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Deng S, Liu J, Niu C. HDL and Cholesterol Ester Transfer Protein (CETP). ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1377:13-26. [PMID: 35575918 DOI: 10.1007/978-981-19-1592-5_2] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cholesterol ester transfer protein (CETP) is important clinically and is one of the major targets in cardiovascular disease studies. With high conformational flexibility, its tunnel structure allows unforced movement of high-density lipoproteins (HDLs), VLDLs, and LDLs. Research in reverse cholesterol transports (RCT) reveals that the regulation of CETP activity can change the concentration of cholesteryl esters (CE) in HDLs, VLDLs, and LDLs. These molecular insights demonstrate the mechanisms of CETP activities and manifest the correlation between CETP and HDL. However, animal and cell experiments focused on CETP give controversial results. Inhibiting CETP is found to be beneficial to anti-atherosclerosis in terms of increasing plasma HDL-C, while it is also claimed that CETP weakens atherosclerosis formation by promoting RCT. Currently, the CETP-related drugs are still immature. Research on CETP inhibitors is targeted at improving efficacy and minimizing adverse reactions. As for CETP agonists, research has proved that they also can be used to resist atherosclerosis.
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Affiliation(s)
- Siying Deng
- Beijing Tiantan Hospital, China National Clinical Research Center for Neurological Diseases, Advanced Innovation Center for Human Brain Protection, The Capital Medical University, Beijing, China
| | | | - Chenguang Niu
- Key Laboratory of Clinical Resources Translation, First Affiliated Hospital, Henan University, Kaifeng, Henan, China.
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Oliveira HCF, Raposo HF. Cholesteryl Ester Transfer Protein and Lipid Metabolism and Cardiovascular Diseases. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1276:15-25. [PMID: 32705591 DOI: 10.1007/978-981-15-6082-8_2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In this chapter, we present the major advances in CETP research since the detection, isolation, and characterization of its activity in the plasma of humans and several species. Since CETP is a major modulator of HDL plasma levels, the clinical importance of CETP activity was recognized very early. We describe the participation of CETP in reverse cholesterol transport, conflicting results in animal and human genetic studies, possible new functions of CETP, and the results of the main clinical trials on CETP inhibition. Despite major setbacks in clinical trials, the hypothesis that CETP inhibitors are anti-atherogenic in humans is still being tested.
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Affiliation(s)
- Helena C F Oliveira
- Department of Structural and Functional Biology, Biology Institute, State University of Campinas, Campinas, SP, Brazil.
| | - Helena F Raposo
- Department of Structural and Functional Biology, Biology Institute, State University of Campinas, Campinas, SP, Brazil
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Zhang J, Niimi M, Yang D, Liang J, Xu J, Kimura T, Mathew AV, Guo Y, Fan Y, Zhu T, Song J, Ackermann R, Koike Y, Schwendeman A, Lai L, Pennathur S, Garcia-Barrio M, Fan J, Chen YE. Deficiency of Cholesteryl Ester Transfer Protein Protects Against Atherosclerosis in Rabbits. Arterioscler Thromb Vasc Biol 2017; 37:1068-1075. [PMID: 28428219 DOI: 10.1161/atvbaha.117.309114] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/05/2017] [Indexed: 11/16/2022]
Abstract
OBJECTIVE CETP (cholesteryl ester transfer protein) plays an important role in lipoprotein metabolism; however, whether inhibition of CETP activity can prevent cardiovascular disease remains controversial. APPROACH AND RESULTS We generated CETP knockout (KO) rabbits by zinc finger nuclease gene editing and compared their susceptibility to cholesterol diet-induced atherosclerosis to that of wild-type (WT) rabbits. On a chow diet, KO rabbits showed higher plasma levels of high-density lipoprotein (HDL) cholesterol than WT controls, and HDL particles of KO rabbits were essentially rich in apolipoprotein AI and apolipoprotein E contents. When challenged with a cholesterol-rich diet for 18 weeks, KO rabbits not only had higher HDL cholesterol levels but also lower total cholesterol levels than WT rabbits. Analysis of plasma lipoproteins revealed that reduced plasma total cholesterol in KO rabbits was attributable to decreased apolipoprotein B-containing particles, while HDLs remained higher than that in WT rabbits. Both aortic and coronary atherosclerosis was significantly reduced in KO rabbits compared with WT rabbits. Apolipoprotein B-depleted plasma isolated from CETP KO rabbits showed significantly higher capacity for cholesterol efflux from macrophages than that from WT rabbits. Furthermore, HDLs isolated from CETP KO rabbits suppressed tumor necrosis factor-α-induced vascular cell adhesion molecule 1 and E-selectin expression in cultured endothelial cells. CONCLUSIONS These results provide evidence that genetic ablation of CETP activity protects against cholesterol diet-induced atherosclerosis in rabbits.
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Affiliation(s)
- Jifeng Zhang
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.).
| | - Manabu Niimi
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Dongshan Yang
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Jingyan Liang
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Jie Xu
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Tokuhide Kimura
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Anna V Mathew
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Yanhong Guo
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Yanbo Fan
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Tianqing Zhu
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Jun Song
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Rose Ackermann
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Yui Koike
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Anna Schwendeman
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Liangxue Lai
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Subramaniam Pennathur
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Minerva Garcia-Barrio
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.)
| | - Jianglin Fan
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.).
| | - Y Eugene Chen
- From the Center for Advanced Models for Translational Sciences and Therapeutics, Department of Internal Medicine (J.Z., D.Y., J.L., J.X., Y.G., Y.F., T.Z., J.S., Y.K., M.G.-B., Y.E.C.), Department of Internal Medicine, Nephrology (A.V.M., S.P.), University of Michigan Medical Center, Ann Arbor; Department of Molecular Pathology, Faculty of Medicine, Graduate School of Medical Sciences, University of Yamanashi, Japan (M.N., T.K., J.F.); Department of Pharmaceutical Sciences, Biointerfaces Institute, College of Pharmacy, University of Michigan (R.A., A.S.); and Key Laboratory of Regenerative Biology, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences (L.L.).
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Yamashita S, Matsuzawa Y. Re-evaluation of cholesteryl ester transfer protein function in atherosclerosis based upon genetics and pharmacological manipulation. Curr Opin Lipidol 2016; 27:459-72. [PMID: 27454452 DOI: 10.1097/mol.0000000000000332] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
PURPOSE OF REVIEW To re-evaluate the functions of plasma cholesteryl ester transfer protein (CETP) in atherosclerosis based upon recent findings from human genetics and pharmacological CETP manipulation. RECENT FINDINGS CETP is involved in the transfer of cholesteryl ester from HDL to apolipoprotein B-containing lipoproteins, a key step of reverse cholesterol transport (RCT). CETP inhibitors have been developed to raise serum HDL-cholesterol (HDL-C) levels and reduce cardiovascular events. However, outcome studies of three CETP inhibitors (torcetrapib, dalcetrapib and evacetrapib) were prematurely terminated because of increased mortality or futility despite marked increases in HDL-cholesterol and decreases in LDL-cholesterol except for dalcetrapib. Patients with CETP deficiency show remarkable changes in HDL and LDL and are sometimes accompanied by atherosclerotic cardiovascular diseases. Recent prospective epidemiological studies demonstrated atheroprotective roles of CETP. CETP inhibition induces formation of small dense LDL and possibly dysfunctional HDL and downregulates hepatic scavenger receptor class B type I (SR-BI). Therefore, CETP inhibitors may interrupt LDL receptor and SR-BI-mediated cholesterol delivery back to the liver. SUMMARY For future drug development, the opposite strategy, namely enhancers of RCT via CETP and SR-BI activation as well as the inducers of apolipoprotein A-I or HDL production might be a better approach rather than delaying HDL metabolism by inhibiting a main stream of RCT in vivo.
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Affiliation(s)
- Shizuya Yamashita
- aDepartment of Community Medicine bDepartment of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita cRinku General Medical Center, Izumisano dSumitomo Hospital, Kita-ku, Osaka, Japan
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Greene DJ, Izem L, Morton RE. Defective triglyceride biosynthesis in CETP-deficient SW872 cells. J Lipid Res 2015. [PMID: 26203075 DOI: 10.1194/jlr.m056481] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
We previously reported that reducing the expression of cholesteryl ester transfer protein (CETP) disrupts cholesterol homeostasis in SW872 cells and causes an ∼50% reduction in TG. The causes of this reduced TG content, investigated here, could not be attributed to changes in the differentiation status of CETP-deficient cells, nor was there evidence of endoplasmic reticulum (ER) stress. In short-term studies, the total flux of oleate through the TG biosynthetic pathway was not altered in CETP-deficient cells, although mRNA levels of some pathway enzymes were different. However, the conversion of diglyceride (DG) to TG was impaired. In longer-term studies, newly synthesized TG was not effectively transported to lipid droplets, yet this lipid did not accumulate in the ER, apparently due to elevated lipase activity in this organelle. DG, shown to be a novel CETP substrate, was also inefficiently transferred to lipid droplets. This may reduce TG synthesis on droplets by resident diacylglycerol acyltransferase. Overall, these data suggest that the decreased TG content of CETP-deficient cells arises from the reduced conversion of DG to TG in the ER and/or on the lipid droplet surface, and enhanced TG degradation in the ER due to its ineffective transport from this organelle.
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Affiliation(s)
- Diane J Greene
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Lahoucine Izem
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Richard E Morton
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
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Izem L, Greene DJ, Bialkowska K, Morton RE. Overexpression of full-length cholesteryl ester transfer protein in SW872 cells reduces lipid accumulation. J Lipid Res 2015; 56:515-525. [PMID: 25593327 DOI: 10.1194/jlr.m053678] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Cells produce two cholesteryl ester transfer protein (CETP) isoforms, full-length and a shorter variant produced by alternative splicing. Blocking synthesis of both isoforms disrupts lipid metabolism and storage. To further define the role of CETP in cellular lipid metabolism, we stably overexpressed full-length CETP in SW872 cells. These CETP(+) cells had several-fold higher intracellular CETP and accumulated 50% less TG due to a 26% decrease in TG synthesis and 2.5-fold higher TG turnover rate. Reduced TG synthesis was due to decreased fatty acid uptake and impaired conversion of diglyceride to TG even though diacylglycerol acyltransferase activity was normal. Sterol-regulatory element binding protein 1 mRNA levels were normal, and although PPARγ expression was reduced, the expression of several of its target genes including adipocyte triglyceride lipase, FASN, and APOE was normal. CETP(+) cells contained smaller lipid droplets, consistent with their higher levels of perilipin protein family (PLIN) 3 compared with PLIN1 and PLIN2. Intracellular CETP was mostly associated with the endoplasmic reticulum, although CETP near lipid droplets poorly colocalized with this membrane. A small pool of CETP resided in the cytoplasm, and a subfraction coisolated with lipid droplets. These data show that overexpression of full-length CETP disrupts lipid homeostasis resulting in the formation of smaller, more metabolically active lipid droplets.
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Affiliation(s)
- Lahoucine Izem
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Diane J Greene
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Katarzyna Bialkowska
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
| | - Richard E Morton
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195.
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Horie T, Nishino T, Baba O, Kuwabara Y, Nakao T, Nishiga M, Usami S, Izuhara M, Nakazeki F, Ide Y, Koyama S, Sowa N, Yahagi N, Shimano H, Nakamura T, Hasegawa K, Kume N, Yokode M, Kita T, Kimura T, Ono K. MicroRNA-33b knock-in mice for an intron of sterol regulatory element-binding factor 1 (Srebf1) exhibit reduced HDL-C in vivo. Sci Rep 2014; 4:5312. [PMID: 24931346 PMCID: PMC4058878 DOI: 10.1038/srep05312] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Accepted: 05/30/2014] [Indexed: 01/21/2023] Open
Abstract
MicroRNAs (miRs) are small non-protein-coding RNAs that bind to specific mRNAs and inhibit translation or promote mRNA degradation. Recent reports, including ours, indicated that miR-33a located within the intron of sterol regulatory element-binding protein (SREBP) 2 controls cholesterol homeostasis and can be a possible therapeutic target for treating atherosclerosis. Primates, but not rodents, express miR-33b from an intron of SREBF1. Therefore, humanized mice, in which a miR-33b transgene is inserted within a Srebf1 intron, are required to address its function in vivo. We successfully established miR-33b knock-in (KI) mice and found that protein levels of known miR-33a target genes, such as ABCA1, ABCG1, and SREBP-1, were reduced compared with those in wild-type mice. As a consequence, macrophages from the miR-33b KI mice had a reduced cholesterol efflux capacity via apoA-I and HDL-C. Moreover, HDL-C levels were reduced by almost 35% even in miR-33b KI hetero mice compared with the control mice. These results indicate that miR-33b may account for lower HDL-C levels in humans than those in mice and that miR-33b is possibly utilized for a feedback mechanism to regulate its host gene SREBF1. Our mice will also aid in elucidating the roles of miR-33a/b in different genetic disease models.
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Affiliation(s)
- Takahiro Horie
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
- Department of Clinical Innovative Medicine, Institute for Advancement of Clinical and Translational Science, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
- These authors contributed equally to this work
| | - Tomohiro Nishino
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
- These authors contributed equally to this work
| | - Osamu Baba
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Yasuhide Kuwabara
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Tetsushi Nakao
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Masataka Nishiga
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Shunsuke Usami
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Masayasu Izuhara
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Fumiko Nakazeki
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Yuya Ide
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Satoshi Koyama
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Naoya Sowa
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Naoya Yahagi
- Department of Internal Medicine (Endocrinology and Metabolism), Graduate School of Comprehensive Human Sciences, Nutrigenomics Research Group, Faculty of Medicine, and International Institute for Integrative Sleep Medicine (IIIS), World Premir International Research Center Initiative (WPI), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Hitoshi Shimano
- Department of Internal Medicine (Endocrinology and Metabolism), Graduate School of Comprehensive Human Sciences, Nutrigenomics Research Group, Faculty of Medicine, and International Institute for Integrative Sleep Medicine (IIIS), World Premir International Research Center Initiative (WPI), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Tomoyuki Nakamura
- Department of Pharmacology, Kansai Medical University, Moriguchi, Osaka 570-8506, Japan
| | - Koji Hasegawa
- Division of Translational Research, National Hospital Organization, Kyoto Medical Center, Kyoto 612-8555, Japan
| | - Noriaki Kume
- Division of Clinical Pharmacy, Faculty of Pharmaceutical Sciences, Kobe Gakuin University, Kobe 650-8586, Japan
| | - Masayuki Yokode
- Department of Clinical Innovative Medicine, Institute for Advancement of Clinical and Translational Science, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Toru Kita
- Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe 650-0046, Japan
| | - Takeshi Kimura
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
| | - Koh Ono
- Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto 606-8507, Japan
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8
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Hime NJ, Black AS, Bonnet DJ, Curtiss LK. Bone marrow-derived HL mitigates bone marrow-derived CETP-mediated decreases in HDL in mice globally deficient in HL and the LDLr. J Lipid Res 2014; 55:1864-75. [PMID: 24818611 DOI: 10.1194/jlr.m046318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The objective of this study was to determine the combined effects of HL and cholesteryl ester transfer protein (CETP), derived exclusively from bone marrow (BM), on plasma lipids and atherosclerosis in high-fat-fed, atherosclerosis-prone mice. We transferred BM expressing these proteins into male and female double-knockout HL-deficient, LDL receptor-deficient mice (HL(-/-)LDLr(-/-)). Four BM chimeras were generated, where BM-derived cells expressed 1) HL but not CETP, 2) CETP and HL, 3) CETP but not HL, or 4) neither CETP nor HL. After high-fat feeding, plasma HDL-cholesterol (HDL-C) was decreased in mice with BM expressing CETP but not HL (17 ± 4 and 19 ± 3 mg/dl, female and male mice, respectively) compared with mice with BM expressing neither CETP nor HL (87 ± 3 and 95 ± 4 mg/dl, female and male mice, respectively, P < 0.001 for both sexes). In female mice, the presence of BM-derived HL mitigated this CETP-mediated decrease in HDL-C. BM-derived CETP decreased the cholesterol component of HDL particles and increased plasma cholesterol. BM-derived HL mitigated these effects of CETP. Atherosclerosis was not significantly different between BM chimeras. These results suggest that BM-derived HL mitigates the HDL-lowering, HDL-modulating, and cholesterol-raising effects of BM-derived CETP and warrant further studies to characterize the functional properties of these protein interactions.
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Affiliation(s)
- Neil J Hime
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Audrey S Black
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - David J Bonnet
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Linda K Curtiss
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
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9
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Morton RE, Izem L. Cholesteryl ester transfer proteins from different species do not have equivalent activities. J Lipid Res 2013; 55:258-65. [PMID: 24293641 DOI: 10.1194/jlr.m043646] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Site-specific changes in the amino acid composition of human cholesteryl ester transfer protein (CETP) modify its preference for triglyceride (TG) versus cholesteryl ester (CE) as substrate. CETP homologs are found in many species but little is known about their activity. Here, we examined the lipid transfer properties of CETP species with 80-96% amino acid identity to human CETP. TG/CE transfer ratios for recombinant rabbit, monkey, and hamster CETPs were 1.40-, 1.44-, and 6.08-fold higher than human CETP, respectively. In transfer assays between VLDL and HDL, net transfers of CE into VLDL by human and monkey CETPs were offset by equimolar net transfers of TG toward HDL. For hamster CETP this process was not equimolar but resulted in a net flow of lipid (TG) into HDL. When assayed for the ability to transfer lipid to an acceptor particle lacking CE and TG, monkey and hamster CETPs were most effective, although all CETP species were able to promote this one-way movement of neutral lipid. We conclude that CETPs from human, monkey, rabbit, and hamster are not functionally equivalent. Most unique was hamster CETP, which strongly prefers TG as a substrate and promotes the net flow of lipid from VLDL to HDL.
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Affiliation(s)
- Richard E Morton
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195
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10
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Sung KC, Wild SH, Byrne CD. Controlling for apolipoprotein A-I concentrations changes the inverse direction of the relationship between high HDL-C concentration and a measure of pre-clinical atherosclerosis. Atherosclerosis 2013; 231:181-6. [PMID: 24267222 DOI: 10.1016/j.atherosclerosis.2013.09.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 09/07/2013] [Accepted: 09/09/2013] [Indexed: 02/03/2023]
Abstract
BACKGROUND The independent effect of high density lipoprotein cholesterol (HDL-C) concentration to confer cardiovascular disease protection has been questioned. We investigated whether the inverse association between HDL-C concentration and a measure of preclinical atherosclerosis was modified by other risk factors. METHODS Cross-sectional data were analysed from an occupational cohort of 12,031 men who had measurements of cardiovascular risk factors and a cardiac computed tomography (CT) estimation of coronary artery calcium (CAC) score, a measure of pre-clinical atherosclerosis. Logistic regression was used to describe associations between both HDL-C and Apo-A-I concentrations and their ratio as exposures, and CAC scores > 0, ≥ 20 and ≥ 100, as outcomes. RESULTS 1351 (11.2%), 665 (5.5%) and 230 (1.9%) of participants had a CAC score > 0, ≥ 20 and ≥ 100, respectively. Adjusting for age, glucose, triglyceride, LDL-C, systolic blood pressure, waist circumference, prior cerebrovascular accident, prior coronary artery disease, prior hypertension, alcohol consumption, smoking status and exercise, a negative association existed between HDL-C and CAC score. (E.g. odds ratio (OR) for top compared to bottom HDL-C quartile for CAC > 0 = 0.78 [95%CI 0.64, 0.94], p = 0.01). Further adjustment for Apo A-I changed the direction of the association between HDL-C and CAC score > 0 (OR for top compared to bottom quartiles 1.61 [95%CI 1.18, 2.21], p = 0.003). Sensitivity analyses showed that point estimates for ORs were very similar regardless of CAC score threshold (CAC > 0, ≥ 20 and ≥ 100). CONCLUSION Controlling for Apo A-I concentrations changes the inverse direction of relationship between high HDL-C concentration and a measure of pre-clinical atherosclerosis.
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Affiliation(s)
- Ki-Chul Sung
- Division of Cardiology, Department of Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, #108, Pyung Dong, Jongro-Ku, Seoul 110-746, Republic of Korea.
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11
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Chan CYT, Chan YC, Cheuk BL, Cheng SW. A pilot study on low-density lipoprotein receptor-related protein-1 in Chinese patients with abdominal aortic aneurysm. Eur J Vasc Endovasc Surg 2013; 46:549-56. [PMID: 24054777 DOI: 10.1016/j.ejvs.2013.08.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/09/2013] [Accepted: 08/09/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVE There are no published data on the expression of low-density lipoprotein receptor-related protein 1 (LRP1) in human aortic tissues with abdominal aortic aneurysm (AAA), although some researchers have suggested that LRP1 may be a crucial regulator in the pathogenesis of AAA. The aim of this pilot study is to investigate LRP1 expression in aortic tissues from Chinese patients with AAA compared with normal control tissues. MATERIALS AND METHODS This study used human abdominal aortic tissues with or without AAA as a research model. Aneurysmal abdominal aortas were collected from Chinese patients with AAA (n = 12) during open surgical aneurysmal repair at our institution, and normal control non-aneurysmal abdominal aortas were collected from Chinese healthy organ donors (n = 12) during organ transplantation. Protein expression of LRP1 was analyzed by western blotting and immunohistochemistry. RESULTS LRP1 protein expression was significantly lower in AAA (mean LRP1AAA/LRP1(Normal Control) = 0.51 ± 0.28) than in normal control aortic tissues (mean LRP1(Normal Control)/LRP1(Normal Control) = 1 ± 0.18) in our small sample cohort (p < .001). No significant correlation was shown between LRP1 protein expression and the size of AAA (p > .05). CONCLUSIONS Our pilot result suggests that a reduction in LRP1 protein expression may be associated with aneurysm progression.
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Affiliation(s)
- C Y T Chan
- Department of Surgery, University of Hong Kong Medical Centre, Pokfulam, Hong Kong
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12
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Niculescu LS, Robciuc MR, Sanda GM, Sima AV. Apolipoprotein A–I stimulates cholesteryl ester transfer protein and apolipoprotein E secretion from lipid-loaded macrophages; the role of NF-κB and PKA signaling pathways. Biochem Biophys Res Commun 2011; 415:497-502. [DOI: 10.1016/j.bbrc.2011.10.101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 10/21/2011] [Indexed: 11/28/2022]
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13
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Cheng TJ, Chuu JJ, Chang CY, Tsai WC, Chen KJ, Guo HR. Atherosclerosis induced by arsenic in drinking water in rats through altering lipid metabolism. Toxicol Appl Pharmacol 2011; 256:146-53. [PMID: 21851829 DOI: 10.1016/j.taap.2011.08.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Revised: 07/19/2011] [Accepted: 08/01/2011] [Indexed: 01/09/2023]
Abstract
Arsenic in drinking water is a global environmental health problem, and the exposure may increase cardiovascular and cerebrovascular diseases mortalities, most likely through causing atherosclerosis. However, the mechanism of atherosclerosis formation after arsenic exposure is still unclear. To study the mechanism of atherosclerosis formation after arsenic exposure and explore the role of high cholesterol diet (HCD) in this process, we fed spontaneous hypertensive rats and Wistar Kyoto rats with basal diet or HCD and provided with them drinking water containing arsenic at different ages and orders for 20 consecutive weeks. We measured high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), total cholesterol, triglycerides, heat shock protein 70 (HSP 70), and high sensitive C-reactive protein (hs-CRP) at predetermined intervals and determined expressions of cholesteryl ester transfer protein-1 (CETP-1) and liver X receptor β (LXRβ) in the liver. Atherosclerosis was determined by examining the aorta with hematoxylin and eosin stain. After 20 weeks, we found arsenic, alone or combined with HCD, may promote atherosclerosis formation with transient increases in HSP 70 and hs-CRP. Early combination exposure decreased the HDL-C/LDL-C ratio without changing the levels of total cholesterol and triglyceride until 30 weeks old. Both CETP-1 and LXRβ activities were suppressed, most significantly in early combination exposure. In conclusion, arsenic exposure may induce atherosclerosis through modifying reverse cholesterol transport in cholesterol metabolism and suppressing LXRβ and CEPT-1 expressions. For decreasing atherosclerosis related mortality associated with arsenic, preventing exposure from environmental sources in early life is an important element.
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Affiliation(s)
- Tain-Junn Cheng
- Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 704, Taiwan
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14
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MicroRNA-33 encoded by an intron of sterol regulatory element-binding protein 2 (Srebp2) regulates HDL in vivo. Proc Natl Acad Sci U S A 2010; 107:17321-6. [PMID: 20855588 DOI: 10.1073/pnas.1008499107] [Citation(s) in RCA: 314] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sterol regulatory element-binding protein 2 (SREBP-2) transcription factor has been identified as a key protein in cholesterol metabolism through the transactivation of the LDL receptor and cholesterol biosynthesis genes. Here, we generated mice lacking microRNA (miR)-33, encoded by an intron of the Srebp2, and showed that miR-33 repressed the expression of ATP-binding cassette transporter A1 (ABCA1) protein, a key regulator of HDL synthesis by mediating cholesterol efflux from cells to apolipoprotein A (apoA)-I. In fact, peritoneal macrophages derived from miR-33-deficient mice showed a marked increase in ABCA1 levels and higher apoA-I-dependent cholesterol efflux than those from WT mice. ABCA1 protein levels in liver were also higher in miR-33-deficient mice than in WT mice. Moreover, miR-33-deficient mice had significantly higher serum HDL cholesterol levels than WT mice. These data establish a critical role for miR-33 in the regulation of ABCA1 expression and HDL biogenesis in vivo.
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15
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Kappelle PJWH, van Tol A, Wolffenbuttel BHR, Dullaart RPF. Cholesteryl Ester Transfer Protein Inhibition in Cardiovascular Risk Management: Ongoing Trials will End the Confusion. Cardiovasc Ther 2010; 29:e89-99. [DOI: 10.1111/j.1755-5922.2010.00201.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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16
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Hildebrand RB, Lammers B, Meurs I, Korporaal SJA, De Haan W, Zhao Y, Kruijt JK, Praticò D, Schimmel AWM, Holleboom AG, Hoekstra M, Kuivenhoven JA, Van Berkel TJC, Rensen PCN, Van Eck M. Restoration of high-density lipoprotein levels by cholesteryl ester transfer protein expression in scavenger receptor class B type I (SR-BI) knockout mice does not normalize pathologies associated with SR-BI deficiency. Arterioscler Thromb Vasc Biol 2010; 30:1439-45. [PMID: 20431066 DOI: 10.1161/atvbaha.110.205153] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Disruption of scavenger receptor class B type I (SR-BI) in mice impairs high-density lipoprotein (HDL)-cholesterol (HDL-C) delivery to the liver and induces susceptibility to atherosclerosis. In this study, it was investigated whether introduction of cholesteryl ester transfer protein (CETP) can normalize HDL-C transport to the liver and reduce atherosclerosis in SR-BI knockout (KO) mice. METHODS AND RESULTS Expression of human CETP in SR-BI(KO) mice resulted in decreased plasma HDL-C levels, both on chow diet (1.8-fold, P<0.001) and on challenge with Western-type diet (1.6-fold, P<0.01). Furthermore, the presence of CETP partially normalized the abnormally large HDL particles observed in SR-BI(KO) mice. Unexpectedly, expression of CETP in SR-BI(KO) mice did not reduce atherosclerotic lesion development, probably because of consequences of SR-BI deficiency, including the persistence of higher VLDL-cholesterol (VLDL-C) levels, unchanged elevated free cholesterol/total cholesterol ratio, and the increased oxidative status of the animals. In addition, CETP expression did not normalize other characteristics of SR-BI deficiency, including female infertility, reticulocytosis, thrombocytopenia, and impaired platelet aggregation. CONCLUSIONS CETP restores HDL-C levels in SR-BI(KO) mice, but it does not change the susceptibility to atherosclerosis and other typical characteristics that are associated with SR-BI disruption. This may indicate that the pathophysiology of SR-BI deficiency is not a direct consequence of changes in the HDL pool.
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Affiliation(s)
- Reeni B Hildebrand
- Leiden/Amsterdam Center for Drug Research, Division of Biopharmaceutics, Leiden, the Netherlands
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17
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Lakomy D, Rébé C, Sberna AL, Masson D, Gautier T, Chevriaux A, Raveneau M, Ogier N, Nguyen AT, Gambert P, Grober J, Bonnotte B, Solary E, Lagrost L. Liver X receptor-mediated induction of cholesteryl ester transfer protein expression is selectively impaired in inflammatory macrophages. Arterioscler Thromb Vasc Biol 2009; 29:1923-9. [PMID: 19679828 DOI: 10.1161/atvbaha.109.193201] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Cholesteryl ester transfer protein (CETP) is a target gene for the liver X receptor (LXR). The aim of this study was to further explore this regulation in the monocyte-macrophage lineage and its modulation by lipid loading and inflammation, which are key steps in the process of atherogenesis. METHODS AND RESULTS Exposure of bone marrow-derived macrophages from human CETP transgenic mice to the T0901317 LXR agonist increased CETP, PLTP, and ABCA1 mRNA levels. T0901317 also markedly increased CETP mRNA levels and CETP production in human differentiated macrophages, whereas it had no effect on CETP expression in human peripheral blood monocytes. In inflammatory mouse and human macrophages, LXR-mediated CETP gene upregulation was inhibited, even though ABCA1, ABCG1, and SREBP1c inductions were maintained. The inhibition of CETP gene response to LXR agonists in inflammatory cells was independent of lipid loading (ie, oxidized LDL increased CETP production in noninflammatory macrophages with a synergistic effect of synthetic LXR agonists). CONCLUSIONS LXR-mediated induction of human CETP expression is switched on during monocyte-to-macrophage differentiation, is magnified by lipid loading, and is selectively lost in inflammatory macrophages, which suggests that inflammatory cells may not increase the circulating CETP pool on LXR agonist treatment.
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18
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Dullaart RPF, Borggreve SE, Hillege HL, Dallinga-Thie GM. The association of HDL cholesterol concentration with the −629C>A CETP promoter polymorphism is not fully explained by its relationship with plasma cholesteryl ester transfer. Scandinavian Journal of Clinical and Laboratory Investigation 2009; 68:99-105. [PMID: 17852818 DOI: 10.1080/00365510701519719] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVE HDL cholesterol is associated with the -629C>A cholesteryl ester transfer protein (CETP) promoter polymorphism. This relationship may in part be explained via effects on plasma cholesteryl ester transfer (CET), which reflects the activity of CETP in the context of endogenous lipoproteins, but also via CET independent pathways involved in HDL metabolism. In this study, we determined the contributions of the CETP -629 C>A genotype, plasma CETP mass and cholesteryl ester transfer to HDL cholesterol. MATERIAL AND METHODS The -629 C>A CETP gene promoter polymorphism, plasma CETP mass, CET, HDL cholesterol, lipids and apolipoprotein (apo) A-I were measured in 220 non-diabetic men without cardiovascular disease. RESULTS Plasma CETP mass (p<0.001) and CET (p<0.001) were higher, whereas HDL cholesterol (p<0.05) and plasma apo A-I levels (p<0.05) were lower in CC compared to AA carriers. Univariate regression analysis showed that plasma CET was related to the CETP genotype (p = 0.004), plasma CETP mass (p<0.001) and triglycerides (p<0.001). In a multiple linear regression model, HDL cholesterol was related to CETP genotype (p = 0.04) and plasma triglycerides (p<0.001) without independent contributions of plasma CETP mass and CET (p>0.20 for both). CONCLUSIONS This study suggests that, despite a relationship between a common CETP gene variation and plasma cholesteryl ester transfer, the association between CETP gene and HDL cholesterol appears to be at least in part unexplained by the plasma cholesteryl ester transfer process.
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Affiliation(s)
- R P F Dullaart
- Department of Endocrinology, University of Groningen, Hanzeplein 1, PO Box 30.001, 9700 RB Groningen, The Netherlands.
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19
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Mukhamedova N, Escher G, D'Souza W, Tchoua U, Grant A, Krozowski Z, Bukrinsky M, Sviridov D. Enhancing apolipoprotein A-I-dependent cholesterol efflux elevates cholesterol export from macrophages in vivo. J Lipid Res 2008; 49:2312-22. [PMID: 18622028 DOI: 10.1194/jlr.m800095-jlr200] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eight proteins potentially involved in cholesterol efflux [ABCA1, ABCG1, CYP27A1, phospholipid transfer protein (PLTP), scavenger receptor type BI (SR-BI), caveolin-1, cholesteryl ester transfer protein, and apolipoprotein A-I (apoA-I)] were overexpressed alone or in combination in RAW 264.7 macrophages. When apoA-I was used as an acceptor, overexpression of the combination of ABCA1, CYP27A1, PLTP, and SR-BI (Combination I) enhanced the efflux by 4.3-fold. It was established that the stimulation of efflux was due to increased abundance of ABCA1 and increased apoA-I binding to non-ABCA1 sites on macrophages. This combination caused only a small increase of the efflux to isolated HDL. When HDL was used as an acceptor, overexpression of caveolin-1 or a combination of caveolin-1 and SR-BI (Combination II) was the most active, doubling the efflux to HDL, without affecting the efflux to apoA-I. When tested in the in vivo mouse model of cholesterol efflux, overexpression of ABCA1 and Combination I elevated cholesterol export from macrophages to plasma, liver, and feces, whereas overexpression of caveolin-1 or Combination II did not have an effect. We conclude that pathways of cholesterol efflux using apoA-I as an acceptor make a predominant contribution to cholesterol export from macrophages in vivo.
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20
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Hime NJ, Black AS, Bulgrien JJ, Curtiss LK. Leukocyte-derived hepatic lipase increases HDL and decreases en face aortic atherosclerosis in LDLr-/- mice expressing CETP. J Lipid Res 2008; 49:2113-23. [PMID: 18599739 DOI: 10.1194/jlr.m700564-jlr200] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
In addition to hepatic expression, cholesteryl ester transfer protein (CETP) and hepatic lipase (HL) are expressed by human macrophages. The combined actions of these proteins have profound effects on HDL structure and function. It is not known how these HDL changes influence atherosclerosis. To elucidate the role of leukocyte-derived HL on atherosclerosis in a background of CETP expression, we studied low density lipoprotein receptor-deficient mice expressing human CETP (CETPtgLDLr -/-) with a leukocyte-derived HL deficiency (HL -/- BM). HL(-/-) bone marrow (BM), CETPtgLDLr(-/-) mice were generated via bone marrow transplantation. Wild-type bone marrow was transplanted into CETPtgLDLr(-/-) mice to generate HL +/+ BM, CETPtgLDLr(-/-) controls. The chimeras were fed a high-fat, high-cholesterol diet for 14 weeks to promote atherosclerosis. In female HL(-/-) BM, CETPtgLDLr(-/-) mice plasma HDL-cholesterol concentration during high-fat feeding was decreased 27% when compared with HL +/+ BM, CETPtgLDLr(-/-) mice (P < 0.05), and this was associated with a 96% increase in en face aortic atherosclerosis (P < 0.05). In male CETPtgLDLr(-/-) mice, leukocyte-derived HL deficiency was associated with a 16% decrease in plasma HDL-cholesterol concentration and a 25% increase in aortic atherosclerosis. Thus, leukocyte-derived HL in CETPtgLDLr(-/-) mice has an atheroprotective role that may involve increased HDL levels.
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Affiliation(s)
- Neil J Hime
- Department of Immunology, The Scripps Research Institute, La Jolla, California, USA.
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21
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22
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Dullaart RPF, Sluiter WJ. Common variation in the CETP gene and the implications for cardiovascular disease and its treatment: an updated analysis. Pharmacogenomics 2008; 9:747-63. [DOI: 10.2217/14622416.9.6.747] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Human plasma contains cholesteryl ester transfer protein (CETP) which, besides other functions, enables the transfer of cholesteryl esters in plasma from high-density lipoproteins (HDL) towards triglyceride-rich lipoproteins, thereby contributing to lower HDL cholesterol. Variations in the CETP gene, including the intronic TaqIB polymorphism (rs708272), are common in the population. Although HDL cholesterol is approximately 10% higher in TaqIB B2B2 than in B1B1 carriers, the association of this polymorphism with cardiovascular disease has not been unequivocally established. We present an updated pooled analysis concerning the association of cardiovascular disease with the TaqIB polymorphism, including only studies that predominantly comprise Caucasian subjects. The distribution of this CETP genotype was observed to be different in population-based studies (n = 10,526) compared with studies in populations selected by high cardiovascular risk (n = 10,947), with B2B2 carriers being less frequent among cases from high-risk populations compared with cases from population-based studies (p = 0.0009 for the difference in genotype distribution). In population-based studies, the odds ratio (OR) for cardiovascular disease was found to be 1.45 (95% CI: 1.07–1.95) in B2B2 compared with B1B1 carriers, contrasting the lower OR of 0.84 (95% CI: 0.74–0.96) in B2B2 versus B1B1 carriers from high-risk populations. Thus, it is possible that in the general population, the B2 allele is associated with higher cardiovascular risk, despite higher HDL cholesterol. Our analysis agrees with the contention that selection towards a lower frequency of B2B2 homozygotes may have occurred in selected populations, which would result in a apparently protective effect of the B2 allele when determined in high-risk populations. We also evaluated whether the TaqIB polymorphism would predict efficacy of lipid-lowering treatment with respect to plasma lipids and cardiovascular outcome, but the results of published studies were contradictory. Likewise, no definite conclusion can be made at present concerning the effect of this CETP polymorphism on the lipid response to diet intervention.
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Affiliation(s)
- Robin P F Dullaart
- Department of Endocrinology, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands
| | - Wim J Sluiter
- Department of Endocrinology, University Medical Center Groningen, PO Box 30.001, 9700 RB Groningen, The Netherlands
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Abstract
The dramatic failure of clinical trials evaluating the cholesterol ester transfer protein inhibitor torcetrapib has led to considerable doubt about the value of raising high-density lipoprotein cholesterol (HDL-C) as a treatment for cardiovascular disease. These results have underscored the intricacy of HDL metabolism, with functional quality perhaps being a more important consideration than the circulating quantity of HDL. As a result, HDL-based therapeutics that maintain or enhance HDL functionality warrant closer investigation. In this article, we review the complexity of HDL metabolism, discuss clinical-trial data for HDL-raising agents, including possible reasons for the failure of torcetrapib, and consider the potential for future HDL-based therapies.
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Abstract
PURPOSE OF REVIEW Macrophage reverse cholesterol transport is one of the key mechanisms mediating the protective effects of high-density lipoproteins on atherosclerosis. This review focuses on the recent developments in our understanding of molecular mechanisms of macrophage reverse transport and regulators that play important roles during this process. RECENT FINDINGS Macrophage reverse cholesterol transport is promoted by apolipoprotein A-I overexpression and reduced in the setting of apolipoprotein A-I deficiency. A liver X receptor agonist markedly increases macrophage reverse cholesterol transport. ATP-binding cassette transporter A1 and ATP-binding cassette transporter G1 are liver X receptor-responsive macrophage genes that promote cholesterol efflux to lipid-free apolipoprotein A-I and mature high-density lipoprotein, respectively. The direct roles of ATP-binding cassette transporter A1 and ATP-binding cassette transporter G1 in macrophage reverse cholesterol transport in vivo remain unclear. Therapeutically promoting macrophage reverse cholesterol transport has been recognized as one of the promising means to prevent atherosclerosis. SUMMARY Increasing evidence has suggested that ATP-binding cassette transporter A1 and ATP-binding cassette transporter G1 are involved in macrophage reverse cholesterol transport. In-depth understanding of the molecular mechanisms will enable us to develop new therapeutic means to protect against atherosclerosis.
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Affiliation(s)
- Xun Wang
- Institute for Translational Medicine and Therapeutics and Cardiovascular Institute, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104-6160, USA
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25
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Lee-Rueckert M, Vikstedt R, Metso J, Jauhiainen M, Kovanen PT. Association of cholesteryl ester transfer protein with HDL particles reduces its proteolytic inactivation by mast cell chymase. J Lipid Res 2008; 49:358-68. [DOI: 10.1194/jlr.m700392-jlr200] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Contribution of Cdc42 to Cholesterol Efflux in Fibroblasts from Tangier Disease and Werner Syndrome. Methods Enzymol 2008; 439:159-69. [DOI: 10.1016/s0076-6879(07)00412-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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27
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Tchoua U, D'Souza W, Mukhamedova N, Blum D, Niesor E, Mizrahi J, Maugeais C, Sviridov D. The effect of cholesteryl ester transfer protein overexpression and inhibition on reverse cholesterol transport. Cardiovasc Res 2007; 77:732-9. [DOI: 10.1093/cvr/cvm087] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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28
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Izem L, Morton RE. Possible role for intracellular cholesteryl ester transfer protein in adipocyte lipid metabolism and storage. J Biol Chem 2007; 282:21856-65. [PMID: 17522050 DOI: 10.1074/jbc.m701075200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cholesteryl ester transfer protein (CETP) transfers cholesteryl ester (CE) and triglyceride (TG) between lipoproteins in plasma. However, short term suppression of CETP biosynthesis in cells alters cellular cholesterol homeostasis, demonstrating an intracellular role for CETP as well. The consequences of chronic CETP deficiency in lipid-storing cells normally expressing CETP have not been reported. Here, SW872 adipocytes stably expressing antisense CETP cDNA and synthesizing 20% of normal CETP were created. CETP-deficient cells had 4-fold more CE but an approximately 3-fold decrease in cholesterol biosynthesis. This phenotype of cholesterol overload is consistent with the observed 45% reduction in low density lipoprotein receptor and 2.5-fold increase in ABCA1 levels. However, cholesterol mass in CETP-deficient adipocytes was actually reduced. Strikingly, CETP-deficient adipocytes stored <50% of normal TG, principally reflecting reduced synthesis. The hydrolysis of cellular CE and TG in CETP-deficient cells was reduced by >50%, although hydrolase/lipase activity was increased 3-fold. Notably, the incorporation of recently synthesized CE and TG into lipid storage droplets in CETP-deficient cells was just 40% of control, suggesting that these lipids are inefficiently transported to droplets where the hydrolase/lipase resides. The capacity of cellular CETP to transport CE and TG into storage droplets was directly demonstrated in vitro. Overall, chronic CETP deficiency disrupts lipid homeostasis and compromises the TG storage function of adipocytes. Inefficient CETP-mediated translocation of CE and TG from the endoplasmic reticulum to their site of storage may partially explain these defects. These studies in adipocytic cells strongly support a novel role for CETP in intracellular lipid transport and storage.
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Affiliation(s)
- Lahoucine Izem
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
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29
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Intrinsic enzymes of high-density lipoprotein. J Clin Lipidol 2007; 1:20-30. [DOI: 10.1016/j.jacl.2007.01.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2007] [Revised: 01/30/2007] [Accepted: 01/30/2007] [Indexed: 11/23/2022]
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30
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Van Eck M, Ye D, Hildebrand RB, Kar Kruijt J, de Haan W, Hoekstra M, Rensen PCN, Ehnholm C, Jauhiainen M, Van Berkel TJC. Important role for bone marrow-derived cholesteryl ester transfer protein in lipoprotein cholesterol redistribution and atherosclerotic lesion development in LDL receptor knockout mice. Circ Res 2007; 100:678-85. [PMID: 17293475 DOI: 10.1161/01.res.0000260202.79927.4f] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Abundant amounts of cholesteryl ester transfer protein (CETP) are found in macrophage-derived foam cells in the arterial wall, but its function in atherogenesis is unknown. To investigate the role of macrophage CETP in atherosclerosis, LDL receptor knockout mice were transplanted with bone marrow from CETP transgenic mice, which express the human CETP transgene under control of its natural promoter and major regulatory elements. CETP production by bone marrow-derived cells induced a 1.8-fold (P<0.01) increase in atherosclerotic lesion development. The increase in lesion size coincided with an increase in VLDL/LDL cholesterol and a decrease in HDL cholesterol. The cholesterol redistribution in serum was a direct effect of the substantial serum CETP activity and mass (38+/-3 nmol/mL/h and 4.8+/-0.5 microg/mL, respectively) induced by CETP production by bone marrow-derived cells. Conversely, specific disruption of CETP production by bone marrow-derived cells in CETP transgenic mice resulted in a approximately 2-fold (P<0.0001) reduction in serum CETP activity and mass, demonstrating the quantitative relevance of bone marrow-derived CETP. Finally, we show that in liver Kupffer cells, hepatic macrophages, contribute approximately 50% to the total hepatic CETP expression. In conclusion, bone marrow-derived CETP induces a proatherogenic lipoprotein profile and promotes the development of atherosclerotic lesions in LDL receptor knockout mice. Most importantly, we show for the first time that bone marrow-derived CETP is an important contributor to total serum CETP activity and mass.
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Affiliation(s)
- Miranda Van Eck
- Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, Gorlaeus Laboratories, Leiden University, Leiden, The Netherlands.
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31
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Harder C, Lau P, Meng A, Whitman SC, McPherson R. Cholesteryl ester transfer protein (CETP) expression protects against diet induced atherosclerosis in SR-BI deficient mice. Arterioscler Thromb Vasc Biol 2007; 27:858-64. [PMID: 17272756 DOI: 10.1161/01.atv.0000259357.42089.dc] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE To determine whether expression of the human CETP transgene protects against diet-induced atherosclerosis in SR-BI deficient mice. METHODS AND RESULTS SR-BI deficient (-/-) mice were crossed with CETP transgenic (CETPtg) mice to produce a colony of SR-BI(-/-) x CETPtg mice in a C57Bl/6 background. Age and sex matched groups of genetically modified and wild-type C57Bl/6 mice were fed a high fat, high cholesterol diet for 22 weeks. In both wild-type and SR-BI(-/-) mice, expression of the CETP transgene reduced the cholesterol content and increased the density of lipoprotein particles in the HDL density range. In SR-BI(-/-) x CETPtg mice, CETP activity inversely correlated with total plasma cholesterol levels and shifted the buoyant HDL typical of SR-BI deficiency toward a more normal density HDL particle. Atherosclerosis at the level of the aortic arch was evident in both male and female SR-BI deficient mice but occurred to a greater extent in the females. Expression of CETP markedly attenuated the development of atherosclerosis in SR-BI deficient mice fed an atherogenic diet (P<0.003). CONCLUSIONS Expression of the human CETP transgene protects SR-BI deficient mice from atherosclerosis, consistent with a role for CETP in remodeling HDL and providing an alternative pathway for the selective uptake of HDL-CE by the liver.
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Affiliation(s)
- Christopher Harder
- Lipoprotein and Atherosclerosis Research Group, University of Ottawa Heart Institute, Ottawa, Canada
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32
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Dullaart RPF, Dallinga-Thie GM, Wolffenbuttel BHR, van Tol A. CETP inhibition in cardiovascular risk management: a critical appraisal. Eur J Clin Invest 2007; 37:90-8. [PMID: 17217373 DOI: 10.1111/j.1365-2362.2007.01756.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In view of the cardioprotective effect of high-density lipoproteins (HDL) and the limited effects of statin and fibrate therapy on HDL cholesterol, it is clinically relevant to test whether pharmacological treatment aimed at raising HDL lowers cardiovascular risk. Cholesteryl ester transfer protein (CETP) is a new therapeutic target, because the cholesteryl ester transfer process lowers HDL cholesterol and contributes to an atherogenic lipoprotein profile, particularly when plasma triglycerides are high. Clinical evidence suggests that coronary artery calcification as well as intima media thickness is positively related to plasma cholesteryl ester transfer, and that high plasma CETP concentration is associated with increased cardiovascular risk in hypertriglyceridaemia. However, CETP could also have anti-atherogenic potential, since it provides a potentially beneficial route for delivery of HDL-derived cholesteryl esters to the liver. In addition, CETP could also favourably stimulate peripheral cell cholesterol removal and enhance hepatic cholesterol uptake. Recent evidence suggests that a high CETP level may confer lower cardiovascular risk in the context of low triglycerides. At maximal doses, the CETP inhibitors JTT-705 and torcetrapib elicit a marked rise in HDL cholesterol of up to 34% and 91-106%, respectively. The effectiveness of these drugs on (intermediate) clinical outcome measures is currently being tested in large-scale phase III clinical trials, with torcetrapib being only evaluated in combination therapy with atorvastatin. When and how to use CETP inhibitors, e.g. in combination with a statin or a fibrate, is a major challenge. We propose that low HDL cholesterol in the context of high triglycerides, such as found in type 2 diabetes mellitus, could become an important indication area for this new class of drugs.
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Affiliation(s)
- R P F Dullaart
- University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.
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33
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Westerterp M, van der Hoogt CC, de Haan W, Offerman EH, Dallinga-Thie GM, Jukema JW, Havekes LM, Rensen PCN. Cholesteryl Ester Transfer Protein Decreases High-Density Lipoprotein and Severely Aggravates Atherosclerosis in
APOE*3-Leiden
Mice. Arterioscler Thromb Vasc Biol 2006; 26:2552-9. [PMID: 16946130 DOI: 10.1161/01.atv.0000243925.65265.3c] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Objective—
The role of cholesteryl ester transfer protein (CETP) in the development of atherosclerosis is still undergoing debate. Therefore, we evaluated the effect of human CETP expression on atherosclerosis in
APOE*3-Leiden
(
E3L
) mice with a humanized lipoprotein profile.
Methods and Results—
E3L
mice were crossbred with human
CETP
transgenic mice. On a chow diet, CETP expression increased plasma total cholesterol (TC) (+43%;
P
<0.05). To evaluate the effects of CETP on the development of atherosclerosis, mice were fed a Western-type diet containing 0.25% cholesterol, leading to 4.3-fold elevated TC levels in both
E3L
and
CETP.E3L
mice (
P
<0.01). On both diets, CETP expression shifted the distribution of cholesterol from high-density lipoprotein (HDL) toward very-low-density lipoprotein (VLDL)/low-density lipoprotein (LDL). Moreover, plasma of
CETP.E3L
mice had reduced capacity (−39%;
P
<0.05) to induce SR-BI–mediated cholesterol efflux from Fu5AH cells than plasma of
E3L
mice. After 19 weeks on the Western-type diet,
CETP.E3L
mice showed a 7.0-fold increased atherosclerotic lesion area in the aortic root compared with
E3L
mice (
P
<0.0001).
Conclusions—
CETP expression in
E3L
mice shifts the distribution of cholesterol from HDL to VLDL/LDL, reduces plasma-mediated SR-BI–dependent cholesterol efflux, and represents a clear pro-atherogenic factor in
E3L
mice. We anticipate that the
CETP.E3L
mouse will be a valuable model for the preclinical evaluation of HDL-raising interventions on atherosclerosis development.
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Affiliation(s)
- Marit Westerterp
- Department of Biomedical Research, Gaubius Laboratory, CE Leiden, The Netherlands.
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34
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Klerkx AHEM, El Harchaoui K, van der Steeg WA, Boekholdt SM, Stroes ESG, Kastelein JJP, Kuivenhoven JA. Cholesteryl ester transfer protein (CETP) inhibition beyond raising high-density lipoprotein cholesterol levels: pathways by which modulation of CETP activity may alter atherogenesis. Arterioscler Thromb Vasc Biol 2006; 26:706-15. [PMID: 16439711 DOI: 10.1161/01.atv.0000205595.19612.c9] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Raising high-density lipoprotein cholesterol (HDL-C) is a promising strategy in the struggle to prevent cardiovascular disease, and cholesteryl ester transfer protein (CETP) inhibitors have been developed to accomplish this. The first results are encouraging, and, in fact, in rabbits, inhibition of CETP reduces atherosclerosis. Because human data regarding the reduction of atheroma burden require more time, the biochemical mechanisms underlying the putative atheroprotection of CETP inhibitors are currently dissected, and several pathways have emerged. First, CETP inhibition increases HDL-C and reduces low-density lipoprotein cholesterol (LDL-C) levels consistent with CETP lipid transfer activity and its role in reverse cholesterol transport (RCT). This coincides with putative beneficial increases in both HDL and LDL size. However, many aspects regarding the impact of CETP inhibition on the RCT pathway remain elusive, in particular whether the first step concerning cholesterol efflux from peripheral tissues to HDL is influenced. Moreover, the relevance of scavenger receptor BI and consequently the central role of HDL in human RCT is still unclear. Second, CETP inhibition was shown recently to increase antioxidant enzymes associated with HDL, in turn associated with decreased oxidation of LDL. Atheroprotection in man is currently anticipated based on the improvement of these biochemical parameters known to influence atherosclerosis, but final confirmation regarding the impact of CETP inhibition on cardiovascular outcome will have to come from trials evaluating clinical end points.
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Affiliation(s)
- Anke H E M Klerkx
- Department of Experimental Vascular Medicine, Academic Medical Center, Amsterdam, The Netherlands
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35
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Sikorski JA. Oral Cholesteryl Ester Transfer Protein (CETP) Inhibitors: A Potential New Approach for Treating Coronary Artery Disease. J Med Chem 2005; 49:1-22. [PMID: 16392785 DOI: 10.1021/jm058224l] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- James A Sikorski
- Discovery Medicinal Chemistry, AtheroGenics, Inc., 8995 Westside Parkway, Alpharetta, Georgia 30004.
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36
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Zhang Z, Hirano KI, Tsukamoto K, Ikegami C, Koseki M, Saijo K, Ohno T, Sakai N, Hiraoka H, Shimomura I, Yamashita S. Defective cholesterol efflux in Werner syndrome fibroblasts and its phenotypic correction by Cdc42, a RhoGTPase. Exp Gerontol 2005; 40:286-94. [PMID: 15820609 DOI: 10.1016/j.exger.2005.01.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Revised: 12/14/2004] [Accepted: 01/13/2005] [Indexed: 11/18/2022]
Abstract
Werner syndrome (WS) is characterized by the early onset of senescent phenotypes including premature atherosclerotic cardiovascular diseases, although the underlying molecular mechanism for atherosclerosis has not been fully understood yet. Cholesterol efflux from the cells is the initial step of reverse cholesterol transport, a major protective system against atherosclerosis. The aim of the present study was to determine whether this crucial step may be altered in WS. We examined intracellular lipid transport and cholesterol efflux and the expression levels of its related molecules in skin fibroblasts obtained from patients with WS. Cholesterol efflux was markedly reduced in the WS fibroblasts in association with increased cellular cholesterol. Fluorescent recovery after photobleaching (FRAP) technique revealed that intracellular lipid transport around Golgi apparatus was markedly reduced when using a C6-NBD-Ceramide as a tracer. Cdc42 protein and its GTP-bound form were markedly reduced in the WS fibroblasts. The complementation of wild-type Cdc42 corrected cholesterol efflux, intracellular lipid transport, and cellular cholesterol levels in the WS fibroblasts. These data indicated that the reduced expression of Cdc42 may be responsible for the abnormal lipid transport, which in turn might be related to the cardiovascular manifestations in WS.
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Affiliation(s)
- Zhongyan Zhang
- Department of Internal Medicine and Molecular Science, Graduate School of Medicine, Osaka University, 2-2, Yamadaoka, Suita, Osaka 565-0871, Japan
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37
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Fu Y, Hoang A, Escher G, Parton RG, Krozowski Z, Sviridov D. Expression of Caveolin-1 Enhances Cholesterol Efflux in Hepatic Cells. J Biol Chem 2004; 279:14140-6. [PMID: 14729661 DOI: 10.1074/jbc.m311061200] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
HepG2 cells were stably transfected with human caveolin-1 (HepG2/cav cells). Transfection resulted in expression of caveolin-1 mRNA, a high abundance of caveolin-1 protein, and the formation of caveolae on the plasma membrane. Cholesterol efflux from HepG2/cav cells was 280 and 45% higher than that from parent HepG2 cells when human plasma and human apoA-I, respectively, were used as acceptors. The difference in efflux was eliminated by treatment of cells with progesterone. There was no difference in cholesterol efflux to cyclodextrin. Cholesterol efflux from plasma membrane vesicles was similar for the two cell types. Transfection led to a 40% increase in the amount of plasma membrane cholesterol in cholesterol-rich domains (caveolae and/or rafts) and a 67% increase in the rate of cholesterol trafficking from intracellular compartments to these domains. Cholesterol biosynthesis in HepG2/cav cells was increased by 2-fold, and cholesterol esterification was reduced by 50% compared with parent HepG2 cells. The proliferation rate of transfected cells was significantly lower than that of non-transfected cells. Transfection did not affect expression of ABCA1 or the abundance of ABCA1 protein, but decreased secretion of apoA-I. We conclude that overexpression of caveolin-1 in hepatic cells stimulates cholesterol efflux by enhancing transfer of cholesterol to cholesterol-rich domains in the plasma membrane.
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Affiliation(s)
- Ying Fu
- Wynn Domain, Baker Heart Research Institute, Melbourne, Victoria 8008, Australia
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38
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Le Goff W, Guerin M, Chapman MJ. Pharmacological modulation of cholesteryl ester transfer protein, a new therapeutic target in atherogenic dyslipidemia. Pharmacol Ther 2004; 101:17-38. [PMID: 14729390 DOI: 10.1016/j.pharmthera.2003.10.001] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In mediating the transfer of cholesteryl esters (CE) from antiatherogenic high density lipoprotein (HDL) to proatherogenic apolipoprotein (apo)-B-containing lipoprotein particles (including very low density lipoprotein [VLDL], VLDL remnants, intermediate density lipoprotein [IDL], and low density lipoprotein [LDL]), the CE transfer protein (CETP) plays a critical role not only in the reverse cholesterol transport (RCT) pathway but also in the intravascular remodeling and recycling of HDL particles. Dyslipidemic states associated with premature atherosclerotic disease and high cardiovascular risk are characterized by a disequilibrium due to an excess of circulating concentrations of atherogenic lipoproteins relative to those of atheroprotective HDL, thereby favoring arterial cholesterol deposition and enhanced atherogenesis. In such states, CETP activity is elevated and contributes significantly to the cholesterol burden in atherogenic apoB-containing lipoproteins. In reducing the numbers of acceptor particles for HDL-derived CE, both statins (VLDL, VLDL remnants, IDL, and LDL) and fibrates (primarily VLDL and VLDL remnants) act to attenuate potentially proatherogenic CETP activity in dyslipidemic states; simultaneously, CE are preferentially retained in HDL and thereby contribute to elevation in HDL-cholesterol content. Mutations in the CETP gene associated with CETP deficiency are characterized by high HDL-cholesterol levels (>60 mg/dL) and reduced cardiovascular risk. Such findings are consistent with studies of pharmacologically mediated inhibition of CETP in the rabbit, which argue strongly in favor of CETP inhibition as a valid therapeutic approach to delay atherogenesis. Consequently, new organic inhibitors of CETP are under development and present a potent tool for elevation of HDL in dyslipidemias involving low HDL levels and premature coronary artery disease, such as the dyslipidemia of type II diabetes and the metabolic syndrome. The results of clinical trials to evaluate the impact of CETP inhibition on premature atherosclerosis are eagerly awaited.
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Affiliation(s)
- Wilfried Le Goff
- Institut National de la Santé et de la Recherche Médicale (INSERM) Unité 551, "Dyslipoproteinemia and Atherosclerosis: Genetics, Metabolism and Therapy", Hôpital de la Pitié, 83 boulevard de l'Hôpital, 75651 Cedex 13, Paris, France
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39
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Borggreve SE, De Vries R, Dullaart RPF. Alterations in high-density lipoprotein metabolism and reverse cholesterol transport in insulin resistance and type 2 diabetes mellitus: role of lipolytic enzymes, lecithin:cholesterol acyltransferase and lipid transfer proteins. Eur J Clin Invest 2003; 33:1051-69. [PMID: 14636288 DOI: 10.1111/j.1365-2362.2003.01263.x] [Citation(s) in RCA: 191] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Insulin resistance and type 2 diabetes mellitus are generally accompanied by low HDL cholesterol and high plasma triglycerides, which are major cardiovascular risk factors. This review describes abnormalities in HDL metabolism and reverse cholesterol transport, i.e. the transport of cholesterol from peripheral cells back to the liver for metabolism and biliary excretion, in insulin resistance and type 2 diabetes mellitus. Several enzymes including lipoprotein lipase (LPL), hepatic lipase (HL) and lecithin: cholesterol acyltransferase (LCAT), as well as cholesteryl ester transfer protein (CETP) and phospholipid transfer protein (PLTP), participate in HDL metabolism and remodelling. Lipoprotein lipase hydrolyses lipoprotein triglycerides, thus providing lipids for HDL formation. Hepatic lipase reduces HDL particle size by hydrolysing its triglycerides and phospholipids. A decreased postheparin plasma LPL/HL ratio is a determinant of low HDL2 cholesterol in insulin resistance. The esterification of free cholesterol by LCAT increases HDL particle size. Plasma cholesterol esterification is unaltered or increased in type 2 diabetes mellitus, probably depending on the extent of triglyceride elevation. Subsequent CETP action results in transfer of cholesteryl esters from HDL towards triglyceride-rich lipoproteins, and is involved in decreasing HDL size. An increased plasma cholesteryl ester transfer is frequently observed in insulin-resistant conditions, and is considered to be a determinant of low HDL cholesterol. Phospholipid transfer protein generates small pre beta-HDL particles that are initial acceptors of cell-derived cholesterol. Its activity in plasma is elevated in insulin resistance and type 2 diabetes mellitus in association with high plasma triglycerides and obesity. In insulin resistance, the ability of plasma to promote cellular cholesterol efflux may be maintained consequent to increases in PLTP activity and pre beta-HDL. However, cellular cholesterol efflux to diabetic plasma is probably impaired. Besides, cellular abnormalities that are in part related to impaired actions of ATP binding cassette transporter 1 and scavenger receptor class B type I are likely to result in diminished cellular cholesterol efflux in the diabetic state. Whether hepatic metabolism of HDL-derived cholesterol and subsequent hepatobiliary transport is altered in insulin resistance and type 2 diabetes mellitus is unknown. Specific CETP inhibitors have been developed that exert major HDL cholesterol-raising effects in humans and retard atherosclerosis in animals. As an increased CETP-mediated cholesteryl ester transfer represents a plausible metabolic intermediate between high triglycerides and low HDL cholesterol, studies are warranted to evaluate the effects of these agents in insulin resistance- and diabetes-associated dyslipidaemia.
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Affiliation(s)
- S E Borggreve
- Department of Endocrinology, University Hospital Groningen, Groningen, The Netherlands
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40
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O'Brien KD, Vuletic S, McDonald TO, Wolfbauer G, Lewis K, Tu AY, Marcovina S, Wight TN, Chait A, Albers JJ. Cell-associated and extracellular phospholipid transfer protein in human coronary atherosclerosis. Circulation 2003; 108:270-4. [PMID: 12835223 DOI: 10.1161/01.cir.0000079163.97653.cd] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Phospholipid transfer protein (PLTP) plays an important role in HDL particle metabolism and may modulate hepatic secretion of apolipoprotein B-containing lipoproteins. However, whether PLTP might participate directly in human atherosclerotic lesion formation is unknown. METHODS AND RESULTS The cellular and extracellular distributions of PLTP were determined in normal and atherosclerotic human coronary lesions with a monoclonal antibody to human PLTP. Cell types (smooth muscle cells [SMCs] or macrophages), apolipoproteins (apoA-I, apoB, and apoE), and extracellular matrix proteoglycans (biglycan and versican) were identified on adjacent sections with monospecific antibodies. Minimal extracellular PLTP was detected in nonatherosclerotic coronary arteries, but extracellular and cellular PLTP immunostaining was widespread in atherosclerotic lesions. PLTP was detected in foam cell SMCs and in foam cell macrophages, which suggests that cellular cholesterol accumulation might increase PLTP expression in both cell types. This was confirmed by in vitro studies demonstrating that cholesterol loading of macrophages leads to 2- to 3-fold increases in PLTP steady-state mRNA levels, protein expression, and activity. PLTP also was detected in an extracellular distribution, colocalizing with apoA-I, apoB, apoE, and the vascular proteoglycan biglycan. In gel mobility shift assays, both active and inactive recombinant PLTP markedly increased HDL binding to biglycan, which suggests that PLTP may mediate lipoprotein binding to proteoglycans independent of its phospholipid transfer activity. CONCLUSIONS PLTP is present in human atherosclerotic lesions, and its distribution suggests roles for PLTP in both cellular cholesterol metabolism and lipoprotein retention on extracellular matrix.
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Affiliation(s)
- Kevin D O'Brien
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Wash, USA
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41
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Reinhard EJ, Wang JL, Durley RC, Fobian YM, Grapperhaus ML, Hickory BS, Massa MA, Norton MB, Promo MA, Tollefson MB, Vernier WF, Connolly DT, Witherbee BJ, Melton MA, Regina KJ, Smith ME, Sikorski JA. Discovery of a simple picomolar inhibitor of cholesteryl ester transfer protein. J Med Chem 2003; 46:2152-68. [PMID: 12747787 DOI: 10.1021/jm020528+] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel series of substituted N-[3-(1,1,2,2-tetrafluoroethoxy)benzyl]-N-(3-phenoxyphenyl)-trifluoro-3-amino-2-propanols is described which potently and reversibly inhibit cholesteryl ester transfer protein (CETP). Starting from the initial lead 1, various substituents were introduced into the 3-phenoxyaniline group to optimize the relative activity for inhibition of the CETP-mediated transfer of [3H]-cholesteryl ester from HDL donor particles to LDL acceptor particles either in buffer or in human serum. The better inhibitors in the buffer assay clustered among compounds in which the phenoxy group was substituted at the 3, 4, or 5 positions. In general, small lipophilic alkyl, haloalkyl, haloalkoxy, and halogen moieties increased potency relative to 1, while analogues containing electron-donating or hydrogen bond accepting groups exhibited lower potency. Compounds with polar or strong electron-withdrawing groups also displayed lower potency. Replacement of the phenoxy ring in 1 with either simple aliphatic or cycloalkyl ethers as well as basic heteroaryloxy groups led to reduced potency. From the better compounds, a representative series 4a-i was prepared as the chirally pure R(+) enantiomers, and from these, the 4-chloro-3-ethylphenoxy analogue was identified as a potent inhibitor of CETP activity in buffer (4a, IC50 0.77 nM, 59 nM in human serum). The simple R(+) enantiomer 4a represents the most potent acyclic CETP inhibitor reported. The chiral synthesis and biochemical characterization of 4a are reported along with its preliminary pharmacological assessment in animals.
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Affiliation(s)
- Emily J Reinhard
- Pharmacia Discovery Research (Pfizer Global Research and Development), 700 Chesterfield Parkway West, Chesterfield, Missouri 63017-1732, USA
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42
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Cazita PM, Berti JA, Aoki C, Gidlund M, Harada LM, Nunes VS, Quintão ECR, Oliveira HCF. Cholesteryl ester transfer protein expression attenuates atherosclerosis in ovariectomized mice. J Lipid Res 2003; 44:33-40. [PMID: 12518020 DOI: 10.1194/jlr.m100440-jlr200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Reduced estrogen levels result in loss of protection from coronary heart disease in postmenopausal women. Enhanced and diminished atherosclerosis have been associated with plasma levels of cholesteryl ester transfer protein (CETP); however, little is known about the role of CETP-ovarian hormone interactions in atherogenesis. We assessed the severity of diet-induced atherosclerosis in ovariectomized (OV) CETP transgenic mice crossbred with LDL receptor knockout mice. Compared with OV CETP expressing ((+)), OV CETP non-expressing ((-)) mice had higher plasma levels of total, VLDL-, LDL-, and HDL-cholesterol, as well as higher antibodies titers against oxidized LDL. The mean aortic lesion area was 2-fold larger in OV CETP(-) than in OV CETP(+) mice (147 +/- 90 vs. 73 +/- 42 x 10(3) micro m(2), respectively). Estrogen therapy in OV mice blunted the CETP dependent differences in plasma lipoproteins, oxLDL antibodies, and atherosclerosis severity. Macrophages from OV CETP(+) mice took up less labeled cholesteryl ether (CEt) from acetyl-LDL than macrophages from OV CETP(-) mice. Estrogen replacement induced a further reduction in CEt uptake and an elevation in HDL mediated cholesterol efflux from pre-loaded OV CETP(+) as compared with OV CETP(-) macrophages. These findings support the proposed anti-atherogenic role of CETP in specific metabolic settings.
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Affiliation(s)
- Patrícia M Cazita
- Laboratório de Lípides, Faculdade de Medicina da Universidade de São Paulo, 01246-903, SP, Brazil
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