conservation of alanine at the +7 position of mature ECM lipoproteins, lysine at the +2 position of IM lipoproteins, and no noticable conservation within the OM lipoproteins. Site directed mutagenesis and immuno transmission electron microscopy showed that alanine at the +7 position is essential for sorting of the lipoprotein FibA into the ECM. FibA appears at normal levels in the ECM even when a +2 lysine is added to the signal sequence. These results suggest that ECM proteins have a unique method of secretion. It is now possible to target lipoproteins to specific IM, OM and ECM locations by manipulating the amino acid

Hepatic lipase, genetically elevated high-density lipoprotein, and risk of ischemic cardiovascular disease

DEFF Research Database (Denmark)

Johannsen, Trine Holm; Kamstrup, Pia R; Andersen, Rolf V

2008-01-01

73M, N193S, S267F, L334F, T383M, and -480c>t influence levels of lipids, lipoproteins, and apolipoproteins and risk of ICD. DESIGN: For the cross-sectional study, we genotyped 9003 individuals from the Copenhagen City Heart Study; hereof were 8971 individuals included in the prospective study, 1747...

Remnant Cholesterol, Low-Density Lipoprotein Cholesterol, and Blood Pressure as Mediators From Obesity to Ischemic Heart Disease

DEFF Research Database (Denmark)

Varbo, Anette; Benn, Marianne; Smith, George Davey

2015-01-01

RATIONALE: Obesity leads to increased ischemic heart disease (IHD) risk, but the risk is thought to be mediated through intermediate variables and may not be caused by increased weight per se. OBJECTIVE: To test the hypothesis that the increased IHD risk because of obesity is mediated through...... variables and using genetic variants associated with these. During ≤22 years of follow-up 13 945 participants developed IHD. The increased IHD risk caused by obesity was partly mediated through elevated levels of nonfasting remnant cholesterol and low-density lipoprotein cholesterol, through elevated blood...... obesity were low-density lipoprotein cholesterol with 8%, systolic blood pressure with 7%, and remnant cholesterol with 7% excess risk of IHD. Corresponding observational excess risks using conventional body mass index were 21%, 11%, and 20%, respectively. CONCLUSIONS: The increased IHD risk because...

Baseline blood pressure, low- and high-density lipoproteins, and triglycerides and the risk of vascular events in the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial

DEFF Research Database (Denmark)

Amarenco, Pierre; Goldstein, Larry B; Callahan, Alfred

2009-01-01

AND RESULTS: The SPARCL trial randomized 4731 patients with recent stroke or transient ischemic attack (TIA) and no known coronary heart disease and LDL-C between 100 and 190 mg/dL to either atorvastatin 80 mg/d or placebo. Baseline assessment included SBP, DBP and measurements of low-density lipoprotein...... associated with MCVE. Atorvastatin treatment was similarly effective regardless of baseline lipoprotein levels....

Interactions of Solutol HS 15 and Cremophor EL with plasma lipoproteins.

Science.gov (United States)

Woodburn, K; Sykes, E; Kessel, D

1995-07-01

Two emulsifying agents, Solutol HS15 and Cremophor EL, were compared with regard to their effects on human plasma lipoproteins in vitro and on mouse plasma lipoproteins in vitro and in vivo. Both agents promoted binding of a hydrophobic photosensitizing agent (C8KC) to a circulating plasma species of low bouyant density. Persistence of this material was greater with Cremophor than with Solutol. Experiments carried out with labeled Solutol indicated that the vehicle itself is a component of this new species. High concentrations of either vehicle ( > or = 0.06%) led to decreased electrophoretic mobility of human LDL and HDL in vitro. In the mouse, a different effect was observed, resulting in complex changes in electrophoretic mobility of plasma lipoproteins. The plasma half-life of C8KC in the circulation of the mouse was correlated with the persistence of an altered electrophoretic lipoprotein pattern. Since Solutol and C8KC showed similar half-lives, this result suggests that the plasma half-life of the sensitizer is correlated with the persistence of the vehicle. While Solutol and Cremophor were designed to be vehicles for drug formulation, they also influence persistence of some drugs in the circulation.

Effect of short-term low- and high-fat diets on low-density lipoprotein particle size in normolipidemic subjects.

Science.gov (United States)

Guay, Valérie; Lamarche, Benoît; Charest, Amélie; Tremblay, André J; Couture, Patrick

2012-01-01

High-fat, low-carbohydrate diets have been shown to raise plasma cholesterol levels, an effect associated with the formation of large low-density lipoprotein (LDL) particles. However, the impact of dietary intervention on time-course changes in LDL particle size has not been investigated. To test whether a short-term dietary intervention affects LDL particle size, we conducted a randomized, double-blind, crossover study using an intensive dietary modification in 12 nonobese healthy men with normal plasma lipid profile. Participants were subjected to 2 isocaloric 3-day diets: high-fat diet (37% energy from fat and 50% from carbohydrates) and low-fat diet (25% energy from fat and 62% from carbohydrates). Plasma lipid levels and LDL particle size were assessed on fasting blood samples after 3 days of feeding on each diet. The LDL particles were characterized by polyacrylamide gradient gel electrophoresis. Compared with the low-fat diet, plasma cholesterol, LDL cholesterol, and high-density lipoprotein cholesterol were significantly increased (4.45 vs 4.78 mmol/L, P = .04; 2.48 vs 2.90 mmol/L, P = .005; and 1.29 vs 1.41 mmol/L, P = .005, respectively) following the 3-day high-fat diet. Plasma triglycerides and fasting apolipoprotein B-48 levels were significantly decreased after the high-fat diet compared with the low-fat diet (1.48 vs 1.01 mmol/L, P = .0003 and 9.6 vs 5.5 mg/L, P = .008, respectively). The high-fat diet was also associated with a significant increase in LDL particle size (255.0 vs 255.9 Å;P = .01) and a significant decrease in the proportion of small LDL particle (vs 44.6%, P = .01). As compared with a low-fat diet, the cholesterol-raising effect of a high-fat diet is associated with the formation of large LDL particles after only 3 days of feeding. Copyright © 2012 Elsevier Inc. All rights reserved.

A lipoprotein lipase mutation (Asn291Ser) is associated with reduced HDL cholesterol levels in premature atherosclerosis

NARCIS (Netherlands)

Reymer, P.W.A.; Gagné, S E; Groenemeyer, B E; Zhang, H; Forsyth, I; Jansen, H; Seidell, J C; Kromhout, D.; Lie, K E; Kastelein, J.J.

1995-01-01

A reduction of high density lipoprotein cholesterol (HDC) is recognized as an important risk factor for coronary artery disease (CAD). We now show in approximately 1 in 20 males with proven atherosclerosis that an Asn291Ser mutation in the human lipoprotein lipase (LPL) gene is associated with

Cellular uptake of lipoproteins and Persistent Organic Compounds - An update and new data

DEFF Research Database (Denmark)

Hjelmborg, Philip Sebastian; Andreassen, Thomas Kjærgaard; Bonefeld-Jørgensen, Eva Cecilie

2008-01-01

including the pesticide DDT (p,p'-dichlorodiphenyltrichloroethane), and especially its metabolite DDE (p,p'-dichlorodiphenyldichloroethene), interacts with nuclear hormone receptors causing these to malfunction, which in turn results in a range of deleterious health effects in humans. The aim of the present...... study was to determine the role of lipoprotein receptors in mouse embryonic fibroblast (MEF) cells in conjunction with uptake of DDT-lipoprotein complexes from supplemented media in vitro. Uptake of DDT by MEF cells was investigated using MEF1 cells carrying the receptors LRP (low-density lipoprotein...... receptor-related protein) and LDLR (low density lipoprotein receptor) present and MEF4 cells with no LRP and LDLR expression. Cells were incubated together with the complex of LDL and [14C]DDT. The receptor function was further evaluated by adding the 40 kDa receptor-associated protein (RAP) which blocks...

Osbpl8 deficiency in mouse causes an elevation of high-density lipoproteins and gender-specific alterations of lipid metabolism.

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Olivier Béaslas

Full Text Available OSBP-related protein 8 (ORP8 encoded by Osbpl8 is an endoplasmic reticulum sterol sensor implicated in cellular lipid metabolism. We generated an Osbpl8(-/- (KO C57Bl/6 mouse strain. Wild-type and Osbpl8KO animals at the age of 13-weeks were fed for 5 weeks either chow or high-fat diet, and their plasma lipids/lipoproteins and hepatic lipids were analyzed. The chow-fed Osbpl8KO male mice showed a marked elevation of high-density lipoprotein (HDL cholesterol (+79% and phospholipids (+35%, while only minor increase of apolipoprotein A-I (apoA-I was detected. In chow-fed female KO mice a less prominent increase of HDL cholesterol (+27% was observed, while on western diet the HDL increment was prominent in both genders. The HDL increase was accompanied by an elevated level of HDL-associated apolipoprotein E in male, but not female KO animals. No differences between genotypes were observed in lecithin:cholesterol acyltransferase (LCAT or hepatic lipase (HL activity, or in the fractional catabolic rate of fluorescently labeled mouse HDL injected in chow-diet fed animals. The Osbpl8KO mice of both genders displayed reduced phospholipid transfer protein (PLTP activity, but only on chow diet. These findings are consistent with a model in which Osbpl8 deficiency results in altered biosynthesis of HDL. Consistent with this hypothesis, ORP8 depleted mouse hepatocytes secreted an increased amount of nascent HDL into the culture medium. In addition to the HDL phenotype, distinct gender-specific alterations in lipid metabolism were detected: Female KO animals on chow diet showed reduced lipoprotein lipase (LPL activity and increased plasma triglycerides, while the male KO mice displayed elevated plasma cholesterol biosynthetic markers cholestenol, desmosterol, and lathosterol. Moreover, modest gender-specific alterations in the hepatic expression of lipid homeostatic genes were observed. In conclusion, we report the first viable OsbplKO mouse model

X-ray and neutron small-angle scattering studies of human serum lipoproteins

International Nuclear Information System (INIS)

Luzzati, V.; Tardieu, A.; Mateu, L.; Sardet, C.; Stuhrmann, H.B.; Aggerbeck, L.; Scanu, A.M.

1976-01-01

The paper describes an extended x-ray study of two types of human serum lipoproteins and a neutron study of one of them. The results are similar and to some extent complementary. Serum lipoproteins provide an excellent illustration of the wealth of information that can be obtained by a small-angle scattering approach to the structure of particles with non-uniform density distribution, by using solvents of variable density

Skeletal muscle insulin resistance associated with cholesterol-induced activation of macrophages is prevented by high density lipoprotein.

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Andrew L Carey

Full Text Available BACKGROUND: Emerging evidence suggests that high density lipoprotein (HDL may modulate glucose metabolism through multiple mechanisms including pancreatic insulin secretion as well as insulin-independent glucose uptake into muscle. We hypothesized that HDL may also increase skeletal muscle insulin sensitivity via cholesterol removal and anti-inflammatory actions in macrophages associated with excess adiposity and ectopic lipid deposition. METHODS: Human primary and THP-1 macrophages were treated with vehicle (PBS or acetylated low density lipoprotein (acLDL with or without HDL for 18 hours. Treatments were then removed, and macrophages were incubated with fresh media for 4 hours. This conditioned media was then applied to primary human skeletal myotubes derived from vastus lateralis biopsies taken from patients with type 2 diabetes to examine insulin-stimulated glucose uptake. RESULTS: Conditioned media from acLDL-treated primary and THP-1 macrophages reduced insulin-stimulated glucose uptake in primary human skeletal myotubes compared with vehicle (primary macrophages, 168±21% of basal uptake to 104±19%; THP-1 macrophages, 142±8% of basal uptake to 108±6%; P<0.05. This was restored by co-treatment of macrophages with HDL. While acLDL increased total intracellular cholesterol content, phosphorylation of c-jun N-terminal kinase and secretion of pro- and anti-inflammatory cytokines from macrophages, none were altered by co-incubation with HDL. Insulin-stimulated Akt phosphorylation in human skeletal myotubes exposed to conditioned media was unaltered by either treatment condition. CONCLUSION: Inhibition of insulin-stimulated glucose uptake in primary human skeletal myotubes by conditioned media from macrophages pre-incubated with acLDL was restored by co-treatment with HDL. However, these actions were not linked to modulation of common pro- or anti-inflammatory mediators or insulin signaling via Akt.

Assessment of permeation of lipoproteins in human carotid tissue

Science.gov (United States)

Ghosn, Mohamad G.; Syed, Saba H.; Leba, Michael; Morrisett, Joel D.; Tuchin, Valery V.; Larin, Kirill V.

2010-02-01

Cardiovascular disease is among the leading causes of death in the United States. Specifically, atherosclerosis is an increasingly devastating contributor to the tally and has been found to be a byproduct of arterial permeability irregularities in regards to lipoprotein penetration. To further explore arterial physiology and molecular transport, the imaging technique of Optical Coherence Tomography (OCT) was employed. With OCT, the permeation of glucose (MW = 180 Da), low density lipoprotein (LDL; MW = 2.1 × 106 Da), and high density lipoprotein (HDL; MW = 2.5 × 105 Da) in human carotid tissue was studied to determine the effect of different molecular characteristics on permeation in atherosclerotic tissues. The permeability rates calculated from the diffusion of the molecular agents into the abnormal carotid tissue samples is compared to those of normal, healthy tissue. The results show that in the abnormal tissue, the permeation of agents correlate to the size constraints. The larger molecules of LDL diffuse the slowest, while the smallest molecules of glucose diffuse the fastest. However, in normal tissue, LDL permeates at a faster rate than the other two agents, implying the existence of a transport mechanism that facilitates the passage of LDL molecules. These results highlight the capability of OCT as a sensitive and specific imaging technique as well as provide significant information to the understanding of atherosclerosis and its effect on tissue properties.

Anthocyanins increase low-density lipoprotein and plasma cholesterol and do not reduce atherosclerosis in Watanabe Heritable Hyperlipidemic rabbits

DEFF Research Database (Denmark)

Nielsen, I. L. F.; Rasmussen, S.E.; Mortensen, Alicja

2005-01-01

a purified anthocyanin fraction front black currants, a black currant juice, probucol or control diet for 16 weeks. Purified anthocyanins significantly increased plasma cholesterol and low-density lipoprotein (LDL) cholesterol. Intake of black currant juice had no effect on total plasma cholesterol......, but lowered very-low-density lipoprotein (VLDL) cholesterol significantly. There were no significant effects of either purified anthocyanins or black currant juice on aortic cholesterol or development of atherosclerosis after 16 weeks. Probucol had no effect on plasma cholesterol but significantly lowered......, antioxidant enzymes, protein and lipid oxidation were not affected by any of the anthocyanin treatments. Adverse effects of purified anthocyanins were observed on plasma- and LDL-cholesterol. These effects were not observed with black currant juice, suggesting that black currants may contain components...

Obesity and high-density lipoprotein cholesterol in black and white 9- and 10-year-old girls : The National Heart, Lung, and Blood Institute Growth and Health Study

NARCIS (Netherlands)

Morrison, JA; Sprecher, D; McMahon, RP; Schreiber, GB; Khoury, PR

It has been hypothesized that the role of obesity in the pathogenesis of coronary heart disease (CHD) may be mediated in part through its inverse relationship with high-density lipoprotein cholesterol (HDL-C). Obesity is inversely correlated with HDL-C, and HDL-C has been shown to be protective

Enhanced susceptibility of low-density lipoproteins to oxidation in coronary bypass patients with progression of atherosclerosis

NARCIS (Netherlands)

Rijke, Y.B. de; Verwey, H.F.; Vogelezang, C.J.M.; Velde, E.A. van der; Princen, H.M.G.; Laarse, A. van der; Bruschke, A.V.G.; Berkel, T.J.C. van

1995-01-01

Oxidation of low-density lipoprotein (LDL) may play a causal role in atherosclerosis. In this study we analyzed whether the severity of progression of coronary atherosclerosis is related to the susceptibility of LDL to oxidative modification. On the basis of repeated coronary angiography, 28

Comparative studies of vertebrate scavenger receptor class B type 1: a high-density lipoprotein binding protein

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Holmes RS

2012-06-01

Full Text Available Roger S Holmes,1,2 Laura A Cox11Department of Genetics and Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, USA; 2School of Biomolecular and Physical Sciences, Griffith University, Nathan, Queensland, AustraliaAbstract: Scavenger receptor class B type 1 protein (SCARB1 plays an essential role in cholesterol homeostasis and functions in binding high density lipoprotein cholesterol (HDL in liver and other tissues of the body. SCARB1 also functions in lymphocyte homeostasis and in the uptake of hepatitis C virus (HCV by the liver. A genetic deficiency of this protein results in autoimmune disorders and significant changes in blood cholesterol phenotype. Comparative SCARB1 amino acid sequences and structures and SCARB1 gene locations were examined using data from several vertebrate genome projects. Vertebrate SCARB1 sequences shared 50%–99% identity as compared with 28%–31% sequence identities with other CD36-like superfamily members, ie, SCARB2 and SCARB3 (also called CD36. At least eight N-glycosylation sites were conserved among most of the vertebrate SCARB1 proteins examined. Sequence alignments, key amino acid residues, and conserved predicted secondary structures were also studied, including: cytoplasmic, transmembrane, and exoplasmic sequences; conserved N-terminal and C-terminal transmembrane glycines which participate in oligomer formation; conserved cystine disulfides and a free SH residue which participates in lipid transport; carboxyl terminal PDZ-binding domain sequences (Ala507-Arg/Lys508-Leu509; and 30 conserved proline and 18 conserved glycine residues, which may contribute to short loop formation within the exoplasmic HDL-binding sequence. Vertebrate SCARB1 genes usually contained 12 coding exons. The human SCARB1 gene contained CpG islands, micro RNA binding sites, and several transcription factor binding sites (including PPARG which may contribute to the high level (13.7 times

Aminoacylation of the N-terminal cysteine is essential for Lol-dependent release of lipoproteins from membranes but does not depend on lipoprotein sorting signals.

Science.gov (United States)

Fukuda, Ayumu; Matsuyama, Shin-Ichi; Hara, Takashi; Nakayama, Jiro; Nagasawa, Hiromichi; Tokuda, Hajime

2002-11-08

Lipoproteins are present in a wide variety of bacteria and are anchored to membranes through lipids attached to the N-terminal cysteine. The Lol system of Escherichia coli mediates the membrane-specific localization of lipoproteins. Aspartate at position 2 functions as a Lol avoidance signal and causes the retention of lipoproteins in the inner membrane, whereas lipoproteins having residues other than aspartate at position 2 are released from the inner membrane and localized to the outer membrane by the Lol system. Phospholipid:apolipoprotein transacylase, Lnt, catalyzes the last step of lipoprotein modification, converting apolipoprotein into mature lipoprotein. To reveal the importance of this aminoacylation for the Lol-dependent membrane localization, apolipoproteins were prepared by inhibiting lipoprotein maturation. Lnt was also purified and used to convert apolipoprotein into mature lipoprotein in vitro. The release of these lipoproteins was examined in proteoliposomes. We show here that the aminoacylation is essential for the Lol-dependent release of lipoproteins from membranes. Furthermore, lipoproteins with aspartate at position 2 were found to be aminoacylated both in vivo and in vitro, indicating that the lipoprotein-sorting signal does not affect lipid modification.

Identifying low density lipoprotein cholesterol associated variants in the Annexin A2 (ANXA2) gene

DEFF Research Database (Denmark)

Fairoozy, Roaa Hani; Cooper, Jackie; White, Jon

2017-01-01

Background and aims: Annexin-A2 (AnxA2) is an endogenous inhibitor of proprotein convertase subtilisin/kexin type-9 (PCSK9). The repeat-one (R1) domain of AnxA2 binds to PCSK9, blocking its ability to promote degradation of low-density lipoprotein cholesterol-receptors (LDL-R) and thereby regulat...

Plasma levels of HDL subpopulations and remnant lipoproteins predict the extent of angiographically defined disease in post-menopausal women

Science.gov (United States)

The association of coronary heart disease (CHD) with subpopulations of triglyceride (TG)-rich lipoproteins and high-density lipoproteins (HDL) is established in men, but has not been well characterized in women. Plasma HDL subpopulation concentrations, quantified by 2-dimensional gel electrophoresis...

Involvement of microtubules in lipoprotein degradation and utilization for steroidogenesis in cultured rat luteal cells

International Nuclear Information System (INIS)

Rajan, V.P.; Menon, K.M.

1985-01-01

Cells isolated from superovulated rat ovaries metabolize low density lipoprotein (LDL) and high density lipoprotein (HDL) of human or rat origin and use the lipoprotein-derived cholesterol as a precursor for progesterone production. Under in vitro conditions, both lipoproteins are internalized and degraded in the lysosomes, although degradation of HDL is of lower magnitude than that of LDL. In this report we have examined the role of cellular microtubules in the internalization and degradation of human LDL and HDL in cultured rat luteal cells. The microtubule depolymerizing agents colchicine, podophyllotoxin, vinblastine, and nocodazole as well as taxol, deuterium oxide, and dimethyl sulfoxide, which are known to rapidly polymerize cellular tubulin into microtubules, were used to block the function of microtubules. When these antimicrotubule agents were included in the incubations, degradation of the apolipoproteins of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL by the luteal cells was inhibited by 50-85% compared to untreated control values. Maximum inhibitory effects were observed when the cells were preincubated with the inhibitor for at least 4 h at 37 C before treatment with the labeled lipoprotein. Lipoprotein-stimulated progesterone production by luteal cells was also inhibited by 50% or more in the presence of antimicrotubule agents. However, basal and hCG-stimulated progesterone production were unaffected by these inhibitors. The binding of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL to luteal cell plasma membrane receptors was not affected by the microtubule inhibitors. Although binding was unaffected and degradation was impaired in the presence of the inhibitors, there was no detectable accumulation of undegraded lipoprotein within the cells during the 24 h of study

A More Flexible Lipoprotein Sorting Pathway

Science.gov (United States)

Chahales, Peter

2015-01-01

Lipoprotein biogenesis in Gram-negative bacteria occurs by a conserved pathway, each step of which is considered essential. In contrast to this model, LoVullo and colleagues demonstrate that the N-acyl transferase Lnt is not required in Francisella tularensis or Neisseria gonorrhoeae. This suggests the existence of a more flexible lipoprotein pathway, likely due to a modified Lol transporter complex, and raises the possibility that pathogens may regulate lipoprotein processing to modulate interactions with the host. PMID:25755190

Analyzing the molecular mechanism of lipoprotein localization in Brucella.

Science.gov (United States)

Goolab, Shivani; Roth, Robyn L; van Heerden, Henriette; Crampton, Michael C

2015-01-01

Bacterial lipoproteins possess diverse structure and functionality, ranging from bacterial physiology to pathogenic processes. As such many lipoproteins, originating from Brucella are exploited as potential vaccines to countermeasure brucellosis infection in the host. These membrane proteins are translocated from the cytoplasm to the cell membrane where they are anchored peripherally by a multifaceted targeting mechanism. Although much research has focused on the identification and classification of Brucella lipoproteins and their potential use as vaccine candidates for the treatment of Brucellosis, the underlying route for the translocation of these lipoproteins to the outer surface of the Brucella (and other pathogens) outer membrane (OM) remains mostly unknown. This is partly due to the complexity of the organism and evasive tactics used to escape the host immune system, the variation in biological structure and activity of lipoproteins, combined with the complex nature of the translocation machinery. The biosynthetic pathway of Brucella lipoproteins involves a distinct secretion system aiding translocation from the cytoplasm, where they are modified by lipidation, sorted by the lipoprotein localization machinery pathway and thereafter equipped for export to the OM. Surface localized lipoproteins in Brucella may employ a lipoprotein flippase or the β-barrel assembly complex for translocation. This review provides an overview of the characterized Brucella OM proteins that form part of the OM, including a handful of other characterized bacterial lipoproteins and their mechanisms of translocation. Lipoprotein localization pathways in gram negative bacteria will be used as a model to identify gaps in Brucella lipoprotein localization and infer a potential pathway. Of particular interest are the dual topology lipoproteins identified in Escherichia coli and Haemophilus influenza. The localization and topology of these lipoproteins from other gram negative bacteria

Analyzing the molecular mechanism of lipoprotein localization in Brucella

Science.gov (United States)

Goolab, Shivani; Roth, Robyn L.; van Heerden, Henriette; Crampton, Michael C.

2015-01-01

Bacterial lipoproteins possess diverse structure and functionality, ranging from bacterial physiology to pathogenic processes. As such many lipoproteins, originating from Brucella are exploited as potential vaccines to countermeasure brucellosis infection in the host. These membrane proteins are translocated from the cytoplasm to the cell membrane where they are anchored peripherally by a multifaceted targeting mechanism. Although much research has focused on the identification and classification of Brucella lipoproteins and their potential use as vaccine candidates for the treatment of Brucellosis, the underlying route for the translocation of these lipoproteins to the outer surface of the Brucella (and other pathogens) outer membrane (OM) remains mostly unknown. This is partly due to the complexity of the organism and evasive tactics used to escape the host immune system, the variation in biological structure and activity of lipoproteins, combined with the complex nature of the translocation machinery. The biosynthetic pathway of Brucella lipoproteins involves a distinct secretion system aiding translocation from the cytoplasm, where they are modified by lipidation, sorted by the lipoprotein localization machinery pathway and thereafter equipped for export to the OM. Surface localized lipoproteins in Brucella may employ a lipoprotein flippase or the β-barrel assembly complex for translocation. This review provides an overview of the characterized Brucella OM proteins that form part of the OM, including a handful of other characterized bacterial lipoproteins and their mechanisms of translocation. Lipoprotein localization pathways in gram negative bacteria will be used as a model to identify gaps in Brucella lipoprotein localization and infer a potential pathway. Of particular interest are the dual topology lipoproteins identified in Escherichia coli and Haemophilus influenza. The localization and topology of these lipoproteins from other gram negative bacteria

Highly absorptive curcumin reduces serum atherosclerotic low-density lipoprotein levels in patients with mild COPD

Directory of Open Access Journals (Sweden)

Funamoto M

2016-08-01

Full Text Available Masafumi Funamoto,1,2 Yoichi Sunagawa,1–3 Yasufumi Katanasaka,1–3 Yusuke Miyazaki,1,2 Atsushi Imaizumi,4 Hideaki Kakeya,5 Hajime Yamakage,2 Noriko Satoh-Asahara,2 Maki Komiyama,2 Hiromichi Wada,2 Koji Hasegawa,2 Tatsuya Morimoto1–3 1Division of Molecular Medicine, School of Pharmaceutical Sciences, University of Shizuoka, Shizuoka, 2Clinical Research Institute, National Hospital Organization Kyoto Medical Center, Kyoto, 3Shizuoka General Hospital, Shizuoka, 4Theravalues Corporation, Kioicho, Tokyo, 5Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan Purpose: COPD is mainly caused by tobacco smoking and is associated with a high frequency of coronary artery disease. There is growing recognition that the inflammation in COPD is not only confined to the lungs but also involves the systemic circulation and can impact nonpulmonary organs, including blood vessels. α1-antitrypsin–low-density lipoprotein (AT-LDL complex is an oxidatively modified LDL that accelerates atherosclerosis. Curcumin, one of the best-investigated natural products, is a powerful antioxidant. However, the effects of curcumin on AT-LDL remain unknown. We hypothesized that Theracurmin®, a highly absorptive curcumin with improved bioavailability using a drug delivery system, ameliorates the inflammatory status in subjects with mild COPD.Patients and methods: This is a randomized, double-blind, parallel-group study. Subjects with stages I–II COPD according to the Japanese Respiratory Society criteria were randomly assigned to receive 90 mg Theracurmin® or placebo twice a day for 24 weeks, and changes in inflammatory parameters were evaluated.Results: There were no differences between the Theracurmin® and placebo groups in terms of age, male/female ratio, or body mass index in 39 evaluable subjects. The percent changes in blood pressure

Impaired low-density lipoprotein receptor activity in chronic B-lymphocytic leukaemia cells

Energy Technology Data Exchange (ETDEWEB)

Juliusson, G.; Vitols, S.

1988-01-01

Cellular degradation of /sup 125/I-labelled low-density lipoprotein (LDL) was analysed in freshly isolated blood mononuclear cells from 26 patients with chronic B-lymphocytic leukaemia (CLL) and 8 healthy subjects, and in cells following 1,2 and 3 d of culture in medium containing 10% human lipoprotein-deficient serum (LPDS). Fresh CLL cells had lower LDL degradation rates than mononuclear cells from healthy subjects (p < 0.01). The LDL degradation rates increased during culture (p < 0.001), but to a lesser degree in CLL cells than in normal blood mononuclear cells (p < 0.001). The cellular degradation rate of /sup 125/I-LDL was markedly inhibited by an excess of unlabelled LDL, indicating that most of the /sup 125/I-LDL that was degraded had been internalized following binding to the LPDS-induced LDL degradation of CLL cells and the thymidine uptake in CLL cell cultures with (r = 0.70, p < 0.001) and without (r = 0.59, p < 0.01) the B cell mitogen, Epstein-Barr virus. The results indicate that LDL receptors might be involved in the regulation of CLL cell proliferation.

Moderate alcohol consumption and changes in postprandial lipoproteins of premenopausal and postmenopausal women: a diet-controlled, randomized intervention study.

Science.gov (United States)

van der Gaag, M S; Sierksma, A; Schaafsma, G; van Tol, A; Geelhoed-Mieras, T; Bakker, M; Hendriks, H F

2000-01-01

Moderate alcohol consumption is associated with a reduced risk of coronary heart disease. Earlier studies in men have shown that moderate alcohol consumption affects lipoprotein metabolism and hemostasis. In this diet-controlled, randomized, crossover trial, we investigated the effect on lipoprotein metabolism of moderate consumption of red wine or red grape juice with evening dinner for 3 weeks in premenopausal women using oral contraceptives and in postmenopausal women. After 3 weeks, blood samples were collected 1 hour before dinner up to 19 hours after starting dinner at 2-hour or 4-hour intervals. Plasma triglyceride concentrations and very low density lipoprotein (VLDL) triglyceride levels peaked 3 hours after dinner with wine in both premenopausal and postmenopausal women. After wine consumption, the overall high-density lipoprotein (HDL) cholesterol level was increased in postmenopausal women (mean increase 0.17 mmol/L, or 12%, p = 0.03), and the plasma low-density lipoprotein (LDL) cholesterol level was reduced in premenopausal women (mean reduction 0.35 mmol/L, or 12%, p = 0.01) as compared with grape juice consumption. The findings suggest that postprandial lipoprotein metabolism after moderate alcohol consumption differs between oral contraceptive-using premenopausal women and postmenopausal women. The response of postmenopausal women to alcohol resembled the response found in earlier studies in men.

Pemberian Whey-Dangke dalam Air Minum Menekan Kadar Kolesterol, Trigliserida dan Lipoprotein Darah Ayam Broiler

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Sulmiyati Sulmiyati

2017-06-01

Full Text Available Tujuan penelitian untuk mengetahui pengaruh penambahan whey dangke terhadap kadar kolesterol, trigliserida, LDL (low density lipoprotein, HDL (high density lipoprotein, VLDL (very low density lipoprotein darah ayam broiler dan mengukur konsentrasi pemberian whey dangke dalam air minum yang diberikan. Penelitian dilakukan dengan menggunakan Rancangan Acak Lengkap dengan enam perlakuan pemberian whey dangke dalam air minum dengan empat ulangan. Konsentrasi P0 adalah kelompok kontrol 0%; P1=pemberian whey dangke dengan konsentrasi 10%; P2 = pemberian whey dangke dengan konsentrasi 20%; P3 = pemberian whey dangke dengan konsentrasi 30%; P4 = pemberian whey dangke dengan konsentrasi 40%; dan P5 = pemberian whey dangke dengan konsentrasi 50%. Pemberian whey dangke pada ayam broiler strain cobb SR 707 dilakukan selama 15 hari (umur 20–35 hari. Parameter yang diamati adalah kadar kolesterol, trigliserida, LDL, HDL, dan VLDL darah ayam broiler. Data dianalisis dengan analisis sidik ragam, dan jika menunjukkan pengaruh nyata dilanjutkan dengan Uji Beda Nyata Terkecil (BNT. Hasil penelitian menunjukkan bahwa pemberian whey dangke dalam air minum tidak memberikan pengaruh yang nyata (P>0,05 terhadap parameter kolesterol, trigliserida, dan lipoprotein. Namun, terlihat kecenderungan penurunan kadar kolesterol seiring dengan peningkatan konsentrasi pemberian whey dangke. Hasil penelitian dapat disimpulkan bahwa hasil uji in vivo menunjukkan pemberian whey dangke dalam air minum pada ayam broiler pada konsentrasi 50% memperlihatkan penurunan kadar kolesterol hingga 15%. Abstract The purposes of research is to determine the effect of whey dangke against cholesterol levels, triglycerides, LDL, HDL, and VLDL broiler blood and measuring the concentration of whey dangke in water provided. The research was conducted using a completely randomized design with six treatments and four replications. P0 is the control group 0%; P1 = whey dangke added with a concentration

Measurement of rhesus monkey (Macaca mulatta) apolipoprotein B in serum by radioimmunoassay: comparison of immunoreactivities of rhesus and human low density lipoproteins

International Nuclear Information System (INIS)

Karlin, J.B.; Juhn, D.J.; Fless, G.; Scanu, A.M.; Rubenstein, A.H.

1978-01-01

A sensitive and specific double antibody radioimmunoassay for the major apolipoprotein (apoB) of rhesus (Macaca mulatta) serum very low density lipoprotein (VLDL) and low density lipoprotein (LDL) is described. The antiserum was raised to LDL (d 1.030 to 1.040 g/ml) and the LDL 2 (d 1.020 to 1.050 g/ml) was labeled with 125 I by the chloramine-T or iodine monochloride method. The assay, which was sensitive to 0.02 to 0.5 μg of LDL 2 , had an interassay coefficient of variation of 4.5%. This assay was successfully used to measure apoB in the whole serum and low density lipoproteins of control monkeys maintained on a standard Purina monkey chow (PMC) diet and of three groups of monkeys fed atherogenic diets: an average American diet, a 25% peanut oil and 2% cholesterol-supplemented PMC diet, and a 25% coconut oil and 2% cholesterol-supplemented PMC diet

Blood Lipoproteins under the Action of Exogenous Sex Steroids in the Postresuscitation Period

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L. N. Shcherbakova

2011-01-01

Full Text Available Objective: to study the effect of reproductive hormones on the blood lipoprotein spectrum in the postresuscitation period after cardiac arrest. Materials and methods. Experiments were carried out on 66 mature albino rats of either sex weighing 200—250 g. Ten-minute cardiac arrest was induced by intrathoracic ligation of the vascular bundle. At 30 min after resuscitation, 49 animals were intramuscularly injected placebo and 17 animals were administered gyn-odian depot (Schering, Germany. The investigators measured the plasma concentrations of progesterone, 17-OH progesterone, androstenedione, dehydroepiandrosterone sulfate, testosterone, estradiol, and estriol, as well as the levels of triglycerides, total, and high-density lipoprotein (HDL, low-density lipoprotein (LDL, and very low-density lipoprotein (VLDL cholesterols. Blood was sampled on days 2 and 16 in the absence of therapy and on day 16 of sex steroid therapy. Results. By day 2 postresuscitation, the progesterone/estradiol ratio increased by approximately 1.8 times in males and females. Despite the fact that there were no changes in the concentrations of triglycerides, VLDL and HDL cholesterols in both males and females at that time, but the level of LDL cholesterol increased. Gender-related differences in the LDL spectrum by day 2 postresuscitation remained only in the levels of LDL cholesterol. Despite the normalization of progesterone levels, the concentrations of triglycerides and VLDL cholesterol decreased by day 16 of the postresuscitative period in the absence of therapy. There were no gender-related differences in the lipoprotein spectrum at this stage. The exogenous estradiol in combination with dehydroepiandrosterone caused a significant increase in the concentration of HLD cholesterol and a reduction in that of VLDL cholesterol in males and females both. Conclusion. Under gynodian action, the lipid spectrum was indicative of the exogenous estra-diol and

Low-Density Lipoproteins Oxidation and Endometriosis

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Grzegorz Polak

2013-01-01

Full Text Available The etiopathogenesis of endometriosis still remains unknown. Recent data provide new valuable information concerning the role of oxidative stress in the pathophysiology of the disease. It has been proved that levels of different lipid peroxidation end products are increased in both peritoneal fluid (PF and serum of endometriotic patients. We assessed the concentration of oxidized low-density lipoproteins (oxLDL in PF of 110 women with different stages of endometriosis and 119 women with serous ( or dermoid ( ovarian cysts, as the reference groups. PF oxLDL levels were evaluated by ELISA. We found that concentrations of oxLDL in PF of endometriotic women were significantly higher compared to women with serous but not dermoid ovarian cysts. Interestingly, by analyzing concentrations of oxLDL in women with different stages of the disease, it was noted that they are significantly higher only in the subgroup of patients with stage IV endometriosis as compared to women with ovarian serous cysts. In case of minimal, mild, and moderate disease, PF oxLDL levels were similar to those noted in reference groups. Our results indicate that disrupted oxidative status in the peritoneal cavity of women with endometriosis may play a role in the pathogenesis of advanced stages of the disease.

Quantitative lipidomic analysis of plasma and plasma lipoproteins using MALDI-TOF mass spectrometry.

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Serna, Jorge; García-Seisdedos, David; Alcázar, Alberto; Lasunción, Miguel Ángel; Busto, Rebeca; Pastor, Óscar

2015-07-01

Knowledge of the plasma lipid composition is essential to clarify the specific roles of different lipid species in various pathophysiological processes. In this study, we developed an analytical strategy combining high-performance liquid chromatography with evaporative light scattering detection (HPLC-ELSD) and off-line coupling with matrix-assisted laser desorption/ionization with time-of-flight mass spectrometry (MALDI-TOF/MS) to determine the composition of plasma and major lipoproteins at two levels, lipid classes and lipid species. We confirmed the suitability of MALDI-TOF/MS as a quantitative measurement tool studying the linearity and repeatability for triglycerides (TG), phosphatidylethanolamine (PE) and phosphatidylcholine (PC). Moreover, data obtained with this method were correlated with other lipid classes and species measurements using currently available technologies. To establish the potential utility of our approach, human plasma very low density- (VLDL), low density- (LDL) and high density- (HDL) lipoproteins from 10 healthy donors were separated using ultracentrifugation, and compositions of nine lipid classes, cholesteryl esters (CE), TG, free cholesterol (FC), PE, phosphatidylinositol (PI), sulfatides (S), PC, lysophosphatidylcholine (LPC) and sphingomyelin (SM), analyzed. In total, 157 lipid species in plasma, 182 in LDL, 171 in HDL, and 148 in VLDL were quantified. The lipidomic profile was consistent with known differences in lipid classes, but also revealed unexpected differences in lipid species distribution of lipoproteins, particularly for LPC and SM. In summary, the methodology developed in this study constitutes a valid approach to determine the lipidomic composition of plasma and lipoproteins. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Evidence for low high-density lipoprotein cholesterol levels in Australian indigenous peoples: a systematic review.

Science.gov (United States)

Lyons, Jasmine G; O'Dea, Kerin; Walker, Karen Z

2014-06-02

Low plasma high-density lipoprotein cholesterol (HDL-C) levels are a strong, independent, but poorly understood risk factor for cardiovascular disease (CVD). Although this atherogenic lipid abnormality has been widely reported in Australia's Indigenous peoples, Aboriginal and Torres Strait Islanders, the evidence has not come under systematic review. This review therefore examines published data for Indigenous Australians reporting 1) mean HDL-C levels for both sexes and 2) factors associated with low HDL-C. PubMed, Medline and Informit ATSI Health databases were systematically searched between 1950 and 2012 for studies on Indigenous Australians reporting mean HDL-C levels in both sexes. Retrieved studies were evaluated by standard criteria. Low HDL-C was defined as: Indigenous populations living in rural and remote communities. Inverse associations between HDL-C and central obesity, diabetes prevalence and inflammatory markers suggest a particularly adverse CVD risk factor profile. An absence of sex dichotomy in HDL-C levels warrants further investigation.

Transvascular lipoprotein transport in patients with chronic renal disease

DEFF Research Database (Denmark)

Jensen, Trine Krogsgaard; Nordestgaard, Børge Grønne; Feldt-Rasmussen, Bo

2004-01-01

BACKGROUND: While increased plasma cholesterol is a well-established cardiovascular risk factor in the general population, this is not so among patients with chronic renal disease. We hypothesized that the transvascular lipoprotein transport, in addition to the lipoprotein concentration in plasma......, determines the degree of atherosclerosis among patients with chronic renal disease. METHODS: We used an in vivo method for measurement of transvascular transport of low-density lipoprotein (LDL) in 21 patients with chronic renal disease and in 42 healthy control patients. Autologous 131-iodinated LDL...... was reinjected intravenously, and the 1-hour fractional escape rate was taken as index of transvascular transport. RESULTS: Transvascular LDL transport tended to be lower in patients with chronic renal disease than in healthy control patients [3.3 (95% CI 2.4-4.2) vs. 4.2 (3.7-4.2)%/hour; NS]. However...

[Influence of diets with a high content of qualitatively different carbohydrates on the metabolism of blood lipoproteins].

Science.gov (United States)

Liapkov, B G; Listratenkova, E F

1977-01-01

The feeding of rats for a space of 30 days on diets with elevated content of starch or saccharose (71 per cent of the total calorific value) was followed by an accelerated synthesis and secretion into the blood of pre-beta-lipoproteins. The ration with succharose, however, produced a much greater effect on the rate of synthesis of pre-beta-lipoproteins than did the one containing starch. The action of both carbohydrate-rich rations was noted to be attended by a growing rate of the apoproteids and glycerides exchange in the low-density lipoproteins. The feature distinguishing the effect produced by the ration with saccharose, as compared with that containing starch, was an accelerated etherification of cholesterol in the blood.

Lipid peroxide levels of serum lipoprotein fractions of diabetic patients with angiopathy and 60Co-irradiated rabbit

International Nuclear Information System (INIS)

Tsunekawa, Hiroshi

1982-01-01

For a better understanding of the relationship between lipid peroxide (LPO) and vascular diseases, the author determined LPO levels and lipid contents of serum lipoprotein fractions of diabetics with angiopathy. The LPO level in high density lipoprotein (HDL) fraction of diabetic serum was significantly higher than that of normal serum whereas no significant increase was observed in the levels of very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions of diabetic serum. As to the ratios of LPO to total lipids in these lipoprotein fractions, it was found that the ratio in HDL fraction of the diabetics was markedly higher than that of the normals. These results suggest that the increase in LPO levels in the sera of diabetic patiens is due to that in HDL fraction. To study further this problem, the author employed 60 Co-irradiated rabbit as a model, since it was already reported that radiation affects lipid metabolism and LPO formation, and that it induces the development of atherosclerosis. Upon irradiation with 60 Co ranging from 100R to 700R, serum LPO level of rabbit was significantly increased. Although elevation of LPO level was found in each serum lipoprotein fraction of VLDL, LDL and HDL, LPO level per lipid content was significantly increased only in HDL fraction. In the irradiated rabbit, significant elevation of the level of LPO was also observed in the liver, while no significant increase was found in the kidney and spleen. These results indicate that high level of LPO observed in the serum of irradiated rabbit would be the reflection of the increased LPO in the liver. (J.P.N.)

Mice with chimeric livers are an improved model for human lipoprotein metabolism.

Science.gov (United States)

Ellis, Ewa C S; Naugler, Willscott Edward; Nauglers, Scott; Parini, Paolo; Mörk, Lisa-Mari; Jorns, Carl; Zemack, Helen; Sandblom, Anita Lövgren; Björkhem, Ingemar; Ericzon, Bo-Göran; Wilson, Elizabeth M; Strom, Stephen C; Grompe, Markus

2013-01-01

Rodents are poor model for human hyperlipidemias because total cholesterol and low density lipoprotein levels are very low on a normal diet. Lipoprotein metabolism is primarily regulated by hepatocytes and we therefore assessed whether chimeric mice extensively repopulated with human cells can model human lipid and bile acid metabolism. FRG [ F ah(-/-) R ag2(-/-)Il2r g (-/-)]) mice were repopulated with primary human hepatocytes. Serum lipoprotein lipid composition and distribution (VLDL, LDL, and HDL) was analyzed by size exclusion chromatography. Bile was analyzed by LC-MS or by GC-MS. RNA expression levels were measured by quantitative RT-PCR. Chimeric mice displayed increased LDL and VLDL fractions and a lower HDL fraction compared to wild type, thus significantly shifting the ratio of LDL/HDL towards a human profile. Bile acid analysis revealed a human-like pattern with high amounts of cholic acid and deoxycholic acid (DCA). Control mice had only taurine-conjugated bile acids as expcted, but highly repopulated mice had glycine-conjugated cholic acid as found in human bile. RNA levels of human genes involved in bile acid synthesis including CYP7A1, and CYP27A1 were significantly upregulated as compared to human control liver. However, administration of recombinant hFGF19 restored human CYP7A1 levels to normal. Humanized-liver mice showed a typical human lipoprotein profile with LDL as the predominant lipoprotein fraction even on a normal diet. The bile acid profile confirmed presence of an intact enterohepatic circulation. Although bile acid synthesis was deregulated in this model, this could be fully normalized by FGF19 administration. Taken together these data indicate that chimeric FRG-mice are a useful new model for human lipoprotein and bile-acid metabolism.

Inhibition of triacylglycerol and apoprotein B secretion and of low density lipoprotein binding in Hep G2 cells by eicosapentaenoic acid

International Nuclear Information System (INIS)

Wong, S.H.; Nestel, P.J.

1987-01-01

The consumption of long chain polyunsaturated fatty acids of fish oils leads to profound lowering of plasma triacylglyercol (TAG) but not of plasma cholesterol. Reasons for this were investigated with the human hepatoma cell line, the Hep G2 cell. Incubations with oleic acid (OA), linoleic acid (LA) and the characteristic marine fatty acid eicosapentaenoic acid (EPA) enriched cellular TAG mass, though least with EPA. However, secretion of very low density lipoprotein (VLDL)-TAG and apoprotein B (apo B), measured from [ 3 H]-glycerol and [ 3 H]-leucine was markedly inhibited by EPA. Preincubation with LA reduced VLDL-TAG but not apo B secretion in comparison with OA which stimulated both. A possible effect on low density lipoprotein (LDL) removal was studied by measuring [ 125 I]-LDL binding. Preincubation with either EPA or LA inhibited the saturable binding of LDL, observed with OA and control incubations. The binding of lipoproteins containing chylomicron remnants was not affected by any of the fatty acids

Distinct functional domains contribute to degradation of the low density lipoprotein receptor (LDLR) by the E3 ubiquitin ligase inducible Degrader of the LDLR (IDOL)

NARCIS (Netherlands)

Sorrentino, Vincenzo; Scheer, Lilith; Santos, Ana; Reits, Eric; Bleijlevens, Boris; Zelcer, Noam

2011-01-01

We recently identified the liver X receptor-regulated E3 ubiquitin ligase inducible degrader of the LDL receptor (IDOL) as a modulator of lipoprotein metabolism. Acting as an E3 ubiquitin ligase, IDOL triggers ubiquitination and subsequent degradation of the low density lipoprotein receptor (LDLR).

Investigation of the mechanism for penetration of low density lipoprotein into the arterial wall

Science.gov (United States)

Glukhova, O. E.; Zyktin, A. A.; Slepchenkov, M. M.

2018-02-01