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Kennelly JP, Tontonoz P. Cholesterol Transport to the Endoplasmic Reticulum. Cold Spring Harb Perspect Biol 2023; 15:cshperspect.a041263. [PMID: 35940908 PMCID: PMC9899650 DOI: 10.1101/cshperspect.a041263] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Most cholesterol in mammalian cells is stored in the plasma membrane (PM). Cholesterol transport from the PM to low-sterol regulatory regions of the endoplasmic reticulum (ER) controls cholesterol synthesis and uptake, and thereby influences the rates of cholesterol flux between tissues of complex organisms. Cholesterol transfer to the ER is also required for steroidogenesis, oxysterol and bile acid synthesis, and cholesterol esterification. The ER-resident Aster proteins (Aster-A, -B, and -C) form contacts with the PM to move cholesterol to the ER in mammals. Mice lacking Aster-B have low adrenal cholesteryl ester stores and impaired steroidogenesis because of a defect in cholesterol transport from high-density lipoprotein (HDL) to the ER. This work reviews the molecular characteristics of Asters, their role in HDL- and low-density lipoprotein (LDL)-cholesterol movement, and how cholesterol transferred to the ER is utilized by cells. The roles of other lipid transporters and of membrane lipid organization in maintaining aspects of cholesterol homeostasis are also highlighted.
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Affiliation(s)
- John P Kennelly
- Department of Pathology and Laboratory Medicine, Department of Biological Chemistry, Molecular Biology Institute, University of California, Los Angeles, California 90095, USA
| | - Peter Tontonoz
- Department of Pathology and Laboratory Medicine, Department of Biological Chemistry, Molecular Biology Institute, University of California, Los Angeles, California 90095, USA
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2
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Bruno F, Camuso S, Capuozzo E, Canterini S. The Antifungal Antibiotic Filipin as a Diagnostic Tool of Cholesterol Alterations in Lysosomal Storage Diseases and Neurodegenerative Disorders. Antibiotics (Basel) 2023; 12:antibiotics12010122. [PMID: 36671323 PMCID: PMC9855188 DOI: 10.3390/antibiotics12010122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Revised: 01/05/2023] [Accepted: 01/05/2023] [Indexed: 01/10/2023] Open
Abstract
Cholesterol is the most considerable member of a family of polycyclic compounds understood as sterols, and represents an amphipathic molecule, such as phospholipids, with the polar hydroxyl group located in position 3 and the rest of the molecule is completely hydrophobic. In cells, it is usually present as free, unesterified cholesterol, or as esterified cholesterol, in which the hydroxyl group binds to a carboxylic acid and thus generates an apolar molecule. Filipin is a naturally fluorescent antibiotic that exerts a primary antifungal effect with low antibacterial activity, interfering with the sterol stabilization of the phospholipid layers and favoring membrane leakage. This polyene macrolide antibiotic does not bind to esterified sterols, but only to non-esterified cholesterol, and it is commonly used as a marker to label and quantify free cholesterol in cells and tissues. Several lines of evidence have indicated that filipin staining could be a good diagnostic tool for the cholesterol alterations present in neurodegenerative (e.g., Alzheimer's Disease and Huntington Disease) and lysosomal storage diseases (e.g., Niemann Pick type C Disease and GM1 gangliosidosis). Here, we have discussed the uses and applications of this fluorescent molecule in lipid storage diseases and neurodegenerative disorders, exploring not only the diagnostic strength of filipin staining, but also its limitations, which over the years have led to the development of new diagnostic tools to combine with filipin approach.
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Affiliation(s)
- Francesco Bruno
- Regional Neurogenetic Centre (CRN), Department of Primary Care, ASP Catanzaro, 88046 Lamezia Terme, Italy
- Association for Neurogenetic Research (ARN), 88046 Lamezia Terme, Italy
| | - Serena Camuso
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy
| | - Elisabetta Capuozzo
- Department of Biochemical Sciences, Sapienza University of Rome, 00185 Rome, Italy
- Correspondence: (E.C.); (S.C.)
| | - Sonia Canterini
- Division of Neuroscience, Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy
- Correspondence: (E.C.); (S.C.)
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3
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Aureli M, Mauri L, Carsana EV, Dobi D, Breviario S, Lunghi G, Sonnino S. Gangliosides and Cell Surface Ganglioside Metabolic Enzymes in the Nervous System. ADVANCES IN NEUROBIOLOGY 2023; 29:305-332. [DOI: 10.1007/978-3-031-12390-0_11] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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4
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Onufer EJ, Czepielewski RS, Han YH, Courtney CM, Sutton S, Sescleifer A, Randolph GJ, Warner BW. Lipid absorption and overall intestinal lymphatic transport are impaired following partial small bowel resection in mice. Sci Rep 2022; 12:11527. [PMID: 35798817 PMCID: PMC9262882 DOI: 10.1038/s41598-022-15848-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Accepted: 06/30/2022] [Indexed: 01/16/2023] Open
Abstract
Short bowel syndrome (SBS) is associated with diminished levels of serum fats caused by unknown mechanisms. We have shown that mesenteric lymphatics remodel to a more primitive state one week after small bowel resection (SBR); therefore, this study focuses on the effect of chronic lymphatic remodeling and magnitude of resection on intestinal lipid uptake and transport. C57BL6 and Prox1 creER-Rosa26LSLTdTomato (lymphatic reporter) mice underwent 50% or 75% proximal SBR or sham operations. Functional transport of lipids and fecal fat content was measured and lymphatic vasculature was compared via imaging. There was a significant reduction in functional transport of cholesterol and triglyceride after SBR with increasing loss of bowel, mirrored by a progressive increase in fecal fat content. We also describe significant morphological changes in the lymphatic vasculature in both the lamina propria and mesentery. Intestinal lymphatic drainage assay in vivo demonstrated a marked reduction of systemic absorption after resection. Intestinal lymphatic vessels significantly remodel in the setting of chronic SBS. This remodeling may account at least in part for impaired intestinal uptake and transport of fat via the compromised lymphatic architecture. We believe that these changes may contribute to the development of intestinal failure associated liver disease (IFALD), a major morbidity in patients with SBS.
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Affiliation(s)
- Emily J Onufer
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Rafael S Czepielewski
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO, USA
| | - Yong-Hyun Han
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO, USA
- Laboratory of Pathology and Physiology, College of Pharmacy, Kangwon National University, Chuncheon, 24341, South Korea
| | - Cathleen M Courtney
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | - Stephanie Sutton
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA
| | | | - Gwendalyn J Randolph
- Department of Pathology and Immunology, Washington University in St. Louis, St. Louis, MO, USA
| | - Brad W Warner
- Division of Pediatric Surgery, Department of Surgery, St. Louis Children's Hospital, Washington University in St. Louis School of Medicine, St. Louis, MO, USA.
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5
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Jing W, Pilato JL, Kay C, Feng S, Tuipulotu DE, Mathur A, Shen C, Ngo C, Zhao A, Miosge LA, Ali SA, Gardiner EE, Awad MM, Lyras D, Robertson AAB, Kaakoush NO, Man SM. Clostridium septicum α-toxin activates the NLRP3 inflammasome by engaging GPI-anchored proteins. Sci Immunol 2022; 7:eabm1803. [PMID: 35594341 DOI: 10.1126/sciimmunol.abm1803] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Clostridium species are a group of Gram-positive bacteria that cause diseases in humans, such as food poisoning, botulism, and tetanus. Here, we analyzed 10 different Clostridium species and identified that Clostridium septicum, a pathogen that causes sepsis and gas gangrene, activates the mammalian cytosolic inflammasome complex in mice and humans. Mechanistically, we demonstrate that α-toxin secreted by C. septicum binds to glycosylphosphatidylinositol (GPI)-anchored proteins on the host plasma membrane, oligomerizing and forming a membrane pore that is permissive to efflux of magnesium and potassium ions. Efflux of these cytosolic ions triggers the activation of the innate immune sensor NLRP3, inducing activation of caspase-1 and gasdermin D, secretion of the proinflammatory cytokines interleukin-1β and interleukin-18, pyroptosis, and plasma membrane rupture via ninjurin-1. Furthermore, α-toxin of C. septicum induces rapid inflammasome-mediated lethality in mice and pharmacological inhibition of the NLRP3 inflammasome using MCC950 prevents C. septicum-induced lethality. Overall, our results reveal that cytosolic innate sensing of α-toxin is central to the recognition of C. septicum infection and that therapeutic blockade of the inflammasome pathway may prevent sepsis and death caused by toxin-producing pathogens.
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Affiliation(s)
- Weidong Jing
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Jordan Lo Pilato
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Callum Kay
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Shouya Feng
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Daniel Enosi Tuipulotu
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Anukriti Mathur
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Cheng Shen
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Chinh Ngo
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Anyang Zhao
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Lisa A Miosge
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Sidra A Ali
- Division of Genome Science and Cancer, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Elizabeth E Gardiner
- Division of Genome Science and Cancer, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
| | - Milena M Awad
- Infection and Immunity Program and Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Dena Lyras
- Infection and Immunity Program and Department of Microbiology, Monash Biomedicine Discovery Institute, Monash University, Clayton, Australia
| | - Avril A B Robertson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Australia
| | | | - Si Ming Man
- Division of Immunity, Inflammation and Infection, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
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6
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Islam MM, Hlushchenko I, Pfisterer SG. Low-Density Lipoprotein Internalization, Degradation and Receptor Recycling Along Membrane Contact Sites. Front Cell Dev Biol 2022; 10:826379. [PMID: 35141225 PMCID: PMC8819725 DOI: 10.3389/fcell.2022.826379] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 01/04/2022] [Indexed: 12/12/2022] Open
Abstract
Low-density lipoprotein (LDL) internalization, degradation, and receptor recycling is a fundamental process underlying hypercholesterolemia, a high blood cholesterol concentration, affecting more than 40% of the western population. Membrane contact sites influence endosomal dynamics, plasma membrane lipid composition, and cellular cholesterol distribution. However, if we focus on LDL-related trafficking events we mostly discuss them in an isolated fashion, without cellular context. It is our goal to change this perspective and to highlight that all steps from LDL internalization to receptor recycling are likely associated with dynamic membrane contact sites in which endosomes engage with the endoplasmic reticulum and other organelles.
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Štimac I, Jug Vučko N, Blagojević Zagorac G, Marcelić M, Mahmutefendić Lučin H, Lučin P. Dynamin Inhibitors Prevent the Establishment of the Cytomegalovirus Assembly Compartment in the Early Phase of Infection. Life (Basel) 2021; 11:life11090876. [PMID: 34575026 PMCID: PMC8469281 DOI: 10.3390/life11090876] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 08/21/2021] [Accepted: 08/23/2021] [Indexed: 12/30/2022] Open
Abstract
Cytomegalovirus (CMV) infection initiates massive rearrangement of cytoplasmic organelles to generate assembly compartment (AC). The earliest events, the establishment of the preAC, are initiated in the early phase as an extensive reorganization of early endosomes (EEs), endosomal recycling compartment (ERC), trans-Golgi network (TGN), and the Golgi. Here, we demonstrate that dynamin inhibitors (Dynasore, Dyngo-4a, MiTMAB, and Dynole-34-2) block the establishment of the preAC in murine CMV (MCMV) infected cells. In this study, we extensively analyzed the effect of Dynasore on the Golgi reorganization sequence into the outer preAC. We also monitored the development of the inner preAC using a set of markers that define EEs (Rab5, Vps34, EEA1, and Hrs), the EE-ERC interface (Rab10), the ERC (Rab11, Arf6), three layers of the Golgi (GRASP65, GM130, Golgin97), and late endosomes (Lamp1). Dynasore inhibited the pericentriolar accumulation of all markers that display EE-ERC-TGN interface in the inner preAC and prevented Golgi unlinking and dislocation to the outer preAC. Furthermore, in pulse-chase experiments, we demonstrated that the presence of dynasore only during the early phase of MCMV infection (4-14 hpi) is sufficient to prevent not only AC formation but also the synthesis of late-phase proteins and virion production. Therefore, our results indicate that dynamin-2 acts as a part of the machinery required for AC generation and rearrangement of EE/ERC/Golgi membranes in the early phase of CMV infection.
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Affiliation(s)
- Igor Štimac
- Department of Physiology and Immunology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (I.Š.); (N.J.V.); (G.B.Z.); (M.M.); (P.L.)
| | - Natalia Jug Vučko
- Department of Physiology and Immunology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (I.Š.); (N.J.V.); (G.B.Z.); (M.M.); (P.L.)
| | - Gordana Blagojević Zagorac
- Department of Physiology and Immunology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (I.Š.); (N.J.V.); (G.B.Z.); (M.M.); (P.L.)
- Nursing Department, University North, University Center Varaždin, Jurja Križanića 31b, 42000 Varaždin, Croatia
| | - Marina Marcelić
- Department of Physiology and Immunology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (I.Š.); (N.J.V.); (G.B.Z.); (M.M.); (P.L.)
| | - Hana Mahmutefendić Lučin
- Department of Physiology and Immunology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (I.Š.); (N.J.V.); (G.B.Z.); (M.M.); (P.L.)
- Nursing Department, University North, University Center Varaždin, Jurja Križanića 31b, 42000 Varaždin, Croatia
- Correspondence:
| | - Pero Lučin
- Department of Physiology and Immunology, Faculty of Medicine, University of Rijeka, 51000 Rijeka, Croatia; (I.Š.); (N.J.V.); (G.B.Z.); (M.M.); (P.L.)
- Nursing Department, University North, University Center Varaždin, Jurja Križanića 31b, 42000 Varaždin, Croatia
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8
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Lu M, Ward E, van Tartwijk FW, Kaminski CF. Advances in the study of organelle interactions and their role in neurodegenerative diseases enabled by super-resolution microscopy. Neurobiol Dis 2021; 159:105475. [PMID: 34390833 DOI: 10.1016/j.nbd.2021.105475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 07/28/2021] [Accepted: 08/09/2021] [Indexed: 10/20/2022] Open
Abstract
From the first illustrations of neuronal morphology by Ramón y Cajal to the recent three-dimensional reconstruction of synaptic connections, the development of modern neuroscience has greatly benefited from breakthroughs in imaging technology. This also applies specifically to the study of neurodegenerative diseases. Much of the research into these diseases relies on the direct visualisation of intracellular structures and their dynamics in degenerating neural cells, which cannot be fully resolved by diffraction-limited microscopes. Progress in the field has therefore been closely linked to the development of super-resolution imaging methods. Their application has greatly advanced our understanding of disease mechanisms, ranging from the structural progression of protein aggregates to defects in organelle morphology. Recent super-resolution studies have specifically implicated the disruption of inter-organelle interactions in multiple neurodegenerative diseases. In this article, we describe some of the key super-resolution techniques that have contributed to this field. We then discuss work to visualise changes in the structure and dynamics of organelles and associated dysfunctions. Finally, we consider what future developments in imaging technology may further our knowledge of these processes.
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Affiliation(s)
- Meng Lu
- Cambridge Infinitus Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK; Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Edward Ward
- Cambridge Infinitus Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK; Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Francesca W van Tartwijk
- Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK
| | - Clemens F Kaminski
- Cambridge Infinitus Research Centre, Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK; Department of Chemical Engineering and Biotechnology, University of Cambridge, Cambridge CB3 0AS, UK; UK Dementia Research Institute at the University of Cambridge and Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0AH, UK.
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9
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Daniloski Z, Jordan TX, Wessels HH, Hoagland DA, Kasela S, Legut M, Maniatis S, Mimitou EP, Lu L, Geller E, Danziger O, Rosenberg BR, Phatnani H, Smibert P, Lappalainen T, tenOever BR, Sanjana NE. Identification of Required Host Factors for SARS-CoV-2 Infection in Human Cells. Cell 2021; 184:92-105.e16. [PMID: 33147445 PMCID: PMC7584921 DOI: 10.1016/j.cell.2020.10.030] [Citation(s) in RCA: 370] [Impact Index Per Article: 123.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/25/2020] [Accepted: 10/20/2020] [Indexed: 12/21/2022]
Abstract
To better understand host-virus genetic dependencies and find potential therapeutic targets for COVID-19, we performed a genome-scale CRISPR loss-of-function screen to identify host factors required for SARS-CoV-2 viral infection of human alveolar epithelial cells. Top-ranked genes cluster into distinct pathways, including the vacuolar ATPase proton pump, Retromer, and Commander complexes. We validate these gene targets using several orthogonal methods such as CRISPR knockout, RNA interference knockdown, and small-molecule inhibitors. Using single-cell RNA-sequencing, we identify shared transcriptional changes in cholesterol biosynthesis upon loss of top-ranked genes. In addition, given the key role of the ACE2 receptor in the early stages of viral entry, we show that loss of RAB7A reduces viral entry by sequestering the ACE2 receptor inside cells. Overall, this work provides a genome-scale, quantitative resource of the impact of the loss of each host gene on fitness/response to viral infection.
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Affiliation(s)
- Zharko Daniloski
- New York Genome Center, New York, NY, USA; Department of Biology, New York University, New York, NY, USA
| | - Tristan X Jordan
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Hans-Hermann Wessels
- New York Genome Center, New York, NY, USA; Department of Biology, New York University, New York, NY, USA
| | - Daisy A Hoagland
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Silva Kasela
- New York Genome Center, New York, NY, USA; Department of Systems Biology, Columbia University, New York, NY, USA
| | - Mateusz Legut
- New York Genome Center, New York, NY, USA; Department of Biology, New York University, New York, NY, USA
| | | | - Eleni P Mimitou
- Technology Innovation Lab, New York Genome Center, New York, NY, USA
| | - Lu Lu
- New York Genome Center, New York, NY, USA; Department of Biology, New York University, New York, NY, USA
| | - Evan Geller
- New York Genome Center, New York, NY, USA; Department of Biology, New York University, New York, NY, USA
| | - Oded Danziger
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Brad R Rosenberg
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Hemali Phatnani
- New York Genome Center, New York, NY, USA; Department of Neurology, Columbia University Irving Medical Center, New York, NY, USA
| | - Peter Smibert
- Technology Innovation Lab, New York Genome Center, New York, NY, USA
| | - Tuuli Lappalainen
- New York Genome Center, New York, NY, USA; Department of Systems Biology, Columbia University, New York, NY, USA
| | - Benjamin R tenOever
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Neville E Sanjana
- New York Genome Center, New York, NY, USA; Department of Biology, New York University, New York, NY, USA.
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10
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Vos DY, van de Sluis B. Function of the endolysosomal network in cholesterol homeostasis and metabolic-associated fatty liver disease (MAFLD). Mol Metab 2021; 50:101146. [PMID: 33348067 PMCID: PMC8324686 DOI: 10.1016/j.molmet.2020.101146] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/26/2020] [Accepted: 12/14/2020] [Indexed: 02/08/2023] Open
Abstract
Background Metabolic-associated fatty liver disease (MAFLD), also known as non-alcoholic fatty liver disease, has become the leading cause of chronic liver disease worldwide. In addition to hepatic accumulation of triglycerides, dysregulated cholesterol metabolism is an important contributor to the pathogenesis of MAFLD. Maintenance of cholesterol homeostasis is highly dependent on cellular cholesterol uptake and, subsequently, cholesterol transport to other membrane compartments, such as the endoplasmic reticulum (ER). Scope of review The endolysosomal network is key for regulating cellular homeostasis and adaptation, and emerging evidence has shown that the endolysosomal network is crucial to maintain metabolic homeostasis. In this review, we will summarize our current understanding of the role of the endolysosomal network in cholesterol homeostasis and its implications in MAFLD pathogenesis. Major conclusions Although multiple endolysosomal proteins have been identified in the regulation of cholesterol uptake, intracellular transport, and degradation, their physiological role is incompletely understood. Further research should elucidate their role in controlling metabolic homeostasis and development of fatty liver disease. The intracellular cholesterol transport is tightly regulated by the endocytic and lysosomal network. Dysfunction of the endolysosomal network affects hepatic lipid homeostasis. The endosomal sorting of lipoprotein receptors is precisely regulated and is not a bulk process.
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Affiliation(s)
- Dyonne Y Vos
- Department of Pediatrics, section Molecular Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Bart van de Sluis
- Department of Pediatrics, section Molecular Genetics, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
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11
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Shah M, Kumar S. Role of cholesterol in anatid herpesvirus 1 infections in vitro. Virus Res 2020; 290:198174. [DOI: 10.1016/j.virusres.2020.198174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 09/17/2020] [Accepted: 09/17/2020] [Indexed: 01/08/2023]
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12
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Gowrishankar S, Cologna SM, Givogri MI, Bongarzone ER. Deregulation of signalling in genetic conditions affecting the lysosomal metabolism of cholesterol and galactosyl-sphingolipids. Neurobiol Dis 2020; 146:105142. [PMID: 33080336 PMCID: PMC8862610 DOI: 10.1016/j.nbd.2020.105142] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 09/04/2020] [Accepted: 10/14/2020] [Indexed: 12/15/2022] Open
Abstract
The role of lipids in neuroglial function is gaining momentum in part due to a better understanding of how many lipid species contribute to key cellular signalling pathways at the membrane level. The description of lipid rafts as membrane domains composed by defined classes of lipids such as cholesterol and sphingolipids has greatly helped in our understanding of how cellular signalling can be regulated and compartmentalized in neurons and glial cells. Genetic conditions affecting the metabolism of these lipids greatly impact on how some of these signalling pathways work, providing a context to understand the biological function of the lipid. Expectedly, abnormal metabolism of several lipids such as cholesterol and galactosyl-sphingolipids observed in several metabolic conditions involving lysosomal dysfunction are often accompanied by neuronal and myelin dysfunction. This review will discuss the role of lysosomal biology in the context of deficiencies in the metabolism of cholesterol and galactosyl-sphingolipids and their impact on neural function in three genetic disorders: Niemann-Pick type C, Metachromatic leukodystrophy and Krabbe’s disease.
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Affiliation(s)
- S Gowrishankar
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL, USA.
| | - S M Cologna
- Department of Chemistry, University of Illinois, Chicago, IL, USA.
| | - M I Givogri
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL, USA.
| | - E R Bongarzone
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL, USA.
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13
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Dubey V, Bozorg B, Wüstner D, Khandelia H. Cholesterol binding to the sterol-sensing region of Niemann Pick C1 protein confines dynamics of its N-terminal domain. PLoS Comput Biol 2020; 16:e1007554. [PMID: 33021976 PMCID: PMC7537887 DOI: 10.1371/journal.pcbi.1007554] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 07/02/2020] [Indexed: 12/12/2022] Open
Abstract
Lysosomal accumulation of cholesterol is a hallmark of Niemann Pick type C (NPC) disease caused by mutations primarily in the lysosomal membrane protein NPC1. NPC1 contains a transmembrane sterol-sensing domain (SSD), which is supposed to regulate protein activity upon cholesterol binding, but the mechanisms underlying this process are poorly understood. Using atomistic simulations, we show that in the absence of cholesterol in the SSD, the luminal domains of NPC1 are highly dynamic, resulting in the disengagement of the NTD from the rest of the protein. The disengaged NPC1 adopts a flexed conformation that approaches the lipid bilayer, and could represent a conformational state primed to receive a sterol molecule from the soluble lysosomal cholesterol carrier NPC2. The binding of cholesterol to the SSD of NPC1 allosterically suppresses the conformational dynamics of the luminal domains resulting in an upright NTD conformation. The presence of an additional 20% cholesterol in the membrane has negligible impact on this process. The additional presence of an NTD-bound cholesterol suppresses the flexing of the NTD. We propose that cholesterol acts as an allosteric effector, and the modulation of NTD dynamics by the SSD-bound cholesterol constitutes an allosteric feedback mechanism in NPC1 that controls cholesterol abundance in the lysosomal membrane. Cholesterol is absorbed from LDL particles in esterified form, and is broken down to free cholesterol in the lysosomes of cells, from where cholesterol must be transported to other cellular compartments such as the plasma membrane. The Niemann Pick type C (NPC) diseases arise from deficient cholesterol transport and result from mutations in the cholesterol transport protein NPC1. Using computer simulations, we show that cholesterol, when bound to one part of NPC1, can control the structural transitions of an 8-nm distant, different part of NPC1 protein called the N-terminal domain (NTD). Such long-range control of protein conformations (allostery), controls a wide range of cellular functions mediated by proteins. Fundamental molecular insights into the function of the NPC1 protein can potentially lead to better pharmaceutical interventions for the NPC diseases.
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Affiliation(s)
- Vikas Dubey
- PhyLife Physical Life Sciences, Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Behruz Bozorg
- PhyLife Physical Life Sciences, Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Daniel Wüstner
- PhyLife Physical Life Sciences, Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Himanshu Khandelia
- PhyLife Physical Life Sciences, Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Department of Physics Chemistry, and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- MEMPHYS: Center for Biomembrane Physics, Odense M, Denmark
- * E-mail:
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14
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Ke XX, Chao H, Abbas MN, Kausar S, Gul I, Ji H, Yang L, Cui H. Niemann-Pick type C1 regulates cholesterol transport and metamorphosis in silkworm, Bombyx mori (Dazao). Int J Biol Macromol 2020; 152:525-534. [DOI: 10.1016/j.ijbiomac.2020.02.296] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 02/07/2020] [Accepted: 02/25/2020] [Indexed: 01/29/2023]
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15
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Subramanian K, Hutt DM, Scott SM, Gupta V, Mao S, Balch WE. Correction of Niemann-Pick type C1 trafficking and activity with the histone deacetylase inhibitor valproic acid. J Biol Chem 2020; 295:8017-8035. [PMID: 32354745 DOI: 10.1074/jbc.ra119.010524] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 04/13/2020] [Indexed: 12/12/2022] Open
Abstract
Niemann-Pick type C (NPC) disease is primarily caused by mutations in the NPC1 gene and is characterized by the accumulation of unesterified cholesterol and lipids in the late endosomal (LE) and lysosomal (Ly) compartments. The most prevalent disease-linked mutation is the I1061T variant of NPC1, which exhibits defective folding and trafficking from the endoplasmic reticulum to the LE/Ly compartments. We now show that the FDA-approved histone deacetylase inhibitor (HDACi) valproic acid (VPA) corrects the folding and trafficking defect associated with I1061T-NPC1 leading to restoration of cholesterol homeostasis, an effect that is largely driven by a reduction in HDAC7 expression. The VPA-mediated trafficking correction is in part associated with an increase in the acetylation of lysine residues in the cysteine-rich domain of NPC1. The HDACi-mediated correction is synergistically improved by combining it with the FDA-approved anti-malarial, chloroquine, a known lysosomotropic compound, which improved the stability of the LE/Ly-localized fraction of the I1061T variant. We posit that combining the activity of VPA, to modulate epigenetically the cellular acetylome, with chloroquine, to alter the lysosomal environment to favor stability of the trafficked I1061T variant protein can have a significant therapeutic benefit in patients carrying at least one copy of the I1061T variant of NPC1, the most common disease-associated mutation leading to NPC disease. Given its ability to cross the blood-brain barrier, we posit VPA provides a potential mechanism to improve the response to 2-hydroxypropyl-β-cyclodextrin, by restoring a functional NPC1 to the cholesterol managing compartment as an adjunct therapy.
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Affiliation(s)
| | - Darren M Hutt
- Department of Molecular Medicine, Scripps Research, La Jolla, California, USA
| | - Samantha M Scott
- Department of Molecular Medicine, Scripps Research, La Jolla, California, USA
| | - Vijay Gupta
- Department of Molecular Medicine, Scripps Research, La Jolla, California, USA
| | - Shu Mao
- Department of Biochemistry, Weill Cornell Medical College, New York, New York, USA
| | - William E Balch
- Department of Molecular Medicine, Scripps Research, La Jolla, California, USA
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16
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Martello A, Platt FM, Eden ER. Staying in touch with the endocytic network: The importance of contacts for cholesterol transport. Traffic 2020; 21:354-363. [PMID: 32129938 PMCID: PMC8650999 DOI: 10.1111/tra.12726] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/21/2020] [Accepted: 03/02/2020] [Indexed: 12/16/2022]
Abstract
Cholesterol homeostasis is critical for cell function and human health. Cholesterol is heterogeneously distributed among cellular membranes, with the redistribution of endocytosed dietary cholesterol playing a pivotal role in the regulation of cholesterol homeostasis. While gaps remain in our understanding of intracellular dietary cholesterol transport, a highly complex network of pathways is starting to emerge, often involving inter‐dependent vesicular and non‐vesicular transport mechanisms. The last decade has seen a surge in interest in non‐vesicular transport and inter‐organellar communication at membrane contact sites. By providing platforms for protein interactions, signalling events, lipid exchange and calcium flux, membrane contact sites (MCS) are now appreciated as controlling the fate of large amounts of lipid and play central roles in the regulation and co‐ordination of endocytic trafficking. Here, we review the role of MCS in multiple pathways for cholesterol export from the endocytic pathway and highlight the intriguing interplay between vesicular and non‐vesicular transport mechanisms and relationship with neurodegenerative disease.
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Affiliation(s)
| | - Fran M Platt
- Department of Pharmacology, University of Oxford, Oxford, UK
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17
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Meng Y, Heybrock S, Neculai D, Saftig P. Cholesterol Handling in Lysosomes and Beyond. Trends Cell Biol 2020; 30:452-466. [PMID: 32413315 DOI: 10.1016/j.tcb.2020.02.007] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2020] [Revised: 02/14/2020] [Accepted: 02/21/2020] [Indexed: 01/06/2023]
Abstract
Lysosomes are of major importance for the regulation of cellular cholesterol homeostasis. Food-derived cholesterol and cholesterol esters contained within lipoproteins are delivered to lysosomes by endocytosis. From the lysosomal lumen, cholesterol is transported to the inner surface of the lysosomal membrane through the glycocalyx; this shuttling requires Niemann-Pick C (NPC) 1 and NPC2 proteins. The lysosomal membrane proteins lysosomal-associated membrane protein (LAMP)-2 and lysosomal integral membrane protein (LIMP)-2/SCARB2 also bind cholesterol. LAMP-2 may serve as a cholesterol reservoir, whereas LIMP-2, like NPC1, is able to transport cholesterol through a transglycocalyx tunnel. Contact sites and fusion events between lysosomes and other organelles mediate the distribution of cholesterol. Lysosomal cholesterol content is sensed thereby regulating mammalian target of rapamycin complex (mTORC)-dependent signaling. This review summarizes our understanding of the major steps in cholesterol handling from the moment it enters the lysosome until it leaves this compartment.
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Affiliation(s)
- Ying Meng
- Department of Cell Biology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Saskia Heybrock
- Biochemisches Institut, Christian-Albrechts-Universität Kiel, Kiel, Germany
| | - Dante Neculai
- Department of Cell Biology, School of Basic Medical Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Paul Saftig
- Biochemisches Institut, Christian-Albrechts-Universität Kiel, Kiel, Germany.
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18
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Lee CA, Blackstone C. ER morphology and endo-lysosomal crosstalk: Functions and disease implications. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158544. [PMID: 31678515 DOI: 10.1016/j.bbalip.2019.158544] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/13/2019] [Accepted: 09/16/2019] [Indexed: 02/03/2023]
Abstract
The endoplasmic reticulum (ER) is a continuous endomembrane system comprising the nuclear envelope, ribosome-studded sheets, dense peripheral matrices, and an extensive polygonal network of interconnected tubules. In addition to performing numerous critical cellular functions, the ER makes extensive contacts with other organelles, including endosomes and lysosomes. The molecular and functional characterization of these contacts has advanced significantly over the past several years. These contacts participate in key functions such as cholesterol transfer, endosome tubule fission, and Ca2+ exchange. Disruption of key proteins at these sites can result in often severe diseases, particularly those affecting the nervous system.
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Affiliation(s)
- Crystal A Lee
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Craig Blackstone
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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19
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Johnson KA, Endapally S, Vazquez DC, Infante RE, Radhakrishnan A. Ostreolysin A and anthrolysin O use different mechanisms to control movement of cholesterol from the plasma membrane to the endoplasmic reticulum. J Biol Chem 2019; 294:17289-17300. [PMID: 31597703 DOI: 10.1074/jbc.ra119.010393] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2019] [Revised: 10/08/2019] [Indexed: 01/30/2023] Open
Abstract
Recent studies using two cholesterol-binding bacterial toxin proteins, perfringolysin O (PFO) and domain 4 of anthrolysin O (ALOD4), have shown that cholesterol in the plasma membranes (PMs) of animal cells resides in three distinct pools. The first pool comprises mobile cholesterol, accessible to both PFO and ALOD4, that is rapidly transported to the endoplasmic reticulum (ER) to signal cholesterol excess and maintain cholesterol homeostasis. The second is a sphingomyelin (SM)-sequestered pool inaccessible to PFO and ALOD4 but that becomes accessible by treatment with SM-degrading sphingomyelinase (SMase). The third is an essential pool also inaccessible to PFO and ALOD4 that cannot be liberated by SMase treatment. The accessible cholesterol pool can be trapped on PMs of live cells by nonlytic ALOD4, blocking its transport to the ER. However, studies of the two other pools have been hampered by a lack of available tools. Here, we used ostreolysin A (OlyA), which specifically binds SM/cholesterol complexes in membranes, to study the SM-sequestered cholesterol pool. Binding of nonlytic OlyA to SM/cholesterol complexes in PMs of live cells depleted the accessible PM cholesterol pool detectable by ALOD4. Consequently, transport of accessible cholesterol from PM to ER ceased, thereby activating SREBP transcription factors and increasing cholesterol synthesis. Thus, OlyA and ALOD4 both control movement of PM cholesterol, but through different lipid-binding mechanisms. We also found that PM-bound OlyA was rapidly internalized into cells, whereas PM-bound ALOD4 remained on the cell surface. Our findings establish OlyA and ALOD4 as complementary tools to investigate cellular cholesterol transport.
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Affiliation(s)
- Kristen A Johnson
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Shreya Endapally
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Danya C Vazquez
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Rodney E Infante
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390 .,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390.,Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, Texas 75390.,Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Arun Radhakrishnan
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas 75390
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20
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NPC1 regulates ER contacts with endocytic organelles to mediate cholesterol egress. Nat Commun 2019; 10:4276. [PMID: 31537798 PMCID: PMC6753064 DOI: 10.1038/s41467-019-12152-2] [Citation(s) in RCA: 159] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Accepted: 08/19/2019] [Indexed: 12/19/2022] Open
Abstract
Transport of dietary cholesterol from endocytic organelles to the endoplasmic reticulum (ER) is essential for cholesterol homoeostasis, but the mechanism and regulation of this transport remains poorly defined. Membrane contact sites (MCS), microdomains of close membrane apposition, are gaining attention as important platforms for non-vesicular, inter-organellar communication. Here we investigate the impact of ER-endocytic organelle MCS on cholesterol transport. We report a role for Niemann-Pick type C protein 1 (NPC1) in tethering ER-endocytic organelle MCS where it interacts with the ER-localised sterol transport protein Gramd1b to regulate cholesterol egress. We show that artificially tethering MCS rescues the cholesterol accumulation that characterises NPC1-deficient cells, consistent with direct lysosome to ER cholesterol transport across MCS. Finally, we identify an expanded population of lysosome-mitochondria MCS in cells depleted of NPC1 or Gramd1b that is dependent on the late endosomal sterol-binding protein STARD3, likely underlying the mitochondrial cholesterol accumulation in NPC1-deficient cells. Though endocytosed dietary cholesterol is transferred to the endoplasmic reticulum (ER), how this is regulated is unclear. Here, the authors report a role for Niemann-Pick Type C Protein 1 (NPC1) in tethering endocytic organelles to the ER, which may contribute to interorganelle cholesterol transport.
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21
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Cholesterol transport through the peroxisome-ER membrane contacts tethered by PI(4,5)P 2 and extended synaptotagmins. SCIENCE CHINA-LIFE SCIENCES 2019; 62:1117-1135. [PMID: 31144242 DOI: 10.1007/s11427-019-9569-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 05/20/2019] [Indexed: 10/26/2022]
Abstract
Most mammalian cells take up cholesterol from low-density lipoproteins (LDLs) via receptor-mediated endocytosis. After reaching lysosomes, LDL-derived cholesterol continues to transport to downstream organelles including the ER for specific structural and functional needs. Peroxisomes are recently found to receive cholesterol from lysosomes through lysosome-peroxisome membrane contacts. However, whether and how cholesterol is conveyed from peroxisomes to the ER remain unknown. Here, by combining high-resolution microscopic analyses and in vitro reconstitution of highly purified organelles or artificial liposomes, we demonstrate that peroxisomes form membrane contacts with the ER through the interaction between peroxisomal PI(4,5)P2 and ER-resident extended synaptotagmin-1, 2 and 3 (E-Syts). Depletion of peroxisomal PI(4,5)P2 or E-Syts markedly decreases peroxisome-ER membrane contacts and induces cholesterol accumulation in lysosomes. Furthermore, we show that cholesterol is delivered from 3H-labeled peroxisomes or PI(4,5)P2-containing liposomes to the ER in vitro, and that the presence of peroxisomes augments cholesterol transfer from lysosomes to the ER. Together, our study reveals a new cholesterol transport pathway along the lysosome-peroxisome-ER membrane contacts in the cell.
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22
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Rodriguez-Agudo D, Malacrida L, Kakiyama G, Sparrer T, Fortes C, Maceyka M, Subler MA, Windle JJ, Gratton E, Pandak WM, Gil G. StarD5: an ER stress protein regulates plasma membrane and intracellular cholesterol homeostasis. J Lipid Res 2019; 60:1087-1098. [PMID: 31015253 DOI: 10.1194/jlr.m091967] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 04/08/2019] [Indexed: 01/01/2023] Open
Abstract
How plasma membrane (PM) cholesterol is controlled is poorly understood. Ablation of the gene encoding the ER stress steroidogenic acute regulatory-related lipid transfer domain (StarD)5 leads to a decrease in PM cholesterol content, a decrease in cholesterol efflux, and an increase in intracellular neutral lipid accumulation in macrophages, the major cell type that expresses StarD5. ER stress increases StarD5 expression in mouse hepatocytes, which results in an increase in accessible PM cholesterol in WT but not in StarD5-/- hepatocytes. StarD5-/- mice store higher levels of cholesterol and triglycerides, which leads to altered expression of cholesterol-regulated genes. In vitro, a recombinant GST-StarD5 protein transfers cholesterol between synthetic liposomes. StarD5 overexpression leads to a marked increase in PM cholesterol. Phasor analysis of 6-dodecanoyl-2-dimethylaminonaphthalene fluorescence lifetime imaging microscopy data revealed an increase in PM fluidity in StarD5-/- macrophages. Taken together, these studies show that StarD5 is a stress-responsive protein that regulates PM cholesterol and intracellular cholesterol homeostasis.
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Affiliation(s)
- Daniel Rodriguez-Agudo
- Departments of Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,McGuire Veterans Affairs Medical Center, Richmond, VA 23248
| | - Leonel Malacrida
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California at Irvine, Irvine, CA 92697.,Area de Investigación Respiratoria, Departamento de Fisiopatologia, Hospital de Clinicas, Facultad de Medicina, Universidad de la Republica, Montevideo, Uruguay
| | - Genta Kakiyama
- Departments of Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,McGuire Veterans Affairs Medical Center, Richmond, VA 23248
| | - Tavis Sparrer
- Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
| | - Carolina Fortes
- Departments of Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,Departmento de Biologia Molecular y Bioquimica, Universidad de Malaga, Malaga, Spain
| | - Michael Maceyka
- Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
| | - Mark A Subler
- Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
| | - Jolene J Windle
- Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA 23298.,Human and Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
| | - Enrico Gratton
- Laboratory for Fluorescence Dynamics, Department of Biomedical Engineering, University of California at Irvine, Irvine, CA 92697
| | - William M Pandak
- Departments of Medicine, Virginia Commonwealth University School of Medicine, Richmond, VA 23298 .,McGuire Veterans Affairs Medical Center, Richmond, VA 23248
| | - Gregorio Gil
- Biochemistry and Molecular Biology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298 .,Massey Cancer Center, Virginia Commonwealth University School of Medicine, Richmond, VA 23298
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23
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Hammond N, Munkacsi AB, Sturley SL. The complexity of a monogenic neurodegenerative disease: More than two decades of therapeutic driven research into Niemann-Pick type C disease. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1109-1123. [PMID: 31002946 DOI: 10.1016/j.bbalip.2019.04.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 03/31/2019] [Accepted: 04/06/2019] [Indexed: 12/17/2022]
Abstract
Niemann-Pick type C (NP-C) disease is a rare and fatal neurodegenerative disease typified by aberrations in intracellular lipid transport. Cholesterol and other lipids accumulate in the late endosome/lysosome of all diseased cells thereby causing neuronal and visceral atrophy. A cure for NP-C remains elusive despite the extensive molecular advances emanating from the identification of the primary genetic defect in 1997. Penetration of the blood-brain barrier and efficacy in the viscera are prerequisites for effective therapy, however the rarity of NP-C disease is the major impediment to progress. Disease diagnosis is challenging and establishment of appropriate test populations for clinical trials difficult. Fortunately, disease models that span the diversity of microbial and metazoan life have been utilized to advance the quest for a therapy. The complexity of lipid storage in this disorder and in the model systems, has led to multiple theories on the primary disease mechanism and consequently numerous and varied proposed interventions. Here, we conduct an evaluation of these studies.
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Affiliation(s)
- Natalie Hammond
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand
| | - Andrew B Munkacsi
- School of Biological Sciences, Victoria University of Wellington, Wellington 6012, New Zealand.
| | - Stephen L Sturley
- Department of Biology, Barnard College-Columbia University, New York, NY 10027, United States of America.
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24
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Infectious Entry of Merkel Cell Polyomavirus. J Virol 2019; 93:JVI.02004-18. [PMID: 30626687 DOI: 10.1128/jvi.02004-18] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/23/2018] [Indexed: 12/17/2022] Open
Abstract
Merkel cell polyomavirus (MCPyV) is a small, nonenveloped tumor virus associated with an aggressive form of skin cancer, Merkel cell carcinoma (MCC). MCPyV infections are highly prevalent in the human population, with MCPyV virions being continuously shed from human skin. However, the precise host cell tropism(s) of MCPyV remains unclear: MCPyV is able to replicate within a subset of dermal fibroblasts, but MCPyV DNA has also been detected in a variety of other tissues. However, MCPyV appears different from other polyomaviruses, as it requires sulfated polysaccharides, such as heparan sulfates and/or chondroitin sulfates, for initial attachment. Like other polyomaviruses, MCPyV engages sialic acid as a (co)receptor. To explore the infectious entry process of MCPyV, we analyzed the cell biological determinants of MCPyV entry into A549 cells, a highly transducible lung carcinoma cell line, in comparison to well-studied simian virus 40 and a number of other viruses. Our results indicate that MCPyV enters cells via caveolar/lipid raft-mediated endocytosis but not macropinocytosis, clathrin-mediated endocytosis, or glycosphingolipid-enriched carriers. The viruses were internalized in small endocytic pits that led the virus to endosomes and from there to the endoplasmic reticulum (ER). Similar to other polyomaviruses, trafficking required microtubular transport, acidification of endosomes, and a functional redox environment. To our surprise, the virus was found to acquire a membrane envelope within endosomes, a phenomenon not reported for other viruses. Only minor amounts of viruses reached the ER, while the majority was retained in endosomal compartments, suggesting that endosome-to-ER trafficking is a bottleneck during infectious entry.IMPORTANCE MCPyV is the first polyomavirus directly implicated in the development of an aggressive human cancer, Merkel cell carcinoma (MCC). Although MCPyV is constantly shed from healthy skin, the MCC incidence increases among aging and immunocompromised individuals. To date, the events connecting initial MCPyV infection and subsequent transformation still remain elusive. MCPyV differs from other known polyomaviruses concerning its cell tropism, entry receptor requirements, and infection kinetics. In this study, we examined the cellular requirements for endocytic entry as well as the subcellular localization of incoming virus particles. A thorough understanding of the determinants of the infectious entry pathway and the specific biological niche will benefit prevention of virus-derived cancers such as MCC.
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25
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Luo J, Jiang LY, Yang H, Song BL. Intracellular Cholesterol Transport by Sterol Transfer Proteins at Membrane Contact Sites. Trends Biochem Sci 2019; 44:273-292. [DOI: 10.1016/j.tibs.2018.10.001] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/06/2018] [Accepted: 10/10/2018] [Indexed: 12/20/2022]
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26
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O' Connor D, Byrne A, Keyes TE. Linker length in fluorophore–cholesterol conjugates directs phase selectivity and cellular localisation in GUVs and live cells. RSC Adv 2019; 9:22805-22816. [PMID: 35514503 PMCID: PMC9067298 DOI: 10.1039/c9ra03905h] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 07/14/2019] [Indexed: 01/07/2023] Open
Abstract
Lipid membrane fluorescent probes that are both domain-selective and compatible with demanding microscopy methods are crucial to elucidate the presence and function of rafts and domains in cells and biophysical models. Whereas targeting fluorescent probes to liquid-disordered (Ld) domains is relatively facile, it is far more difficult to direct probes with high selectivity to liquid-ordered (Lo) domains. Here, a simple, one-pot approach to probe–cholesterol conjugation is described using Steglich esterification to synthesise two identical BODIPY derivatives that differ only in the length of the aliphatic chain between the dye and cholesterol. In the first, BODIPY-Ar-Chol, the probe and cholesterol were directly ester linked and in the second BODIPY-Ahx-Chol, a hexyl linker separated probe from cholesterol. Uptake and distribution of each probe was compared in ternary, phase separated giant unilamellar vesicles (GUVs) using a commercial Ld marker as a reference. BODIPY-Ar-Chol targets almost exclusively the Ld domains with selectivity of >90% whereas by contrast introducing the C6 linker between the probe and cholesterol drove the probe to Lo with excellent selectivity (>80%). The profound impact of the linker length extended also to uptake and distribution in live mammalian cells. BODIPY-Ahx-Chol associates strongly with the plasma membrane where it partitioned preferably into opposing micron dimensioned do-mains to a commercial Ld marker and its concentration at the membrane was reduced by cyclodextrin treatment of the cells. By contrast the BODIPY-Ahx-Chol permeated the membrane and localised strongly to lipid droplets within the cell. The data demonstrates the profound influence of linker length in cholesterol bioconjugates in directing the probe. By inserting a hexyl linker between a BODIPY probe and cholesterol pendant, the localization of the probe at ternary phase separated GUVs switches from Ld to Lo domains with high specificity.![]()
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Affiliation(s)
- Darragh O' Connor
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Aisling Byrne
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
| | - Tia E. Keyes
- School of Chemical Sciences
- National Centre for Sensor Research
- Dublin City University
- Dublin 9
- Ireland
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Wang WA, Agellon LB, Michalak M. Endoplasmic reticulum calcium dictates the distribution of intracellular unesterified cholesterol. Cell Calcium 2018; 76:116-121. [PMID: 30463032 DOI: 10.1016/j.ceca.2018.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/07/2018] [Accepted: 11/07/2018] [Indexed: 01/06/2023]
Abstract
Endoplasmic reticulum (ER) luminal Ca2+ influences many functions of this organelle, notably the synthesis and quality control of proteins and lipids. Cholesterol is an essential component of biological membranes and a precursor for many biologically important signaling molecules. The sterol regulatory element-binding proteins (SREBPs) are key regulators of lipid metabolism. These transcription factors are synthesized as ER membrane-bound precursor proteins that are proteolytically processed in response to cellular cholesterol status. Recently, ER Ca2+ status was shown to be an important determinant of the basal sensitivity of the sterol sensing mechanism inherent to the SREBP processing pathway. This article discusses the emerging relationship between cellular Ca2+ and cholesterol metabolism.
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Affiliation(s)
- Wen-An Wang
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2S7, Canada
| | - Luis B Agellon
- School of Human Nutrition, McGill University, Ste. Anne de Bellevue, Quebec, H9X 3V9, Canada.
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2S7, Canada.
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Hanada K. Lipid transfer proteins rectify inter-organelle flux and accurately deliver lipids at membrane contact sites. J Lipid Res 2018; 59:1341-1366. [PMID: 29884707 PMCID: PMC6071762 DOI: 10.1194/jlr.r085324] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Revised: 05/24/2018] [Indexed: 12/22/2022] Open
Abstract
The endoplasmic reticulum (ER) is the main center for the synthesis of various lipid types in cells, and newly synthesized lipids are delivered from the ER to other organelles. In the past decade, various lipid transfer proteins (LTPs) have been recognized as mediators of lipid transport from the ER to other organelles; inter-organelle transport occurs at membrane contact sites (MCSs) and in a nonvesicular manner. Although the intermembrane transfer reaction catalyzed by LTPs is an equilibrium reaction, various types of newly synthesized lipids are transported unidirectionally in cells. This review provides a brief history of the inter-organelle trafficking of lipids and summarizes the structural and biochemical characteristics of the ceramide transport protein (CERT) as a typical LTP acting at MCSs. In addition, this review compares several LTP-mediated inter-organelle lipid trafficking systems and proposes that LTPs generate unidirectional fluxes of specific lipids between different organelles by indirect coupling with the metabolic reactions that occur in specific organelles. Moreover, the available data also suggest that the major advantage of LTP-mediated lipid transport at MCSs may be the accuracy of delivery. Finally, how cholesterol is enriched in the plasma membrane is discussed from a thermodynamic perspective.
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Affiliation(s)
- Kentaro Hanada
- Department of Biochemistry and Cell Biology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan
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Hönig E, Ringer K, Dewes J, von Mach T, Kamm N, Kreitzer G, Jacob R. Galectin-3 modulates the polarized surface delivery of β1-integrin in epithelial cells. J Cell Sci 2018; 131:jcs.213199. [PMID: 29748377 DOI: 10.1242/jcs.213199] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 04/30/2018] [Indexed: 12/25/2022] Open
Abstract
Epithelial cells require a precise intracellular transport and sorting machinery to establish and maintain their polarized architecture. This machinery includes β-galactoside-binding galectins for targeting of glycoprotein to the apical membrane. Galectin-3 sorts cargo destined for the apical plasma membrane into vesicular carriers. After delivery of cargo to the apical milieu, galectin-3 recycles back into sorting organelles. We analysed the role of galectin-3 in the polarized distribution of β1-integrin in MDCK cells. Integrins are located primarily at the basolateral domain of epithelial cells. We demonstrate that a minor pool of β1-integrin interacts with galectin-3 at the apical plasma membrane. Knockdown of galectin-3 decreases apical delivery of β1-integrin. This loss is restored by supplementation with recombinant galectin-3 and galectin-3 overexpression. Our data suggest that galectin-3 targets newly synthesized β1-integrin to the apical membrane and promotes apical delivery of β1-integrin internalized from the basolateral membrane. In parallel, knockout of galectin-3 results in a reduction in cell proliferation and an impairment in proper cyst development. Our results suggest that galectin-3 modulates the surface distribution of β1-integrin and affects the morphogenesis of polarized cells.
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Affiliation(s)
- Ellena Hönig
- Department of Cell Biology and Cell Pathology, Philipps-Universität Marburg, Marburg 35037, Germany
| | - Karina Ringer
- Department of Cell Biology and Cell Pathology, Philipps-Universität Marburg, Marburg 35037, Germany.,DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps-Universität Marburg, Marburg 35043, Germany
| | - Jenny Dewes
- Department of Cell Biology and Cell Pathology, Philipps-Universität Marburg, Marburg 35037, Germany
| | - Tobias von Mach
- Department of Cell Biology and Cell Pathology, Philipps-Universität Marburg, Marburg 35037, Germany
| | - Natalia Kamm
- Department of Cell Biology and Cell Pathology, Philipps-Universität Marburg, Marburg 35037, Germany
| | - Geri Kreitzer
- Department of Molecular, Cellular and Biomedical Sciences, City University of New York School of Medicine, City College of New York, NY 10031, USA
| | - Ralf Jacob
- Department of Cell Biology and Cell Pathology, Philipps-Universität Marburg, Marburg 35037, Germany .,DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, Philipps-Universität Marburg, Marburg 35043, Germany
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Abstract
PURPOSE OF REVIEW Cholesterol is delivered to the limiting membrane of late endosomes by Niemann-Pick Type C1 and C2 proteins. This review summarizes recent evidence that cholesterol transfer from endosomes to the endoplasmic reticulum and other organelles is mediated by lipid-binding proteins that localize to membrane contact sites (MCS). RECENT FINDINGS LDL-cholesterol in the late endosomal/lysosomes is exported to the plasma membrane, where most cholesterol resides, and the endoplasmic reticulum, which harbors the regulatory complexes and enzymes that control the synthesis and esterification of cholesterol. A major advance in dissecting these cholesterol transport pathways was identification of frequent and dynamic MCS between endosomes and the endoplasmic reticulum, peroxisomes and plasma membrane. Positioned at these MCS are members of the oxysterol-binding protein (OSBP) and steroidogenic acute regulatory protein-related lipid-transfer family of lipid transfer proteins that bridge the opposing membranes and directly or indirectly mediate cholesterol transfer. OSBP-related protein 1L (ORP1L), ORP5 and ORP6 mediate cholesterol transfer to the endoplasmic reticulum that regulates cholesterol homeostasis. ORP1L and STARD3 also move cholesterol from the endoplasmic reticulum-to-late endosomal/lysosomes under low-cholesterol conditions to facilitate intraluminal vesicle formation. Cholesterol transport also occurs at MCS with peroxisomes and possibly the plasma membrane. SUMMARY Frequent contacts between organelles and the endo-lysosomal vesicles are sites for bidirectional transfer of cholesterol.
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Affiliation(s)
- Neale D Ridgway
- Department of Biochemistry & Molecular Biology
- Department of Pediatrics, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kexin Zhao
- Department of Biochemistry & Molecular Biology
- Department of Pediatrics, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia, Canada
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31
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Verderio C, Gabrielli M, Giussani P. Role of sphingolipids in the biogenesis and biological activity of extracellular vesicles. J Lipid Res 2018; 59:1325-1340. [PMID: 29853528 DOI: 10.1194/jlr.r083915] [Citation(s) in RCA: 139] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 05/06/2018] [Indexed: 12/11/2022] Open
Abstract
Extracellular vesicles (EVs) are membrane vesicles released by both eukaryotic and prokaryotic cells; they not only serve physiological functions, such as disposal of cellular components, but also play pathophysiologic roles in inflammatory and degenerative diseases. Common molecular mechanisms for EV biogenesis are evident in different cell biological contexts across eukaryotic phyla, and inhibition of this biogenesis may provide an avenue for therapeutic research. The involvement of sphingolipids (SLs) and their enzymes on EV biogenesis and release has not received much attention in current research. Here, we review how SLs participate in EV biogenesis by shaping membrane curvature and how they contribute to EV action in target cells. First, we describe how acid and neutral SMases, by generating the constitutive SL, ceramide, facilitate biogenesis of EVs at the plasma membrane and inside the endocytic compartment. We then discuss the involvement of other SLs, such as sphingosine-1-phosphate and galactosyl-sphingosine, in EV formation and cargo sorting. Last, we look ahead at some biological effects of EVs mediated by changes in SL levels in recipient cells.
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Affiliation(s)
- Claudia Verderio
- Consiglio Nazionale delle Ricerche (CNR) Institute of Neuroscience, 20129 Milano, Italy .,Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Humanitas, 20089 Rozzano, Italy
| | - Martina Gabrielli
- Consiglio Nazionale delle Ricerche (CNR) Institute of Neuroscience, 20129 Milano, Italy
| | - Paola Giussani
- Department of Biotechnology and Translational Medicine, University of Milano, 20090 Segrate, Italy
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32
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Sameni S, Malacrida L, Tan Z, Digman MA. Alteration in Fluidity of Cell Plasma Membrane in Huntington Disease Revealed by Spectral Phasor Analysis. Sci Rep 2018; 8:734. [PMID: 29335600 PMCID: PMC5768877 DOI: 10.1038/s41598-018-19160-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 12/22/2017] [Indexed: 12/18/2022] Open
Abstract
Huntington disease (HD) is a late-onset genetic neurodegenerative disorder caused by expansion of cytosine-adenine-guanine (CAG) trinucleotide in the exon 1 of the gene encoding the polyglutamine (polyQ). It has been shown that protein degradation and lipid metabolism is altered in HD. In many neurodegenerative disorders, impaired lipid homeostasis is one of the early events in the disease onset. Yet, little is known about how mutant huntingtin may affect phospholipids membrane fluidity. Here, we investigated how membrane fluidity in the living cells (differentiated PC12 and HEK293 cell lines) are affected using a hyperspectral imaging of widely used probes, LAURDAN. Using phasor approach, we characterized the fluorescence of LAURDAN that is sensitive to the polarity of the immediate environment. LAURDAN is affected by the physical order of phospholipids (lipid order) and reports the membrane fluidity. We also validated our results using a different fluorescent membrane probe, Nile Red (NR). The plasma membrane in the cells expressing expanded polyQ shows a shift toward increased membrane fluidity revealed by both LAURDAN and NR spectral phasors. This finding brings a new perspective in the understanding of the early stages of HD that can be used as a target for drug screening.
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Affiliation(s)
- Sara Sameni
- Laboratory for Fluorescence Dynamics, University of California Irvine, Irvine, CA, USA
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA
| | - Leonel Malacrida
- Laboratory for Fluorescence Dynamics, University of California Irvine, Irvine, CA, USA
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA
- Departamento de Fisiopatología, Hospital de Clinicas, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - Zhiqun Tan
- Institute for Memory Impairments and Neurological Disorders, University of California Irvine, Irvine, USA
| | - Michelle A Digman
- Laboratory for Fluorescence Dynamics, University of California Irvine, Irvine, CA, USA.
- Department of Biomedical Engineering, University of California Irvine, Irvine, CA, USA.
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Badana AK, Chintala M, Gavara MM, Naik S, Kumari S, Kappala VR, Iska BR, Malla RR. Lipid rafts disruption induces apoptosis by attenuating expression of LRP6 and survivin in triple negative breast cancer. Biomed Pharmacother 2017; 97:359-368. [PMID: 29091885 DOI: 10.1016/j.biopha.2017.10.045] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Revised: 10/08/2017] [Accepted: 10/09/2017] [Indexed: 01/18/2023] Open
Abstract
Triple negative breast cancer is a clinically challenging subtype due to lack of biomarker for rational targeted therapy. Lipid rafts are cholesterol enriched rigid platforms, which colocalize signalling molecules of cancer progression. This study explores the effect of lipid rafts disruption by cholesterol depleting agent, MβCD on induction of apoptosis and expression of WNT receptor LRP6, survivin and common apoptotic markers in TNBC cell lines. The in vitro effect of lipid rafts disruption on viability, single cell reproductive ability, proliferation and migration were evaluated by MTT, clonogenic, BrdU incorporation and wound scratch assays, respectively. The morphological changes were assessed by tryphan blue, Wright and Giemsa staining; nuclear changes by Hoechst staining. The induction of apoptosis was evaluated by AO/EtBr staining, DNA damage and DNA fragmentation assays. Expression of Caveolin-1, LRP6, β-Catenin, Survivin, Bcl2, BAX, Caspase-3, Ki67 and c-myc were analyzed by PCR and Western blotting techniques. The lipid raft disruption resulted in reduction of the proliferation of MDA-MB 231 and MDA-MB 468 cells by 56.3 and 42.0%; survival fraction by 54.7 and 59.4%; migration by 44.3 and 48.4%, respectively. It also induced apoptosis by causing cell shrinkage, membrane blebbing, nuclear condensation, chromatin cleavage, oligonucleotide fragmentation with an apoptotic index of 59.1 and 46.6% in MDA-MB 231 and 468 cells, respectively. Further, it downregulated the expression of caveolin-1, LRP6, β-catenin, survivin, Bcl2, ki67, c-myc and upregulated BAX, caspase-3. The cholesterol supplementation enhanced the clonogenic potential and upregulated the expression of caveolin-1 and LRP6. The results underline a potential effect of lipid rafts disruption on induction of apoptosis in TNBC cells.
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Affiliation(s)
- Anil Kumar Badana
- Cancer Biology Research Laboratory, Department of Biochemistry, GIS, GITAM University, Visakhapatnam, India
| | - Madhuri Chintala
- Department of Obstetrics & Gynecology, Andhra Medical College, Visakhapatnam, India
| | - Murali Mohan Gavara
- Cancer Biology Research Laboratory, Department of Biochemistry, GIS, GITAM University, Visakhapatnam, India
| | - Shailender Naik
- Cancer Biology Research Laboratory, Department of Biochemistry, GIS, GITAM University, Visakhapatnam, India
| | - Seema Kumari
- Cancer Biology Research Laboratory, Department of Biochemistry, GIS, GITAM University, Visakhapatnam, India
| | | | | | - Rama Rao Malla
- Cancer Biology Research Laboratory, Department of Biochemistry, GIS, GITAM University, Visakhapatnam, India; Department of Biochemistry, GIS, GITAM University, Visakhapatnam, India.
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Chandler RJ, Williams IM, Gibson AL, Davidson CD, Incao AA, Hubbard BT, Porter FD, Pavan WJ, Venditti CP. Systemic AAV9 gene therapy improves the lifespan of mice with Niemann-Pick disease, type C1. Hum Mol Genet 2017; 26:52-64. [PMID: 27798114 DOI: 10.1093/hmg/ddw367] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 10/21/2016] [Indexed: 12/31/2022] Open
Abstract
Niemann-Pick disease, type C1 (NPC1) is a heritable lysosomal storage disease characterized by a progressive neurological degeneration that causes disability and premature death. A murine model of NPC1 disease (Npc1-/-) displays a rapidly progressing form of NPC1 disease which is characterized by weight loss, ataxia, increased cholesterol storage, loss of cerebellar Purkinje neurons and early lethality. To test the potential efficacy of gene therapy for NPC1, we constructed adeno-associated virus serotype 9 (AAV9) vectors to deliver the NPC1 gene under the transcriptional control of the neuronal-specific (CamKII) or a ubiquitous (EF1a) promoter. The Npc1-/- mice that received a single dose of AAV9-CamKII-NPC1 as neonates (2.6 × 1011GC) or at weaning (1.3 × 1012GC), and the mice that received a single dose of AAV9-EF1a-NPC1 at weaning (1.2 × 1012GC), exhibited an increased life span, characterized by delayed weight loss and diminished motor decline. Cholesterol storage and Purkinje neuron loss were also reduced in the central nervous system of AAV9 treated Npc1-/- mice. Treatment with AAV9-EF1a-NPC1, as compared to AAV9-CamKII-NPC1, resulted in significantly increased survival (mean survival increased from 69 days to 166 and 97 days, respectively) and growth, and reduced hepatic-cholesterol accumulation. Our results provide the first demonstration that gene therapy may represent a therapeutic option for NPC1 patients and suggest that extraneuronal NPC1 expression can further augment the lifespan of the Npc1-/- mice after systemic AAV gene delivery.
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Affiliation(s)
- Randy J Chandler
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
| | - Ian M Williams
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
| | - Alana L Gibson
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
| | - Cristin D Davidson
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Center, Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Arturo A Incao
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
| | - Brandon T Hubbard
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
| | - Forbes D Porter
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
| | - William J Pavan
- Genetic Disease Research Branch, National Human Genome Research Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
| | - Charles P Venditti
- Medical Genomics and Metabolic Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, USA
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The Role of Mitochondria in the Activation/Maintenance of SOCE: Membrane Contact Sites as Signaling Hubs Sustaining Store-Operated Ca2+ Entry. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:277-296. [DOI: 10.1007/978-3-319-57732-6_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
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36
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Villa-Pulgarín JA, Gajate C, Botet J, Jimenez A, Justies N, Varela-M RE, Cuesta-Marbán Á, Müller I, Modolell M, Revuelta JL, Mollinedo F. Mitochondria and lipid raft-located FOF1-ATP synthase as major therapeutic targets in the antileishmanial and anticancer activities of ether lipid edelfosine. PLoS Negl Trop Dis 2017; 11:e0005805. [PMID: 28829771 PMCID: PMC5568728 DOI: 10.1371/journal.pntd.0005805] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 07/13/2017] [Indexed: 11/18/2022] Open
Abstract
Background Leishmaniasis is the world’s second deadliest parasitic disease after malaria, and current treatment of the different forms of this disease is far from satisfactory. Alkylphospholipid analogs (APLs) are a family of anticancer drugs that show antileishmanial activity, including the first oral drug (miltefosine) for leishmaniasis and drugs in preclinical/clinical oncology trials, but their precise mechanism of action remains to be elucidated. Methodology/Principal findings Here we show that the tumor cell apoptosis-inducer edelfosine was the most effective APL, as compared to miltefosine, perifosine and erucylphosphocholine, in killing Leishmania spp. promastigotes and amastigotes as well as tumor cells, as assessed by DNA breakdown determined by flow cytometry. In studies using animal models, we found that orally-administered edelfosine showed a potent in vivo antileishmanial activity and diminished macrophage pro-inflammatory responses. Edelfosine was also able to kill Leishmania axenic amastigotes. Edelfosine was taken up by host macrophages and killed intracellular Leishmania amastigotes in infected macrophages. Edelfosine accumulated in tumor cell mitochondria and Leishmania kinetoplast-mitochondrion, and led to mitochondrial transmembrane potential disruption, and to the successive breakdown of parasite mitochondrial and nuclear DNA. Ectopic expression of Bcl-XL inhibited edelfosine-induced cell death in both Leishmania parasites and tumor cells. We found that the cytotoxic activity of edelfosine against Leishmania parasites and tumor cells was associated with a dramatic recruitment of FOF1-ATP synthase into lipid rafts following edelfosine treatment in both parasites and cancer cells. Raft disruption and specific FOF1-ATP synthase inhibition hindered edelfosine-induced cell death in both Leishmania parasites and tumor cells. Genetic deletion of FOF1-ATP synthase led to edelfosine drug resistance in Saccharomyces cerevisiae yeast. Conclusions/Significance The present study shows that the antileishmanial and anticancer actions of edelfosine share some common signaling processes, with mitochondria and raft-located FOF1-ATP synthase being critical in the killing process, thus identifying novel druggable targets for the treatment of leishmaniasis. Leishmaniasis is a major health problem worldwide, and can result in loss of human life or a lifelong stigma because of bodily scars. According to World Health Organization, leishmaniasis is considered as an emerging and uncontrolled disease, and its current treatment is far from ideal, with only a few drugs available that could lead to drug resistance or cause serious side-effects. Here, we have found that mitochondria and raft-located FOF1-ATPase synthase are efficient druggable targets, through which an ether lipid named edelfosine exerts its antileishmanial action. Edelfosine effectively kills Leishmania spp. promastigotes and amastigotes. Our experimental animal models demonstrate that oral administration of edelfosine exerts a potent antileishmanial activity, while inhibits macrophage pro-inflammatory responses. Our results show that both Leishmania and tumor cells share mitochondria and raft-located FOF1-ATPase synthase as major druggable targets in leishmaniasis and cancer therapy. These data, showing a potent antileishmanial activity of edelfosine and unveiling its mechanism of action, together with the inhibition of the inflammatory responses elicited by macrophages, suggest that the ether lipid edelfosine is a promising oral drug for leishmaniasis, and highlight mitochondria and lipid raft-located FOF1-ATP synthase as major therapeutic targets for the treatment of this disease.
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Affiliation(s)
- Janny A Villa-Pulgarín
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Consuelo Gajate
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Laboratory of Cell Death and Cancer Therapy, Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
| | - Javier Botet
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca, Spain
| | - Alberto Jimenez
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca, Spain
| | - Nicole Justies
- Department of Cellular Immunology, Max-Planck-Institut für Immunbiologie und Epigenetik, Freiburg, Germany
| | - Rubén E Varela-M
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Álvaro Cuesta-Marbán
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain
| | - Ingrid Müller
- Department of Medicine, Section of Immunology, St. Mary's Campus, Imperial College London, London, United Kingdom
| | - Manuel Modolell
- Department of Cellular Immunology, Max-Planck-Institut für Immunbiologie und Epigenetik, Freiburg, Germany
| | - José L Revuelta
- Metabolic Engineering Group, Departamento de Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, Salamanca, Spain
| | - Faustino Mollinedo
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de Salamanca, Campus Miguel de Unamuno, Salamanca, Spain.,Laboratory of Cell Death and Cancer Therapy, Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
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Fiederling F, Weschenfelder M, Fritz M, von Philipsborn A, Bastmeyer M, Weth F. Ephrin-A/EphA specific co-adaptation as a novel mechanism in topographic axon guidance. eLife 2017; 6. [PMID: 28722651 PMCID: PMC5517148 DOI: 10.7554/elife.25533] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 06/26/2017] [Indexed: 12/30/2022] Open
Abstract
Genetic hardwiring during brain development provides computational architectures for innate neuronal processing. Thus, the paradigmatic chick retinotectal projection, due to its neighborhood preserving, topographic organization, establishes millions of parallel channels for incremental visual field analysis. Retinal axons receive targeting information from quantitative guidance cue gradients. Surprisingly, novel adaptation assays demonstrate that retinal growth cones robustly adapt towards ephrin-A/EphA forward and reverse signals, which provide the major mapping cues. Computational modeling suggests that topographic accuracy and adaptability, though seemingly incompatible, could be reconciled by a novel mechanism of coupled adaptation of signaling channels. Experimentally, we find such 'co-adaptation' in retinal growth cones specifically for ephrin-A/EphA signaling. Co-adaptation involves trafficking of unliganded sensors between the surface membrane and recycling endosomes, and is presumably triggered by changes in the lipid composition of membrane microdomains. We propose that co-adaptative desensitization eventually relies on guidance sensor translocation into cis-signaling endosomes to outbalance repulsive trans-signaling.
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Affiliation(s)
- Felix Fiederling
- Department of Cell and Neurobiology, Karlsruhe Institute of Technology, Zoological Institute, Karlruhe, Germany
| | - Markus Weschenfelder
- Department of Cell and Neurobiology, Karlsruhe Institute of Technology, Zoological Institute, Karlruhe, Germany
| | - Martin Fritz
- Department of Cell and Neurobiology, Karlsruhe Institute of Technology, Zoological Institute, Karlruhe, Germany
| | - Anne von Philipsborn
- Department of Cell and Neurobiology, Karlsruhe Institute of Technology, Zoological Institute, Karlruhe, Germany
| | - Martin Bastmeyer
- Department of Cell and Neurobiology, Karlsruhe Institute of Technology, Zoological Institute, Karlruhe, Germany
| | - Franco Weth
- Department of Cell and Neurobiology, Karlsruhe Institute of Technology, Zoological Institute, Karlruhe, Germany
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38
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Formichi P, Battisti C, De Santi MM, Guazzo R, Tripodi SA, Radi E, Rossi B, Tarquini E, Federico A. Primary cilium alterations and expression changes of Patched1 proteins in niemann-pick type C disease. J Cell Physiol 2017; 233:663-672. [PMID: 28332184 DOI: 10.1002/jcp.25926] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Accepted: 03/20/2017] [Indexed: 01/07/2023]
Abstract
Niemann-Pick type C disease (NPC) is a disorder characterized by abnormal intracellular accumulation of unesterified cholesterol and glycolipids. Two distinct disease-causing genes have been isolated, NPC1 and NPC2. The NPC1 protein is involved in the sorting and recycling of cholesterol and glycosphingolipids in the late endosomal/lysosomal system. It has extensive homology with the Patched1 (Ptc1) receptor, a transmembrane protein localized in the primary cilium, and involved in the Hedgehog signaling (Shh) pathway. We assessed the presence of NPC1 and Ptc1 proteins and evaluated the relative distribution and morphology of primary cilia in fibroblasts from five NPC1 patients and controls, and in normal fibroblasts treated with 3-ß-[2-(diethylamino)ethoxy]androst-5-en-17-one (U18666A), a cholesterol transport-inhibiting drug that is widely used to mimic NPC. Immunofluorescence and western blot analyses showed a significant decrease in expression of NPC1 and Ptc1 in NPC1 fibroblasts, while they were normally expressed in U18666A-treated fibroblasts. Moreover, fibroblasts from NPC1 patients and U18666A-treated cells showed a lower percentage distribution of primary cilia and a significant reduction in median cilia length with respect to controls. These are the first results demonstrating altered cytoplasmic expression of Ptc1 and reduced number and length of primary cilia, where Ptc1 is located, in fibroblasts from NPC1 patients. We suggest that the alterations in Ptc1 expression in cells from NPC1 patients are closely related to NPC1 expression deficit, while the primary cilia alterations observed in NPC1 and U18666A-treated fibroblasts may represent a secondary event derived from a defective metabolic pathway.
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Affiliation(s)
- Patrizia Formichi
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Carla Battisti
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | | | | | | | - Elena Radi
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
| | | | - Ermelinda Tarquini
- Unit of Clinic Neurology and Neurometabolic Diseases, AOU Siena, Siena, Italy
| | - Antonio Federico
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
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39
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Deng L, Peng Y, Jiang Y, Wu Y, Ding Y, Wang Y, Xu D, Fu Q. Imipramine Protects against Bone Loss by Inhibition of Osteoblast-Derived Microvesicles. Int J Mol Sci 2017; 18:ijms18051013. [PMID: 28481322 PMCID: PMC5454926 DOI: 10.3390/ijms18051013] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 04/02/2017] [Accepted: 05/03/2017] [Indexed: 12/30/2022] Open
Abstract
The maintenance of bone homeostasis is largely dependent upon cellular communication between osteoclasts and osteoblasts. Microvesicles (MVs) represent a novel mechanism for osteoblasts and osteoclasts communication, as has been demonstrated in our previous study. Sphingomyelinases catalyze the hydrolysis of sphingomyelin, which leads to increased membrane fluidity and facilitates MV generation. This effect can be inhibited by imipramine, an inhibitor of acid sphingomyelinase (ASM), which is also known as a member of tricyclic antidepressants (TCAs). A recent study has reported that in vitro treatment of imipramine blocked MVs release from glial cells. However, whether imipramine has this effect on osteoblast-derived MVs and whether it is involved in MV generation in vivo is unclear. Here, our investigations found that imipramine slightly reduced the expression of osteoblast differentiation of related genes, but did not impact parathyroid hormone (PTH) regulation for these genes and also did not affect receptor activator of nuclear factor-κB ligand (RANKL)-mediated osteoclast formation; however, imipramine treatment blocked MVs released from osteoblasts and inhibited MV-induced osteoclast formation. In vivo, mice administrated with imipramine were protected from ovariectomy-induced bone loss as evaluated by various bone structural parameters and serum levels of biochemical markers. Our results suggest that inhibiting the production of MVs containing RANKL in vivo is very important for preventing bone loss.
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Affiliation(s)
- Lili Deng
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu, China.
| | - Ying Peng
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu, China.
| | - Yuhai Jiang
- Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214123, Jiangsu, China.
| | - Yu Wu
- Wuxi Medical School, Jiangnan University, Wux i214122, Jiangsu, China.
| | - Yuedi Ding
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu, China.
| | - Yaping Wang
- Wuxi Second People's Hospital of Nanjing Medical University, Wuxi 214123, Jiangsu, China.
| | - Dong Xu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu, China.
| | - Qiang Fu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu, China.
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40
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Infante RE, Radhakrishnan A. Continuous transport of a small fraction of plasma membrane cholesterol to endoplasmic reticulum regulates total cellular cholesterol. eLife 2017; 6. [PMID: 28414269 PMCID: PMC5433840 DOI: 10.7554/elife.25466] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/16/2017] [Indexed: 01/15/2023] Open
Abstract
Cells employ regulated transport mechanisms to ensure that their plasma membranes (PMs) are optimally supplied with cholesterol derived from uptake of low-density lipoproteins (LDL) and synthesis. To date, all inhibitors of cholesterol transport block steps in lysosomes, limiting our understanding of post-lysosomal transport steps. Here, we establish the cholesterol-binding domain 4 of anthrolysin O (ALOD4) as a reversible inhibitor of cholesterol transport from PM to endoplasmic reticulum (ER). Using ALOD4, we: (1) deplete ER cholesterol without altering PM or overall cellular cholesterol levels; (2) demonstrate that LDL-derived cholesterol travels from lysosomes first to PM to meet cholesterol needs, and subsequently from PM to regulatory domains of ER to suppress activation of SREBPs, halting cholesterol uptake and synthesis; and (3) determine that continuous PM-to-ER cholesterol transport allows ER to constantly monitor PM cholesterol levels, and respond rapidly to small declines in cellular cholesterol by activating SREBPs, increasing cholesterol uptake and synthesis.
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Affiliation(s)
- Rodney Elwood Infante
- Departments of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States.,Internal Medicine, University of Texas Southwestern Medical Center, Dallas, United States
| | - Arun Radhakrishnan
- Departments of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, United States
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41
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Luo J, Jiang L, Yang H, Song BL. Routes and mechanisms of post-endosomal cholesterol trafficking: A story that never ends. Traffic 2017; 18:209-217. [DOI: 10.1111/tra.12471] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 02/08/2017] [Accepted: 02/08/2017] [Indexed: 12/22/2022]
Affiliation(s)
- Jie Luo
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences; Wuhan University; Wuhan China
| | - Luyi Jiang
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences; Wuhan University; Wuhan China
| | - Hongyuan Yang
- School of Biotechnology and Biomolecular Sciences; The University of New South Wales; Sydney Australia
| | - Bao-Liang Song
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences; Wuhan University; Wuhan China
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42
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Transport Assays for Sterol-Binding Proteins: Stopped-Flow Fluorescence Methods for Investigating Intracellular Cholesterol Transport Mechanisms of NPC2 Protein. Methods Mol Biol 2017. [PMID: 28205170 DOI: 10.1007/978-1-4939-6875-6_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
In this chapter we describe the use of stopped flow fluorescence spectroscopy to analyze the kinetic mechanisms of protein mediated cholesterol transfer to, from, and between model membranes. These assays allow for the detection of protein-membrane interactions that may occur during cholesterol transfer by simply modifying donor or acceptor concentrations, membrane composition, or buffer properties, and analyzing resultant transfer rates.
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43
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Patterson MC, Walkley SU. Niemann-Pick disease, type C and Roscoe Brady. Mol Genet Metab 2017; 120:34-37. [PMID: 27923544 DOI: 10.1016/j.ymgme.2016.11.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 11/21/2016] [Accepted: 11/21/2016] [Indexed: 10/20/2022]
Abstract
The Niemann-Pick family of diseases was poorly understood until Roscoe Brady and his colleagues began their investigations in the 1960s. Following Brady's discovery of the defect in acid sphingomyelinase in Niemann-Pick disease, types A and B, Peter Pentchev, a senior scientist in the group, launched a series of investigations of an unusual lipid storage disease in a spontaneous mouse model. These led initially to identification of the cholesterol trafficking defect in the mouse, and then in human Niemann-Pick disease, type C (NPC). This discovery formed the basis of the standard diagnostic test for NPC for the next three decades. Subsequently, an international collaboration was established, based at the Brady lab at NIH, which culminated in discovery of the NPC1 gene. Roscoe Brady, Peter Pentchev and their colleagues defined and refined the clinical biochemical and pathological phenotypes of NPC in a series of elegant parallel studies. They also identified abnormal oxysterols in NPC; later work has proved such compounds to be sensitive biomarkers of the disease. The dedication of the Brady lab to NPC, and the discoveries that flowed therefrom, provided critical foundations for the current explosion of progress in this disease.
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Affiliation(s)
- Marc C Patterson
- Department of Neurology, Mayo Clinic Children's Center, RO_MA_16_03ECON, 200 First Street SW, Rochester, MN 55905, United States; Department of Pediatrics and Medical Genetics, Mayo Clinic Children's Center, RO_MA_16_03ECON, 200 First Street SW, Rochester, MN 55905, United States.
| | - Steven U Walkley
- Department of Neuroscience, Rose F. Kennedy Intellectual and Developmental Disabilities Research Center, Albert Einstein College of Medicine, Bronx, New York, NY, United States.
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44
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Leclercq L. Interactions between cyclodextrins and cellular components: Towards greener medical applications? Beilstein J Org Chem 2016; 12:2644-2662. [PMID: 28144335 PMCID: PMC5238526 DOI: 10.3762/bjoc.12.261] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 11/25/2016] [Indexed: 11/23/2022] Open
Abstract
In the field of host-guest chemistry, some of the most widely used hosts are probably cyclodextrins (CDs). As CDs are able to increase the water solubility of numerous drugs by inclusion into their hydrophobic cavity, they have been widespread used to develop numerous pharmaceutical formulations. Nevertheless, CDs are also able to interact with endogenous substances that originate from an organism, tissue or cell. These interactions can be useful for a vast array of topics including cholesterol manipulation, treatment of Alzheimer's disease, control of pathogens, etc. In addition, the use of natural CDs offers the great advantage of avoiding or reducing the use of common petroleum-sourced drugs. In this paper, the general features and applications of CDs have been reviewed as well as their interactions with isolated biomolecules leading to the formation of inclusion or exclusion complexes. Finally, some potential medical applications are highlighted throughout several examples.
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Affiliation(s)
- Loïc Leclercq
- Univ. Lille, CNRS, ENSCL, UMR 8181 – UCCS - Equipe CÏSCO, F-59000 Lille, France
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45
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Averaimo S, Assali A, Ros O, Couvet S, Zagar Y, Genescu I, Rebsam A, Nicol X. A plasma membrane microdomain compartmentalizes ephrin-generated cAMP signals to prune developing retinal axon arbors. Nat Commun 2016; 7:12896. [PMID: 27694812 PMCID: PMC5059439 DOI: 10.1038/ncomms12896] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 08/11/2016] [Indexed: 01/11/2023] Open
Abstract
The development of neuronal circuits is controlled by guidance molecules that are hypothesized to interact with the cholesterol-enriched domains of the plasma membrane termed lipid rafts. Whether such domains enable local intracellular signalling at the submicrometre scale in developing neurons and are required for shaping the nervous system connectivity in vivo remains controversial. Here, we report a role for lipid rafts in generating domains of local cAMP signalling in axonal growth cones downstream of ephrin-A repulsive guidance cues. Ephrin-A-dependent retraction of retinal ganglion cell axons involves cAMP signalling restricted to the vicinity of lipid rafts and is independent of cAMP modulation outside of this microdomain. cAMP modulation near lipid rafts controls the pruning of ectopic axonal branches of retinal ganglion cells in vivo, a process requiring intact ephrin-A signalling. Together, our findings indicate that lipid rafts structure the subcellular organization of intracellular cAMP signalling shaping axonal arbors during the nervous system development.
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Affiliation(s)
- Stefania Averaimo
- Sorbonne Universités, UPMC University Paris 06, UMR_S 968, Institut de la Vision, Paris F-75012, France.,CNRS, UMR_7210, Paris F-75012, France.,INSERM, UMR_S 968, Paris F-75012, France
| | - Ahlem Assali
- Sorbonne Universités, UPMC University Paris 06, UMR_S 839, Paris F-75005, France.,INSERM UMR_S 839, Paris F-75005, France.,Institut du Fer à Moulin, Paris F-75005, France
| | - Oriol Ros
- Sorbonne Universités, UPMC University Paris 06, UMR_S 968, Institut de la Vision, Paris F-75012, France.,CNRS, UMR_7210, Paris F-75012, France.,INSERM, UMR_S 968, Paris F-75012, France
| | - Sandrine Couvet
- Sorbonne Universités, UPMC University Paris 06, UMR_S 968, Institut de la Vision, Paris F-75012, France.,CNRS, UMR_7210, Paris F-75012, France.,INSERM, UMR_S 968, Paris F-75012, France
| | - Yvrick Zagar
- Sorbonne Universités, UPMC University Paris 06, UMR_S 968, Institut de la Vision, Paris F-75012, France.,CNRS, UMR_7210, Paris F-75012, France.,INSERM, UMR_S 968, Paris F-75012, France
| | - Ioana Genescu
- Sorbonne Universités, UPMC University Paris 06, UMR_S 968, Institut de la Vision, Paris F-75012, France.,CNRS, UMR_7210, Paris F-75012, France.,INSERM, UMR_S 968, Paris F-75012, France
| | - Alexandra Rebsam
- Sorbonne Universités, UPMC University Paris 06, UMR_S 839, Paris F-75005, France.,INSERM UMR_S 839, Paris F-75005, France.,Institut du Fer à Moulin, Paris F-75005, France
| | - Xavier Nicol
- Sorbonne Universités, UPMC University Paris 06, UMR_S 968, Institut de la Vision, Paris F-75012, France.,CNRS, UMR_7210, Paris F-75012, France.,INSERM, UMR_S 968, Paris F-75012, France
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46
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Wang H, Feng Z, Wu D, Fritzsching KJ, Rigney M, Zhou J, Jiang Y, Schmidt-Rohr K, Xu B. Enzyme-Regulated Supramolecular Assemblies of Cholesterol Conjugates against Drug-Resistant Ovarian Cancer Cells. J Am Chem Soc 2016; 138:10758-61. [PMID: 27529637 PMCID: PMC5010010 DOI: 10.1021/jacs.6b06075] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
![]()
We
report that phosphotyrosine–cholesterol conjugates effectively
and selectively kill cancer cells, including platinum-resistant ovarian
cancer cells. The conjugate increases the degree of noncovalent oligomerization
upon enzymatic dephosphorylation in aqueous buffer. This enzymatic
conversion also results in the assembly of the cholesterol conjugates
inside and outside cells and leads to cell death. Preliminary mechanistic
studies suggest that the formed assemblies of the conjugates not only
interact with actin filaments and microtubules but also affect lipid
rafts. As the first report of multifaceted supramolecular assemblies
of cholesterol conjugates against cancer cells, this work illustrates
the integration of enzyme catalysis and self-assembly of essential
biological small molecules on and inside cancer cells as a promising
strategy for developing multifunctional therapeutics to treat drug-resistant
cancers.
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Affiliation(s)
- Huaimin Wang
- Department of Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02453, United States
| | - Zhaoqianqi Feng
- Department of Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02453, United States
| | - Dongdong Wu
- Department of Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02453, United States
| | - Keith J Fritzsching
- Department of Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02453, United States
| | - Mike Rigney
- Department of Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02453, United States
| | - Jie Zhou
- Department of Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02453, United States
| | - Yujie Jiang
- Department of Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02453, United States
| | - Klaus Schmidt-Rohr
- Department of Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02453, United States
| | - Bing Xu
- Department of Chemistry, Brandeis University , 415 South Street, Waltham, Massachusetts 02453, United States
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47
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Nagaraj V, Kazim AS, Helgeson J, Lewold C, Barik S, Buda P, Reinbothe TM, Wennmalm S, Zhang E, Renström E. Elevated Basal Insulin Secretion in Type 2 Diabetes Caused by Reduced Plasma Membrane Cholesterol. Mol Endocrinol 2016; 30:1059-1069. [PMID: 27533789 PMCID: PMC5045496 DOI: 10.1210/me.2016-1023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Elevated basal insulin secretion under fasting conditions together with insufficient stimulated insulin release is an important hallmark of type 2 diabetes, but the mechanisms controlling basal insulin secretion remain unclear. Membrane rafts exist in pancreatic islet cells and spatially organize membrane ion channels and proteins controlling exocytosis, which may contribute to the regulation of insulin secretion. Membrane rafts (cholesterol and sphingolipid containing microdomains) were dramatically reduced in human type 2 diabetic and diabetic Goto-Kakizaki (GK) rat islets when compared with healthy islets. Oxidation of membrane cholesterol markedly reduced microdomain staining intensity in healthy human islets, but was without effect in type 2 diabetic islets. Intriguingly, oxidation of cholesterol affected glucose-stimulated insulin secretion only modestly, whereas basal insulin release was elevated. This was accompanied by increased intracellular Ca2+ spike frequency and Ca2+ influx and explained by enhanced single Ca2+ channel activity. These results suggest that the reduced presence of membrane rafts could contribute to the elevated basal insulin secretion seen in type 2 diabetes.
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Affiliation(s)
- Vini Nagaraj
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
| | - Abdulla S Kazim
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
| | - Johan Helgeson
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
| | - Clemens Lewold
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
| | - Satadal Barik
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
| | - Pawel Buda
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
| | - Thomas M Reinbothe
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
| | - Stefan Wennmalm
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
| | - Enming Zhang
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
| | - Erik Renström
- Department of Clinical Sciences Malmö (V.N., A.S.K., J.H., C.L., S.B., P.B., T.M.R., E.Z., E.R.), Lund University Diabetes Centre, Lund University, SE-20502 Malmö, Sweden; and Science for Life Laboratory (S.W.), KTH Royal Institute of Technology, SE-171 77 Stockholm, Sweden
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48
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Eden ER. The formation and function of ER-endosome membrane contact sites. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1861:874-879. [PMID: 26898183 PMCID: PMC4917889 DOI: 10.1016/j.bbalip.2016.01.020] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 01/27/2016] [Accepted: 01/29/2016] [Indexed: 02/02/2023]
Abstract
Recent advances in membrane contact site (MCS) biology have revealed key roles for MCSs in inter-organellar exchange, the importance of which is becoming increasingly apparent. Roles for MCSs in many essential physiological processes including lipid transfer, calcium exchange, receptor tyrosine kinase signalling, lipid droplet formation, autophagosome formation, organelle dynamics and neurite outgrowth have been reported. The ER forms an extensive and dynamic network of MCSs with a diverse range of functionally distinct organelles. MCSs between the ER and endocytic pathway are particularly abundant, suggesting important physiological roles. Here, our current knowledge of the formation and function of ER contact sites with endocytic organelles from studies in mammalian systems is reviewed. Their relatively poorly defined molecular composition and recently identified functions are discussed. In addition, likely, but yet to be established, roles for these contacts in lipid transfer and calcium signalling are considered. This article is part of a Special Issue entitled: The cellular lipid landscape edited by Tim P. Levine and Anant K. Menon.
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49
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Abstract
PURPOSE OF REVIEW In this article, we summarize the present information related to the export of LDL-derived cholesterol from late endosomes, with a focus on Nieman-Pick disease, type C1 (NPC1) cholesterol delivery toward the endoplasmic reticulum (ER). We review data suggesting that several pathways may operate in parallel, including membrane transport routes and membrane contact sites (MCSs). RECENT FINDINGS There is increasing appreciation that MCSs provide an important mechanism for intermembrane lipid transfer. In late endosome-ER contacts, three protein bridges involving oxysterol binding protein related protein (ORP)1L-vesicle associated membrane protein-associated protein (VAP), steroidogenic acute regulatory protein (StAR)D3-VAP and ORP5-NPC1 proteins have been reported. How much they contribute to the flux of LDL-cholesterol to the ER is currently open. Studies for lipid transfer via MCSs have been most advanced in Saccharomyces cerevisiae. Recently, a new sterol-binding protein family conserved between yeast and man was identified. Its members localize at MCSs and were named lipid transfer protein anchored at membrane contact sites (Lam) proteins. In yeast, sterol transfer between the ER and the yeast lysosome may be facilitated by a Lam protein. SUMMARY Increasing insights into the role of MCSs in directional sterol delivery between membranes propose that they might provide routes for LDL-cholesterol transfer to the ER. Future work should reveal which specific contacts may operate for this, and how they are controlled by cholesterol homeostatic machineries.
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Affiliation(s)
- Simon G Pfisterer
- Department of Anatomy and Research Programs Unit, Faculty of Medicine, University of Helsinki, Finland and Minerva Foundation Institute for Medical Research, Helsinki, Finland
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50
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Mangelis A, Dieterich P, Peitzsch M, Richter S, Jühlen R, Hübner A, Willenberg HS, Deussen A, Lenders JWM, Eisenhofer G. Computational analysis of liquid chromatography-tandem mass spectrometric steroid profiling in NCI H295R cells following angiotensin II, forskolin and abiraterone treatment. J Steroid Biochem Mol Biol 2016; 155:67-75. [PMID: 26435452 DOI: 10.1016/j.jsbmb.2015.09.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Revised: 09/24/2015] [Accepted: 09/28/2015] [Indexed: 01/03/2023]
Abstract
Adrenal steroid hormones, which regulate a plethora of physiological functions, are produced via tightly controlled pathways. Investigations of these pathways, based on experimental data, can be facilitated by computational modeling for calculations of metabolic rate alterations. We therefore used a model system, based on mass balance and mass reaction equations, to kinetically evaluate adrenal steroidogenesis in human adrenal cortex-derived NCI H295R cells. For this purpose a panel of 10 steroids was measured by liquid chromatographic-tandem mass spectrometry. Time-dependent changes in cell incubate concentrations of steroids - including cortisol, aldosterone, dehydroepiandrosterone and their precursors - were measured after incubation with angiotensin II, forskolin and abiraterone. Model parameters were estimated based on experimental data using weighted least square fitting. Time-dependent angiotensin II- and forskolin-induced changes were observed for incubate concentrations of precursor steroids with peaks that preceded maximal increases in aldosterone and cortisol. Inhibition of 17-alpha-hydroxylase/17,20-lyase with abiraterone resulted in increases in upstream precursor steroids and decreases in downstream products. Derived model parameters, including rate constants of enzymatic processes, appropriately quantified observed and expected changes in metabolic pathways at multiple conversion steps. Our data demonstrate limitations of single time point measurements and the importance of assessing pathway dynamics in studies of adrenal cortical cell line steroidogenesis. Our analysis provides a framework for evaluation of steroidogenesis in adrenal cortical cell culture systems and demonstrates that computational modeling-derived estimates of kinetic parameters are an effective tool for describing perturbations in associated metabolic pathways.
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Affiliation(s)
- Anastasios Mangelis
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany.
| | - Peter Dieterich
- Institute of Physiology, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Mirko Peitzsch
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Susan Richter
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Ramona Jühlen
- Department of Pediatrics, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Angela Hübner
- Department of Pediatrics, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Holger S Willenberg
- Department of Internal Medicine III, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; Division of Endocrinology and Metabolism, Rostock University Medical Center, Ernst-Heydemann-Str. 6, 18057 Rostock, Germany
| | - Andreas Deussen
- Institute of Physiology, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - Jacques W M Lenders
- Department of Internal Medicine III, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; Department of General Internal Medicine, Radboud University Medical Center, Geert Grooteplein 8, 6525 Nijmegen, The Netherlands
| | - Graeme Eisenhofer
- Institute of Clinical Chemistry and Laboratory Medicine, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; Department of Internal Medicine III, University Hospital Carl Gustav Carus, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
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