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Arandhara VL, McClure CP, Tarr AW, Chappell S, Morgan K, Baumert TF, Irving WL, Ball JK. Scavenger receptor class B type I genetic variants associated with disease severity in chronic hepatitis C virus infection. J Med Virol 2023; 95:e28331. [PMID: 36415047 PMCID: PMC10100136 DOI: 10.1002/jmv.28331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 11/15/2022] [Accepted: 11/20/2022] [Indexed: 11/24/2022]
Abstract
Analysis of host genetic polymorphisms is an increasingly important tool for understanding and predicting pathogenesis and treatment response of viral diseases. The gene locus of scavenger receptor class B type I (SR-BI), encoding a cell entry factor and receptor for hepatitis C virus (HCV), contains several genetic polymorphisms. We applied a probe extension assay to determine the frequency of six single nucleotide polymorphisms (SNPs) within the SR-BI gene locus in 374 individuals with history of HCV infection. In addition, SR-BI messenger RNA (mRNA) levels were analyzed in liver biopsy specimens of chronically infected HCV subjects. The rs5888 variant allele T was present at a higher frequency in subjects with advanced fibrosis (χ2 , p = 0.016) and after adjusting for age, duration of infection and alcohol intake as confounding factors. Haplotype analysis of SNP frequencies showed that a haplotype consisting of rs61932577 variant allele C and rs5888 variant allele T was associated with an increased risk of advanced liver fibrosis (defined by an Ishak score 4-6) (adjusted odds ratio 2.81; 95% confidence interval 1.06-7.46. p = 0.038). Carriers of the rs5888 variant allele T displayed reduced SR-BI mRNA expression in liver biopsy specimens. In conclusion the rs5888 polymorphism variant is associated with decreased SR-BI expression and an increased risk of development of advanced fibrosis in chronic HCV infection. These findings provide further evidence for a role of SR-BI in HCV pathogenesis and provides a genetic marker for prediction of those infected individuals at greater risk of developing severe disease.
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Affiliation(s)
- Victoria L Arandhara
- School of Life Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Charles Patrick McClure
- School of Life Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, UK.,Wolfson Centre for Global Virus Research, The University of Nottingham, Queen's Medical Centre, Nottingha, UK.,NIHR Nottingham Biomedical Research Centre at the Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, UK
| | - Alexander W Tarr
- School of Life Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, UK.,Wolfson Centre for Global Virus Research, The University of Nottingham, Queen's Medical Centre, Nottingha, UK.,NIHR Nottingham Biomedical Research Centre at the Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, UK
| | - Sally Chappell
- School of Life Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Kevin Morgan
- School of Life Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Thomas F Baumert
- Institut de Recherche sur les Maladies Virales et Hépatiques, Université de Strasbourg, Inserm, Strasbourg, France.,IHU Strasbourg, Pôle hépato-digestif, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - William L Irving
- School of Life Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, UK.,Wolfson Centre for Global Virus Research, The University of Nottingham, Queen's Medical Centre, Nottingha, UK.,NIHR Nottingham Biomedical Research Centre at the Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, UK
| | - Jonathan K Ball
- School of Life Sciences, The University of Nottingham, Queen's Medical Centre, Nottingham, UK.,Wolfson Centre for Global Virus Research, The University of Nottingham, Queen's Medical Centre, Nottingha, UK.,NIHR Nottingham Biomedical Research Centre at the Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham, UK
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2
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May SC, Sahoo D. A short amphipathic alpha helix in scavenger receptor BI facilitates bidirectional HDL-cholesterol transport. J Biol Chem 2022; 298:102333. [PMID: 35926711 PMCID: PMC9436806 DOI: 10.1016/j.jbc.2022.102333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 11/24/2022] Open
Abstract
During reverse cholesterol transport, high-density lipoprotein (HDL) carries excess cholesterol from peripheral cells to the liver for excretion in bile. The first and last steps of this pathway involve the HDL receptor, scavenger receptor BI (SR-BI). While the mechanism of SR-BI-mediated cholesterol transport has not yet been established, it has long been suspected that cholesterol traverses through a hydrophobic tunnel in SR-BI’s extracellular domain. Confirmation of a hydrophobic tunnel is hindered by the lack of a full-length SR-BI structure. Part of SR-BI’s structure has been resolved, encompassing residues 405 to 475, which includes the C-terminal transmembrane domain and its adjacent extracellular region. Within the extracellular segment is an amphipathic helix (residues 427–436, referred to as AH(427–436)) that showed increased protection from solvent in NMR-based studies. Homology models predict that hydrophobic residues in AH(427–436) line a core cavity in SR-BI’s extracellular region that may facilitate cholesterol transport. Therefore, we hypothesized that hydrophobic residues in AH(427–436) are required for HDL cholesterol transport. Here, we tested this hypothesis by mutating individual residues along AH(427–436) to a charged residue (aspartic acid), transiently transfecting COS-7 cells with plasmids encoding wild-type and mutant SR-BI, and performing functional analyses. We found that mutating hydrophobic, but not hydrophilic, residues in AH(427–436) impaired SR-BI bidirectional cholesterol transport. Mutating phenylalanine-430 was particularly detrimental to SR-BI’s functions, suggesting that this residue may facilitate important interactions for cholesterol delivery within the hydrophobic tunnel. Our results support the hypothesis that a hydrophobic tunnel within SR-BI mediates cholesterol transport.
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Affiliation(s)
- Sarah C May
- Department of Medicine, Division of Endocrinology & Molecular Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA; Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Daisy Sahoo
- Department of Medicine, Division of Endocrinology & Molecular Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, USA; Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, USA; Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, USA.
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3
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Powers HR, Sahoo D. SR-B1's Next Top Model: Structural Perspectives on the Functions of the HDL Receptor. Curr Atheroscler Rep 2022; 24:277-288. [PMID: 35107765 PMCID: PMC8809234 DOI: 10.1007/s11883-022-01001-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2021] [Indexed: 02/04/2023]
Abstract
PURPOSE OF REVIEW The binding of high-density lipoprotein (HDL) to its primary receptor, scavenger receptor class B type 1 (SR-B1), is critical for lowering plasma cholesterol levels and reducing cardiovascular disease risk. This review provides novel insights into how the structural elements of SR-B1 drive efficient function with an emphasis on bidirectional cholesterol transport. RECENT FINDINGS We have generated a new homology model of full-length human SR-B1 based on the recent resolution of the partial structures of other class B scavenger receptors. Interrogating this model against previously published observations allows us to generate structurally informed hypotheses about SR-B1's ability to mediate HDL-cholesterol (HDL-C) transport. Furthermore, we provide a structural perspective as to why human variants of SR-B1 may result in impaired HDL-C clearance. A comprehensive understanding of SR-B1's structure-function relationships is critical to the development of therapeutic agents targeting SR-B1 and modulating cardiovascular disease risk.
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Affiliation(s)
- Hayley R. Powers
- grid.30760.320000 0001 2111 8460Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI USA
| | - Daisy Sahoo
- grid.30760.320000 0001 2111 8460Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI USA ,grid.30760.320000 0001 2111 8460Department of Medicine, Division of Endocrinology & Molecular Medicine, Medical College of Wisconsin, Milwaukee, WI USA ,grid.30760.320000 0001 2111 8460Cardiovascular Center, H4930 Health Research Center, Medical College of Wisconsin, 8701 W. Watertown Plank Road, Milwaukee, WI 53226 USA
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4
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HDL and Lipid Metabolism. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1377:49-61. [DOI: 10.1007/978-981-19-1592-5_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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5
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The computational analyses, molecular dynamics of fatty-acid transport mechanism to the CD36 receptor. Sci Rep 2021; 11:23207. [PMID: 34853341 PMCID: PMC8636502 DOI: 10.1038/s41598-021-01373-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 09/21/2021] [Indexed: 01/08/2023] Open
Abstract
The transmembrane glycoprotein CD36, which is responsible of the metabolic disorders, and the elevated intake of fat induces lipid buildup, is a multifunctional scavenger receptor signaling those functions in high-affinity tissue uptake of long-chain fatty acids. In this study, we used series of molecular dynamics simulations of the wild type and mutants types K164A CD36 protein interacting with one palmitic acid (PLM) besides simulations of the wild type interacting with the three PLM to find out the mechanism of the functioning of the complex CD36/Fatty acids and the unraveling of the role of the mutation. Additionally we determined whether Lys164, mostly exposed to protein surface, played important roles in fatty acid uptake. These simulations revealed, the conformational changes induced by Lys164 residue and the altered interactions induced by the mutagenesis of surface lysine that was badly influencing the folding, utility, solubility, and stability form of the variant. Furthermore, Lys164 residue provided the structural basis of forming an opening at the region of principal portal for the dissociation of palmitic acid. The results of our simulations revealed hole two fatty acids found in CD36 cavity structure and it was the most preferred to CD36 structure stabilization.
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Axmann M, Plochberger B, Mikula M, Weber F, Strobl WM, Stangl H. Plasma Membrane Lipids: An Important Binding Site for All Lipoprotein Classes. MEMBRANES 2021; 11:membranes11110882. [PMID: 34832111 PMCID: PMC8622984 DOI: 10.3390/membranes11110882] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 11/12/2021] [Accepted: 11/12/2021] [Indexed: 12/23/2022]
Abstract
Cholesterol is one of the main constituents of plasma membranes; thus, its supply is of utmost importance. This review covers the known mechanisms of cholesterol transfer from circulating lipoprotein particles to the plasma membrane, and vice versa. To achieve homeostasis, the human body utilizes cellular de novo synthesis and extracellular transport particles for supply of cholesterol and other lipids via the blood stream. These lipoprotein particles can be classified according to their density: chylomicrons, very low, low, and high-density lipoprotein (VLDL, LDL, and HDL, respectively). They deliver and receive their lipid loads, most importantly cholesterol, to and from cells by several redundant routes. Defects in one of these pathways (e.g., due to mutations in receptors) usually are not immediately fatal. Several redundant pathways, at least temporarily, compensate for the loss of one or more of them, but the defects trigger systemic diseases, such as atherosclerosis later on. Recently, intracellular membrane–membrane contact sites were shown to be involved in intracellular cholesterol transfer and the plasma membrane itself has been proposed to act as a binding site for lipoprotein-mediated cargo unloading.
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Affiliation(s)
- Markus Axmann
- School of Medical Engineering and Applied Social Sciences, University of Applied Sciences Upper Austria, Garnisonstrasse 21, 4020 Linz, Austria; (M.A.); (B.P.); (F.W.)
| | - Birgit Plochberger
- School of Medical Engineering and Applied Social Sciences, University of Applied Sciences Upper Austria, Garnisonstrasse 21, 4020 Linz, Austria; (M.A.); (B.P.); (F.W.)
| | - Mario Mikula
- Center for Pathobiochemistry and Genetics, Institute for Medical Genetics, Medical University of Vienna, Währingerstrasse 10, 1090 Vienna, Austria;
| | - Florian Weber
- School of Medical Engineering and Applied Social Sciences, University of Applied Sciences Upper Austria, Garnisonstrasse 21, 4020 Linz, Austria; (M.A.); (B.P.); (F.W.)
| | - Witta Monika Strobl
- Center for Pathobiochemistry and Genetics, Institute for Medical Chemistry, Medical University of Vienna, Währingerstrasse 10, 1090 Vienna, Austria;
| | - Herbert Stangl
- Center for Pathobiochemistry and Genetics, Institute for Medical Chemistry, Medical University of Vienna, Währingerstrasse 10, 1090 Vienna, Austria;
- Correspondence:
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7
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Zhou J, Zhou JF, Wang Y, Feng GP, Fang WH, Kang W, Ma LB, Li XC. SpSR-B2 functions as a potential pattern recognition receptor involved in antiviral and antibacterial immune responses of mud crab Scylla paramamosain. Int J Biol Macromol 2021; 193:2173-2182. [PMID: 34780895 DOI: 10.1016/j.ijbiomac.2021.11.048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/06/2021] [Accepted: 11/07/2021] [Indexed: 10/19/2022]
Abstract
Although class B scavenger receptors (SR-Bs) in mammals are multifunctional molecules, the functions of SR-Bs in invertebrates remain largely unknown. In this study, we characterized an SR-B homolog, namely SpSR-B2, from Scylla paramamosain. SpSR-B2 shared high similarity with mammalian SR-Bs, and exhibited specific binding activity to ac-LDL, indicating that it may be a new member of SR-B class in invertebrates. SpSR-B2 was upregulated after challenge with white spot syndrome virus (WSSV) or bacteria. Binding assays showed that SpSR-B2 specifically interacted with WSSV envelope protein VP24. Besides, SpSR-B2 could bind to all tested bacterial cells and agglutinate these bacteria. SpSR-B2 also exhibited a strong binding activity to LPS but weak binding activities to other tested polysaccharides. These findings indicated that SpSR-B2 was a potential recognition molecule for viral protein VP24 and bacterial LPS. Knockdown of SpSR-B2 resulted in dramatically decreased expressions of certain antimicrobial peptides (AMPs), and overexpression of SpSR-B2 led to the increased expression of the AMP of SpALF2, suggesting that SpSR-B2 could regulate the expression of AMPs. Taken together, this study revealed that SpSR-B2 functioned as a potential pattern recognition receptor participating in antiviral and antibacterial immunity, and provided new insights into the immune functions of invertebrate SR-Bs.
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Affiliation(s)
- Jian Zhou
- Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture and Rural affairs, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China
| | - Jun-Fang Zhou
- Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture and Rural affairs, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China
| | - Yue Wang
- Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture and Rural affairs, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China
| | - Guang-Peng Feng
- Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture and Rural affairs, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China
| | - Wen-Hong Fang
- Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture and Rural affairs, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China
| | - Wei Kang
- Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture and Rural affairs, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China
| | - Ling-Bo Ma
- Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture and Rural affairs, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China
| | - Xin-Cang Li
- Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture and Rural affairs, East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China.
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8
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Li H, Yu XH, Ou X, Ouyang XP, Tang CK. Hepatic cholesterol transport and its role in non-alcoholic fatty liver disease and atherosclerosis. Prog Lipid Res 2021; 83:101109. [PMID: 34097928 DOI: 10.1016/j.plipres.2021.101109] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 05/31/2021] [Accepted: 06/02/2021] [Indexed: 12/12/2022]
Abstract
Non-alcoholic fatty liver disease (NAFLD) is a quickly emerging global health problem representing the most common chronic liver disease in the world. Atherosclerotic cardiovascular disease represents the leading cause of mortality in NAFLD patients. Cholesterol metabolism has a crucial role in the pathogenesis of both NAFLD and atherosclerosis. The liver is the major organ for cholesterol metabolism. Abnormal hepatic cholesterol metabolism not only leads to NAFLD but also drives the development of atherosclerotic dyslipidemia. The cholesterol level in hepatocytes reflects the dynamic balance between endogenous synthesis, uptake, esterification, and export, a process in which cholesterol is converted to neutral cholesteryl esters either for storage in cytosolic lipid droplets or for secretion as a major constituent of plasma lipoproteins, including very-low-density lipoproteins, chylomicrons, high-density lipoproteins, and low-density lipoproteins. In this review, we describe decades of research aimed at identifying key molecules and cellular players involved in each main aspect of hepatic cholesterol metabolism. Furthermore, we summarize the recent advances regarding the biological processes of hepatic cholesterol transport and its role in NAFLD and atherosclerosis.
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Affiliation(s)
- Heng Li
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China
| | - Xiao-Hua Yu
- Institute of Clinical Medicine, The Second Affiliated Hospital of Hainan Medical University, Haikou, Hainan 460106, China
| | - Xiang Ou
- Department of Endocrinology, the First Hospital of Changsha, Changsha, Hunan 410005, China
| | - Xin-Ping Ouyang
- Department of Physiology, Institute of Neuroscience Research, Hengyang Key Laboratory of Neurodegeneration and Cognitive Impairment, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
| | - Chao-Ke Tang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China.
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9
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Berberine Attenuates Cholesterol Accumulation in Macrophage Foam Cells by Suppressing AP-1 Activity and Activation of the Nrf2/HO-1 Pathway. J Cardiovasc Pharmacol 2020; 75:45-53. [PMID: 31895879 DOI: 10.1097/fjc.0000000000000769] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Atherosclerosis is a chronic inflammation condition resulting from the interaction between lipoproteins, monocyte-derived macrophages, T lymphocytes, and other cellular elements in the arterial wall. Macrophage-derived foam cells play a key role in both early and advanced stage of atherosclerosis. Previous studies have shown that berberine could inhibit foam cell formation and prevent experimental atherosclerosis. However, its underlying molecular mechanisms have not been fully clarified. In this study, we explored the cholesterol-lowering effects of berberine in macrophage-derived foam cells and investigated its possible mechanisms in prevention and treatment of atherosclerosis. Here, we demonstrated that berberine could inhibit atherosclerosis in apolipoprotein E-deficient mice and induce cholesterol reduction as well as decrease the content of macrophages. Berberine can regulate oxLDL uptake and cholesterol efflux, thus suppresses foam cell formation. Mechanisms study showed that berberine can suppress scavenger receptor expression via inhibiting the activity of AP-1 and upregulate ATP-binding cassette transporter via activating Nrf2/HO-1 signaling in human macrophage. In summary, berberine significantly inhibits atherosclerotic disease development by regulating lipid homeostasis and suppressing macrophage foam cell formation.
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10
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Jomard A, Osto E. High Density Lipoproteins: Metabolism, Function, and Therapeutic Potential. Front Cardiovasc Med 2020; 7:39. [PMID: 32296714 PMCID: PMC7136892 DOI: 10.3389/fcvm.2020.00039] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Accepted: 02/28/2020] [Indexed: 12/16/2022] Open
Abstract
High Density Lipoproteins (HDLs) have long been considered as “good cholesterol,” beneficial to the whole body and, in particular, to cardio-vascular health. However, HDLs are complex particles that undergoes dynamic remodeling through interactions with various enzymes and tissues throughout their life cycle, making the complete understanding of its functions and roles more complicated than initially expected. In this review, we explore the novel understanding of HDLs' behavior in health and disease as a multifaceted class of lipoprotein, with different size subclasses, molecular composition, receptor interactions, and functionality. Further, we report on emergent HDL-based therapeutics tested in small and larger scale clinical trials and their mixed successes.
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Affiliation(s)
- Anne Jomard
- Laboratory of Translational Nutrition Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.,Institute of Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland
| | - Elena Osto
- Laboratory of Translational Nutrition Biology, Swiss Federal Institute of Technology (ETH), Zurich, Switzerland.,Institute of Clinical Chemistry, University Hospital Zurich, Zurich, Switzerland.,Department of Cardiology, Heart Center, University Hospital Zurich, Zurich, Switzerland
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11
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Hong M, Li J, Li S, Almutairi MM. Resveratrol Derivative, Trans-3, 5, 4'-Trimethoxystilbene, Prevents the Developing of Atherosclerotic Lesions and Attenuates Cholesterol Accumulation in Macrophage Foam Cells. Mol Nutr Food Res 2020; 64:e1901115. [PMID: 31965713 DOI: 10.1002/mnfr.201901115] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/04/2019] [Indexed: 12/28/2022]
Abstract
SCOPE Recent studies have demonstrated that trans-3, 5, 4'-Trimethoxystilbene (TMS), a novel derivative of resveratrol, may suppress the foam cells formation and restrain atherosclerosis in vitro and in vivo. Herein, the molecular mechanisms underlying the protective effects of TMS against atherosclerosis are further delineated. METHODS AND RESULTS In the present study, the cholesterol-lowering effects of TMS in macrophage-derived foam cell by animal studies, Oil Red O staining, and lipid uptake as well as efflux analysis, are explored. Real-time PCR, western blotting analysis, luciferase reporter assay, electrophoretic mobility shift assay, and immunofluorescent staining are applied for investigating the mechanism involved in atherosclerosis prevention by TMS. Herein, it is revealed that TMS, at a dosage of 10 mg kg-1 day-1 , may suppress atherosclerotic plaques within the aorta and arterial intima in apolipoprotein Edeficient mice (ApoE)-/- mice by reducing cholesterol level and macrophages content. Exposure of macrophages to TMS (10 µM) can suppress foam cells formation via regulating oxidized low density lipoprotein and cholesterol content in human macrophages through inhibiting scavenger receptors expression and activator protein-1(AP-1) activity. In addition, TMS can activate ERK/Nrf2/HO-1 signaling which increases the expression of ATP-binding cassette transporters. CONCLUSION In conclusion, TMS may inhibit the progress of atherosclerosis through regulating cholesterol homeostasis and inhibiting macrophage-derived foam cells formation.
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Affiliation(s)
- Ming Hong
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, China
- Institute of Clinical Pharmacology, Guangzhou University of Chinese Medicine, Guangzhou, 510000, China
| | - Jinke Li
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS, 64101, USA
| | - Siying Li
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS, 64101, USA
| | - Mohammed M Almutairi
- Department of Pharmacology & Toxicology, University of Kansas, Lawrence, KS, 64101, USA
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12
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Gerold G, Moeller R, Pietschmann T. Hepatitis C Virus Entry: Protein Interactions and Fusion Determinants Governing Productive Hepatocyte Invasion. Cold Spring Harb Perspect Med 2020; 10:cshperspect.a036830. [PMID: 31427285 DOI: 10.1101/cshperspect.a036830] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Hepatitis C virus (HCV) entry is among the best-studied uptake processes for human pathogenic viruses. Uptake follows a spatially and temporally tightly controlled program. Numerous host factors including proteins, lipids, and glycans promote productive uptake of HCV particles into human liver cells. The virus initially attaches to surface proteoglycans, lipid receptors such as the scavenger receptor BI (SR-BI), and to the tetraspanin CD81. After lateral translocation of virions to tight junctions, claudin-1 (CLDN1) and occludin (OCLN) are essential for entry. Clathrin-mediated endocytosis engulfs HCV particles, which fuse with endosomal membranes after pH drop. Uncoating of the viral RNA genome in the cytoplasm completes the entry process. Here we systematically review and classify HCV entry factors by their mechanistic role, relevance, and level of evidence. Finally, we report on more recent knowledge on determinants of membrane fusion and close with an outlook on future implications of HCV entry research.
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Affiliation(s)
- Gisa Gerold
- TWINCORE, Center for Experimental and Clinical Infection Research, Institute for Experimental Virology, 30625 Hannover, Germany.,Department of Clinical Microbiology, Virology & Wallenberg Centre for Molecular Medicine (WCMM), Umeå University, 901 85 Umeå, Sweden
| | - Rebecca Moeller
- TWINCORE, Center for Experimental and Clinical Infection Research, Institute for Experimental Virology, 30625 Hannover, Germany
| | - Thomas Pietschmann
- TWINCORE, Center for Experimental and Clinical Infection Research, Institute for Experimental Virology, 30625 Hannover, Germany
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13
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Wang W, Yan Z, Hu J, Shen WJ, Azhar S, Kraemer FB. Scavenger receptor class B, type 1 facilitates cellular fatty acid uptake. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158554. [PMID: 31678516 DOI: 10.1016/j.bbalip.2019.158554] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 09/21/2019] [Accepted: 09/25/2019] [Indexed: 02/07/2023]
Abstract
SR-B1 belongs to the class B scavenger receptor, or CD36 super family. SR-B1 and CD36 share an affinity for a wide array of ligands. Although they exhibit similar ligand binding specificity, SR-B1 and CD36 have some very specific lipid transport functions. Whereas SR-B1 primarily facilitates the selective delivery of cholesteryl esters (CEs) and cholesterol from HDL particles to the liver and non-placental steroidogenic tissues, as well as participating in cholesterol efflux from cells, CD36 primarily mediates the uptake of long-chain fatty acids in high fatty acid-requiring organs such as the heart, skeletal muscle and adipose tissue. However, CD36 also mediates cholesterol efflux and facilitates selective lipoprotein-CE delivery, although less efficiently than SR-B1. Interestingly, the ability or efficiency of SR-B1 to mediate fatty acid uptake has not been reported. In this paper, using overexpression and siRNA-mediated knockdown of SR-B1, we show that SR-B1 possesses the ability to facilitate fatty acid uptake. Moreover, this function is not blocked by BLT-1, a specific chemical inhibitor of HDL-CE uptake activity of SR-B1, nor by sulfo-N-succinimidyl oleate, which inhibits fatty acid uptake by CD36. Attenuated fatty acid uptake was also observed in primary adipocytes isolated from SR-B1 knockout mice. In conclusion, facilitation of fatty acid uptake is an additional function that is mediated by SR-B1.
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Affiliation(s)
- Wei Wang
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States of America; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America; Department of Endocrinology, Peking University First Hospital, Beijing, China
| | - Zhe Yan
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States of America; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America; Department of Endocrinology and Metabolism, West China Hospital of Sichuan University, Chengdu, China
| | - Jie Hu
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States of America; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America
| | - Wen-Jun Shen
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States of America; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America.
| | - Salman Azhar
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States of America; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America
| | - Fredric B Kraemer
- Division of Endocrinology, Gerontology and Metabolism, Stanford University, Stanford, CA 94305, United States of America; Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, United States of America.
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14
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Abstract
The reduction of plasma apolipoprotein B (apoB) containing lipoproteins has long been pursued as the main modifiable risk factor for the development of cardiovascular disease (CVD). This has led to an intense search for strategies aiming at reducing plasma apoB-lipoproteins, culminating in reduction of overall CV risk. Despite 3 decades of progress, CVD remains the leading cause of morbidity and mortality worldwide and, as such, new therapeutic targets are still warranted. Clinical and preclinical research has moved forward from the original concept, under which some lipids must be accumulated and other removed to achieve the ideal condition in disease prevention, into the concept that mechanisms that orchestrate lipid movement between lipoproteins, cells and organelles is equally involved in CVD. As such, this review scrutinizes potentially atherogenic changes in lipid trafficking and assesses the molecular mechanisms behind it. New developments in risk assessment and new targets for the mitigation of residual CVD risk are also addressed.
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Affiliation(s)
- Andrei C Sposito
- Atherosclerosis and Vascular Biology Laboratory (Aterolab), State University of Campinas (Unicamp), São Paulo, Brazil.
| | | | - Joaquim Barreto
- Atherosclerosis and Vascular Biology Laboratory (Aterolab), State University of Campinas (Unicamp), São Paulo, Brazil
| | - Ilaria Zanotti
- Department of Food and Drug, University of Parma, Parma, Italy
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15
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Abstract
Metabolism and Function of High-Density Lipoproteins (HDL) Abstract. HDL has long been considered as 'good cholesterol', beneficial to the whole body and in particular to cardio-vascular health. However, HDL is a complex particle that undergoes dynamic remodeling through interactions with various enzymes and tissue types throughout its life cycle. In this review, we explore the novel understanding of HDL as a multifaceted class of lipoprotein, with multiple subclasses of different size, molecular composition, receptor interactions, and functionality, in health and disease. Further, we report on emergent HDL based therapeutics tested in small and larger scale clinical trials and their mixed successes.
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Affiliation(s)
- Anne Jomard
- 1 Eidgenössische Technische Hochschule (ETH), Labor für Translationale Ernährungsbiologie, Zürich
| | - Elena Osto
- 1 Eidgenössische Technische Hochschule (ETH), Labor für Translationale Ernährungsbiologie, Zürich
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16
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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: 136] [Impact Index Per Article: 22.7] [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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17
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Cooke AL, Morris J, Melchior JT, Street SE, Jerome WG, Huang R, Herr AB, Smith LE, Segrest JP, Remaley AT, Shah AS, Thompson TB, Davidson WS. A thumbwheel mechanism for APOA1 activation of LCAT activity in HDL. J Lipid Res 2018; 59:1244-1255. [PMID: 29773713 DOI: 10.1194/jlr.m085332] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 05/08/2018] [Indexed: 01/28/2023] Open
Abstract
APOA1 is the most abundant protein in HDL. It modulates interactions that affect HDL's cardioprotective functions, in part via its activation of the enzyme, LCAT. On nascent discoidal HDL, APOA1 comprises 10 α-helical repeats arranged in an anti-parallel stacked-ring structure that encapsulates a lipid bilayer. Previous chemical cross-linking studies suggested that these APOA1 rings can adopt at least two different orientations, or registries, with respect to each other; however, the functional impact of these structural changes is unknown. Here, we placed cysteine residues at locations predicted to form disulfide bonds in each orientation and then measured APOA1's ability to adopt the two registries during HDL particle formation. We found that most APOA1 oriented with the fifth helix of one molecule across from fifth helix of the other (5/5 helical registry), but a fraction adopted a 5/2 registry. Engineered HDLs that were locked in 5/5 or 5/2 registries by disulfide bonds equally promoted cholesterol efflux from macrophages, indicating functional particles. However, unlike the 5/5 registry or the WT, the 5/2 registry impaired LCAT cholesteryl esterification activity (P < 0.001), despite LCAT binding equally to all particles. Chemical cross-linking studies suggest that full LCAT activity requires a hybrid epitope composed of helices 5-7 on one APOA1 molecule and helices 3-4 on the other. Thus, APOA1 may use a reciprocating thumbwheel-like mechanism to activate HDL-remodeling proteins.
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Affiliation(s)
- Allison L Cooke
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - Jamie Morris
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - John T Melchior
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - Scott E Street
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - W Gray Jerome
- Departments of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Rong Huang
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
| | - Andrew B Herr
- Division of Immunobiology and Center for Systems Immunology Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Loren E Smith
- Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Jere P Segrest
- Medicine, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Alan T Remaley
- Lipoprotein Metabolism Section, Cardiovascular-Pulmonary Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Amy S Shah
- Division of Endocrinology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229
| | - Thomas B Thompson
- Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati, Cincinnati, OH 45237
| | - W Sean Davidson
- Departments of Pathology and Laboratory Medicine University of Cincinnati, Cincinnati, OH 45237
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18
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Shen WJ, Asthana S, Kraemer FB, Azhar S. Scavenger receptor B type 1: expression, molecular regulation, and cholesterol transport function. J Lipid Res 2018; 59:1114-1131. [PMID: 29720388 DOI: 10.1194/jlr.r083121] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 04/26/2018] [Indexed: 12/16/2022] Open
Abstract
Cholesterol is required for maintenance of plasma membrane fluidity and integrity and for many cellular functions. Cellular cholesterol can be obtained from lipoproteins in a selective pathway of HDL-cholesteryl ester (CE) uptake without parallel apolipoprotein uptake. Scavenger receptor B type 1 (SR-B1) is a cell surface HDL receptor that mediates HDL-CE uptake. It is most abundantly expressed in liver, where it provides cholesterol for bile acid synthesis, and in steroidogenic tissues, where it delivers cholesterol needed for storage or steroidogenesis in rodents. SR-B1 transcription is regulated by trophic hormones in the adrenal gland, ovary, and testis; in the liver and elsewhere, SR-B1 is subject to posttranscriptional and posttranslational regulation. SR-B1 operates in several metabolic processes and contributes to pathogenesis of atherosclerosis, inflammation, hepatitis C virus infection, and other conditions. Here, we summarize characteristics of the selective uptake pathway and involvement of microvillar channels as facilitators of selective HDL-CE uptake. We also present the potential mechanisms of SR-B1-mediated selective cholesterol transport; the transcriptional, posttranscriptional, and posttranslational regulation of SR-B1; and the impact of gene variants on expression and function of human SR-B1. A better understanding of this unique pathway and SR-B1's role may yield improved therapies for a wide variety of conditions.
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Affiliation(s)
- Wen-Jun Shen
- Geriatric Research, Education, and Clinical Research Center (GRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304 and Division of Endocrinology, Gerontology, and Metabolism, Stanford University School of Medicine, Stanford, CA 94305
| | - Shailendra Asthana
- Drug Discovery Research Center (DDRC), Translational Health Science and Technology Institute (THSTI), NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Fredric B Kraemer
- Geriatric Research, Education, and Clinical Research Center (GRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304 and Division of Endocrinology, Gerontology, and Metabolism, Stanford University School of Medicine, Stanford, CA 94305
| | - Salman Azhar
- Geriatric Research, Education, and Clinical Research Center (GRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304 and Division of Endocrinology, Gerontology, and Metabolism, Stanford University School of Medicine, Stanford, CA 94305
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19
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20
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Shen WJ, Azhar S, Kraemer FB. SR-B1: A Unique Multifunctional Receptor for Cholesterol Influx and Efflux. Annu Rev Physiol 2017; 80:95-116. [PMID: 29125794 DOI: 10.1146/annurev-physiol-021317-121550] [Citation(s) in RCA: 226] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The scavenger receptor, class B type 1 (SR-B1), is a multiligand membrane receptor protein that functions as a physiologically relevant high-density lipoprotein (HDL) receptor whose primary role is to mediate selective uptake or influx of HDL-derived cholesteryl esters into cells and tissues. SR-B1 also facilitates the efflux of cholesterol from peripheral tissues, including macrophages, back to liver. As a regulator of plasma membrane cholesterol content, SR-B1 promotes the uptake of lipid soluble vitamins as well as viral entry into host cells. These collective functions of SR-B1 ultimately affect programmed cell death, female fertility, platelet function, vasculature inflammation, and diet-induced atherosclerosis and myocardial infarction. SR-B1 has also been identified as a potential marker for cancer diagnosis and prognosis. Finally, the SR-B1-linked selective HDL-cholesteryl ester uptake pathway is now being evaluated as a gateway for the delivery of therapeutic and diagnostic agents. In this review, we focus on the regulation and functional significance of SR-B1 in mediating cholesterol movement into and out of cells.
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Affiliation(s)
- Wen-Jun Shen
- Division of Endocrinology, Gerontology and Metabolism, Stanford University School of Medicine, Stanford, California 94305; .,VA Palo Alto Health Care System, Palo Alto, California 94304
| | - Salman Azhar
- Division of Endocrinology, Gerontology and Metabolism, Stanford University School of Medicine, Stanford, California 94305; .,VA Palo Alto Health Care System, Palo Alto, California 94304
| | - Fredric B Kraemer
- Division of Endocrinology, Gerontology and Metabolism, Stanford University School of Medicine, Stanford, California 94305; .,VA Palo Alto Health Care System, Palo Alto, California 94304
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21
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PrabhuDas MR, Baldwin CL, Bollyky PL, Bowdish DME, Drickamer K, Febbraio M, Herz J, Kobzik L, Krieger M, Loike J, McVicker B, Means TK, Moestrup SK, Post SR, Sawamura T, Silverstein S, Speth RC, Telfer JC, Thiele GM, Wang XY, Wright SD, El Khoury J. A Consensus Definitive Classification of Scavenger Receptors and Their Roles in Health and Disease. THE JOURNAL OF IMMUNOLOGY 2017; 198:3775-3789. [PMID: 28483986 DOI: 10.4049/jimmunol.1700373] [Citation(s) in RCA: 217] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 03/13/2017] [Indexed: 02/07/2023]
Abstract
Scavenger receptors constitute a large family of proteins that are structurally diverse and participate in a wide range of biological functions. These receptors are expressed predominantly by myeloid cells and recognize a diverse variety of ligands including endogenous and modified host-derived molecules and microbial pathogens. There are currently eight classes of scavenger receptors, many of which have multiple names, leading to inconsistencies and confusion in the literature. To address this problem, a workshop was organized by the United States National Institute of Allergy and Infectious Diseases, National Institutes of Health, to help develop a clear definition of scavenger receptors and a standardized nomenclature based on that definition. Fifteen experts in the scavenger receptor field attended the workshop and, after extensive discussion, reached a consensus regarding the definition of scavenger receptors and a proposed scavenger receptor nomenclature. Scavenger receptors were defined as cell surface receptors that typically bind multiple ligands and promote the removal of nonself or altered-self targets. They often function by mechanisms that include endocytosis, phagocytosis, adhesion, and signaling that ultimately lead to the elimination of degraded or harmful substances. Based on this definition, nomenclature and classification of these receptors into 10 classes were proposed. This classification was discussed at three national meetings and input from participants at these meetings was requested. The following manuscript is a consensus statement that combines the recommendations of the initial workshop and incorporates the input received from the participants at the three national meetings.
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Affiliation(s)
- Mercy R PrabhuDas
- Division of Allergy, Immunology and Transplantation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852;
| | - Cynthia L Baldwin
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003.,Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA 01003
| | - Paul L Bollyky
- Department of Medicine, Stanford University, Stanford, CA 94305
| | - Dawn M E Bowdish
- Department of Pathology and Molecular Medicine, McMaster Immunology Research Centre, M.G. DeGroote Institute of Infectious Disease Research, McMaster University, Hamilton, Ontario L8S 4K1, Canada
| | - Kurt Drickamer
- Department of Life Sciences, Imperial College, London SW7 2AZ, United Kingdom
| | - Maria Febbraio
- Department of Dentistry, Katz Group Centre for Pharmacy and Health Research, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta T6G 2E1, Canada
| | - Joachim Herz
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390.,Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390.,Department of Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center, Dallas, TX 75390.,Center for Translational Neurodegeneration Research, University of Texas Southwestern Medical Center, Dallas, TX 75390.,Peter O'Donnell Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Lester Kobzik
- Department of Environmental Health, Harvard School of Public Health, Boston, MA 02115
| | - Monty Krieger
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - John Loike
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032
| | - Benita McVicker
- University of Nebraska Medical Center, Omaha VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105
| | - Terry K Means
- Center for Immunology and Inflammatory Diseases, Division of Rheumatology, Allergy, and Immunology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA 02129
| | - Soren K Moestrup
- Department of Biomedicine, University of Aarhus, 8000 Aarhus C, Denmark
| | - Steven R Post
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, AR 72205
| | - Tatsuya Sawamura
- Department of Physiology, Research Institute, Shinshu University School of Medicine, Matsumoto, Nagano, Japan
| | - Samuel Silverstein
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY 10032
| | - Robert C Speth
- Department of Pharmaceutical Sciences, Nova Southeastern University, Fort Lauderdale, FL 33328
| | - Janice C Telfer
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003
| | - Geoffrey M Thiele
- Division of Rheumatology, Department of Medicine, College of Medicine, University of Nebraska Medical Center, Omaha, NE 68105
| | - Xiang-Yang Wang
- Department of Human and Molecular Genetics, Institute of Molecular Medicine, Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
| | - Samuel D Wright
- Cardiovascular Therapeutics, CSL Behring, King of Prussia, PA 19406; and
| | - Joseph El Khoury
- Infectious Disease Division, Center for Immunology and Inflammatory Diseases, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129
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22
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Wei P, Sun FD, Zuo LM, Qu J, Chen P, Xu LD, Luo SZ. Critical residues and motifs for homodimerization of the first transmembrane domain of the plasma membrane glycoprotein CD36. J Biol Chem 2017; 292:8683-8693. [PMID: 28336533 DOI: 10.1074/jbc.m117.779595] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 03/09/2017] [Indexed: 12/19/2022] Open
Abstract
The plasma transmembrane (TM) glycoprotein CD36 is critically involved in many essential signaling processes, especially the binding/uptake of long-chain fatty acids and oxidized low-density lipoproteins. The association of CD36 potentially activates cytosolic protein tyrosine kinases that are thought to associate with the C-terminal cytoplasmic tail of CD36. To understand the mechanisms by which CD36 mediates ligand binding and signal transduction, we have characterized the homo-oligomeric interaction of CD36 TM domains in membrane environments and with molecular dynamics (MD) simulations. Analysis of pyrene- and coumarin-labeled TM1 peptides in SDS by FRET confirmed the homodimerization of the CD36 TM1 peptide. Homodimerization assays of CD36 TM domains with the TOXCAT technique showed that its first TM (TM1) domain, but not the second TM (TM2) domain, could homodimerize in a cell membrane. Small-residue, site-specific mutation scanning revealed that the CD36 TM1 dimerization is mediated by the conserved small residues Gly12, Gly16, Ala20, and Gly23 Furthermore, molecular dynamics (MD) simulation studies demonstrated that CD36 TM1 exhibited a switching dimerization with two right-handed packing modes driven by the 12GXXXGXXXA20 and 20AXXG23 motifs, and the mutational effect of G16I and G23I revealed these representative conformations of CD36 TM1. This packing switch pattern of CD36 TM1 homodimer was further examined and confirmed by FRET analysis of monobromobimane (mBBr)-labeled CD36 TM1 peptides. Overall, this work provides a structural basis for understanding the role of TM association in regulating signal transduction via CD36.
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Affiliation(s)
- Peng Wei
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China.,the School of Basic Medical Science, Beijing University of Chinese Medicine, Beijing 100029, China, and
| | - Fu-de Sun
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Li-Min Zuo
- the Institute of Medicinal Biotechnology, Chinese Academy of Medical Science, Beijing 100050, China
| | - Jing Qu
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Peng Chen
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Li-da Xu
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China
| | - Shi-Zhong Luo
- From the Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing 100029, China,
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23
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Hoekstra M. SR-BI as target in atherosclerosis and cardiovascular disease - A comprehensive appraisal of the cellular functions of SR-BI in physiology and disease. Atherosclerosis 2017; 258:153-161. [DOI: 10.1016/j.atherosclerosis.2017.01.034] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 01/25/2017] [Accepted: 01/27/2017] [Indexed: 12/12/2022]
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24
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Hersoug LG, Møller P, Loft S. Gut microbiota-derived lipopolysaccharide uptake and trafficking to adipose tissue: implications for inflammation and obesity. Obes Rev 2016; 17:297-312. [PMID: 26712364 DOI: 10.1111/obr.12370] [Citation(s) in RCA: 174] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Revised: 11/18/2015] [Accepted: 11/19/2015] [Indexed: 12/12/2022]
Abstract
The composition of the gut microbiota and excessive ingestion of high-fat diets (HFD) are considered to be important factors for development of obesity. In this review we describe a coherent mechanism of action for the development of obesity, which involves the composition of gut microbiota, HFD, low-grade inflammation, expression of fat translocase and scavenger receptor CD36, and the scavenger receptor class B type 1 (SR-BI). SR-BI binds to both lipids and lipopolysaccharide (LPS) from Gram-negative bacteria, which may promote incorporation of LPS in chylomicrons (CMs). These CMs are transported via lymph to the circulation, where LPS is transferred to other lipoproteins by translocases, preferentially to HDL. LPS increases the SR-BI binding, transcytosis of lipoproteins over the endothelial barrier,and endocytosis in adipocytes. Especially large size adipocytes with high metabolic activity absorb LPS-rich lipoproteins. In addition, macrophages in adipose tissue internalize LPS-lipoproteins. This may contribute to the polarization from M2 to M1 phenotype, which is a consequence of increased LPS delivery into the tissue during hypertrophy. In conclusion, evidence suggests that LPS is involved in the development of obesity as a direct targeting molecule for lipid delivery and storage in adipose tissue.
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Affiliation(s)
- L-G Hersoug
- Section of Environmental Health, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - P Møller
- Section of Environmental Health, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - S Loft
- Section of Environmental Health, Department of Public Health, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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25
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Tsay HJ, Huang YC, Chen YJ, Lee YH, Hsu SM, Tsai KC, Yang CN, Huang FL, Shie FS, Lee LC, Shiao YJ. Identifying N-linked glycan moiety and motifs in the cysteine-rich domain critical for N-glycosylation and intracellular trafficking of SR-AI and MARCO. J Biomed Sci 2016; 23:27. [PMID: 26892079 PMCID: PMC4758095 DOI: 10.1186/s12929-016-0244-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/03/2016] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND The accumulation of soluble oligomeric amyloid-β peptide (oAβ) proceeding the formation of senile plaques contributes to synaptic and memory deficits in Alzheimer's disease. Our previous studies have indentified scavenger receptor A (SR-A), especially SR-A type I (SR-AI), as prominent scavenger receptors on mediating oAβ clearance by microglia while glycan moiety and scavenger receptor cysteine-rich (SRCR) domain may play the critical role. Macrophage receptor with collagenous structure (MARCO), another member of class A superfamily with a highly conserved SRCR domain, may also play the similar role on oAβ internalization. However, the role of N-glycosylation and SRCR domain of SR-AI and MARCO on oAβ internalization remains unclear. RESULT We found that oAβ internalization was diminished in the cells expressing SR-AI harboring mutations of dual N-glycosylation sites (i.e. N120Q-N143Q and N143Q-N184Q) while they were normally surface targeted. Normal oAβ internalization was observed in 10 SR-AI-SRCR and 4 MARCO-SRCR surface targeted mutants. Alternatively, the SRCR mutants at β-sheet and α-helix and on disulfide bone formation obstructed receptor's N-glycosylation and surface targeting. CONCLUSION Our study reveals that N-glycan moiety is more critical than SRCR domain for SR-A-mediated oAβ internalization.
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Affiliation(s)
- Huey-Jen Tsay
- Institute of Neuroscience, Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Yung-Cheng Huang
- Department of Physical Medicine and Rehabilitation, Cheng Hsin General Hospital, Taipei, 112, Taiwan, R.O.C.
| | - Yi-Jen Chen
- Institute of Neuroscience, Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Yun-Hao Lee
- Institute of Neuroscience, Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Shu-Meng Hsu
- Institute of Neuroscience, Brain Research Center, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Keng-Chang Tsai
- Division of Chinese Materia Medica Development, National Research Institute of Chinese Medicine, Taipei, 11221, Taiwan, R.O.C.
| | - Cheng-Ning Yang
- Institute of Anatomy and Cell Biology, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Fong-Lee Huang
- Institute of Anatomy and Cell Biology, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
| | - Feng-Shiun Shie
- Center for Neuropsychiatric Research, National Health Research Institutes, No. 35 Keyan Road, Zhunan Town, Miaoli County, 350, Taiwan, R.O.C.
| | - Lin-Chien Lee
- Department of Physical Medicine and Rehabilitation, Cheng Hsin General Hospital, Taipei, 11220, Taiwan, R.O.C.
| | - Young-Ji Shiao
- Division of Basic Chinese Medicine, National Research Institute of Chinese Medicine, Taipei, 11221, Taiwan, R.O.C. .,Institute of Biopharmaceutical Science, National Yang-Ming University, Taipei, 11221, Taiwan, R.O.C.
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26
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Abstract
The adrenal gland is one of the prominent sites for steroid hormone synthesis. Lipoprotein-derived cholesterol esters (CEs) delivered via SR-B1 constitute the dominant source of cholesterol for steroidogenesis, particularly in rodents. Adrenocorticotropic hormone (ACTH) stimulates steroidogenesis through downstream actions on multiple components involved in steroidogenesis. Both acute and chronic ACTH treatments can modulate SR-B1 function, including its transcription, posttranscriptional stability, phosphorylation and dimerization status, as well as the interaction with other protein partners, all of which result in changes in the ability of SR-B1 to mediate HDL-CE uptake and the supply of cholesterol for conversion to steroids. Here, we provide a review of the recent findings on the regulation of adrenal SR-B1 function by ACTH.
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Affiliation(s)
- Wen-Jun Shen
- The Division of Endocrinology, Stanford University, Stanford, CA, USA
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Salman Azhar
- The Division of Endocrinology, Stanford University, Stanford, CA, USA
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
| | - Fredric B. Kraemer
- The Division of Endocrinology, Stanford University, Stanford, CA, USA
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, CA, USA
- *Correspondence: Fredric B. Kraemer,
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27
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Holme RL, Miller JJ, Nicholson K, Sahoo D. Tryptophan 415 Is Critical for the Cholesterol Transport Functions of Scavenger Receptor BI. Biochemistry 2015; 55:103-13. [PMID: 26652912 DOI: 10.1021/acs.biochem.5b00804] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
High density lipoproteins (HDL) are anti-atherogenic particles, primarily due to their role in the reverse cholesterol transport pathway whereby HDL delivers cholesteryl esters (CE) to the liver for excretion upon interaction with its receptor, scavenger receptor BI (SR-BI). We designed experiments to test the hypothesis that one or more of the eight highly conserved tryptophan (Trp; W) residues in SR-BI are critical for mediating function. We created a series of Trp-to-phenylalanine (Phe, F) mutant receptors, as well as Trp-less SR-BI (ΔW-SR-BI), and assessed their ability to mediate cholesterol transport. Wild-type (WT) or mutant SR-BI receptors were transiently expressed in COS-7 cells, and cell surface expression was confirmed. Next, we showed that Trp-less- and W415F-SR-BI had significantly decreased abilities to bind HDL and promote selective uptake of HDL-CE, albeit with higher selective uptake efficiency as compared to WT-SR-BI. Interestingly, only Trp-less-, but not W415F-SR-BI, showed an impaired ability to mediate efflux of free cholesterol (FC). Furthermore, both W415F- and Trp-less-SR-BI were unable to reorganize plasma membrane pools of FC based on lack of sensitivity to exogenous cholesterol oxidase. Restoration of Trp 415 into the Trp-less-SR-BI background was unable to rescue Trp-less-SR-BI's impaired functions, suggesting that Trp 415 is critical, but not sufficient for full receptor function. Furthermore, with the exception of Trp 262, restoration of individual extracellular Trp residues, in combination with Trp 415, into the Trp-less-SR-BI background partially rescued SR-BI function, indicating that Trp 415 must be present in combination with other Trp residues for proper cholesterol transport functions.
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Affiliation(s)
- Rebecca L Holme
- Department of Biochemistry, Medical College of Wisconsin , Milwaukee, Wisconsin, United States
| | - James J Miller
- Department of Biochemistry, Medical College of Wisconsin , Milwaukee, Wisconsin, United States
| | - Kay Nicholson
- Department of Medicine, Division of Endocrinology, Metabolism & Clinical Nutrition, Medical College of Wisconsin , Milwaukee, Wisconsin, United States
| | - Daisy Sahoo
- Department of Medicine, Division of Endocrinology, Metabolism & Clinical Nutrition, Medical College of Wisconsin , Milwaukee, Wisconsin, United States.,Department of Biochemistry, Medical College of Wisconsin , Milwaukee, Wisconsin, United States.,Cardiovascular Center, Medical College of Wisconsin , Milwaukee, Wisconsin, United States
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Chadwick AC, Holme RL, Chen Y, Thomas MJ, Sorci-Thomas MG, Silverstein RL, Pritchard KA, Sahoo D. Acrolein impairs the cholesterol transport functions of high density lipoproteins. PLoS One 2015; 10:e0123138. [PMID: 25849485 PMCID: PMC4388475 DOI: 10.1371/journal.pone.0123138] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Accepted: 02/17/2015] [Indexed: 12/22/2022] Open
Abstract
High density lipoproteins (HDL) are considered athero-protective, primarily due to their role in reverse cholesterol transport, where they transport cholesterol from peripheral tissues to the liver for excretion. The current study was designed to determine the impact of HDL modification by acrolein, a highly reactive aldehyde found in high abundance in cigarette smoke, on the cholesterol transport functions of HDL. HDL was chemically-modified with acrolein and immunoblot and mass spectrometry analyses confirmed apolipoprotein crosslinking, as well as acrolein adducts on apolipoproteins A-I and A-II. The ability of acrolein-modified HDL (acro-HDL) to serve as an acceptor of free cholesterol (FC) from COS-7 cells transiently expressing SR-BI was significantly decreased. Further, in contrast to native HDL, acro-HDL promotes higher neutral lipid accumulation in murine macrophages as judged by Oil Red O staining. The ability of acro-HDL to mediate efficient selective uptake of HDL-cholesteryl esters (CE) into SR-BI-expressing cells was reduced compared to native HDL. Together, the findings from our studies suggest that acrolein modification of HDL produces a dysfunctional particle that may ultimately promote atherogenesis by impairing functions that are critical in the reverse cholesterol transport pathway.
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Affiliation(s)
- Alexandra C. Chadwick
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Rebecca L. Holme
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Yiliang Chen
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Michael J. Thomas
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States of America
| | - Mary G. Sorci-Thomas
- Department of Pathology, Wake Forest School of Medicine, Winston-Salem, North Carolina, United States of America
| | - Roy L. Silverstein
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin, United States of America
| | - Kirkwood A. Pritchard
- Department of Surgery, Children’s Research Institute, Milwaukee, Wisconsin, United States of America
| | - Daisy Sahoo
- Department of Medicine, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, Wisconsin, United States of America
- * E-mail:
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29
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Zhao Y, Hoekstra M, Korporaal SJA, Van Berkel TJC, Van Eck M. HDL Receptor Scavenger Receptor BI. Atherosclerosis 2015. [DOI: 10.1002/9781118828533.ch25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Zannis VI, Fotakis P, Koukos G, Kardassis D, Ehnholm C, Jauhiainen M, Chroni A. HDL biogenesis, remodeling, and catabolism. Handb Exp Pharmacol 2015; 224:53-111. [PMID: 25522986 DOI: 10.1007/978-3-319-09665-0_2] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In this chapter, we review how HDL is generated, remodeled, and catabolized in plasma. We describe key features of the proteins that participate in these processes, emphasizing how mutations in apolipoprotein A-I (apoA-I) and the other proteins affect HDL metabolism. The biogenesis of HDL initially requires functional interaction of apoA-I with the ATP-binding cassette transporter A1 (ABCA1) and subsequently interactions of the lipidated apoA-I forms with lecithin/cholesterol acyltransferase (LCAT). Mutations in these proteins either prevent or impair the formation and possibly the functionality of HDL. Remodeling and catabolism of HDL is the result of interactions of HDL with cell receptors and other membrane and plasma proteins including hepatic lipase (HL), endothelial lipase (EL), phospholipid transfer protein (PLTP), cholesteryl ester transfer protein (CETP), apolipoprotein M (apoM), scavenger receptor class B type I (SR-BI), ATP-binding cassette transporter G1 (ABCG1), the F1 subunit of ATPase (Ecto F1-ATPase), and the cubulin/megalin receptor. Similarly to apoA-I, apolipoprotein E and apolipoprotein A-IV were shown to form discrete HDL particles containing these apolipoproteins which may have important but still unexplored functions. Furthermore, several plasma proteins were found associated with HDL and may modulate its biological functions. The effect of these proteins on the functionality of HDL is the topic of ongoing research.
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Affiliation(s)
- Vassilis I Zannis
- Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA, 02118, USA,
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Chadwick AC, Jensen DR, Peterson FC, Volkman BF, Sahoo D. Expression, purification and reconstitution of the C-terminal transmembrane domain of scavenger receptor BI into detergent micelles for NMR analysis. Protein Expr Purif 2014; 107:35-42. [PMID: 25461971 DOI: 10.1016/j.pep.2014.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/24/2014] [Accepted: 11/04/2014] [Indexed: 01/26/2023]
Abstract
Scavenger receptor class B type I (SR-BI), the high density lipoprotein (HDL) receptor, is important for the delivery of HDL-cholesteryl esters to the liver for excretion via bile formation. The focus on therapeutic strategies aimed at reducing cholesterol levels highlights the critical need to understand the structural features of SR-BI that drive cholesterol removal. Yet, in the absence of a high-resolution structure of SR-BI, our understanding of how SR-BI interacts with HDL is limited. In this study, we have optimized the NMR solution conditions for the structural analysis of the C-terminal transmembrane domain of SR-BI that harbors putative domains required for receptor oligomerization. An isotopically-labeled SR-BI peptide encompassing residues 405-475 was bacterially-expressed and purified. [U-(15)N]-SR-BI(405-475) was incorporated into different detergent micelles and assessed by (1)H-(15)N-HSQC in order to determine which detergent micelle best maintained SR-BI(405-475) in a folded, native conformation for subsequent NMR analyses. We also determined the optimal detergent concentration used in micelles, as well as temperature, solution buffer and pH conditions. Based on (1)H-(15)N-HSQC peak dispersion, intensity, and uniformity, we determined that [U-(15)N]-SR-BI(405-475) should be incorporated into 5% detergent micelles consisting of 1-palmitoyl-2-hydroxy-sn-glycero-3-phospho-[1'-rac-glycerol] (LPPG) and data collected at 40°C in a non-buffered solution at pH 6.8. Furthermore, we demonstrate the ability of SR-BI(405-475) to form dimers upon chemical crosslinking. These studies represent the first steps in obtaining high-resolution structural information by NMR for the HDL receptor that plays a critical role in regulating whole body cholesterol removal.
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Affiliation(s)
- Alexandra C Chadwick
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Davin R Jensen
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Francis C Peterson
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
| | - Brian F Volkman
- Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Daisy Sahoo
- Department of Medicine, Division of Endocrinology, Metabolism & Clinical Nutrition, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA; Department of Biochemistry, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA; Cardiovascular Center, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
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Kartz GA, Holme RL, Nicholson K, Sahoo D. SR-BI/CD36 chimeric receptors define extracellular subdomains of SR-BI critical for cholesterol transport. Biochemistry 2014; 53:6173-82. [PMID: 25211142 PMCID: PMC4188264 DOI: 10.1021/bi500706x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
High-density lipoproteins (HDLs) are athero-protective, primarily because of their ability to promote cholesterol flux from peripheral tissues to the liver by reverse cholesterol transport (RCT). The delivery of HDL-cholesteryl esters (CE) into cells is mediated by the HDL receptor, scavenger receptor class B type I (SR-BI), a promising target for enhancing whole body cholesterol disposal and preventing cardiovascular disease. A detailed understanding of the structural determinants underlying proper SR-BI/HDL alignment that supports the selective uptake of HDL-CE into cells remains lacking. To this end, we exploited CD36, a class B scavenger receptor with a predicted topology similar to that of SR-BI that binds HDL but is unable to mediate efficient selective uptake of HDL-CE. We generated a series of SR-BI/CD36 chimeric receptors that span the extracellular (EC) domain of SR-BI to delineate regions that are essential for SR-BI's cholesterol transport functions. All 16 SR-BI/CD36 chimeras were transiently expressed in COS-7 cells, and their plasma membrane localization was confirmed. The majority of SR-BI/CD36 chimeric receptors displayed significant reductions in their ability to (i) bind HDL, (ii) deliver HDL-CE to cells, (iii) mediate efflux of free cholesterol (FC) to HDL, and (iv) redistribute plasma membrane domains of FC. We also demonstrated that changes in SR-BI function were independent of receptor oligomerization. Altogether, we have identified discrete subdomains, particularly in the N-terminal and C-terminal regions of the EC domain of SR-BI, that are critical for productive receptor-ligand interactions and the various cholesterol transport functions of SR-BI.
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Affiliation(s)
- Gabriella A Kartz
- Departments of Pharmacology & Toxicology, ‡Biochemistry, and §Medicine, Medical College of Wisconsin , Milwaukee, Wisconsin 53226, United States
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Abstract
Most types of cells in the body do not express the capability of catabolizing cholesterol, so cholesterol efflux is essential for homeostasis. For instance, macrophages possess four pathways for exporting free (unesterified) cholesterol to extracellular high density lipoprotein (HDL). The passive processes include simple diffusion via the aqueous phase and facilitated diffusion mediated by scavenger receptor class B, type 1 (SR-BI). Active pathways are mediated by the ATP-binding cassette (ABC) transporters ABCA1 and ABCG1, which are membrane lipid translocases. The efflux of cellular phospholipid and free cholesterol to apolipoprotein A-I promoted by ABCA1 is essential for HDL biogenesis. Current understanding of the molecular mechanisms involved in these four efflux pathways is presented in this minireview.
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Affiliation(s)
- Michael C Phillips
- From the Division of Translational Medicine and Human Genetics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104-5158
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Shen WJ, Hu J, Hu Z, Kraemer FB, Azhar S. Scavenger receptor class B type I (SR-BI): a versatile receptor with multiple functions and actions. Metabolism 2014; 63:875-86. [PMID: 24854385 PMCID: PMC8078058 DOI: 10.1016/j.metabol.2014.03.011] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 03/12/2014] [Accepted: 03/18/2014] [Indexed: 11/16/2022]
Abstract
Scavenger receptor class B type I (SR-BI), is a physiologically relevant HDL receptor that mediates selective uptake of lipoprotein (HDL)-derived cholesteryl ester (CE) in vitro and in vivo. Mammalian SR-BI is a 509-amino acid, ~82 kDa glycoprotein that contains N- and C-terminal cytoplasmic domains, two-transmembrane domains, as well as a large extracellular domain containing 5-6 cysteine residues and multiple sites for N-linked glycosylation. The size and structural characteristics of SR-BI, however, vary considerably among lower vertebrates and insects. Recently, significant progress has been made in understanding the molecular mechanisms involved in the posttranscriptional/posttranslational regulation of SR-BI in a tissue specific manner. The purpose of this review is to summarize the current body of knowledge about the events and molecules connected with the posttranscriptional/posttranslational regulation of SR-BI and to update the molecular and functional characteristics of the insect SR-BI orthologs.
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MESH Headings
- Animals
- Biological Transport
- Gene Expression Regulation
- Glycosylation
- Humans
- Insect Proteins/chemistry
- Insect Proteins/genetics
- Insect Proteins/metabolism
- Lipoproteins, HDL/chemistry
- Lipoproteins, HDL/genetics
- Lipoproteins, HDL/metabolism
- Liver/metabolism
- Organ Specificity
- Protein Conformation
- Protein Processing, Post-Translational
- Receptors, Lipoprotein/chemistry
- Receptors, Lipoprotein/genetics
- Receptors, Lipoprotein/metabolism
- Scavenger Receptors, Class B/chemistry
- Scavenger Receptors, Class B/genetics
- Scavenger Receptors, Class B/metabolism
- Species Specificity
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Affiliation(s)
- Wen-Jun Shen
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304; Division of Endocrinology, Stanford University, Stanford, California 94305
| | - Jie Hu
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304
| | - Zhigang Hu
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304; Division of Endocrinology, Stanford University, Stanford, California 94305
| | - Fredric B Kraemer
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304; Division of Endocrinology, Stanford University, Stanford, California 94305
| | - Salman Azhar
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304; Division of Gastroenterology and Hepatology, Stanford University, Stanford, California 94305.
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Martin SS, Jones SR, Toth PP. High-density lipoprotein subfractions: current views and clinical practice applications. Trends Endocrinol Metab 2014; 25:329-36. [PMID: 24931711 DOI: 10.1016/j.tem.2014.05.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 05/12/2014] [Accepted: 05/13/2014] [Indexed: 01/26/2023]
Abstract
High-density lipoprotein (HDL) is astonishingly complex, but the de facto standard for its measurement has been remarkably simple: total cholesterol content. It is time to prioritize higher-resolution HDL measurement techniques that capture better the biologically and clinically important characteristics of HDL. Scientific advances have ushered in a new era in which we view HDL in terms of its subfractions, particle structure, metabolism, and functional integration of its proteome and lipidome. HDL subfractions appear to be associated with function. In general, smaller, denser HDL3 is more tightly linked to favorable atheroprotective functions and clinical outcomes. Techniques to measure the cholesterol content or particle concentrations of HDL subfractions are available clinically. In the future, we anticipate subfractionating HDL based on its functional properties.
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Affiliation(s)
- Seth S Martin
- Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
| | - Steven R Jones
- Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA
| | - Peter P Toth
- Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD, USA; Department of Preventive Cardiology, CGH Medical Center, Sterling, IL, and University of Illinois School of Medicine, Peoria, IL, USA.
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Medina-Echeverz J, Fioravanti J, Díaz-Valdés N, Frank K, Aranda F, Gomar C, Ardaiz N, Dotor J, Umansky V, Prieto J, Berraondo P. Harnessing high density lipoproteins to block transforming growth factor beta and to inhibit the growth of liver tumor metastases. PLoS One 2014; 9:e96799. [PMID: 24797128 PMCID: PMC4010484 DOI: 10.1371/journal.pone.0096799] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 04/11/2014] [Indexed: 11/30/2022] Open
Abstract
Transforming growth factor β (TGF-β) is a powerful promoter of cancer progression and a key target for antitumor therapy. As cancer cells exhibit active cholesterol metabolism, high density lipoproteins (HDLs) appear as an attractive delivery system for anticancer TGFβ-inhibitory molecules. We constructed a plasmid encoding a potent TGF-β-blocking peptide (P144) linked to apolipoprotein A-I (ApoA-I) through a flexible linker (pApoLinkerP144). The ApoLinkerP144 sequence was then incorporated into a hepatotropic adeno-associated vector (AAVApoLinkerP144). The aim was to induce hepatocytes to produce HDLs containing a modified ApoA-I capable of blocking TGF-β. We observed that transduction of the murine liver with pApoLinkerP144 led to the appearance of a fraction of circulating HDL containing the fusion protein. These HDLs were able to attenuate TGF-β signaling in the liver and to enhance IL-12 -mediated IFN-γ production. Treatment of liver metastasis of MC38 colorectal cancer with AAVApoLinkerP144 resulted in a significant reduction of tumor growth and enhanced expression of IFN-γ and GM-CSF in cancerous tissue. ApoLinkerP144 also delayed MC38 liver metastasis in Rag2−/−IL2rγ−/− immunodeficient mice. This effect was associated with downregulation of TGF-β target genes essential for metastatic niche conditioning. Finally, in a subset of ret transgenic mice, a model of aggressive spontaneous metastatic melanoma, AAVApoLinkerP144 delayed tumor growth in association with increased CD8+ T cell numbers in regional lymph nodes. In conclusion, modification of HDLs to transport TGF-β-blocking molecules is a novel and promising approach to inhibit the growth of liver metastases by immunological and non-immunological mechanisms.
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Affiliation(s)
- José Medina-Echeverz
- Division of Hepatology and Gene Therapy, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Jessica Fioravanti
- Division of Hepatology and Gene Therapy, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Nancy Díaz-Valdés
- Division of Hepatology and Gene Therapy, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
- Skin Cancer Unit, German Cancer Research Center, Heidelberg and Department of Dermatology, Venereology and Allergology, University Medical Center Mannheim, Ruprecht-Karl University of Heidelberg, Mannheim, Heidelberg, Germany
| | - Kathrin Frank
- Skin Cancer Unit, German Cancer Research Center, Heidelberg and Department of Dermatology, Venereology and Allergology, University Medical Center Mannheim, Ruprecht-Karl University of Heidelberg, Mannheim, Heidelberg, Germany
| | - Fernando Aranda
- Division of Hepatology and Gene Therapy, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Celia Gomar
- Division of Hepatology and Gene Therapy, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Nuria Ardaiz
- Division of Hepatology and Gene Therapy, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | | | - Viktor Umansky
- Skin Cancer Unit, German Cancer Research Center, Heidelberg and Department of Dermatology, Venereology and Allergology, University Medical Center Mannheim, Ruprecht-Karl University of Heidelberg, Mannheim, Heidelberg, Germany
| | - Jesús Prieto
- Division of Hepatology and Gene Therapy, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
- Liver Unit, University of Navarra Clinic, Networked Biomedical Research Center of Hepatic and Digestive Diseases, Pamplona, Spain
- * E-mail: (PB); (JP)
| | - Pedro Berraondo
- Division of Hepatology and Gene Therapy, Center for Applied Medical Research, University of Navarra, Pamplona, Spain
- * E-mail: (PB); (JP)
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Prabhudas M, Bowdish D, Drickamer K, Febbraio M, Herz J, Kobzik L, Krieger M, Loike J, Means TK, Moestrup SK, Post S, Sawamura T, Silverstein S, Wang XY, El Khoury J. Standardizing scavenger receptor nomenclature. THE JOURNAL OF IMMUNOLOGY 2014; 192:1997-2006. [PMID: 24563502 DOI: 10.4049/jimmunol.1490003] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Scavenger receptors constitute a large family of proteins that are structurally diverse and participate in a wide range of biological functions. These receptors are expressed predominantly by myeloid cells and recognize a variety of ligands, including endogenous and modified host-derived molecules and microbial pathogens. There are currently eight classes of scavenger receptors, many of which have multiple names, leading to inconsistencies and confusion in the literature. To address this problem, a workshop was organized by the U.S. National Institute of Allergy and Infectious Diseases, National Institutes of Health to help develop a clear definition of scavenger receptors and a standardized nomenclature based on that definition. Fifteen experts in the scavenger receptor field attended the workshop and, after extensive discussion, reached a consensus regarding the definition of scavenger receptors and a proposed scavenger receptor nomenclature. Scavenger receptors were defined as cell surface receptors that typically bind multiple ligands and promote the removal of non-self or altered-self targets. They often function by mechanisms that include endocytosis, phagocytosis, adhesion, and signaling that ultimately lead to the elimination of degraded or harmful substances. Based on this definition, nomenclature and classification of these receptors into 10 classes were proposed. The discussion and nomenclature recommendations described in this report only refer to mammalian scavenger receptors. The purpose of this article is to describe the proposed mammalian nomenclature and classification developed at the workshop and to solicit additional feedback from the broader research community.
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Affiliation(s)
- Mercy Prabhudas
- Division of Allergy, Immunology and Transplantation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
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Ott C, Jacobs K, Haucke E, Navarrete Santos A, Grune T, Simm A. Role of advanced glycation end products in cellular signaling. Redox Biol 2014; 2:411-29. [PMID: 24624331 PMCID: PMC3949097 DOI: 10.1016/j.redox.2013.12.016] [Citation(s) in RCA: 779] [Impact Index Per Article: 77.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 12/19/2013] [Indexed: 12/18/2022] Open
Abstract
Improvements in health care and lifestyle have led to an elevated lifespan and increased focus on age-associated diseases, such as neurodegeneration, cardiovascular disease, frailty and arteriosclerosis. In all these chronic diseases protein, lipid or nucleic acid modifications are involved, including cross-linked and non-degradable aggregates, such as advanced glycation end products (AGEs). Formation of endogenous or uptake of dietary AGEs can lead to further protein modifications and activation of several inflammatory signaling pathways. This review will give an overview of the most prominent AGE-mediated signaling cascades, AGE receptor interactions, prevention of AGE formation and the impact of AGEs during pathophysiological processes.
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Key Words
- ADAMST, a disintegrin and metalloproteinase with a thrombospondin type 1 motif
- AGE, advanced glycation end products
- AGE-receptors
- Advanced glycation end products
- Age-associated diseases
- Aggregates
- Aging
- E, from embryonic day
- EGFR, epidermal growth factor receptor
- ERK, extracellular-signal regulated kinase
- F3NK, fructosamine 3-phosphokinase
- FKHRL1, forkhead transcription factor
- HDL, high density lipoprotein
- HMGB1, high-mobility-group-protein B1
- HNE, 4-hydroxy-trans-2-nonenal
- Jak1/2, Janus kinase 1/2
- LDL, low density lipoprotein
- MDA, malondialdehyde
- MEKK, mitogen-activated protein/ERK kinase kinases
- MnSOD, manganese superoxide dismutase
- NF-κB
- Nf-κB, nuclear factor-light-chain-enhancer of activated B
- Oxidative stress
- PIK3, phosphoinositol 3 kinase
- RAGE
- RAGE, receptor of AGEs
- RCC, reactive carbonyl compounds
- Reactive carbonyl compounds
- S100B, S100 calcium binding protein B
- SIRt1, NAD+-dependent deacetylase and survival factor 1
- SR-A, scavenger receptor class A
- Signaling
- Stat 1/2, signal transducers and activators of transcription 1/2
- VSMC, vascular smooth muscle cells
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Affiliation(s)
- Christiane Ott
- Department of Nutritional Toxicology, Institute of Nutrition, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Kathleen Jacobs
- Clinic for Cardiothoracic Surgery, University Hospital Halle (Saale), Martin-Luther-University of Halle-Wittenberg, Ernst-Grube Strasse 40, D-06120 Halle (Saale), Germany
| | - Elisa Haucke
- Institute for Anatomy and Cell Biology, Faculty of Medicine, Martin-Luther-University of Halle-Wittenberg, 06108 Halle (Saale), Germany
| | - Anne Navarrete Santos
- Institute for Anatomy and Cell Biology, Faculty of Medicine, Martin-Luther-University of Halle-Wittenberg, 06108 Halle (Saale), Germany
| | - Tilman Grune
- Department of Nutritional Toxicology, Institute of Nutrition, Friedrich Schiller University Jena, 07743 Jena, Germany
| | - Andreas Simm
- Clinic for Cardiothoracic Surgery, University Hospital Halle (Saale), Martin-Luther-University of Halle-Wittenberg, Ernst-Grube Strasse 40, D-06120 Halle (Saale), Germany
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Neculai D, Schwake M, Ravichandran M, Zunke F, Collins RF, Peters J, Neculai M, Plumb J, Loppnau P, Pizarro JC, Seitova A, Trimble WS, Saftig P, Grinstein S, Dhe-Paganon S. Structure of LIMP-2 provides functional insights with implications for SR-BI and CD36. Nature 2013; 504:172-6. [PMID: 24162852 DOI: 10.1038/nature12684] [Citation(s) in RCA: 207] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2012] [Accepted: 09/20/2013] [Indexed: 11/09/2022]
Abstract
Members of the CD36 superfamily of scavenger receptor proteins are important regulators of lipid metabolism and innate immunity. They recognize normal and modified lipoproteins, as well as pathogen-associated molecular patterns. The family consists of three members: SR-BI (which delivers cholesterol to the liver and steroidogenic organs and is a co-receptor for hepatitis C virus), LIMP-2/LGP85 (which mediates lysosomal delivery of β-glucocerebrosidase and serves as a receptor for enterovirus 71 and coxsackieviruses) and CD36 (a fatty-acid transporter and receptor for phagocytosis of effete cells and Plasmodium-infected erythrocytes). Notably, CD36 is also a receptor for modified lipoproteins and β-amyloid, and has been implicated in the pathogenesis of atherosclerosis and of Alzheimer's disease. Despite their prominent roles in health and disease, understanding the function and abnormalities of the CD36 family members has been hampered by the paucity of information about their structure. Here we determine the crystal structure of LIMP-2 and infer, by homology modelling, the structure of SR-BI and CD36. LIMP-2 shows a helical bundle where β-glucocerebrosidase binds, and where ligands are most likely to bind to SR-BI and CD36. Remarkably, the crystal structure also shows the existence of a large cavity that traverses the entire length of the molecule. Mutagenesis of SR-BI indicates that the cavity serves as a tunnel through which cholesterol(esters) are delivered from the bound lipoprotein to the outer leaflet of the plasma membrane. We provide evidence supporting a model whereby lipidic constituents of the ligands attached to the receptor surface are handed off to the membrane through the tunnel, accounting for the selective lipid transfer characteristic of SR-BI and CD36.
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Affiliation(s)
- Dante Neculai
- Cell Biology Program, The Hospital for Sick Children, Toronto M5G 1X8, Canada
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Liu Z, Wang J, Huang E, Gao S, Li H, Lu J, Tian K, Little PJ, Shen X, Xu S, Liu P. Tanshinone IIA suppresses cholesterol accumulation in human macrophages: role of heme oxygenase-1. J Lipid Res 2013; 55:201-13. [PMID: 24302760 DOI: 10.1194/jlr.m040394] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Accumulation of foam cells in the neointima represents a key event in atherosclerosis. We previously demonstrated that Tanshinone IIA (Tan), a lipophilic bioactive compound extracted from Salvia miltiorrhiza Bunge, inhibits experimental atherogenesis, yet the detailed mechanisms are not fully understood. In this study, we sought to explore the potential effects of Tan on lipid accumulation in macrophage foam cells and the underlying molecular mechanisms. Our data indicate that Tan treatment reduced the content of macrophages, cholesterol accumulation, and the development of atherosclerotic plaque in apolipoprotein E-deficient mice. In human macrophages, Tan ameliorated oxidized low density lipoporotein (oxLDL)-elicited foam cell formation by inhibiting oxLDL uptake and promoting cholesterol efflux. Mechanistically, Tan markedly reduced the expression of scavenger receptor class A and increased the expression of ATP-binding cassette transporter A1 (ABCA1) and ABCG1 in lipid-laden macrophages via activation of the extracellular signal-regulated kinase (ERK)/nuclear factor-erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. Tan treatment induced the phosphorylation and nuclear translocation of Nrf2 and subsequently increased the expression of HO-1, and these effects were abolished by the specific ERK inhibitors, PD98059 and U0126. Moreover, HO-1 small interfering RNA or zinc protoporphyrin (a HO-1 inhibitor) abrogated Tan-mediated suppression of lipid accumulation in macrophages. Our current findings demonstrate that a novel HO-1-dependent mechanism is involved in the regulation of cholesterol balance by Tan.
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Affiliation(s)
- Zhiping Liu
- Department of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, Guangdong, China
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Shah AS, Tan L, Long JL, Davidson WS. Proteomic diversity of high density lipoproteins: our emerging understanding of its importance in lipid transport and beyond. J Lipid Res 2013; 54:2575-85. [PMID: 23434634 PMCID: PMC3770071 DOI: 10.1194/jlr.r035725] [Citation(s) in RCA: 276] [Impact Index Per Article: 25.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 02/18/2013] [Indexed: 01/09/2023] Open
Abstract
Recent applications of mass spectrometry technology have dramatically increased our understanding of the proteomic diversity of high density lipoproteins (HDL). Depending on the method of HDL isolation, upwards of 85 proteins have been identified, and the list continues to grow. In addition to proteins consistent with traditionally accepted roles in lipid transport, HDL carries surprising constituents, such as members of the complement pathway, protease inhibitors involved in hemostasis, acute-phase response proteins, immune function mediators, and even metal-binding proteins. This compositional diversity fits well with hundreds of studies demonstrating a wide functional pleiotrophy, including roles in lipid transport, oxidation, inflammation, hemostasis, and immunity. This review summarizes the progression of our understanding of HDL proteomic complexity and points out key experimental observations that reinforce the functional diversity of HDL. The possibility of specific HDL subspecies with distinct functions, the evidence supporting this concept, and some of the best examples of experimentally defined HDL subspecies are also discussed. Finally, key challenges facing the field are highlighted, particularly the need to identify and define the function of HDL subspecies to better inform attempts to pharmacologically manipulate HDL for the benefit of cardiovascular disease and possibly other maladies.
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Affiliation(s)
- Amy S. Shah
- Division of Endocrinology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH
| | - Lirong Tan
- Division of Biomedical Informatics, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH; and
| | - Jason Lu Long
- Division of Biomedical Informatics, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH; and
| | - W. Sean Davidson
- Center for Lipid and Arteriosclerosis Science, University of Cincinnati, Cincinnati, OH
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Abstract
PURPOSE OF REVIEW Selective lipid uptake (SLU) is known to be a major pathway of lipoprotein cholesterol metabolism in experimental animals and humans, but remains poorly understood. This review provides a brief overview of SLU mediated by the HDL receptor scavenger receptor B-type I (SR-BI), and highlights several surprising new findings related to the impact of SLU pathways in cholesterol homeostasis. RECENT FINDINGS Under certain conditions, SR-BI-mediated SLU contributes to reverse cholesterol transport (RCT) independently of ABCG5/G8-mediated biliary cholesterol secretion, implying a novel trafficking mechanism. Hepatic SR-BI expression and RCT are decreased in diabetic mice. Farnesoid X receptor (FXR) and the microRNAs miR-185, miR-96 and miR-223 are emerging therapeutic targets for increasing SR-BI expression. SR-BI-independent selective cholesteryl ester uptake is a newly characterized pathway in macrophage foam cells. SUMMARY New findings underscore the importance of SR-BI-mediated SLU in hepatic SLU and RCT, while indicating that further investigation is needed to define SLU pathways, including SR-BI-independent macrophage selective cholesteryl ester uptake. The intracellular trafficking of cholesterol in these pathways appears to be critical to their normal function and is a major subject of ongoing studies.
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Affiliation(s)
- Jason M. Meyer
- Departments of Internal Medicine and Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, USA
| | - Gregory A. Graf
- Department Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky, USA
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, USA
- Barnstable Brown Kentucky Diabetes and Obesity Center, University of Kentucky, Lexington, Kentucky, USA
| | - Deneys R. van der Westhuyzen
- Department of Veterans Affairs Medical Center, University of Kentucky, Lexington, Kentucky, USA
- Departments of Internal Medicine and Molecular and Cellular Biochemistry, University of Kentucky, Lexington, Kentucky, USA
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, Kentucky, USA
- Barnstable Brown Kentucky Diabetes and Obesity Center, University of Kentucky, Lexington, Kentucky, USA
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Toth PP, Barter PJ, Rosenson RS, Boden WE, Chapman MJ, Cuchel M, D'Agostino RB, Davidson MH, Davidson WS, Heinecke JW, Karas RH, Kontush A, Krauss RM, Miller M, Rader DJ. High-density lipoproteins: A consensus statement from the National Lipid Association. J Clin Lipidol 2013; 7:484-525. [DOI: 10.1016/j.jacl.2013.08.001] [Citation(s) in RCA: 240] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 08/03/2013] [Indexed: 12/21/2022]
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Röhrl C, Stangl H. HDL endocytosis and resecretion. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1831:1626-33. [PMID: 23939397 PMCID: PMC3795453 DOI: 10.1016/j.bbalip.2013.07.014] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2013] [Revised: 07/22/2013] [Accepted: 07/26/2013] [Indexed: 12/23/2022]
Abstract
HDL removes excess cholesterol from peripheral tissues and delivers it to the liver and steroidogenic tissues via selective lipid uptake without catabolism of the HDL particle itself. In addition, endocytosis of HDL holo-particles has been debated for nearly 40years. However, neither the connection between HDL endocytosis and selective lipid uptake, nor the physiological relevance of HDL uptake has been delineated clearly. This review will focus on HDL endocytosis and resecretion and its relation to cholesterol transfer. We will discuss the role of HDL endocytosis in maintaining cholesterol homeostasis in tissues and cell types involved in atherosclerosis, focusing on liver, macrophages and endothelium. We will critically summarize the current knowledge on the receptors mediating HDL endocytosis including SR-BI, F1-ATPase and CD36 and on intracellular HDL transport routes. Dependent on the tissue, HDL is either resecreted (retro-endocytosis) or degraded after endocytosis. Finally, findings on HDL transcytosis across the endothelial barrier will be summarized. We suggest that HDL endocytosis and resecretion is a rather redundant pathway under physiologic conditions. In case of disturbed lipid metabolism, however, HDL retro-endocytosis represents an alternative pathway that enables tissues to maintain cellular cholesterol homeostasis.
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Affiliation(s)
- Clemens Röhrl
- Department of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria
| | - Herbert Stangl
- Department of Medical Chemistry, Center for Pathobiochemistry and Genetics, Medical University of Vienna, Vienna, Austria.
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Canton J, Neculai D, Grinstein S. Scavenger receptors in homeostasis and immunity. Nat Rev Immunol 2013; 13:621-34. [PMID: 23928573 DOI: 10.1038/nri3515] [Citation(s) in RCA: 563] [Impact Index Per Article: 51.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Scavenger receptors were originally identified by their ability to recognize and to remove modified lipoproteins; however, it is now appreciated that they carry out a striking range of functions, including pathogen clearance, lipid transport, the transport of cargo within the cell and even functioning as taste receptors. The large repertoire of ligands recognized by scavenger receptors and their broad range of functions are not only due to the wide range of receptors that constitute this family but also to their ability to partner with various co-receptors. The ability of individual scavenger receptors to associate with different co-receptors makes their responsiveness extremely versatile. This Review highlights recent insights into the structural features that determine the function of scavenger receptors and the emerging role that these receptors have in immune responses, notably in macrophage polarization and in the pathogenesis of diseases such as atherosclerosis and Alzheimer's disease.
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Affiliation(s)
- Johnathan Canton
- Cell Biology Program, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada
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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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Yeap YY, Trevaskis NL, Quach T, Tso P, Charman WN, Porter CJH. Intestinal Bile Secretion Promotes Drug Absorption from Lipid Colloidal Phases via Induction of Supersaturation. Mol Pharm 2013; 10:1874-89. [DOI: 10.1021/mp3006566] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
| | | | | | - Patrick Tso
- Department of Pathology
and Laboratory
Medicine, University of Cincinnati, Cincinnati, Ohio 45221, United
States
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Hu Z, Hu J, Zhang Z, Shen WJ, Yun CC, Berlot CH, Kraemer FB, Azhar S. Regulation of expression and function of scavenger receptor class B, type I (SR-BI) by Na+/H+ exchanger regulatory factors (NHERFs). J Biol Chem 2013; 288:11416-35. [PMID: 23482569 DOI: 10.1074/jbc.m112.437368] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Scavenger receptor class B, type I (SR-BI) binds HDL and mediates selective delivery of cholesteryl esters (CEs) to the liver, adrenals, and gonads for product formation (bile acids and steroids). Because relatively little is known about SR-BI posttranslational regulation in steroidogenic cells, we examined the roles of Na(+)/H(+) exchanger regulatory factors (NHERFs) in regulating SR-BI expression, SR-BI-mediated selective CE uptake, and steroidogenesis. NHERF1 and NHERF2 mRNA and protein are expressed at varying levels in model steroidogenic cell lines and the adrenal, with only low expression of PDZK1 (NHERF3) and NHERF4. Dibutyryl cyclic AMP decreased NHERF1 and NHERF2 and increased SR-BI mRNA expression in primary rat granulosa cells and MLTC-1 cells, whereas ACTH had no effect on NHERF1 and NHERF2 mRNA levels but decreased their protein levels in rat adrenals. Co-immunoprecipitation, colocalization, bimolecular fluorescence complementation, and mutational analysis indicated that SR-BI associates with NHERF1 and NHERF2. NHERF1 and NHERF2 down-regulated SR-BI protein expression through inhibition of its de novo synthesis. NHERF1 and NHERF2 also inhibited SR-BI-mediated selective CE transport and steroidogenesis, which were markedly attenuated by partial deletions of the PDZ1 or PDZ2 domain of NHERF1, the PDZ2 domain of NHERF2, or the MERM domains of NHERF1/2 or by gene silencing of NHERF1/2. Moreover, an intact COOH-terminal PDZ recognition motif (EAKL) in SR-BI is needed. Transient transfection of hepatic cell lines with NHERF1 or NHERF2 caused a significant reduction in endogenous protein levels of SR-BI. Collectively, these data establish NHERF1 and NHERF2 as SR-BI protein binding partners that play a negative role in the regulation of SR-BI expression, selective CE transport, and steroidogenesis.
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Affiliation(s)
- Zhigang Hu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, California 94304, USA
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Hu Z, Shen WJ, Kraemer FB, Azhar S. MicroRNAs 125a and 455 repress lipoprotein-supported steroidogenesis by targeting scavenger receptor class B type I in steroidogenic cells. Mol Cell Biol 2012; 32:5035-45. [PMID: 23045399 PMCID: PMC3510537 DOI: 10.1128/mcb.01002-12] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 10/03/2012] [Indexed: 12/25/2022] Open
Abstract
We sought to identify and characterize microRNA (miRNAs) that posttranscriptionally regulate the expression of scavenger receptor class B type I (SR-BI) and SR-BI-linked selective high-density lipoprotein (HDL) cholesteryl ester (CE) transport and steroidogenesis. Four miRNAs (miRNA-125a, miRNA-125b, miRNA-145, and miRNA-455) with a potential to regulate SR-BI were identified in silico and validated by quantitative real-time PCR (qRT-PCR), Western blot analysis, and SR-BI 3' untranslated region (UTR) reporter assays. In vitro treatment of primary rat granulosa cells and MLTC-1 cells with cyclic AMP (cAMP) or in vivo treatment of rat adrenals with adrenocorticotropic hormone (ACTH) decreased the expression of miRNA-125a, miRNA-125b, and miRNA-455 and reciprocally increased SR-BI expression. Using luciferase constructs containing the 3' untranslated region of SR-BI combined with miRNA overexpression and mutagenesis, we have provided evidence that steroidogenic SR-BI is a direct target of miRNA-125a and miRNA-455. Moreover, the transfection of Leydig tumor cells with precursor miRNA 125a (pre-miRNA-125a) or pre-miRNA-455 resulted in the suppression of SR-BI at both the transcript and protein levels and reduced selective HDL CE uptake and HDL-stimulated progesterone production. Transfection of liver Hepa 1-6 cells with pre-miRNA-125a significantly reduced SR-BI expression and its selective transport function. In contrast, overexpression of miRNA-145 did not affect SR-BI expression or selective HDL CE uptake mediated by SR-BI in steroidogenic cell lines. These data suggest that a trophic hormone and cAMP inversely regulate the expression of SR-BI and miRNA-125a and miRNA-455 in steroidogenic tissues/cells and that both miRNA-125a and miRNA-455, by targeting steroidogenic SR-BI, negatively regulate selective HDL CE uptake and HDL CE-supported steroid hormone production.
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Affiliation(s)
- Zhigang Hu
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California, USA
- Division of Endocrinology
| | - Wen-Jun Shen
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California, USA
- Division of Endocrinology
| | - Fredric B. Kraemer
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California, USA
- Division of Endocrinology
| | - Salman Azhar
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California, USA
- Division of Gastroenterology and Hepatology, Stanford University, Stanford, California, USA
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50
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Okumura-Noji K, Miura Y, Lu R, Asai K, Ohta N, Brindley PJ, Yokoyama S. CD36-related protein in Schistosoma japonicum: candidate mediator of selective cholesteryl ester uptake from high-density lipoprotein for egg maturation. FASEB J 2012. [PMID: 23195036 DOI: 10.1096/fj.12-219816] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Familial cholesteryl ester transfer protein (CETP) deficiency is more common in some East Asian populations than elsewhere, suggesting the possibility of a selective advantage of this genetic defect against regional infectious diseases. Historically, infection with the Asian blood fluke Schistosoma japonicum has been endemic in these regions, including Japan. We previously reported that eggs of S. japonicum require cholesteryl ester uptake from normal high-density lipoprotein (HDL) but not from CETP-deficient HDL for their maturation to miracidia, a critical step of the hepatic pathogenesis of schistosomiasis. Herein we show that cholesteryl ester uptake is selective from HDL, and identified CD36-related protein (CD36RP) as a candidate to mediate the reaction. CD36RP was cloned from the adult and the egg developmental stages of S. japonicum, with 1880 bp encoding 506 amino acid residues exhibiting the CD36 domains and two transmembrane regions. Using antibodies against recombinant peptides representing the potential extracellular domains of CD36RP, Western blotting detected a protein with a molecular mass of 82 kDa in the particulate fraction of the adult parasite cells, which was reduced to 62 kDa after N-glycanase treatment. The extracellular domain peptide bound human HDL, as established by immunoblots following nondenaturing gel electrophoresis. Antibodies against the extracellular domain suppressed HDL cholesteryl ester uptake and maturation of the eggs in vitro. CD36RP is a candidate receptor on eggs of S. japonicum that facilitates uptake of HDL cholesteryl ester necessary for egg embryonation and maturation.
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Affiliation(s)
- Kuniko Okumura-Noji
- Nutritional Health Science Research Centre and Food and Nutritional Sciences, Chubu University, Kasugai 487-8501, Japan
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