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Boehm-Cagan A, Bar R, Harats D, Shaish A, Levkovitz H, Bielicki JK, Johansson JO, Michaelson DM. Differential Effects of apoE4 and Activation of ABCA1 on Brain and Plasma Lipoproteins. PLoS One 2016; 11:e0166195. [PMID: 27824936 PMCID: PMC5100931 DOI: 10.1371/journal.pone.0166195] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Accepted: 10/24/2016] [Indexed: 01/28/2023] Open
Abstract
Apolipoprotein E4 (apoE4), the leading genetic risk factor for Alzheimer's disease (AD), is less lipidated compared to the most common and AD-benign allele, apoE3. We have recently shown that i.p. injections of the ATP-binding cassette A1 (ABCA1) agonist peptide CS-6253 to apoE mice reverse the hypolipidation of apoE4 and the associated brain pathology and behavioral deficits. While in the brain apoE is the main cholesterol transporter, in the periphery apoE and apoA-I both serve as the major cholesterol transporters. We presently investigated the extent to which apoE genotype and CS-6253 treatment to apoE3 and apoE4-targeted replacement mice affects the plasma levels and lipid particle distribution of apoE, and those of plasma and brain apoA-I and apoJ. This revealed that plasma levels of apoE4 were lower and eluted faster following FPLC than plasma apoE3. Treatment with CS-6253 increased the levels of plasma apoE4 and rendered the elution profile of apoE4 similar to that of apoE3. Similarly, the levels of plasma apoA-I were lower in the apoE4 mice compared to apoE3 mice, and this effect was partially reversed by CS-6253. Conversely, the levels of apoA-I in the brain which were higher in the apoE4 mice, were unaffected by CS-6253. The plasma levels of apoJ were higher in apoE4 mice than apoE3 mice and this effect was abolished by CS-6253. Similar but less pronounced effects were obtained in the brain. In conclusion, these results suggest that apoE4 affects the levels of apoA-I and apoJ and that the anti-apoE4 beneficial effects of CS-6253 may be related to both central and peripheral mechanisms.
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Affiliation(s)
- Anat Boehm-Cagan
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Roni Bar
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Dror Harats
- Sackler Faculty of Medicine, Tel-Aviv University, Tel Aviv 6997801, Israel
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel-Hashomer 5265601, Israel
| | - Aviv Shaish
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel-Hashomer 5265601, Israel
| | - Hana Levkovitz
- The Bert W. Strassburger Lipid Center, Sheba Medical Center, Tel-Hashomer 5265601, Israel
| | - John K. Bielicki
- Life Sciences Division, Lawrence Berkeley National Laboratory, University of California, Berkeley, California, 94720, United States of America
| | - Jan O. Johansson
- Artery Therapeutics, Inc. San Ramon, California, United States of America
| | - Daniel M. Michaelson
- The Department of Neurobiology, The George S. Wise Faculty of Life Sciences, The Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- * E-mail:
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2
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Gardner LA, Levin MC. Importance of Apolipoprotein A-I in Multiple Sclerosis. Front Pharmacol 2015; 6:278. [PMID: 26635608 PMCID: PMC4654019 DOI: 10.3389/fphar.2015.00278] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Accepted: 11/04/2015] [Indexed: 12/12/2022] Open
Abstract
Jean-Martin Charcot has first described multiple sclerosis (MS) as a disease of the central nervous system (CNS) over a century ago. MS remains incurable today, and treatment options are limited to disease modifying drugs. Over the years, significant advances in understanding disease pathology have been made in autoimmune and neurodegenerative components. Despite the fact that brain is the most lipid rich organ in human body, the importance of lipid metabolism has not been extensively studied in this disorder. In MS, the CNS is under attack by a person's own immune system. Autoantigens and autoantibodies are known to cause devastation of myelin through up regulation of T-cells and cytokines, which penetrate through the blood-brain barrier to cause inflammation and myelin destruction. The anti-inflammatory role of high-density lipoproteins (HDLs) has been implicated in a plethora of biological processes: vasodilation, immunity to infection, oxidation, inflammation, and apoptosis. However, it is not known what role HDL plays in neurological function and myelin repair in MS. Understanding of lipid metabolism in the CNS and in the periphery might unveil new therapeutic targets and explain the partial success of some existing MS therapies.
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Affiliation(s)
- Lidia A. Gardner
- Research Service, VA Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Michael C. Levin
- Research Service, VA Medical Center, Memphis, TN, USA
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, USA
- Neuroscience Institute, University of Tennessee Health Science Center, Memphis, TN, USA
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Dafnis I, Metso J, Zannis VI, Jauhiainen M, Chroni A. Influence of Isoforms and Carboxyl-Terminal Truncations on the Capacity of Apolipoprotein E To Associate with and Activate Phospholipid Transfer Protein. Biochemistry 2015; 54:5856-66. [PMID: 26337529 DOI: 10.1021/acs.biochem.5b00681] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Phospholipid transfer protein (PLTP), a main protein in lipid and lipoprotein metabolism, exists in high-activity (HA-PLTP) and low-activity (LA-PLTP) forms in human plasma. Proper phospholipid transfer activity of PLTP is modulated by interactions with various apolipoproteins (apo) including apoE. The domains of apoE involved in interactions with PLTP are not known. Here we analyzed the capacity of recombinant apoE isoforms and apoE4 mutants with progressive carboxyl-terminal deletions to bind to and activate HA-PLTP and LA-PLTP. Our analyses demonstrated that lipid-free apoE isoforms bind to both HA-PLTP and LA-PLTP, resulting in phospholipid transfer activation, with apoE3 inducing the highest PLTP activation. The isoform-specific differences in apoE/PLTP binding and PLTP activation were abolished following apoE lipidation. Lipid-free apoE4[Δ(260-299)], apoE4[Δ(230-299)], apoE4[Δ(203-299)], and apoE4[Δ(186-299)] activated HA-PLTP by 120-160% compared to full-length apoE4. Lipid-free apoE4[Δ(186-299)] also activated LA-PLTP by 85% compared to full-length apoE4. All lipidated truncated apoE4 forms displayed a similar effect on HA-PLTP and LA-PLTP activity as full-length apoE4. Strikingly, lipid-free or lipidated full-length apoE4 and apoE4[Δ(186-299)] demonstrated similar binding capacity to LA-PLTP and HA-PLTP. Biophysical studies showed that the carboxyl-terminal truncations of apoE4 resulted in small changes of the structural or thermodynamic properties of lipidated apoE4, that were much less pronounced compared to changes observed previously for lipid-free apoE4. Overall, our findings show an isoform-dependent binding to and activation of PLTP by lipid-free apoE. Furthermore, the domain of apoE4 required for PLTP activation resides within its amino-terminal 1-185 region. The apoE/PLTP interactions can be modulated by the conformation and lipidation state of apoE.
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Affiliation(s)
- Ioannis Dafnis
- Institute of Biosciences and Applications, National Center for Scientific Research "Demokritos" , Agia Paraskevi 15310, Athens, Greece
| | - Jari Metso
- Genomics and Biomarkers Unit, Biomedicum, National Institute for Health and Welfare , Helsinki 00290, Finland
| | - Vassilis I Zannis
- Departments of Medicine and Biochemistry, Molecular Genetics, Whitaker Cardiovascular Institute, Boston University School of Medicine , Boston, Massachusetts 02118, United States
| | - Matti Jauhiainen
- Genomics and Biomarkers Unit, Biomedicum, National Institute for Health and Welfare , Helsinki 00290, Finland
| | - Angeliki Chroni
- Institute of Biosciences and Applications, National Center for Scientific Research "Demokritos" , Agia Paraskevi 15310, Athens, Greece
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Chirackal Manavalan AP, Kober A, Metso J, Lang I, Becker T, Hasslitzer K, Zandl M, Fanaee-Danesh E, Pippal JB, Sachdev V, Kratky D, Stefulj J, Jauhiainen M, Panzenboeck U. Phospholipid transfer protein is expressed in cerebrovascular endothelial cells and involved in high density lipoprotein biogenesis and remodeling at the blood-brain barrier. J Biol Chem 2014; 289:4683-98. [PMID: 24369175 PMCID: PMC3931031 DOI: 10.1074/jbc.m113.499129] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Phospholipid transfer protein (PLTP) is a key protein involved in biogenesis and remodeling of plasma HDL. Several neuroprotective properties have been ascribed to HDL. We reported earlier that liver X receptor (LXR) activation promotes cellular cholesterol efflux and formation of HDL-like particles in an established in vitro model of the blood-brain barrier (BBB) consisting of primary porcine brain capillary endothelial cells (pBCEC). Here, we report PLTP synthesis, regulation, and its key role in HDL metabolism at the BBB. We demonstrate that PLTP is highly expressed and secreted by pBCEC. In a polarized in vitro model mimicking the BBB, pBCEC secreted phospholipid-transfer active PLTP preferentially to the basolateral ("brain parenchymal") compartment. PLTP expression levels and phospholipid transfer activity were enhanced (up to 2.5-fold) by LXR activation using 24(S)-hydroxycholesterol (a cerebral cholesterol metabolite) or TO901317 (a synthetic LXR agonist). TO901317 administration elevated PLTP activity in BCEC from C57/BL6 mice. Preincubation of HDL3 with human plasma-derived active PLTP resulted in the formation of smaller and larger HDL particles and enhanced the capacity of the generated HDL particles to remove cholesterol from pBCEC by up to 3-fold. Pre-β-HDL, detected by two-dimensional crossed immunoelectrophoresis, was generated from HDL3 in pBCEC-derived supernatants, and their generation was markedly enhanced (1.9-fold) upon LXR activation. Furthermore, RNA interference-mediated PLTP silencing (up to 75%) reduced both apoA-I-dependent (67%) and HDL3-dependent (30%) cholesterol efflux from pBCEC. Based on these findings, we propose that PLTP is actively involved in lipid transfer, cholesterol efflux, HDL genesis, and remodeling at the BBB.
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Affiliation(s)
| | | | - Jari Metso
- the National Institute for Health and Welfare, Biomedicum, FI-00290 Helsinki, Finland, and
| | - Ingrid Lang
- Institute of Cell Biology, Histology, and Embryology, and
| | | | | | - Martina Zandl
- From the Institute of Pathophysiology and Immunology
| | | | | | - Vinay Sachdev
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria
| | - Jasminka Stefulj
- the Department of Molecular Biology, Ruder Boskovic Institute, 10000 Zagreb, Croatia
| | - Matti Jauhiainen
- the National Institute for Health and Welfare, Biomedicum, FI-00290 Helsinki, Finland, and
| | - Ute Panzenboeck
- From the Institute of Pathophysiology and Immunology, , To whom correspondence should be addressed: Institute of Pathophysiology and Immunology, Medical University of Graz, Heinrichstrasse 31a, 8010 Graz, Austria. Tel.: 43-316-3801955; Fax: 43-316-3809640; E-mail:
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5
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Niculescu LS, Sanda GM, Sima AV. HDL inhibits endoplasmic reticulum stress by stimulating apoE and CETP secretion from lipid-loaded macrophages. Biochem Biophys Res Commun 2013; 434:173-8. [PMID: 23537656 DOI: 10.1016/j.bbrc.2013.03.050] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2013] [Accepted: 03/11/2013] [Indexed: 11/30/2022]
Abstract
The role of HDL in the modulation of endoplasmic reticulum (ER) stress in macrophage-derived foam cells is not completely understood. Therefore, we aimed to investigate whether HDL may inhibit ER stress in correlation with the secretion of apoE and CETP from lipid-loaded macrophages. To this purpose, THP-1 macrophages were loaded with lipids by incubation with human oxidized LDL (oxLDL) and then exposed to human HDL3. ER stress signaling markers, protein kinase/Jun-amino-terminal kinase (SAPK/JNK p54/p46) and eukaryotic initiation factor-2α (eIF2α), as well as the secreted apoE and CETP, were evaluated by immunoblot analysis. Out of the many different bioactive lipids of oxLDL, we tested the effect of 9-hydroxy-octadecadienoic acid (9-HODE) and 4-hydroxynonenal (4-HNE) on ER stress. Tunicamycin was used as positive control for ER stress induction. Results showed that oxLDL, 9-HODE and 4-HNE induce ER stress in human macrophages by activation of eIF-2α and SAPK/JNK (p54/p46) signaling pathways. OxLDL stimulated apoE and CETP secretion, while tunicamycin determined a reduction of the secreted apoE and CETP, both in control and lipid-loaded macrophages. The addition of HDL3 to the culture medium of tunicamycin-treated cells induced: (i) the reduction of ER stress, expressed as decreased levels of eIF-2α and SAPK/JNK, and (ii) a partial recovery of the secreted apoE and CETP levels in lipid-loaded macrophages. These data suggest a new mechanism by which HDL3 diminish ER stress and stimulate cholesterol efflux from lipid-loaded macrophages.
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Affiliation(s)
- Loredan S Niculescu
- Institute of Cellular Biology and Pathology N. Simionescu of the Romanian Academy, Bucharest, Romania
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Miller NE, Olszewski WL, Hattori H, Miller IP, Kujiraoka T, Oka T, Iwasaki T, Nanjee MN. Lipoprotein remodeling generates lipid-poor apolipoprotein A-I particles in human interstitial fluid. Am J Physiol Endocrinol Metab 2013; 304:E321-8. [PMID: 23233540 PMCID: PMC3566430 DOI: 10.1152/ajpendo.00324.2012] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although much is known about the remodeling of high density lipoproteins (HDLs) in blood, there is no information on that in interstitial fluid, where it might have a major impact on the transport of cholesterol from cells. We incubated plasma and afferent (prenodal) peripheral lymph from 10 healthy men at 37°C in vitro and followed the changes in HDL subclasses by nondenaturing two-dimensional crossed immunoelectrophoresis and size-exclusion chromatography. In plasma, there was always initially a net conversion of small pre-β-HDLs to cholesteryl ester (CE)-rich α-HDLs. By contrast, in lymph, there was only net production of pre-β-HDLs from α-HDLs. Endogenous cholesterol esterification rate, cholesteryl ester transfer protein (CETP) concentration, CE transfer activity, phospholipid transfer protein (PLTP) concentration, and phospholipid transfer activity in lymph averaged 5.0, 10.4, 8.2, 25.0, and 82.0% of those in plasma, respectively (all P < 0.02). Lymph PLTP concentration, but not phospholipid transfer activity, was positively correlated with that in plasma (r = +0.63, P = 0.05). Mean PLTP-specific activity was 3.5-fold greater in lymph, reflecting a greater proportion of the high-activity form of PLTP. These findings suggest that cholesterol esterification rate and PLTP specific activity are differentially regulated in the two matrices in accordance with the requirements of reverse cholesterol transport, generating lipid-poor pre-β-HDLs in the extracellular matrix for cholesterol uptake from neighboring cells and converting pre-β-HDLs to α-HDLs in plasma for the delivery of cell-derived CEs to the liver.
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7
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Audet A, Côté N, Couture C, Bossé Y, Després JP, Pibarot P, Mathieu P. Amyloid substance within stenotic aortic valves promotes mineralization. Histopathology 2012; 61:610-9. [DOI: 10.1111/j.1365-2559.2012.04265.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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8
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Niculescu LS, Robciuc MR, Sanda GM, Sima AV. Apolipoprotein A–I stimulates cholesteryl ester transfer protein and apolipoprotein E secretion from lipid-loaded macrophages; the role of NF-κB and PKA signaling pathways. Biochem Biophys Res Commun 2011; 415:497-502. [DOI: 10.1016/j.bbrc.2011.10.101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 10/21/2011] [Indexed: 11/28/2022]
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9
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Cheung MC, Wolfbauer G, Albers JJ. Different phospholipid transfer protein complexes contribute to the variation in plasma PLTP specific activity. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1811:343-7. [PMID: 21303701 DOI: 10.1016/j.bbalip.2011.02.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 01/15/2011] [Accepted: 02/01/2011] [Indexed: 11/28/2022]
Abstract
Phospholipid transfer protein (PLTP) facilitates the transfer of phospholipids among lipoproteins. Over half of the PLTP in human plasma has been found to have little phospholipid transfer activity (inactive PLTP). We recently observed that plasma PLTP specific activity is inversely correlated with high-density lipoprotein (HDL) level and particle size in healthy adults. The purpose of this study was to evaluate the factors that contribute to the variation in plasma PLTP specific activity. Analysis of the specific activity of PLTP complexes in nine plasma samples from healthy adults revealed two clusters of inactive PLTP complexes with mean molecular weights (MW) of 342kDa and 146kDa. The large and small inactive PLTP complexes represented 52±8% (range 39-63%) and 8±8% (range 1-28%) of the plasma PLTP, respectively. Active PLTP complexes had a mean MW of 207kDa and constituted 40±6% (range 33-50%) of the plasma PLTP. The specific activity of active PLTP varied from 16 to 32μmol/μg/h. These data demonstrate for the first time the existence of small inactive plasma PLTP complexes. Variation in the amount of the two clusters of inactive PLTP complexes and the specific activity of the active PLTP contribute to the variation in plasma PLTP specific activity.
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Affiliation(s)
- Marian C Cheung
- Division of Metabolism, Endocrinology and Nutrition, Northwest Lipid Metabolism and Diabetes Research Laboratories, Department of Medicine, University of Washington, Seattle, WA 98109-4517, USA
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