1
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Robert J, Osto E, von Eckardstein A. The Endothelium Is Both a Target and a Barrier of HDL's Protective Functions. Cells 2021; 10:1041. [PMID: 33924941 PMCID: PMC8146309 DOI: 10.3390/cells10051041] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/19/2021] [Accepted: 04/26/2021] [Indexed: 12/11/2022] Open
Abstract
The vascular endothelium serves as a barrier between the intravascular and extravascular compartments. High-density lipoproteins (HDL) have two kinds of interactions with this barrier. First, bloodborne HDL must pass the endothelium to access extravascular tissues, for example the arterial wall or the brain, to mediate cholesterol efflux from macrophages and other cells or exert other functions. To complete reverse cholesterol transport, HDL must even pass the endothelium a second time to re-enter circulation via the lymphatics. Transendothelial HDL transport is a regulated process involving scavenger receptor SR-BI, endothelial lipase, and ATP binding cassette transporters A1 and G1. Second, HDL helps to maintain the integrity of the endothelial barrier by (i) promoting junction closure as well as (ii) repair by stimulating the proliferation and migration of endothelial cells and their progenitor cells, and by preventing (iii) loss of glycocalix, (iv) apoptosis, as well as (v) transmigration of inflammatory cells. Additional vasoprotective functions of HDL include (vi) the induction of nitric oxide (NO) production and (vii) the inhibition of reactive oxygen species (ROS) production. These vasoprotective functions are exerted by the interactions of HDL particles with SR-BI as well as specific agonists carried by HDL, notably sphingosine-1-phophate (S1P), with their specific cellular counterparts, e.g., S1P receptors. Various diseases modify the protein and lipid composition and thereby the endothelial functionality of HDL. Thorough understanding of the structure-function relationships underlying the multiple interactions of HDL with endothelial cells is expected to elucidate new targets and strategies for the treatment or prevention of various diseases.
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Affiliation(s)
| | | | - Arnold von Eckardstein
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, 8091 Zurich, Switzerland; (J.R.); (E.O.)
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2
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Jang E, Robert J, Rohrer L, von Eckardstein A, Lee WL. Transendothelial transport of lipoproteins. Atherosclerosis 2020; 315:111-125. [PMID: 33032832 DOI: 10.1016/j.atherosclerosis.2020.09.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 02/06/2023]
Abstract
The accumulation of low-density lipoproteins (LDL) in the arterial wall plays a pivotal role in the initiation and pathogenesis of atherosclerosis. Conversely, the removal of cholesterol from the intima by cholesterol efflux to high density lipoproteins (HDL) and subsequent reverse cholesterol transport shall confer protection against atherosclerosis. To reach the subendothelial space, both LDL and HDL must cross the intact endothelium. Traditionally, this transit is explained by passive filtration. This dogma has been challenged by the identification of several rate-limiting factors namely scavenger receptor SR-BI, activin like kinase 1, and caveolin-1 for LDL as well as SR-BI, ATP binding cassette transporter G1, and endothelial lipase for HDL. In addition, estradiol, vascular endothelial growth factor, interleukins 6 and 17, purinergic signals, and sphingosine-1-phosphate were found to regulate transendothelial transport of either LDL or HDL. Thorough understanding of transendothelial lipoprotein transport is expected to elucidate new therapeutic targets for the treatment or prevention of atherosclerotic cardiovascular disease and the development of strategies for the local delivery of drugs or diagnostic tracers into diseased tissues including atherosclerotic lesions.
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Affiliation(s)
- Erika Jang
- Keenan Centre for Biomedical Research, St. Michael's Hospital, Toronto, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Canada
| | - Jerome Robert
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Switzerland
| | - Lucia Rohrer
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Switzerland
| | - Arnold von Eckardstein
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Switzerland.
| | - Warren L Lee
- Keenan Centre for Biomedical Research, St. Michael's Hospital, Toronto, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Canada; Interdepartmental Division of Critical Care, Department of Medicine, University of Toronto, Canada; Department of Biochemistry, University of Toronto, Canada; Institute of Medical Science, University of Toronto, Canada.
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3
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Moessinger C, Nilsson I, Muhl L, Zeitelhofer M, Heller Sahlgren B, Skogsberg J, Eriksson U. VEGF-B signaling impairs endothelial glucose transcytosis by decreasing membrane cholesterol content. EMBO Rep 2020; 21:e49343. [PMID: 32449307 PMCID: PMC7332976 DOI: 10.15252/embr.201949343] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Revised: 04/07/2020] [Accepted: 04/21/2020] [Indexed: 01/03/2023] Open
Abstract
Regulation of endothelial nutrient transport is poorly understood. Vascular endothelial growth factor B (VEGF‐B) signaling in endothelial cells promotes uptake and transcytosis of fatty acids from the bloodstream to the underlying tissue, advancing pathological lipid accumulation and lipotoxicity in diabetic complications. Here, we demonstrate that VEGF‐B limits endothelial glucose transport independent of fatty acid uptake. Specifically, VEGF‐B signaling impairs recycling of low‐density lipoprotein receptor (LDLR) to the plasma membrane, leading to reduced cholesterol uptake and membrane cholesterol loading. Reduced cholesterol levels in the membrane leads to a decrease in glucose transporter 1 (GLUT1)‐dependent endothelial glucose uptake. Inhibiting VEGF‐B in vivo reconstitutes membrane cholesterol levels and restores glucose uptake, which is of particular relevance for conditions involving insulin resistance and diabetic complications. In summary, our study reveals a mechanism whereby VEGF‐B regulates endothelial nutrient uptake and highlights the impact of membrane cholesterol for regulation of endothelial glucose transport.
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Affiliation(s)
- Christine Moessinger
- Vascular Biology Division, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Ingrid Nilsson
- Vascular Biology Division, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Lars Muhl
- Vascular Biology Division, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Manuel Zeitelhofer
- Vascular Biology Division, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Benjamin Heller Sahlgren
- Vascular Biology Division, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Josefin Skogsberg
- Vascular Biology Division, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
| | - Ulf Eriksson
- Vascular Biology Division, Department of Medical Biochemistry and Biophysics, Karolinska Institute, Stockholm, Sweden
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4
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Cardner M, Yalcinkaya M, Goetze S, Luca E, Balaz M, Hunjadi M, Hartung J, Shemet A, Kränkel N, Radosavljevic S, Keel M, Othman A, Karsai G, Hornemann T, Claassen M, Liebisch G, Carreira E, Ritsch A, Landmesser U, Krützfeldt J, Wolfrum C, Wollscheid B, Beerenwinkel N, Rohrer L, von Eckardstein A. Structure-function relationships of HDL in diabetes and coronary heart disease. JCI Insight 2020; 5:131491. [PMID: 31830004 PMCID: PMC7030825 DOI: 10.1172/jci.insight.131491] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 12/04/2019] [Indexed: 12/24/2022] Open
Abstract
High-density lipoproteins (HDL) contain hundreds of lipid species and proteins and exert many potentially vasoprotective and antidiabetogenic activities on cells. To resolve structure-function-disease relationships of HDL, we characterized HDL of 51 healthy subjects and 98 patients with diabetes (T2DM), coronary heart disease (CHD), or both for protein and lipid composition, as well as functionality in 5 cell types. The integration of 40 clinical characteristics, 34 nuclear magnetic resonance (NMR) features, 182 proteins, 227 lipid species, and 12 functional read-outs by high-dimensional statistical modeling revealed, first, that CHD and T2DM are associated with different changes of HDL in size distribution, protein and lipid composition, and function. Second, different cellular functions of HDL are weakly correlated with each other and determined by different structural components. Cholesterol efflux capacity (CEC) was no proxy of other functions. Third, 3 potentially novel determinants of HDL function were identified and validated by the use of artificially reconstituted HDL, namely the sphingadienine-based sphingomyelin SM 42:3 and glycosylphosphatidylinositol-phospholipase D1 for the ability of HDL to inhibit starvation-induced apoptosis of human aortic endothelial cells and apolipoprotein F for the ability of HDL to promote maximal respiration of brown adipocytes.
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Affiliation(s)
- Mathias Cardner
- Department of Biosystems Science and Engineering, Swiss Federal Institute of Technology in Zurich (ETH Zurich), Basel, Switzerland
- Swiss Institute of Bioinformatics (SIB), Basel, Switzerland
| | - Mustafa Yalcinkaya
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
| | - Sandra Goetze
- Department of Health Sciences and Technology and
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Edlira Luca
- Department of Diabetology and Endocrinology, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
| | | | - Monika Hunjadi
- Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Johannes Hartung
- Department of Cardiology, University Medicine Charité Berlin, Berlin, Germany
| | | | - Nicolle Kränkel
- Department of Cardiology, University Medicine Charité Berlin, Berlin, Germany
| | - Silvija Radosavljevic
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
| | - Michaela Keel
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
| | - Alaa Othman
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
| | - Gergely Karsai
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
| | - Thorsten Hornemann
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
| | - Manfred Claassen
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
- Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Gerhard Liebisch
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Regensburg, Regensburg, Germany
| | | | - Andreas Ritsch
- Department of Internal Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Ulf Landmesser
- Department of Cardiology, University Medicine Charité Berlin, Berlin, Germany
| | - Jan Krützfeldt
- Department of Diabetology and Endocrinology, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
| | | | - Bernd Wollscheid
- Department of Health Sciences and Technology and
- Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Niko Beerenwinkel
- Department of Biosystems Science and Engineering, Swiss Federal Institute of Technology in Zurich (ETH Zurich), Basel, Switzerland
- Swiss Institute of Bioinformatics (SIB), Basel, Switzerland
| | - Lucia Rohrer
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
| | - Arnold von Eckardstein
- Institute of Clinical Chemistry, University of Zurich and University Hospital of Zurich, Zurich, Switzerland
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5
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Yalcinkaya M, Kerksiek A, Gebert K, Annema W, Sibler R, Radosavljevic S, Lütjohann D, Rohrer L, von Eckardstein A. HDL inhibits endoplasmic reticulum stress-induced apoptosis of pancreatic β-cells in vitro by activation of Smoothened. J Lipid Res 2020; 61:492-504. [PMID: 31907205 DOI: 10.1194/jlr.ra119000509] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/18/2019] [Indexed: 01/20/2023] Open
Abstract
Loss of pancreatic β-cell mass and function as a result of sustained ER stress is a core step in the pathogenesis of diabetes mellitus type 2. The complex control of β-cells and insulin production involves hedgehog (Hh) signaling pathways as well as cholesterol-mediated effects. In fact, data from studies in humans and animal models suggest that HDL protects against the development of diabetes through inhibition of ER stress and β-cell apoptosis. We investigated the mechanism by which HDL inhibits ER stress and apoptosis induced by thapsigargin, a sarco/ER Ca2+-ATPase inhibitor, in β-cells of a rat insulinoma cell line, INS1e. We further explored effects on the Hh signaling receptor Smoothened (SMO) with pharmacologic agonists and inhibitors. Interference with sterol synthesis or efflux enhanced β-cell apoptosis and abrogated the anti-apoptotic activity of HDL. During ER stress, HDL facilitated the efflux of specific oxysterols, including 24-hydroxycholesterol (OHC). Supplementation of reconstituted HDL with 24-OHC enhanced and, in cells lacking ABCG1 or the 24-OHC synthesizing enzyme CYP46A1, restored the protective activity of HDL. Inhibition of SMO countered the beneficial effects of HDL and also LDL, and SMO agonists decreased β-cell apoptosis in the absence of ABCG1 or CYP46A1. The translocation of the SMO-activated transcription factor glioma-associated oncogene GLI-1 was inhibited by ER stress but restored by both HDL and 24-OHC. In conclusion, the protective effect of HDL to counter ER stress and β-cell death involves the transport, generation, and mobilization of oxysterols for activation of the Hh signaling receptor SMO.
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Affiliation(s)
- Mustafa Yalcinkaya
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland
| | - Anja Kerksiek
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Katrin Gebert
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland
| | - Wijtske Annema
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland
| | - Rahel Sibler
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland
| | - Silvija Radosavljevic
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Lucia Rohrer
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland
| | - Arnold von Eckardstein
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland
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6
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Zanoni P, Velagapudi S, Yalcinkaya M, Rohrer L, von Eckardstein A. Endocytosis of lipoproteins. Atherosclerosis 2018; 275:273-295. [PMID: 29980055 DOI: 10.1016/j.atherosclerosis.2018.06.881] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/04/2018] [Accepted: 06/22/2018] [Indexed: 02/06/2023]
Abstract
During their metabolism, all lipoproteins undergo endocytosis, either to be degraded intracellularly, for example in hepatocytes or macrophages, or to be re-secreted, for example in the course of transcytosis by endothelial cells. Moreover, there are several examples of internalized lipoproteins sequestered intracellularly, possibly to exert intracellular functions, for example the cytolysis of trypanosoma. Endocytosis and the subsequent intracellular itinerary of lipoproteins hence are key areas for understanding the regulation of plasma lipid levels as well as the biological functions of lipoproteins. Indeed, the identification of the low-density lipoprotein (LDL)-receptor and the unraveling of its transcriptional regulation led to the elucidation of familial hypercholesterolemia as well as to the development of statins, the most successful therapeutics for lowering of cholesterol levels and risk of atherosclerotic cardiovascular diseases. Novel limiting factors of intracellular trafficking of LDL and the LDL receptor continue to be discovered and to provide drug targets such as PCSK9. Surprisingly, the receptors mediating endocytosis of high-density lipoproteins or lipoprotein(a) are still a matter of controversy or even new discovery. Finally, the receptors and mechanisms, which mediate the uptake of lipoproteins into non-degrading intracellular itineraries for re-secretion (transcytosis, retroendocytosis), storage, or execution of intracellular functions, are largely unknown.
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Affiliation(s)
- Paolo Zanoni
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Srividya Velagapudi
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Mustafa Yalcinkaya
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Lucia Rohrer
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Arnold von Eckardstein
- Institute for Clinical Chemistry, University and University Hospital Zurich, Zurich, Switzerland; Centre for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
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7
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Zannis VI, Su S, Fotakis P. Role of apolipoproteins, ABCA1 and LCAT in the biogenesis of normal and aberrant high density lipoproteins. J Biomed Res 2017; 31:471. [PMID: 29109329 PMCID: PMC6307667 DOI: 10.7555/jbr.31.20160082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/30/2016] [Indexed: 12/28/2022] Open
Abstract
In this review, we focus on the pathway of biogenesis of HDL, the essential role of apoA-I, ATP binding cassette transporter A1 (ABCA1), and lecithin: cholesterol acyltransferase (LCAT) in the formation of plasma HDL; the generation of aberrant forms of HDL containing mutant apoA-I forms and the role of apoA-IV and apoE in the formation of distinct HDL subpopulations. The biogenesis of HDL requires functional interactions of the ABCA1 with apoA-I (and to a lesser extent with apoE and apoA-IV) and subsequent interactions of the nascent HDL species thus formed with LCAT. Mutations in apoA-I, ABCA1 and LCAT either prevent or impair the formation of HDL and may also affect the functionality of the HDL species formed. Emphasis is placed on three categories of apoA-I mutations. The first category describes a unique bio-engineered apoA-I mutation that disrupts interactions between apoA-I and ABCA1 and generates aberrant preβ HDL subpopulations that cannot be converted efficiently to α subpopulations by LCAT. The second category describes natural and bio-engineered apoA-I mutations that generate preβ and small size α4 HDL subpopulations, and are associated with low plasma HDL levels. These phenotypes can be corrected by excess LCAT. The third category describes bio-engineered apoA-I mutations that induce hypertriglyceridemia that can be corrected by excess lipoprotein lipase and also have defective maturation of HDL. The HDL phenotypes described here may serve in the future for diagnosis, prognoses and potential treatment of abnormalities that affect the biogenesis and functionality of HDL.
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Affiliation(s)
- Vassilis I. Zannis
- . Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
- . Department University of Crete, School of Medicine, Heraklion, Crete, Greece
| | - Shi Su
- . Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
| | - Panagiotis Fotakis
- . Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118, USA
- . Department University of Crete, School of Medicine, Heraklion, Crete, Greece
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8
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Kober AC, Manavalan APC, Tam-Amersdorfer C, Holmér A, Saeed A, Fanaee-Danesh E, Zandl M, Albrecher NM, Björkhem I, Kostner GM, Dahlbäck B, Panzenboeck U. Implications of cerebrovascular ATP-binding cassette transporter G1 (ABCG1) and apolipoprotein M in cholesterol transport at the blood-brain barrier. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1862:573-588. [PMID: 28315462 DOI: 10.1016/j.bbalip.2017.03.003] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 03/07/2017] [Accepted: 03/12/2017] [Indexed: 02/03/2023]
Abstract
Impaired cholesterol/lipoprotein metabolism is linked to neurodegenerative diseases such as Alzheimer's disease (AD). Cerebral cholesterol homeostasis is maintained by the highly efficient blood-brain barrier (BBB) and flux of the oxysterols 24(S)-hydroxycholesterol and 27-hydroxycholesterol, potent liver-X-receptor (LXR) activators. HDL and their apolipoproteins are crucial for cerebral lipid transfer, and loss of ATP binding cassette transporters (ABC)G1 and G4 results in toxic accumulation of oxysterols in the brain. The HDL-associated apolipoprotein (apo)M is positively correlated with pre-β HDL formation in plasma; its presence and function in the brain was thus far unknown. Using an in vitro model of the BBB, we examined expression, regulation, and functions of ABCG1, ABCG4, and apoM in primary porcine brain capillary endothelial cells (pBCEC). RT Q-PCR analyses and immunoblotting revealed that in addition to ABCA1 and scavenger receptor, class B, type I (SR-BI), pBCEC express high levels of ABCG1, which was up-regulated by LXR activation. Immunofluorescent staining, site-specific biotinylation and immunoprecipitation revealed that ABCG1 is localized both to early and late endosomes and on apical and basolateral plasma membranes. Using siRNA interference to silence ABCG1 (by 50%) reduced HDL-mediated [3H]-cholesterol efflux (by 50%) but did not reduce [3H]-24(S)-hydroxycholesterol efflux. In addition to apoA-I, pBCEC express and secrete apoM mainly to the basolateral (brain) compartment. HDL enhanced expression and secretion of apoM by pBCEC, apoM-enriched HDL promoted cellular cholesterol efflux more efficiently than apoM-free HDL, while apoM-silencing diminished cellular cholesterol release. We suggest that ABCG1 and apoM are centrally involved in regulation of cholesterol metabolism/turnover at the BBB.
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Affiliation(s)
| | | | | | - Andreas Holmér
- Department of Translational Medicine, University Hospital SUS, Malmö, Lund University, Sweden
| | - Ahmed Saeed
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, Karolinska Institute Huddinge, Huddinge, Sweden
| | - Elham Fanaee-Danesh
- Institute of Pathophysiology and Immunology, Medical University of Graz, Graz, Austria
| | - Martina Zandl
- Institute of Pathophysiology and Immunology, Medical University of Graz, Graz, Austria
| | | | - Ingemar Björkhem
- Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska University Hospital, Karolinska Institute Huddinge, Huddinge, Sweden
| | - Gerhard M Kostner
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Björn Dahlbäck
- Department of Translational Medicine, University Hospital SUS, Malmö, Lund University, Sweden
| | - Ute Panzenboeck
- Institute of Pathophysiology and Immunology, Medical University of Graz, Graz, Austria.
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9
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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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10
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Perisa D, Rohrer L, Kaech A, von Eckardstein A. Itinerary of high density lipoproteins in endothelial cells. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:98-107. [DOI: 10.1016/j.bbalip.2015.11.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 11/02/2015] [Accepted: 11/09/2015] [Indexed: 01/30/2023]
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11
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Nguyen SD, Maaninka K, Lappalainen J, Nurmi K, Metso J, Öörni K, Navab M, Fogelman AM, Jauhiainen M, Lee-Rueckert M, Kovanen PT. Carboxyl-Terminal Cleavage of Apolipoprotein A-I by Human Mast Cell Chymase Impairs Its Anti-Inflammatory Properties. Arterioscler Thromb Vasc Biol 2015; 36:274-84. [PMID: 26681753 PMCID: PMC4725095 DOI: 10.1161/atvbaha.115.306827] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 11/18/2015] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Apolipoprotein A-I (apoA-I) has been shown to possess several atheroprotective functions, including inhibition of inflammation. Protease-secreting activated mast cells reside in human atherosclerotic lesions. Here we investigated the effects of the neutral proteases released by activated mast cells on the anti-inflammatory properties of apoA-I. APPROACH AND RESULTS Activation of human mast cells triggered the release of granule-associated proteases chymase, tryptase, cathepsin G, carboxypeptidase A, and granzyme B. Among them, chymase cleaved apoA-I with the greatest efficiency and generated C-terminally truncated apoA-I, which failed to bind with high affinity to human coronary artery endothelial cells. In tumor necrosis factor-α-activated human coronary artery endothelial cells, the chymase-cleaved apoA-I was unable to suppress nuclear factor-κB-dependent upregulation of vascular cell adhesion molecule-1 (VCAM-1) and to block THP-1 cells from adhering to and transmigrating across the human coronary artery endothelial cells. Chymase-cleaved apoA-I also had an impaired ability to downregulate the expression of tumor necrosis factor-α, interleukin-1β, interleukin-6, and interleukin-8 in lipopolysaccharide-activated GM-CSF (granulocyte-macrophage colony-stimulating factor)- and M-CSF (macrophage colony-stimulating factor)-differentiated human macrophage foam cells and to inhibit reactive oxygen species formation in PMA (phorbol 12-myristate 13-acetate)-activated human neutrophils. Importantly, chymase-cleaved apoA-I showed reduced ability to inhibit lipopolysaccharide-induced inflammation in vivo in mice. Treatment with chymase blocked the ability of the apoA-I mimetic peptide L-4F, but not of the protease-resistant D-4F, to inhibit proinflammatory gene expression in activated human coronary artery endothelial cells and macrophage foam cells and to prevent reactive oxygen species formation in activated neutrophils. CONCLUSIONS The findings identify C-terminal cleavage of apoA-I by human mast cell chymase as a novel mechanism leading to loss of its anti-inflammatory functions. When targeting inflamed protease-rich atherosclerotic lesions with apoA-I, infusions of protease-resistant apoA-I might be the appropriate approach.
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Affiliation(s)
- Su Duy Nguyen
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Katariina Maaninka
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Jani Lappalainen
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Katariina Nurmi
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Jari Metso
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Katariina Öörni
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Mohamad Navab
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Alan M Fogelman
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Matti Jauhiainen
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Miriam Lee-Rueckert
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.)
| | - Petri T Kovanen
- From the Wihuri Research Institute, Biomedicum Helsinki, Helsinki, Finland (S.D.N., K.M., J.L., K.N., K.Ö., M.L.-R., P.T.K.); National Institute for Health and Welfare, Genomics and Biomarkers Unit, Biomedicum Helsinki, Helsinki, Finland (J.M., M.J.); and Division of Cardiology, Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles (M.N., A.M.F.).
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12
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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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13
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Karlsson H, Kontush A, James RW. Functionality of HDL: antioxidation and detoxifying effects. Handb Exp Pharmacol 2015; 224:207-228. [PMID: 25522989 DOI: 10.1007/978-3-319-09665-0_5] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
High-density lipoproteins (HDL) are complexes of multiple talents, some of which have only recently been recognised but all of which are under active investigation. Clinical interest initially arose from their amply demonstrated role in atherosclerotic disease with their consequent designation as a major cardiovascular disease (CVD) risk factor. However, interest is no longer confined to vascular tissues, with the reports of impacts of the lipoprotein on pancreatic, renal and nervous tissues, amongst other possible targets. The ever-widening scope of HDL talents also encompasses environmental hazards, including infectious agents and environmental toxins. In almost all cases, HDL would appear to have a beneficial impact on health. It raises the intriguing question of whether these various talents emanate from a basic ancestral function to protect the cell.The following chapter will illustrate and review our current understanding of some of the functions attributed to HDL. The first section will look at the antioxidative functions of HDL and possible mechanisms that are involved. The second section will focus specifically on paraoxonase-1 (PON1), which appears to bridge the divide between the two HDL functions discussed herein. This will lead into the final section dealing with HDL as a detoxifying agent protecting against exposure to environmental pathogens and other toxins.
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Affiliation(s)
- Helen Karlsson
- Occupational and Environmental Medicine, Heart Medical Centre, County Council of Ostergotland, Linkoping University, SE-58185, Linkoping, Sweden,
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14
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Sutter I, Park R, Othman A, Rohrer L, Hornemann T, Stoffel M, Devuyst O, von Eckardstein A. Apolipoprotein M modulates erythrocyte efflux and tubular reabsorption of sphingosine-1-phosphate. J Lipid Res 2014; 55:1730-7. [PMID: 24950692 DOI: 10.1194/jlr.m050021] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Indexed: 01/04/2023] Open
Abstract
Sphingosine-1-phosphate (S1P) mediates several cytoprotective functions of HDL. apoM acts as a S1P binding protein in HDL. Erythrocytes are the major source of S1P in plasma. After glomerular filtration, apoM is endocytosed in the proximal renal tubules. Human or murine HDL elicited time- and dose-dependent S1P efflux from erythrocytes. Compared with HDL of wild-type (wt) mice, S1P efflux was enhanced in the presence of HDL from apoM transgenic mice, but not diminished in the presence of HDL from apoM knockout (Apom(-/-)) mice. Artificially reconstituted and apoM-free HDL also effectively induced S1P efflux from erythrocytes. S1P and apoM were not measurable in the urine of wt mice. Apom(-/-) mice excreted significant amounts of S1P. apoM was detected in the urine of mice with defective tubular endocytosis because of knockout of the LDL receptor-related protein, chloride-proton exchanger ClC-5 (Clcn5(-/-)), or the cysteine transporter cystinosin. Urinary levels of S1P were significantly elevated in Clcn5(-/-) mice. In contrast to Apom(-/-) mice, these mice showed normal plasma concentrations for apoM and S1P. In conclusion, HDL facilitates S1P efflux from erythrocytes by both apoM-dependent and apoM-independent mechanisms. Moreover, apoM facilitates tubular reabsorption of S1P from the urine, however, with no impact on S1P plasma concentrations.
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Affiliation(s)
- Iryna Sutter
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland; Competence Center for Integrated Human Physiology and Institute of Physiology
| | - Rebekka Park
- ETH Zurich, Zurich, Switzerland; and Competence Center for Systems Physiology and Metabolic Diseases ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Alaa Othman
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland; Competence Center for Integrated Human Physiology ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Lucia Rohrer
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland; Competence Center for Integrated Human Physiology and Institute of Physiology
| | - Thorsten Hornemann
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland; Competence Center for Integrated Human Physiology and Institute of Physiology
| | - Markus Stoffel
- ETH Zurich, Zurich, Switzerland; and Competence Center for Systems Physiology and Metabolic Diseases ETH Zurich and University of Zurich, Zurich, Switzerland
| | - Olivier Devuyst
- and Institute of Physiology University of Zurich, Zurich, Switzerland; Institute of Molecular Health Sciences
| | - Arnold von Eckardstein
- Institute of Clinical Chemistry, University and University Hospital of Zurich, Zurich, Switzerland; Competence Center for Integrated Human Physiology and Institute of Physiology ETH Zurich and University of Zurich, Zurich, Switzerland
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15
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Randolph GJ, Miller NE. Lymphatic transport of high-density lipoproteins and chylomicrons. J Clin Invest 2014; 124:929-35. [PMID: 24590278 DOI: 10.1172/jci71610] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The life cycles of VLDLs and most LDLs occur within plasma. By contrast, the role of HDLs in cholesterol transport from cells requires that they readily gain access to and function within interstitial fluid. Studies of lymph derived from skin, connective tissue, and adipose tissue have demonstrated that particles as large as HDLs require transport through lymphatics to return to the bloodstream during reverse cholesterol transport. Targeting HDL for therapeutic purposes will require understanding its biology in the extravascular compartment, within the interstitium and lymph, in health and disease, and we herein review the processes that mediate the transport of HDLs and chylomicrons through the lymphatic vasculature.
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16
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Song K, Han Y, Zhang L, Liu G, Yang P, Cheng X, Bu L, Sheng H, Qu S. ATP Synthase β-Chain Overexpression in SR-BI Knockout Mice Increases HDL Uptake and Reduces Plasma HDL Level. Int J Endocrinol 2014; 2014:356432. [PMID: 25114680 PMCID: PMC4120797 DOI: 10.1155/2014/356432] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 06/03/2014] [Accepted: 06/07/2014] [Indexed: 11/23/2022] Open
Abstract
HDL cholesterol is known to be inversely correlated with cardiovascular disease due to its diverse antiatherogenic functions. SR-BI mediates the selective uptake of HDL-C. SR-BI knockout diminishes but does not completely block the transport of HDL; other receptors may be involved. Ectopic ATP synthase β-chain in hepatocytes has been previously characterized as an apoA-I receptor, triggering HDL internalization. This study was undertaken to identify the overexpression of ectopic ATP synthase β-chain on DIL-HDL uptake in primary hepatocytes in vitro and on plasma HDL levels in SR-BI knockout mice. Human ATP synthase β-chain cDNA was delivered to the mouse liver by adenovirus and GFP adenovirus as control. The adenovirus-mediated overexpression of β-chain was identified at both mRNA and protein levels on mice liver and validated by its increasing of DiL-HDL uptake in primary hepatocytes. In response to hepatic overexpression of β-chain, plasma HDL-C levels and cholesterol were reduced in SR-BI knockout mice, compared with the control. The present data suggest that ATP synthase β-chain can serve as the endocytic receptor of HDL, and its overexpression can reduce plasma HDL-C.
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Affiliation(s)
- Kexiu Song
- Department of Endocrinology, Shanghai Tenth People's Hospital, Tongji University, 301 Middle Yanchang Road, Shanghai 200072, China
| | - Yingchun Han
- Institute of Cardiovascular Science, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Linhua Zhang
- Department of Endocrinology, Shanghai Tenth People's Hospital, Tongji University, 301 Middle Yanchang Road, Shanghai 200072, China
| | - Guoqing Liu
- Institute of Cardiovascular Science, Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Peking University Health Science Center, Beijing 100191, China
| | - Peng Yang
- Department of Endocrinology, Shanghai Tenth People's Hospital, Tongji University, 301 Middle Yanchang Road, Shanghai 200072, China
| | - Xiaoyun Cheng
- Department of Endocrinology, Shanghai Tenth People's Hospital, Tongji University, 301 Middle Yanchang Road, Shanghai 200072, China
| | - Le Bu
- Department of Endocrinology, Shanghai Tenth People's Hospital, Tongji University, 301 Middle Yanchang Road, Shanghai 200072, China
| | - Hui Sheng
- Department of Endocrinology, Shanghai Tenth People's Hospital, Tongji University, 301 Middle Yanchang Road, Shanghai 200072, China
- Nanjing Medical University, Nanjing 210029, China
| | - Shen Qu
- Department of Endocrinology, Shanghai Tenth People's Hospital, Tongji University, 301 Middle Yanchang Road, Shanghai 200072, China
- Nanjing Medical University, Nanjing 210029, China
- *Shen Qu:
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17
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Puyal J, Pétremand J, Dubuis G, Rummel C, Widmann C. HDLs protect the MIN6 insulinoma cell line against tunicamycin-induced apoptosis without inhibiting ER stress and without restoring ER functionality. Mol Cell Endocrinol 2013; 381:291-301. [PMID: 23994023 DOI: 10.1016/j.mce.2013.08.016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 08/22/2013] [Accepted: 08/22/2013] [Indexed: 12/31/2022]
Abstract
HDLs protect pancreatic beta cells against apoptosis induced by several endoplasmic reticulum (ER) stressors, including thapsigargin, cyclopiazonic acid, palmitate and insulin over-expression. This protection is mediated by the capacity of HDLs to maintain proper ER morphology and ER functions such as protein folding and trafficking. Here, we identified a distinct mode of protection exerted by HDLs in beta cells challenged with tunicamycin (TM), a protein glycosylation inhibitor inducing ER stress. HDLs were found to inhibit apoptosis induced by TM in the MIN6 insulinoma cell line and this correlated with the maintenance of a normal ER morphology. Surprisingly however, this protective response was neither associated with a significant ER stress reduction, nor with restoration of protein folding and trafficking in the ER. These data indicate that HDLs can use at least two mechanisms to protect beta cells against ER stressors. One that relies on the maintenance of ER function and one that operates independently of ER function modulation. The capacity of HDLs to activate several anti-apoptotic pathways in beta cells may explain their ability to efficiently protect these cells against a variety of insults.
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Affiliation(s)
- Julien Puyal
- Department of Fundamental Neurosciences, University of Lausanne, Switzerland
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18
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Fotakis P, Tiniakou I, Kateifides AK, Gkolfinopoulou C, Chroni A, Stratikos E, Zannis VI, Kardassis D. Significance of the hydrophobic residues 225-230 of apoA-I for the biogenesis of HDL. J Lipid Res 2013; 54:3293-302. [PMID: 24123812 DOI: 10.1194/jlr.m043489] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
We studied the significance of four hydrophobic residues within the 225-230 region of apoA-I on its structure and functions and their contribution to the biogenesis of HDL. Adenovirus-mediated gene transfer of an apoA-I[F225A/V227A/F229A/L230A] mutant in apoA-I⁻/⁻ mice decreased plasma cholesterol, HDL cholesterol, and apoA-I levels. When expressed in apoA-I⁻/⁻ × apoE⁻/⁻ mice, approximately 40% of the mutant apoA-I as well as mouse apoA-IV and apoB-48 appeared in the VLDL/IDL/LDL. In both mouse models, the apoA-I mutant generated small spherical particles of pre-β- and α4-HDL mobility. Coexpression of the apoA-I mutant and LCAT increased and shifted the-HDL cholesterol peak toward lower densities, created normal αHDL subpopulations, and generated spherical-HDL particles. Biophysical analyses suggested that the apoA-I[225-230] mutations led to a more compact folding that may limit the conformational flexibility of the protein. The mutations also reduced the ability of apoA-I to promote ABCA1-mediated cholesterol efflux and to activate LCAT to 31% and 66%, respectively, of the WT control. Overall, the apoA-I[225-230] mutations inhibited the biogenesis of-HDL and led to the accumulation of immature pre-β- and α4-HDL particles, a phenotype that could be corrected by administration of LCAT.
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Affiliation(s)
- Panagiotis Fotakis
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118
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19
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Fotakis P, Kateifides AK, Gkolfinopoulou C, Georgiadou D, Beck M, Gründler K, Chroni A, Stratikos E, Kardassis D, Zannis VI. Role of the hydrophobic and charged residues in the 218-226 region of apoA-I in the biogenesis of HDL. J Lipid Res 2013; 54:3281-92. [PMID: 23990662 DOI: 10.1194/jlr.m038356] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the significance of hydrophobic and charged residues 218-226 on the structure and functions of apoA-I and their contribution to the biogenesis of HDL. Adenovirus-mediated gene transfer of apoA-I[L218A/L219A/V221A/L222A] in apoA-I⁻/⁻ mice decreased plasma cholesterol and apoA-I levels to 15% of wild-type (WT) control mice and generated pre-β- and α4-HDL particles. In apoA-I⁻/⁻ × apoE⁻/⁻ mice, the same mutant formed few discoidal and pre-β-HDL particles that could not be converted to mature α-HDL particles by excess LCAT. Expression of the apoA-I[E223A/K226A] mutant in apoA-I⁻/⁻ mice caused lesser but discrete alterations in the HDL phenotype. The apoA-I[218-222] and apoA-I[E223A/K226A] mutants had 20% and normal capacity, respectively, to promote ABCA1-mediated cholesterol efflux. Both mutants had ∼65% of normal capacity to activate LCAT in vitro. Biophysical analyses suggested that both mutants affected in a distinct manner the structural integrity and plasticity of apoA-I that is necessary for normal functions. We conclude that the alteration of the hydrophobic 218-222 residues of apoA-I disrupts apoA-I/ABCA1 interactions and promotes the generation of defective pre-β particles that fail to mature into α-HDL subpopulations, thus resulting in low plasma apoA-I and HDL. Alterations of the charged 223, 226 residues caused milder but discrete changes in HDL phenotype.
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Affiliation(s)
- Panagiotis Fotakis
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, MA 02118
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20
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Oda MN, Budamagunta MS, Borja MS, Petrlova J, Voss JC, Lagerstedt JO. The secondary structure of apolipoprotein A-I on 9.6-nm reconstituted high-density lipoprotein determined by EPR spectroscopy. FEBS J 2013; 280:3416-24. [PMID: 23668303 PMCID: PMC3906832 DOI: 10.1111/febs.12334] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 05/09/2013] [Accepted: 05/09/2013] [Indexed: 01/09/2023]
Abstract
Apolipoprotein A-I (ApoA-I) is the major protein component of high-density lipoprotein (HDL), and is critical for maintenance of cholesterol homeostasis. During reverse cholesterol transport, HDL transitions between an array of subclasses, differing in size and composition. This process requires ApoA-I to adapt to changes in the shape of the HDL particle, transiting from an apolipoprotein to a myriad of HDL subclass-specific conformations. Changes in ApoA-I structure cause alterations in HDL-specific enzyme and receptor-binding properties, and thereby direct the HDL particle through the reverse cholesterol transport pathway. In this study, we used site-directed spin label spectroscopy to examine the conformational details of the ApoA-I central domain on HDL. The motional dynamics and accessibility to hydrophobic/hydrophilic relaxation agents of ApoA-I residues 99–163 on 9.6-nm reconstituted HDL was analyzed by EPR. In previous analyses, we examined residues 6–98 and 164–238 (of ApoA-I's 243 residues), and combining these findings with the current results, we have generated a full-length map of the backbone structure of reconstituted HDL-associated ApoA-I. Remarkably, given that the majority of ApoA-I's length is composed of amphipathic helices, we have identified nonhelical residues, specifically the presence of a β-strand (residues 149–157). The significance of these nonhelical residues is discussed, along with the other features, in the context of ApoA-I function in contrast to recent models derived by other methods.
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Affiliation(s)
- Michael N Oda
- Children's Hospital Oakland Research Institute, CA, USA
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21
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Chong URW, Abdul-Rahman PS, Abdul-Aziz A, Hashim OH, Mat Junit S. Tamarindus indica extract alters release of alpha enolase, apolipoprotein A-I, transthyretin and Rab GDP dissociation inhibitor beta from HepG2 cells. PLoS One 2012; 7:e39476. [PMID: 22724021 PMCID: PMC3378544 DOI: 10.1371/journal.pone.0039476] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 05/25/2012] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND The plasma cholesterol and triacylglycerol lowering effects of Tamarindus indica extract have been previously described. We have also shown that the methanol extract of T. indica fruit pulp altered the expression of lipid-associated genes including ABCG5 and APOAI in HepG2 cells. In the present study, effects of the same extract on the release of proteins from the cells were investigated using the proteomics approach. METHODOLOGY/PRINCIPAL FINDINGS When culture media of HepG2 cells grown in the absence and presence of the methanol extract of T. indica fruit pulp were subjected to 2-dimensional gel electrophoresis, the expression of seven proteins was found to be significantly different (p<0.03125). Five of the spots were subsequently identified as alpha enolase (ENO1), transthyretin (TTR), apolipoprotein A-I (ApoA-I; two isoforms), and rab GDP dissociation inhibitor beta (GDI-2). A functional network of lipid metabolism, molecular transport and small molecule biochemistry that interconnects the three latter proteins with the interactomes was identified using the Ingenuity Pathways Analysis software. CONCLUSION/SIGNIFICANCE The methanol extract of T. indica fruit pulp altered the release of ENO1, ApoA-I, TTR and GDI-2 from HepG2 cells. Our results provide support on the effect of T. indica extract on cellular lipid metabolism, particularly that of cholesterol.
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Affiliation(s)
- Ursula Rho Wan Chong
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Puteri Shafinaz Abdul-Rahman
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- University of Malaya Centre for Proteomics Research, Medical Biotechnology Laboratory, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Azlina Abdul-Aziz
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- University of Malaya Centre for Proteomics Research, Medical Biotechnology Laboratory, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Onn Haji Hashim
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- University of Malaya Centre for Proteomics Research, Medical Biotechnology Laboratory, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Sarni Mat Junit
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- University of Malaya Centre for Proteomics Research, Medical Biotechnology Laboratory, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
- * E-mail:
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22
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Abstract
PURPOSE OF REVIEW HDL and their main apolipoprotein (apo) constituent apoA-I are antiatherogenic. This has been predominantly attributed to the ability of apoA-I/HDL to efflux cholesterol from macrophages within atherosclerotic plaques. It is now emerging that a number of the protective properties of HDL may be due to their effects on the endothelium. RECENT FINDINGS In addition to their well characterized anti-inflammatory and antioxidant effects, apoA-I and HDL regulate several other key biological pathways known to preserve endothelial function and promote vascular repair. The ATP-binding cassette (ABC) transporters ABCA1 and ABCG1, and the scavenger receptor B type 1 mediate multiple intracellular signaling pathways as well as the efflux of cholesterol and/or oxysterols in response to apoA-I/HDL. Although cholesterol efflux triggers a host of signaling events in endothelial cells, there is evidence that some of the beneficial actions of HDL may occur independently of efflux. SUMMARY Current data suggest that in endothelial cells ABCA1 and ABCG1 mediate the activation of intracellular signaling pathways primarily through the efflux of cholesterol and oxysterols to apoA-I/HDL. Interaction between HDL and scavenger receptor B type 1 initiates the greatest number of known signaling pathways and there is evidence that some of these are activated independent of efflux.
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Affiliation(s)
- Hamish C Prosser
- Translational Research Group, Heart Research Institute Department of Cardiology, Royal Prince Alfred Hospital Department of Medicine, University of Sydney, Sydney, New South Wales, Australia Immunobiology Unit, Heart Research Institute
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23
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Cavelier C, Ohnsorg PM, Rohrer L, von Eckardstein A. The β-Chain of Cell Surface F
0
F
1
ATPase Modulates ApoA-I and HDL Transcytosis Through Aortic Endothelial Cells. Arterioscler Thromb Vasc Biol 2012; 32:131-9. [DOI: 10.1161/atvbaha.111.238063] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Objective—
Both HDLs and their major protein constituent apolipoprotein A-I (apoA-I) are transported through aortic endothelial cells. The knock-down of the ATP-binding cassette transporters A1 (ABCA1), G1 (ABCG1), and of the scavenger receptor-BI (SR-BI) diminishes but does not completely block the transport of apoA-I or HDL, so that other receptors appear to be involved. The ectopic β-chain of F
0
F
1
ATPase has been previously characterized as an apoA-I receptor, triggering HDL internalization in hepatocytes.
Methods and Results—
The ectopic presence of the β-chain of F
0
F
1
ATPase on the surface of endothelial cells was confirmed by cell surface biotinylation. RNA-interference and the F
0
F
1
ATPase inhibitory peptide IF
1
reduced cell binding of apoA-I but not HDL, as well as association and transendothelial transport of both apoA-I and HDL. Furthermore, apoA-I stimulated F
0
F
1
ATPase catalyzed ATP hydrolysis. The generated ADP as well as apoA-I stimulated the binding, cell association, and internalization of HDL. Both in the presence and absence of ADP inhibition of the purinergic receptor P2Y
12
but not P2Y
1
decreased the cell association of apoA-I and HDL. Coinhibition of β-ATPase and ABCA1 had no additive effects on the cell association and transport of apoA-I. Reduced cell association of HDL by β-ATPase inhibition was not further decreased by additional knock-down of ABCG1 or SR-BI.
Conclusion—
Binding of apoA-I to ectopic F
0
F
1
ATPase triggers the generation of ADP, which via activation of the purinergic receptor P2Y
12
stimulates the uptake and transport of HDL and initially lipid-free apoA-I by endothelial cells.
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Affiliation(s)
- Clara Cavelier
- From the Institute of Clinical Chemistry (C.C., P.M.O., L.R., A.v.E.), University and University Hospital Zurich, Zurich, Switzerland; Life Science Zurich PhD Program on Systems Biology of Complex Diseases (P.M.O.), Competence Center for Systems Physiology and Metabolic Diseases (P.M.O., A.v.E.), Swiss Federal Institute of Technology Zurich and University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (L.R., A.v.E.), University of Zurich, Zurich, Switzerland
| | - Pascale M. Ohnsorg
- From the Institute of Clinical Chemistry (C.C., P.M.O., L.R., A.v.E.), University and University Hospital Zurich, Zurich, Switzerland; Life Science Zurich PhD Program on Systems Biology of Complex Diseases (P.M.O.), Competence Center for Systems Physiology and Metabolic Diseases (P.M.O., A.v.E.), Swiss Federal Institute of Technology Zurich and University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (L.R., A.v.E.), University of Zurich, Zurich, Switzerland
| | - Lucia Rohrer
- From the Institute of Clinical Chemistry (C.C., P.M.O., L.R., A.v.E.), University and University Hospital Zurich, Zurich, Switzerland; Life Science Zurich PhD Program on Systems Biology of Complex Diseases (P.M.O.), Competence Center for Systems Physiology and Metabolic Diseases (P.M.O., A.v.E.), Swiss Federal Institute of Technology Zurich and University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (L.R., A.v.E.), University of Zurich, Zurich, Switzerland
| | - Arnold von Eckardstein
- From the Institute of Clinical Chemistry (C.C., P.M.O., L.R., A.v.E.), University and University Hospital Zurich, Zurich, Switzerland; Life Science Zurich PhD Program on Systems Biology of Complex Diseases (P.M.O.), Competence Center for Systems Physiology and Metabolic Diseases (P.M.O., A.v.E.), Swiss Federal Institute of Technology Zurich and University of Zurich, Zurich, Switzerland; Zurich Center for Integrative Human Physiology (L.R., A.v.E.), University of Zurich, Zurich, Switzerland
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Ohnsorg PM, Mary JL, Rohrer L, Pech M, Fingerle J, von Eckardstein A. Trimerized apolipoprotein A-I (TripA) forms lipoproteins, activates lecithin:cholesterol acyltransferase, elicits lipid efflux, and is transported through aortic endothelial cells. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1811:1115-23. [DOI: 10.1016/j.bbalip.2011.09.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2011] [Revised: 08/11/2011] [Accepted: 09/02/2011] [Indexed: 02/03/2023]
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