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Andraski AB, Sacks FM, Aikawa M, Singh SA. Understanding HDL Metabolism and Biology Through In Vivo Tracer Kinetics. Arterioscler Thromb Vasc Biol 2024; 44:76-88. [PMID: 38031838 PMCID: PMC10842918 DOI: 10.1161/atvbaha.123.319742] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 11/07/2023] [Indexed: 12/01/2023]
Abstract
HDL (high-density lipoprotein), owing to its high protein content and small size, is the densest circulating lipoprotein. In contrast to lipid-laden VLDL (very-low-density lipoprotein) and LDL (low-density lipoprotein) that promote atherosclerosis, HDL is hypothesized to mitigate atherosclerosis via reverse cholesterol transport, a process that entails the uptake and clearance of excess cholesterol from peripheral tissues. This process is mediated by APOA1 (apolipoprotein A-I), the primary structural protein of HDL, as well as by the activities of additional HDL proteins. Tracer-dependent kinetic studies are an invaluable tool to study HDL-mediated reverse cholesterol transport and overall HDL metabolism in humans when a cardiovascular disease therapy is investigated. Unfortunately, HDL cholesterol-raising therapies have not been successful at reducing cardiovascular events suggesting an incomplete picture of HDL biology. However, as HDL tracer studies have evolved from radioactive isotope- to stable isotope-based strategies that in turn are reliant on mass spectrometry technologies, the complexity of the HDL proteome and its metabolism can be more readily addressed. In this review, we outline the motivations, timelines, advantages, and disadvantages of the various tracer kinetics strategies. We also feature the metabolic properties of select HDL proteins known to regulate reverse cholesterol transport, which in turn underscore that HDL lipoproteins comprise a heterogeneous particle population whose distinct protein constituents and kinetics likely determine its function and potential contribution to cholesterol clearance.
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Affiliation(s)
- Allison B. Andraski
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA
| | - Frank M. Sacks
- Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA
| | - Masanori Aikawa
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
| | - Sasha A. Singh
- Center for Interdisciplinary Cardiovascular Sciences, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA
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2
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Khan AA, Kim N, Korstanje R, Choi S. Loss-of-function mutation in Pcsk1 increases serum APOA1 level and LCAT activity in mice. Lab Anim Res 2022; 38:1. [PMID: 34996527 PMCID: PMC8739671 DOI: 10.1186/s42826-021-00111-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 12/29/2021] [Indexed: 01/20/2023] Open
Abstract
Background The convertase subtilisin/kexin family 1 gene (PCSK1) has been associated in various human genetics studies with a wide spectrum of metabolic phenotypes, including early-onset obesity, hyperphagia, diabetes insipidus, and others. Despite the evident influence of PCSK1 on obesity and the known functions of other PCSKs in lipid metabolism, the role of PCSK1 specifically in lipid and cholesterol metabolism remains unclear. This study evaluated the effect of loss of PCSK1 function on high-density lipoprotein (HDL) metabolism in mice. Results HDL cholesterol, apolipoprotein A1 (APOA1) levels in serum and liver, and the activities of two enzymes (lecithin-cholesterol acyltransferase, LCAT and phospholipid transfer protein, PLTP) were evaluated in 8-week-old mice with a non-synonymous single nucleotide mutation leading to an amino acid substitution in PCSK1, which results in a loss of protein’s function. Mutant mice had similar serum HDL cholesterol concentration but increased levels of serum total and mature APOA1, and LCAT activity in comparison to controls. Conclusions This study presents the first evaluation of the role of PCSK1 in HDL metabolism using a loss-of-function mutant mouse model. Further investigations will be needed to determine the underlying molecular mechanism.
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Affiliation(s)
| | - Nakyung Kim
- Cerebrovascular Haematology-Immunology Priority Research Center, Medical Science Research Institute, Dongguk University Ilsan Hospital, Goyang, 10326, Republic of Korea
| | - Ron Korstanje
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Seungbum Choi
- The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA. .,Cerebrovascular Haematology-Immunology Priority Research Center, Medical Science Research Institute, Dongguk University Ilsan Hospital, Goyang, 10326, Republic of Korea.
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3
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Singh SA, Andraski AB, Higashi H, Lee LH, Ramsaroop A, Sacks FM, Aikawa M. Metabolism of PLTP, CETP, and LCAT on multiple HDL sizes using the Orbitrap Fusion Lumos. JCI Insight 2021; 6:143526. [PMID: 33351780 PMCID: PMC7934878 DOI: 10.1172/jci.insight.143526] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/16/2020] [Indexed: 11/18/2022] Open
Abstract
Recent in vivo tracer studies demonstrated that targeted mass spectrometry (MS) on the Q Exactive Orbitrap could determine the metabolism of HDL proteins 100s-fold less abundant than apolipoprotein A1 (APOA1). In this study, we demonstrate that the Orbitrap Lumos can measure tracer in proteins whose abundances are 1000s-fold less than APOA1, specifically the lipid transfer proteins phospholipid transfer protein (PLTP), cholesterol ester transfer protein (CETP), and lecithin-cholesterol acyl transferase (LCAT). Relative to the Q Exactive, the Lumos improved tracer detection by reducing tracer enrichment compression, thereby providing consistent enrichment data across multiple HDL sizes from 6 participants. We determined by compartmental modeling that PLTP is secreted in medium and large HDL (alpha2, alpha1, and alpha0) and is transferred from medium to larger sizes during circulation from where it is catabolized. CETP is secreted mainly in alpha1 and alpha2 and remains in these sizes during circulation. LCAT is secreted mainly in medium and small HDL (alpha2, alpha3, prebeta). Unlike PLTP and CETP, LCAT’s appearance on HDL is markedly delayed, indicating that LCAT may reside for a time outside of systemic circulation before attaching to HDL in plasma. The determination of these lipid transfer proteins’ unique metabolic structures was possible due to advances in MS technologies.
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Affiliation(s)
- Sasha A Singh
- Center for Interdisciplinary Cardiovascular Sciences, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Allison B Andraski
- Department of Nutrition and Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
| | - Hideyuki Higashi
- Center for Interdisciplinary Cardiovascular Sciences, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Lang Ho Lee
- Center for Interdisciplinary Cardiovascular Sciences, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ashisha Ramsaroop
- Center for Interdisciplinary Cardiovascular Sciences, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Frank M Sacks
- Department of Nutrition and Department of Molecular Metabolism, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA.,Channing Division of Network Medicine, Department of Medicine, and
| | - Masanori Aikawa
- Center for Interdisciplinary Cardiovascular Sciences, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Channing Division of Network Medicine, Department of Medicine, and.,Center for Excellence in Vascular Biology, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
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4
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Vitali C, Remaley AT, Cuchel M. Is Low-Density Lipoprotein Cholesterol the Key to Interpret the Role of Lecithin:Cholesterol Acyltransferase in Atherosclerosis? Circulation 2018; 138:1008-1011. [PMID: 30354544 DOI: 10.1161/circulationaha.118.035358] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Cecilia Vitali
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia (C.V., M.C.)
| | - Alan T Remaley
- Lipoprotein Metabolism Section, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD (A.T.R.)
| | - Marina Cuchel
- Division of Translational Medicine and Human Genetics, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia (C.V., M.C.)
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5
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Bisgaier CL, Ackermann R, Rea T, Rodrigueza WV, Hartman D. ApoA-IMilano phospholipid complex (ETC-216) infusion in human volunteers. Insights into the phenotypic characteristics of ApoA-IMilano carriers. Pharmacol Res 2016; 111:86-99. [DOI: 10.1016/j.phrs.2016.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2015] [Revised: 05/02/2016] [Accepted: 05/02/2016] [Indexed: 12/15/2022]
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Dullaart RPF, Garcia E, Jeyarajah E, Gruppen EG, Connelly MA. Plasma phospholipid transfer protein activity is inversely associated with betaine in diabetic and non-diabetic subjects. Lipids Health Dis 2016; 15:143. [PMID: 27581838 PMCID: PMC5007837 DOI: 10.1186/s12944-016-0313-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 08/23/2016] [Indexed: 12/24/2022] Open
Abstract
Background The choline metabolite, betaine, plays a role in lipid metabolism, and may predict the development of cardiovascular disease and type 2 diabetes mellitus (T2DM). Phospholipid transfer protein (PLTP) and lecithin:cholesterol acyltransferase (LCAT) require phosphatidylcholine as substrate, raising the possibility that there is an intricate relationship of these protein factors with choline metabolism. Here we determined the relationships of PLTP and LCAT activity with betaine in subjects with and without T2DM. Methods Plasma betaine (nuclear magnetic resonance spectroscopy), PLTP activity (liposome-vesicle HDL system), LCAT activity (exogenous substrate assay) and (apo)lipoproteins were measured in 65 type 2 diabetic (T2DM) and in 55 non-diabetic subjects. Results PLTP and LCAT activity were elevated in T2DM (p < 0.05), whereas the difference in betaine was not significant. In age-, sex- and diabetes status-controlled correlation analysis, betaine was inversely correlated with triglycerides and positively with HDL cholesterol (p < 0.05 to 0.01). PLTP and LCAT activity were positively correlated with triglycerides and inversely with HDL cholesterol (p < 0.05 to 0.001). PLTP (r = −0.245, p = 0.006) and LCAT activity (r = −0.195, p = 0.035) were correlated inversely with betaine. The inverse association of PLTP activity with betaine remained significant after additional adjustment for body mass index and lipoprotein variables (β = −0.179, p = 0.034), whereas its association with LCAT activity lost significance (β = −0.056, p = 0.44). Conclusions Betaine may influence lipoprotein metabolism via an effect on PLTP activity.
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Affiliation(s)
- R P F Dullaart
- Department of Endocrinology, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, Groningen, 9700 RB, The Netherlands.
| | - Erwin Garcia
- LipoScience, Laboratory Corporation of America® Holdings, Raleigh, NC, USA
| | - Elias Jeyarajah
- LipoScience, Laboratory Corporation of America® Holdings, Raleigh, NC, USA
| | - Eke G Gruppen
- Departments of Endocrinology and Nephrology, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands
| | - Margery A Connelly
- LipoScience, Laboratory Corporation of America® Holdings, Raleigh, NC, USA
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7
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Siebel AL, Trinh SK, Formosa MF, Mundra PA, Natoli AK, Reddy-Luthmoodoo M, Huynh K, Khan AA, Carey AL, van Hall G, Cobelli C, Dalla-Man C, Otvos JD, Rye KA, Johansson J, Gordon A, Wong NCW, Sviridov D, Barter P, Duffy SJ, Meikle PJ, Kingwell BA. Effects of the BET-inhibitor, RVX-208 on the HDL lipidome and glucose metabolism in individuals with prediabetes: A randomized controlled trial. Metabolism 2016; 65:904-14. [PMID: 27173469 DOI: 10.1016/j.metabol.2016.03.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 02/18/2016] [Accepted: 03/03/2016] [Indexed: 12/14/2022]
Abstract
AIMS High-density lipoprotein (HDL) and apolipoprotein A-I (apoA-I) can modulate glucose metabolism through multiple mechanisms. This study determined the effects of a novel bromodomain and extra-terminal (BET) inhibitor (RVX-208) and putative apoA-I inducer on lipid species contained within HDL (HDL lipidome) and glucose metabolism. MATERIALS AND METHODS Twenty unmedicated males with prediabetes received 100mg b.i.d. RVX-208 and placebo for 29-33days separated by a wash-out period in a randomized, cross-over design trial. Plasma HDL-cholesterol and apoA-I were assessed as well as lipoprotein particle size and distribution using NMR spectroscopy. An oral glucose tolerance test (OGTT) protocol with oral and infused stable isotope tracers was employed to assess postprandial plasma glucose, indices of insulin secretion and insulin sensitivity, glucose kinetics and lipolysis. Whole plasma and HDL lipid profiles were measured using mass spectrometry. RESULTS RVX-208 treatment for 4weeks increased 6 sphingolipid and 4 phospholipid classes in the HDL lipidome (p≤0.05 versus placebo), but did not change conventional clinical lipid measures. The concentration of medium-sized HDL particles increased by 11% (P=0.01) and small-sized HDL particles decreased by 10% (P=0.04) after RVX-208 treatment. In response to a glucose load, after RVX-208 treatment, plasma glucose peaked at a similar level to placebo, but 30min later with a more sustained elevation (treatment effect, P=0.003). There was a reduction and delay in total (P=0.001) and oral (P=0.003) glucose rates of appearance in plasma and suppression of endogenous glucose production (P=0.014) after RVX-208 treatment. The rate of glucose disappearance was also lower following RVX-208 (P=0.016), with no effect on glucose oxidation or total glucose disposal. CONCLUSIONS RVX-208 increased 10 lipid classes in the plasma HDL fraction, without altering the concentrations of either apoA-I or HDL-cholesterol (HDL-C). RVX-208 delayed and reduced oral glucose absorption and endogenous glucose production, with plasma glucose maintained via reduced peripheral glucose disposal. If sustained, these effects may protect against the development of type 2 diabetes.
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Affiliation(s)
- Andrew L Siebel
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Si Khiang Trinh
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | | | | | - Alaina K Natoli
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | | | - Kevin Huynh
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Anmar A Khan
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Andrew L Carey
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Gerrit van Hall
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claudio Cobelli
- Department of Information Engineering, University of Padova, Padova, Italy
| | - Chiara Dalla-Man
- Department of Information Engineering, University of Padova, Padova, Italy
| | | | - Kerry-Anne Rye
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | | | | | | | - Dmitri Sviridov
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Philip Barter
- School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, Australia
| | | | - Peter J Meikle
- Baker IDI Heart and Diabetes Institute, Melbourne, Australia
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8
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Lacko AG, Sabnis NA, Nagarajan B, McConathy WJ. HDL as a drug and nucleic acid delivery vehicle. Front Pharmacol 2015; 6:247. [PMID: 26578957 PMCID: PMC4620406 DOI: 10.3389/fphar.2015.00247] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 10/12/2015] [Indexed: 01/13/2023] Open
Abstract
This review is intended to evaluate the research findings and potential clinical applications of drug transport systems, developed based on the concepts of the structure/function and physiological role(s) of high density lipoprotein type nanoparticles. These macromolecules provide targeted transport of cholesteryl esters (a highly lipophilic payload) in their natural/physiological environment. The ability to accommodate highly water insoluble constituents in their core regions enables High density lipoproteins (HDL) type nanoparticles to effectively transport hydrophobic drugs subsequent to systemic administration. Even though the application of reconstituted HDL in the treatment of a number of diseases is reviewed, the primary focus is on the application of HDL type drug delivery agents in cancer chemotherapy. The use of both native and synthetic HDL as drug delivery agents is compared to evaluate their respective potentials for commercial and clinical development. The current status and future perspectives for HDL type nanoparticles are discussed, including current obstacles and future applications in therapeutics.
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Affiliation(s)
- Andras G Lacko
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center , Fort Worth, TX, USA ; Department of Pediatrics, University of North Texas Health Science Center , Fort Worth, TX, USA
| | - Nirupama A Sabnis
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center , Fort Worth, TX, USA ; Department of Pediatrics, University of North Texas Health Science Center , Fort Worth, TX, USA
| | - Bhavani Nagarajan
- Department of Integrative Physiology and Anatomy, University of North Texas Health Science Center , Fort Worth, TX, USA
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9
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Javaheri A, Kolansky DM, Cuchel M. Reconstituted high-density lipoprotein therapies: a cause for optimism. Arterioscler Thromb Vasc Biol 2014; 34:1800-2. [PMID: 25142879 DOI: 10.1161/atvbaha.114.304156] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Ali Javaheri
- From the Division of Cardiovascular Medicine (A.J., D.M.K.) and Division of Translational Medicine and Human Genetics (M.C.), Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Daniel M Kolansky
- From the Division of Cardiovascular Medicine (A.J., D.M.K.) and Division of Translational Medicine and Human Genetics (M.C.), Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Marina Cuchel
- From the Division of Cardiovascular Medicine (A.J., D.M.K.) and Division of Translational Medicine and Human Genetics (M.C.), Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia.
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10
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Kingwell BA, Chapman MJ, Kontush A, Miller NE. HDL-targeted therapies: progress, failures and future. Nat Rev Drug Discov 2014; 13:445-64. [DOI: 10.1038/nrd4279] [Citation(s) in RCA: 256] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Randolph GJ, Miller NE. Lymphatic transport of high-density lipoproteins and chylomicrons. J Clin Invest 2014; 124:929-35. [PMID: 24590278 DOI: 10.1172/jci71610] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The life cycles of VLDLs and most LDLs occur within plasma. By contrast, the role of HDLs in cholesterol transport from cells requires that they readily gain access to and function within interstitial fluid. Studies of lymph derived from skin, connective tissue, and adipose tissue have demonstrated that particles as large as HDLs require transport through lymphatics to return to the bloodstream during reverse cholesterol transport. Targeting HDL for therapeutic purposes will require understanding its biology in the extravascular compartment, within the interstitium and lymph, in health and disease, and we herein review the processes that mediate the transport of HDLs and chylomicrons through the lymphatic vasculature.
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12
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Abstract
PURPOSE OF REVIEW New therapeutic strategies are needed for the rapid stabilization of acute coronary syndrome (ACS) patients by treating nonculprit lesions. Reconstituted HDL (rHDL), which is apoA-I combined with phospholipids, is currently being tested in clinical trials for this purpose and is the subject of this review. RECENT FINDINGS At least four different formulations (SRC-rHDL, CSL-111, CSL-112 and ETC-216) have been tested in clinical trials. The various rHDL preparations have been shown to be effective in the rapid mobilization of excess cholesterol from cells and in regressing atherosclerotic plaques in animal models. Two of the rHDL agents, namely ETC-216 and CSL-111, have been shown to be effective after only a few treatments in reducing plaque volume in ACS patients, as assessed by intravascular ultrasound, but no clinical trials assessing clinical endpoints have yet been completed. SUMMARY rHDL is a promising new potential therapy for ACS patients, but much work remains to be done, and there are many unresolved questions. Progress in developing rHDL into a therapy will depend on improving our understanding of their mechanism of action, determining the optimum formulation and delivery and how to monitor rHDL therapy.
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Affiliation(s)
- Brian R Krause
- aAlphaCore Pharma, Ann Arbor, Michigan bLipoprotein Metabolism Section, Cardiopulmonary Branch, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
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13
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Leman LJ, Maryanoff BE, Ghadiri MR. Molecules that mimic apolipoprotein A-I: potential agents for treating atherosclerosis. J Med Chem 2013; 57:2169-96. [PMID: 24168751 DOI: 10.1021/jm4005847] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Certain amphipathic α-helical peptides can functionally mimic many of the properties of full-length apolipoproteins, thereby offering an approach to modulate high-density lipoprotein (HDL) for combating atherosclerosis. In this Perspective, we summarize the key findings and advances over the past 25 years in the development of peptides that mimic apolipoproteins, especially apolipoprotein A-I (apoA-I). This assemblage of information provides a reasonably clear picture of the state of the art in the apolipoprotein mimetic field, an appreciation of the potential for such agents in pharmacotherapy, and a sense of the opportunities for optimizing the functional properties of HDL.
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Affiliation(s)
- Luke J Leman
- Department of Chemistry and The Skaggs Institute for Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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14
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Miller NE, Olszewski WL, Hattori H, Miller IP, Kujiraoka T, Oka T, Iwasaki T, Nanjee MN. Lipoprotein remodeling generates lipid-poor apolipoprotein A-I particles in human interstitial fluid. Am J Physiol Endocrinol Metab 2013; 304:E321-8. [PMID: 23233540 PMCID: PMC3566430 DOI: 10.1152/ajpendo.00324.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although much is known about the remodeling of high density lipoproteins (HDLs) in blood, there is no information on that in interstitial fluid, where it might have a major impact on the transport of cholesterol from cells. We incubated plasma and afferent (prenodal) peripheral lymph from 10 healthy men at 37°C in vitro and followed the changes in HDL subclasses by nondenaturing two-dimensional crossed immunoelectrophoresis and size-exclusion chromatography. In plasma, there was always initially a net conversion of small pre-β-HDLs to cholesteryl ester (CE)-rich α-HDLs. By contrast, in lymph, there was only net production of pre-β-HDLs from α-HDLs. Endogenous cholesterol esterification rate, cholesteryl ester transfer protein (CETP) concentration, CE transfer activity, phospholipid transfer protein (PLTP) concentration, and phospholipid transfer activity in lymph averaged 5.0, 10.4, 8.2, 25.0, and 82.0% of those in plasma, respectively (all P < 0.02). Lymph PLTP concentration, but not phospholipid transfer activity, was positively correlated with that in plasma (r = +0.63, P = 0.05). Mean PLTP-specific activity was 3.5-fold greater in lymph, reflecting a greater proportion of the high-activity form of PLTP. These findings suggest that cholesterol esterification rate and PLTP specific activity are differentially regulated in the two matrices in accordance with the requirements of reverse cholesterol transport, generating lipid-poor pre-β-HDLs in the extracellular matrix for cholesterol uptake from neighboring cells and converting pre-β-HDLs to α-HDLs in plasma for the delivery of cell-derived CEs to the liver.
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15
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Chen Z, O'Neill EA, Meurer RD, Gagen K, Luell S, Wang SP, Ichetovkin M, Frantz-Wattley B, Eveland S, Strack AM, Fisher TS, Johns DG, Sparrow CP, Wright SD, Hubbard BK, Carballo-Jane E. Reconstituted HDL Elicits Marked Changes in Plasma Lipids Following Single-Dose Injection in C57Bl/6 Mice. J Cardiovasc Pharmacol Ther 2011; 17:315-23. [DOI: 10.1177/1074248411426144] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Zhu Chen
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Edward A. O'Neill
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Roger D. Meurer
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Karen Gagen
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Silvi Luell
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Sheng-Ping Wang
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Marina Ichetovkin
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | | | - Suzanne Eveland
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Alison M. Strack
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Timothy S. Fisher
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Douglas G. Johns
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Carl P. Sparrow
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | | | - Brian K. Hubbard
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
| | - Ester Carballo-Jane
- Cardiovascular Diseases, Merck Sharp & Dohme Corp., Whitehouse Station, NJ, USA
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16
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Albers JJ, Vuletic S, Cheung MC. Role of plasma phospholipid transfer protein in lipid and lipoprotein metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:345-57. [PMID: 21736953 DOI: 10.1016/j.bbalip.2011.06.013] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Revised: 06/01/2011] [Accepted: 06/14/2011] [Indexed: 12/13/2022]
Abstract
The understanding of the physiological and pathophysiological role of PLTP has greatly increased since the discovery of PLTP more than a quarter of century ago. A comprehensive review of PLTP is presented on the following topics: PLTP gene organization and structure; PLTP transfer properties; different forms of PLTP; characteristics of plasma PLTP complexes; relationship of plasma PLTP activity, mass and specific activity with lipoprotein and metabolic factors; role of PLTP in lipoprotein metabolism; PLTP and reverse cholesterol transport; insights from studies of PLTP variants; insights of PLTP from animal studies; PLTP and atherosclerosis; PLTP and signal transduction; PLTP in the brain; and PLTP in human disease. PLTP's central role in lipoprotein metabolism and lipid transport in the vascular compartment has been firmly established. However, more studies are needed to further delineate PLTP's functions in specific tissues, such as the lung, brain and adipose tissue. Furthermore, the specific role that PLTP plays in human diseases, such as atherosclerosis, cancer, or neurodegenerative disease, remains to be clarified. Exciting directions for future research include evaluation of PLTP's physiological relevance in intracellular lipid metabolism and signal transduction, which undoubtedly will advance our knowledge of PLTP functions in health and disease. This article is part of a Special Issue entitled Advances in High Density Lipoprotein Formation and Metabolism: A Tribute to John F. Oram (1945-2010).
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Affiliation(s)
- John J Albers
- Northwest Lipid Metabolism and Diabetes Research Laboratories, Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, 401 Queen Anne Ave N, Seattle, WA 98109, USA.
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Dergunov AD. Apolipoprotein E genotype as a most significant predictor of lipid response at lipid-lowering therapy: mechanistic and clinical studies. Biomed Pharmacother 2011; 65:597-603. [PMID: 21705182 DOI: 10.1016/j.biopha.2011.04.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 04/14/2011] [Indexed: 11/24/2022] Open
Abstract
APOE alleles and apolipoprotein E isoforms control plasma cholesterol level on population level. Among three ɛ2, ɛ3, ɛ4 alleles, ɛ4 allele is associated with the increase in cholesterol level, risk of atherosclerosis and Alzheimer disease, while ɛ2 allele is associated with the decrease in cholesterol level and risk of atherosclerosis. The increase in plasma triglyceride is an independent risk factor of atherosclerosis and triglyceride-high density lipoprotein coupling determines the efficiency of reverse cholesterol transport. The impairment of this coupling specifically at hypertriglyceridemia may be followed by specific lipoprotein markers. The influence of major lipid-lowering drugs on lipoprotein metabolism and association of apoE isoforms with the efficiency of therapy by statins and fibrates are summarized both at isolated and combined increase in plasma triglyceride and cholesterol. APOE polymorphism seems to be a single genetic variant with a confirmed stratification both at candidate gene and at wide genome analyses.
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Affiliation(s)
- A D Dergunov
- National Research Centre for Preventive Medicine, 10, Petroverigsky Street, 101990 Moscow, Russia.
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18
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Abstract
Cholesterol efflux from lipid-loaded cells is a key athero-protective event that counteracts cholesterol uptake. The imbalance between cholesterol efflux and uptake determines the prevention or development of atherosclerosis. Many proteins and factors participate in the cholesterol efflux event. However, there are currently no systematic models of reverse cholesterol transport (RCT) that include most RCT-related factors and events. On the basis of recent research findings from other and our laboratories, we propose a novel model of one center and four systems with coupling transportation and networking regulation. This model represents a common way of cholesterol efflux; however, the systems in the model consist of different proteins/factors in different cells. In this review, we evaluate the novel model in vascular smooth muscle cells (VSMCs) and macrophages, which are the most important original cells of foam cells. This novel model consists of 1) a caveolae transport center, 2) an intracellular trafficking system of the caveolin-1 complex, 3) a transmembrane transport system of the ABC-A1 complex, 4) a transmembrane transport system of the SR-B1 complex, and 5) an extracelluar trafficking system of HDL/Apo-A1. In brief, the caveolin-1 system transports cholesterol from intracellular compartments to caveolae. Subsequently, both ABC-A1 and SR-B1 complex systems transfer cholesterol from caveolae to extracellular HDL/Apo-A1. The four systems are linked by a regulatory network. This model provides a simple and concise way to understand the dynamic process of atherosclerosis.
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Tardif JC. Emerging high-density lipoprotein infusion therapies: fulfilling the promise of epidemiology? J Clin Lipidol 2010; 4:399-404. [PMID: 21122683 DOI: 10.1016/j.jacl.2010.08.018] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2010] [Accepted: 08/18/2010] [Indexed: 12/20/2022]
Abstract
High-density lipoprotein (HDL) plays a key role in reverse cholesterol transport but also activates nitric oxide synthase and stimulates prostacyclin release, enhances endothelial repair, inhibits cell adhesion molecule expression on vascular endothelium and monocyte recruitment into the arterial wall, and exerts antithrombotic effects. In experimental animals, infusions of HDL or apolipoprotein A-1 (apoA-1) halt the progression or induce regression of atherosclerosis, with favorable effects on plaque composition. Remarkably, a benefit is observed after a single infusion. In a pilot study, weekly infusions of ETC-216, a formulation of recombinant apoA-1 Milano, were administered at two doses for 5 weeks to patients beginning within 2 weeks of an acute coronary syndrome (ACS). Among the 47 patients completing the study, percent atheroma volume by intracoronary ultrasound was reduced in the combined active treatment groups but not in the placebo group. In a larger trial, the Effect of rHDL on Atherosclerosis-Safety and efficacy (ERASE), 183 post-ACS patients were randomized to 4 weekly infusions of placebo or one of two doses of CSL-111, which consists of apoA-1 derived from human plasma and combined with soybean phosphatidylcholine. The greater dose was discontinued because of a high incidence of hepatic enzyme elevation. Among the 136 patients with evaluable end point data, percent change in atheroma volume, the primary endpoint, improved significantly in the CSL-111 group but not in the placebo group. The secondary end points of plaque characterization indices and quantitative coronary angiographic changes both improved significantly in the CSL-111 group compared with the group receiving placebo. Taken together, this evidence suggests that infusions of HDL or apoA-1 may reduce events, particularly among patients with ACS.
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Affiliation(s)
- Jean-Claude Tardif
- Department of Medicine, Research Centre, Montreal Heart Institute, 5000 Belanger Street, Montreal, Quebec H1T1C8, Canada.
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20
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Jafri H, Alsheikh-Ali AA, Karas RH. Baseline and on-treatment high-density lipoprotein cholesterol and the risk of cancer in randomized controlled trials of lipid-altering therapy. J Am Coll Cardiol 2010; 55:2846-54. [PMID: 20579542 DOI: 10.1016/j.jacc.2009.12.069] [Citation(s) in RCA: 121] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 12/14/2009] [Accepted: 12/17/2009] [Indexed: 02/07/2023]
Abstract
OBJECTIVES We sought to examine the relationship between high-density lipoprotein cholesterol (HDL-C) levels and the risk of the development of cancer in large randomized controlled trials (RCTs) of lipid-altering interventions. BACKGROUND Epidemiologic data demonstrate an inverse relationship between serum total cholesterol levels and incident cancer. We recently reported that lower levels of low-density lipoprotein cholesterol are associated with a significantly higher risk of incident cancer in a meta-analysis of large RCTs of statin therapy. However, little is known about the relationship between HDL-C levels and cancer risk. METHODS A systematic MEDLINE search identified lipid intervention RCTs with >or=1,000 person-years of follow-up, providing baseline HDL-C levels and rates of incident cancer. Using random-effects meta-regressions, we evaluated the relationship between baseline HDL-C and incident cancer in each RCT arm. RESULTS A total of 24 eligible RCTs were identified (28 pharmacologic intervention arms and 23 control arms), with 625,477 person-years of follow-up and 8,185 incident cancers. There was a significant inverse association between baseline HDL-C levels and the rate of incident cancer (p = 0.018). The inverse association persisted after adjusting for baseline low-density lipoprotein cholesterol, age, body mass index (BMI), diabetes, sex, and smoking status, such that for every 10-mg/dl increment in HDL-C, there was a 36% (95% confidence interval: 24% to 47%) relatively lower rate of the development of cancer (p < 0.001). CONCLUSIONS There is a significant inverse association between HDL-C and the risk of incident cancer that is independent of LDL-C, age, BMI, diabetes, sex, and smoking.
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Affiliation(s)
- Haseeb Jafri
- Molecular Cardiology Research Institute, Department of Medicine, Tufts Medical Center and Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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21
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Apolipoprotein A-I mimetic peptides: a potential new therapy for the prevention of atherosclerosis. Cardiol Rev 2010; 18:141-7. [PMID: 20395699 DOI: 10.1097/crd.0b013e3181c4b508] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The beneficial effects of high-density lipoprotein (HDL) on atherosclerosis have largely been attributed to its major protein, apolipoprotein A-I (apoA-I). Used as a therapeutic intervention, apoA-I is a large protein that requires venous administration, and is both difficult and expensive to manufacture. Because of these problems with apoA-I, the generation of smaller, easier to manufacture apoA-I mimetic peptides has become a target for pharmacologic development in the therapeutic management of human atherosclerosis. A potent apoA-I mimetic peptide, 4F, was found to have significant activity in various inflammatory states in both mice and monkeys. The anti-inflammatory and antiatherogenic effects of 4F include increased pre-beta HDL formation, increased cholesterol efflux, the conversion of pro-inflammatory HDL to anti-inflammatory HDL, and reduced lipoprotein oxidation. In addition, improved arterial vasoreactivity is another important function of 4F. In a rat model of diabetes, D-4F increased arterial concentrations of heme oxygenase-1 (HO-1) and superoxide dismutase, decreased superoxide levels, reduced levels of circulating endothelial cells, decreased endothelial cell fragmentation, and restored arterial vasoreactivity to normal. In a mouse model of systemic sclerosis, D-4F functioned to improve vasodilation and angiogenic potential, while reducing myocardial inflammation and oxidative stress. With respect to mouse models of heart transplant-associated atherosclerosis, D-4F induced HO-1. In addition, D-4F was shown to improve cognitive performance in low-density lipoprotein-receptor null mice with Western diet-induced cognitive decline. D-4F also reduced the kidney content of oxidized phospholipids in a mouse model of hyperlipidemia-induced renal inflammation. In early human studies in patients with significant cardiovascular risk, a single dose of oral D-4F was found to safely improve the anti-inflammatory index of HDL. L-4F is also being studied in clinical trials as a potential treatment modality for obesity and the metabolic syndrome.
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Cuchel M, Lund-Katz S, de la Llera-Moya M, Millar JS, Chang D, Fuki I, Rothblat GH, Phillips MC, Rader DJ. Pathways by which reconstituted high-density lipoprotein mobilizes free cholesterol from whole body and from macrophages. Arterioscler Thromb Vasc Biol 2009; 30:526-32. [PMID: 20018934 DOI: 10.1161/atvbaha.109.196105] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Reconstituted high-density lipoprotein (rHDL) is of interest as a potential novel therapy for atherosclerosis because of its ability to promote free cholesterol (FC) mobilization after intravenous administration. We performed studies to identify the underlying molecular mechanisms by which rHDL promote FC mobilization from whole body in vivo and macrophages in vitro. METHODS AND RESULTS Wild-type (WT), SR-BI knockout (KO), ABCA1 KO, and ABCG1 KO mice received either rHDL or phosphate-buffered saline intravenously. Blood was drawn before and at several time points after injection for apolipoprotein A-I, phosphatidylcholine, and FC measurement. In WT mice, serum FC peaked at 20 minutes and rapidly returned toward baseline levels by 24 hours. Unexpectedly, ABCA1 KO and ABCG1 KO mice did not differ from WT mice regarding the kinetics of FC mobilization. In contrast, in SR-BI KO mice the increase in FC level at 20 minutes was only 10% of that in control mice (P<0.01). Bone marrow-derived macrophages from WT, SR-BI O, ABCA1 KO, and ABCG1 KO mice were incubated in vitro with rHDL and cholesterol efflux was determined. Efflux from SR-BI KO and ABCA1 KO macrophages was not different from WT macrophages. In contrast, efflux from ABCG1 KO macrophages was approximately 50% lower as compared with WT macrophages (P<0.001). CONCLUSIONS The bulk mobilization of FC observed in circulation after rHDL administration is primarily mediated by SR-BI. However, cholesterol mobilization from macrophages to rHDL is primarily mediated by ABCG1.
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Affiliation(s)
- Marina Cuchel
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Maloney Building, Room 8039, 3600 Spruce Street, Philadelphia, PA 19104, USA.
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Meyer P, Nigam A, Marcil M, Tardif JC. The therapeutic potential of high-density lipoprotein mimetic agents in coronary artery disease. Curr Atheroscler Rep 2009; 11:329-33. [DOI: 10.1007/s11883-009-0049-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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24
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Abstract
Strategies to decrease the progression and burden of atherosclerosis by capitalizing on the protective effect of high-density lipoprotein (HDL) and/or apolipoprotein A1 (apoA-I) levels remain active. Although efforts to raise HDL through the administration of oral agents are still being pursued, the disappointing results demonstrated with torcetrapib, an agent that elevated serum HDL and apoA-I levels through the inhibition of cholesterol ester transfer protein, have raised questions regarding this approach. An alternate strategy that consists of short-term infusions of reconstituted HDL or apoA-I is currently under evaluation. Several infusion compounds have been evaluated in clinical trials that utilize cardiovascular imaging technologies and biomarkers to assess potential clinical efficacy. Although these compounds are still in early-stage development, the results of these trials have supported the viability of this line of investigation. This review addresses the potential of HDL and/or apoA-I infusions as a possible therapeutic strategy for the treatment of coronary artery disease.
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Kapur NK, Ashen D, Blumenthal RS. High density lipoprotein cholesterol: an evolving target of therapy in the management of cardiovascular disease. Vasc Health Risk Manag 2008; 4:39-57. [PMID: 18629371 PMCID: PMC2464766 DOI: 10.2147/vhrm.2008.04.01.39] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Since the pioneering work of John Gofman in the 1950s, our understanding of high density lipoprotein cholesterol (HDL-C) and its relationship to coronary heart disease (CHD) has grown substantially. Numerous clinical trials since the Framingham Study in 1977 have demonstrated an inverse relationship between HDL-C and one’s risk of developing CHD. Over the past two decades, preclinical research has gained further insight into the nature of HDL-C metabolism, specifically regarding the ability of HDL-C to promote reverse cholesterol transport (RCT). Recent attempts to harness HDL’s ability to enhance RCT have revealed the complexity of HDL-C metabolism. This review provides a detailed update on HDL-C as an evolving therapeutic target in the management of cardiovascular disease.
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Affiliation(s)
- Navin K Kapur
- Division of Cardiology, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.
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26
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Shah PK. Emerging HDL-based therapies for atherothrombotic vascular disease. CURRENT TREATMENT OPTIONS IN CARDIOVASCULAR MEDICINE 2008; 9:60-70. [PMID: 17378977 DOI: 10.1007/s11936-007-0052-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Statin therapy has been a significant advance in the management of dyslipidemia and atherothrombotic cardiovascular disease with a resultant 30% to 40% reduction in cardiovascular events; however, a significant number of events continue to occur in statin-treated patients, including in patients treated with high-dose statins targeted to achieve mean low-density lipoprotein cholesterol levels in the range of 60 to 80 mg/dL. Therefore, development and testing of new therapies that exploit the vascular protective effects of high-density lipoprotein (HDL) constitutes a rational and complementary approach. A number of HDL-based therapies are in various stages of development and testing. It is hoped that one or more of these new HDL-based therapies, if proven effective and safe, will become a part of our armamentarium against vaso-occlusive cardiovascular disease. A paradigm could emerge in which patients recovering from acute coronary syndromes and at high risk of recurrent events could be treated with rapid-acting HDL-based therapy, such as infusions of recombinant HDL or even HDL delipidation, followed by more sustained long-term HDL-based therapies, such as oral agents and perhaps even HDL-based gene therapy.
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Affiliation(s)
- Prediman K Shah
- Division of Cardiology and Atherosclerosis Research Center, Cedars Sinai Medical Center, Suite 5531, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA.
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27
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Sanyal S, Karas RH, Kuvin JT. Present-day uses of niacin: effects on lipid and non-lipid parameters. Expert Opin Pharmacother 2007; 8:1711-7. [PMID: 17685887 DOI: 10.1517/14656566.8.11.1711] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Existing guidelines for the prevention and treatment of coronary artery disease focus on lowering low-density lipoprotein cholesterol (LDL-C) as the primary lipid target. However, there has been increasing interest in raising high-density lipoprotein cholesterol (HDL-C) due to strong evidence linking low HDL-C levels with an increased risk of atherosclerosis. Raising HDL-C levels with lifestyle changes and pharmacologic interventions appear to reduce the risk of coronary artery disease beyond that of lowering LDL-C alone. Niacin has a substantial HDL-C raising effect, and also may beneficially alter total cholesterol, LDL-C and triglyceride levels. Niacin also exhibits antioxidant, anti-inflammatory and other beneficial effects on atherosclerosis. Niacin is safe and effective to use in women, in patients with diabetes mellitus and/or metabolic syndrome, and when used in combination with statins. Niacin has the promise of being a powerful pharmacologic agent in the fight against atherosclerotic disease, although additional clinical studies are required to examine this further.
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Affiliation(s)
- Sanjukta Sanyal
- Tufts-New England Medical Center, Department of Medicine, Division of Cardiology, Boston, Massachusetts 02111, USA
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Navab M, Anantharamaiah GM, Reddy ST, Fogelman AM. Apolipoprotein A-I mimetic peptides and their role in atherosclerosis prevention. ACTA ACUST UNITED AC 2006; 3:540-7. [PMID: 16990839 DOI: 10.1038/ncpcardio0661] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Accepted: 06/23/2006] [Indexed: 11/09/2022]
Abstract
The importance of apolipoprotein A-I (apoA-I) in atherosclerosis was established by testing in animal models, and its potential usefulness in humans has been confirmed in preliminary studies. ApoA-I is a large protein comprising 243 amino acids, which means that venous administration is necessary. In addition, manufacture of apoA-I is difficult and expensive. Research has, therefore, been directed towards finding smaller peptide mimetics that produce similar results to apoA-I, but that are easier to manufacture and administer. The earliest peptides mimicked some of the lipid-binding properties of apoA-I but did not prevent atherosclerosis in mice. A detailed study of the physical-chemical characteristics of these peptides led to the realization that the hydrophobic region of the peptide was critical in determining bioactivity. A potent peptide, 4F, which was synthesized wholly from D-amino acids, could be given orally. Use of 4F significantly improved the function of HDL in mice and monkeys. When 4F was administered in combination with a statin, lesion size and macrophage content were reduced in mice with atherosclerosis, and lesions regressed in older mice. Vasoreactivity and endothelial sloughing were also improved in other rodent studies. Early human clinical trials are now being carried out on 4F. Here, we review the studies on apoA-I mimetic peptides that have been carried out so far.
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Affiliation(s)
- Mohamad Navab
- Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA.
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Navab M, Anantharamaiah GM, Reddy ST, Van Lenten BJ, Datta G, Garber D, Fogelman AM. Potential clinical utility of high-density lipoprotein-mimetic peptides. Curr Opin Lipidol 2006; 17:440-4. [PMID: 16832169 DOI: 10.1097/01.mol.0000236371.27508.d4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW To determine the potential clinical utility of high-density lipoprotein-mimetic peptides. RECENT FINDINGS Oral administration of D-4F together with pravastatin caused lesion regression in old apoE null mice. Administration of D-4F to low-density lipoprotein receptor null mice fed a Western diet reduced the association of myeloperoxidase with apoA-I and reduced the 3-nitrotyrosine content of apoA-I. Oral D-4F improved arterial vasoreactivity independent of apoA-I. Mice genetically lacking apoA-I showed significant improvement in vasoreactivity but, in contrast to mice with apoA-I, did not demonstrate reduced arterial wall thickness after D-4F treatment. In a rat model of diabetes, D-4F administration induced heme oxygenase-1 and extracellular superoxide dismutase, prevented endothelial sloughing, and dramatically improved arterial vasoreactivity. A peptide with 10 D-amino acid residues taken from the sequence of apoJ rendered high-density lipoprotein anti-inflammatory in mice and monkeys, and dramatically reduced atherosclerosis in apoE null mice. Oral administration of tetrapeptides synthesized from either L-amino acids or D-amino acids rendered high-density lipoprotein anti-inflammatory in mice and monkeys, and reduced atherosclerosis in apoE null mice. SUMMARY Peptides that sequester lipoprotein lipid hydroperoxides release a series of high-density lipoprotein-associated antioxidant enzymes such as paraoxonase from inhibition and protect apoA-I from oxidative damage that would impair cholesterol efflux.
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Affiliation(s)
- Mohamad Navab
- David Geffen School of Medicine at UCLA, Los Angeles, California, USA.
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Cheung MC, Albers JJ. Active plasma phospholipid transfer protein is associated with apoA-I- but not apoE-containing lipoproteins. J Lipid Res 2006; 47:1315-21. [PMID: 16520487 DOI: 10.1194/jlr.m600042-jlr200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Plasma phospholipid transfer protein (PLTP) is a multifaceted protein with diverse biological functions. It has been shown to exist in both active and inactive forms. To determine the nature of lipoproteins associated with active PLTP, plasma samples were adsorbed with anti-A-I, anti-A-II, or anti-E immunoadsorbent, and PLTP activity was measured in the resulting plasma devoid of apolipoprotein A-I (apoA-I), apoA-II, or apoE. Anti-A-I and anti-A-II immunoadsorbents removed 98 +/- 1% (n = 8) and 38 +/- 25% (n = 7) of plasma PLTP activity, respectively. In contrast, only 1 +/- 5% of plasma PLTP activity was removed by anti-E immunoadsorbent (n = 7). Dextran sulfate (DS) cellulose did not bind apoA-I, but it removed 83 +/- 5% (n = 4) of the PLTP activity in plasma. In size-exclusion chromatography, PLTP activity removed by anti-A-I or anti-A-II immunoadsorbent was associated primarily with particles of a size corresponding to HDL, whereas a substantial portion of the PLTP activity dissociated from DS cellulose was found in particles larger or smaller than HDL. These data show the following: 1) active plasma PLTP is associated primarily with apoA-I- but not apoE-containing lipoproteins; 2) active PLTP is present in HDL particles with and without apoA-II, and its distribution between these two HDL subpopulations varies widely among individuals; and 3) DS cellulose can remove active PLTP from apoA-I-containing lipoproteins, and this process creates new active PLTP-containing particles in vitro.
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Affiliation(s)
- Marian C Cheung
- Division of Metabolism, Endocrinology, and Nutrition, Department of Medicine, School of Medicine, University of Washington, Seattle, WA, USA.
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31
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Oomen PHN, van Tol A, Hattori H, Smit AJ, Scheek LM, Dullaart RPF. Human plasma phospholipid transfer protein activity is decreased by acute hyperglycaemia: studies without and with hyperinsulinaemia in Type 1 diabetes mellitus. Diabet Med 2005; 22:768-74. [PMID: 15910630 DOI: 10.1111/j.1464-5491.2005.01521.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
AIMS Little is known about the regulation of phospholipid transfer protein (PLTP), that plays a key role in lipoprotein metabolism. PLTP secretion may be up-regulated by glucose in vitro, whereas plasma PLTP activity is decreased by exogenous hyperinsulinaemia and glucose-induced hyperinsulinaemia in vivo. In the present study, we evaluated the separate effects of hyperglycaemia and hyperinsulinaemia in C-peptide-negative Type 1 diabetic patients. METHODS The protocol was carried out in 16 patients (eight females). In each individual, plasma PLTP mass and activity (measured by enzyme-linked immuno-sorbent assay and liposome-high density lipoprotein system, respectively) as well as plasma cholesteryl ester transfer protein (CETP) activity, lipids and apolipoprotein levels were determined at the end of four different glucose clamps, each lasting 210 min: standard insulin (30 mU/kg/h) and standard glucose (glucose 5.0 mmol/l) (SI-SG), standard insulin and high glucose (glucose 12 mmol/l) (SI-HG), high insulin (150 mU/kg/h) and standard glucose (HI-SG), and high insulin and high glucose (HI-HG). RESULTS Plasma lipids and (apo)lipoproteins, measured at the end of the SI-HG, HI-SG and HI-HG clamps, were not significantly different compared with the levels obtained at the end of the SI-SG clamp. Median plasma PLTP mass and activity at the end of the SI-SG clamp were 12.8 mg/l and 13.2 micromol/ml/h, respectively. Median plasma PLTP mass decreased by 9.1% at the end of the HI-HG clamp (P < 0.01), whereas the changes at the end of the SI-HG and HI-SG clamps were not significant. Median plasma PLTP activity decreased by 5.7, 4.6 and 8.6% at the end of the SI-HG, HI-SG and HI-HG clamps, respectively (all P < 0.05). Median plasma CETP activity was 177 nmol/ml/h at the end of the SI-SG clamp, and decreased by 4.9% (P < 0.05) and by 8.3% (P < 0.05) at the end of the HI-SG and the HI-HG clamps, respectively. Plasma CETP activity did not change significantly at the end of the SI-HG clamp. CONCLUSIONS The present study demonstrates that plasma PLTP activity is independently decreased by acute hyperglycaemia and hyperinsulinaemia in humans in vivo. These data do not support a direct role of short-term hyperglycaemia in up-regulating plasma PLTP levels.
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Affiliation(s)
- P H N Oomen
- Department of Endocrinology, University Hospital Groningen, Groningen, The Netherlands.
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Navab M, Anantharamaiah GM, Reddy ST, Van Lenten BJ, Datta G, Garber D, Fogelman AM. Human apolipoprotein A-I and A-I mimetic peptides: potential for atherosclerosis reversal. Curr Opin Lipidol 2004; 15:645-9. [PMID: 15529023 DOI: 10.1097/00041433-200412000-00004] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Recent publications related to the potential use of apolipoprotein (apo)A-I and apoA-I mimetic peptides in the treatment of atherosclerosis are reviewed. RECENT FINDINGS A preliminary report indicating that infusion of apoA-IMilano into humans once weekly for 5 weeks caused a significant decrease in coronary artery atheroma volume has sparked great interest in the potential therapeutic use of apoA-I. Recent studies have revealed that HDL quality (e.g. HDL apolipoprotein and lipid content, including oxidized lipids, particle size and electrophoretic mobility, associated enzymatic activities, inflammatory/anti-inflammatory properties, and ability to promote cholesterol efflux) may be more important than HDL-cholesterol levels. Therefore, when developing new strategies to raise HDL-cholesterol concentrations by interfering with HDL metabolism, one must consider the quality of the resulting HDL. In animal models, raising HDL-cholesterol levels by administering oral phospholipids improved both the quantity and quality of HDL and was associated with lesion regression. An apoA-I mimetic peptide, namely 4F synthesized from D-amino acids (D-4F), administered orally to mice did not raise HDL-cholesterol concentrations but promoted the formation of pre-beta HDL containing increased paraoxonase activity, resulting in significant improvements in HDL's anti-inflammatory properties and ability to promote cholesterol efflux from macrophages in vitro. Oral D-4F also promoted reverse cholesterol efflux from macrophages in vivo. SUMMARY The quality of HDL may be more important than HDL-cholesterol levels. ApoA-I and apoA-I mimetic peptides appear to have significant therapeutic potential in atherosclerosis.
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Affiliation(s)
- Mohamad Navab
- David Geffen School of Medicine at UCLA, Los Angeles, California 90095, USA.
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Kujiraoka T, Hattori H, Ito M, Nanjee MN, Ishihara M, Nagano M, Iwasaki T, Cooke CJ, Olszewski WL, Stepanova IP, Egashira T, Miller NE. Effects of intravenous apolipoprotein A-I/phosphatidylcholine discs on paraoxonase and platelet-activating factor acetylhydrolase in human plasma and tissue fluid. Atherosclerosis 2004; 176:57-62. [PMID: 15306175 DOI: 10.1016/j.atherosclerosis.2004.03.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Revised: 03/01/2004] [Accepted: 03/19/2004] [Indexed: 11/25/2022]
Abstract
We have previously shown that intravenous apolipoprotein (apo) A-I/phosphatidylcholine (apo A-I/PC) discs increase plasma high-density lipoprotein (HDL) concentration in humans. We have now studied the associated changes in two enzymes, paraoxonase (PON) and platelet-activating factor acetylhydrolase (PAF-AH) that are carried in whole or in part by HDLs, and are thought to influence atherogenesis by hydrolyzing oxidized phospholipids in lipoproteins. Apo A-I/PC discs (40 mg/kg over 4 h) were infused into eight healthy males. Although plasma apo A-I and HDL cholesterol increased on average by 178 and 158%, respectively, plasma total PON and total PAF-AH concentrations did not rise. By the end of the infusion, HDL-associated PAF-AH had increased by 0.56 +/- 0.14 microg/mL (mean +/- S.D., P < 0.01), and nonHDL-associated PAF-AH had decreased by 0.84 +/- 0.11 microg/mL (P < 0.05). These changes were accompanied by an increase in the HDL-associated PAF-AH/apo A-I ratio from 0.19 to 0.35 (P < 0.05), and by a decrease in the nonHDL-associated PAF-AH/apo B ratio from 2.1 to 1.4 (P < 0.05). No changes in PON or PAF-AH concentrations were detected in prenodal lymph (tissue fluid), collected continuously from the leg. Our results show that the total concentrations of PON and PAF-AH in plasma are uninfluenced by plasma HDL concentration. PAF-AH transfers readily between HDLs and LDLs in vivo, and its distribution between them is determined partly by their relative concentrations and partly by HDL composition.
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Affiliation(s)
- Takeshi Kujiraoka
- Department of Advanced Medical Technology and Development, BML Inc, 1361-1 Matoba, Kawagoe, Saitama 350-1101, Japan
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Ng DS. Treating low HDL—From bench to bedside. Clin Biochem 2004; 37:649-59. [PMID: 15302606 DOI: 10.1016/j.clinbiochem.2004.04.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2004] [Revised: 04/05/2004] [Accepted: 04/05/2004] [Indexed: 01/21/2023]
Abstract
The inverse relationship between the plasma high-density lipoprotein cholesterol (HDL-C) and the risk of coronary heart disease (CHD) is well recognized in the general population. However, the development of effective therapeutics targeting HDL continues to be challenging, which is due in part to the heterogeneity of its structure and composition and the complexity of its metabolism. In this paper, we review a number of recent advances in our understanding of HDL metabolism and its role in atherogenesis. We discuss the HDL-C raising effect of a selected number of currently available lipid-modifying drugs and on a selected number of novel HDL-targeted therapeutic strategies under development.
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Affiliation(s)
- Dominic S Ng
- Department of Medicine, St. Michael's Hospital, Toronto, Ontario, Canada.
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Yatsuya H, Tamakoshi K, Hattori H, Otsuka R, Wada K, Zhang H, Mabuchi T, Ishikawa M, Murata C, Yoshida T, Kondo T, Toyoshima H. Serum phospholipid transfer protein mass as a possible protective factor for coronary heart diseases. Circ J 2004; 68:11-6. [PMID: 14695459 DOI: 10.1253/circj.68.11] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Phospholipid transfer protein (PLTP) can generate pre-beta high-density lipoprotein (HDL), an efficient acceptor of peripheral cholesterol, by mediating a process called HDL conversion. The transfer of phospholipids to immature HDL is also essential in maintaining reverse cholesterol transport. The phospholipid transfer activity of PLTP has been associated with various patho-physiological conditions; however, little information is available concerning the relationship between PLTP mass and disease. METHODS AND RESULTS Using a sandwich enzyme-linked immunosorbent assay, PLTP concentration was measured and related to the risk of developing cardiovascular disease in a worksite-based cohort of Japanese men (n=2,567). Multiple linear regression analysis showed significant associations between PLTP and HDL cholesterol, triglycerides, low-density lipoprotein cholesterol, and body mass index (standardized beta=0.395, -0.191, -0.064, and -0.064, respectively; R(2)=0.31). During the follow-up period, there were 10 cases of coronary heart disease (CHD) and 7 of stroke. The multivariate adjusted relative risk of CHD was 0.46 (95% confidence interval, 0.20-1.07) for an increase of 1 standard deviation in the PLTP value (p=0.071). PLTP concentration was not related to the risk of stroke. CONCLUSIONS The results of this prospective study indicate that the serum PLTP concentration would serve as a predictor of CHD, independent of HDL cholesterol, triglycerides and other established risk factors.
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Affiliation(s)
- Hiroshi Yatsuya
- Department of Public Health/Health Information Dynamics, Nagoya University Graduate School of Medicine, Japan
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Asztalos BF. High-density lipoprotein metabolism and progression of atherosclerosis: new insights from the HDL Atherosclerosis Treatment Study. Curr Opin Cardiol 2004; 19:385-91. [PMID: 15218401 DOI: 10.1097/01.hco.0000126979.41946.7e] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW The purpose of this review is to summarize the current understanding of the potentially antiatherogenic properties of high-density lipoprotein related to its different components. RECENT FINDINGS Recent findings on the role of the different high-density lipoprotein subspecies in reverse cholesterol transport, inflammation, endothelial dysfunction, and low-density lipoprotein oxidation are covered. Special emphasis is put on the heterogeneity of high-density lipoprotein and functional changes related to specific high-density lipoprotein particles with the potential therapeutic alterations of high-density lipoprotein metabolism. SUMMARY The diverse action of high-density lipoprotein observed could be explained by the heterogeneity of high-density lipoprotein particles with completely different composition and properties. The modification of specific high-density lipoprotein subpopulations to reach the maximum atheroprotective effects under various pathologic conditions bears great potential in lipid research.
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Affiliation(s)
- Bela F Asztalos
- Lipid Metabolism Laboratory, Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts 02111, USA.
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Abstract
PURPOSE OF REVIEW This review highlights the recent key advances in our understanding of the role of phospholipid transfer protein in lipid and lipoprotein metabolism. RECENT FINDINGS The overexpression of human phospholipid transfer protein in mice is associated with an increase in atherosclerosis. This is consistent with earlier studies using mouse models suggesting that phospholipid transfer protein was pro-atherogenic. The presence of phospholipid transfer protein in macrophages and atherosclerotic lesions suggests that it could be either anti-atherogenic by facilitating lipid efflux or pro-atherogenic by facilitating lipid retention. Phospholipid transfer protein may also be a key player in reverse cholesterol transport, as it interacts with the adenosine triphosphate-binding cassette transporter A1 and facilitates lipid efflux from peripheral cells. Both the release of chymase, a neutral protease, from mast cells and the oxidation of HDL by hypochlorous acid can impair the function of phospholipid transfer protein in reverse cholesterol transport. Studies of phospholipid transfer protein-mediated phospholipid transfer activity in humans support a role for phospholipid transfer protein in hypertriglyceridemia, obesity, diabetes, inflammation and coronary artery disease, and in the modulation of LDL particle density and size. Furthermore, recent evidence suggests that phospholipid transfer protein may play a role in reproductive processes, in lipid and lipoprotein metabolism in the central nervous system, and in neurodegenerative disease. SUMMARY Phospholipid transfer protein is emerging as a multifaceted and multifunctional player in lipid and lipoprotein metabolism, but much additional work will be required to understand the significance of these recent findings for clinical practice.
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Affiliation(s)
- John J Albers
- Department of Medicine and Northwest Lipid Research Laboratories, University of Washington, 2121 North 35th Street, Seattle, WA 98103, USA.
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Olchawa B, Kingwell BA, Hoang A, Schneider L, Miyazaki O, Nestel P, Sviridov D. Physical Fitness and Reverse Cholesterol Transport. Arterioscler Thromb Vasc Biol 2004; 24:1087-91. [PMID: 15072992 DOI: 10.1161/01.atv.0000128124.72935.0f] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Physical exercise is associated with a decreased risk of cardiovascular disease, which may be partly caused by the effect of exercise on the lipoprotein profile. The most consistent effect of exercise on lipoprotein metabolism is an increase in high-density lipoprotein (HDL). METHODS AND RESULTS Parameters of reverse cholesterol transport (RCT) in 25 endurance-trained male athletes were compared with 33 age-matched males enjoying an active lifestyle. VO2max was higher in athletes than in controls (53.4+/-1.2 versus 38.8+/-1.0 mL/min per kg; P<0.01). The following differences in parameters of RCT were found: (1) plasma HDL cholesterol and apoA-I levels were higher in athletes compared with controls (1.7+/-0.1 versus 1.4+/-0.1 mmol/L; P<0.001; and 145+/-2 versus 128+/-3 mg/dL; P<0.001, respectively). Both correlated with VO2max up to the value of 51 mL/min per kg; (2) prebeta1-HDL was higher in athletes than in controls (54+/-4 versus 37+/-3 microg/mL; P<0.001) and correlated positively with VO2max; (3) lecithin cholesterol: acyltransferase activity was higher in athletes (29.8+/-1.2 versus 24.2+/-1.4 nmol/microL per hour; P<0.005); and (4) the capacity of plasma to promote cholesterol efflux from macrophages was higher in athletes (18.8%+/-0.8% versus 16.2%+/-0.3%; P<0.03). CONCLUSIONS The likely reason for higher HDL concentration in physically fit people is increased formation of HDL from apoA-I and cellular lipids.
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Affiliation(s)
- Beata Olchawa
- Baker Heart Research Institute, (Wynn Domain), Melbourne, Victoria, Australia
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