Apoprotein B of lipoprotein(a) of human plasma.
Ontology highlight
ABSTRACT:
SUBMITTER: Mondola P
PROVIDER: S-EPMC1153975 | biostudies-other | 1982 Nov
REPOSITORIES: biostudies-other
Similar Datasets
Project description:Background and objectivesIn dialysis patients, the associations between apoprotein profile and all-cause or cardiovascular disease (CVD)-related mortality are not well known. We, therefore, investigated whether apoprotein levels are associated with these events.Design, setting, participants, & measurementsWe undertook a prospective observational cohort study of prevalent hemodialysis patients aged ≥18 years (n=1081), who were followed for 4 years (2011-2014). Outcomes were all-cause and CVD-related mortality. Predictors used were baseline apoprotein levels, particularly the apoprotein B (apo B)/ apoprotein A-1 (apo A-1) ratio. A Cox regression analysis was used to calculate the hazard ratios (HRs) for mortality. Apo A-1, apo B, and apo B/ apo A-1 ratio were analyzed with adjustments in three models: model 1, basic adjustment for age and sex; model 2, basic adjustments plus dialysis conditions (dialysis vintage, mean predialysis systolic blood pressure, dry weight, and mean intradialytic weight gain); and model 3, model 2 plus metabolic and inflammatory conditions (basal kidney disease, serum albumin, C-reactive protein level, and statin use).ResultsOf the 1081 patients included in the study, 203 deaths were recorded, 92 of which were related to CVD. The apo B/ apo A-1 ratio was significantly associated with all-cause and CVD-related mortality when analyzed by 1-SD increments or quartile IV versus I in all models. In model 3, HRs and 95% confidence intervals (95% CIs) for 1-SD increments of apo B/ apo A-1 ratio for all-cause mortality or CVD-related mortality were: HR, 1.16 (95% CI, 1.00 to 1.35), or HR, 1.38 (95% CI, 1.11 to 1.71), respectively, and for quartile IV versus I: HR, 1.65 (95% CI, 1.05 to 2.57), or HR, 2.56 (95% CI, 1.21 to 5.40), respectively. Apo A-1 was significantly associated with both mortalities in models 1 and 2. However, apo B was only significantly associated with CVD-related mortality in model 3.ConclusionsApoprotein measurement, especially the apo B/ apo A-1 ratio, was significantly associated with all-cause and CVD-related mortality in prevalent dialysis patients.
| S-EPMC4858486 | biostudies-literature
Project description:Monitoring cholesterol levels is strongly recommended to identify patients at risk for myocardial infarction. However, clinical markers beyond "bad" and "good" cholesterol are needed to precisely predict individual lipid disorders. Our work contributes to this aim by bringing together experiment and theory. We developed a novel computer-based model of the human plasma lipoprotein metabolism in order to simulate the blood lipid levels in high resolution. Instead of focusing on a few conventionally used predefined lipoprotein density classes (LDL, HDL), we consider the entire protein and lipid composition spectrum of individual lipoprotein complexes. Subsequently, their distribution over density (which equals the lipoprotein profile) is calculated. As our main results, we (i) successfully reproduced clinically measured lipoprotein profiles of healthy subjects; (ii) assigned lipoproteins to narrow density classes, named high-resolution density sub-fractions (hrDS), revealing heterogeneous lipoprotein distributions within the major lipoprotein classes; and (iii) present model-based predictions of changes in the lipoprotein distribution elicited by disorders in underlying molecular processes. In its present state, the model offers a platform for many future applications aimed at understanding the reasons for inter-individual variability, identifying new sub-fractions of potential clinical relevance and a patient-oriented diagnosis of the potential molecular causes for individual dyslipidemia.
| S-EPMC2361219 | biostudies-literature
Project description:Low-density lipoprotein (LDL) aggregation is central in triggering atherogenesis. A minor fraction of electronegative plasma LDL, termed LDL(-), plays a special role in atherogenesis. To better understand this role, we analyzed the kinetics of aggregation, fusion and disintegration of human LDL and its fractions, LDL(+) and LDL(-). Thermal denaturation of LDL was monitored by spectroscopy and electron microscopy. Initially, LDL(-) aggregated and fused faster than LDL(+), but later the order reversed. Most LDL(+) disintegrated and precipitated upon prolonged heating. In contrast, LDL(-) partially retained lipoprotein morphology and formed soluble aggregates. Biochemical analysis of all fractions showed no significant degradation of major lipids, mild phospholipid oxidation, and an increase in non-esterified fatty acid (NEFA) upon thermal denaturation. The main baseline difference between LDL subfractions was higher content of NEFA in LDL(-). Since NEFA promote lipoprotein fusion, increased NEFA content can explain rapid initial aggregation and fusion of LDL(-) but not its resistance to extensive disintegration. Partial hydrolysis of apoB upon heating was similar in LDL subfractions, suggesting that minor proteins importantly modulate LDL disintegration. Unlike LDL(+), LDL(-) contains small amounts of apoA-I and apoJ. Addition of exogenous apoA-I to LDL(+) hampered lipoprotein aggregation, fusion and precipitation, while depletion of endogenous apoJ had an opposite effect. Therefore, the initial rapid aggregation of LDL(-) is apparently counterbalanced by the stabilizing effects of minor proteins such as apoA-I and apoJ. These results help identify key determinants for LDL aggregation, fusion and coalescence into lipid droplets in vivo.
| S-EPMC5572826 | biostudies-literature
Project description:Background. Apolipoprotein (Apo) E plays a key role in the handling of lipoprotein particles with ApoE2 and ApoE4 frequently having opposite effects compared to ApoE3. Some individuals simultaneously carry both E2 and E4 alleles. The impact of the ApoE2/4 genotype on lipid concentrations and its consequences on health remain poorly documented. Objective. This study compared the lipid profile between ApoE2/4 carriers and other ApoE genotypes in relation to the waist circumference. Methods. Cholesterol, triglyceride (TG), and ApoB concentrations were measured among 2,680 Caucasians. Multivariate logistic regression models were used to estimate the contribution of ApoE2/4 to various dyslipidemic profiles associated with abdominal obesity. Results. In presence of abdominal obesity, the lipid profile was as deteriorated in ApoE2/4 carriers as in carriers of other ApoE genotypes. There was a more pronounced effect on TG-rich lipoproteins, particularly in ApoE2/2 (a feature of type III dysbetalipoproteinemia), and non-high-density lipoprotein (HDL) cholesterol in ApoE4/4. Compared to ApoE2/2, ApoE2/4 carriers presented lower very-low-density lipoprotein (VLDL) cholesterol concentrations and VLDL-cholesterol/TG ratios, with or without obesity, and higher low-density lipoprotein (LDL) cholesterol concentrations. Conclusion. In presence of abdominal obesity, the influence of the ApoE2 allele could be less pronounced than that of ApoE4 among ApoE2/4 individuals.
| S-EPMC4641183 | biostudies-literature
Project description:Virtually all apoprotein B (apoB)-containing lipoproteins of the peripheral interstitial fluid of subjects with primary lymphoedema float in the ultracentrifugal field in the density interval 1.019-1.063 g/ml; in this respect they are similar to plasma low-density lipoproteins (LDL). 2. Virtually all apo-B-containing lipoproteins of interstitial fluid migrate in the electrophoretic field with pre-beta mobility; in this respect they are similar to plasma very-low-density lipoproteins. 3. The apoB of lipoproteins of interstitial fluid does not differ in terms of Mr from apoB-100 of human plasma [Kane, Hardman & Paulus (1980) Proc. Natl. Acad. Sci. U.S.A. 77, 2465-2469] as determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 4. Both apoB of interstitial fluid and plasma are heterogenous in terms of their charge as determined by isoelectric focusing of their complexes with the nonionic detergent Nonidet P40. ApoB of plasma LDL focuses between pH5.9 and 6.65, and that of interstitial fluid LDL between pH 5.9 and 6.1. Thus the overall charge of apoB of interstitial fluid is more negative than that of its plasma LDL counterpart.
| S-EPMC1144142 | biostudies-other
Project description:An integrative analysis of human biofluid data in the exRNA Atlas revealed the existence of distinct extracellular RNA cargo types. To gain further insight on the biological nature of these cargo types, we correlated exRNA Atlas cargo profiles with a variety of other RNA-seq profiles. This study focuses on lipoprotein particle (LPP) exRNA profiles obtained via sequential density ultracentrifugation (SD-UC) and fast protein liquid chromatography (FPLC).
2018-12-20 | GSE124131 | GEO
Project description:Genome wide association, epidemiological, and clinical studies have established high lipoprotein(a) [Lp(a)] as a causal risk factor for atherosclerotic cardiovascular disease (ASCVD). Lp(a) is an apoB100 containing lipoprotein covalently bound to apolipoprotein(a) [apo(a)], a glycoprotein. Plasma Lp(a) levels are to a large extent determined by genetics. Its link to cardiovascular disease (CVD) may be driven by its pro-inflammatory effects, of which its association with oxidized phospholipids (oxPL) bound to Lp(a) is the most studied. Various inflammatory conditions, such as rheumatoid arthritis (RA), systemic lupus erythematosus, acquired immunodeficiency syndrome, and chronic renal failure are associated with high Lp(a) levels. In cases of RA, high Lp(a) levels are reversed by interleukin-6 receptor (IL-6R) blockade by tocilizumab, suggesting a potential role for IL-6 in regulating Lp(a) plasma levels. Elevated levels of IL-6 and IL-6R polymorphisms are associated with CVD. Therapies aimed at lowering apo(a) and thereby reducing plasma Lp(a) levels are in clinical trials. Their results will determine if reductions in apo(a) and Lp(a) decrease cardiovascular outcomes. As we enter this new arena of available treatments, there is a need to improve our understanding of mechanisms. This review will focus on the role of Lp(a) in inflammation and CVD.
| S-EPMC9247870 | biostudies-literature
Project description:Plasma levels of high density lipoprotein cholesterol (HDL-C) are inversely proportional to the incidence of cardiovascular disease. Recent applications of modern proteomic technologies have identified upward of 50 distinct proteins associated with HDL particles with many of these newly discovered proteins implicating HDL in nonlipid transport processes including complement activation, acute phase response and innate immunity. However, almost all MS-based proteomic studies on HDL to date have utilized density gradient ultracentrifugation techniques for HDL isolation prior to analysis. These involve high shear forces and salt concentrations that can disrupt HDL protein interactions and alter particle function. Here, we used high-resolution size exclusion chromatography to fractionate normal human plasma to 17 phospholipid-containing subfractions. Then, using a phospholipid binding resin, we identified proteins that associate with lipoproteins of various sizes by electrospray ionization mass spectrometry. We identified 14 new phospholipid-associated proteins that migrate with traditionally defined HDL, several of which further support roles for HDL in complement regulation and protease inhibition. The increased fractionation inherent to this method allowed us to visualize HDL protein distribution across particle size with unprecedented resolution. The observed heterogeneity across subfractions suggests the presence of HDL particle subpopulations each with distinct protein components that may prove to impart distinct physiological functions.
| S-EPMC3100175 | biostudies-literature
Project description:Extracellular vesicles (EVs) consist of lipid bilayers, occur in various biofluids, and are invaluable in biomarker screening. Liquid chromatography coupled with high-resolution mass spectrometry (LC-MS) was recently used to study comprehensive EV lipid profiles in vitro. The aim of this study was to establish a lipidomics platform for human plasma and serum EVs for comprehensive characterization of their lipid profiles, and to compare them with those of other lipid-containing particles, such as high-density lipoproteins (HDL), and low/very low-density lipoproteins (LDL/VLDL). Isolation was validated by specific protein markers; CD9 and MHC class for EVs, apoA-I for HDL, and apoB-100 for LDL/VLDL. Lipidomics identified 264 lipids from isolated plasma EVs, HDL, and LDL/VLDL. The absolute lipid levels per unit protein content in the EVs were more than eight times lower than those of the lipoproteins. Moreover, the EVs had higher lysoglycerophospholipid levels than HDL or LDL/VLDL. Similar profiles were also determined for human serum. The present study found that the lipid profiles of EVs are unique and distinctly different from those of lipoproteins. The lipidomics platform applied to human plasma and serum EVs could generate important information for the exploration and qualification of biomarkers in disease diagnosis.
| S-EPMC6918450 | biostudies-literature
Project description:RationaleSingle-nucleotide polymorphisms near the ILRUN (inflammation and lipid regulator with ubiquitin-associated-like and NBR1 [next to BRCA1 gene 1 protein]-like domains) gene are genome-wide significantly associated with plasma lipid traits and coronary artery disease (CAD), but the biological basis of this association is unknown.ObjectiveTo investigate the role of ILRUN in plasma lipid and lipoprotein metabolism.Methods and resultsILRUN encodes a protein that contains a ubiquitin-associated-like domain, suggesting that it may interact with ubiquitinylated proteins. We generated mice globally deficient for Ilrun and found they had significantly lower plasma cholesterol levels resulting from reduced liver lipoprotein production. Liver transcriptome analysis uncovered altered transcription of genes downstream of lipid-related transcription factors, particularly PPARα (peroxisome proliferator-activated receptor alpha), and livers from Ilrun-deficient mice had increased PPARα protein. Human ILRUN was shown to bind to ubiquitinylated proteins including PPARα, and the ubiquitin-associated-like domain of ILRUN was found to be required for its interaction with PPARα.ConclusionsThese findings establish ILRUN as a novel regulator of lipid metabolism that promotes hepatic lipoprotein production. Our results also provide functional evidence that ILRUN may be the casual gene underlying the observed genetic associations with plasma lipids at 6p21 in human.
| S-EPMC7644615 | biostudies-literature