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Mahrooz A. Pleiotropic functions and clinical importance of circulating HDL-PON1 complex. Adv Clin Chem 2024; 121:132-171. [PMID: 38797541 DOI: 10.1016/bs.acc.2024.04.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
High density lipoprotein (HDL) functions are mostly mediated through a complex proteome, particularly its enzymes. HDL can provide a scaffold for the assembly of several proteins that affect each other's function. HDL particles, particularly small, dense HDL3, are rich in paraoxonase 1 (PON1), which is an important enzyme in the functionality of HDL, so the antioxidant and antiatherogenic properties of HDL are largely attributed to this enzyme. There is an increasing need to represent a valid, reproducible, and reliable method to assay HDL function in routine clinical laboratories. In this context, HDL-associated proteins may be key players; notably PON1 activity (its arylesterase activity) may be a proper candidate because its decreased activity can be considered an important risk factor for HDL dysfunctionality. Of note, automated methods have been developed for the measurement of serum PON1 activity that facilitates its assay in large sample numbers. Arylesterase activity is proposed as a preferred activity among the different activities of PON1 for its assay in epidemiological studies. The binding of PON1 to HDL is critical for the maintenance of its activity and it appears apolipoprotein A-I plays an important role in HDL-PON1 interaction as well as in the biochemical and enzymatic properties of PON1. The interrelationships between HDL, PON1, and HDL's other components are complex and incompletely understood. The purpose of this review is to discuss biochemical and clinical evidence considering the interactions of PON1 with HDL and the role of this enzyme as an appropriate biomarker for HDL function as well as a potential therapeutic target.
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Affiliation(s)
- Abdolkarim Mahrooz
- Immunogenetics Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Department of Clinical Biochemistry and Medical Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
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Denimal D, Monier S, Bouillet B, Vergès B, Duvillard L. High-Density Lipoprotein Alterations in Type 2 Diabetes and Obesity. Metabolites 2023; 13:metabo13020253. [PMID: 36837872 PMCID: PMC9967905 DOI: 10.3390/metabo13020253] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/07/2023] [Accepted: 02/07/2023] [Indexed: 02/12/2023] Open
Abstract
Alterations affecting high-density lipoproteins (HDLs) are one of the various abnormalities observed in dyslipidemia in type 2 diabetes mellitus (T2DM) and obesity. Kinetic studies have demonstrated that the catabolism of HDL particles is accelerated. Both the size and the lipidome and proteome of HDL particles are significantly modified, which likely contributes to some of the functional defects of HDLs. Studies on cholesterol efflux capacity have yielded heterogeneous results, ranging from a defect to an improvement. Several studies indicate that HDLs are less able to inhibit the nuclear factor kappa-B (NF-κB) proinflammatory pathway, and subsequently, the adhesion of monocytes on endothelium and their recruitment into the subendothelial space. In addition, the antioxidative function of HDL particles is diminished, thus facilitating the deleterious effects of oxidized low-density lipoproteins on vasculature. Lastly, the HDL-induced activation of endothelial nitric oxide synthase is less effective in T2DM and metabolic syndrome, contributing to several HDL functional defects, such as an impaired capacity to promote vasodilatation and endothelium repair, and difficulty counteracting the production of reactive oxygen species and inflammation.
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Affiliation(s)
- Damien Denimal
- INSERM, UMR1231, University of Burgundy, 21000 Dijon, France
- Department of Biochemistry, CHU Dijon Bourgogne, 21000 Dijon, France
- Correspondence:
| | - Serge Monier
- INSERM, UMR1231, University of Burgundy, 21000 Dijon, France
| | - Benjamin Bouillet
- INSERM, UMR1231, University of Burgundy, 21000 Dijon, France
- Department of Endocrinology and Diabetology, CHU Dijon Bourgogne, 21000 Dijon, France
| | - Bruno Vergès
- INSERM, UMR1231, University of Burgundy, 21000 Dijon, France
- Department of Endocrinology and Diabetology, CHU Dijon Bourgogne, 21000 Dijon, France
| | - Laurence Duvillard
- INSERM, UMR1231, University of Burgundy, 21000 Dijon, France
- Department of Biochemistry, CHU Dijon Bourgogne, 21000 Dijon, France
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3
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Metzinger MP, Saldanha S, Gulati J, Patel KV, El‐Ghazali A, Deodhar S, Joshi PH, Ayers C, Rohatgi A. Effect of Anacetrapib on Cholesterol Efflux Capacity: A Substudy of the DEFINE Trial. J Am Heart Assoc 2020; 9:e018136. [PMID: 33263263 PMCID: PMC7955402 DOI: 10.1161/jaha.120.018136] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Background Anacetrapib is the only cholesteryl ester transfer protein inhibitor proven to reduce coronary heart disease (CHD). However, its effects on reverse cholesterol transport have not been fully elucidated. Macrophage cholesterol efflux (CEC), the initial step of reverse cholesterol transport, is inversely associated with CHD and may be affected by sex as well as haptoglobin copy number variants among patients with diabetes mellitus. We investigated the effect of anacetrapib on CEC and whether this effect is modified by sex, diabetes mellitus, and haptoglobin polymorphism. Methods and Results A total of 574 participants with CHD were included from the DEFINE (Determining the Efficacy and Tolerability of CETP Inhibition With Anacetrapib) trial. CEC was measured at baseline and 24‐week follow‐up using J774 macrophages, boron dipyrromethene difluoride–labeled cholesterol, and apolipoprotein B–depleted plasma. Haptoglobin copy number variant was determined using an ELISA assay. Anacetrapib increased CEC, adjusted for baseline CEC, risk factors, and changes in lipids/apolipoproteins (standard β, 0.23; 95% CI, 0.05–0.41). This CEC‐raising effect was seen only in men (P interaction=0.002); no effect modification was seen by diabetes mellitus status. Among patients with diabetes mellitus, anacetrapib increased CEC in those with the normal 1‐1 haptoglobin genotype (standard β, 0.42; 95% CI, 0.16–0.69) but not the dysfunctional 2‐1/2‐2 genotypes (P interaction=0.02). Conclusions Among patients with CHD, anacetrapib at a dose linked to improved CHD outcomes significantly increased CEC independent of changes in high‐density lipoprotein cholesterol or other lipids, with effect modification by sex and a novel pharmacogenomic interaction by haptoglobin genotype, suggesting a putative mechanism for reduced risk requiring validation.
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Affiliation(s)
- Mark P. Metzinger
- Division of CardiologyDepartment of Internal MedicineUT Southwestern Medical CenterDallasTX
| | - Suzanne Saldanha
- Division of CardiologyDepartment of Internal MedicineUT Southwestern Medical CenterDallasTX
| | - Jaskeerat Gulati
- Division of CardiologyDepartment of Internal MedicineUT Southwestern Medical CenterDallasTX
| | - Kershaw V. Patel
- Division of CardiologyDepartment of Internal MedicineUT Southwestern Medical CenterDallasTX
| | - Ayea El‐Ghazali
- Division of CardiologyDepartment of Internal MedicineUT Southwestern Medical CenterDallasTX
| | - Sneha Deodhar
- Division of CardiologyDepartment of Internal MedicineUT Southwestern Medical CenterDallasTX
| | - Parag H. Joshi
- Division of CardiologyDepartment of Internal MedicineUT Southwestern Medical CenterDallasTX
| | - Colby Ayers
- Division of CardiologyDepartment of Internal MedicineUT Southwestern Medical CenterDallasTX
| | - Anand Rohatgi
- Division of CardiologyDepartment of Internal MedicineUT Southwestern Medical CenterDallasTX
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4
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Abstract
Cardiovascular disease, with atherosclerosis as the major underlying factor, remains the leading cause of death worldwide. It is well established that cholesterol ester-enriched foam cells are the hallmark of atherosclerotic plaques. Multiple lines of evidence support that enhancing foam cell cholesterol efflux by HDL (high-density lipoprotein) particles, the first step of reverse cholesterol transport (RCT), is a promising antiatherogenic strategy. Yet, excitement towards the therapeutic potential of manipulating RCT for the treatment of cardiovascular disease has faded because of the lack of the association between cardiovascular disease risk and what was typically measured in intervention trials, namely HDL cholesterol, which has an inconsistent relationship to HDL function and RCT. In this review, we will summarize some of the potential reasons for this inconsistency, update the mechanisms of RCT, and highlight conditions in which impaired HDL function or RCT contributes to vascular disease. On balance, the evidence still argues for further research to better understand how HDL functionality contributes to RCT to develop prevention and treatment strategies to reduce the risk of cardiovascular disease.
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Affiliation(s)
- Mireille Ouimet
- Department of Biochemistry, Microbiology and Immunology, Faculty of Medicine, University of Ottawa Heart Institute, University of Ottawa, Canada (M.O.)
| | - Tessa J Barrett
- Division of Cardiology, Department of Medicine, New York University School of Medicine, New York (T.J.B., E.A.F.)
| | - Edward A Fisher
- Division of Cardiology, Department of Medicine, New York University School of Medicine, New York (T.J.B., E.A.F.)
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5
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In vitro oxidized HDL and HDL from type 2 diabetes patients have reduced ability to efflux oxysterols from THP-1 macrophages. Biochimie 2018; 153:232-237. [PMID: 29704538 DOI: 10.1016/j.biochi.2018.04.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 04/23/2018] [Indexed: 02/02/2023]
Abstract
Oxidized LDL (OxLDL) that are enriched in products of lipid peroxidation including oxysterols have been shown to induce cellular oxidative stress and cytotoxicity therefore accelerating atheroma plaque formation. Upon oxLDL exposure of THP-1 macrophages, intracellular oxidation of LDL derived-cholesterol as well as endogenous cholesterol was increased. The oxysterols intracellularly produced were efficiently exported to HDL whereas apolipoprotein A1 was inefficient. These findings prompted us to investigate the consequences of modification of HDL by oxidation and glycation as observed in type 2 diabetes with respect to oxysterol and cholesterol efflux. We show that efflux of oxysterols was significantly impaired after in vitro oxidation and glycoxidation of HDL whereas glycation alone had no impact. Cholesterol efflux was only slightly decreased by oxHDL or glycoxidized HDL and not changed with glycated HDL. The defect of HDL towards oxysterol efflux was also observed with HDL isolated from diabetic subjects as compared to healthy controls. These findings support a deleterious cellular retention of oxysterols due to dysfunctional HDL in type 2 diabetes.
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6
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Impaired HDL cholesterol efflux in metabolic syndrome is unrelated to glucose tolerance status: the CODAM study. Sci Rep 2016; 6:27367. [PMID: 27270665 PMCID: PMC4897620 DOI: 10.1038/srep27367] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 05/13/2016] [Indexed: 12/27/2022] Open
Abstract
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.
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7
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Huang H, McIntosh AL, Landrock KK, Landrock D, Storey SM, Martin GG, Gupta S, Atshaves BP, Kier AB, Schroeder F. Human FABP1 T94A variant enhances cholesterol uptake. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:946-55. [PMID: 25732850 DOI: 10.1016/j.bbalip.2015.02.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 02/19/2015] [Accepted: 02/20/2015] [Indexed: 01/09/2023]
Abstract
Although expression of the human liver fatty acid binding protein (FABP1) T94A variant alters serum lipoprotein cholesterol levels in human subjects, nothing is known whereby the variant elicits these effects. This issue was addressed by in vitro cholesterol binding assays using purified recombinant wild-type (WT) FABP1 T94T and T94A variant proteins and in cultured primary human hepatocytes expressing the FABP1 T94T (genotyped as TT) or T94A (genotyped as CC) proteins. The human FABP1 T94A variant protein had 3-fold higher cholesterol-binding affinity than the WT FABP1 T94T as shown by NBD-cholesterol fluorescence binding assays and by cholesterol isothermal titration microcalorimetry (ITC) binding assays. CC variant hepatocytes also exhibited 30% higher total FABP1 protein. HDL- and LDL-mediated NBD-cholesterol uptake was faster in CC variant than TT WT human hepatocytes. VLDL-mediated uptake of NBD-cholesterol did not differ between CC and TT human hepatocytes. The increased HDL- and LDL-mediated NBD-cholesterol uptake was not associated with any significant change in mRNA levels of SCARB1, LDLR, CETP, and LCAT encoding the key proteins in lipoprotein cholesterol uptake. Thus, the increased HDL- and LDL-mediated NBD-cholesterol uptake by CC hepatocytes may be associated with higher affinity of T94A protein for cholesterol and/or increased total T94A protein level.
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Affiliation(s)
- Huan Huang
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA
| | - Avery L McIntosh
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA
| | - Kerstin K Landrock
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467, USA
| | - Danilo Landrock
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467, USA
| | - Stephen M Storey
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA
| | - Gregory G Martin
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA
| | - Shipra Gupta
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Barbara P Atshaves
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Ann B Kier
- Department of Pathobiology, Texas A&M University, TVMC, College Station, TX 77843-4467, USA
| | - Friedhelm Schroeder
- Department of Physiology and Pharmacology, Texas A&M University, TVMC, College Station, TX 77843-4466, USA.
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8
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Biomarkers associated with high-density lipoproteins in atherosclerotic kidney disease. Clin Exp Nephrol 2013; 18:247-50. [PMID: 24052156 DOI: 10.1007/s10157-013-0865-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Accepted: 08/29/2013] [Indexed: 10/26/2022]
Abstract
High-density lipoproteins (HDL) originate as discoidal particles that are rapidly converted by lecithin:cholesterol acyltransferase (LCAT) into the spherical particles that predominate in normal human plasma. Spherical HDL consist of multiple populations of particles that vary widely in size, composition and function. Human population studies have established that high plasma HDL cholesterol levels are associated with a reduced incidence of cardiovascular disease. The mechanistic basis of this relationship is not well understood, but most likely involves a number of the cardioprotective functions of HDL. These include the ability of apolipoprotein (apo) A-I, the main apolipoprotein constituent of HDL, to remove cholesterol from macrophages in the artery wall. HDL also have antioxidant and anti-inflammatory properties that are potentially cardioprotective. Evidence that some of these beneficial properties are compromised in people with diabetes and renal disease is emerging. Persistently elevated plasma glucose levels in people with diabetes and poor glycemic control can lead to irreversible, non-enzymatic glycation of plasma proteins, including apoA-I. Non-enzymatically glycated proteins are also prevalent in people with diabetes and end-stage renal disease who are at high cardiovascular risk. Evidence that non-enzymatically glycated apoA-I inhibits the LCAT reaction and impairs some of the cardioprotective properties of HDL is also emerging. This review is concerned with how non-enzymatic glycation of apoA-I affects the ability of LCAT to convert discoidal HDL into spherical HDL, how it affects cholesterol efflux from macrophages and how it affects the anti-inflammatory and antioxidant properties of HDL.
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9
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Brown BE, Nobecourt E, Zeng J, Jenkins AJ, Rye KA, Davies MJ. Apolipoprotein A-I glycation by glucose and reactive aldehydes alters phospholipid affinity but not cholesterol export from lipid-laden macrophages. PLoS One 2013; 8:e65430. [PMID: 23741493 PMCID: PMC3669297 DOI: 10.1371/journal.pone.0065430] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2012] [Accepted: 04/29/2013] [Indexed: 11/18/2022] Open
Abstract
Increased protein glycation in people with diabetes may promote atherosclerosis. This study examined the effects of non-enzymatic glycation on the association of lipid-free apolipoproteinA-I (apoA-I) with phospholipid, and cholesterol efflux from lipid-loaded macrophages to lipid-free and lipid-associated apoA-I. Glycation of lipid-free apoA-I by methylglyoxal and glycolaldehyde resulted in Arg, Lys and Trp loss, advanced glycation end-product formation and protein cross-linking. The association of apoA-I glycated by glucose, methylglyoxal or glycolaldehyde with phospholipid multilamellar vesicles was impaired in a glycating agent dose-dependent manner, with exposure of apoA-I to both 30 mM glucose (42% decrease in kslow) and 3 mM glycolaldehyde (50% decrease in kfast, 60% decrease in kslow) resulting is significantly reduced affinity. Cholesterol efflux to control or glycated lipid-free apoA-I, or discoidal reconstituted HDL containing glycated apoA-I (drHDL), was examined using cholesterol-loaded murine (J774A.1) macrophages treated to increase expression of ATP binding cassette transporters A1 (ABCA1) or G1 (ABCG1). Cholesterol efflux from J774A.1 macrophages to glycated lipid-free apoA-I via ABCA1 or glycated drHDL via an ABCG1-dependent mechanism was unaltered, as was efflux to minimally modified apoA-I from people with Type 1 diabetes, or controls. Changes to protein structure and function were prevented by the reactive carbonyl scavenger aminoguanidine. Overall these studies demonstrate that glycation of lipid-free apoA-I, particularly late glycation, modifies its structure, its capacity to bind phospholipids and but not ABCA1- or ABCG1-dependent cholesterol efflux from macrophages.
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Affiliation(s)
- Bronwyn E. Brown
- The Heart Research Institute, Sydney, New South Wales, Australia
- Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia
| | | | - Jingmin Zeng
- The Heart Research Institute, Sydney, New South Wales, Australia
| | - Alicia J. Jenkins
- Department of Medicine (St Vincent's), The University of Melbourne, Melbourne, Victoria, Australia
| | - Kerry-Anne Rye
- The Heart Research Institute, Sydney, New South Wales, Australia
- Department of Medicine (St Vincent's), The University of Melbourne, Melbourne, Victoria, Australia
- Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia
| | - Michael J. Davies
- The Heart Research Institute, Sydney, New South Wales, Australia
- Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia
- * E-mail:
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10
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Younis NN, Durrington PN. HDL functionality in diabetes mellitus: potential importance of glycation. ACTA ACUST UNITED AC 2012. [DOI: 10.2217/clp.12.60] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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11
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Freark de Boer J, Annema W, Schreurs M, van der Veen JN, van der Giet M, Nijstad N, Kuipers F, Tietge UJF. Type I diabetes mellitus decreases in vivo macrophage-to-feces reverse cholesterol transport despite increased biliary sterol secretion in mice. J Lipid Res 2011; 53:348-357. [PMID: 22180634 DOI: 10.1194/jlr.m018671] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Type I diabetes mellitus (T1DM) increases atherosclerotic cardiovascular disease; however, the underlying pathophysiology is still incompletely understood. We investigated whether experimental T1DM impacts HDL-mediated reverse cholesterol transport (RCT). C57BL/6J mice with alloxan-induced T1DM had higher plasma cholesterol levels (P < 0.05), particularly within HDL, and increased hepatic cholesterol content (P < 0.001). T1DM resulted in increased bile flow (2.1-fold; P < 0.05) and biliary secretion of bile acids (BA, 10.5-fold; P < 0.001), phospholipids (4.5-fold; P < 0.001), and cholesterol (5.5-fold; P < 0.05). Hepatic cholesterol synthesis was unaltered, whereas BA synthesis was increased in T1DM (P < 0.001). Mass fecal BA output was significantly higher in T1DM mice (1.5-fold; P < 0.05), fecal neutral sterol excretion did not change due to increased intestinal cholesterol absorption (2.1-fold; P < 0.05). Overall in vivo macrophage-to-feces RCT, using [(3)H]cholesterol-loaded primary mouse macrophage foam cells, was 20% lower in T1DM (P < 0.05), mainly due to reduced tracer excretion within BA (P < 0.05). In vitro experiments revealed unchanged cholesterol efflux toward T1DM HDL, whereas scavenger receptor class BI-mediated selective uptake from T1DM HDL was lower in vitro and in vivo (HDL kinetic experiments) (P < 0.05), conceivably due to increased glycation of HDL-associated proteins (+65%, P < 0.01). In summary, despite higher mass biliary sterol secretion T1DM impairs macrophage-to-feces RCT, mainly by decreasing hepatic selective uptake, a mechanism conceivably contributing to increased cardiovascular disease in T1DM.
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Affiliation(s)
- Jan Freark de Boer
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University Medical Center Groningen, Groningen, The Netherlands
| | - Wijtske Annema
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University Medical Center Groningen, Groningen, The Netherlands; Top Institute Food and Nutrition, Wageningen, The Netherlands
| | - Marijke Schreurs
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University Medical Center Groningen, Groningen, The Netherlands; Department of Pathology and Medical Biology, Medical Biology Section, Molecular Genetics, University Medical Center Groningen, Groningen, The Netherlands
| | - Jelske N van der Veen
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University Medical Center Groningen, Groningen, The Netherlands
| | - Markus van der Giet
- Medizinische Klinik IV-Nephrology, Charite-Campus Benjamin Franklin, Berlin, Germany
| | - Niels Nijstad
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University Medical Center Groningen, Groningen, The Netherlands
| | - Folkert Kuipers
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University Medical Center Groningen, Groningen, The Netherlands; Department of Laboratory Medicine, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands;, University Medical Center Groningen, Groningen, The Netherlands
| | - Uwe J F Tietge
- Department of Pediatrics, Center for Liver, Digestive, and Metabolic Diseases, University Medical Center Groningen, Groningen, The Netherlands; Top Institute Food and Nutrition, Wageningen, The Netherlands.
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12
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Abstract
High-density lipoprotein (HDL) plays an important protective role against atherosclerosis, and the anti-atherogenic properties of HDL include the promotion of cellular cholesterol efflux and reverse cholesterol transport (RCT), as well as antioxidant, anti-inflammatory and anticoagulant effects. RCT is a complex pathway, which transports cholesterol from peripheral cells and tissues to the liver for its metabolism and biliary excretion. The major steps in the RCT pathway include the efflux of free cholesterol mediated by cholesterol transporters from cells to the main extracellular acceptor HDL, the conversion of free cholesterol to cholesteryl esters and the subsequent removal of cholesteryl ester in HDL by the liver. The efficiency of RCT is influenced by the mobilization of cellular lipids for efflux and the intravascular remodelling and kinetics of HDL metabolism. Despite the increased cardiovascular risk in people with type 2 diabetes, current knowledge on RCT in diabetes is limited. In this article, abnormalities in RCT in type 2 diabetes mellitus and therapeutic strategies targeting HDL and RCT will be reviewed.
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Affiliation(s)
- K C B Tan
- Department of Medicine, University of Hong Kong, Hong Kong.
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13
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Ribeiro ICD, Iborra RT, Neves MQTS, Lottenberg SA, Charf AM, Nunes VS, Negrão CE, Nakandakare ER, Quintão ECR, Passarelli M. HDL atheroprotection by aerobic exercise training in type 2 diabetes mellitus. Med Sci Sports Exerc 2008; 40:779-86. [PMID: 18408623 DOI: 10.1249/mss.0b013e3181632d2d] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
PURPOSE In this study we analyzed the role played by aerobic exercise training in the plasma lipoprotein profile, prebeta 1-HDL concentration, and in the in vitro HDL3 ability to remove cholesterol from macrophages and inhibit LDL oxidation in type 2 diabetes mellitus (DM) patients and control subjects, in the fasting and postprandial states. METHODS Healthy controls (HTC, N = 11; 1 M/10 F) and subjects with type 2 diabetes mellitus (DMT, N = 11; 3M/8F) were engaged in a 4-month aerobic training program, and compared with a group of sedentary subjects with type 2 diabetes mellitus (DMS, N = 10; 4 M/6 F). All groups were submitted to an oral fat load test to analyze all parameters, both at the beginning of the investigation protocol (basal) and at the end of the study period (final). RESULTS Exercising did not modify body weight, BMI, plasma concentrations of total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides (TG), glucose, insulin, or HOMA-IR, but it reduced the waist circumference. The HDL3 composition did not change, and its ability to remove cell cholesterol was unaltered by aerobic training. In DMT but not in HTC, aerobic training improved 15% the HDL3 protective effect against LDL maximal oxidation rate in the fasting state, and reduced 24% the plasma prebeta 1-HDL concentration in the postprandial state, suggesting an enhanced prebeta 1-HDL conversion into larger, more mature HDL particles. In this regard, regular aerobic exercise enriched HDL2 with TG in the fasting and postprandial states in HTC and in the fasting phase in DMT. CONCLUSION Our results show that aerobic exercise training in diabetes mellitus improves the HDL efficiency against LDL oxidation and favors HDL maturation. These findings were independent of changes in insulin resistance and of the rise of plasma HDL cholesterol concentration.
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Affiliation(s)
- Isabel C D Ribeiro
- Lipids Laboratory, Faculty of Medical Sciences, University of São Paulo. São Paulo, Brazil
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14
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Iborra RT, Ribeiro ICD, Neves MQTS, Charf AM, Lottenberg SA, Negrão CE, Nakandakare ER, Passarelli M. Aerobic exercise training improves the role of high-density lipoprotein antioxidant and reduces plasma lipid peroxidation in type 2 diabetes mellitus. Scand J Med Sci Sports 2008; 18:742-50. [PMID: 18248546 DOI: 10.1111/j.1600-0838.2007.00748.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In this study, we analyzed the effect of aerobic exercise training (AET) and of a single bout of exercise on plasma oxidative stress and on antioxidant defenses in type 2 diabetes mellitus (DM) and in healthy control subjects (C). DM and C did not differ regarding triglycerides, high-density lipoprotein cholesterol (HDL-c), insulin, and HOMA index at baseline and after AET. To measure the lag time for low-density lipoprotein (LDL) oxidation (LAG) and the maximal rate of conjugated diene formation (MCD), participants' plasma HDL(2) and HDL(3) were incubated with LDL from pooled healthy donors' plasma. In the presence of HDL(3), both LAG and MCD were similar in C and DM, but only in DM did AET improve LAG and reduce MCD. In the presence of HDL(2), the lower baseline LAG in DM equaled C after AET. MCD was unchanged in DM after AET, but was lower than C only after AET. Furthermore, after AET plasma thiobarbituric acid-reactive substances were reduced only in DM subjects. Despite not modifying the total plasma antioxidant status and serum paraoxonase-1 activity in both groups, AET lowered the plasma lipid peroxides, corrected the HDL(2), and improved the HDL(3) antioxidant efficiency in DM independent of the changes in blood glucose, insulin, and plasma HDL concentration and composition.
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Affiliation(s)
- R T Iborra
- Lipids Laboratory (LIM 10), Faculty of Medical Sciences, University of São Paulo, São Paulo, SP, Brazil
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15
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Rosenblat M, Volkova N, Coleman R, Almagor Y, Aviram M. Antiatherogenicity of extra virgin olive oil and its enrichment with green tea polyphenols in the atherosclerotic apolipoprotein-E-deficient mice: enhanced macrophage cholesterol efflux. J Nutr Biochem 2007; 19:514-523. [PMID: 17904345 DOI: 10.1016/j.jnutbio.2007.06.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2007] [Revised: 05/29/2007] [Accepted: 06/13/2007] [Indexed: 02/06/2023]
Abstract
The antiatherogenic properties of extra virgin olive oil (EVOO) enriched with green tea polyphenols (GTPPs; hereafter called EVOO-GTPP), in comparison to EVOO, were studied in the atherosclerotic apolipoprotein-E-deficient (E0) mice. E0 mice (eight mice in each group) consumed EVOO or EVOO-GTPP (7 microl/mouse/day, for 2 months) by gavage feeding. The placebo group received only water. At the end of the study, blood samples, peritoneal macrophages and aortas were collected. Consumption of EVOO or EVOO-GTPP resulted in a minimal increase in serum total and high-density lipoprotein (HDL) cholesterol levels (by 12%) and in serum paraoxonase 1 activity (by 6% and 10%). EVOO-GTPP (but not EVOO) decreased the susceptibility of the mouse serum to AAPH-induced lipid peroxidation (by 18%), as compared to the placebo-treated mice. The major effect of both EVOO and EVOO-GTPP consumption was on HDL-mediated macrophage cholesterol efflux. Consumption of EVOO stimulated cholesterol efflux rate from mouse peritoneal macrophages (MPMs) by 42%, while EVOO-GTPP increased it by as much as 139%, as compared to MPMs from placebo-treated mice. Finally, the atherosclerotic lesion size of mice was significantly reduced by 11% or 20%, after consumption of EVOO or EVOO-GTPP, respectively. We thus conclude that EVOO possesses beneficial antiatherogenic effects, and its enrichment with GTPPs further improved these effects, leading to the attenuation of atherosclerosis development.
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Affiliation(s)
- Mira Rosenblat
- The Lipid Research Laboratory, Technion Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Rambam Medical Center, Haifa 31096, Israel
| | - Nina Volkova
- The Lipid Research Laboratory, Technion Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Rambam Medical Center, Haifa 31096, Israel
| | - Raymond Coleman
- Department of Anatomy and Cell Biology, Technion Faculty of Medicine, Haifa 31096, Israel
| | - Yaron Almagor
- Department of Cardiology, Shaarei Zedek Medical Center, Jerusalem 91031, Israel
| | - Michael Aviram
- The Lipid Research Laboratory, Technion Faculty of Medicine, The Rappaport Family Institute for Research in the Medical Sciences, Rambam Medical Center, Haifa 31096, Israel
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16
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de Vries R, Groen AK, Perton FG, Dallinga-Thie GM, van Wijland MJA, Dikkeschei LD, Wolffenbuttel BHR, van Tol A, Dullaart RPF. Increased cholesterol efflux from cultured fibroblasts to plasma from hypertriglyceridemic type 2 diabetic patients: roles of pre beta-HDL, phospholipid transfer protein and cholesterol esterification. Atherosclerosis 2007; 196:733-41. [PMID: 17275009 DOI: 10.1016/j.atherosclerosis.2006.12.027] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Revised: 12/03/2006] [Accepted: 12/21/2006] [Indexed: 11/26/2022]
Abstract
We tested whether hypertriglyceridemia associated with type 2 diabetes mellitus is accompanied by alterations in pre beta-HDL, which are considered to be initial acceptors of cell-derived cholesterol, and by changes in the ability of plasma to promote cellular cholesterol efflux. In 28 hypertriglyceridemic and 56 normotriglyceridemic type 2 diabetic patients, and in 56 control subjects, we determined plasma lipids, HDL cholesterol and phospholipids, plasma pre beta-HDL and pre beta-HDL formation, phospholipid transfer protein (PLTP) activity, plasma cholesterol esterification (EST) and cholesteryl ester transfer (CET) and the ability of plasma to stimulate cholesterol efflux out of cultured human fibroblasts. HDL cholesterol and HDL phospholipids were lower, whereas plasma PLTP activity, EST and CET were higher in hypertriglyceridemic diabetic patients than in the other groups. Pre beta-HDL levels and pre beta-HDL formation were unaltered, although the relative amount of pre beta-HDL (expressed as % of total plasma apo A-I) was increased in hypertriglyeridemic diabetic patients. Cellular cholesterol efflux to plasma from hypertriglyceridemic diabetic patients was increased compared to efflux to normotriglyceridemic diabetic and control plasma, but efflux to normotriglyceridemic diabetic and control plasma did not differ. Multiple linear regression analysis demonstrated that cellular cholesterol efflux to plasma was positively and independently related to pre beta-HDL formation, PLTP activity and EST (multiple r=0.48), but not to the diabetic state. In conclusion, cholesterol efflux from fibroblasts to normotriglyceridemic diabetic plasma is unchanged. Efflux to hypertriglyceridemic diabetic plasma is enhanced, in association with increased plasma PLTP activity and cholesterol esterification. Unaltered pre beta-HDL formation in diabetic hypertriglyceridemia, despite low apo A-I, could contribute to maintenance of cholesterol efflux.
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Affiliation(s)
- R de Vries
- Department of Endocrinology, University Medical Centre Groningen, University of Groningen, PO Box 30.001, Groningen, 9700 RB, The Netherlands
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17
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Catanozi S, Rocha JC, Passarelli M, Mesquita CH, Suguiama VY, Guzzo ML, dos Santos Filho A, Quintão ECR, Nakandakare ER. Diminished macrophage cholesterol removal rate by the altered HDL metabolism in the Nagase analbuminemic rat. Lipids 2006; 41:663-8. [PMID: 17069350 DOI: 10.1007/s11745-006-5017-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dyslipoproteinemia of the Nagase analbuminemic rat (NAR) is characterized by elevated concentrations of VLDL and LDL attributed to increased rates of liver lipoprotein synthesis. Increased lysophosphatidylcholine (LPC) in NAR HDL has been attributed to high plasma LCAT activity. We show here that, as compared with Sprague-Dawley rats (SDR), NAR plasma triacylglycerol (TAG), total cholesterol (TC), HDL TAG, protein, total phospholipids (PL), LPC, and PS are increased. These alterations rendered the NAR HDL particle more susceptible to the activity of the enzyme hepatic lipoprotein lipase (HL), which otherwise was unaltered in our study. Fractional catabolic rates in blood of the autologous 125I-apoHDL (median and lower quartile values), were, respectively, 0.231 and 1.645 (n = 10) in NAR as compared with 0.140 and 0.109 (n = 10) in SDR (P = 0.012), corresponding to synthesis rates of HDL protein of 89.8 +/- 33.7 mg/d in NAR and 17.4 +/- 6.5 mg/d in SDR (P = 0.0122). Furthermore, Swiss mouse macrophage free-cholesterol (FC) efflux rates, measured as the percent [14C]-cholesterol efflux/6 h, were 8.2 +/- 2.3 (n = 9) in NAR HDL and 11.2 +/- 3.2 (n = 10) in SDR HDL (P = 0.03). Therefore, in NAR the modification of the HDL composition slows down the cell FC efflux rate, and together with the increased rate of plasma HDL metabolism influences the reverse cholesterol transport system.
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Affiliation(s)
- Sergio Catanozi
- Lipids Laboratory (LIM 10), Faculty of Medical Sciences, University of São Paulo, São Paulo, Brazil.
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18
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Norata GD, Pirillo A, Catapano AL. Modified HDL: biological and physiopathological consequences. Nutr Metab Cardiovasc Dis 2006; 16:371-386. [PMID: 16829346 DOI: 10.1016/j.numecd.2006.01.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2005] [Accepted: 01/03/2006] [Indexed: 01/26/2023]
Abstract
Epidemiological and clinical studies have demonstrated the inverse association between HDL cholesterol levels (HDL-C) and the risk of coronary heart disease (CHD). This correlation is believed to relate to the ability of HDL to promote reverse cholesterol transport. Remodeling of HDL due to chemical/physical modifications can dramatically affect its functions, leading to dysfunctional HDL that could promote atherogenesis. HDL modification can be achieved by different means: (i) non-enzymatic modifications, owing to the presence of free metal ions in the atherosclerotic plaques; (ii) cell-associated enzymes, which can degrade the apoproteins without significant changes in the lipid moiety, or can alternatively induce apoprotein cross-linking and lipid oxidation; (iii) association with acute phase proteins, whose circulating levels are significantly increased during inflammation which may modify HDL structure and functions; and (iv) metabolic modifications, such as glycation that occurs under hyperglycaemic conditions. Available data suggest that HDL can easily be modified losing their anti-atherogenic activities. These observation results mainly from in vitro studies, while few in vivo data, are available. Furthermore the in vivo mechanisms involved in HDL modification are ill understood. A better knowledge of these pathways may provide possible therapeutic target aimed at reducing HDL modification.
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Machado AP, Pinto RS, Moysés ZP, Nakandakare ER, Quintão ECR, Passarelli M. Aminoguanidine and metformin prevent the reduced rate of HDL-mediated cell cholesterol efflux induced by formation of advanced glycation end products. Int J Biochem Cell Biol 2005; 38:392-403. [PMID: 16288898 DOI: 10.1016/j.biocel.2005.09.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2005] [Revised: 09/09/2005] [Accepted: 09/29/2005] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The mechanisms whereby advanced glycation end products (AGE) contribute to atherogenesis in diabetes mellitus are not fully understood. In this study we analyzed in vitro the influence of advanced glycated albumin (AGE-albumin) as well as the role of the AGE inhibitors--aminoguanidine (AMG) and metformin (MF)--on the cell cholesterol efflux. METHODS HDL3 and albumin-mediated cholesterol efflux was measured in mouse peritoneal macrophages and in SR-BI transfected cells that had been treated along time with dicarbonyl sugars or AGE-albumin, both in the presence or in the absence of AMG and MF. 125I-HDL3 cell binding and 125I-AGE-albumin cell degradation were measured. Carboxymethyllysine (CML) formation and SR-BI expressions were determined by immunoblot. RESULTS AGE-albumin efficiently trapped cell cholesterol but impaired the HDL-mediated cell cholesterol efflux by decreasing HDL binding to the cell surface and inducing intracellular glycoxidation, without interfering with the SR-BI expression. Cell treatment with dicarbonyl sugars also disrupted the HDL-mediated cell cholesterol efflux, but this was prevented by AMG and MF that reduced CML formation. CONCLUSIONS By adversely impairing the HDL-mediated cell cholesterol removal rate, AGE-albumin and cell glycoxidation could facilitate the development of premature atherosclerosis in diabetes mellitus (DM) and in other diseases associated with carbonyl and oxidative stress like in chronic uremia. Thus, drugs that prevent AGE formation may be useful to correct disturbances in cell cholesterol transport.
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Affiliation(s)
- Adriana P Machado
- Lipids Laboratory (LIM-10), University of São Paulo Medical School, Av. Dr. Arnaldo 455, Room 3317, CEP 01246-000 São Paulo, Brazil
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Wolffenbuttel BHR, Franken AAM, Vincent HH. Cholesterol-lowering effects of rosuvastatin compared with atorvastatin in patients with type 2 diabetes -- CORALL study. J Intern Med 2005; 257:531-9. [PMID: 15910557 DOI: 10.1111/j.1365-2796.2005.01499.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
OBJECTIVES To compare the efficacy of the newest cholesterol-lowering drug, rosuvastatin (RSV) with atorvastatin (ATV) in subjects with type 2 diabetes. DESIGN A 24-week, open-label, randomized, parallel-group, phase IIIb, multicentre study. SETTING Diabetes outpatient clinics of 26 hospitals in The Netherlands. SUBJECTS A total of 263 patients with type 2 diabetes treated with oral agents or insulin, age (mean +/- SD) 60 +/- 10 years, body mass index (BMI) 31.4 +/- 6.1 kg m(-2), 46% males. INTERVENTION After a 6-week dietary lead-in period, patients were randomized to RSV (n = 131) or ATV (n = 132) treatment in a dose escalation scheme (RSV: 10, 20 and 40 mg or ATV: 20, 40 and 80 mg for 6 weeks each sequentially). MAIN OUTCOME MEASURES Primary outcome was the change in apolipoprotein B (apoB) and apoB/apolipoprotein A1 (apoA1) ratio, which has been suggested a better predictor for cardiovascular events than total (TC) or low-density lipoprotein cholesterol (LDL-C). Secondary outcomes were the changes in other lipid parameters. RESULTS Baseline LDL-C in the RSV and ATV groups was 4.23 +/- 0.98 mmol L(-1) and 4.43 +/-0.99 mmol L(-1), whilst apoB/apoA1 was 0.86 +/-0.22 and 0.92 +/- 0.35, respectively. A greater reduction in apoB/apoA1 was seen with RSV (-34.9%, -39.2% and -40.5%) than with ATV (-32.4%, -34.7% and -35.8%, P < 0.05 at weeks 12 and 18). Significantly greater reductions in LDL-C were also seen with RSV (-45.9%, -50.6% and -53.6%) than with ATV (-41.3%, -45.6% and -47.8%, all P < 0.05). The American Diabetes Association (ADA) LDL-C goal of < 2.6 mmol L(-1) was reached by 82%, 84% and 92% of patients with RSV and 74%, 79% and 81% with ATV. Triglyceride reductions ranged from 16 to 24% and were not different between treatments. Both treatments were well-tolerated: nine patients in the RSV and 11 in the ATV group withdrew from treatment because of adverse events after randomization. CONCLUSION In subjects with type 2 diabetes, greater improvements of apoB/apoA1 and across the lipid profile were observed with RSV compared with ATV.
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de Vries R, Kerstens MN, Sluiter WJ, Groen AK, van Tol A, Dullaart RPF. Cellular cholesterol efflux to plasma from moderately hypercholesterolaemic type 1 diabetic patients is enhanced, and is unaffected by simvastatin treatment. Diabetologia 2005; 48:1105-13. [PMID: 15875154 DOI: 10.1007/s00125-005-1760-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2004] [Accepted: 02/07/2005] [Indexed: 01/06/2023]
Abstract
AIM/HYPOTHESIS Cellular cholesterol efflux to plasma is important in reverse cholesterol transport and may be affected by simvastatin in type 1 diabetes mellitus. METHODS In 14 moderately hypercholesterolaemic type 1 diabetic and 13 healthy men we determined plasma (apo)lipoproteins, pre-beta HDL formation, cholesteryl ester transfer protein (CETP) activity, phospholipid transfer protein (PLTP) activity, cholesterol esterification, cholesteryl ester transfer and the capacity of plasma to induce cholesterol efflux out of Fu5AH cells and fibroblasts. After diet run-in, diabetic patients were randomly treated with simvastatin 10, 20, 40 mg and placebo, once daily each, for 6 weeks in a double-blind crossover design. RESULTS Plasma very low density lipid protein (VLDL)+LDL cholesterol, LDL cholesterol, HDL phospholipids, apolipoprotein (apo) A-I, apo B, CETP activity, PLTP activity, cholesterol esterification, cholesteryl ester transfer and the capacity of plasma to induce cholesterol efflux from Fu5AH cells and fibroblasts were higher in diabetic patients. Pre-beta HDL formation was unaltered. Simvastatin treatment decreased VLDL+LDL cholesterol, LDL cholesterol, triglycerides and apo B, CETP activity, cholesterol esterification and cholesteryl ester transfer. HDL cholesterol increased and its change was correlated with the change in cholesteryl ester transfer. The ability to promote cholesterol efflux from Fu5AH cells and fibroblasts did not change after simvastatin. CONCLUSIONS/INTERPRETATION The capacity of plasma from moderately hypercholesterolaemic type 1 diabetic patients to induce cholesterol efflux out of Fu5AH cells and fibroblasts is enhanced, probably due to higher apo A-I, HDL phospholipids and PLTP activity. Simvastatin increases HDL cholesterol in type 1 diabetic patients via lowering of plasma cholesteryl ester transfer. The HDL changes after simvastatin do not increase cellular cholesterol efflux further.
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Affiliation(s)
- R de Vries
- Department of Endocrinology, University of Groningen and University Medical Center Groningen, P.O. Box 30.001, Groningen, 9700, The Netherlands.
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Borggreve SE, De Vries R, Dullaart RPF. Alterations in high-density lipoprotein metabolism and reverse cholesterol transport in insulin resistance and type 2 diabetes mellitus: role of lipolytic enzymes, lecithin:cholesterol acyltransferase and lipid transfer proteins. Eur J Clin Invest 2003; 33:1051-69. [PMID: 14636288 DOI: 10.1111/j.1365-2362.2003.01263.x] [Citation(s) in RCA: 191] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Insulin resistance and type 2 diabetes mellitus are generally accompanied by low HDL cholesterol and high plasma triglycerides, which are major cardiovascular risk factors. This review describes abnormalities in HDL metabolism and reverse cholesterol transport, i.e. the transport of cholesterol from peripheral cells back to the liver for metabolism and biliary excretion, in insulin resistance and type 2 diabetes mellitus. Several enzymes including lipoprotein lipase (LPL), hepatic lipase (HL) and lecithin: cholesterol acyltransferase (LCAT), as well as cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP), participate in HDL metabolism and remodelling. Lipoprotein lipase hydrolyses lipoprotein triglycerides, thus providing lipids for HDL formation. Hepatic lipase reduces HDL particle size by hydrolysing its triglycerides and phospholipids. A decreased postheparin plasma LPL/HL ratio is a determinant of low HDL2 cholesterol in insulin resistance. The esterification of free cholesterol by LCAT increases HDL particle size. Plasma cholesterol esterification is unaltered or increased in type 2 diabetes mellitus, probably depending on the extent of triglyceride elevation. Subsequent CETP action results in transfer of cholesteryl esters from HDL towards triglyceride-rich lipoproteins, and is involved in decreasing HDL size. An increased plasma cholesteryl ester transfer is frequently observed in insulin-resistant conditions, and is considered to be a determinant of low HDL cholesterol. Phospholipid transfer protein generates small pre beta-HDL particles that are initial acceptors of cell-derived cholesterol. Its activity in plasma is elevated in insulin resistance and type 2 diabetes mellitus in association with high plasma triglycerides and obesity. In insulin resistance, the ability of plasma to promote cellular cholesterol efflux may be maintained consequent to increases in PLTP activity and pre beta-HDL. However, cellular cholesterol efflux to diabetic plasma is probably impaired. Besides, cellular abnormalities that are in part related to impaired actions of ATP binding cassette transporter 1 and scavenger receptor class B type I are likely to result in diminished cellular cholesterol efflux in the diabetic state. Whether hepatic metabolism of HDL-derived cholesterol and subsequent hepatobiliary transport is altered in insulin resistance and type 2 diabetes mellitus is unknown. Specific CETP inhibitors have been developed that exert major HDL cholesterol-raising effects in humans and retard atherosclerosis in animals. As an increased CETP-mediated cholesteryl ester transfer represents a plausible metabolic intermediate between high triglycerides and low HDL cholesterol, studies are warranted to evaluate the effects of these agents in insulin resistance- and diabetes-associated dyslipidaemia.
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Affiliation(s)
- S E Borggreve
- Department of Endocrinology, University Hospital Groningen, Groningen, The Netherlands
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