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Liu H, Xie H, Li C, Wang L, Chen Q, Ouyang X, Yan C. Diaporisoindole B Reduces Lipid Accumulation in THP-1 Macrophage Cells via MAPKs and PPARγ-LXRα Pathways and Promotes the Reverse Cholesterol Transport by Upregulating SR-B1 and LDLR in HepG2 Cells. JOURNAL OF NATURAL PRODUCTS 2022; 85:2769-2778. [PMID: 36399085 DOI: 10.1021/acs.jnatprod.2c00715] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Diaporisoindole B (DPB), an isoprenylisoindole alkaloid isolated from the mangrove endophytic fungus Diaporthe sp. SYSU-HQ3, has been proved to have a good anti-inflammatory activity in macrophage cells. In this study, we found that DPB was able to reduce lipid accumulation in THP-1 macrophage-derived foam cells. DPB could inhibit the lipid influx-related gene CD36 and increase the expression of lipid efflux-related genes ATP binding cassette transporter A1 (ABCA1), ATP binding cassette transporter G1 (ABCG1), and scavenger receptor B1 (SR-B1). Moreover, DPB elevated low-density lipoprotein receptor (LDLR) protein expression in HepG2 cells, which can increase the transport of LDL. Meanwhile, DPB could downregulate the expression levels of proteins related to cholesterol and fatty acid synthesis. Further study showed that DPB could activate peroxisome proliferator-activated receptor gamma (PPARγ) and inhibit mitogen-activated protein kinase (MAPK) phosphorylation. Taken together, our findings demonstrated that DPB could reduce lipid accumulation in THP-1 macrophage cells by reducing the intake of lipids and promoting the efflux of lipids and also could promote the reverse cholesterol transport (RCT) mechanism by upregulating SR-B1 and LDLR in HepG2 cells.
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Affiliation(s)
- Hongju Liu
- School of Pharmacy, Guangdong Medical University, 1 Xincheng Avenue, Dongguan 523808, People's Republic of China
| | - Huiyi Xie
- School of Pharmacy, Guangdong Medical University, 1 Xincheng Avenue, Dongguan 523808, People's Republic of China
| | - Changqun Li
- School of Pharmacy, Guangdong Medical University, 1 Xincheng Avenue, Dongguan 523808, People's Republic of China
| | - Lingling Wang
- School of Pharmacy, Guangdong Medical University, 1 Xincheng Avenue, Dongguan 523808, People's Republic of China
| | - Qiling Chen
- School of Pharmacy, Guangdong Medical University, 1 Xincheng Avenue, Dongguan 523808, People's Republic of China
| | - Xin Ouyang
- School of Pharmacy, Guangdong Medical University, 1 Xincheng Avenue, Dongguan 523808, People's Republic of China
| | - Chong Yan
- School of Pharmacy, Guangdong Medical University, 1 Xincheng Avenue, Dongguan 523808, People's Republic of China
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2
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Di Bartolo BA, Cartland SP, Genner S, Manuneedhi Cholan P, Vellozzi M, Rye KA, Kavurma MM. HDL Improves Cholesterol and Glucose Homeostasis and Reduces Atherosclerosis in Diabetes-Associated Atherosclerosis. J Diabetes Res 2021; 2021:6668506. [PMID: 34095317 PMCID: PMC8163542 DOI: 10.1155/2021/6668506] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/11/2021] [Accepted: 02/17/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND AND AIMS Apolipoprotein A-I (ApoA-I), the main component of high-density lipoprotein (HDL), not only promotes reverse cholesterol transport (RCT) in atherosclerosis but also increases insulin secretion in pancreatic β-cells, suggesting that interventions which raise HDL levels may be beneficial in diabetes-associated cardiovascular disease (CVD). Previously, we showed that TNF-related apoptosis-inducing ligand (TRAIL) deletion in Apolipoprotein Eknockout (Apoe-/- ) mice results in diabetes-accelerated atherosclerosis in response to a "Western" diet. Here, we sought to identify whether reconstituted HDL (rHDL) could improve features of diabetes-associated CVD in Trail-/-Apoe-/- mice. METHODS AND RESULTS Trail-/-Apoe-/- and Apoe-/- mice on a "Western" diet for 12 weeks received 3 weekly infusions of either PBS (vehicle) or rHDL (containing ApoA-I (20 mg/kg) and 1-palmitoyl-2-linoleoyl phosphatidylcholine). Administration of rHDL reduced total plasma cholesterol, triglyceride, and glucose levels in Trail-/-Apoe-/- but not in Apoe-/- mice, with no change in weight gain observed. rHDL treatment also improved glucose clearance in response to insulin and glucose tolerance tests. Immunohistological analysis of pancreata revealed increased insulin expression/production and a reduction in macrophage infiltration in mice with TRAIL deletion. Furthermore, atherosclerotic plaque size in Trail-/-Apoe-/- mice was significantly reduced associating with increased expression of the M2 macrophage marker CD206, suggesting HDL's involvement in the polarization of macrophages. rHDL also increased vascular mRNA expression of RCT transporters, ABCA1 and ABCG1, in Trail-/-Apoe-/- but not in Apoe-/- mice. Conclusions. rHDL improves features of diabetes-associated atherosclerosis in mice. These findings support the therapeutic potential of rHDL in the treatment of atherosclerosis and associated diabetic complications. More studies are warranted to understand rHDL's mechanism of action.
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MESH Headings
- ATP Binding Cassette Transporter 1/genetics
- ATP Binding Cassette Transporter 1/metabolism
- ATP Binding Cassette Transporter, Subfamily G, Member 1/genetics
- ATP Binding Cassette Transporter, Subfamily G, Member 1/metabolism
- Animals
- Anticholesteremic Agents/administration & dosage
- Apolipoprotein A-I/administration & dosage
- Atherosclerosis/blood
- Atherosclerosis/drug therapy
- Atherosclerosis/genetics
- Biomarkers/blood
- Blood Glucose/drug effects
- Blood Glucose/metabolism
- Cholesterol/blood
- Diabetes Mellitus/blood
- Diabetes Mellitus/drug therapy
- Diet, Western
- Disease Models, Animal
- Dyslipidemias/blood
- Dyslipidemias/drug therapy
- Dyslipidemias/genetics
- Homeostasis
- Humans
- Hypoglycemic Agents/administration & dosage
- Lipoproteins, HDL/administration & dosage
- Macrophages/drug effects
- Macrophages/metabolism
- Male
- Mice, Knockout, ApoE
- Phosphatidylcholines/administration & dosage
- Plaque, Atherosclerotic
- TNF-Related Apoptosis-Inducing Ligand/genetics
- TNF-Related Apoptosis-Inducing Ligand/metabolism
- Mice
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Affiliation(s)
- Belinda A. Di Bartolo
- The University of Sydney, Kolling Institute of Medical Research, Sydney, Australia
- Faculty of Medicine and Health, Sydney, Australia
- Heart Research Institute, Sydney, Australia
- The University of New South Wales, Faculty of Medicine, Sydney, Australia
| | - Siân P. Cartland
- Faculty of Medicine and Health, Sydney, Australia
- Heart Research Institute, Sydney, Australia
- The University of New South Wales, Faculty of Medicine, Sydney, Australia
| | | | | | | | - Kerry-Anne Rye
- The University of New South Wales, Faculty of Medicine, Sydney, Australia
| | - Mary M. Kavurma
- Faculty of Medicine and Health, Sydney, Australia
- Heart Research Institute, Sydney, Australia
- The University of New South Wales, Faculty of Medicine, Sydney, Australia
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3
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Wang D, Yang Y, Lei Y, Tzvetkov NT, Liu X, Yeung AWK, Xu S, Atanasov AG. Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products. Pharmacol Rev 2019; 71:596-670. [PMID: 31554644 DOI: 10.1124/pr.118.017178] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.
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Affiliation(s)
- Dongdong Wang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Yang Yang
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Yingnan Lei
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Nikolay T Tzvetkov
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Xingde Liu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Andy Wai Kan Yeung
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Suowen Xu
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
| | - Atanas G Atanasov
- The Second Affiliated Hospital of Guizhou University of Traditional Chinese Medicine, Guiyang, China (D.W., X.L.); Department of Molecular Biology, Institute of Genetics and Animal Breeding of the Polish Academy of Sciences, Jastrzębiec, Poland (D.W., Y.Y., Y.L., A.G.A.); Department of Pharmacognosy, University of Vienna, Vienna, Austria (A.G.A.); Institute of Clinical Chemistry, University Hospital Zurich, Schlieren, Switzerland (D.W.); Institute of Molecular Biology "Roumen Tsanev," Department of Biochemical Pharmacology and Drug Design, Bulgarian Academy of Sciences, Sofia, Bulgaria (N.T.T.); Pharmaceutical Institute, University of Bonn, Bonn, Germany (N.T.T.); Aab Cardiovascular Research Institute, Department of Medicine, University of Rochester, Rochester, New York (S.X.); Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China (A.W.K.Y.); and Institute of Neurobiology, Bulgarian Academy of Sciences, Sofia, Bulgaria (A.G.A.)
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4
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Chernikov IV, Vlassov VV, Chernolovskaya EL. Current Development of siRNA Bioconjugates: From Research to the Clinic. Front Pharmacol 2019; 10:444. [PMID: 31105570 PMCID: PMC6498891 DOI: 10.3389/fphar.2019.00444] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 04/08/2019] [Indexed: 12/12/2022] Open
Abstract
Small interfering RNAs (siRNAs) acting via RNA interference mechanisms are able to recognize a homologous mRNA sequence in the cell and induce its degradation. The main problems in the development of siRNA-based drugs for therapeutic use are the low efficiency of siRNA delivery to target cells and the degradation of siRNAs by nucleases in biological fluids. Various approaches have been proposed to solve the problem of siRNA delivery in vivo (e.g., viruses, cationic lipids, polymers, nanoparticles), but all have limitations for therapeutic use. One of the most promising approaches to solve the problem of siRNA delivery to target cells is bioconjugation; i.e., the covalent connection of siRNAs with biogenic molecules (lipophilic molecules, antibodies, aptamers, ligands, peptides, or polymers). Bioconjugates are "ideal nanoparticles" since they do not need a positive charge to form complexes, are less toxic, and are less effectively recognized by components of the immune system because of their small size. This review is focused on strategies and principles for constructing siRNA bioconjugates for in vivo use.
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Affiliation(s)
- Ivan V Chernikov
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Valentin V Vlassov
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
| | - Elena L Chernolovskaya
- Laboratory of Nucleic Acids Biochemistry, Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
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5
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Mamazhakypov A, Schermuly RT, Schaefer L, Wygrecka M. Lipids - two sides of the same coin in lung fibrosis. Cell Signal 2019; 60:65-80. [PMID: 30998969 DOI: 10.1016/j.cellsig.2019.04.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 04/07/2019] [Accepted: 04/12/2019] [Indexed: 12/16/2022]
Abstract
Idiopathic pulmonary fibrosis (IPF) is characterized by progressive extracellular matrix deposition in the lung parenchyma leading to the destruction of lung structure, respiratory failure and premature death. Recent studies revealed that the pathogenesis of IPF is associated with alterations in the synthesis and the activity of lipids, lipid regulating proteins and cell membrane lipid transporters and receptors in different lung cells. Furthermore, deregulated lipid metabolism was found to contribute to the profibrotic phenotypes of lung fibroblasts and alveolar epithelial cells. Consequently, several pharmacological agents, targeting lipids, lipid mediators, and lipoprotein receptors, was successfully tested in the animal models of lung fibrosis and entered early phase clinical trials. In this review, we highlight new therapeutic options to counteract disturbed lipid hemostasis in the maladaptive lung remodeling.
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Affiliation(s)
- Argen Mamazhakypov
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center, Giessen, Germany.
| | - Ralph T Schermuly
- Department of Internal Medicine, Universities of Giessen and Marburg Lung Center, Giessen, Germany.
| | - Liliana Schaefer
- Goethe University School of Medicine, Frankfurt am Main, Germany.
| | - Malgorzata Wygrecka
- Department of Biochemistry, Universities of Giessen and Marburg Lung Center, Giessen, Germany.
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6
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Yu XH, Zhang DW, Zheng XL, Tang CK. Cholesterol transport system: An integrated cholesterol transport model involved in atherosclerosis. Prog Lipid Res 2018; 73:65-91. [PMID: 30528667 DOI: 10.1016/j.plipres.2018.12.002] [Citation(s) in RCA: 129] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 10/30/2018] [Accepted: 12/01/2018] [Indexed: 02/07/2023]
Abstract
Atherosclerosis, the pathological basis of most cardiovascular disease (CVD), is closely associated with cholesterol accumulation in the arterial intima. Excessive cholesterol is removed by the reverse cholesterol transport (RCT) pathway, representing a major antiatherogenic mechanism. In addition to the RCT, other pathways are required for maintaining the whole-body cholesterol homeostasis. Thus, we propose a working model of integrated cholesterol transport, termed the cholesterol transport system (CTS), to describe body cholesterol metabolism. The novel model not only involves the classical view of RCT but also contains other steps, such as cholesterol absorption in the small intestine, low-density lipoprotein uptake by the liver, and transintestinal cholesterol excretion. Extensive studies have shown that dysfunctional CTS is one of the major causes for hypercholesterolemia and atherosclerosis. Currently, several drugs are available to improve the CTS efficiently. There are also several therapeutic approaches that have entered into clinical trials and shown considerable promise for decreasing the risk of CVD. In recent years, a variety of novel findings reveal the molecular mechanisms for the CTS and its role in the development of atherosclerosis, thereby providing novel insights into the understanding of whole-body cholesterol transport and metabolism. In this review, we summarize the latest advances in this area with an emphasis on the therapeutic potential of targeting the CTS in CVD patients.
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Affiliation(s)
- Xiao-Hua Yu
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Medical Research Experiment Center, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan 421001, China
| | - Da-Wei Zhang
- Department of Pediatrics and Group on the Molecular and Cell Biology of Lipids, University of Alberta, Alberta, Canada
| | - Xi-Long Zheng
- Department of Biochemistry and Molecular Biology, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary, Health Sciences Center, 3330 Hospital Dr NW, Calgary, Alberta T2N 4N1, Canada
| | - Chao-Ke Tang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Medical Research Experiment Center, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, Hunan 421001, China.
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Wang D, Hiebl V, Ladurner A, Latkolik SL, Bucar F, Heiß EH, Dirsch VM, Atanasov AG. 6-Dihydroparadol, a Ginger Constituent, Enhances Cholesterol Efflux from THP-1-Derived Macrophages. Mol Nutr Food Res 2018; 62:e1800011. [PMID: 29802792 PMCID: PMC6099374 DOI: 10.1002/mnfr.201800011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/24/2018] [Indexed: 01/24/2023]
Abstract
SCOPE Ginger is reported to be used for the prevention and treatment of cardiovascular diseases (CVD). Cholesterol efflux from macrophage foam cells is an important process in reverse cholesterol transport, whose increase may help to prevent or treat CVD. In this study, we investigated the effects of 6-dihydroparadol from ginger on macrophage cholesterol efflux. METHODS AND RESULTS We show that 6-dihydroparadol concentration-dependently enhances both apolipoprotein A1- and human plasma-mediated cholesterol efflux from cholesterol-loaded THP-1-derived macrophages using macrophage cholesterol efflux assay. 6-Dihydroparadol increases protein levels of both ATP-binding cassette transporters A1 and G1 (ATP-binding cassette transporter A1 [ABCA1] and ATP-binding cassette transporter G1 [ABCG1]) according to Western blot analysis. The ABCA1 inhibitor probucol completely abolishes 6-dihydroparadol-enhanced cholesterol efflux. Furthermore, increased ABCA1 protein levels in the presence of 6-dihydroparadol were associated with both increased ABCA1 mRNA levels and increased ABCA1 protein stability. Enhanced ABCG1 protein levels were only associated with increased protein stability. Increased ABCA1 protein stability appeared to be the result of a reduced proteasomal degradation of the transporter in the presence of 6-dihydroparadol. CONCLUSION We identified 6-dihydroparadol from ginger as a novel promoter of cholesterol efflux from macrophages that increases both ABCA1 and ABCG1 protein abundance. This newly identified bioactivity might contribute to the antiatherogenic effects of ginger.
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Affiliation(s)
- Dongdong Wang
- Department of PharmacognosyUniversity of ViennaAlthanstrasse 141090ViennaAustria
- Institute of Genetics and Animal Breeding of the Polish Academy of Sciencesul. Postepu 36A05–552JastrzebiecPoland
- Institute of Clinical ChemistryUniversity Hospital ZurichUniversity of ZurichWagistrasse 148952SchlierenSwitzerland
| | - Verena Hiebl
- Department of PharmacognosyUniversity of ViennaAlthanstrasse 141090ViennaAustria
| | - Angela Ladurner
- Department of PharmacognosyUniversity of ViennaAlthanstrasse 141090ViennaAustria
| | - Simone L. Latkolik
- Department of PharmacognosyUniversity of ViennaAlthanstrasse 141090ViennaAustria
| | - Franz Bucar
- Department of Pharmacognosy, Institute of Pharmaceutical SciencesUniversity of Graz8010GrazAustria
| | - Elke H. Heiß
- Department of PharmacognosyUniversity of ViennaAlthanstrasse 141090ViennaAustria
| | - Verena M. Dirsch
- Department of PharmacognosyUniversity of ViennaAlthanstrasse 141090ViennaAustria
| | - Atanas G. Atanasov
- Department of PharmacognosyUniversity of ViennaAlthanstrasse 141090ViennaAustria
- Institute of Genetics and Animal Breeding of the Polish Academy of Sciencesul. Postepu 36A05–552JastrzebiecPoland
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Pizzini A, Lunger L, Demetz E, Hilbe R, Weiss G, Ebenbichler C, Tancevski I. The Role of Omega-3 Fatty Acids in Reverse Cholesterol Transport: A Review. Nutrients 2017; 9:nu9101099. [PMID: 28984832 PMCID: PMC5691715 DOI: 10.3390/nu9101099] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 09/22/2017] [Accepted: 09/28/2017] [Indexed: 01/31/2023] Open
Abstract
The beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs) on cardiovascular disease have been studied extensively. However, it remains unclear to what extent n-3 PUFAs may impact Reverse Cholesterol Transport (RCT). RCT describes a mechanism by which excess cholesterol from peripheral tissues is transported to the liver for hepatobiliary excretion, thereby inhibiting foam cell formation and the development of atherosclerosis. The aim of this review is to summarize the literature and to provide an updated overview of the effects of n-3 PUFAs on key players in RCT, including apoliprotein AI (apoA-I), ATP-binding cassette transporter A1 (ABCA1), ABCG1, apoE, scavenger receptor class B type I (SR-BI), cholesteryl ester transfer protein (CETP), low-density lipoprotein receptor (LDLr), cholesterol 7 alpha-hydroxylase (CYP7A1) and ABCG5/G8. Based on current knowledge, we conclude that n-3 PUFAs may beneficially affect RCT, mainly by influencing high-density lipoprotein (HDL) remodeling and by promoting hepatobiliary sterol excretion.
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Affiliation(s)
- Alex Pizzini
- Department of Internal Medicine II, Infectious Diseases, Pneumology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
| | - Lukas Lunger
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology and Metabolism, Medical University of Innsbruck, 6020 Innsbruck, Austria.
| | - Egon Demetz
- Department of Internal Medicine II, Infectious Diseases, Pneumology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
| | - Richard Hilbe
- Department of Internal Medicine II, Infectious Diseases, Pneumology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
| | - Guenter Weiss
- Department of Internal Medicine II, Infectious Diseases, Pneumology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
| | - Christoph Ebenbichler
- Department of Internal Medicine I, Gastroenterology, Hepatology, Endocrinology and Metabolism, Medical University of Innsbruck, 6020 Innsbruck, Austria.
| | - Ivan Tancevski
- Department of Internal Medicine II, Infectious Diseases, Pneumology, Rheumatology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
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Wang N, Tall AR. Cholesterol in platelet biogenesis and activation. Blood 2016; 127:1949-53. [PMID: 26929273 PMCID: PMC4841038 DOI: 10.1182/blood-2016-01-631259] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 02/11/2016] [Indexed: 02/06/2023] Open
Abstract
Hypercholesterolemia is a risk factor for atherothrombotic disease, largely attributed to its impact on atherosclerotic lesional cells such as macrophages. Platelets are involved in immunity and inflammation and impact atherogenesis, primarily by modulating immune and inflammatory effector cells. There is evidence that hypercholesterolemia increases the risk of atherosclerosis and thrombosis by modulating platelet biogenesis and activity. This review highlights recent findings on the impact of aberrant cholesterol metabolism on platelet biogenesis and activity and their relevance in atherosclerosis and thrombosis.
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Affiliation(s)
- Nan Wang
- Division of Molecular Medicine, Department of Medicine, Columbia University Medical Center, New York, NY
| | - Alan R Tall
- Division of Molecular Medicine, Department of Medicine, Columbia University Medical Center, New York, NY
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ZHOU LINGYAN, LI CONGCONG, GAO LING, WANG AIHONG. High-density lipoprotein synthesis and metabolism (Review). Mol Med Rep 2015; 12:4015-4021. [DOI: 10.3892/mmr.2015.3930] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Accepted: 03/26/2015] [Indexed: 11/06/2022] Open
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11
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Riwanto M, Rohrer L, von Eckardstein A, Landmesser U. Dysfunctional HDL: from structure-function-relationships to biomarkers. Handb Exp Pharmacol 2015; 224:337-366. [PMID: 25522994 DOI: 10.1007/978-3-319-09665-0_10] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Reduced plasma levels of HDL-C are associated with an increased risk of CAD and myocardial infarction, as shown in various prospective population studies. However, recent clinical trials on lipid-modifying drugs that increase plasma levels of HDL-C have not shown significant clinical benefit. Notably, in some recent clinical studies, there is no clear association of higher HDL-C levels with a reduced risk of cardiovascular events observed in patients with existing CAD. These observations have prompted researchers to shift from a cholesterol-centric view of HDL towards assessing the function and composition of HDL particles. Of importance, experimental and translational studies have further demonstrated various potential antiatherogenic effects of HDL. HDL has been proposed to promote macrophage reverse cholesterol transport and to protect endothelial cell functions by prevention of oxidation of LDL and its adverse endothelial effects. Furthermore, HDL from healthy subjects can directly stimulate endothelial cell production of nitric oxide and exert anti-inflammatory and antiapoptotic effects. Of note, increasing evidence suggests that the vascular effects of HDL can be highly heterogeneous and HDL may lose important anti-atherosclerotic properties and turn dysfunctional in patients with chronic inflammatory disorders. A greater understanding of mechanisms of action of HDL and its altered vascular effects is therefore critical within the context of HDL-targeted therapies.
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Affiliation(s)
- Meliana Riwanto
- Cardiology, University Heart Center, University Hospital Zurich and Center of Molecular Cardiology, University of Zurich, Rämistrasse 100, CH 8091, Zurich, Switzerland
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12
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Scichilone N, Rizzo M, Benfante A, Catania R, Giglio RV, Nikolic D, Montalto G, Bellia V. Serum low density lipoprotein subclasses in asthma. Respir Med 2013; 107:1866-72. [PMID: 24075885 DOI: 10.1016/j.rmed.2013.09.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 09/03/2013] [Accepted: 09/04/2013] [Indexed: 12/21/2022]
Abstract
BACKGROUND The levels of serum low-density lipoproteins (LDL) have been implicated in the inflammatory cascade in a murine model of asthma. Recent findings suggest that LDL may modulate the inflammatory state of the asthmatic airways in humans. OBJECTIVE We explored whether LDL subclasses are associated with the occurrence and severity of asthma. METHODS 24 asthmatics (M/F: 11/13) and 24 healthy individuals, with normal BMI and absence of metabolic syndrome, matched for age and gender. Serum concentrations of LDL subclasses were distributed as seven bands (LDL-1 and -2 defined as large, least pro-inflammatory LDL, and LDL-3 to -7 defined as small, most pro-inflammatory LDL), using the LipoPrint(©) System (Quantimetrix Corporation, Redondo Beach, CA, USA). RESULTS LDL-1 was similar in the two groups (56 ± 16% vs. 53 ± 11, p = NS), while LDL-2 was significantly lower in asthmatics as compared to controls (35 ± 8% vs. 43 ± 10%, p = 0.0074). LDL-3 levels were two-fold higher in the asthmatics, but the difference did not reach the statistical significance (8 ± 7.3% vs. 4 ± 3%, p = NS). Smaller subclasses LDL-4 to LDL-7 were undetectable in controls. In asthmatics, LDL-1 was positively associated with VC% predicted (r = +0.572, p = 0.0035) and FEV1% predicted (r = +0.492, p = 0.0146). LDL-3 was inversely correlated with both VC% predicted (r = -0.535, p = 0.0071) and FEV1% predicted (r = -0.465, p = 0.0222). CONCLUSIONS The findings of this pilot study suggest a role of LDL in asthma, and advocate for larger studies to confirm the association between asthma and dyslipidemia.
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Affiliation(s)
- Nicola Scichilone
- BioMedical Department of Internal Medicine and Medical Specialties (DiBiMIS), University of Palermo, Italy; Euro-Mediterranean Institute of Science and Technology, Italy.
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Chadwick AC, Sahoo D. Functional genomics of the human high-density lipoprotein receptor scavenger receptor BI: an old dog with new tricks. Curr Opin Endocrinol Diabetes Obes 2013; 20:124-31. [PMID: 23403740 PMCID: PMC3967407 DOI: 10.1097/med.0b013e32835ed575] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
PURPOSE OF REVIEW The athero-protective role of scavenger receptor BI (SR-BI) is primarily attributed to its ability to selectively transfer cholesteryl esters from high-density lipoproteins (HDLs) to the liver during reverse cholesterol transport (RCT). In this review, we highlight recent findings that reveal the impact of SR-BI on lipid levels and cardiovascular disease in humans. Moreover, additional responsibilities of SR-BI in modulating adrenal and platelet function, as well as female fertility in humans, are discussed. RECENT FINDINGS Heterozygote carriers of P297S, S112F and T175A-mutant SR-BI receptors were identified in patients with high HDL-cholesterol levels. HDL from P297S-SR-BI carriers was unable to mediate macrophage cholesterol efflux, whereas hepatocytes expressing P297S-SR-BI were unable to mediate the selective uptake of HDL-cholesteryl esters. S112F and T175A-mutant receptors exhibited similar impaired cholesterol transport functions in vitro. Reduced SR-BI function in P297S carriers was also associated with decreased steroidogenesis and altered platelet function. Further, human population studies identified SCARB1 variants associated with female infertility. SUMMARY Identification of SR-BI variants confirms the key role of this receptor in influencing lipid levels and RCT in humans. A deeper understanding of the contributions of SR-BI to steroidogenesis, platelet function and fertility is required in light of exploration of HDL-raising therapies aimed at reducing cardiovascular risk.
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Affiliation(s)
- Alexandra C. Chadwick
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
| | - Daisy Sahoo
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA
- Department of Medicine, Division of Endocrinology, Metabolism & Clinical Nutrition, Milwaukee, WI, 53226, USA
- To whom correspondence should be addressed: H4930 Health Research Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, Phone: 1-414-955-7414; Fax: 1-414-456-6570,
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14
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Brown RJ, Shao F, Baldán A, Albert CJ, Ford DA. Cholesterol efflux analyses using stable isotopes and mass spectrometry. Anal Biochem 2012; 433:56-64. [PMID: 23072980 DOI: 10.1016/j.ab.2012.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Revised: 10/03/2012] [Accepted: 10/05/2012] [Indexed: 11/18/2022]
Abstract
Cholesterol efflux from macrophages and the vascular wall is the initial step of the cardiovascular protective reverse cholesterol transport process. This study demonstrates a mass spectrometry based assay to measure the cellular and medium content of [d(7)]cholesterol and unlabeled cholesterol that can be used to measure cholesterol efflux from cell lines. Using a triple-quadrupole electrospray ionization-MS instrument in direct infusion mode, product ion scanning for m/z 83, neutral loss (NL) 375.5 scanning, and NL 368.5 scanning were used to detect cholesterol (as an acetylated derivative), [d(7)]cholesteryl ester (CE), and unlabeled CE, respectively. The same mass of [d(7)]cholesterol was substituted for [(3)H]cholesterol under standard efflux assay conditions. At the end of [d(7)]cholesterol loading, the intracellular mass of [d(7)]cholesterol was twofold greater than that of unlabeled cholesterol, and the intracellular [d(7)]CE profile was similar to that of unlabeled CE. Efflux of cholesterol to apolipoprotein A-I and high-density lipoproteins was similar comparing efflux of either [d(7)]cholesterol or [(3)H]cholesterol as measured by following efflux of the tracers only. This technique also can be used to assess the efflux of unlabeled cholesterol to acceptors in medium that are initially cholesterol-free (e.g., apolipoprotein A-I). Taken together, this mass spectrometry-based assay provides new molecular detail to assess cholesterol efflux.
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Affiliation(s)
- Robert J Brown
- Department of Biochemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X9, Canada.
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15
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Chadwick AC, Sahoo D. Functional characterization of newly-discovered mutations in human SR-BI. PLoS One 2012; 7:e45660. [PMID: 23029167 PMCID: PMC3448639 DOI: 10.1371/journal.pone.0045660] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Accepted: 08/20/2012] [Indexed: 12/27/2022] Open
Abstract
In rodents, SR-BI has been firmly established as a physiologically relevant HDL receptor that mediates removal of HDL-cholesteryl esters (CE). However, its role in human lipoprotein metabolism is less defined. Recently, two unique point mutations in human SR-BI - S112F or T175A - were identified in subjects with high HDL-cholesterol (HDL-C) levels. We hypothesized that mutation of these conserved residues would compromise the cholesterol-transport functions of SR-BI. To test this hypothesis, S112F- and T175A-SR-BI were generated by site-directed mutagenesis. Cell surface expression was confirmed for both mutant receptors in COS-7 cells upon transient transfection, albeit at lower levels for T175A-SR-BI. Both mutant receptors displayed defective HDL binding, selective uptake of HDL-CE and release of free cholesterol (FC) from cells to HDL. Mutant receptors were also unable to re-organize plasma membrane pools of FC. While these impaired functions were independent of receptor oligomerization, inability of T175A-SR-BI to mediate cholesterol-transport functions could be related to altered N-linked glycosylation status. In conclusion, high HDL-C levels observed in carriers of S112F- or T175A-SR-BI mutant receptors are consistent with the inability of these SR-BI receptors to mediate efficient selective uptake of HDL-CE, and suggest that increased plasma HDL concentrations in these settings may not be associated with lower risk of cardiovascular disease.
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Affiliation(s)
- Alexandra C Chadwick
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, USA
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16
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Song G, Zong C, Liu Q, Si Y, Liu J, Li W, Zhu P, Qin S. SR-BI associates with ABCG1 and inhibits ABCG1-mediated cholesterol efflux from cells to high-density lipoprotein 3. Lipids Health Dis 2012; 11:118. [PMID: 22984960 PMCID: PMC3512508 DOI: 10.1186/1476-511x-11-118] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 09/14/2012] [Indexed: 11/10/2022] Open
Abstract
Background The single and combined effects of scavenger receptor-BI (SR-BI), ATP-binding cassette transporter (ABC) A1 and G1 on cholesterol efflux from Chinese Hamster Ovary (CHO) cells were investigated. Results When apolipoproteinA-I (apoA-I) was used as an acceptor, ABCA1 overexpression led to an increase in total cholesterol (TC) in medium which is attributable to a 2-fold increase in free cholesterol (FC) content. When high-density lipoprotein 3 (HDL3) was used as an acceptor, SR-BI overexpression not only promoted FC efflux, but also promoted the uptake of cholesteryl ester (CE) into cells, resulting in no TC varieties in medium. Overexpression of ABCG1 increased both the FC and CE levels in medium. However, when apoA-I and HDL3 were both used as acceptors, coexpression of SR-BI has no effect on ABCA1-mediated increased FC and TC accumulation in medium. Interestingly, coexpression of SR-BI with ABCG1 blocked the ABCG1-mediated cholesterol efflux to HDL3, mostly by promoting the reuptake of CE from the medium. Furthermore, co-immunoprecipitation experiments revealed that SR-BI interacted with ABCG1 in BHK cells overexpressing ABCG1 and SR-BI. Conclusions We found SR-BI associates with ABCG1 and inhibits ABCG1-mediated cholesterol efflux from cells to HDL3.
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Affiliation(s)
- Guohua Song
- Key Laboratory of Atherosclerosis in Universities of Shandong, Taishan Medical University, Taian, China
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17
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Gowdy KM, Fessler MB. Emerging roles for cholesterol and lipoproteins in lung disease. Pulm Pharmacol Ther 2012; 26:430-7. [PMID: 22706330 DOI: 10.1016/j.pupt.2012.06.002] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Revised: 05/25/2012] [Accepted: 06/05/2012] [Indexed: 01/02/2023]
Abstract
Dyslipidemia, the condition of elevated serum triglycerides, elevated low-density lipoprotein cholesterol, and/or low high-density lipoprotein cholesterol, is a public health problem of growing concern. Dyslipidemia clusters with other disorders of the metabolic syndrome that together influence, and may derive from, chronic inflammation. While best recognized as a risk factor for atherosclerotic cardiovascular disease, lipid dysregulation has recently been shown to influence a variety of disease processes in several organ systems. This review highlights our current understanding of the role of cholesterol and its homeostatic trafficking in pulmonary physiology and pathophysiology. Gene-targeted mice deficient in regulatory proteins that govern reverse cholesterol transport (e.g., ATP Binding Cassette transporter G1, apolipoprotein E) have recently been shown to have abnormal lung physiology, including dysregulated pulmonary innate and adaptive immune responses to the environment. It has also recently been shown that diet-induced dyslipidemia alters trafficking of immune cells to the lung in a manner that may have important implications for the pathogenesis of acute lung injury, asthma, pneumonia, and other lung disorders. Conversely, cholesterol-targeting pharmacologic agents, such as statins, apolipoprotein mimetic peptides, and Liver X Receptor agonists, have shown early promise in the treatment of several lung disorders. An improved understanding of the precise molecular mechanisms by which cholesterol and its trafficking modify pulmonary immunity will be required before the full implications of dyslipidemia as a lung disease modifier, and the full potential of lipid-targeting agents as pulmonary therapeutics, can be realized.
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Affiliation(s)
- Kymberly M Gowdy
- Laboratory of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, 111 TW Alexander Drive, PO Box 12233, MD D2-01, Research Triangle Park, NC 27709, USA.
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Rosenson RS, Brewer HB, Davidson WS, Fayad ZA, Fuster V, Goldstein J, Hellerstein M, Jiang XC, Phillips MC, Rader DJ, Remaley AT, Rothblat GH, Tall AR, Yvan-Charvet L. Cholesterol efflux and atheroprotection: advancing the concept of reverse cholesterol transport. Circulation 2012; 125:1905-19. [PMID: 22508840 PMCID: PMC4159082 DOI: 10.1161/circulationaha.111.066589] [Citation(s) in RCA: 692] [Impact Index Per Article: 57.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Robert S Rosenson
- Mount Sinai Heart, Mount Sinai School of Medicine, One Gustave L. Levy Place, Box 1030, New York, NY 10029, USA.
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Besler C, Lüscher TF, Landmesser U. Molecular mechanisms of vascular effects of High-density lipoprotein: alterations in cardiovascular disease. EMBO Mol Med 2012; 4:251-68. [PMID: 22431312 PMCID: PMC3376856 DOI: 10.1002/emmm.201200224] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Revised: 01/28/2012] [Accepted: 02/03/2012] [Indexed: 12/12/2022] Open
Abstract
Low high-density lipoprotein (HDL)-cholesterol levels are associated with an increased risk of coronary artery disease (CAD) and myocardial infarction, which has triggered the hypothesis that HDL, in contrast to low-density lipoprotein (LDL), acts as an anti-atherogenic lipoprotein. Moreover, experimental studies have identified potential anti-atherogenic properties of HDL, including promotion of macrophage cholesterol efflux and direct endothelial-protective effects of HDL, such as stimulation of endothelial nitric oxide production and repair, anti-apoptotic, anti-inflammatory and anti-thrombotic properties. Studies in gene-targeted mice, however, have also indicated that increasing HDL-cholesterol plasma levels can either limit (e.g. apolipoprotein A-I) or accelerate (e.g. Scavenger receptor class B type I) atherosclerosis. Moreover, vascular effects of HDL have been observed to be heterogenous and are altered in patients with CAD or diabetes, a condition that has been termed 'HDL dysfunction'. These alterations in biological functions of HDL may need to be taken into account for HDL-targeted therapies and considering raising of HDL-cholesterol levels alone is likely not sufficient in this respect. It will therefore be important to further determine, which biological functions of HDL are critical for its anti-atherosclerotic properties, as well as how these can be measured and targeted.
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Affiliation(s)
- Christian Besler
- Department of Cardiology, Cardiovascular Center, University Hospital Zurich, Zurich, Switzerland
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20
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Abstract
A low plasma level of HDL cholesterol is an atherosclerotic risk factor; however, emerging evidence suggests that low HDL levels might also contribute to the pathophysiology of type 2 diabetes mellitus (T2DM) through direct effects on plasma glucose. In the past decade, animal and clinical studies have uncovered a previously undescribed spectrum of HDL actions, indicating that HDL may control glucose homeostasis through mechanisms including insulin secretion, direct glucose uptake by muscle via the AMP-activated protein kinase, and possibly enhanced insulin sensitivity. These effects are mediated by multiple cell types via mechanisms including preservation of cell function through cellular lipid removal and also via direct signaling events. We suggest a paradigm shift from HDL being a bystander to being an active player in diabetic pathophysiology, which raises the possibility that HDL elevation could be a novel therapeutic avenue for T2DM. The entry of HDL-raising agents of the cholesteryl ester transfer protein (CETP) inhibitor class into late-phase clinical trials creates potential for rapid clinical translation. This Review will discuss the emerging evidence for a role of HDL-mediated glucose regulation in the pathophysiology of T2DM, and will also outline the therapeutic potential for HDL elevation for the prevention and management of T2DM.
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Affiliation(s)
- Brian G Drew
- Metabolic and Vascular Physiology Laboratory, Baker IDI Heart & Diabetes Institute, PO Box 6492, St Kilda Road Central, Melbourne, VIC 8008, Australia
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Ji A, Wroblewski JM, Cai L, de Beer MC, Webb NR, van der Westhuyzen DR. Nascent HDL formation in hepatocytes and role of ABCA1, ABCG1, and SR-BI. J Lipid Res 2011; 53:446-455. [PMID: 22190590 DOI: 10.1194/jlr.m017079] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
To study the mechanisms of hepatic HDL formation, we investigated the roles of ABCA1, ABCG1, and SR-BI in nascent HDL formation in primary hepatocytes isolated from mice deficient in ABCA1, ABCG1, or SR-BI and from wild-type (WT) mice. Under basal conditions, in WT hepatocytes, cholesterol efflux to exogenous apoA-I was accompanied by conversion of apoA-I to HDL-sized particles. LXR activation by T0901317 markedly enhanced the formation of larger HDL-sized particles as well as cellular cholesterol efflux to apoA-I. Glyburide treatment completely abolished the formation of 7.4 nm diameter and greater particles but led to the formation of novel 7.2 nm-sized particles. However, cells lacking ABCA1 failed to form such particles. ABCG1-deficient cells showed similar capacity to efflux cholesterol to apoA-I and to form nascent HDL particles compared with WT cells. Cholesterol efflux to apoA-I and nascent HDL formation were slightly but significantly enhanced in SR-BI-deficient cells compared with WT cells under basal but not LXR activated conditions. As in WT but not in ABCA1-deficient hepatocytes, 7.2 nm-sized particles generated by glyburide treatment were also detected in ABCG1-deficient and SR-BI-deficient hepatocytes. Our data indicate that hepatic nascent HDL formation is highly dependent on ABCA1 but not on ABCG1 or SR-BI.
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Affiliation(s)
- Ailing Ji
- Departments of Internal Medicine, University of Kentucky, Lexington, KY; Cardiovascular Research Center, University of Kentucky, Lexington, KY; Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Joanne M Wroblewski
- Departments of Internal Medicine, University of Kentucky, Lexington, KY; Cardiovascular Research Center, University of Kentucky, Lexington, KY; Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Lei Cai
- Departments of Internal Medicine, University of Kentucky, Lexington, KY; Cardiovascular Research Center, University of Kentucky, Lexington, KY; Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Maria C de Beer
- Physiology, University of Kentucky, Lexington, KY; Cardiovascular Research Center, University of Kentucky, Lexington, KY; Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Nancy R Webb
- Departments of Internal Medicine, University of Kentucky, Lexington, KY; Cardiovascular Research Center, University of Kentucky, Lexington, KY; Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY
| | - Deneys R van der Westhuyzen
- Departments of Internal Medicine, University of Kentucky, Lexington, KY; Cardiovascular Research Center, University of Kentucky, Lexington, KY; Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY; Molecular and Cellular Biochemistry and Physiology, University of Kentucky, Lexington, KY; Department of Veterans Affairs Medical Center, Lexington, KY.
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Camont L, Chapman J, Kontush A. Functionality of HDL particles: Heterogeneity and relationships to cardiovascular disease. ARCHIVES OF CARDIOVASCULAR DISEASES SUPPLEMENTS 2011. [DOI: 10.1016/s1878-6480(11)70784-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Ji A, Meyer JM, Cai L, Akinmusire A, de Beer MC, Webb NR, van der Westhuyzen DR. Scavenger receptor SR-BI in macrophage lipid metabolism. Atherosclerosis 2011; 217:106-12. [PMID: 21481393 DOI: 10.1016/j.atherosclerosis.2011.03.017] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2010] [Revised: 03/07/2011] [Accepted: 03/11/2011] [Indexed: 12/15/2022]
Abstract
OBJECTIVE To investigate the mechanisms by which macrophage scavenger receptor BI (SR-BI) regulates macrophage cholesterol homeostasis and protects against atherosclerosis. METHODS AND RESULTS The expression and function of SR-BI was investigated in cultured mouse bone marrow-derived macrophages (BMM). SR-BI, the other scavenger receptors SRA and CD36 and the ATP-binding cassette transporters ABCA1 and ABCG1 were each distinctly regulated during BMM differentiation. SR-BI levels increased transiently to significant levels during culture. SR-BI expression in BMM was reversibly down-regulated by lipid loading with modified LDL; SR-BI was shown to be present both on the cell surface as well as intracellularly. BMM exhibited selective HDL CE uptake, however, this was not dependent on SR-BI or another potential candidate glycosylphosphatidylinositol anchored high density lipoprotein binding protein 1 (GPIHBP1). SR-BI played a significant role in facilitating bidirectional cholesterol flux in non lipid-loaded cells. SR-BI expression enhanced both cell cholesterol efflux and cholesterol influx from HDL, but did not lead to altered cellular cholesterol mass. SR-BI-dependent efflux occurred to larger HDL particles but not to smaller HDL(3). Following cholesterol loading, ABCA1 and ABCG1 were up-regulated and served as the major contributors to cholesterol efflux, while SR-BI expression was down-regulated. CONCLUSION Our results suggest that SR-BI plays a significant role in macrophage cholesterol flux that may partly account for its effects on atherogenesis.
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Affiliation(s)
- Ailing Ji
- Department of Internal Medicine, University of Kentucky, Lexington, KY 40536, USA.
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Zhao Y, Van Berkel TJ, Van Eck M. Relative roles of various efflux pathways in net cholesterol efflux from macrophage foam cells in atherosclerotic lesions. Curr Opin Lipidol 2010; 21:441-53. [PMID: 20683325 DOI: 10.1097/mol.0b013e32833dedaa] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Cholesterol efflux mechanisms are essential for macrophage cholesterol homeostasis. HDL, an important cholesterol efflux acceptor, comprises a class of heterogeneous particles that induce cholesterol efflux via distinct pathways. This review focuses on the understanding of the different cholesterol efflux pathways and physiological acceptors involved, and their regulation in atherosclerotic lesions. RECENT FINDINGS The synergistic interactions of ATP-binding cassette transporters A1 and G1 as well as ATP-binding cassette transporter A1 and scavenger receptor class B type I are essential for cellular cholesterol efflux and the prevention of macrophage foam cell formation. However, the importance of aqueous diffusion should also not be underestimated. Significant progress has been made in understanding the mechanisms underlying ATP-binding cassette A1-mediated cholesterol efflux and regulation of its expression and trafficking. Conditions locally in the atherosclerotic lesion, for example, lipids, cytokines, oxidative stress, and hypoxia, as well as systemic factors, including inflammation and diabetes, critically influence the expression of cholesterol transporters on macrophage foam cells. Furthermore, HDL modification and remodeling in atherosclerosis, inflammation, and diabetes impairs its function as an acceptor for cellular cholesterol. SUMMARY Recent advances in the understanding of the regulation of cholesterol transporters and their acceptors in atherosclerotic lesions indicate that HDL-based therapies should aim to enhance the activity of cholesterol transporters and improve both the quantity and quality of HDL.
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Affiliation(s)
- Ying Zhao
- Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, University of Leiden, Leiden, The Netherlands
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25
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Sankaranarayanan S, de la Llera-Moya M, Drazul-Schrader D, Asztalos BF, Weibel GL, Rothblat GH. Importance of macrophage cholesterol content on the flux of cholesterol mass. J Lipid Res 2010; 51:3243-9. [PMID: 20713652 DOI: 10.1194/jlr.m008441] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Net flux of cholesterol represents the difference between efflux and influx and can result in net cell-cholesterol accumulation, net cell-cholesterol depletion, or no change in cellular cholesterol content. We measured radiolabeled cell-cholesterol efflux and cell-cholesterol mass using cholesterol-normal and -enriched J774 and elicited mouse peritoneal macrophage cells. Net cell-cholesterol effluxes were observed when cholesterol-enriched J774 cells were incubated with 3.5% apolipoprotein (apo) B depleted human serum, HDL(3), and apo A-I. Net cell-cholesterol influxes were observed when cholesterol-normal J774 cells were incubated with the same acceptors except apo A-I. When incubated with 2.5% individual sera, cholesterol mass efflux in free cholesterol (FC)-enriched J774 cells correlated with the HDL-cholesterol (HDL-C) concentrations (r(2) = 0.4; P=0.003), whereas cholesterol mass influx in cholesterol-normal J774 cells correlated with the LDL cholesterol (LDL-C) concentrations (r(2) = 0.6; P<0.0001) of the individual sera. A positive correlation was observed between measurements of [(3)H]cholesterol efflux and reductions in cholesterol mass (r(2) = 0.4; P=0.001) in FC-enriched J774 cells. In conclusion, isotopic efflux measurements from cholesterol-normal or cholesterol-enriched cells provide an accurate measurement of relative ability of an acceptor to remove labeled cholesterol under a specific set of experimental conditions, i.e., efflux potential. Moreover, isotopic efflux measurements can reflect changes in cellular cholesterol mass if the donor cells are enriched with cholesterol.
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Affiliation(s)
- Sandhya Sankaranarayanan
- Division of Gastroenterology, Hepatology, and Nutrition, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
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Abstract
Dysregulation of cholesterol balance contributes significantly to atherosclerotic cardiovascular disease (ASCVD), the leading cause of death in the United States. The intestine has the unique capability to act as a gatekeeper for entry of cholesterol into the body, and inhibition of intestinal cholesterol absorption is now widely regarded as an attractive non-statin therapeutic strategy for ASCVD prevention. In this chapter we discuss the current state of knowledge regarding sterol transport across the intestinal brush border membrane. The purpose of this work is to summarize substantial progress made in the last decade in regards to protein-mediated sterol trafficking, and to discuss this in the context of human disease.
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Affiliation(s)
| | - Liqing Yu
- Address correspondence to: Liqing Yu, M.D., Ph.D., Department of Pathology Section on Lipid Sciences, Wake Forest University School of Medicine, Medical Center Blvd, Winston-Salem, NC 27157-1040, Tel: 336-716-0920, Fax: 336-716-6279,
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27
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Murphy AJ, Woollard KJ. High-density lipoprotein: A potent inhibitor of inflammation. Clin Exp Pharmacol Physiol 2009; 37:710-8. [DOI: 10.1111/j.1440-1681.2009.05338.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Gillard BK, Lin HYA, Massey JB, Pownall HJ. Apolipoproteins A-I, A-II and E are independently distributed among intracellular and newly secreted HDL of human hepatoma cells. Biochim Biophys Acta Mol Cell Biol Lipids 2009; 1791:1125-32. [PMID: 19635584 DOI: 10.1016/j.bbalip.2009.07.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2009] [Revised: 07/13/2009] [Accepted: 07/16/2009] [Indexed: 12/17/2022]
Abstract
Whereas hepatocytes secrete the major human plasma high density lipoproteins (HDL)-protein, apo A-I, as lipid-free and lipidated species, the biogenic itineraries of apo A-II and apo E are unknown. Human plasma and HepG2 cell-derived apo A-II and apo E occur as monomers, homodimers and heterodimers. Dimerization of apo A-II, which is more lipophilic than apo A-I, is catalyzed by lipid surfaces. Thus, we hypothesized that lipidation of intracellular and secreted apo A-II exceeds that of apo A-I, and once lipidated, apo A-II dimerizes. Fractionation of HepG2 cell lysate and media by size exclusion chromatography showed that intracellular apo A-II and apo E are fully lipidated and occur on nascent HDL and VLDL respectively, while only 45% of intracellular apo A-I is lipidated. Secreted apo A-II and apo E occur on small HDL and on LDL and large HDL respectively. HDL particles containing both apo A-II and apo A-I form only after secretion from both HepG2 and Huh7 hepatoma cells. Apo A-II dimerizes intracellularly while intracellular apo E is monomeric but after secretion associates with HDL and subsequently dimerizes. Thus, HDL apolipoproteins A-I, A-II and E have distinct intracellular and post-secretory pathways of hepatic lipidation and dimerization in the process of HDL formation. These early forms of HDL are expected to follow different apolipoprotein-specific pathways through plasma remodeling and reverse cholesterol transport.
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Affiliation(s)
- Baiba K Gillard
- Section of Atherosclerosis and Vascular Medicine, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, MS-A601, Houston, TX 77030, USA.
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Abstract
PURPOSE OF REVIEW Aberrations in cerebral cholesterol homeostasis can lead to severe neurological diseases and have been linked to Alzheimer's disease. Many proteins involved in peripheral cholesterol metabolism are also present in the brain. Yet, brain cholesterol metabolism is very different from that in the remainder of the body. This review reports on present insights into the regulation of cerebral cholesterol homeostasis, focusing on cholesterol trafficking between astrocytes and neurons. RECENT FINDINGS Astrocytes are a major site of cholesterol synthesis. They secrete cholesterol in the form of apolipoprotein E-containing HDL-like particles. After birth, neurons are thought to reduce their cholesterol synthesis and rely predominantly on astrocytes for their cholesterol supply. How exactly neurons regulate their cholesterol supply is largely unknown. A role for the brain-specific cholesterol metabolite, 24(S)-hydroxycholesterol, in this process was recently proposed. Recent findings strengthen the link between brain cholesterol metabolism and factors involved in synaptic plasticity, a process essential for learning and memory functions, as well as regeneration, which are affected in Alzheimer's disease. SUMMARY Insight into the regulation of cerebral cholesterol homeostasis will provide possibilities to modulate the key steps involved and may lead to the development of therapies for the prevention as well as treatment of neurodegenerative diseases such as Alzheimer's disease.
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Affiliation(s)
- Monique Mulder
- Department of Internal Medicine and Division of Pharmacology, Vascular and Metabolic diseases, Erasmus Medical Center, Rotterdam, The Netherlands.
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Terasaka N, Yu S, Yvan-Charvet L, Wang N, Mzhavia N, Langlois R, Pagler T, Li R, Welch CL, Goldberg IJ, Tall AR. ABCG1 and HDL protect against endothelial dysfunction in mice fed a high-cholesterol diet. J Clin Invest 2008; 118:3701-13. [PMID: 18924609 DOI: 10.1172/jci35470] [Citation(s) in RCA: 184] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Accepted: 09/10/2008] [Indexed: 11/17/2022] Open
Abstract
Plasma HDL levels are inversely related to the incidence of atherosclerotic disease. Some of the atheroprotective effects of HDL are likely mediated via preservation of EC function. Whether the beneficial effects of HDL on ECs depend on its involvement in cholesterol efflux via the ATP-binding cassette transporters ABCA1 and ABCG1, which promote efflux of cholesterol and oxysterols from macrophages, has not been investigated. To address this, we assessed endothelial function in Abca1(-/-), Abcg1(-/-), and Abca1(-/-)Abcg1(-/-) mice fed either a high-cholesterol diet (HCD) or a Western diet (WTD). Non-atherosclerotic arteries from WTD-fed Abcg1(-/-) and Abca1(-/-)Abcg1(-/-) mice exhibited a marked decrease in endothelium-dependent vasorelaxation, while Abca1(-/-) mice had a milder defect. In addition, eNOS activity was reduced in aortic homogenates generated from Abcg1(-/-) mice fed either a HCD or a WTD, and this correlated with decreased levels of the active dimeric form of eNOS. More detailed analysis indicated that ABCG1 was expressed primarily in ECs, and that these cells accumulated the oxysterol 7-ketocholesterol (7-KC) when Abcg1(-/-) mice were fed a WTD. Consistent with these data, ABCG1 had a major role in promoting efflux of cholesterol and 7-KC in cultured human aortic ECs (HAECs). Furthermore, HDL treatment of HAECs prevented 7-KC-induced ROS production and active eNOS dimer disruption in an ABCG1-dependent manner. Our data suggest that ABCG1 and HDL maintain EC function in HCD-fed mice by promoting efflux of cholesterol and 7-oxysterols and preserving active eNOS dimer levels.
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Affiliation(s)
- Naoki Terasaka
- Division of Molecular Medicine, Columbia University College of Physicians and Surgeons, New York, New York, USA.
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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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Tall AR, Yvan-Charvet L, Terasaka N, Pagler T, Wang N. HDL, ABC transporters, and cholesterol efflux: implications for the treatment of atherosclerosis. Cell Metab 2008; 7:365-75. [PMID: 18460328 DOI: 10.1016/j.cmet.2008.03.001] [Citation(s) in RCA: 412] [Impact Index Per Article: 25.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Revised: 02/19/2008] [Accepted: 03/03/2008] [Indexed: 11/29/2022]
Abstract
High-density lipoprotein (HDL) has been identified as a potential target in the treatment of atherosclerotic vascular disease. The failure of torcetrapib, an inhibitor of cholesteryl ester transfer protein (CETP) that markedly increased HDL levels in a clinical trial, has called into doubt the efficacy of HDL elevation. Recent analysis suggests that failure may have been caused by off-target toxicity and that HDL is functional and promotes regression of atherosclerosis. New studies highlight the central importance of the ATP-binding cassette (ABC) transporters ABCA1 and ABCG1 in reducing macrophage foam cell formation, inflammation, and atherosclerosis. A variety of approaches to increasing HDL may eventually be successful in treating atherosclerosis.
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Affiliation(s)
- Alan R Tall
- Division of Molecular Medicine, Department of Medicine, Columbia University, New York, NY 10032, USA
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Abstract
Cholesterol is an essential structural component in the cell membranes of most vertebrates. The biophysical properties of cholesterol and the enzymology of cholesterol metabolism provide the basis for how cells handle cholesterol and exchange it with one another. A tightly controlled--but only partially characterized--network of cellular signalling and lipid transfer systems orchestrates the functional compartmentalization of this lipid within and between organellar membranes. This largely dictates the exchange of cholesterol between tissues at the whole body level. Increased understanding of these processes and their integration at the organ systems level provides fundamental insights into the physiology of cholesterol trafficking.
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Affiliation(s)
- Elina Ikonen
- Institute of Biomedicine/Anatomy, University of Helsinki, Haartmaninkatu 8, University of Helsinki, Helsinki FI-00014, Finland.
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