1
|
Abstract
In the view of progressively aging human population and increased occurrence of dysmetabolic disorders, such as diabetes mellitus, cognitive impairment becomes a major threat to the national health. To date, the molecular mechanisms of cognitive dysfunction are partially described for diabetes and diseases of different nature, such as Alzheimer disease or Parkinson disease. The emergence of data pointing towards pleotropic effects of hypoglycaemic medicines indicates involvement of their targets in pathogenesis of cognitive impairment. We are aiming here to review available data on the most widely used hypoglycaemic drug, glibenclamide and find possible relationship of its targets to the pathogenesis of cognitive impairment.
Collapse
Affiliation(s)
- Alexander Zubov
- I.P. Pavlov Department of Physiology, Federal State Budget Scientific Institution "Institute of Experimental Medicine", St. Petersburg, Russia
| | - Zamira Muruzheva
- I.P. Pavlov Department of Physiology, Federal State Budget Scientific Institution "Institute of Experimental Medicine", St. Petersburg, Russia
| | - Maria Tikhomirova
- I.P. Pavlov Department of Physiology, Federal State Budget Scientific Institution "Institute of Experimental Medicine", St. Petersburg, Russia
| | - Marina Karpenko
- I.P. Pavlov Department of Physiology, Federal State Budget Scientific Institution "Institute of Experimental Medicine", St. Petersburg, Russia
| |
Collapse
|
2
|
Shinozaki Y, Leung A, Namekata K, Saitoh S, Nguyen HB, Takeda A, Danjo Y, Morizawa YM, Shigetomi E, Sano F, Yoshioka N, Takebayashi H, Ohno N, Segawa T, Miyake K, Kashiwagi K, Harada T, Ohnuma SI, Koizumi S. Astrocytic dysfunction induced by ABCA1 deficiency causes optic neuropathy. SCIENCE ADVANCES 2022; 8:eabq1081. [PMID: 36332025 PMCID: PMC9635836 DOI: 10.1126/sciadv.abq1081] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 09/16/2022] [Indexed: 06/16/2023]
Abstract
Astrocyte abnormalities have received great attention for their association with various diseases in the brain but not so much in the eye. Recent independent genome-wide association studies of glaucoma, optic neuropathy characterized by retinal ganglion cell (RGC) degeneration, and vision loss found that single-nucleotide polymorphisms near the ABCA1 locus were common risk factors. Here, we show that Abca1 loss in retinal astrocytes causes glaucoma-like optic neuropathy in aged mice. ABCA1 was highly expressed in retinal astrocytes in mice. Thus, we generated macroglia-specific Abca1-deficient mice (Glia-KO) and found that aged Glia-KO mice had RGC degeneration and ocular dysfunction without affected intraocular pressure, a conventional risk factor for glaucoma. Single-cell RNA sequencing revealed that Abca1 deficiency in aged Glia-KO mice caused astrocyte-triggered inflammation and increased the susceptibility of certain RGC clusters to excitotoxicity. Together, astrocytes play a pivotal role in eye diseases, and loss of ABCA1 in astrocytes causes glaucoma-like neuropathy.
Collapse
Affiliation(s)
- Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
- GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Alex Leung
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Sei Saitoh
- Section of Electron Microscopy, Supportive Center for Brain Research, National Institute for Physiological Sciences (NIPS), Aichi, Japan
- Department of Anatomy II and Cell Biology, Fujita Health University School of Medicine, Aichi, Japan
| | - Huy Bang Nguyen
- Division of Neurobiology and Bioinformatics, NIPS, Aichi, Japan
- Department of Anatomy, Faculty of Medicine, University of Medicine and Pharmacy (UMP), Ho Chi Minh City, Vietnam
| | - Akiko Takeda
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Yosuke Danjo
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Yosuke M. Morizawa
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Eiji Shigetomi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
- GLIA Center, University of Yamanashi, Yamanashi, Japan
| | - Fumikazu Sano
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Nozomu Yoshioka
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Hirohide Takebayashi
- Division of Neurobiology and Anatomy, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan
| | - Nobuhiko Ohno
- Division of Ultrastructural Research, NIPS, Aichi, Japan
- Department of Anatomy, Jichi Medical University, Tochigi, Japan
| | - Takahiro Segawa
- Center for Life Science Research, University of Yamanashi, Yamanashi, Japan
| | - Kunio Miyake
- Department of Health Sciences, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Kenji Kashiwagi
- Department of Ophthalmology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Shin-ichi Ohnuma
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, Japan
- GLIA Center, University of Yamanashi, Yamanashi, Japan
| |
Collapse
|
3
|
Kotlyarov S, Kotlyarova A. The Importance of the Plasma Membrane in Atherogenesis. MEMBRANES 2022; 12:1036. [PMID: 36363591 PMCID: PMC9698587 DOI: 10.3390/membranes12111036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 10/20/2022] [Accepted: 10/21/2022] [Indexed: 06/16/2023]
Abstract
Atherosclerotic cardiovascular diseases are an important medical problem due to their high prevalence, impact on quality of life and prognosis. The pathogenesis of atherosclerosis is an urgent medical and social problem, the solution of which may improve the quality of diagnosis and treatment of patients. Atherosclerosis is a complex chain of events, which proceeds over many years and in which many cells in the bloodstream and the vascular wall are involved. A growing body of evidence suggests that there are complex, closely linked molecular mechanisms that occur in the plasma membranes of cells involved in atherogenesis. Lipid transport, innate immune system receptor function, and hemodynamic regulation are linked to plasma membranes and their biophysical properties. A better understanding of these interrelationships will improve diagnostic quality and treatment efficacy.
Collapse
Affiliation(s)
- Stanislav Kotlyarov
- Department of Nursing, Ryazan State Medical University, 390026 Ryazan, Russia
| | - Anna Kotlyarova
- Department of Pharmacy Management and Economics, Ryazan State Medical University, 390026 Ryazan, Russia
| |
Collapse
|
4
|
Juhl AD, Wüstner D. Pathways and Mechanisms of Cellular Cholesterol Efflux-Insight From Imaging. Front Cell Dev Biol 2022; 10:834408. [PMID: 35300409 PMCID: PMC8920967 DOI: 10.3389/fcell.2022.834408] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 02/04/2022] [Indexed: 12/24/2022] Open
Abstract
Cholesterol is an essential molecule in cellular membranes, but too much cholesterol can be toxic. Therefore, mammalian cells have developed complex mechanisms to remove excess cholesterol. In this review article, we discuss what is known about such efflux pathways including a discussion of reverse cholesterol transport and formation of high-density lipoprotein, the function of ABC transporters and other sterol efflux proteins, and we highlight their role in human diseases. Attention is paid to the biophysical principles governing efflux of sterols from cells. We also discuss recent evidence for cholesterol efflux by the release of exosomes, microvesicles, and migrasomes. The role of the endo-lysosomal network, lipophagy, and selected lysosomal transporters, such as Niemann Pick type C proteins in cholesterol export from cells is elucidated. Since oxysterols are important regulators of cellular cholesterol efflux, their formation, trafficking, and secretion are described briefly. In addition to discussing results obtained with traditional biochemical methods, focus is on studies that use established and novel bioimaging approaches to obtain insight into cholesterol efflux pathways, including fluorescence and electron microscopy, atomic force microscopy, X-ray tomography as well as mass spectrometry imaging.
Collapse
Affiliation(s)
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, PhyLife, Physical Life Sciences, University of Southern Denmark, Odense, Denmark
| |
Collapse
|
5
|
Chen W, Li L, Wang J, Zhang R, Zhang T, Wu Y, Wang S, Xing D. The ABCA1-efferocytosis axis: A new strategy to protect against atherosclerosis. Clin Chim Acta 2021; 518:1-8. [PMID: 33741356 DOI: 10.1016/j.cca.2021.02.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/13/2022]
Abstract
Atherosclerosis, a disease process characterized by lipid accumulation and inflammation, is the main cause of coronary heart disease (CHD) and myocardial infarction (MI). Efferocytosis involves the clearance of apoptotic cells by phagocytes. Successful engulfment triggers the release of anti-inflammatory cytokines to suppress atherosclerosis. ABCA1 is a key mediator of cholesterol efflux to apoA-I for the generation of HDL-C in reverse cholesterol transport (RCT). Intriguingly, ABCA1 promotes not only cholesterol efflux but also efferocytosis. ABCA1 promotes efferocytosis by regulating the release of "find-me" ligands, including LPC, and the exposure, release, and expression of "eat-me" ligands, including PtdSer, ANXA1, ANXA5, MEGF10, and GULP1. ABCA1 has a pathway similar to TG2, which is an "eat-me" ligand. ABCA1 has the highest known homology to ABCA7, which controls efferocytosis as the engulfment and processing ligand. In addition, ABCA1 can form several regulatory feedback axes with ANXA1, MEGF10, GULP1, TNFα, and IL-6. Therefore, ABCA1 is the central factor that links cholesterol efflux and apoptotic cell clearance. Several drugs have been studied or approved for apoptotic cell clearance, such as CD47 antibody and PD1-/PD-L1 antibody. In this article, we review the role and mechanism of action of ABCA1 in efferocytosis and focus on new insights into the ABCA1-efferocytosis axis and its potential as a novel therapeutic target in atherosclerosis.
Collapse
Affiliation(s)
- Wujun Chen
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao Cancer Institute, Qingdao, Shandong 266071, China
| | - Lu Li
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao Cancer Institute, Qingdao, Shandong 266071, China
| | - Jie Wang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao Cancer Institute, Qingdao, Shandong 266071, China
| | - Renshuai Zhang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao Cancer Institute, Qingdao, Shandong 266071, China
| | - Tingting Zhang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao Cancer Institute, Qingdao, Shandong 266071, China
| | - Yudong Wu
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao Cancer Institute, Qingdao, Shandong 266071, China.
| | - Shuai Wang
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao Cancer Institute, Qingdao, Shandong 266071, China; School of Medical Imaging, Radiotherapy Department of Affiliated Hospital, Weifang Medical University, Weifang, Shandong 261053, China.
| | - Dongming Xing
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao University, Qingdao Cancer Institute, Qingdao, Shandong 266071, China; School of Life Sciences, Tsinghua University, Beijing 100084, China.
| |
Collapse
|
6
|
Varga K, Jiang ZJ, Gong LW. Phosphatidylserine is critical for vesicle fission during clathrin-mediated endocytosis. J Neurochem 2019; 152:48-60. [PMID: 31587282 DOI: 10.1111/jnc.14886] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Revised: 09/25/2019] [Accepted: 10/01/2019] [Indexed: 12/11/2022]
Abstract
Phosphatidylserine (PS), a negatively charged phospholipid present predominantly at the inner leaflet of the plasma membrane, has been widely implicated in many cellular processes including membrane trafficking. Along this line, PS has been demonstrated to be important for endocytosis, however, the involved mechanisms remain uncertain. By monitoring clathrin-mediated endocytosis (CME) of single vesicles in mouse chromaffin cells using cell-attached capacitance measurements that offer millisecond time resolution, we demonstrate in the present study that the fission-pore duration is reduced by PS addition, indicating a stimulatory role of PS in regulating the dynamics of vesicle fission during CME. Furthermore, our results show that the PS-mediated effect on the fission-pore duration is Ca2+ -dependent and abolished in the absence of synaptotagmin 1 (Syt1), implying that Syt1 is necessary for the stimulatory role of PS in vesicle fission during CME. Consistently, a Syt1 mutant with a defective PS-Syt1 interaction increases the fission-pore duration. Taken together, our study suggests that PS-Syt1 interaction may be critical in regulating fission dynamics during CME.
Collapse
Affiliation(s)
- Kelly Varga
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.,Department of Biological Sciences, University of North Texas at Dallas, Dallas, Texas, USA
| | - Zhong-Jiao Jiang
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Liang-Wei Gong
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| |
Collapse
|
7
|
Pasello M, Giudice AM, Scotlandi K. The ABC subfamily A transporters: Multifaceted players with incipient potentialities in cancer. Semin Cancer Biol 2019; 60:57-71. [PMID: 31605751 DOI: 10.1016/j.semcancer.2019.10.004] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 09/30/2019] [Accepted: 10/04/2019] [Indexed: 12/12/2022]
Abstract
Overexpression of ATP-binding cassette (ABC) transporters is a cause of drug resistance in a plethora of tumors. More recent evidence indicates additional contribution of these transporters to other processes, such as tumor cell dissemination and metastasis, thereby extending their possible roles in tumor progression. While the role of some ABC transporters, such as ABCB1, ABCC1 and ABCG2, in multidrug resistance is well documented, the mechanisms by which ABC transporters affect the proliferation, differentiation, migration and invasion of cancer cells are still poorly defined and are frequently controversial. This review, summarizes recent advances that highlight the role of subfamily A members in cancer. Emerging evidence highlights the potential value of ABCA members as biomarkers of risk and response in different tumors, but information is disperse and very little is known about their possible mechanisms of action. The only clear evidence is that ABCA members are involved in lipid metabolism and homeostasis. In particular, the relationship between ABCA1 and cholesterol is becoming evident in different fields of biology, including cancer. In parallel, emerging findings indicate that cholesterol, the main component of cell membranes, can influence many physiological and pathological processes, including cell migration, cancer progression and metastasis. This review aims to link the dispersed knowledge regarding the relationship of ABCA members with lipid metabolism and cancer in an effort to stimulate and guide readers to areas that the writers consider to have significant impact and relevant potentialities.
Collapse
Affiliation(s)
- Michela Pasello
- CRS Development of Biomolecular Therapies, Experimental Oncology Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, 40136, Italy.
| | - Anna Maria Giudice
- CRS Development of Biomolecular Therapies, Experimental Oncology Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, 40136, Italy; Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, 40126, Italy
| | - Katia Scotlandi
- CRS Development of Biomolecular Therapies, Experimental Oncology Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, 40136, Italy.
| |
Collapse
|
8
|
Key CCC, Liu M, Kurtz CL, Chung S, Boudyguina E, Dinh TA, Bashore A, Phelan PE, Freedman BI, Osborne TF, Zhu X, Ma L, Sethupathy P, Biddinger SB, Parks JS. Hepatocyte ABCA1 Deletion Impairs Liver Insulin Signaling and Lipogenesis. Cell Rep 2018; 19:2116-2129. [PMID: 28591582 DOI: 10.1016/j.celrep.2017.05.032] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 03/07/2017] [Accepted: 05/09/2017] [Indexed: 10/19/2022] Open
Abstract
Plasma membrane (PM) free cholesterol (FC) is emerging as an important modulator of signal transduction. Here, we show that hepatocyte-specific knockout (HSKO) of the cellular FC exporter, ATP-binding cassette transporter A1 (ABCA1), leads to decreased PM FC content and defective trafficking of lysosomal FC to the PM. Compared with controls, chow-fed HSKO mice had reduced hepatic (1) insulin-stimulated Akt phosphorylation, (2) activation of the lipogenic transcription factor Sterol Regulatory Element Binding Protein (SREBP)-1c, and (3) lipogenic gene expression. Consequently, Western-type diet-fed HSKO mice were protected from steatosis. Surprisingly, HSKO mice had intact glucose metabolism; they showed normal gluconeogenic gene suppression in response to re-feeding and normal glucose and insulin tolerance. We conclude that: (1) ABCA1 maintains optimal hepatocyte PM FC, through intracellular FC trafficking, for efficient insulin signaling; and (2) hepatocyte ABCA1 deletion produces a form of selective insulin resistance so that lipogenesis is suppressed but glucose metabolism remains normal.
Collapse
Affiliation(s)
- Chia-Chi C Key
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Mingxia Liu
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - C Lisa Kurtz
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Soonkyu Chung
- Department of Nutrition and Health Sciences, University of Nebraska, Lincoln, NE 68588, USA
| | - Elena Boudyguina
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Timothy A Dinh
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Alexander Bashore
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Peter E Phelan
- Integrative Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute, Orlando, FL 32827, USA
| | - Barry I Freedman
- Section on Nephrology, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Timothy F Osborne
- Integrative Metabolism Program, Sanford Burnham Prebys Medical Discovery Institute, Orlando, FL 32827, USA
| | - Xuewei Zhu
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Lijun Ma
- Section on Nephrology, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA
| | - Praveen Sethupathy
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Sudha B Biddinger
- Division of Endocrinology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02062, USA
| | - John S Parks
- Section on Molecular Medicine, Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA; Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, NC 27157, USA.
| |
Collapse
|
9
|
Haerian BS, Haerian MS, Roohi A, Mehrad-Majd H. ABCA1 genetic polymorphisms and type 2 diabetes mellitus and its complications. Meta Gene 2017. [DOI: 10.1016/j.mgene.2017.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
|
10
|
van der Mark VA, Ghiboub M, Marsman C, Zhao J, van Dijk R, Hiralall JK, Ho-Mok KS, Castricum Z, de Jonge WJ, Oude Elferink RPJ, Paulusma CC. Phospholipid flippases attenuate LPS-induced TLR4 signaling by mediating endocytic retrieval of Toll-like receptor 4. Cell Mol Life Sci 2016; 74:715-730. [PMID: 27628304 PMCID: PMC5272906 DOI: 10.1007/s00018-016-2360-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 08/31/2016] [Accepted: 09/06/2016] [Indexed: 01/01/2023]
Abstract
P4-ATPases are lipid flippases that catalyze the transport of phospholipids to create membrane phospholipid asymmetry and to initiate the biogenesis of transport vesicles. Here we show, for the first time, that lipid flippases are essential to dampen the inflammatory response and to mediate the endotoxin-induced endocytic retrieval of Toll-like receptor 4 (TLR4) in human macrophages. Depletion of CDC50A, the β-subunit that is crucial for the activity of multiple P4-ATPases, resulted in endotoxin-induced hypersecretion of proinflammatory cytokines, enhanced MAP kinase signaling and constitutive NF-κB activation. In addition, CDC50A-depleted THP-1 macrophages displayed reduced tolerance to endotoxin. Moreover, endotoxin-induced internalization of TLR4 was strongly reduced and coincided with impaired endosomal MyD88-independent signaling. The phenotype of CDC50A-depleted cells was also induced by separate knockdown of two P4-ATPases, namely ATP8B1 and ATP11A. We conclude that lipid flippases are novel elements of the innate immune response that are essential to attenuate the inflammatory response, possibly by mediating endotoxin-induced internalization of TLR4.
Collapse
Affiliation(s)
- Vincent A van der Mark
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Mohammed Ghiboub
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Casper Marsman
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Jing Zhao
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Remco van Dijk
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Johan K Hiralall
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Kam S Ho-Mok
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Zoë Castricum
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Wouter J de Jonge
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Ronald P J Oude Elferink
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands
| | - Coen C Paulusma
- Tytgat Institute for Liver and Intestinal Research, Academic Medical Center, Meibergdreef 69-71, 1105 BK, Amsterdam, The Netherlands.
| |
Collapse
|
11
|
Gulshan K, Brubaker G, Conger H, Wang S, Zhang R, Hazen SL, Smith JD. PI(4,5)P2 Is Translocated by ABCA1 to the Cell Surface Where It Mediates Apolipoprotein A1 Binding and Nascent HDL Assembly. Circ Res 2016; 119:827-38. [PMID: 27514935 DOI: 10.1161/circresaha.116.308856] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 08/11/2016] [Indexed: 12/23/2022]
Abstract
RATIONALE The molecular mechanism by which ATP-binding cassette transporter A1 (ABCA1) mediates cellular binding of apolipoprotein A-I (apoA1) and nascent high-density lipoprotein (HDL) assembly is not well understood. OBJECTIVE To determine the cell surface lipid that mediates apoA1 binding to ABCA1-expressing cells and the role it plays in nascent HDL assembly. METHODS AND RESULTS Using multiple biochemical and biophysical methods, we found that apoA1 binds specifically to phosphatidylinositol (4,5) bis-phosphate (PIP2). Flow cytometry and PIP2 reporter-binding assays demonstrated that ABCA1 led to PIP2 redistribution from the inner to the outer leaflet of the plasma membrane. Enzymatic cleavage of cell surface PIP2 or decreased cellular PIP2 by knockdown of phosphatidylinositol-5-phosphate 4-kinase impaired apoA1 binding and cholesterol efflux to apoA1. PIP2 also increased the spontaneous solubilization of phospholipid liposomes by apoA1. Using site-directed mutagenesis, we found that ABCA1's PIP2 and phosphatidylserine translocase activities are independent from each other. Furthermore, we discovered that PIP2 is effluxed from cells to apoA1, where it is associated with HDL in plasma, and that PIP2 on HDL is taken up by target cells in a scavenger receptor-BI-dependent manner. Mouse plasma PIP2 levels are apoA1 gene dosage-dependent and are >1 μM in apoA1 transgenic mice. CONCLUSIONS ABCA1 has PIP2 floppase activity, which increases cell surface PIP2 levels that mediate apoA1 binding and lipid efflux during nascent HDL assembly. We found that PIP2 itself is effluxed to apoA1 and it circulates on plasma HDL, where it can be taken up via the HDL receptor scavenger receptor-BI.
Collapse
Affiliation(s)
- Kailash Gulshan
- From the Department of Cellular and Molecular Medicine (K.G., G.B., H.C., S.W., R.Z., S.L.H., J.D.S.) and Department of Cardiovascular Medicine (S.L.H., J.D.S.), Cleveland Clinic, OH.
| | - Gregory Brubaker
- From the Department of Cellular and Molecular Medicine (K.G., G.B., H.C., S.W., R.Z., S.L.H., J.D.S.) and Department of Cardiovascular Medicine (S.L.H., J.D.S.), Cleveland Clinic, OH
| | - Heather Conger
- From the Department of Cellular and Molecular Medicine (K.G., G.B., H.C., S.W., R.Z., S.L.H., J.D.S.) and Department of Cardiovascular Medicine (S.L.H., J.D.S.), Cleveland Clinic, OH
| | - Shuhui Wang
- From the Department of Cellular and Molecular Medicine (K.G., G.B., H.C., S.W., R.Z., S.L.H., J.D.S.) and Department of Cardiovascular Medicine (S.L.H., J.D.S.), Cleveland Clinic, OH
| | - Renliang Zhang
- From the Department of Cellular and Molecular Medicine (K.G., G.B., H.C., S.W., R.Z., S.L.H., J.D.S.) and Department of Cardiovascular Medicine (S.L.H., J.D.S.), Cleveland Clinic, OH
| | - Stanley L Hazen
- From the Department of Cellular and Molecular Medicine (K.G., G.B., H.C., S.W., R.Z., S.L.H., J.D.S.) and Department of Cardiovascular Medicine (S.L.H., J.D.S.), Cleveland Clinic, OH
| | - Jonathan D Smith
- From the Department of Cellular and Molecular Medicine (K.G., G.B., H.C., S.W., R.Z., S.L.H., J.D.S.) and Department of Cardiovascular Medicine (S.L.H., J.D.S.), Cleveland Clinic, OH.
| |
Collapse
|
12
|
Wüstner D, Solanko K. How cholesterol interacts with proteins and lipids during its intracellular transport. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1908-26. [DOI: 10.1016/j.bbamem.2015.05.010] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Revised: 04/14/2015] [Accepted: 05/13/2015] [Indexed: 12/13/2022]
|
13
|
Sun Y, Drubin DG. The functions of anionic phospholipids during clathrin-mediated endocytosis site initiation and vesicle formation. J Cell Sci 2012; 125:6157-65. [PMID: 23097040 DOI: 10.1242/jcs.115741] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Anionic phospholipids PI(4,5)P2 and phosphatidylserine (PS) are enriched in the cytosolic leaflet of the plasma membrane where endocytic sites form. In this study, we investigated the roles of PI(4,5)P2 and PS in clathrin-mediated endocytosis (CME) site initiation and vesicle formation in Saccharomyces cerevisiae. Live-cell imaging of endocytic protein dynamics in an mss4(ts) mutant, which has severely reduced PI(4,5)P2 levels, revealed that PI(4,5)P2 is required for endocytic membrane invagination but is less important for endocytic site initiation. We also demonstrated that, in various deletion mutants of genes encoding components of the Rcy1-Ypt31/32 GTPase pathway, endocytic proteins dynamically assemble not only on the plasma membrane but also on intracellular membrane compartments, which are likely derived from early endosomes. In rcy1Δ cells, fluorescent biosensors indicated that PI(4,5)P2 only localized to the plasma membrane while PS localized to both the plasma membrane and intracellular membranes. Furthermore, we found that polarized endocytic patch establishment is defective in the PS-deficient cho1Δ mutant. We propose that PS is important for directing endocytic proteins to the plasma membrane and that PI(4,5)P2 is required to facilitate endocytic membrane invagination.
Collapse
Affiliation(s)
- Yidi Sun
- Department of Molecular and Cell Biology, University of California Berkeley, CA 94720, USA
| | | |
Collapse
|
14
|
Arciello A, De Marco N, Del Giudice R, Guglielmi F, Pucci P, Relini A, Monti DM, Piccoli R. Insights into the fate of the N-terminal amyloidogenic polypeptide of ApoA-I in cultured target cells. J Cell Mol Med 2012; 15:2652-63. [PMID: 21306558 PMCID: PMC4373434 DOI: 10.1111/j.1582-4934.2011.01271.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Apolipoprotein A-I (ApoA-I) is an extracellular lipid acceptor, whose role in cholesterol efflux and high-density lipoprotein formation is mediated by ATP-binding cassette transporter A1 (ABCA1). Nevertheless, some ApoA-I variants are associated to systemic forms of amyloidosis, characterized by extracellular fibril deposition in peripheral organs. Heart amyloid fibrils were found to be mainly constituted by the 93-residue N-terminal fragment of ApoA-I, named [1-93]ApoA-I. In this paper, rat cardiomyoblasts were used as target cells to analyse binding, internalization and intracellular fate of the fibrillogenic polypeptide in comparison to full-length ApoA-I. We provide evidence that the polypeptide: (i) binds to specific sites on cell membrane (K(d) = 5.90 ± 0.70 × 10(-7) M), where it partially co-localizes with ABCA1, as also described for ApoA-I; (ii) is internalized mostly by chlatrin-mediated endocytosis and lipid rafts, whereas ApoA-I is internalized preferentially by chlatrin-coated pits and macropinocytosis and (iii) is rapidly degraded by proteasome and lysosomes, whereas ApoA-I partially co-localizes with recycling endosomes. Vice versa, amyloid fibrils, obtained by in vitro aggregation of [1-93]ApoA-I, were found to be unable to enter the cells. We propose that internalization and intracellular degradation of [1-93]ApoA-I may divert the polypeptide from amyloid fibril formation and contribute to the slow progression and late onset that characterize this pathology.
Collapse
Affiliation(s)
- Angela Arciello
- Department of Structural and Functional Biology, University of Naples Federico II, School of Biotechnological Sciences, Naples, Italy
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Kruth HS. Receptor-independent fluid-phase pinocytosis mechanisms for induction of foam cell formation with native low-density lipoprotein particles. Curr Opin Lipidol 2011; 22:386-93. [PMID: 21881499 PMCID: PMC4174540 DOI: 10.1097/mol.0b013e32834adadb] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
PURPOSE OF REVIEW Because early findings indicated that native low-density lipoprotein (LDL) did not substantially increase macrophage cholesterol content during in-vitro incubations, investigators presumed that LDL must be modified in some way to trigger its uptake by the macrophage. The purpose of this review is to discuss recent findings showing that native unmodified LDL can induce massive macrophage cholesterol accumulation mimicking macrophage foam cell formation that occurs within atherosclerotic plaques. RECENT FINDINGS Macrophages that show high rates of fluid-phase pinocytosis also show similar high rates of uptake of native unmodified LDL through nonreceptor mediated uptake within both macropinosomes and micropinosomes. Nonsaturable fluid-phase uptake of LDL by macrophages converts the macrophages into foam cells. Different macrophage phenotypes demonstrate either constitutive fluid-phase pinocytosis or inducible fluid-phase pinocytosis. Fluid-phase pinocytosis has been demonstrated by macrophages within mouse atherosclerotic plaques indicating that this pathway contributes to plaque macrophage cholesterol accumulation. SUMMARY Contrary to what has been believed previously, macrophages can take up large amounts of native unmodified LDL by receptor-independent, fluid-phase pinocytosis converting these macrophages into foam cells. Thus, targeting macrophage fluid-phase pinocytosis should be considered when investigating strategies to limit macrophage cholesterol accumulation in atherosclerotic plaques.
Collapse
Affiliation(s)
- Howard S Kruth
- Section of Experimental Atherosclerosis, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland 20892-1422, USA.
| |
Collapse
|
16
|
Higashi N, Matsumura Y, Mizuno F, Kasahara K, Sugiura S, Mikasa K, Kita E. Enhanced expression of ATP-binding cassette transporter A1 in non-rafts decreases the sensitivity of vascular endothelial cells to Shiga toxin. Microb Pathog 2010; 49:141-52. [DOI: 10.1016/j.micpath.2010.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 05/06/2010] [Accepted: 05/17/2010] [Indexed: 11/16/2022]
|
17
|
Chung S, Timmins JM, Duong M, Degirolamo C, Rong S, Sawyer JK, Singaraja RR, Hayden MR, Maeda N, Rudel LL, Shelness GS, Parks JS. Targeted deletion of hepatocyte ABCA1 leads to very low density lipoprotein triglyceride overproduction and low density lipoprotein hypercatabolism. J Biol Chem 2010; 285:12197-209. [PMID: 20178985 DOI: 10.1074/jbc.m109.096933] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Loss of ABCA1 activity in Tangier disease (TD) is associated with abnormal apoB lipoprotein (Lp) metabolism in addition to the complete absence of high density lipoprotein (HDL). We used hepatocyte-specific ABCA1 knock-out (HSKO) mice to test the hypothesis that hepatic ABCA1 plays dual roles in regulating Lp metabolism and nascent HDL formation. HSKO mice recapitulated the TD lipid phenotype with postprandial hypertriglyceridemia, markedly decreased LDL, and near absence of HDL. Triglyceride (TG) secretion was 2-fold higher in HSKO compared with wild type mice, primarily due to secretion of larger TG-enriched VLDL secondary to reduced hepatic phosphatidylinositol 3-kinase signaling. HSKO mice also displayed delayed clearance of postprandial TG and reduced post-heparin plasma lipolytic activity. In addition, hepatic LDLr expression and plasma LDL catabolism were increased 2-fold in HSKO compared with wild type mice. Last, adenoviral repletion of hepatic ABCA1 in HSKO mice normalized plasma VLDL TG and hepatic phosphatidylinositol 3-kinase signaling, with a partial recovery of HDL cholesterol levels, providing evidence that hepatic ABCA1 is involved in the reciprocal regulation of apoB Lp production and HDL formation. These findings suggest that altered apoB Lp metabolism in TD subjects may result from hepatic VLDL TG overproduction and increased hepatic LDLr expression and highlight hepatic ABCA1 as an important regulatory factor for apoB-containing Lp metabolism.
Collapse
Affiliation(s)
- Soonkyu Chung
- Department of Pathology/Section on Lipid Sciences, Wake Forest University Health Sciences, Winston-Salem, North Carolina 27157, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Nandi S, Ma L, Denis M, Karwatsky J, Li Z, Jiang XC, Zha X. ABCA1-mediated cholesterol efflux generates microparticles in addition to HDL through processes governed by membrane rigidity. J Lipid Res 2009; 50:456-466. [DOI: 10.1194/jlr.m800345-jlr200] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|
19
|
Zarubica A, Plazzo AP, Stöckl M, Trombik T, Hamon Y, Müller P, Pomorski T, Herrmann A, Chimini G. Functional implications of the influence of ABCA1 on lipid microenvironment at the plasma membrane: a biophysical study. FASEB J 2009; 23:1775-85. [PMID: 19151332 DOI: 10.1096/fj.08-122192] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The ABCA1 transporter orchestrates cellular lipid homeostasis by promoting the release of cholesterol to plasmatic acceptors. The molecular mechanism is, however, unknown. We report here on the biophysical analysis in living HeLa cells of the ABCA1 lipid microenvironment at the plasma membrane. The modifications of membrane attributes induced by ABCA1 were assessed at both the outer and inner leaflet by monitoring either the lifetime of membrane inserted fluorescent lipid analogues by fluorescence lifetime imaging microscopy (FLIM) or, respectively, the membrane translocation of cationic sensors. Analysis of the partitioning of dedicated probes in plasma membrane blebs vesiculated from these cells allowed visualization of ABCA1 partitioning into the liquid disordered-like phase and corroborated the idea that ABCA1 destabilizes the lipid arrangement at the membrane. Specificity was demonstrated by comparison with cells expressing an inactive transporter. The physiological relevance of these modifications was finally demonstrated by the reduced membrane mobility and function of transferrin receptors under the influence of an active ABCA1. Collectively, these data assess that the control of both transversal and lateral lipid distribution at the membrane is the primary function of ABCA1 and positions the effluxes of cholesterol from cell membranes downstream to the redistribution of the sterol into readily extractable membrane pools.
Collapse
Affiliation(s)
- Ana Zarubica
- Centre d'Immunologie de Marseille Luminy, Institut National de la Santè et de la Recherche Médicale, Centre National de la Recherche Scientifique, Université de la Méditerranée, Parc Scientifique de Luminy case 906, 13288 Marseille, Cedex 09 France
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Fukuda M, Nakano M, Miyazaki M, Tanaka M, Saito H, Kobayashi S, Ueno M, Handa T. Conformational change of apolipoprotein A-I and HDL formation from model membranes under intracellular acidic conditions. J Lipid Res 2008; 49:2419-26. [DOI: 10.1194/jlr.m800287-jlr200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
|
21
|
Abstract
PURPOSE OF REVIEW The lipid efflux pathway is important for both HDL formation and the reverse cholesterol transport pathway. This review is focused on recent findings on the mechanism of lipid efflux and its regulation, particularly in macrophages. RECENT FINDINGS Significant progress has been made on understanding the sequence of events that accompany the interaction of apolipoproteins A-I with cell surface ATP-binding cassette transporter A1 and its subsequent lipidation. Continued research on the regulation of ATP-binding cassette transporter A1 and ATP-binding cassette transporter G1 expression and traffic has also generated new paradigms for the control of lipid efflux from macrophages and its contribution to reverse cholesterol transport. In addition, the mobilization of cholesteryl esters from lipid droplets represents a new step in the control of cholesterol efflux. SUMMARY The synergy between lipid transporters is a work in progress, but its importance in reverse cholesterol transport is clear. The regulation of efflux implies both the regulation of relevant transporters and the cellular trafficking of cholesterol.
Collapse
Affiliation(s)
- Yves L Marcel
- Lipoprotein and Atherosclerosis Research Group, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
| | | | | |
Collapse
|
22
|
Wright J, Morales MM, Sousa-Menzes J, Ornellas D, Sipes J, Cui Y, Cui I, Hulamm P, Cebotaru V, Cebotaru L, Guggino WB, Guggino SE. Transcriptional adaptation to Clcn5 knockout in proximal tubules of mouse kidney. Physiol Genomics 2008; 33:341-54. [DOI: 10.1152/physiolgenomics.00024.2008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Dent disease has multiple defects attributed to proximal tubule malfunction including low-molecular-weight proteinuria, aminoaciduria, phosphaturia, and glycosuria. To understand the changes in kidney function of the Clc5 chloride/proton exchanger gene knockout mouse model of Dent disease, we examined gene expression profiles from proximal S1 and S2 tubules of mouse kidneys. We found many changes in gene expression not known previously to be altered in this disease. Genes involved in lipid metabolism, organ development, and organismal physiological processes had the greatest number of significantly changed transcripts. In addition, genes of catalytic activity and transporter activity also had a great number of changed transcripts. Overall, 720 genes are expressed differentially in the proximal tubules of the Dent Clcn5 knockout mouse model compared with those of control wild-type mice. The fingerprint of these gene changes may help us to understand the phenotype of Dent disease.
Collapse
Affiliation(s)
- Jerry Wright
- Department of Physiology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Marcelo M. Morales
- Instituto de Biophysica Carlos Chagas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jackson Sousa-Menzes
- Instituto de Biophysica Carlos Chagas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Debora Ornellas
- Instituto de Biophysica Carlos Chagas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Jennifer Sipes
- Department of Medicine, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Yan Cui
- Department of Medicine, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Isabelle Cui
- Department of Medicine, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Phuson Hulamm
- Department of Medicine, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Valeriu Cebotaru
- Department of Medicine, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Liudmila Cebotaru
- Department of Medicine, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
| | - William B. Guggino
- Instituto de Biophysica Carlos Chagas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Sandra E. Guggino
- Department of Medicine, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
- Department of Physiology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland
| |
Collapse
|
23
|
Denis M, Landry YD, Zha X. ATP-binding cassette A1-mediated lipidation of apolipoprotein A-I occurs at the plasma membrane and not in the endocytic compartments. J Biol Chem 2008; 283:16178-86. [PMID: 18385134 DOI: 10.1074/jbc.m709597200] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
ATP-binding cassette transporter (ABC) A1 is required for the lipidation of apolipoprotein A-I to generate high density lipoprotein (HDL). This process is proposed to occur through a retro-endocytosis pathway in which apoA-I internalizes with ABCA1 and generates HDL from the endosomal compartments before resecretion. The aim of this study was to determine the route of apoA-I endocytosis and whether endocytosis contributes to HDL biogenesis. Using confocal microscopy, we found that internalized apoA-I only transiently colocalized with transferrin, a retro-endocytosis marker. Instead, apoA-I perfectly colocalized with a bulk phase uptake marker (fluorescein isothiocyanate-dextran) and, at later time points, with LysoTracker in several cell models including macrophages, fibroblasts, and baby hamster kidney cells. ABCA1 colocalized poorly with internalized apoA-I. To determine the contribution of internalized apoA-I to HDL biogenesis, we specifically removed apoA-I from the cell surface and analyzed the fate of internalized apoA-I. We found that 23% of cell-associated apoA-I was internalized at steady state. Of internalized apoA-I, only 20% was converted to HDL, and the rest was degraded, consistent with a lysosomal destination. We also found that apoA-I was released approximately five times faster from the plasma membrane than from the intracellular compartments. From these kinetic parameters, we estimated that approximately 5.6% of apoA-I that interacts with cells is degraded and that internalized apoA-I contributes to approximately 1.4% of total HDL production. We also found that blocking endocytosis with sucrose or cytochalasin D did not decrease cholesterol efflux or HDL biogenesis. We therefore conclude that the plasma membrane is the main platform where ABCA1-mediated lipidation of apoA-I occurs.
Collapse
Affiliation(s)
- Maxime Denis
- Ottawa Health Research Institute, and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ontario K1Y 4E9, Canada
| | | | | |
Collapse
|
24
|
Argraves KM, Argraves WS. HDL serves as a S1P signaling platform mediating a multitude of cardiovascular effects. J Lipid Res 2007; 48:2325-33. [PMID: 17698855 DOI: 10.1194/jlr.r700011-jlr200] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The lysosphingolipid sphingosine 1-phosphate (S1P) is a component of HDL. Findings from a growing number of studies indicate that S1P is a mediator of many of the cardiovascular effects of HDL, including the ability to promote vasodilation, vasoconstriction, and angiogenesis, protect against ischemia/reperfusion injury, and inhibit/reverse atherosclerosis. These latter cardioprotective effects are being shown to involve the S1P-mediated suppression of inflammatory processes, including reduction of the endothelial expression of monocyte and lymphocyte adhesion molecules, decreased recruitment of polymorphonuclear cells to sites of infarction, and blocking of cardiomyocyte apoptosis after myocardial infarction. This review article summarizes the evidence that S1P as a component of HDL serves to regulate vascular cell and lymphocyte behaviors associated with cardiovascular (patho)physiology.
Collapse
Affiliation(s)
- Kelley M Argraves
- Department of Cell Biology and Anatomy, Medical University of South Carolina, Charleston, SC 29425, USA.
| | | |
Collapse
|
25
|
Orlowski S, Coméra C, Tercé F, Collet X. Lipid rafts: dream or reality for cholesterol transporters? EUROPEAN BIOPHYSICS JOURNAL: EBJ 2007; 36:869-85. [PMID: 17576551 DOI: 10.1007/s00249-007-0193-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 05/11/2007] [Accepted: 05/15/2007] [Indexed: 01/12/2023]
Abstract
As a key constituent of the cell membranes, cholesterol is an endogenous component of mammalian cells of primary importance, and is thus subjected to highly regulated homeostasis at the cellular level as well as at the level of the whole body. This regulation requires adapted mechanisms favoring the handling of cholesterol in aqueous compartments, as well as its transfer into or out of membranes, involving membrane proteins. A membrane exhibits functional properties largely depending on its lipid composition and on its structural organization, which very often involves cholesterol-rich microdomains. Then there is the appealing possibility that cholesterol may regulate its own transmembrane transport at a purely functional level, independently of any transcriptional regulation based on cholesterol-sensitive nuclear factors controling the expression level of lipid transport proteins. Indeed, the main cholesterol "transporters" presently believed to mediate for instance the intestinal absorption of cholesterol, that are SR-BI, NPC1L1, ABCA1, ABCG1, ABCG5/G8 and even P-glycoprotein, all present privileged functional relationships with membrane cholesterol-containing microdomains. In particular, they all more or less clearly induce membrane disorganization, supposed to facilitate cholesterol exchanges with the close aqueous medium. The actual lipid substrates handled by these transporters are not yet unambiguously determined, but they likely concern the components of membrane microdomains. Conversely, raft alterations may provide specific modulations of the transporter activities, as well as they can induce indirect effects via local perturbations of the membrane. Finally, these cholesterol transporters undergo regulated intracellular trafficking, with presumably some relationships to rafts which remain to be clarified.
Collapse
Affiliation(s)
- Stéphane Orlowski
- SB2SM/IBTS and URA 2096 CNRS, CEA, Centre de Saclay, 91191, Gif-sur-Yvette cedex, France.
| | | | | | | |
Collapse
|
26
|
Schroeder LK, Kremer S, Kramer MJ, Currie E, Kwan E, Watts JL, Lawrenson AL, Hermann GJ. Function of the Caenorhabditis elegans ABC transporter PGP-2 in the biogenesis of a lysosome-related fat storage organelle. Mol Biol Cell 2007; 18:995-1008. [PMID: 17202409 PMCID: PMC1805080 DOI: 10.1091/mbc.e06-08-0685] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Caenorhabditis elegans gut granules are intestine specific lysosome-related organelles with birefringent and autofluorescent contents. We identified pgp-2, which encodes an ABC transporter, in screens for genes required for the proper formation of gut granules. pgp-2(-) embryos mislocalize birefringent material into the intestinal lumen and are lacking in acidified intestinal V-ATPase-containing compartments. Adults without pgp-2(+) function similarly lack organelles with gut granule characteristics. These cellular phenotypes indicate that pgp-2(-) animals are defective in gut granule biogenesis. Double mutant analysis suggests that pgp-2(+) functions in parallel with the AP-3 adaptor complex during gut granule formation. We find that pgp-2 is expressed in the intestine where it functions in gut granule biogenesis and that PGP-2 localizes to the gut granule membrane. These results support a direct role of an ABC transporter in regulating lysosome biogenesis. Previously, pgp-2(+) activity has been shown to be necessary for the accumulation of Nile Red-stained fat in C. elegans. We show that gut granules are sites of fat storage in C. elegans embryos and adults. Notably, levels of triacylglycerides are relatively normal in animals defective in the formation of gut granules. Our results provide an explanation for the loss of Nile Red-stained fat in pgp-2(-) animals as well as insight into the specialized function of this lysosome-related organelle.
Collapse
Affiliation(s)
| | - Susan Kremer
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| | - Maxwell J. Kramer
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| | - Erin Currie
- *Department of Biology and
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| | - Elizabeth Kwan
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| | - Jennifer L. Watts
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164
| | | | - Greg J. Hermann
- *Department of Biology and
- Program in Biochemistry and Molecular Biology, Lewis and Clark College, Portland, OR 97219; and
| |
Collapse
|
27
|
Landry YD, Denis M, Nandi S, Bell S, Vaughan AM, Zha X. ATP-binding cassette transporter A1 expression disrupts raft membrane microdomains through its ATPase-related functions. J Biol Chem 2006; 281:36091-101. [PMID: 16984907 DOI: 10.1074/jbc.m602247200] [Citation(s) in RCA: 174] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
ATP-binding cassette transporter A1 (ABCA1) is known to mediate cholesterol efflux to lipid-poor apolipoprotein A-I. In addition, ABCA1 has been shown to influence functions of the plasma membrane, such as endocytosis and phagocytosis. Here, we report that ABCA1 expression results in a significant redistribution of cholesterol and sphingomyelin from rafts to non-rafts. Caveolin, a raft/caveolae marker also redistributes from punctate caveolae-like structures to the general area of the plasma membrane upon ABCA1 expression. Furthermore, we observed significant reduction of Akt activation in ABCA1-expressing cells, consistent with raft disruption. Cholesterol content in the plasma membrane is, however, not altered. Moreover, we provide evidence that a non-functional ABCA1 with mutation in an ATP-binding domain, A937V, fails to redistribute cholesterol, sphingomyelin, or caveolin. A937V also fails to influence Akt activation. Finally, we show that apolipoprotein A-I preferentially associates with non-raft membranes in ABCA1-expressing cells. Our results thus demonstrate that ABCA1 causes a change in overall lipid packing of the plasma membrane, likely through its ATPase-related functions. Such reorganization by ABCA1 effectively expands the non-raft membrane fractions and, consequentially, pre-conditions cells for cholesterol efflux.
Collapse
Affiliation(s)
- Yves D Landry
- Ottawa Health Research Institute and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1Y 4E9, Canada
| | | | | | | | | | | |
Collapse
|
28
|
Pennings M, Meurs I, Ye D, Out R, Hoekstra M, Van Berkel TJC, Van Eck M. Regulation of cholesterol homeostasis in macrophages and consequences for atherosclerotic lesion development. FEBS Lett 2006; 580:5588-96. [PMID: 16935283 DOI: 10.1016/j.febslet.2006.08.022] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2006] [Revised: 07/28/2006] [Accepted: 08/06/2006] [Indexed: 11/25/2022]
Abstract
Foam cell formation due to excessive accumulation of cholesterol by macrophages is a pathological hallmark of atherosclerosis. Macrophages cannot limit the uptake of cholesterol and therefore depend on cholesterol efflux pathways for preventing their transformation into foam cells. Several ABC-transporters, including ABCA1 and ABCG1, facilitate the efflux of cholesterol from macrophages. These transporters, however, also affect membrane lipid asymmetry which may have important implications for cellular endocytotic pathways. We propose that in addition to the generally accepted role of these ABC-transporters in the prevention of foam cell formation by induction of cholesterol efflux from macrophages, they also influence the macrophage endocytotic uptake.
Collapse
Affiliation(s)
- Marieke Pennings
- Division of Biopharmaceutics, Leiden/Amsterdam Center for Drug Research, Gorlaeus Laboratories, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
29
|
Cavelier C, Lorenzi I, Rohrer L, von Eckardstein A. Lipid efflux by the ATP-binding cassette transporters ABCA1 and ABCG1. Biochim Biophys Acta Mol Cell Biol Lipids 2006; 1761:655-66. [PMID: 16798073 DOI: 10.1016/j.bbalip.2006.04.012] [Citation(s) in RCA: 178] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2006] [Revised: 04/05/2006] [Accepted: 04/28/2006] [Indexed: 11/23/2022]
Abstract
Plasma levels of high-density lipoproteins (HDL) and apolipoprotein A-I (apoA-I) are inversely correlated with the risk of cardiovascular disease. One major atheroprotective mechanism of HDL and apoA-I is their role in reverse cholesterol transport, i.e., the transport of excess cholesterol from foam cells to the liver for secretion. The ATP-binding cassette transporters ABCA1 and ABCG1 play a pivotal role in this process by effluxing lipids from foam cells to apoA-I and HDL, respectively. In the liver, ABCA1 activity is one rate-limiting step in the formation of HDL. In macrophages, ABCA1 and ABCG1 prevent the excessive accumulation of lipids and thereby protect the arteries from developing atherosclerotic lesions. However, the mechanisms by which ABCA1 and ABCG1 mediate lipid removal are still unclear. Particularly, three questions remain controversial and are discussed in this review: (1) Do apoA-I and HDL directly interact with ABCA1 and ABCG1, respectively? (2) Does cholesterol efflux involve retroendocytosis of apoA-I or HDL? (3) Which lipids are directly transported by ABCA1 and ABCG1?
Collapse
Affiliation(s)
- Clara Cavelier
- Institute of Clinical Chemistry, University Hospital Zurich, University Zurich, Rämistrasse 100, CH 8091 Zurich, Switzerland
| | | | | | | |
Collapse
|
30
|
van Meer G, Halter D, Sprong H, Somerharju P, Egmond MR. ABC lipid transporters: extruders, flippases, or flopless activators? FEBS Lett 2005; 580:1171-7. [PMID: 16376334 DOI: 10.1016/j.febslet.2005.12.019] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Revised: 12/06/2005] [Accepted: 12/06/2005] [Indexed: 01/02/2023]
Abstract
Many mammalian ABC transporters move membrane lipids to acceptor lipid assemblies in the extracellular aqueous milieu. Because the desorption from the membrane costs more energy than provided by two ATPs, the transporter probably only translocates the lipid to a partially hydrophilic site on its extracellular face. From this high-energy site, the lipid may efficiently move to the acceptor, which ideally is bound to the transporter, or, in the absence of an acceptor, fall back into the membrane. If the lipid originated from the cytosolic membrane surface, this represents lipid flop and is probably a side activity of the transporters.
Collapse
Affiliation(s)
- Gerrit van Meer
- Membrane Enzymology, Bijvoet Center and Institute of Biomembranes, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands.
| | | | | | | | | |
Collapse
|
31
|
Abstract
The alpha-tocopherol transfer protein (alpha-TTP) is required to prevent vitamin E deficiency in humans and in alpha-TTP null mice. Whereas alpha-TTP is not required to facilitate intestinal absorption of vitamin E, it is required to maintain normal alpha-tocopherol concentrations in plasma and extrahepatic tissues. alpha-Tocopherol secretion from the liver in very low density lipoproteins (VLDLs) is impaired in humans with a defect in the alpha-TTP gene. In perfusions of isolated cynomolgus monkey livers, VLDLs were preferentially enriched in RRR-alpha-tocopherol. The mechanism by which alpha-TTP incorporates alpha-tocopherol into nascent VLDLs is the topic of this report. VLDL assembly is a multistep secretory process that occurs within the membrane compartments of the endoplasmic reticulum and Golgi apparatus. Thus, we postulated that alpha-TTP might transfer alpha-tocopherol onto nascent VLDLs either in the endoplasmic reticulum or in the Golgi apparatus. To test these possibilities, we isolated nascent VLDLs from highly purified RER and Golgi apparatus membrane fractions from livers of rats fed equimolar ratios of RRR- and SRR-alpha-tocopherols labeled with different amounts of deuterium. Although the plasma was enriched in RRR-alpha-tocopherol 14 hours after the dose, no enrichment of nascent VLDL precursors from either of the secretory compartments was detected, indicating that VLDL enrichment with alpha-tocopherol may occur as a post-VLDL secretory process. Therefore, we hypothesize that alpha-TTP may facilitate movement of alpha-tocopherol to the hepatocyte plasma membrane (by unknown mechanisms) where newly secreted, nascent VLDLs could acquire both alpha-tocopherol and unesterified cholesterol while within the space of Disse. Clearly, critical information is lacking in our understanding of the mechanism by which alpha-TTP facilitates the preferential enrichment of VLDLs with alpha-tocopherol.
Collapse
Affiliation(s)
- Maret G Traber
- Linus Pauling Institute, Oregon State University, Corvallis, OR 97331-6512, USA.
| | | | | |
Collapse
|
32
|
Alder-Baerens N, Müller P, Pohl A, Korte T, Hamon Y, Chimini G, Pomorski T, Herrmann A. Headgroup-specific exposure of phospholipids in ABCA1-expressing cells. J Biol Chem 2005; 280:26321-9. [PMID: 15905177 DOI: 10.1074/jbc.m413993200] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
ABCA1 has been established to be required for the efflux of cholesterol and phospholipids to apolipoproteins such as apoA-I. At present, it is unclear whether ABCA1-mediated lipid exposure is specific with regard to lipid headgroups and whether it requires calcium activation and the presence of a lipid acceptor. In the present work, we found exofacial exposure of endogenous phosphatidylserine in the absence of apoA-I to be enhanced in ABCA1-GFP expressing MDCKII and HeLa cells compared with control cells. By using C6-N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) (NBD)-labeled phospholipid analogues, we observed elevated redistribution of phosphatidylserine and phosphatidylethanolamine but not of phosphatidylcholine analogues from the cytoplasmic to the exoplasmic leaflet of the plasma membrane of ABCA1-GFP expressing cells. Whereas glyburide affected neither the level of exofacial endogenous PS nor the outward movement of the amino phospholipid analogues, the latter was sensitive to intracellular Ca2+ in ABCA1-GFP expressing cells, further enhancing outward analogue redistribution with respect to control cells. Both receptor-mediated endocytosis and fluidphase endocytosis were reduced in MDCKII cells expressing ABCA1-GFP. Glyburide raised the level of receptor-mediated endocytosis in the ABCA1-GFP expressing cell to the level of control cells in the absence of glyburide. In control cells, however, fluid-phase endocytosis but not receptor-mediated endocytosis was significantly reduced upon glyburide treatment.
Collapse
Affiliation(s)
- Nele Alder-Baerens
- Humboldt University of Berlin, Institute of Biology, Center of Biophysics and Bioinformatics, Invalidenstrasse 42, 10115 Berlin, Germany
| | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
PURPOSE OF REVIEW Vitamin E deficiency in humans has lead to the discovery of regulatory mechanisms that control plasma alpha-tocopherol concentrations and prevent the accumulation of other molecules with vitamin E-antioxidant activity, such as gamma-tocopherol. This review describes these regulatory mechanisms. RECENT FINDINGS alpha-tocopherol regulatory proteins have been cloned and crystallized and their mechanisms of action are under intense scrutiny. Studies of vitamin E metabolism suggest that xenobiotic metabolism may not only regulate vitamin E concentrations, but that vitamin E may regulate xenobiotic clearance pathways. SUMMARY Advances in our understanding of vitamin E nutrition suggest that vitamin E is a potent molecule that is closely regulated such that alpha-tocopherol is at the appropriate tissue concentrations necessary for some as yet to be described functions.
Collapse
Affiliation(s)
- Maret G Traber
- Linus Pauling Institute, Oregon State University Corvallis, Oregon 97331, USA.
| |
Collapse
|
34
|
Pohl A, Devaux PF, Herrmann A. Function of prokaryotic and eukaryotic ABC proteins in lipid transport. Biochim Biophys Acta Mol Cell Biol Lipids 2004; 1733:29-52. [PMID: 15749056 DOI: 10.1016/j.bbalip.2004.12.007] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2004] [Revised: 11/08/2004] [Accepted: 12/16/2004] [Indexed: 12/23/2022]
Abstract
ATP binding cassette (ABC) proteins of both eukaryotic and prokaryotic origins are implicated in the transport of lipids. In humans, members of the ABC protein families A, B, C, D and G are mutated in a number of lipid transport and metabolism disorders, such as Tangier disease, Stargardt syndrome, progressive familial intrahepatic cholestasis, pseudoxanthoma elasticum, adrenoleukodystrophy or sitosterolemia. Studies employing transfection, overexpression, reconstitution, deletion and inhibition indicate the transbilayer transport of endogenous lipids and their analogs by some of these proteins, modulating lipid transbilayer asymmetry. Other proteins appear to be involved in the exposure of specific lipids on the exoplasmic leaflet, allowing their uptake by acceptors and further transport to specific sites. Additionally, lipid transport by ABC proteins is currently being studied in non-human eukaryotes, e.g. in sea urchin, trypanosomatides, arabidopsis and yeast, as well as in prokaryotes such as Escherichia coli and Lactococcus lactis. Here, we review current information about the (putative) role of both pro- and eukaryotic ABC proteins in the various phenomena associated with lipid transport. Besides providing a better understanding of phenomena like lipid metabolism, circulation, multidrug resistance, hormonal processes, fertilization, vision and signalling, studies on pro- and eukaryotic ABC proteins might eventually enable us to put a name on some of the proteins mediating transbilayer lipid transport in various membranes of cells and organelles. It must be emphasized, however, that there are still many uncertainties concerning the functions and mechanisms of ABC proteins interacting with lipids. In particular, further purification and reconstitution experiments with an unambiguous role of ATP hydrolysis are needed to demonstrate a clear involvement of ABC proteins in lipid transbilayer asymmetry.
Collapse
Affiliation(s)
- Antje Pohl
- Humboldt-University Berlin, Institute of Biology, Invalidenstr. 42, D-10115 Berlin, Germany.
| | | | | |
Collapse
|
35
|
Pomorski T, Holthuis JCM, Herrmann A, van Meer G. Tracking down lipid flippases and their biological functions. J Cell Sci 2004; 117:805-13. [PMID: 14963021 DOI: 10.1242/jcs.01055] [Citation(s) in RCA: 162] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The various organellar membranes of eukaryotic cells display striking differences in the composition, leaflet distribution and transbilayer movement of their lipids. In membranes such as the endoplasmic reticulum, phospholipids can move readily across the bilayer, aided by membrane proteins that facilitate a passive equilibration of lipids between both membrane halves. In the plasma membrane, and probably also in the late Golgi and endosomal compartments, flip-flop of phospholipids is constrained and subject to a dynamic, ATP-dependent regulation that involves members of distinct protein families. Recent studies in yeast, parasites such as Leishmania, and mammalian cells have identified several candidates for lipid flippases, and whereas some of these serve a fundamental role in the release of lipids from cells, others appear to have unexpected and important functions in vesicular traffic: their activities are required to support vesicle formation in the secretory and endocytic pathways.
Collapse
Affiliation(s)
- Thomas Pomorski
- Institut für Biologie, Humboldt-Universität zu Berlin, 10115 Berlin, Germany.
| | | | | | | |
Collapse
|
36
|
Bared SM, Buechler C, Boettcher A, Dayoub R, Sigruener A, Grandl M, Rudolph C, Dada A, Schmitz G. Association of ABCA1 with syntaxin 13 and flotillin-1 and enhanced phagocytosis in tangier cells. Mol Biol Cell 2004; 15:5399-407. [PMID: 15469992 PMCID: PMC532019 DOI: 10.1091/mbc.e04-03-0182] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The ATP-binding cassette transporter A1 (ABCA1) facilitates the cellular release of cholesterol and choline-phospholipids to apolipoprotein A-I (apoA-I) and several studies indicate that vesicular transport is associated with ABCA1 function. Syntaxins play a major role in vesicular fusion and have also been demonstrated to interact with members of the ABC-transporter family. Therefore, we focused on the identification of syntaxins that directly interact with ABCA1. The expression of syntaxins and ABCA1 in cultured human monocytes during M-CSF differentiation and cholesterol loading was investigated and syntaxins 3, 6, and 13 were found induced in foam cells together with ABCA1. Immunoprecipitation experiments revealed a direct association of syntaxin 13 and full-length ABCA1, whereas syntaxin 3 and 6 failed to interact with ABCA1. The colocalization of ABCA1 and syntaxin 13 was also shown by immunofluorescence microscopy. Silencing of syntaxin 13 by small interfering RNA (siRNA) led to reduced ABCA1 protein levels and hence to a significant decrease in apoA-I-dependent choline-phospholipid efflux. ABCA1 is localized in Lubrol WX-insoluble raft microdomains in macrophages and syntaxin 13 and flotillin-1 were also detected in these detergent resistant microdomains along with ABCA1. Syntaxin 13, flotillin-1, and ABCA1 were identified as phagosomal proteins, indicating the involvement of the phagosomal compartment in ABCA1-mediated lipid efflux. In addition, the uptake of latex phagobeads by fibroblasts with mutated ABCA1 was enhanced when compared with control cells and the recombinant expression of functional ABCA1 normalized the phagocytosis rate in Tangier fibroblasts. It is concluded that ABCA1 forms a complex with syntaxin 13 and flotillin-1, residing at the plasma membrane and in phagosomes that are partially located in raft microdomains.
Collapse
Affiliation(s)
- Salim Maa Bared
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, 93040 Regensburg, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Kälin N, Fernandes J, Hrafnsdóttir S, van Meer G. Natural phosphatidylcholine is actively translocated across the plasma membrane to the surface of mammalian cells. J Biol Chem 2004; 279:33228-36. [PMID: 15175345 DOI: 10.1074/jbc.m401751200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The cell surface of eukaryotic cells is enriched in choline phospholipids, whereas the aminophospholipids are concentrated at the cytosolic side of the plasma membrane by the activity of one or more P-type ATPases. Lipid translocation has been investigated mostly by using short chain lipid analogs because assays for endogenous lipids are inherently complicated. In the present paper, we optimized two independent assays for the translocation of natural phosphatidylcholine (PC) to the cell surface based on the hydrolysis of outer leaflet phosphoglycerolipids by exogenous phospholipase A2 and the exchange of outer leaflet PC by a transfer protein. We report that PC reached the cell surface in the absence of vesicular traffic by a pathway that involved translocation across the plasma membrane. In erythrocytes, PC that was labeled at the inside of the plasma membrane was translocated to the cell surface with a half-time of 30 min. This translocation was probably mediated by an ATPase, because it required ATP and was vanadate-sensitive. The inhibition of PC translocation by glibenclamide, an inhibitor of various ATP binding cassette transporters, and its reduction in erythrocytes from both Abcb1a/1b and Abcb4 knockout mice, suggest the involvement of ATP binding cassette transporters in natural PC cell surface translocation. The relative importance of the outward translocation of PC as compared with the well characterized fast inward translocation of phosphatidylserine for the overall asymmetric phospholipid organization in plasma membranes remains to be established.
Collapse
Affiliation(s)
- Nanette Kälin
- Department of Membrane Enzymology, CBLE, Institute of Biomembranes, Padualaan 8, 3584 CH Utrecht, The Netherlands.
| | | | | | | |
Collapse
|
38
|
Buechler C, Bodzioch M, Bared SM, Sigruener A, Boettcher A, Lapicka-Bodzioch K, Aslanidis C, Duong CQ, Grandl M, Langmann T, Dembinska-Kiec A, Schmitz G. Expression pattern and raft association of NIPSNAP3 and NIPSNAP4, highly homologous proteins encoded by genes in close proximity to the ATP-binding cassette transporter A1. Genomics 2004; 83:1116-24. [PMID: 15177564 DOI: 10.1016/j.ygeno.2003.12.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2003] [Accepted: 12/20/2003] [Indexed: 10/26/2022]
Abstract
The highly homologous genes NIPSNAP3 and NIPSNAP4, with 87% amino acid identity, are members of the NIPSNAP family with putative roles in vesicular trafficking. NIPSNAP3 mRNA and NIPSNAP4 mRNA and protein were detected in multiple tissues and cells at varying degrees. Interestingly, NIPSNAP3 is most highly expressed in skeletal muscle, where NIPSNAP4 has a low mRNA abundance. NIPSNAP4 was found associated with membranes and partly localized in rafts. The ubiquitous expression of the highly conserved NIPSNAPs and their association with membranes further support an important cellular function of these proteins probably linked to vesicular trafficking. The NIPSNAP3 and NIPSNAP4 genes are located in close proximity to the 3' end of the ATP-binding cassette transporter A1 (ABCA1), whose mutations cause familial high-density lipoprotein deficiency syndromes. The adjacent genomic location and the finding that ABCA1 is a regulator of vesicular trafficking may indicate a functional relation of these proteins, even though NIPSNAP4 does not interact directly with ABCA1 nor is its expression altered in cells with mutated ABCA1.
Collapse
Affiliation(s)
- Christa Buechler
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Franz-Josef-Strauss-Allee 11, 93042 Regensburg, Germany
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Smith JD, Le Goff W, Settle M, Brubaker G, Waelde C, Horwitz A, Oda MN. ABCA1 mediates concurrent cholesterol and phospholipid efflux to apolipoprotein A-I. J Lipid Res 2004; 45:635-44. [PMID: 14703508 DOI: 10.1194/jlr.m300336-jlr200] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Prior studies provide data supporting the notion that ATP binding cassette transporter A1 (ABCA1) promotes lipid efflux to extracellular acceptors in a two-step process: first, ABCA1 mediates phospholipid efflux to an apolipoprotein, and second, this apolipoprotein-phospholipid complex accepts free cholesterol in an ABCA1-independent manner. In the current study using RAW264.7 cells, ABCA1-mediated free cholesterol and phospholipid efflux to apolipoprotein A-I (apoA-I) were tightly coupled to each other both temporally and after treatment with ABCA1 inhibitors. The time course and temperature dependence of ABCA1-mediated lipid efflux to apoA-I support a role for endocytosis in this process. Cyclodextrin treatment of RAW264.7 cells partially inhibited 8Br-cAMP-induced efflux of free cholesterol and phospholipid to apoA-I. ABCA1-expressing cells are more sensitive to cell damage by high-dose cyclodextrin and vanadate, leading to increased lactate dehydrogenase leakage and phospholipid release even in the absence of the acceptor apoA-I. Finally, we could not reproduce a two-step effect on lipid efflux using conditioned medium from ABCA1-expressing cells pretreated with cyclodextrin.
Collapse
Affiliation(s)
- Jonathan D Smith
- Department of Cell Biology NC10, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
| | | | | | | | | | | | | |
Collapse
|
40
|
Parodi-Talice A, Araújo JM, Torres C, Pérez-Victoria JM, Gamarro F, Castanys S. The overexpression of a new ABC transporter in Leishmania is related to phospholipid trafficking and reduced infectivity. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1612:195-207. [PMID: 12787938 DOI: 10.1016/s0005-2736(03)00131-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This paper reports the characterization of a new ABC transporter (LtrABC1.1), related to the human ABCA subfamily, in the protozoan parasite Leishmania tropica. LtrABC1.1 is a tandem duplicated gene flanked by inverted repeats. LtrABC1.1 is expressed mainly in the flagellar pocket of the parasite. Drug resistance studies in Leishmania overexpressing LtrABC1.1 showed the transporter not to confer resistance to a range of unrelated drugs. LtrABC1.1 appears to be involved in lipid movements across the plasma membrane of the parasite since overexpression reduces the accumulation of fluorescent phospholipid analogues. The activity of this protein may also affect membrane movement processes since secreted acid phosphatase (SAP) activity was significantly lower in promastigotes overexpressing LtrABC1.1. In vitro infection experiments with macrophages indicated LtrABC1.1-transfected parasites to be significantly less infective. Together, these results suggest that this new ABC transporter could play a role in lipid movements across the plasma membrane, and that its activity might influence vesicle trafficking. This is the first ABCA-like transporter described in unicellular eukaryotes.
Collapse
Affiliation(s)
- Adriana Parodi-Talice
- Instituto de Parasitología y Biomedicina López-Neyra, Consejo Superior de Investigaciones Científicas, c/Ventanilla 11, Granada 18001, Spain
| | | | | | | | | | | |
Collapse
|
41
|
Abstract
Observational studies provide overwhelming evidence that a low high-density lipoprotein (HDL)-cholesterol level increases the risk of coronary events, both in healthy subjects and in patients with coronary heart disease. Based on in vitro experiments, several mechanistic explanations for the atheroprotective function of HDL have been suggested. However, few of these were verified in vivo in humans or in experiments with transgenic animals. The HDL functions currently most widely held to account for the antiatherogenic effect include participation in reverse cholesterol transport, protection against endothelial dysfunction, and inhibition of oxidative stress. This review summarizes current views on the molecular mechanism underlying these atheroprotective effects of HDL.
Collapse
Affiliation(s)
- Gerd Assmann
- Institut für Klinische Chemie und Laboratoriumsmedizin, Westfälische Wilhelms-Universität, Münster, Germany.
| | | |
Collapse
|
42
|
Zha X, Gauthier A, Genest J, McPherson R. Secretory vesicular transport from the Golgi is altered during ATP-binding cassette protein A1 (ABCA1)-mediated cholesterol efflux. J Biol Chem 2003; 278:10002-5. [PMID: 12551894 DOI: 10.1074/jbc.c300024200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Apolipoprotein AI (apoAI)-mediated cholesterol efflux is a process by which cells export excess cellular cholesterol to apoAI to form high density lipoprotein. ATP-binding cassette protein A1 (ABCA1) has recently been identified as the key regulator of this process. The pathways of intracellular cholesterol transport during efflux are largely unknown nor is the molecular mechanism by which ABCA1 governs cholesterol efflux well understood. Here, we report that, in both macrophages and fibroblasts, the secretory vesicular transport changes in response to apoAI-mediated cholesterol efflux. Vesicular transport from the Golgi to the plasma membrane increased 2-fold during efflux. This increase in vesicular transport during efflux was observed in both raft-poor and raft-rich vesicle populations originated from the Golgi. Importantly, enhanced vesicular transport in response to apoAI is absent in Tangier fibroblasts, a cell type with deficient cholesterol efflux due to functional ABCA1 mutations. These findings are consistent with an efflux model whereby cholesterol is transported from the storage site to the plasma membrane via the Golgi. ABCA1 may influence cholesterol efflux in part by enhancing vesicular trafficking from the Golgi to the plasma membrane.
Collapse
Affiliation(s)
- Xiaohui Zha
- Lipoprotein & Atherosclerosis Group, University of Ottawa Heart Institute, Ontario K1Y 4W7, Canada
| | | | | | | |
Collapse
|
43
|
Buechler C, Bared SM, Aslanidis C, Ritter M, Drobnik W, Schmitz G. Molecular and functional interaction of the ATP-binding cassette transporter A1 with Fas-associated death domain protein. J Biol Chem 2002; 277:41307-10. [PMID: 12235128 DOI: 10.1074/jbc.c200436200] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
ATP-binding cassette transporter A1 (ABCA1) is a major regulator of cellular cholesterol and phospholipid homeostasis. Its function has not been fully characterized and may depend on the association with additional proteins. To identify ABCA1-interacting proteins a human liver yeast two-hybrid library was screened with the 144 C-terminal amino acids of ABCA1. Fas-associated death domain protein (FADD) was identified to bind to ABCA1, and this interaction was confirmed by pull-down assays and co-immunoprecipitations. Recombinant expression of a dominant negative form of FADD or the C terminus of ABCA1 in the human hepatoma cell line HepG2 markedly reduced the transfer of phospholipids to apoA-I. This indicates that the binding of additional proteins, one of them being full-length FADD, is required for ABCA1 function. The association of FADD with ABCA1 provides an unexpected link between high density lipoprotein metabolism and an adaptor molecule mainly described in death receptor signal transduction.
Collapse
Affiliation(s)
- Christa Buechler
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Germany
| | | | | | | | | | | |
Collapse
|
44
|
Burgess JW, Kiss RS, Zheng H, Zachariah S, Marcel YL. Trypsin-sensitive and lipid-containing sites of the macrophage extracellular matrix bind apolipoprotein A-I and participate in ABCA1-dependent cholesterol efflux. J Biol Chem 2002; 277:31318-26. [PMID: 12050168 DOI: 10.1074/jbc.m204200200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A unique property of the extracellular matrix of J774 and THP-1 cells has been identified, which contributes to the ability of these cells to promote cholesterol efflux. We demonstrate high level apolipoprotein (apo) A-I binding to macrophage cells (THP-1 and J774) and to their extracellular matrix (ECM). However, high level apoA-I binding is not observed on fibroblasts, HepG2 cells, or U937 cells (a macrophage cell line that does not efflux cholesterol to apoA-I or bind apoA-I on their respective ECM). Binding to the ECM of THP-1 or J774 macrophages depends on the presence of apoA-I C-terminal helices and is markedly reduced with a mutant lacking residues 187-243 (apoA-I Delta(187-243)), suggesting that the hydrophobic C terminus forms a hydrophobic interaction with the ECM. ApoA-I binding is lost upon trypsin treatment or with Triton X-100, a preparation method that de-lipidates the ECM. However, binding is recovered with re-lipidation, and is preserved with ECM prepared using cytochalasin B, which conserves the endogenous phospholipid levels of the ECM. We also demonstrate that specific cholesterol efflux to apoA-I is much reduced in cells released from their native ECM, but fully restored when ECM-depleted cells are added back to ECM in the presence of apoA-I. The apoA-I-mediated efflux is deficient in plated or suspension U937 macrophages, but is restored to high levels when the suspension U937 cells are reconstituted with the ECM of J774 cells. The ECM-dependent activity was much reduced in the presence of glyburide, indicating participation of ABCA1 (ATP-binding cassette transporter 1) in the efflux mechanism. These studies establish a novel binding site for apoA-I on the macrophage ECM that may function together with ABCA1 in promoting cholesterol efflux.
Collapse
Affiliation(s)
- Jim W Burgess
- Lipoprotein and Atherosclerosis Research Group, University of Ottawa Heart Institute, Ontario K1Y 4W7, Canada
| | | | | | | | | |
Collapse
|
45
|
Abstract
PURPOSE OF REVIEW Two hallmarks of cardiovascular disease are the presence of sterol-laden macrophages in the artery wall and reduced plasma HDL levels. A cell membrane protein named ATP-binding cassette transporter A1 (ABCA1) mediates secretion of excess cholesterol from cells into the HDL metabolic pathway. The discovery of ABCA1 in 1999 triggered a deluge of studies conducted to characterize the properties of this important transporter. The present review summarizes the more recent of those studies and evaluates their implications for the role of ABCA1 in cholesterol transport, HDL metabolism, and atherogenesis. RECENT FINDINGS Cell culture experiments have shown that ABCA1 transports cholesterol, phospholipids, and other lipophilic molecules across the plasma membrane, where they are picked up by apolipoproteins containing little or no lipids, but the mechanisms involved are still unclear. It is now apparent that factors in addition to sterols modulate ABCA1 expression by diverse transcriptional and post-transcriptional processes. Studies in humans and mice with ABCA1 mutations revealed that the relative activity of ABCA1 determines plasma HDL levels and influences susceptibility to cardiovascular disease. Mouse models are beginning to provide insights into the function of ABCA1 in vivo but are also raising new questions regarding the contribution of ABCA1 to total cholesterol flux. SUMMARY Recent studies underscore the critical role of ABCA1 in clearing excess cholesterol from macrophages and generating HDL particles, implicating ABCA1 as an attractive new therapeutic target for treating cardiovascular disease.
Collapse
Affiliation(s)
- John F Oram
- Department of Medicine, University of Washington, Seattle 98195-6426, USA.
| |
Collapse
|
46
|
Smith JD, Waelde C, Horwitz A, Zheng P. Evaluation of the role of phosphatidylserine translocase activity in ABCA1-mediated lipid efflux. J Biol Chem 2002; 277:17797-803. [PMID: 11893753 DOI: 10.1074/jbc.m201594200] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The following two theories for the mechanism of ABCA1 in lipid efflux to apolipoprotein acceptors have been proposed: 1) that ABCA1 directly binds the apolipoprotein ligand and then facilitates lipid efflux and 2) that ABCA1 acts as a phosphatidylserine (PS) translocase, increasing PS levels in the plasma membrane exofacial leaflet, and that this is sufficient to facilitate apolipoprotein binding and lipid assembly. Upon induction of ABCA1 in RAW264.7 cells by cAMP analogues there was a moderate increase in cell surface PS as detected by annexin V binding, whereas apoAI binding was increased more robustly. Apoptosis induced large increases in annexin V and apoAI binding; however, apoptotic cells did not efflux lipids to apoAI. Annexin V did not act as a cholesterol acceptor, and it did not compete for the cholesterol acceptor or cell binding activity of apoAI. ApoAI binds to ABCA1-expressing cells, and with incubation at 37 degrees C apoAI is co-localized within the cells in ABCA1-containing endosomes. Fluorescent recovery after photobleaching demonstrated that apoAI bound to ABCA1-expressing cells was relatively immobile, suggesting that it was bound either directly or indirectly to an integral membrane protein. Although ABCA1 induction was associated with a small increase in cell surface PS, these results argue against the notion that this cell surface PS is sufficient to mediate cellular apoAI binding and lipid efflux.
Collapse
|
47
|
Lin G. Insights of high-density lipoprotein apolipoprotein-mediated lipid efflux from cells. Biochem Biophys Res Commun 2002; 291:727-31. [PMID: 11866424 DOI: 10.1006/bbrc.2002.6505] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
High-density lipoprotein (HDL) protects against cardiovascular diseases by removal of excess lipids from cells. HDL apolipoprotein-mediated lipid efflux involves multiple cellular proteins to remove both cholesterol and phospholipids that are otherwise stored in the cells. This article reviews recent progress in the understanding of receptors, signal mediators, Golgi and vesicle transport related to the pathway and proposes a model of HDL apolipoprotein receptor-mediated exocytosis of cellular cholesterol. Such an exocytotic pathway could provide the most effective mechanism to remove excess cellular lipids and prevent atherogenesis.
Collapse
Affiliation(s)
- Guorong Lin
- Department of Pathology, University of Washington, Seattle, Washington 98195-7470, USA.
| |
Collapse
|
48
|
Abstract
HDL metabolism is crucial in maintaining cellular cholesterol and phospholipid homeostasis and prevention of atherosclerosis progression. Recent work identified the ATP-binding cassette transporter A1 (ABCA1) as the major regulator of plasma high density lipoprotein (HDL) cholesterol responsible for the removal of excess cholesterol from peripheral cells and tissues. Here we discuss some novel aspects of the ABCA1 network: 1) the cellular pathways involved in cholesterol and phospholipid efflux, 2) regulation of ABCA1, 3) sulfonylurea receptor 1 (SUR1)- or cystic fibrosis transmembrane conductance regulator (CFTR)-like function of ABCA1, 4) interaction of the ABCA1 C-terminus with beta2-syntrophin, 5) ABCA1 modulation of the Rho GTPase Cdc42, 6) localization of ABCA1 in plasma membrane microdomains and intracellular sites, 7) differential effects of prebeta-HDL precursors on ABCA1 mediated alpha-HDL particle formation and 8) ABCA1 in platelets and its relation to phosphatidylserine-flippase activity. A complex regulatory network and additional antiatherogenic features that may depend on the composition of prebeta-HDL precursor particles are believed to coordinate ABCA1 function in reverse cholesterol and phospholipid transport. Distinct prebeta-HDL ligand-specific receptor-clusters are involved that may modulate specific signaling pathways with varying outcomes related to prebeta-HDL particle composition, the cell-type and the cellular response status.
Collapse
Affiliation(s)
- Gerd Schmitz
- Institute of Clinical Chemistry and Laboratory Medicine, University of Regensburg, Germany.
| | | |
Collapse
|