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Sample records for plasma hdl cholesterol

  1. Mechanism of transfer of LDL-derived free cholesterol to HDL subfractions in human plasma

    SciTech Connect

    Miida, T.; Fielding, C.J.; Fielding, P.E. )

    1990-11-01

    The transfer of ({sup 3}H)cholesterol in low-density lipoprotein (LDL) to different high-density lipoprotein (HDL) species in native human plasma was determined by using nondenaturing two-dimensional electrophoresis. Transfer from LDL had a t{sub 1/2} at 37{degree}C of 51 {plus minus} 8 min and an activation energy of 18.0 kCal mol{sup {minus}1}. There was unexpected specificity among HDL species as acceptors of LDL-derived labeled cholesterol. The largest fraction of the major {alpha}-migrating class (HDL{sub 2b}) was the major initial acceptor of LDL-derived cholesterol. Kinetic analysis indicated a rapid secondary transfer from HDL{sub 2b} to smaller {alpha}HDL (particularly HDL{sub 3}) driven enzymatically by the lecithin-cholesterol acyltransferase reaction. Rates of transfer among {alpha}HDL were most rapid from the largest {alpha}HDL fraction (HDL{sub 2b}), suggesting possible protein-mediated facilitation. Simultaneous measurements of the transport of LDL-derived and cell-derived isotopic cholesterol indicated that the former preferably utilized the {alpha}HDL pathyway, with little label in pre-{beta}HDL. The same experiments confirmed earlier data that cell-derived cholesterol is preferentially channeled through pre-{beta}HDL. The authors suggest that the functional heterogeneity of HDL demonstrated here includes the ability to independently process cell- and LDL-derived free cholesterol.

  2. Subjects with Low Plasma HDL Cholesterol Levels Are Characterized by an Inflammatory and Oxidative Phenotype

    PubMed Central

    Holven, Kirsten B.; Retterstøl, Kjetil; Ueland, Thor; Ulven, Stine M.; Nenseter, Marit S.; Sandvik, Marit; Narverud, Ingunn; Berge, Knut E.; Ose, Leiv; Aukrust, Pål; Halvorsen, Bente

    2013-01-01

    Background Epidemiological studies have shown that low plasma levels of high-density lipoprotein (HDL) cholesterol are associated with increased risk of cardiovascular disease, but the mechanisms for the possible atheroprotective effects of HDL cholesterol have still not been fully clarified, in particular in relation to clinical studies. Objective To examine the inflammatory, anti-oxidative and metabolic phenotype of subjects with low plasma HDL cholesterol levels. Methods and Results Fifteen subjects with low HDL cholesterol levels (eleven males and four females) and 19 subjects with high HDL (three males and 16 females) were recruited. Low HDL cholesterol was defined as ≤10th age/sex specific percentile and high HDL-C was defined as ≥90 age/sex specific percentile. Inflammatory markers in circulation and PBMC gene expression of cholesterol efflux mediators were measured. Our main findings were: (i) subjects with low plasma HDL cholesterol levels were characterized by increased plasma levels of CRP, MMP-9, neopterin, CXCL16 and ICAM-1 as well as low plasma levels of adiponectin, suggesting an inflammatory phenotype; (ii) these individuals also had reduced paraoxonase (PON)1 activity in plasma and PON2 gene expression in peripheral blood mononuclear cells (PBMC) accompanied by increased plasma levels of oxidized LDL suggesting decreased anti-oxidative capacity; and (iii) PBMC from low HDL subjects also had decreased mRNA levels of ABCA1 and ABCG1, suggesting impaired reverse cholesterol transport. Conclusion Subjects with low plasma HDL cholesterol levels are characterized by an inflammatory and oxidative phenotype that could contribute to the increased risk of atherosclerotic disorders in these subjects with low HDL levels. PMID:24244297

  3. Detergent-Mediated Phospholipidation of Plasma Lipoproteins Increases HDL Cholesterophilicity and Cholesterol Efflux Via SR-BI†

    PubMed Central

    Pownall, Henry J.

    2008-01-01

    Cellular cholesterol efflux is an early, obligatory step in reverse cholesterol transport, the putative antiatherogenic mechanism by which human plasma high density lipoproteins (HDL) transport cholesterol from peripheral tissue to the liver for recycling or disposal. HDL-phospholipid content is the essential cholesterol-binding component of lipoproteins and therefore a major determinant of cholesterol efflux. Thus, increased phospholipidation of lipoproteins, particularly HDL, is one strategy for increasing cholesterol efflux. This study validates a simple, new detergent perturbation method for the phospholipidation of plasma lipoproteins; we have quantified the cholesterophilicity of human plasma lipoproteins and the effects of lipoprotein phospholipidation on cholesterophilicity and cellular cholesterol efflux mediated by the class B type I scavenger receptor (SR-BI). We determined that low density lipoproteins (LDL) are more cholesterophilic than HDL and that LDL has a higher affinity for phospholipids than HDL whereas HDL has a higher phospholipid capacity than LDL. Phospholipidation of total human plasma lipoproteins enhances cholesterol efflux, an effect that occurs largely through the preferential phospholipidation of HDL. We conclude that increasing HDL phospholipid increases its cholesterophilicity thereby making it a better acceptor of cellular cholesterol efflux. Phospholipidation of lipoproteins by detergent perturbation is a simple way to increase HDL cholesterophilicity and cholesterol efflux in a way that may be clinically useful. PMID:16981711

  4. Plasma triglyceride/HDL-cholesterol ratio, insulin resistance, and cardiometabolic risk in young adults

    PubMed Central

    Murguía-Romero, Miguel; Jiménez-Flores, J. Rafael; Sigrist-Flores, Santiago C.; Espinoza-Camacho, Miguel A.; Jiménez-Morales, Mayra; Piña, Enrique; Méndez-Cruz, A. René; Villalobos-Molina, Rafael; Reaven, Gerald M.

    2013-01-01

    Studies in mature adults suggest that the plasma concentration ratio of triglyceride (TG)/HDL-cholesterol (HDL-C) provides a simple way to identify apparently healthy individuals who are insulin resistant (IR) and at increased cardiometabolic risk. This study extends these observations by examining the clinical utility of the TG/HDL-C ratio and the metabolic syndrome (MetS) in 2,244 healthy college students (17–24 years old) of Mexican Mestizo ancestry. The TG/HDL-C ratio separating the 25% with the highest value was used to identify IR and increased cardiometabolic risk. Cardiometabolic risk factors were more adverse in men and women whose TG/HDL-C ratios exceeded 3.5 and 2.5, respectively, and approximately one third were identified as being IR. The MetS identified fewer individuals as being IR, but their risk profile was accentuated. In conclusion, both a higher TG/HDL-C ratio and a diagnosis of the MetS identify young IR individuals with an increased cardiometabolic risk profile. The TG/HDL-C ratio identified a somewhat greater number of “high risk” subjects, whereas the MetS found a group whose risk profile was somewhat magnified. These findings suggest that the TG/HDL-C ratio may serve as a simple and clinically useful approach to identify apparently healthy, young individuals who are IR and at increased cardiometabolic risk. PMID:23863983

  5. Epistasis contributes to the genetic buffering of plasma HDL cholesterol in mice

    PubMed Central

    Churchill, Gary A.

    2010-01-01

    Stressful environmental factors, such as a high-fat diet, can induce responses in the expression of genes that act to maintain physiological homeostasis. We observed variation in plasma concentrations of high-density lipoprotein (HDL) cholesterol across inbred mouse strains in response to high dietary fat intake. Several strains, including C57BL/6J, have stable levels of plasma HDL independent of diet, whereas other strains, including DBA2/J, show marked changes in plasma HDL. To explore this phenomenon further, we used publicly available data from a C57BL/6J × DBA/2J intercross to identify genetic factors that associate with HDL under high-fat diet conditions. Our analysis identified an epistatic interaction that plays a role in the buffering of HDL levels in C57BL/6J mice, and we have identified Arl4d as a candidate gene that mediates this effect. Structural modeling further elucidates the interaction of genetic factors that contribute to the robustness of HDL in response to high-fat diet in the C57BL/6J strain. PMID:20858711

  6. [Role of HDL in Cholesterol Efflux and Reverse Cholesterol Transport].

    PubMed

    Ayaori, Makoto

    2016-01-01

    Low plasma levels of HDL-cholesterol (HDL-C) have been consistently associated with an increased risk of atherosclerotic cardiovascular diseases (CVD), and it is thus considered to be an anti-atherogenic lipoprotein. The development of novel therapies to enhance the atheroprotective properties of HDL may have the potential to further reduce the residual risk. Reverse cholesterol transport (RCT) is believed to be a primary atheroprotective property of HDL and its major protein, apolipoprotein A-I(apoA-I). HDL and apoA-I have been shown to promote the efflux of excess cholesterol from macrophage-derived foam cells via the cholesterol transporters, ATP-binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor class B, type I (SR-BI), and then transport it back to the liver for excretion into bile and eventually into the feces. In this regard, a validated murine assay that quantifies macrophage RCT may be a better predictor of atherosclerosis than the steady-state plasma concentration of HDL-C. Indeed, a recent clinical study demonstrated that the ability of serum HDL to mediate cholesterol efflux from macrophages was independently and negatively associated with the CVD risk even after adjustment for HDL-C levels, suggesting that HDL functionality is more important than its quantity. Therefore, the future development of HDL-targeted therapy should take both aspects into consideration to further reduce the residual risk.

  7. [Role of HDL in Cholesterol Efflux and Reverse Cholesterol Transport].

    PubMed

    Ayaori, Makoto

    2016-01-01

    Low plasma levels of HDL-cholesterol (HDL-C) have been consistently associated with an increased risk of atherosclerotic cardiovascular diseases (CVD), and it is thus considered to be an anti-atherogenic lipoprotein. The development of novel therapies to enhance the atheroprotective properties of HDL may have the potential to further reduce the residual risk. Reverse cholesterol transport (RCT) is believed to be a primary atheroprotective property of HDL and its major protein, apolipoprotein A-I(apoA-I). HDL and apoA-I have been shown to promote the efflux of excess cholesterol from macrophage-derived foam cells via the cholesterol transporters, ATP-binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor class B, type I (SR-BI), and then transport it back to the liver for excretion into bile and eventually into the feces. In this regard, a validated murine assay that quantifies macrophage RCT may be a better predictor of atherosclerosis than the steady-state plasma concentration of HDL-C. Indeed, a recent clinical study demonstrated that the ability of serum HDL to mediate cholesterol efflux from macrophages was independently and negatively associated with the CVD risk even after adjustment for HDL-C levels, suggesting that HDL functionality is more important than its quantity. Therefore, the future development of HDL-targeted therapy should take both aspects into consideration to further reduce the residual risk. PMID:27192798

  8. Variation in the Phosphoinositide 3-Kinase Gamma Gene Affects Plasma HDL-Cholesterol without Modification of Metabolic or Inflammatory Markers

    PubMed Central

    Kächele, Martin; Hennige, Anita M.; Machann, Jürgen; Hieronimus, Anja; Lamprinou, Apostolia; Machicao, Fausto; Schick, Fritz; Fritsche, Andreas; Stefan, Norbert; Nürnberg, Bernd; Häring, Hans-Ulrich; Staiger, Harald

    2015-01-01

    Objective Phosphoinositide 3-kinase γ (PI3Kγ) is a G-protein-coupled receptor-activated lipid kinase mainly expressed in leukocytes and cells of the cardiovascular system. PI3Kγ plays an important signaling role in inflammatory processes. Since subclinical inflammation is a hallmark of atherosclerosis, obesity-related insulin resistance, and pancreatic β-cell failure, we asked whether common genetic variation in the PI3Kγ gene (PIK3CG) contributes to body fat content/distribution, serum adipokine/cytokine concentrations, alterations in plasma lipid profiles, insulin sensitivity, insulin release, and glucose homeostasis. Study Design Using a tagging single nucleotide polymorphism (SNP) approach, we analyzed genotype-phenotype associations in 2,068 German subjects genotyped for 10 PIK3CG SNPs and characterized by oral glucose tolerance tests. In subgroups, data from hyperinsulinaemic-euglycaemic clamps, magnetic resonance spectroscopy of the liver, whole-body magnetic resonance imaging, and intravenous glucose tolerance tests were available, and peripheral blood mononuclear cells (PBMCs) were used for gene expression analysis. Results After appropriate adjustment, none of the PIK3CG tagging SNPs was significantly associated with body fat content/distribution, adipokine/cytokine concentrations, insulin sensitivity, insulin secretion, or blood glucose concentrations (p>0.0127, all; Bonferroni-corrected α-level: 0.0051). However, six non-linked SNPs displayed at least nominal associations with plasma HDL-cholesterol concentrations, two of them (rs4288294 and rs116697954) reaching the level of study-wide significance (p = 0.0003 and p = 0.0004, respectively). More precisely, rs4288294 and rs116697954 influenced HDL2-, but not HDL3-, cholesterol. With respect to the SNPs’ in vivo functionality, rs4288294 was significantly associated with PIK3CG mRNA expression in PBMCs. Conclusions We could demonstrate that common genetic variation in the PIK3CG locus, possibly

  9. Raising HDL cholesterol in women

    PubMed Central

    Eapen, Danny J; Kalra, Girish L; Rifai, Luay; Eapen, Christina A; Merchant, Nadya; Khan, Bobby V

    2010-01-01

    High-density lipoprotein cholesterol (HDL-C) concentration is essential in the determination of coronary heart disease (CHD) risk in women. This is especially true in the postmenopausal state, where lipid profiles and CHD risk mimic that of age-matched men. Thus, interventions designed to reduce CHD risk by raising HDL-C levels may have particular significance during the transition to menopause. This review discusses HDL-C-raising therapies and the role of HDL in the primary prevention of CHD in women. Lifestyle-based interventions such as dietary change, aerobic exercise regimens, and smoking cessation are initial steps that are effective in raising HDL-C, and available data suggest women respond similarly to men with these interventions. When combined with pharmacotherapy, the effects of these lifestyle alterations are further amplified. Though studies demonstrating gender-specific differences in therapy are limited, niacin continues to be the most effective agent in raising HDL-C levels, especially when used in combination with fibrate or statin therapy. Emerging treatments such as HDL mimetic therapy show much promise in further raising HDL-C levels and improving cardiovascular outcomes. PMID:21072287

  10. Endothelial expression of human ABCA1 in mice increases plasma HDL cholesterol and reduces diet-induced atherosclerosis[S

    PubMed Central

    Vaisman, Boris L.; Demosky, Stephen J.; Stonik, John A.; Ghias, Mona; Knapper, Cathy L.; Sampson, Maureen L.; Dai, Cuilian; Levine, Stewart J.; Remaley, Alan T.

    2012-01-01

    The role of endothelial ABCA1 expression in reverse cholesterol transport (RCT) was examined in transgenic mice, using the endothelial-specific Tie2 promoter. Human ABCA1 (hABCA1) was significantly expressed in endothelial cells (EC) of most tissues except the liver. Increased expression of ABCA1 was not observed in resident peritoneal macrophages. ApoA-I-mediated cholesterol efflux from aortic EC was 2.6-fold higher (P < 0.0001) for cells from transgenic versus control mice. On normal chow diet, Tie2 hABCA1 transgenic mice had a 25% (P < 0.0001) increase in HDL-cholesterol (HDL-C) and more than a 2-fold increase of eNOS mRNA in the aorta (P < 0.04). After 6 months on a high-fat, high-cholesterol (HFHC) diet, transgenic mice compared with controls had a 40% increase in plasma HDL-C (P < 0.003) and close to 40% decrease in aortic lesions (P < 0.02). Aortas from HFHC-fed transgenic mice also showed gene expression changes consistent with decreased inflammation and apoptosis. Beneficial effects of the ABCA1 transgene on HDL-C levels or on atherosclerosis were absent when the transgene was transferred onto ApoE or Abca1 knockout mice. In summary, expression of hABCA1 in EC appears to play a role in decreasing diet-induced atherosclerosis in mice and is associated with increased plasma HDL-C levels and beneficial gene expression changes in EC. PMID:22039582

  11. HDL and cholesterol handling in the brain.

    PubMed

    Vitali, Cecilia; Wellington, Cheryl L; Calabresi, Laura

    2014-08-01

    Cholesterol is an essential component of both the peripheral nervous system and central nervous system (CNS) of mammals. Brain cholesterol is synthesized in situ by astrocytes and oligodendrocytes and is almost completely isolated from other pools of cholesterol in the body, but a small fraction can be taken up from the circulation as 27-hydroxycholesterol, or via the scavenger receptor class B type I. Glial cells synthesize native high-density lipoprotein (HDL)-like particles, which are remodelled by enzymes and lipid transfer proteins, presumably as it occurs in plasma. The major apolipoprotein constituent of HDL in the CNS is apolipoprotein E, which is produced by astrocytes and microglia. Apolipoprotein A-I, the major protein component of plasma HDL, is not synthesized in the CNS, but can enter and become a component of CNS lipoproteins. Low HDL-C levels have been shown to be associated with cognitive impairment and various neurodegenerative diseases. On the contrary, no clear association with brain disorders has been shown in genetic HDL defects, with the exception of Tangier disease. Mutations in a wide variety of lipid handling genes can result in human diseases, often with a neuronal phenotype caused by dysfunctional intracellular lipid trafficking.

  12. Association of metabolic and genetic factors with cholesterol esterification rate in HDL plasma and atherogenic index of plasma in a 40 years old Slovak population.

    PubMed

    Rašlová, K; Dobiášová, M; Hubáček, J A; Bencová, D; Siváková, D; Danková, Z; Franeková, J; Jabor, A; Gašparovič, J; Vohnout, B

    2011-01-01

    We assessed association between novel biomarkers of cardiovascular disease and conventional factors in 40 years old subjects (208 men and 266 women) from the general population of Slovakia. FER(HDL) (cholesterol esterification rate in HDL plasma), AIP--Atherogenic Index of Plasma [Log(TG/HDL-C)] as markers of lipoprotein particle size, and CILP2, FTO and MLXIPL polymorphisms, were examined in relation to biomarkers and conventional risk factors. Univariate analyses confirmed correlation between AIP, FER(HDL) and the most of measured parameters. Relations between AIP and CILP2, FTO and MLXIPL were not significant. However, CILP2 was significantly related to FER(HDL) in both genders. In multivariate analysis BMI was the strongest correlate of AIP levels. In multivariate model variability of FER(HDL) was best explained by AIP (R(2) = 0.55) in both genders with still significant effect of CILP2 SNP in men. In a model where AIP was omitted, TG levels explained 43 % of the FER(HDL) variability in men, while in women HDL-C was the major determinant (42 %). In conclusions, FER(HDL) and AIP related to the known markers of cardiovascular risk provide means to express their subtle interactions by one number. Our novel finding of association between CILP2 polymorphism and FER(HDL) supports its role in lipid metabolism.

  13. Variation at the hepatic lipase and apolipoprotein AI/CIII/AIV loci is a major cause of genetically determined variation in plasma HDL cholesterol levels.

    PubMed Central

    Cohen, J C; Wang, Z; Grundy, S M; Stoesz, M R; Guerra, R

    1994-01-01

    Genetic factors have been shown to play an important role in determining interindividual variation in plasma HDL-C levels, but the specific genetic determinants of HDL cholesterol (HDL-C) levels have not been elucidated. In this study, the effects of variation in the genomic regions encoding hepatic lipase, apolipoprotein AI/CIII/AIV, and the cholesteryl ester transfer protein on plasma HDL-C levels were examined in 73 normotriglyceridemic, Caucasian nuclear families. Genetic factors accounted for 56.5 +/- 13% of the interindividual variation in plasma HDL-C levels. For each candidate gene, adjusted plasma HDL-C levels of sibling pairs who shared zero, one, or two parental alleles identical-by-descent were compared using sibling-pair linkage analysis. Allelic variation in the genes encoding hepatic lipase and apolipoprotein AI/CIII/AIV accounted for 25 and 22%, respectively, of the total interindividual variation in plasma HDL-C levels. In contrast, none of the variation in plasma HDL-C levels could be accounted for by allelic variation in the cholesteryl ester transfer protein. These findings indicate that a major fraction of the genetically determined variation in plasma HDL-C levels is conferred by allelic variation at the hepatic lipase and the apolipoprotein AI/CIII/AIV gene loci. PMID:7989594

  14. Identification of four novel genes contributing to familial elevated plasma HDL cholesterol in humans.

    PubMed

    Singaraja, Roshni R; Tietjen, Ian; Hovingh, G Kees; Franchini, Patrick L; Radomski, Chris; Wong, Kenny; vanHeek, Margaret; Stylianou, Ioannis M; Lin, Linus; Wang, Liangsu; Mitnaul, Lyndon; Hubbard, Brian; Winther, Michael; Mattice, Maryanne; Legendre, Annick; Sherrington, Robin; Kastelein, John J; Akinsanya, Karen; Plump, Andrew; Hayden, Michael R

    2014-08-01

    While genetic determinants strongly influence HDL cholesterol (HDLc) levels, most genetic causes underlying variation in HDLc remain unknown. We aimed to identify novel rare mutations with large effects in candidate genes contributing to extreme HDLc in humans, utilizing family-based Mendelian genetics. We performed next-generation sequencing of 456 candidate HDLc-regulating genes in 200 unrelated probands with extremely low (≤10th percentile) or high (≥90th percentile) HDLc. Probands were excluded if known mutations existed in the established HDLc-regulating genes ABCA1, APOA1, LCAT, cholesteryl ester transfer protein (CETP), endothelial lipase (LIPG), and UDP-N-acetyl-α-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase 2 (GALNT2). We identified 93 novel coding or splice-site variants in 72 candidate genes. Each variant was genotyped in the proband's family. Family-based association analyses were performed for variants with sufficient power to detect significance at P < 0.05 with a total of 627 family members being assessed. Mutations in the genes glucokinase regulatory protein (GCKR), RNase L (RNASEL), leukocyte immunoglobulin-like receptor 3 (LILRA3), and dynein axonemal heavy chain 10 (DNAH10) segregated with elevated HDLc levels in families, while no mutations associated with low HDLc. Taken together, we have identified mutations in four novel genes that may play a role in regulating HDLc levels in humans. PMID:24891332

  15. HDL Function, Dysfunction, and Reverse Cholesterol Transport

    PubMed Central

    Fisher, Edward A.; Feig, Jonathan E.; Hewing, Bernd; Hazen, Stanley L.; Smith, Jonathan D.

    2012-01-01

    Although high HDL-cholesterol levels are associated with decreased cardiovascular risk in epidemiological studies, recent genetic and pharmacological findings have raised doubts about the beneficial effects of HDL. Raising HDL levels in animal models by infusion or over expression of apolipoprotein A-I has shown clear vascular improvements, such as delayed atherosclerotic lesion progression and accelerated lesion regression, along with increased reverse cholesterol transport. Inflammation and other factors, such as myeloperoxidase mediated oxidation, can impair HDL production and HDL function, in regard to its reverse cholesterol transport, antioxidant, and anti-inflammatory activities. Thus, tests of HDL function, which have not yet been developed as routine diagnostic assays, may prove useful and be a better predictor of cardiovascular risk than HDL-cholesterol levels. PMID:23152494

  16. Intestinal nuclear receptors in HDL cholesterol metabolism

    PubMed Central

    Degirolamo, Chiara; Sabbà, Carlo; Moschetta, Antonio

    2015-01-01

    The intestine plays a pivotal role in cholesterol homeostasis by functioning as an absorptive and secretory organ in the reverse cholesterol transport pathway. Enterocytes control cholesterol absorption, apoAI synthesis, HDL biogenesis, and nonbiliary cholesterol fecal disposal. Thus, intestine-based therapeutic interventions may hold promise in the management of diseases driven by cholesterol overload. Lipid-sensing nuclear receptors (NRs) are highly expressed in the intestinal epithelium and regulate transcriptionally the handling of cholesterol by the enterocytes. Here, we discuss the NR regulation of cholesterol fluxes across the enterocytes with special emphasis on NR exploitation as a bona fide novel HDL-raising strategy. PMID:25070952

  17. [The new atherogenic plasma index reflects the triglyceride and HDL-cholesterol ratio, the lipoprotein particle size and the cholesterol esterification rate: changes during lipanor therapy].

    PubMed

    Dobiásová, M; Frohlich, J

    2000-03-01

    The new atherogenic plasma index (AIP) is a logarithmic transformation of the ratio of the molar triglyceride (TG) concentration and high density lipoprotein cholesterol (HDL-C). AIP correlates closely with the size of LDL particles (r = 0.8) and esterification rate of plasma cholesterol devoid of apo B lipoproteins (FERHDL), r = 0.9 which are considered at present the most sensitive indicators of the atherogenic plasma profile. AIP was recommended by the authors, based on analysis of results of 11 previous studies (1156 subjects) where FERHDL and plasma lipid parameters were investigated in different groups of people who differed as to the atherogenic risk. The AIP index was moreover used for evaluation of a clinical study comprising 609 patients with hyperlipidaemia, who were treated for three months with ciprofibrate (Lipanor). The mean AIP values of non-risk groups (plasma from umbilical blood, children, healthy women etc.) equalled zero or were lower, while with an increasing atherogenic risk (men, women after the menopause) AIP reached positive values, incl. high positive values in risk groups (plasma of diabetic subjects, patients with HLP, patients with positive angiography, myocardial infarction etc.). In all groups women had lower AIP values as compared with males. In patients after Lipanor therapy the AIP declined (from 0.58 +/- 0.17 to 0.33_0.18 in men, from 0.50 +/- 0.18 to 0.21 +/- 0.19 in women). If we consider AIP values from negative ones to 0.15 as "safe" from the aspect of atherogenicity, before Lipanor treatment these "safe" levels were recorded in 1.5% men and in 5.2% women and after treatment in 32% men and 48% women. The results indicate, that AIP which reflects the plasma lipoprotein profile quantifies the relations between TG and HDL-C and thus can be an objective indicator of the atherogenic risk and effectiveness of treatment and it is useful because it can be assessed in any surgery. PMID:11048517

  18. Low Plasma Hdl Cholesterol and Elevated C Reactive Protein further Increase Cardiovascular Disease Risk in Latinos with Type 2 Diabetes

    PubMed Central

    Calle, Mariana C; Vega-López, Sonia; Segura-Pérez, Sofia; Volek, Jeff S; Pérez-Escamilla, Rafael; Fernandez, Maria Luz

    2011-01-01

    The purpose of this study was to determine whether low plasma HDL and high C reactive protein (CRP) concentrations would further increase cardiovascular disease (CVD) risk in Latinos with poorly controlled type-2 diabetes, already at high risk for CVD. Subjects (n = 68) were grouped into High-HDL (≥ or 1.03 or 1.3 mmol/L) or Low-HDL (<1.03 or 1.3 mmol/L) for men and women, respectively. Following classification, risk factors for CVD including apolipoproteins, lipoprotein size and subfraction distribution were assesed. Similarly, participants were divided according to their CRP levels (≥ or < 3mg/L) and key inflammatory markers as well as leptin and adiponectin were analyzed. The Low-HDL group had higher concentrations of the atherogenic particles, large and medium VLDL and the smaller LDL subfractions compared to the High-HDL group (p<0.001). Consistently, VLDL diameter was larger and LDL diameter smaller in the Low HDL group (p<0.001). The High-CRP group had larger waist circumference (p<0.001) and body mass index (p<0.001) than the Low-CRP group. Leptin was also higher in the High- CRP group (p< 0.01). These data suggest that Latinos with type-2 diabetes having either Low-HDL or High-CRP concentrations are at a higher risk for atherosclerosis and CVD than their counterparts who have High-HDL or Low-CRP. PMID:22407331

  19. [Therapeutic targets in the treatment of dyslipidemia: HDL and non-HDL cholesterol].

    PubMed

    Brea Hernando, Ángel Julián

    2014-07-01

    Atherogenic dyslipidemia (AD) consists of the combination of an increase in very low density lipoproteins (VLDL), which results in increased plasma triglyceride (TG) levels, with a reduction of levels of high-density lipoprotein bound cholesterol (HDL-C), also accompanied by a high proportion of small and dense LDL particles. AD is considered the main cause of the residual risk of experiencing cardiovascular disease (CVD), which is still presented by any patient on treatment with statins despite maintaining low-density lipoprotein bound cholesterol (LDL-C) levels below the values considered to be the objective. Non-HDL cholesterol (non-HDL-c) reflects the number of atherogenic particles present in the plasma. This includes VLDL, intermediate density lipoproteins (IDL) and LDL. Non-HDL-c provides a better estimate of cardiovascular risk than LDL-c, especially in the presence of hypertriglyceridemia or AD. The European guidelines for managing dyslipidemia recommend that non-HDL-c values be less than 100 and 130 mg/dL for individuals with very high and high cardiovascular risk, respectively. However, these guidelines state that there is insufficient evidence to suggest that raising HDL-c levels incontrovertibly results in a reduction in CVD. Therefore, the guidelines do not set recommended HDL-c levels as a therapeutic objective. The guidelines, however, state that individuals with AD on treatment with statins could benefit from an additional reduction in their risk by using fibrates. PMID:25043539

  20. [Therapeutic targets in the treatment of dyslipidemia: HDL and non-HDL cholesterol].

    PubMed

    Brea Hernando, Ángel Julián

    2014-07-01

    Atherogenic dyslipidemia (AD) consists of the combination of an increase in very low density lipoproteins (VLDL), which results in increased plasma triglyceride (TG) levels, with a reduction of levels of high-density lipoprotein bound cholesterol (HDL-C), also accompanied by a high proportion of small and dense LDL particles. AD is considered the main cause of the residual risk of experiencing cardiovascular disease (CVD), which is still presented by any patient on treatment with statins despite maintaining low-density lipoprotein bound cholesterol (LDL-C) levels below the values considered to be the objective. Non-HDL cholesterol (non-HDL-c) reflects the number of atherogenic particles present in the plasma. This includes VLDL, intermediate density lipoproteins (IDL) and LDL. Non-HDL-c provides a better estimate of cardiovascular risk than LDL-c, especially in the presence of hypertriglyceridemia or AD. The European guidelines for managing dyslipidemia recommend that non-HDL-c values be less than 100 and 130 mg/dL for individuals with very high and high cardiovascular risk, respectively. However, these guidelines state that there is insufficient evidence to suggest that raising HDL-c levels incontrovertibly results in a reduction in CVD. Therefore, the guidelines do not set recommended HDL-c levels as a therapeutic objective. The guidelines, however, state that individuals with AD on treatment with statins could benefit from an additional reduction in their risk by using fibrates.

  1. HDL phospholipid content and cholesterol efflux capacity are reduced in patients with very high HDL-C and coronary disease

    PubMed Central

    Agarwala, Anandita P.; Rodrigues, Amrith; Risman, Marjorie; McCoy, Mary; Trindade, Kevin; Qu, Liming; Cuchel, Marina; Billheimer, Jeffrey; Rader, Daniel J.

    2015-01-01

    Objective Plasma levels of high-density lipoprotein cholesterol (HDL-C) are strongly inversely associated with coronary artery disease (CAD), and high HDL-C is generally associated with reduced risk of CAD. Extremely high HDL-C with CAD is an unusual phenotype, and we hypothesized that the HDL in such individuals may have an altered composition and reduced function when compared to controls with similarly high HDL-C and no CAD. Approach 55 subjects with very high HDL-C (mean 86 mg/dL) and onset of CAD around age 60 with no known risk factors for CAD (‘cases’) were identified through systematic recruitment. 120 control subjects without CAD, matched for race, gender, and HDL-C level (‘controls’), were identified. In all subjects, HDL composition was analyzed and HDL cholesterol efflux capacity was assessed. Results HDL phospholipid composition was significantly lower in cases (92 ± 37 mg/dL) than in controls (109 ± 43 mg/dL, p= 0.0095). HDL cholesterol efflux capacity was significantly lower in cases (1.96 ± 0.39) compared with controls (2.11 ± 0.43, p= 0.04). Conclusions In persons with very high HDL-C, reduced HDL phospholipid content and cholesterol efflux capacity is associated with the paradoxical development of CAD. PMID:25838421

  2. Discovery of XEN445: a potent and selective endothelial lipase inhibitor raises plasma HDL-cholesterol concentration in mice.

    PubMed

    Sun, Shaoyi; Dean, Richard; Jia, Qi; Zenova, Alla; Zhong, Jing; Grayson, Celene; Xie, Clark; Lindgren, Andrea; Samra, Pritpaul; Sojo, Luis; van Heek, Margaret; Lin, Linus; Percival, David; Fu, Jian-Min; Winther, Michael D; Zhang, Zaihui

    2013-12-15

    Endothelial lipase (EL) activity has been implicated in HDL metabolism and in atherosclerotic plaque development; inhibitors are proposed to be efficacious in the treatment of dyslipidemia related cardiovascular disease. We describe here the discovery of a novel class of anthranilic acids EL inhibitors. XEN445 (compound 13) was identified as a potent and selective EL inhibitor, that showed good ADME and PK properties, and demonstrated in vivo efficacy in raising plasma HDLc concentrations in mice. PMID:24211162

  3. Plasma triacylglycerol and HDL cholesterol concentrations confirm self-reported changes in carbohydrate and fat intakes in women in a diet intervention trial.

    PubMed

    Rock, Cheryl L; Flatt, Shirley W; Thomson, Cynthia A; Stefanick, Marcia L; Newman, Vicky A; Jones, Lovell; Natarajan, Loki; Pierce, John P; Chang, R Jeffrey; Witztum, Joseph L

    2004-02-01

    Diet intervention trials are currently testing whether reduced fat intake can reduce the risk and progression of breast cancer. Energy from dietary fat is generally replaced by energy from carbohydrate in these studies, and altering the proportion of energy from dietary carbohydrate and fat has been shown to affect plasma lipid concentrations in controlled feeding studies. The purpose of this study was to examine the effect of increased carbohydrate and reduced fat intakes on plasma lipids in a randomized, controlled trial that is testing the effect of diet modification on risk for recurrence and survival in women previously treated for breast cancer. Plasma concentrations of lipids and related factors were measured at enrollment and 1-y follow-up in 393 women enrolled in the trial. Dietary goals for the intervention group focused on an increase in vegetable, fruit and fiber intakes, and reduced fat intake. Women assigned to the intervention group significantly reduced fat intake (from 28.1 to 21.0% of energy), and significantly increased intakes of carbohydrate (from 56.9 to 65.3% of energy) and fiber (from 21.0 to 29.6 g/d) (P < 0.05). Body weight did not change significantly in either study group. A small but significant increase in fasting plasma triacylglycerol concentration, and decreases in HDL cholesterol and apoprotein-A1 concentrations, were observed in the intervention group (P < 0.05) but not in the comparison group. Changes in total cholesterol, LDL cholesterol, apoprotein-B, lipoprotein (a), and insulin concentrations, and in the LDL cholesterol/HDL cholesterol ratio, were not observed in either group. The lipid responses that were observed in this study provide biological evidence that validates the self-reported change in dietary intakes of fat and carbohydrate in response to the intervention efforts. The degree of change in these lipid concentrations was small and does not suggest increased cardiovascular disease risk.

  4. Serum opacity factor enhances HDL-mediated cholesterol efflux, esterification and anti inflammatory effects.

    PubMed

    Tchoua, Urbain; Rosales, Corina; Tang, Daming; Gillard, Baiba K; Vaughan, Ashley; Lin, Hu Yu; Courtney, Harry S; Pownall, Henry J

    2010-12-01

    Serum opacity factor (SOF) is a streptococcal protein that disrupts the structure of human high density lipoproteins (HDL) releasing lipid-free apo A-I while forming a large cholesteryl ester-rich particle and a small neo HDL. Given its low cholesterol and high phospholipid contents, we tested the hypotheses that neo HDL is a better substrate for cholesterol esterification via lecithin:cholesterol acyltransferase (LCAT), better than HDL as an acceptor of THP-1 macrophage cholesterol efflux, and improves reduction of oxidized LDL-induced production of inflammatory markers. We observed that both cholesterol efflux and esterification were improved by recombinant (r)SOF treatment of whole plasma and that the underlying cause of the improved cholesterol esterification in plasma and macrophage cholesterol efflux to rSOF-treated plasma was due to the rSOF-mediated conversion of HDL to neo HDL. Moreover, the reduction of secretion of TNF-α and IL-6 by THP-1 cells by neo HDL was twice that of HDL. Studies in BHK cells overexpressing cholesterol transporters showed that efflux to neo HDL occurred primarily via ABCA1 not ABCG1. Thus, rSOF improves two steps in reverse cholesterol transport with a concomitant reduction in the release of macrophage markers of inflammation. We conclude that rSOF catalyzes a novel reaction that might be developed as a new therapy that prevents or reverses atherosclerosis via improved reverse cholesterol transport.

  5. HDL-Mediated Cellular Cholesterol Efflux Assay Method.

    PubMed

    Hafiane, Anouar; Genest, Jacques

    2015-01-01

    Biomarkers of high-density lipoprotein (HDL) function may provide mechanistic insights and better cardiovascular risk discrimination than HDL-cholesterol mass. The purpose of this work is to describe a simplified experimental protocol that can be used in the determination of cholesterol efflux from macrophages cultured cells and be brought to a medium throughput volume. The cellular cholesterol efflux assay is designed to quantify the rate of cholesterol efflux from cultured cells to an acceptor particle or to plasma. This assay is multi step, cell based assay. Various factors, if not carefully controlled may influence the accuracy and reproducibility of the assay. Attempts were made to address factors influencing this assay and to provide a standardized method that is relatively rapid and scalable. We demonstrate that further centrifugation of the HDL fraction is necessary to avoid apolipoprotein B contamination when using polyethylene glycol (PEG) method. We demonstrate also no effect on cholesterol efflux efficiency when using PEG with plasma or serum. This method has been previously applied in our laboratory in context of cardiovascular research, cardiovascular disease and pharmacologic therapies. PMID:26663796

  6. Enhanced placental cholesterol efflux by fetal HDL in Smith–Lemli–Opitz syndrome

    PubMed Central

    Jenkins, Katie T.; Merkens, Louise S.; Tubb, Matthew R.; Myatt, Leslie; Davidson, W. Sean; Steiner, Robert D.; Woollett, Laura A.

    2010-01-01

    Previous studies from this laboratory have shown that maternal-derived cholesterol can be effluxed from trophoblasts to fetal HDL and plasma. We had the opportunity to study for the first time the ability of HDL and plasma from a fetus with the Smith–Lemli–Opitz syndrome (SLOS) to efflux cholesterol from trophoblasts. It was unclear whether cholesterol could be effluxed to fetuses with SLOS since lipoprotein levels are often very low. To answer this question, cord blood was collected from the placentas of an SLOS fetus and unaffected fetuses just after delivery. Plasma cholesterol concentrations were very low in the affected fetus; cholesterol, 7-dehydrocholesterol, and 8-dehydocholesterol concentrations were 14.1, 4.5, and 5.2 mg/dl, respectively. The HDL from the fetal SLOS effluxed ≈50% more cholesterol from a trophoblast cell line, were smaller in size, and had a lower cholesterol to phospholipid ratio as compared to HDL from unaffected fetuses or adults. Plasma from the SLOS fetus effluxed cholesterol to a similar percentage as unaffected fetal plasma or adult plasma, possibly due to fewer HDL particles as demonstrated in previous SLOS patients. These novel data demonstrate that the cholesterol-deficient SLOS fetus is able to obtain cholesterol from trophoblasts at a time when cholesterol is playing a critical role in development, and has implications for design of treatments for cholesterol deficiency syndromes as well as understanding of prenatal cholesterol transport in humans. PMID:18346920

  7. Low HDL cholesterol, aggression and altered central serotonergic activity.

    PubMed

    Buydens-Branchey, L; Branchey, M; Hudson, J; Fergeson, P

    2000-03-01

    Many studies support a significant relation between low cholesterol levels and poor impulse, aggression and mood control. Evidence exists also for a causal link between low brain serotonin (5-HT) activity and these behaviors. Mechanisms linking cholesterol and hostile or self-destructive behavior are unknown, but it has been suggested that low cholesterol influences 5-HT function. This study was designed to explore the relationship between plasma cholesterol, measures of impulsivity and aggression, and indices of 5-HT function in personality disordered cocaine addicts. Thirty-eight hospitalized male patients (age 36.8+/-7.1) were assessed with the DSM-III-R, the Buss-Durkee Hostility Inventory (BDHI), the Barratt Impulsiveness Scale (BIS) and the Brown-Goodwin Assessment for Life History of Aggression. Fasting basal cholesterol (total, LDL and HDL) was determined 2 weeks after cocaine discontinuation. On the same day 5-HT function was assessed by neuroendocrine (cortisol and prolactin) and psychological (NIMH and 'high' self-rating scales) responses following meta-chlorophenylpiperazine (m-CPP) challenges. Reduced neuroendocrine responses, 'high' feelings and increased 'activation-euphoria' following m-CPP have been interpreted as indicating 5-HT alterations in a variety of psychiatric conditions. Significantly lower levels of HDL cholesterol were found in patients who had a history of aggression (P=0.005). Lower levels of HDL cholesterol were also found to be significantly associated with more intense 'high' and 'activation-euphoria' responses as well as with blunted cortisol responses to m-CPP (P=0.033, P=0.025 and P=0.018, respectively). This study gives further support to existing evidence indicating that in some individuals, the probability of exhibiting impulsive and violent behaviors may be increased when cholesterol is low. It also suggests that low cholesterol and alterations in 5-HT activity may be causally related.

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

    PubMed

    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

    2013-06-01

    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 study this, steroid hormone profiles in urine were assessed in male subjects suffering from functional mutations in ATP binding cassette transporter A1 (ABCA1) (n = 24), lecithin:cholesterol acyltransferase (LCAT) (n = 40), as well as in 11 subjects with low HDL cholesterol (HDL-C) without ABCA1/LCAT mutations. HDL-C levels were 39% lower in the ABCA1, LCAT, and low HDL-C groups compared with controls (all P < 0.001). In all groups with low HDL-C levels, urinary excretion of 17-ketogenic steroids was reduced by 33%, 27%, and 32% compared with controls (all P < 0.04). In seven carriers of either type of mutation, adrenocorticotropic hormone (ACTH) stimulation did not reveal differences from normolipidemic controls. In conclusion, this study shows that basal but not stimulated corticosteroid metabolism is attenuated in subjects with low HDL-C, irrespective of its molecular origin. These findings lend support to a role for HDL as a cholesterol donor for basal adrenal steroidogenesis in humans. PMID:23511897

  9. Targeted next-generation sequencing to diagnose disorders of HDL cholesterol[S

    PubMed Central

    Sadananda, Singh N.; Foo, Jia Nee; Toh, Meng Tiak; Cermakova, Lubomira; Trigueros-Motos, Laia; Chan, Teddy; Liany, Herty; Collins, Jennifer A.; Gerami, Sima; Singaraja, Roshni R.; Hayden, Michael R.; Francis, Gordon A.; Frohlich, Jiri; Khor, Chiea Chuen; Brunham, Liam R.

    2015-01-01

    A low level of HDL cholesterol (HDL-C) is a common clinical scenario and an important marker for increased cardiovascular risk. Many patients with very low or very high HDL-C have a rare mutation in one of several genes, but identification of the molecular abnormality in patients with extreme HDL-C is rarely performed in clinical practice. We investigated the accuracy and diagnostic yield of a targeted next-generation sequencing (NGS) assay for extreme levels of HDL-C. We developed a targeted NGS panel to capture the exons, intron/exon boundaries, and untranslated regions of 26 genes with highly penetrant effects on plasma lipid levels. We sequenced 141 patients with extreme HDL-C levels and prioritized variants in accordance with medical genetics guidelines. We identified 35 pathogenic and probably pathogenic variants in HDL genes, including 21 novel variants, and performed functional validation on a subset of these. Overall, a molecular diagnosis was established in 35.9% of patients with low HDL-C and 5.2% with high HDL-C, and all prioritized variants identified by NGS were confirmed by Sanger sequencing. Our results suggest that a molecular diagnosis can be identified in a substantial proportion of patients with low HDL-C using targeted NGS. PMID:26255038

  10. Niacin Therapy, HDL Cholesterol, and Cardiovascular Disease: Is the HDL Hypothesis Defunct?

    PubMed Central

    Mani, Preethi; Rohatgi, Anand

    2016-01-01

    High-density lipoprotein cholesterol (HDL-C) has been shown in epidemiologic studies to be associated with cardiovascular (CV) risk and thus significant efforts have been focused on HDL-C modulation. Multiple pharmaceutical agents have been developed with the goal of increasing HDL-C. Niacin, the most widely used medication to raise HDL-C, increases HDL-C by up to 25 % and was shown in multiple surrogate end point studies to reduce CV risk. However, two large randomized controlled trials of niacin, AIM-HIGH and HPS2-THRIVE, have shown that despite its effects on HDL-C, niacin does not decrease the incidence of CV events and may have significant adverse effects. Studies of other classes of agents such as cholesteryl ester transfer protein (CETP) inhibitors have also shown that even dramatic increases in HDL-C do not necessarily translate to reduction in clinical events. While these findings have cast doubt upon the importance of HDL-C modulation on CV risk, it is becoming increasingly clear that HDL function-related measures may be better targets for CV risk reduction. Increasing ApoA-I, the primary apolipoprotein associated with HDL, correlates with reduced risk of events, and HDL particle concentration (HDL-P) inversely associates with incident CV events adjusted for HDL-C and LDL particle measures. Cholesterol efflux, the mechanism by which macrophages in vessel walls secrete cholesterol outside cells, correlates with both surrogate end points and clinical events. The effects of niacin on these alternate measures of HDL have been conflicting. Further studies should determine if modulation of these HDL function markers translates to clinical benefits. Although the HDL cholesterol hypothesis may be defunct, the HDL function hypothesis is now poised to be rigorously tested. PMID:26048725

  11. Niacin Therapy, HDL Cholesterol, and Cardiovascular Disease: Is the HDL Hypothesis Defunct?

    PubMed

    Mani, Preethi; Rohatgi, Anand

    2015-08-01

    High-density lipoprotein cholesterol (HDL-C) has been shown in epidemiologic studies to be associated with cardiovascular (CV) risk and thus significant efforts have been focused on HDL-C modulation. Multiple pharmaceutical agents have been developed with the goal of increasing HDL-C. Niacin, the most widely used medication to raise HDL-C, increases HDL-C by up to 25 % and was shown in multiple surrogate end point studies to reduce CV risk. However, two large randomized controlled trials of niacin, AIM-HIGH and HPS2-THRIVE, have shown that despite its effects on HDL-C, niacin does not decrease the incidence of CV events and may have significant adverse effects. Studies of other classes of agents such as cholesteryl ester transfer protein (CETP) inhibitors have also shown that even dramatic increases in HDL-C do not necessarily translate to reduction in clinical events. While these findings have cast doubt upon the importance of HDL-C modulation on CV risk, it is becoming increasingly clear that HDL function-related measures may be better targets for CV risk reduction. Increasing ApoA-I, the primary apolipoprotein associated with HDL, correlates with reduced risk of events, and HDL particle concentration (HDL-P) inversely associates with incident CV events adjusted for HDL-C and LDL particle measures. Cholesterol efflux, the mechanism by which macrophages in vessel walls secrete cholesterol outside cells, correlates with both surrogate end points and clinical events. The effects of niacin on these alternate measures of HDL have been conflicting. Further studies should determine if modulation of these HDL function markers translates to clinical benefits. Although the HDL cholesterol hypothesis may be defunct, the HDL function hypothesis is now poised to be rigorously tested.

  12. The effects of ABCG5/G8 polymorphisms on plasma HDL cholesterol concentrations depend on smoking habit in the Boston Puerto Rican Health Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background-Low high-density lipoprotein cholesterol (HDL-C) is associated with an increased risk for atherosclerosis and concentrations are modulated by genetic and environmental factors such as smoking. Objective- To assess whether the association of common single nucleotide polymorphisms (SNPs...

  13. [Low HDL-cholesterol--an important risk factor for cardiovascular diseases].

    PubMed

    Reiner, Zeljko; Muacević-Katanec, Diana; Katanec, Davor; Tedeschi-Reiner, Eugenia

    2011-01-01

    It has been known for quite a long time that the concentration of HDL-cholesterol correlates inversely with cardiovascular disease (CVD) risk and that low HDL-cholesterol is an independent CVD risk factor. This review aims to highlight evidence on several topics concerning the role of HDL particles and the importance of HDL-cholesterol. The main antiatherogenic functions of HDL particles are presented in details--reverse cholesterol transport, but also their anti-oxidant, anti-inflammatory, anti-thrombotic and anti-apoptotic properties as well as endothelial stabilizing and repair properties. Lifestyle management of low HDL-cholesterol is explained, particularly physical activity and aerobic exercise, smoking cessation, weight reduction in the overweight individuals and composition of the diet but also moderate alcohol consumption stressing the fact that HDL particles from alcoholics are dysfunctional. This is important since it has been shown that it is not only the quantity of HDL particles, and thus HDL-cholesterol level in plasma, that matters, but their quality and impaired functionality as well. HDL from diabetic subjects also lose some of their antiatherogenic properties but a common feature of patients with diabetes type 2 is atherogenic dyslipidemia which is characterized exactly by low HDL-cholesterol and high triglycerides. Diabetic patients with such dyslipidemia are at particularly high CVD risk and the results of recent studies such as ACCORD-Lipid suggest that in them treatment of these lipid abnormalities may be beneficial. Treatment options with fibrates, particularly fenofibrate, and niacin are discussed based upon published trials, as well as combination therapy with these medicines and other lipid-lowering drugs.

  14. Approach to the Patient with Extremely Low HDL-Cholesterol

    PubMed Central

    deGoma, Emil M.

    2012-01-01

    Patients with extremely low high-density lipoprotein-cholesterol (HDL-C) pose distinct challenges to clinical diagnosis and management. Confirmation of HDL-C levels below 20 mg/dl in the absence of severe hypertriglyceridemia should be followed by evaluation for secondary causes, such as androgen use, malignancy, and primary monogenic disorders, namely, apolipoprotein A-I mutations, Tangier disease, and lecithin-cholesterol acyltransferase deficiency. Global cardiovascular risk assessment is a critical component of comprehensive evaluation, although the association between extremely low HDL-C levels and atherosclerosis remains unclear. Therapeutic interventions address reversible causes of low HDL-C, multiorgan abnormalities that may accompany primary disorders and cardiovascular risk modification when appropriate. Uncommon encounters with patients exhibiting extremely low HDL-C provide an opportunity to directly observe the role of HDL metabolism in atherosclerosis and beyond the vascular system. PMID:23043194

  15. Rare variant in scavenger receptor BI raises HDL cholesterol and increases risk of coronary heart disease

    PubMed Central

    Zanoni, Paolo; Khetarpal, Sumeet A.; Larach, Daniel B.; Hancock-Cerutti, William F.; Millar, John S.; Cuchel, Marina; DerOhannessian, Stephanie; Kontush, Anatol; Surendran, Praveen; Saleheen, Danish; Trompet, Stella; Jukema, J. Wouter; De Craen, Anton; Deloukas, Panos; Sattar, Naveed; Ford, Ian; Packard, Chris; Majumder, Abdullah al Shafi; Alam, Dewan S.; Di Angelantonio, Emanuele; Abecasis, Goncalo; Chowdhury, Rajiv; Erdmann, Jeanette; Nordestgaard, Børge G.; Nielsen, Sune F.; Tybjærg-Hansen, Anne; Schmidt, Ruth Frikke; Kuulasmaa, Kari; Liu, Dajiang J.; Perola, Markus; Blankenberg, Stefan; Salomaa, Veikko; Männistö, Satu; Amouyel, Philippe; Arveiler, Dominique; Ferrieres, Jean; Müller-Nurasyid, Martina; Ferrario, Marco; Kee, Frank; Willer, Cristen J.; Samani, Nilesh; Schunkert, Heribert; Butterworth, Adam S.; Howson, Joanna M. M.; Peloso, Gina M.; Stitziel, Nathan O.; Danesh, John; Kathiresan, Sekar; Rader, Daniel J.

    2016-01-01

    Scavenger receptor BI (SR-BI) is the major receptor for high-density lipoprotein (HDL) cholesterol (HDL-C). In humans, high amounts of HDL-C in plasma are associated with a lower risk of coronary heart disease (CHD). Mice that have depleted Scarb1 (SR-BI knockout mice) have markedly elevated HDL-C levels but, paradoxically, increased atherosclerosis. The impact of SR-BI on HDL metabolism and CHD risk in humans remains unclear. Through targeted sequencing of coding regions of lipid-modifying genes in 328 individuals with extremely high plasma HDL-C levels, we identified a homozygote for a loss-of-function variant, in which leucine replaces proline 376 (P376L), in SCARB1, the gene encoding SR-BI. The P376L variant impairs posttranslational processing of SR-BI and abrogates selective HDL cholesterol uptake in transfected cells, in hepatocyte-like cells derived from induced pluripotent stem cells from the homozygous subject, and in mice. Large population-based studies revealed that subjects who are heterozygous carriers of the P376L variant have significantly increased levels of plasma HDL-C. P376L carriers have a profound HDL-related phenotype and an increased risk of CHD (odds ratio = 1.79, which is statistically significant). PMID:26965621

  16. Non-HDL Cholesterol and Evaluation of Cardiovascular Disease Risk

    PubMed Central

    2010-01-01

    Cardiovascular disease (CVD), such as coronary heart disease (CHD), is the most frequent cause of death worldwide, especially in developed countries. The latest recommendations of European and American Cardiological Associations emphasize the role of non-HDL cholesterol (non-HDL-C) in evaluating the risk of CVD. Although this parameter has a lot of advantages, it is rarely used by general practitioners in lipid profile assessment. The aim of this article is to present the recent informations on the usage of non-HDL-C in the primary prevention of cardiovascular disease and to compare its diagnostic value to traditional and new CVD risk factors.

  17. Prosopis farcta beans increase HDL cholesterol and decrease LDL cholesterol in ostriches (Struthio camelus).

    PubMed

    Omidi, Arash; Ansari nik, Hossein; Ghazaghi, Mahmood

    2013-02-01

    Ten blue-neck male ostriches (Struthio camelus) were fed Prosopis farcta beans throughout a 30-day experiment. Blood samples were collected from ostriches on days 0 and 30 to measure levels of high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, triglyceride, total serum protein, albumin, globulin, cholesterol, calcium, inorganic phosphorus, the activity of aspartate aminotransferase, alanine aminotransferase, and γ-glutamyl transferase (γ-GT). From days 0 to 30, HDL cholesterol, total protein, and globulins levels increased significantly whereas LDL cholesterol, inorganic phosphorus, and γ-GT activity decreased significantly.

  18. Predominance of large LDL and reduced HDL2 cholesterol in normolipidemic men with coronary artery disease.

    PubMed

    Campos, H; Roederer, G O; Lussier-Cacan, S; Davignon, J; Krauss, R M

    1995-08-01

    Previous studies have indicated that a predominance of small, dense LDL particles is associated with coronary artery disease (CAD) risk. In the present study we examined the LDL peak particle diameter (determined by lipid-stained 2% to 16% gradient gel electrophoresis) in 92 normolipidemic men with CAD (total cholesterol < 200 mg/dL and triglyceride < 250 mg/dL) and 92 matched healthy controls. Plasma triglyceride, LDL cholesterol, and apo B levels were similar in subjects with CAD and in control subjects, whereas subjects with CAD had decreased HDL2 cholesterol levels (mean +/- SEM, 10 +/- 0.7 compared with 15 +/- 0.7 mg/dL in control subjects; P < .0002). Mean LDL particle diameter (+/- SEM) was increased in the subjects with CAD compared with control subjects (26.8 +/- 0.08 and 26.4 +/- 0.08 nm, respectively; P < .001). The association between large LDL size and CAD was significant (P < .0001) after adjustments were made for age, body mass index, HDL cholesterol levels, and VLDL cholesterol levels. An LDL particle size distribution characterized by a predominance of the largest of three classes of LDL particles (> 26.8 nm) was more prevalent among subjects with CAD (43%) than among control subjects (25%) (P < .002). Among subjects with this LDL size profile, subjects with CAD had significantly higher (P < .05) VLDL triglyceride, VLDL cholesterol, and VLDL apo B levels and significantly lower (P < .0001) HDL2 cholesterol levels than controls.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. Ciprofibrate therapy in patients with hypertriglyceridemia and low high density lipoprotein (HDL)-cholesterol: greater reduction of non-HDL cholesterol in subjects with excess body weight (The CIPROAMLAT study)

    PubMed Central

    Aguilar-Salinas, Carlos A; Assis-Luores-Vale, Andréia; Stockins, Benjamín; Rengifo, Hector Mario; Filho, José Dondici; Neto, Abrahão Afiune; Rabelo, Lísia Marcílio; Torres, Kerginaldo Paulo; Oliveira, José Egídio Paulo de; Machado, Carlos Alberto; Reyes, Eliana; Saavedra, Victor; Florenzano, Fernando; Hernández, Ma Victoria; Jiménez, Sergio Hernandez; Ramírez, Erika; Vazquez, Cuauhtémoc; Salinas, Saul; Hernández, Ismael; Medel, Octavio; Moreno, Ricardo; Lugo, Paula; Alvarado, Ricardo; Mehta, Roopa; Gutierrez, Victor; Gómez Pérez, Francisco J

    2004-01-01

    Background Hypertriglyceridemia in combination with low HDL cholesterol levels is a risk factor for cardiovascular disease. Our objective was to evaluate the efficacy of ciprofibrate for the treatment of this form of dyslipidemia and to identify factors associated with better treatment response. Methods Multicenter, international, open-label study. Four hundred and thirty seven patients were included. The plasma lipid levels at inclusion were fasting triglyceride concentrations between 1.6–3.9 mM/l and HDL cholesterol ≤ 1.05 mM/l for women and ≤ 0.9 mM/l for men. The LDL cholesterol was below 4.2 mM/l. All patients received ciprofibrate 100 mg/d. Efficacy and safety parameters were assessed at baseline and at the end of the treatment. The primary efficacy parameter of the study was percentage change in triglycerides from baseline. Results After 4 months, plasma triglyceride concentrations were decreased by 44% (p < 0.001). HDL cholesterol concentrations were increased by 10% (p < 0.001). Non-HDL cholesterol was decreased by 19%. A greater HDL cholesterol response was observed in lean patients (body mass index < 25 kg/m2) compared to the rest of the population (8.2 vs 19.7%, p < 0.001). In contrast, cases with excess body weight had a larger decrease in non-HDL cholesterol levels (-20.8 vs -10.8%, p < 0.001). There were no significant complications resulting from treatment with ciprofibrate. Conclusions Ciprofibrate is efficacious for the correction of hypertriglyceridemia / low HDL cholesterol. A greater decrease in non-HDL cholesterol was found among cases with excess body weight. The mechanism of action of ciprofibrate may be influenced by the pathophysiology of the disorder being treated. PMID:15272932

  20. Improvement of HDL- and LDL-cholesterol levels in diabetic subjects by feeding bread containing chitosan.

    PubMed

    Ausar, S F; Morcillo, M; León, A E; Ribotta, P D; Masih, R; Vilaro Mainero, M; Amigone, J L; Rubin, G; Lescano, C; Castagna, L F; Beltramo, D M; Diaz, G; Bianco, I D

    2003-01-01

    In this work we evaluated the efficacy and safety of a bread formulation containing chitosan in dyslipidemic type 2 diabetic subjects. For this purpose a total of 18 patients were allowed to incorporate to their habitual diets 120 g/day of bread containing 2% (wt/wt) chitosan (chitosan group, n= 9) or standard bread (control group, n= 9). Before the study and after 12 weeks on the modified diet, the following parameters were evaluated: body weight, plasma cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglyceride, and hemoglobin A(1c) (HbA(1c)). Compared with the control group, the patients receiving chitosan-containing bread decreased their mean levels of LDL-cholesterol and significantly increased their mean levels of HDL-cholesterol at the end of the study. There were no significant differences in the body weight, serum triglyceride, and HbA(1c). These results suggest that chitosan incorporated into bread formulations could improve the lipoprotein balance similar to typical biliary salts trappers, increasing the HDL- and lowering the LDL-cholesterol, without changing the triglyceride levels. These results warrant further studies over a longer period of time to evaluate if a persistent improvement in levels of lipoproteins can be attained with this strategy.

  1. Low HDL cholesterol is associated with increased atherogenic lipoproteins and insulin resistance in women classified with metabolic syndrome

    PubMed Central

    Jones, Jennifer J; Ackerman, Daniela; Barona, Jacqueline; Calle, Mariana; Comperatore, Michael V; Kim, Jung-Eun; Andersen, Catherine; Leite, Jose O; Volek, Jeff S; McIntosh, Mark; Kalynych, Colleen; Najm, Wadie; Lerman, Robert H

    2010-01-01

    Both metabolic syndrome (MetS) and elevated LDL cholesterol (LDL-C) increase the risk for cardiovascular disease (CVD). We hypothesized that low HDL cholesterol (HDL-C) would further increase CVD risk in women having both conditions. To assess this, we recruited 89 women with MetS (25-72 y) and LDL-C ≥ 2.6 mmol/L. To determine whether plasma HDL-C concentrations were associated with dietary components, circulating atherogenic particles, and other risk factors for CVD, we divided the subjects into two groups: high HDL-C (H-HDL) (≥ 1.3 mmol/L, n = 32) and low HDL-C (L-HDL) (< 1.3 mmol/L, n = 57). Plasma lipids, insulin, adiponectin, apolipoproteins, oxidized LDL, Lipoprotein(a), and lipoprotein size and subfractions were measured, and 3-d dietary records were used to assess macronutrient intake. Women with L-HDL had higher sugar intake and glycemic load (P < 0.05), higher plasma insulin (P < 0.01), lower adiponectin (P < 0.05), and higher numbers of atherogenic lipoproteins such as large VLDL (P < 0.01) and small LDL (P < 0.001) than the H-HDL group. Women with L-HDL also had larger VLDL and both smaller LDL and HDL particle diameters (P < 0.001). HDL-C was positively correlated with LDL size (r = 0.691, P < 0.0001) and HDL size (r = 0.606, P < 0.001), and inversely correlated with VLDL size (r = -0.327, P < 0.01). We concluded that L-HDL could be used as a marker for increased numbers of circulating atherogenic lipoproteins as well as increased insulin resistance in women who are already at risk for CVD. PMID:21286407

  2. Low HDL cholesterol is associated with increased atherogenic lipoproteins and insulin resistance in women classified with metabolic syndrome.

    PubMed

    Fernandez, Maria Luz; Jones, Jennifer J; Ackerman, Daniela; Barona, Jacqueline; Calle, Mariana; Comperatore, Michael V; Kim, Jung-Eun; Andersen, Catherine; Leite, Jose O; Volek, Jeff S; McIntosh, Mark; Kalynych, Colleen; Najm, Wadie; Lerman, Robert H

    2010-12-01

    Both metabolic syndrome (MetS) and elevated LDL cholesterol (LDL-C) increase the risk for cardiovascular disease (CVD). We hypothesized that low HDL cholesterol (HDL-C) would further increase CVD risk in women having both conditions. To assess this, we recruited 89 women with MetS (25-72 y) and LDL-C ≥ 2.6 mmol/L. To determine whether plasma HDL-C concentrations were associated with dietary components, circulating atherogenic particles, and other risk factors for CVD, we divided the subjects into two groups: high HDL-C (H-HDL) (≥ 1.3 mmol/L, n = 32) and low HDL-C (L-HDL) (< 1.3 mmol/L, n = 57). Plasma lipids, insulin, adiponectin, apolipoproteins, oxidized LDL, Lipoprotein(a), and lipoprotein size and subfractions were measured, and 3-d dietary records were used to assess macronutrient intake. Women with L-HDL had higher sugar intake and glycemic load (P < 0.05), higher plasma insulin (P < 0.01), lower adiponectin (P < 0.05), and higher numbers of atherogenic lipoproteins such as large VLDL (P < 0.01) and small LDL (P < 0.001) than the H-HDL group. Women with L-HDL also had larger VLDL and both smaller LDL and HDL particle diameters (P < 0.001). HDL-C was positively correlated with LDL size (r = 0.691, P < 0.0001) and HDL size (r = 0.606, P < 0.001), and inversely correlated with VLDL size (r = -0.327, P < 0.01). We concluded that L-HDL could be used as a marker for increased numbers of circulating atherogenic lipoproteins as well as increased insulin resistance in women who are already at risk for CVD.

  3. The effect of ABCG5/G8 polymorphisms on plasma HDL cholesterol levels depends on the ABCA1 gene variation in the Boston Puerto Rican Health Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: ATP-binding cassette transporters G5/G8 have shown an association with HDL-C. One of the most likely mechanisms to explain those associations is through ABCA1. Objective: To assess whether the effect of ABCG5/G8 polymorphisms on HDL-C is dependent on ABCA1, we studied potential interacti...

  4. Impaired HDL cholesterol efflux in metabolic syndrome is unrelated to glucose tolerance status: the CODAM study

    PubMed Central

    Annema, Wijtske; Dikkers, Arne; de Boer, Jan Freark; van Greevenbroek, Marleen M. J.; van der Kallen, Carla J. H.; Schalkwijk, Casper G.; Stehouwer, Coen D. A.; Dullaart, Robin P. F.; Tietge, Uwe J. F.

    2016-01-01

    Type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) increase atherosclerotic cardiovascular disease risk. Cholesterol efflux capacity (CEC) is a key metric of the anti-atherosclerotic functionality of high-density lipoproteins (HDL). The present study aimed to delineate if T2DM and MetS cross-sectionally associate with altered CEC in a large high cardiometabolic risk population. CEC was determined from THP-1 macrophage foam cells towards apolipoprotein B-depleted plasma from 552 subjects of the CODAM cohort (288 controls, 126 impaired glucose metabolism [IGM], 138 T2DM). MetS was present in 297 participants. CEC was not different between different glucose tolerance categories but was lower in MetS (P < 0.001), at least partly attributable to lower HDL cholesterol (HDL-C) and apoA-I levels (P < 0.001 for each). Low grade inflammation was increased in IGM, T2DM and MetS as determined by a score comprising 8 different biomarkers (P < 0.05-< 0.001; n = 547). CEC inversely associated with low-grade inflammation taking account of HDL-C or apoA-I in MetS (P < 0.02), but not in subjects without MetS (interaction: P = 0.015). This study demonstrates that IGM and T2DM do not impact the HDL CEC function, while efflux is lower in MetS, partly dependent on plasma HDL-C levels. Enhanced low-grade inflammation in MetS may conceivably impair CEC even independent of HDL-C and apoA-I. PMID:27270665

  5. Intracellular cholesterol transport proteins enhance hydrolysis of HDL-CEs and facilitate elimination of cholesterol into bile.

    PubMed

    Wang, Jing; Bie, Jinghua; Ghosh, Shobha

    2016-09-01

    While HDL-associated unesterified or free cholesterol (FC) is thought to be rapidly secreted into the bile, the fate of HDL-associated cholesteryl esters (HDL-CEs) that represent >80% of HDL-cholesterol, is only beginning to be understood. In the present study, we examined the hypothesis that intracellular cholesterol transport proteins [sterol carrier protein 2 (SCP2) and fatty acid binding protein-1 (FABP1)] not only facilitate CE hydrolase-mediated hydrolysis of HDL-CEs, but also enhance elimination of cholesterol into bile. Adenovirus-mediated overexpression of FABP1 or SCP2 in primary hepatocytes significantly increased hydrolysis of HDL-[(3)H]CE, reduced resecretion of HDL-CE-derived FC as nascent HDL, and increased its secretion as bile acids. Consistently, the flux of [(3)H]cholesterol from HDL-[(3)H]CE to biliary bile acids was increased by overexpression of SCP2 or FABP1 in vivo and reduced in SCP2(-/-) mice. Increased flux of HDL-[(3)H]CE to biliary FC was noted with FABP1 overexpression and in SCP2(-/-) mice that have increased FABP1 expression. Lack of a significant decrease in the flux of HDL-[(3)H]CE to biliary FC or bile acids in FABP1(-/-) mice indicates the likely compensation of its function by an as yet unidentified mechanism. Taken together, these studies demonstrate that FABP1 and SCP2 facilitate the preferential movement of HDL-CEs to bile for final elimination. PMID:27381048

  6. HDL-apolipoprotein A-I exchange is independently associated with cholesterol efflux capacity

    PubMed Central

    Borja, Mark S.; Ng, Kit F.; Irwin, Angela; Hong, Jaekyoung; Wu, Xing; Isquith, Daniel; Zhao, Xue-Qiao; Prazen, Bryan; Gildengorin, Virginia; Oda, Michael N.; Vaisar, Tomáš

    2015-01-01

    HDL is the primary mediator of cholesterol mobilization from the periphery to the liver via reverse cholesterol transport (RCT). A critical first step in this process is the uptake of cholesterol from lipid-loaded macrophages by HDL, a function of HDL inversely associated with prevalent and incident cardiovascular disease. We hypothesized that the dynamic ability of HDL to undergo remodeling and exchange of apoA-I is an important and potentially rate-limiting aspect of RCT. In this study, we investigated the relationship between HDL-apoA-I exchange (HAE) and serum HDL cholesterol (HDL-C) efflux capacity. We compared HAE to the total and ABCA1-specific cholesterol efflux capacity of 77 subjects. We found that HAE was highly correlated with both total (r = 0.69, P < 0.0001) and ABCA1-specific (r = 0.47, P < 0.0001) efflux, and this relationship remained significant after adjustment for HDL-C or apoA-I. Multivariate models of sterol efflux capacity indicated that HAE accounted for approximately 25% of the model variance for both total and ABCA1-specific efflux. We conclude that the ability of HDL to exchange apoA-I and remodel, as measured by HAE, is a significant contributor to serum HDL efflux capacity, independent of HDL-C and apoA-I, indicating that HDL dynamics are an important factor in cholesterol efflux capacity and likely RCT. PMID:26254308

  7. HDL-apolipoprotein A-I exchange is independently associated with cholesterol efflux capacity.

    PubMed

    Borja, Mark S; Ng, Kit F; Irwin, Angela; Hong, Jaekyoung; Wu, Xing; Isquith, Daniel; Zhao, Xue-Qiao; Prazen, Bryan; Gildengorin, Virginia; Oda, Michael N; Vaisar, Tomáš

    2015-10-01

    HDL is the primary mediator of cholesterol mobilization from the periphery to the liver via reverse cholesterol transport (RCT). A critical first step in this process is the uptake of cholesterol from lipid-loaded macrophages by HDL, a function of HDL inversely associated with prevalent and incident cardiovascular disease. We hypothesized that the dynamic ability of HDL to undergo remodeling and exchange of apoA-I is an important and potentially rate-limiting aspect of RCT. In this study, we investigated the relationship between HDL-apoA-I exchange (HAE) and serum HDL cholesterol (HDL-C) efflux capacity. We compared HAE to the total and ABCA1-specific cholesterol efflux capacity of 77 subjects. We found that HAE was highly correlated with both total (r = 0.69, P < 0.0001) and ABCA1-specific (r = 0.47, P < 0.0001) efflux, and this relationship remained significant after adjustment for HDL-C or apoA-I. Multivariate models of sterol efflux capacity indicated that HAE accounted for approximately 25% of the model variance for both total and ABCA1-specific efflux. We conclude that the ability of HDL to exchange apoA-I and remodel, as measured by HAE, is a significant contributor to serum HDL efflux capacity, independent of HDL-C and apoA-I, indicating that HDL dynamics are an important factor in cholesterol efflux capacity and likely RCT.

  8. Emerging therapies for raising high-density lipoprotein cholesterol (HDL-C) and augmenting HDL particle functionality.

    PubMed

    Barylski, Marcin; Toth, Peter P; Nikolic, Dragana; Banach, Maciej; Rizzo, Manfredi; Montalto, Giuseppe

    2014-06-01

    High-density lipoprotein (HDL) particles are highly complex polymolecular aggregates capable of performing a remarkable range of atheroprotective functions. Considerable research is being performed throughout the world to develop novel pharmacologic approaches to: (1) promote apoprotein A-I and HDL particle biosynthesis; (2) augment capacity for reverse cholesterol transport so as to reduce risk for the development and progression of atherosclerotic disease; and (3) modulate the functionality of HDL particles in order to increase their capacity to antagonize oxidation, inflammation, thrombosis, endothelial dysfunction, insulin resistance, and other processes that participate in arterial wall injury. HDL metabolism and the molecular constitution of HDL particles are highly complex and can change in response to both acute and chronic alterations in the metabolic milieu. To date, some of these interventions have been shown to positively impact rates of coronary artery disease progression. However, none of them have as yet been shown to significantly reduce risk for cardiovascular events. In the next 3-5 years a variety of pharmacologic interventions for modulating HDL metabolism and functionality will be tested in large, randomized, prospective outcomes trials. It is hoped that one or more of these therapeutic approaches will result in the ability to further reduce risk for cardiovascular events once low-density lipoprotein cholesterol and non-HDL-cholesterol targets have been attained. PMID:24840270

  9. Increased HDL cholesterol levels in mice with XX versus XY sex chromosomes

    PubMed Central

    Link, Jenny C.; Chen, Xuqi; Prien, Christopher; Borja, Mark S.; Hammerson, Bradley; Oda, Michael N.; Arnold, Arthur P.; Reue, Karen

    2015-01-01

    Objective The molecular mechanisms underlying sex differences in dyslipidemia are poorly understood. We aimed to distinguish genetic and hormonal regulators of sex differences in plasma lipid levels. Approach and Results We assessed the role of gonadal hormones and sex chromosome complement on lipid levels using the Four Core Genotypes mouse model (XX females, XX males, XY females, and XY males). In gonadally intact mice fed a chow diet, lipid levels were influenced by both male–female gonadal sex and XX–XY chromosome complement. Gonadectomy of adult mice revealed that the male–female differences are dependent on acute effects of gonadal hormones. In both intact and gonadectomized animals, XX mice had higher HDL cholesterol (HDL-C) levels than XY mice, regardless of male–female sex. Feeding a cholesterol-enriched diet produced distinct patterns of sex differences in lipid levels compared to a chow diet, revealing the interaction of gonadal and chromosomal sex with diet. Notably, under all dietary and gonadal conditions, HDL-C levels were higher in mice with two X chromosomes compared to mice with an X and Y chromosome. By generating mice with XX, XY and XXY chromosome complements, we determined that the presence of two X chromosomes, and not the absence of the Y chromosome, influences HDL-C concentration. Conclusions We demonstrate that having two X chromosomes versus an X and Y chromosome complement drives sex differences in HDL-C. It is conceivable that increased expression of genes escaping X-inactivation in XX mice regulates downstream processes to establish sexual dimorphism in plasma lipid levels. PMID:26112012

  10. Evidence for a role of CETP in HDL remodeling and cholesterol efflux: role of cysteine 13 of CETP.

    PubMed

    Maugeais, Cyrille; Perez, Anne; von der Mark, Elisabeth; Magg, Christine; Pflieger, Philippe; Niesor, Eric J

    2013-11-01

    Cholesteryl ester transfer protein (CETP), a key regulator of high-density lipoprotein (HDL) metabolism, induces HDL remodeling by transferring lipids between apolipoprotein B-containing lipoproteins and HDL, and/or by promoting lipid transfer between HDL subparticles. In this study, we investigated the mechanism as to how CETP induces the generation of lipid-poor particles (pre-β-HDL) from HDL, which increases ATP-binding cassette transporter 1-mediated cholesterol efflux. This CETP-dependent HDL remodeling is enhanced by the CETP modulator dalcetrapib both in plasma and isolated HDL. The interaction of dalcetrapib with cysteine 13 of CETP is required, since this effect was abolished when using mutant CETP in which cysteine 13 was substituted for a serine residue. Other thiol-containing compounds were identified as CETP modulators interacting with cysteine 13 of CETP. In order to mimic dalcetrapib-bound CETP, mutant CETP proteins were prepared by replacing cysteine 13 with the bulky amino acid tyrosine or tryptophan. The resultant mutants showed virtually no CETP-dependent lipid transfer activity but demonstrated preserved CETP-dependent pre-β-HDL generation. Overall, these data demonstrate that the two functions of CETP i.e., cholesteryl ester transfer and HDL remodeling can be uncoupled by interaction of thiol-containing compounds with cysteine 13 of CETP or by introducing large amino acid residues in place of cysteine 13.

  11. Metabolism of low-density lipoprotein free cholesterol by human plasma lecithin-cholesterol acyltransferase

    SciTech Connect

    Fielding, P.E.; Miida, Takashi; Fielding, C.J. )

    1991-09-03

    The metabolism of cholesterol derived from ({sup 3}H) cholesterol-labeled low-density lipoprotein (LDL) was determined in human blood plasma. LDL-derived free cholesterol first appeared in large {alpha}-migrating HDL (HDL{sub 2}) and was then transferred to small {alpha}-HDL (HDL{sub 3}) for esterification. The major part of such esters was retained within HDL of increasing size in the course of lecithin-cholesterol acyltransferase (LCAT) activity; the balance was recovered in LDL. Transfer of preformed cholesteryl esters within HDL contributed little to the labeled cholesteryl ester accumulating HDL{sub 2}. When cholesterol for esterification was derived instead from cell membranes, a significantly smaller proportion of this cholesteryl ester was subsequently recovered in LDL. These data suggest compartmentation of cholesteryl esters within plasma that have been formed from cell membrane or LDL free cholesterol, and the role for HDL{sub 2} as a relatively unreactive sink for LCAT-derived cholesteryl esters.

  12. A nutrient-dense, high-fiber, fruit-based supplement bar increases HDL cholesterol, particularly large HDL, lowers homocysteine, and raises glutathione in a 2-wk trial.

    PubMed

    Mietus-Snyder, Michele L; Shigenaga, Mark K; Suh, Jung H; Shenvi, Swapna V; Lal, Ashutosh; McHugh, Tara; Olson, Don; Lilienstein, Joshua; Krauss, Ronald M; Gildengoren, Ginny; McCann, Joyce C; Ames, Bruce N

    2012-08-01

    Dietary intake modulates disease risk, but little is known how components within food mixtures affect pathophysiology. A low-calorie, high-fiber, fruit-based nutrient-dense bar of defined composition (e.g., vitamins and minerals, fruit polyphenolics, β-glucan, docosahexaenoic acid) appropriate for deconstruction and mechanistic studies is described and evaluated in a pilot trial. The bar was developed in collaboration with the U.S. Department of Agriculture. Changes in cardiovascular disease and diabetes risk biomarkers were measured after 2 wk twice-daily consumption of the bar, and compared against baseline controls in 25 healthy adults. Plasma HDL-cholesterol (HDL-c) increased 6.2% (P=0.001), due primarily to a 28% increase in large HDL (HDL-L; P<0.0001). Total plasma homocysteine (Hcy) decreased 19% (P=0.017), and glutathione (GSH) increased 20% (P=0.011). The changes in HDL and Hcy are in the direction associated with decreased risk of cardiovascular disease and cognitive decline; increased GSH reflects improved antioxidant defense. Changes in biomarkers linked to insulin resistance and inflammation were not observed. A defined food-based supplement can, within 2 wk, positively impact metabolic biomarkers linked to disease risk. These results lay the groundwork for mechanistic/deconstruction experiments to identify critical bar components and putative synergistic combinations responsible for observed effects.

  13. Incubation of MDCO-216 (ApoA-IMilano/POPC) with Human Serum Potentiates ABCA1-Mediated Cholesterol Efflux Capacity, Generates New Prebeta-1 HDL, and Causes an Increase in HDL Size.

    PubMed

    Kempen, Herman J; Schranz, Dorota B; Asztalos, Bela F; Otvos, James; Jeyarajah, Elias; Drazul-Schrader, Denise; Collins, Heidi L; Adelman, Steven J; Wijngaard, Peter L J

    2014-01-01

    MDCO-216 is a complex of dimeric ApoA-IMilano and palmitoyl oleoyl phosphatidylcholine (POPC), previously shown to reduce atherosclerotic plaque burden. Here we studied the effect of incubation of human plasma or serum with MDCO-216 on cholesterol efflux capacity from J774 cells, on prebeta-1 high density lipoprotein (prebeta-1 HDL) and on HDL size assessed by proton nuclear magnetic resonance ((1)H-NMR). MDCO-216 incubated in buffer containing 4% human serum albumin stimulated both ABCA1-mediated efflux and ABCA1-independent cholesterol efflux from J774 macrophages. When incubated with human serum a dose- and time-dependent synergistic increase of the ABCA1-mediated efflux capacity were observed. Using a commercially available ELISA for prebeta-1 HDL, MDCO-216 as such was poorly detected (12-15% of nominal amount of protein). Prebeta-1 HDL was rapidly lost when human plasma alone is incubated at 37°C. In contrast, incubation of human plasma with MDCO-216 at 37°C produced a large amount of new prebeta-1 HDL. Native 2D electrophoresis followed by immunoblotting with an apoA-I antibody, which also detects ApoA-I Milano, confirmed the increase in prebeta-1 HDL upon incubation at 37°C. With the increase of prebeta-1 HDL, the concomitant disappearance of the small alpha-3 and alpha-4 HDL and MDCO-216 and an increase in the large alpha-1 and alpha-2 HDL were observed. Immunoblotting with Mab 17F3 specific for ApoA-I Milano showed the appearance of ApoA-I Milano in alpha-1 and alpha-2, but not in prebeta-1 HDL. (1)H-NMR analysis of plasma incubated with MDCO-216 confirmed rapid disappearance of small-sized HDL particles and increase of medium- and large-sized HDL particles accompanied with a decrease in total HDL particle number. In conclusion, incubation of human plasma or serum with MDCO-216 strongly enhanced ABCA1-mediated cholesterol efflux, caused a strong increase of prebeta-1 HDL, and drastically changed the distribution of HDL subpopulations. Overall, the

  14. Incubation of MDCO-216 (ApoA-IMilano/POPC) with Human Serum Potentiates ABCA1-Mediated Cholesterol Efflux Capacity, Generates New Prebeta-1 HDL, and Causes an Increase in HDL Size

    PubMed Central

    Schranz, Dorota B.; Asztalos, Bela F.; Otvos, James; Drazul-Schrader, Denise; Wijngaard, Peter L. J.

    2014-01-01

    MDCO-216 is a complex of dimeric ApoA-IMilano and palmitoyl oleoyl phosphatidylcholine (POPC), previously shown to reduce atherosclerotic plaque burden. Here we studied the effect of incubation of human plasma or serum with MDCO-216 on cholesterol efflux capacity from J774 cells, on prebeta-1 high density lipoprotein (prebeta-1 HDL) and on HDL size assessed by proton nuclear magnetic resonance (1H-NMR). MDCO-216 incubated in buffer containing 4% human serum albumin stimulated both ABCA1-mediated efflux and ABCA1-independent cholesterol efflux from J774 macrophages. When incubated with human serum a dose- and time-dependent synergistic increase of the ABCA1-mediated efflux capacity were observed. Using a commercially available ELISA for prebeta-1 HDL, MDCO-216 as such was poorly detected (12–15% of nominal amount of protein). Prebeta-1 HDL was rapidly lost when human plasma alone is incubated at 37°C. In contrast, incubation of human plasma with MDCO-216 at 37°C produced a large amount of new prebeta-1 HDL. Native 2D electrophoresis followed by immunoblotting with an apoA-I antibody, which also detects ApoA-I Milano, confirmed the increase in prebeta-1 HDL upon incubation at 37°C. With the increase of prebeta-1 HDL, the concomitant disappearance of the small alpha-3 and alpha-4 HDL and MDCO-216 and an increase in the large alpha-1 and alpha-2 HDL were observed. Immunoblotting with Mab 17F3 specific for ApoA-I Milano showed the appearance of ApoA-I Milano in alpha-1 and alpha-2, but not in prebeta-1 HDL. 1H-NMR analysis of plasma incubated with MDCO-216 confirmed rapid disappearance of small-sized HDL particles and increase of medium- and large-sized HDL particles accompanied with a decrease in total HDL particle number. In conclusion, incubation of human plasma or serum with MDCO-216 strongly enhanced ABCA1-mediated cholesterol efflux, caused a strong increase of prebeta-1 HDL, and drastically changed the distribution of HDL subpopulations. Overall, the results

  15. Hemorheological and Glycemic Parameters and HDL Cholesterol for the Prediction of Cardiovascular Events

    PubMed Central

    Cho, Sung Woo; Kim, Byung Gyu; Kim, Byung Ok; Byun, Young Sup; Goh, Choong Won; Rhee, Kun Joo; Kwon, Hyuck Moon; Lee, Byoung Kwon

    2016-01-01

    Background Hemorheological and glycemic parameters and high density lipoprotein (HDL) cholesterol are used as biomarkers of atherosclerosis and thrombosis. Objective To investigate the association and clinical relevance of erythrocyte sedimentation rate (ESR), fibrinogen, fasting glucose, glycated hemoglobin (HbA1c), and HDL cholesterol in the prediction of major adverse cardiovascular events (MACE) and coronary heart disease (CHD) in an outpatient population. Methods 708 stable patients who visited the outpatient department were enrolled and followed for a mean period of 28.5 months. Patients were divided into two groups, patients without MACE and patients with MACE, which included cardiac death, acute myocardial infarction, newly diagnosed CHD, and cerebral vascular accident. We compared hemorheological and glycemic parameters and lipid profiles between the groups. Results Patients with MACE had significantly higher ESR, fibrinogen, fasting glucose, and HbA1c, while lower HDL cholesterol compared with patients without MACE. High ESR and fibrinogen and low HDL cholesterol significantly increased the risk of MACE in multivariate regression analysis. In patients with MACE, high fibrinogen and HbA1c levels increased the risk of multivessel CHD. Furthermore, ESR and fibrinogen were significantly positively correlated with HbA1c and negatively correlated with HDL cholesterol, however not correlated with fasting glucose. Conclusion Hemorheological abnormalities, poor glycemic control, and low HDL cholesterol are correlated with each other and could serve as simple and useful surrogate markers and predictors for MACE and CHD in outpatients. PMID:26690693

  16. Beneficial Effect of Higher Dietary Fiber Intake on Plasma HDL-C and TC/HDL-C Ratio among Chinese Rural-to-Urban Migrant Workers

    PubMed Central

    Zhou, Quan; Wu, Jiang; Tang, Jie; Wang, Jia-Ji; Lu, Chu-Hong; Wang, Pei-Xi

    2015-01-01

    Research has shown that high-dose supplemental dietary fiber intake has beneficial effects on cardiovascular risk factors. To clarify such a relationship, we examined the association between daily dietary fiber intake and plasma lipids using a cross-sectional design including 1034 (M 502, F 532) rural-to-urban workers in China. We found a dose-response relationship between increased dietary fiber intakes and increase of HDL cholesterol in male workers. There was also a dose-response relationship between increased dietary fiber intake and decreased total cholesterol to HDL cholesterol (TC/HDL-C) ratio in both male and female workers, after adjusting for potential confounders (p for trend, all p < 0.05). When the average dietary fiber intake increased from less than 18 g/day to over 30 g/day, the average HDL cholesterol level increased by 10.1%, and the TC/HDL-C ratio decreased by 14.4% for males (p = 0.020) and by 11.1% for females (p = 0.048). In conclusion, higher daily dietary fiber consumption is associated with beneficial effect on cholesterol for rural-to-urban workers in China, suggesting its potential beneficial effect on decreasing the risk of cardiovascular diseases. PMID:25938914

  17. Genetic variants in ABCA1 promoter affect transcription activity and plasma HDL level in pigs.

    PubMed

    Dang, Xiao-yong; Chu, Wei-wei; Shi, Heng-chuan; Yu, Shi-gang; Han, Hai-yin; Gu, Shu-Hua; Chen, Jie

    2015-01-25

    Excess accumulation of cholesterol in plasma may result in coronary artery disease. Numerous studies have demonstrated that ATP-binding cassette protein A1 (ABCA1) mediates the efflux of cholesterol and phospholipids to apolipoproteins, a process necessary for plasma high density lipoprotein (HDL) formation. Higher plasma levels of HDL are associated with lower risk for cardiovascular disease. Studies of human disease and animal models had shown that an increased hepatic ABCA1 activity relates to an enhanced plasma HDL level. In this study, we hypothesized that functional mutations in the ABCA1 promoter in pigs may affect gene transcription activity, and consequently the HDL level in plasma. The promoter region of ABCA1 was comparatively scanned by direct sequencing with pool DNA of high- and low-HDL groups (n=30 for each group). Two polymorphisms, c. - 608A>G and c. - 418T>A, were revealed with reverse allele distribution in the two groups. The two polymorphisms were completely linked and formed only G-A or A-T haplotypes when genotyped in a larger population (n=526). Furthermore, we found that the G-A/G-A genotype was associated with higher HDL and ABCA1 mRNA level than A-T/A-T genotype. Luciferase assay also revealed that G-A haplotype promoter had higher activity than A-T haplotype. Single-nucleotide mutant assay showed that c.-418T>A was the causal mutation for ABCA1 transcription activity alteration. Conclusively, we identified two completely linked SNPs in porcine ABCA1 promoter region which have influence on the plasma HDL level by altering ABCA1 gene transcriptional activity.

  18. HDL genetic defects.

    PubMed

    Nair, Devaki R; Nair, Arun; Jain, Anjly

    2014-01-01

    High density lipoprotein cholesterol (HDL-C) and its related apolipoproteins form part of the reverse cholesterol transport system that removes excessive cholesterol from the periphery to the liver. Many transport proteins and enzymes that are involved in this process are susceptible to genetic defects that influence plasma HDL-C concentrations and HDL function. The HDL-C concentration in the blood may not be as important as the function of this lipid fraction. The genetic defects affecting plasma HDL-C concentrations do not always show a consistent relationship with atherosclerosis. Familial hypoalphalipoproteinaemia is associated with mutations in genes responsible for the transport proteins or the enzymes involved in the biogenesis of HDL-C. Inheritance of a Milano mutation of apolipoprotein A1 decreases the risk of atherosclerotic disease despite low circulating levels of HDL-C. Tangier disease and Fish Eye disease are caused by mutations in the ATP binding cassette A1 (ABCA1), a transport protein, and lecithin cholesterol acyl transferase (LCAT), an enzyme, involved in the esterification of cholesterol, respectively. Patients with these conditions have very low levels of HDL-C concentration. The association between both these conditions and the risk of cardiovascular disease (CVD) is variable and inconsistent. Understanding the molecular mechanism of HDL biogenesis not only helped in defining the pathophysiology of low and high HDL-C syndromes, but also in developing new treatment options to raise HDL-C levels. PMID:24953397

  19. Decreased APOE-containing HDL subfractions and cholesterol efflux capacity of serum in mice lacking Pcsk9

    PubMed Central

    2013-01-01

    Background Studies in animals showed that PCSK9 is involved in HDL metabolism. We investigated the molecular mechanism by which PCSK9 regulates HDL cholesterol concentration and also whether Pcsk9 inactivation might affect cholesterol efflux capacity of serum and atherosclerotic fatty streak volume. Methods Mass spectrometry and western blot were used to analyze the level of apolipoprotein E (APOE) and A1 (APOA1). A mouse model overexpressing human LDLR was used to test the effect of high levels of liver LDLR on the concentration of HDL cholesterol and APOE-containing HDL subfractions. Pcsk9 knockout males lacking LDLR and APOE were used to test whether LDLR and APOE are necessary for PCSK9-mediated HDL cholesterol regulation. We also investigated the effects of Pcsk9 inactivation on cholesterol efflux capacity of serum using THP-1 and J774.A1 macrophage foam cells and atherosclerotic fatty streak volume in the aortic sinus of Pcsk9 knockout males fed an atherogenic diet. Results APOE and APOA1 were reduced in the same HDL subfractions of Pcsk9 knockout and human LDLR transgenic male mice. In Pcsk9/Ldlr double-knockout mice, HDL cholesterol concentration was lower than in Ldlr knockout mice and higher than in wild-type controls. In Pcsk9/Apoe double-knockout mice, HDL cholesterol concentration was similar to that of Apoe knockout males. In Pcsk9 knockout males, THP-1 macrophage cholesterol efflux capacity of serum was reduced and the fatty streak lesion volume was similar to wild-type controls. Conclusions In mice, LDLR and APOE are important factors for PCSK9-mediated HDL regulation. Our data suggest that, although LDLR plays a major role in PCSK9-mediated regulation of HDL cholesterol concentration, it is not the only mechanism and that, regardless of mechanism, APOE is essential. Pcsk9 inactivation decreases the HDL cholesterol concentration and cholesterol efflux capacity in serum, but does not increase atherosclerotic fatty streak volume. PMID:23883163

  20. Associations of high HDL cholesterol level with all-cause mortality in patients with heart failure complicating coronary heart disease

    PubMed Central

    Cai, Anping; Li, Xida; Zhong, Qi; Li, Minming; Wang, Rui; Liang, Yingcong; Chen, Wenzhong; Huang, Tehui; Li, Xiaohong; Zhou, Yingling; Li, Liwen

    2016-01-01

    Abstract The aim of the present study was to evaluate the association between HDL cholesterol level and all-cause mortality in patients with ejection fraction reduced heart failure (EFrHF) complicating coronary heart disease (CHD). A total of 323 patients were retrospectively recruited. Patients were divided into low and high HDL cholesterol groups. Between-group differences and associations between HDL cholesterol level and all-cause mortality were assessed. Patients in the high HDL cholesterol group had higher HDL cholesterol level and other lipid components (P <0.05 for all comparison). Lower levels of alanine aminotransferase (ALT), high-sensitivity C-reactive protein (Hs-CRP), and higher albumin (ALB) level were observed in the high HDL cholesterol group (P <0.05 for all comparison). Although left ventricular ejection fraction (LVEF) were comparable (28.8 ± 4.5% vs 28.4 ± 4.6%, P = 0.358), mean mortality rate in the high HDL cholesterol group was significantly lower (43.5% vs 59.1%, P = 0.007). HDL cholesterol level was positively correlated with ALB level, while inversely correlated with ALT, Hs-CRP, and NYHA classification. Logistic regression analysis revealed that after extensively adjusted for confounding variates, HDL cholesterol level remained significantly associated with all-cause mortality although the magnitude of association was gradually attenuated with odds ratio of 0.007 (95% confidence interval 0.001–0.327, P = 0.012). Higher HDL cholesterol level is associated with better survival in patients with EFrHF complicating CHD, and future studies are necessary to demonstrate whether increasing HDL cholesterol level will confer survival benefit in these populations of patients. PMID:27428188

  1. The relationship between non-HDL cholesterol and macrophage phenotypes in human adipose tissue

    PubMed Central

    Poledne, Rudolf; Kralova Lesna, Ivana; Kralova, Anna; Fronek, Jiri; Cejkova, Sona

    2016-01-01

    Data from experimental animal models and in vitro studies suggest that both hyperlipoproteinemia and obesity predispose to development of proinflammatory pathways of macrophages within adipose tissue. The aim of this study was to analyze whether non-HDL cholesterol concentration in healthy living kidney donors (LKDs) is related to the number and phenotype of proinflammatory macrophages in visceral and subcutaneous adipose tissue. Adipose tissue samples were collected by cleansing the kidney grafts of LKDs obtained peroperatively. The stromal vascular fractions of these tissues were analyzed by flow cytometry. Proinflammatory macrophages were defined as CD14+ cells coexpressing CD16+ and high-expression CD36 as well (CD14+CD16+CD36+++), while CD16 negativity and CD163 positivity identified alternatively stimulated, anti-inflammatory macrophages. Non-HDL cholesterol concentration positively correlated to proinflammatory macrophages within visceral adipose tissue, with increased strength with more precise phenotype determination. On the contrary, the proportion of alternatively stimulated macrophages correlated negatively with non-HDL cholesterol. The present study suggests a relationship of non-HDL cholesterol concentration to the number and phenotype proportion of macrophages in visceral adipose tissue of healthy humans. PMID:27481939

  2. Proteomic analysis of HDL from inbred mouse strains implicates APOE associated with HDL in reduced cholesterol efflux capacity via the ABCA1 pathway[S

    PubMed Central

    Pamir, Nathalie; Hutchins, Patrick; Ronsein, Graziella; Vaisar, Tomas; Reardon, Catherine A.; Getz, Godfrey S.; Lusis, Aldons J.; Heinecke, Jay W.

    2016-01-01

    Cholesterol efflux capacity associates strongly and negatively with the incidence and prevalence of human CVD. We investigated the relationships of HDL’s size and protein cargo with its cholesterol efflux capacity using APOB-depleted serum and HDLs isolated from five inbred mouse strains with different susceptibilities to atherosclerosis. Like humans, mouse HDL carried >70 proteins linked to lipid metabolism, the acute-phase response, proteinase inhibition, and the immune system. HDL’s content of specific proteins strongly correlated with its size and cholesterol efflux capacity, suggesting that its protein cargo regulates its function. Cholesterol efflux capacity with macrophages strongly and positively correlated with retinol binding protein 4 (RBP4) and PLTP, but not APOA1. In contrast, ABCA1-specific cholesterol efflux correlated strongly with HDL’s content of APOA1, APOC3, and APOD, but not RBP4 and PLTP. Unexpectedly, APOE had a strong negative correlation with ABCA1-specific cholesterol efflux capacity. Moreover, the ABCA1-specific cholesterol efflux capacity of HDL isolated from APOE-deficient mice was significantly greater than that of HDL from wild-type mice. Our observations demonstrate that the HDL-associated APOE regulates HDL’s ABCA1-specific cholesterol efflux capacity. These findings may be clinically relevant because HDL’s APOE content associates with CVD risk and ABCA1 deficiency promotes unregulated cholesterol accumulation in human macrophages. PMID:26673204

  3. Plasma kinetics of an LDL-like nanoemulsion and lipid transfer to HDL in subjects with glucose intolerance

    PubMed Central

    Bertato, Marina P; Oliveira, Carolina P; Wajchenberg, Bernardo L; Lerario, Antonio C; Maranhão, Raul C

    2012-01-01

    OBJECTIVE: Glucose intolerance is frequently associated with an altered plasma lipid profile and increased cardiovascular disease risk. Nonetheless, lipid metabolism is scarcely studied in normolipidemic glucose-intolerant patients. The aim of this study was to investigate whether important lipid metabolic parameters, such as the kinetics of LDL free and esterified cholesterol and the transfer of lipids to HDL, are altered in glucose-intolerant patients with normal plasma lipids. METHODS: Fourteen glucose-intolerant patients and 15 control patients were studied; none of the patients had cardiovascular disease manifestations, and they were paired for age, sex, race and co-morbidities. A nanoemulsion resembling a LDL lipid composition (LDE) labeled with 14C-cholesteryl ester and 3H-free cholesterol was intravenously injected, and blood samples were collected over a 24-h period to determine the fractional clearance rate of the labels by compartmental analysis. The transfer of free and esterified cholesterol, triglycerides and phospholipids from the LDE to HDL was measured by the incubation of the LDE with plasma and radioactivity counting of the supernatant after chemical precipitation of non-HDL fractions. RESULTS: The levels of LDL, non-HDL and HDL cholesterol, triglycerides, apo A1 and apo B were equal in both groups. The 14C-esterified cholesterol fractional clearance rate was not different between glucose-intolerant and control patients, but the 3H-free- cholesterol fractional clearance rate was greater in glucose-intolerant patients than in control patients. The lipid transfer to HDL was equal in both groups. CONCLUSION: In these glucose-intolerant patients with normal plasma lipids, a faster removal of LDE free cholesterol was the only lipid metabolic alteration detected in our study. This finding suggests that the dissociation of free cholesterol from lipoprotein particles occurs in normolipidemic glucose intolerance and may participate in atherogenic

  4. A thiocarbamate inhibitor of endothelial lipase raises HDL cholesterol levels in mice.

    PubMed

    Greco, M N; Connelly, M A; Leo, G C; Olson, M W; Powell, E; Huang, Z; Hawkins, M; Smith, C; Schalk-Hihi, C; Darrow, A L; Xin, H; Lang, W; Damiano, B P; Hlasta, D J

    2013-05-01

    By screening directed libraries of serine hydrolase inhibitors using the cell surface form of endothelial lipase (EL), we identified a series of carbamate-derived (EL) inhibitors. Compound 3 raised plasma HDL-C levels in the mouse, and a correlation was found between HDL-C and plasma compound levels. Spectroscopic and kinetic studies support a covalent mechanism of inhibition. Our findings represent the first report of EL inhibition as an effective means for increasing HDL-C in an in vivo model. PMID:23528297

  5. Novel apo E-derived ABCA1 agonist peptide (CS-6253) promotes reverse cholesterol transport and induces formation of preβ-1 HDL in vitro

    DOE PAGESBeta

    Hafiane, Anouar; Bielicki, John K.; Johansson, Jan O.; Genest, Jacques; Zhu, Xuewei

    2015-07-24

    Apolipoprotein (apo) mimetic peptides replicate some aspects of HDL function. We have previously reported the effects of compound ATI-5261 on its ability to replicate many functions of native apo A-I in the process of HDL biogenesis. ATI-5261 induced muscle toxicity in wild type C57Bl/6 mice, increased CPK, ALT and AST and increase in triglyceride (Tg) levels. Aromatic phenylalanine residues on the non-polar face of ATI-5261, together with positively charged arginine residues at the lipid-water interface were responsible for these effects. This information was used to create a novel analog (CS-6253) that was non-toxic. We evaluated this peptide designed from themore » carboxyl terminus of apo E, in its ability to mimic apo A-I functionality. Our data shows that the lipidated particles generated by incubating cells overexpressing ABCA1 with lipid free CS-6253 enhances the rate of ABCA1 lipid efflux with high affinity interactions with native ABCA1 oligomeric forms and plasma membrane micro-domains. Interaction between ABCA1 and lipid free CS-6253 resulted in formation of nascent HDL-CS-6253 particles that are actively remodeled in plasma. Mature HDL-CS-6253 particles deliver cholesterol to liver cells via SR-BI in-vitro. CS-6253 significantly increases cholesterol efflux in murine macrophages and in human THP-1 macrophage-derived foam cells expressing ABCA1. Addition of CS-6253 to plasma dose-dependently displaced apo A-I from α-HDL particles and led to de novo formation of preβ-1 HDL that stimulates ABCA1 dependent cholesterol efflux efficiently. When incubated with human plasma CS-6253 was also found to bind with HDL and LDL and promoted the transfer of cholesterol from HDL to LDL predominantly. Our data shows that CS-6253 mimics apo A-I in its ability to promote ABCA1-mediated formation of nascent HDL particles, and enhances formation of preβ-1 HDL with increase in the cycling of apo A-I between the preβ and α-HDL particles in-vitro. These mechanisms are

  6. The effect of phospholipid composition of reconstituted HDL on its cholesterol efflux and anti-inflammatory properties[S

    PubMed Central

    Schwendeman, Anna; Sviridov, Denis O.; Yuan, Wenmin; Guo, Yanhong; Morin, Emily E.; Yuan, Yue; Stonik, John; Freeman, Lita; Ossoli, Alice; Thacker, Seth; Killion, Salena; Pryor, Milton; Chen, Y. Eugene; Turner, Scott; Remaley, Alan T.

    2015-01-01

    The goal of this study was to understand how the reconstituted HDL (rHDL) phospholipid (PL) composition affects its cholesterol efflux and anti-inflammatory properties. An ApoA-I mimetic peptide, 5A, was combined with either SM or POPC. Both lipid formulations exhibited similar in vitro cholesterol efflux by ABCA1, but 5A-SM exhibited higher ABCG1- and SR-BI-mediated efflux relative to 5A-POPC (P < 0.05). Injection of both rHDLs in rats resulted in mobilization of plasma cholesterol, although the relative potency was 3-fold higher for the same doses of 5A-SM than for 5A-POPC. Formation of preβ HDL was observed following incubation of rHDLs with both human and rat plasma in vitro, with 5A-SM inducing a higher extent of preβ formation relative to 5A-POPC. Both rHDLs exhibited anti-inflammatory properties, but 5A-SM showed higher inhibition of TNF-α, IL-6, and IL-1β release than did 5A-POPC (P < 0.05). Both 5A-SM and 5A-POPC showed reduction in total plaque area in ApoE−/− mice, but only 5A-SM showed a statistically significant reduction over placebo control and baseline (P < 0.01). The type of PL used to reconstitute peptide has significant influence on rHDL’s anti-inflammatory and anti-atherosclerosis properties. PMID:26117661

  7. 9-cis β-Carotene Increased Cholesterol Efflux to HDL in Macrophages.

    PubMed

    Bechor, Sapir; Zolberg Relevy, Noa; Harari, Ayelet; Almog, Tal; Kamari, Yehuda; Ben-Amotz, Ami; Harats, Dror; Shaish, Aviv

    2016-01-01

    Cholesterol efflux from macrophages is a key process in reverse cholesterol transport and, therefore, might inhibit atherogenesis. 9-cis-β-carotene (9-cis-βc) is a precursor for 9-cis-retinoic-acid (9-cis-RA), which regulates macrophage cholesterol efflux. Our objective was to assess whether 9-cis-βc increases macrophage cholesterol efflux and induces the expression of cholesterol transporters. Enrichment of a mouse diet with βc from the alga Dunaliella led to βc accumulation in peritoneal macrophages. 9-cis-βc increased the mRNA levels of CYP26B1, an enzyme that regulates RA cellular levels, indicating the formation of RA from βc in RAW264.7 macrophages. Furthermore, 9-cis-βc, as well as all-trans-βc, significantly increased cholesterol efflux to high-density lipoprotein (HDL) by 50% in RAW264.7 macrophages. Likewise, food fortification with 9-cis-βc augmented cholesterol efflux from macrophages ex vivo. 9-cis-βc increased both the mRNA and protein levels of ABCA1 and apolipoprotein E (APOE) and the mRNA level of ABCG1. Our study shows, for the first time, that 9-cis-βc from the diet accumulates in peritoneal macrophages and increases cholesterol efflux to HDL. These effects might be ascribed to transcriptional induction of ABCA1, ABCG1, and APOE. These results highlight the beneficial effect of βc in inhibition of atherosclerosis by improving cholesterol efflux from macrophages. PMID:27447665

  8. 9-cis β-Carotene Increased Cholesterol Efflux to HDL in Macrophages

    PubMed Central

    Bechor, Sapir; Zolberg Relevy, Noa; Harari, Ayelet; Almog, Tal; Kamari, Yehuda; Ben-Amotz, Ami; Harats, Dror; Shaish, Aviv

    2016-01-01

    Cholesterol efflux from macrophages is a key process in reverse cholesterol transport and, therefore, might inhibit atherogenesis. 9-cis-β-carotene (9-cis-βc) is a precursor for 9-cis-retinoic-acid (9-cis-RA), which regulates macrophage cholesterol efflux. Our objective was to assess whether 9-cis-βc increases macrophage cholesterol efflux and induces the expression of cholesterol transporters. Enrichment of a mouse diet with βc from the alga Dunaliella led to βc accumulation in peritoneal macrophages. 9-cis-βc increased the mRNA levels of CYP26B1, an enzyme that regulates RA cellular levels, indicating the formation of RA from βc in RAW264.7 macrophages. Furthermore, 9-cis-βc, as well as all-trans-βc, significantly increased cholesterol efflux to high-density lipoprotein (HDL) by 50% in RAW264.7 macrophages. Likewise, food fortification with 9-cis-βc augmented cholesterol efflux from macrophages ex vivo. 9-cis-βc increased both the mRNA and protein levels of ABCA1 and apolipoprotein E (APOE) and the mRNA level of ABCG1. Our study shows, for the first time, that 9-cis-βc from the diet accumulates in peritoneal macrophages and increases cholesterol efflux to HDL. These effects might be ascribed to transcriptional induction of ABCA1, ABCG1, and APOE. These results highlight the beneficial effect of βc in inhibition of atherosclerosis by improving cholesterol efflux from macrophages. PMID:27447665

  9. Human pedigree-based quantitative-trait-locus mapping: localization of two genes influencing HDL-cholesterol metabolism.

    PubMed

    Almasy, L; Hixson, J E; Rainwater, D L; Cole, S; Williams, J T; Mahaney, M C; VandeBerg, J L; Stern, M P; MacCluer, J W; Blangero, J

    1999-06-01

    Common disorders with genetic susceptibilities involve the action of multiple genes interacting with each other and with environmental factors, making it difficult to localize the specific genetic loci responsible. An important route to the disentangling of this complex inheritance is through the study of normal physiological variation in quantitative risk factors that may underlie liability to disease. We present an analysis of HDL-cholesterol (HDL-C), which is inversely correlated with risk of heart disease. A variety of HDL subphenotypes were analyzed, including HDL particle-size classes and the concentrations and proportions of esterified and unesterified HDL-C. Results of a complete genomic screen in large, randomly ascertained pedigrees implicated two loci, one on chromosome 8 and the other on chromosome 15, that influence a component of HDL-C-namely, unesterified HDL2a-C. Multivariate analyses of multiple HDL phenotypes and simultaneous multilocus analysis of the quantitative-trait loci identified permit further characterization of the genetic effects on HDL-C. These analyses suggest that the action of the chromosome 8 locus is specific to unesterified cholesterol levels, whereas the chromosome 15 locus appears to influence both HDL-C concentration and distribution of cholesterol among HDL particle sizes.

  10. Suppression of liver Apo E secretion leads to HDL/cholesterol immaturity in rats administered ethinylestradiol.

    PubMed

    Yamaguchi, Kosuke; Ishii, Mariko; Maeda, Naoyuki; Iwano, Hidetomo; Yokota, Hiroshi

    2016-09-01

    Ethinylestradiol (EE), a main component of the combined oral contraceptive pill, is associated with an increased risk of arterial diseases. However, the toxicity mechanism of EE is poorly understood. In this study, we found that the exposure to EE reduced the serum apolipoprotein E (Apo E) level and high-density lipoprotein (HDL)/cholesterol concentration in adult female rats. Diethylstilbestrol showed the same effects and both reductions were suppressed by coadministration of tamoxifen (TAM). Liver perfusion experiments revealed that the secretion rate of Apo E from the liver was significantly reduced. It is concluded that EE damages the maturation of HDL/cholesterol by delaying Apo E secretion from the liver, and this may lead to an increased risk of arterial diseases, such as atheromas. PMID:27642556

  11. Monogenic causes of elevated HDL cholesterol and implications for development of new therapeutics.

    PubMed

    Larach, Daniel B; Cuchel, Marina; Rader, Daniel J

    2013-12-01

    Identification of the CETP, LIPG (encoding endothelial lipase) and APOC3 genes, and ana lysis of rare genetic variants in them, have allowed researchers to increase understanding of HDL metabolism significantly. However, development of cardiovascular risk-reducing therapeutics targeting the proteins encoded by these genes has been less straightforward. The failure of two CETP inhibitors is complex but illustrates a possible over-reliance on HDL cholesterol as a marker of therapeutic efficacy. The case of endothelial lipase exemplifies the importance of utilizing population-wide genetic studies of rare variants in potential therapeutic targets to gain information on cardiovascular disease end points. Similar population-wide studies of cardiovascular end points make apoC-III a potentially attractive target for lipid-related drug discovery. These three cases illustrate the positives and negatives of single-gene studies relating to HDL-related cardiovascular drug discovery; such studies should focus not only on HDL cholesterol and other components of the lipid profile, but also on the effect genetic variants have on cardiovascular end points. PMID:25374625

  12. Adiponectin and the mediation of HDL-cholesterol change with improved lifestyle: the Look AHEAD Study.

    PubMed

    Belalcazar, L Maria; Lang, Wei; Haffner, Steven M; Hoogeveen, Ron C; Pi-Sunyer, F Xavier; Schwenke, Dawn C; Balasubramanyam, Ashok; Tracy, Russell P; Kriska, Andrea P; Ballantyne, Christie M

    2012-12-01

    Adipose tissue dysfunction plays a key role in the development of the metabolic abnormalities characteristic of type 2 diabetes (T2DM) and participates actively in lipid metabolism. Adiponectin, found abundantly in circulation and a marker of adipose health, is decreased in obese persons with T2DM. We investigated whether the changes in adiponectin with an intensive lifestyle intervention (ILI) for weight loss could potentially mediate the increase in low HDL-cholesterol (HDL-C) with ILI. Adiponectin and its fractions were determined using an ELISA with selective protease treatment in 1,397 participants from Look AHEAD, a trial examining whether ILI will reduce cardiovascular events in overweight/obese subjects with T2DM when compared with a control arm, diabetes support and education (DSE). Multivariable regression and mediational analyses were performed for adiponectin and its high-molecular-weight (HMW) and non-HMW fractions. ILI increased baseline HDL-C by 9.7% and adiponectin by 11.9%; changes with DSE were 1.3% and 0.2%, respectively (P < 0.0001). In a model including changes in weight, fitness, triglycerides, and glucose control and that adjusted for demographics and medical history, adiponectin changes remained significantly associated with HDL-C change. Data supported the contribution of changes in both HMW- and non-HMW-adiponectin to the improvement in HDL-C with ILI.

  13. Adiponectin and the mediation of HDL-cholesterol change with improved lifestyle: the Look AHEAD Study.

    PubMed

    Belalcazar, L Maria; Lang, Wei; Haffner, Steven M; Hoogeveen, Ron C; Pi-Sunyer, F Xavier; Schwenke, Dawn C; Balasubramanyam, Ashok; Tracy, Russell P; Kriska, Andrea P; Ballantyne, Christie M

    2012-12-01

    Adipose tissue dysfunction plays a key role in the development of the metabolic abnormalities characteristic of type 2 diabetes (T2DM) and participates actively in lipid metabolism. Adiponectin, found abundantly in circulation and a marker of adipose health, is decreased in obese persons with T2DM. We investigated whether the changes in adiponectin with an intensive lifestyle intervention (ILI) for weight loss could potentially mediate the increase in low HDL-cholesterol (HDL-C) with ILI. Adiponectin and its fractions were determined using an ELISA with selective protease treatment in 1,397 participants from Look AHEAD, a trial examining whether ILI will reduce cardiovascular events in overweight/obese subjects with T2DM when compared with a control arm, diabetes support and education (DSE). Multivariable regression and mediational analyses were performed for adiponectin and its high-molecular-weight (HMW) and non-HMW fractions. ILI increased baseline HDL-C by 9.7% and adiponectin by 11.9%; changes with DSE were 1.3% and 0.2%, respectively (P < 0.0001). In a model including changes in weight, fitness, triglycerides, and glucose control and that adjusted for demographics and medical history, adiponectin changes remained significantly associated with HDL-C change. Data supported the contribution of changes in both HMW- and non-HMW-adiponectin to the improvement in HDL-C with ILI. PMID:22956782

  14. CNR1 Genotype Influences HDL-Cholesterol Response to Change in Dietary Fat Intake

    PubMed Central

    Keil, Charles D.; Jiang, Lan; Feng, Qiping; Chiu, Sally; Krauss, Ronald M.; Wilke, Russell A.

    2012-01-01

    Background Success in further reducing the burden of cardiovascular disease (CVD) is threatened by the increasing prevalence of obesity-related atherogenic dyslipidemia. HDL-cholesterol (HDL-C) level is inversely correlated with CVD risk; each 1 mg/dl decrease in HDL-C is associated with a 6% reduction in risk. We previously showed that a common CNR1 haplotype, H3 (frequency 20%), is protective against the reduction in HDL-C that typically accompanies weight gain. In the present study, we extend that observation by reporting the effect of CNR1 haplotype on HDL-C response to modification of dietary fat intake in weight maintenance and weight loss. Methods Six haplotype tagging SNPs that cover the CNR1 gene locus were genotyped in 590 adults of varying body mass index (cohort 1 is 411 males with BMI 18.5–30.0 kg/m2; cohort 2 is 71 females with BMI18.5–30.0 kg/m2; and cohort 3 is 108 females with BMI 30–39.9 kg/m2). Dietary intakes were modified so that fat intake in the “high fat” condition was 15–20% greater than in the “low fat” condition, and lipid profiles were compared between carriers versus noncarriers for each of the five commonly observed CNR1 haplotypes (H1–H5). Results In normal to overweight subjects on eucaloric diets, the H3 haplotype was significantly associated with short-term high fat diet induced changes in HDL-C level in females (carriers 5.9 mg/dl>noncarriers, p = 0.007). The H3 haplotype was also significantly associated with HDL-C level after 16 weeks on high fat calorie restricted diet in obese females (carriers 6.8 mg/dl>noncarriers, p = 0.009). Conclusion Variability within the CNR1 gene locus contributes to gender-related differences in the HDL-cholesterol response to change in dietary fat intake. Functional characterization of this relationship in vitro may offer insights that potentially yield therapeutic guidance targeting dietary macronutrient composition, a direction much needed in the current epidemic of

  15. Seven Direct Methods for Measuring HDL and LDL Cholesterol Compared with Ultracentrifugation Reference Measurement Procedures

    PubMed Central

    Miller, W. Greg; Myers, Gary L.; Sakurabayashi, Ikunosuke; Bachmann, Lorin M.; Caudill, Samuel P.; Dziekonski, Andrzej; Edwards, Selvin; Kimberly, Mary M.; Korzun, William J.; Leary, Elizabeth T.; Nakajima, Katsuyuki; Nakamura, Masakazu; Nilsson, Göran; Shamburek, Robert D.; Vetrovec, George W.; Warnick, G. Russell; Remaley, Alan T.

    2015-01-01

    BACKGROUND Methods from 7 manufacturers and 1 distributor for directly measuring HDL cholesterol (C) and LDL-C were evaluated for imprecision, trueness, total error, and specificity in nonfrozen serum samples. METHODS We performed each direct method according to the manufacturer’s instructions, using a Roche/Hitachi 917 analyzer, and compared the results with those obtained with reference measurement procedures for HDL-C and LDL-C. Imprecision was estimated for 35 runs performed with frozen pooled serum specimens and triplicate measurements on each individual sample. Sera from 37 individuals without disease and 138 with disease (primarily dyslipidemic and cardiovascular) were measured by each method. Trueness and total error were evaluated from the difference between the direct methods and reference measurement procedures. Specificity was evaluated from the dispersion in differences observed. RESULTS Imprecision data based on 4 frozen serum pools showed total CVs <3.7% for HDL-C and <4.4% for LDL-C. Bias for the nondiseased group ranged from −5.4% to 4.8% for HDL-C and from −6.8% to 1.1% for LDL-C, and for the diseased group from −8.6% to 8.8% for HDL-C and from −11.8% to 4.1% for LDL-C. Total error for the nondiseased group ranged from −13.4% to 13.6% for HDL-C and from −13.3% to 13.5% for LDL-C, and for the diseased group from −19.8% to 36.3% for HDL-C and from −26.6% to 31.9% for LDL-C. CONCLUSIONS Six of 8 HDL-C and 5 of 8 LDL-C direct methods met the National Cholesterol Education Program total error goals for nondiseased individuals. All the methods failed to meet these goals for diseased individuals, however, because of lack of specificity toward abnormal lipoproteins. PMID:20378768

  16. An isoenergetic very low carbohydrate diet improves serum HDL cholesterol and triacylglycerol concentrations, the total cholesterol to HDL cholesterol ratio and postprandial pipemic responses compared with a low fat diet in normal weight, normolipidemic women.

    PubMed

    Volek, Jeff S; Sharman, Matthew J; Gómez, Ana L; Scheett, Timothy P; Kraemer, William J

    2003-09-01

    Very low carbohydrate diets are popular, yet little is known about their effects on blood lipids and other cardiovascular disease risk factors. We reported previously that a very low carbohydrate diet favorably affected fasting and postprandial triacylglycerols, LDL subclasses and HDL cholesterol (HDL-C) in men but the effects in women are unclear. We compared the effects of a very low carbohydrate and a low fat diet on fasting lipids, postprandial lipemia and markers of inflammation in women. We conducted a balanced, randomized, two-period, crossover study in 10 healthy normolipidemic women who consumed both a low fat (<30% fat) and a very low carbohydrate (<10% carbohydrate) diet for 4 wk each. Two blood draws were performed on separate days at 0, 2 and 4 wk and an oral fat tolerance test was performed at baseline and after each diet period. Compared with the low fat diet, the very low carbohydrate diet increased (P cholesterol (16%), LDL cholesterol (LDL-C) (15%) and HDL-C (33%) and decreased serum triacylglycerols (-30%), the total cholesterol to HDL ratio (-13%) and the area under the 8-h postprandial triacylglycerol curve (-31%). There were no significant changes in LDL size or markers of inflammation (C-reactive protein, interleukin-6, tumor necrosis factor-alpha) after the very low carbohydrate diet. In normal weight, normolipidemic women, a short-term very low carbohydrate diet modestly increased LDL-C, yet there were favorable effects on cardiovascular disease risk status by virtue of a relatively larger increase in HDL-C and a decrease in fasting and postprandial triaclyglycerols.

  17. Plasma lipidomics discloses metabolic syndrome with a specific HDL phenotype.

    PubMed

    Jové, Mariona; Naudí, Alba; Portero-Otin, Manuel; Cabré, Rosanna; Rovira-Llopis, Susana; Bañuls, Celia; Rocha, Milagros; Hernández-Mijares, Antonio; Victor, Victor M; Pamplona, Reinald

    2014-12-01

    Lipidomics reveals a remarkable diversity of lipids in human plasma. In this study, we have performed an in-depth lipidomic analysis of human plasma from healthy individuals and subjects with metabolic syndrome (MetS) in order to determine the lipidomic profile that allows prognosis of a pathological subpopulation with altered high-density lipoprotein (HDL) metabolism. The MetS population was categorized as having pathological or nonpathological HDL. Anthropometric parameters, cardiovascular risk markers, and lipoprotein subclasses of HDL and low-density lipoproteins were also evaluated. Lipidomic analysis revealed 357 differential molecules that were clustered (k means) in the two groups. The molecules identified in the whole lipidome showed that MetS subjects presented lower levels of glycerolipids and higher levels of glycerophospholipids with respect to control subjects. In contrast, when only statistically differential lipids were taken into account, differences were found between the two groups in almost cases. Furthermore, levels of saturated fatty acids were higher in patients with pathological HDL levels than in controls, whereas levels of unsaturated fatty acids were lower. These results highlight the potential of lipidomics as a clinical tool for risk assessment and monitoring of disease.

  18. Niacin Reduces Atherosclerosis Development in APOE*3Leiden.CETP Mice Mainly by Reducing NonHDL-Cholesterol

    PubMed Central

    Heemskerk, Mattijs M.; Pieterman, Elsbet J.; van Klinken, Jan B.; van den Berg, Sjoerd A. A.; Smit, Johannes W. A.; Havekes, Louis M.; Rensen, Patrick C. N.; van der Hoorn, José W. A.; Princen, Hans M. G.; Jukema, J. Wouter

    2013-01-01

    Objective Niacin potently lowers triglycerides, mildly decreases LDL-cholesterol, and largely increases HDL-cholesterol. Despite evidence for an atheroprotective effect of niacin from previous small clinical studies, the large outcome trials, AIM-HIGH and HPS2-THRIVE did not reveal additional beneficial effects of niacin (alone or in combination with laropiprant) on top of statin treatment. We aimed to address this apparent discrepancy by investigating the effects of niacin without and with simvastatin on atherosclerosis development and determine the underlying mechanisms, in APOE*3Leiden.CETP mice, a model for familial dysbetalipoproteinemia (FD). Approach and Results Mice were fed a western-type diet containing cholesterol without or with niacin (120 mg/kg/day), simvastatin (36 mg/kg/day) or their combination for 18 weeks. Similarly as in FD patients, niacin reduced total cholesterol by -39% and triglycerides by −50%, (both P<0.001). Simvastatin and the combination reduced total cholesterol (−30%; −55%, P<0.001) where the combination revealed a greater reduction compared to simvastatin (−36%, P<0.001). Niacin decreased total cholesterol and triglycerides primarily by increasing VLDL clearance. Niacin increased HDL-cholesterol (+28%, P<0.01) and mildly increased reverse cholesterol transport. All treatments reduced monocyte adhesion to the endothelium (−46%; −47%, P<0.01; −53%, P<0.001), atherosclerotic lesion area (−78%; −49%, P<0.01; −87%, P<0.001) and severity. Compared to simvastatin, the combination increased plaque stability index [(SMC+collagen)/macrophages] (3-fold, P<0.01). Niacin and the combination reduced T cells in the aortic root (−71%, P<0.01; −81%, P<0.001). Lesion area was strongly predicted by nonHDL-cholesterol (R2 = 0.69, P<0.001) and to a much lesser extent by HDL-cholesterol (R2 = 0.20, P<0.001). Conclusion Niacin decreases atherosclerosis development mainly by reducing nonHDL-cholesterol with modest HDL-cholesterol

  19. Variability of plasma HDL subclass concentrations in men and women over time.

    PubMed

    Williams, P T; Dreon, D M; Blanche, P J; Krauss, R M

    1997-04-01

    Plasma HDL subclasses were examined by gradient gel electrophoresis in repeated samples to assess variability over time. Absorbance of the protein stain was used as an index of mass concentrations at 0.01-nm intervals within five HDL subclasses: HDL3c (7.2 to 7.8 nm), HDL3b (7.8 to 8.2 nm), HDL3a (8.2 to 8.8 nm), HDL2a (8.8 to 9.7 nm), and HDL2b (9.7 to 12 nm). Three separate longitudinal studies of men showed that repeated samples of HDL over time were correlated most strongly within HDL2b, somewhat less within HDL2a, and more weakly within HDL3a, HDL3b, and HDL3c. As in men, repeated samples in women from two studies were significantly correlated within the HDL2b, HDL2a, and HDL3b intervals. Plasma HDL2b levels were significantly more stable in men than in women. Although the variability of HDL subclass measurements includes both methodological and physiological sources, differences in laboratory measurement error do not appear to explain the differences in correlations among subclasses. Specifically, analysis of 288 replications from frozen aliquots suggested that laboratory error had the least effect on correlations involving HDL3 subclasses and only slightly greater effect on correlations involving HDL2 subclasses. Our results suggest that for plasma sampled over time, the stability of HDL subclass levels increases with particle size. Prior reports of subclass-specific correlations between HDL and other variables (eg, diet, exercise, and other lipids) are unlikely to be artifacts of laboratory precision but could arise from subclass differences in variability that are physiological.

  20. THE CONSUMPTION OF RED PUPUNHA (BACTRIS GASIPAES KUNTH) INCREASES HDL CHOLESTEROL AND REDUCES WEIGHT GAIN OF LACTATING AND POST-LACTATING WISTAR RATS

    PubMed Central

    Carvalho, R. Piccolotto; Lemos, J.R. Gonzaga; de Aquino Sales, R. Souza; Martins, M. Gassen; Nascimento, C.H.; Bayona, M.; Marcon, J.L.; Monteiro, J. Barros

    2014-01-01

    Introduction The lactating and post-lactating periods are marked by large metabolic change. Production of milk is 60% lipid dependent. We reported in a recent scientific meeting that Red pupunha palm tree fruit increases HDL cholesterol in lactating rats. This study evaluated if consumption of Red Pupunha by adult female rats has a beneficial impact on the lipid metabolism of lacting and post-lacting adult rats. Objective Evaluate if consumption of red pupunha has a beneficial effect in the lipid metabolism of lacting and post-lacting adult Wistar rats. Research Methods Four groups including two for control; (1) control adult lactating rats, (2) control adults post-lactating rats; and two experimental groups; (3) pupunha adults lactating rats and (4) pupunha adult post-lactating rats were evaluated and compared regarding: weight gain, food consumption, plasma total protein, glucose, total lipid, triglycerides, total cholesterol and HDL-cholesterol levels. The mean difference and its 95% confidence intervals were used for group comparisons. Group comparisons were evaluated by using analysis of variance (one-way ANOVA). The statistical significance of the pairwise differences among groups was assessed by using the two-sided Tukey test. Results There were no important differences in food consumption, plasma glucose, total lipids and triglycerides among groups. The red pupunha lactating group gain less weight showing lower body mass index (BMI) than controls (p < 0.05). Total cholesterol was lower in red pupunha lactating than in controls but not in the red pupunha post-lactating group as compared to controls. Triglycerides were lower in the post-lactating red pupunha group as compared to the control group (p = 0.039) but not for the lactating groups. Red pupunha lactating and post-lactating groups had higher HDL-cholesterol than their corresponding control groups (p ≤ 0.01). Conclusion Original findings include the beneficial effect of red pupunha in post

  1. Effect of cigarette smoke and dietary cholesterol on plasma lipoprotein composition

    SciTech Connect

    Hojnacki, J.L.; Mulligan, J.J.; Cluette, J.E.; Kew, R.R.; Stack, D.J.; Huber, G.L.

    1981-01-01

    Pigeons were assigned to four treatment groups: 1) Controls fed a chow diet ad libitum and retained in their cages; 2) Sham pigeons fed a cholesterol-saturated fat diet and exposed to fresh air by the Lorillard smoking machine; 3) Low nicotine-low carbon monoxide (LoLo) animals also fed the cholesterol diet and exposed to low concentrations of cigarette smoke; and 4) High nicotine-high carbon monoxide (HiHi) birds fed the cholesterol diet and subjected to high concentrations of inhalants. Plasma very low density (VLDL), low density (LDL), and high density (HDL) lipoproteins were isolated by density gradient ultracentrifugation. Smoke-related differences appeared in HiHi HDL which contained relatively more free and esterified cholesterol and total lipid, but less total protein than HDL from Sham-smoked pigeons. VLDL from birds exposed to cigarette smoke (LoLo and HiHi) contained relatively more total lipid, but less total protein than VLDL from Sham pigeons. Inhalation smoke produced a marked depression in the HDL2/HDL3 ratio resulting from an increased proportion of the HDL3 subfraction relative to HDL2. Pigeons fed the cholesterol-saturated fat diet circulated HDL with greater free and esterified cholesterol mass than Controls. Diet also altered the type of cholesteryl ester present in HDL with cholesteryl linoleate representing the predominant form in Control pigeons and cholesteryl oleate in cholesterol-fed birds. These results demonstrate that cigarette smoking can mediate alterations in lipoprotein composition independent of changes induced by dietary cholesterol and saturated fat.

  2. Reflex Testing for Carbohydrate-Deficient Transferrin (CDT) in Insurance Applicants with Elevated High Density Lipoprotein Cholesterol (HDL).

    PubMed

    Singh, Gurmukh

    2015-01-01

    Objectives .- Ascertain the utility of testing carbohydrate deficient transferrin (CDT) levels in insurance applicants with elevated high density lipoprotein cholesterol (HDL) levels. Background .- Chronic alcoholism is not uncommon and is a risk factor for health and longevity and thus of interest to providers of insurance. A number of tests serve as markers of alcohol use, eg, blood alcohol level, elevated liver enzymes, ethyl glucuronide in urine, whole blood associated aldehyde (WBAA), macrocytosis, elevated HDL, elevated CDT and others. WBAA and CDT are usually only done, if some other screening test suggests alcohol use. HDL testing is routinely done for assessing cardiac risk, however, chronic alcohol intake tends to raise HDL and some insurance providers reflex to CDT testing when HDL is elevated. Methods .- A number of the clients of Heritage Labs Inc. have rules in place to test for CDT levels in specimens showing elevated HDL levels. The commonest HDL level that serves as the trigger for reflex testing for CDT is 80mg/dL. The results of this practice were analyzed to assess the utility of reflex testing for CDT to identify chronic alcohol abusers among the applicants. Results .- In examining the results of CDT levels done as a reflex test due to elevated HDL levels, about 2% of the applicants, 0.7% of women and 3% of men, tested positive for elevated CDT levels. Conclusions .- The incidence of elevated CDT levels is high enough to warrant routinely testing for this analyte in applicants, especially men, with high HDL levels. PMID:27584808

  3. Marrubium vulgare extract inhibits human-LDL oxidation and enhances HDL-mediated cholesterol efflux in THP-1 macrophage.

    PubMed

    Berrougui, Hicham; Isabelle, Maxim; Cherki, Mounia; Khalil, Abdelouahed

    2006-12-14

    The objective of the present study was to elucidate the beneficial properties of aqueous extracts of Marrubium vulgare (AEM) towards cardiovascular disease by protecting human-LDL against lipid peroxidation and promoting HDL-mediated cholesterol efflux. Human-LDL were oxidised by incubation with CuSO(4) in the presence of increased concentrations of AEM (0-100 microg/ml). LDL lipid peroxidation was evaluated by conjugated diene formation, vitamin E disappearance as well as LDL-electrophoretic mobility. HDL-mediated cholesterol efflux assay was carried out in human THP-1 macrophages. Incubation of LDL with AEM significantly prolonged the lag phase (P=0.014), lowered the progression rate of lipid peroxidation (P=0.004), reduced the disappearance of vitamin E and the electrophoretic mobility in a dose-dependent manner. Also, incubation of HDL with AEM significantly increased HDL-mediated cholesterol efflux from THP-1 macrophages implicating an independent ATP binding cassette A1 (ABCA1) pathways. Our findings suggest that M. vulgare provides a source of natural antioxidants, which inhibit LDL oxidation and enhance reverse cholesterol transport and thus can prevent cardiovascular diseases development. These antioxidant properties increase the anti-atherogenic potential of HDL.

  4. Increased hepatic cholesterol esterification with essential fatty acid deficiency (EFAD): relationship to plasma lipoprotein (LP) cholesterol content

    SciTech Connect

    Ney, D.M.; Ziboh, V.A.; Schneeman, B.O.

    1986-03-01

    EFAD in the rat is associated with hepatic accumulation of esterified cholesterol and altered distribution of cholesterol between plasma and hepatic tissue. Little is known regarding the impact of EFAD on LP composition. To determine the relationship between hepatic cholesterol esterification and plasma lP composition in control (C) and EFAD male Wistar rats, the authors induced EFAD with continuous intragastric (IG) infusion of EFA-free solutions containing 3.5% of calories as triolein for 7 and 14 days. C animals received IG infusion of solutions containing 3.5% of calories as linoleic acid. Data in the EFAD groups reveal: (i) marked decreases in hepatic EFAs and increases in monoenoic acids; (ii) progressive increases in hepatic content of triglyceride and esterified cholesterol with 7 and 14 days of feeding; (iii) assay of acyl CoA:cholesterol acyltransferase activity in hepatic tissue using /sup 14/C-cholesterol demonstrates an increase in hepatic cholesterol esterification when compared to C animals. Increased hepatic cholesterol esterification correlates with elevated levels of esterified cholesterol in plasma VLDL and HDL particles. These data indicate that the elevated levels of cholesterol esters in LP particles is due, at least in part, to increased hepatic cholesterol esterification with EFAD.

  5. Anthocyanin-rich black elderberry extract improves markers of HDL function and reduces aortic cholesterol in hyperlipidemic mice.

    PubMed

    Farrell, Nicholas; Norris, Gregory; Lee, Sang Gil; Chun, Ock K; Blesso, Christopher N

    2015-04-01

    Serum high-density lipoprotein-cholesterol (HDL-C) is a risk factor considered to be protective of atherosclerosis. However, atherosclerosis is an inflammatory disease and contributes to impairment in high-density lipoprotein (HDL) function, including reductions in HDL-C, HDL antioxidant and anti-inflammatory activities. Anthocyanins are polyphenols that have demonstrated antioxidant and anti-inflammatory properties. The objective of this study was to determine whether an anthocyanin-rich black elderberry extract (Sambucus nigra) (BEE) (13% anthocyanins) would protect against inflammation-related impairments in HDL function and atherosclerosis in apoE(-/-) mice, a mouse model of hyperlipidemia and HDL dysfunction. We fed an AIN-93M diet supplemented with 1.25% (w/w) BEE or control diet to 10 week old male apoE(-/-) mice for 6 weeks. The BEE fed to mice was rich in cyanidin 3-sambubioside (∼ 9.8% w/w) and cyanidin 3-glucoside (∼ 3.8% w/w). After 6 weeks, serum lipids did not differ significantly between groups, while aspartate transaminase (AST) and fasting glucose were reduced in BEE-fed mice. Hepatic and intestinal mRNA changes with BEE-feeding were consistent with an improvement in HDL function (Apoa1, Pon1, Saa1, Lcat, Clu) and a reduction in hepatic cholesterol levels (increased Ldlr and Hmgcr, reduced Cyp7a1). In BEE-fed mice, serum paraoxonase-1 (PON1) arylesterase activity was significantly higher. In addition, mice fed BEE had significantly lower serum chemokine (C-C motif) ligand 2 (CCL2) compared to control-fed mice. Notably, we observed significant reductions in total cholesterol content of the aorta of BEE-fed mice, indicating less atherosclerosis progression. This study suggests that black elderberry may have the potential to influence HDL dysfunction associated with chronic inflammation by impacting hepatic gene expression. PMID:25758596

  6. Comparison of vegetarian diets and omnivorous diets on plasma level of HDL-c: a meta-analysis.

    PubMed

    Zhang, Zili; Wang, Jian; Chen, Sifan; Wei, Zhaoyu; Li, Zhengtu; Zhao, Siwen; Lu, Wenju

    2014-01-01

    Low plasma level of high density lipoprotein cholesterol (HDL-c) was an independent risk factor for cardio vascular disorder, and associated with poor outcomes in pulmonary arterial hypertension. To compare the effects of vegetarian diets and omnivorous diets on HDL-c in plasma, we identified cross-sectional and cohort studies related to HDL-c listed on PubMed and ISI Web of Knowledge as well as the corresponding references (until Nov, 2013). Twelve studies with a total of 4177 individuals were selected for meta-analysis. This meta-analysis indicates that vegetarian diets did not alter plasma HDL-c concentrations, as it wasn't initially expected by the authors [Standardized Mean Difference (SMD) = 0.02 mmol/l; 95% confidence interval (CI): -0.19 to 0.22 mmol/l]. In Asia and Latin America countries, no significant differences in HDL-c levels between vegetarians and omnivores were found (SMD = -0.09 mmol/l; 95% CI: -0.43 to 0.25 mmol/l). In Europe and North America countries, the plasma level of HDL-c was also not different between the two diets (SMD = 0.09 mmol/l; 95% CI: -0.19 to 0.36 mmol/l). In light of this meta-analysis, we conclude that there is no evidence that plasma HDL-c levels differs in vegetarians and omnivores, even after adjusting for cultural circumstances.

  7. Levels of Cholesterol in Small LDL Particles Predict Atherosclerosis Progression and Incident CHD in the HDL-Atherosclerosis Treatment Study (HATS)

    PubMed Central

    Williams, Paul T.; Zhao, Xue-Qiao; Marcovina, Santica M.; Brown, B. Greg; Krauss, Ronald M.

    2013-01-01

    Objective Test whether angiographically-documented changes in percent stenosis and clinical endpoints (coronary-related deaths, myocardial infarctions, stroke, revascularization for worsening ischemia) in the HDL-Atherosclerosis Treatment Study (HATS) were attributable to specific LDL-subclasses. Methods Gradient gel electrophoresis of on-study LDL-subclass cholesterol concentrations were measured in 32 placebo, 33 simvastatin-niacin, 38 antioxidant, and 39 simvastatin-niacin & antioxidant treated participants. The prespecified primary end point was the mean change per patient from the initial arteriogram to the final arteriogram in the percent stenosis caused by the most severe lesion in each of the nine proximal coronary segments. Results The change in the percent stenosis of the most severe proximal lesions increased in association with higher concentrations of the small LDL subfractions LDL-IIIb (24.2–24.6 nm) and LDL-IVa (23.3–24.1 nm) before (both P = 0.002) and after (P = 0.01 and P = 0.03 respectively) adjustment for treatment group and on-study HDL-cholesterol, LDL-cholesterol, and triglyceride concentrations. The associations appeared specific to lesions with <30% baseline stenosis. When adjusted for age, sex, baseline BMI and cigarette use, the odds for primary clinical endpoints (death from coronary causes, nonfatal myocardial infarction, stroke, or revascularization for worsening ischemia) were significantly greater in subjects with higher on-study LDL-IIIb levels both before (P = 0.01) and after (P = 0.03) adjustment for treatment group and the standard lipid values. Conclusions Plasma LDL-IIIb cholesterol concentrations were related to changes in coronary artery stenosis and cardiovascular events in patients with coronary artery disease and low HDL-cholesterol. Trial Registration ClinicalTrials.gov NCT00000553 PMID:23460815

  8. Non-leaky vesiculation of large unilamellar vesicles (LUV) induced by plasma high density lipoproteins (HDL): Detection by HPLC

    SciTech Connect

    Tischler, U.; Rueckert, D.S.; Schubert, R.; Jaroni, H.W.; Schmidt, K.H.

    1989-05-15

    Interaction of large unilamellar phosphatidylcholine vesicles (LUV, 75nm) and plasma high density lipoproteins (HDL) resulted in a non-leaky vesiculation of LUV. This vesiculation was detected by a HPLC-system consisting of a combination of three TSK-gel columns (6000PW, 5000PW, 3000SW). With increasing incubation time liposomal (/sup 14/C)PC, entrapped (/sup 3/H)inulin, and apoprotein of HDL origin decreased. The decrease was accompanied by a formation of new particles, consisting of liposomal PC and apoprotein. These particles also enclosed (3H)inulin, reflecting a hydrophilic inner space. The formation of the particles reached a maximum after one day of incubation. Retention time was 21 minutes for LUV, 28 minutes for the new particles, and 36 minutes for HDL. In vesicles with membranes consisting of phosphatidylcholine and 30% cholesterol no interactions were observed.

  9. Rapid labeling of lipoproteins in plasma with radioactive cholesterol. Application for measurement of plasma cholesterol esterification

    SciTech Connect

    Yen, F.T.; Nishida, T. )

    1990-02-01

    In order to efficiently and rapidly label lipoproteins in plasma with ({sup 3}H)cholesterol, micelles consisting of lysophosphatidylcholine (lysoPC) and ({sup 3}H)cholesterol (molar ratio, 50:1) were prepared. When trace amounts of these micelles were injected into plasma, ({sup 3}H)cholesterol rapidly equilibrated among the plasma lipoproteins, as compared to ({sup 3}H)cholesterol from an albumin-stabilized emulsion. The distributions of both ({sup 3}H)cholesterol and unlabeled free cholesterol in plasma lipoproteins were similar in labeled plasma samples. This method of labeling can be used for the measurement of cholesterol esterification, or lecithin:cholesterol acyltransferase activity, in small amounts (20-40 microliters) of plasma samples.

  10. Wheat germ policosanol failed to lower plasma cholesterol in subjects with normal to mildly elevated cholesterol concentrations.

    PubMed

    Lin, Yuguang; Rudrum, Mike; van der Wielen, Reggy P J; Trautwein, Elke A; McNeill, Gerald; Sierksma, Aafje; Meijer, Gert W

    2004-10-01

    Sugar cane policosanol, a mixture of long-chain primary alcohols (approximately 67% as octacosanol), has been reported to lower plasma low-density lipoprotein (LDL)-cholesterol. We investigated the effect of wheat germ policosanol (WGP) on plasma lipid profiles in 58 adults (30 men and 28 women, aged 49 +/- 11 years) with normal to mildly elevated plasma cholesterol concentrations in a double-blind, randomized, parallel placebo-controlled study. Subjects consumed chocolate pellets with or without 20 mg/d WGP for 4 weeks. Plasma lipid concentrations, routine blood chemistry and hematology were determined at the start and the end of the study. The initial plasma total, LDL-cholesterol, high-density lipoprotein (HDL)-cholesterol, and triacylglycerol concentrations in the WGP and the control groups were identical. Over the 4 weeks, neither the WGP nor the control treatment significantly changed plasma total cholesterol, LDL- and HDL-cholesterol, or triacylglycerol concentrations when compared to baseline values. In addition, there was no significant difference in plasma lipid profiles between the WGP and the control groups at the end of the study. WGP did not result in any adverse effects as indicated by plasma activities of L-gamma-glutamyltransferase (gamma-GT), ALT, AST, bilirubin concentrations, and blood cell profiles. Chemical analysis showed that WGP consists of 8% hexacosanol, 67% octacosanol, 12% triacosanol, and 13% other long-chain alcohols, which is similar to the composition of sugar cane policosanol. In conclusion, WGP at 20 mg/d had no beneficial effects on blood lipid profiles. It therefore seems unlikely that the long chain (C24-34) alcohols have any cholesterol-lowering activity.

  11. Hepatic lipase promoter C-514T polymorphism influences serial changes in HDL cholesterol levels since childhood: the Bogalusa Heart Study.

    PubMed

    Chen, Wei; Srinivasan, Sathanur R; Boerwinkle, Eric; Berenson, Gerald S

    2003-07-01

    Hepatic lipase (HL) is an important determinant of high-density lipoprotein (HDL) concentrations. A common C-to-T substitution at position -514 of the promoter region of the HL gene has been shown to be associated with HL activity and HDL cholesterol (HDL-C) levels. The current study examines the influence of this polymorphism on both levels and serial changes of HDL-C from childhood to adulthood in a community-based sample of 707 white and 291 black unrelated individuals aged 4-38 years using a repeated measures analysis. The frequency of the -514T allele was lower in whites than in blacks (0.228 vs. 0.545, P<0.001). After adjusting for age and BMI, the genotype effect on longitudinal profiles of HDL-C levels was significant (P=0.003) in white males with values in the order of T/T>T/C>C/C. Although a similar trend was seen, the genotype effect was not significant in white females and blacks. Further, the slopes of the age trajectories of HDL-C were similar in three genotype groups in blacks and whites. A sex-genotype interaction effect (P=0.043) on longitudinal profiles of HDL-C levels was found in whites, but not in blacks. White males showed a stronger genotype effect (3.6 mg/dl, P=0.003) than white females (0.5 mg/dl, P=0.601). Thus, the -514T variant of the HL gene is consistently associated with higher levels of HDL-C longitudinally since childhood, but not with rate of change over time. These results suggest that the HL gene may play an important role in the regulation of HDL-C levels from childhood to adulthood, especially in white males.

  12. A lipoprotein lipase gene polymorphism interacts with consumption of alcohol and unsaturated fat to modulate serum HDL-cholesterol concentrations.

    PubMed

    Baik, Inkyung; Lee, Seungku; Kim, Seong Hwan; Shin, Chol

    2013-10-01

    There are limited data from prospective studies regarding interactions between lipoprotein lipase gene (LPL) and lifestyle factors in association with HDL-cholesterol (HDL-C) concentrations, a biomarker of coronary heart disease risk. Our prospective cohort study investigated the interactive effects of a common LPL polymorphism and lifestyle factors, including obesity, smoking, alcohol consumption, physical activity, and dietary intake, on follow-up measurements of HDL-C and triglyceride (TG) concentrations. A total of 5314 Korean men and women aged 40-69 y participated in the study. Serum HDL-C and TG concentrations were measured in all participants at baseline and 6-y follow-up examinations. On the basis of genome-wide association data for HDL-C and TG concentrations, we selected the most significant polymorphism (rs10503669), which was in high linkage disequilibrium with the serine 447 stop (S447×) mutation (D' = 0.99) of LPL. We found that carrying the T allele reflecting the LPL ×447 allele was positively associated with follow-up measurement of HDL-C concentrations (P < 0.001). In the linear regression model adjusted for baseline HDL-C concentration and potential risk factors, we observed interactive effects of the polymorphism and consumption of alcohol (P-interaction < 0.01) and unsaturated fat (P-interaction < 0.05) on follow-up measurement of HDL-C concentrations. We also observed interactive effects of the polymorphism and body mass index (P-interaction < 0.01) on follow-up measurement of TG concentrations after adjusting for the baseline level and potential risk factors. Our findings suggest that carriers of the LPL ×447 allele benefit from moderate alcohol consumption and a diet high in unsaturated fat to minimize reduction of blood HDL-C concentrations and that obese persons who do not carry the LPL ×447 allele need to control body weight to prevent hypertriglyceridemia.

  13. Novel apo E-derived ABCA1 agonist peptide (CS-6253) promotes reverse cholesterol transport and induces formation of preβ-1 HDL in vitro

    SciTech Connect

    Hafiane, Anouar; Bielicki, John K.; Johansson, Jan O.; Genest, Jacques; Zhu, Xuewei

    2015-07-24

    Apolipoprotein (apo) mimetic peptides replicate some aspects of HDL function. We have previously reported the effects of compound ATI-5261 on its ability to replicate many functions of native apo A-I in the process of HDL biogenesis. ATI-5261 induced muscle toxicity in wild type C57Bl/6 mice, increased CPK, ALT and AST and increase in triglyceride (Tg) levels. Aromatic phenylalanine residues on the non-polar face of ATI-5261, together with positively charged arginine residues at the lipid-water interface were responsible for these effects. This information was used to create a novel analog (CS-6253) that was non-toxic. We evaluated this peptide designed from the carboxyl terminus of apo E, in its ability to mimic apo A-I functionality. Our data shows that the lipidated particles generated by incubating cells overexpressing ABCA1 with lipid free CS-6253 enhances the rate of ABCA1 lipid efflux with high affinity interactions with native ABCA1 oligomeric forms and plasma membrane micro-domains. Interaction between ABCA1 and lipid free CS-6253 resulted in formation of nascent HDL-CS-6253 particles that are actively remodeled in plasma. Mature HDL-CS-6253 particles deliver cholesterol to liver cells via SR-BI in-vitro. CS-6253 significantly increases cholesterol efflux in murine macrophages and in human THP-1 macrophage-derived foam cells expressing ABCA1. Addition of CS-6253 to plasma dose-dependently displaced apo A-I from α-HDL particles and led to de novo formation of preβ-1 HDL that stimulates ABCA1 dependent cholesterol efflux efficiently. When incubated with human plasma CS-6253 was also found to bind with HDL and LDL and promoted the transfer of cholesterol from HDL to LDL predominantly. Our data shows that CS-6253 mimics apo A-I in its ability to promote ABCA1-mediated formation of nascent HDL particles, and enhances formation of preβ-1 HDL with increase in the cycling of apo A-I between the preβ and α-HDL particles in-vitro. These

  14. Macadamia nut consumption lowers plasma total and LDL cholesterol levels in hypercholesterolemic men.

    PubMed

    Garg, Manohar L; Blake, Robert J; Wills, Ron B H

    2003-04-01

    This study was conducted to assess the cholesterol-lowering potential of macadamia nuts. Seventeen hypercholesterolemic men (mean age 54 y) were given macadamia nuts (40-90 g/d), equivalent to 15% energy intake, for 4 wk. Plasma total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and homocysteine concentrations and the fatty acid composition of plasma lipids were determined before and after treatment. Plasma MUFA 16:1(n-7), 18:1(n-7) and 20:1(n-9) were elevated after intervention with macadamia nuts. Plasma (n-6) and (n-3) PUFA concentrations were unaffected by macadamia nut consumption. Plasma total cholesterol and LDL cholesterol concentrations decreased by 3.0 and 5.3%, respectively, and HDL cholesterol levels increased by 7.9% in hypercholesterolemic men after macadamia nut consumption. Plasma triglyceride and homocysteine concentrations were not affected by treatment. Macadamia nut consumption was associated with a significant increase in the relative intake of MUFA and a reduced relative intake of saturated fatty acids and PUFA. This study demonstrates that macadamia nut consumption as part of a healthy diet favorably modifies the plasma lipid profile in hypercholesterolemic men despite their diet being high in fat.

  15. Macadamia nut consumption lowers plasma total and LDL cholesterol levels in hypercholesterolemic men.

    PubMed

    Garg, Manohar L; Blake, Robert J; Wills, Ron B H

    2003-04-01

    This study was conducted to assess the cholesterol-lowering potential of macadamia nuts. Seventeen hypercholesterolemic men (mean age 54 y) were given macadamia nuts (40-90 g/d), equivalent to 15% energy intake, for 4 wk. Plasma total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides and homocysteine concentrations and the fatty acid composition of plasma lipids were determined before and after treatment. Plasma MUFA 16:1(n-7), 18:1(n-7) and 20:1(n-9) were elevated after intervention with macadamia nuts. Plasma (n-6) and (n-3) PUFA concentrations were unaffected by macadamia nut consumption. Plasma total cholesterol and LDL cholesterol concentrations decreased by 3.0 and 5.3%, respectively, and HDL cholesterol levels increased by 7.9% in hypercholesterolemic men after macadamia nut consumption. Plasma triglyceride and homocysteine concentrations were not affected by treatment. Macadamia nut consumption was associated with a significant increase in the relative intake of MUFA and a reduced relative intake of saturated fatty acids and PUFA. This study demonstrates that macadamia nut consumption as part of a healthy diet favorably modifies the plasma lipid profile in hypercholesterolemic men despite their diet being high in fat. PMID:12672919

  16. Some kinetic properties of plasma lecithin-cholesterol acyltransferase in hyper-alphalipoproteinemia in man

    SciTech Connect

    Nikiforova, A.A.; Alksnis, E.G.; Ivanova, E.M.

    1985-07-01

    The aim of this investigation was to study some kinetic properties of lecithin-cholesterol acyltransferase (LCAT) in the blood plasma of patients with hyper-alpha-lipoproteinemia, enabling the presence of LCAT isozymes in the blood to be detected. The velocity of the LCAT reaction was judged by determining labeled CHE formed from /sup 14/C-nonesterified CH and lecithin of HDL on incubation of the latter with the enzyme. Dependence of the velocity of the LCAT reaction on concentration of substrate (nonesterified HDL cholesterol) in four subjects with hyper-alpha-lipoproteinemia is shown.

  17. HDL cholesterol: all hope is not lost after the torcetrapib setback--emerging therapeutic strategies on the horizon.

    PubMed

    Verma, Nitin; Figueredo, Vincent M

    2014-01-01

    Lowering low-density lipoprotein cholesterol (LDL) has been definitely shown to reduce cardiovascular events and improve clinical outcomes in the literature. As a result, LDL lowering has become the cornerstone of therapeutic approaches to cardiovascular disease prevention. Recently, there has been a focus on targeting other lipid fractions to improve the clinical risk profile of patients. Raising high-density lipoprotein (HDL) has received considerable attention. Low HDL levels are often seen in combination with elevated triglyceride levels. New therapeutic modalities are being developed to increase HDL levels. Recent failure of agents such as cholesteryl ester transferase protein inhibitor torcetrapib has highlighted the importance of measuring functionality of HDL particles and not just focus quantitatively on HDL-C levels. The heterogeneity of HDL within the systemic circulation results from constant remodeling of particles in response to several factors. Established dyslipidemia therapies such as stains, fibrates, and niacin have already been well known in the literature to have a substantial benefit. Lifestyle changes such as smoking cessation and moderate alcohol consumption have also shown to have some benefit. Several novel HDL therapies are currently being developed, but only the cholesteryl ester transferase protein inhibitors have received considerable attention. Although torcetrapib has received some negative attention due to adverse effects, this overall class of therapeutic agents still holds a lot of promise. Newer agents without the concerned toxicities are currently being developed. ApoA-1-related peptides, peroxisome proliferator-activated receptor agonists, endothelial lipase inhibitors, and liver X receptor agonists are some of the other novel agents currently in various stages of development. PMID:22967983

  18. Co-administration of berberine and plant stanols synergistically reduces plasma cholesterol in rats.

    PubMed

    Jia, Xiaoming; Chen, Yanfeng; Zidichouski, Jeffrey; Zhang, Junzeng; Sun, Changhao; Wang, Yanwen

    2008-11-01

    The objective of the present study was to determine the beneficial effects and the safety of oral administration of the combination of berberine (BBR) and plant stanols (PS) on plasma lipid profiles in male Sprague-Dawley rats. Four groups of animals were fed a cornstarch-casein-sucrose-based high-cholesterol (2%, w:w) and high-fat (27.5%) diet. Three treatment groups were supplemented with either BBR (100mgkg(-1)bodyweightd(-1)), PS (1% in diet, w:w), or the combination of both (BBRPS). After 6 wk, animals were sacrificed and followed immediately with the collection of blood and organ samples. Lipid analysis revealed that PS lowered plasma total cholesterol (T-C) by 18% (p=0.067) and non-HDL-cholesterol (non-HDL-C) by 29% (p=0.013) as compared with the control, while BBR had no effect on both T-C and non-HDL-C. The combination treatment of BBRPS reduced plasma T-C by 41% (p=0.0002) and non-HDL-C by 59% (p<0.0001) compared to the control group. BBR reduced plasma TG levels by 31% at a marginal significance relative to the control (p=0.054), whereas PS had no effect. BBRPS showed an additive effect of BBR and PS on plasma TAG. PS and BBRPS both decreased liver cholesterol (p=0.0027 and 0.0002, respectively). BBR and PS, either alone or in combination, did not show any toxic effects as assessed by plasma concentration of hepatic biochemical parameters. These results demonstrate that BBR and PS, when combined, synergistically lower plasma cholesterol levels and significantly reduce liver cholesterol, without the observation of any toxic effects.

  19. Dietary capsanthin, the main carotenoid in paprika (Capsicum annuum), alters plasma high-density lipoprotein-cholesterol levels and hepatic gene expression in rats.

    PubMed

    Aizawa, Koichi; Inakuma, Takahiro

    2009-12-01

    The effects of dietary capsanthin, the main carotenoid in paprika (Capsicum annuum), on lipid metabolism were examined. Young male Wistar rats were fed diets containing paprika powder, paprika organic solvent extract, residue of paprika extract, and purified capsanthin. Administration of purified capsanthin for 2 weeks resulted in a significant increase in plasma HDL-cholesterol (P < 0.05) without detectable differences in plasma total cholesterol and TAG concentrations. A statistically significant correlation (r 0.567; P < 0.001) was found between dietary capsanthin concentrations and plasma HDL-cholesterol concentrations. Animals receiving diets containing two different capsanthin concentrations exhibited dose-dependent increases in plasma HDL-cholesterol (r 0.597; P < 0.005). While capsanthin was absent in the liver of animals fed the basal diet, it increased markedly in capsanthin-fed animals (P < 0.001). Quantitative analyses of hepatic mRNA levels revealed that capsanthin administration resulted in up-regulation of mRNA for apoA5 and lecithin cholesterol acyltransferase (LCAT), without significant differences in other mRNA levels related to HDL-cholesterol metabolism. These results suggest that capsanthin had an HDL-cholesterol-raising effect on plasma, and the potential to increase cholesterol efflux to HDL particles by increasing apoA5 levels and/or enhancement of LCAT activity.

  20. Plasma cholesterol transport in anhepatic rats.

    PubMed Central

    Quarfordt, S H; Landis, B; Cucchiaro, G; Yamaguchi, Y; Oswald, B

    1992-01-01

    The plasma appearance of newly synthesized cholesterol in anhepatic laboratory diet-fed rats was 10% of the intact rat. In intact rats this cholesterol was mainly ester in lower density lipoproteins, but for anhepatic rats it was virtually only free in high density lipoprotein. Chylomicron cholesterol ester was removed much more slowly from anhepatic than control plasma and returned primarily as free in high density lipoproteins, with the control return 10 times the anhepatic return. Lower density lipoprotein cholesterol ester transfer to an extravascular pool in anhepatic rats was less than 10% of controls. The liver was responsible for 95% of the extravascular lower density lipoprotein ester pool and only 50% of the for high density lipoprotein ester. Despite decreased anhepatic lipoprotein catabolism, the mass of both plasma low and high density lipoproteins progressively decreased indicating an even greater decrease in influx. The anhepatic fractional catabolic rate of apo A1 was similar to controls, but that of apo E was considerably less. Despite the unchanged catabolism of apo A1 and the reduced catabolism of apo E, plasma apo A1 decreased less than apo E after hepatectomy. The anhepatic data confirm the pivotal role of the liver in maintaining plasma low and high density lipoprotein cholesterol concentrations. They suggest that, in addition to its anabolic and catabolic functions, the liver also acts as a reservoir buffering changes in plasma concentration. Images PMID:1569195

  1. Effects of dietary zinc and copper supplementation on serum triglyceride, total-cholesterol and HDL-cholesterol concentrations on young Sprague Dawley male rats

    SciTech Connect

    Frimpong, N.A.; Magee, A.C.

    1986-03-01

    To determine the effects of the level of zinc (Zn) and copper (Cu) supplementation and of Zn/Cu ratio on serum triglycerides (TG), total-cholesterol (TC), and HDL-cholesterol (HDL-C) concentrations, groups of weanling male Sprague Dawley rats were fed diets containing 4 levels of Cu (0, 0.56, 1.68, and 5.04 ppm) and 4 levels of Zn (0, 5, 10 and 20 ppm) for 6 weeks (Low supplementation, Expt I), or a high Zn and Cu supplements each at 4 levels (0, 5.6, 16.8, and 50.4 ppm Cu, plus 0, 50, 100, and 200 ppm Zn) for 6 weeks (Expt II). The effects of Zn/Cu ratios on the parameters were evaluated by combining data from Expt I and Expt II treatments with the same Zn/Cu ratios but different levels of Zn and Cu. Results of the combined data indicated that an increase in dietary Zn was associated with significant (p less than or equal to 0.01) increase in serum triglyceride concentrations, while an increase in dietary Cu was associated with significant (p less than or equal to 0.01) decrease in serum TC and HDL-C concentrations. Dietary Zn/Cu ratios had no significant effect on serum lipids. There is the indication that the absolute levels of the minerals in the diet may be more important in lipid metabolism. These results are in agreement with previous reports.

  2. [A rapid method for continuous flow measurement of cholesterol contained in high density lipoproteins (HDL) (author's transl)].

    PubMed

    Ponsot, P; Yvert, J P; Chevrier, M; Bon, R

    1981-01-01

    The authors utilized a reagent containing concanavalin A, a vegetal lecithin, to selectively precipitate lipoproteins containing apoprotein B, a component of VLDL, LDL, and Lp (a) which are well known for their atherogenic risk. During this precipitation "true" high density lipoproteins remain in solution. HDL cholesterol determination which constitutes an indirect indication of HDL activity or concentrations is performed by an enzymatic method using an automated continuous flow technique carried out on an Auto Analyzer II (Technicon Corp.). This rapid, easy determination obtains results comparable to other methods, particularly those chosen by the Société Française de Biologie Clinique (French Society of Clinical Biology). This technique should permit all laboratories to confirm an atherogenic index.

  3. Hydrogen-rich water decreases serum LDL-cholesterol levels and improves HDL function in patients with potential metabolic syndrome

    PubMed Central

    Song, Guohua; Li, Min; Sang, Hui; Zhang, Liying; Li, Xiuhong; Yao, Shutong; Yu, Yang; Zong, Chuanlong; Xue, Yazhuo; Qin, Shucun

    2013-01-01

    We have found that hydrogen (dihydrogen; H2) has beneficial lipid-lowering effects in high-fat diet-fed Syrian golden hamsters. The objective of this study was to characterize the effects of H2-rich water (0.9–1.0 l/day) on the content, composition, and biological activities of serum lipoproteins on 20 patients with potential metabolic syndrome. Serum analysis showed that consumption of H2-rich water for 10 weeks resulted in decreased serum total-cholesterol (TC) and LDL-cholesterol (LDL-C) levels. Western blot analysis revealed a marked decrease of apolipoprotein (apo)B100 and apoE in serum. In addition, we found H2 significantly improved HDL functionality assessed in four independent ways, namely, i) protection against LDL oxidation, ii) inhibition of tumor necrosis factor (TNF)-α-induced monocyte adhesion to endothelial cells, iii) stimulation of cholesterol efflux from macrophage foam cells, and iv) protection of endothelial cells from TNF-α-induced apoptosis. Further, we found consumption of H2-rich water resulted in an increase in antioxidant enzyme superoxide dismutase and a decrease in thiobarbituric acid-reactive substances in whole serum and LDL. In conclusion, supplementation with H2-rich water seems to decrease serum LDL-C and apoB levels, improve dyslipidemia-injured HDL functions, and reduce oxidative stress, and it may have a beneficial role in prevention of potential metabolic syndrome. PMID:23610159

  4. Hydrogen-rich water decreases serum LDL-cholesterol levels and improves HDL function in patients with potential metabolic syndrome.

    PubMed

    Song, Guohua; Li, Min; Sang, Hui; Zhang, Liying; Li, Xiuhong; Yao, Shutong; Yu, Yang; Zong, Chuanlong; Xue, Yazhuo; Qin, Shucun

    2013-07-01

    We have found that hydrogen (dihydrogen; H2) has beneficial lipid-lowering effects in high-fat diet-fed Syrian golden hamsters. The objective of this study was to characterize the effects of H2-rich water (0.9-1.0 l/day) on the content, composition, and biological activities of serum lipoproteins on 20 patients with potential metabolic syndrome. Serum analysis showed that consumption of H2-rich water for 10 weeks resulted in decreased serum total-cholesterol (TC) and LDL-cholesterol (LDL-C) levels. Western blot analysis revealed a marked decrease of apolipoprotein (apo)B100 and apoE in serum. In addition, we found H2 significantly improved HDL functionality assessed in four independent ways, namely, i) protection against LDL oxidation, ii) inhibition of tumor necrosis factor (TNF)-α-induced monocyte adhesion to endothelial cells, iii) stimulation of cholesterol efflux from macrophage foam cells, and iv) protection of endothelial cells from TNF-α-induced apoptosis. Further, we found consumption of H2-rich water resulted in an increase in antioxidant enzyme superoxide dismutase and a decrease in thiobarbituric acid-reactive substances in whole serum and LDL. In conclusion, supplementation with H2-rich water seems to decrease serum LDL-C and apoB levels, improve dyslipidemia-injured HDL functions, and reduce oxidative stress, and it may have a beneficial role in prevention of potential metabolic syndrome.

  5. Corn fiber oil lowers plasma cholesterol levels and increases cholesterol excretion greater than corn oil and similar to diets containing soy sterols and soy stanols in hamsters.

    PubMed

    Wilson, T A; DeSimone, A P; Romano, C A; Nicolosi, R J

    2000-09-01

    The aims of this study were to compare the cholesterol-lowering properties of corn fiber oil (CFO) to corn oil (CO), whether the addition of soy stanols or soy sterols to CO at similar levels in CFO would increase CO's cholesterol-lowering properties, and the mechanism(s) of action of these dietary ingredients. Fifty male Golden Syrian hamsters were divided into 5 groups of 10 hamsters each, based on similar plasma total cholesterol (TC) levels. The first group of hamsters was fed a chow-based hypercholesterolemic diet containing either 5% coconut oil + 0.24% cholesterol (coconut oil), 5% CO, 5% CFO, 5% CO + 0.6% soy sterols (sterol), or 5% CO + 0.6% soy stanols (stanol) in place of the coconut oil for 4 weeks. The stanol diet significantly inhibited the elevation of plasma TC compared to all other dietary treatments. Also, the CFO and sterol diets significantly inhibited the elevation of plasma TC compared to the CO and coconut oil diets. The CFO, sterol, and stanol diets significantly inhibited the elevation of plasma non-high density lipoprotein cholesterol compared to the CO and coconut oil diets. The stanol diet significantly inhibited the elevation of plasma high density lipoprotein cholesterol (HDL-C) compared to all other dietary treatments. The sterol diet significantly inhibited the elevation of plasma HDL-C compared to the CO and coconut oil diets, whereas the CFO diet significantly inhibited the elevation of plasma HDL-C compared to the coconut oil diet only. No differences were observed between the CFO and CO for plasma HDL-C. There were no differences observed between groups for plasma triglycerides. The CO and CFO diets had significantly less hepatic TC compared to the coconut oil, sterol, and stanol diets. The CO and CFO diets had significantly less hepatic free cholesterol compared to the sterol and stanol diets but not compared to the coconut oil diet; whereas the coconut oil and sterol diets had significantly less hepatic free cholesterol

  6. Anion Exchange HPLC Isolation of High-Density Lipoprotein (HDL) and On-Line Estimation of Proinflammatory HDL

    PubMed Central

    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. PMID:24609013

  7. Increased plasma cholesterol esterification by LCAT reduces diet-induced atherosclerosis in SR-BI knockout mice.

    PubMed

    Thacker, Seth G; Rousset, Xavier; Esmail, Safiya; Zarzour, Abdalrahman; Jin, Xueting; Collins, Heidi L; Sampson, Maureen; Stonik, John; Demosky, Stephen; Malide, Daniela A; Freeman, Lita; Vaisman, Boris L; Kruth, Howard S; Adelman, Steven J; Remaley, Alan T

    2015-07-01

    LCAT, a plasma enzyme that esterifies cholesterol, has been proposed to play an antiatherogenic role, but animal and epidemiologic studies have yielded conflicting results. To gain insight into LCAT and the role of free cholesterol (FC) in atherosclerosis, we examined the effect of LCAT over- and underexpression in diet-induced atherosclerosis in scavenger receptor class B member I-deficient [Scarab(-/-)] mice, which have a secondary defect in cholesterol esterification. Scarab(-/-)×LCAT-null [Lcat(-/-)] mice had a decrease in HDL-cholesterol and a high plasma ratio of FC/total cholesterol (TC) (0.88 ± 0.033) and a marked increase in VLDL-cholesterol (VLDL-C) on a high-fat diet. Scarab(-/-)×LCAT-transgenic (Tg) mice had lower levels of VLDL-C and a normal plasma FC/TC ratio (0.28 ± 0.005). Plasma from Scarab(-/-)×LCAT-Tg mice also showed an increase in cholesterol esterification during in vitro cholesterol efflux, but increased esterification did not appear to affect the overall rate of cholesterol efflux or hepatic uptake of cholesterol. Scarab(-/-)×LCAT-Tg mice also displayed a 51% decrease in aortic sinus atherosclerosis compared with Scarab(-/-) mice (P < 0.05). In summary, we demonstrate that increased cholesterol esterification by LCAT is atheroprotective, most likely through its ability to increase HDL levels and decrease pro-atherogenic apoB-containing lipoprotein particles. PMID:25964513

  8. Cholesterol Asymmetry in Synaptic Plasma Membranes

    PubMed Central

    Wood, W. Gibson; Igbavboa, Urule; Müller, Walter E.; Eckert, Gunter P.

    2010-01-01

    Lipids are essential for the structural and functional integrity of membranes. Membrane lipids are not randomly distributed but are localized in different domains. A common characteristic of these membrane domains is their association with cholesterol. Lipid rafts and caveolae are examples of cholesterol enriched domains, which have attracted keen interest. However, two other important cholesterol domains are the exofacial and cytofacial leaflets of the plasma membrane. The two leaflets that make up the bilayer differ in their fluidity, electrical charge, lipid distribution, and active sites of certain proteins. The synaptic plasma membrane (SPM) cytofacial leaflet contains over 85% of the total SPM cholesterol as compared with the exofacial leaflet. This asymmetric distribution of cholesterol is not fixed or immobile but can be modified by different conditions in vivo: 1) chronic ethanol consumption; 2) statins; 3) aging; and 4) apoE isoform. Several potential candidates have been proposed as mechanisms involved in regulation of SPM cholesterol asymmetry: apoE, low-density-lipoprotein receptor, sterol carrier protein-2, fatty acid binding proteins, polyunsaturated fatty acids, p-glycoprotein and caveolin-1. This review examines cholesterol asymmetry in SPM, potential mechanisms of regulation and impact on membrane structure and function. PMID:21214553

  9. Mining the LIPG allelic spectrum reveals the contribution of rare and common regulatory variants to HDL cholesterol.

    PubMed

    Khetarpal, Sumeet A; Edmondson, Andrew C; Raghavan, Avanthi; Neeli, Hemanth; Jin, Weijun; Badellino, Karen O; Demissie, Serkalem; Manning, Alisa K; DerOhannessian, Stephanie L; Wolfe, Megan L; Cupples, L Adrienne; Li, Mingyao; Kathiresan, Sekar; Rader, Daniel J

    2011-12-01

    Genome-wide association studies (GWAS) have successfully identified loci associated with quantitative traits, such as blood lipids. Deep resequencing studies are being utilized to catalogue the allelic spectrum at GWAS loci. The goal of these studies is to identify causative variants and missing heritability, including heritability due to low frequency and rare alleles with large phenotypic impact. Whereas rare variant efforts have primarily focused on nonsynonymous coding variants, we hypothesized that noncoding variants in these loci are also functionally important. Using the HDL-C gene LIPG as an example, we explored the effect of regulatory variants identified through resequencing of subjects at HDL-C extremes on gene expression, protein levels, and phenotype. Resequencing a portion of the LIPG promoter and 5' UTR in human subjects with extreme HDL-C, we identified several rare variants in individuals from both extremes. Luciferase reporter assays were used to measure the effect of these rare variants on LIPG expression. Variants conferring opposing effects on gene expression were enriched in opposite extremes of the phenotypic distribution. Minor alleles of a common regulatory haplotype and noncoding GWAS SNPs were associated with reduced plasma levels of the LIPG gene product endothelial lipase (EL), consistent with its role in HDL-C catabolism. Additionally, we found that a common nonfunctional coding variant associated with HDL-C (rs2000813) is in linkage disequilibrium with a 5' UTR variant (rs34474737) that decreases LIPG promoter activity. We attribute the gene regulatory role of rs34474737 to the observed association of the coding variant with plasma EL levels and HDL-C. Taken together, the findings show that both rare and common noncoding regulatory variants are important contributors to the allelic spectrum in complex trait loci. PMID:22174694

  10. Bioinformatic Analysis of Plasma Apolipoproteins A-I and A-II Revealed Unique Features of A-I/A-II HDL Particles in Human Plasma.

    PubMed

    Kido, Toshimi; Kurata, Hideaki; Kondo, Kazuo; Itakura, Hiroshige; Okazaki, Mitsuyo; Urata, Takeyoshi; Yokoyama, Shinji

    2016-01-01

    Plasma concentration of apoA-I, apoA-II and apoA-II-unassociated apoA-I was analyzed in 314 Japanese subjects (177 males and 137 females), including one (male) homozygote and 37 (20 males and 17 females) heterozygotes of genetic CETP deficiency. ApoA-I unassociated with apoA-II markedly and linearly increased with HDL-cholesterol, while apoA-II increased only very slightly and the ratio of apoA-II-associated apoA-I to apoA-II stayed constant at 2 in molar ratio throughout the increase of HDL-cholesterol, among the wild type and heterozygous CETP deficiency. Thus, overall HDL concentration almost exclusively depends on HDL with apoA-I without apoA-II (LpAI) while concentration of HDL containing apoA-I and apoA-II (LpAI:AII) is constant having a fixed molar ratio of 2 : 1 regardless of total HDL and apoA-I concentration. Distribution of apoA-I between LpAI and LpAI:AII is consistent with a model of statistical partitioning regardless of sex and CETP genotype. The analysis also indicated that LpA-I accommodates on average 4 apoA-I molecules and has a clearance rate indistinguishable from LpAI:AII. Independent evidence indicated LpAI:A-II has a diameter 20% smaller than LpAI, consistent with a model having two apoA-I and one apoA-II. The functional contribution of these particles is to be investigated. PMID:27526664

  11. Bioinformatic Analysis of Plasma Apolipoproteins A-I and A-II Revealed Unique Features of A-I/A-II HDL Particles in Human Plasma

    PubMed Central

    Kido, Toshimi; Kurata, Hideaki; Kondo, Kazuo; Itakura, Hiroshige; Okazaki, Mitsuyo; Urata, Takeyoshi; Yokoyama, Shinji

    2016-01-01

    Plasma concentration of apoA-I, apoA-II and apoA-II-unassociated apoA-I was analyzed in 314 Japanese subjects (177 males and 137 females), including one (male) homozygote and 37 (20 males and 17 females) heterozygotes of genetic CETP deficiency. ApoA-I unassociated with apoA-II markedly and linearly increased with HDL-cholesterol, while apoA-II increased only very slightly and the ratio of apoA-II-associated apoA-I to apoA-II stayed constant at 2 in molar ratio throughout the increase of HDL-cholesterol, among the wild type and heterozygous CETP deficiency. Thus, overall HDL concentration almost exclusively depends on HDL with apoA-I without apoA-II (LpAI) while concentration of HDL containing apoA-I and apoA-II (LpAI:AII) is constant having a fixed molar ratio of 2 : 1 regardless of total HDL and apoA-I concentration. Distribution of apoA-I between LpAI and LpAI:AII is consistent with a model of statistical partitioning regardless of sex and CETP genotype. The analysis also indicated that LpA-I accommodates on average 4 apoA-I molecules and has a clearance rate indistinguishable from LpAI:AII. Independent evidence indicated LpAI:A-II has a diameter 20% smaller than LpAI, consistent with a model having two apoA-I and one apoA-II. The functional contribution of these particles is to be investigated. PMID:27526664

  12. Different palm oil preparations reduce plasma cholesterol concentrations and aortic cholesterol accumulation compared to coconut oil in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Kotyla, Timothy; Sundram, Kalyana; Kritchevsky, David

    2005-10-01

    Several studies have reported on the effect of refined, bleached and deodorized palm oil (RBD-PO) incorporation into the diet on blood cholesterol concentrations and on the development of atherosclerosis. However, very little work has been reported on the influence of red palm oil (RPO), which is higher in carotenoid and tocopherol content than RBD-PO. Thus, we studied the influence of RPO, RBD-PO and a RBD-PO plus red palm oil extract (reconstituted RBD-PO) on plasma cholesterol concentrations and aortic accumulation vs. hamsters fed coconut oil. Forty-eight F1B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three/cage) in hanging polystyrene cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks at which time they were bled after an overnight fast and segregated into four groups of 12 with similar plasma cholesterol concentrations. Group 1 continued on the HCD, Group 2 was fed the HCD containing 10% RPO in place of coconut oil, Group 3 was fed the HCD containing 10% RBD-PO in place of coconut oil and Group 4 was fed the HCD with 10% reconstituted RBD-PO for an additional 10 weeks. Plasma total cholesterol (TC) and non-high-density lipoprotein-cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the hamsters fed the RPO (-42% and -48%), RBD-PO (-32% and -36%) and the reconstituted RBD-PO (-37% and -41%) compared to the coconut oil-fed hamsters. Plasma HDL-C concentrations were significantly higher by 14% and 31% in hamsters fed the RBD-PO and RPO compared to the coconut oil-fed hamsters. Plasma triglyceride (TG) concentrations were significantly lower in hamsters fed RBD-PO (-32%) and the reconstituted RBD-PO (-31%) compared to the coconut oil-fed hamsters. The plasma gamma-tocopherol concentrations were higher

  13. Different palm oil preparations reduce plasma cholesterol concentrations and aortic cholesterol accumulation compared to coconut oil in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Kotyla, Timothy; Sundram, Kalyana; Kritchevsky, David

    2005-10-01

    Several studies have reported on the effect of refined, bleached and deodorized palm oil (RBD-PO) incorporation into the diet on blood cholesterol concentrations and on the development of atherosclerosis. However, very little work has been reported on the influence of red palm oil (RPO), which is higher in carotenoid and tocopherol content than RBD-PO. Thus, we studied the influence of RPO, RBD-PO and a RBD-PO plus red palm oil extract (reconstituted RBD-PO) on plasma cholesterol concentrations and aortic accumulation vs. hamsters fed coconut oil. Forty-eight F1B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three/cage) in hanging polystyrene cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks at which time they were bled after an overnight fast and segregated into four groups of 12 with similar plasma cholesterol concentrations. Group 1 continued on the HCD, Group 2 was fed the HCD containing 10% RPO in place of coconut oil, Group 3 was fed the HCD containing 10% RBD-PO in place of coconut oil and Group 4 was fed the HCD with 10% reconstituted RBD-PO for an additional 10 weeks. Plasma total cholesterol (TC) and non-high-density lipoprotein-cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the hamsters fed the RPO (-42% and -48%), RBD-PO (-32% and -36%) and the reconstituted RBD-PO (-37% and -41%) compared to the coconut oil-fed hamsters. Plasma HDL-C concentrations were significantly higher by 14% and 31% in hamsters fed the RBD-PO and RPO compared to the coconut oil-fed hamsters. Plasma triglyceride (TG) concentrations were significantly lower in hamsters fed RBD-PO (-32%) and the reconstituted RBD-PO (-31%) compared to the coconut oil-fed hamsters. The plasma gamma-tocopherol concentrations were higher

  14. Individual Variation in the Effects of Dietary Cholesterol on Plasma Lipoproteins and Cellular Cholesterol Homeostasis in Man

    PubMed Central

    Mistry, P.; Miller, N. E.; Laker, M.; Hazzard, W. R.; Lewis, B.

    1981-01-01

    The effects of dietary cholesterol on plasma lipoproteins and cholesterol homeostasis in blood mononuclear cells have been examined in healthy adults. Addition of 1,500 mg of cholesterol to the daily diet of 37 subjects for 14 d was associated with a wide range of response of plasma total cholesterol concentration (from −6 to +75 mg/dl; mean change, +29 mg/dl; P < 0.001). Increases in plasma cholesterol reflected increased cholesterol concentrations in intermediate density lipoprotein (IDL; 1.006-1.019 g/ml), low density lipoprotein (LDL; 1.019-1.063 g/ml), and the HDL2 subclass (1.063-1.125 g/ml) of high density lipoprotein, which on average accounted for 20, 58, and 22%, respectively, of the total increment. Similar responses occurred in 14 other subjects given 750 mg cholesterol per day for 28 d. Plasma apolipoprotein B concentrations in IDL and LDL also increased. These effects on plasma lipoproteins were accompanied by three changes in freshly isolated blood mononuclear cells: (a) an increase in cell cholesterol content (mean change, +17%; P < 0.01); (b) suppression of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase activity (−32%; P < 0.001); and (c) reduction of LDL receptor activity (−74%; P < 0.01), quantified as the rate of degradation of 125I-LDL to noniodide trichloroacetic acid-soluble material. These results provide the first direct evidence for the modulation of LDL receptor activity and HMG CoA reductase activity in a peripheral cell type in response to a dietary perturbation of human lipoprotein metabolism. The percentage increase in LDL cholesterol was negatively correlated with the percentage decrease in HMG CoA reductase activity (r = −0.49, P < 0.01). An additional negative correlation existed between the increment in plasma cholesterol concentration and the capacity of cells to degrade 125I-LDL after derepression by preincubation for 72 h in lipoprotein-deficient medium (r = −0.74, P < 0.001). Thus, differences between

  15. HDL biogenesis, remodeling, and catabolism.

    PubMed

    Zannis, Vassilis I; Fotakis, Panagiotis; Koukos, Georgios; Kardassis, Dimitris; Ehnholm, Christian; Jauhiainen, Matti; Chroni, Angeliki

    2015-01-01

    In this chapter, we review how HDL is generated, remodeled, and catabolized in plasma. We describe key features of the proteins that participate in these processes, emphasizing how mutations in apolipoprotein A-I (apoA-I) and the other proteins affect HDL metabolism. The biogenesis of HDL initially requires functional interaction of apoA-I with the ATP-binding cassette transporter A1 (ABCA1) and subsequently interactions of the lipidated apoA-I forms with lecithin/cholesterol acyltransferase (LCAT). Mutations in these proteins either prevent or impair the formation and possibly the functionality of HDL. Remodeling and catabolism of HDL is the result of interactions of HDL with cell receptors and other membrane and plasma proteins including hepatic lipase (HL), endothelial lipase (EL), phospholipid transfer protein (PLTP), cholesteryl ester transfer protein (CETP), apolipoprotein M (apoM), scavenger receptor class B type I (SR-BI), ATP-binding cassette transporter G1 (ABCG1), the F1 subunit of ATPase (Ecto F1-ATPase), and the cubulin/megalin receptor. Similarly to apoA-I, apolipoprotein E and apolipoprotein A-IV were shown to form discrete HDL particles containing these apolipoproteins which may have important but still unexplored functions. Furthermore, several plasma proteins were found associated with HDL and may modulate its biological functions. The effect of these proteins on the functionality of HDL is the topic of ongoing research. PMID:25522986

  16. Randomised controlled trial of the effect of long-term selenium supplementation on plasma cholesterol in an elderly Danish population.

    PubMed

    Cold, Frederik; Winther, Kristian H; Pastor-Barriuso, Roberto; Rayman, Margaret P; Guallar, Eliseo; Nybo, Mads; Griffin, Bruce A; Stranges, Saverio; Cold, Søren

    2015-12-14

    Although cross-sectional studies have shown a positive association between Se and cholesterol concentrations, a recent randomised controlled trial in 501 elderly UK individuals of relatively low-Se status found that Se supplementation for 6 months lowered total plasma cholesterol. The Danish PRECISE (PREvention of Cancer by Intervention with Selenium) pilot study (ClinicalTrials.gov ID: NCT01819649) was a 5-year randomised, double-blinded, placebo-controlled trial with four groups (allocation ratio 1:1:1:1). Men and women aged 60-74 years (n 491) were randomised to 100 (n 124), 200 (n 122) or 300 (n 119) μg Se-enriched yeast or matching placebo-yeast tablets (n 126) daily for 5 years. A total of 468 participants continued the study for 6 months and 361 participants, equally distributed across treatment groups, continued for 5 years. Plasma samples were analysed for total and HDL-cholesterol and for total Se concentrations at baseline, 6 months and 5 years. The effect of different doses of Se supplementation on plasma lipid and Se concentrations was estimated by using linear mixed models. Plasma Se concentration increased significantly and dose-dependently in the intervention groups after 6 months and 5 years. Total cholesterol decreased significantly both in the intervention groups and in the placebo group after 6 months and 5 years, with small and nonsignificant differences in changes in plasma concentration of total cholesterol, HDL-cholesterol, non-HDL-cholesterol and total:HDL-cholesterol ratio between intervention and placebo groups. The effect of long-term supplementation with Se on plasma cholesterol concentrations or its sub-fractions did not differ significantly from placebo in this elderly population. PMID:26420334

  17. Randomised controlled trial of the effect of long-term selenium supplementation on plasma cholesterol in an elderly Danish population.

    PubMed

    Cold, Frederik; Winther, Kristian H; Pastor-Barriuso, Roberto; Rayman, Margaret P; Guallar, Eliseo; Nybo, Mads; Griffin, Bruce A; Stranges, Saverio; Cold, Søren

    2015-12-14

    Although cross-sectional studies have shown a positive association between Se and cholesterol concentrations, a recent randomised controlled trial in 501 elderly UK individuals of relatively low-Se status found that Se supplementation for 6 months lowered total plasma cholesterol. The Danish PRECISE (PREvention of Cancer by Intervention with Selenium) pilot study (ClinicalTrials.gov ID: NCT01819649) was a 5-year randomised, double-blinded, placebo-controlled trial with four groups (allocation ratio 1:1:1:1). Men and women aged 60-74 years (n 491) were randomised to 100 (n 124), 200 (n 122) or 300 (n 119) μg Se-enriched yeast or matching placebo-yeast tablets (n 126) daily for 5 years. A total of 468 participants continued the study for 6 months and 361 participants, equally distributed across treatment groups, continued for 5 years. Plasma samples were analysed for total and HDL-cholesterol and for total Se concentrations at baseline, 6 months and 5 years. The effect of different doses of Se supplementation on plasma lipid and Se concentrations was estimated by using linear mixed models. Plasma Se concentration increased significantly and dose-dependently in the intervention groups after 6 months and 5 years. Total cholesterol decreased significantly both in the intervention groups and in the placebo group after 6 months and 5 years, with small and nonsignificant differences in changes in plasma concentration of total cholesterol, HDL-cholesterol, non-HDL-cholesterol and total:HDL-cholesterol ratio between intervention and placebo groups. The effect of long-term supplementation with Se on plasma cholesterol concentrations or its sub-fractions did not differ significantly from placebo in this elderly population.

  18. Serum amyloid A impairs the antiinflammatory properties of HDL

    PubMed Central

    Han, Chang Yeop; Tang, Chongren; Guevara, Myriam E.; Wei, Hao; Wietecha, Tomasz; Shao, Baohai; Subramanian, Savitha; Omer, Mohamed; Wang, Shari; O’Brien, Kevin D.; Marcovina, Santica M.; Wight, Thomas N.; Vaisar, Tomas; de Beer, Maria C.; de Beer, Frederick C.; Osborne, William R.; Elkon, Keith B.; Chait, Alan

    2015-01-01

    HDL from healthy humans and lean mice inhibits palmitate-induced adipocyte inflammation; however, the effect of the inflammatory state on the functional properties of HDL on adipocytes is unknown. Here, we found that HDL from mice injected with AgNO3 fails to inhibit palmitate-induced inflammation and reduces cholesterol efflux from 3T3-L1 adipocytes. Moreover, HDL isolated from obese mice with moderate inflammation and humans with systemic lupus erythematosus had similar effects. Since serum amyloid A (SAA) concentrations in HDL increase with inflammation, we investigated whether elevated SAA is a causal factor in HDL dysfunction. HDL from AgNO3-injected mice lacking Saa1.1 and Saa2.1 exhibited a partial restoration of antiinflammatory and cholesterol efflux properties in adipocytes. Conversely, incorporation of SAA into HDL preparations reduced antiinflammatory properties but not to the same extent as HDL from AgNO3-injected mice. SAA-enriched HDL colocalized with cell surface–associated extracellular matrix (ECM) of adipocytes, suggesting impaired access to the plasma membrane. Enzymatic digestion of proteoglycans in the ECM restored the ability of SAA-containing HDL to inhibit palmitate-induced inflammation and cholesterol efflux. Collectively, these findings indicate that inflammation results in a loss of the antiinflammatory properties of HDL on adipocytes, which appears to partially result from the SAA component of HDL binding to cell-surface proteoglycans, thereby preventing access of HDL to the plasma membrane. PMID:26642365

  19. Serum amyloid A impairs the antiinflammatory properties of HDL.

    PubMed

    Han, Chang Yeop; Tang, Chongren; Guevara, Myriam E; Wei, Hao; Wietecha, Tomasz; Shao, Baohai; Subramanian, Savitha; Omer, Mohamed; Wang, Shari; O'Brien, Kevin D; Marcovina, Santica M; Wight, Thomas N; Vaisar, Tomas; de Beer, Maria C; de Beer, Frederick C; Osborne, William R; Elkon, Keith B; Chait, Alan

    2016-01-01

    HDL from healthy humans and lean mice inhibits palmitate-induced adipocyte inflammation; however, the effect of the inflammatory state on the functional properties of HDL on adipocytes is unknown. Here, we found that HDL from mice injected with AgNO3 fails to inhibit palmitate-induced inflammation and reduces cholesterol efflux from 3T3-L1 adipocytes. Moreover, HDL isolated from obese mice with moderate inflammation and humans with systemic lupus erythematosus had similar effects. Since serum amyloid A (SAA) concentrations in HDL increase with inflammation, we investigated whether elevated SAA is a causal factor in HDL dysfunction. HDL from AgNO3-injected mice lacking Saa1.1 and Saa2.1 exhibited a partial restoration of antiinflammatory and cholesterol efflux properties in adipocytes. Conversely, incorporation of SAA into HDL preparations reduced antiinflammatory properties but not to the same extent as HDL from AgNO3-injected mice. SAA-enriched HDL colocalized with cell surface-associated extracellular matrix (ECM) of adipocytes, suggesting impaired access to the plasma membrane. Enzymatic digestion of proteoglycans in the ECM restored the ability of SAA-containing HDL to inhibit palmitate-induced inflammation and cholesterol efflux. Collectively, these findings indicate that inflammation results in a loss of the antiinflammatory properties of HDL on adipocytes, which appears to partially result from the SAA component of HDL binding to cell-surface proteoglycans, thereby preventing access of HDL to the plasma membrane. PMID:26642365

  20. Isolation and partial characterization of high-density lipoprotein HDL1 from rat plasma by gradient centrifugation.

    PubMed Central

    Lusk, L T; Walker, L F; DuBien, L H; Getz, G S

    1979-01-01

    The lipoproteins isolated from rat plasma by flotation in the density range 1.019-1.063 g/ml were further characterized. Using rate zonal ultracentrifugation, we isolated two lipoproteins in almost equal proportions from this density range. Similar isolations may be accomplished with density gradients in a swinging-bucket rotor. On isopycnic-density-gradient ultracentrifugation one component banded at rho = 1.031 g/ml and the other at rho = 1.054 g/ml. More that 98% of the apoprotein of the lighter component was B protein, and hence this particle is LD (low-density) lipoprotein. Of the apoproteins of the rho = 1.054 g/ml particles, designated lipoprotein HDL1, over 60% was arginine-rich peptide, and the remainder was A-I, A-IV and C peptides. The molecular weight of these lipoproteins determined by agarose column chromatography was 2.36 x 10(6) for LD lipoprotein and 1.30 x 10(6) for lipoprotein HDL1. On electron microscopy the radius of LD lipoprotein was 14.0 nm and that of lipoprotein HDL1 was 10.0 nm, in contrast with molecular radii of 10.4 nm and 8.4 nm respectively determined from the gel-permeation-chromatography data. The lipid and phospholipid composition of both particles was determined. Lipoprotein HDL1 was notable for both the concentration of its esterified cholesterol, which was similar to that of LD lipoprotein, and the low triacylglycerol content, resembling that of HD lipoprotein. The possible origin of lipoprotein HDL1 is discussed. Images Fig. 1. PMID:230819

  1. Coffee intake can promote activity of antioxidant enzymes with increasing MDA level and decreasing HDL-cholesterol in physically trained rats.

    PubMed

    Choi, Eun-Young; Jang, Jin-Young; Cho, Youn-Ok

    2010-08-01

    This study investigated the effect of coffee intake and exercise on the antioxidative activity and plasma cholesterol profile of physically trained rats while they were exercising. Forty eight rats were under either the control diet with water (C) or control diet with coffee (CF) and at the same time they were given physical training for 4 weeks. In terms of physical training, the rats were exercised on a treadmill for 30 minutes everyday. At the end of 4 weeks, animals in each dietary group were subdivided into 3 groups: before-exercise (BE); during-exercise (DE); after-exercise (AE). Animals in the DE group were exercised on a treadmill for one hour, immediately before being sacrificed. Animals in the AE group were allowed to take a rest for one hour after exercise. TG levels were significantly high in coffee intake group than in control group. Also TG level of AE group was significantly higher than that of BE group. Exercise and coffee-exercise interaction effects were significant in total cholesterol (P = 0.0004, 0.0170). The AE of coffee intake group showed highest total cholesterol levels. HDL-cholesterol was significantly lower in coffee intake group than in control group. Coffee, exercise, and coffee-exercise interaction effects were significant in SOD (P = 0.0001, 0.0001, and 0.0001). The AE and BE of coffee intake group showed higher SOD levels than the other four groups. Catalase activities were significantly higher in coffee intake group than control group. No significant main effect was found in GSH/GSSG. Coffee, exercise, and coffee-exercise interaction effects were significant in MDA levels (P = 0.0464, 0.0016, and 0.0353). The DE and AE of coffee intake group and the DE of control group showed higher MDA levels than the BE of control group. Therefore, coffee intake can promote activities of antioxidant enzyme but it also increases MDA and decreases HDL-cholesterol in physically trained rats.

  2. Coffee intake can promote activity of antioxidant enzymes with increasing MDA level and decreasing HDL-cholesterol in physically trained rats

    PubMed Central

    Choi, Eun-Young; Jang, Jin-Young

    2010-01-01

    This study investigated the effect of coffee intake and exercise on the antioxidative activity and plasma cholesterol profile of physically trained rats while they were exercising. Forty eight rats were under either the control diet with water (C) or control diet with coffee (CF) and at the same time they were given physical training for 4 weeks. In terms of physical training, the rats were exercised on a treadmill for 30 minutes everyday. At the end of 4 weeks, animals in each dietary group were subdivided into 3 groups: before-exercise (BE); during-exercise (DE); after-exercise (AE). Animals in the DE group were exercised on a treadmill for one hour, immediately before being sacrificed. Animals in the AE group were allowed to take a rest for one hour after exercise. TG levels were significantly high in coffee intake group than in control group. Also TG level of AE group was significantly higher than that of BE group. Exercise and coffee-exercise interaction effects were significant in total cholesterol (P = 0.0004, 0.0170). The AE of coffee intake group showed highest total cholesterol levels. HDL-cholesterol was significantly lower in coffee intake group than in control group. Coffee, exercise, and coffee-exercise interaction effects were significant in SOD (P = 0.0001, 0.0001, and 0.0001). The AE and BE of coffee intake group showed higher SOD levels than the other four groups. Catalase activities were significantly higher in coffee intake group than control group. No significant main effect was found in GSH/GSSG. Coffee, exercise, and coffee-exercise interaction effects were significant in MDA levels (P = 0.0464, 0.0016, and 0.0353). The DE and AE of coffee intake group and the DE of control group showed higher MDA levels than the BE of control group. Therefore, coffee intake can promote activities of antioxidant enzyme but it also increases MDA and decreases HDL-cholesterol in physically trained rats. PMID:20827343

  3. Comparison of NCEP performance specifications for triglycerides, HDL-, and LDL-cholesterol with operating specifications based on NCEP clinical and analytical goals.

    PubMed

    Fallest-Strobl, P C; Olafsdottir, E; Wiebe, D A; Westgard, J O

    1997-11-01

    The National Cholesterol Education Program (NCEP) performance specifications for methods that measure triglycerides, HDL-cholesterol, and LDL-cholesterol have been evaluated by deriving operating specifications from the NCEP analytical total error requirements and the clinical requirements for interpretation of the tests. We determined the maximum imprecision and inaccuracy that would be allowable to control routine methods with commonly used single and multirule quality-control procedures having 2 and 4 control measurements per run, and then compared these estimates with the NCEP guidelines. The NCEP imprecision specifications meet the operating imprecision necessary to assure meeting the NCEP clinical quality requirements for triglycerides and HDL-cholesterol but not for LDL-cholesterol. More importantly, the NCEP imprecision specifications are not adequate to assure meeting the NCEP analytical total error requirements for any of these three tests. Our findings indicate that the NCEP recommendations fail to adequately consider the quality-control requirements necessary to detect medically important systematic errors.

  4. Metabolism of HDL and its regulation.

    PubMed

    Kardassis, D; Mosialou, I; Kanaki, M; Tiniakou, I; Thymiakou, E

    2014-01-01

    Epidemiological studies have shown that low plasma levels of High Density Lipoprotein Cholesterol (HDL-C) are associated with an increased risk for myocardial infarction. These studies suggested that by increasing HDL-C levels one could reduce cardiovascular risk. However, emerging evidence from studies in animals and humans indicate that high levels of HDL-C are not sufficient to confer atheroprotection but that the functionality of the HDL particles is equally important. The picture is complicated further by the finding that HDL functionality is compromised in patients with chronic inflammatory diseases such as Coronary Artery Disease (CAD), diabetes and rheumatoid arthritis. Despite these obstacles, HDL raising is still a promising strategy for the reduction of CAD risk. Low HDL-C can be caused by inactivating mutations in apoA-I, ATP Binding Cassette Transporter A1 (ABCA1) or Lecithin-Cholesterol Acyl Transferase (LCAT) which affect HDL biogenesis and maturation whereas high HDL-C can be caused by mutations in Cholesteryl Ester Transfer Protein (CETP) or Scavenger receptor Class B Type I (SR-BI). Recent studies suggest that heterogeneity in HDL levels in the population is polygenic in origin. One approach to raise plasma HDL-C is to increase the rate of HDL biosynthesis by capitalizing on the mechanisms that control the transcription of genes that play key roles in HDL biogenesis. We review some of the genetic and non-genetic factors that affect plasma HDL levels and functions and discuss the mechanisms that regulate HDL metabolism at the level of gene transcription in the liver focusing on apoA-I, ABCA1 and apoM. PMID:24606515

  5. Relationship between plasma cholesterol levels and cholesterol esterification in isolated human mononuclear cells

    SciTech Connect

    Dallongeville, J.; Davignon, J.; Lussier-Cacan, S. )

    1990-01-01

    The authors studied the relationship between plasma lipoprotein concentrations and cholesterol esterification in freshly isolated human mononuclear cells from 27 normolipidemic and 32 hyperlipidemic individuals. Cells were either incubated for 5 hours with radiolabeled oleate immediately after isolation or were preincubated for 18 hours in the presence of exogenous cholesterol, and then incubated with ({sup 14}C)sodium-oleate-albumin complex. In the absence of exogenous cholesterol, control and hypercholesterolemic subjects had similarly low values of intracellular cholesterol esterification. In the presence of exogenous cholesterol, both hypertriglyceridemic and hypercholesterolemic subjects had higher cholesterol esterification than controls. There was a significant correlation between the rate of cholesterol esterification and plasma total cholesterol. These results suggest that plasma cholesterol levels may regulate mononuclear cell intra-cellular cholesterol esterification in humans.

  6. Soy protein with or without isoflavones, soy germ and soy germ extract, and daidzein lessen plasma cholesterol levels in golden Syrian hamsters.

    PubMed

    Song, Tongtong; Lee, Sun-Ok; Murphy, Patricia A; Hendrich, Suzanne

    2003-10-01

    Dietary isolated soy protein (ISP, containing approximately equal amounts of daidzein and genistein), ethanol-extracted ISP (ISP (-)), soygerm or soygerm extract (containing large amounts of daidzein and glycitein and little genistein) and the isoflavone, daidzein, were hypothesized to lessen plasma cholesterol in comparison with casein. Sixty male and 60 female golden Syrian hamsters (6-8 weeks of age) were randomly assigned to six treatments fed for 10 weeks. Four of the experimental diets (ISP, daidzein, soygerm, and soygerm extract) contained 1.3 mmol total isoflavones/kg. The ISP (-) diet contained 0.013 mmol isoflavone/kg, whereas the casein diet contained no isoflavones. Hamsters fed ISP, ISP (-), daidzein, soygerm, and soygerm extract had significantly less plasma total cholesterol (by 16%-28%), less non-HDL cholesterol (by 15%-50%) and less non-HDL/HDL cholesterol ratios compared with hamsters fed casein (P < 0.01). For male hamsters, there were no differences among treatments in plasma HDL concentrations. Female hamsters fed ISP (-) had significantly greater HDL levels (P < 0.01) than females fed casein or daidzein. Triglyceride concentration was significantly less in hamsters fed ISP (-) compared with the casein-fed females. Because soy protein with or without isoflavones, soygerm and soygerm extract, and daidzein lessened plasma cholesterol to an approximately equal extent, soy protein alone, varying mixtures of isoflavones, and other extractable components of soy are responsible for cholesterol-lessening effects of soy foods, mainly due to their effects to lessen LDL cholesterol.

  7. Correlation between high density lipoprotein-cholesterol and remodeling index in patients with coronary artery disease: IDEAS (IVUS diagnostic evaluation of atherosclerosis in Singapore)-HDL study.

    PubMed

    Lee, Chi-Hang; Tai, Bee-Choo; Lim, Gek-Hsiang; Chan, Mark Y; Low, Adrian F; Tan, Kathryn C; Chia, Boon-Lock; Tan, Huay-Cheem

    2012-01-01

    Serum level of high density lipoprotein (HDL)-cholesterol is associated with risk of coronary artery disease. We correlated the serum level of cholesterol with coronary artery remodeling index of patients with coronary artery disease. A total of 120 patients with de novo lesions located in native coronary artery were studied. Remodeling index was based on intravascular ultrasound (IVUS) interrogation of the lesions using the static approach, and was defined as external elastic membrane (EEM) area at lesion/average EEM area at proximal and distal reference segments. The average remodeling index was 0.9 (SD: 0.2). The remodeling index was not associated with any of the demographic and coronary risk factors. Stable angina was associated with a low remodeling index. Remodeling index correlated with white blood cell count and HDL-cholesterol, but not with total cholesterol, LDL-cholesterol and triglyceride. In the multiple linear regression analysis, HDL-cholesterol and procedure indication were the only 2 significant predictors of remodeling index. An increase of 1 mg/dL of HDL-cholesterol resulted in a decrease of 0.003 (95% CI: 0.0001, 0.007; P = 0.046) in remodeling index, after adjusting for procedural indications. When stratified according to diabetic status, the negative correlation persisted in non-diabetic (P = 0.023), but not in diabetic, patients (P = 0.707). We found a negative correlation between HDL-cholesterol level and remodeling index. Diabetic status may have an influence on the observed relationship. PMID:21197580

  8. The serum LDL/HDL cholesterol ratio is influenced more favorably by exchanging saturated with unsaturated fat than by reducing saturated fat in the diet of women.

    PubMed

    Müller, Hanne; Lindman, Anja S; Brantsaeter, Anne Lise; Pedersen, Jan I

    2003-01-01

    We compared the effects of a high fat diet [38.4% of energy (E%) from fat; HSAFA diet, polyunsaturated/saturated fatty acid (P/S) ratio = 0.14], a low fat diet (19.7 E% from fat; LSAFA diet, P/S = 0.17), both based on coconut oil, and a diet with a high content of mono- and polyunsaturated fatty acids (PUFA; 38.2 E% from fat; HUFA diet, P/S = 1.9) on serum lipoproteins. The 25 women studied consumed each diet for 3-wk periods in a crossover design. The two high fat diets were identical except for the quality of the test fat. The LSAFA diet was identical to the HSAFA diet except that half the fat was replaced by carbohydrates. Serum total cholesterol, LDL cholesterol and apoB concentrations did not differ between the HSAFA and the LSAFA diet periods. Total cholesterol, LDL cholesterol and apoB were lower when women consumed the HUFA diet than when they consumed the other two diets. HDL cholesterol and apoA-I were 15 and 11%, respectively, higher when women consumed the HSAFA diet than when they consumed the LSAFA diet; HDL cholesterol and apoA-I were lower when women consumed the HUFA diet than when they consumed the HSAFA diet, but not the LSAFA diet. The LDL cholesterol/HDL cholesterol and apoB/apoA-I ratios were higher when women consumed the LSAFA diet than when they consumed the HSAFA diet. The LDL/HDL cholesterol ratio was higher when women consumed either the LSAFA or the HSAFA diet than when they consumed the HUFA diet, whereas apoB/apoA-I was higher when women consumed the LSAFA diet than when they consumed the HUFA diet. Triacylglycerol and VLDL cholesterol were higher when women consumed the LSAFA diet than when they consumed either the HSAFA or the HUFA diet. We conclude that, to influence the LDL/HDL cholesterol ratio, changing the proportions of dietary fatty acids may be more important than restricting the percentage of total or saturated fat energy, at least when derived mainly from lauric and myristic acids, both of which increase HDL cholesterol.

  9. Extra Virgin Olive Oil Polyphenols Promote Cholesterol Efflux and Improve HDL Functionality

    PubMed Central

    Berrougui, Hicham; Ikhlef, Souad; Khalil, Abdelouahed

    2015-01-01

    Results of the present work give evidence from the beneficial role of extra virgin olive of oil (EVOO) consumption towards oxidative stress and cardiovascular diseases. Polyphenols contained in EVOO are responsible for inhibiting lipoproteins oxidative damages and promoting reverse cholesterol transport process via ABCA1 pathway. PMID:26495005

  10. Postmenopausal Women Have Higher HDL and Decreased Incidence of Low HDL than Premenopausal Women with Metabolic Syndrome

    PubMed Central

    Fernandez, Maria Luz; Murillo, Ana Gabriela

    2016-01-01

    It is well known that plasma lipids, waist circumference (WC) and blood pressure (BP) increase following menopause. In addition, there is a perceived notion that plasma high-density lipoprotein-cholesterol (HDL-C) concentrations also decrease in postmenopausal women. In this cross-sectional study, we evaluated plasma lipids, fasting glucose, anthropometrics and BP in 88 post and 100 pre-menopausal women diagnosed with metabolic syndrome. No differences were observed in plasma low-density lipoprotein-cholesterol cholesterol, triglycerides, fasting glucose or systolic and diastolic BP between groups. However, plasma HDL-C was higher (p < 0.01) in postmenopausal women and the percentage of women who had low HDL (<50 mg/dL) was higher (p < 0.01) among premenopausal women. In addition, negative correlations were found between WC and HDL-C (r = −0.148, p < 0.05) and BMI and HDL-C (r = −0.258, p < 0.01) for all subjects indicating that increases in weight and abdominal fat have a deleterious effect on plasma HDL-C. Interestingly, there was a positive correlation between age and plasma HDL-C (r = 0.237 p < 0.01). The results from this study suggest that although HDL is decreased by visceral fat and overall weight, low HDL is not a main characteristic of metabolic syndrome in postmenopausal women. Further, HDL appears to increase, not decrease, with age. PMID:27417608

  11. Postmenopausal Women Have Higher HDL and Decreased Incidence of Low HDL than Premenopausal Women with Metabolic Syndrome.

    PubMed

    Fernandez, Maria Luz; Murillo, Ana Gabriela

    2016-01-01

    It is well known that plasma lipids, waist circumference (WC) and blood pressure (BP) increase following menopause. In addition, there is a perceived notion that plasma high-density lipoprotein-cholesterol (HDL-C) concentrations also decrease in postmenopausal women. In this cross-sectional study, we evaluated plasma lipids, fasting glucose, anthropometrics and BP in 88 post and 100 pre-menopausal women diagnosed with metabolic syndrome. No differences were observed in plasma low-density lipoprotein-cholesterol cholesterol, triglycerides, fasting glucose or systolic and diastolic BP between groups. However, plasma HDL-C was higher (p < 0.01) in postmenopausal women and the percentage of women who had low HDL (<50 mg/dL) was higher (p < 0.01) among premenopausal women. In addition, negative correlations were found between WC and HDL-C (r = -0.148, p < 0.05) and BMI and HDL-C (r = -0.258, p < 0.01) for all subjects indicating that increases in weight and abdominal fat have a deleterious effect on plasma HDL-C. Interestingly, there was a positive correlation between age and plasma HDL-C (r = 0.237 p < 0.01). The results from this study suggest that although HDL is decreased by visceral fat and overall weight, low HDL is not a main characteristic of metabolic syndrome in postmenopausal women. Further, HDL appears to increase, not decrease, with age. PMID:27417608

  12. Plasma lipids, lipoprotein metabolism and HDL lipid transfers are equally altered in metabolic syndrome and in type 2 diabetes.

    PubMed

    Silva, Vanessa M; Vinagre, Carmen G C; Dallan, Luis A O; Chacra, Ana P M; Maranhão, Raul C

    2014-07-01

    Metabolic syndrome (MetS) refers to states of insulin resistance that predispose to development of cardiovascular disease and type 2 diabetes (T2DM). The aim was to investigate whether plasma lipids and lipid metabolism differ in MetS patients compared to those with T2DM with poor glycemic control (glycated hemoglobin > 7.0). Eighteen patients with T2DM, 18 with MetS and 14 controls, paired for age (40-70 years) and body mass index (BMI), were studied. Plasma lipids and the kinetics of a triacylglycerol-rich emulsion labeled with [(3)H]-triolein ([(3)H]-TAG) and [(14)C]-cholesteryl esters ([(14)C]-CE) injected intravenously followed by one-hour blood sampling were determined. Lipid transfers from an artificial nanoemulsion donor to high-density lipoprotien (HDL) were assayed in vitro. Low-density lipoprotein (LDL) and HDL cholesterol (mg/dl) were not different in T2DM (128 ± 7; 42 ± 7) and MetS (142 ± 6; 39 ± 3), but triacylglycerols were even higher in MetS (215 ± 13) than in T2DM (161 ±11, p < 0.05). Fractional clearance rate (FCR, in min(1)) of [(3)H]-TAG and [(14)C]-CE were equal in T2DM (0.008 ± 0.018; 0.005 ± 0.024) and MetS (0.010 ± 0.016; 0.006 ± 0.013), and both were reduced compared to controls. The transfer of non-esterified cholesterol, phospholipids and triacylglycerols to HDL was higher in MetS and T2DM than in controls (p < 0.01). Cholesteryl ester transfer and HDL size were equal in all groups. Results imply that MetS is equal to poorly controlled T2DM concerning the disturbances of plasma lipid metabolism examined here, and suggest that there are different thresholds for the insulin action on glucose and lipids. These findings highlight the magnitude of the lipid disturbances in MetS, and may have implications in the prevention of cardiovascular diseases. PMID:24719245

  13. Plasma lipids, lipoprotein metabolism and HDL lipid transfers are equally altered in metabolic syndrome and in type 2 diabetes.

    PubMed

    Silva, Vanessa M; Vinagre, Carmen G C; Dallan, Luis A O; Chacra, Ana P M; Maranhão, Raul C

    2014-07-01

    Metabolic syndrome (MetS) refers to states of insulin resistance that predispose to development of cardiovascular disease and type 2 diabetes (T2DM). The aim was to investigate whether plasma lipids and lipid metabolism differ in MetS patients compared to those with T2DM with poor glycemic control (glycated hemoglobin > 7.0). Eighteen patients with T2DM, 18 with MetS and 14 controls, paired for age (40-70 years) and body mass index (BMI), were studied. Plasma lipids and the kinetics of a triacylglycerol-rich emulsion labeled with [(3)H]-triolein ([(3)H]-TAG) and [(14)C]-cholesteryl esters ([(14)C]-CE) injected intravenously followed by one-hour blood sampling were determined. Lipid transfers from an artificial nanoemulsion donor to high-density lipoprotien (HDL) were assayed in vitro. Low-density lipoprotein (LDL) and HDL cholesterol (mg/dl) were not different in T2DM (128 ± 7; 42 ± 7) and MetS (142 ± 6; 39 ± 3), but triacylglycerols were even higher in MetS (215 ± 13) than in T2DM (161 ±11, p < 0.05). Fractional clearance rate (FCR, in min(1)) of [(3)H]-TAG and [(14)C]-CE were equal in T2DM (0.008 ± 0.018; 0.005 ± 0.024) and MetS (0.010 ± 0.016; 0.006 ± 0.013), and both were reduced compared to controls. The transfer of non-esterified cholesterol, phospholipids and triacylglycerols to HDL was higher in MetS and T2DM than in controls (p < 0.01). Cholesteryl ester transfer and HDL size were equal in all groups. Results imply that MetS is equal to poorly controlled T2DM concerning the disturbances of plasma lipid metabolism examined here, and suggest that there are different thresholds for the insulin action on glucose and lipids. These findings highlight the magnitude of the lipid disturbances in MetS, and may have implications in the prevention of cardiovascular diseases.

  14. An interaction between the TaqIB polymorphism of cholesterol ester transfer protein and smoking is associated with changes in plasma high-density lipoprotein cholesterol levels in Turks.

    PubMed

    Hodoğlugil, U; Williamson, D W; Huang, Y; Mahley, R W

    2005-08-01

    Low levels of high-density lipoprotein cholesterol (HDL-C) are an independent risk factor for atherosclerosis. We investigated the effects of the TaqIB polymorphism of cholesterol ester transfer protein (CETP) on CETP activity and plasma HDL-C levels in random nondiabetic and self-reported diabetic subjects in a population with very low HDL-C levels. The rare B2B2 genotype was associated with significantly higher HDL-C levels and lower CETP activity in random subjects and with higher HDL-C in diabetic subjects. After stratification of random subjects by smoking status, the common B1B1 genotype was associated with lower HDL-C levels than the B2B2 genotype. Although smoking was associated with lower HDL-C, especially in men, HDL-C levels between smokers and nonsmokers were not different in subjects with the B1B2 or B2B2 genotypes. However, smoking (20+ cigarettes/day) was associated with a marked reduction in HDL-C in the B1B1 subjects. The B1B1/smoking interaction was not reflected in a difference in CETP activity. High triglycerides and elevated body mass index (BMI) lower HDL-C. The B2B2 genotype was associated with the highest HDL-C levels, and these levels were significantly lower in the hypertriglyceridemic subjects (>or=50th percentile). The lowest HDL-C levels were seen in hypertriglyceridemic subjects with the B1B1 genotype. Although BMI (>or=50th vs<50th percentile) did not affect HDL-C in B2B2 subjects, a high BMI was associated with markedly lower HDL-C in B1B1 subjects. Thus, HDL-C levels in Turks may be modulated by an interaction between the CETP TaqIB polymorphism and smoking, as well as an interaction with hypertriglyceridemia and BMI.

  15. Betatrophin Acts as a Diagnostic Biomarker in Type 2 Diabetes Mellitus and Is Negatively Associated with HDL-Cholesterol

    PubMed Central

    Yi, Min; Chen, Rong-ping; Yang, Rui; Guo, Xian-feng; Zhang, Jia-chun; Chen, Hong

    2015-01-01

    Objective. By assessing its circulating concentrations in type 2 diabetes mellitus (T2DM) patients, we aimed to explore the associations of betatrophin with various metabolic parameters and evaluate its diagnostic value in T2DM. Methods. A total of 58 non-diabetes-mellitus (NDM) subjects and 73 age- and sex-matched newly diagnosed T2DM patients were enrolled. Correlation analyses between circulating betatrophin levels and multiple metabolic parameters were performed. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic value of betatrophin concentration in T2DM. Results. Circulating betatrophin levels were approximately 1.8 times higher in T2DM patients than in NDM individuals (median 747.12 versus 407.41 pg/mL, P < 0.001). Correlation analysis showed that betatrophin was negatively associated with high-density lipoprotein cholesterol (HDL-C) levels in all subjects. ROC curve analysis identified betatrophin as a potent diagnostic biomarker for T2DM. The optimal cut-off point of betatrophin concentration for predicting T2DM was 501.23 pg/mL. Conclusions. Serum betatrophin levels were markedly increased in newly diagnosed T2DM patients and further elevated in obese T2DM subjects. Betatrophin was negatively correlated with HDL-C levels. Our findings indicate that betatrophin could be a potent diagnostic biomarker for T2DM. PMID:26819617

  16. Human plasma lecithin-cholesterol acyltransferase

    SciTech Connect

    Jauhiainen, M.; Stevenson, K.J.; Dolphin, P.J.

    1988-05-15

    Lecithin-cholesterol acyltransferase (LCAT) is a plasma enzyme which catalyzes the transacylation of the fatty acid at the sn-2 position of lecithin to cholesterol forming lysolecithin and cholesteryl ester. The substrates for and products of this reaction are present within the plasma lipoproteins upon which the enzyme acts to form the majority of cholesteryl ester in human plasma. The authors proposed a covalent catalytic mechanism of action for LCAT in which serine and histidine residues mediate lecithin cleavage and two cysteine residues cholesterol esterification. With the aid of sulfhydryl reactive trivalent organoarsenical compounds which are specific for vicinal thiols they have probed the geometry of the catalytic site. They conclude that the two catalytic cysteine residues of LCAT (Cys/sup 31/ and Cys /sup 184/) are vicinal with a calculated distance between their sulfur atoms of 3.50-3.62 A. The additional residue alkylated by teh bifunctional reagent is within the catalytic site and may represent a previously identified catalytic serine or histidine residue.

  17. Effect of dietary cholesterol with or without saturated fat on plasma lipoprotein cholesterol levels in the laboratory opossum (Monodelphis domestica) model for diet-induced hyperlipidaemia.

    PubMed

    Kushwaha, Rampratap S; VandeBerg, Jane F; VandeBerg, John L

    2004-07-01

    Laboratory opossums (Monodelphis domestica) show extreme genetic variability in their responsiveness to dietary lipids; a great proportion of the genetic variability in responsiveness is due to a single major gene. To determine whether the major gene for dietary response detected by genetic analysis in opossums is responsive to dietary cholesterol or dietary saturated fat, or a combination of both, we used males and females of susceptible and resistant lines of laboratory opossums that were 5 to 7 months old. The animals were challenged with three different experimental diets (high-cholesterol diets with or without high saturated fat from lard or coconut oil) and plasma lipoproteins were measured. Plasma and VLDL+LDL-cholesterol concentrations increased several-fold when the animals were fed the diet containing elevated cholesterol (P<0.001) or elevated cholesterol and fat (P<0.001) and differed between the two lines when they were fed high-cholesterol diets with or without fat (P<0.001). Plasma HDL-cholesterol concentrations were higher (P<0.05) in animals of the resistant line than in the susceptible line when they were fed the basal diet (550 (SEM 30) v. 440 (SEM 20) mg/l) and when they were fed the low-cholesterol and high-fat diet (600 (SEM 30) v. 490 (SEM 30) mg/l). Dietary coconut oil and lard had similar effects on plasma lipoprotein cholesterol concentrations in the susceptible line of opossums. A reduction in dietary cholesterol by 50 % with either the lard or coconut oil blunted the plasma cholesterol response. The results from the present studies suggest that the major gene for dietary response previously detected by genetic analysis in laboratory opossums affects the response to dietary cholesterol but not to saturated fat.

  18. Consumption of olive oil has opposite effects on plasma total cholesterol and sphingomyelin concentrations in rats.

    PubMed

    Geelen, M J; Beynen, A C

    2000-05-01

    The hypothesis that olive-oil consumption alters plasma sphingomyelin concentrations and hepatic sphingomyelin metabolism was tested. Rats were fed on purified, high-cholesterol diets with either coconut fat or olive-oil (180 g/kg). In accordance with previous work, olive-oil v. coconut-fat consumption significantly elevated hepatic and total plasma cholesterol concentrations. During the course of the experiment, the concentration of plasma sphingomyelin rose in the coconut-fat group and remained constant in the olive-oil group. When compared with the coconut-fat-fed group, the plasma sphingomyelin levels were significantly lower in the olive-oil-fed group after 14 and 21 d of treatment. Dietary olive oil raised the amounts of cholesterol and sphingomyelin in the VLDL density region, and this change was associated with a reduction in the cholesterol and sphingomyelin contents of the LDL and HDL density ranges. Olive-oil consumption reduced the activity of serine palmitoyltransferase, while the activities of phosphatidylcholine:ceramide cholinephosphotransferase and phosphatidylethanolamine:ceramide ethanolaminephosphotransferase were left unchanged. Dietary olive oil also enhanced the activity of acidic sphingomyelinase, but not that of neutral sphingomyelinase. The present data indicate that dietary olive oil v. coconut fat has opposite effects on total plasma cholesterol and sphingomyelin concentrations. The lower plasma sphingomyelin levels observed in olive-oil-fed, as compared with coconut-fat-fed rats, may be explained by a simultaneous elevation and reduction in sphingomyelin catabolism and synthesis respectively, as based on the measured enzyme activities.

  19. Anacetrapib and dalcetrapib differentially alters HDL metabolism and macrophage-to-feces reverse cholesterol transport at similar levels of CETP inhibition in hamsters.

    PubMed

    Briand, François; Thieblemont, Quentin; Muzotte, Elodie; Burr, Noémie; Urbain, Isabelle; Sulpice, Thierry; Johns, Douglas G

    2014-10-01

    Cholesteryl ester transfer protein (CETP) inhibitors dalcetrapib and anacetrapib differentially alter LDL- and HDL-cholesterol levels, which might be related to the potency of each drug to inhibit CETP activity. We evaluated the effects of both drugs at similar levels of CETP inhibition on macrophage-to-feces reverse cholesterol transport (RCT) in hamsters. In normolipidemic hamsters, both anacetrapib 30 mg/kg QD and dalcetrapib 200 mg/kg BID inhibited CETP activity by ~60%. After injection of 3H-cholesteryl oleate labeled HDL, anacetrapib and dalcetrapib reduced HDL-cholesteryl esters fractional catabolic rate (FCR) by 30% and 26% (both P<0.001 vs. vehicle) respectively, but only dalcetrapib increased HDL-derived 3H-tracer fecal excretion by 30% (P<0.05 vs. vehicle). After 3H-cholesterol labeled macrophage intraperitoneal injection, anacetrapib stimulated 3H-tracer appearance in HDL, but both drugs did not promote macrophage-derived 3H-tracer fecal excretion. In dyslipidemic hamsters, both anacetrapib 1 mg/kg QD and dalcetrapib 200 mg/kg BID inhibited CETP activity by ~65% and reduced HDL-cholesteryl ester FCR by 36% (both P<0.001 vs. vehicle), but only anacetrapib increased HDL-derived 3H-tracer fecal excretion significantly by 39%. After 3H-cholesterol labeled macrophage injection, only anacetrapib 1 mg/kg QD stimulated macrophage-derived 3H-tracer appearance in HDL. These effects remained weaker than those observed with anacetrapib 60 mg/kg QD, which induced a maximal inhibition of CETP and stimulation of macrophage-derived 3H-tracer fecal excretion. In contrast, dalcetrapib 200 mg/kg BID reduced macrophage-derived 3H-tracer fecal excretion by 23% (P<0.05 vs. vehicle). In conclusion, anacetrapib and dalcetrapib differentially alter HDL metabolism and RCT in hamsters. A stronger inhibition of CETP may be required to promote macrophage-to-feces reverse cholesterol transport in dyslipidemic hamsters.

  20. HDL endocytosis and resecretion.

    PubMed

    Röhrl, Clemens; Stangl, Herbert

    2013-11-01

    HDL removes excess cholesterol from peripheral tissues and delivers it to the liver and steroidogenic tissues via selective lipid uptake without catabolism of the HDL particle itself. In addition, endocytosis of HDL holo-particles has been debated for nearly 40years. However, neither the connection between HDL endocytosis and selective lipid uptake, nor the physiological relevance of HDL uptake has been delineated clearly. This review will focus on HDL endocytosis and resecretion and its relation to cholesterol transfer. We will discuss the role of HDL endocytosis in maintaining cholesterol homeostasis in tissues and cell types involved in atherosclerosis, focusing on liver, macrophages and endothelium. We will critically summarize the current knowledge on the receptors mediating HDL endocytosis including SR-BI, F1-ATPase and CD36 and on intracellular HDL transport routes. Dependent on the tissue, HDL is either resecreted (retro-endocytosis) or degraded after endocytosis. Finally, findings on HDL transcytosis across the endothelial barrier will be summarized. We suggest that HDL endocytosis and resecretion is a rather redundant pathway under physiologic conditions. In case of disturbed lipid metabolism, however, HDL retro-endocytosis represents an alternative pathway that enables tissues to maintain cellular cholesterol homeostasis.

  1. HDL drug carriers for targeted therapy.

    PubMed

    Liu, Xing; Suo, Rong; Xiong, Sheng-Lin; Zhang, Qing-Hai; Yi, Guang-Hui

    2013-01-16

    Plasma concentrations of high-density lipoprotein cholesterol (HDL-C) are strongly and inversely associated with cardiovascular risk. HDL is not a simple lipid transporter, but possesses multiple anti-atherosclerosis activities because it contains special proteins, signaling lipid, and microRNAs. Natural or recombinant HDLs have emerged as potential carriers for delivering a drug to a specified target. However, HDL function also depends on enzymes that alter its structure and composition, as well as cellular receptors and membrane micro-domains that facilitate interactions with the microenvironment. In this review, four mechanisms predicted to enhance functions or targeted therapy of HDL in vivo are discussed. The first involves caveolae-mediated recruitment of HDL signal to bind their receptors. The second involves scavenger receptor class B type I (SR-BI) mediating anchoring and fluidity for signal-lipid of HDL. The third involves lecithin-cholesterol acyltransferase (LCAT) concentrating the signaling lipid at the surface of the HDL particle. The fourth involves microRNAs (miRNAs) being delivered in the blood to special targets by HDL. Exploitation of these four mechanisms will promote HDL to carry targeted drugs and increase HDL's clinical value. PMID:23063777

  2. Effect of ezetimibe on plasma cholesterol levels, cholesterol absorption, and secretion of biliary cholesterol in laboratory opossums with high and low responses to dietary cholesterol.

    PubMed

    Chan, Jeannie; Kushwaha, Rampratap S; Vandeberg, Jane F; Vandeberg, John L

    2008-12-01

    Partially inbred lines of laboratory opossums differ in plasma low-density lipoprotein cholesterol concentration and cholesterol absorption on a high-cholesterol diet. The aim of the present studies was to determine whether ezetimibe inhibits cholesterol absorption and eliminates the differences in plasma cholesterol and hepatic cholesterol metabolism between high and low responders on a high-cholesterol diet. Initially, we determined that the optimum dose of ezetimibe was 5 mg/(kg d) and treated 6 high- and 6 low-responding opossums with this dose (with equal numbers of controls) for 3 weeks while the opossums consumed a high-cholesterol and low-fat diet. Plasma and low-density lipoprotein cholesterol concentrations decreased significantly (P < .05) in treated but not in untreated high-responding opossums. Plasma cholesterol concentrations increased slightly (P < .05) in untreated low responders but not in treated low responders. The percentage of cholesterol absorption was significantly higher in untreated high responders than in other groups. Livers from high responders with or without treatment were significantly (P < .01) heavier than livers from low responders with or without treatment. Hepatic cholesterol concentrations in untreated high responders were significantly (P < .05) higher than those in low responders with or without treatment (P < .001). The gall bladder bile cholesterol concentrations in untreated high responders were significantly (P < .05) lower than those in other groups. A decrease in biliary cholesterol in low responders treated with ezetimibe was associated with a decrease in hepatic expression of ABCG5 and ABCG8. These studies suggest that ezetimibe decreases plasma cholesterol levels in high responders mainly by decreasing cholesterol absorption and increasing biliary cholesterol concentrations. Because ezetimibe's target is NPC1L1 and NPC1L1 is expressed in the intestine of opossums, its effect on cholesterol absorption may be mediated

  3. Rice bran oil and oryzanol reduce plasma lipid and lipoprotein cholesterol concentrations and aortic cholesterol ester accumulation to a greater extent than ferulic acid in hypercholesterolemic hamsters.

    PubMed

    Wilson, Thomas A; Nicolosi, Robert J; Woolfrey, Benjamin; Kritchevsky, David

    2007-02-01

    Our laboratory has reported that the hypolipidemic effect of rice bran oil (RBO) is not entirely explained by its fatty acid composition. Because RBO has a greater content of the unsaponifiables, which also lower cholesterol compared to most vegetable oils, we wanted to know whether oryzanol or ferulic acid, two major unsaponifiables in RBO, has a greater cholesterol-lowering activity. Forty-eight F(1)B Golden Syrian hamsters (Mesocricetus auratus) (BioBreeders, Watertown, MA) were group housed (three per cage) in cages with bedding in an air-conditioned facility maintained on a 12-h light/dark cycle. The hamsters were fed a chow-based hypercholesterolemic diet (HCD) containing 10% coconut oil and 0.1% cholesterol for 2 weeks, at which time they were bled after an overnight fast (16 h) and segregated into 4 groups of 12 with similar plasma cholesterol concentrations. Group 1 (control) continued on the HCD, group 2 was fed the HCD containing 10% RBO in place of coconut oil, group 3 was fed the HCD plus 0.5% ferulic acid and group 4 was fed the HCD plus 0.5% oryzanol for an additional 10 weeks. After 10 weeks on the diets, plasma total cholesterol (TC) and non-high-density lipoprotein cholesterol (HDL-C) (very low- and low-density lipoprotein) concentrations were significantly lower in the RBO (-64% and -70%, respectively), the ferulic acid (-22% and -24%, respectively) and the oryzanol (-70% and -77%, respectively) diets compared to control. Plasma TC and non-HDL-C concentrations were also significantly lower in the RBO (-53% and -61%, respectively) and oryzanol (-61% and -70%, respectively) diets compared to the ferulic acid. Compared to control and ferulic acid, plasma HDL-C concentrations were significantly higher in the RBO (10% and 20%, respectively) and oryzanol (13% and 24%, respectively) diets. The ferulic acid diet had significantly lower plasma HDL-C concentrations compared to the control (-9%). The RBO and oryzanol diets were significantly lower for

  4. Plasma lecithin:cholesterol acyltransferase and carotid intima-media thickness in European individuals at high cardiovascular risk

    PubMed Central

    Calabresi, Laura; Baldassarre, Damiano; Simonelli, Sara; Gomaraschi, Monica; Amato, Mauro; Castelnuovo, Samuela; Frigerio, Beatrice; Ravani, Alessio; Sansaro, Daniela; Kauhanen, Jussi; Rauramaa, Rainer; de Faire, Ulf; Hamsten, Anders; Smit, Andries J.; Mannarino, Elmo; Humphries, Steve E.; Giral, Philippe; Veglia, Fabrizio; Sirtori, Cesare R.; Franceschini, Guido; Tremoli, Elena

    2011-01-01

    Lecithin:cholesterol acyltransferase (LCAT) is the enzyme responsible for cholesterol esterification in plasma. LCAT is a major factor in HDL remodeling and metabolism, and it has long been believed to play a critical role in macrophage reverse cholesterol transport (RCT). The effect of LCAT on human atherogenesis is still controversial. In the present study, the plasma LCAT concentration was measured in all subjects (n = 540) not on drug treatment at the time of enrollment in the multicenter, longitudinal, observational IMPROVE study. Mean and maximum intima-media thickness (IMT) of the whole carotid tree was measured by B-mode ultrasonography in all subjects. In the entire cohort, LCAT quartiles were not associated with carotid mean and maximum IMT (P for trend 0.95 and 0.18, respectively), also after adjustment for age, gender, HDL-cholesterol (HDL-C), and triglycerides. No association between carotid IMT and LCAT quartiles was observed in men (P=0.30 and P=0.99 for mean and maximum IMT, respectively), whereas carotid IMT increased with LCAT quartiles in women (P for trend 0.14 and 0.019 for mean and maximum IMT, respectively). The present findings support the concept that LCAT is not required for an efficient reverse cholesterol transport and that a low plasma LCAT concentration and activity is not associated with increased atherosclerosis. PMID:21596929

  5. Decrease in plasma high-density lipoprotein cholesterol levels at puberty in boys with delayed adolescence: correlation with plasma testosterone levels

    SciTech Connect

    Kirkland, R.T.; Keenan, B.S.; Probstfield, J.L.; Patsch, W.; Lin, T.L.; Clayton, G.W.; Insull, W. Jr.

    1987-01-23

    A three-phase study tested the hypothesis that the decrease in the high-density lipoprotein cholesterol (HDL-C) level observed in boys at puberty is related to an increase in the plasma testosterone concentration. In phase I, 57 boys aged 10 to 17 years were categorized into four pubertal stages based on clinical parameters and plasma testosterone levels. These four groups showed increasing plasma testosterone values and decreasing HDL-C levels. In phase II, 14 boys with delayed adolescence were treated with testosterone enanthate. Plasma testosterone levels during therapy were in the adult male range. Levels of HDL-C decreased by a mean of 7.4 mg/dL (0.20 mmol/L) and 13.7 mg/dL (0.35 mmol/L), respectively, after the first two doses. In phase III, 13 boys with delayed adolescence demonstrated increasing plasma testosterone levels and decreasing HDL-C levels during spontaneous puberty. Levels of HDL-C and apolipoprotein A-1 were correlated during induced and spontaneous puberty. Testosterone should be considered a significant determinant of plasma HDL-C levels during pubertal development.

  6. Increased plasma cholesterol esterification by LCAT reduces diet-induced atherosclerosis in SR-BI knockout mice[S

    PubMed Central

    Thacker, Seth G.; Rousset, Xavier; Esmail, Safiya; Zarzour, Abdalrahman; Jin, Xueting; Collins, Heidi L.; Sampson, Maureen; Stonik, John; Demosky, Stephen; Malide, Daniela A.; Freeman, Lita; Vaisman, Boris L.; Kruth, Howard S.; Adelman, Steven J.; Remaley, Alan T.

    2015-01-01

    LCAT, a plasma enzyme that esterifies cholesterol, has been proposed to play an antiatherogenic role, but animal and epidemiologic studies have yielded conflicting results. To gain insight into LCAT and the role of free cholesterol (FC) in atherosclerosis, we examined the effect of LCAT over- and underexpression in diet-induced atherosclerosis in scavenger receptor class B member I-deficient [Scarab(−/−)] mice, which have a secondary defect in cholesterol esterification. Scarab(−/−)×LCAT-null [Lcat(−/−)] mice had a decrease in HDL-cholesterol and a high plasma ratio of FC/total cholesterol (TC) (0.88 ± 0.033) and a marked increase in VLDL-cholesterol (VLDL-C) on a high-fat diet. Scarab(−/−)×LCAT-transgenic (Tg) mice had lower levels of VLDL-C and a normal plasma FC/TC ratio (0.28 ± 0.005). Plasma from Scarab(−/−)×LCAT-Tg mice also showed an increase in cholesterol esterification during in vitro cholesterol efflux, but increased esterification did not appear to affect the overall rate of cholesterol efflux or hepatic uptake of cholesterol. Scarab(−/−)×LCAT-Tg mice also displayed a 51% decrease in aortic sinus atherosclerosis compared with Scarab(−/−) mice (P < 0.05). In summary, we demonstrate that increased cholesterol esterification by LCAT is atheroprotective, most likely through its ability to increase HDL levels and decrease pro-atherogenic apoB-containing lipoprotein particles. PMID:25964513

  7. Ileorectostomy or cecectomy but not colectomy abolishes the plasma cholesterol-lowering effect of dietary beet fiber in rats.

    PubMed

    Nishimura, N; Nishikawa, H; Kiriyama, S

    1993-07-01

    Adult male rats were fed a cholesterol-free diet with no added fiber (fiber-free) or with 10% cellulose or beet fiber. After 7 d of feeding, plasma total cholesterol concentrations were significantly lower in rats fed beet fiber than in those fed fiber-free or cellulose diets. This difference was due mainly to lower HDL cholesterol concentrations and remained significant for 28 d. The hypocholesterolemic effect of beet fiber relative to fiber-free disappeared when the cecum and colon were concurrently resected (ileorectostomy). Plasma cholesterol concentrations were the same in colectomized rats as in sham-operated rats fed the same diet and significantly lower in animals fed the beet fiber diet than in those fed the fiber-free diet. In cecectomized rats fed beet fiber, plasma cholesterol concentrations were intermediate between sham-operated rats fed the beet fiber diet and cecectomized or sham-operated rats fed the fiber-free diet. Fecal bile acid excretion was higher in rats fed the beet fiber diet than in those fed the fiber-free diet but did not correlate with plasma total cholesterol concentration. In rats with intact ceca, cecal total and individual short-chain fatty acids correlated negatively with plasma total cholesterol concentration. Dietary beet fiber lowers plasma cholesterol concentrations in rats, and the lower digestive tract, especially the cecum, seems to be necessary for this effect.

  8. Ablating L-FABP in SCP-2/SCP-x null mice impairs bile acid metabolism and biliary HDL-cholesterol secretion.

    PubMed

    Martin, Gregory G; Atshaves, Barbara P; Landrock, Kerstin K; Landrock, Danilo; Storey, Stephen M; Howles, Philip N; Kier, Ann B; Schroeder, Friedhelm

    2014-12-01

    On the basis of their abilities to bind bile acids and/or cholesterol, the physiological role(s) of liver fatty acid-binding protein (L-FABP) and sterol carrier protein (SCP) 2/SCP-x (SCP-2/SCP-x) gene products in biliary bile acid and cholesterol formation was examined in gene-ablated male mice. L-FABP (LKO) or L-FABP/SCP-2/SCP-x [triple-knockout (TKO)] ablation markedly decreased hepatic bile acid concentration, while SCP-2/SCP-x [double-knockout (DKO)] ablation alone had no effect. In contrast, LKO increased biliary bile acid, while DKO and TKO had no effect on biliary bile acid levels. LKO and DKO also altered biliary bile acid composition to increase bile acid hydrophobicity. Furthermore, LKO and TKO decreased hepatic uptake and biliary secretion of high-density lipoprotein (HDL)-derived 22-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-23,24-bisnor-5-cholen-3β-ol (NBD-cholesterol), while DKO alone had no effect. Finally, LKO and, to a lesser extent, DKO decreased most indexes contributing to cholesterol solubility in biliary bile. These results suggest different, but complementary, roles for L-FABP and SCP-2/SCP-x in biliary bile acid and cholesterol formation. L-FABP appears to function more in hepatic retention of bile acids as well as hepatic uptake and biliary secretion of HDL-cholesterol. Conversely, SCP-2/SCP-x may function more in formation and biliary secretion of bile acid, with less impact on hepatic uptake or biliary secretion of HDL-cholesterol.

  9. Association of Serum Cholesterol, Triglyceride, High and Low Density Lipoprotein (HDL and LDL) Levels in Chronic Periodontitis Subjects with Risk for Cardiovascular Disease (CVD): A Cross Sectional Study

    PubMed Central

    Sandi, R.M.; Pol, K.G.; Basavaraj, P.; Khuller, Nitin; Singh, Shilpi

    2014-01-01

    Purpose: To assess serum cholesterol, triglycerides, high and low density lipoprotein (HDL and LDL) levels (serum lipid profile) in subjects with chronic periodontitis and the possible association for risk of cardiovascular disease (CVD). Materials and Methods: Total of 80 participants (42 males and 38 females) who were in the age range of 30-65 years were divided into test group (group I- 40 subjects with chronic periodontitis) and control group (group II- 40 subjects with healthy periodontium), based on their periodontal disease statuses. Three ml of venous blood samples were taken for measurement of parameters of lipid metabolism [serum cholesterol (chol); triglycerides (Tg); HDL and LDL. Results: Significant increase in serum cholesterol and LDL (P<0.05) were observed in test group (group I), whereas serum triglycerides and HDL (P>0.66) showed no significant increase in test group (group I) as compared to their values in the control group (group II). A P-value of < 0.05 was considered for statistical significance. Conclusions: Subjects with chronic periodontitis showed increased serum cholesterol and LDL levels. This may suggest that these subjects are potentially at a risk of getting CVD. PMID:24596778

  10. Regional variations in HDL metabolism in human fat cells: effect of cell size

    SciTech Connect

    Despres, J.; Fong, B.S.; Julien, P.; Jimenez, J.; Angel, A.

    1987-05-01

    Abdominal obesity is related to reduced plasma high-density lipoprotein (HDL) cholesterol, and both are associated with cardiovascular disease risk. The authors have observed that plasma membranes from abdominal subcutaneous adipocytes have a greater HDL binding capacity than omental fat cell plasma membranes. The present study examined whether these binding characteristics could be due to differences in fat cell size or cholesterol concentration between the two adipose depots. Abdominal subcutaneous and deep omental fat were obtained from massively obese patients at surgery. Subcutaneous abdominal fat cells were significantly larger and their cellular cholesterol content greater than omental adipocytes. The uptake of HDL by collagenase-isolated fat cells was studied by incubating the cells for 2 h at 37/sup 0/C with 10 ..mu..g/ml /sup 125/I-HDL/sub 2/ or /sup 125/I-HDL/sub 3/. In both depots, the cellular uptake of /sup 125/I-HDL/sub 2/ and /sup 125/I-HDL/sub 3/ was specifically inhibited by addition of 25-fold excess unlabeled HDL and a close correlation was observed between the cellular uptake of /sup 125/I-HDL/sub 2/ and /sup 125/I-HDL/sub 3/. In obese patients, the uptake of /sup 125/I-HDL was higher in subcutaneous cells than in omental cells. The cellular /sup 125/I-HDL uptake was significantly correlated with adipocyte size and fat cell cholesterol content but not with adipocyte cholesterol concentration. These results suggest that the higher HDL uptake observed in subcutaneous cells compared with omental cells in obesity is the result of differences in adipocyte size rather than differences in the cholesterol concentration (cholesterol-to-triglyceride ratio). The increased interaction of HDL with hypertrophied abdominal adipocytes may play an important role in determining the lipid composition of HDL in obesity.

  11. A fluorescent cholesterol analogue for observation of free cholesterol in the plasma membrane of live cells.

    PubMed

    Ogawa, Yoshikatsu; Tanaka, Mutsuo

    2016-01-01

    Free cholesterol in mammalian cells resides mostly in the plasma membrane, where it plays an important role in cellular homeostasis. We synthesized a new fluorescent cholesterol analogue that retained an intact alkyl chain and the sterane backbone of cholesterol. The hydroxyl group of cholesterol was converted into an amino group that was covalently linked to the fluorophore tetramethylrhodamine to retain the ability to form hydrogen bonds with adjacent molecules. Incubating live MDCK (Madin-Darby canine kidney) cells with our fluorescent cholesterol analogue resulted in the generation of intense signals that were detected by microscopy at the plasma membrane. Incubation with the analogue exerted minimal, if any, influence on cell growth, indicating that it could serve as a useful tool for analyzing free cholesterol at the plasma membrane.

  12. Effects of cigarette smoking on HDL quantity and function: implications for atherosclerosis.

    PubMed

    He, Bai-mei; Zhao, Shui-ping; Peng, Zhen-yu

    2013-11-01

    Cigarette smoking has been identified as an independent and preventable risk factor for atherosclerosis and cardiovascular disease. Population studies have shown that plasma high density lipoprotein (HDL) cholesterol levels are inversely related to the risk of developing cardiovascular disease. Cigarette smoking is associated with reduced HDL cholesterol levels. Cigarette smoking can alter the critical enzymes of lipid transport, lowering lecithin: cholesterol acyltransferase (LCAT) activity and altering cholesterol ester transfer protein (CETP) and hepatic lipase activity, which attributes to its impact on HDL metabolism and HDL subfractions distribution. In addition, HDL is susceptible to oxidative modifications by cigarette smoking, which makes HDL become dysfunctional and lose its atheroprotective properties in smokers. Therefore, cigarette smoking has a negative impact on both HDL quantity and function, which can explain, in part, the increased risk of cardiovascular disease in smokers. PMID:23852759

  13. Plasma levels of HDL subpopulations and remnant lipoproteins predict the extent of angiographically defined disease in post-menopausal women

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  14. The low-resolution structure of nHDL reconstituted with DMPC with and without cholesterol reveals a mechanism for particle expansion[S

    PubMed Central

    Gogonea, Valentin; Gerstenecker, Gary S.; Wu, Zhiping; Lee, Xavier; Topbas, Celalettin; Wagner, Matthew A.; Tallant, Thomas C.; Smith, Jonathan D.; Callow, Philip; Pipich, Vitaliy; Malet, Hélène; Schoehn, Guy; DiDonato, Joseph A.; Hazen, Stanley L.

    2013-01-01

    Small-angle neutron scattering (SANS) with contrast variation was used to obtain the low-resolution structure of nascent HDL (nHDL) reconstituted with dimyristoyl phosphatidylcholine (DMPC) in the absence and presence of cholesterol, [apoA1:DMPC (1:80, mol:mol) and apoA1:DMPC:cholesterol (1:86:9, mol:mol:mol)]. The overall shape of both particles is discoidal with the low-resolution structure of apoA1 visualized as an open, contorted, and out of plane conformation with three arms in nascent HDL/dimyristoyl phosphatidylcholine without cholesterol (nHDLDMPC) and two arms in nascent HDL/dimyristoyl phosphatidylcholine with cholesterol (nHDLDMPC+Chol). The low-resolution shape of the lipid phase in both nHDLDMPC and nHDLDMPC+Chol were oblate ellipsoids, and fit well within their respective protein shapes. Modeling studies indicate that apoA1 is folded onto itself in nHDLDMPC, making a large hairpin, which was also confirmed independently by both cross-linking mass spectrometry and hydrogen-deuterium exchange (HDX) mass spectrometry analyses. In nHDLDMPC+Chol, the lipid was expanded and no hairpin was visible. Importantly, despite the overall discoidal shape of the whole particle in both nHDLDMPC and nHDLDMPC+Chol, an open conformation (i.e., not a closed belt) of apoA1 is observed. Collectively, these data show that full length apoA1 retains an open architecture that is dictated by its lipid cargo. The lipid is likely predominantly organized as a bilayer with a micelle domain between the open apoA1 arms. The apoA1 configuration observed suggests a mechanism for accommodating changing lipid cargo by quantized expansion of hairpin structures. PMID:23349207

  15. Relationship of Lifestyle Medical Advice and Non-HDL Cholesterol Control of a Nationally Representative US Sample with Hypercholesterolemia by Race/Ethnicity

    PubMed Central

    Vaccaro, Joan Anne; Huffman, Fatma G.

    2012-01-01

    Objective. The main purpose of this study was to evaluate the associations of lifestyle medical advice and non-HDL cholesterol control of a nationally representative US sample of adults with hypercholesterolemia by race/ethnicity. Methods. Data were collected by appending sociodemographic, anthropometric, and laboratory data from two cycles of the National Health and Nutrition Survey (2007-2008 and 2009-2010). This study acquired data from male and female adults aged ≥ 20 years (N = 11,577), classified as either Mexican American (MA), (n = 2173), other Hispanic (OH) (n = 1298), Black non-Hispanic (BNH) (n = 2349), or White non-Hispanic (WNH) (n = 5737). Results. Minorities were more likely to report having received dietary, weight management, and exercise recommendations by healthcare professionals than WNH, adjusting for confounders. Approximately 80% of those receiving medical advice followed the recommendation, regardless of race/ethnicity. Of those who received medical advice, reporting “currently controlling or losing weight” was associated with lower non-HDL cholesterol. BNH who reported “currently controlling or losing weight” had higher non-HDL cholesterol than WNH who reported following the advice. Conclusion. The results suggest that current methods of communicating lifestyle advice may not be adequate across race/ethnicity and that a change in perspective and delivery of medical recommendations for persons with hypercholesterolemia is needed. PMID:23119150

  16. HDL Cholesterol Test

    MedlinePlus

    Advertisement Proceeds from website advertising help sustain Lab Tests Online. AACC is a not-for-profit organization ... for trustworthy health information. Verify Compliance . Produced by Advertisement

  17. Early postoperative changes of HDL subfraction profile and HDL-associated enzymes after laparoscopic sleeve gastrectomy.

    PubMed

    Doğan, Serdar; Aslan, Ibrahim; Eryılmaz, Ramazan; Ensari, Cemal Ozben; Bilecik, Tuna; Aslan, Mutay

    2013-12-01

    This study aimed to determine early postoperative changes of LDL/HDL subfraction profile and HDL-associated enzymes following laparoscopic sleeve gastrectomy (LSG). Thirteen obese patients (mean body mass index (BMI) 52.74 ± 10.97 kg/m(2)) underwent LSG and normal weight control patients (mean BMI 23.56 ± 1.92 kg/m(2)) underwent laparoscopic abdominal surgery. Fasting blood samples were collected prior to surgery, at day 1 after surgery, and after postoperation oral feeding. LDL and HDL subfraction analysis was done by continuous disk polyacrylamide gel electrophoresis. Plasma levels of cholesteryl ester transfer protein (CETP), lecithin-cholesterol acyltransferase (LCAT), and apolipoprotein A-1 (apoA-I) were determined by enzyme-linked immunosorbent assay. Measurement of CETP and LCAT activity was performed via fluorometric analysis. LDL subfraction profile showed no change in both LSG and control group patients. No significant difference was observed in HDL cholesterol, HDL-subfraction distribution, and apoA-I levels in the control group. LSG patients showed a significant increase in HDL-large and a significant decrease in HDL-small fractions at postoperation day 1 compared to preoperation. HDL cholesterol significantly decreased and apoA-I significantly increased in LSG patients after postoperation oral feeding compared to both preoperation and postoperation day 1. Changes in HDL subfraction profile at postoperation day 1 after LSG were accompanied by a significant decrease in CETP protein, LCAT protein, and LCAT activity as compared to preoperation levels. Early changes in HDL subfraction profile and HDL-associated enzymes following LSG suggest that the surgical procedure, irrespective of changes in body weight, affects reverse cholesterol transport. PMID:23760763

  18. Rapid on-line determination of cholesterol distribution among plasma lipoproteins after high-performance gel filtration chromatography.

    PubMed

    Kieft, K A; Bocan, T M; Krause, B R

    1991-05-01

    A high-performance gel chromatography (HPGC) system has been developed which allows the unattended on-line determination of lipoprotein cholesterol distribution (VLDL-C, LDL-C, HDL-C), within 40 min, in microliter quantities of plasma using a single, relatively inexpensive column (Superose 6HR). The FAST cholesterol reagent (Sclavo) and a knitted PFTE Kratos reaction coil (Applied Biosystems) were found to provide optimal sensitivity, linearity, resolution, and dispersion characteristics. Validation is provided by comparison to target values for human quality control reference sera, and by comparing the values obtained by HPGC to the beta-quant method (LRC). The utility of the system is illustrated by comparing profiles from seven different species with normal or elevated plasma cholesterol concentrations. This technique allows rapid analysis of samples, regardless of species, without the use of precipitating agents or the ultracentrifuge. It could also be applied for the direct clinical determination of LDL-cholesterol. PMID:2072044

  19. Candidate genetic analysis of plasma high-density lipoprotein-cholesterol and severity of coronary atherosclerosis

    PubMed Central

    Chen, Suet Nee; Cilingiroglu, Mehmet; Todd, Josh; Lombardi, Raffaella; Willerson, James T; Gotto, Antonio M; Ballantyne, Christie M; Marian, AJ

    2009-01-01

    Background Plasma level of high-density lipoprotein-cholesterol (HDL-C), a heritable trait, is an important determinant of susceptibility to atherosclerosis. Non-synonymous and regulatory single nucleotide polymorphisms (SNPs) in genes implicated in HDL-C synthesis and metabolism are likely to influence plasma HDL-C, apolipoprotein A-I (apo A-I) levels and severity of coronary atherosclerosis. Methods We genotyped 784 unrelated Caucasian individuals from two sets of populations (Lipoprotein and Coronary Atherosclerosis Study- LCAS, N = 333 and TexGen, N = 451) for 94 SNPs in 42 candidate genes by 5' nuclease assays. We tested the distribution of the phenotypes by the Shapiro-Wilk normality test. We used Box-Cox regression to analyze associations of the non-normally distributed phenotypes (plasma HDL-C and apo A-I levels) with the genotypes. We included sex, age, body mass index (BMI), diabetes mellitus (DM), and cigarette smoking as covariates. We calculated the q values as indicators of the false positive discovery rate (FDR). Results Plasma HDL-C levels were associated with sex (higher in females), BMI (inversely), smoking (lower in smokers), DM (lower in those with DM) and SNPs in APOA5, APOC2, CETP, LPL and LIPC (each q ≤0.01). Likewise, plasma apo A-I levels, available in the LCAS subset, were associated with SNPs in CETP, APOA5, and APOC2 as well as with BMI, sex and age (all q values ≤0.03). The APOA5 variant S19W was also associated with minimal lumen diameter (MLD) of coronary atherosclerotic lesions, a quantitative index of severity of coronary atherosclerosis (q = 0.018); mean number of coronary artery occlusions (p = 0.034) at the baseline and progression of coronary atherosclerosis, as indicated by the loss of MLD. Conclusion Putatively functional variants of APOA2, APOA5, APOC2, CETP, LPL, LIPC and SOAT2 are independent genetic determinants of plasma HDL-C levels. The non-synonymous S19W SNP in APOA5 is also an independent determinant of plasma

  20. A functional ABCA1 gene variant is associated with low HDL-cholesterol levels and shows evidence of positive selection in Native Americans.

    PubMed

    Acuña-Alonzo, Víctor; Flores-Dorantes, Teresa; Kruit, Janine K; Villarreal-Molina, Teresa; Arellano-Campos, Olimpia; Hünemeier, Tábita; Moreno-Estrada, Andrés; Ortiz-López, Ma Guadalupe; Villamil-Ramírez, Hugo; León-Mimila, Paola; Villalobos-Comparan, Marisela; Jacobo-Albavera, Leonor; Ramírez-Jiménez, Salvador; Sikora, Martin; Zhang, Lin-Hua; Pape, Terry D; Granados-Silvestre, Ma de Angeles; Montufar-Robles, Isela; Tito-Alvarez, Ana M; Zurita-Salinas, Camilo; Bustos-Arriaga, José; Cedillo-Barrón, Leticia; Gómez-Trejo, Celta; Barquera-Lozano, Rodrigo; Vieira-Filho, Joao P; Granados, Julio; Romero-Hidalgo, Sandra; Huertas-Vázquez, Adriana; González-Martín, Antonio; Gorostiza, Amaya; Bonatto, Sandro L; Rodríguez-Cruz, Maricela; Wang, Li; Tusié-Luna, Teresa; Aguilar-Salinas, Carlos A; Lisker, Ruben; Moises, Regina S; Menjivar, Marta; Salzano, Francisco M; Knowler, William C; Bortolini, M Cátira; Hayden, Michael R; Baier, Leslie J; Canizales-Quinteros, Samuel

    2010-07-15

    It has been suggested that the higher susceptibility of Hispanics to metabolic disease is related to their Native American heritage. A frequent cholesterol transporter ABCA1 (ATP-binding cassette transporter A1) gene variant (R230C, rs9282541) apparently exclusive to Native American individuals was associated with low high-density lipoprotein cholesterol (HDL-C) levels, obesity and type 2 diabetes in Mexican Mestizos. We performed a more extensive analysis of this variant in 4405 Native Americans and 863 individuals from other ethnic groups to investigate genetic evidence of positive selection, to assess its functional effect in vitro and to explore associations with HDL-C levels and other metabolic traits. The C230 allele was found in 29 of 36 Native American groups, but not in European, Asian or African individuals. C230 was observed on a single haplotype, and C230-bearing chromosomes showed longer relative haplotype extension compared with other haplotypes in the Americas. Additionally, single-nucleotide polymorphism data from the Human Genome Diversity Panel Native American populations were enriched in significant integrated haplotype score values in the region upstream of the ABCA1 gene. Cells expressing the C230 allele showed a 27% cholesterol efflux reduction (P< 0.001), confirming this variant has a functional effect in vitro. Moreover, the C230 allele was associated with lower HDL-C levels (P = 1.77 x 10(-11)) and with higher body mass index (P = 0.0001) in the combined analysis of Native American populations. This is the first report of a common functional variant exclusive to Native American and descent populations, which is a major determinant of HDL-C levels and may have contributed to the adaptive evolution of Native American populations. PMID:20418488

  1. A functional ABCA1 gene variant is associated with low HDL-cholesterol levels and shows evidence of positive selection in Native Americans

    PubMed Central

    Acuña-Alonzo, Víctor; Flores-Dorantes, Teresa; Kruit, Janine K.; Villarreal-Molina, Teresa; Arellano-Campos, Olimpia; Hünemeier, Tábita; Moreno-Estrada, Andrés; Ortiz-López, Ma Guadalupe; Villamil-Ramírez, Hugo; León-Mimila, Paola; Villalobos-Comparan, Marisela; Jacobo-Albavera, Leonor; Ramírez-Jiménez, Salvador; Sikora, Martin; Zhang, Lin-Hua; Pape, Terry D.; de Ángeles Granados-Silvestre, Ma; Montufar-Robles, Isela; Tito-Alvarez, Ana M.; Zurita-Salinas, Camilo; Bustos-Arriaga, José; Cedillo-Barrón, Leticia; Gómez-Trejo, Celta; Barquera-Lozano, Rodrigo; Vieira-Filho, Joao P.; Granados, Julio; Romero-Hidalgo, Sandra; Huertas-Vázquez, Adriana; González-Martín, Antonio; Gorostiza, Amaya; Bonatto, Sandro L.; Rodríguez-Cruz, Maricela; Wang, Li; Tusié-Luna, Teresa; Aguilar-Salinas, Carlos A.; Lisker, Ruben; Moises, Regina S.; Menjivar, Marta; Salzano, Francisco M.; Knowler, William C.; Bortolini, M. Cátira; Hayden, Michael R.; Baier, Leslie J.; Canizales-Quinteros, Samuel

    2010-01-01

    It has been suggested that the higher susceptibility of Hispanics to metabolic disease is related to their Native American heritage. A frequent cholesterol transporter ABCA1 (ATP-binding cassette transporter A1) gene variant (R230C, rs9282541) apparently exclusive to Native American individuals was associated with low high-density lipoprotein cholesterol (HDL-C) levels, obesity and type 2 diabetes in Mexican Mestizos. We performed a more extensive analysis of this variant in 4405 Native Americans and 863 individuals from other ethnic groups to investigate genetic evidence of positive selection, to assess its functional effect in vitro and to explore associations with HDL-C levels and other metabolic traits. The C230 allele was found in 29 of 36 Native American groups, but not in European, Asian or African individuals. C230 was observed on a single haplotype, and C230-bearing chromosomes showed longer relative haplotype extension compared with other haplotypes in the Americas. Additionally, single-nucleotide polymorphism data from the Human Genome Diversity Panel Native American populations were enriched in significant integrated haplotype score values in the region upstream of the ABCA1 gene. Cells expressing the C230 allele showed a 27% cholesterol efflux reduction (P< 0.001), confirming this variant has a functional effect in vitro. Moreover, the C230 allele was associated with lower HDL-C levels (P = 1.77 × 10−11) and with higher body mass index (P = 0.0001) in the combined analysis of Native American populations. This is the first report of a common functional variant exclusive to Native American and descent populations, which is a major determinant of HDL-C levels and may have contributed to the adaptive evolution of Native American populations. PMID:20418488

  2. A functional ABCA1 gene variant is associated with low HDL-cholesterol levels and shows evidence of positive selection in Native Americans

    PubMed Central

    Acuña-Alonzo, Víctor; Flores-Dorantes, Teresa; Kruit, Janine K.; Villarreal-Molina, Teresa; Arellano-Campos, Olimpia; Hünemeier, Tábita; Moreno-Estrada, Andrés; Ortiz-López, Ma Guadalupe; Villamil-Ramírez, Hugo; León-Mimila, Paola; Villalobos-Comparan, Marisela; Jacobo-Albavera, Leonor; Ramírez-Jiménez, Salvador; Sikora, Martin; Zhang, Lin-Hua; Pape, Terry D.; de Ángeles Granados-Silvestre, Ma; Montufar-Robles, Isela; Tito-Alvarez, Ana M.; Zurita-Salinas, Camilo; Bustos-Arriaga, José; Cedillo-Barrón, Leticia; Gómez-Trejo, Celta; Barquera-Lozano, Rodrigo; Vieira-Filho, Joao P.; Granados, Julio; Romero-Hidalgo, Sandra; Huertas-Vázquez, Adriana; González-Martín, Antonio; Gorostiza, Amaya; Bonatto, Sandro L.; Rodríguez-Cruz, Maricela; Wang, Li; Tusié-Luna, Teresa; Aguilar-Salinas, Carlos A.; Lisker, Ruben; Moises, Regina S.; Menjivar, Marta; Salzano, Francisco M.; Knowler, William C.; Bortolini, M. Cátira; Hayden, Michael R.; Baier, Leslie J.; Canizales-Quinteros, Samuel

    2010-01-01

    It has been suggested that the higher susceptibility of Hispanics to metabolic disease is related to their Native American heritage. A frequent cholesterol transporter ABCA1 (ATP-binding cassette transporter A1) gene variant (R230C, rs9282541) apparently exclusive to Native American individuals was associated with low high-density lipoprotein cholesterol (HDL-C) levels, obesity and type 2 diabetes in Mexican Mestizos. We performed a more extensive analysis of this variant in 4405 Native Americans and 863 individuals from other ethnic groups to investigate genetic evidence of positive selection, to assess its functional effect in vitro and to explore associations with HDL-C levels and other metabolic traits. The C230 allele was found in 29 of 36 Native American groups, but not in European, Asian or African individuals. C230 was observed on a single haplotype, and C230-bearing chromosomes showed longer relative haplotype extension compared with other haplotypes in the Americas. Additionally, single-nucleotide polymorphism data from the Human Genome Diversity Panel Native American populations were enriched in significant integrated haplotype score values in the region upstream of the ABCA1 gene. Cells expressing the C230 allele showed a 27% cholesterol efflux reduction (P< 0.001), confirming this variant has a functional effect in vitro. Moreover, the C230 allele was associated with lower HDL-C levels (P = 1.77 × 10−11) and with higher body mass index (P = 0.0001) in the combined analysis of Native American populations. This is the first report of a common functional variant exclusive to Native American and descent populations, which is a major determinant of HDL-C levels and may have contributed to the adaptive evolution of Native American populations. PMID:20418488

  3. Low HDL cholesterol as a cardiovascular risk factor in rural, urban, and rural-urban migrants: PERU MIGRANT cohort study

    PubMed Central

    Lazo-Porras, María; Bernabe-Ortiz, Antonio; Málaga, Germán; Gilman, Robert H.; Acuña-Villaorduña, Ana; Cardenas-Montero, Deborah; Smeeth, Liam; Miranda, J. Jaime

    2016-01-01

    Introduction Whilst the relationship between lipids and cardiovascular mortality has been well studied and appears to be controversial, very little has been explored in the context of rural-to-urban migration in low-resource settings. Objective Determine the profile and related factors for HDL-c patterns (isolated and non-isolated low HDL-c) in three population-based groups according to their migration status, and determine the effect of HDL-c patterns on the rates of cardiovascular outcomes (i.e. non-fatal stroke and non-fatal myocardial infarction) and mortality. Methods Cross-sectional and 5-year longitudinal data from the PERU MIGRANT study, designed to assess the effect of migration on cardiovascular risk profiles and mortality in Peru. Two different analyses were performed: first, we estimated prevalence and associated factors with isolated and non-isolated low HDL-c at baseline. Second, using longitudinal information, relative risk ratios (RRR) of composite outcomes of mortality, non-fatal stroke and non-fatal myocardial infarction were calculated according to HDL-c levels at baseline. Results Data from 988 participants, rural (n = 201), rural-to-urban migrants (n = 589), and urban (n = 199) groups, was analysed. Low HDL-c was present in 56.5% (95%CI: 53.4%–59.6%) without differences by study groups. Isolated low HDL-c was found in 36.5% (95%CI: 33.5–39.5%), with differences between study groups. In multivariable analysis, urban group (vs. rural), female gender, overweight and obesity were independently associated with isolated low HDL-c. Only female gender, overweight and obesity were associated with non-isolated low HDL-c. Longitudinal analyses showed that non-isolated low HDL-c increased the risk of negative cardiovascular outcomes (RRR = 3.46; 95%CI: 1.23–9.74). Conclusions Isolated low HDL-c was the most common dyslipidaemia in the study population and was more frequent in rural subjects. Non-isolated low HDL-c increased three-to fourfold

  4. Substitution of whole cows' milk with defatted milk for 4 months reduced serum total cholesterol, HDL-cholesterol and total apoB in a sample of Mexican school-age children (6-16 years of age).

    PubMed

    Villalpando, Salvador; Lara Zamudio, Yaveth; Shamah-Levy, Teresa; Mundo-Rosas, Verónica; Manzano, Alejandra Contreras; Lamadrid-Figueroa, Héctor

    2015-09-14

    We carried out this study to compare the effect of consuming whole, partially defatted and defatted cows' milk for 4 months on serum concentrations of blood indicators of cardiovascular risk (CVR) in Mexican children and adolescents. Children aged between 6 and 16 years living in indigenous boarding schools in Mexico and who were usual consumers of whole milk were recruited to this study. Totally, thirteen boarding schools were randomly selected to receive full supplies of whole, partially defatted and defatted cows' milk for 4 months. Serum total cholesterol (TC), TAG, HDL-cholesterol, apoA and total apoB, and Lp(a) concentrations were measured before and after the intervention. Comparisons were made with multi-level mixed-effects linear regression models using the difference in differences approach. Compared with the whole milk group, TC, LDL-cholesterol, HDL-cholesterol and total apoB were lower in defatted milk consumers by -0·43, -0·28, -0·16 mmol/l and -0·05 g/l, respectively (all P<0·001). Compared with the whole milk group, the group that consumed partially defatted milk showed a significant decrease in the concentrations of LDL-cholesterol (-0·12, P=0·01), apoA (-0·05 g/l, P=0·01) and total apoB (-0·05 g/l, P=0·001). Defatted milk intake for 4 months reduced some of the serum indicators of CVR.

  5. Low Maternal Vitamin B12 Status Is Associated with Lower Cord Blood HDL Cholesterol in White Caucasians Living in the UK

    PubMed Central

    Adaikalakoteswari, Antonysunil; Vatish, Manu; Lawson, Alexander; Wood, Catherine; Sivakumar, Kavitha; McTernan, Philip G.; Webster, Craig; Anderson, Neil; Yajnik, Chittaranjan S.; Tripathi, Gyanendra; Saravanan, Ponnusamy

    2015-01-01

    Background and Aims: Studies in South Asian population show that low maternal vitamin B12 associates with insulin resistance and small for gestational age in the offspring. Low vitamin B12 status is attributed to vegetarianism in these populations. It is not known whether low B12 status is associated with metabolic risk of the offspring in whites, where the childhood metabolic disorders are increasing rapidly. Here, we studied whether maternal B12 levels associate with metabolic risk of the offspring at birth. Methods: This is a cross-sectional study of 91 mother-infant pairs (n = 182), of white Caucasian origin living in the UK. Blood samples were collected from white pregnant women at delivery and their newborns (cord blood). Serum vitamin B12, folate, homocysteine as well as the relevant metabolic risk factors were measured. Results: The prevalence of low serum vitamin B12 (<191 ng/L) and folate (<4.6 μg/L) were 40% and 11%, respectively. Maternal B12 was inversely associated with offspring’s Homeostasis Model Assessment 2-Insulin Resistance (HOMA-IR), triglycerides, homocysteine and positively with HDL-cholesterol after adjusting for age and BMI. In regression analysis, after adjusting for likely confounders, maternal B12 is independently associated with neonatal HDL-cholesterol and homocysteine but not triglycerides or HOMA-IR. Conclusions: Our study shows that low B12 status is common in white women and is independently associated with adverse cord blood cholesterol. PMID:25849948

  6. Localization of genes for V+LDL plasma cholesterol levels on two diets in the opossum Monodelphis domestica[S

    PubMed Central

    Kammerer, Candace M.; Rainwater, David L.; Gouin, Nicolas; Jasti, Madhuri; Douglas, Kory C.; Dressen, Amy S.; Ganta, Prasanth; VandeBerg, John L.; Samollow, Paul B.

    2010-01-01

    Plasma cholesterol levels among individuals vary considerably in response to diet. However, the genes that influence this response are largely unknown. Non-HDL (V+LDL) cholesterol levels vary dramatically among gray, short-tailed opossums fed an atherogenic diet, and we previously reported that two quantitative trait loci (QTLs) influenced V+LDL cholesterol on two diets. We used hypothesis-free, genome-wide linkage analyses on data from 325 pedigreed opossums and located one QTL for V+LDL cholesterol on the basal diet on opossum chromosome 1q [logarithm of the odds (LOD) = 3.11, genomic P = 0.019] and another QTL for V+LDL on the atherogenic diet (i.e., high levels of cholesterol and fat) on chromosome 8 (LOD = 9.88, genomic P = 5 × 10−9). We then employed a novel strategy involving combined analyses of genomic resources, expression analysis, sequencing, and genotyping to identify candidate genes for the chromosome 8 QTL. A polymorphism in ABCB4 was strongly associated (P = 9 × 10−14) with the plasma V+LDL cholesterol concentrations on the high-cholesterol, high-fat diet. The results of this study indicate that genetic variation in ABCB4, or closely linked genes, is responsible for the dramatic differences among opossums in their V+LDL cholesterol response to an atherogenic diet. PMID:20650928

  7. Conversion of α-linolenic acid to long-chain omega-3 fatty acid derivatives and alterations of HDL density subfractions and plasma lipids with dietary polyunsaturated fatty acids in Monk parrots (Myiopsitta monachus).

    PubMed

    Petzinger, C; Larner, C; Heatley, J J; Bailey, C A; MacFarlane, R D; Bauer, J E

    2014-04-01

    The effect of α-linolenic acid from a flaxseed (FLX)-enriched diet on plasma lipid and fatty acid metabolism and possible atherosclerosis risk factors was studied in Monk parrots (Myiopsitta monachus). Twenty-four Monk parrots were randomly assigned to diets containing either 10% ground SUNs or 10% ground FLXs. Feed intake was calculated daily. Blood samples, body condition scores and body weights were obtained at -5 weeks, day 0, 7, 14, 28, 42 and 70. Plasma samples were analysed for total cholesterol, free cholesterol, triacylglycerols and lipoproteins. Phospholipid subfraction fatty acid profiles were determined. By day 70, the FLX group had significantly higher plasma phospholipid fatty acids including 18:3n-3 (α-linolenic acid), 20:5n-3 (eicosapentaenoic acid) and 22:6n-3 (docosahexaenoic acid). The sunflower group had significantly higher plasma phospholipid levels of 20:4n-6 (arachidonic acid). By day 70, the high-density lipoprotein (HDL) peak shifted resulting in significantly different HDL peak densities between the two experimental groups (1.097 g/ml FLX group and 1.095 g/ml SUN group, p = 0.028). The plasma fatty acid results indicate that Monk parrots can readily convert α-linolenic acid to the long-chain omega-3 derivatives including docosahexaenoic acid and reduce 20:4n-6 accumulation in plasma phospholipids. The reason for a shift in the HDL peak density is unknown at this time. PMID:23600588

  8. Conversion of α-linolenic acid to long-chain omega-3 fatty acid derivatives and alterations of HDL density subfractions and plasma lipids with dietary polyunsaturated fatty acids in Monk parrots (Myiopsitta monachus).

    PubMed

    Petzinger, C; Larner, C; Heatley, J J; Bailey, C A; MacFarlane, R D; Bauer, J E

    2014-04-01

    The effect of α-linolenic acid from a flaxseed (FLX)-enriched diet on plasma lipid and fatty acid metabolism and possible atherosclerosis risk factors was studied in Monk parrots (Myiopsitta monachus). Twenty-four Monk parrots were randomly assigned to diets containing either 10% ground SUNs or 10% ground FLXs. Feed intake was calculated daily. Blood samples, body condition scores and body weights were obtained at -5 weeks, day 0, 7, 14, 28, 42 and 70. Plasma samples were analysed for total cholesterol, free cholesterol, triacylglycerols and lipoproteins. Phospholipid subfraction fatty acid profiles were determined. By day 70, the FLX group had significantly higher plasma phospholipid fatty acids including 18:3n-3 (α-linolenic acid), 20:5n-3 (eicosapentaenoic acid) and 22:6n-3 (docosahexaenoic acid). The sunflower group had significantly higher plasma phospholipid levels of 20:4n-6 (arachidonic acid). By day 70, the high-density lipoprotein (HDL) peak shifted resulting in significantly different HDL peak densities between the two experimental groups (1.097 g/ml FLX group and 1.095 g/ml SUN group, p = 0.028). The plasma fatty acid results indicate that Monk parrots can readily convert α-linolenic acid to the long-chain omega-3 derivatives including docosahexaenoic acid and reduce 20:4n-6 accumulation in plasma phospholipids. The reason for a shift in the HDL peak density is unknown at this time.

  9. High intake of fatty fish, but not of lean fish, affects serum concentrations of TAG and HDL-cholesterol in healthy, normal-weight adults: a randomised trial.

    PubMed

    Hagen, Ingrid V; Helland, Anita; Bratlie, Marianne; Brokstad, Karl A; Rosenlund, Grethe; Sveier, Harald; Mellgren, Gunnar; Gudbrandsen, Oddrun A

    2016-08-01

    The aim of the present study was to examine whether high intake of lean or fatty fish (cod and farmed salmon, respectively) by healthy, normal-weight adults would affect risk factors of type 2 diabetes and CVD when compared with lean meat (chicken). More knowledge is needed concerning the potential health effects of high fish intake (>300 g/week) in normal-weight adults. In this randomised clinical trial, thirty-eight young, healthy, normal-weight participants consumed 750 g/week of lean or fatty fish or lean meat (as control) for 4 weeks at dinner according to provided recipes to ensure similar ways of preparations and choices of side dishes between the groups. Energy and macronutrient intakes at baseline and end point were similar in all groups, and there were no changes in energy and macronutrient intakes within any of the groups during the course of the study. High intake of fatty fish, but not lean fish, significantly reduced TAG and increased HDL-cholesterol concentrations in fasting serum when compared with lean meat intake. When compared with lean fish intake, fatty fish intake increased serum HDL-cholesterol. No differences were observed between lean fish, fatty fish and lean meat groups regarding fasting and postprandial glucose regulation. These findings suggest that high intake of fatty fish, but not of lean fish, could beneficially affect serum concentrations of TAG and HDL-cholesterol, which are CVD risk factors, in healthy, normal-weight adults, when compared with high intake of lean meat. PMID:27363518

  10. High intake of fatty fish, but not of lean fish, affects serum concentrations of TAG and HDL-cholesterol in healthy, normal-weight adults: a randomised trial.

    PubMed

    Hagen, Ingrid V; Helland, Anita; Bratlie, Marianne; Brokstad, Karl A; Rosenlund, Grethe; Sveier, Harald; Mellgren, Gunnar; Gudbrandsen, Oddrun A

    2016-08-01

    The aim of the present study was to examine whether high intake of lean or fatty fish (cod and farmed salmon, respectively) by healthy, normal-weight adults would affect risk factors of type 2 diabetes and CVD when compared with lean meat (chicken). More knowledge is needed concerning the potential health effects of high fish intake (>300 g/week) in normal-weight adults. In this randomised clinical trial, thirty-eight young, healthy, normal-weight participants consumed 750 g/week of lean or fatty fish or lean meat (as control) for 4 weeks at dinner according to provided recipes to ensure similar ways of preparations and choices of side dishes between the groups. Energy and macronutrient intakes at baseline and end point were similar in all groups, and there were no changes in energy and macronutrient intakes within any of the groups during the course of the study. High intake of fatty fish, but not lean fish, significantly reduced TAG and increased HDL-cholesterol concentrations in fasting serum when compared with lean meat intake. When compared with lean fish intake, fatty fish intake increased serum HDL-cholesterol. No differences were observed between lean fish, fatty fish and lean meat groups regarding fasting and postprandial glucose regulation. These findings suggest that high intake of fatty fish, but not of lean fish, could beneficially affect serum concentrations of TAG and HDL-cholesterol, which are CVD risk factors, in healthy, normal-weight adults, when compared with high intake of lean meat.

  11. Nicotinic Acid Accelerates HDL Cholesteryl Ester Turnover in Obese Insulin-Resistant Dogs

    PubMed Central

    Le Bloc'h, Jérôme; Leray, Véronique; Nazih, Hassan; Gauthier, Olivier; Serisier, Samuel; Magot, Thierry; Krempf, Michel; Nguyen, Patrick; Ouguerram, Khadija

    2015-01-01

    Aim Nicotinic acid (NA) treatment decreases plasma triglycerides and increases HDL cholesterol, but the mechanisms involved in these change are not fully understood. A reduction in cholesteryl ester transfer protein (CETP) activity has been advanced to explain most lipid-modulating effects of NA. However, due to the central role of CETP in reverse cholesterol transport in humans, other effects of NA may have been hidden. As dogs have no CETP activity, we conducted this study to examine the specific effects of extended-release niacin (NA) on lipids and high-density lipoprotein (HDL) cholesteryl ester (CE) turnover in obese Insulin-Resistant dogs with increase plasma triglycerides. Methods HDL kinetics were assessed in fasting dogs before and four weeks after NA treatment through endogenous labeling of cholesterol and apolipoprotein AI by simultaneous infusion of [1,2 13C2] acetate and [5,5,5 2H3] leucine for 8 h. Kinetic data were analyzed by compartmental modeling. In vitro cell cholesterol efflux of serum from NA-treated dogs was also measured. Results NA reduced plasma total cholesterol, low-density lipoprotein cholesterol, HDL cholesterol, triglycerides (TG), and very-low-density lipoprotein TG concentrations (p < 0.05). The kinetic study also showed a higher cholesterol esterification rate (p < 0.05). HDL-CE turnover was accelerated (p < 0.05) via HDL removal through endocytosis and selective CE uptake (p < 0.05). We measured an elevated in vitro cell cholesterol efflux (p < 0.05) with NA treatment in accordance with a higher cholesterol esterification. Conclusion NA decreased HDL cholesterol but promoted cholesterol efflux and esterification, leading to improved reverse cholesterol transport. These results highlight the CETP-independent effects of NA in changes of plasma lipid profile. PMID:26366727

  12. Levels and changes of HDL cholesterol and apolipoprotein A-I in relation to risk of cardiovascular events among statin-treated patients; a meta-analysis

    PubMed Central

    Boekholdt, S. Matthijs; Arsenault, Benoit J.; Hovingh, G. Kees; Mora, Samia; Pedersen, Terje R.; LaRosa, John C.; Welch, K.M.A.; Amarenco, Pierre; DeMicco, David A.; Tonkin, Andrew M.; Sullivan, David R.; Kirby, Adrienne; Colhoun, Helen M.; Hitman, Graham A.; Betteridge, D. John; Durrington, Paul N.; Clearfield, Michael B.; Downs, John R.; Gotto, Antonio M.; Ridker, Paul M.; Kastelein, John J.P.

    2013-01-01

    Background It is unclear whether levels of high-density lipoprotein cholesterol (HDL-C) or apolipoprotein A-I (apoA-I) remain inversely associated with cardiovascular risk among patients who achieve very low levels of low-density lipoprotein cholesterol (LDL-C) on statin therapy. It is also unknown whether a rise in HDL-C or apoA-I after initiation of statin therapy is associated with a reduced cardiovascular risk. Methods and results We performed a meta-analysis of 8 statin trials in which lipids and apolipoproteins were determined in all study participants at baseline and at 1-year follow-up. Individual patient data were obtained for 38,153 trial participants allocated to statin therapy, of whom 5387 suffered a major cardiovascular event. HDL-C levels were associated with a reduced risk of major cardiovascular events (adjusted hazard ratio 0.83, 95%CI 0.81–0.86 per 1 standard deviation increment), as were apoA-I levels (HR 0.79, 95%CI 0.72–0.82). This association was also observed among patients achieving on-statin LDL-C levels < 50 mg/dL. An increase of HDL-C was not associated with reduced cardiovascular risk (HR 0.98, 95%CI 0.94–1.01 per 1 standard deviation increment), whereas a rise in apoA-I was (HR 0.93, 95%CI 0.90–0.97). Conclusions Among patients treated with statin therapy, HDL-C and apoA-I levels were strongly associated with a reduced cardiovascular risk, even among those achieving very low LDL-C. An apoA-I increase was associated with a reduced risk of major cardiovascular events, whereas for HDL-C this was not the case. These findings suggest that therapies that increase apoA-I concentration require further exploration with regard to cardiovascular risk reduction. PMID:23965489

  13. Inflammation Modulates Human HDL Composition and Function in vivo

    PubMed Central

    de la Llera Moya, Margarita; McGillicuddy, Fiona C; Hinkle, Christine C; Byrne, Michael; Joshi, Michelle R; Nguyen, Vihn; Tabita-Martinez, Jennifer; Wolfe, Megan L; Badellino, Karen; Pruscino, Leticia; Mehta, Nehal N; Asztalos, Bela F; Reilly, Muredach P

    2012-01-01

    Objectives Inflammation may directly impair HDL functions, in particular reverse cholesterol transport (RCT), but limited data support this concept in humans. Methods and Results We employed low-dose human endotoxemia to assess the effects of inflammation on HDL and RCT-related parameters in vivo. Endotoxemia induced remodelling of HDL with depletion of pre-β1a HDL particles determined by 2-D gel electrophoresis (-32.2 ± 9.3% at 24h, p<0.05) as well as small (-23.0 ± 5.1%, p<0.01, at 24h) and medium (-57.6 ± 8.0% at 16h, p<0.001) HDL estimated by nuclear magnetic resonance (NMR). This was associated with induction of class II secretory phospholipase A2 (~36 fold increase) and suppression of lecithin:cholesterol acyltransferase activity (-20.8 ± 3.4% at 24h, p<0.01) and cholesterol ester transfer protein mass (-22.2 ± 6.8% at 24h, p<0.001). The HDL fraction, isolated following endotoxemia, had reduced capacity to efflux cholesterol in vitro from SR-BI and ABCA1, but not ABCG1 transporter cell models. Conclusions These data support the concept that “atherogenic-HDL dysfunction” and impaired RCT occur in human inflammatory syndromes, largely independent of changes in plasma HDL-C and ApoA-I levels. PMID:22456230

  14. HDL Cholesterol Level Is Associated with Contrast Induced Acute Kidney Injury in Chronic Kidney Disease Patients Undergoing PCI

    PubMed Central

    Park, Hoon Suk; Kim, Chan Joon; Hwang, Byung-Hee; Kim, Tae-Hoon; Koh, Yoon Seok; Park, Hun-Jun; Her, Sung-Ho; Jang, Sung Won; Park, Chul-Soo; Lee, Jong Min; Kim, Hee-Yeol; Jeon, Doo Soo; Kim, Pum-Joon; Yoo, Ki-Dong; Chang, Kiyuk; Jin, Dong Chan; Seung, Ki-Bae

    2016-01-01

    Chronic kidney disease (CKD) is a significant risk factor for contrast induced acute kidney injury (CI-AKI) after percutaneous coronary intervention (PCI). This study included 1592 CKD patients extracted from a prospective multicenter, all comer-based registry of patients undergoing PCI. In multivariate logistic analysis for CI-AKI development, a significant linear trend was observed between the quartiles of HDL-C (quartile 1 vs. 2: odds ratio [OR], 0.716; 95% confidence interval [CI], 0.421–1.219; quartile 1 vs. 3: OR, 0.534; 95% CI, 0.301–0.947; quartile 1 vs. 4: OR, 0.173; 95% CI, 0.079–0.377; P for trend < 0.001). HDL-C quartiles were also negatively correlated with the incidence of CI-AKI; 19.0%, 12.1%, 8.7%, and 3.7% for quartile 1(Q1) (<34 mg/dL), Q2 (34–40 mg/dL), Q3 (40–48 mg/dL), and Q4 (>48 mg/dL) respectively (P < 0.001 overall and for the trend). Multivariate Cox regression analysis for the long term mortality, the highest HDL-C quartile was associated with decreased mortality compared with the lowest HDL-C quartile (hazard ratio [HR] 0.516, 95% CI, 0.320–0.832, P = 0.007). Our study suggests more intensive strategies should be considered for preventing CI-AKI in CKD patients with low serum HDL-C level who is planned for PCI. PMID:27775043

  15. Hypertriglyceridaemia and low plasma HDL in a patient with apolipoprotein A-V deficiency due to a novel mutation in the APOA5 gene.

    PubMed

    Priore Oliva, C; Carubbi, F; Schaap, F G; Bertolini, S; Calandra, S

    2008-04-01

    APOA5 encodes a novel apolipoprotein (apo A-V) which appears to be a modulator of plasma triglyceride (TG). In apoA5 knock out mice plasma TG level increases almost fourfold, whereas in human APOA5 transgenic mice it decreases by 70%. Some SNPs in the APOA5 gene have been associated with variations in plasma TG in humans. In addition, hypertriglyceridaemic (HTG) patients have been identified who carried rare nonsense mutations in the APOA5 gene (Q139X and Q148X), predicted to result in apo A-V deficiency. In this study we report a 17-year-old male with high TG and low high density lipoprotein cholesterol (HDL-C), who at the age of two had been found to have severe HTG and eruptive xanthomas suggesting a chylomicronaemia syndrome. Plasma postheparin LPL activity, however, was normal and no mutations were found in LPL and APOC2 genes. The sequence of APOA5 gene revealed that the patient was homozygous for a point mutation (c.289 C>T) in exon 4, converting glutamine codon at position 97 into a termination codon (Q97X). Apo A-V was not detected in patient's plasma, indicating that he had complete apo A-V deficiency. The administration of a low-fat and low-oligosaccharide diet, either alone or supplemented with omega-3 fatty acids, started early in life, reduced plasma TG to a great extent but had a negligible effect on plasma HDL-C. Loss of function mutations of APOA5 gene may be the cause of severe HTG in patients without mutations in LPL and APOC2 genes. PMID:18324930

  16. HDL and Cognition in Neurodegenerative Disorders

    PubMed Central

    Hottman, David A.; Chernick, Dustin; Cheng, Shaowu; Wang, Zhe; Li, Ling

    2014-01-01

    High-density lipoproteins (HDL) are a heterogeneous group of lipoproteins composed of various lipids and proteins. HDL is formed both in the systemic circulation and in the brain. In addition to being a crucial player in the reverse cholesterol transport pathway, HDL possesses a wide range of other functions including anti-oxidation, anti-inflammation, pro-endothelial function, anti-thrombosis, and modulation of immune function. It has been firmly established that high plasma levels of HDL protect against cardiovascular disease. Accumulating evidence indicates that the beneficial role of HDL extends to many other systems including the central nervous system. Cognition is a complex brain function that includes all aspects of perception, thought, and memory. Cognitive function often declines during aging and this decline manifests as cognitive impairment/dementia in age-related and progressive neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. A growing concern is that no effective therapy is currently available to prevent or treat these devastating diseases. Emerging evidence suggests that HDL may play a pivotal role in preserving cognitive function under normal and pathological conditions. This review attempts to summarize recent genetic, clinical and experimental evidence for the impact of HDL on cognition in aging and in neurodegenerative disorders as well as the potential of HDL-enhancing approaches to improve cognitive function. PMID:25131449

  17. Endothelial lipase is a major determinant of HDL level

    SciTech Connect

    Ishida, Tatsuro; Choi, Sungshin; Kundu, Ramendra K.; Hirata, Ken-Ichi; Rubin, Edward M.; Cooper, Allen D.; Quertermous, Thomas

    2003-01-30

    For the past three decades, epidemiologic studies have consistently demonstrated an inverse relationship between plasma HDL cholesterol (HDL-C) concentrations and coronary heart disease (CHD). Population-based studies have provided compelling evidence that low HDL-C levels are a risk factor for CHD, and several clinical interventions that increased plasma levels of HDL-C were associated with a reduction in CHD risk. These findings have stimulated extensive investigation into the determinants of plasma HDL-C levels. Turnover studies using radiolabeled apolipoprotein A-I, the major protein component of HDL, suggest that plasma HDL-C concentrations are highly correlated with the rate of clearance of apolipoprotein AI. However, the metabolic mechanisms by which HDL are catabolized have not been fully defined. Previous studies in humans with genetic deficiency of cholesteryl ester transfer protein, and in mice lacking the scavenger receptor BI (SR-BI), have demonstrated that these proteins participate in the removal of cholesterol from HDL, while observations in individuals with mutations in hepatic lipase indicate that this enzyme hydrolyzes HDL triglycerides. In this issue of the JCI, reports from laboratories of Tom Quertermous and Dan Rader now indicate that endothelial lipase (LIPG), a newly identified member of the lipase family, catalyzes the hydrolysis of HDL phospholipids and facilitates the clearance of HDL from the circulation. Endothelial lipase was initially cloned by both of these laboratories using entirely different strategies. Quertermous and his colleagues identified endothelial lipase as a transcript that was upregulated in cultured human umbilical vein endothelial cells undergoing tube formation, whereas the Rader group cloned endothelial lipase as a transcript that was upregulated in the human macrophage-like cell line THP-1 exposed to oxidized LDL. Database searches revealed that endothelial lipase shows strong sequence similarity to lipoprotein

  18. Poland and United States Collaborative Study on Cardiovascular Epidemiology. A comparison of HDL cholesterol and its subfractions in populations covered by the United States Atherosclerosis Risk in Communities Study and the Pol-MONICA Project.

    PubMed

    Broda, G; Davis, C E; Pajak, A; Williams, O D; Rywik, S L; Baczyńska, E; Folsom, A R; Szklo, M

    1996-02-01

    HDL cholesterol (HDL-C) levels are inversely related to coronary heart disease (CHD) risk, and HDL-C distributions vary among countries. Poland is one of the few developed countries in which CHD rates are increasing at the same time that US rates have been falling, but whether these differences are explained by differences in risk factors such as HDL-C has not been determined. To examine this possibility, levels of HDL-C and its subfractions were compared in US and Polish urban and rural men and women aged 45 to 64 years. Age-adjusted HDL-C means were 0.20 mmol/L higher in urban Polish men and 0.37 mmol/L higher in rural Polish men than in their US counterparts (P < .0001); means in urban Polish women were 0.06 mmol/L higher (P < .05) and in rural Polish women 0.09 mmol/L higher (P < .001) than in their US counterparts. Adjustment for age, education, alcohol intake, smoking, BMI, heart rate, and menopause status (in women) had little effect on differences. Means of HDL2 and HDL3 levels showed similar between-country differences, although differences were minimal for HDL2 in urban men and women, and HDL3 means did not differ between rural women. BMI was inversely related to HDL-C and both subfractions in all gender-country-site strata (P < .001), and alcohol was directly related to HDL-C (P < .001) in all strata except Polish women. Cigarette smoking was negatively related to HDL-C and both subfractions in all US samples except HDL2 in urban men, whereas in Polish samples, significant associations were found only in urban women for HDL-C and in rural and urban women for HDL3. Age, heart rate, and education showed inconsistent or no association with HDL-C and its subfractions in either country. This profile of HDL-C and its subfractions in Polish samples contrasts sharply with the opposite trend in CHD mortality rates, which suggests either that other risk factors may account for the trends or that the relationship between HDL-C and CHD may differ between the two

  19. New micromethod for measuring cholesterol in plasma lipoprotein fractions.

    PubMed

    Bronzert, T J; Brewer, H B

    1977-11-01

    A method is described for the reliable, fast, and relatively inexpensive fractionation of plasma lipoproteins and quantitation of their cholesterol content. This procedure requires 350 microliter of plasma and can be completed within 3 h. Plasma lipoproteins (175 microliter of plasma) were prestained with Fat Red 7B and centrifuged (Beckman Airfuge) at plasma density (d = 1.006 kg/liter) and at a solvent density of 1.060 kg/liter, adjusted by adding solid KBr. Prestained centrifuged samples demonstrated the characteristic elevation of chylomicrons in phenotypes I and V, low-density lipoproteins of phenotype II, very-low-density lipoproteins in phenotype IV and V, and continuum of pink color throughout the centrifuge tube, diagnostic of the floating beta lipoprotein of type III. Centrifuged samples were separated into top and bottom fractions by aspiration. Cholesterol was quantitated with an enzymic oxygen-electrode analyzer (Beckman Cholesterol Analyzer). Correlation coefficients between cholesterol values for plasma from normal hyperlipidemic individuals obtained with the Beckman Analyzer vs. the Technicon AutoAnalyzer II and SMAC systems were 0.977 and 0.973, respectively.

  20. Linkage between cholesterol 7alpha-hydroxylase and high plasma low-density lipoprotein cholesterol concentrations.

    PubMed Central

    Wang, J; Freeman, D J; Grundy, S M; Levine, D M; Guerra, R; Cohen, J C

    1998-01-01

    Interindividual differences in plasma low-density lipoprotein cholesterol (LDL-C) levels reflect both environmental variation and genetic polymorphism, but the specific genes involved and their relative contributions to the variance in LDL-C are not known. In this study we investigated the relationship between plasma LDL-C concentrations and three genes with pivotal roles in LDL metabolism: the low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), and cholesterol 7alpha-hydroxylase (CYP7). Analysis of 150 nuclear families indicated statistically significant linkage between plasma LDL-C concentrations and CYP7, but not LDLR or APOB. Further sibling pair analyses using individuals with high plasma LDL-C concentrations as probands indicated that the CYP7 locus was linked to high plasma LDL-C, but not to low plasma LDL-C concentrations. This finding was replicated in an independent sample. DNA sequencing revealed two linked polymorphisms in the 5' flanking region of CYP7. The allele defined by these polymorphisms was associated with increased plasma LDL-C concentrations, both in sibling pairs and in unrelated individuals. Taken together, these findings indicate that polymorphism in CYP7 contributes to heritable variation in plasma LDL-C concentrations. Common polymorphisms in LDLR and APOB account for little of the heritable variation in plasma LDL-C concentrations in the general population. PMID:9502769

  1. Artichoke leaf extract (Cynara scolymus) reduces plasma cholesterol in otherwise healthy hypercholesterolemic adults: a randomized, double blind placebo controlled trial.

    PubMed

    Bundy, Rafe; Walker, Ann F; Middleton, Richard W; Wallis, Carol; Simpson, Hugh C R

    2008-09-01

    Cardiovascular diseases are the chief causes of death in the UK, and are associated with high circulating levels of total cholesterol in the plasma. Artichoke leaf extracts (ALEs) have been reported to reduce plasma lipids levels, including total cholesterol, although high quality data is lacking. The objective of this trial was to assess the effect of ALE on plasma lipid levels and general well-being in otherwise healthy adults with mild to moderate hypercholesterolemia. 131 adults were screened for total plasma cholesterol in the range 6.0-8.0 mmol/l, with 75 suitable volunteers randomised onto the trial. Volunteers consumed 1280 mg of a standardised ALE, or matched placebo, daily for 12 weeks. Plasma total cholesterol decreased in the treatment group by an average of 4.2% (from 7.16 (SD 0.62) mmol/l to 6.86 (SD 0.68) mmol/l) and increased in the control group by an average of 1.9% (6.90 (SD 0.49) mmol/l to 7.03 (0.61) mmol/l), the difference between groups being statistically significant (p=0.025). No significant differences between groups were observed for LDL cholesterol, HDL cholesterol or triglyceride levels. General well-being improved significantly in both the treatment (11%) and control groups (9%) with no significant differences between groups. In conclusion, ALE consumption resulted in a modest but favourable statistically significant difference in total cholesterol after 12 weeks. In comparison with a previous trial, it is suggested that the apparent positive health status of the study population may have contributed to the modesty of the observed response.

  2. Increasing amounts of dietary myristic acid modify the plasma cholesterol level and hepatic mass of scavenger receptor BI without affecting bile acid biosynthesis in hamsters.

    PubMed

    Loison, Carole; Mendy, François; Serougne, Colette; Lutton, Claude

    2002-01-01

    The purpose of this study was to analyze the effects of increasing amounts of dietary myristic acid (0.03 to 4.2% of the total dietary energy) on the plasma and hepatic cholesterol metabolism. Six groups of hamsters received semi-purified diets containing 0.05% cholesterol and 12.5% lipids and differing only by the nature of the triglycerides (Safflower oil, lard, lard/coconut oil (1:1), milk fat, milk fat/coconut oil (1:1), coconut oil) for 3 weeks. A positive regression between the plasma cholesterol level and the dietary myristic acid level was observed (r = 0.60, P < 0.0001). However, it is noteworthy that the increase in plasma total cholesterol only reflects an increase in the level of HDL-cholesterol. In parallel, the mass SR-BI decreased linearly with the increased level of myristic acid in the diet, whereas the LDL-R did not change. This study shows that increasing amounts of myristic acid (0.03 to 4.2%) do not alter the cholesterol or bile acid metabolism and increase only the HDL-C. PMID:12216956

  3. Hepatic lipase- and endothelial lipase-deficiency in mice promotes macrophage-to-feces RCT and HDL antioxidant properties.

    PubMed

    Escolà-Gil, Joan Carles; Chen, Xiangyu; Julve, Josep; Quesada, Helena; Santos, David; Metso, Jari; Tous, Monica; Jauhiainen, Matti; Blanco-Vaca, Francisco

    2013-04-01

    Hepatic lipase (HL) and endothelial lipase (EL) are negative regulators of plasma HDL cholesterol (HDLc) levels and presumably could affect two main HDL atheroprotective functions, macrophage-to-feces reverse cholesterol transport (RCT) and HDL antioxidant properties. In this study, we assessed the effects of both HL and EL deficiency on macrophage-specific RCT process and HDL ability to protect against LDL oxidation. HL- and EL-deficient and wild-type mice were injected intraperitoneally with [(3)H]cholesterol-labeled mouse macrophages, after which the appearance of [(3)H]cholesterol in plasma, liver, and feces was determined. The degree of HDL oxidation and the protection of oxidative modification of LDL co-incubated with HDL were evaluated by measuring conjugated diene kinetics. Plasma levels of HDLc, HDL phospholipids, apoA-I, and platelet-activated factor acetyl-hydrolase were increased in both HL- and EL-deficient mice. These genetically modified mice displayed increased levels of radiolabeled, HDL-bound [(3)H]cholesterol 48h after the label injection. The magnitude of macrophage-derived [(3)H]cholesterol in feces was also increased in both the HL- and EL-deficient mice. HDL from the HL- and EL-deficient mice was less prone to oxidation and had a higher ability to protect LDL from oxidation, compared with the HDL derived from the wild-type mice. These changes were correlated with plasma apoA-I and apoA-I/HDL total protein levels. In conclusion, targeted inactivation of both HL and EL in mice promoted macrophage-to-feces RCT and enhanced HDL antioxidant properties. PMID:23328279

  4. Background diet and fat type alters plasma lipoprotein response but not aortic cholesterol accumulation in F1B Golden Syrian hamsters.

    PubMed

    Dillard, Alice; Matthan, Nirupa R; Spartano, Nicole L; Butkowski, Ann E; Lichtenstein, Alice H

    2013-12-01

    Dietary modification alters plasma lipoprotein profiles and atherosclerotic lesion progression in humans and some animal models. Variability in response to diet induced atherosclerosis has been reported in hamsters. Assessed was the interaction between background diet composition and dietary fat type on aortic cholesterol accumulation, lipoprotein profiles, hepatic lipids and selected genes. F1B Golden Syrian hamsters (20/group) were fed (12 weeks) semi-purified or non-purified diets containing either 10 % (w/w) coconut oil or safflower oil and 0.15 % (w/w) cholesterol. The non-purified diets relative to semi-purified diets resulted in significantly higher TC (72 % [percent difference] and 38 %, coconut oil and safflower oil, respectively) and nHDL-C (84 and 61 %, coconut oil and safflower oil, respectively), and lower HDL-C (-47 and -45 %, coconut oil and safflower oil, respectively) concentrations. Plasma triacylglycerol concentrations in the hamsters fed the non-purified coconut oil-supplemented diets were three- to fourfold higher than non-purified safflower oil-supplemented, and both semi-purified diets. With the exception of HDL-C, a significant effect of fat type was observed in TC, nHDL-C and triacylglycerol (all P < 0.05) concentrations. Regardless of diet induced differences in lipoprotein profiles, there was no significant effect on aortic cholesterol accumulation. There was an inverse relationship between plasma nHDL-C and triacylglycerol, and hepatic cholesteryl ester content (P < 0.001). Diet induced differences in hepatic gene transcription (LDL receptor, apoB-100, microsomal transfer protein) were not reflected in protein concentrations. Although hamsters fed non-purified and/or saturated fatty acid-supplemented diets had more atherogenic lipoprotein profiles compared to hamsters fed semi-purified and/or polyunsaturated fatty acid-supplemented diets these differences were not reflected in aortic cholesterol accumulation.

  5. Effect of plant sterol-enriched diets on plasma and egg yolk cholesterol concentrations and cholesterol metabolism in laying hens.

    PubMed

    Liu, X; Zhao, H L; Thiessen, S; House, J D; Jones, P J H

    2010-02-01

    Egg exists as a major dietary source of cholesterol in Western diets. In North America, laying hen diets are usually devoid of cholesterol when diets are formulated to exclude animal-based products. Hence, laying hens meet their physiological cholesterol requirement through de novo synthesis. Plant sterols exert a cholesterol-lowering effect in humans by interfering with intestinal sterol absorption. However, it is unknown whether plant sterol supplementation could be effective in reducing intestinal reabsorption of biliary cholesterol in laying hens, thus modulating whole body cholesterol in favor of lower plasma and yolk cholesterol content. The current study was designed to investigate the effect of diets enriched with 0, 0.5, 1, and 2% plant sterols on cholesterol absorption, synthesis, as well as plasma, liver, and egg yolk cholesterol concentrations in laying hens. After 8 wk of plant sterol intervention (first 2 wk were acclimatization), feed intake, BW, egg weight, egg yolk weight, egg production, Haugh units, liver mass, plasma, and hepatic cholesterol concentrations did not differ as a function of plant sterol supplementation. Egg cholesterol concentrations (mg/g) fluctuated during the 6-wk experimental period. At wk 6, a minor reduction in egg yolk cholesterol concentration (mg per g of yolk, P<0.05, vs. control) was observed in hens fed 1 and 2% cholesterol-enriched diets, respectively. However, such result failed to affect total egg cholesterol content. No statistical difference was observed across treatments over 6 wk. Neither cholesterol absorption rates nor synthesis differed as a function of treatment. Results suggested that overall cholesterol content in egg yolk was not affected by feeding hens plant sterol-enriched diets over 6 wk. PMID:20075279

  6. Dietary cholesterol and the plasma lipids and lipoproteins in the Tarahumara Indians: a people habituated to a low cholesterol diet after weaning.

    PubMed

    McMurry, M P; Connor, W E; Cerqueira, M T

    1982-04-01

    Eight Tarahumara Indian men participated in a metabolic study to measure the responsiveness of their plasma cholesterol levels to dietary cholesterol. They were fed isocaloric cholesterol-free and high cholesterol diets containing 20% fat, 15% protein, and 65% carbohydrate calories. On admission to the study, the Tarahumaras had a low mean plasma cholesterol concentration (120 mg/dl), reflecting their habitual low cholesterol diet. After 3 wk of a cholesterol-free diet their cholesterol levels were 113 mg/dl. The men were then fed a high cholesterol diet (1000 mg/day) which increased the mean total plasma cholesterol to 147 mg/dl (p less than 0.01) and also increased the low-density lipoprotein cholesterol concentration. Tarahumaras, habituated to a low cholesterol diet after weaning, had the typical hypercholesterolemic response to a high cholesterol diet that has been previously observed in subjects whose lifelong diet was high in cholesterol content.

  7. A review on lecithin:cholesterol acyltransferase deficiency.

    PubMed

    Saeedi, Ramesh; Li, Min; Frohlich, Jiri

    2015-05-01

    Lecithin cholesterol acyl transferase (LCAT) is a plasma enzyme which esterifies cholesterol, and plays a key role in the metabolism of high-density lipoprotein cholesterol (HDL-C). Genetic disorders of LCAT are associated with lipoprotein abnormalities including low levels of HDL-C and presence of lipoprotein X, and clinical features mainly corneal opacities, changes in erythrocyte morphology and renal failure. Recombinant LCAT is being developed for the treatment of patients with LCAT deficiency. PMID:25172171

  8. Acute Cocoa Supplementation Increases Postprandial HDL Cholesterol and Insulin in Obese Adults with Type 2 Diabetes after Consumption of a High-Fat Breakfast123

    PubMed Central

    Basu, Arpita; Betts, Nancy M; Leyva, Misti J; Fu, Dongxu; Aston, Christopher E; Lyons, Timothy J

    2015-01-01

    Background: Dietary cocoa is an important source of flavonoids and is associated with favorable cardiovascular disease effects, such as improvements in vascular function and lipid profiles, in nondiabetic adults. Type 2 diabetes (T2D) is associated with adverse effects on postprandial serum glucose, lipids, inflammation, and vascular function. Objective: We examined the hypothesis that cocoa reduces metabolic stress in obese T2D adults after a high-fat fast-food–style meal. Methods: Adults with T2D [n = 18; age (mean ± SE): 56 ± 3 y; BMI (in kg/m2): 35.3 ± 2.0; 14 women; 4 men] were randomly assigned to receive cocoa beverage (960 mg total polyphenols; 480 mg flavanols) or flavanol-free placebo (110 mg total polyphenols; <0.1 mg flavanols) with a high-fat fast-food–style breakfast [766 kcal, 50 g fat (59% energy)] in a crossover trial. After an overnight fast (10–12 h), participants consumed the breakfast with cocoa or placebo, and blood sample collection [glucose, insulin, lipids, and high-sensitivity C-reactive protein (hsCRP)] and vascular measurements were conducted at 0.5, 1, 2, 4, and 6 h postprandially on each study day. Insulin resistance was evaluated by homeostasis model assessment. Results: Over the 6-h study, and specifically at 1 and 4 h, cocoa increased HDL cholesterol vs. placebo (overall Δ: 1.5 ± 0.8 mg/dL; P ≤ 0.01) but had no effect on total and LDL cholesterol, triglycerides, glucose, and hsCRP. Cocoa increased serum insulin concentrations overall (Δ: 5.2 ± 3.2 mU/L; P < 0.05) and specifically at 4 h but had no overall effects on insulin resistance (except at 4 h, P < 0.05), systolic or diastolic blood pressure, or small artery elasticity. However, large artery elasticity was overall lower after cocoa vs. placebo (Δ: −1.6 ± 0.7 mL/mm Hg; P < 0.05), with the difference significant only at 2 h. Conclusion: Acute cocoa supplementation showed no clear overall benefit in T2D patients after a high-fat fast-food–style meal challenge

  9. Atheroprotective role of high-density lipoprotein (HDL)-associated sphingosine-1-phosphate (S1P).

    PubMed

    Potì, Francesco; Simoni, Manuela; Nofer, Jerzy-Roch

    2014-08-01

    Numerous epidemiological studies documented an inverse relationship between plasma high-density lipoprotein (HDL) cholesterol levels and the extent of atherosclerotic disease. However, clinical interventions targeting HDL cholesterol failed to show clinical benefits with respect to cardiovascular risk reduction, suggesting that HDL components distinct from cholesterol may account for anti-atherogenic effects attributed to this lipoprotein. Sphingosine-1-phosphate (S1P)-a lysosphingolipid exerting its biological activity via binding to specific G protein-coupled receptors and regulating a wide array of biological responses in a variety of different organs and tissues including the cardiovascular system-has been identified as an integral constituent of HDL particles. In the present review, we discuss current evidence from epidemiological studies, experimental approaches in vitro, and animal models of atherosclerosis, suggesting that S1P contributes to atheroprotective effects exerted by HDL particles. PMID:24891400

  10. Large-Scale Candidate Gene Analysis of HDL Particle Features

    PubMed Central

    Kaess, Bernhard M.; Tomaszewski, Maciej; Braund, Peter S.; Stark, Klaus; Rafelt, Suzanne; Fischer, Marcus; Hardwick, Robert; Nelson, Christopher P.; Debiec, Radoslaw; Huber, Fritz; Kremer, Werner; Kalbitzer, Hans Robert; Rose, Lynda M.; Chasman, Daniel I.; Hopewell, Jemma; Clarke, Robert; Burton, Paul R.; Tobin, Martin D.

    2011-01-01

    Background HDL cholesterol (HDL-C) is an established marker of cardiovascular risk with significant genetic determination. However, HDL particles are not homogenous, and refined HDL phenotyping may improve insight into regulation of HDL metabolism. We therefore assessed HDL particles by NMR spectroscopy and conducted a large-scale candidate gene association analysis. Methodology/Principal Findings We measured plasma HDL-C and determined mean HDL particle size and particle number by NMR spectroscopy in 2024 individuals from 512 British Caucasian families. Genotypes were 49,094 SNPs in >2,100 cardiometabolic candidate genes/loci as represented on the HumanCVD BeadChip version 2. False discovery rates (FDR) were calculated to account for multiple testing. Analyses on classical HDL-C revealed significant associations (FDR<0.05) only for CETP (cholesteryl ester transfer protein; lead SNP rs3764261: p = 5.6*10−15) and SGCD (sarcoglycan delta; rs6877118: p = 8.6*10−6). In contrast, analysis with HDL mean particle size yielded additional associations in LIPC (hepatic lipase; rs261332: p = 6.1*10−9), PLTP (phospholipid transfer protein, rs4810479: p = 1.7*10−8) and FBLN5 (fibulin-5; rs2246416: p = 6.2*10−6). The associations of SGCD and Fibulin-5 with HDL particle size could not be replicated in PROCARDIS (n = 3,078) and/or the Women's Genome Health Study (n = 23,170). Conclusions We show that refined HDL phenotyping by NMR spectroscopy can detect known genes of HDL metabolism better than analyses on HDL-C. PMID:21283740

  11. Glucuronic acid epimerase is associated with plasma triglyceride and high-density lipoprotein cholesterol levels in Turks.

    PubMed

    Hodoğlugil, Uğur; Williamson, David W; Yu, Yi; Farrer, Lindsay A; Mahley, Robert W

    2011-05-01

    We narrowed chromosome 15q21-23 linkage to plasma high-density lipoprotein cholesterol (HDL-C) levels in Turkish families by fine mapping, then focused on glucuronic acid epimerase (GLCE), a heparan sulfate proteoglycan (HSPG) biosynthesis enzyme. HSPGs participate in lipid metabolism along with apolipoprotein (apo) E. Of 31 SNPs in the GLCE locus, nine analyzed by haplotype were associated with HDL-C and triglyceride levels (permuted p = 0.006 and 0.013, respectively) in families. Of five tagging GLCE SNPs in two cohorts of unrelated subjects, three (rs16952868, rs11631403, and rs3865014) were associated with triglyceride and HDL-C levels in males (nonpermuted p < 0.05). The association was stronger in APOE 2/3 subjects (apoE2 has reduced binding to HSPGs) and reached multiple-testing significance (p < 0.05) in both males and females (n= 2612). Similar results were obtained in the second cohort (n= 1164). Interestingly, at the GLCE locus, bounded by recombination hotspots, Turks had a minor allele frequency of SNPs resembling Chinese more than European ancestry; adjoining regions resembled the European pattern. Studies of glce(+/-) apoe(-/-) mice fed a chow or high-fat diet supported a role for GLCE in lipid metabolism. Thus, SNPs in GLCE are associated with triglyceride and HDL-C levels in Turks, and mouse studies support a role for glce in lipid metabolism.

  12. Does Glycine max leaves or Garcinia Cambogia promote weight-loss or lower plasma cholesterol in overweight individuals: a randomized control trial

    PubMed Central

    2011-01-01

    Background Natural food supplements with high flavonoid content are often claimed to promote weight-loss and lower plasma cholesterol in animal studies, but human studies have been more equivocal. The aim of this study was firstly to determine the effectiveness of natural food supplements containing Glycine max leaves extract (EGML) or Garcinia cambogia extract (GCE) to promote weight-loss and lower plasma cholesterol. Secondly to examine whether these supplements have any beneficial effect on lipid, adipocytokine or antioxidant profiles. Methods Eighty-six overweight subjects (Male:Female = 46:40, age: 20~50 yr, BMI > 23 < 29) were randomly assigned to three groups and administered tablets containing EGML (2 g/day), GCE (2 g/day) or placebo (starch, 2 g/day) for 10 weeks. At baseline and after 10 weeks, body composition, plasma cholesterol and diet were assessed. Blood analysis was also conducted to examine plasma lipoproteins, triglycerides, adipocytokines and antioxidants. Results EGML and GCE supplementation failed to promote weight-loss or any clinically significant change in %body fat. The EGML group had lower total cholesterol after 10 weeks compared to the placebo group (p < 0.05). EGML and GCE had no effect on triglycerides, non-HDL-C, adipocytokines or antioxidants when compared to placebo supplementation. However, HDL-C was higher in the EGML group (p < 0.001) after 10 weeks compared to the placebo group. Conclusions Ten weeks of EGML or GCE supplementation did not promote weight-loss or lower total cholesterol in overweight individuals consuming their habitual diet. Although, EGML did increase plasma HDL-C levels which is associated with a lower risk of atherosclerosis. PMID:21936892

  13. Sex-specific HDL Cholesterol Changes with Weight Loss and Their Association with Anthropometric variables: the LIFE Study

    PubMed Central

    Yatsuya, Hiroshi; Jeffery, Robert W; Erickson, Darin J; Welsh, Ericka M; Flood, Andrew P; Jaeb, Melanie A; Laqua, Patricia S; Mitchell, Nathan; Langer, Shelby L; Levy, Rona L

    2010-01-01

    Decrease in the level of high density lipoprotein cholesterol (HDLC) has been observed in women who start dieting, but not in men. Patterns of HDLC change during intentional weight loss through 30-months of follow-up, and their association with changes in anthropometric measurements were examined in obese women (N=112) and men (N=100). Missing HDLC values at 6-, 12-, 18-, and 30-month follow-up (N=16, 34, 55, and 50, respectively) due to drop-out were imputed by multiple imputation. Mean ages and body mass indices (BMIs) of subjects at baseline were 47.2 years and 34.8 kg/m2 for women, and 50.4 years and 35.0 kg/m2 for men. On average, participants lost weight steadily for 12 months, followed by slow regain. During the first six months, HDLC decreased significantly in women (−4.1 mg/dl, P=0.0007), but not in men. Significant HDLC increases were observed in both men and women from 6- to 12-month follow-up. HDLC changes in women were positively associated with changes in hip circumference from baseline to 12-month independent of changes in triglycerides, glucose and insulin. Rapid decrease of predominantly subcutaneous fat in the femoral and gluteal area might be associated with HDLC decrease in women during initial weight loss. PMID:20885387

  14. Impaired Cholesterol Efflux Capacity of High-Density Lipoprotein Isolated From Interstitial Fluid in Type 2 Diabetes Mellitus—Brief Report

    PubMed Central

    Tietge, Uwe J.F.; Dikkers, Arne; Parini, Paolo; Angelin, Bo; Rudling, Mats

    2016-01-01

    Objective— Patients with type 2 diabetes mellitus (T2D) have an increased risk of cardiovascular disease, the mechanism of which is incompletely understood. Their high-density lipoprotein (HDL) particles in plasma have been reported to have impaired cholesterol efflux capacity. However, the efflux capacity of HDL from interstitial fluid (IF), the starting point for reverse cholesterol transport, has not been studied. We here investigated the cholesterol efflux capacity of HDL from IF and plasma from T2D patients and healthy controls. Approach and Results— HDL was isolated from IF and peripheral plasma from 35 T2D patients and 35 age- and sex-matched healthy controls. Cholesterol efflux to HDL was determined in vitro, normalized for HDL cholesterol, using cholesterol-loaded macrophages. Efflux capacity of plasma HDL was 10% lower in T2D patients than in healthy controls, in line with previous observations. This difference was much more pronounced for HDL from IF, where efflux capacity was reduced by 28% in T2D. Somewhat surprisingly, the efflux capacity of HDL from IF was lower than that of plasma HDL, by 15% and 32% in controls and T2D patients, respectively. Conclusion— These data demonstrate that (1) HDL from IF has a lower cholesterol efflux capacity than plasma HDL and (2) the efflux capacity of HDL from IF is severely impaired in T2D when compared with controls. Because IF comprises the compartment where reverse cholesterol transport is initiated, the marked reduction in cholesterol efflux capacity of IF-HDL from T2D patients may play an important role for their increased risk to develop atherosclerosis. PMID:27034474

  15. Cis-9, trans-11 and trans-10, cis-12 CLA mixture does not change body composition, induces insulin resistance and increases serum HDL cholesterol level in rats.

    PubMed

    de Almeida, Mariana Macedo; de Souza, Yamara Oliveira; Dutra Luquetti, Sheila Cristina Potente; Sabarense, Céphora Maria; do Amaral Corrêa, José Otávio; da Conceição, Ellen Paula Santos; Lisboa, Patrícia Cristina; de Moura, Egberto Gaspar; Andrade Soares, Sara Malaguti; Moura Gualberto, Ana Cristina; Gameiro, Jacy; da Gama, Marco Antônio Sundfeld; Ferraz Lopes, Fernando César; González Garcia, Raúl Marcel

    2015-01-01

    Synthetic supplements of conjugated linoleic acid (CLA) containing 50:50 mixture of cis-9, trans-11 and trans-10, cis-12 CLA isomers have been commercialized in some places for reducing body fat. However the safety of this CLA mixture is controversial and in some countries the CLA usage as food supplement is not authorized. Changes in insulinemic control and serum lipids profile are potential negative effects related to consumption of CLA mixture. The present study aimed to evaluate the effects of a diet containing mixture of cis-9, trans-11 and trans-10, cis-12 CLA on prevention of obesity risk as well as on potential side effects such as insulin resistance and dyslipidemia in Wistar rats. Thirty male Wistar rats were randomly assigned to the following dietary treatments (n=10/group), for 60 days: Normolipidic Control (NC), diet containing 4.0% soybean oil (SO); High Fat-Control (HF-C), diet containing 24.0% SO; High Fat-synthetic CLA (HF-CLA), diet containing 1.5% of an isomeric CLA mixture (Luta-CLA 60) and 22.5% SO. Luta-CLA 60 (BASF) contained nearly 60% of CLA (cis-9, trans-11 and trans-10, cis-12 CLA at 50:50 ratio). The HF-CLA diet contained 0.3% of each CLA isomer. HF-CLA diet had no effect on dietary intake and body composition. HF-CLA-fed rats had lower levels of PPARγ protein in retroperitoneal adipose tissue, hyperinsulinemia compared to HF-C-fed rats, hyperglycemia compared to NC-fed rats while no differences in glycemia were observed between NC and HF-C groups, increased HOMA index and higher levels of serum HDL cholesterol. Thus, feeding rats with a high fat diet containing equal parts of cis-9, trans-11 and trans-10, cis-12 CLA isomers had no effect on body composition and induced insulin resistance. Despite HF-CLA-fed rats had increased serum HDL cholesterol levels, caution should be taken before synthetic supplements containing cis-9, trans-11 and trans-10, cis-12 CLA are recommended as a nutritional strategy for weight management.

  16. Association of HDL-Related Loci with Age-Related Macular Degeneration and Plasma Lutein and Zeaxanthin: the Alienor Study

    PubMed Central

    Merle, Bénédicte M. J.; Maubaret, Cécilia; Korobelnik, Jean-François; Delyfer, Marie-Noëlle; Rougier, Marie-Bénédicte; Lambert, Jean-Charles; Amouyel, Philippe; Malet, Florence; Le Goff, Mélanie; Dartigues, Jean-François; Barberger-Gateau, Pascale; Delcourt, Cécile

    2013-01-01

    Background Several genes implicated in high-density lipoprotein (HDL) metabolism have been reported to be associated with age-related macular degeneration (AMD). Furthermore, HDL transport the two carotenoids, lutein and zeaxanthin, which are highly suspected to play a key-role in the protection against AMD. The objective is to confirm the associations of HDL-related loci with AMD and to assess their associations with plasma lutein and zeaxanthin concentrations. Methods Alienor study is a prospective population-based study on nutrition and age-related eye diseases performed in 963 elderly residents of Bordeaux, France. AMD was graded according to the international classification, from non-mydriatic colour retinal photographs. Plasma lutein and zeaxanthin were determined by normal-phase high-performance liquid chromatography. The following polymorphisms were studied: rs493258 and rs10468017 (LIPC), rs3764261 (CETP), rs12678919 (LPL) and rs1883025 (ABCA1). Results After multivariate adjustment, the TT genotype of the LIPC rs493258 variant was significantly associated with a reduced risk for early and late AMD (OR=0.64, 95%CI: 0.41-0.99; p=0.049 and OR=0.26, 95%CI: 0.08-0.85; p=0.03, respectively), and with higher plasma zeaxanthin concentrations (p=0.03), while plasma lipids were not significantly different according to this SNP. Besides, the LPL variant was associated with early AMD (OR=0.67, 95%CI: 0.45-1.00; p=0.05) and both with plasma lipids and plasma lutein (p=0.047). Associations of LIPC rs10468017, CETP and ABCA1 polymorphisms with AMD did not reach statistical significance. Conclusion These findings suggest that LIPC and LPL genes could both modify the risk for AMD and the metabolism of lutein and zeaxanthin. PMID:24223199

  17. CC-Chemokine Ligand 2 (CCL2) Suppresses High Density Lipoprotein (HDL) Internalization and Cholesterol Efflux via CC-Chemokine Receptor 2 (CCR2) Induction and p42/44 Mitogen-activated Protein Kinase (MAPK) Activation in Human Endothelial Cells.

    PubMed

    Sun, Run-Lu; Huang, Can-Xia; Bao, Jin-Lan; Jiang, Jie-Yu; Zhang, Bo; Zhou, Shu-Xian; Cai, Wei-Bin; Wang, Hong; Wang, Jing-Feng; Zhang, Yu-Ling

    2016-09-01

    High density lipoprotein (HDL) has been proposed to be internalized and to promote reverse cholesterol transport in endothelial cells (ECs). However, the mechanism underlying these processes has not been studied. In this study, we aim to characterize HDL internalization and cholesterol efflux in ECs and regulatory mechanisms. We found mature HDL particles were reduced in patients with coronary artery disease (CAD), which was associated with an increase in CC-chemokine ligand 2 (CCL2). In cultured primary human coronary artery endothelial cells and human umbilical vein endothelial cells, we determined that CCL2 suppressed the binding (4 °C) and association (37 °C) of HDL to/with ECs and HDL cellular internalization. Furthermore, CCL2 inhibited [(3)H]cholesterol efflux to HDL/apoA1 in ECs. We further found that CCL2 induced CC-chemokine receptor 2 (CCR2) expression and siRNA-CCR2 reversed CCL2 suppression on HDL binding, association, internalization, and on cholesterol efflux in ECs. Moreover, CCL2 induced p42/44 mitogen-activated protein kinase (MAPK) phosphorylation via CCR2, and p42/44 MAPK inhibition reversed the suppression of CCL2 on HDL metabolism in ECs. Our study suggests that CCL2 was elevated in CAD patients. CCL2 suppressed HDL internalization and cholesterol efflux via CCR2 induction and p42/44 MAPK activation in ECs. CCL2 induction may contribute to impair HDL function and form atherosclerosis in CAD.

  18. CC-Chemokine Ligand 2 (CCL2) Suppresses High Density Lipoprotein (HDL) Internalization and Cholesterol Efflux via CC-Chemokine Receptor 2 (CCR2) Induction and p42/44 Mitogen-activated Protein Kinase (MAPK) Activation in Human Endothelial Cells *

    PubMed Central

    Sun, Run-Lu; Huang, Can-Xia; Bao, Jin-Lan; Jiang, Jie-Yu; Zhang, Bo; Zhou, Shu-Xian; Cai, Wei-Bin; Wang, Hong; Wang, Jing-Feng; Zhang, Yu-Ling

    2016-01-01

    High density lipoprotein (HDL) has been proposed to be internalized and to promote reverse cholesterol transport in endothelial cells (ECs). However, the mechanism underlying these processes has not been studied. In this study, we aim to characterize HDL internalization and cholesterol efflux in ECs and regulatory mechanisms. We found mature HDL particles were reduced in patients with coronary artery disease (CAD), which was associated with an increase in CC-chemokine ligand 2 (CCL2). In cultured primary human coronary artery endothelial cells and human umbilical vein endothelial cells, we determined that CCL2 suppressed the binding (4 °C) and association (37 °C) of HDL to/with ECs and HDL cellular internalization. Furthermore, CCL2 inhibited [3H]cholesterol efflux to HDL/apoA1 in ECs. We further found that CCL2 induced CC-chemokine receptor 2 (CCR2) expression and siRNA-CCR2 reversed CCL2 suppression on HDL binding, association, internalization, and on cholesterol efflux in ECs. Moreover, CCL2 induced p42/44 mitogen-activated protein kinase (MAPK) phosphorylation via CCR2, and p42/44 MAPK inhibition reversed the suppression of CCL2 on HDL metabolism in ECs. Our study suggests that CCL2 was elevated in CAD patients. CCL2 suppressed HDL internalization and cholesterol efflux via CCR2 induction and p42/44 MAPK activation in ECs. CCL2 induction may contribute to impair HDL function and form atherosclerosis in CAD. PMID:27458015

  19. Association between periodontal disease and plasma levels of cholesterol and triglycerides

    PubMed Central

    Lafaurie, Gloria Inés; Millán, Lina Viviana; Ardila, Carlos Martin; Duque, Andrés; Novoa, Camilo; López, Diego; Contreras, Adolfo

    2013-01-01

    Objective: untreated periodontal disease seems to cause low grade systemic inflammation and blood lipid alteration leading to increased cardiovascular disease risk. To start testing this hypothesis in colombian patients, a multicentre study was conducted including the three main state capitals: bogota, medellin and cali. Methods: in this study 192 (28.4%) advanced and 256 (37.8%) moderate periodontitis patients were investigated for socio-demographic variables, city of precedence, periodontal parameters, smoking, red complex periodontopathic bacteria, serum antibodies against porphyromonas gingivalis and aggregatibacter actinomycetemcomitans and blood lipids including total cholesterol, hdl, ldl and triglycerides (tg). Those parameters were compared to 229 (33.8%) controls having periodontal health or gingivitis. Results: advanced periodontitis had worst periodontal indexes, than moderate periodontitis and controls. Interestingly, higher hdl and tg levels were present in periodontitis. Bmi <30 and smoking were associated with increased hdl, hdl-35, ldl and tg, while glycemia >100 mg/dl associated with hdl, hdl-35 and tg. Tannerella forsythia showed a significant association with hdl-35 in bivariate analysis and serum igg1 against p. Gingivalis associated with hdl-35 and serum igg1 against t. Forsythia associated with tg and serum igg2 against a. Actinomycetemcomitans correlated with levels of hdl y hdl-35. In logistic regression the periodontitis patients from cali presented reduced hdl levels as compared to bogota and medellin patients. Presence of igg1 antibodies against p. Gingivalis and a. Actinomycetemcomitans correlated with reduced hdl levels. Conclusion: this study confirmed that untreated periodontitis generates alteration in serum lipid levels and systemic bacterial exposure against important periodontopathic bacteria could be the biological link. PMID:24892452

  20. Bile acids reduce endocytosis of high-density lipoprotein (HDL) in HepG2 cells.

    PubMed

    Röhrl, Clemens; Eigner, Karin; Fruhwürth, Stefanie; Stangl, Herbert

    2014-01-01

    High-density lipoprotein (HDL) transports lipids to hepatic cells and the majority of HDL-associated cholesterol is destined for biliary excretion. Cholesterol is excreted into the bile directly or after conversion to bile acids, which are also present in the plasma as they are effectively reabsorbed through the enterohepatic cycle. Here, we provide evidence that bile acids affect HDL endocytosis. Using fluorescent and radiolabeled HDL, we show that HDL endocytosis was reduced in the presence of high concentrations of taurocholate, a natural non-cell-permeable bile acid, in human hepatic HepG2 and HuH7 cells. In contrast, selective cholesteryl-ester (CE) uptake was increased. Taurocholate exerted these effects extracellularly and independently of HDL modification, cell membrane perturbation or blocking of endocytic trafficking. Instead, this reduction of endocytosis and increase in selective uptake was dependent on SR-BI. In addition, cell-permeable bile acids reduced HDL endocytosis by farnesoid X receptor (FXR) activation: chenodeoxycholate and the non-steroidal FXR agonist GW4064 reduced HDL endocytosis, whereas selective CE uptake was unaltered. Reduced HDL endocytosis by FXR activation was independent of SR-BI and was likely mediated by impaired expression of the scavenger receptor cluster of differentiation 36 (CD36). Taken together we have shown that bile acids reduce HDL endocytosis by transcriptional and non-transcriptional mechanisms. Further, we suggest that HDL endocytosis and selective lipid uptake are not necessarily tightly linked to each other.

  1. Bile acids reduce endocytosis of high-density lipoprotein (HDL) in HepG2 cells.

    PubMed

    Röhrl, Clemens; Eigner, Karin; Fruhwürth, Stefanie; Stangl, Herbert

    2014-01-01

    High-density lipoprotein (HDL) transports lipids to hepatic cells and the majority of HDL-associated cholesterol is destined for biliary excretion. Cholesterol is excreted into the bile directly or after conversion to bile acids, which are also present in the plasma as they are effectively reabsorbed through the enterohepatic cycle. Here, we provide evidence that bile acids affect HDL endocytosis. Using fluorescent and radiolabeled HDL, we show that HDL endocytosis was reduced in the presence of high concentrations of taurocholate, a natural non-cell-permeable bile acid, in human hepatic HepG2 and HuH7 cells. In contrast, selective cholesteryl-ester (CE) uptake was increased. Taurocholate exerted these effects extracellularly and independently of HDL modification, cell membrane perturbation or blocking of endocytic trafficking. Instead, this reduction of endocytosis and increase in selective uptake was dependent on SR-BI. In addition, cell-permeable bile acids reduced HDL endocytosis by farnesoid X receptor (FXR) activation: chenodeoxycholate and the non-steroidal FXR agonist GW4064 reduced HDL endocytosis, whereas selective CE uptake was unaltered. Reduced HDL endocytosis by FXR activation was independent of SR-BI and was likely mediated by impaired expression of the scavenger receptor cluster of differentiation 36 (CD36). Taken together we have shown that bile acids reduce HDL endocytosis by transcriptional and non-transcriptional mechanisms. Further, we suggest that HDL endocytosis and selective lipid uptake are not necessarily tightly linked to each other. PMID:25010412

  2. Reduced glomerular filtration rate, inflammation and HDL cholesterol as main determinants of superoxide production in non-dialysis chronic kidney disease patients.

    PubMed

    Morena, Marion; Patrier, Laure; Jaussent, Isabelle; Bargnoux, Anne-Sophie; Dupuy, Anne-Marie; Badiou, Stéphanie; Leray-Moragues, Hélène; Klouche, Kada; Canaud, Bernard; Cristol, Jean-Paul

    2011-06-01

    Enhanced oxidative stress partly resulting from an over-production of superoxide anion (O(2)(•-)) represents a novel and particular risk factor in chronic kidney disease (CKD) patients. This study was therefore designed to evaluate O(2)(•-) determinants in this population. O(2)(•-) production was evaluated using chemiluminescence method in 136 CKD patients (79M/57F, median age: 69.5 [27.4-94.6]). Renal function (evaluated by the glomerular filtration rate using modification of diet in renal disease (MDRD)), inflammation, lipids, nutritional and bone mineral as well as clinical parameters were evaluated. Potential relationships between O(2)(•-) and these clinico-biological parameters were investigated to identify main determinants of such a pathological process. Enhanced O(2)(•-) production has been observed at the pre-dialysis phase: stages 4 and 5 of CKD (p = 0.0065). In multivariate analysis, low eGFR (MDRD <30 mL/min/1.73 m(2); p = 0.046), high fibrinogen (≥3.7 g/L; p = 0.044) and abnormal HDL cholesterol (<1.42 mmol/L and ≥ 1.75 mmol/L; p = 0.042) were the main determinants of O(2)(•-) production in CKD patients.

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

    PubMed Central

    Subedi, Bishnu H; Joshi, Parag H; Jones, Steven R; Martin, Seth S; Blaha, Michael J; Michos, Erin D

    2014-01-01

    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. PMID:24748800

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

    PubMed

    Subedi, Bishnu H; Joshi, Parag H; Jones, Steven R; Martin, Seth S; Blaha, Michael J; Michos, Erin D

    2014-01-01

    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.

  5. Novel method for reducing plasma cholesterol: a ligand replacement therapy

    PubMed Central

    Anantharamaiah, GM; Goldberg, Dennis

    2015-01-01

    Despite wide use of statins, significant cardiovascular disease risk persists. High-density lipoprotein based therapy has not yielded any positive results in combating this disease. Newer methods to rapidly decrease plasma cholesterol are much needed. While apolipoprotein B is a ligand for low-density lipoprotein receptor, which clears low-density lipoprotein cholesterol in a highly regulated pathway, apolipoprotein E (apoE) is a ligand for clearing other apolipoprotein B containing atherogenic lipoproteins via an alternate receptor pathway, especially the heparin sulfate proteoglycans on the liver cell surface. We describe here a novel method that replaces apoE as a ligand to clear all of the atherogenic lipoproteins via the heparin sulfate proteoglycans pathway. This ligand replacement apoE mimetic peptide therapy, having been designated as an orphan drug by the US FDA, is in clinical trials. PMID:25937835

  6. Modulation of HDL metabolism by the niacin receptor GPR109A in mouse hepatocytes.

    PubMed

    Li, Xiaoyu; Millar, John S; Brownell, Nicholas; Briand, François; Rader, Daniel J

    2010-11-01

    The niacin receptor GPR109A is a G(i)-protein-coupled receptor which mediates the effects of niacin on inhibiting intracellular triglyceride lipolysis in adipocytes. However, the role of GPR109A in mediating the effects of niacin on high density lipoprotein (HDL) metabolism is unclear. We found niacin has no effect on HDL-C in GPR109A knockout mice. Furthermore, niacin lowered intracellular cAMP in primary hepatocytes mediated by GPR109A. We used an adeno-associated viral (AAV) serotype 8 vector encoding GPR109A under the control of the hepatic-specific thyroxine-binding globulin promoter to specifically overexpress GPR109A in mouse liver. Plasma HDL-C, hepatic ABCA1 and the HDL cholesterol production rate were significantly reduced in mice overexpressing GPR109A. Overexpression of GPR109A reduced primary hepatocyte free cholesterol efflux to apoA-I; conversely, GPR109A deficient hepatocytes had increased ABCA1-mediated cholesterol efflux. These data support the concept that the HDL-C lowering effect of niacin in wild-type mice is mediated through stimulation of GPR109A in hepatocytes; such an effect then leads to reduced hepatocyte ABCA1 expression and activity, decreased cholesterol efflux to nascent apoA-I, and reduced HDL-C levels. These results indicate that niacin-mediated activation of GP109A in liver lowers ABCA1 expression leading to reduced hepatic cholesterol efflux to HDL.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. The role of the lymphatic system in cholesterol transport

    PubMed Central

    Huang, Li-Hao; Elvington, Andrew; Randolph, Gwendalyn J.

    2015-01-01

    Reverse cholesterol transport (RCT) is the pathway for removal of peripheral tissue cholesterol and involves transport of cholesterol back to liver for excretion, starting from cellular cholesterol efflux facilitated by lipid-free apolipoprotein A1 (ApoA1) or other lipidated high-density lipoprotein (HDL) particles within the interstitial space. Extracellular cholesterol then is picked up and transported through the lymphatic vasculature before entering into bloodstream. There is increasing evidence supporting a role for enhanced macrophage cholesterol efflux and RCT in ameliorating atherosclerosis, and recent data suggest that these processes may serve as better diagnostic biomarkers than plasma HDL levels. Hence, it is important to better understand the processes governing ApoA1 and HDL influx into peripheral tissues from the bloodstream, modification and facilitation of cellular cholesterol removal within the interstitial space, and transport through the lymphatic vasculature. New findings will complement therapeutic strategies for the treatment of atherosclerotic vascular disease. PMID:26388772

  9. Degradation of plasma membrane phosphatidylcholine appears not to affect the cellular cholesterol distribution.

    PubMed

    Pörn, M I; Ares, M P; Slotte, J P

    1993-08-01

    To clarify the role of possible cholesterol/phosphatidylcholine interactions in cellular cholesterol distribution, we have used a phosphatidylcholine-specific phospholipase C from Bacillus cereus to degrade the cell surface phosphatidylcholine of cultured human fibroblasts. Of cellular phosphatidylcholine, approximately 15% was susceptible to degradation by the phospholipase. In spite of the dramatic redistribution of cellular cholesterol that can be observed after sphingomyelin depletion, the degradation of cell surface phosphatidylcholine did not affect the distribution of cholesterol in fibroblasts. In cholesterol-depleted cells as well as in cholesterol-loaded cells, the size of the cell surface cholesterol pool (susceptible to cholesterol oxidase) remained unchanged after phosphatidylcholine degradation. The rate of cholesterol esterification with [3H]oleic acid and the rate of [3H]cholesterol efflux from fibroblasts to high density lipoproteins also remained unchanged after degradation of plasma membrane phosphatidylcholine. An increase in the level of [3H]cholesterol efflux to high density lipoproteins was observed after degradation of plasma membrane sphingomyelin with exogenous sphingomyelinase, in-contrast to earlier reports, where no such effect was observed. The results suggest that interactions between cholesterol and phosphatidylcholine in the fibroblast plasma membranes are less important than cholesterol/sphingomyelin interactions for the asymmetric distribution of cellular cholesterol.

  10. Xanthophylls, phytosterols and pre-β1-HDL are differentially affected by fenofibrate and niacin HDL-raising in a cross-over study.

    PubMed

    Niesor, Eric J; Gauthamadasa, Kekulawalage; Silva, R A Gangani D; Suchankova, Gabriela; Kallend, David; Gylling, Helena; Asztalos, Bela; Damonte, Elisabetta; Rossomanno, Simona; Abt, Markus; Davidson, W Sean; Benghozi, Renee

    2013-12-01

    Fenofibrate and extended-release (ER) niacin similarly raise high-density lipoprotein cholesterol (HDL-C) concentration but their effects on levels of potent plasma antioxidant xanthophylls (lutein and zeaxanthin) and phytosterols obtained from dietary sources, and any relationship with plasma lipoproteins and pre-β1-HDL levels, have not been investigated. We studied these parameters in 66 dyslipidemic patients treated for 6 week with fenofibrate (160 mg/day) or ER-niacin (0.5 g/day for 3 week, then 1 g/day) in a cross-over study. Both treatments increased HDL-C (16 %) and apolipoprotein (apo) A-I (7 %) but only fenofibrate increased apoA-II (28 %). Lutein and zeaxanthin levels were unaffected by fenofibrate but inversely correlated with percentage change in apoB and low-density lipoprotein cholesterol and positively correlated with end of treatment apoA-II. ApoA-II in isolated HDL in vitro bound more lutein than apoA-I. Xanthophylls were increased by ER-niacin (each ~30 %) without any correlation to lipoprotein or apo levels. Only fenofibrate markedly decreased plasma markers of cholesterol absorption; pre-β1-HDL was significantly decreased by fenofibrate (-19 %, p < 0.0001), with little change (3.4 %) for ER-niacin. Although fenofibrate and ER-niacin similarly increased plasma HDL-C and apoA-I, effects on plasma xanthophylls, phytosterols and pre-β1-HDL differed markedly, suggesting differences in intestinal lipidation of HDL. In addition, the in vitro investigations suggest an important role of plasma apoA-II in xanthophyll metabolism.

  11. Protective Effects of HDL Against Ischemia/Reperfusion Injury

    PubMed Central

    Gomaraschi, Monica; Calabresi, Laura; Franceschini, Guido

    2016-01-01

    Several lines of evidence suggest that, besides being a strong independent predictor of the occurrence of primary coronary events, a low plasma high density lipoprotein (HDL) cholesterol level is also associated with short- and long-term unfavorable prognosis in patients, who have recovered from a myocardial infarction, suggesting a direct detrimental effect of low HDL on post-ischemic myocardial function. Experiments performed in ex vivo and in vivo models of myocardial ischemia/reperfusion (I/R) injury have clearly shown that HDL are able to preserve cardiac function when given before ischemia or at reperfusion; the protective effects of HDL against I/R injury have been also confirmed in other tissues and organs, as brain and hind limb. HDL were shown to act on coronary endothelial cells, by limiting the increase of endothelium permeability and promoting vasodilation and neoangiogenesis, on white blood cells, by reducing their infiltration into the ischemic tissue and the release of pro-inflammatory and matrix-degrading molecules, and on cardiomyocytes, by preventing the activation of the apoptotic cascade. Synthetic HDL retains the cardioprotective activity of plasma-derived HDL and may become a useful adjunctive therapy to improve clinical outcomes in patients with acute coronary syndromes or undergoing coronary procedures. PMID:26834639

  12. The effects of ABCG5/G8 polymorphisms on HDL-cholesterol concentrations depend on ABCA1 genetic variants in the Boston Puerto Rican health study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background and aims: ATP-binding cassette transporters G5/G8 (ABCG5/G8) are associated with HDL-C concentrations. To assess whether the effect of ABCG5/G8 genetic variants on HDL-C concentrations is dependent on ATP-binding cassette transporters A1 (ABCA1), we studied potential interactions between ...

  13. [Comparative study of the consumption of virgin olive oil or seje on lipid profile and oxidation resistance of high density lipoprotein (HDL) of rat plasma].

    PubMed

    Isabel Giacopini, María; Guerrero, Omaira; Moya, Manuel; Bosch, Virgilio

    2011-06-01

    We compared the effect of the consumption of seje oil (Oenocarpus bataua), with that of olive oil, on plasma lipids and susceptibility in vitro to oxidation of high density lipoprotein (HDL) in the rat. Two groups often male Sprague Dawley rats were fed ad libitum, for a lapse of eight week, with a purified diets with 10g de seje oil or olive oil/100 g of diet (GS y GO respectively). The animals were exsanguinated at the end of the experimental after a 14 hour fast. Plasma was isolated by centrifugation, and the fractions of lipoproteins were separated from the plasma by sequential ultracentrifugation. Rats of GO had a statistically significant lower in concentration of TG (p < 0.05) compared with GS group. HDL fractions in both groups were oxidatively modified by incubation with copper ions. Differences in the fractions susceptibilities to peroxidation were studied by measuring the formation of thiobarbituric acid reactive substance (TBARS) for 3 hours. HDL in GS had a statistically significant decrease in TBARS formation (p < 0.05) relative to HDL of GO. This may be explained by the lower concentration of polyunsaturated fatty acids of HDL in GS compared with HDL in GO.

  14. Expression of the human apolipoprotein A-I gene in transgenic mice alters high density lipoprotein (HDL) particle size distribution and diminishes selective uptake of HDL cholesteryl esters

    SciTech Connect

    Chajekshaul, T.; Hayek, T.; Walsh, A.; Breslow, J.L. )

    1991-08-01

    Transgenic mice carrying the human apolipoprotein (apo) A-I gene (HuAITg mice) were used to examine the effects of overexpression of the human gene on high density lipoprotein (HDL) particle size distribution and metabolism. On a chow diet, control mice had HDL cholesterol and apo A-I levels of 49 {plus minus} 2 and 137 {plus minus} 12 mg/dl of plasma, respectively. HuAITg mice had HDL cholesterol, human apo A-I, and mouse apo A-I levels of 88 {plus minus} 2, 255 {plus minus} 19, and 16 {plus minus} 2 mg/dl, respectively. Nondenaturing gradient gel electrophoresis revealed control mouse plasma HDL to be primarily monodisperse with a particle diameter of 10.2 nm, whereas HuAITg mouse plasma HDL was polydisperse with particles of diameter 11.4, 10.2, and 8.7 nm, which correspond in size to human HDL1, HDL2, and HDL3, respectively. In vivo turnover studies of HDL labeled with (3H)cholesteryl linoleyl ether and 125I-apo A-I were performed. In control animals, the fractional catabolic rate (FCR) for HDL cholesteryl ester was significantly more than the apo A-I FCR. In the HuAITg mice, the HDL cholesteryl ester FCR was the same as the apo A-I FCR. There were no significant differences between control and HuAITg animals in the sites of tissue removal of HDL cholesteryl ester, with the liver extracting most of the injected radioactivity. Control and HuAITg animals had comparable liver and intestinal cholesterol synthesis and LDL FCR. In conclusion, HuAITg mice have principally human and not mouse apo A-I in their plasma. This apparently causes a change in HDL particle size distribution in the transgenic mice to one resembling the human pattern. The replacement of mouse by human apo A-I also apparently causes the loss of the selective uptake pathway of HDL cholesteryl esters present in control mice.

  15. A genetic variant of the CAPN10 gene in Mexican subjects with dyslipidemia is associated with increased HDL-cholesterol concentrations after the consumption of a soy protein and soluble fiber dietary portfolio.

    PubMed

    Guevara-Cruz, Martha; Torres, Nimbe; Tovar, Armando R; Tejero, M Elizabeth; Castellanos-Jankiewicz, Ashley; del Bosque-Plata, Laura

    2014-09-01

    Dyslipidemia is a major public health problem, and therefore, it is important to develop dietary strategies to diminish the prevalence of this disorder. It was recently reported that diet may play an important role in triggering insulin resistance by interacting with genetic variants at the CAPN10 gene locus in patients with metabolic syndrome. Nonetheless, it remains unknown whether genetic variants of genes involved in the development of type 2 diabetes are associated with variations in high-density lipoprotein cholesterol (HDL-C). The study used a single-center, prospective, cohort design. Here, we assessed the effect of four variants of the CAPN10 gene on HDL-C levels in response to a soy protein and soluble fiber dietary portfolio in subjects with dyslipidemia. In 31 Mexican dyslipidemic individuals, we analyzed four CAPN10 gene variants (rs5030952, rs2975762, rs3792267, and rs2975760) associated with type 2 diabetes. Subjects with the GG genotype of the rs2975762 variant of the CAPN10 gene were better responders to dietary intervention, showing increased HDL-C concentrations from the first month of treatment. HDL-C concentrations in participants with the wild type genotype increased by 17.0%, whereas the HDL-C concentration in subjects with the variant genotypes increased by only 3.22% (p = 0.03); the low-density lipoprotein cholesterol levels of GG carriers tended to decrease (-12.6%). These results indicate that Mexican dyslipidemic carriers of the rs2975762-GG genotype are better responders to this dietary intervention.

  16. Forty-three loci associated with plasma lipoprotein size, concentration, and cholesterol content in genome-wide analysis.

    PubMed

    Chasman, Daniel I; Paré, Guillaume; Mora, Samia; Hopewell, Jemma C; Peloso, Gina; Clarke, Robert; Cupples, L Adrienne; Hamsten, Anders; Kathiresan, Sekar; Mälarstig, Anders; Ordovas, José M; Ripatti, Samuli; Parker, Alex N; Miletich, Joseph P; Ridker, Paul M

    2009-11-01

    While conventional LDL-C, HDL-C, and triglyceride measurements reflect aggregate properties of plasma lipoprotein fractions, NMR-based measurements more accurately reflect lipoprotein particle concentrations according to class (LDL, HDL, and VLDL) and particle size (small, medium, and large). The concentrations of these lipoprotein sub-fractions may be related to risk of cardiovascular disease and related metabolic disorders. We performed a genome-wide association study of 17 lipoprotein measures determined by NMR together with LDL-C, HDL-C, triglycerides, ApoA1, and ApoB in 17,296 women from the Women's Genome Health Study (WGHS). Among 36 loci with genome-wide significance (P<5x10(-8)) in primary and secondary analysis, ten (PCCB/STAG1 (3q22.3), GMPR/MYLIP (6p22.3), BTNL2 (6p21.32), KLF14 (7q32.2), 8p23.1, JMJD1C (10q21.3), SBF2 (11p15.4), 12q23.2, CCDC92/DNAH10/ZNF664 (12q24.31.B), and WIPI1 (17q24.2)) have not been reported in prior genome-wide association studies for plasma lipid concentration. Associations with mean lipoprotein particle size but not cholesterol content were found for LDL at four loci (7q11.23, LPL (8p21.3), 12q24.31.B, and LIPG (18q21.1)) and for HDL at one locus (GCKR (2p23.3)). In addition, genetic determinants of total IDL and total VLDL concentration were found at many loci, most strongly at LIPC (15q22.1) and APOC-APOE complex (19q13.32), respectively. Associations at seven more loci previously known for effects on conventional plasma lipid measures reveal additional genetic influences on lipoprotein profiles and bring the total number of loci to 43. Thus, genome-wide associations identified novel loci involved with lipoprotein metabolism-including loci that affect the NMR-based measures of concentration or size of LDL, HDL, and VLDL particles-all characteristics of lipoprotein profiles that may impact disease risk but are not available by conventional assay. PMID:19936222

  17. Effect of fermented milk containing Lactobacillus acidophilus and Bifidobacterium longum on plasma lipids of women with normal or moderately elevated cholesterol.

    PubMed

    Andrade, Sara; Borges, Nuno

    2009-11-01

    This study aimed to evaluate the effect of milk fermented with Lactobacillus acidophilus 145 and Bifidobacterium longum BB536 on plasma lipids in a sample of adult women. A double-blind, placebo controlled, cross-over study (two periods of four weeks each separated by a 1-week washout period) was performed in 34 women, aged between 18 and 65 years. Group A consumed 125 g fermented milk three times a day for the first 4 weeks while group B consumed regular yoghurt under the same conditions. (Groups A and B switched products for the second treatment period). Women taking the test product with a baseline total cholesterol above 190 mg/dl showed a significant reduction in LDL cholesterol. HDL cholesterol was also reduced by the test product. We conclude that the fermented milk may help to reduce LDL levels in hypercholesterolemic adult women.

  18. Sphingolipid domains in the plasma membranes of fibroblasts are not enriched with cholesterol

    SciTech Connect

    Frisz, Jessica F.; Klitzing, Haley A.; Lou, Kaiyan; Hutcheon, Ian D.; Weber, Peter K.; Zimmerberg, Joshua; Kraft, Mary L.

    2013-04-22

    The plasma membranes of mammalian cells are widely expected to contain domains that are enriched with cholesterol and sphingolipids. In this work, we have used high-resolution secondary ion mass spectrometry to directly map the distributions of isotope-labeled cholesterol and sphingolipids in the plasma membranes of intact fibroblast cells. Although acute cholesterol depletion reduced sphingolipid domain abundance, cholesterol was evenly distributed throughout the plasma membrane and was not enriched within the sphingolipid domains. As a result, we rule out favorable cholesterol-sphingolipid interactions as dictating plasma membrane organization in fibroblast cells. Because the sphingolipid domains are disrupted by drugs that depolymerize the cells actin cytoskeleton, cholesterol must instead affect the sphingolipid organization via an indirect mechanism that involves the cytoskeleton.

  19. Sphingolipid domains in the plasma membranes of fibroblasts are not enriched with cholesterol

    DOE PAGESBeta

    Frisz, Jessica F.; Klitzing, Haley A.; Lou, Kaiyan; Hutcheon, Ian D.; Weber, Peter K.; Zimmerberg, Joshua; Kraft, Mary L.

    2013-04-22

    The plasma membranes of mammalian cells are widely expected to contain domains that are enriched with cholesterol and sphingolipids. In this work, we have used high-resolution secondary ion mass spectrometry to directly map the distributions of isotope-labeled cholesterol and sphingolipids in the plasma membranes of intact fibroblast cells. Although acute cholesterol depletion reduced sphingolipid domain abundance, cholesterol was evenly distributed throughout the plasma membrane and was not enriched within the sphingolipid domains. As a result, we rule out favorable cholesterol-sphingolipid interactions as dictating plasma membrane organization in fibroblast cells. Because the sphingolipid domains are disrupted by drugs that depolymerize themore » cells actin cytoskeleton, cholesterol must instead affect the sphingolipid organization via an indirect mechanism that involves the cytoskeleton.« less

  20. Sphingolipid Domains in the Plasma Membranes of Fibroblasts Are Not Enriched with Cholesterol*

    PubMed Central

    Frisz, Jessica F.; Klitzing, Haley A.; Lou, Kaiyan; Hutcheon, Ian D.; Weber, Peter K.; Zimmerberg, Joshua; Kraft, Mary L.

    2013-01-01

    The plasma membranes of mammalian cells are widely expected to contain domains that are enriched with cholesterol and sphingolipids. In this work, we have used high-resolution secondary ion mass spectrometry to directly map the distributions of isotope-labeled cholesterol and sphingolipids in the plasma membranes of intact fibroblast cells. Although acute cholesterol depletion reduced sphingolipid domain abundance, cholesterol was evenly distributed throughout the plasma membrane and was not enriched within the sphingolipid domains. Thus, we rule out favorable cholesterol-sphingolipid interactions as dictating plasma membrane organization in fibroblast cells. Because the sphingolipid domains are disrupted by drugs that depolymerize the cells actin cytoskeleton, cholesterol must instead affect the sphingolipid organization via an indirect mechanism that involves the cytoskeleton. PMID:23609440

  1. Anacetrapib reduces progression of atherosclerosis, mainly by reducing non-HDL-cholesterol, improves lesion stability and adds to the beneficial effects of atorvastatin

    PubMed Central

    Kühnast, Susan; van der Tuin, Sam J.L.; van der Hoorn, José W.A.; van Klinken, Jan B.; Simic, Branko; Pieterman, Elsbet; Havekes, Louis M.; Landmesser, Ulf; Lüscher, Thomas F.; Willems van Dijk, Ko; Rensen, Patrick C.N.; Jukema, J. Wouter; Princen, Hans M.G.

    2015-01-01

    Background The residual risk that remains after statin treatment supports the addition of other LDL-C-lowering agents and has stimulated the search for secondary treatment targets. Epidemiological studies propose HDL-C as a possible candidate. Cholesteryl ester transfer protein (CETP) transfers cholesteryl esters from atheroprotective HDL to atherogenic (V)LDL. The CETP inhibitor anacetrapib decreases (V)LDL-C by ∼15–40% and increases HDL-C by ∼40–140% in clinical trials. We evaluated the effects of a broad dose range of anacetrapib on atherosclerosis and HDL function, and examined possible additive/synergistic effects of anacetrapib on top of atorvastatin in APOE*3Leiden.CETP mice. Methods and results Mice were fed a diet without or with ascending dosages of anacetrapib (0.03; 0.3; 3; 30 mg/kg/day), atorvastatin (2.4 mg/kg/day) alone or in combination with anacetrapib (0.3 mg/kg/day) for 21 weeks. Anacetrapib dose-dependently reduced CETP activity (−59 to −100%, P < 0.001), thereby decreasing non-HDL-C (−24 to −45%, P < 0.001) and increasing HDL-C (+30 to +86%, P < 0.001). Anacetrapib dose-dependently reduced the atherosclerotic lesion area (−41 to −92%, P < 0.01) and severity, increased plaque stability index and added to the effects of atorvastatin by further decreasing lesion size (−95%, P < 0.001) and severity. Analysis of covariance showed that both anacetrapib (P < 0.05) and non-HDL-C (P < 0.001), but not HDL-C (P = 0.76), independently determined lesion size. Conclusion Anacetrapib dose-dependently reduces atherosclerosis, and adds to the anti-atherogenic effects of atorvastatin, which is mainly ascribed to a reduction in non-HDL-C. In addition, anacetrapib improves lesion stability. PMID:25142968

  2. Advances in the Study of the Antiatherogenic Function and Novel Therapies for HDL

    PubMed Central

    Cao, Peiqiu; Pan, Haitao; Xiao, Tiancun; Zhou, Ting; Guo, Jiao; Su, Zhengquan

    2015-01-01

    The hypothesis that raising high-density lipoprotein cholesterol (HDL-C) levels could improve the risk for cardiovascular disease (CVD) is facing challenges. There is multitudinous clear clinical evidence that the latest failures of HDL-C-raising drugs show no clear association with risks for CVD. At the genetic level, recent research indicates that steady-state HDL-C concentrations may provide limited information regarding the potential antiatherogenic functions of HDL. It is evident that the newer strategies may replace therapeutic approaches to simply raise plasma HDL-C levels. There is an urgent need to identify an efficient biomarker that accurately predicts the increased risk of atherosclerosis (AS) in patients and that may be used for exploring newer therapeutic targets. Studies from recent decades show that the composition, structure and function of circulating HDL are closely associated with high cardiovascular risk. A vast amount of data demonstrates that the most important mechanism through which HDL antagonizes AS involves the reverse cholesterol transport (RCT) process. Clinical trials of drugs that specifically target HDL have so far proven disappointing, so it is necessary to carry out review on the HDL therapeutics. PMID:26225968

  3. Remarkable quantitative and qualitative differences in HDL after niacin or fenofibrate therapy in type 2 diabetic patients.

    PubMed

    Masana, Luís; Cabré, Anna; Heras, Mercedes; Amigó, Núria; Correig, Xavier; Martínez-Hervás, Sergio; Real, José T; Ascaso, Juan F; Quesada, Helena; Julve, Josep; Palomer, Xavier; Vázquez-Carrera, Manuel; Girona, Josefa; Plana, Núria; Blanco-Vaca, Francisco

    2015-02-01

    HDL-increasing drugs such as fenofibrate and niacin have failed to decrease the cardiovascular risk in patients with type 2 diabetes. Drug-mediated quantitative and qualitative HDL modifications could be involved in these negative results. To evaluate the quantitative and qualitative effects of niacin and fenofibrate on HDL in patients with type 2 diabetes, a prospective, randomised controlled intervention trial was conducted. Thirty type 2 diabetic patients with low HDL were randomised to receive either fenofibrate (FFB) or niacin + laropiprant (ERN/LPR) as an add-on to simvastatin treatment for 12 weeks according to a crossover design. At the basal point and after each intervention period, physical examinations and comprehensive standard biochemical determinations and HDL metabolomics were performed. Thirty nondiabetic patients with normal HDL were used as a basal control group. ERN/LRP, but not FFB, significantly increased HDL cholesterol. Neither ERN/LRP nor FFB reversed the HDL particle size or particle number to normal. ERN/LRP increased apoA-I but not apoA-II, whereas FFB produced the opposite effect. FFB significantly increased Preβ1-HDL, whereas ERN/LRP tended to lower Preβ1-HDL. CETP and LCAT activities were significantly decreased only by ERN/LRP. PAF-AH activity in HDL and plasma decreased with the use of both agents. Despite their different actions on antioxidant parameters, none of the treatments induced detectable antioxidant improvements. ERN/LRP and FFB had strikingly different effects on HDL quantity and quality, as well as on HDL cholesterol concentrations. When prescribing HDL cholesterol increasing drugs, this differential action should be considered.

  4. Remarkable quantitative and qualitative differences in HDL after niacin or fenofibrate therapy in type 2 diabetic patients.

    PubMed

    Masana, Luís; Cabré, Anna; Heras, Mercedes; Amigó, Núria; Correig, Xavier; Martínez-Hervás, Sergio; Real, José T; Ascaso, Juan F; Quesada, Helena; Julve, Josep; Palomer, Xavier; Vázquez-Carrera, Manuel; Girona, Josefa; Plana, Núria; Blanco-Vaca, Francisco

    2015-02-01

    HDL-increasing drugs such as fenofibrate and niacin have failed to decrease the cardiovascular risk in patients with type 2 diabetes. Drug-mediated quantitative and qualitative HDL modifications could be involved in these negative results. To evaluate the quantitative and qualitative effects of niacin and fenofibrate on HDL in patients with type 2 diabetes, a prospective, randomised controlled intervention trial was conducted. Thirty type 2 diabetic patients with low HDL were randomised to receive either fenofibrate (FFB) or niacin + laropiprant (ERN/LPR) as an add-on to simvastatin treatment for 12 weeks according to a crossover design. At the basal point and after each intervention period, physical examinations and comprehensive standard biochemical determinations and HDL metabolomics were performed. Thirty nondiabetic patients with normal HDL were used as a basal control group. ERN/LRP, but not FFB, significantly increased HDL cholesterol. Neither ERN/LRP nor FFB reversed the HDL particle size or particle number to normal. ERN/LRP increased apoA-I but not apoA-II, whereas FFB produced the opposite effect. FFB significantly increased Preβ1-HDL, whereas ERN/LRP tended to lower Preβ1-HDL. CETP and LCAT activities were significantly decreased only by ERN/LRP. PAF-AH activity in HDL and plasma decreased with the use of both agents. Despite their different actions on antioxidant parameters, none of the treatments induced detectable antioxidant improvements. ERN/LRP and FFB had strikingly different effects on HDL quantity and quality, as well as on HDL cholesterol concentrations. When prescribing HDL cholesterol increasing drugs, this differential action should be considered. PMID:25528430

  5. Transport of cholesterol from the endoplasmic reticulum to the plasma membrane

    PubMed Central

    1985-01-01

    We have studied the transport of newly synthesized cholesterol from the endoplasmic reticulum to the plasma membrane in Chinese hamster ovary cells using a cell fractionation assay. We found that transport is dependent on metabolic energy, but that the maintenance of the high differential concentration of cholesterol in the plasma membrane is not an energy-requiring process. We have tested a variety of inhibitors for their effect on cholesterol transport and found that cytochalasin B, colchicine, monensin, cycloheximide, and NH4Cl did not have any effect. The cholesterol transport process shows a sharp temperature dependence; it ceases at 15 degrees C, whereas cholesterol synthesis continues. When synthesis occurs at 15 degrees C, the newly synthesized cholesterol accumulates in the endoplasmic reticulum and in a low density, lipid-rich vesicle fraction. These results suggest that cholesterol is transported via a vesicular system. PMID:4040520

  6. High-Density Lipoprotein, Lecithin: Cholesterol Acyltransferase, and Atherosclerosis.

    PubMed

    Ossoli, Alice; Pavanello, Chiara; Calabresi, Laura

    2016-06-01

    Epidemiological data clearly show the existence of a strong inverse correlation between plasma high-density lipoprotein cholesterol (HDL-C) concentrations and the incidence of coronary heart disease. This relation is explained by a number of atheroprotective properties of HDL, first of all the ability to promote macrophage cholesterol transport. HDL are highly heterogeneous and are continuously remodeled in plasma thanks to the action of a number of proteins and enzymes. Among them, lecithin:cholesterol acyltransferase (LCAT) plays a crucial role, being the only enzyme able to esterify cholesterol within lipoproteins. LCAT is synthetized by the liver and it has been thought to play a major role in reverse cholesterol transport and in atheroprotection. However, data from animal studies, as well as human studies, have shown contradictory results. Increased LCAT concentrations are associated with increased HDL-C levels but not necessarily with atheroprotection. On the other side, decreased LCAT concentration and activity are associated with decreased HDL-C levels but not with increased atherosclerosis. These contradictory results confirm that HDL-C levels per se do not represent the functionality of the HDL system. PMID:27302716

  7. High-Density Lipoprotein, Lecithin: Cholesterol Acyltransferase, and Atherosclerosis

    PubMed Central

    Ossoli, Alice; Pavanello, Chiara

    2016-01-01

    Epidemiological data clearly show the existence of a strong inverse correlation between plasma high-density lipoprotein cholesterol (HDL-C) concentrations and the incidence of coronary heart disease. This relation is explained by a number of atheroprotective properties of HDL, first of all the ability to promote macrophage cholesterol transport. HDL are highly heterogeneous and are continuously remodeled in plasma thanks to the action of a number of proteins and enzymes. Among them, lecithin:cholesterol acyltransferase (LCAT) plays a crucial role, being the only enzyme able to esterify cholesterol within lipoproteins. LCAT is synthetized by the liver and it has been thought to play a major role in reverse cholesterol transport and in atheroprotection. However, data from animal studies, as well as human studies, have shown contradictory results. Increased LCAT concentrations are associated with increased HDL-C levels but not necessarily with atheroprotection. On the other side, decreased LCAT concentration and activity are associated with decreased HDL-C levels but not with increased atherosclerosis. These contradictory results confirm that HDL-C levels per se do not represent the functionality of the HDL system. PMID:27302716

  8. Detection of cholesterol-rich microdomains in the inner leaflet of the plasma membrane

    SciTech Connect

    Hayashi, Masami; Shimada, Yukiko; Inomata, Mitsushi; Ohno-Iwashita, Yoshiko . E-mail: iwashita@tmig.or.jp

    2006-12-22

    The C-terminal domain (D4) of perfringolysin O binds selectively to cholesterol in cholesterol-rich microdomains. To address the issue of whether cholesterol-rich microdomains exist in the inner leaflet of the plasma membrane, we expressed D4 as a fusion protein with EGFP in MEF cells. More than half of the EGFP-D4 expressed in stable cell clones was bound to membranes in raft fractions. Depletion of membrane cholesterol with {beta}-cyclodextrin reduced the amount of EGFP-D4 localized in raft fractions, confirming EGFP-D4 binding to cholesterol-rich microdomains. Subfractionation of the raft fractions showed most of the EGFP-D4 bound to the plasma membrane rather than to intracellular membranes. Taken together, these results strongly suggest the existence of cholesterol-rich microdomains in the inner leaflet of the plasma membrane.

  9. Lowering of plasma cholesterol in herbivores and omnivores by low molecular weight dextran.

    PubMed

    Adam, O; Krejci, K

    1989-01-01

    Two rabbits and two home pigs were infused in a cross-over design with equal volumes, adapted to the plasma volumes of the animals, of dextran-40 and saline. The infusions resulted in a reduction of plasma cholesterol and control parameters, such as plasma protein, hemoglobin, and hematocrit. The reduction of hemoglobin and hematocrit was related to plasma expansion with both infusion regimens. With dextran-40 infusions the reduction of plasma protein was greater than hemodilution in both species (-18% in rabbits and -20% in home pigs), because of steric exclusion of the protein. Lowering of plasma cholesterol in rabbits was comparable to the reduction in plasma protein, whereas in home pigs the reduction of plasma cholesterol (-25%) surpassed that of plasma protein. Reports in the literature have shown that dextran infusions increase cholesterol concentration in liver cells, leading to a reduction of intestinal cholesterol resorption in omnivores. This dextran effect is supposed to be responsible for the observed additional reduction of plasma cholesterol levels in omnivores.

  10. Hemagglutinin clusters in the plasma membrane are not enriched with cholesterol and sphingolipids.

    PubMed

    Wilson, Robert L; Frisz, Jessica F; Klitzing, Haley A; Zimmerberg, Joshua; Weber, Peter K; Kraft, Mary L

    2015-04-01

    The clusters of the influenza envelope protein, hemagglutinin, within the plasma membrane are hypothesized to be enriched with cholesterol and sphingolipids. Here, we directly tested this hypothesis by using high-resolution secondary ion mass spectrometry to image the distributions of antibody-labeled hemagglutinin and isotope-labeled cholesterol and sphingolipids in the plasma membranes of fibroblast cells that stably express hemagglutinin. We found that the hemagglutinin clusters were neither enriched with cholesterol nor colocalized with sphingolipid domains. Thus, hemagglutinin clustering and localization in the plasma membrane is not controlled by cohesive interactions between hemagglutinin and liquid-ordered domains enriched with cholesterol and sphingolipids, or from specific binding interactions between hemagglutinin, cholesterol, and/or the majority of sphingolipid species in the plasma membrane. PMID:25863057

  11. Hemagglutinin Clusters in the Plasma Membrane Are Not Enriched with Cholesterol and Sphingolipids

    PubMed Central

    Wilson, Robert L.; Frisz, Jessica F.; Klitzing, Haley A.; Zimmerberg, Joshua; Weber, Peter K.; Kraft, Mary L.

    2015-01-01

    The clusters of the influenza envelope protein, hemagglutinin, within the plasma membrane are hypothesized to be enriched with cholesterol and sphingolipids. Here, we directly tested this hypothesis by using high-resolution secondary ion mass spectrometry to image the distributions of antibody-labeled hemagglutinin and isotope-labeled cholesterol and sphingolipids in the plasma membranes of fibroblast cells that stably express hemagglutinin. We found that the hemagglutinin clusters were neither enriched with cholesterol nor colocalized with sphingolipid domains. Thus, hemagglutinin clustering and localization in the plasma membrane is not controlled by cohesive interactions between hemagglutinin and liquid-ordered domains enriched with cholesterol and sphingolipids, or from specific binding interactions between hemagglutinin, cholesterol, and/or the majority of sphingolipid species in the plasma membrane. PMID:25863057

  12. Clinically used selective estrogen receptor modulators affect different steps of macrophage-specific reverse cholesterol transport

    PubMed Central

    Fernández-Suárez, María E.; Escolà-Gil, Joan C.; Pastor, Oscar; Dávalos, Alberto; Blanco-Vaca, Francisco; Lasunción, Miguel A.; Martínez-Botas, Javier; Gómez-Coronado, Diego

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are widely prescribed drugs that alter cellular and whole-body cholesterol homeostasis. Here we evaluate the effect of SERMs on the macrophage-specific reverse cholesterol transport (M-RCT) pathway, which is mediated by HDL. Treatment of human and mouse macrophages with tamoxifen, raloxifene or toremifene induced the accumulation of cytoplasmic vesicles of acetyl-LDL-derived free cholesterol. The SERMs impaired cholesterol efflux to apolipoprotein A-I and HDL, and lowered ABCA1 and ABCG1 expression. These effects were not altered by the antiestrogen ICI 182,780 nor were they reproduced by 17β-estradiol. The treatment of mice with tamoxifen or raloxifene accelerated HDL-cholesteryl ester catabolism, thereby reducing HDL-cholesterol concentrations in serum. When [3H]cholesterol-loaded macrophages were injected into mice intraperitoneally, tamoxifen, but not raloxifene, decreased the [3H]cholesterol levels in serum, liver and feces. Both SERMs downregulated liver ABCG5 and ABCG8 protein expression, but tamoxifen reduced the capacity of HDL and plasma to promote macrophage cholesterol efflux to a greater extent than raloxifene. We conclude that SERMs interfere with intracellular cholesterol trafficking and efflux from macrophages. Tamoxifen, but not raloxifene, impair M-RCT in vivo. This effect is primarily attributable to the tamoxifen-mediated reduction of the capacity of HDL to promote cholesterol mobilization from macrophages. PMID:27601313

  13. Clinically used selective estrogen receptor modulators affect different steps of macrophage-specific reverse cholesterol transport.

    PubMed

    Fernández-Suárez, María E; Escolà-Gil, Joan C; Pastor, Oscar; Dávalos, Alberto; Blanco-Vaca, Francisco; Lasunción, Miguel A; Martínez-Botas, Javier; Gómez-Coronado, Diego

    2016-09-07

    Selective estrogen receptor modulators (SERMs) are widely prescribed drugs that alter cellular and whole-body cholesterol homeostasis. Here we evaluate the effect of SERMs on the macrophage-specific reverse cholesterol transport (M-RCT) pathway, which is mediated by HDL. Treatment of human and mouse macrophages with tamoxifen, raloxifene or toremifene induced the accumulation of cytoplasmic vesicles of acetyl-LDL-derived free cholesterol. The SERMs impaired cholesterol efflux to apolipoprotein A-I and HDL, and lowered ABCA1 and ABCG1 expression. These effects were not altered by the antiestrogen ICI 182,780 nor were they reproduced by 17β-estradiol. The treatment of mice with tamoxifen or raloxifene accelerated HDL-cholesteryl ester catabolism, thereby reducing HDL-cholesterol concentrations in serum. When [(3)H]cholesterol-loaded macrophages were injected into mice intraperitoneally, tamoxifen, but not raloxifene, decreased the [(3)H]cholesterol levels in serum, liver and feces. Both SERMs downregulated liver ABCG5 and ABCG8 protein expression, but tamoxifen reduced the capacity of HDL and plasma to promote macrophage cholesterol efflux to a greater extent than raloxifene. We conclude that SERMs interfere with intracellular cholesterol trafficking and efflux from macrophages. Tamoxifen, but not raloxifene, impair M-RCT in vivo. This effect is primarily attributable to the tamoxifen-mediated reduction of the capacity of HDL to promote cholesterol mobilization from macrophages.

  14. Clinically used selective estrogen receptor modulators affect different steps of macrophage-specific reverse cholesterol transport.

    PubMed

    Fernández-Suárez, María E; Escolà-Gil, Joan C; Pastor, Oscar; Dávalos, Alberto; Blanco-Vaca, Francisco; Lasunción, Miguel A; Martínez-Botas, Javier; Gómez-Coronado, Diego

    2016-01-01

    Selective estrogen receptor modulators (SERMs) are widely prescribed drugs that alter cellular and whole-body cholesterol homeostasis. Here we evaluate the effect of SERMs on the macrophage-specific reverse cholesterol transport (M-RCT) pathway, which is mediated by HDL. Treatment of human and mouse macrophages with tamoxifen, raloxifene or toremifene induced the accumulation of cytoplasmic vesicles of acetyl-LDL-derived free cholesterol. The SERMs impaired cholesterol efflux to apolipoprotein A-I and HDL, and lowered ABCA1 and ABCG1 expression. These effects were not altered by the antiestrogen ICI 182,780 nor were they reproduced by 17β-estradiol. The treatment of mice with tamoxifen or raloxifene accelerated HDL-cholesteryl ester catabolism, thereby reducing HDL-cholesterol concentrations in serum. When [(3)H]cholesterol-loaded macrophages were injected into mice intraperitoneally, tamoxifen, but not raloxifene, decreased the [(3)H]cholesterol levels in serum, liver and feces. Both SERMs downregulated liver ABCG5 and ABCG8 protein expression, but tamoxifen reduced the capacity of HDL and plasma to promote macrophage cholesterol efflux to a greater extent than raloxifene. We conclude that SERMs interfere with intracellular cholesterol trafficking and efflux from macrophages. Tamoxifen, but not raloxifene, impair M-RCT in vivo. This effect is primarily attributable to the tamoxifen-mediated reduction of the capacity of HDL to promote cholesterol mobilization from macrophages. PMID:27601313

  15. Cholesterol and Statins

    MedlinePlus

    ... the liver makes ldl & hdl In the liver, triglycerides, cholesterol, and proteins form together to make LDL ... This is especially important for individuals with high triglyceride and/or low HDL levels who are overweight ...

  16. Nascent HDL formation by hepatocytes is reduced by the concerted action of serum amyloid A and endothelial lipase.

    PubMed

    Wroblewski, Joanne M; Jahangiri, Anisa; Ji, Ailing; de Beer, Frederick C; van der Westhuyzen, Deneys R; Webb, Nancy R

    2011-12-01

    Inflammation is associated with significant decreases in plasma HDL-cholesterol (HDL-C) and apoA-I levels. Endothelial lipase (EL) is known to be an important determinant of HDL-C in mice and in humans and is upregulated during inflammation. In this study, we investigated whether serum amyloid A (SAA), an HDL apolipoprotein highly induced during inflammation, alters the ability of EL to metabolize HDL. We determined that EL hydrolyzes SAA-enriched HDL in vitro without liberating lipid-free apoA-I. Coexpression of SAA and EL in mice by adenoviral vector produced a significantly greater reduction in HDL-C and apoA-I than a corresponding level of expression of either SAA or EL alone. The loss of HDL occurred without any evidence of HDL remodeling to smaller particles that would be expected to have more rapid turnover. Studies with primary hepatocytes demonstrated that coexpression of SAA and EL markedly impeded ABCA1-mediated lipidation of apoA-I to form nascent HDL. Our findings suggest that a reduction in nascent HDL formation may be partly responsible for reduced HDL-C during inflammation when both EL and SAA are known to be upregulated. PMID:21957202

  17. HDL from apoA1 transgenic mice expressing the 4WF isoform is resistant to oxidative loss of function[S

    PubMed Central

    Berisha, Stela Z.; Brubaker, Greg; Kasumov, Takhar; Hung, Kimberly T.; DiBello, Patricia M.; Huang, Ying; Li, Ling; Willard, Belinda; Pollard, Katherine A.; Nagy, Laura E.; Hazen, Stanley L.; Smith, Jonathan D.

    2015-01-01

    HDL functions are impaired by myeloperoxidase (MPO), which selectively targets and oxidizes human apoA1. We previously found that the 4WF isoform of human apoA1, in which the four tryptophan residues are substituted with phenylalanine, is resistant to MPO-mediated loss of function. The purpose of this study was to generate 4WF apoA1 transgenic mice and compare functional properties of the 4WF and wild-type human apoA1 isoforms in vivo. Male mice had significantly higher plasma apoA1 levels than females for both isoforms of human apoA1, attributed to different production rates. With matched plasma apoA1 levels, 4WF transgenics had a trend for slightly less HDL-cholesterol versus human apoA1 transgenics. While 4WF transgenics had 31% less reverse cholesterol transport (RCT) to the plasma compartment, equivalent RCT to the liver and feces was observed. Plasma from both strains had similar ability to accept cholesterol and facilitate ex vivo cholesterol efflux from macrophages. Furthermore, we observed that 4WF transgenic HDL was partially (∼50%) protected from MPO-mediated loss of function while human apoA1 transgenic HDL lost all ABCA1-dependent cholesterol acceptor activity. In conclusion, the structure and function of HDL from 4WF transgenic mice was not different than HDL derived from human apoA1 transgenic mice. PMID:25561462

  18. HDL and endothelial protection

    PubMed Central

    Tran-Dinh, A; Diallo, D; Delbosc, S; Varela-Perez, L Maria; Dang, QB; Lapergue, B; Burillo, E; Michel, JB; Levoye, A; Martin-Ventura, JL; Meilhac, O

    2013-01-01

    High-density lipoproteins (HDLs) represent a family of particles characterized by the presence of apolipoprotein A-I (apoA-I) and by their ability to transport cholesterol from peripheral tissues back to the liver. In addition to this function, HDLs display pleiotropic effects including antioxidant, anti-apoptotic, anti-inflammatory, anti-thrombotic or anti-proteolytic properties that account for their protective action on endothelial cells. Vasodilatation via production of nitric oxide is also a hallmark of HDL action on endothelial cells. Endothelial cells express receptors for apoA-I and HDLs that mediate intracellular signalling and potentially participate in the internalization of these particles. In this review, we will detail the different effects of HDLs on the endothelium in normal and pathological conditions with a particular focus on the potential use of HDL therapy to restore endothelial function and integrity. PMID:23488589

  19. Data in support of a central role of plasminogen activator inhibitor-2 polymorphism in recurrent cardiovascular disease risk in the setting of high HDL cholesterol and C-reactive protein using Bayesian network modeling.

    PubMed

    Corsetti, James P; Salzman, Peter; Ryan, Dan; Moss, Arthur J; Zareba, Wojciech; Sparks, Charles E

    2016-09-01

    Data is presented that was utilized as the basis for Bayesian network modeling of influence pathways focusing on the central role of a polymorphism of plasminogen activator inhibitor-2 (PAI-2) on recurrent cardiovascular disease risk in patients with high levels of HDL cholesterol and C-reactive protein (CRP) as a marker of inflammation, "Influences on Plasminogen Activator Inhibitor-2 Polymorphism-Associated Recurrent Cardiovascular Disease Risk in Patients with High HDL Cholesterol and Inflammation" (Corsetti et al., 2016; [1]). The data consist of occurrence of recurrent coronary events in 166 post myocardial infarction patients along with 1. clinical data on gender, race, age, and body mass index; 2. blood level data on 17 biomarkers; and 3. genotype data on 53 presumptive CVD-related single nucleotide polymorphisms. Additionally, a flow diagram of the Bayesian modeling procedure is presented along with Bayesian network subgraphs (root nodes to outcome events) utilized as the data from which PAI-2 associated influence pathways were derived (Corsetti et al., 2016; [1]).

  20. Biomimetic, synthetic HDL nanostructures for lymphoma

    PubMed Central

    Yang, Shuo; Damiano, Marina G.; Zhang, Heng; Tripathy, Sushant; Luthi, Andrea J.; Rink, Jonathan S.; Ugolkov, Andrey V.; T. K. Singh, Amareshwar; Dave, Sandeep S.; Gordon, Leo I.; Thaxton, C. Shad

    2013-01-01

    New therapies that challenge existing paradigms are needed for the treatment of cancer. We report a nanoparticle-enabled therapeutic approach to B-cell lymphoma using synthetic high density lipoprotein nanoparticles (HDL-NPs). HDL-NPs are synthesized using a gold nanoparticle template to control conjugate size and ensure a spherical shape. Like natural HDLs, biomimetic HDL-NPs target scavenger receptor type B-1, a high-affinity HDL receptor expressed by lymphoma cells. Functionally, compared with natural HDL, the gold NP template enables differential manipulation of cellular cholesterol flux in lymphoma cells, promoting cellular cholesterol efflux and limiting cholesterol delivery. This combination of scavenger receptor type B-1 binding and relative cholesterol starvation selectively induces apoptosis. HDL-NP treatment of mice bearing B-cell lymphoma xenografts selectively inhibits B-cell lymphoma growth. As such, HDL-NPs are biofunctional therapeutic agents, whose mechanism of action is enabled by the presence of a synthetic nanotemplate. HDL-NPs are active in B-cell lymphomas and potentially, other malignancies or diseases of pathologic cholesterol accumulation. PMID:23345442

  1. Common polymorphisms of ATP binding cassette transporter A1, including a functional promoter polymorphism, associated with plasma high density lipoprotein cholesterol levels in Turks.

    PubMed

    Hodoğlugil, Uğur; Williamson, David W; Huang, Yadong; Mahley, Robert W

    2005-12-01

    The role of high levels of high density lipoprotein cholesterol (HDL-C) in protection against development of atherosclerosis is generally attributed to its role in reverse cholesterol transport, and the ATP binding cassette transporter A1 (ABCA1) is a key element of this process. We examined polymorphisms in ABCA1 in Turks, a population characterized by very low HDL-C levels. We discovered 36 variations in ABCA1 and genotyped informative polymorphisms in over 2,300 subjects. The rare alleles of C-14T and V771M polymorphisms were associated with higher HDL-C levels in men and, in combination with the rare alleles of R219K and I883M, respectively, with higher HDL-C in both sexes. Rare alleles of the C-14T and V771M polymorphisms were more frequent in the high HDL-C (>OR=40mg/dl) than in the low HDL-C group (plasma HDL-C levels in Turks.

  2. Enhanced HDL Functionality in Small HDL Species Produced Upon Remodeling of HDL by Reconstituted HDL, CSL112

    PubMed Central

    Didichenko, Svetlana A.; Navdaev, Alexei V.; Cukier, Alexandre M.O.; Gille, Andreas; Schuetz, Patrick; Spycher, Martin O.; Thérond, Patrice; Chapman, M. John; Kontush, Anatol

    2016-01-01

    Rationale: CSL112, human apolipoprotein A-I (apoA-I) reconstituted with phosphatidylcholine, is known to cause a dramatic rise in small high-density lipoprotein (HDL). Objective: To explore the mechanisms by which the formation of small HDL particles is induced by CSL112. Methods and Results: Infusion of CSL112 into humans caused elevation of 2 small diameter HDL fractions and 1 large diameter fraction. Ex vivo studies showed that this remodeling does not depend on lipid transfer proteins or lipases. Rather, interaction of CSL112 with purified HDL spontaneously gave rise to 3 HDL species: a large, spherical species composed of apoA-I from native HDL and CSL112; a small, disc-shaped species composed of apoA-I from CSL112, but smaller because of the loss of phospholipids; and the smallest species, lipid-poor apoA-I composed of apoA-I from HDL and CSL112. Time-course studies suggest that remodeling occurs by an initial fusion of CSL112 with HDL and subsequent fission leading to the smaller forms. Functional studies showed that ATP-binding cassette transporter 1–dependent cholesterol efflux and anti-inflammatory effects in whole blood were carried by the 2 small species with little activity in the large species. In contrast, the ability to inactivate lipid hydroperoxides in oxidized low-density lipoprotein was carried predominantly by the 2 largest species and was low in lipid-poor apoA-I. Conclusions: We have described a mechanism for the formation of small, highly functional HDL species involving spontaneous fusion of discoidal HDL with spherical HDL and subsequent fission. Similar remodeling is likely to occur during the life cycle of apoA-I in vivo. PMID:27436846

  3. Origins and determinants of HDL populations and their subpopulations

    SciTech Connect

    Nichols, A.V.; Gong, E.L.

    1990-06-01

    This paper describes the origins and determinants of High Density Lipoproteins (HDL) populations and their subpopulations. Our survey of compositional properties of small HDL particles indicates considerable variation in core lipid content reflecting in large part the origins of such particles. Whether small HDL particles of different core content and apolipoprotein composition differ in their metabolic properties and function in reverse cholesterol transport remains to be established. Our studies demonstrate that lipolysis-derived products can facilitate formation in vitro of small Apolipoprotein (AI) particles with properties approximating those of plasma pre-{beta} HDL. Of particular interest is our observation that small AI particles are an exclusive reassembly product in mixtures containing POPE and FFA. This observation may be relevant to the physiologic origins of PE in lipoprotein structure and its role in metabolism and secretion of nascent HDL. Lastly our observations on the reactivity of small AI particles, containing FFA, with LCAT and LDL suggest further linkages between triglyceride and HDL metabolism. 19 refs., 4 figs., 5 tabs.

  4. Overexpression of lecithin:cholesterol acyltransferase in transgenic rabbits prevents diet-induced atherosclerosis.

    PubMed Central

    Hoeg, J M; Santamarina-Fojo, S; Bérard, A M; Cornhill, J F; Herderick, E E; Feldman, S H; Haudenschild, C C; Vaisman, B L; Hoyt, R F; Demosky, S J; Kauffman, R D; Hazel, C M; Marcovina, S M; Brewer, H B

    1996-01-01

    Lecithin:cholesterol acyltransferase (LCAT) is a key plasma enzyme in cholesterol and high density lipoprotein (HDL) metabolism. Transgenic rabbits overexpressing human LCAT had 15-fold greater plasma LCAT activity that nontransgenic control rabbits. This degree of overexpression was associated with a 6.7-fold increase in the plasma HDL cholesterol concentration in LCAT transgenic rabbits. On a 0.3% cholesterol diet, the HDL cholesterol concentrations increased from 24 +/- 1 to 39 +/- 3 mg/dl in nontransgenic control rabbits (n = 10; P < 0.05) and increased from 161 +/- 5 to 200 +/- 21 mg/dl (P < 0.001) in the LCAT transgenic rabbits (n = 9). Although the baseline non-HDL concentrations of control (4 +/- 3 mg/dl) and transgenic rabbits (18 +/- 4 mg/dl) were similar, the cholesterol-rich diet raised the non-HDL cholesterol concentrations, reflecting the atherogenic very low density, intermediate density, and low density lipoprotein particles observed by gel filtration chromatography. The non-HDL cholesterol rose to 509 +/- 57 mg/dl in controls compared with only 196 +/- 14 mg/dl in the LCAT transgenic rabbits (P < 0.005). The differences in the plasma lipoprotein response to a cholesterol-rich diet observed in the transgenic rabbits paralleled the susceptibility to developing aortic atherosclerosis. Compared with nontransgenic controls, LCAT transgenic rabbits were protected from diet-induced atherosclerosis with significant reductions determined by both quantitative planimetry (-86%; P < 0.003) and quantitative immunohistochemistry (-93%; P < 0.009). Our results establish the importance of LCAT in the metabolism of both HDL and apolipoprotein B-containing lipoprotein particles with cholesterol feeding and the response to diet-induced atherosclerosis. In addition, these findings identify LCAT as a new target for therapy to prevent atherosclerosis. Images Fig. 2 Fig. 3 Fig. 4 PMID:8876155

  5. Apolipoprotein A-II is a key regulatory factor of HDL metabolism as appears from studies with transgenic animals and clinical outcomes.

    PubMed

    Maïga, Sira Fatoumata; Kalopissis, Athina-Despina; Chabert, Michèle

    2014-01-01

    The structure and metabolism of HDL are linked to their major apolipoproteins (apo) A-I and A-II. HDL metabolism is very dynamic and depends on the constant remodeling by lipases, lipid transfer proteins and receptors. HDL exert several cardioprotective effects, through their antioxidant and antiinflammatory capacities and through the stimulation of reverse cholesterol transport from extrahepatic tissues to the liver for excretion into bile. HDL also serve as plasma reservoir for C and E apolipoproteins, as transport vehicles for a great variety of proteins, and may have more physiological functions than previously recognized. In this review we will develop several aspects of HDL metabolism with emphasis on the structure/function of apo A-I and apo A-II. An important contribution to our understanding of the respective roles of apo A-I and apo A-II comes from studies using transgenic animal models that highlighted the stabilizatory role of apo A-II on HDL through inhibition of their remodeling by lipases. Clinical studies coupled with proteomic analyses revealed the presence of dysfunctional HDL in patients with cardiovascular disease. Beyond HDL cholesterol, a new notion is the functionality of HDL particles. In spite of abundant literature on HDL metabolic properties, a major question remains unanswered: which HDL particle(s) confer(s) protection against cardiovascular risk? PMID:24012775

  6. Plasma cholesterol-suppressing effect of papain-hydrolyzed pork meat in rats fed hypercholesterolemic diet.

    PubMed

    Morimatsu, F; Ito, M; Budijanto, S; Watanabe, I; Furukawa, Y; Kimura, S

    1996-04-01

    The effects of papain-hydrolyzed pork meat on plasma and liver cholesterol levels were studied in rats fed a cholesterol-enriched diet. In rats fed the low-molecular-weight fraction of papain-hydrolyzed pork meat, the plasma cholesterol concentration, more particularly the VLDL and LDL cholesterol concentrations, were significantly lower (p < 0.01) than in the rats fed untreated pork meat or soybean protein. Feeding with this fraction rather than with untreated pork meat also led to a significantly lower liver cholesterol concentration (p < 0.01) and increased fecal excretion of neutral and acidic steroids. The low-molecular-weight fraction contained peptides with molecular weights of 3,000 or less and had an amino acid composition similar to that of pork meat itself. This study suggests that peptides produced by papain-hydrolysis of pork meat have a hypocholesterolemic activity through their interference with the steroid absorption process. PMID:8780972

  7. Metabolic and functional relevance of HDL subspecies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Though the association of high-density lipoprotein cholesterol (HDL-C) with cardiovascular disease (CVD) was described as early as 1950, HDL’s role in CVD still remains to be fully elucidated. There are numerous publications showing the inverse relationship between HDL-C and CVD risk; however, in t...

  8. Effects of sphingomyelin degradation on cholesterol mobilization and efflux to high-density lipoproteins in cultured fibroblasts.

    PubMed

    Slotte, J P; Tenhunen, J; Pörn, I

    1990-06-27

    The hydrolysis of sphingomyelin from cellular plasma membranes imposes many consequences on cellular cholesterol homeostasis by causing a rapid and dramatic redistribution of plasma membrane cholesterol within the cells (Slotte, J.P. and Bierman, E.L. (1988) Biochem. J. 250, 653-658). The objective of this study was to examine the effects of an extracellular cholesterol acceptor on the directions of the sphingomyelinase-induced cholesterol flow in cultured fibroblasts. We have used HDL3 as a physiological acceptor for cholesterol, and measured the effects of sphingomyelin hydrolysis on efflux and endogenous esterification of cellular [3H]cholesterol. Treatment of cells with sphingomyelinase did induce a dramatically increased esterification of plasma-membrane-derived [3H]cholesterol. The presence of HDL3 in the medium (100 micrograms/ml) did not prevent or reduce the extent of the sphingomyelinase-induced cellular esterification of [3H]cholesterol. Degradation of cellular sphingomyelin (75% hydrolysis) also did not enhance the rate of [3H]cholesterol efflux from the plasma membranes to HDL3. In addition, we also observed that the degradation of sphingomyelin in the HDL3 particles (complete degradation) did not change the apparent rate of [3H]cholesterol transfer from HDL3 to the cells. These findings together indicate that hydrolysis of sphingomyelin did not markedly affect the rates of cholesterol surface transfer between HDL3 and cells. By whatever mechanism cholesterol is forced to be translocated from the plasma membranes subsequent to the degradation of sphingomyelin, it appears that the sterol flow is specifically directed towards the interior of the cells.

  9. HDL in innate and adaptive immunity.

    PubMed

    Catapano, Alberico Luigi; Pirillo, Angela; Bonacina, Fabrizia; Norata, Giuseppe Danilo

    2014-08-01

    During infections or acute conditions high-density lipoproteins cholesterol (HDL-C) levels decrease very rapidly and HDL particles undergo profound changes in their composition and function. These changes are associated with poor prognosis following endotoxemia or sepsis and data from genetically modified animal models support a protective role for HDL. The same is true for some parasitic infections, where the key player appears to be a specific and minor component of HDL, namely apoL-1. The ability of HDL to influence cholesterol availability in lipid rafts in immune cells results in the modulation of toll-like receptors, MHC-II complex, as well as B- and T-cell receptors, while specific molecules shuttled by HDL such as sphingosine-1-phosphate (S1P) contribute to immune cells trafficking. Animal models with defects associated with HDL metabolism and/or influencing cell cholesterol efflux present features related to immune disorders. All these functions point to HDL as a platform integrating innate and adaptive immunity. The aim of this review is to provide an overview of the connection between HDL and immunity in atherosclerosis and beyond. PMID:24935428

  10. HDL: bridging past and present with a look at the future

    PubMed Central

    Scanu, Angelo M.; Edelstein, Celina

    2008-01-01

    Clinical and epidemiological studies have shown that HDLs, a class of plasma lipoproteins, heterogeneous in size and density, have an atheroprotective role attributed, for years, to their capacity to promote the efflux of cholesterol from activated cholesterol-loaded arterial macrophages. Recent studies, however, have recognized that the physical heterogeneity of HDLs is associated with multiple functions that involve both the protein and the lipid components of these particles. ApoA-I, quantitatively the major protein constituent, has an amphipathic structure suited for transport of lipids. It readily interacts with the ATP-binding cassette transporter ABCA1, the SR-B1 scavenger receptor; activates the enzyme lecithin-cholesterol acyl transferase (LCAT), which is critical for HDL maturation. It also has antioxidant and antiinflammatory properties, along with the HDL-associated enzymes paraoxonase, platelet activating factor acetylhydrolase (PAF), and glutathione peroxidase. Regarding the lipid moiety, an atheroprotective role has been recognized for lysosphingolipids, particularly sphingosine-1-phosphate (S1P). All of these atheroprotective functions are lost in the post-translational dependent dysfunctional plasma HDLs of subjects with systemic inflammation, coronary heart disease, diabetes, and chronic renal disease. The emerging notion that particle quality has more predictive power than quantity has stimulated further exploration of the HDL proteome, already revealing unsuspected pro- or antiatherogenic proteins/peptides associated with HDL.—Scanu, A. M., Edelstein, C. HDL: bridging past and present with a look at the future. PMID:18716026

  11. A complete backbone spectral assignment of human apolipoprotein AI on a 38 kDa preβHDL (Lp1-AI) particle

    SciTech Connect

    Ren, Xuefeng; Yang, Yunhuang; Neville, T.; Hoyt, David W.; Sparks, Daniel L.; Wang, Jianjun

    2007-06-12

    Apolipoprotein A-I (apoAI, 243-residues) is the major protein component of the high-density lipoprotein (HDL) that has been a hot subject of interests because of its anti-atherogenic properties. This important property of apoAI is related to its roles in reverse cholesterol transport pathway. Upon lipid-binding, apoAI undergoes conformational changes from lipid-free to several different HDL-associated states (1). These different conformational states regulate HDL formation, maturation and transportation. Two initial conformational states of apoAI are lipid-free apoAI and apoAI/preβHDL that recruit phospholipids and cholesterol to form HDL particles. In particular, lipid-free apoAI specifically binds to phospholipids to form lipid-poor apoAI, including apoAI/preβ-HDL (~37 kDa). As a unique class of lipid poor HDL, both in vitro and in vivo evidence demonstrates that apoAI/preβ-HDLs are the most effective acceptors specifically for free cholesterol in human plasma and serves as the precursor of HDL particles (2). Here we report a complete backbone spectral assignment of human apoAI/preβHDL. Secondary structure prediction using backbone NMR parameters indicates that apoAI/preβHDL displays a two-domain structure: the N-terminal four helix-bundle domain (residues 1-186) and the C-terminal flexible domain (residues 187-243). A structure of apoAI/preβ-HDL is the first lipid-associated structure of apoAI and is critical for us to understand how apoAI recruits cholesterol to initialize HDL formation. BMRB deposit with accession number: 15093.

  12. The role of HDL in plaque stabilization and regression: basic mechanisms and clinical implications.

    PubMed

    Feig, Jonathan E; Feig, Jessica L; Dangas, George D

    2016-11-01

    On the basis of studies that extend back to the early 1900s, regression and stabilization of atherosclerosis in humans has progressed from being a concept to one that is achievable. Successful attempts at regression generally applied robust measures to improve plasma lipoprotein profiles. Possible mechanisms responsible for lesion shrinkage include decreased retention of atherogenic apolipoprotein B within the arterial wall, efflux of cholesterol and other toxic lipids from plaques, emigration of lesional foam cells out of the arterial wall, and influx of healthy phagocytes that remove necrotic debris as well as other components of the plaque. Currently available clinical agents, however, still fail to stop most cardiovascular events. For years, HDL has been considered the 'good cholesterol.' Clinical intervention studies to causally link plasma HDL-C levels to decreased progression or to the regression of atherosclerotic plaques are relatively few because of the lack of therapeutic agents that can selectively and potently increase HDL-C. The negative results of studies that were carried out have led to uncertainty as to the role that HDL plays in atherosclerosis. It is becoming clearer, however, that HDL function rather than quantity is most crucial and, therefore, discovery of agents that enhance the quality of HDL should be the goal.

  13. The Effect of Natural LCAT Mutations on the Biogenesis of HDL.

    PubMed

    Fotakis, Panagiotis; Kuivenhoven, Jan Albert; Dafnis, Eugene; Kardassis, Dimitris; Zannis, Vassilis I

    2015-06-01

    We have investigated how the natural LCAT[T147I] and LCAT[P274S] mutations affect the pathway of biogenesis of HDL. Gene transfer of WT LCAT in LCAT(-/-) mice increased 11.8-fold the plasma cholesterol, whereas the LCAT[T147I] and LCAT[P274S] mutants caused a 5.2- and 2.9-fold increase, respectively. The LCAT[P274S] and the WT LCAT caused a monophasic distribution of cholesterol in the HDL region, whereas the LCAT[T147I] caused a biphasic distribution of cholesterol in the LDL and HDL region. Fractionation of plasma showed that the expression of WT LCAT increased plasma apoE and apoA-IV levels and shifted the distribution of apoA-I to lower densities. The LCAT[T147I] and LCAT[P274S] mutants restored partially apoA-I in the HDL3 fraction and LCAT[T147I] increased apoE in the VLD/IDL/LDL fractions. The in vivo functionality of LCAT was further assessed based on is its ability to correct the aberrant HDL phenotype that was caused by the apoA-I[L159R]FIN mutation. Co-infection of apoA-I(-/-) mice with this apoA-I mutant and either of the two mutant LCAT forms restored only partially the HDL biogenesis defect that was caused by the apoA-I[L159R]FIN and generated a distinct aberrant HDL phenotype. PMID:25948084

  14. Temperature effect of cholesterol association with synaptosomal plasma membranes of rabbit brain.

    PubMed Central

    Deliconstantinos, G

    1984-01-01

    Association of exogenous cholesterol with rabbit brain synaptosomal plasma membranes follows an exponential path described by the general formula y = a X ebx. The co-operative nature of this association was shown when increasing amounts of unlabelled cholesterol glucoside (up to 0.5 mM) were added to a fixed amount (5 microM) of [14C]cholesterol, when a biphasic curve of the binding of [14C]cholesterol into the membranes was obtained. Arrhenius plots of this association revealed two break points which occur at 25 degrees C and 42 degrees C. The first break apparently corresponds to the transition from the crystalline to the gel phase. The second break may be due to the (continuously) increasing entropy of the system which creates at a certain point difficulties in the binding of cholesterol into the lipid bilayer. PMID:6487274

  15. A single infusion of MDCO-216 (ApoA-1 Milano/POPC) increases ABCA1-mediated cholesterol efflux and pre-beta 1 HDL in healthy volunteers and patients with stable coronary artery disease

    PubMed Central

    Kallend, D.G.; Reijers, J.A.A.; Bellibas, S.E.; Bobillier, A.; Kempen, H.; Burggraaf, J.; Moerland, M.; Wijngaard, P.L.J.

    2016-01-01

    Aims Apolipoprotein A-1 (ApoA-1), based on epidemiology, is inversely associated with cardiovascular (CV) events. Human carriers of the ApoA-1 Milano variant have a reduced incidence of CV disease. Regression of atherosclerotic plaque burden was previously observed on intravascular ultrasound (IVUS) with ETC-216, a predecessor of MDCO-216. MDCO-216, a complex of dimeric ApoA-1 Milano and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, is being developed to reduce atherosclerotic plaque burden and CV events. We investigated the efficacy and safety of a single infusion of MDCO-216 in healthy volunteers and in patients with coronary artery disease (CAD). Methods and results Twenty-four healthy volunteers and 24 patients with documented CAD received a 2-h infusion of MDCO-216 in a randomized, placebo controlled, single ascending dose study. Five cohorts of healthy volunteers and four cohorts of CAD patients received ApoA-1 Milano doses ranging from 5 to 40 mg/kg. Subjects were followed for 30 days. Dose-dependent increases in ApoA-1, phospholipid, and pre-beta 1 HDL and decreases in ApoE were observed. Prominent and sustained increases in triglyceride, and decreases in HDL-C, endogenous ApoA-1 and ApoA-II occurred at doses >20 mg/kg and profound increases in ABCA1-mediated cholesterol efflux were observed. Other lipid and lipoprotein parameters were generally unchanged. MDCO-216 was well tolerated. Conclusions MDCO-216-modulated lipid parameters profoundly increased ABCA1-mediated cholesterol efflux and was well tolerated. These single-dose data support further development of this agent for reducing atherosclerotic disease and subsequent CV events. PMID:27418968

  16. Chlordecone altered hepatic disposition of [{sup 14}C]cholesterol and plasma cholesterol distribution but not SR-BI or ABCG8 proteins in livers of C57BL/6 mice

    SciTech Connect

    Lee, Junga; Scheri, Richard C.; Curtis, Lawrence R.

    2008-06-15

    Organochlorine (OC) insecticides continue to occur in tissues of humans and wildlife throughout the world although they were banned in the United States a few decades ago. Low doses of the OC insecticide chlordecone (CD) alter hepatic disposition of lipophilic xenobiotics and perturb lipid homeostasis in rainbow trout, mice and rats. CD pretreatment altered tissue and hepatic subcellular distribution of exogenous [{sup 14}C]cholesterol (CH) equivalents 4 and 16 h after a bolus intraperitoneal (ip) injection of 5 ml corn oil/kg that contained 10 mg CH/kg. CD pretreatment altered tissue distribution of exogenously administered [{sup 14}C]CH by decreased hepatic and renal accumulation, and increased biliary excretion up to 300%. Biliary excretion of polar [{sup 14}C]CH metabolites was not altered by CD. CD pretreatment decreased subcellular distribution of [{sup 14}C]CH equivalents in hepatic cytosol and microsomes and lipoprotein-rich fraction-to-homogenate ratio. CD pretreatment increased the ratio of [{sup 14}C]CH equivalents in high density lipoprotein (HDL) to that in plasma and reduced [{sup 14}C]CH equivalents in the non-HDL fraction 4 h after a bolus lipid dose. CD pretreatment increased plasma non-HDL total CH by 80% 4 h after a bolus lipid dose. Scavenger receptor class B type I (SR-BI) and ATP-binding cassette transporter G8 (ABCG8) proteins were quantified by western blotting in hepatic membranes from control and CD treated mice. Liver membrane contents of SR-BI and ABCG8 proteins were unchanged by CD pretreatment. The data demonstrated that a single dose of CD altered CH homeostasis and lipoprotein metabolism.

  17. Subfractions of high-density lipoprotein (HDL) and dysfunctional HDL in chronic kidney disease patients

    PubMed Central

    Banach, Maciej

    2016-01-01

    A number of studies have shown that chronic kidney disease (CKD) is associated with increased risk for cardiovascular disease (CVD). Chronic kidney disease is characterized by significant disturbances in lipoprotein metabolism, including differences in quantitative and qualitative content of high-density lipoprotein (HDL) particles. Recent studies have revealed that serum HDL cholesterol levels do not predict CVD in CKD patients; thus CKD-induced modifications in high-density lipoprotein (HDL) may be responsible for the increase in CV risk in CKD patients. Various methods are available to separate several subclasses of HDL and confirm their atheroprotective properties. However, under pathological conditions associated with inflammation and oxidation, HDL can progressively lose normal biological activities and be converted into dysfunctional HDL. In this review, we highlight the current state of knowledge on subfractions of HDL and HDL dysfunction in CKD. PMID:27478466

  18. Vegetarians have higher plasma alpha-tocopherol relative to cholesterol than do nonvegetarians.

    PubMed

    Pronczuk, A; Kipervarg, Y; Hayes, K C

    1992-02-01

    Biological antioxidants are thought to play a protective role in certain disease processes, including atherosclerosis. To compare the relative antioxidant/atherogenic risk between vegetarians (presumed lower risk) and omnivores (higher risk), the alpha-tocopherol, total cholesterol and fatty acid (FA) profiles were determined in the plasma of 79 vegetarians (28 males, 51 females) and 79 age- and sex-matched nonvegetarians. In the vegetarian group, mean (+/- SEM) plasma alpha-tocopherol was 714 +/- 46 micrograms/dl for males and 725 +/- 24 for females; corresponding cholesterol values were 122 +/- 5 mg/dl and 138 +/- 3, respectively, which were significantly lower than the respective control values (928 +/- 38; 883 +/- 23 and 206 +/- 6; 188 +/- 4). However, when plasma tocopherol was expressed in terms of cholesterol, the tocopherol: cholesterol molar ratio was significantly enhanced for both male (27%) and female (11%) vegetarians. Vegetarians also had a lower atherosclerosis risk based on their plasma FA profile (higher linoleic:oleic acid ratio) which correlated well (r = 0.72; p less than 0.001) with plasma alpha-tocopherol:cholesterol molar ratio. Since the bulk of tocopherol is transported in low-density lipoprotein, this lipoprotein in vegetarians may be better protected against lipid peroxidation, a process believed to be important in the pathogenesis of atherosclerosis.

  19. Effects of a carbohydrate-restricted diet with and without supplemental soluble fiber on plasma low-density lipoprotein cholesterol and other clinical markers of cardiovascular risk.

    PubMed

    Wood, Richard J; Fernandez, Maria Luz; Sharman, Matthew J; Silvestre, Ricardo; Greene, Christine M; Zern, Tosca L; Shrestha, Sudeep; Judelson, Daniel A; Gomez, Ana L; Kraemer, William J; Volek, Jeff S

    2007-01-01

    Carbohydrate-restricted diets (CRDs) promote weight loss, reductions in plasma triacylglycerol (TAG) levels, and increases in high-density lipoprotein cholesterol (HDL-C) levels but may cause undesirable low-density lipoprotein cholesterol (LDL-C) responses in some people. The objective of the present study was to determine the effect of adding soluble fiber to a CRD on plasma LDL-C and other traditionally measured markers of cardiovascular disease. Using a parallel-arm, double-blind, placebo-controlled design, 30 overweight and obese men (body mass index, 25-35 kg/m(2)) were randomly assigned to supplement a CRD with soluble fiber (Konjac-mannan, 3g/d) (n = 15) or placebo (n = 15). Plasma lipids, anthropometrics, body composition, blood pressure, and nutrient intake were evaluated at baseline and at 6 and 12 weeks. Compliance was excellent as assessed by 7-day weighed dietary records and ketonuria. Both groups experienced decreases in (P < .01) body weight, percent body fat, systolic blood pressure, waist circumference, and plasma glucose levels. After 12 weeks, HDL-C and TAG improved significantly in the fiber (10% and -34%) and placebo (14%, -43%) groups. LDL-C decreased by 17.6% (P < .01) at week 6 and 14.1% (P < .01) at week 12 in the fiber group. Conversely, LDL-C reductions were significant in the placebo group only after 12 weeks (-6.0%, P < .05). We conclude that although clearly effective at lowering LDL-C, adding soluble fiber to a CRD during active and significant weight loss provides no additional benefits to the diet alone. Furthermore, a CRD led to clinically important positive alterations in cardiovascular disease risk factors.

  20. Imaging approaches for analysis of cholesterol distribution and dynamics in the plasma membrane.

    PubMed

    Wüstner, Daniel; Modzel, Maciej; Lund, Frederik W; Lomholt, Michael A

    2016-09-01

    Cholesterol is an important lipid component of the plasma membrane (PM) of mammalian cells, where it is involved in control of many physiological processes, such as endocytosis, cell migration, cell signalling and surface ruffling. In an attempt to explain these functions of cholesterol, several models have been put forward about cholesterol's lateral and transbilayer organization in the PM. In this article, we review imaging techniques developed over the last two decades for assessing the distribution and dynamics of cholesterol in the PM of mammalian cells. Particular focus is on fluorescence techniques to study the lateral and inter-leaflet distribution of suitable cholesterol analogues in the PM of living cells. We describe also several methods for determining lateral cholesterol dynamics in the PM including fluorescence recovery after photobleaching (FRAP), fluorescence correlation spectroscopy (FCS), single particle tracking (SPT) and spot variation FCS coupled to stimulated emission depletion (STED) microscopy. For proper interpretation of such measurements, we provide some background in probe photophysics and diffusion phenomena occurring in cell membranes. In particular, we show the equivalence of the reaction-diffusion approach, as used in FRAP and FCS, and continuous time random walk (CTRW) models, as often invoked in SPT studies. We also discuss mass spectrometry (MS) based imaging of cholesterol in the PM of fixed cells and compare this method with fluorescence imaging of sterols. We conclude that evidence from many experimental techniques converges towards a model of a homogeneous distribution of cholesterol with largely free and unhindered diffusion in both leaflets of the PM. PMID:27016337

  1. A COCONUT EXTRA VIRGIN OIL-RICH DIET INCREASES HDL CHOLESTEROL AND DECREASES WAIST CIRCUMFERENCE AND BODY MASS IN CORONARY ARTERY DISEASE PATIENTS.

    PubMed

    Cardoso, Diuli A; Moreira, Annie S B; de Oliveira, Glaucia M M; Raggio Luiz, Ronir; Rosa, Glorimar

    2015-11-01

    diferencia significativa entre los grupos para DC (-2,1 ± 2,7 cm; p < 0,01). Además, se produjo un aumento en las concentraciones de HDL-C, Apo A, con una diferencia significativa en GD, solo para HDL-C (3,1 ± 7,4 mg/dl; p = 0,02). Conclusión: se observó que el tratamiento nutricional asociado con el consumo de aceite de coco virgen extra redujo la CC e incrementó los niveles de HDL-C en pacientes con CAD.

  2. Double Potential Pulse Chronocoulometry for Detection of Plasma Membrane Cholesterol Efflux at Disk Platinum Microelectrodes

    PubMed Central

    West, Richard H.; Lu, Hui; Shaw, Kendrick; Chiel, Hillel J.; Kelley, Thomas J.; Burgess, James D.

    2016-01-01

    A double potential pulse scheme is reported for observation of cholesterol efflux from the plasma membrane of a single neuron cell. Capillary Pt disk microelectrodes having a thin glass insulator allow the 10 μm diameter electrode and cell to be viewed under optical magnification. The electrode, covalently functionalized with cholesterol oxidase, is positioned in contact with the cell surface resulting in enzyme catalyzed cholesterol oxidation and efflux of cholesterol from the plasma membrane at the electrode contact site. Enzymatically generated hydrogen peroxide accumulates at the electrode/cell interface during a 5 s hold-time and is oxidized during application of a potential pulse. A second, replicate potential pulse is applied 0.5 s after the first potential pulse to gauge background charge prior to significant accumulation of hydrogen peroxide. The difference in charge passed between the first and second potential pulse provides a measure of hydrogen peroxide generated by the enzyme and is an indication of the cholesterol efflux. Control experiments for bare Pt microelectrodes in contact with the cell plasma membrane show difference charge signals in the range of about 7–10 pC. Enzyme-modified electrodes in contact with the plasma membrane show signals in the range of 16–26 pC. PMID:27330196

  3. Relationship of drinking water disinfectants to plasma cholesterol and thyroid hormone levels in experimental studies

    SciTech Connect

    Revis, N.W.; McCauley, P.; Bull, R.; Holdsworth, G.

    1986-03-01

    The effects of drinking water containing 2 or 15 ppm chlorine (pH 6.5 and 8.5), chlorine dioxide, and monochloramine on thyroid function and plasma cholesterol were studied because previous investigators have reported cardiovascular abnormalities in experimental animals exposed to chlorinated water. Plasma thyroxine (T4) levels, as compared to controls, were significantly decreased in pigeons fed a normal or high-cholesterol diet and drinking water containing these drinking water disinfectants at a concentration of 15 ppm (the exception was chlorine at pH 6.5) for 3 months. In most of the treatment groups, T4 levels were significantly lower following the exposure to drinking water containing the 2 ppm dose. Increase in plasma cholesterol were frequently observed in the groups with lower T4 levels. This association was most evident in pigeons fed the high-cholesterol diet and exposed to these disinfectants at a dose of 15 ppm. The factor(s) associated with the effect of these disinfectants on plasma T4 and cholesterol is not known. The authors suggest however that these effects are probably mediated by products formed when these disinfectants react with organic matter in the upper gastrointestinal tract.

  4. Grape Polyphenols Increase the Activity of HDL Enzymes in Old and Obese Rats

    PubMed Central

    Zagayko, Andriy L.; Kravchenko, Ganna B.; Krasilnikova, Oksana A.; Ogai, Yuri O.

    2013-01-01

    HDL particles are protein-rich particles that act as a vehicle for reverse cholesterol transport from tissues to the liver. The purpose of this study was to investigate age-dependent changes in the functional activity of HDL and the effect of high-energy diet on this index, as well as to correct it under the influence of grape polyphenols from “Enoant” obtained from Vitis vinifera grapes. We observed the age-dependent composition changes in HDL particle. It was shown that total lipids and triacylglycerol (TG) levels were higher in 24-month-old animals. In obese rats, HDL total lipids and TG levels were higher in 24-month-old than in the 3-month-old and 12-month-old groups but did not differ from 24-month-old group. The plasma HDL paraoxonase (PON) and lecithin:cholesterol acyltransferase (LCAT) activity levels were decreased in old-aged rats, and cholesteryl ester transfer protein (CETP) activity was higher in old rats. Keeping 12-month-old animals on high-fructose diet completely leveled the age differences in the data that have been measured between 12-month-old and 24-month-old rats. After “Enoant” administration, an increase of HDL PON and LCAT activity levels and a reduction of CETP activity were found in 24-month-old and obese rats. PMID:23936611

  5. Grape polyphenols increase the activity of HDL enzymes in old and obese rats.

    PubMed

    Zagayko, Andriy L; Kravchenko, Ganna B; Krasilnikova, Oksana A; Ogai, Yuri O

    2013-01-01

    HDL particles are protein-rich particles that act as a vehicle for reverse cholesterol transport from tissues to the liver. The purpose of this study was to investigate age-dependent changes in the functional activity of HDL and the effect of high-energy diet on this index, as well as to correct it under the influence of grape polyphenols from "Enoant" obtained from Vitis vinifera grapes. We observed the age-dependent composition changes in HDL particle. It was shown that total lipids and triacylglycerol (TG) levels were higher in 24-month-old animals. In obese rats, HDL total lipids and TG levels were higher in 24-month-old than in the 3-month-old and 12-month-old groups but did not differ from 24-month-old group. The plasma HDL paraoxonase (PON) and lecithin:cholesterol acyltransferase (LCAT) activity levels were decreased in old-aged rats, and cholesteryl ester transfer protein (CETP) activity was higher in old rats. Keeping 12-month-old animals on high-fructose diet completely leveled the age differences in the data that have been measured between 12-month-old and 24-month-old rats. After "Enoant" administration, an increase of HDL PON and LCAT activity levels and a reduction of CETP activity were found in 24-month-old and obese rats. PMID:23936611

  6. Synthetic High-Density Lipoprotein-Like Nanocarrier Improved Cellular Transport of Lysosomal Cholesterol in Human Sterol Carrier Protein-Deficient Fibroblasts.

    PubMed

    Nam, Da-Eun; Kim, Ok-Kyung; Park, Yoo Kyoung; Lee, Jeongmin

    2016-01-01

    Sterol carrier protein-2 (SCP-2), which is not found in tissues of people with Zellweger syndrome, facilitates the movement of cholesterol within cells, resulting in abnormal accumulation of cholesterol in SCP-2-deficient cells. This study investigated whether synthetic high-density lipoprotein-like nanocarrier (sHDL-NC) improves the cellular transport of lysosomal cholesterol to plasma membrane in SCP-2-deficient fibroblasts. Human SCP-2-deficient fibroblasts were incubated with [(3)H-cholesterol]LDL as a source of cholesterol and sHDL-NC. The cells were fractionated by centrifugation permit tracking of [(3)H]-cholesterol from lysosome into plasma membrane. Furthermore, cellular content of cholesteryl ester as a storage form and mRNA expression of low-density lipoprotein (LDL) receptor were measured to support the cholesterol transport to plasma membrane. Incubation with sHDL-NC for 8 h significantly increased uptake of [(3)H]-cholesterol to lysosome by 53% and further enhanced the transport of [(3)H]-cholesterol to plasma membrane by 32%. Treatment with sHDL-NC significantly reduced cellular content of cholesteryl ester and increased mRNA expression of LDL receptor (LDL-R). In conclusion, sHDL-NC enables increased transport of lysosomal cholesterol to plasma membrane. In addition, these data were indirectly supported by decreased cellular content of cholesteryl ester and increased gene expression of LDL-R. Therefore, sHDL-NC may be a useful vehicle for transporting cholesterol, which may help to prevent accumulation of cholesterol in SCP-2-deficient fibroblasts.

  7. Dietary Conjugated Linoleic Acid Alters Oxidative Stability and Alleviates Plasma Cholesterol Content in Meat of Broiler Chickens

    PubMed Central

    Kumari Ramiah, Suriya; Meng, Goh Yong

    2014-01-01

    This study was conducted to investigate the effects of dietary conjugated linoleic acid (CLA) on fatty acid composition, lipoprotein content, lipid peroxidation, and meat colour of broiler chickens. A total of 180 broiler chickens were allocated to 3 dietary treatments (0, 2.5, and 5% Lutrell) and given a standard broiler starter diet and finisher diet. Body weight of chickens and feed intake were recorded weekly. After slaughter, the breast meat was aged at 4°C for 0, 3, and 6 days. The fatty acid composition was measured in the breast meat. Body weight (BW) and feed efficiency were decreased by dietary CLA level (P < 0.05). Chicken fed with 2.5% Lutrell had the highest feed intake compared to the control (CON) group. The total CLA increased significantly (P < 0.05) in breast meat from birds supplemented with CLA. Propensity for lipid peroxidation was significantly higher after 6 days of meat storage (P < 0.05) and the redness in chicken breast meat was lower in CLA-fed birds (P < 0.05). It is also notable that a 5% Lutrell supplementation decreased the plasma total cholesterol (TC), low density protein (LDL), and HDL (high-density lipoprotein)/LDL ratio in chickens (P < 0.05). PMID:25386625

  8. Home-Use Tests - Cholesterol

    MedlinePlus

    ... this test does: This is a home-use test kit to measure total cholesterol. What cholesterol is: Cholesterol is a fat (lipid) in your blood. High-density lipoprotein (HDL) ("good" cholesterol) helps protect your heart, but low-density lipoprotein (LDL) ("bad" cholesterol) can clog the arteries of your ...

  9. Effects of Dietary Palmitoleic Acid on Plasma Lipoprotein Profile and Aortic Cholesterol Accumulation Are Similar to Those of Other Unsaturated Fatty Acids in the F1B Golden Syrian Hamster 1–3

    PubMed Central

    Matthan, Nirupa R.; Dillard, Alice; Lecker, Jaime L.; Ip, Blanche; Lichtenstein, Alice H.

    2008-01-01

    The lower susceptibility of palmitoleic acid (16:1) to oxidation compared to PUFA may confer functional advantages with respect to finding acceptable alternatives to partially hydrogenated fats, but limited data are available on its effect on cardiovascular risk factors. This study investigated the effect of diets (10% fat, 0.1% cholesterol, wt:wt) enriched with macadamia [monounsaturated fatty acid (MUFA)16:1], palm (SFA,16:0), canola (MUFA,18:1), or safflower (PUFA,18:2) oils on lipoprotein profiles and aortic cholesterol accumulation in F1B Golden Syrian hamsters (n = 16/group). After 12 wk, 8 hamsters in each group were killed (phase 1). The remaining hamsters fed palm oil were changed to a diet containing coconut oil, while hamsters in the other diet groups continued on their original diets for an additional 6 wk (phase 2). With minor exceptions, the time course and dietary SFA source did not alter the study outcomes. Macadamia oil-fed hamsters had lower non-HDL cholesterol and triglyceride concentrations compared with the palm and coconut oil-fed hamsters and higher HDL-cholesterol compared with the coconut, canola, and safflower oil-fed hamsters. The aortic cholesterol concentration was not affected by dietary fat type. The hepatic cholesterol concentration was higher in the unsaturated compared with the saturated oil-fed hamsters. RBC membrane and aortic cholesteryl ester, triglyceride, and phospholipid fatty acid profiles reflected that of the dietary oil. These data suggest that an oil relatively high in palmitoleic acid does not adversely affect plasma lipoprotein profiles or aortic cholesterol accumulation and was similar to other unsaturated fatty acid-rich oils. PMID:19106316

  10. Effects of dietary palmitoleic acid on plasma lipoprotein profile and aortic cholesterol accumulation are similar to those of other unsaturated fatty acids in the F1B golden Syrian hamster.

    PubMed

    Matthan, Nirupa R; Dillard, Alice; Lecker, Jaime L; Ip, Blanche; Lichtenstein, Alice H

    2009-02-01

    The lower susceptibility of palmitoleic acid (16:1) to oxidation compared to PUFA may confer functional advantages with respect to finding acceptable alternatives to partially hydrogenated fats, but limited data are available on its effect on cardiovascular risk factors. This study investigated the effect of diets (10% fat, 0.1% cholesterol, wt:wt) enriched with macadamia [monounsaturated fatty acid (MUFA)16:1], palm (SFA,16:0), canola (MUFA,18:1), or safflower (PUFA,18:2) oils on lipoprotein profiles and aortic cholesterol accumulation in F1B Golden Syrian hamsters (n = 16/group). After 12 wk, 8 hamsters in each group were killed (phase 1). The remaining hamsters fed palm oil were changed to a diet containing coconut oil, while hamsters in the other diet groups continued on their original diets for an additional 6 wk (phase 2). With minor exceptions, the time course and dietary SFA source did not alter the study outcomes. Macadamia oil-fed hamsters had lower non-HDL cholesterol and triglyceride concentrations compared with the palm and coconut oil-fed hamsters and higher HDL-cholesterol compared with the coconut, canola, and safflower oil-fed hamsters. The aortic cholesterol concentration was not affected by dietary fat type. The hepatic cholesterol concentration was higher in the unsaturated compared with the saturated oil-fed hamsters. RBC membrane and aortic cholesteryl ester, triglyceride, and phospholipid fatty acid profiles reflected that of the dietary oil. These data suggest that an oil relatively high in palmitoleic acid does not adversely affect plasma lipoprotein profiles or aortic cholesterol accumulation and was similar to other unsaturated fatty acid-rich oils. PMID:19106316

  11. Plasma cholesterol-lowering effect on rats of dietary fiber extracted from immature plants.

    PubMed

    Nishimura, N; Taniguchi, Y; Kiriyama, S

    2000-12-01

    Crude dietary fiber samples were prepared from beet, cabbage, Japanese radish, onion and mung bean sprouts (BF, CF, RF, OF and MF, respectively). These samples contained total dietary fiber at the levels of 814, 699, 760, 693 and 666 g/kg, respectively. To examine the effect of these dietary fiber sources on the plasma cholesterol concentration, male Sprague-Dawley rats were fed on a fiber-free (FF) diet or on an FF diet supplemented with 5% or 10% dietary fiber. Dietary fiber extracted from vegetables, wood cellulose (CL), pectin (PE) and guar gum (GG) were used as the fiber sources. Compared with the rats fed on the FF diet, a significant reduction in the plasma cholesterol concentration was observed in the rats fed on BF, CF, RF, MF, PE or GG after a 21-d feeding period. Cecal acetate, n-butyrate and total short-chain fatty acids were significantly higher in the rats fed on these dietary fibers, except for CF, than in those fed on the FF diet. A negative correlation was apparent between the total dietary fiber content, hemicellulose content and pectin content of each dietary fiber source and the plasma cholesterol concentration. These results suggest that some vegetable fibers exert a plasma cholesterol-lowering effect through cecal fermentation of these fibers.

  12. Effect of frequency of dosing of plant sterols on plasma cholesterol levels and synthesis rate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to compare the effects of plant sterols (PS) consumed as a single dose (single) at breakfast or as three doses consumed with breakfast, lunch and dinner (divided) on plasma lipoprotien levels and cholesterol endogenous fractional synthesis rate (FSR). A randomized, placebo-controll...

  13. Significance of the hydrophobic residues 225-230 of apoA-I for the biogenesis of HDL.

    PubMed

    Fotakis, Panagiotis; Tiniakou, Ioanna; Kateifides, Andreas K; Gkolfinopoulou, Christina; Chroni, Angeliki; Stratikos, Efstratios; Zannis, Vassilis I; Kardassis, Dimitris

    2013-12-01

    We studied the significance of four hydrophobic residues within the 225-230 region of apoA-I on its structure and functions and their contribution to the biogenesis of HDL. Adenovirus-mediated gene transfer of an apoA-I[F225A/V227A/F229A/L230A] mutant in apoA-I⁻/⁻ mice decreased plasma cholesterol, HDL cholesterol, and apoA-I levels. When expressed in apoA-I⁻/⁻ × apoE⁻/⁻ mice, approximately 40% of the mutant apoA-I as well as mouse apoA-IV and apoB-48 appeared in the VLDL/IDL/LDL. In both mouse models, the apoA-I mutant generated small spherical particles of pre-β- and α4-HDL mobility. Coexpression of the apoA-I mutant and LCAT increased and shifted the-HDL cholesterol peak toward lower densities, created normal αHDL subpopulations, and generated spherical-HDL particles. Biophysical analyses suggested that the apoA-I[225-230] mutations led to a more compact folding that may limit the conformational flexibility of the protein. The mutations also reduced the ability of apoA-I to promote ABCA1-mediated cholesterol efflux and to activate LCAT to 31% and 66%, respectively, of the WT control. Overall, the apoA-I[225-230] mutations inhibited the biogenesis of-HDL and led to the accumulation of immature pre-β- and α4-HDL particles, a phenotype that could be corrected by administration of LCAT. PMID:24123812

  14. Dietary cholesterol, heart disease risk and cognitive dissonance.

    PubMed

    McNamara, Donald J

    2014-05-01

    In the 1960s, the thesis that dietary cholesterol contributes to blood cholesterol and heart disease risk was a rational conclusion based on the available science at that time. Fifty years later the research evidence no longer supports this hypothesis yet changing the dietary recommendation to limit dietary cholesterol has been a slow and at times contentious process. The preponderance of the clinical and epidemiological data accumulated since the original dietary cholesterol restrictions were formulated indicate that: (1) dietary cholesterol has a small effect on the plasma cholesterol levels with an increase in the cholesterol content of the LDL particle and an increase in HDL cholesterol, with little effect on the LDL:HDL ratio, a significant indicator of heart disease risk, and (2) the lack of a significant relationship between cholesterol intake and heart disease incidence reported from numerous epidemiological surveys. Over the last decade, many countries and health promotion groups have modified their dietary recommendations to reflect the current evidence and to address a now recognised negative consequence of ineffective dietary cholesterol restrictions (such as inadequate choline intake). In contrast, health promotion groups in some countries appear to suffer from cognitive dissonance and continue to promote an outdated and potentially hazardous dietary recommendation based on an invalidated hypothesis. This review evaluates the evidence for and against dietary cholesterol restrictions and the potential consequences of such restrictions.

  15. Pleiotropic effects on subclasses of HDL, adiposity and glucose metabolism in adult Alaskan Eskimos

    PubMed Central

    Tejero, ME; Voruganti, VS; Cai, G; Cole, SA; Laston, S; Wenger, CR; MacCluer, JW; Dyke, B; Devereux, R; Ebbesson, SO; Fabsitz, RR; Howard, BV; Comuzzie, AG

    2012-01-01

    The aim of the present study was to analyze the heritability and the presence of pleiotropic effects on subfractions of high density lipoproteins (HDLs) as measured by nuclear magnetic resonance (NMR), parameters for adiposity and glucose metabolism in adult Alaskan Eskimos. The present family study included 1214 adult Alaskan Eskimos (537 male/677 female). Body weight, height, circumferences, selected skinfolds and blood pressure were measured in all participants. Blood samples were collected under fasting conditions for isolation of plasma. Glucose, insulin, subclasses and size of lipoproteins, triglycerides, total and HDL cholesterol and lipoprotein (a) were measured in plasma. HbA1c was measured in total blood. Univariate and bivariate quantitative genetic analyses were conducted between HDL subclasses and size and the anthropometric and biochemical measures using the variance decomposition approach. Variation in all the analyzed traits exhibits a significant genetic component. Heritabilities ranged between 0.18 ± 0.11 for LDL2 (intermediate) to 0.89 ± 0.07 for small HDL. No common genetic effects were found on the HDL subclasses (small, intermediate and large). Small HDL particles were genetically correlated with LDL particles and HbA1c. Negative genetic correlations were observed between intermediate and large HDL subfractions and HDL size and measures of adiposity, LDL and parameters for glucose metabolism (HbA1, insulin). These observations confirm the presence of possible pleiotropic effects on HDL, adiposity and cardiovascular risk factors and provide novel insight on the relationship between HDL subclasses, adiposity and glucose regulation. PMID:19950191

  16. The transport of low density lipoprotein-derived cholesterol to the plasma membrane is defective in NPC1 cells.

    PubMed

    Wojtanik, Kari M; Liscum, Laura

    2003-04-25

    Niemann-Pick disease type C (NPC) is characterized by lysosomal storage of cholesterol and gangliosides, which results from defects in intracellular lipid trafficking. Most studies of NPC1 have focused on its role in intracellular cholesterol movement. Our hypothesis is that NPC1 facilitates the egress of cholesterol from late endosomes, which are where active NPC1 is located. When NPC1 is defective, cholesterol does not exit late endosomes; instead, it is carried along to lysosomal storage bodies, where it accumulates. In this study, we addressed whether cholesterol is transported from endosomes to the plasma membrane before reaching NPC1-containing late endosomes. Our study was conducted in Chinese hamster ovary cell lines that display the classical NPC biochemical phenotype and belong to the NPC1 complementation group. We used three approaches to test whether low density lipoprotein (LDL)-derived cholesterol en route to NPC1-containing organelles passes through the plasma membrane. First, we used cyclodextrins to measure the arrival of LDL cholesterol at the plasma membrane and found that the arrival of LDL cholesterol in a cyclodextrin-accessible pool was significantly delayed in NPC1 cells. Second, the movement of LDL cholesterol to NPC1-containing late endosomes was assessed and found to be normal in Chinese hamster ovary mutant 3-6, which exhibits defective movement of plasma membrane cholesterol to intracellular membranes. Third, we examined the movement of plasma membrane cholesterol to the endoplasmic reticulum and found that this pathway is intact in NPC1 cells, i.e. it does not pass through NPC1-containing late endosomes. Our data suggest that in NPC1 cells LDL cholesterol traffics directly through endosomes to lysosomes, bypassing the plasma membrane, and is trapped there because of dysfunctional NPC1. PMID:12591922

  17. Rationale and design of a secondary prevention trial of lowering normal plasma cholesterol levels after acute myocardial infarction: the Cholesterol and Recurrent Events trial (CARE)

    PubMed

    Sacks, F M; Pfeffer, M A; Moye', L; Brown, L E; Hamm, P; Cole, T G; Hawkins, C M; Braunwald, E

    1991-12-01

    Recent clinical trials of primary and secondary prevention of cardiovascular disease have demonstrated that lowering plasma cholesterol decreases the incidence of coronary heart disease in patients with elevated plasma cholesterol. However, it is not known whether patients with established coronary artery disease and normal plasma cholesterol can be benefited. Several previous prevention trials reviewed in this report found that patients who had plasma cholesterol levels at baseline in the upper portion of the eligibility range (e.g., greater than 240 mg/dl) received greater benefit from hypolipidemic diet or drug therapy than patients who had lower plasma cholesterol levels at baseline. The recent availability of drugs that are more potent and less prone to cause adverse reactions than previous regimens permits this important question to be addressed. The Cholesterol and Recurrent Events trial is testing whether pravastatin, a hydroxymethylglutaryl coenzyme A reductase inhibitor, will decrease the sum of fatal coronary heart disease and nonfatal myocardial infarction (MI) in patients who have recovered from a MI and who have normal total cholesterol levels. Fatal cardiovascular disease and total mortality are important secondary end points. The trial is enrolling 4,000 men and women from 80 centers throughout North America, age 21 to 75 years, who have survived MI for 3 to 20 months, who have plasma total cholesterol less than 240 mg/dl (6.2 mmol/liter) and low-density cholesterol of 115 to 174 mg/dl (3.0 to 4.5 mmol/liter), and who are representative of the general population of patients with MI. Patients are randomized to either active or inactive drug therapy. Active therapy consists of pravastatin, 40 mg/day, designed to achieve an average decrease in low-density lipoprotein cholesterol of approximately 30%, and an increase in high-density lipoprotein of 5%. The average duration of follow-up will be greater than or equal to 5 years. To protect against a lower

  18. How to Get Your Cholesterol Tested

    MedlinePlus

    ... HDL) cholesterol, low-density lipoprotein (LDL) cholesterol and triglycerides. A small sample of blood will be drawn ... the amount of LDL (bad) cholesterol level and triglycerides can be affected by what you've recently ...

  19. Dialysis Modalities and HDL Composition and Function

    PubMed Central

    Holzer, Michael; Schilcher, Gernot; Curcic, Sanja; Trieb, Markus; Ljubojevic, Senka; Stojakovic, Tatjana; Scharnagl, Hubert; Kopecky, Chantal M.; Rosenkranz, Alexander R.; Heinemann, Akos

    2015-01-01

    Lipid abnormalities may have an effect on clinical outcomes of patients on dialysis. Recent studies have indicated that HDL dysfunction is a hallmark of ESRD. In this study, we compared HDL composition and metrics of HDL functionality in patients undergoing hemodialysis (HD) or peritoneal dialysis (PD) with those in healthy controls. We detected a marked suppression of several metrics of HDL functionality in patients on HD or PD. Compositional analysis revealed that HDL from both dialysis groups shifted toward a more proinflammatory phenotype with profound alterations in the lipid moiety and protein composition. With regard to function, cholesterol efflux and anti-inflammatory and antiapoptotic functions seemed to be more severely suppressed in patients on HD, whereas HDL-associated paraoxonase activity was lowest in patients on PD. Quantification of enzyme activities involved in HDL metabolism suggested that HDL particle maturation and remodeling are altered in patients on HD or PD. In summary, our study provides mechanistic insights into the formation of dysfunctional HDL in patients with ESRD who are on HD or PD. PMID:25745027

  20. microRNAs and HDL life cycle

    PubMed Central

    Canfrán-Duque, Alberto; Ramírez, Cristina M.; Goedeke, Leigh; Lin, Chin-Sheng; Fernández-Hernando, Carlos

    2014-01-01

    miRNAs have emerged as important regulators of lipoprotein metabolism. Work over the past few years has demonstrated that miRNAs control the expression of most of the genes associated with high-density lipoprotein (HDL) metabolism, including the ATP transporters, ABCA1 and ABCG1, and the scavenger receptor SRB1. These findings strongly suggest that miRNAs regulate HDL biogenesis, cellular cholesterol efflux, and HDL cholesterol (HDL-C) uptake in the liver, thereby controlling all of the steps of reverse cholesterol transport. Recent work in animal models has demonstrated that manipulating miRNA levels including miR-33 can increase circulating HDL-C. Importantly, antagonizing miR-33 in vivo enhances the regression and reduces the progression of atherosclerosis. These findings support the idea of developing miRNA inhibitors for the treatment of dyslipidaemia and related cardiovascular disorders such as atherosclerosis. This review article focuses on how HDL metabolism is regulated by miRNAs and how antagonizing miRNA expression could be a potential therapy for treating cardiometabolic diseases. PMID:24895349

  1. microRNAs and HDL life cycle.

    PubMed

    Canfrán-Duque, Alberto; Ramírez, Cristina M; Goedeke, Leigh; Lin, Chin-Sheng; Fernández-Hernando, Carlos

    2014-08-01

    miRNAs have emerged as important regulators of lipoprotein metabolism. Work over the past few years has demonstrated that miRNAs control the expression of most of the genes associated with high-density lipoprotein (HDL) metabolism, including the ATP transporters, ABCA1 and ABCG1, and the scavenger receptor SRB1. These findings strongly suggest that miRNAs regulate HDL biogenesis, cellular cholesterol efflux, and HDL cholesterol (HDL-C) uptake in the liver, thereby controlling all of the steps of reverse cholesterol transport. Recent work in animal models has demonstrated that manipulating miRNA levels including miR-33 can increase circulating HDL-C. Importantly, antagonizing miR-33 in vivo enhances the regression and reduces the progression of atherosclerosis. These findings support the idea of developing miRNA inhibitors for the treatment of dyslipidaemia and related cardiovascular disorders such as atherosclerosis. This review article focuses on how HDL metabolism is regulated by miRNAs and how antagonizing miRNA expression could be a potential therapy for treating cardiometabolic diseases. PMID:24895349

  2. ApoA-IV promotes the biogenesis of apoA-IV-containing HDL particles with the participation of ABCA1 and LCAT.

    PubMed

    Duka, Adelina; Fotakis, Panagiotis; Georgiadou, Dimitra; Kateifides, Andreas; Tzavlaki, Kalliopi; von Eckardstein, Leonard; Stratikos, Efstratios; Kardassis, Dimitris; Zannis, Vassilis I

    2013-01-01

    The objective of this study was to establish the role of apoA-IV, ABCA1, and LCAT in the biogenesis of apoA-IV-containing HDL (HDL-A-IV) using different mouse models. Adenovirus-mediated gene transfer of apoA-IV in apoA-I(-/-) mice did not change plasma lipid levels. ApoA-IV floated in the HDL2/HDL3 region, promoted the formation of spherical HDL particles as determined by electron microscopy, and generated mostly α- and a few pre-β-like HDL subpopulations. Gene transfer of apoA-IV in apoA-I(-/-) × apoE(-/-) mice increased plasma cholesterol and triglyceride levels, and 80% of the protein was distributed in the VLDL/IDL/LDL region. This treatment likewise generated α- and pre-β-like HDL subpopulations. Spherical and α-migrating HDL particles were not detectable following gene transfer of apoA-IV in ABCA1(-/-) or LCAT(-/-) mice. Coexpression of apoA-IV and LCAT in apoA-I(-/-) mice restored the formation of HDL-A-IV. Lipid-free apoA-IV and reconstituted HDL-A-IV promoted ABCA1 and scavenger receptor BI (SR-BI)-mediated cholesterol efflux, respectively, as efficiently as apoA-I and apoE. Our findings are consistent with a novel function of apoA-IV in the biogenesis of discrete HDL-A-IV particles with the participation of ABCA1 and LCAT, and may explain previously reported anti-inflammatory and atheroprotective properties of apoA-IV. PMID:23132909

  3. Cholesterol Modulates CFTR Confinement in the Plasma Membrane of Primary Epithelial Cells

    PubMed Central

    Abu-Arish, Asmahan; Pandzic, Elvis; Goepp, Julie; Matthes, Elizabeth; Hanrahan, John W.; Wiseman, Paul W.

    2015-01-01

    The cystic fibrosis transmembrane conductance regulator (CFTR) is a plasma-membrane anion channel that, when mutated, causes the disease cystic fibrosis. Although CFTR has been detected in a detergent-resistant membrane fraction prepared from airway epithelial cells, suggesting that it may partition into cholesterol-rich membrane microdomains (lipid rafts), its compartmentalization has not been demonstrated in intact cells and the influence of microdomains on CFTR lateral mobility is unknown. We used live-cell imaging, spatial image correlation spectroscopy, and k-space image correlation spectroscopy to examine the aggregation state of CFTR and its dynamics both within and outside microdomains in the plasma membrane of primary human bronchial epithelial cells. These studies were also performed during treatments that augment or deplete membrane cholesterol. We found two populations of CFTR molecules that were distinguishable based on their dynamics at the cell surface. One population showed confinement and had slow dynamics that were highly cholesterol dependent. The other, more abundant population was less confined and diffused more rapidly. Treatments that deplete the membrane of cholesterol caused the confined fraction and average number of CFTR molecules per cluster to decrease. Elevating cholesterol had the opposite effect, increasing channel aggregation and the fraction of channels displaying confinement, consistent with CFTR recruitment into cholesterol-rich microdomains with dimensions below the optical resolution limit. Viral infection caused the nanoscale microdomains to fuse into large platforms and reduced CFTR mobility. To our knowledge, these results provide the first biophysical evidence for multiple CFTR populations and have implications for regulation of their surface expression and channel function. PMID:26153705

  4. The Human ABCG1 Transporter Mobilizes Plasma Membrane and Late Endosomal Non-Sphingomyelin-Associated-Cholesterol for Efflux and Esterification

    PubMed Central

    Neufeld, Edward B.; O’Brien, Katherine; Walts, Avram D.; Stonik, John A.; Malide, Daniela; Combs, Christian A.; Remaley, Alan T.

    2014-01-01

    We have previously shown that GFP-tagged human ABCG1 on the plasma membrane (PM) and in late endosomes (LE) mobilizes sterol on both sides of the membrane lipid bilayer, thereby increasing cellular cholesterol efflux to lipid surfaces. In the present study, we examined ABCG1-induced changes in membrane cholesterol distribution, organization, and mobility. ABCG1-GFP expression increased the amount of mobile, non-sphingomyelin(SM)-associated cholesterol at the PM and LE, but not the amount of SM-associated-cholesterol or SM. ABCG1-mobilized non-SM-associated-cholesterol rapidly cycled between the PM and LE and effluxed from the PM to extracellular acceptors, or, relocated to intracellular sites of esterification. ABCG1 increased detergent-soluble pools of PM and LE cholesterol, generated detergent-resistant, non-SM-associated PM cholesterol, and increased resistance to both amphotericin B-induced (cholesterol-mediated) and lysenin-induced (SM-mediated) cytolysis, consistent with altered organization of both PM cholesterol and SM. ABCG1 itself resided in detergent-soluble membrane domains. We propose that PM and LE ABCG1 residing at the phase boundary between ordered (Lo) and disordered (Ld) membrane lipid domains alters SM and cholesterol organization thereby increasing cholesterol flux between Lo and Ld, and hence, the amount of cholesterol available for removal by acceptors on either side of the membrane bilayer for either efflux or esterification. PMID:25485894

  5. Nitric oxide, cholesterol oxides and endothelium-dependent vasodilation in plasma of patients with essential hypertension.

    PubMed

    Moriel, P; Sevanian, A; Ajzen, S; Zanella, M T; Plavnik, F L; Rubbo, H; Abdalla, D S P

    2002-11-01

    The objective of the present study was to identify disturbances of nitric oxide radical (.NO) metabolism and the formation of cholesterol oxidation products in human essential hypertension. The concentrations of.NO derivatives (nitrite, nitrate, S-nitrosothiols and nitrotyrosine), water and lipid-soluble antioxidants and cholesterol oxides were measured in plasma of 11 patients with mild essential hypertension (H: 57.8 +/- 9.7 years; blood pressure, 148.3 +/- 24.8/90.8 +/- 10.2 mmHg) and in 11 healthy subjects (N: 48.4 +/- 7.0 years; blood pressure, 119.4 +/- 9.4/75.0 +/- 8.0 mmHg). Nitrite, nitrate and S-nitrosothiols were measured by chemiluminescence and nitrotyrosine was determined by ELISA. Antioxidants were determined by reverse-phase HPLC and cholesterol oxides by gas chromatography. Hypertensive patients had reduced endothelium-dependent vasodilation in response to reactive hyperemia (H: 9.3 and N: 15.1% increase of diameter 90 s after hyperemia), and lower levels of ascorbate (H: 29.2 +/- 26.0, N: 54.2 +/- 24.9 micro M), urate (H: 108.5 +/- 18.9, N: 156.4 +/- 26.3 micro M), beta-carotene (H: 1.1 +/- 0.8, N: 2.5 +/- 1.2 nmol/mg cholesterol), and lycopene (H: 0.4 +/- 0.2, N: 0.7 +/- 0.2 nmol/mg cholesterol), in plasma, compared to normotensive subjects. The content of 7-ketocholesterol, 5alpha-cholestane-3beta,5,6beta-triol and 5,6alpha-epoxy-5alpha-cholestan-3alpha-ol in LDL, and the concentration of endothelin-1 (H: 0.9 +/- 0.2, N: 0.7 +/- 0.1 ng/ml) in plasma were increased in hypertensive patients. No differences were found for.NO derivatives between groups. These data suggest that an increase in cholesterol oxidation is associated with endothelium dysfunction in essential hypertension and oxidative stress, although.NO metabolite levels in plasma are not modified in the presence of elevated cholesterol oxides. PMID:12426629

  6. Effects of short-term niacin treatment on plasma lipoprotein concentrations in African green monkeys (Chlorocebus aethiops).

    PubMed

    Chauke, Chesa G; Arieff, Zainunisha; Kaur, Mandeep; Seier, Jurgen V

    2014-02-01

    Niacin is the most effective drug available for raising levels of high-density lipoprotein (HDL) cholesterol. To evaluate its effects on plasma lipid concentrations, the authors administered a low dose of niacin to healthy, adult, female African green monkeys for 3 months. In the treated monkeys, low-density lipoprotein cholesterol concentrations decreased by 43% from baseline, whereas concentrations of HDL cholesterol and apolipoprotein A-I increased by 49% and 34%, respectively. The results suggest that in this primate model, a low dose of niacin can effectively increase concentrations of HDL cholesterol.

  7. Relative atherogenicity and predictive value of non-high-density lipoprotein cholesterol for coronary heart disease.

    PubMed

    Miller, Michael; Ginsberg, Henry N; Schaefer, Ernst J

    2008-04-01

    Although low-density lipoprotein cholesterol (LDL-C) is a well-established atherogenic factor for coronary heart disease, it does not completely represent the risk associated with atherogenic lipoproteins in the presence of high triglyceride (TG) levels. Constituent lipoproteins constituting non-high-density lipoprotein cholesterol (non-HDL-C) include atherogenic TG-rich lipoproteins, cholesteryl ester-enriched remnants of TG-rich lipoproteins, and lipoprotein(a). Recent observational and intervention studies suggest that the predictive value of non-HDL-C for cardiovascular risk and mortality is better than low-density lipoprotein cholesterol and that non-HDL-C correlates highly with plasma apolipoprotein B levels. Currently, the National Cholesterol Education Program Adult Treatment Panel III guidelines identify non-HDL-C as a secondary target of therapy in patients with TG elevation (> or =200 mg/dl) after the attainment of LDL-C target goals. In patients with coronary heart disease or coronary heart disease risk equivalents, an optional non-HDL-C goal is <100 mg/dl. To achieve the non-HDL-C goal, statin therapy may be intensified or combined with ezetimibe, niacin, a fibrate, or omega-3 fatty acids. In conclusion, non-HDL-C remains an important target of therapy for patients with elevated TGs, although its widespread adoption has yet to gain a foothold among health care professionals treating patients with dyslipidemia. PMID:18359322

  8. [Role of the ABC transporters A1 and G1, key reverse cholesterol transport proteins, in atherosclerosis].

    PubMed

    Demina, E P; Miroshnikova, V V; Schwarzman, A L

    2016-01-01

    Atherosclerosis is one of the most common causes of death worldwide. Epidemiology studies firmly established an inverse relationship between atherogenesis and distorted lipid metabolism, in particular, higher levels of total cholesterol, an accumulation of CH-laden macrophages (foam cells), and lower plasma levels of antiatherogenic high density lipoprotein (HDL). It is believed that the reverse cholesterol transport, a process that removes excess cholesterol from peripheral tissues/cells including macrophages to circulating HDL, is one of the main mechanisms responsible for anti-atherogenic properties of HDL. The key proteins of reverse cholesterol transport-ATP-binding cassette transporters A1 (ABCA1) and G1 (ABCG1)-mediate the cholesterol efflux from macrophages and prevent their transformation into foam cells. This review focuses on the role of ABC transporters A1 and G1 in the pathogenesis of atherosclerosis.

  9. Niacin and cholesterol: role in cardiovascular disease (review).

    PubMed

    Ganji, Shobha H; Kamanna, Vaijinath S; Kashyap, Moti L

    2003-06-01

    Niacin has been widely used as a pharmacologic agent to regulate abnormalities in plasma lipid and lipoprotein metabolism and in the treatment of atherosclerotic cardiovascular disease. Although the use of niacin in the treatment of dyslipidemia has been reported as early as 1955, only recent studies have yielded an understanding about the cellular and molecular mechanism of action of niacin on lipid and lipoprotein metabolism. In brief, the beneficial effect of niacin to reduce triglycerides and apolipoprotein-B containing lipoproteins (e.g., VLDL and LDL) are mainly through: a) decreasing fatty acid mobilization from adipose tissue triglyceride stores, and b) inhibiting hepatocyte diacylglycerol acyltransferase and triglyceride synthesis leading to increased intracellular apo B degradation and subsequent decreased secretion of VLDL and LDL particles. The mechanism of action of niacin to raise HDL is by decreasing the fractional catabolic rate of HDL-apo AI without affecting the synthetic rates. Additionally, niacin selectively increases the plasma levels of Lp-AI (HDL subfraction without apo AII), a cardioprotective subfraction of HDL in patients with low HDL. Using human hepatocytes (Hep G2 cells) as an in vitro model system, recent studies indicate that niacin selectively inhibits the uptake/removal of HDL-apo AI (but not HDL-cholesterol ester) by hepatocytes, thereby increasing the capacity of retained HDL-apo AI to augment cholesterol efflux through reverse cholesterol transport pathway. The studies discussed in this review provide evidence to extend the role of niacin as a lipid-lowering drug beyond its role as a vitamin.

  10. [Cholesterol bound to high density lipoproteins: critical review of the methods of analysis and personal data].

    PubMed

    Orso Giacone, G

    1982-01-01

    It is widely known that atherosclerosis through its complication, i.e. heart and brain infarction, is at the present the main cause of death. The atherosclerotic process has been shown in correlation with hyperlipemia especially as far as the plasma lipoprotein cholesterol level is concerned. A preminent role in removing cholesterol from tissues and arterial walls then in preventing atherosclerosis is played by a specific class of plasma lipoproteins, the high density lipoproteins (HDL). Since the HDL-colesterol level seems to have an inverse correlation with the atherosclerotic disease it is of primary importance to define a reliable and reproducible technique to measure it. One of the aims of this paper was to examine the different methods now available for such a determination. This analysis has underlined the discrepancy among the reference values reported in the literature. However, all the authors agree that only the simultaneous measurement of total and HDL-colesterol levels is of prognostic value. Personal studies are here reported on the relationship between total and HDL-colesterol levels and risk factor of cardiovascular diseases. The two mentioned laboratory analyses have been performed on blood samples from 250 between male and female human subjects of different age. The obtained results show that the highest HDL-colesterol concentrations determined by a lipoprotein precipitation procedure with dextran sulphate, are typical in the first ten years of life both in male and in female, while the lowest levels of plasma HDL-cholesterol have been evintiated during the fifth decade of life, when the total cholesterol and the risk of cardiovascular complications rich the highest values. In a following set of investigations, the already examined blood parameters together with the risk factor values have been examined in two groups of subjects, the first one represented by adult healthy persons the second one by patients of similar age from a cardiovascular

  11. [Cholesterol bound to high density lipoproteins: critical review of the methods of analysis and personal data].

    PubMed

    Orso Giacone, G

    1982-01-01

    It is widely known that atherosclerosis through its complication, i.e. heart and brain infarction, is at the present the main cause of death. The atherosclerotic process has been shown in correlation with hyperlipemia especially as far as the plasma lipoprotein cholesterol level is concerned. A preminent role in removing cholesterol from tissues and arterial walls then in preventing atherosclerosis is played by a specific class of plasma lipoproteins, the high density lipoproteins (HDL). Since the HDL-colesterol level seems to have an inverse correlation with the atherosclerotic disease it is of primary importance to define a reliable and reproducible technique to measure it. One of the aims of this paper was to examine the different methods now available for such a determination. This analysis has underlined the discrepancy among the reference values reported in the literature. However, all the authors agree that only the simultaneous measurement of total and HDL-colesterol levels is of prognostic value. Personal studies are here reported on the relationship between total and HDL-colesterol levels and risk factor of cardiovascular diseases. The two mentioned laboratory analyses have been performed on blood samples from 250 between male and female human subjects of different age. The obtained results show that the highest HDL-colesterol concentrations determined by a lipoprotein precipitation procedure with dextran sulphate, are typical in the first ten years of life both in male and in female, while the lowest levels of plasma HDL-cholesterol have been evintiated during the fifth decade of life, when the total cholesterol and the risk of cardiovascular complications rich the highest values. In a following set of investigations, the already examined blood parameters together with the risk factor values have been examined in two groups of subjects, the first one represented by adult healthy persons the second one by patients of similar age from a cardiovascular

  12. Effect of cholesterol lowering treatment on plasma markers of endothelial dysfunction in chronic kidney disease.

    PubMed

    Zinellu, Angelo; Sotgia, Salvatore; Mangoni, Arduino A; Sotgiu, Elisabetta; Ena, Sara; Satta, Andrea E; Carru, Ciriaco

    2016-09-10

    The elevated cardiovascular morbidity and mortality in chronic kidney disease (CKD) is linked with endothelial dysfunction secondary to the pro-inflammatory and pro-oxidative state typical of this pathology. In consideration of the well-known pleiotropic effect of statins, we investigated the effect of cholesterol lowering treatment on endothelial dysfunction markers (MED), asymmetric dimethylarginine (ADMA), vascular cell (VCAM) and intercellular (ICAM) adhesion molecule. Plasma MED concentrations, inflammation and oxidative stress indices [Kynurenine/Tryptophan (Kyn/Trp) ratio, malondialdehyde (MDA) and allantoin/uric acid (All/UA) ratio] were measured in 30 CKD patients randomized to three cholesterol lowering regimens for 12 months (simvastatin 40mg/day, ezetimibe/simvastatin 10/20mg/day, or ezetimibe/simvastatin 10/40mg/day). Treatment significantly reduced ADMA concentrations in all patients [0.694μmol/L (0.606-0.761) at baseline vs. 0.622μmol/L (0.563-0.681) after treatment, p<0.001]. ADMA reduction was paralleled by a significant decrease of MDA, All/AU ratio and Kyn/Trp ratio, but not VCAM and ICAM plasma concentrations. Cholesterol lowering treatment was associated with a significant reduction in plasma ADMA concentrations in CKD patients. This might be mediated by reduced oxidative stress and inflammation.

  13. Streptococcal serum opacity factor promotes cholesterol ester metabolism and bile acid secretion in vitro and in vivo.

    PubMed

    Gillard, Baiba K; Rodriguez, Perla J; Fields, David W; Raya, Joe L; Lagor, William R; Rosales, Corina; Courtney, Harry S; Gotto, Antonio M; Pownall, Henry J

    2016-03-01

    Plasma high density lipoprotein-cholesterol (HDL-C) concentrations negatively correlate with atherosclerotic cardiovascular disease. HDL is thought to have several atheroprotective functions, which are likely distinct from the epidemiological inverse relationship between HDL-C levels and risk. Specifically, strategies that reduce HDL-C while promoting reverse cholesterol transport (RCT) may have therapeutic value. The major product of the serum opacity factor (SOF) reaction versus HDL is a cholesteryl ester (CE)-rich microemulsion (CERM), which contains apo E and the CE of ~400,000 HDL particles. Huh7 hepatocytes take up CE faster when delivered as CERM than as HDL, in part via the LDL-receptor (LDLR). Here we compared the final RCT step, hepatic uptake and subsequent intracellular processing to cholesterol and bile salts for radiolabeled HDL-, CERM- and LDL-CE by Huh7 cells and in vivo in C57BL/6J mice. In Huh7 cells, uptake from LDL was greater than from CERM (2-4X) and HDL (5-10X). Halftimes for [(14)C]CE hydrolysis were 3.0±0.2, 4.4±0.6 and 5.4±0.7h respectively for HDL, CERM and LDL-CE. The fraction of sterols secreted as bile acids was ~50% by 8h for all three particles. HDL, CERM and LDL-CE metabolism in mice showed efficient plasma clearance of CERM-CE, liver uptake and metabolism, and secretion as bile acids into the gall bladder. This work supports the therapeutic potential of the SOF reaction, which diverts HDL-CE to the LDLR, thereby increasing hepatic CE uptake, and sterol disposal as bile acids. PMID:26709142

  14. Plasma lipid, lipoprotein and apolipoprotein profiles in Nigerian university athletes and non-athletes.

    PubMed Central

    Oyelola, O O; Rufai, M A

    1993-01-01

    The fasting plasma lipid, lipoprotein and apolipoprotein profiles were determined in 14 healthy Nigerian male athletes and controls matched for sex and anthropometric parameters. The mean levels of total cholesterol (P < 0.05), low-density lipoprotein (LDL) cholesterol, apolipoprotein (apo) AII and E were significantly lower (P < 0.01) in the athletes than in the controls. However, there were no statistically significant differences (P > 0.05) between the mean values of the plasma triglycerides, high-density lipoprotein (HDL), very low-density lipoprotein (VLDL) cholesterol, apo AI, B, Lp(a), LpA1 and CIII:NonB respectively for the athletes and controls. A priori, the potential effect on cardiovascular disease (CVD) risk was also compared using three predictor ratios - total cholesterol: HDL cholesterol (TC:HDL), LDL cholesterol: HDL cholesterol and apo B:AI. The mean of the three ratios was lower in the athletes than in the controls; however, the differences were not statistically significant (P > 0.05). Based on our data, exercise appears to decrease the TC:HDL ratio in the athletes by lowering LDL-cholesterol, while the HDL-cholesterol is unaffected. We conclude that physical activity has salutary effects on the lipid, lipoprotein and apolipoprotein profiles of healthy Nigerian men. PMID:8130968

  15. High-Density Lipoprotein Function Measurement in Human Studies: Focus on Cholesterol Efflux Capacity.

    PubMed

    Rohatgi, Anand

    2015-01-01

    A low plasma level of high-density lipoprotein (HDL) cholesterol (HDL-C) is a major risk factor for the development of atherosclerotic cardiovascular disease (ASCVD). However, several observations have highlighted the shortcomings of using cholesterol content as the sole reflection of HDL metabolism. In particular, several large randomized controlled trials of extended release niacin and cholesteryl-ester transfer protein (CETP) inhibitors on background statin therapy have failed to show improvement in ASCVD outcomes despite significant increases in HDL-C. Reverse cholesterol transport (RCT) is the principal HDL function that impacts macrophage foam cell formation and other functions such as endothelial activation of endothelial nitric oxide synthase, monocyte adhesion, and platelet aggregation. Cholesterol efflux from macrophages to plasma/serum reflects the first critical step of RCT and is considered a key anti-atherosclerotic function of HDL. Whether this function is operative in humans remains to be seen, but recent studies assessing cholesterol efflux in humans suggest that the cholesterol efflux capacity (CEC) of human plasma or serum is a potent marker of ASCVD risk. This review describes the methodology of measuring CEC ex vivo from human samples and the findings to date linking CEC to human disease. Studies to date confirm that CEC can be reliably measured using stored human blood samples as cholesterol acceptors and suggest that CEC may be a promising new biomarker for atherosclerotic and metabolic diseases. Further studies are needed to standardize measurements and clarify the role CEC may play in predicting risk of developing disease and response to therapies. PMID:25968932

  16. High-Density Lipoprotein Function Measurement in Human Studies: Focus on Cholesterol Efflux Capacity

    PubMed Central

    Rohatgi, Anand

    2015-01-01

    A low plasma level of high-density lipoprotein (HDL) cholesterol (HDL-C) is a major risk factor for the development of atherosclerotic cardiovascular disease (ASCVD). However, several observations have highlighted the shortcomings of using cholesterol content as the sole reflection of HDL metabolism. In particular, several large randomized controlled trials of extended release niacin and cholesteryl-ester transfer protein (CETP) inhibitors on background statin therapy have failed to show improvement in ASCVD outcomes despite significant increases in HDL-C. Reverse cholesterol transport (RCT) is the principal HDL function that impacts macrophage foam cell formation and other functions such as endothelial activation of endothelial nitric oxide synthase, monocyte adhesion, and platelet aggregation. Cholesterol efflux from macrophages to plasma/serum reflects the first critical step of RCT and is considered a key anti-atherosclerotic function of HDL. Whether this function is operative in humans remains to be seen, but recent studies assessing cholesterol efflux in humans suggest that the cholesterol efflux capacity (CEC) of human plasma or serum is a potent marker of ASCVD risk. This review describes the methodology of measuring CEC ex vivo from human samples and the findings to date linking CEC to human disease. Studies to date confirm that CEC can be reliably measured using stored human blood samples as cholesterol acceptors and suggest that CEC may be a promising new biomarker for atherosclerotic and metabolic diseases. Further studies are needed to standardize measurements and clarify the role CEC may play in predicting risk of developing disease and response to therapies. PMID:25968932

  17. High-Density Lipoprotein Function Measurement in Human Studies: Focus on Cholesterol Efflux Capacity.

    PubMed

    Rohatgi, Anand

    2015-01-01

    A low plasma level of high-density lipoprotein (HDL) cholesterol (HDL-C) is a major risk factor for the development of atherosclerotic cardiovascular disease (ASCVD). However, several observations have highlighted the shortcomings of using cholesterol content as the sole reflection of HDL metabolism. In particular, several large randomized controlled trials of extended release niacin and cholesteryl-ester transfer protein (CETP) inhibitors on background statin therapy have failed to show improvement in ASCVD outcomes despite significant increases in HDL-C. Reverse cholesterol transport (RCT) is the principal HDL function that impacts macrophage foam cell formation and other functions such as endothelial activation of endothelial nitric oxide synthase, monocyte adhesion, and platelet aggregation. Cholesterol efflux from macrophages to plasma/serum reflects the first critical step of RCT and is considered a key anti-atherosclerotic function of HDL. Whether this function is operative in humans remains to be seen, but recent studies assessing cholesterol efflux in humans suggest that the cholesterol efflux capacity (CEC) of human plasma or serum is a potent marker of ASCVD risk. This review describes the methodology of measuring CEC ex vivo from human samples and the findings to date linking CEC to human disease. Studies to date confirm that CEC can be reliably measured using stored human blood samples as cholesterol acceptors and suggest that CEC may be a promising new biomarker for atherosclerotic and metabolic diseases. Further studies are needed to standardize measurements and clarify the role CEC may play in predicting risk of developing disease and response to therapies.

  18. Unrefined and refined black raspberry seed oils significantly lower triglycerides and moderately affect cholesterol metabolism in male Syrian hamsters.

    PubMed

    Ash, Mark M; Wolford, Kate A; Carden, Trevor J; Hwang, Keum Taek; Carr, Timothy P

    2011-09-01

    Unrefined and refined black raspberry seed oils (RSOs) were examined for their lipid-modulating effects in male Syrian hamsters fed high-cholesterol (0.12% g/g), high-fat (9% g/g) diets. Hamsters fed the refined and the unrefined RSO diets had equivalently lower plasma total cholesterol and high-density lipoprotein (HDL) cholesterol in comparison with the atherogenic coconut oil diet. The unrefined RSO treatment group did not differ in liver total and esterified cholesterol from the coconut oil-fed control animals, but the refined RSO resulted in significantly elevated liver total and esterified cholesterol concentrations. The unrefined RSO diets significantly lowered plasma triglycerides (46%; P=.0126) in comparison with the coconut oil diet, whereas the refined RSO only tended to lower plasma triglyceride (29%; P=.1630). Liver triglyceride concentrations were lower in the unrefined (46%; P=.0002) and refined (36%; P=.0005) RSO-fed animals than the coconut oil group, with the unrefined RSO diet eliciting a lower concentration than the soybean oil diet. Both RSOs demonstrated a null or moderate effect on cholesterol metabolism despite enrichment in linoleic acid, significantly lowering HDL cholesterol but not non-HDL cholesterol. Dramatically, both RSOs significantly reduced hypertriglyceridemia, most likely due to enrichment in α-linolenic acid. As a terrestrial source of α-linolenic acid, black RSOs, both refined and unrefined, provide a promising alternative to fish oil supplementation in management of hypertriglyceridemia, as demonstrated in hamsters fed high levels of dietary triglyceride and cholesterol.

  19. In vitro stimulation of HDL anti-inflammatory activity and inhibition of LDL pro-inflammatory activity in the plasma of patients with end-stage renal disease by an apoA-1 mimetic peptide

    PubMed Central

    Vaziri, Nosratola D; Moradi, Hamid; Pahl, Madeleine V; Fogelman, Alan M; Navab, Mohamad

    2010-01-01

    Features of end-stage renal disease such as oxidative stress, inflammation, hypertension, and dyslipidemia are associated with accelerated atherosclerosis and increased risk of death from cardiovascular disease. By inhibiting the formation and increasing the disposal of oxidized lipids, HDL exerts potent antioxidant and anti-inflammatory actions. Given that apolipoproteinA-1 can limit atherosclerosis, we hypothesized that an apolipoproteinA-1 mimetic peptide, 4F, may reduce the proinflammatory properties of LDL and enhance the anti-inflammatory properties of HDL in uremic plasma. To test this, plasma from each of 12 stable hemodialysis patients and age-matched control subjects was incubated with 4F or vehicle. The isolated HDL and LDL fractions were added to cultured human aortic endothelial cells to quantify monocyte chemotactic activity, thus measuring their pro- or anti-inflammatory index. The LDL from the hemodialysis patients was more pro-inflammatory and their HDL was less anti-inflammatory than those of the control subjects. Pre-incubation of the plasma from the hemodialysis patients with 4F decreased LDL pro-inflammatory activity and enhanced HDL anti-inflammatory activity. Whether 4F or other apolipoproteinA-1 mimetic peptides will have any therapeutic benefit in end-stage renal disease will have to be examined directly in clinical studies. PMID:19471321

  20. Reduction in Postoperative High-Density Lipoprotein Cholesterol Levels in Children Undergoing the Fontan Operation

    PubMed Central

    Argraves, W. Scott; Graham, Eric M.; Slate, Elizabeth H.; Atz, Andrew M.; Bradley, Scott M.; McQuinn, Tim C.; Wilkerson, Brent A.; Wing, Shane B.

    2015-01-01

    Despite the emerging relevance of high-density lipoprotein (HDL) in the inflammatory cascade and vascular barrier integrity, HDL levels in children undergoing cardiac surgery are unexplored. As a measure of HDL levels, the HDL-cholesterol (HDL-C) in single-ventricle patients was quantified before and after the Fontan operation, and it was determined whether relationships existed between the duration and the type of postoperative pleural effusions. The study prospectively enrolled 12 children undergoing the Fontan operation. Plasma HDL-C levels were measured before and after cardiopulmonary bypass. The outcome variables of interest were the duration and type of chest tube drainage (chylous vs. nonchylous). The Kendall rank correlation coefficient and the Wilcoxon rank sum test were used. There were 11 complete observations. The median preoperative HDL-C level for all the subjects was 30 mg/dl (range, 24–53 mg/dl), and the median postcardiopulmonary bypass level was 21 mg/dl (range, 14–46 mg/dl) (p = 0.004). There was a tendency toward a moderate inverse correlation (–0.42) between the postcardiopulmonary bypass HDL-C level and the duration of chest tube drainage, but the result was not statistically significant (p = 0.07). In the chylous effusion group, the median postcardiopulmonary bypass HDL-C tended to be lower (16 vs. 23 mg/dl; p = 0.09). After the Fontan operation, the plasma HDL-C levels in children are significantly reduced. It is reasonable to conclude that the reduction in HDL-C reflects reduced plasma levels of HDL particles, which may have pertinent implications in postoperative pleural effusions given the antiinflammatory and endothelial barrier functions of HDL. PMID:22411716

  1. The cholesterol lowering property of coriander seeds (Coriandrum sativum): mechanism of action.

    PubMed

    Dhanapakiam, P; Joseph, J Mini; Ramaswamy, V K; Moorthi, M; Kumar, A Senthil

    2008-01-01

    Coriandrum sativum (Coriander) has been documented as a traditional treatment for cholesterol and diabetes patients. In the present study, coriander seeds incorporated into diet and the effect of the administration of coriander seeds on the metabolism of lipids was studied in rats, fed with high fat diet and added cholesterol. The seeds had a significant hypolipidemic action. In the experimental group of rats (tissue) the level of total cholesterol and triglycerides increased significantly There was significant increase in beta-hydroxy, beta-methyl glutaryl CoA reductase and plasma lecithin cholesterol acyl transferase activity were noted in the experimental group. The level of low density lipoprotein (LDL) + very low density lipoprotein (VLDL) cholesterol decreased while that of high density lipoprotein (HDL) cholesterol increased in the experimental group compared to the control group. The increased activity of plasma LCAT enhanced degradation of cholesterol to fecal bile acids and neutral sterols appeared to account for its hypocholesterolemic effect.

  2. Creosote Bush (Larrea tridentata) Improves Insulin Sensitivity and Reduces Plasma and Hepatic Lipids in Hamsters Fed a High Fat and Cholesterol Diet.

    PubMed

    Del Vecchyo-Tenorio, Georgina; Rodríguez-Cruz, Maricela; Andrade-Cetto, Adolfo; Cárdenas-Vázquez, René

    2016-01-01

    Creosote bush, Larrea tridentata (Sesse y Moc. Ex DC, Zygophyllaceae) is a shrub found in the deserts of Northern Mexico and Southwestern United States. In traditional medicine, it is used to treat a variety of illnesses including type 2 diabetes. The present study aims to investigate the effects of creosote bush ethanolic extract on plasma and liver parameters associated with the metabolic syndrome in hamsters fed a high fat and cholesterol diet (HFD), comparing them with those induced by ezetimibe (EZ). Seven groups of six hamsters each were formed. Six groups were fed HFD for 2 weeks. The following 2 weeks, the HFD groups received: (1) only HFD, (2) HFD + 3 mg% EZ, (3) HFD + 0.2% creosote bush ethanolic extract, (4) only standard diet (Std Diet), (5) Std Diet + 3 mg% EZ, (6) Std Diet + 0.2% creosote bush ethanolic extract. The beneficial effects of creosote bush ethanolic extract in the HFD hamster model were a reduction of insulin resistance, associated with lower serum insulin and leptin, lower hepatic lipid peroxidation and higher liver antioxidant capacity. Plasma and liver lipids tended or were reduced to values closer to those of animals fed standard diet. A similar effect on lipids was induced by EZ, although with even lower hepatic cholesterol and total lipids concentrations. In general, the change from HFD to standard diet plus ethanolic extract induced the same but deeper changes, including a reduction in plasma glucose and an increase in the percentage of HDL cholesterol. Unlike creosote bush extract, EZ increased food consumption and neutral fecal steroids, with no significant effect on body weight, epididymal fat pads, liver peroxidation or antioxidant capacity. Also EZ did not modify serum insulin and leptin. However, insulin sensitivity improved to values similar to those induced by the extract. This suggests that the mechanism of action of creosote bush ethanolic extract is different to inhibition of cholesterol absorption or increase excretion

  3. Creosote Bush (Larrea tridentata) Improves Insulin Sensitivity and Reduces Plasma and Hepatic Lipids in Hamsters Fed a High Fat and Cholesterol Diet.

    PubMed

    Del Vecchyo-Tenorio, Georgina; Rodríguez-Cruz, Maricela; Andrade-Cetto, Adolfo; Cárdenas-Vázquez, René

    2016-01-01

    Creosote bush, Larrea tridentata (Sesse y Moc. Ex DC, Zygophyllaceae) is a shrub found in the deserts of Northern Mexico and Southwestern United States. In traditional medicine, it is used to treat a variety of illnesses including type 2 diabetes. The present study aims to investigate the effects of creosote bush ethanolic extract on plasma and liver parameters associated with the metabolic syndrome in hamsters fed a high fat and cholesterol diet (HFD), comparing them with those induced by ezetimibe (EZ). Seven groups of six hamsters each were formed. Six groups were fed HFD for 2 weeks. The following 2 weeks, the HFD groups received: (1) only HFD, (2) HFD + 3 mg% EZ, (3) HFD + 0.2% creosote bush ethanolic extract, (4) only standard diet (Std Diet), (5) Std Diet + 3 mg% EZ, (6) Std Diet + 0.2% creosote bush ethanolic extract. The beneficial effects of creosote bush ethanolic extract in the HFD hamster model were a reduction of insulin resistance, associated with lower serum insulin and leptin, lower hepatic lipid peroxidation and higher liver antioxidant capacity. Plasma and liver lipids tended or were reduced to values closer to those of animals fed standard diet. A similar effect on lipids was induced by EZ, although with even lower hepatic cholesterol and total lipids concentrations. In general, the change from HFD to standard diet plus ethanolic extract induced the same but deeper changes, including a reduction in plasma glucose and an increase in the percentage of HDL cholesterol. Unlike creosote bush extract, EZ increased food consumption and neutral fecal steroids, with no significant effect on body weight, epididymal fat pads, liver peroxidation or antioxidant capacity. Also EZ did not modify serum insulin and leptin. However, insulin sensitivity improved to values similar to those induced by the extract. This suggests that the mechanism of action of creosote bush ethanolic extract is different to inhibition of cholesterol absorption or increase excretion

  4. Creosote Bush (Larrea tridentata) Improves Insulin Sensitivity and Reduces Plasma and Hepatic Lipids in Hamsters Fed a High Fat and Cholesterol Diet

    PubMed Central

    Del Vecchyo-Tenorio, Georgina; Rodríguez-Cruz, Maricela; Andrade-Cetto, Adolfo; Cárdenas-Vázquez, René

    2016-01-01

    Creosote bush, Larrea tridentata (Sesse y Moc. Ex DC, Zygophyllaceae) is a shrub found in the deserts of Northern Mexico and Southwestern United States. In traditional medicine, it is used to treat a variety of illnesses including type 2 diabetes. The present study aims to investigate the effects of creosote bush ethanolic extract on plasma and liver parameters associated with the metabolic syndrome in hamsters fed a high fat and cholesterol diet (HFD), comparing them with those induced by ezetimibe (EZ). Seven groups of six hamsters each were formed. Six groups were fed HFD for 2 weeks. The following 2 weeks, the HFD groups received: (1) only HFD, (2) HFD + 3 mg% EZ, (3) HFD + 0.2% creosote bush ethanolic extract, (4) only standard diet (Std Diet), (5) Std Diet + 3 mg% EZ, (6) Std Diet + 0.2% creosote bush ethanolic extract. The beneficial effects of creosote bush ethanolic extract in the HFD hamster model were a reduction of insulin resistance, associated with lower serum insulin and leptin, lower hepatic lipid peroxidation and higher liver antioxidant capacity. Plasma and liver lipids tended or were reduced to values closer to those of animals fed standard diet. A similar effect on lipids was induced by EZ, although with even lower hepatic cholesterol and total lipids concentrations. In general, the change from HFD to standard diet plus ethanolic extract induced the same but deeper changes, including a reduction in plasma glucose and an increase in the percentage of HDL cholesterol. Unlike creosote bush extract, EZ increased food consumption and neutral fecal steroids, with no significant effect on body weight, epididymal fat pads, liver peroxidation or antioxidant capacity. Also EZ did not modify serum insulin and leptin. However, insulin sensitivity improved to values similar to those induced by the extract. This suggests that the mechanism of action of creosote bush ethanolic extract is different to inhibition of cholesterol absorption or increase excretion

  5. In vivo efficacy of HDL-like nanolipid particles containing multivalent peptide mimetics of apolipoprotein A-I[S

    PubMed Central

    Zhao, Yannan; Black, Audrey S.; Bonnet, David J.; Maryanoff, Bruce E.; Curtiss, Linda K.; Leman, Luke J.; Ghadiri, M. Reza

    2014-01-01

    We have observed that molecular constructs based on multiple apoA-I mimetic peptides attached to a branched scaffold display promising anti-atherosclerosis functions in vitro. Building on these promising results, we now describe chronic in vivo studies to assess anti-atherosclerotic efficacy of HDL-like nanoparticles assembled from a trimeric construct, administered over 10 weeks either ip or orally to LDL receptor-null mice. When dosed ip, the trimer-based nanolipids markedly reduced plasma LDL-cholesterol levels by 40%, unlike many other apoA-I mimetic peptides, and were substantially atheroprotective. Surprisingly, these nanoparticles were also effective when administered orally at a dose of 75 mg/kg, despite the peptide construct being composed of l-amino acids and being undetectable in the plasma. The orally administered nanoparticles reduced whole aorta lesion areas by 55% and aortic sinus lesion volumes by 71%. Reductions in plasma cholesterol were due to the loss of non-HDL lipoproteins, while plasma HDL-cholesterol levels were increased. At a 10-fold lower oral dose, the nanoparticles were marginally effective in reducing atherosclerotic lesions. Intriguingly, analogous results were obtained with nanolipids of the corresponding monomeric peptide. These nanolipid formulations provide an avenue for developing orally efficacious therapeutic agents to manage atherosclerosis. PMID:24975585

  6. Inflammation modulates human HDL composition and function in vivo

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Inflammation may directly impair HDL functions, in particular reverse cholesterol transport (RCT), but limited data support this concept in humans. Our study was designed to investigate this relationship. We employed low-dose human endotoxemia to assess the effects of inflammation on HDL and RCT-rel...

  7. Single nucleotide polymorphisms in CETP, SLC46A1, SLC19A1, CD36, BCMO1, APOA5, and ABCA1 are significant predictors of plasma HDL in healthy adults

    PubMed Central

    2013-01-01

    Background In a marker-trait association study we estimated the statistical significance of 65 single nucleotide polymorphisms (SNP) in 23 candidate genes on HDL levels of two independent Caucasian populations. Each population consisted of men and women and their HDL levels were adjusted for gender and body weight. We used a linear regression model. Selected genes corresponded to folate metabolism, vitamins B-12, A, and E, and cholesterol pathways or lipid metabolism. Methods Extracted DNA from both the Sacramento and Beltsville populations was analyzed using an allele discrimination assay with a MALDI-TOF mass spectrometry platform. The adjusted phenotype, y, was HDL levels adjusted for gender and body weight only statistical analyses were performed using the genotype association and regression modules from the SNP Variation Suite v7. Results Statistically significant SNP (where P values were adjusted for false discovery rate) included: CETP (rs7499892 and rs5882); SLC46A1 (rs37514694; rs739439); SLC19A1 (rs3788199); CD36 (rs3211956); BCMO1 (rs6564851), APOA5 (rs662799), and ABCA1 (rs4149267). Many prior association trends of the SNP with HDL were replicated in our cross-validation study. Significantly, the association of SNP in folate transporters (SLC46A1 rs37514694 and rs739439; SLC19A1 rs3788199) with HDL was identified in our study. Conclusions Given recent literature on the role of niacin in the biogenesis of HDL, focus on status and metabolism of B-vitamins and metabolites of eccentric cleavage of β-carotene with lipid metabolism is exciting for future study. PMID:23656756

  8. Cholesterol and F-actin are required for clustering of recycling synaptic vesicle proteins in the presynaptic plasma membrane.

    PubMed

    Dason, Jeffrey S; Smith, Alex J; Marin, Leo; Charlton, Milton P

    2014-02-15

    Synaptic vesicles (SVs) and their proteins must be recycled for sustained synaptic transmission. We tested the hypothesis that SV cholesterol is required for proper sorting of SV proteins during recycling in live presynaptic terminals. We used the reversible block of endocytosis in the Drosophila temperature-sensitive dynamin mutant shibire-ts1 to trap exocytosed SV proteins, and then examined the effect of experimental treatments on the distribution of these proteins within the presynaptic plasma membrane by confocal microscopy. SV proteins synaptotagmin, vglut and csp were clustered following SV trapping in control experiments but dispersed in samples treated with the cholesterol chelator methyl-β-cyclodextrin to extract SV cholesterol. There was accumulation of phosphatidylinositol (4,5)-bisphosphate (PIP2) in presynaptic terminals following SV trapping and this was reduced following SV cholesterol extraction. Reduced PIP2 accumulation was associated with disrupted accumulation of actin in presynaptic terminals. Similar to vesicular cholesterol extraction, disruption of actin by latrunculin A after SV proteins had been trapped on the plasma membrane resulted in the dispersal of SV proteins and prevented recovery of synaptic transmission due to impaired endocytosis following relief of the endocytic block. Our results demonstrate that vesicular cholesterol is required for aggregation of exocytosed SV proteins in the presynaptic plasma membrane and are consistent with a mechanism involving regulation of PIP2 accumulation and local actin polymerization by cholesterol. Thus, alteration of membrane or SV lipids may affect the ability of synapses to undergo sustained synaptic transmission by compromising the recycling of SV proteins.

  9. Leukocyte-derived hepatic lipase increases HDL and decreases en face aortic atherosclerosis in LDLr−/− mice expressing CETP*s⃞

    PubMed Central

    Hime, Neil J.; Black, Audrey S.; Bulgrien, Josh J.; Curtiss, Linda K.

    2008-01-01

    In addition to hepatic expression, cholesteryl ester transfer protein (CETP) and hepatic lipase (HL) are expressed by human macrophages. The combined actions of these proteins have profound effects on HDL structure and function. It is not known how these HDL changes influence atherosclerosis. To elucidate the role of leukocyte-derived HL on atherosclerosis in a background of CETP expression, we studied low density lipoprotein receptor-deficient mice expressing human CETP (CETPtgLDLr−/−) with a leukocyte-derived HL deficiency (HL−/− BM). HL−/− bone marrow (BM), CETPtgLDLr−/− mice were generated via bone marrow transplantation. Wild-type bone marrow was transplanted into CETPtgLDLr−/− mice to generate HL+/+ BM, CETPtgLDLr−/− controls. The chimeras were fed a high-fat, high-cholesterol diet for 14 weeks to promote atherosclerosis. In female HL−/− BM, CETPtgLDLr−/− mice plasma HDL-cholesterol concentration during high-fat feeding was decreased 27% when compared with HL+/+ BM, CETPtgLDLr−/− mice (P < 0.05), and this was associated with a 96% increase in en face aortic atherosclerosis (P < 0.05). In male CETPtgLDLr−/− mice, leukocyte-derived HL deficiency was associated with a 16% decrease in plasma HDL-cholesterol concentration and a 25% increase in aortic atherosclerosis. Thus, leukocyte-derived HL in CETPtgLDLr−/− mice has an atheroprotective role that may involve increased HDL levels. PMID:18599739

  10. Capsaicinoids but not their analogue capsinoids lower plasma cholesterol and possess beneficial vascular activity.

    PubMed

    Huang, Weihuan; Cheang, Wai San; Wang, Xiaobo; Lei, Lin; Liu, Yuwei; Ma, Ka Ying; Zheng, Fangrui; Huang, Yu; Chen, Zhen-Yu

    2014-08-20

    Capsaicinoids exist in chili peppers, whereas capsinoids are present in some sweet peppers. The present study investigated the effects of capsaicinoids and capsinoids on plasma lipids, relaxation of the aorta, atherosclerotic plaque development, and fecal sterol excretion in hamsters fed a high-cholesterol diet. Five groups of male hamsters were given the control diet or one of the four experimental diets containing 1.3 mmol of capsaicinoids (NL), 2.6 mmol of capsaicinoids (NH), 1.3 mmol of capsinoids (OL), or 2.6 mmol of capsinoids (OH), respectively. Results showed capsaicinoids but not capsinoids could decrease plasma total cholesterol (TC), reduce the formation of atherosclerotic plaque, and relax the aortic artery. This was accompanied by a 28-175% increase in fecal excretion of acidic sterols in hamsters fed the diets containing capsaicinoids. Similarly, capsaicinoids but not capsinoids could decrease the pad weights of epididymal and prerenal adipose tissues. It was concluded that capsaicinoids but not capsinoids could favorably modulate plasma lipids and possess beneficial vascular activity. PMID:25078570

  11. Capsaicinoids but not their analogue capsinoids lower plasma cholesterol and possess beneficial vascular activity.

    PubMed

    Huang, Weihuan; Cheang, Wai San; Wang, Xiaobo; Lei, Lin; Liu, Yuwei; Ma, Ka Ying; Zheng, Fangrui; Huang, Yu; Chen, Zhen-Yu

    2014-08-20

    Capsaicinoids exist in chili peppers, whereas capsinoids are present in some sweet peppers. The present study investigated the effects of capsaicinoids and capsinoids on plasma lipids, relaxation of the aorta, atherosclerotic plaque development, and fecal sterol excretion in hamsters fed a high-cholesterol diet. Five groups of male hamsters were given the control diet or one of the four experimental diets containing 1.3 mmol of capsaicinoids (NL), 2.6 mmol of capsaicinoids (NH), 1.3 mmol of capsinoids (OL), or 2.6 mmol of capsinoids (OH), respectively. Results showed capsaicinoids but not capsinoids could decrease plasma total cholesterol (TC), reduce the formation of atherosclerotic plaque, and relax the aortic artery. This was accompanied by a 28-175% increase in fecal excretion of acidic sterols in hamsters fed the diets containing capsaicinoids. Similarly, capsaicinoids but not capsinoids could decrease the pad weights of epididymal and prerenal adipose tissues. It was concluded that capsaicinoids but not capsinoids could favorably modulate plasma lipids and possess beneficial vascular activity.

  12. Modification of LCAT activity and HDL structure. New links between cigarette smoke and coronary heart disease risk.

    PubMed

    McCall, M R; van den Berg, J J; Kuypers, F A; Tribble, D L; Krauss, R M; Knoff, L J; Forte, T M

    1994-02-01

    The mechanism(s) through which smoking influences the progression of atherosclerosis is poorly understood. Recent evidence suggests that oxidants present in the gas phase of cigarette smoke are involved. We exposed human plasma to the filtered gas phase of cigarette smoke to assess its effects on plasma components involved in the antiatherogenic reverse cholesterol transport pathway. In our model, freshly isolated plasma (24 mL) was exposed to filtered air or gas-phase cigarette smoke for up to 6 hours at 37 degrees C. Lecithin-cholesterol acyltransferase (LCAT) activity was dramatically inhibited by cigarette smoke. A single 15-minute exposure to the smoke from an eighth of a cigarette was sufficient to reduce LCAT activity by 7%; additional exposures resulted in further decreases in activity. At 6 hours, only 22% of control LCAT activity remained in plasma exposed to smoke. Compared with control, gas-phase cigarette smoke-exposed plasma possessed high-density lipoprotein (HDL) with increased (16%) negative charge and with cross-linked apolipoproteins AI and AII. These data demonstrate that gas-phase cigarette smoke can inhibit a key enzyme (LCAT) and modify an integral lipid transport particle (HDL) that are essential components for the normal function of the reverse cholesterol transport pathway. Gas-phase cigarette smoke-induced modification of the reverse cholesterol transport pathway may provide a new mechanistic link between cigarette smoke and coronary heart disease risk.

  13. Association between Plasma PFOA and PFOS Levels and Total Cholesterol in a Middle-Aged Danish Population

    PubMed Central

    Eriksen, Kirsten T.; Raaschou-Nielsen, Ole; McLaughlin, Joseph K.; Lipworth, Loren; Tjønneland, Anne; Overvad, Kim; Sørensen, Mette

    2013-01-01

    Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) are used in a variety of consumer products and have been detected worldwide in human blood. Recent studies mainly of highly exposed populations have indicated that PFOA and PFOS may affect serum cholesterol levels, but the magnitude of the effect may be inconsistent across exposure levels. The aim of the present cross-sectional study was to investigate the association between plasma PFOA and PFOS and total cholesterol in a general, middle-aged Danish population. The study population comprised 753 individuals (663 men and 90 women), 50–65 years of age, nested within a Danish cohort of 57,053 participants. Blood samples were taken from all cohort members at enrolment (1993–1997) and stored in a biobank at -150°C. Plasma levels of PFOA and PFOS and serum levels of total cholesterol were measured. The associations between plasma PFOA and PFOS levels and total cholesterol levels were analysed by generalized linear models, both crude and adjusted for potential confounders. We observed statistically significant positive associations between both perfluorinated compounds and total cholesterol, e.g. a 4.4 [95% CI  =  1.1–7.8] higher concentration of total cholesterol (mg/dL) per interquartile range of PFOA plasma level. Sex and prevalent diabetes appeared to modify the association between PFOA and PFOS, respectively, and cholesterol. In conclusion, this study indicated positive associations between plasma PFOA and PFOS levels and total cholesterol in a middle-aged Danish population, although whether the observed pattern of results reflects a causal association is unclear. PMID:23441227

  14. A plasma lipoprotein containing only apolipoprotein E and with gamma mobility on electrophoresis releases cholesterol from cells.

    PubMed Central

    Huang, Y; von Eckardstein, A; Wu, S; Maeda, N; Assmann, G

    1994-01-01

    Previous studies have identified lipid-poor high density lipoproteins with electrophoretic pre-beta mobility as the initial acceptors of cell-derived cholesterol in human plasma. These lipoproteins contain apolipoprotein A-I (apo A-I) as their sole apolipoprotein. In the present study, incubation of human plasma with [3H]cholesterol-laden skin fibroblasts has led to the identification of another lipoprotein that serves as a potent initial acceptor of cell-derived cholesterol. This lipoprotein, which we term gamma-LpE, exhibits gamma mobility on agarose gel electrophoresis. As determined by nondenaturing PAGE and by electron microscopy, the size of the spherical particle ranges between 12 and 16 nm. SDS/PAGE and subsequent immunoblotting identified apoE as its sole apolipoprotein. Plasma from normal and apoA-I-deficient mice, but not from apoE-deficient mice, released [3H]cholesterol from fibroblasts into a gamma-migrating lipoprotein. Cell culture media from hepatoma cells or mouse peritoneal macrophages, both of which contain apoE of cellular origin, also promoted efflux of [3H]cholesterol from fibroblasts into a gamma-migrating fraction. This was not observed with cell culture medium from fibroblasts alone. In conclusion, our results strongly indicate the presence in human plasma of a lipoprotein containing only apoE, gamma-LpE, which is secreted by peripheral cells and is a potent acceptor of cell-derived cholesterol. Images PMID:8127890

  15. Cholesterol and Your Child

    MedlinePlus

    ... traveling together are called lipoproteins . Two kinds — low-density lipoprotein (LDL) and high-density lipoprotein (HDL) — are the ones that most of us have heard about. Low-density lipoproteins , or "bad cholesterol," are the primary cholesterol ...

  16. Development and partial metabolic characterization of a dietary cholesterol-resistant colony of rabbits

    SciTech Connect

    Overturf, M.L.; Smith, S.A.; Hewett-Emmett, D.; Loose-Mitchell, D.S.; Soma, M.R.; Gotto, A.M. Jr.; Morrisett, J.D. )

    1989-02-01

    A colony of New Zealand white rabbits has been developed which, when fed a cholesterol-supplemented diet, exhibit unusual resistance to hypercholesterolemia and atherosclerosis, disorders usually observed in normal cholesterol-fed rabbits. When resistant rabbits (RT) were fed a normal low cholesterol diet (ND), their plasma lipoprotein patterns were significantly different from those of normal rabbits (NR) fed the same diet. The low density lipoprotein cholesterol (LDL-c)/high density lipoprotein cholesterol (HDL-c) ratio and LDL-c/very low density lipoprotein cholesterol (VLDL-c) ratio were lower in the resistant rabbits. The hydrated density of HDL of the normal-responsive rabbits was greater than that of the resistant rabbits. LDL from resistant rabbits contained a lower proportion of esterified cholesterol and protein than LDL from normal rabbits. Peripheral mononuclear cells from resistant rabbits bound about 30% more {sup 125}I-labeled rabbit LDL than mononuclear cells from normal rabbits. These results demonstrate that the plasma cholesterol levels of these animals is at least partly under genetic control and that compositional differences exist between the major plasma lipoprotein classes of normal and resistant rabbits even during the ingestion of low-cholesterol diet. The results indicate that at least a part of the difference in the cholesterolemic responses between the two rabbit groups is due to an enhanced LDL uptake by the mononuclear cells, and presumably by other somatic cells of the resistant group.

  17. Phytosterol intake and dietary fat reduction are independent and additive in their ability to reduce plasma LDL cholesterol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The plasma LDL-cholesterol-lowering effect of plant sterols (PS) appears to be independent of background diet, but definitive proof is lacking. The effect of background diet on plasma concentrations of PS has not been reported. We determined the effects of manipulating dietary contents of PS and f...

  18. Vitamin D Supplementation Causes a Decrease in Blood Cholesterol in Professional Rowers.

    PubMed

    Jastrzebski, Zbigniew; Kortas, Jakub; Kaczor, Katarzyna; Antosiewicz, Jedrzej

    2016-01-01

    In the skin vitamin D3 is synthesized from cholesterol, which leaves the question whether a feedback mechanism controlling the level of blood cholesterol exists. Here we investigate the effects of vitamin D3 supplementation on serum lipids in professional rowers. The rowers were divided into two groups following the same training schedule for 4 wk: one received placebo (TP) while the second received 5,000 IU of vitamin D3 every day (TD3). Plasma total antioxidant status, total triglycerides (TG), total cholesterol (TC), high-density lipoprotein (HDL)-cholesterol (HDL-C), low-density lipoprotein (LDL)-cholesterol (LDL-C) and 25-hydroxyvitamin D (25-OH-D3) were determined in pre- and post-intervention. The ratios of TC/HDL-C and LDL-C/HDL-C were also calculated. Furthermore, maximal oxygen uptake was also measured at baseline. There were significant decreases over time in the TD3 group in TC 186±18 vs 163±21 (p<0.05) and HDL-C; LDL-C also decreased, but the changes were not statistically significant. Moreover, the supplementation caused a significant rise in blood 25-OH-D3 (+98%). Neither training nor vitamin D3 supplementation had an effect on total antioxidant status. In conclusion, the alterations in the lipoprotein profile seen in this study would suggest that effects of regular exercise on lipoprotein profile may linked to vitamin D3 status. PMID:27264092

  19. High-density lipoprotein cholesterol strongly discriminates between healthy free-living and disabled octo-nonagenarians: a cross sectional study. Associazione Medica Sabin.

    PubMed

    Zuliani, G; Palmieri, E; Volpato, S; Bader, G; Mezzetti, A; Costantini, F; Sforza, G R; Imbastaro, T; Romagnoni, F; Fellin, R

    1997-10-01

    Aging is frequently associated with a deterioration in health and functional status, which often induces important modifications in several biological parameters, including plasma lipids; as a consequence, the real "meaning" of lipoprotein parameters in old individuals is complex. A cross sectional study was carried out in order to investigate the lipoprotein profile in very old individuals with or without disability, and evaluate the possible influence of other biological variables on plasma lipids. One hundred selected healthy free-living (FL) and 62 disabled (DIS) subjects aged over 80 were enrolled; 91 healthy adults matched for origin were included as controls. Lipoprotein profile [total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, apoprotein A-I and B], anthropometric parameters, and ADL were measured. The FL octo-nonagenarians featured higher HDL-cholesterol levels than adult controls. DIS octo-nonagenarians showed lower total and HDL-C levels than FL. Discriminant analysis indicated that HDL-cholesterol and apoprotein A-I, but not total cholesterol, strongly discriminated between FL and DIS octo-nonagenarians. Multivariate analysis demonstrated that the waist/hip ratio, an index of visceral adiposity, was negatively associated with HDL-C levels in FL, but not in DIS elderly. We conclude that: 1) in very old individuals, the absence or presence of disability is strongly associated with high or low HDL-cholesterol values, respectively; 2) HDL-C and apo A-I are the parameters which better discriminate between FL and DIS octo-nonagenarians; and 3) the differences in HDL-C levels between FL and DIS are not due to modifications in anthropometric parameters. Prospective studies are needed to better understand the relationship between high-density lipoprotein levels, disability and aging. PMID:9458994

  20. Enzymatic assay of total cholesterol in serum or plasma by amperometric measurement of rate of oxygen depletion following saponification.

    PubMed

    Kumar, A; Christian, G D

    1977-01-17

    A method for serum or plasma cholesterol assay involving amperometric measurement of the rate of oxygen depletion in the cholesterol oxidase-catalyzed oxidation of cholesterol is described. The hydrolysis of the serum cholesterol esters is accomplished by saponification of 50 mul of sample with 0.2 ml of ethanolic KOH (1.0 mol/1) containing 0.5% Triton X-100 for 5 min at 75 degrees C. The rate of oxygen consumption in a 25-mul aliquot of this is measured with a Clark electrode in a Beckman Glucose Analyzer and the assay takes about one minute after incubation; results are read digitally on the instrument. The analyzer cell contains 1 ml of 1 M phosphate buffer, pH 7.4, with 100 mg sodium cholate/100 ml and 0.1-0.2 U cholesterol oxidase.

  1. Case report: A novel apolipoprotein A-I missense mutation apoA-I (Arg149Ser)Boston associated with decreased lecithin-cholesterol acyltransferase activation and cellular cholesterol efflux.

    PubMed

    Anthanont, Pimjai; Asztalos, Bela F; Polisecki, Eliana; Zachariah, Benoy; Schaefer, Ernst J

    2015-01-01

    We report a novel heterozygous apolipoprotein A-I (apoA-I) missense mutation (c.517C>A, p.Arg149Ser, designated as apoA-IBoston) in a 67-year-old woman and her 2 sons, who had mean serum high-density lipoprotein (HDL) cholesterol, apoA-I, and apoA-I in very large α-1 HDL that were 10%, 35%, and 16% of normal, respectively (all P < .05). The percentage of HDL cholesterol in the esterified form was also significantly (P < .05) reduced to 52% of control values. Cholesteryl ester tranfer protein (CETP) activity was normal. The mean global, adenosine triphosphate (ATP)-binding cassette transporter A1 and scavenger receptor B type I-mediated cellular cholesterol efflux capacity in apoB-depleted serum from affected family members were 41%, 37%, 47%, 54%, and 48% of control values, respectively (all P < .05). lecithin-cholesterol acyltransferase (LCAT) activity in plasma was 71% of controls, whereas in the cell-based assay, it was 73% of control values (P < .05). The data indicate that this novel apoA-I missense is associated with markedly decreased levels of HDL cholesterol and very large α-1 HDL, as well as decreased serum cellular cholesterol efflux and LCAT activity, but not with premature coronary heart disease, similar to other apoA-I mutations that have been associated with decreased LCAT activity.

  2. Case report: A novel apolipoprotein A-I missense mutation apoA-I (Arg149Ser)Boston associated with decreased lecithin-cholesterol acyltransferase activation and cellular cholesterol efflux.

    PubMed

    Anthanont, Pimjai; Asztalos, Bela F; Polisecki, Eliana; Zachariah, Benoy; Schaefer, Ernst J

    2015-01-01

    We report a novel heterozygous apolipoprotein A-I (apoA-I) missense mutation (c.517C>A, p.Arg149Ser, designated as apoA-IBoston) in a 67-year-old woman and her 2 sons, who had mean serum high-density lipoprotein (HDL) cholesterol, apoA-I, and apoA-I in very large α-1 HDL that were 10%, 35%, and 16% of normal, respectively (all P < .05). The percentage of HDL cholesterol in the esterified form was also significantly (P < .05) reduced to 52% of control values. Cholesteryl ester tranfer protein (CETP) activity was normal. The mean global, adenosine triphosphate (ATP)-binding cassette transporter A1 and scavenger receptor B type I-mediated cellular cholesterol efflux capacity in apoB-depleted serum from affected family members were 41%, 37%, 47%, 54%, and 48% of control values, respectively (all P < .05). lecithin-cholesterol acyltransferase (LCAT) activity in plasma was 71% of controls, whereas in the cell-based assay, it was 73% of control values (P < .05). The data indicate that this novel apoA-I missense is associated with markedly decreased levels of HDL cholesterol and very large α-1 HDL, as well as decreased serum cellular cholesterol efflux and LCAT activity, but not with premature coronary heart disease, similar to other apoA-I mutations that have been associated with decreased LCAT activity. PMID:26073399

  3. Separation of the principal HDL subclasses by iodixanol ultracentrifugation

    PubMed Central

    Harman, Nicola L.; Griffin, Bruce A.; Davies, Ian G.

    2013-01-01

    HDL subclasses detection, in cardiovascular risk, has been limited due to the time-consuming nature of current techniques. We have developed a time-saving and reliable separation of the principal HDL subclasses employing iodixanol density gradient ultracentrifugation (IxDGUC) combined with digital photography. HDL subclasses were separated in 2.5 h from prestained plasma on a three-step iodixanol gradient. HDL subclass profiles were generated by digital photography and gel scan software. Plasma samples (n = 46) were used to optimize the gradient for the resolution of HDL heterogeneity and to compare profiles generated by IxDGUC with gradient gel electrophoresis (GGE); further characterization from participants (n = 548) with a range of lipid profiles was also performed. HDL subclass profiles generated by IxDGUC were comparable to those separated by GGE as indicated by a significant association between areas under the curve for both HDL2 and HDL3 (HDL2, r = 0.896, P < 0.01; HDL3, r = 0.894, P < 0.01). The method was highly reproducible, with intra- and interassay coefficient of variation percentage < 5 for percentage area under the curve HDL2 and HDL3, and < 1% for peak Rf and peak density. The method provides time-saving and cost-effective detection and preparation of the principal HDL subclasses. PMID:23690506

  4. Higher Plasma LDL-Cholesterol is Associated with Preserved Executive and Fine Motor Functions in Parkinson’s Disease

    PubMed Central

    Sterling, Nicholas W.; Lichtenstein, Maya; Lee, Eun-Young; Lewis, Mechelle M.; Evans, Alicia; Eslinger, Paul J.; Du, Guangwei; Gao, Xiang; Chen, Honglei; Kong, Lan; Huang, Xuemei

    2016-01-01

    Plasma low density lipoprotein (LDL) cholesterol has been associated both with risk of Parkinson’s disease (PD) and with age-related changes in cognitive function. This prospective study examined the relationship between baseline plasma LDL-cholesterol and cognitive changes in PD and matched Controls. Fasting plasma LDL-cholesterol levels were obtained at baseline from 64 non-demented PD subjects (62.7 ± 7.9 y) and 64 Controls (61.3 ± 6.8 y). Subjects underwent comprehensive neuropsychological testing at baseline, 18-, and 36-months. Linear mixed-effects modeling was used to assess the relationships between baseline LDL-cholesterol levels and longitudinal cognitive changes. At baseline, PD patients had lower scores of fine motor (p<0.0001), executive set shifting (p=0.018), and mental processing speed (p=0.049) compared to Controls. Longitudinally, Controls demonstrated improved fine motor and memory test scores (p=0.044, and p=0.003), whereas PD patients demonstrated significantly accelerated loss in fine motor skill (p=0.002) compared to Controls. Within the PD group, however, higher LDL-cholesterol levels were associated with improved executive set shifting (β=0.003, p<0.001) and fine motor scores (β=0.002, p=0.030) over time. These associations were absent in Controls (p>0.7). The cholesterol - executive set shifting association differed significantly between PDs and Controls (interaction p=0.005), whereas the cholesterol - fine motor association difference did not reach significance (interaction, p=0.104). In summary, higher plasma LDL-cholesterol levels were associated with better executive function and fine motor performance over time in PD, both of which may reflect an effect on nigrostriatal mediation. Confirmation of these results and elucidation of involved mechanisms are warranted, and might lead to feasible therapeutic strategies. PMID:27330838

  5. Higher Plasma LDL-Cholesterol is Associated with Preserved Executive and Fine Motor Functions in Parkinson's Disease.

    PubMed

    Sterling, Nicholas W; Lichtenstein, Maya; Lee, Eun-Young; Lewis, Mechelle M; Evans, Alicia; Eslinger, Paul J; Du, Guangwei; Gao, Xiang; Chen, Honglei; Kong, Lan; Huang, Xuemei

    2016-05-01

    Plasma low density lipoprotein (LDL) cholesterol has been associated both with risk of Parkinson's disease (PD) and with age-related changes in cognitive function. This prospective study examined the relationship between baseline plasma LDL-cholesterol and cognitive changes in PD and matched Controls. Fasting plasma LDL-cholesterol levels were obtained at baseline from 64 non-demented PD subjects (62.7 ± 7.9 y) and 64 Controls (61.3 ± 6.8 y). Subjects underwent comprehensive neuropsychological testing at baseline, 18-, and 36-months. Linear mixed-effects modeling was used to assess the relationships between baseline LDL-cholesterol levels and longitudinal cognitive changes. At baseline, PD patients had lower scores of fine motor (p<0.0001), executive set shifting (p=0.018), and mental processing speed (p=0.049) compared to Controls. Longitudinally, Controls demonstrated improved fine motor and memory test scores (p=0.044, and p=0.003), whereas PD patients demonstrated significantly accelerated loss in fine motor skill (p=0.002) compared to Controls. Within the PD group, however, higher LDL-cholesterol levels were associated with improved executive set shifting (β=0.003, p<0.001) and fine motor scores (β=0.002, p=0.030) over time. These associations were absent in Controls (p>0.7). The cholesterol - executive set shifting association differed significantly between PDs and Controls (interaction p=0.005), whereas the cholesterol - fine motor association difference did not reach significance (interaction, p=0.104). In summary, higher plasma LDL-cholesterol levels were associated with better executive function and fine motor performance over time in PD, both of which may reflect an effect on nigrostriatal mediation. Confirmation of these results and elucidation of involved mechanisms are warranted, and might lead to feasible therapeutic strategies. PMID:27330838

  6. Higher Plasma LDL-Cholesterol is Associated with Preserved Executive and Fine Motor Functions in Parkinson's Disease.

    PubMed

    Sterling, Nicholas W; Lichtenstein, Maya; Lee, Eun-Young; Lewis, Mechelle M; Evans, Alicia; Eslinger, Paul J; Du, Guangwei; Gao, Xiang; Chen, Honglei; Kong, Lan; Huang, Xuemei

    2016-05-01

    Plasma low density lipoprotein (LDL) cholesterol has been associated both with risk of Parkinson's disease (PD) and with age-related changes in cognitive function. This prospective study examined the relationship between baseline plasma LDL-cholesterol and cognitive changes in PD and matched Controls. Fasting plasma LDL-cholesterol levels were obtained at baseline from 64 non-demented PD subjects (62.7 ± 7.9 y) and 64 Controls (61.3 ± 6.8 y). Subjects underwent comprehensive neuropsychological testing at baseline, 18-, and 36-months. Linear mixed-effects modeling was used to assess the relationships between baseline LDL-cholesterol levels and longitudinal cognitive changes. At baseline, PD patients had lower scores of fine motor (p<0.0001), executive set shifting (p=0.018), and mental processing speed (p=0.049) compared to Controls. Longitudinally, Controls demonstrated improved fine motor and memory test scores (p=0.044, and p=0.003), whereas PD patients demonstrated significantly accelerated loss in fine motor skill (p=0.002) compared to Controls. Within the PD group, however, higher LDL-cholesterol levels were associated with improved executive set shifting (β=0.003, p<0.001) and fine motor scores (β=0.002, p=0.030) over time. These associations were absent in Controls (p>0.7). The cholesterol - executive set shifting association differed significantly between PDs and Controls (interaction p=0.005), whereas the cholesterol - fine motor association difference did not reach significance (interaction, p=0.104). In summary, higher plasma LDL-cholesterol levels were associated with better executive function and fine motor performance over time in PD, both of which may reflect an effect on nigrostriatal mediation. Confirmation of these results and elucidation of involved mechanisms are warranted, and might lead to feasible therapeutic strategies.

  7. Plasma proteomic analysis of stable coronary artery disease indicates impairment of reverse cholesterol pathway

    PubMed Central

    Basak, Trayambak; Tanwar, Vinay Singh; Bhardwaj, Gourav; Bhardwaj, Nitin; Ahmad, Shadab; Garg, Gaurav; V, Sreenivas; Karthikeyan, Ganesan; Seth, Sandeep; Sengupta, Shantanu

    2016-01-01

    Coronary artery disease (CAD) is one of the largest causes of death worldwide yet the traditional risk factors, although useful in identifying people at high risk, lack the desired predictive accuracy. Techniques like quantitative plasma proteomics holds immense potential to identify newer markers and this study (conducted in three phases) was aimed to identify differentially expressed proteins in stable CAD patients. In the first (discovery) phase, plasma from CAD cases (angiographically proven) and controls were subjected to iTRAQ based proteomic analysis. Proteins found to be differentially expressed were then validated in the second and third (verification and validation) phases in larger number of (n = 546) samples. After multivariate logistic regression adjusting for confounding factors (age, diet, etc.), four proteins involved in the reverse cholesterol pathway (Apo A1, ApoA4, Apo C1 and albumin) along with diabetes and hypertension were found to be significantly associated with CAD and could account for approximately 88% of the cases as revealed by ROC analysis. The maximum odds ratio was found to be 6.70 for albumin (p < 0.0001), followed by Apo AI (5.07, p < 0.0001), Apo CI (4.03, p = 0.001), and Apo AIV (2.63, p = 0.003). Down-regulation of apolipoproteins and albumin implicates the impairment of reverse cholesterol pathway in CAD. PMID:27350024

  8. Interrelationships among HDL metabolism, aging, and atherosclerosis.

    PubMed

    Walter, Michael

    2009-09-01

    HDL plasma concentrations decline with age in prospective studies. Decline in HDL concentration and function may occur secondary because of hormonal changes, inflammatory processes, and diabetes mellitus. Beyond these effects specific aging processes may be involved. Replicative aging, the telomere-driven loss of divisional capacity, is a species-specific aging mechanism that may decrease HDL concentration and function. Cross-sectionally, by contrast, HDL levels do not change much or even slightly increase with age, suggesting that only people with still high HDL concentrations survive. A selection bias by HDL lowering genetic variation may explain why HDL deficiency is extremely rare among centenarians. Vice versa, HDL may modulate the aging process, not only by its well-known antiatherogenic effects, eg, its ability to remove cellular lipids and by antiatherogenic pleiotropic effects on cell survival, but possibly also by direct interfering with aging signaling or survival factor KLOTHO. Most of the current findings, however, are based on cell culture and selected animal experiments and await further confirmation by appropriate in vivo models.

  9. The ATP-binding cassette transporter-2 (ABCA2) regulates esterification of plasma membrane cholesterol by modulation of sphingolipid metabolism

    PubMed Central

    Davis, Warren

    2015-01-01

    The ATP-binding cassette transporters are a large family (~ 48 genes divided into seven families A–G) of proteins that utilize the energy of ATP-hydrolysis to pump substrates across lipid bilayers against a concentration gradient. The ABC “A” subfamily is comprised of 13 members and transport sterols, phospholipids and bile acids. ABCA2 is the most abundant ABC transporter in human and rodent brain with highest expression in oligodendrocytes, although it is also expressed in neurons. Several groups have studied a possible connection between ABCA2 and Alzheimer’s disease as well as early atherosclerosis. ABCA2 expression levels have been associated with changes in cholesterol and sphingolipid metabolism. In this paper, we hypothesized that ABCA2 expression level may regulate esterification of plasma membrane-derived cholesterol by modulation of sphingolipid metabolism. ABCA2 overexpression in N2a neuroblastoma cells was associated with an altered bilayer distribution of the sphingolipid ceramide that inhibited acylCoA:cholesterol acyltransferase (ACAT) activity and cholesterol esterification. In contrast, depletion of endogenous ABCA2 in the rat schwannoma cell line D6P2T increased esterification of plasma membrane cholesterol following treatment with exogenous bacterial sphingomyelinase. These findings suggest that control of ABCA2 expression level may be a key locus of regulation for esterification of plasma membrane-derived cholesterol through modulation of sphingolipid metabolism. PMID:24201375

  10. [Cholesterol of the high-density lipoprotein subclasses in the native inhabitants of the Chukchi National Autonomous Okrug].

    PubMed

    Polesskiĭ, V A; Chepurnenko, N V; Koshechkin, V A; Morozov, V V; Gerasimova, E N

    1980-12-01

    The authors studied the content of total cholesterol (Ch), triglycerides (TG), CS of high density lipoprotein (HDL2 and HDL3) subclasses and testosterone in blood plasma of 30-59-year-old males, natives or newcomers of Chukotsk, and compared the results with the corresponding values determined in the male population of Moscow. It was established that the mean HDL Ch concentration in blood plasma was higher and the content of TG and to a lesser degree that of total CS, was lower in the Chukchi males than in the male Moscow population and in the newcomers who were examined. It was also shown that in hypo- and hyper-alphalipoproteinemia in all groups examined, the content of HDL2 Ch changed for the most part (decreased or increased, respectively) while the level of HDL3 Ch remained relatively stable.

  11. Excess cholesterol induces mouse egg activation and may cause female infertility

    PubMed Central

    Yesilaltay, Ayce; Dokshin, Gregoriy A.; Busso, Dolores; Wang, Li; Galiani, Dalia; Chavarria, Tony; Vasile, Eliza; Quilaqueo, Linda; Orellana, Juan Andrés; Walzer, Dalia; Shalgi, Ruth; Dekel, Nava; Albertini, David F.; Rigotti, Attilio; Page, David C.; Krieger, Monty

    2014-01-01

    The HDL receptor scavenger receptor, class B type I (SR-BI) controls the structure and fate of plasma HDL. Female SR-BI KO mice are infertile, apparently because of their abnormal cholesterol-enriched HDL particles. We examined the growth and meiotic progression of SR-BI KO oocytes and found that they underwent normal germinal vesicle breakdown; however, SR-BI KO eggs, which had accumulated excess cholesterol in vivo, spontaneously activated, and they escaped metaphase II (MII) arrest and progressed to pronuclear, MIII, and anaphase/telophase III stages. Eggs from fertile WT mice were activated when loaded in vitro with excess cholesterol by a cholesterol/methyl-β-cyclodextrin complex, phenocopying SR-BI KO oocytes. In vitro cholesterol loading of eggs induced reduction in maturation promoting factor and MAPK activities, elevation of intracellular calcium, extrusion of a second polar body, and progression to meiotic stages beyond MII. These results suggest that the infertility of SR-BI KO females is caused, at least in part, by excess cholesterol in eggs inducing premature activation and that cholesterol can activate WT mouse eggs to escape from MII arrest. Analysis of SR-BI KO female infertility raises the possibility that abnormalities in cholesterol metabolism might underlie some cases of human female infertility of unknown etiology. PMID:25368174

  12. The pleiotropic role of HDL in autoimmune diseases.

    PubMed

    Parra, Sandra; Castro, Antoni; Masana, Luis

    2015-01-01

    As is widely known, the classic function of HDL is reverse cholesterol transport (RCT), thus removing cholesterol from peripheral tissues. Early epidemiological studies, such as Framingham's, stated that increased HDL levels were associated with a significant decrease in relative risk for cardiovascular disease (CVD) mortality. However, those with heightened expectations in recent years for the development of therapeutic targets to increase HDL levels have been disappointed, because efforts have demonstrated the opposite effect on cardiovascular and global mortality. However, in contrast, studies have highlighted the complexity and the intriguing role of HDL in different pathological conditions, such as infections, neoplasms, and autoimmune diseases. In this review an attempt is made to summarize some biological pathways that link HDL function with the immune system, and its possible clinical repercussions in autoimmune diseases.

  13. Association between lipids, lipoproteins composition of HDL particles and triglyceride-rich lipoproteins, and LCAT and CETP activity in post-renal transplant patients.

    PubMed

    Kimak, Elżbieta; Bylina, Jerzy; Solski, Janusz; Hałabiś, Magdalena; Baranowicz-Gąszczyk, Iwona; Książek, Andrzej

    2013-11-01

    High-density lipoprotein (HDL) remodeling within the plasma compartment and the association between lecithin-cholesterol acyltransferase (LCAT) and cholesterol ester transfer protein (CETP) activity, and lipid, lipoprotein concentrations and composition were investigated. The aim was to examine the high sensitivity of C-reactive protein (hsCRP), lipid, apolipoprotein B (apoB), apoAI, total apoAII, apoAIInonB, apoB-containing apoAII (apoB:AII), total apoCIII, apoCIIInonB, apoB-containing apoCIII (apoB:CIII) concentration and LCAT and CETP activity to gain an insight into the association between them and LCAT and CETP, 57 post-renal transplant (Tx) patients with and without statin therapy and in 15 healthy subjects. Tx patients had moderate hypertriglyceridemia, hypercholesterolemia, and dyslipoproteinemia, disturbed triglyceride-rich lipoproteins (TRLs) and HDL composition, decreased LCAT, and slightly increased hsCRP but no CETP activity. Spearman's correlation test showed the association between lipids and lipoproteins and LCAT or CETP, and multiple ridge stepwise forward regression showed that immunosuppressive therapy in Tx patients can disturb HDL and TRLs composition. The results suggest that inhibition or activation of LCAT is due, in part, to HDL-associated lipoprotein. Lipoprotein composition of apoAI, apoAIInonB, and apoCIIInonB in HDL particle and apoB:AII TRLs can contribute to decrease LCAT mass in Tx patients. Tx patients without statin and with lower triglycerides but higher HDL cholesterol concentration and disturbed lipoprotein composition of ApoAI and apoAII in HDL particle can decrease LCAT, increase LDL cholesterol, aggravate renal graft, and accelerate atherosclerosis and chronic heart diseases. PMID:23479335

  14. Effects of Adiposity on Plasma Lipid Response to Reductions in Dietary Saturated Fatty Acids and Cholesterol1

    PubMed Central

    Flock, Michael R.; Green, Michael H.; Kris-Etherton, Penny M.

    2011-01-01

    Dietary SFA and cholesterol are major targets for reducing plasma total and LDL cholesterol as a strategy to decrease cardiovascular disease risk. However, many studies show that excess adiposity attenuates the expected lipid and lipoprotein response to a plasma cholesterol–lowering diet. Diets low in SFA and cholesterol are less effective in improving the lipid profile in obese individuals and in patients with metabolic syndrome. In contrast, lean persons are more responsive to reductions in dietary SFA and cholesterol. Multiple mechanisms likely contribute to the altered plasma lipid responses to dietary changes in individuals with excess adiposity. The greater rate of hepatic cholesterol synthesis in obese individuals suppresses the expression of hepatic LDL receptors (LDLR), thereby reducing hepatic LDL uptake. Insulin resistance develops as a result of adipose-tissue induced inflammation, causing significant changes in enzymes necessary for normal lipid metabolism. In addition, the LDLR-mediated uptake in obesity is attenuated by alterations in neuroendocrine regulation of hormonal secretions (e.g. growth hormone, thyroid hormone, and cortisol) as well as the unique gut microbiota, the latter of which appears to affect lipid absorption. Reducing adipose tissue mass, especially from the abdominal region, is an effective strategy to improve the lipid response to dietary interventions by reducing inflammation, enhancing insulin sensitivity, and improving LDLR binding. Thus, normalizing adipose tissue mass is an important goal for maximizing the diet response to a plasma cholesterol–lowering diet. PMID:22332058

  15. Synthetic High-Density Lipoprotein (sHDL) Inhibits Steroid Production in HAC15 Adrenal Cells.

    PubMed

    Taylor, Matthew J; Sanjanwala, Aalok R; Morin, Emily E; Rowland-Fisher, Elizabeth; Anderson, Kyle; Schwendeman, Anna; Rainey, William E

    2016-08-01

    High density lipoprotein (HDL) transported cholesterol represents one of the sources of substrate for adrenal steroid production. Synthetic HDL (sHDL) particles represent a new therapeutic option to reduce atherosclerotic plaque burden by increasing cholesterol efflux from macrophage cells. The effects of the sHDL particles on steroidogenic cells have not been explored. sHDL, specifically ETC-642, was studied in HAC15 adrenocortical cells. Cells were treated with sHDL, forskolin, 22R-hydroxycholesterol, or pregnenolone. Experiments included time and concentration response curves, followed by steroid assay. Quantitative real-time RT-PCR was used to study mRNA of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, lanosterol 14-α-methylase, cholesterol side-chain cleavage enzyme, and steroid acute regulatory protein. Cholesterol assay was performed using cell culture media and cell lipid extracts from a dose response experiment. sHDL significantly inhibited production of cortisol. Inhibition occurred in a concentration- and time-dependent manner and in a concentration range of 3μM-50μM. Forskolin (10μM) stimulated cortisol production was also inhibited. Incubation with 22R-hydroxycholesterol (10μM) and pregnenolone (10μM) increased cortisol production, which was unaffected by sHDL treatment. sHDL increased transcript levels for the rate-limiting cholesterol biosynthetic enzyme, 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase. Extracellular cholesterol assayed in culture media showed a positive correlation with increasing concentration of sHDL, whereas intracellular cholesterol decreased after treatment with sHDL. The current study suggests that sHDL inhibits HAC15 adrenal cell steroid production by efflux of cholesterol, leading to an overall decrease in steroid production and an adaptive rise in adrenal cholesterol biosynthesis. PMID:27253994

  16. An adhesion-based method for plasma membrane isolation: evaluating cholesterol extraction from cells and their membranes.

    PubMed

    Bezrukov, Ludmila; Blank, Paul S; Polozov, Ivan V; Zimmerberg, Joshua

    2009-11-15

    A method to isolate large quantities of directly accessible plasma membrane from attached cells is presented. The method is based on the adhesion of cells to an adsorbed layer of polylysine on glass plates, followed by hypotonic lysis with ice-cold distilled water and subsequent washing steps. Optimal conditions for coating glass plates and time for cell attachment were established. No additional chemical or mechanical treatments were used. Contamination of the isolated plasma membrane by cell organelles was less than 5%. The method uses inexpensive, commercially available polylysine and reusable glass plates. Plasma membrane preparations can be made in 15 min. Using this method, we determined that methyl-beta-cyclodextrin differentially extracts cholesterol from fibroblast cells and their plasma membranes and that these differences are temperature dependent. Determination of the cholesterol/phospholipid ratio from intact cells does not reflect methyl-beta-cyclodextrin plasma membrane extraction properties.

  17. HDL measures, particle heterogeneity, proposed nomenclature, and relation to atherosclerotic cardiovascular events

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A growing body of evidence from epidemiological data, animal studies, and clinical trials supports HDL as the next target to reduce residual cardiovascular risk in statin-treated, high-risk patients. For more than 3 decades, HDL cholesterol has been employed as the principal clinical measure of HDL ...

  18. Comprehensive Evaluation of the Association of APOE Genetic Variation with Plasma Lipoprotein Traits in U.S. Whites and African Blacks

    PubMed Central

    Radwan, Zaheda H.; Wang, Xingbin; Waqar, Fahad; Pirim, Dilek; Niemsiri, Vipavee; Hokanson, John E.; Hamman, Richard F.; Bunker, Clareann H.; Barmada, M. Michael; Demirci, F. Yesim; Kamboh, M. Ilyas

    2014-01-01

    Although common APOE genetic variation has a major influence on plasma LDL-cholesterol, its role in affecting HDL-cholesterol and triglycerides is not well established. Recent genome-wide association studies suggest that APOE also affects plasma variation in HDL-cholesterol and triglycerides. It is thus important to resequence the APOE gene to identify both common and uncommon variants that affect plasma lipid profile. Here, we have sequenced the APOE gene in 190 subjects with extreme HDL-cholesterol levels selected from two well-defined epidemiological samples of U.S. non-Hispanic Whites (NHWs) and African Blacks followed by genotyping of identified variants in the entire datasets (623 NHWs, 788 African Blacks) and association analyses with major lipid traits. We identified a total of 40 sequence variants, of which 10 are novel. A total of 32 variants, including common tagSNPs (≥5% frequency) and all uncommon variants (<5% frequency) were successfully genotyped and considered for genotype-phenotype associations. Other than the established associations of APOE*2 and APOE*4 with LDL-cholesterol, we have identified additional independent associations with LDL-cholesterol. We have also identified multiple associations of uncommon and common APOE variants with HDL-cholesterol and triglycerides. Our comprehensive sequencing and genotype-phenotype analyses indicate that APOE genetic variation impacts HDL-cholesterol and triglycerides in addition to affecting LDL-cholesterol. PMID:25502880

  19. Atomistic MD simulation reveals the mechanism by which CETP penetrates into HDL enabling lipid transfer from HDL to CETP

    PubMed Central

    Cilpa-Karhu, Geraldine; Jauhiainen, Matti; Riekkola, Marja-Liisa

    2015-01-01

    Inhibition of cholesterol ester transfer protein (CETP), a protein mediating transfer of neutral lipids between lipoproteins, has been proposed as a means to elevate atheroprotective HDL subpopulations and thereby reduce atherosclerosis. However, off-target and adverse effects of the inhibition have raised doubts about the molecular mechanism of CETP-HDL interaction. Recent experimental findings have demonstrated the penetration of CETP into HDL. However, atomic level resolution of CETP penetration into HDL, a prerequisite for a better understanding of CETP functionality and HDL atheroprotection, is missing. We constructed an HDL particle that mimics the actual human HDL mass composition and investigated for the first time, by large-scale atomistic molecular dynamics, the interaction of an upright CETP with a human HDL-mimicking model. The results demonstrated how CETP can penetrate the HDL particle surface, with the formation of an opening in the N barrel domain end of CETP, put in evidence the major anchoring role of a tryptophan-rich region of this domain, and unveiled the presence of a phenylalanine barrier controlling further access of HDL-derived lipids to the tunnel of CETP. The findings reveal novel atomistic details of the CETP-HDL interaction mechanism and can provide new insight into therapeutic strategies. PMID:25424006

  20. Resveratrol Protects Rabbits Against Cholesterol Diet-Induced Hyperlipidaemia.

    PubMed

    Tanko, Y; Jimoh, A; Ahmed, A; Mohammed, A; Ayo, J O

    2016-01-01

    The excessive consumption of high cholesterol diet has been associated with an increased incidence oflipidaemia. Lipidaemia is enhanced by formation of oxidative stress, lipid peroxidation and hyperglycaemia. The aim ofthese experiments was to investigate the protective effect of resveratrol co-administered with cholesterol diet inducedhyperlipidaemia in rabbits. Thirty rabbits divided into six groups of five animal (group= 5) each: group 1 = normal control,group 2 = cholesterol diet/high fat diet group only (HFD), group 3 = resveratrol 200 mg/kg (R200), group 4 = resveratrol400 mg/kg (R400), group 5 = HFD + R200 and group 6 = HFD + R400. The normal group was fed with standard animalfeeds only; while the HFD groups were fed with standard animal feeds + cholesterol diet (10% Groundnut oil, 20%Groundnut mill and 2% cholesterol). Resveratrol-treated rabbits received resveratrol suspended in 10 g/Lcarboxymethylcellulose (CMC) and the control group received the vehicle only, CMC. The preparations were administeredfor 8 weeks of experimental protocol. At the end of the study period, the animals were sacrificed. Blood and plasma sampleswere collected. Serum evaluation of lipid profile such as total cholesterol (TC), triacylglycerol (Tg), low density lipoproteincholesterol (LDP-c) and high density lipoprotein cholesterol (HDL-c) were also assessed. The results obtained showsignificant (P < 0.05) decrease in total cholesterol (TC), Low density lipoprotein cholesterol (LDP-c), total triacylglyceroland an increase in high density lipoprotein cholesterol (HDL-c) in resveratrol treated groups compared to HFD group only.In conclusion, the findings indicated that Resveratrol may contain polar products able to lower plasma lipid concentrationsand might be beneficial in treatment of hyperlipidemia and atherosclerosis. PMID:27574767

  1. Ultrafast Diffusion of a Fluorescent Cholesterol Analog in Compartmentalized Plasma Membranes

    PubMed Central

    Hiramoto-Yamaki, Nao; Tanaka, Kenji A K; Suzuki, Kenichi G N; Hirosawa, Koichiro M; Miyahara, Manami S H; Kalay, Ziya; Tanaka, Koichiro; Kasai, Rinshi S; Kusumi, Akihiro; Fujiwara, Takahiro K

    2014-01-01

    Cholesterol distribution and dynamics in the plasma membrane (PM) are poorly understood. The recent development of Bodipy488-conjugated cholesterol molecule (Bdp-Chol) allowed us to study cholesterol behavior in the PM, using single fluorescent-molecule imaging. Surprisingly, in the intact PM, Bdp-Chol diffused at the fastest rate ever found for any molecules in the PM, with a median diffusion coefficient (D) of 3.4 µm2/second, which was ∼10 times greater than that of non-raft phospholipid molecules (0.33 µm2/second), despite Bdp-Chol's probable association with raft domains. Furthermore, Bdp-Chol exhibited no sign of entrapment in time scales longer than 0.5 milliseconds. In the blebbed PM, where actin filaments were largely depleted, Bdp-Chol and Cy3-conjugated dioleoylphosphatidylethanolamine (Cy3-DOPE) diffused at comparable Ds (medians = 5.8 and 6.2 µm2/second, respectively), indicating that the actin-based membrane skeleton reduces the D of Bdp-Chol only by a factor of ∼2 from that in the blebbed PM, whereas it reduces the D of Cy3-DOPE by a factor of ∼20. These results are consistent with the previously proposed model, in which the PM is compartmentalized by the actin-based membrane-skeleton fence and its associated transmembrane picket proteins for the macroscopic diffusion of all of the membrane molecules, and suggest that the probability of Bdp-Chol passing through the compartment boundaries, once it enters the boundary, is ∼10× greater than that of Cy3-DOPE. Since the compartment sizes are greater than those of the putative raft domains, we conclude that raft domains coexist with membrane-skeleton-induced compartments and are contained within them. PMID:24506328

  2. Comparison of effects of diet versus exercise weight loss regimens on LDL and HDL particle size in obese adults

    PubMed Central

    2011-01-01

    Background Obesity is associated with an atherogenic lipid profile characterized by a predominance of small LDL and HDL particles. Weight loss, by dietary restriction or exercise, increases LDL particle size. Whether these interventions can augment HDL size in conjunction with LDL size remains unknown. Objective This study compared the effects of alternate day fasting (ADF), calorie restriction (CR), and endurance exercise on LDL and HDL particle size in overweight and obese subjects. Methods In a 12-week parallel-arm trial, adult subjects (n = 60) were randomized to 1 of 4 groups: 1) ADF (75% energy restriction for 24-h alternated with ad libitum feeding for 24-h), 2) CR (25% energy restriction every day), 3) exercise (moderate intensity training 3 x/week), or 4) control. Results Body weight was reduced (P < 0.001) by ADF, CR, and exercise (5.2 ± 1.1%, 5.0 ± 1.4%, 5.1 ± 0.9%, respectively). Plasma LDL cholesterol decreased (P < 0.05) with ADF (10 ± 4%) and CR (8 ± 4%), whereas HDL cholesterol increased (P < 0.05) with exercise (16 ± 5%). Integrated LDL particle size was augmented (P = 0.01) by ADF and CR. The proportion of small LDL particles decreased (P = 0.04) with ADF only, and the proportion of large HDL particles increased (P = 0.03) with exercise only. Conclusion These results indicate that dietary restriction increases LDL particle size, while endurance training augments HDL particle size, with minimal weight loss. None of these interventions concomitantly increased both LDL and HDL particle size, however. PMID:21767400

  3. Role of the hydrophobic and charged residues in the 218-226 region of apoA-I in the biogenesis of HDL.

    PubMed

    Fotakis, Panagiotis; Kateifides, Andreas K; Gkolfinopoulou, Christina; Georgiadou, Dimitra; Beck, Melissa; Gründler, Katharina; Chroni, Angeliki; Stratikos, Efstratios; Kardassis, Dimitris; Zannis, Vassilis I

    2013-12-01

    We investigated the significance of hydrophobic and charged residues 218-226 on the structure and functions of apoA-I and their contribution to the biogenesis of HDL. Adenovirus-mediated gene transfer of apoA-I[L218A/L219A/V221A/L222A] in apoA-I⁻/⁻ mice decreased plasma cholesterol and apoA-I levels to 15% of wild-type (WT) control mice and generated pre-β- and α4-HDL particles. In apoA-I⁻/⁻ × apoE⁻/⁻ mice, the same mutant formed few discoidal and pre-β-HDL particles that could not be converted to mature α-HDL particles by excess LCAT. Expression of the apoA-I[E223A/K226A] mutant in apoA-I⁻/⁻ mice caused lesser but discrete alterations in the HDL phenotype. The apoA-I[218-222] and apoA-I[E223A/K226A] mutants had 20% and normal capacity, respectively, to promote ABCA1-mediated cholesterol efflux. Both mutants had ∼65% of normal capacity to activate LCAT in vitro. Biophysical analyses suggested that both mutants affected in a distinct manner the structural integrity and plasticity of apoA-I that is necessary for normal functions. We conclude that the alteration of the hydrophobic 218-222 residues of apoA-I disrupts apoA-I/ABCA1 interactions and promotes the generation of defective pre-β particles that fail to mature into α-HDL subpopulations, thus resulting in low plasma apoA-I and HDL. Alterations of the charged 223, 226 residues caused milder but discrete changes in HDL phenotype. PMID:23990662

  4. Rapid turn-over of plasma membrane sphingomyelin and cholesterol in baby hamster kidney cells after exposure to sphingomyelinase.

    PubMed

    Slotte, J P; Härmälä, A S; Jansson, C; Pörn, M I

    1990-12-14

    Plasma membrane sphingomyelin in baby hamster kidney (BHK-21) cells was hydrolyzed with sphingomyelinase (Staphylococcus aureus) and the effects on membrane cholesterol translocation and the properties of membrane bound adenylate cyclase and Na+/K(+)-ATPase were determined. Exposure of confluent BHK-21 cells to 0.1 U/ml of sphingomyelinase led to the degradation (at 37 degrees C) of about 60% of cell sphingomyelin. No simultaneous hydrolysis of phosphatidylcholine occurred. The hydrolysis of sphingomyelin subsequently led to the translocation (within 40 min) of about 50-60% of cell [3H]cholesterol from a cholesterol oxidase susceptible pool to an oxidase resistant compartment. The translocation of [3H]cholesterol from the cell surface to intracellular membranes was accompanied by a paralleled increase in [3H]cholesterol ester formation. When cells were first exposed to sphingomyelinase (to degrade sphingomyelin) and then incubated without the enzyme in serum-free media, the mass of cell sphingomyelin decreased initially (by 60%), but then began to increase and reached control levels within 3-4 h. The rapid re-synthesis of sphingomyelin was accompanied by an equally rapid normalization of cell [3H]cholesterol distribution. The re-formation of cell sphingomyelin also led to a decreased content of cellular [3H]cholesterol esters, indicating that unesterified [3H]cholesterol was pulled out of the cholesterol ester cycle and transported to the cell surface. Exposure of BHK-21 cells to sphingomyelinase further led to a dramatically decreased activity of ouabain-sensitive Na+/K(+)-ATPase, whereas forskolin-stimulated adenylate cyclase activity was not affected. The activity of Na+/K(+)-ATPase returned to normal in parallel with the normalization of cell sphingomyelin mass and cholesterol distribution. We conclude that sphingomyelin has profound effects on the steady-state distribution of cell cholesterol, and that manipulations of cell sphingomyelin levels directly and

  5. Rapid turn-over of plasma membrane sphingomyelin and cholesterol in baby hamster kidney cells after exposure to sphingomyelinase.

    PubMed

    Slotte, J P; Härmälä, A S; Jansson, C; Pörn, M I

    1990-12-14

    Plasma membrane sphingomyelin in baby hamster kidney (BHK-21) cells was hydrolyzed with sphingomyelinase (Staphylococcus aureus) and the effects on membrane cholesterol translocation and the properties of membrane bound adenylate cyclase and Na+/K(+)-ATPase were determined. Exposure of confluent BHK-21 cells to 0.1 U/ml of sphingomyelinase led to the degradation (at 37 degrees C) of about 60% of cell sphingomyelin. No simultaneous hydrolysis of phosphatidylcholine occurred. The hydrolysis of sphingomyelin subsequently led to the translocation (within 40 min) of about 50-60% of cell [3H]cholesterol from a cholesterol oxidase susceptible pool to an oxidase resistant compartment. The translocation of [3H]cholesterol from the cell surface to intracellular membranes was accompanied by a paralleled increase in [3H]cholesterol ester formation. When cells were first exposed to sphingomyelinase (to degrade sphingomyelin) and then incubated without the enzyme in serum-free media, the mass of cell sphingomyelin decreased initially (by 60%), but then began to increase and reached control levels within 3-4 h. The rapid re-synthesis of sphingomyelin was accompanied by an equally rapid normalization of cell [3H]cholesterol distribution. The re-formation of cell sphingomyelin also led to a decreased content of cellular [3H]cholesterol esters, indicating that unesterified [3H]cholesterol was pulled out of the cholesterol ester cycle and transported to the cell surface. Exposure of BHK-21 cells to sphingomyelinase further led to a dramatically decreased activity of ouabain-sensitive Na+/K(+)-ATPase, whereas forskolin-stimulated adenylate cyclase activity was not affected. The activity of Na+/K(+)-ATPase returned to normal in parallel with the normalization of cell sphingomyelin mass and cholesterol distribution. We conclude that sphingomyelin has profound effects on the steady-state distribution of cell cholesterol, and that manipulations of cell sphingomyelin levels directly and

  6. Effects of Plasma Membrane Cholesterol Level and Cytoskeleton F-Actin on Cell Protrusion Mechanics

    PubMed Central

    Khatibzadeh, Nima; Spector, Alexander A.; Brownell, William E.; Anvari, Bahman

    2013-01-01

    Protrusions are deformations that form at the surface of living cells during biological activities such as cell migration. Using combined optical tweezers and fluorescent microscopy, we quantified the mechanical properties of protrusions in adherent human embryonic kidney cells in response to application of an external force at the cell surface. The mechanical properties of protrusions were analyzed by obtaining the associated force-length plots during protrusion formation, and force relaxation at constant length. Protrusion mechanics were interpretable by a standard linear solid (Kelvin) model, consisting of two stiffness parameters, k0 and k1 (with k0>k1), and a viscous coefficient. While both stiffness parameters contribute to the time-dependant mechanical behavior of the protrusions, k0 and k1 in particular dominated the early and late stages of the protrusion formation and elongation process, respectively. Lowering the membrane cholesterol content by 25% increased the k0 stiffness by 74%, and shortened the protrusion length by almost half. Enhancement of membrane cholesterol content by nearly two-fold increased the protrusion length by 30%, and decreased the k0 stiffness by nearly two-and-half-fold as compared with control cells. Cytoskeleton integrity was found to make a major contribution to protrusion mechanics as evidenced by the effects of F-actin disruption on the resulting mechanical parameters. Viscoelastic behavior of protrusions was further characterized by hysteresis and force relaxation after formation. The results of this study elucidate the coordination of plasma membrane composition and cytoskeleton during protrusion formation. PMID:23451167

  7. Effects of cholesterol on plasma membrane lipid order in MCF-7 cells by two-photon microscopy

    NASA Astrophysics Data System (ADS)

    Zeng, Yixiu; Chen, Jianling; Yang, Hongqin; Wang, Yuhua; Li, Hui; Xie, Shusen

    2014-09-01

    Lipid rafts are cholesterol- and glycosphingolipids- enriched microdomains on plasma membrane surface of mammal cells, involved in a variety of cellular processes. Depleting cholesterol from the plasma membrane by drugs influences the trafficking of lipid raft markers. Optical imaging techniques are powerful tools to study lipid rafts in live cells due to its noninvasive feature. In this study, breast cancer cells MCF-7 were treated with different concentrations of MβCD to deplete cholesterol and an environmentally sensitive fluorescence probe, Laurdan was loaded to image lipid order by two-photon microscopy. The generalized polarization (GP) values were calculated to distinguish the lipid order and disorder phase. GP images and GP distributions of native and cholesterol-depleted MCF-7 cells were obtained. Our results suggest that even at low concentration (0.5 mM) of MβCD, the morphology of the MCF-7 cells changes. Small high GP areas (lipid order phase) decrease more rapidly than low GP areas (lipid disorder phase), indicating that lipid raft structure was altered more severely than nonraft domains. The data demonstrates that cholesterol dramatically affect raft coverage and plasma membrane fluidity in living cells.

  8. High-density lipoprotein cholesterol is positively associated with hypertension in apparently healthy Japanese men and women.

    PubMed

    Oda, E; Kawai, R

    2011-01-01

    Among five components of metabolic syndrome, high-density lipoprotein (HDL) cholesterol is unique because it is not significantly associated with blood pressure. This study looks at cross-sectional relationships between HDL cholesterol and hypertension using medical check-up data from 1803 apparently healthy Japanese men aged 49.9 +/- 9.0 years, and 1150 Japanese women aged 49.5 +/- 9.0 years. Pearson's correlation coefficients between systolic blood pressure (SBP)/diastolic blood pressure (DBP) and HDL cholesterol were -0.01 (ns)/-0.01 (ns) in men and -0.04 (ns)/-0.01 (ns) in women. The standardised partial regression coefficient of HDL cholesterol for SBP/DBP (mmHg) controlling for age, body mass index (BMI), fasting plasma glucose (FPG), triglycerides, high-sensitivity C-reactive protein (hs-CRP) and low-density lipoprotein (LDL) cholesterol were 0.15 (P < 0.0001)/0.15 (P < 0.0001) in men and 0.10 (P < 0.0001)/0.12 (P < 0.0001) in women. The odds ratio (OR; 95% confidence interval [CI]) of a 1 mg/dL increment of HDL cholesterol for hypertension controlling for age, BMI, FPG, triglycerides, hs-CRP, LDL cholesterol, metabolic syndrome, diabetes, exercise status, drinking status, and smoking status was 1.03 (1.02-1.04; P < 0.001) in men and 1.03 (1.01-1.05; P = 0.002) in women. Thus, HDL cholesterol was independently positively associated with hypertension in apparently healthy Japanese men and women. PMID:21473259

  9. Phospholipid liposomes acquire apolipoprotein E in atherogenic plasma and block cholesterol loading of cultured macrophages.

    PubMed Central

    Williams, K J; Tall, A R; Bisgaier, C; Brocia, R

    1987-01-01

    A single infusion of phospholipid liposomes promptly and persistently abolished the ability of hypercholesterolemic rabbit plasma to cause cholesteryl ester loading in cultured macrophages. This phospholipid enrichment of plasma caused moderate stimulation of cellular cholesterol efflux and, unexpectedly, almost complete inhibition of cellular uptake of beta-very low density lipoprotein (beta-VLDL), the major cholesteryl ester-rich particle in hypercholesterolemic rabbit plasma. Cell viability and LDL receptor activity were unaffected. Incubation of liposomes with beta-VLDL resulted in transfer of apolipoprotein-E (apoE) to the liposomes; reisolated apoE-phospholipid liposomes then competed efficiently for cellular apoprotein receptors. Thus, a major mechanism by which phospholipid infusions result in diminished accumulation of cholesteryl ester in cultured macrophages is by blocking cellular uptake of beta-VLDL. The liposomes deplete beta-VLDL of apoE, then compete for receptor-mediated uptake. These results suggest a novel mechanism contributing to the known antiatherogenic effect of phospholipid infusions: infused liposomes acquire apoE, then block uptake of atherogenic lipoproteins by arterial wall macrophages. Images PMID:3571495

  10. Oxidized Phospholipids Inhibit the Formation of Cholesterol-Dependent Plasma Membrane Nanoplatforms.

    PubMed

    Brameshuber, Mario; Sevcsik, Eva; Rossboth, Benedikt K; Manner, Christina; Deigner, Hans-Peter; Peksel, Begüm; Péter, Mária; Török, Zsolt; Hermetter, Albin; Schütz, Gerhard J

    2016-01-01

    We previously developed a single-molecule microscopy method termed TOCCSL (thinning out clusters while conserving stoichiometry of labeling), which allows for direct imaging of stable nanoscopic platforms with raft-like properties diffusing in the plasma membrane. As a consensus raft marker, we chose monomeric GFP linked via a glycosylphosphatidylinositol (GPI) anchor to the cell membrane (mGFP-GPI). With this probe, we previously observed cholesterol-dependent homo-association to nanoplatforms diffusing in the plasma membrane of live CHO cells. Here, we report the release of this homo-association upon addition of 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC) or 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine, two oxidized phospholipids (oxPLs) that are typically present in oxidatively modified low-density lipoprotein. We found a dose-response relationship for mGFP-GPI nanoplatform disintegration upon addition of POVPC, correlating with the signal of the apoptosis marker Annexin V-Cy3. Similar concentrations of lysolipid showed no effect, indicating that the observed phenomena were not linked to properties of the lipid bilayer itself. Inhibition of acid sphingomyelinase by NB-19 before addition of POVPC completely abolished nanoplatform disintegration by oxPLs. In conclusion, we were able to determine how oxidized lipid species disrupt mGFP-GPI nanoplatforms in the plasma membrane. Our results favor an indirect mechanism involving acid sphingomyelinase activity rather than a direct interaction of oxPLs with nanoplatform constituents.

  11. Diet rich in high glucoraphanin broccoli reduces plasma LDL cholesterol: Evidence from randomised controlled trials

    PubMed Central

    Armah, Charlotte N; Derdemezis, Christos; Traka, Maria H; Dainty, Jack R; Doleman, Joanne F; Saha, Shikha; Leung, Wing; Potter, John F; Lovegrove, Julie A; Mithen, Richard F

    2015-01-01

    Scope Cruciferous-rich diets have been associated with reduction in plasma LDL-cholesterol (LDL-C), which may be due to the action of isothiocyanates derived from glucosinolates that accumulate in these vegetables. This study tests the hypothesis that a diet rich in high glucoraphanin (HG) broccoli will reduce plasma LDL-C. Methods and results One hundred and thirty volunteers were recruited to two independent double-blind, randomly allocated parallel dietary intervention studies, and were assigned to consume either 400 g standard broccoli or 400 g HG broccoli per week for 12 weeks. Plasma lipids were quantified before and after the intervention. In study 1 (37 volunteers), the HG broccoli diet reduced plasma LDL-C by 7.1% (95% CI: –1.8%, –12.3%, p = 0.011), whereas standard broccoli reduced LDL-C by 1.8% (95% CI +3.9%, –7.5%, ns). In study 2 (93 volunteers), the HG broccoli diet resulted in a reduction of 5.1% (95% CI: –2.1%, –8.1%, p = 0.001), whereas standard broccoli reduced LDL-C by 2.5% (95% CI: +0.8%, –5.7%, ns). When data from the two studies were combined the reduction in LDL-C by the HG broccoli was significantly greater than standard broccoli (p = 0.031). Conclusion Evidence from two independent human studies indicates that consumption of high glucoraphanin broccoli significantly reduces plasma LDL-C. PMID:25851421

  12. Hepatic Gene Expression Related to Lower Plasma Cholesterol in Hamsters Fed High Fat Diets Supplemented with Blueberry Pomace and Extract

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We analyzed plasma lipid profiles, and genes related to cholesterol and bile acid metabolism, and inflammation in livers as well as adipose tissue from Syrian Golden hamsters fed high-fat diets supplemented with blueberry (BB) pomace byproducts including 8% dried whole blueberry peels (BBPWHL), 2% d...

  13. Glucomannan and glucomannan plus spirulina added to pork significantly block dietary cholesterol effects on lipoproteinemia, arylesterase activity, and CYP7A1 expression in Zucker fa/fa rats.

    PubMed

    González-Torres, Laura; Vázquez-Velasco, Miguel; Olivero-David, Raúl; Bastida, Sara; Benedí, Juana; González, Rafaela Raposo; González-Muñoz, Ma José; Sánchez-Muniz, Francisco J

    2015-12-01

    Zucker fa/fa rats easily develop dyslipidemia and obesity. Restructured pork (RP) is a suitable matrix for including functional ingredients. The effects of glucomannan- RP or glucomannan plus spirulina-enriched RP on plasma lipid/lipoprotein levels, cytochrome P450 7A1 (CYP7A1) expression, and arylesterase activity in growing fa/fa rats fed high-energy, high-fat cholesterol-enriched diets were tested. Groups of six rats each received diet containing 15% control-RP (C), 15% glucomannan-RP diet (G), 15% glucomannan + spirulina-RP diet (GS), and same diets enriched with 2.4% cholesterol and 0.49% cholic acid (cholesterol-enriched control (HC), cholesterol-enriched glucomannan (HG), and cholesterol-enriched glucomannan + spirulina (HGS) diets) over a 7-week period. C diet induced obesity, severe hyperglycemia, moderate hypercholesterolemia, and hypertriglyceridemia. Those facts were not significantly modified by G or GS diets. G diet increased CYP7A1 expression but decreased the total cholesterol/high density lipoproteins (HDL)-cholesterol ratio (p < 0.05) vs. C diet. GS vs. G diet increased (p < 0.05) CYP7A1 expression. HC vs. C diet reduced food intake, body weight gain, and plasma glucose (p < 0.01) but increased cholesterolemia (p < 0.01), lipidemia (plasma cholesterol plus triglycerides) (p < 0.001), cholesterol/triglyceride ratio in very low density lipoproteins (VLDL), and HDL (p < 0.05), cholesterol transported by VLDL and intermediate density lipoproteins (IDL) + low density lipoproteins (LDL), total cholesterol/HDL-cholesterol ratio and CYP7A1 expression (at least p < 0.05). HG and HGS diets vs. HC noticeably reduced lipidemia (p < 0.001), normalized VLDL and IDL + LDL lipid composition, and increased CYP7A1 expression (p < 0.01) but did not modify the cholesterol/HDL-cholesterol ratio. HGS vs. HG decreased triglyceridemia, the triglyceride-glucose (TyG) index and increased arylesterase/HDL-cholesterol activity (p < 0

  14. Procollagen C-endopeptidase Enhancer Protein 2 (PCPE2) Reduces Atherosclerosis in Mice by Enhancing Scavenger Receptor Class B1 (SR-BI)-mediated High-density Lipoprotein (HDL)-Cholesteryl Ester Uptake.

    PubMed

    Pollard, Ricquita D; Blesso, Christopher N; Zabalawi, Manal; Fulp, Brian; Gerelus, Mark; Zhu, Xuewei; Lyons, Erica W; Nuradin, Nebil; Francone, Omar L; Li, Xiang-An; Sahoo, Daisy; Thomas, Michael J; Sorci-Thomas, Mary G

    2015-06-19

    Studies in human populations have shown a significant correlation between procollagen C-endopeptidase enhancer protein 2 (PCPE2) single nucleotide polymorphisms and plasma HDL cholesterol concentrations. PCPE2, a 52-kDa glycoprotein located in the extracellular matrix, enhances the cleavage of C-terminal procollagen by bone morphogenetic protein 1 (BMP1). Our studies here focused on investigating the basis for the elevated concentration of enlarged plasma HDL in PCPE2-deficient mice to determine whether they protected against diet-induced atherosclerosis. PCPE2-deficient mice were crossed with LDL receptor-deficient mice to obtain LDLr(-/-), PCPE2(-/-) mice, which had elevated HDL levels compared with LDLr(-/-) mice with similar LDL concentrations. We found that LDLr(-/-), PCPE2(-/-) mice had significantly more neutral lipid and CD68+ infiltration in the aortic root than LDLr(-/-) mice. Surprisingly, in light of their elevated HDL levels, the extent of aortic lipid deposition in LDLr(-/-), PCPE2(-/-) mice was similar to that reported for LDLr(-/-), apoA-I(-/-) mice, which lack any apoA-I/HDL. Furthermore, LDLr(-/-), PCPE2(-/-) mice had reduced HDL apoA-I fractional clearance and macrophage to fecal reverse cholesterol transport rates compared with LDLr(-/-) mice, despite a 2-fold increase in liver SR-BI expression. PCPE2 was shown to enhance SR-BI function by increasing the rate of HDL-associated cholesteryl ester uptake, possibly by optimizing SR-BI localization and/or conformation. We conclude that PCPE2 is atheroprotective and an important component of the reverse cholesterol transport HDL system.

  15. Procollagen C-endopeptidase Enhancer Protein 2 (PCPE2) Reduces Atherosclerosis in Mice by Enhancing Scavenger Receptor Class B1 (SR-BI)-mediated High-density Lipoprotein (HDL)-Cholesteryl Ester Uptake*

    PubMed Central

    Pollard, Ricquita D.; Blesso, Christopher N.; Zabalawi, Manal; Fulp, Brian; Gerelus, Mark; Zhu, Xuewei; Lyons, Erica W.; Nuradin, Nebil; Francone, Omar L.; Li, Xiang-An; Sahoo, Daisy; Thomas, Michael J.; Sorci-Thomas, Mary G.

    2015-01-01

    Studies in human populations have shown a significant correlation between procollagen C-endopeptidase enhancer protein 2 (PCPE2) single nucleotide polymorphisms and plasma HDL cholesterol concentrations. PCPE2, a 52-kDa glycoprotein located in the extracellular matrix, enhances the cleavage of C-terminal procollagen by bone morphogenetic protein 1 (BMP1). Our studies here focused on investigating the basis for the elevated concentration of enlarged plasma HDL in PCPE2-deficient mice to determine whether they protected against diet-induced atherosclerosis. PCPE2-deficient mice were crossed with LDL receptor-deficient mice to obtain LDLr−/−, PCPE2−/− mice, which had elevated HDL levels compared with LDLr−/− mice with similar LDL concentrations. We found that LDLr−/−, PCPE2−/− mice had significantly more neutral lipid and CD68+ infiltration in the aortic root than LDLr−/− mice. Surprisingly, in light of their elevated HDL levels, the extent of aortic lipid deposition in LDLr−/−, PCPE2−/− mice was similar to that reported for LDLr−/−, apoA-I−/− mice, which lack any apoA-I/HDL. Furthermore, LDLr−/−, PCPE2−/− mice had reduced HDL apoA-I fractional clearance and macrophage to fecal reverse cholesterol transport rates compared with LDLr−/− mice, despite a 2-fold increase in liver SR-BI expression. PCPE2 was shown to enhance SR-BI function by increasing the rate of HDL-associated cholesteryl ester uptake, possibly by optimizing SR-BI localization and/or conformation. We conclude that PCPE2 is atheroprotective and an important component of the reverse cholesterol transport HDL system. PMID:25947382

  16. Lipoprotein hydrophobic core lipids are partially extruded to surface in smaller HDL: "Herniated" HDL, a common feature in diabetes.

    PubMed

    Amigó, Núria; Mallol, Roger; Heras, Mercedes; Martínez-Hervás, Sergio; Blanco Vaca, Francisco; Escolà-Gil, Joan Carles; Plana, Núria; Yanes, Óscar; Masana, Lluís; Correig, Xavier

    2016-01-18

    Recent studies have shown that pharmacological increases in HDL cholesterol concentrations do not necessarily translate into clinical benefits for patients, raising concerns about its predictive value for cardiovascular events. Here we hypothesize that the size-modulated lipid distribution within HDL particles is compromised in metabolic disorders that have abnormal HDL particle sizes, such as type 2 diabetes mellitus (DM2). By using NMR spectroscopy combined with a biochemical volumetric model we determined the size and spatial lipid distribution of HDL subclasses in a cohort of 26 controls and 29 DM2 patients before and after two drug treatments, one with niacin plus laropiprant and another with fenofibrate as an add-on to simvastatin. We further characterized the HDL surface properties using atomic force microscopy and fluorescent probes to show an abnormal lipid distribution within smaller HDL particles, a subclass particularly enriched in the DM2 patients. The reduction in the size, force cholesterol esters and triglycerides to emerge from the HDL core to the surface, making the outer surface of HDL more hydrophobic. Interestingly, pharmacological interventions had no effect on this undesired configuration, which may explain the lack of clinical benefits in DM2 subjects.

  17. Peptides identified in soybean protein increase plasma cholesterol in mice on hypercholesterolemic diets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The in vitro micellar cholesterol displacement assay has been used to identify peptides that may potentially reduce cholesterol in vivo. We tested two of these peptides, LPYPR and WGAPSI, derived from soybean protein (SP) that have been reported to displace cholesterol from micelles by feeding them...

  18. Aronia melanocarpa (chokeberry) polyphenol-rich extract improves antioxidant function and reduces total plasma cholesterol in apolipoprotein E knockout mice.

    PubMed

    Kim, Bohkyung; Ku, Chai Siah; Pham, Tho X; Park, Youngki; Martin, Derek A; Xie, Liyang; Taheri, Rod; Lee, Jiyoung; Bolling, Bradley W

    2013-05-01

    We hypothesized that a polyphenol-rich chokeberry extract (CBE) would modulate hepatic lipid metabolism and improve antioxidant function in apolipoprotein E knockout (apoE(-/-)) mice. ApoE(-/-) mice were fed diets containing 15% fat with 0.2% cholesterol alone or supplemented with 0.005% or 0.05% CBE for 4 weeks. CBE polyphenol content was determined by the total phenols, 4-dimethylaminocinnamaldehyde, and ultra high-performance liquid chromatography-mass spectrometry methods. The 0.05% CBE diet provided mice with mean daily doses of 1.2 mg gallic acid equivalents of total phenols, 0.19 mg anthocyanins, 0.17 mg phenolic acids, 0.06 mg proanthocyanidins (as catechin-equivalents), and 0.02 mg flavonols. The 0.05% CBE group had 12% less plasma total cholesterol concentrations than the control. Despite the hypocholesterolemic effect of CBE, hepatic mRNA levels of low-density lipoprotein receptor, hydroxyl-3-methylglutaryl coenzyme A reductase and cholesterol 7α-hydroxylase in CBE-fed mice were not significantly different from controls. Dietary CBE did not alter hepatic lipid content or the hepatic expression of genes involved in lipogenesis and fatty acid β-oxidation such as fatty acid synthase, carnitine palmitoyltransferase 1 and acyl-CoA oxidase. Plasma paraoxonase and catalase activities were significantly increased in mice fed 0.05% CBE. Both CBE diets increased hepatic glutathione peroxidase (GPx) activity but the 0.05% CBE group had 24% less proximal intestine GPx activity relative to controls. Thus, dietary CBE lowered total cholesterol and improved plasma and hepatic antioxidant function at nutritionally-relevant doses in apoE(-/-) mice. Furthermore, the CBE cholesterol-lowering mechanism in apoE(-/-) mice was independent of hepatic expression of genes involved in cholesterol metabolism.

  19. The amount of dietary cholesterol changes the mode of effects of (n-3) polyunsaturated fatty acid on lipoprotein cholesterol in hamsters.

    PubMed

    Lin, Mei-Huei; Lu, Shao-Chun; Huang, Po-Chao; Liu, Young-Chau; Liu, Shyun-Yeu

    2004-01-01

    This study was designed to investigate the effects of the interaction between dietary (n-3) polyunsaturated fatty acids (PUFA) and different dietary cholesterol content on plasma and liver cholesterol in hamsters. Male Syrian hamsters consumed diets containing an incremental increase in dietary cholesterol content (0, 0.025, 0.05, 0.1 and 0.2%, w/w) with either (n-3) PUFA (21 g/100 g fatty acids) or (n-6) PUFA (37.4 g/100 g fatty acids) fat for 6 weeks. In hamsters fed the nonatherogenic diet (0 or 0.025% dietary cholesterol), very low density lipoprotein (VLDL)-cholesterol levels in the (n-3) PUFA group were not significantly different from those in the (n-6) PUFA group, and low density lipoprotein (LDL)-cholesterol levels in the (n-3) PUFA group were significantly lower than those in the (n-6) PUFA group. In contrast, in hamsters fed the atherogenic diet (0.1 or 0.2% dietary cholesterol), VLDL- and LDL-cholesterol levels in the (n-3) PUFA group were significantly higher than those in the (n-6) PUFA group, in a dose-dependent manner. When the hamsters were fed with 0, 0.025, 0.05, 0.1 or 0.2% (w/w) dietary cholesterol, high density lipoprotein (HDL) cholesterol concentration was significantly lower in the (n-3) PUFA group than those in the (n-6) PUFA group. Hepatic cholesteryl esters were significantly lower, while hepatic microsomal acyl-coenzyme A:cholesterol acyltransferase activity and VLDL-cholesteryl esters were significantly higher in hamsters fed (n-3) PUFA with the atherogenic diet (0.1 or 0.2% dietary cholesterol) than in those fed (n-6) PUFA with the atherogenic diet. Our results demonstrate that the amount of dietary cholesterol is an important factor in determining the mode and extent of effects of dietary (n-3) PUFA, especially on VLDL- and LDL-cholesterol levels. When dietary cholesterol intake was above 0.1% (w/w), the plasma cholesterol-lowering effect of (n-3) PUFA disappeared, and instead, it showed a cholesterol-increasing effect. However, the

  20. Disruption of the murine procollagen C-proteinase enhancer 2 gene causes accumulation of pro-apoA-I and increased HDL levels

    PubMed Central

    Francone, Omar L.; Ishida, Brian Y.; de la Llera-Moya, Margarita; Royer, Lori; Happe, Christiane; Zhu, Jian; Chalkey, Robert J.; Schaefer, Peter; Cox, Cheryl; Burlingame, Al; Kane, John P.; Rothblat, George H.

    2011-01-01

    Given the increased prevalence of cardiovascular disease in the world, the search for genetic variations that impact risk factors associated with the development of this disease continues. Multiple genetic association studies demonstrate that procollagen C-proteinase enhancer 2 (PCPE2) modulates HDL levels. Recent studies revealed an unexpected role for this protein in the proteolytic processing of pro-apolipoprotein (apo) A-I by enhancing the cleavage of the hexapeptide extension present at the N-terminus of apoA-I. To investigate the role of the PCPE2 protein in an in vivo model, PCPE2-deficient (PCPE2 KO) mice were examined, and a detailed characterization of plasma lipid profiles, apoA-I, HDL speciation, and function was done. Results of isoelectric focusing (IEF) electrophoresis together with the identification of the amino terminal peptides DEPQSQWDK and WHVWQQDEPQSQWDVK, representing mature apoA-I and pro-apoA-I, respectively, in serum from PCPE2 KO mice confirmed that PCPE2 has a role in apoA-I maturation. Lipid profiles showed a marked increase in plasma apoA-I and HDL-cholesterol (HDL-C) levels in PCPE2 KO mice compared with wild-type littermates, regardless of gender or diet. Changes in HDL particle size and electrophoretic mobility observed in PCPE2 KO mice suggest that the presence of pro-apoA-I impairs the maturation of HDL. ABCA1-dependent cholesterol efflux is defective in PCPE2 KO mice, suggesting that the functionality of HDL is altered. PMID:21771977

  1. Modifying plasma low-density lipoprotein and high-density lipoprotein cholesterol: what combinations are available in the future?

    PubMed

    Kastelein, John J P

    2005-11-01

    Despite a growing body of research on the benefit of combination drug therapy for dyslipidemia in the metabolic syndrome or diabetes mellitus, there are insufficient outcome data on the use of combination therapy as well as inadequate data to compare certain combination regimens. The focus of the therapeutic approach in treating the metabolic syndrome has been almost exclusively on low-density lipoprotein (LDL) cholesterol for approximately the past 10 years, and specifically on statin therapy. Although results of epidemiologic studies as well as clinical trials using angiographic and clinical end points confirm the association of LDL cholesterol and risk of coronary artery disease, data are lacking regarding the effects of combination therapy in the management of coronary artery disease. Management of the metabolic syndrome focusing on the modification of plasma LDL as well as high-density lipoprotein cholesterol is reviewed. Future management strategies with the use of novel combination therapy is also discussed. PMID:16291010

  2. Evaluation of HDL-modulating interventions for cardiovascular risk reduction using a systems pharmacology approach.

    PubMed

    Gadkar, Kapil; Lu, James; Sahasranaman, Srikumar; Davis, John; Mazer, Norman A; Ramanujan, Saroja

    2016-01-01

    The recent failures of cholesteryl ester transport protein inhibitor drugs to decrease CVD risk, despite raising HDL cholesterol (HDL-C) levels, suggest that pharmacologic increases in HDL-C may not always reflect elevations in reverse cholesterol transport (RCT), the process by which HDL is believed to exert its beneficial effects. HDL-modulating therapies can affect HDL properties beyond total HDL-C, including particle numbers, size, and composition, and may contribute differently to RCT and CVD risk. The lack of validated easily measurable pharmacodynamic markers to link drug effects to RCT, and ultimately to CVD risk, complicates target and compound selection and evaluation. In this work, we use a systems pharmacology model to contextualize the roles of different HDL targets in cholesterol metabolism and provide quantitative links between HDL-related measurements and the associated changes in RCT rate to support target and compound evaluation in drug development. By quantifying the amount of cholesterol removed from the periphery over the short-term, our simulations show the potential for infused HDL to treat acute CVD. For the primary prevention of CVD, our analysis suggests that the induction of ApoA-I synthesis may be a more viable approach, due to the long-term increase in RCT rate.

  3. Parabolic relationship between plasma triacylglycerols and LDL-cholesterol in familial combined hyperlipidaemia: the multiple-type hyperlipidaemia explained?

    PubMed

    Brouwers, Martijn C G J; de Graaf, Jacqueline; van Greevenbroek, Marleen M J; Georgieva, Anna M; van der Kallen, Carla J H; Ter Avest, Ewoud; Stehouwer, Coen D A; Stalenhoef, Anton F; de Bruin, Tjerk W A

    2008-03-01

    FCHL (familial combined hyperlipidaemia) is a highly prevalent genetic lipid disorder that accounts for a substantial number of premature cardiovascular events. To date, FCHL has been complicated by the different lipid phenotypes that are present within one family and one individual patient over time. In the present study, we hypothesized that a parabolic relationship between plasma triacylglycerols (triglycerides) and LDL (low-density lipoprotein)-cholesterol can explain this so-called 'multiple-type hyperlipidaemia' in FCHL. Our hypothesis was tested in two well-documented FCHL cohorts [Maastricht (n=145) and Nijmegen (n=299)] that were followed over a 5-year interval. Three groups were constructed depending on plasma triacylglycerols: group A (individuals with both measurements below 1.5 mmol/l), group B (one measurement below and one measurement above 1.5 mmol/l) and group C (both measurement above 1.5 mmol/l). In both male, but not female, cohorts, a significant positive relationship between plasma triacylglycerols and LDL-cholesterol was observed in group A (P=0.02 for Maastricht cohort and P=0.001 for the Nijmegen cohort), a significant negative relationship in group C (P=0.01 for Maastricht cohort and P=0.02 for the Nijmegen cohort), and a relationship intermediate to group A and C in group B. In contrast, both apoB (apolipoprotein B) levels and the prevalence of cardiovascular disease were related with plasma triacylglycerols in a more linear fashion. In conclusion, a parabolic relationship between plasma triacylglycerols and LDL-cholesterol explains the 'multiple-type hyperlipidaemia' in FCHL. In addition, the linear relationship between triacylglycerols and both apoB levels and the prevalence of cardiovascular disease substantiate the use of apoB instead of LDL-cholesterol in the diagnosis of FCHL and the prediction of cardiovascular disease.

  4. A whole-grain cereal-rich diet increases plasma betaine, and tends to decrease total and LDL-cholesterol compared with a refined-grain diet in healthy subjects.

    PubMed

    Ross, Alastair B; Bruce, Stephen J; Blondel-Lubrano, Anny; Oguey-Araymon, Sylviane; Beaumont, Maurice; Bourgeois, Alexandre; Nielsen-Moennoz, Corine; Vigo, Mario; Fay, Laurent-Bernard; Kochhar, Sunil; Bibiloni, Rodrigo; Pittet, Anne-Cécile; Emady-Azar, Shahram; Grathwohl, Dominik; Rezzi, Serge

    2011-05-01

    Epidemiological studies have repeatedly found that whole-grain (WG) cereal foods reduce the risk of several lifestyle-related diseases, though consistent clinical outcomes and mechanisms are elusive. To compare the effects of a WG-rich diet with a matched refined-grain (RG) diet on plasma biomarkers and bowel health parameters, seventeen healthy subjects (eleven females and six males) completed an exploratory cross-over study with a 2-week intervention diet based on either WG- or RG-based foods, separated by a washout of at least 5 weeks. Both diets were the same except for the use of WG (150 g/d) or RG foods. Subjects undertook a 4 h postprandial challenge on day 8 of each intervention diet. After 2 weeks, the WG diet tended to decrease plasma total and LDL-cholesterol (both P = 0·09), but did not change plasma HDL-cholesterol, fasting glucose, C-reactive protein or homocysteine compared with the RG diet. Plasma betaine and alkylresorcinol concentrations were elevated after 1 week of the WG diet (P = 0·01 and P < 0·0001, respectively). Clostridium leptum populations in faeces were increased after the WG diet, along with a trend for decreased faecal water pH (P = 0·096) and increased stool frequency (P < 0·0001) compared with the RG diet. A short controlled intervention trial with a variety of commercially available WG-based products tended to improve biomarkers of CVD compared with a RG diet. Changes in faecal microbiota related to increased fibre fermentation and increased plasma betaine concentrations point to both fibre and phytochemical components of WG being important in mediating any potential health effects.

  5. A whole-grain cereal-rich diet increases plasma betaine, and tends to decrease total and LDL-cholesterol compared with a refined-grain diet in healthy subjects.

    PubMed

    Ross, Alastair B; Bruce, Stephen J; Blondel-Lubrano, Anny; Oguey-Araymon, Sylviane; Beaumont, Maurice; Bourgeois, Alexandre; Nielsen-Moennoz, Corine; Vigo, Mario; Fay, Laurent-Bernard; Kochhar, Sunil; Bibiloni, Rodrigo; Pittet, Anne-Cécile; Emady-Azar, Shahram; Grathwohl, Dominik; Rezzi, Serge

    2011-05-01

    Epidemiological studies have repeatedly found that whole-grain (WG) cereal foods reduce the risk of several lifestyle-related diseases, though consistent clinical outcomes and mechanisms are elusive. To compare the effects of a WG-rich diet with a matched refined-grain (RG) diet on plasma biomarkers and bowel health parameters, seventeen healthy subjects (eleven females and six males) completed an exploratory cross-over study with a 2-week intervention diet based on either WG- or RG-based foods, separated by a washout of at least 5 weeks. Both diets were the same except for the use of WG (150 g/d) or RG foods. Subjects undertook a 4 h postprandial challenge on day 8 of each intervention diet. After 2 weeks, the WG diet tended to decrease plasma total and LDL-cholesterol (both P = 0·09), but did not change plasma HDL-cholesterol, fasting glucose, C-reactive protein or homocysteine compared with the RG diet. Plasma betaine and alkylresorcinol concentrations were elevated after 1 week of the WG diet (P = 0·01 and P < 0·0001, respectively). Clostridium leptum populations in faeces were increased after the WG diet, along with a trend for decreased faecal water pH (P = 0·096) and increased stool frequency (P < 0·0001) compared with the RG diet. A short controlled intervention trial with a variety of commercially available WG-based products tended to improve biomarkers of CVD compared with a RG diet. Changes in faecal microbiota related to increased fibre fermentation and increased plasma betaine concentrations point to both fibre and phytochemical components of WG being important in mediating any potential health effects. PMID:21272402

  6. Autoimmune Lymphoproliferative Syndrome: A Rare Cause of Disappearing HDL Syndrome.

    PubMed

    Sriram, Swetha; Joshi, Avni Y; Rodriguez, Vilmarie; Kumar, Seema

    2016-01-01

    The term disappearing HDL syndrome refers to development of severe high density lipoprotein cholesterol (HDL-C) deficiency in noncritically ill patients with previously normal HDL-C and triglyceride levels. Autoimmune lymphoproliferative syndrome (ALPS) is a disorder of the immune system due to an inability to regulate lymphocyte homeostasis resulting in lymphadenopathy and hepatosplenomegaly. We describe a 17-year-old boy who was evaluated in the lipid clinic for history of undetectable or low HDL-C and low density lipoprotein cholesterol (LDL-C) levels. Past medical history was significant for ALPS IA diagnosed at 10 years of age when he presented with bilateral cervical adenopathy. He was known to have a missense mutation in one allele of the FAS protein extracellular domain consistent with ALPS type 1A. HDL-C and LDL-C levels had been undetectable on multiple occasions, though lipids had not been measured prior to the diagnosis of ALPS. He had been receiving sirolimus for immunosuppression. The HDL-C and LDL-C levels correlated with disease activity and improved to normal levels during times when the activity of ALPS was controlled. This case highlights the importance of considering ALPS as a cause of low HDL-C and LDL-C levels in a child with evidence of lymphoproliferation. PMID:27579193

  7. Autoimmune Lymphoproliferative Syndrome: A Rare Cause of Disappearing HDL Syndrome

    PubMed Central

    Sriram, Swetha; Joshi, Avni Y.; Rodriguez, Vilmarie

    2016-01-01

    The term disappearing HDL syndrome refers to development of severe high density lipoprotein cholesterol (HDL-C) deficiency in noncritically ill patients with previously normal HDL-C and triglyceride levels. Autoimmune lymphoproliferative syndrome (ALPS) is a disorder of the immune system due to an inability to regulate lymphocyte homeostasis resulting in lymphadenopathy and hepatosplenomegaly. We describe a 17-year-old boy who was evaluated in the lipid clinic for history of undetectable or low HDL-C and low density lipoprotein cholesterol (LDL-C) levels. Past medical history was significant for ALPS IA diagnosed at 10 years of age when he presented with bilateral cervical adenopathy. He was known to have a missense mutation in one allele of the FAS protein extracellular domain consistent with ALPS type 1A. HDL-C and LDL-C levels had been undetectable on multiple occasions, though lipids had not been measured prior to the diagnosis of ALPS. He had been receiving sirolimus for immunosuppression. The HDL-C and LDL-C levels correlated with disease activity and improved to normal levels during times when the activity of ALPS was controlled. This case highlights the importance of considering ALPS as a cause of low HDL-C and LDL-C levels in a child with evidence of lymphoproliferation. PMID:27579193

  8. High-Density Lipoproteins (HDL) – Nature’s Multi-Functional Nanoparticles

    PubMed Central

    Kuai, Rui; Li, Dan; Chen, Y. Eugene; Moon, James J.; Schwendeman, Anna

    2016-01-01

    High-density lipoproteins (HDL) are endogenous nanoparticles involved in the transport and metabolism of cholesterol, phospholipids, and triglycerides. HDL is well known as the ―good‖ cholesterol because it not only removes excess cholesterol from atherosclerotic plaques but also has anti-inflammatory and anti-oxidative properties, which protect the cardiovascular system. Circulating HDL also transports endogenous proteins, vitamins, hormones, and microRNA to various organs. Compared with other synthetic nanocarriers, such as liposomes, micelles, inorganic and polymeric nanoparticles, HDL has unique features that allow them to deliver cargo to specific targets more efficiently. These attributes include their ultra-small size (8-12 nm in diameter), high tolerability in humans (up to 8 g of protein per infusion), long circulating half-life (12-24 hours), and intrinsic targeting properties to different recipient cells. Various recombinant ApoA proteins and ApoA mimetic peptides have been recently developed for the preparation of reconstituted HDL that exhibits properties similar to endogenous HDL and has a potential for industrial scale-up. In this review, we will summarize: a) clinical pharmacokinetics and safety of reconstituted HDL products, b) comparison of HDL with inorganic and other organic nanoparticles, c) the rationale for using HDL as drug delivery vehicles for important therapeutic indications, d) the current state-of-the-art in HDL production, and e) HDL-based drug delivery strategies for small molecules, peptides/proteins, nucleic acids, and imaging agents targeted to various organs. PMID:26889958

  9. HDL-apoA-I Exchange: Rapid Detection and Association with Atherosclerosis

    PubMed Central

    Borja, Mark S.; Zhao, Lei; Hammerson, Bradley; Tang, Chongren; Yang, Richard; Carson, Nancy; Fernando, Gayani; Liu, Xiaoqin; Budamagunta, Madhu S.; Genest, Jacques; Shearer, Gregory C.; Duclos, Franck; Oda, Michael N.

    2013-01-01

    High density lipoprotein (HDL) cholesterol levels are associated with decreased risk of cardiovascular disease, but not all HDL are functionally equivalent. A primary determinant of HDL functional status is the conformational adaptability of its main protein component, apoA-I, an exchangeable apolipoprotein. Chemical modification of apoA-I, as may occur under conditions of inflammation or diabetes, can severely impair HDL function and is associated with the presence of cardiovascular disease. Chemical modification of apoA-I also impairs its ability to exchange on and off HDL, a critical process in reverse cholesterol transport. In this study, we developed a method using electron paramagnetic resonance spectroscopy (EPR) to quantify HDL-apoA-I exchange. Using this approach, we measured the degree of HDL-apoA-I exchange for HDL isolated from rabbits fed a high fat, high cholesterol diet, as well as human subjects with acute coronary syndrome and metabolic syndrome. We observed that HDL-apoA-I exchange was markedly reduced when atherosclerosis was present, or when the subject carries at least one risk factor of cardiovascular disease. These results show that HDL-apoA-I exchange is a clinically relevant measure of HDL function pertinent to cardiovascular disease. PMID:24015188

  10. Focus on lipids: high-density lipoprotein cholesterol and its associated lipoproteins in cardiac and renal disease.

    PubMed

    Shin, Hyun Joon; McCullough, Peter A

    2014-01-01

    High-density lipoprotein cholesterol (HDL-C) contains dozens of apoproteins that participate in normal cholesterol metabolism with a reliance on renal catabolism for clearance from the body. The plasma pool of HDL-C has been an excellent inverse predictor of cardiovascular events. However, when HDL-C concentrations have been manipulated with the use of niacin, fibric acid derivatives, and cholesteryl ester transferase protein inhibitors, there has been no improvement in outcomes in patients where the low-density lipoprotein cholesterol has been well treated with statins. Apolipoprotein L1 (APOL1) is one of the minor apoproteins of HDL-C, newly discovered in 1997. Circulating APOL1 is a 43-kDa protein mainly found in the HDL3 subfraction. In patients with chronic kidney disease (CKD), mutant forms of APOL1 have been associated with rapidly progressive CKD and end-stage renal disease (ESRD). Because mutant forms of APOL1 are more prevalent in African Americans compared to Caucasians, it may explain some of the racial disparities seen in the pool of patients with ESRD in the United States. Thus, HDL-C is an important lipoprotein carrying apoproteins that play roles in vascular and kidney disease. PMID:25343842

  11. Lowering plasma cholesterol levels halts progression of aortic valve disease in mice

    PubMed Central

    Miller, Jordan D.; Weiss, Robert M.; Serrano, Kristine M.; Brooks, Robert M.; Berry, Christopher J.; Zimmerman, Kathy; Young, Stephen G.; Heistad, Donald D.

    2009-01-01

    Background Treatment of hyperlipidemia produces functional and structural improvements in atherosclerotic vessels. However, the effects of treating hyperlipidemia on the structure and function of the aortic valve has been controversial, and any effects could be confounded by pleiotropic effects of hypolipidemic treatment. The goal of this study was to determine whether reducing elevated plasma lipid levels with a “genetic switch” in Reversa mice (Ldlr−/−/Apob100/100/Mttpfl/fl/Mx1Cre+/+) reduces oxidative stress, reduces proosteogenic signaling, and retards the progression of aortic valve disease. Methods and Results After 6 months of hypercholesterolemia, Reversa mice exhibited increases in superoxide, lipid deposition, myofibroblast activation, calcium deposition, and pro-osteogenic protein expression in the aortic valve. Maximum aortic valve cusp separation, as judged by echocardiography, was not altered. During an additional 6 months of hypercholesterolemia, superoxide levels, valvular lipid deposition, and myofibroblast activation remained elevated. Furthermore, calcium deposition and pro-osteogenic gene expression became more pronounced and the aortic cusp separation decreased from 0.85 ± 0.04 to 0.70 ± 0.04 mm (mean ± SE; p < 0.05). Rapid normalization of cholesterol levels at 6 months of age (by inducing expression of Cre recombinase) normalized aortic valve superoxide levels, decreased myofibroblast activation, reduced valvular calcium burden, suppressed pro-osteogenic signaling cascades, and prevented the reductions in aortic valve cusp separation. Conclusions Collectively, these data indicate that reducing plasma lipid levels by genetic inactivation of the mttp gene in hypercholesterolemic mice with early aortic valve disease normalizes oxidative stress, reduces pro-osteogenic signaling, and halts the progression of aortic valve stenosis. PMID:19433756

  12. SEC24A deficiency lowers plasma cholesterol through reduced PCSK9 secretion

    PubMed Central

    Chen, Xiao-Wei; Wang, He; Bajaj, Kanika; Zhang, Pengcheng; Meng, Zhuo-Xian; Ma, Danjun; Bai, Yongsheng; Liu, Hui-Hui; Adams, Elizabeth; Baines, Andrea; Yu, Genggeng; Sartor, Maureen A; Zhang, Bin; Yi, Zhengping; Lin, Jiandie; Young, Stephen G; Schekman, Randy; Ginsburg, David

    2013-01-01

    The secretory pathway of eukaryotic cells packages cargo proteins into COPII-coated vesicles for transport from the endoplasmic reticulum (ER) to the Golgi. We now report that complete genetic deficiency for the COPII component SEC24A is compatible with normal survival and development in the mouse, despite the fundamental role of SEC24 in COPII vesicle formation and cargo recruitment. However, these animals exhibit markedly reduced plasma cholesterol, with mutations in Apoe and Ldlr epistatic to Sec24a, suggesting a receptor-mediated lipoprotein clearance mechanism. Consistent with these data, hepatic LDLR levels are up-regulated in SEC24A-deficient cells as a consequence of specific dependence of PCSK9, a negative regulator of LDLR, on SEC24A for efficient exit from the ER. Our findings also identify partial overlap in cargo selectivity between SEC24A and SEC24B, suggesting a previously unappreciated heterogeneity in the recruitment of secretory proteins to the COPII vesicles that extends to soluble as well as trans-membrane cargoes. DOI: http://dx.doi.org/10.7554/eLife.00444.001 PMID:23580231

  13. Citrulline increases cholesterol efflux from macrophages in vitro and ex vivo via ATP-binding cassette transporters

    PubMed Central

    Uto-Kondo, Harumi; Ayaori, Makoto; Nakaya, Kazuhiro; Takiguchi, Shunichi; Yakushiji, Emi; Ogura, Masatsune; Terao, Yoshio; Ozasa, Hideki; Sasaki, Makoto; Komatsu, Tomohiro; Sotherden, Grace Megumi; Hosoai, Tamaki; Sakurada, Masami; Ikewaki, Katsunori

    2014-01-01

    Reverse cholesterol transport (RCT) is a mechanism critical to the anti-atherogenic property of HDL. Although citrulline contributes to the amelioration of atherosclerosis via endothelial nitric oxide production, it remains unclear whether it affects RCT. This study was undertaken to clarify the effects of citrulline on expressions of specific transporters such as ATP binding cassette transporters (ABC)A1 and ABCG1, and the cholesterol efflux from macrophages to apolipoprotein (apo) A-I or HDL in vitro and ex vivo. Citrulline increased ABCA1 and ABCG1 mRNA and protein levels in THP-1 macrophages, translating into enhanced apoA-I- and HDL-mediated cholesterol efflux. In the human crossover study, 8 healthy male volunteers (age 30–49 years) consumed either 3.2 g/day citrulline or placebo for 1 week. Citrulline consumption brought about significant increases in plasma levels of citrulline and arginine. Supporting the in vitro data, monocyte-derived macrophages (MDM) differentiated under autologous post-citrulline sera demonstrated enhancement of both apoA-I- and HDL-mediated cholesterol efflux through increased ABCA1 and ABCG1 expressions, compared to MDM differentiated under pre-citrulline sera. However, the placebo did not modulate these parameters. Therefore, in addition to improving endothelium function, citrulline might have an anti-atherogenic property by increasing RCT of HDL. PMID:25120277

  14. Lipoprotein Concentration, Particle Number, Size and Cholesterol Efflux Capacity are associated with Mitochondrial Oxidative Stress and Function in an HIV Positive Cohort

    PubMed Central

    Parikh, Nisha I; Gerschenson, Mariana; Bennett, Kara; Gangcuangco, Louie Mar M.; Lopez, Mary S.; Mehta, Nehal N.; Playford, Martin P.; Nakamoto, Beau K.; Seto, Todd B.; Chow, Dominic C.; Shikuma, Cecilia M.

    2015-01-01

    Background Association of lipoprotein particle size/number and HDL function with mitochondrial oxidative stress and function may underlie the excess cardiovascular (CVD) risk in HIV. Methods and Results Among HIV infected individuals on stable highly active antiretroviral therapy, we related standard and novel lipid measures [plasma total cholesterol, triglycerides, HDL-C, LDL-C, lipoprotein particle (-P) subclass size and number and HDL function (via cholesterol-efflux capacity)] with oxidative stress [peripheral blood mononuclear cell’s mitochondrial-specific 8-oxo-deoxyguanine (8-oxo-dG)] and function markers [oxidative phosphorylation (OXPHOS) NADH dehydrogenase (Complex I) and cytochrome c oxidase (Complex IV) enzyme activities]. Multivariable-adjusted logistic and linear regression analyses were employed adjusting for age, gender, CD4 nadir, viral load, smoking, diabetes, HOMA-IR, hypertension and lipid medications. Among 150 HIV-infected persons (mean age 52 years, 12% women, median CD4 count 524 cell/mm3), low HDL-C and high total cholesterol/HDL-C ratio were related to PBMC 8-oxo-deoxyguanine (p=0.01 and 0.02 respectively). Large HDL-P and HDL-P size were inversely related to PBMC 8-oxo-deoxyguanine (p=0.04). Small LDL-P (p=0.01) and total LDL-P (p=0.01) were related to decreased OXPHOS Complex I activity. LDL-P was related to decreased OXPHOS Complex IV activity (p=0.02). Cholesterol efflux capacity was associated with increased OXPHOS Complex IV activity. Conclusions HDL concentration and particle size and number are related to decreased PBMC mitochondrial oxidative stress whereas HDL function is positively related to mitochondrial oxidative function. The association we find between atherogenic lipoprotein profile and increased oxidative stress and function suggests these pathways may be important in the pathogenesis of cardiometabolic disease in HIV disease. PMID:25574857

  15. Distinct composition of human fetal HDL attenuates its anti-oxidative capacity.

    PubMed

    Sreckovic, Ivana; Birner-Gruenberger, Ruth; Obrist, Britta; Stojakovic, Tatjana; Scharnagl, Hubert; Holzer, Michael; Scholler, Monika; Philipose, Sonia; Marsche, Gunther; Lang, Uwe; Desoye, Gernot; Wadsack, Christian

    2013-04-01

    In human high-density lipoprotein (HDL) represents the major cholesterol carrying lipoprotein class in cord blood, while cholesterol is mainly carried by low-density lipoprotein in maternal serum. Additionally, to carrying cholesterol, HDL also associates with a range of proteins as cargo. We tested the hypothesis that fetal HDL carries proteins qualitatively and quantitatively different from maternal HDL. These differences then contribute to distinct HDL functionality in both circulations. Shotgun proteomics and biochemical analyses were used to assess composition/function of fetal and maternal HDL isolated from uncomplicated human pregnancies at term of gestation. The pattern of analyzed proteins that were statistically elevated in fetal HDL (apoE, proteins involved in coagulation, transport processes) suggests a particle characteristic for the light HDL2 sub-fraction. In contrast, proteins that were enriched in maternal HDL (apoL, apoF, PON1, apoD, apoCs) have been described almost exclusively in the dense HDL3 fraction and relevant to its anti-oxidative function and role in innate immunity. Strikingly, PON1 mass and activity were 5-fold lower (p<0.01) in the fetus, which was accompanied by attenuation of anti-oxidant capacity of fetal HDL. Despite almost equal quantity of CETP in maternal and fetal HDL, its enzymatic activity was 55% lower (p<0.001) in the fetal circulation, whereas LCAT activity was not altered. These findings indicate that maternally derived HDL differs from fetal HDL with respect to its proteome, size and function. Absence of apoA-1, apoL and PON1 on fetal HDL is associated with decreased anti-oxidative properties together with deficiency in innate immunity collectively indicating distinct HDLs in fetuses. PMID:23321267

  16. LCAT synthesized by primary astrocytes esterifies cholesterol on glia-derived lipoproteins

    PubMed Central

    Hirsch-Reinshagen, Veronica; Donkin, James; Stukas, Sophie; Chan, Jennifer; Wilkinson, Anna; Fan, Jianjia; Parks, John S.; Kuivenhoven, Jan Albert; Lütjohann, Dieter; Pritchard, Haydn; Wellington, Cheryl L.

    2009-01-01

    Lipid trafficking in the brain is essential for the maintenance and repair of neuronal membranes, especially after neurotoxic insults. However, brain lipid metabolism is not completely understood. In plasma, LCAT catalyses the esterification of free cholesterol on circulating lipoproteins, a key step in the maturation of HDL. Brain lipoproteins are apolipoprotein E (apoE)-containing, HDL-like particles secreted initially as lipid-poor discs by glial cells. LCAT is synthesized within the brain, suggesting that it may play a key role in the maturation of these lipoproteins. Here we demonstrate that astrocytes are the primary producers of brain LCAT. This LCAT esterifies free cholesterol on nascent apoE-containing lipopoproteins secreted from glia. ApoE is the major LCAT activator in glia-conditioned media (GCM), and both the cholesterol transporter ABCA1 and apoE are required to generate glial LCAT substrate particles. LCAT deficiency leads to the appearance of abnormal ∼8 nm particles in GCM, and exogenous LCAT restores the lipoprotein particle distribution to the wild-type (WT) pattern. In vivo, complete LCAT deficiency results in a dramatic increase in apoE-HDL and reduced apolipoprotein A-I (apoA-I)-HDL in murine cerebrospinal fluid (CSF). These data show that brain LCAT esterifies cholesterol on glial-derived apoE-lipoproteins, and influences CSF apoE and apoA-I levels. PMID:19065001

  17. HDL-mimetic PLGA nanoparticle to target atherosclerosis plaque macrophages.

    PubMed

    Sanchez-Gaytan, Brenda L; Fay, Francois; Lobatto, Mark E; Tang, Jun; Ouimet, Mireille; Kim, YongTae; van der Staay, Susanne E M; van Rijs, Sarian M; Priem, Bram; Zhang, Liangfang; Fisher, Edward A; Moore, Kathryn J; Langer, Robert; Fayad, Zahi A; Mulder, Willem J M

    2015-03-18

    High-density lipoprotein (HDL) is a natural nanoparticle that exhibits an intrinsic affinity for atherosclerotic plaque macrophages. Its natural targeting capability as well as the option to incorporate lipophilic payloads, e.g., imaging or therapeutic components, in both the hydrophobic core and the phospholipid corona make the HDL platform an attractive nanocarrier. To realize controlled release properties, we developed a hybrid polymer/HDL nanoparticle composed of a lipid/apolipoprotein coating that encapsulates a poly(lactic-co-glycolic acid) (PLGA) core. This novel HDL-like nanoparticle (PLGA-HDL) displayed natural HDL characteristics, including preferential uptake by macrophages and a good cholesterol efflux capacity, combined with a typical PLGA nanoparticle slow release profile. In vivo studies carried out with an ApoE knockout mouse model of atherosclerosis showed clear accumulation of PLGA-HDL nanoparticles in atherosclerotic plaques, which colocalized with plaque macrophages. This biomimetic platform integrates the targeting capacity of HDL biomimetic nanoparticles with the characteristic versatility of PLGA-based nanocarriers.

  18. Cooperation between hepatic cholesteryl ester hydrolase and scavenger receptor BI for hydrolysis of HDL-CE.

    PubMed

    Yuan, Quan; Bie, Jinghua; Wang, Jing; Ghosh, Siddhartha S; Ghosh, Shobha

    2013-11-01

    Liver is the sole organ responsible for the final elimination of cholesterol from the body either as biliary cholesterol or bile acids. High density lipoprotein (HDL)-derived cholesterol is the major source of biliary sterols and represents a mechanism for the removal of cholesterol from peripheral tissues including artery wall-associated macrophage foam cells. Via selective uptake through scavenger receptor BI (SR-BI), HDL-cholesterol is thought to be directly secreted into bile, and HDL cholesteryl esters (HDL-CEs) enter the hepatic metabolic pool and need to be hydrolyzed prior to conversion to bile acids. However, the identity of hepatic CE hydrolase (CEH) as well as the role of SR-BI in bile acid synthesis remains elusive. In this study we examined the role of human hepatic CEH (CES1) in facilitating hydrolysis of SR-BI-delivered HDL-CEs. Over-expression of CEH led to increased hydrolysis of HDL-[³H]CE in primary hepatocytes and SR-BI expression was required for this process. Intracellular CEH associated with BODIPY-CE delivered by selective uptake via SR-BI. CEH and SR-BI expression enhanced the movement of [³H]label from HDL-[³H]CE to bile acids in vitro and in vivo. Taken together, these studies demonstrate that SR-BI-delivered HDL-CEs are hydrolyzed by hepatic CEH and utilized for bile acid synthesis. PMID:23990661

  19. Cholesterol transport from plasma membranes to intracellular membranes is inhibited by 3 beta-[2-(diethylamino)ethoxy]androst-5-en-17-one.

    PubMed

    Härmälä, A S; Pörn, M I; Mattjus, P; Slotte, J P

    1994-03-24

    The compound U1866A (3 beta-[2-(diethylamino)ethoxy]androst-5-en-17-one) has been shown to inhibit the cellular transfer of low-density lipoprotein-derived cholesterol from lysosomes to plasma membranes (Liscum and Faust (1989) J. Biol. Chem. 264, 11796-806). We have in this study examined the effects of U18666A on cholesterol translocation from plasma membranes to intracellular membranes. Translocation of plasma membrane cholesterol was induced by degradation of plasma membrane sphingomyelin. The sphingomyelinase-induced activation of the acyl-CoA cholesterol acyl transferase (ACAT) reaction was completely inhibited in a dose-dependent manner by U18666A, both in cultured human skin fibroblasts and baby hamster kidney cells. Half-maximal inhibition (within 60 min) was obtained with 0.5-1 microgram/ml of U18666A. A time-course study indicated that the onset of inhibition was rapid (within 10-15 min), and reversible if U18666A was removed from the incubation mixture. Using a cholesterol oxidase assay, we observed that the extent of plasma membrane cholesterol translocation in sphingomyelinase-treated HSF cells was significantly lowered in the presence of U18666A (at 3 micrograms/ml). The effect of U18666A on cholesterol translocation was also fully reversible when the drug was withdrawn. In mouse Leydig tumor cells, labeled to constant specific activity with [3H]cholesterol, the compound U18666A inhibited in a dose-dependent manner the cyclic AMP-stimulated secretion of [3H]steroid hormones. The effects seen with compound U18666A appeared to be specific for this molecule, since another hydrophobic amine, imipramine, did not in our experiments affect cholesterol translocation or ACAT activation. Since different cell types display sensitivity to U18666A in various intracellular cholesterol transfer processes, they appear to have a common U18666A-sensitive regulatory mechanism.

  20. Cholesterol transport from plasma membranes to intracellular membranes is inhibited by 3 beta-[2-(diethylamino)ethoxy]androst-5-en-17-one.

    PubMed

    Härmälä, A S; Pörn, M I; Mattjus, P; Slotte, J P

    1994-03-24

    The compound U1866A (3 beta-[2-(diethylamino)ethoxy]androst-5-en-17-one) has been shown to inhibit the cellular transfer of low-density lipoprotein-derived cholesterol from lysosomes to plasma membranes (Liscum and Faust (1989) J. Biol. Chem. 264, 11796-806). We have in this study examined the effects of U18666A on cholesterol translocation from plasma membranes to intracellular membranes. Translocation of plasma membrane cholesterol was induced by degradation of plasma membrane sphingomyelin. The sphingomyelinase-induced activation of the acyl-CoA cholesterol acyl transferase (ACAT) reaction was completely inhibited in a dose-dependent manner by U18666A, both in cultured human skin fibroblasts and baby hamster kidney cells. Half-maximal inhibition (within 60 min) was obtained with 0.5-1 microgram/ml of U18666A. A time-course study indicated that the onset of inhibition was rapid (within 10-15 min), and reversible if U18666A was removed from the incubation mixture. Using a cholesterol oxidase assay, we observed that the extent of plasma membrane cholesterol translocation in sphingomyelinase-treated HSF cells was significantly lowered in the presence of U18666A (at 3 micrograms/ml). The effect of U18666A on cholesterol translocation was also fully reversible when the drug was withdrawn. In mouse Leydig tumor cells, labeled to constant specific activity with [3H]cholesterol, the compound U18666A inhibited in a dose-dependent manner the cyclic AMP-stimulated secretion of [3H]steroid hormones. The effects seen with compound U18666A appeared to be specific for this molecule, since another hydrophobic amine, imipramine, did not in our experiments affect cholesterol translocation or ACAT activation. Since different cell types display sensitivity to U18666A in various intracellular cholesterol transfer processes, they appear to have a common U18666A-sensitive regulatory mechanism. PMID:8130265

  1. HDL/ApoA-1 infusion and ApoA-1 gene therapy in atherosclerosis

    PubMed Central

    Chyu, Kuang-Yuh; Shah, Prediman K.

    2015-01-01

    The HDL hypothesis stating that simply raising HDL cholesterol (HDL-C) may produce cardiovascular benefits has been questioned recently based on several randomized clinical trials using CETP inhibitors or niacin to raise HDL-C levels. However, extensive pre-clinical data support the vascular protective effects of administration of exogenous ApoA-1 containing preβ-HDL like particles. Several small proof-of-concept clinical trials using such HDL/ApoA-1 infusion therapy have shown encouraging results but definitive proof of efficacy must await large scale clinical trials. In addition to HDL infusion therapy an alternative way to exploit beneficial cardiovascular effects of HDL/ApoA-1 is to use gene transfer. Preclinical studies have shown evidence of benefit using this approach; however clinical validation is yet lacking. This review summarizes our current knowledge of the aforementioned strategies. PMID:26388776

  2. HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; Johns, Douglas G.; Charles, M. Arthur; Ren, Gang

    2015-03-01

    Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobic environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.

  3. HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

    SciTech Connect

    Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; Johns, Douglas G.; Charles, M. Arthur; Ren, Gang

    2015-03-04

    Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobic environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.

  4. HDL surface lipids mediate CETP binding as revealed by electron microscopy and molecular dynamics simulation

    DOE PAGESBeta

    Zhang, Meng; Charles, River; Tong, Huimin; Zhang, Lei; Patel, Mili; Wang, Francis; Rames, Matthew J.; Ren, Amy; Rye, Kerry-Anne; Qiu, Xiayang; et al

    2015-03-04

    Cholesteryl ester transfer protein (CETP) mediates the transfer of cholesterol esters (CE) from atheroprotective high-density lipoproteins (HDL) to atherogenic low-density lipoproteins (LDL). CETP inhibition has been regarded as a promising strategy for increasing HDL levels and subsequently reducing the risk of cardiovascular diseases (CVD). Although the crystal structure of CETP is known, little is known regarding how CETP binds to HDL. Here, we investigated how various HDL-like particles interact with CETP by electron microscopy and molecular dynamics simulations. Results showed that CETP binds to HDL via hydrophobic interactions rather than protein-protein interactions. The HDL surface lipid curvature generates a hydrophobicmore » environment, leading to CETP hydrophobic distal end interaction. This interaction is independent of other HDL components, such as apolipoproteins, cholesteryl esters and triglycerides. Thus, disrupting these hydrophobic interactions could be a new therapeutic strategy for attenuating the interaction of CETP with HDL.« less

  5. The Effect of Residing Altitude on Levels of High-Density Lipoprotein Cholesterol: A Pilot Study From the Omani Arab Population.

    PubMed

    Al Riyami, Nafila B; Banerjee, Yajnavalka; Al-Waili, Khalid; Rizvi, Syed G; Al-Yahyaee, Said; Hassan, Mohammed O; Albarwani, Sulayma; Al-Rasadi, Khalid; Bayoumi, Riad A

    2015-07-01

    Lower mortality rates from coronary heart disease and higher levels of serum high-density lipoprotein cholesterol (HDL-C) have been observed in populations residing at high altitude. However, this effect has not been investigated in Arab populations, which exhibit considerable genetic homogeneity. We assessed the relationship between residing altitude and HDL-C in 2 genetically similar Omani Arab populations residing at different altitudes. The association between the levels of HDL-C and other metabolic parameters was also investigated. The levels of HDL-C were significantly higher in the high-altitude group compared with the low-altitude group. Stepwise regression analysis showed that altitude was the most significant factor affecting HDL-C, followed by gender, serum triglycerides, and finally the 2-hour postprandial plasma glucose. This finding is consistent with previously published studies from other populations and should be taken into consideration when comparing cardiovascular risk factors in populations residing at different altitudes.

  6. Acrolein impairs the cholesterol transport functions of high density lipoproteins.

    PubMed

    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.

  7. Lycopene from two food sources does not affect antioxidant or cholesterol status of middle-aged adults

    PubMed Central

    Collins, JK; Arjmandi, BH; Claypool, PL; Perkins-Veazie, P; Baker, RA; Clevidence, BA

    2004-01-01

    Background Epidemiological studies have reported associations between reduced cardiovascular disease and diets rich in tomato and/or lycopene. Intervention studies have shown that lycopene-containing foods may reduce cholesterol levels and lipid peroxidation, factors implicated in the initiation of cardiovascular disease. The objective of this study was to determine whether consumption of lycopene rich foods conferred cardiovascular protection to middle-aged adults as indicated by plasma lipid concentrations and measures of ex vivo antioxidants. Methods Ten healthy men and women consumed a low lycopene diet with no added lycopene (control treatment) or supplemented with watermelon or tomato juice each containing 20 mg lycopene. Subjects consumed each treatment for three weeks in a crossover design. Plasma, collected weekly was analyzed for total cholesterol, high density lipoprotein cholesterol (HDL-C) and triglyceride concentrations and for the antioxidant biomarkers of malondialdehyde formation products (MDA), plasma glutathione peroxidase (GPX) and ferric reducing ability of plasma (FRAP). Data were analyzed using Proc Mixed Procedure and associations between antioxidant and lipid measures were identified by Pearson's product moment correlation analysis. Results Compared to the control diet, the lycopene-containing foods did not affect plasma lipid concentrations or antioxidant biomarkers. Women had higher total cholesterol, HDL-C and triglyceride concentrations than did the men. Total cholesterol was positively correlated to MDA and FRAP while HDL-C was positively correlated to MDA and GPX. GPX was negatively correlated to triglyceride concentration. Conclusions The inclusion of watermelon or tomato juice containing 20 mg lycopene did not affect plasma lipid concentrations or antioxidant status of healthy subjects. However, plasma cholesterol levels impacted the results of MDA and FRAP antioxidant tests. PMID:15369594

  8. The Role of Brain Cholesterol and its Oxidized Products in Alzheimer's Disease.

    PubMed

    Giudetti, Anna Maria; Romano, Adele; Lavecchia, Angelo Michele; Gaetani, Silvana

    2016-01-01

    The human brain is the most cholesterol-rich organ harboring 25% of the total cholesterol pool of the whole body. Cholesterol present in the central nervous system (CNS) comes, almost entirely, from the endogenous synthesis, being circulating cholesterol unable to cross the blood-brain barrier (BBB). Astrocytes seem to be more active than neurons in this process. Neurons mostly depend on cholesterol delivery from nearby cells for axonal regeneration, neurite extension and synaptogenesis. Within the brain, cholesterol is transported by HDL-like lipoproteins associated to apoE which represents the main apolipoprotein in the CNS. Although CNS cholesterol content is largely independent of dietary intake or hepatic synthesis, a relationship between plasma cholesterol level and neurodegenerative disorders, such as Alzheimer's disease (AD), has often been reported. To this regard, alterations of cholesterol metabolism were suggested to be implicated in the etiology of AD and amyloid production in the brain. Therefore a special attention was dedicated to the study of the main factors controlling cholesterol metabolism in the brain. Brain cholesterol levels are tightly controlled: its excessive amount can be reduced through the conversion into the oxidized form of 24-S-hydroxycholesetrol (24-OH-C), which can reach the blood stream. In fact, the BBB is permeable to 24-OH-C as well as to 27-OH-C, another oxidized form of cholesterol mainly synthesized by non- neural cells. In this review, we summarize the main mechanisms regulating cholesterol homeostasis and review the recent advances on the role played by cholesterol and cholesterol oxidized products in AD. Moreover, we delineate possible pharmacological strategies to control AD progression by affecting cholesterol homeostasis.

  9. Premature and severe cardiovascular disease in a Mexican male with markedly low high-density-lipoprotein-cholesterol levels and a mutation in the lecithin:cholesterol acyltransferase gene: a family study.

    PubMed

    Posadas-Sánchez, Rosalinda; Posadas-Romero, Carlos; Ocampo-Arcos, Wendy Angélica; Villarreal-Molina, María Teresa; Vargas-Alarcón, Gilberto; Antúnez-Argüelles, Erika; Mendoza-Pérez, Enrique; Cardoso-Saldaña, Guillermo; Martínez-Alvarado, Rocío; Medina-Urrutia, Aída; Jorge-Galarza, Esteban

    2014-06-01

    Epidemiological and clinical studies have shown that a low plasma high‑density lipoprotein cholesterol (HDL-C) level is a strong predictor of cardiovascular disease (CVD). Lecithin:cholesterol acyltransferase (LCAT) is a key enzyme in the formation, maturation and function of HDL. Therefore impaired LCAT function may enhance atherosclerosis because of defective cholesterol transport. In this study, we examined a 34-year old LCAT‑deficient patient and eight first-degree family members. There was a strong family history for CVD and type 2 diabetes mellitus (DM2). The proband was found homozygous for a previously reported LCAT gene mutation (Thr37Met). A sister and two sons of the proband were heterozygous for the same mutation. The proband had DM2 and showed severe multivessel coronary artery disease, corneal opacification and extremely low HDL-C levels. Large HDL particles were absent while small HDL particles were increased. The HDL of the patient had a reduced ability to promote cell cholesterol efflux, and the low‑density lipoproteins (LDL) were more susceptible to oxidation. Among his family members, two heterozygotes and one non-carrier had early carotid or coronary atherosclerosis. In conclusion, as the increased LDL oxidability and structural and functional abnormalities of HDL particles have been reported in patients with obesity and diabetes, the results suggested that the adverse coronary risk profile, and not being LCAT deficient, may be responsible for the CVD found in our proband, and for the early atherosclerosis observed in the two heterozygotes and in the wild‑type family members. PMID:24715031

  10. Recombinant human LCAT normalizes plasma lipoprotein profile in LCAT deficiency.

    PubMed

    Simonelli, Sara; Tinti, Cristina; Salvini, Laura; Tinti, Laura; Ossoli, Alice; Vitali, Cecilia; Sousa, Vitor; Orsini, Gaetano; Nolli, Maria Luisa; Franceschini, Guido; Calabresi, Laura

    2013-11-01

    Lecithin:cholesterol acyltransferase (LCAT) is the enzyme responsible for cholesterol esterification in plasma. Mutations in the LCAT gene leads to two rare disorders, familial LCAT deficiency and fish-eye disease, both characterized by severe hypoalphalipoproteinemia associated with several lipoprotein abnormalities. No specific treatment is presently available for genetic LCAT deficiency. In the present study, recombinant human LCAT was expressed and tested for its ability to correct the lipoprotein profile in LCAT deficient plasma. The results show that rhLCAT efficiently reduces the amount of unesterified cholesterol (-30%) and promotes the production of plasma cholesteryl esters (+210%) in LCAT deficient plasma. rhLCAT induces a marked increase in HDL-C levels (+89%) and induces the maturation of small preβ-HDL into alpha-migrating particles. Moreover, the abnormal phospholipid-rich particles migrating in the LDL region were converted in normally sized LDL.

  11. Recombinant human LCAT normalizes plasma lipoprotein profile in LCAT deficiency.

    PubMed

    Simonelli, Sara; Tinti, Cristina; Salvini, Laura; Tinti, Laura; Ossoli, Alice; Vitali, Cecilia; Sousa, Vitor; Orsini, Gaetano; Nolli, Maria Luisa; Franceschini, Guido; Calabresi, Laura

    2013-11-01

    Lecithin:cholesterol acyltransferase (LCAT) is the enzyme responsible for cholesterol esterification in plasma. Mutations in the LCAT gene leads to two rare disorders, familial LCAT deficiency and fish-eye disease, both characterized by severe hypoalphalipoproteinemia associated with several lipoprotein abnormalities. No specific treatment is presently available for genetic LCAT deficiency. In the present study, recombinant human LCAT was expressed and tested for its ability to correct the lipoprotein profile in LCAT deficient plasma. The results show that rhLCAT efficiently reduces the amount of unesterified cholesterol (-30%) and promotes the production of plasma cholesteryl esters (+210%) in LCAT deficient plasma. rhLCAT induces a marked increase in HDL-C levels (+89%) and induces the maturation of small preβ-HDL into alpha-migrating particles. Moreover, the abnormal phospholipid-rich particles migrating in the LDL region were converted in normally sized LDL. PMID:24140107

  12. Association of polymorphisms in genes involved in lipoprotein metabolism with plasma concentrations of remnant lipoproteins and HDL subpopulations before and after hormone therapy in postmenopausal women

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  13. Free cholesterol is a potent regulator of lipid transfer protein function

    SciTech Connect

    Morton, R.E.

    1988-09-05

    This study investigates the effect of altered lipoprotein free cholesterol (FC) content on the transfer of cholesteryl ester (CE) and triglyceride (TG) from very low- (VLDL), low- (LDL), and high-(HDL) density lipoproteins by the plasma-derived lipid transfer protein (LTP). The FC content of VLDL and HDL was selectively altered by incubating these lipoproteins with FC/phospholipid dispersions of varying composition. FC-modified lipoproteins were then equilibrated with (3H) TG, (14C)CE-labeled lipoproteins of another class to facilitate the subsequent modification of the radiolabeled donor lipoproteins. LTP was added and the extent of radiolabeled TG and CE transfer determined after 1 h. With either LDL or VLDL as lipid donor, an increase in the FC content of these lipoproteins caused a concentration-dependent inhibition (up to 50%) of CE transfer from these particles, without any significant effect on TG transfer. In contrast, with HDL as donor, increasing the HDL FC content had little effect on CE transfer from HDL, but markedly stimulated (up to 2.5-fold) the transfer of TG. This differential effect of FC on the unidirectional transfer of radiolabeled lipids from VLDL and HDL led to marked effects on LTP-facilitated net mass transfer of lipids. During long-term incubation of a constant amount of LTP with FC-modified VLDL and HDL, the extent of net mass transfer was linearly related to lipoprotein FC content; a 4-fold increase in FC content resulted in a 3-fold stimulation of the CE mass transferred to VLDL, which was coupled to an equimolar, reciprocal transfer of TG mass to HDL. Since lipid transfer between lipoproteins is integral to the process of reverse cholesterol transport, we conclude that lipoprotein FC levels are a potent, positive regulator of the pathways involved in sterol clearance. FC may modulate lipid transfer by altering the availability of CE and TG to LTP at the lipoprotein surface.

  14. Immunization against proprotein convertase subtilisin-like/kexin type 9 lowers plasma LDL-cholesterol levels in mice.

    PubMed

    Fattori, Elena; Cappelletti, Manuela; Lo Surdo, Paola; Calzetta, Alessandra; Bendtsen, Claus; Ni, Yan G; Pandit, Shilpa; Sitlani, Ayesha; Mesiti, Giuseppe; Carfí, Andrea; Monaci, Paolo

    2012-08-01

    Successful development of drugs against novel targets crucially depends on reliable identification of the activity of the target gene product in vivo and a clear demonstration of its specific functional role for disease development. Here, we describe an immunological knockdown (IKD) method, a novel approach for the in vivo validation and functional study of endogenous gene products. This method relies on the ability to elicit a transient humoral response against the selected endogenous target protein. Anti-target antibodies specifically bind to the target protein and a fraction of them effectively neutralize its activity. We applied the IKD method to the in vivo validation of plasma PCSK9 as a potential target for the treatment of elevated levels of plasma LDL-cholesterol. We show that immunization with human-PCSK9 in mice is able to raise antibodies that cross-react and neutralize circulating mouse-PCSK9 protein thus resulting in increased liver LDL receptor levels and plasma cholesterol uptake. These findings closely resemble those described in PCSK9 knockout mice or in mice treated with antibodies that inhibit PCSK9 by preventing the PCSK9/LDLR interaction. Our data support the IKD approach as an effective method to the rapid validation of new target proteins.

  15. Extended-release niacin alters the metabolism of plasma apolipoprotein (apo) A-I- and apoB-containing lipoproteins

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extended-release niacin effectively lowers plasma TG levels and raises plasma HDL cholesterol levels, but the mechanisms responsible for these effects are unclear. We examined the effects of extended-release niacin (2 g/d) and extended-release niacin (2 g/d) plus lovastatin (40 mg/d), relative to pl...

  16. Cholesterol efflux capacity: An introduction for clinicians.

    PubMed

    Anastasius, Malcolm; Kockx, Maaike; Jessup, Wendy; Sullivan, David; Rye, Kerry-Anne; Kritharides, Leonard

    2016-10-01

    Epidemiologic studies have shown an inverse correlation between high-density lipoprotein (HDL) cholesterol (HDL-C) levels and cardiovascular disease outcomes. However, the hypothesis of a causal relationship between HDL-C and cardiovascular disease has been challenged by genetic and clinical studies. Serum cholesterol efflux capacity (CEC) is an important measure of HDL function in humans. Recent large clinical studies have shown a correlation between in vitro CEC and cardiovascular disease prevalence and incidence, which appears to be independent of HDL-C concentration. The present review summarizes recent large clinical studies and introduces important methodological considerations. Further studies are required to standardize and establish the reproducibility of this measure of HDL function and clarify whether modulating CEC will emerge as a useful therapeutic target. PMID:27659883

  17. Novel concepts in HDL pharmacology

    PubMed Central

    Remaley, Alan T.; Norata, Giuseppe D.; Catapano, Alberico L.

    2014-01-01

    High-density lipoproteins (HDL) are a target for drug development because of their proposed anti-atherogenic properties. In this review, we will briefly discuss the currently established drugs for increasing HDL-C, namely niacin and fibrates, and some of their limitations. Next, we will focus on novel alternative therapies that are currently being developed for raising HDL-C, such as CETP inhibitors. Finally, we will conclude with a review of novel drugs that are being developed for modulating the function of HDL based on HDL mimetics. Gaps in our knowledge and the challenges that will have to be overcome for these new HDL based therapies will also be discussed. PMID:24951539

  18. Increased Free Cholesterol in Plasma Low and Very Low Density Lipoproteins in Non-Insulin-Dependent Diabetes Mellitus: Its Role in the Inhibition of Cholesteryl Ester Transfer

    NASA Astrophysics Data System (ADS)

    Fielding, Christopher J.; Reaven, Gerald M.; Liu, George; Fielding, Phoebe E.

    1984-04-01

    Recombination of low and very low density lipoproteins (VLDL and LDL) from normal subjects with plasma from patients with non-insulin-dependent diabetes mellitus significantly increased the reduced rate of transfer of cholesteryl ester to these lipoproteins, which is characteristic of diabetic plasma, whereas diabetic VLDL and LDL reduced cholesteryl ester transfer rates in normal plasma. VLDL and LDL from diabetic plasma had an increased ratio of free cholesterol to phospholipid compared to normal, and unlike normal VLDL and LDL spontaneously lost free cholesterol to high density lipoprotein. These data suggest that the block to cholesteryl ester transfer to these lipoproteins in non-insulin-dependent diabetes is mediated by their increased free cholesterol content and may be related to the increased risk of these patients for developing atherosclerosis.

  19. Influence of dietary intake and physical activity on annual rhythm of human blood cholesterol concentrations.

    PubMed

    Blüher, M; Hentschel, B; Rassoul, F; Richter, V

    2001-05-01

    Seasonal variation in the plasma total cholesterol (TC) and high-density lipoprotein cholesterol (HDL-C) have been repeatedly reported, with contradictory results regarding the pattern of seasonal variation of these parameters. Furthermore, it is still not well established whether the variation is due to changes in the nutrition or changes in physical activity depending on the season. The aim of this study was therefore to determine plasma TC and HDL-C in different groups of healthy participants: 19 vegetarians with a constant diet independent of the season, 14 athletes with almost constant physical activity over the year, and 114 controls in the age groups 20-26 years (mean age 24 + 1.5 years) and 40-48 years (mean age 44.3 + 2.1 years). Over 2 years, blood samples were collected every 2-3 months and were analyzed for plasma TC and HDL-C. At all visits, body mass index (BMI) and waist-to-hip ratio (WHR) were calculated, and nutrition and physical activity profiles were obtained. The seasonal model was calculated using object-oriented software for the analysis of longitudinal data in S (OSWALD); multiple regression analysis was used to determine the influence of age, gender, diet, and physical activity on seasonal changes of the lipid parameters. In all groups, we found an annual rhythm of the plasma TC and HDL-C concentrations, which can be mathematically described by a sine curve with a maximum in winter and a minimum in summer. This rhythm was independent of the age, gender, BMI, diet, or physical activity. The observed seasonal differences between the maximum and the minimum were about 5%-10% for TC and about 5%-8% for HDL-C concentration. These differences were greater than the determined circadian (TC 3.5%, HDL-C 4%) and day-to-day changes for TC and HDL-C (coefficient of variation <5% for both). In conclusion, annual rhythm of TC and HDL-C is not primarily induced by seasonal differences in dietary intake or physical activity. Therefore, the annual rhythm in

  20. Apolipoprotein modulation of streptococcal serum opacity factor activity against human plasma high-density lipoproteins.

    PubMed

    Rosales, Corina; Gillard, Baiba K; Courtney, Harry S; Blanco-Vaca, Francisco; Pownall, Henry J

    2009-08-25

    Human plasma HDL are the target of streptococcal serum opacity factor (SOF), a virulence factor that clouds human plasma. Recombinant (r) SOF transfers cholesteryl esters (CE) from approximately 400,000 HDL particles to a CE-rich microemulsion (CERM), forms a cholesterol-poor HDL-like particle (neo HDL), and releases lipid-free (LF) apo A-I. Whereas the rSOF reaction requires labile apo A-I, the modulation effects of other apos are not known. We compared the products and rates of the rSOF reaction against human HDL and HDL from mice overexpressing apos A-I and A-II. Kinetic studies showed that the reactivity of various HDL species is apo-specific. LpA-I reacts faster than LpA-I/A-II. Adding apos A-I and A-II inhibited the SOF reaction, an effect that was more profound for apo A-II. The rate of SOF-mediated CERM formation was slower against HDL from mice expressing human apos A-I and A-II than against WT mice HDL and slowest against HDL from apo A-II overexpressing mice. The lower reactivity of SOF against HDL containing human apos is due to the higher hydropathy of human apo A-I, particularly its C-terminus relative to mouse apo A-I, and the higher lipophilicity of human apo A-II. The SOF-catalyzed reaction is the first to target HDL rather than its transporters and receptors in a way that enhances reverse cholesterol transport (RCT). Thus, effects of apos on the SOF reaction are highly relevant. Our studies show that the "humanized" apo A-I-expressing mouse is a good animal model for studies of rSOF effects on RCT in vivo.

  1. Gel coating of edible Brasenia schreberi leaves lowers plasma cholesterol in hamsters (abstract)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The young leaves of B. schreberi are coated with gelatinous water-insoluble mucilage. This mucilage is a polysaccharide composed of galactose, mannose, fucose and other monosaccharides. Since some carbohydrate gels are hypocholesterolemic, we evaluated the cholesterol lowering properties in male h...

  2. Replacement of butter on bread by rapeseed oil and rapeseed oil-containing margarine: effects on plasma fatty acid composition and serum cholesterol.

    PubMed

    Seppänen-Laakso, T; Vanhanen, H; Laakso, I; Kohtamäki, H; Viikari, J

    1992-11-01

    The effects of zero-erucic acid rapeseed oil and rapeseed oil-containing margarine on plasma fatty acid composition and serum cholesterol were studied in butter users (n 43). Compliance to the substitution was followed by fatty acid analysis of total plasma and plasma phospholipids. The amount of substitute fats represented, on average, 21% of total fat and 8% of total energy intake. Changes in the relative fatty acid composition of plasma phospholipids indicated further fatty acid metabolism, and were closely related to the serum cholesterol level. The reduction in saturated fatty acids led to a significant increase in the proportion of n-3 and n-6 polyunsaturated fatty acids (PUFA) with the rapeseed oil diet, whereas the margarine caused a significant rise in n-6 PUFA only. The increase in the proportions of the two PUFA families occurred in accordance with their competitive order, most completely with the rapeseed oil diet. When butter was replaced by rapeseed oil, low-density-lipoprotein-cholesterol decreased by an average of 9.1% without a reduction in high-density-lipoprotein-cholesterol. During margarine substitution the reduction was 5.2%, on average. Of the plasma phospholipids, alpha-linolenic acid and the linoleic:stearic acid ratio, but not oleic acid, were the components most significantly correlated with serum cholesterol levels or the decrease in these levels. The results show that rapeseed oil can act primarily as a source of essential fatty acids, rather than that of monoenes, in the diet of butter users.

  3. In vivo measurement of plasma cholesterol and fatty acid synthesis with deuterated water: determination of the average number of deuterium atoms incorporated.

    PubMed

    Diraison, F; Pachiaudi, C; Beylot, M

    1996-07-01

    Fractional lipid synthesis can be measured using the incorporation of deuterium from deuterated water. The calculations require knowledge of the maximum incorporation number (N) of deuterium atoms in the molecules synthesized. For both tissue palmitate and cholesterol, N values have been found to be higher during in vivo versus in vitro experiments. We determined the N values to be used for measuring the fractional synthesis of plasma cholesterol and of palmitate triglycerides (TG). Rats were given drinking water enriched (7% to 10%) with deuterated water, and N was determined from the mass isotopomer distributions of plasma cholesterol and plasma TG palmitate and the deuterium enrichment of plasma water. We found N to be 21 for palmitate and 27 for cholesterol. These values agree with those reported for tissue palmitate and cholesterol in vivo, and are higher than values found in vitro. We also found large deuterium enrichments in plasma glucose and in liver lactate and pyruvate. We suggest that, compared with in vitro studies, in vivo metabolism of these compounds leads to an additional pathway of incorporation of deuterium into lipids through deuterium-labeled acetyl coenzyme A (CoA). This could explain why N values are higher in vivo than in vitro. PMID:8692014

  4. Evaluation of HDL-modulating interventions for cardiovascular risk reduction using a systems pharmacology approach[S

    PubMed Central

    Gadkar, Kapil; Lu, James; Sahasranaman, Srikumar; Davis, John; Mazer, Norman A.; Ramanujan, Saroja

    2016-01-01

    The recent failures of cholesteryl ester transport protein inhibitor drugs to decrease CVD risk, despite raising HDL cholesterol (HDL-C) levels, suggest that pharmacologic increases in HDL-C may not always reflect elevations in reverse cholesterol transport (RCT), the process by which HDL is believed to exert its beneficial effects. HDL-modulating therapies can affect HDL properties beyond total HDL-C, including particle numbers, size, and composition, and may contribute differently to RCT and CVD risk. The lack of validated easily measurable pharmacodynamic markers to link drug effects to RCT, and ultimately to CVD risk, complicates target and compound selection and evaluation. In this work, we use a systems pharmacology model to contextualize the roles of different HDL targets in cholesterol metabolism and provide quantitative links between HDL-related measurements and the associated changes in RCT rate to support target and compound evaluation in drug development. By quantifying the amount of cholesterol removed from the periphery over the short-term, our simulations show the potential for infused HDL to treat acute CVD. For the primary prevention of CVD, our analysis suggests that the induction of ApoA-I synthesis may be a more viable approach, due to the long-term increase in RCT rate. PMID:26522778

  5. Cholesterol forms and traditional lipid profile for projection of atherogenic dyslipidemia: lipoprotein subfractions and erythrocyte membrane cholesterol.

    PubMed

    Uydu, Hüseyin Avni; Bostan, Mehmet; Atak, Mehtap; Yılmaz, Adnan; Demir, Adem; Akçan, Buket; Sümer, Fatih; Baltaş, Nimet; Karadağ, Zakir; Uğurlu, Yavuz; Orem, Asım

    2014-02-01

    Atherogenic dyslipidemia characterized by abnormal changes in plasma lipid profile such as low high-density lipoprotein (HDL) and increased triglyceride (TG) levels is strongly associated with atherosclerotic diseases. We aimed to evaluate the levels of pro- and antiatherogenic lipids and erythrocyte membrane cholesterol (EMC) content in normo- and dyslipidemic subjects to investigate whether EMC content could be a useful marker for clinical presentation of atherogenic dyslipidemia. Low-density lipoprotein (LDL), HDL and their subfraction levels and erythrocyte lipid content were determined in 64 normolipidemic (NLs), 42 hypercholesterolemic (HCs) and 42 mixed-type dyslipidemic subjects (MTDs). Plasma atherogenic lipid indices [small-dense LDL (sdLDL)/less-dense HDL (LHDL), TC/HDL-C, TG/HDL-C and Apo B/AI] were higher in MTDs compared to NLs (p < 0.001). The highest sdLDL level was observed in HCs (p < 0.01). Despite a slight increase in EMC level in dyslipidemic subgroups, the difference was not statistically significant. A significant negative correlation, however, was observed between EMC and sdLDL/LHDL in HCs (p < 0.035, r = -0.386). Receiver operating characteristic curves to predict sdLDL level showed that TG and EMC levels had higher area under curve values compared to other parameters in HCs. We showed that diameters of larger LDL and HDL particles tend to shift toward smaller values in MTDs. Our results suggest that EMC content and TG levels may be a useful predictor for sdLDL level in hypercholesterolemic patients.

  6. Paraoxonase 1 and HDL maturation.

    PubMed

    Gugliucci, Alejandro; Menini, Teresita

    2015-01-15

    Understanding the kinetics and function of paraoxonase 1 (PON1) is becoming an important issue in atherosclerosis. Low PON1 activity has been consistently linked with an increased risk of major cardiovascular events in the setting of secondary prevention of coronary artery disease. Recent studies have shown that there is a specific interaction of myeloperoxidase (MPO)-apoAI-PON1 on HDL surface that seems to be germane to atherogenesis. MPO specifically inhibits PON1 and PON1 mitigates MPO effects. Surprisingly, very little is known about the routes by which PON1 gets integrated into HDL or its fate during HDL remodeling in the intravascular space. We have developed a method that assesses PON1 activity in the individual HDL subclasses with the aid of which we have shown that PON1 is present across the HDL particle range and preferentially in HDL3, confirming data from ultracentrifugation (UC) studies. Upon HDL maturation ex vivo PON1 is activated and it shows a flux to both smaller and larger HDL particles as well as to VLDL and sdLDL. At the same time apoE, AI and AII are shifted across particle sizes. PON1 activation and flux across HDL particles are blocked by CETP and LCAT inhibitors. In a group of particles with such a complex biology as HDL, knowledge of the interaction between apo-lipoproteins, lipids and enzymes is key for an increased understanding of the yet multiple unknown features of its function. Solving the HDL paradox will necessitate the development of techniques to explore HDL function that are practical and well adapted to clinical studies and eventually become useful in patient monitoring. The confluence of proteomic, functional studies, HDL subclasses, PON1 assays and zymogram will yield data to draw a more elaborate and comprehensive picture of the function of HDL. It must be noted that all these studies are static and conducted in the fasting state. The crucial phase will be achieved when human kinetic studies (both in the fasting and post

  7. HDL-S1P: cardiovascular functions, disease-associated alterations, and therapeutic applications

    PubMed Central

    Levkau, Bodo

    2015-01-01

    Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid contained in High-density lipoproteins (HDL) and has drawn considerable attention in the lipoprotein field as numerous studies have demonstrated its contribution to several functions inherent to HDL. Some of them are partly and some entirely due to the S1P contained in HDL (HDL-S1P). Despite the presence of over 1000 different lipids in HDL, S1P stands out as it possesses its own cell surface receptors through which it exercises key physiological functions. Most of the S1P in human plasma is associated with HDL, and the amount of HDL-S1P influences the quality and quantity of HDL-dependent functions. The main binding partner of S1P in HDL is apolipoprotein M but others may also exist particularly under conditions of acute S1P elevations. HDL not only exercise functions through their S1P content but have also an impact on genuine S1P signaling by influencing S1P bioactivity and receptor presentation. HDL-S1P content is altered in human diseases such as atherosclerosis, coronary artery disease, myocardial infarction, renal insufficiency and diabetes mellitus. Low HDL-S1P has also been linked to impaired HDL functions associated with these disorders. Although the pathophysiological and molecular reasons for such disease-associated shifts in HDL-S1P are little understood, there have been successful approaches to circumvent their adverse implications by pharmacologically increasing HDL-S1P as means to improve HDL function. This mini-review will cover the current understanding of the contribution of HDL-S1P to physiological HDL function, its alteration in disease and ways for its restoration to correct HDL dysfunction. PMID:26539121

  8. Inhibition of soluble epoxide hydrolase in mice promotes reverse cholesterol transport and regression of atherosclerosis.

    PubMed

    Shen, Li; Peng, Hongchun; Peng, Ran; Fan, Qingsong; Zhao, Shuiping; Xu, Danyan; Morisseau, Christophe; Chiamvimonvat, Nipavan; Hammock, Bruce D

    2015-04-01

    Adipose tissue is the body largest free cholesterol reservoir and abundantly expresses ATP binding cassette transporter A1 (ABCA1), which maintains plasma high-density lipoprotein (HDL) levels. HDLs have a protective role in atherosclerosis by mediating reverse cholesterol transport (RCT). Soluble epoxide hydrolase (sEH) is a cytosolic enzyme whose inhibition has various beneficial effects on cardiovascular disease. The sEH is highly expressed in adipocytes, and it converts epoxyeicosatrienoic acids (EETs) into less bioactive dihydroxyeicosatrienoic acids. We previously showed that increasing EETs levels with a sEH inhibitor (sEHI) (t-AUCB) resulted in elevated ABCA1 expression and promoted ABCA1-mediated cholesterol efflux from 3T3-L1 adipocytes. The present study investigates the impacts of t-AUCB in mice deficient for the low density lipoprotein (LDL) receptor (Ldlr(-/-) mice) with established atherosclerotic plaques. The sEH inhibitor delivered in vivo for 4 weeks decreased the activity of sEH in adipose tissue, enhanced ABCA1 expression and cholesterol efflux from adipose depots, and consequently increased HDL levels. Furthermore, t-AUCB enhanced RCT to the plasma, liver, bile and feces. It also showed the reduction of plasma LDL-C levels. Consistently, t-AUCB-treated mice showed reductions in the size of atherosclerotic plaques. These studies establish that raising adipose ABCA1 expression, cholesterol efflux, and plasma HDL levels with t-AUCB treatment promotes RCT, decreasing LDL-C and atherosclerosis regression, suggesting that sEH inhibition may be a promising strategy to treat atherosclerotic vascular disease.

  9. Omega-3 Fatty Acid Enriched Chevon (Goat Meat) Lowers Plasma Cholesterol Levels and Alters Gene Expressions in Rats

    PubMed Central

    Rajion, Mohamed Ali; Meng, Goh Yong; Soleimani Farjam, Abdoreza

    2014-01-01

    In this study, control chevon (goat meat) and omega-3 fatty acid enriched chevon were obtained from goats fed a 50% oil palm frond diet and commercial goat concentrate for 100 days, respectively. Goats fed the 50% oil palm frond diet contained high amounts of α-linolenic acid (ALA) in their meat compared to goats fed the control diet. The chevon was then used to prepare two types of pellets (control or enriched chevon) that were then fed to twenty-male-four-month-old Sprague-Dawley rats (n = 10 in each group) for 12 weeks to evaluate their effects on plasma cholesterol levels, tissue fatty acids, and gene expression. There was a significant increase in ALA and docosahexaenoic acid (DHA) in the muscle tissues and liver of the rats fed the enriched chevon compared with the control group. Plasma cholesterol also decreased (P < 0.05) in rats fed the enriched chevon compared to the control group. The rat pellets containing enriched chevon significantly upregulated the key transcription factor PPAR-γ and downregulated SREBP-1c expression relative to the control group. The results showed that the omega-3 fatty acid enriched chevon increased the omega-3 fatty acids in the rat tissues and altered PPAR-γ and SREBP-1c genes expression. PMID:24719886

  10. The influence of natural short photoperiodic and temperature conditions on plasma thyroid hormones and cholesterol in male Syrian hamsters

    NASA Astrophysics Data System (ADS)

    Vaughan, M. K.; Brainard, G. C.; Reiter, R. J.

    1984-09-01

    Adult male Syrian hamsters were subjected to 1, 3, 5, 7 or 11 weeks of either natural winter conditions or rigorously controlled laboratory conditions (LD 10∶14; 22 ± 2‡C). Although both groups of hamsters gained weight over the course of the experiment, hamsters housed indoors were significantly heavier after 5 weeks of treatment compared to their outdoors counterparts. Animals housed under natural conditions exhibited a significant decrease in circulating levels of thyroxine (T4) and a rapid rise in triiodothyronine (T3) levels; the free T4 and free T3 index (FT4I and FT3I) mirrored the changes in circulating levels of the respective hormones. Laboratory-housed animals had a slight rise in T4 and FT4I at 3 weeks followed by a slow steady decline in these values; T3 and FT3I values did not change remarkably in these animals. Plasma cholesterol declined steadily over the course of the experiment in laboratory-maintained animals but increased slightly during the first 5 weeks in animals under natural conditions. Since the photoperiodic conditions were approximately of the same duration in these 2 groups, it is concluded that the major differences in body weight, thyroid hormone values and plasma cholesterol are due to some component (possibly temperature) in the natural environment.

  11. Omega-3 fatty acid enriched chevon (goat meat) lowers plasma cholesterol levels and alters gene expressions in rats.

    PubMed

    Ebrahimi, Mahdi; Rajion, Mohamed Ali; Meng, Goh Yong; Soleimani Farjam, Abdoreza

    2014-01-01

    In this study, control chevon (goat meat) and omega-3 fatty acid enriched chevon were obtained from goats fed a 50% oil palm frond diet and commercial goat concentrate for 100 days, respectively. Goats fed the 50% oil palm frond diet contained high amounts of α-linolenic acid (ALA) in their meat compared to goats fed the control diet. The chevon was then used to prepare two types of pellets (control or enriched chevon) that were then fed to twenty-male-four-month-old Sprague-Dawley rats (n = 10 in each group) for 12 weeks to evaluate their effects on plasma cholesterol levels, tissue fatty acids, and gene expression. There was a significant increase in ALA and docosahexaenoic acid (DHA) in the muscle tissues and liver of the rats fed the enriched chevon compared with the control group. Plasma cholesterol also decreased (P < 0.05) in rats fed the enriched chevon compared to the control group. The rat pellets containing enriched chevon significantly upregulated the key transcription factor PPAR-γ and downregulated SREBP-1c expression relative to the control group. The results showed that the omega-3 fatty acid enriched chevon increased the omega-3 fatty acids in the rat tissues and altered PPAR-γ and SREBP-1c genes expression.

  12. Management of dyslipidemia in the metabolic syndrome: recommendations of the Spanish HDL-Forum.

    PubMed

    Ascaso, Juan; Gonzalez Santos, Pedro; Hernandez Mijares, Antonio; Mangas Rojas, Alipio; Masana, Luis; Millan, Jesus; Pallardo, Luis Felipe; Pedro-Botet, Juan; Perez Jimenez, Francisco; Pintó, Xavier; Plaza, Ignacio; Rubiés, Juan; Zúñiga, Manuel

    2007-01-01

    In order to characterize the metabolic syndrome it becomes necessary to establish a number of diagnostic criteria. Because of its impact on cardiovascular morbidity/mortality, considerable attention has been focussed on the dyslipidemia accompanying the metabolic syndrome. The aim of this review is to highlight the fundamental aspects of the pathophysiology, diagnosis, and the treatment of the metabolic syndrome dyslipidemia with recommendations to clinicians. The clinical expression of the metabolic syndrome dyslipidemia is characterized by hypertriglyceridemia and low levels of high-density lipoprotein-cholesterol (HDL-C). In addition, metabolic syndrome dyslipidemia is associated with high levels of apolipoprotein (apo) B-100-rich particles of a particularly atherogenic phenotype (small dense low-density lipoprotein-cholesterol [LDL-C]. High levels of triglyceride-rich particles (very low-density lipoprotein) are also evident both at baseline and in overload situations (postprandial hyperlipidemia). Overall, the 'quantitative' dyslipidemia characterized by hypertriglyceridemia and low levels of HDL-C and the 'qualitative' dyslipidemia characterized by high levels of apo B-100- and triglyceride-rich particles, together with insulin resistance, constitute an atherogenic triad in patients with the metabolic syndrome. The therapeutic management of the metabolic syndrome, regardless of the control of the bodyweight, BP, hyperglycemia or overt diabetes mellitus, aims at maintaining optimum plasma lipid levels. Therapeutic goals are similar to those for high-risk situations because of the coexistence of multiple risk factors. The primary goal in treatment should be achieving an LDL-C level of <100 mg/dL (or <70 mg/dL in cases with established ischemic heart disease or risk equivalents). A further goal is increasing the HDL-C level to >or=40 mg/dL in men or 50 mg/dL in women. A non-HDL-C goal of 130 mg/dL should also be aimed at in cases of hypertriglyceridemia

  13. Management of dyslipidemia in the metabolic syndrome: recommendations of the Spanish HDL-Forum.

    PubMed

    Ascaso, Juan; Gonzalez Santos, Pedro; Hernandez Mijares, Antonio; Mangas Rojas, Alipio; Masana, Luis; Millan, Jesus; Pallardo, Luis Felipe; Pedro-Botet, Juan; Perez Jimenez, Francisco; Pintó, Xavier; Plaza, Ignacio; Rubiés, Juan; Zúñiga, Manuel

    2007-01-01

    In order to characterize the metabolic syndrome it becomes necessary to establish a number of diagnostic criteria. Because of its impact on cardiovascular morbidity/mortality, considerable attention has been focussed on the dyslipidemia accompanying the metabolic syndrome. The aim of this review is to highlight the fundamental aspects of the pathophysiology, diagnosis, and the treatment of the metabolic syndrome dyslipidemia with recommendations to clinicians. The clinical expression of the metabolic syndrome dyslipidemia is characterized by hypertriglyceridemia and low levels of high-density lipoprotein-cholesterol (HDL-C). In addition, metabolic syndrome dyslipidemia is associated with high levels of apolipoprotein (apo) B-100-rich particles of a particularly atherogenic phenotype (small dense low-density lipoprotein-cholesterol [LDL-C]. High levels of triglyceride-rich particles (very low-density lipoprotein) are also evident both at baseline and in overload situations (postprandial hyperlipidemia). Overall, the 'quantitative' dyslipidemia characterized by hypertriglyceridemia and low levels of HDL-C and the 'qualitative' dyslipidemia characterized by high levels of apo B-100- and triglyceride-rich particles, together with insulin resistance, constitute an atherogenic triad in patients with the metabolic syndrome. The therapeutic management of the metabolic syndrome, regardless of the control of the bodyweight, BP, hyperglycemia or overt diabetes mellitus, aims at maintaining optimum plasma lipid levels. Therapeutic goals are similar to those for high-risk situations because of the coexistence of multiple risk factors. The primary goal in treatment should be achieving an LDL-C level of <100 mg/dL (or <70 mg/dL in cases with established ischemic heart disease or risk equivalents). A further goal is increasing the HDL-C level to >or=40 mg/dL in men or 50 mg/dL in women. A non-HDL-C goal of 130 mg/dL should also be aimed at in cases of hypertriglyceridemia

  14. Role of HDL in cholesteryl ester metabolism of lipopolysaccharide-activated P388D1 macrophages.

    PubMed

    Uda, Sabrina; Spolitu, Stefano; Angius, Fabrizio; Collu, Maria; Accossu, Simonetta; Banni, Sebastiano; Murru, Elisabetta; Sanna, Francesca; Batetta, Barbara

    2013-11-01

    Infections share with atherosclerosis similar lipid alterations, with accumulation of cholesteryl esters (CEs) in activated macrophages and concomitant decrease of cholesterol-HDL (C-HDL). Yet the precise role of HDL during microbial infection has not been fully elucidated. Activation of P388D1 by lipopolysaccharide (LPS) triggered an increase of CEs and neutral lipid contents, along with a remarkable enhancement in 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate-HDL uptake. Similar results were found in human monocyte-derived macrophages and monocytes cocultured with phytohemagglutinin-activated lymphocytes. Inhibition of cholesterol esterification with Sandoz-58035 resulted in 80% suppression of CE biosynthesis in P388D1. However, only a 35% decrease of CE content, together with increased scavenger receptor class B member 1 (SR-B1) protein expression, was found after 72 h and thereafter up to 16 passages of continuous ACAT suppression. Chronic inhibition blunted the effect of LPS treatment on cholesterol metabolism, increased the ratio of free cholesterol/CE content and enhanced interleukin 6 secretion. These results imply that, besides de novo biosynthesis and acquisition by LDL, HDL contributes probably through SR-B1 to the increased CE content in macrophages, partly explaining the low levels of C-HDL during their activation. Our data suggest that in those conditions where more CEs are required, HDL rather than removing, may supply CEs to the cells. PMID:23956443

  15. Effect of dosage and application mode of L-carnitine on plasma lipid and egg-yolk cholesterol of turkeys, hatchability of eggs and post-hatch growth of their offsprings.

    PubMed

    Oso, A O; Fafiolu, A O; Adeleke, M A; Ladokun, O A; Sobayo, R A; Jegede, A V; Peters, S O; Oyebamiji, O A; Akinsola, J

    2014-08-01

    The effect of dosage and application mode of L-carnitine on plasma lipid and egg-yolk cholesterol of breeder turkeys, hatchability of eggs and post-hatch growth response was investigated using 180 breeder hens. The hens were assigned to six dietary treatments in a 2 × 3 factorial arrangements of two application modes of L-carnitine (diet and drinking water) supplemented at 0, 50 and 100 ppm (mg/kg or mg/l) levels, respectively. Each treatment was replicated five times with six hens per replicate. Dietary inclusion of 50 ppm L-carnitine showed the lowest (p < 0.01) plasma total cholesterol (TC) and low-density lipoprotein concentration (LDL). Breeder hens offered 50 ppm L-carnitine with no regard to application mode recorded the highest (p < 0.01) plasma high-density lipoprotein (HDL). Hens offered 50 and 100 ppm L-carnitine irrespective of application mode also showed reduced (p < 0.01) egg-yolk TC concentration at 32 weeks of age. Dietary supplementation of 50 ppm L-carnitine for breeder turkeys recorded the lowest (p < 0.01) egg-yolk triglyceride (TG) at 40 weeks of age. Hens offered 50 ppm L-carnitine irrespective of application mode recorded the highest (p < 0.05) hen-day egg production. Incidence of dead-in-shell also reduced (p < 0.05) with increasing dosage of L-carnitine. Dietary supplementation of 50 ppm and oral application in drinking water of 100 ppm L-carnitine for breeder turkeys resulted in highest (p < 0.05) egg fertility. Offsprings from breeder hens fed diets supplemented with L-carnitine recorded no post-hatch mortality. Highest (p < 0.05) post-hatch final live weight and weight gain was obtained with poults obtained from hens fed diet supplemented with 50 ppm L-carnitine. In conclusion, dietary supplementation of 50 ppm L-carnitine for turkey hens showed improved serum lipid profile, egg fertility, reduced dead-in-shell, egg-yolk cholesterol and resulted in improved post-hatch growth performance.

  16. Hepatic ACAT2 Knock Down Increases ABCA1 and Modifies HDL Metabolism in Mice

    PubMed Central

    Degirolamo, Chiara; Gomaraschi, Monica; Graham, Mark; Ossoli, Alice; Larsson, Lilian; Calabresi, Laura; Gustafsson, Jan-Åke; Steffensen, Knut R.; Eriksson, Mats; Parini, Paolo

    2014-01-01

    Objectives ACAT2 is the exclusive cholesterol-esterifying enzyme in hepatocytes and enterocytes. Hepatic ABCA1 transfers unesterified cholesterol (UC) to apoAI, thus generating HDL. By changing the hepatic UC pool available for ABCA1, ACAT2 may affect HDL metabolism. The aim of this study was to reveal whether hepatic ACAT2 influences HDL metabolism. Design WT and LXRα/β double knockout (DOKO) mice were fed a western-type diet for 8 weeks. Animals were i.p. injected with an antisense oligonucleotide targeted to hepatic ACAT2 (ASO6), or with an ASO control. Injections started 4 weeks after, or concomitantly with, the beginning of the diet. Results ASO6 reduced liver cholesteryl esters, while not inducing UC accumulation. ASO6 increased hepatic ABCA1 protein independently of the diet conditions. ASO6 affected HDL lipids (increased UC) only in DOKO, while it increased apoE-containing HDL in both genotypes. In WT mice ASO6 led to the appearance of large HDL enriched in apoAI and apoE. Conclusions The use of ASO6 revealed a new pathway by which the liver may contribute to HDL metabolism in mice. ACAT2 seems to be a hepatic player affecting the cholesterol fluxes fated to VLDL or to HDL, the latter via up-regulation of ABCA1. PMID:24695360

  17. Elevated Basal Insulin Secretion in Type 2 Diabetes Caused by Reduced Plasma Membrane Cholesterol

    PubMed Central

    Nagaraj, Vini; Kazim, Abdulla S.; Helgeson, Johan; Lewold, Clemens; Barik, Satadal; Buda, Pawel; Reinbothe, Thomas M.; Wennmalm, Stefan

    2016-01-01

    Elevated basal insulin secretion under fasting conditions together with insufficient stimulated insulin release is an important hallmark of type 2 diabetes, but the mechanisms controlling basal insulin secretion remain unclear. Membrane rafts exist in pancreatic islet cells and spatially organize membrane ion channels and proteins controlling exocytosis, which may contribute to the regulation of insulin secretion. Membrane rafts (cholesterol and sphingolipid containing microdomains) were dramatically reduced in human type 2 diabetic and diabetic Goto-Kakizaki (GK) rat islets when compared with healthy islets. Oxidation of membrane cholesterol markedly reduced microdomain staining intensity in healthy human islets, but was without effect in type 2 diabetic islets. Intriguingly, oxidation of cholesterol affected glucose-stimulated insulin secretion only modestly, whereas basal insulin release was elevated. This was accompanied by increased intracellular Ca2+ spike frequency and Ca2+ influx and explained by enhanced single Ca2+ channel activity. These results suggest that the reduced presence of membrane rafts could contribute to the elevated basal insulin secretion seen in type 2 diabetes. PMID:27533789

  18. Lipoprotein hydrophobic core lipids are partially extruded to surface in smaller HDL: “Herniated” HDL, a common feature in diabetes

    PubMed Central

    Amigó, Núria; Mallol, Roger; Heras, Mercedes; Martínez-Hervás, Sergio; Blanco-Vaca, Francisco; Escolà-Gil, Joan Carles; Plana, Núria; Yanes, Óscar; Masana, Lluís; Correig, Xavier

    2016-01-01

    Recent studies have shown that pharmacological increases in HDL cholesterol concentrations do not necessarily translate into clinical benefits for patients, raising concerns about its predictive value for cardiovascular events. Here we hypothesize that the size-modulated lipid distribution within HDL particles is compromised in metabolic disorders that have abnormal HDL particle sizes, such as type 2 diabetes mellitus (DM2). By using NMR spectroscopy combined with a biochemical volumetric model we determined the size and spatial lipid distribution of HDL subclasses in a cohort of 26 controls and 29 DM2 patients before and after two drug treatments, one with niacin plus laropiprant and another with fenofibrate as an add-on to simvastatin. We further characterized the HDL surface properties using atomic force microscopy and fluorescent probes to show an abnormal lipid distribution within smaller HDL particles, a subclass particularly enriched in the DM2 patients. The reduction in the size, force cholesterol esters and triglycerides to emerge from the HDL core to the surface, making the outer surface of HDL more hydrophobic. Interestingly, pharmacological interventions had no effect on this undesired configuration, which may explain the lack of clinical benefits in DM2 subjects. PMID:26778677

  19. What's Cholesterol?

    MedlinePlus

    ... Most cholesterol is LDL (low-density lipoprotein) cholesterol. LDL cholesterol is more likely to clog blood vessels because ... Here's a way to remember the difference: the LDL cholesterol is the bad kind, so call it "lousy" ...

  20. Robust passive and active efflux of cellular cholesterol to a designer functional mimic of high density lipoprotein

    PubMed Central

    Luthi, Andrea J.; Lyssenko, Nicholas N.; Quach, Duyen; McMahon, Kaylin M.; Millar, John S.; Vickers, Kasey C.; Rader, Daniel J.; Phillips, Michael C.; Mirkin, Chad A.; Thaxton, C. Shad

    2015-01-01

    The ability of HDL to support macrophage cholesterol efflux is an integral part of its atheroprotective action. Augmenting this ability, especially when HDL cholesterol efflux capacity from macrophages is poor, represents a promising therapeutic strategy. One approach to enhancing macrophage cholesterol efflux is infusing blood with HDL mimics. Previously, we reported the synthesis of a functional mimic of HDL (fmHDL) that consists of a gold nanoparticle template, a phospholipid bilayer, and apo A-I. In this work, we characterize the ability of fmHDL to support the well-established pathways of cellular cholesterol efflux from model cell lines and primary macrophages. fmHDL received cell cholesterol by unmediated (aqueous) and ABCG1- and scavenger receptor class B type I (SR-BI)-mediated diffusion. Furthermore, the fmHDL holoparticle accepted cholesterol and phospholipid by the ABCA1 pathway. These results demonstrate that fmHDL supports all the cholesterol efflux pathways available to native HDL and thus, represents a promising infusible therapeutic for enhancing macrophage cholesterol efflux. fmHDL accepts cholesterol from cells by all known pathways of cholesterol efflux: unmediated, ABCG1- and SR-BI-mediated diffusion, and through ABCA1. PMID:25652088