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Apolipoprotein A1-Related Proteins and Reverse Cholesterol Transport in Antiatherosclerosis Therapy: Recent Progress and Future Perspectives. Cardiovasc Ther 2022; 2022:4610834. [PMID: 35087605 PMCID: PMC8763555 DOI: 10.1155/2022/4610834] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 09/30/2021] [Accepted: 12/10/2021] [Indexed: 12/12/2022] Open
Abstract
Hyperlipidemia characterized by abnormal deposition of cholesterol in arteries can cause atherosclerosis and coronary artery occlusion, leading to atherosclerotic coronary heart disease. The body prevents atherosclerosis by reverse cholesterol transport to mobilize and excrete cholesterol and other lipids. Apolipoprotein A1, the major component of high-density lipoprotein, plays a key role in reverse cholesterol transport. Here, we reviewed the role of apolipoprotein A1-targeting molecules in antiatherosclerosis therapy, in particular ATP-binding cassette transporter A1, lecithin-cholesterol acyltransferase, and scavenger receptor class B type 1.
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Sasaki M, Delawary M, Sakurai H, Kobayashi H, Nakao N, Tsuru H, Fukushima Y, Honzumi S, Moriyama S, Wada N, Kaneko T, Yamada K, Terasaka N, Kubota K. Novel LCAT (Lecithin:Cholesterol Acyltransferase) Activator DS-8190a Prevents the Progression of Plaque Accumulation in Atherosclerosis Models. Arterioscler Thromb Vasc Biol 2021; 41:360-376. [PMID: 33086872 DOI: 10.1161/atvbaha.120.314516] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Enhancement of LCAT (lecithin:cholesterol acyltransferase) activity has possibility to be beneficial for atherosclerosis. To evaluate this concept, we characterized our novel, orally administered, small-molecule LCAT activator DS-8190a, which was created from high-throughput screening and subsequent derivatization. We also focused on its mechanism of LCAT activation and the therapeutic activity with improvement of HDL (high-density lipoprotein) functionality. Approach and Results: DS-8190a activated human and cynomolgus monkey but not mouse LCAT enzymes in vitro. DS-8190a was orally administered to cynomolgus monkeys and dose dependently increased LCAT activity (2.0-fold in 3 mg/kg group on day 7), resulting in HDL cholesterol elevation without drastic changes of non-HDL cholesterol. Atheroprotective effects were then evaluated using Ldl-r KO×hLcat Tg mice fed a Western diet for 8 weeks. DS-8190a treatment achieved significant reduction of atherosclerotic lesion area (48.3% reduction in 10 mg/kg treatment group). Furthermore, we conducted reverse cholesterol transport study using Ldl-r KO×hLcat Tg mice intraperitoneally injected with J774A.1 cells loaded with [3H]-cholesterol and confirmed significant increases of [3H] count in plasma (1.4-fold) and feces (1.4-fold on day 2 and 1.5-fold on day3) in the DS-8190a-treated group. With regard to the molecular mechanism involved, direct binding of DS-8190a to human LCAT protein was confirmed by 2 different approaches: affinity purification by DS-8190a-immobilized beads and thermal shift assay. In addition, the candidate binding site of DS-8190a in human LCAT protein was identified by photoaffinity labeling. CONCLUSIONS This study demonstrates the potential of DS-8190a as a novel therapeutic for atherosclerosis. In addition, this compound proves that a small-molecule direct LCAT activator can achieve HDL-C elevation in monkey and reduction of atherosclerotic lesion area with enhanced HDL function in rodent.
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Affiliation(s)
- Masato Sasaki
- Organic Synthesis Department (M.S., N.N.), Daiichi Sankyo RD Novare, Co, Ltd, Tokyo, Japan
| | - Mina Delawary
- Biological Research Laboratories (M.D., H.T., S.H., S.M., K.Y., N.T.), Daiichi Sankyo, Co, Ltd, Tokyo, Japan
| | - Hidetaka Sakurai
- Discovery Science and Technology Department (H.S., Y.F., N.W., K.K.), Daiichi Sankyo RD Novare, Co, Ltd, Tokyo, Japan
| | - Hideki Kobayashi
- Medicinal Chemistry Research Laboratories (H.K., T.K.), Daiichi Sankyo, Co, Ltd, Tokyo, Japan
| | - Naoki Nakao
- Organic Synthesis Department (M.S., N.N.), Daiichi Sankyo RD Novare, Co, Ltd, Tokyo, Japan
| | - Hiromi Tsuru
- Biological Research Laboratories (M.D., H.T., S.H., S.M., K.Y., N.T.), Daiichi Sankyo, Co, Ltd, Tokyo, Japan
| | - Yumiko Fukushima
- Discovery Science and Technology Department (H.S., Y.F., N.W., K.K.), Daiichi Sankyo RD Novare, Co, Ltd, Tokyo, Japan
| | - Shoko Honzumi
- Biological Research Laboratories (M.D., H.T., S.H., S.M., K.Y., N.T.), Daiichi Sankyo, Co, Ltd, Tokyo, Japan
| | - Sachiko Moriyama
- Biological Research Laboratories (M.D., H.T., S.H., S.M., K.Y., N.T.), Daiichi Sankyo, Co, Ltd, Tokyo, Japan
| | - Naoya Wada
- Discovery Science and Technology Department (H.S., Y.F., N.W., K.K.), Daiichi Sankyo RD Novare, Co, Ltd, Tokyo, Japan
| | - Toshio Kaneko
- Medicinal Chemistry Research Laboratories (H.K., T.K.), Daiichi Sankyo, Co, Ltd, Tokyo, Japan
| | - Keisuke Yamada
- Biological Research Laboratories (M.D., H.T., S.H., S.M., K.Y., N.T.), Daiichi Sankyo, Co, Ltd, Tokyo, Japan
| | - Naoki Terasaka
- Biological Research Laboratories (M.D., H.T., S.H., S.M., K.Y., N.T.), Daiichi Sankyo, Co, Ltd, Tokyo, Japan
| | - Kazuishi Kubota
- Discovery Science and Technology Department (H.S., Y.F., N.W., K.K.), Daiichi Sankyo RD Novare, Co, Ltd, Tokyo, Japan
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Law SH, Chan ML, Marathe GK, Parveen F, Chen CH, Ke LY. An Updated Review of Lysophosphatidylcholine Metabolism in Human Diseases. Int J Mol Sci 2019; 20:ijms20051149. [PMID: 30845751 PMCID: PMC6429061 DOI: 10.3390/ijms20051149] [Citation(s) in RCA: 407] [Impact Index Per Article: 81.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 02/27/2019] [Accepted: 02/28/2019] [Indexed: 12/12/2022] Open
Abstract
Lysophosphatidylcholine (LPC) is increasingly recognized as a key marker/factor positively associated with cardiovascular and neurodegenerative diseases. However, findings from recent clinical lipidomic studies of LPC have been controversial. A key issue is the complexity of the enzymatic cascade involved in LPC metabolism. Here, we address the coordination of these enzymes and the derangement that may disrupt LPC homeostasis, leading to metabolic disorders. LPC is mainly derived from the turnover of phosphatidylcholine (PC) in the circulation by phospholipase A2 (PLA2). In the presence of Acyl-CoA, lysophosphatidylcholine acyltransferase (LPCAT) converts LPC to PC, which rapidly gets recycled by the Lands cycle. However, overexpression or enhanced activity of PLA2 increases the LPC content in modified low-density lipoprotein (LDL) and oxidized LDL, which play significant roles in the development of atherosclerotic plaques and endothelial dysfunction. The intracellular enzyme LPCAT cannot directly remove LPC from circulation. Hydrolysis of LPC by autotaxin, an enzyme with lysophospholipase D activity, generates lysophosphatidic acid, which is highly associated with cancers. Although enzymes with lysophospholipase A1 activity could theoretically degrade LPC into harmless metabolites, they have not been found in the circulation. In conclusion, understanding enzyme kinetics and LPC metabolism may help identify novel therapeutic targets in LPC-associated diseases.
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Affiliation(s)
- Shi-Hui Law
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Mei-Lin Chan
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Division of Thoracic Surgery, Department of Surgery, MacKay Memorial Hospital, MacKay Medical College, Taipei 10449, Taiwan.
| | - Gopal K Marathe
- Department of Studies in Biochemistry, Manasagangothri, University of Mysore, Mysore-570006, India.
| | - Farzana Parveen
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
| | - Chu-Huang Chen
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Vascular and Medicinal Research, Texas Heart Institute, Houston, TX 77030, USA.
| | - Liang-Yin Ke
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Center for Lipid Biosciences, Kaohsiung Medical University Hospital, Kaohsiung 80708, Taiwan.
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
- Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan.
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Dong Z, Shi H, Zhao M, Zhang X, Huang W, Wang Y, Zheng L, Xian X, Liu G. Loss of LCAT activity in the golden Syrian hamster elicits pro-atherogenic dyslipidemia and enhanced atherosclerosis. Metabolism 2018. [PMID: 29526535 DOI: 10.1016/j.metabol.2018.03.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE Lecithin cholesterol acyltransferase (LCAT) plays a pivotal role in HDL metabolism but its influence on atherosclerosis remains controversial for decades both in animal and clinical studies. Because lack of cholesteryl ester transfer protein (CETP) is a major difference between murine and humans in lipoprotein metabolism, we aimed to create a novel Syrian Golden hamster model deficient in LCAT activity, which expresses endogenous CETP, to explore its metabolic features and particularly the influence of LCAT on the development of atherosclerosis. METHODS CRISPR/CAS9 gene editing system was employed to generate mutant LCAT hamsters. The characteristics of lipid metabolism and the development of atherosclerosis in the mutant hamsters were investigated using various conventional methods in comparison with wild type control animals. RESULTS Hamsters lacking LCAT activity exhibited pro-atherogenic dyslipidemia as diminished high density lipoprotein (HDL) and ApoAI, hypertriglyceridemia, Chylomicron/VLDL accumulation and significantly increased ApoB100/48. Mechanistic study for hypertriglyceridemia revealed impaired LPL-mediated lipolysis and increased very low density lipoprotein (VLDL) secretion, with upregulation of hepatic genes involved in lipid synthesis and transport. The pro-atherogenic dyslipidemia in mutant hamsters was exacerbated after high fat diet feeding, ultimately leading to near a 3- and 5-fold increase in atherosclerotic lesions by aortic en face and sinus lesion quantitation, respectively. CONCLUSIONS Our findings demonstrate that LCAT deficiency in hamsters develops pro-atherogenic dyslipidemia and promotes atherosclerotic lesion formation.
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Affiliation(s)
- Zhao Dong
- Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100191, China
| | - Haozhe Shi
- Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100191, China
| | - Mingming Zhao
- Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100191, China
| | - Xin Zhang
- Hebei Invivo Biotech Co., Shijiazhuang, China
| | - Wei Huang
- Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100191, China
| | - Yuhui Wang
- Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100191, China
| | - Lemin Zheng
- Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100191, China
| | - Xunde Xian
- Department of Molecular Genetics, UT Southwestern Medical Center, Dallas, TX 75390, USA.
| | - George Liu
- Institute of Cardiovascular Sciences, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University, Beijing 100191, China.
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Korber M, Klein I, Daum G. Steryl ester synthesis, storage and hydrolysis: A contribution to sterol homeostasis. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:1534-1545. [DOI: 10.1016/j.bbalip.2017.09.002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 08/25/2017] [Accepted: 09/05/2017] [Indexed: 02/01/2023]
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Gu X, Wu Z, Huang Y, Wagner MA, Baleanu-Gogonea C, Mehl RA, Buffa JA, DiDonato AJ, Hazen LB, Fox PL, Gogonea V, Parks JS, DiDonato JA, Hazen SL. A Systematic Investigation of Structure/Function Requirements for the Apolipoprotein A-I/Lecithin Cholesterol Acyltransferase Interaction Loop of High-density Lipoprotein. J Biol Chem 2016; 291:6386-95. [PMID: 26797122 DOI: 10.1074/jbc.m115.696088] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Indexed: 11/06/2022] Open
Abstract
The interaction of lecithin-cholesterol acyltransferase (LCAT) with apolipoprotein A-I (apoA-I) plays a critical role in high-density lipoprotein (HDL) maturation. We previously identified a highly solvent-exposed apoA-I loop domain (Leu(159)-Leu(170)) in nascent HDL, the so-called "solar flare" (SF) region, and proposed that it serves as an LCAT docking site (Wu, Z., Wagner, M. A., Zheng, L., Parks, J. S., Shy, J. M., 3rd, Smith, J. D., Gogonea, V., and Hazen, S. L. (2007) Nat. Struct. Mol. Biol. 14, 861-868). The stability and role of the SF domain of apoA-I in supporting HDL binding and activation of LCAT are debated. Here we show by site-directed mutagenesis that multiple residues within the SF region (Pro(165), Tyr(166), Ser(167), and Asp(168)) of apoA-I are critical for both LCAT binding to HDL and LCAT catalytic efficiency. The critical role for possible hydrogen bond interaction at apoA-I Tyr(166) was further supported using reconstituted HDL generated from apoA-I mutants (Tyr(166) → Glu or Asn), which showed preservation in both LCAT binding affinity and catalytic efficiency. Moreover, the in vivo functional significance of NO2-Tyr(166)-apoA-I, a specific post-translational modification on apoA-I that is abundant within human atherosclerotic plaque, was further investigated by using the recombinant protein generated from E. coli containing a mutated orthogonal tRNA synthetase/tRNACUA pair enabling site-specific insertion of the unnatural amino acid into apoA-I. NO2-Tyr(166)-apoA-I, after subcutaneous injection into hLCAT(Tg/Tg), apoA-I(-/-) mice, showed impaired LCAT activation in vivo, with significant reduction in HDL cholesteryl ester formation. The present results thus identify multiple structural features within the solvent-exposed SF region of apoA-I of nascent HDL essential for optimal LCAT binding and catalytic efficiency.
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Affiliation(s)
- Xiaodong Gu
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and
| | - Zhiping Wu
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and
| | - Ying Huang
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and
| | - Matthew A Wagner
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and
| | | | - Ryan A Mehl
- the Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331, and
| | - Jennifer A Buffa
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and
| | - Anthony J DiDonato
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and
| | - Leah B Hazen
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and
| | - Paul L Fox
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and
| | - Valentin Gogonea
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and the Department of Chemistry, Cleveland State University, Cleveland, Ohio 44115
| | - John S Parks
- the Sections on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina 27157
| | - Joseph A DiDonato
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and
| | - Stanley L Hazen
- From the Department of Cellular and Molecular Medicine, Lerner Research Institute, and the Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio 44195,
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7
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Zeng L, Yan J, Luo L, Zhang D. Effects of Pu-erh tea aqueous extract (PTAE) on blood lipid metabolism enzymes. Food Funct 2015; 6:2008-16. [DOI: 10.1039/c5fo00362h] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Effects of Pu-erh tea aqueous extract (PTAE) on blood lipid metabolism enzymes (e.g.HMGR) are assayedin vitro.
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Affiliation(s)
- Liang Zeng
- College of Food Science
- Southwest University
- Chongqing
- China
- TAETEA Group Postdoctoral Research Station
| | - Jingna Yan
- College of Food Science
- Southwest University
- Chongqing
- China
| | - Liyong Luo
- College of Food Science
- Southwest University
- Chongqing
- China
| | - Dongying Zhang
- College of Longrun Pu-erh Tea
- Yunnan Agricultural University
- Kunming
- China
- TAETEA Group Postdoctoral Research Station
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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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Kunnen S, Van Eck M. Lecithin:cholesterol acyltransferase: old friend or foe in atherosclerosis? J Lipid Res 2012; 53:1783-99. [PMID: 22566575 PMCID: PMC3413220 DOI: 10.1194/jlr.r024513] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 04/23/2012] [Indexed: 11/20/2022] Open
Abstract
Lecithin:cholesterol acyltransferase (LCAT) is a key enzyme that catalyzes the esterification of free cholesterol in plasma lipoproteins and plays a critical role in high-density lipoprotein (HDL) metabolism. Deficiency leads to accumulation of nascent preβ-HDL due to impaired maturation of HDL particles, whereas enhanced expression is associated with the formation of large, apoE-rich HDL(1) particles. In addition to its function in HDL metabolism, LCAT was believed to be an important driving force behind macrophage reverse cholesterol transport (RCT) and, therefore, has been a subject of great interest in cardiovascular research since its discovery in 1962. Although half a century has passed, the importance of LCAT for atheroprotection is still under intense debate. This review provides a comprehensive overview of the insights that have been gained in the past 50 years on the biochemistry of LCAT, the role of LCAT in lipoprotein metabolism and the pathogenesis of atherosclerosis in animal models, and its impact on cardiovascular disease in humans.
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Affiliation(s)
- Sandra Kunnen
- Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, Gorlaeus Laboratories, Leiden University, Leiden, The Netherlands
| | - Miranda Van Eck
- Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, Gorlaeus Laboratories, Leiden University, Leiden, The Netherlands
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Kappelle PJWH, de Boer JF, Perton FG, Annema W, de Vries R, Dullaart RPF, Tietge UJF. Increased LCAT activity and hyperglycaemia decrease the antioxidative functionality of HDL. Eur J Clin Invest 2012; 42:487-95. [PMID: 21955281 DOI: 10.1111/j.1365-2362.2011.02604.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Type 2 diabetes mellitus increases the risk of atherosclerotic cardiovascular disease. Antioxidative properties of high density lipoprotein (HDL) are important for atheroprotection. This study investigated whether the antioxidative functionality of HDL is altered in type 2 diabetes mellitus and aimed to identify potential determinants of this parameter. MATERIALS AND METHODS In a cross-sectional study, we investigated 74 patients with type 2 diabetes and 75 control subjects. Antioxidative properties of HDL were measured and expressed as either (i) HDL antioxidative capacity or (ii) HDL antioxidation index after multiplying HDL antioxidative capacity results with individual plasma HDL cholesterol concentrations. Lecithin:cholesterol acyltransferase (LCAT) and paraoxonase-1 (PON-1) activities were determined. RESULTS HDL antioxidative capacity was similar in patients with diabetes and controls, while the HDL antioxidation index was decreased in patients with diabetes (P = 0.005) owing to lower plasma HDL cholesterol (P < 0.001). LCAT activity was higher and PON-1 activity lower in type 2 diabetes mellitus (each P < 0.001). In the combined subjects, HDL antioxidative capacity was inversely related to LCAT activity (P < 0.01). The HDL antioxidation index correlated negatively with blood glucose (P < 0.001), HbA1c and LCAT activity (each P < 0.01), and positively with PON-1 activity (P < 0.01). Multiple linear regression analysis demonstrated that high LCAT activity was associated with both decreased HDL antioxidation capacity (P < 0.05) and index (P < 0.001) independent of diabetes status, glycaemic control and PON-1. CONCLUSIONS Overall, the antioxidative functionality of HDL is impaired in type 2 diabetes mellitus mostly because of lower HDL cholesterol. Hyperglycaemia, increased LCAT activity and lower PON-1 activity likely contribute to impaired antioxidative functionality of HDL.
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Affiliation(s)
- Paul J W H Kappelle
- Department of Endocrinology, Center for Liver, Digestive and Metabolic Diseases, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Rong S, Cao Q, Liu M, Seo J, Jia L, Boudyguina E, Gebre AK, Colvin PL, Smith TL, Murphy RC, Mishra N, Parks JS. Macrophage 12/15 lipoxygenase expression increases plasma and hepatic lipid levels and exacerbates atherosclerosis. J Lipid Res 2012; 53:686-95. [PMID: 22279185 DOI: 10.1194/jlr.m022723] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
12/15 lipoxygenase (12/15LO) oxidizes polyunsaturated fatty acids (PUFAs) to form bioactive lipid mediators. The role of 12/15LO in atherosclerosis development remains controversial. We evaluated atherosclerosis development and lipid metabolism in 12/15LO-LDL receptor (LDLr) double knockout (DK) vs. LDLr knockout (SK) mice fed a PUFA-enriched diet to enhance production of 12/15LO products. Compared with SK controls, DK mice fed a PUFA-enriched diet had decreased plasma and liver lipid levels, hepatic lipogenic gene expression, VLDL secretion, and aortic atherosclerosis and increased VLDL turnover. Bone marrow transplantation and Kupffer cell ablation studies suggested both circulating leukocytes and Kupffer cells contributed to the lipid phenotype in 12/15LO-deficient mice. Conditioned medium from in vitro incubation of DK vs. SK macrophages reduced triglyceride secretion in McArdle 7777 hepatoma cells. Our results suggest that, in the context of dietary PUFA enrichment, macrophage 12/15LO expression adversely affects plasma and hepatic lipid metabolism, resulting in exacerbated atherosclerosis.
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Affiliation(s)
- Shunxing Rong
- Department of Pathology/Section on Lipid Sciences, Wake Forest School of Medicine, Winston-Salem, NC, USA
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The role of lecithin:cholesterol acyltransferase in the modulation of cardiometabolic risks - a clinical update and emerging insights from animal models. Biochim Biophys Acta Mol Cell Biol Lipids 2012; 1821:654-9. [PMID: 22326749 DOI: 10.1016/j.bbalip.2011.12.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 12/20/2011] [Accepted: 12/22/2011] [Indexed: 11/22/2022]
Abstract
Lecithin cholesterol acyltransferase (LCAT) is the key enzyme in mediating the esterification of cholesterol on circulating lipoproteins. It has long been suggested that LCAT plays a crucial role in reverse cholesterol transport, a process depicting the removal of cellular cholesterol through efflux to high density lipoproteins (HDL) and its delivery to the liver for eventual excretion from the body. Although loss-of-function LCAT mutations invariably result in profound HDL deficiency, the role of LCAT in atherogenesis continues to be clouded with controversy. Increasing number of large scale, population-based studies failed to detect an elevated cardiac risk with reduced blood levels of LCAT, suggesting that reduced LCAT activity may not be a risk factor nor a therapeutic target. More recent studies in human LCAT gene mutation carriers tend to suggest that atherogenicity in LCAT deficiency may be dependent on the nature of the mutations, providing plausible explanations for the otherwise contradictory findings. Genetic models of LCAT excess or deficiency yielded mixed findings. Despite its known profound effects on HDL and triglyceride metabolism, the role of LCAT in metabolic disorders, including obesity and diabetes, has not received much attention. Recent studies in LCAT deficient mouse models suggest that absence of LCAT may protect against insulin resistance, diabetes and obesity. Coordinated modulation of a number of anti-obesity and insulin sensitizing pathways has been implicated. Further studies to explore the role of LCAT in the modulation of cardiometabolic disorders and the underlying mechanisms are warranted.
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Rousset X, Shamburek R, Vaisman B, Amar M, Remaley AT. Lecithin cholesterol acyltransferase: an anti- or pro-atherogenic factor? Curr Atheroscler Rep 2011; 13:249-56. [PMID: 21331766 PMCID: PMC3794709 DOI: 10.1007/s11883-011-0171-6] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Lecithin cholesterol acyl transferase (LCAT) is a plasma enzyme that esterifies cholesterol and raises high-density lipoprotein cholesterol, but its role in atherosclerosis is not clearly established. Studies of various animal models have yielded conflicting results, but studies done in rabbits and non-human primates, which more closely simulate human lipoprotein metabolism, indicate that LCAT is likely atheroprotective. Although suggestive, there are also no biomarker studies that mechanistically link LCAT with cardiovascular disease. Imaging studies of patients with LCAT deficiency have also not yielded a clear answer to the role of LCAT in atherosclerosis. Recombinant LCAT, however, is currently being developed as a therapeutic product for enzyme replacement therapy of patients with genetic disorders of LCAT for the prevention and/or treatment of renal disease, but it may also have value for the treatment of acute coronary syndrome.
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Affiliation(s)
- Xavier Rousset
- Institutes of Health, National Heart, Lung and Blood Institute, Cardio-Pulmonary Branch, Lipoprotein Metabolism Section, 10 Center Dr Bldg. 10/8N224, Bethesda, MD 20814, USA.
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14
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Calabresi L, Franceschini G. Lecithin:cholesterol acyltransferase, high-density lipoproteins, and atheroprotection in humans. Trends Cardiovasc Med 2011; 20:50-3. [PMID: 20656215 DOI: 10.1016/j.tcm.2010.03.007] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The lecithin:cholesterol acyltransferase (LCAT) enzyme is responsible for the synthesis of cholesteryl esters in human plasma. Lecithin:cholesterol acyltransferase is a critical enzyme in high-density lipoprotein (HDL) metabolism, and deficiency of LCAT-mediated cholesterol esterification leads to defective HDL maturation with accumulation of nascent pre-beta HDL. In addition to its function in HDL metabolism, LCAT has also long been believed to play a critical role in macrophage reverse cholesterol transport (RCT). However, recent findings have shown that human LCAT overexpression in mice does not enhance macrophage RCT in vivo, and conversely, LCAT-deficient mice display a preserved macrophage RCT despite the severe plasma HDL reduction. In agreement with this observation, defective LCAT activity does not result in enhanced atherosclerosis, despite the reduced HDL cholesterol levels. These findings challenge the notion that LCAT is required for effective atheroprotection and suggest that elevating LCAT expression and/or activity is not a promising therapeutic strategy to reduce cardiovascular risk.
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Affiliation(s)
- Laura Calabresi
- Center E. Grossi Paoletti, Department of Pharmacological Sciences, Università degli Studi di Milano, 20133 Milano, Italy
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15
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Feng Y, Lievens J, Jacobs F, Hoekstra M, Van Craeyveld E, Gordts SC, Snoeys J, De Geest B. Hepatocyte-specific ABCA1 transfer increases HDL cholesterol but impairs HDL function and accelerates atherosclerosis. Cardiovasc Res 2010; 88:376-85. [PMID: 20562425 DOI: 10.1093/cvr/cvq204] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS The ATP-binding cassette transporter A1 (ABCA1) lipidates apolipoprotein (apo) A-I. The hypothesis that hepatocyte-specific ABCA1 overexpression results in high-density lipoprotein (HDL) dysfunction was evaluated by comparing the effects of murine ABCA1 (AdABCA1) and human apo A-I (AdA-I) transfer on lipoprotein profile, HDL function, and progression of atherosclerosis. METHODS AND RESULTS Gene transfer in male and female C57BL/6 apo E(-/-) mice was performed at the age of 3 months with E1E3E4-deleted adenoviral vectors containing hepatocyte-specific expression cassettes. Atherosclerosis was quantified at baseline and 56 days later in AdABCA1, AdA-I, and control mice. HDL cholesterol after AdA-I transfer was 1.7-fold (P < 0.001) and 1.8-fold (P < 0.001) higher in male and female mice, respectively, and potently inhibited atherosclerosis progression compared with respective controls. Notwithstanding a 1.4-fold (P < 0.01) and a 1.7-fold (P < 0.01) increase of HDL cholesterol in male and female mice, respectively, after AdABCA1 transfer, the intima was 2.2-fold (P < 0.001) larger in male and 1.3-fold (P = NS) larger in female mice compared with respective controls. HDL isolated from control and AdA-I mice but not from AdABCA1 mice enhanced endothelial progenitor cell (EPC) migration in vitro and reduced endothelial cell death in vitro after serum and growth factor withdrawal. Scavenger receptor class B type I (SR-BI) protein level in the liver was significantly lower in AdABCA1 mice than in control and AdA-I mice. CONCLUSION Hepatocyte-specific ABCA1 transfer decreases SR-BI protein level in the liver and abrogates beneficial effects of HDL on EPCs and endothelial cells. Decreased HDL function may underlie accelerated atherosclerosis in AdABCA1 apo E(-/-)mice.
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Affiliation(s)
- Yingmei Feng
- Center for Molecular and Vascular Biology, University of Leuven, Campus Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium
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16
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Vergeer M, Holleboom AG, Kastelein JJP, Kuivenhoven JA. The HDL hypothesis: does high-density lipoprotein protect from atherosclerosis? J Lipid Res 2010; 51:2058-73. [PMID: 20371550 DOI: 10.1194/jlr.r001610] [Citation(s) in RCA: 150] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
There is unequivocal evidence of an inverse association between plasma high-density lipoprotein (HDL) cholesterol concentrations and the risk of cardiovascular disease, a finding that has led to the hypothesis that HDL protects from atherosclerosis. This review details the experimental evidence for this "HDL hypothesis". In vitro studies suggest that HDL has a wide range of anti-atherogenic properties but validation of these functions in humans is absent to date. A significant number of animal studies and clinical trials support an atheroprotective role for HDL; however, most of these findings were obtained in the context of marked changes in other plasma lipids. Finally, genetic studies in humans have not provided convincing evidence that HDL genes modulate cardiovascular risk. Thus, despite a wealth of information on this intriguing lipoprotein, future research remains essential to prove the HDL hypothesis correct.
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Affiliation(s)
- Menno Vergeer
- Department of Vascular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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17
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Rader DJ. Lecithin: cholesterol acyltransferase and atherosclerosis: another high-density lipoprotein story that doesn't quite follow the script. Circulation 2009; 120:549-52. [PMID: 19652089 DOI: 10.1161/circulationaha.109.881979] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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18
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Tanigawa H, Billheimer JT, Tohyama JI, Fuki IV, Ng DS, Rothblat GH, Rader DJ. Lecithin: cholesterol acyltransferase expression has minimal effects on macrophage reverse cholesterol transport in vivo. Circulation 2009; 120:160-9. [PMID: 19564558 DOI: 10.1161/circulationaha.108.825109] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Lecithin:cholesterol acyltransferase (LCAT) catalyzes the formation of plasma cholesteryl ester, plays a key role in high-density lipoprotein metabolism, and has been believed to be critical in the process of reverse cholesterol transport (RCT). METHODS AND RESULTS The role of LCAT in RCT from macrophages was quantified with a validated assay involving intraperitoneal injection in mice of (3)H-cholesterol-labeled J774 macrophages and monitoring the appearance of tracer in plasma, liver, bile, and feces. Human LCAT overexpression in human apolipoprotein A-I transgenic mice substantially increased plasma high-density lipoprotein cholesterol levels but surprisingly did not increase macrophage RCT. Even in the setting of coexpression of scavenger receptor BI or cholesteryl ester transfer protein, both of which promoted the transfer of LCAT-derived high-density lipoprotein cholesterol ester to the liver, LCAT overexpression still had no effect on RCT. Serum from LCAT-overexpressing mice had reduced ability to promote cholesterol efflux from macrophages ex vivo via ABCA1. To determine the effect of LCAT deficiency on macrophage RCT, LCAT(-/-) and LCAT(+/-) mice were compared with wild-type mice. Despite extremely low plasma levels of high-density lipoprotein cholesterol, LCAT-deficient mice had only a 50% reduction in RCT. LCAT(+/-) mice had normal RCT despite a significant reduction in high-density lipoprotein cholesterol. Serum from LCAT-deficient mice had increased ability to promote ABCA1-mediated cholesterol efflux from macrophages ex vivo. CONCLUSIONS These results demonstrate that LCAT overexpression does not promote an increased rate of macrophage RCT. Although LCAT activity does become rate limiting in the context of complete LCAT deficiency, RCT is reduced by only 50% even in the absence of LCAT. These data suggest that macrophage RCT may not be as dependent on LCAT activity as has previously been believed.
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Affiliation(s)
- Hiroyuki Tanigawa
- Institute for Translational Medicine and Therapeutics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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19
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Rousset X, Vaisman B, Amar M, Sethi AA, Remaley AT. Lecithin: cholesterol acyltransferase--from biochemistry to role in cardiovascular disease. Curr Opin Endocrinol Diabetes Obes 2009; 16:163-71. [PMID: 19306528 PMCID: PMC2910390 DOI: 10.1097/med.0b013e328329233b] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
PURPOSE OF REVIEW We discuss the latest findings on the biochemistry of lecithin : cholesterol acyltransferase (LCAT), the effect of LCAT on atherosclerosis, clinical features of LCAT deficiency, and the impact of LCAT on cardiovascular disease from human studies. RECENT FINDINGS Although there has been much recent progress in the biochemistry of LCAT and its effect on high-density lipoprotein metabolism, its role in the pathogenesis of atherosclerosis is still not fully understood. Studies from various animal models have revealed a complex interaction between LCAT and atherosclerosis that may be modified by diet and by other proteins that modify lipoproteins. Furthermore, the ability of LCAT to lower apoB appears to be the best way to predict its effect on atherosclerosis in animal models. Recent studies on patients with LCAT deficiency have shown a modest but significant increase in incidence of cardiovascular disease consistent with a beneficial effect of LCAT on atherosclerosis. The role of LCAT in the general population, however, has not revealed a consistent association with cardiovascular disease. SUMMARY Recent research findings from animal and human studies have revealed a potential beneficial role of LCAT in reducing atherosclerosis but additional studies are necessary to better establish the linkage between LCAT and cardiovascular disease.
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Affiliation(s)
- Xavier Rousset
- National Institutes of Health, National Heart, Lung and Blood Institute, Pulmonary and Vascular Medicine Branch, Lipoprotein Metabolism Section, Bethesda, MD. 20814
| | - Boris Vaisman
- National Institutes of Health, National Heart, Lung and Blood Institute, Pulmonary and Vascular Medicine Branch, Lipoprotein Metabolism Section, Bethesda, MD. 20814
| | - Marcelo Amar
- National Institutes of Health, National Heart, Lung and Blood Institute, Pulmonary and Vascular Medicine Branch, Lipoprotein Metabolism Section, Bethesda, MD. 20814
| | - Amar A. Sethi
- National Institutes of Health, National Heart, Lung and Blood Institute, Pulmonary and Vascular Medicine Branch, Lipoprotein Metabolism Section, Bethesda, MD. 20814
| | - Alan T. Remaley
- National Institutes of Health, National Heart, Lung and Blood Institute, Pulmonary and Vascular Medicine Branch, Lipoprotein Metabolism Section, Bethesda, MD. 20814
- To whom correspondence should be addressed: National Institutes of Health, National Heart, Lung and Blood Institute, Pulmonary and Vascular Medicine Branch, Lipoprotein Metabolism Section, 10 Center Dr. Bldg. 10/2C-433, Bethesda, MD. 20814, , 301-402-9796
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20
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Amar MJA, Shamburek RD, Vaisman B, Knapper CL, Foger B, Hoyt RF, Santamarina-Fojo S, Brewer HB, Remaley AT. Adenoviral expression of human lecithin-cholesterol acyltransferase in nonhuman primates leads to an antiatherogenic lipoprotein phenotype by increasing high-density lipoprotein and lowering low-density lipoprotein. Metabolism 2009; 58:568-75. [PMID: 19303980 PMCID: PMC3703629 DOI: 10.1016/j.metabol.2008.11.019] [Citation(s) in RCA: 33] [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] [Received: 05/28/2008] [Accepted: 11/26/2008] [Indexed: 01/30/2023]
Abstract
Lecithin-cholesterol acyltransferase (LCAT), a key enzyme in high-density lipoprotein (HDL) metabolism, has been proposed to have atheroprotective properties by promoting reverse cholesterol transport. Overexpression of LCAT in various animal models, however, has led to conflicting results on its overall effect on lipoproteins and atherosclerosis. In this study, the effect of overexpression of LCAT in nonhuman primates on lipoprotein metabolism is examined. Human LCAT was expressed with adenovirus in squirrel monkeys (n = 8), resulting on day 4 in a 22-fold increase of LCAT activity (257 +/- 23 vs 5618 +/- 799 nmol mL(-1) h(-1), P < .0001). At its peak, LCAT was found to nearly double the level of HDL cholesterol from baseline (113 +/- 7 vs 260 +/- 24 mg/dL, P < .01). High-density lipoprotein formed after treatment with the adenovirus was larger in size, as assessed by fast protein liquid chromatography (FPLC) analysis. By kinetic studies, it was determined that there was a decrease in apolipoprotein (Apo) A-I resident time (0.373 +/- 0.027 vs 0.685 +/- 0.045 d(-1), P < .0001) and almost a doubling in the ApoA-I synthetic rate (22 +/- 2 vs 41 +/- 3 mg kg(-1) d(-1), P < .0001), but no overall change in ApoA-I levels. In addition, increased expression of LCAT was associated with a 37% reduction of ApoB levels (12 +/- 1 vs 19 +/- 1 mg/dL, P < .05) due to increased low-density lipoprotein catabolism (fractional catabolic rate = 1.7 +/- 0.1 d(-1) in controls vs 4.2 +/- 0.3 d(-1) in LCAT-treated group, P < .05). In summary, overexpression of LCAT in nonhuman primates leads to an antiatherogenic lipoprotein profile by increasing HDL cholesterol and lowering ApoB, thus making LCAT a potential drug target for reducing atherosclerosis.
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Affiliation(s)
- Marcelo J A Amar
- Lipoprotein Metabolism Section, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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21
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Apolipoprotein A-I and lecithin:cholesterol acyltransferase transfer induce cholesterol unloading in complex atherosclerotic lesions. Gene Ther 2009; 16:757-65. [PMID: 19242527 DOI: 10.1038/gt.2009.8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Plasma levels of high-density lipoprotein (HDL) cholesterol and its major apolipoprotein (apo), apo A-I, are inversely correlated with the incidence of ischemic cardiovascular diseases. Reverse cholesterol transport is likely the main mechanism underlying the atheroprotective effects of HDL. Here, we investigated whether increased HDL cholesterol following hepatocyte-directed adenoviral rabbit apo A-I (AdrA-I) or rabbit lecithin-cholesterol acyltransferase (LCAT) (AdrLCAT) transfer may induce cholesterol unloading in complex atherosclerotic lesions in heterozygous low-density lipoprotein receptor-deficient rabbits fed a 0.15% cholesterol diet for 420 days before and for 120 days after transfer. HDL cholesterol levels increased 2.0-fold (P<0.001) and 1.9-fold (P<0.001) in the 120 days after transfer with AdrA-I and AdrLCAT, respectively, compared to levels just before transfer whereas non-HDL cholesterol remained unchanged. Increased HDL cholesterol following AdrA-I and AdrLCAT transfer resulted in a 31% (P<0.05) reduction of the intima/media ratio in comparison with the control progression group. Compared to the baseline group killed after 420 days of cholesterol diet, AdrA-I and AdrLCAT transfer reduced the percentage of Oil Red O area 1.6-fold (P<0.001) and 1.4-fold (P<0.001), respectively. In conclusion, increased HDL cholesterol after AdrA-I and AdrLCAT transfer inhibits progression of atherosclerosis and induces cholesterol unloading in complex lesions in rabbits.
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22
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Wang S, Wu D, Matthan NR, Lamon-Fava S, Lecker JL, Lichtenstein AH. Reduction in dietary omega-6 polyunsaturated fatty acids: eicosapentaenoic acid plus docosahexaenoic acid ratio minimizes atherosclerotic lesion formation and inflammatory response in the LDL receptor null mouse. Atherosclerosis 2008; 204:147-55. [PMID: 18842266 DOI: 10.1016/j.atherosclerosis.2008.08.024] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Revised: 07/14/2008] [Accepted: 08/10/2008] [Indexed: 11/26/2022]
Abstract
Dietary very long chain omega (omega)-3 polyunsaturated fatty acids (PUFA) have been associated with reduced CVD risk, the mechanisms of which have yet to be fully elucidated. LDL receptor null mice (LDLr-/-) were used to assess the effect of different ratios of dietary omega-6 PUFA to eicosapentaenoic acid plus docosahexaenoic acid (omega-6:EPA+DHA) on atherogenesis and inflammatory response. Mice were fed high saturated fat diets without EPA and DHA (HSF omega-6), or with omega-6:EPA+DHA at ratios of 20:1 (HSF R=20:1), 4:1 (HSF R=4:1), and 1:1 (HSF R=1:1) for 32 weeks. Mice fed the lowest omega-6:EPA+DHA ratio diet had lower circulating concentrations of non-HDL cholesterol (25%, P<0.05) and interleukin-6 (IL-6) (44%, P<0.05) compared to mice fed the HSF omega-6 diet. Aortic and elicited peritoneal macrophage (Mphi) total cholesterol were 24% (P=0.07) and 25% (P<0.05) lower, respectively, in HSF R=1:1 compared to HSF omega-6 fed mice. MCP-1 mRNA levels and secretion were 37% (P<0.05) and 38% (P<0.05) lower, respectively, in elicited peritoneal Mphi isolated from HSF R=1:1 compared to HSF omega-6 fed mice. mRNA and protein levels of ATP-binding cassette A1, and mRNA levels of TNFalpha were significantly lower in elicited peritoneal Mphi isolated from HSF R=1:1 fed mice, whereas there was no significant effect of diets with different omega-6:EPA+DHA ratios on CD36, Mphi scavenger receptor 1, scavenger receptor B1 and IL-6 mRNA or protein levels. These data suggest that lower omega-6:EPA+DHA ratio diets lowered some measures of inflammation and Mphi cholesterol accumulation, which was associated with less aortic lesion formation in LDLr-/- mice.
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Affiliation(s)
- Shu Wang
- Jean Mayer USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111, USA
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23
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Hovingh GK, Hutten BA, Holleboom AG, Petersen W, Rol P, Stalenhoef A, Zwinderman AH, de Groot E, Kastelein JJP, Kuivenhoven JA. Compromised LCAT Function Is Associated With Increased Atherosclerosis. Circulation 2005; 112:879-84. [PMID: 16061733 DOI: 10.1161/circulationaha.105.540427] [Citation(s) in RCA: 127] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Prospective epidemiological studies have shown that low plasma levels of HDL cholesterol (HDL-C) are associated with an increased risk for cardiovascular disease (CVD). Despite nearly 40 years of research, however, it is unclear whether this also holds true for individuals with severely reduced levels of HDL-C due to mutations in the lecithin:cholesterol acyltransferase (LCAT) gene. Better insight into CVD risk in these individuals may provide clues toward the potential of LCAT as a pharmaceutical target to raise HDL-C levels. METHODS AND RESULTS Lipids, lipoproteins, high-sensitivity C-reactive protein (CRP), and carotid artery intima-media thickness (IMT) were assessed in 47 heterozygotes for LCAT gene mutations and 58 family controls. Compared with controls, heterozygotes presented with a mean 36% decrease in HDL-C levels (P<0.0001), a 23% increase in triglyceride levels (P<0.0001), and a 2.1-fold increase in CRP levels (P<0.0001). Mean carotid IMT was significantly increased in heterozygotes compared with family controls (0.623+/-0.13 versus 0.591+/-0.08 mm). After adjustment for age, gender, and alcohol use, this difference proved statistically significant (P<0.0015). CONCLUSIONS The data show that heterozygosity for LCAT gene defects is associated with low HDL-C levels and elevated concentration of triglycerides and CRP in plasma. This phenotype underlies increased IMT in carriers versus controls, which suggests that LCAT protects against atherosclerosis. This in turn indicates that targeting LCAT to raise HDL-C may reduce CVD risk.
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Affiliation(s)
- G Kees Hovingh
- Department of Vascular Medicine, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
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24
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Stein O, Stein Y. Lipid transfer proteins (LTP) and atherosclerosis. Atherosclerosis 2005; 178:217-30. [PMID: 15694928 DOI: 10.1016/j.atherosclerosis.2004.10.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Revised: 09/07/2004] [Accepted: 10/05/2004] [Indexed: 10/26/2022]
Abstract
This review deals with four lipid transfer proteins (LTP): three are involved in cholesteryl ester (CE) synthesis or transport, the fourth deals with plasma phospholipid (PL) transfer. Experimental models of atherosclerosis, clinical and epidemiological studies provided information as to the relationship of these LTP(s) to atherosclerosis, which is the main focus of this review. Thus, inhibition of acyl-CoA:cholesterol acyltransferase (ACAT) 1 and 2 decreases cholesterol absorption, plasma cholesterol and aortic cholesterol esterification in the aorta. The discovery that tamoxifen is a potent ACAT inhibitor explained the plasma cholesterol lowering of the drug. The use of ACAT inhibition in humans is under current investigation. As low cholesteryl ester transfer protein (CETP) activity is connected with high HDL-C, several CETP inhibitors were tried in rabbits, with variable results. A new CETP inhibitor, Torcetrapib, was tested in humans and there was a 50-100% increase in HDL-C. Lecithin cholesterol acyl-transferase (LCAT) influences oxidative stress, which can be lowered by transient LCAT gene transfer in LCAT-/- mice. Phospholipid transfer protein (PLTP) deficiency reduced apo B production in apo E-/- mice, as well as oxidative stress in four models of mouse atherosclerosis. In conclusion, the ability to increase HDL-C so markedly by inhibitors of CETP introduces us into a new era in prevention and treatment of coronary heart disease (CHD).
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Affiliation(s)
- O Stein
- Department of Experimental Medicine and Cancer Research, Hebrew University-Hadassah Medical School, Jerusalem, Israel
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25
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Zhang AH, Gao S, Fan JL, Huang W, Zhao TQ, Liu G. Increased plasma HDL cholesterol levels and biliary cholesterol excretion in hamster by LCAT overexpression. FEBS Lett 2004; 570:25-9. [PMID: 15251433 DOI: 10.1016/j.febslet.2004.06.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2004] [Revised: 05/21/2004] [Accepted: 06/02/2004] [Indexed: 11/30/2022]
Abstract
Lecithin cholesterol acyltransferase (LCAT) is a key enzyme in the metabolism of high density lipoprotein (HDL), which has been found inversely correlated with atherosclerosis. Adenovirus mediated overexpression of human LCAT (hLCAT) in hamsters resulted in increased levels of plasma total cholesterol, HDL cholesterol, phospholipids and enlarged particle size of HDL. It also increased cholesterol and total bile acid concentrations in bile. Hepatic mRNA level of cholesterol 7alpha-hydroxylase increased 2.7-fold in hamsters. However, such effects were not observed in mice in a parallel experiment. This study suggests that overexpression of hLCAT in hamsters facilitated reverse cholesterol transport. Similar metabolic changes in humans might modify atherogenic risk.
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Affiliation(s)
- Ai-Hong Zhang
- Institute of Cardiovascular Sciences and Key Laboratory of Molecular Cardiology, Ministry of Education, Peking University, 38 Xue Yuan Road, Beijing 100083, PR China
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26
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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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27
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Willner EL, Tow B, Buhman KK, Wilson M, Sanan DA, Rudel LL, Farese RV. Deficiency of acyl CoA:cholesterol acyltransferase 2 prevents atherosclerosis in apolipoprotein E-deficient mice. Proc Natl Acad Sci U S A 2003; 100:1262-7. [PMID: 12538880 PMCID: PMC298761 DOI: 10.1073/pnas.0336398100] [Citation(s) in RCA: 147] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2002] [Indexed: 01/20/2023] Open
Abstract
Deficiency of acyl CoA:cholesterol acyltransferase 2 (ACAT2) in mice results in a reduction in cholesterol ester synthesis in the small intestine and liver, which in turn limits intestinal cholesterol absorption, hepatic cholesterol gallstone formation, and the accumulation of cholesterol esters in the plasma lipoproteins. Here we examined the contribution of ACAT2-derived cholesterol esters to atherosclerosis by crossing ACAT2-deficient (ACAT2(-/-)) mice with apolipoprotein (apo) E-deficient (ApoE(-/-)) mice, an atherosclerosis-susceptible strain that has impaired apoE-mediated clearance of apoB-containing lipoproteins. ACAT2(-/-) ApoE(-/-) mice and ACAT2(+/+) ApoE(-/-) (control) mice had similar elevations of plasma apoB and total plasma lipids; however, the lipid cores of the apoB-containing lipoproteins in ACAT2(-/-) ApoE(-/-) mice contained primarily triglycerides rather than cholesterol esters. At 30 wk of age, only the control mice had significant atherosclerosis, which was nearly absent in ACAT2(-/-) ApoE(-/-) mice. ACAT2 deficiency in the apoE-deficient background also led to a compensatory increase in the activity of lecithincholesterol acyltransferase, the major plasma cholesterol esterification enzyme, which increased high-density lipoprotein cholesterol esters. Our results demonstrate the crucial role of ACAT2-derived cholesterol esters in the development of atherosclerosis in mice and suggest that triglyceride-rich apoB-containing lipoproteins are not as atherogenic as those containing cholesterol esters. Our results also support the rationale of pharmacological inhibition of ACAT2 as a therapy for atherosclerosis.
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Affiliation(s)
- Emily L Willner
- Gladstone Institute of Cardiovascular Disease, P. O. Box 419100, San Francisco, CA 94141-9100, USA
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