Large HDL Research Articles

Alteration in Redox Status and Lipoprotein Profile in COVID-19 Patients with Mild, Moderate, and Severe Pneumonia.

Metabolic alterations, particularly disorders of lipoprotein metabolism in COVID-19, may affect the course and outcome of the disease. This study aims at evaluating the lipoprotein profile and redox status in SARS-CoV-2 infected patients with different pneumonia severity and their association with lethal outcomes. The prospective cohort study was performed on 98 COVID-19 patients with mild, moderate, and severe pneumonia. Lipid and inflammatory parameters, lipoprotein subclasses, and redox status biomarkers were determined at the study entry and after one week. Compared to patients with mild and moderate pneumonia, severely ill patients had higher oxidised low-density lipoprotein (oxLDL) and malondialdehyde levels and lower high-density lipoprotein cholesterol (HDL-C) concentrations and paraoxonase 1 activity. Reduction in the proportion of large HDL 2a subclasses with a concomitant increase in the proportion of smallest HDL 3c and small dense LDL (sdLDL) particles was observed in patients with severe disease during the time. However, these changes were reversed in the mild and moderate groups. The results showed a positive association between changes in oxLDL and total antioxidative status. However, prooxidants and antioxidants in plasma were lower in patients with lethal outcomes. Increased levels of oxLDL and sdLDL particles may contribute to the severity of COVID-19. The role of oxidative stress should be clarified in further studies, mainly its association with lethal outcomes.

Abstract 15399: Proteomic Landscape of Plasma Lipoprotein Responses to Regular Exercise

Introduction: Lipoproteins are among the strongest predictors of CVD and are altered through regular exercise. However, the molecular changes underlying the potential benefits of exercise on plasma lipoproteins are unclear. Methods: Proteins (n=4979) were quantified from the plasma of 647 Black and White adults (56% women, mean age = 34.9 yrs) before and after 20-weeks of endurance exercise training using SomaScan. All subjects had complete data for 7 lipoprotein traits that improved with training: HDL-C, TG, large TG rich lipoprotein particles (LTRLP), small LDL particles (SLDLP), large HDL particles (LHDLP), TRLP size, and LDLP size. Fully adjusted linear mixed models were used to test the association of 1) baseline proteins with baseline lipoproteins and 2) delta proteins with delta lipoproteins (delta = post training - baseline value). Significance was determined as FDR<0.05. Results: We identified numerous proteins associated with baseline levels of at least one of the seven lipoprotein traits (range: 48-1099) and whose changes in response to regular exercise were associated with concomitant changes in lipoproteins (range: 4-95) ( Table 1 ). Substantial overlap was found between proteins associated with lipoproteins across timepoints, with 16 proteins associated with 4 or more lipoprotein traits at both timepoints. Plasma abundance of 12/16 proteins significantly changed with training (FDR <0.05). Additionally, for these proteins plasma abundance changed in concordance with the beneficial direction of the associated lipoprotein trait (e.g., proteins associated with atheroprotective lipoprotein traits increased with training and proteins associated with atherogenic traits decreased). Conclusions: Beneficial alterations to plasma lipoproteins with regular exercise are reflected in changes to the plasma proteome. Proteins identified here may represent novel markers of the benefits of regular exercise and of systemic lipoprotein metabolism.

Association of HDL subfractions with cardiovascular risk in Hungarian general and Roma populations

Abstract Background High-density lipoprotein (HDL) cholesterol levels are inversely associated with cardiovascular risk (CVR). However, HDL cholesterol is not a homogeneous lipid and can be subdivided into subfractions, which are not uniformly associated with CVR. Among Roma populations, the prevalence of reduced HDL cholesterol levels and, consequently, that of cardiovascular diseases is very high. However, it is not known how this reduction affects the different HDL subfractions and whether changes in their representation are associated with changes in CVR. Methods The study aimed to investigate whether there is a difference in the HDL subfraction profile between the Hungarian general (HG) and Roma populations and to determine the association of the different subfractions with the CVR estimated by the Framingham Risk Score (FRS) and the Systematic COronary Risk Evaluation (SCORE) algorithms. HDL cholesterol was separated using the Lipoprint system, which separates 10 subfractions into three classes: large HDL (HDL-L), medium HDL (HDL-I), and small HDL (HDL-S). Analyses were carried out on samples of 100 control subjects (50 Hungarian general and 50 Roma individuals with normal lipid profiles) and 277 individuals with reduced HDL-C levels. Results Our results show that Roma has reduced levels of the overall HDL subfraction profile, with significant decreases in HDL-6, and -7. Regardless of the estimation method, elevated levels (in mmol/L) of HDL-1 to 3 and HDL-L were significantly associated with reduced risk. A higher representation (in %) of HDL-1 to 3 subfractions have a significant risk-reducing, while HDL-8 to 10 have a risk-increasing effect estimated by FRS. Conclusions The results of our study show that levels of CVR protective HDL subfractions are significantly lower in Roma individuals and their reduced levels are associated with increased CVR, suggesting that the distribution of HDL subfractions contributes to the overall unfavourable CVR profile of Roma. Key messages • Levels of HDL-6 and -7 subfractions were significantly lower in the Roma population than in the Hungarian general one. • The HDL subfraction profile of the Roma population is associated with a higher cardiovascular risk among them.

Causal effects of genetically predicted type 2 diabetes mellitus on blood lipid profiles and concentration of particle-size-determined lipoprotein subclasses: A two-sample Mendelian randomization study.

BackgroundObservational studies have shown inconsistent results of the associations between type 2 diabetes mellitus (T2DM) and blood lipid profiles, while there is also a lack of evidence from randomized controlled trials (RCTs) for the causal effects of T2DM on blood lipid profiles and lipoprotein subclasses.ObjectivesOur study aimed at investigating the causal effects of T2DM on blood lipid profiles and concentration of particle-size-determined lipoprotein subclasses by using the two-sample Mendelian randomization (MR) method.MethodsWe obtained genetic variants for T2DM and blood lipid profiles including high-density lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), triglycerides (TG), and total cholesterol (TC) from international genome-wide association studies (GWASs). Two-sample MR method was applied to explore the potential causal effects of genetically predicted T2DM on blood lipid profiles based on different databases, respectively, and results from each MR analysis were further meta-analyzed to obtain the summary results. The causal effects of genetically predicted T2DM on the concentration of different subclasses of lipoproteins that are determined by particle size were also involved in MR analysis.ResultsGenetically predicted 1-unit higher log odds of T2DM had a significant causal effect on a higher level of TG (estimated β coefficient: 0.03, 95% confidence interval [CI]: 0.00 to 0.06) and lower level of HDL-C (estimated β coefficient: −0.09, 95% CI: −0.11 to −0.06). The causality of T2DM on the level of TC or LDL-C was not found (estimated β coefficient: −0.01, 95% CI: −0.02 to 0.01 for TC and estimated β coefficient: 0.01, 95% CI: −0.01 to 0.02 for LDL-C). For different sizes of lipoprotein particles, 1-unit higher log odds of T2DM was causally associated with higher level of small LDL particles, and lower level of medium HDL particles, large HDL particles, and very large HDL particles.ConclusionEvidence from our present study showed causal effects of T2DM on the level of TG, HDL-C, and concentration of different particle sizes of lipoprotein subclasses comprehensively, which might be particularly helpful in illustrating dyslipidemia experienced by patients with T2DM, and further indicate new treatment targets for these patients to prevent subsequent excessive cardiovascular events from a genetic point of view.

Nut consumption is associated with a shift of the NMR lipoprotein subfraction profile to a less atherogenic pattern among older individuals at high CVD risk

BackgroundScientific evidence has accumulated on the beneficial effects of nut consumption on cardiovascular risk and cholesterol reduction, but few studies have examined the effects of nuts on advanced measures of lipoprotein atherogenicity determined by nuclear magnetic resonance (NMR) spectroscopy. We analyzed associations between the amount and type of of nuts consumed and advanced measures of lipoprotein atherogenity and insulin resistance in older individuals at high cardiovascular risk.MethodsThe present observational study was carried out within the framework of the Prevención con Dieta Mediterránea (PREDIMED) trial. Cross-sectional and longitudinal analyses after 1-year of follow-up were conducted in 196 men and women recruited in the PREDIMED-Reus (Spain) center. Dietary intake was assessed using a validated semi-quantitative food questionnaire. Baseline and 1-year fasting plasma lipoprotein and metabolite profiling were performed in plasma using NMR spectra Vantera® Clinical Analyzer. Associations by tertiles of nut consumption between baseline and 1-year changes and advanced measures of lipoprotein atherogenicity, branched chain amminoacids, and measures of insulin resistance were tested by multivariable-adjusted ANCOVA models.ResultsCompared to paticipants in the bottom tertile, those in the top tertile of total nut consumption showed higher levels of large HDL particles and HDL-cholesterol, lower levels of branched-chain amino acids (BCAA) and GlycA, and reduced lipoprotein insulin resistance and diabetes risk index. Participants in the top tertile of walnut consumption disclosed lower levels of very large VLDL, total LDL particles, LDL-cholesterol, and GlycA. Participants in the top tertile of non-walnut nut consumption displayed higher levels of total HDL particles, HDL-cholesterol and apoliporotein A1, lower BCAA and GlycA, and reduced lipoprotein insulin resistance. Participants in the top tertile of 1-year changes in walnut consumption showed increases in medium-sized HDL particles in comparison to the bottom tertile.ConclusionsIn older individuals at high cardiovascular risk, increasing nut consumption was associated with a shift of the NMR lipoprotein subfraction profile to a less atherogenic pattern, as well as lower circulating concentrations of BCAA and decreased insulin resistance. These results provide novel mechanistic insight into the cardiovascular benefit of nut consumption.Trial registration ISRCTN35739639; registration date: 05/10/2005; recruitment start date 01/10/2003.

EXERCISE TRAINING-INDUCED CHANGES IN LIPID TRAITS ARE ASSOCIATED WITH CHANGES IN CIRCULATING PROTEINS AND METABOLITES

PURPOSE: To examine the molecular mechanisms underlying beneficial effects of regular exercise on lipid metabolism. METHODS: Circulating proteins (n = 4979), metabolites (n = 300), and lipids/lipoproteins were measured in 647 Black and White adults from the HERITAGE Family Study at baseline and after 20 weeks of supervised endurance training. The current analysis focused on 7 lipid/lipoprotein traits that significantly changed with training: HDL- cholesterol (HDL-C), triglycerides (TG), large TG-rich lipoprotein particles (LTRLP), large HDL particles (LHDLP), small LDL particles (SLDLP), and mean TRLP (TRLPz) and LDLP size (LDLPz). The relationship between exercise-induced fold changes in circulating molecules and changes in lipid traits was examined using sparse canonical correlation analysis, which tests the joint associations between two sets of variables by creating composite canonical variates. All variables were corrected for age, sex, race, BMI, baseline value, and family membership via linear mixed models. RESULTS: We identified 3 canonical variate pairs of exercise-induced changes in lipid traits and circulating molecules. Molecular variate 1 was positively correlated with changes in TG, LTRLP, SLDLP, and TRLPz (r = 0.29-0.57, p < 0.0001). Conversely, molecular variate 3 was negatively correlated with changes in TG, LTRLP, SLDLP, and TRLPz (r = -0.30 to -0.39, p < 0.0001), and positively correlated with changes in LDLPz (r = 0.38, p < 0.0001). Molecular variate 2 was negatively correlated with HDL-C (r = -0.46, p < 0.0001) and LHDLP (r = -0.22, p < 0.0001) changes with training. Molecular loadings on the respective variates were largely distinct (Table 1). CONCLUSIONS: We identified groups of circulating molecules whose changes in response to exercise training are associated with changes in the plasma lipid and lipoprotein profile and may provide insights into the mechanisms underlying exercise-induced changes in lipid metabolism.

A Randomized Trial of ω-3 Fatty Acid Supplementation and Circulating Lipoprotein Subclasses in Healthy Older Adults

Omega-3 (n-3) PUFAs are recognized for triglyceride-lowering effects in people with dyslipidemia, but it remains unclear if n-3-PUFA intake influences lipoprotein profiles in older adults without hypertriglyceridemia. The objective was to determine the effect of n-3-PUFA supplementation on plasma lipoprotein subfractions in healthy older men and women in the absence of cardiovascular disease (CVD) or hypertriglyceridemia. This was a secondary analysis and considered exploratory. Thirty young (20-35 y old) and 54 older (65-85 y old) men and women were enrolled in the study. Fasting plasma samples were collected. After baseline sample collection, 44 older adults were randomly assigned to receive either n-3-PUFA ethyl esters (3.9g/d) or placebo (corn oil) for 6 mo. Pre- and postintervention plasma samples were used for quantitative lipoprotein subclass analysis using high-resolution proton NMR spectroscopy. The number of large, least-dense LDL particles decreased 17%-18% with n-3 PUFAs compared with placebo (<1% change; P<0.01). The number of small, dense LDL particles increased 26%-44% with n-3 PUFAs compared with placebo (∼11% decrease; P<0.01). The cholesterol content of large HDL particles increased by 32% with n-3 PUFAs and by 2% in placebo (P<0.01). The cholesterol content of small HDL particles decreased by 23% with n-3 PUFAs and by 2% in placebo (P<0.01). Despite increasing abundance of small, dense LDL particles that are associated with CVD risk, n-3 PUFAs reduced total triglycerides, maintained HDL, reduced systolic blood pressure, and shifted the HDL particle distribution toward a favorable cardioprotective profile in healthy older adults without dyslipidemia. This study suggests potential benefits of n-3-PUFA supplementation to lipoprotein profiles in healthy older adults without dyslipidemia, which should be considered when weighing the potential health benefits against the cost and ecological impact of widespread use of n-3-PUFA supplements.This trial was registered at clinicaltrials.gov as NCT03350906.

Prolonged Fasting Alters the Size, Function, and Glycoproteomic Profile of HDL Particles

ObjectivesTo investigate the effects of a single 36-hour fast on HDL glycoproteomic composition on isolated HDL particles. MethodsWe obtained plasma from a previous study where 20 healthy subjects, age 20–40, fasted for 36 hours. HDL was isolated using density-based ultracentrifugation steps, followed by size-exclusion chromatography. Glycoproteomic was analyzed using a targeted LC-MS/MS method, and lipoprotein particle size distribution analysis using nuclear magnetic resonance (NMR) spectroscopy. ResultsHDL-associated apolipoprotein A-IV (ApoA-IV) content was significantly reduced (8918.39 +/– 3823.39 normalized ion counts vs 3690.82 +/– 2147.29 normalized ion count, p adjusted < 0.0001), suggesting a reduction in intestinally-derived HDL after a 36-hour fast. HDL associated apolipoprotein C-III (ApoC-III) di-sialylated glycopeptides decreased in HDL following a 36-hour fast compared to an overnight 12-hour fast (0.1680 +/– 0.0342 normalized ion counts vs 0.1315 +/– 0.0373 normalized ion counts, p adjusted = 0.041). Additionally, particle size distribution analysis showed an increase in abundance of calibrated large HDL of size 9.6–13nm (3.42 +/– 2.218 μmol/L vs 3.885 +/– 2.134 μmol/L, p adjusted = 0.011) and a decrease in abundance of medium HDL of size 8.1–9.5nm (6.88 +/– 1.86 μmol/L vs 5.82 +/– 2.048 μmol/L, p adjusted = 0.019) after a 36-hour fast. There were no significant changes in LDL particle size (21.115 +/– nm s 21.205 +/– 0.458 nm, p adjusted = 0.655) but there was a significant increase in overall calibrated LDL particle concentration (1138.05 +/– 357.94 μmol/L vs 1262.3 +/– 313.33 μmol/L, p adjusted = 0.011) and calibrated small LDL particle concentration (454.85 +/– 187.76 μmol/L vs 598.8 +/– 190.84 μmol/L, p adjusted = 0.025). ConclusionsOur findings indicate that prolonged fasting alters lipoprotein profiles by affecting the proportions of large and small HDL and LDL particles, as well as altering the protein composition of HDL particles, specifically by reducing the abundance of ApoA-IV, which suggests a reduction in the contribution of intestinally-derived HDL particles to the circulating HDL pool. Future studies are needed to determine the long-term effects of multiple bouts of prolonged fasting. Funding SourcesUniversity of California Davis, National Institute on Aging.

Egg Consumption Modulates Expression of Genes Involved in T Cell Activation and Differentiation That Correlate With HDL Profiles

ObjectivesHDL is known to be an important modulator of T cell activity. We have previously demonstrated that whole eggs modulate HDL profiles when compared to egg whites; thus, we investigated whether different egg-based diets affect expression of genes involved in T cell activation and differentiation in a manner that correlates with changes in HDL profiles.MethodsA 16-week randomized, crossover intervention trial was conducted in which healthy, young adult men and women (18–35 y, n = 26) completed a 4-week egg-free dietary period, followed by random assignment to a 4-week 3 whole egg/day or 3 egg white/day diet period. Participants then entered a 4-week egg-free washout period before switching to the alternative egg treatment for 4 weeks. Fasting HDL profiles and peripheral blood mononuclear cell (PBMC) gene expression immune arrays were measured at the conclusion of each dietary period.ResultsOur data showed that whole egg intake had the greatest impact on PBMC expression of genes related to T cell activation and differentiation. Compared to the egg-free diet, expression of CD4, CD34, and CD68 were significantly reduced following the whole egg period. We similarly observed trends toward decreased expression of HLA-DRA, CCL2, TGF-beta, and CCR4 following the whole egg diet, and increased expression of IL-12 beta, CLTA4, and PF4. When analyzing changes in gene expression between the egg white and whole egg diet periods, we identified a total of 25 and 21 genes related to immunity and inflammation that significantly correlated with changes in the number of large HDL particles and apolipoprotein A1 (apoA1) concentrations in serum, respectively. 68% and 76% of genes that correlated with large HDL and apoA1, respectively, were related to modulation of T cell activity, suggesting that egg-induced changes in HDL profiles may have stronger modulatory effects on T cells compared to other immune cell subtypes within PBMC samples.ConclusionsOur findings suggest that whole eggs promote anti-inflammatory and modulatory changes in gene expression related to T cell activation and differentiation, which directly correlate with changes in HDL profiles.Funding SourcesThis study was funded by an Agriculture and Food Research Initiative Grant from the USDA National Institute of Food and Agriculture.

Association of egg consumption, metabolic markers, and risk of cardiovascular diseases: A nested case-control study.

Few studies have assessed the role of individual plasma cholesterol levels in the association between egg consumption and the risk of cardiovascular diseases. This research aims to simultaneously explore the associations of self-reported egg consumption with plasma metabolic markers and these markers with the risk of cardiovascular disease (CVD). Totally 4778 participants (3401 CVD cases subdivided into subtypes and 1377 controls) aged 30-79 were selected based on the China Kadoorie Biobank. Targeted nuclear magnetic resonance was used to quantify 225 metabolites in baseline plasma samples. Linear regression was conducted to assess associations between self-reported egg consumption and metabolic markers, which were further compared with associations between metabolic markers and CVD risk. Egg consumption was associated with 24 out of 225 markers, including positive associations for apolipoprotein A1, acetate, mean HDL diameter, and lipid profiles of very large and large HDL, and inverse associations for total cholesterol and cholesterol esters in small VLDL. Among these 24 markers, 14 were associated with CVD risk. In general, the associations of egg consumption with metabolic markers and of these markers with CVD risk showed opposite patterns. In the Chinese population, egg consumption is associated with several metabolic markers, which may partially explain the protective effect of moderate egg consumption on CVD. This work was supported by the National Natural Science Foundation of China (81973125, 81941018, 91846303, 91843302). The CKB baseline survey and the first re-survey were supported by a grant from the Kadoorie Charitable Foundation in Hong Kong. The long-term follow-up is supported by grants (2016YFC0900500, 2016YFC0900501, 2016YFC0900504, 2016YFC1303904) from the National Key R&D Program of China, National Natural Science Foundation of China (81390540, 81390541, 81390544), and Chinese Ministry of Science and Technology (2011BAI09B01). The funders had no role in the study design, data collection, data analysis and interpretation, writing of the report, or the decision to submit the article for publication.

Eggs Improve Plasma Biomarkers in Patients with Metabolic Syndrome Following a Plant-Based Diet-A Randomized Crossover Study.

Plant-based (PB) diets are considered a healthy dietary pattern; however, eggs are not always included in this dietary regime. We hypothesized that the addition of two eggs per day would increase HDL cholesterol as well as plasma lutein, zeaxanthin and choline in individuals with metabolic syndrome (MetS). In this randomized controlled crossover intervention, we recruited 30 participants (49.3 ± 8 y) with MetS who followed a PB diet for 13 weeks. A registered dietitian advised all subjects on food selection and followed them through the intervention to ensure compliance. Participants underwent a 2-week washout with no eggs or spinach (a source of dietary lutein and zeaxanthin) and were randomly allocated to consume spinach (70 g) with either two eggs (EGG) or the equivalent amount of egg substitute (SUB) for breakfast for 4 weeks. After a 3-week washout, they were allocated the alternate breakfast. A total of 24 participants (13 women/11 men) finished the intervention. Plasma lipids, glucose, insulin, anthropometrics, plasma lutein, zeaxanthin, choline and trimethylamine oxide (TMAO) were assessed at baseline and the end of each intervention. When we compared individuals consuming the EGG versus the SUB breakfast, we observed a lower body weight (p < 0.02) and a higher HDL cholesterol (p < 0.025) after the EGG diet. There were no differences in plasma LDL cholesterol, triglycerides, glucose, insulin, or blood pressure. The number of large HDL particles measured by NMR was higher after EGG (p < 0.01) as compared to SUB. Plasma choline was higher in both treatments (p < 0.01) compared to baseline (8.3 ± 2.1 μmol/L). However, plasma choline values were higher in EGG (10.54 ± 2.8 μmol/L) compared to SUB (9.47 ± 2.7 μmol/L) p < 0.025. Both breakfasts increased plasma lutein compared to baseline (p < 0.01), while plasma zeaxanthin was only increased in the egg intervention (p < 0.01). These results indicate that consuming a plant-based diet in combination with whole eggs increases plasma HDL cholesterol, choline and zeaxanthin, important biomarkers in subjects with MetS.

Exploring the Causal Roles of Circulating Remnant Lipid Profile on Cardiovascular and Cerebrovascular Diseases: Mendelian Randomization Study.

BackgroundCausal evidence of circulating lipids especially the remnant cholesterol with cardiovascular and cerebrovascular disease (CVD) is lacking. This research aimed to explore the causal roles of extensive lipid traits especially the remnant lipids in CVD.MethodsTwo-sample Mendelian randomization (TSMR) analysis was performed based on large-scale meta-analysis datasets in European ancestry. The causal effect of 15 circulating lipid profiles including 6 conventional lipids and 9 remnant lipids on coronary heart disease (CHD) and ischemic stroke (IS), as well as the subtypes, was assessed.ResultsApolipoprotein B (Apo B), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) were still important risk factors for CHD and myocardial infarction (MI) but not for IS. Apo B is the strongest which increased the CHD and MI risk by 44% and 41%, respectively. The odds ratios (ORs) of total TG on CHD and MI were 1.25 (95% confidence interval [CI], 1.13–1.38) and 1.24 (95% CI, 1.11–1.38), respectively. A one standard deviation difference increased TG in medium very-low-density lipoproteins (M.VLDL.TG), TG in small VLDL (S.VLDL.TG), TG in very small VLDL (XS.VLDL.TG), TG in intermediate-density lipoproteins (IDL.TG), TG in very large HDL (XL.HDL.TG), and TG in small HDL (S.HDL.TG) particles also robustly increased the risk of CHD and MI by 9–28% and 9–27%, respectively. TG in very/extremely large VLDL (XXL.VLDL.TG and XL.VLDL.TG) were insignificant or even negatively associated with CHD (in multivariable TSMR), and negatively associated with IS as well.ConclusionThe remnant lipids presented heterogeneity and two-sided effects for the risk of CHD and IS that may partially rely on the particle size. The findings suggested that the remnant lipids were required to be intervened according to specific components. This research confirms the importance of remnant lipids and provides causal evidence for potential targets for intervention.

Abstract 417: Elevation Of Serum Hdl And Apoe Level In A Novel Vps35l Deficient Mouse Model

Aim: Defect of the endosomal protein sorting factor VPS35L causes novel congenital anomalies syndrome, in which cholesterol dysmetabolism is one of the symptoms. To reveal the biochemical mechanisms, the a model mouse was developed and characterized. Methods: Loss-of-function mutation, N995del, VPS35L knock-in (KI) mice were generated. Serum lipoprotein profiles were assessed by LipoSEARCH™ (Immuno-Biological Laboratories, Japan). For biochemical assays, 70 micro-L of serum was sub-fractionated with Superose 6 column in PBS and total and free cholesterol detected using LabAssay™cholesterol (Fujifilm Wako Chemicals, Japan) and Pureauto™S F-CHO-N (SEKISUI MEDICAL, Japan) assay kits. Negative images of fractioned lipoproteins were observed by TEM (JEM-1400Plus, JEOL, Japan). ApoA-I and apoE in the fractions were determined by use of a mouse apoA1 ELISA PRO kit and a mouse apoE ELISA PRO kit (Mabtech AB, Sweden). Mouse liver total RNA was isolated by ISOGEN (Nippon Gene, Japan) and first-strand cDNA generated using the Invitrogen™ SuperScript™IV First-Strand Synthesis system with random hexamers. For quantitative real-time PCR, the StepOnePlus™ real-time PCR system (Thermo Fisher) was used, and the PCR end product of each well confirmed by the melt curve analysis. Results: Lipoprotein analysis indicated the KI mice showed 1.9-fold higher total cholesterol than WT mice. LDL-C and HDL-C were increased 2.9- and 1.9-fold compared to WT mice, respectively. ApoA-I levels in the large HDL and HDL fractions were all significantly increased 1.5-, and 1.6-fold, whereas apoE levels were elevated 25-, and 8.4-fold, respectively. Conclusions: Ablation of VPS35L in MEF(3T3) cells caused loss of endocytosis of the LDL receptor and LRP1, and perhaps even SR-BI, which may lead to increased serum LDL and HDL levels in the loss-of-function KI model mice. Surprisingly. a high level of apoE was detected in KI mice, especially in the HDL fraction. In this case, apoE catabolism became abnormal due to the lack of LRP1 at the cell surface. Abnormal metabolism of apoE may affect the central nervous system or neuron generation. Further examination of the phenotype of this this model mouse line are warranted.

Determination of Serum Progranulin in Patients with Untreated Familial Hypercholesterolemia.

Background: Familial hypercholesterolemia (FH) is an autosomal dominant trait characterized by elevated LDL-C concentrations and is associated with an increased risk of premature atherosclerosis. Progranulin (PGRN) is a multifunctional protein that is known to have various anti-atherogenic effects. To date, the use of serum PGRN in patients with FH has not been studied. Methods: In total, 81 untreated patients with heterozygous FH (HeFH) and 32 healthy control subjects were included in this study. Serum PGRN, sICAM-1, sVCAM-1, oxLDL and TNFα concentrations were determined by ELISA. Lipoprotein subfractions were detected by Lipoprint. We diagnosed FH using the Dutch Lipid Clinic Network criteria. Results: We could not find a significant difference between the PGRN concentrations of the HeFH patients and controls (37.66 ± 9.75 vs. 38.43 ± 7.74 ng/mL, ns.). We found significant positive correlations between triglyceride, TNFα, sVCAM-1, the ratio of small HDL subfraction and PGRN, while significant negative correlations were found between the ratio of large HDL subfraction and PGRN both in the whole study population and in FH patients. PGRN was predicted by sVCAM-1, logTNFα and the ratio of small HDL subfraction. Conclusions: The strong correlations between HDL subfractions, inflammatory markers and PGRN suggest that PGRN may exert its anti-atherogenic effect in HeFH through the alteration of HDL composition and the amelioration of inflammation rather than through decreasing oxidative stress.

The metabolic signature of cardiovascular disease and arterial calcification in patients with chronic kidney disease

Background and aimsThe relationship between chronic kidney disease (CKD) and cardiovascular events is well-established. Clinically recognised risk factors of cardiovascular disease cannot fully explain this association. The objective of the present cross-sectional study was to investigate associations between serum metabolites and prevalent cardiovascular disease, as well as subclinical cardiovascular disease measured as coronary artery calcium score (CACS) in patients with CKD. MethodsMore than 200 preselected metabolites were quantified using nuclear magnetic resonance spectroscopy in 725 patients and 174 controls from the Copenhagen CKD Cohort. CACS was determined by computed tomography. ResultsMean age of patients was 57.8 years, and 444 (61.3%) were men. Most of patients had hypercholesterolemia, and 133 (18.3%) had type 2 diabetes. Overall, 85 metabolites were significantly associated with prevalent cardiovascular disease in a model adjusted for eGFR, age, and sex, as well as Bonferroni correction for multiple testing (p < 0.001). After further adjusting for diabetes, BMI, smoking, and cholesterol-lowering medication, the significance was lost for all but six metabolites (concentration of ApoA-1, cholesterol in total HDL and HDL2, total lipids and phospholipids in large HDL particles, and the ratio of phospholipids to total lipids in smaller VLDL particles). Of the 85 metabolites associated with prevalent cardiovascular disease, 71 were also associated with CACS in a similar pattern. Yet, in the model adjusted for all seven cardiovascular risk factors, only serum glucose levels and the ratio of triglycerides to total lipids in larger LDL particles remained significant. ConclusionsIn patients with CKD, associations with prevalent cardiovascular disease were mainly found for HDL-related metabolites, while CACS was associated with glucose levels and increased triglycerides to total lipids ratio in LDL particles.

The Arg82Cys Polymorphism of the Protein Nepmucin Implies a Role in HDL Metabolism.

ContextBlood lipid levels are linked to the risk of cardiovascular disease and regulated by genetic factors. A low-frequency polymorphism Arg82Cys (rs72836561) in the membrane protein nepmucin, encoded by CD300LG, is associated with lower fasting concentration of high-density lipoprotein cholesterol (HDLc) and higher fasting triglycerides. However, whether the variant is linked to postprandial lipids and glycemic status remains elusive.ObjectiveHere, we augment the genetic effect of Arg82Cys on fasting plasma concentrations of HDL subclasses, postprandial lipemia after a standardized high-fat meal, and glycemic status to further untangle its role in HDL metabolism.MethodsWe elucidated fasting associations with HDL subclasses in a population-based cohort study (Oxford BioBank, OBB), including 4522 healthy men and women. We investigated fasting and postprandial consequences on HDL metabolism in recall-by-genotype (RbG) studies (fasting: 20 carrier/20 noncarrier; postprandial: 7 carrier/17 noncarrier), and shed light on the synergistic interaction with glycemic status.ResultsA lower fasting plasma concentration of cholesterol in large HDL particles was found in healthy male carriers of the Cys82 polymorphism compared to noncarriers, both in the OBB (P = .004) and RbG studies (P = .005). In addition, the Cys82 polymorphism was associated with low fasting plasma concentrations of ApoA1 (P = .008) in the OBB cohort. On the contrary, we did not find differences in postprandial lipemia or 2-hour plasma glucose levels.ConclusionTaken together, our results indicate an association between the Arg82Cys variant and a lower concentration of HDL particles and HDLc, especially in larger HDL subclasses, suggesting a link between nepmucin and HDLc metabolism or maturation.

Effect of thyroid function on pre-β1 high-density lipoprotein levels in patients with Graves' disease undergoing radioiodine treatment.

The metabolism of HDL is altered in thyroid dysfunctions. Preβ-1 HDL is a very small discoidal precursor HDL and promotes cholesterol efflux via ABCA1. The effects of thyroid dysfunctions on pre-β1 HDL are unknown. Thyroid hormone regulates ANGPTL3 expression, which may participate in HDL metabolism in thyroid dysfunctions. To determine the variation of HDL subfractions, especially preβ-1 HDL in thyroid dysfunctions, and whether ANGPTL3 mediates the effect of thyroid function on HDL metabolism. We recruited 26 patients with Graves' disease undergoing radioiodine treatment. They were evaluated at three time points: at baseline, when they were hypothyroid after radioiodine treatment, and when they were on stable levothyroxine replacement and euthyroid. The concentrations of smaller HDL particles Preβ-1 HDL and HDL3 were highest at the hyperthyroid state, and lowest at the hypothyroid state. While the larger HDL particles HDL2 and HDL1 changed just the opposite. Preβ1-HDL and HDL3 were positively correlated to fT3 and fT4, while were negatively correlated to TSH. In contrast, HDL1 was negatively associated with fT3 and fT4, while was positively associated with TSH. The correlations between thyroid hormones and HDL subfractions remained significant after adjusting for ANGPTL3. There is a shift form smaller HDL particles pre-β1 HDL and HDL3 to larger HDL particles HDL2 and HDL1 in hypothyroidism, while the change is just the opposite in hyperthyroidism. In future, cholesterol efflux capacity should be measured to determine if the function of HDL particles also changes with the shifting of HDL subfractions.

The role of HDL- and non-HDL-related parameters in cell-cholesterol efflux capacity

Background and aimsThe regulation of cell-cholesterol efflux is not completely understood. Our aim was to assess the role of HDL- and non-HDL-related parameters in ATP-binding cassette transporter-A1 (ABCA1) and scavenger receptor class B-type-I (SRBI) cell-cholesterol efflux capacity (CEC) in coronary heart disease (CHD) cases and controls. MethodsLipids and apoA-I-containing HDL particles (by 2D gel-electrophoresis and immunodetection) were measured in 534 statin-treated CHD patients and in 1076 age-, gender-, and BMI-matched controls. ABCA1-CEC and SRBI-CEC were measured in apoB-depleted serum of 100 cases and 100 controls. ResultsCases had significantly higher concentrations of preβ-1 particles (88%) and ABCA1-CEC (34%) compared to controls. ABCA1-CEC was positively correlated with the concentrations of preβ-1 particles, triglycerides, small-dense (sd) LDL-C, and LDL-C in both cases and controls. Moreover, both the concentration and the functionality of preβ-1 particles (ABCA1-CEC/mg preβ-1) were positively associated with the concentrations of sdLDL-C and triglycerides. Cases had 27% lower levels of large HDL particles but similar SRBI-CEC compared to controls. SRBI-CEC was correlated positively with HDL-C, apoA-I, and large-HDL particle levels. However, the functionality of large-HDL particles (SRBI-CEC/mg large particles) was significantly and positively correlated with the preβ-1/α-1 ratio, sdLDL-C, and triglycerides. ConclusionsCHD patients have significantly higher concentration, but less functional preβ-1 particles in term of cholesterol efflux capacity compared to controls. Triglyceride-rich lipoproteins have significant influence on either the concentration or the functionality or both of HDL particles and consequently HDL-CEC.

Lutein and docosahexaenoic acid enriched egg consumption improves retina function in healthy Caucasian older adults

• A full-field electroretinogram was used to assess changes in retina function. • Lutein and DHA enriched eggs significantly increased plasma DHA concentrations. • Lutein and DHA enriched eggs improved rod and cone driven bipolar cell function. • Two eggs daily for six weeks did not adversely impact plasma blood lipid parameters. The purpose of this research was to investigate whether the consumption of lutein and DHA enriched eggs can improve visual function among older adults at risk of age-related eye disease. A total of 30 Caucasian older adults (64.0 ± 3.4 years) consumed enriched eggs (0.87 mg lutein/day, 220 mg DHA/day) daily for 6-weeks. Retina function was assessed by full-field electroretinogram along with plasma DHA, plasma lutein, lipid profiles, and lipoprotein subfractions at day 0 (PRE) and 6 weeks (POST). At POST, maximum amplitude of scotopic a-wave and photopic b-wave significantly increased ( P < 0.001); and plasma DHA levels increased by 35.4% ( P < 0.001). Plasma lipid parameters, lutein and LDL sub-fractions remained unchanged, with a significant increase in large HDL particles and a decrease in intermediate sized HDL particles. Overall, the consumption of two lutein and DHA enriched eggs daily improves electrophysiological retina function without adversely altering plasma lipids in Caucasian older adults.

Afamin Levels and Their Correlation with Oxidative and Lipid Parameters in Non-diabetic, Obese Patients

Background: Afamin is a liver-produced bioactive protein and features α- and γ-tocopherol binding sites. Afamin levels are elevated in metabolic syndrome and obesity and correlate well with components of metabolic syndrome. Afamin concentrations, correlations between afamin and vitamin E, afamin and lipoprotein subfractions in non-diabetic, obese patients have not been fully examined. Methods: Fifty non-diabetic, morbidly obese patients and thirty-two healthy, normal-weight individuals were involved in our study. The afamin concentrations were measured by ELISA. Lipoprotein subfractions were determined with gel electrophoresis. Gas chromatography–mass spectrometry was used to measure α- and γ tocopherol levels. Results: Afamin concentrations were significantly higher in the obese patients compared to the healthy control (70.4 ± 12.8 vs. 47.6 ± 8.5 μg/mL, p < 0.001). Positive correlations were found between afamin and fasting glucose, HbA1c, hsCRP, triglyceride, and oxidized LDL level, as well as the amount and ratio of small HDL subfractions. Negative correlations were observed between afamin and mean LDL size, as well as the amount and ratio of large HDL subfractions. After multiple regression analysis, HbA1c levels and small HDL turned out to be independent predictors of afamin. Conclusions: Afamin may be involved in the development of obesity-related oxidative stress via the development of insulin resistance and not by affecting α- and γ-tocopherol levels.