1
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Farley S, Stein F, Haberkant P, Tafesse FG, Schultz C. Trifunctional Sphinganine: A New Tool to Dissect Sphingolipid Function. ACS Chem Biol 2024; 19:336-347. [PMID: 38284972 PMCID: PMC10878393 DOI: 10.1021/acschembio.3c00554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/13/2023] [Accepted: 12/13/2023] [Indexed: 01/30/2024]
Abstract
Functions and cell biology of the sphingolipids sphingosine and sphinganine in cells are not well understood. While some signaling roles for sphingosine have been elucidated, the closely related sphinganine has been described only insofar as it does not elicit many of the same signaling responses. Here, we prepared multifunctionalized derivatives of the two lipid species that differ only in a single double bond of the carbon backbone. Using these novel probes, we were able to define their spatiotemporal distributions within cells. Furthermore, we used these tools to systematically map the protein interactomes of both lipids. The lipid-protein conjugates, prepared through photo-crosslinking in live cells and extraction via click chemistry to azide beads, revealed significant differences in the captured proteins, highlighting their distinct roles in various cellular processes. This work elucidates mechanistic differences between these critical lipids and sets the foundation for further studies of the cellular functions of sphingosine and sphinganine.
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Affiliation(s)
- Scotland Farley
- Department
of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, United States
- Department
of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Frank Stein
- European
Molecular Biology Laboratory, Proteomics
Core Facility, Heidelberg 69117, Germany
| | - Per Haberkant
- European
Molecular Biology Laboratory, Proteomics
Core Facility, Heidelberg 69117, Germany
| | - Fikadu G. Tafesse
- Department
of Molecular Microbiology and Immunology, Oregon Health & Science University, Portland, Oregon 97239, United States
| | - Carsten Schultz
- Department
of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, Oregon 97239, United States
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2
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Carreira AC, Pokorna S, Ventura AE, Walker MW, Futerman AH, Lloyd-Evans E, de Almeida RFM, Silva LC. Biophysical impact of sphingosine and other abnormal lipid accumulation in Niemann-Pick disease type C cell models. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158944. [PMID: 33892149 DOI: 10.1016/j.bbalip.2021.158944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 03/08/2021] [Accepted: 04/12/2021] [Indexed: 10/21/2022]
Abstract
Niemann-Pick disease type C (NPC) is a complex and rare pathology, which is mainly associated to mutations in the NPC1 gene. This disease is phenotypically characterized by the abnormal accumulation of multiple lipid species in the acidic compartments of the cell. Due to the complexity of stored material, a clear molecular mechanism explaining NPC pathophysiology is still not established. Abnormal sphingosine accumulation was suggested as the primary factor involved in the development of NPC, followed by the accumulation of other lipid species. To provide additional mechanistic insight into the role of sphingosine in NPC development, fluorescence spectroscopy and microscopy were used to study the biophysical properties of biological membranes using different cellular models of NPC. Addition of sphingosine to healthy CHO-K1 cells, in conditions where other lipid species are not yet accumulated, caused a rapid decrease in plasma membrane and lysosome membrane fluidity, suggesting a direct effect of sphingosine rather than a downstream event. Changes in membrane fluidity caused by addition of sphingosine were partially sustained upon impaired trafficking and metabolization of cholesterol in these cells, and could recapitulate the decrease in membrane fluidity observed in NPC1 null Chinese Hamster Ovary (CHO) cells (CHO-M12) and in cells with pharmacologically induced NPC phenotype (treated with U18666A). In summary, these results show for the first time that the fluidity of the membranes is altered in models of NPC and that these changes are in part caused by sphingosine, supporting the role of this lipid in the pathophysiology of NPC.
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Affiliation(s)
- Ana C Carreira
- iMed.ULisboa - Research Institute for Medicines, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; Centro de Química e Bioquímica (CQB) e Centro de Química Estrutural (CQE), Faculdade de Ciências, Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016 Lisboa, Portugal; Sir Martin Evans Building, School of Biosciences, Cardiff University, Museum Avenue, Cardiff, UK
| | - Sarka Pokorna
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel; Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences, Dolejškova 3, 182 23 Prague, Czech Republic
| | - Ana E Ventura
- iMed.ULisboa - Research Institute for Medicines, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel; iBB-Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, Lisboa, Portugal
| | - Mathew W Walker
- Sir Martin Evans Building, School of Biosciences, Cardiff University, Museum Avenue, Cardiff, UK
| | - Anthony H Futerman
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Emyr Lloyd-Evans
- Sir Martin Evans Building, School of Biosciences, Cardiff University, Museum Avenue, Cardiff, UK
| | - Rodrigo F M de Almeida
- Centro de Química e Bioquímica (CQB) e Centro de Química Estrutural (CQE), Faculdade de Ciências, Universidade de Lisboa, Ed. C8, Campo Grande, 1749-016 Lisboa, Portugal.
| | - Liana C Silva
- iMed.ULisboa - Research Institute for Medicines, Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal.
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3
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Casasampere M, Izquierdo E, Casas J, Abad JL, Liu X, Xu R, Mao C, Chang YT, Delgado A, Fabrias G. Click and count: specific detection of acid ceramidase activity in live cells. Chem Sci 2020; 11:13044-13051. [PMID: 34094488 PMCID: PMC8163297 DOI: 10.1039/d0sc03166f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 10/16/2020] [Indexed: 01/02/2023] Open
Abstract
The use of intact cells in medical research offers a number of advantages over employing cell-free systems. In diagnostics, cells isolated from liquid biopsies can be directly used, speeding up the time of analysis and diminishing the risk of protein degradation by sample manipulation. In drug discovery, studies in live cells take into account aspects neglected in cell-free systems, such as uptake, metabolization, and subcellular concentration by compartmentalization of potential drug candidates. Therefore, probes for studies in cellulo are of paramount importance. Acid ceramidase (AC) is a lysosomal enzyme that hydrolyses ceramides into sphingoid bases and fatty acids. The essential role of this enzyme in the outburst and progress of several diseases, some of them still incurable, is well sustained. Despite the great clinical relevance of AC as a biomarker and therapeutic target, the specific monitoring of AC activity in live cells has remained elusive due to the concomitant existence of neutral and alkaline ceramidases. In this work, we report that 1-deoxydihydroceramides are exclusively hydrolysed by AC. Using N-octanoyl-18-azidodeoxysphinganine as a probe and a BODIPY-substituted bicyclononyne, we show the click-reliant predominant staining of lysosomes, with extra-lysosomal labeling also occurring in some cells. Importantly, using pharmacological and genetic tools together with high resolution mass spectrometry, we demonstrate that both lysosomal and extra-lysosomal staining are AC-dependent. These findings are translated into the specific flow cytometry monitoring of AC activity in intact cells, which fills an important gap in the field of diseases linked to altered AC activity.
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Affiliation(s)
- Mireia Casasampere
- Research Unit on BioActive Molecules, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) Jordi Girona 18 08034-Barcelona Spain
| | - Eduardo Izquierdo
- Research Unit on BioActive Molecules, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) Jordi Girona 18 08034-Barcelona Spain
| | - Josefina Casas
- Research Unit on BioActive Molecules, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) Jordi Girona 18 08034-Barcelona Spain
- Liver and Digestive Diseases Networking Biomedical Research Centre (CIBEREHD), ISCIII 28029 Madrid Spain
| | - José Luís Abad
- Research Unit on BioActive Molecules, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) Jordi Girona 18 08034-Barcelona Spain
| | - Xiao Liu
- Department of Chemistry, Pohang University of Science and Technology (POSTECH) Pohang Gyeongbuk 37673 Korea
| | - Ruijuan Xu
- Department of Medicine and Cancer Center, The State University of New York at Stony Brook Room 9M-0834, MART Building, 100 Nicolls Road, Stony Brook NY 11794 USA
| | - Cungui Mao
- Department of Medicine and Cancer Center, The State University of New York at Stony Brook Room 9M-0834, MART Building, 100 Nicolls Road, Stony Brook NY 11794 USA
| | - Young-Tae Chang
- Department of Chemistry, Pohang University of Science and Technology (POSTECH) Pohang Gyeongbuk 37673 Korea
- Center for Self-assembly and Complexity, Institute for Basic Science (IBS) Pohang Gyeongbuk 37673 Korea
| | - Antonio Delgado
- Research Unit on BioActive Molecules, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) Jordi Girona 18 08034-Barcelona Spain
- Department of Pharmacology, Toxicology and Medicinal Chemistry, Unit of Pharmaceutical Chemistry (Associated Unit to CSIC), Faculty of Pharmacy, University of Barcelona Avda. Joan XXIII s/n 08028 Barcelona Spain
| | - Gemma Fabrias
- Research Unit on BioActive Molecules, Department of Biological Chemistry, Institute for Advanced Chemistry of Catalonia (IQAC-CSIC) Jordi Girona 18 08034-Barcelona Spain
- Liver and Digestive Diseases Networking Biomedical Research Centre (CIBEREHD), ISCIII 28029 Madrid Spain
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4
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Heybrock S, Kanerva K, Meng Y, Ing C, Liang A, Xiong ZJ, Weng X, Ah Kim Y, Collins R, Trimble W, Pomès R, Privé GG, Annaert W, Schwake M, Heeren J, Lüllmann-Rauch R, Grinstein S, Ikonen E, Saftig P, Neculai D. Lysosomal integral membrane protein-2 (LIMP-2/SCARB2) is involved in lysosomal cholesterol export. Nat Commun 2019; 10:3521. [PMID: 31387993 PMCID: PMC6684646 DOI: 10.1038/s41467-019-11425-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 07/12/2019] [Indexed: 11/30/2022] Open
Abstract
The intracellular transport of cholesterol is subject to tight regulation. The structure of the lysosomal integral membrane protein type 2 (LIMP-2, also known as SCARB2) reveals a large cavity that traverses the molecule and resembles the cavity in SR-B1 that mediates lipid transfer. The detection of cholesterol within the LIMP-2 structure and the formation of cholesterol-like inclusions in LIMP-2 knockout mice suggested the possibility that LIMP2 transports cholesterol in lysosomes. We present results of molecular modeling, crosslinking studies, microscale thermophoresis and cell-based assays that support a role of LIMP-2 in cholesterol transport. We show that the cavity in the luminal domain of LIMP-2 can bind and deliver exogenous cholesterol to the lysosomal membrane and later to lipid droplets. Depletion of LIMP-2 alters SREBP-2-mediated cholesterol regulation, as well as LDL-receptor levels. Our data indicate that LIMP-2 operates in parallel with Niemann Pick (NPC)-proteins, mediating a slower mode of lysosomal cholesterol export.
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Affiliation(s)
- Saskia Heybrock
- Biochemisches Institut, Christian-Albrechts-Universität Kiel, Kiel, Germany
| | - Kristiina Kanerva
- Faculty of Medicine, Anatomy and Stem Cells and Metabolism Research Program, University of Helsinki, Helsinki, Finland
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Ying Meng
- Department of Cell Biology, and Department of Pathology Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Chris Ing
- Program in Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada
| | - Anna Liang
- Program in Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada
| | - Zi-Jian Xiong
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada
| | - Xialian Weng
- Department of Cell Biology, and Department of Pathology Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China
| | - Young Ah Kim
- Department of Chemistry and Biochemistry, Queens College, City University of New York, Flushing, New York, USA
| | - Richard Collins
- Cell Biology Program, Hospital for Sick Children, Toronto, M5G 1X8, Canada
| | - William Trimble
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada
- Cell Biology Program, Hospital for Sick Children, Toronto, M5G 1X8, Canada
- Department of Physiology, University of Toronto, Toronto, M5S 1A8, Canada
| | - Régis Pomès
- Program in Molecular Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada
| | - Gilbert G Privé
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada
- Princes Margaret Cancer Centre, Toronto, ON, Canada
| | - Wim Annaert
- Laboratory for Membrane Trafficking, VIB-Center for Brain and Disease Research, Leuven, Belgium
| | - Michael Schwake
- Faculty of Chemistry, Biochemistry III, University of Bielefeld, 33615, Bielefeld, Germany
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Joerg Heeren
- Institut für Biochemie und Molekulare Zellbiologie, Zentrum für Experimentelle Medizin, Universitätsklinikum Hamburg-Eppendorf, Hamburg-Eppendorf, Germany
| | | | - Sergio Grinstein
- Department of Biochemistry, University of Toronto, Toronto, M5S 1A8, Canada.
- Cell Biology Program, Hospital for Sick Children, Toronto, M5G 1X8, Canada.
| | - Elina Ikonen
- Faculty of Medicine, Anatomy and Stem Cells and Metabolism Research Program, University of Helsinki, Helsinki, Finland.
- Minerva Foundation Institute for Medical Research, Helsinki, Finland.
| | - Paul Saftig
- Biochemisches Institut, Christian-Albrechts-Universität Kiel, Kiel, Germany.
| | - Dante Neculai
- Department of Cell Biology, and Department of Pathology Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, P.R. China.
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5
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Goins L, Spassieva S. Sphingoid bases and their involvement in neurodegenerative diseases. Adv Biol Regul 2018; 70:65-73. [PMID: 30377075 DOI: 10.1016/j.jbior.2018.10.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 06/08/2023]
Abstract
Sphingoid bases (also known as long-chain bases) form the backbone of sphingolipids. Sphingolipids comprise a large group of lipid molecules, which function as the building blocks of biological membranes and play important signaling and regulatory roles within cells. The roles of sphingoid bases in neurotoxicity and neurodegeneration have yet to be fully elucidated, as they are complex and multi-faceted. This comprises a new frontier of research that may provide us with important clues regarding their involvement in neurological health and disease. This paper explores various neurological diseases and conditions which result when the metabolism of sphingoid bases and some of their derivatives, such as sphingosine-1-phosphate and psychosine, becomes compromised due to the inhibition or mutation of key enzymes. Dysregulation of sphingoid base metabolism very often manifests with neurological symptoms, as sphingolipids are highly enriched in the nervous system, where they play important signaling and regulatory roles.
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Affiliation(s)
- Laura Goins
- Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Stefka Spassieva
- Department of Physiology, University of Kentucky, Lexington, KY, USA.
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6
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Malamon JS, Kriete A. Integrated Systems Approach Reveals Sphingolipid Metabolism Pathway Dysregulation in Association with Late-Onset Alzheimer's Disease. BIOLOGY 2018; 7:biology7010016. [PMID: 29425116 PMCID: PMC5872042 DOI: 10.3390/biology7010016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 01/22/2018] [Accepted: 02/06/2018] [Indexed: 01/21/2023]
Abstract
Late-onset Alzheimer’s disease (LOAD) and age are significantly correlated such that one-third of Americans beyond 85 years of age are afflicted. We have designed and implemented a pilot study that combines systems biology approaches with traditional next-generation sequencing (NGS) analysis techniques to identify relevant regulatory pathways, infer functional relationships and confirm the dysregulation of these biological pathways in LOAD. Our study design is a most comprehensive systems approach combining co-expression network modeling derived from RNA-seq data, rigorous quality control (QC) standards, functional ontology, and expression quantitative trait loci (eQTL) derived from whole exome (WES) single nucleotide variant (SNV) genotype data. Our initial results reveal several statistically significant, biologically relevant genes involved in sphingolipid metabolism. To validate these findings, we performed a gene set enrichment analysis (GSEA). The GSEA revealed the sphingolipid metabolism pathway and regulation of autophagy in association with LOAD cases. In the execution of this study, we have successfully tested an integrative approach to identify both novel and known LOAD drivers in order to develop a broader and more detailed picture of the highly complex transcriptional and regulatory landscape of age-related dementia.
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Affiliation(s)
- John Stephen Malamon
- Bossone Research Center, School of Biomedical Engineering, Science and Health Systems, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
| | - Andres Kriete
- Bossone Research Center, School of Biomedical Engineering, Science and Health Systems, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
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7
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Abstract
Gangliosides are sialic acid containing glycosphingolipids, which are abundant in mammalian brain tissue. Several fatal human diseases are caused by defects in glycolipid metabolism. Defects in their degradation lead to an accumulation of metabolites upstream of the defective reactions, whereas defects in their biosynthesis lead to diverse problems in a large number of organs.Gangliosides are primarily positioned with their ceramide anchor in the neuronal plasma membrane and the glycan head group exposed on the cell surface. Their biosynthesis starts in the endoplasmic reticulum with the formation of the ceramide anchor, followed by sequential glycosylation reactions, mainly at the luminal surface of Golgi and TGN membranes, a combinatorial process, which is catalyzed by often promiscuous membrane-bound glycosyltransferases.Thereafter, the gangliosides are transported to the plasma membrane by exocytotic membrane flow. After endocytosis, they are degraded within the endolysosomal compartments by a complex machinery of degrading enzymes, lipid-binding activator proteins, and negatively charged lipids.
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Affiliation(s)
- Bernadette Breiden
- LIMES Institute, Membrane Biology & Lipid Biochemistry Unit, Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Bonn, Germany
| | - Konrad Sandhoff
- LIMES Institute, Membrane Biology & Lipid Biochemistry Unit, Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Bonn, Germany.
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8
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Development of lysosome-mimicking vesicles to study the effect of abnormal accumulation of sphingosine on membrane properties. Sci Rep 2017. [PMID: 28638081 PMCID: PMC5479847 DOI: 10.1038/s41598-017-04125-6] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Synthetic systems are widely used to unveil the molecular mechanisms of complex cellular events. Artificial membranes are key examples of models employed to address lipid-lipid and lipid-protein interactions. In this work, we developed a new synthetic system that more closely resembles the lysosome – the lysosome-mimicking vesicles (LMVs) – displaying stable acid-to-neutral pH gradient across the membrane. To evaluate the advantages of this synthetic system, we assessed the distinct effects of sphingosine (Sph) accumulation in membrane structure and biophysical properties of standard liposomes (no pH gradient) and in LMVs with lipid composition tuned to mimic physiological- or NPC1-like lysosomes. Ternary 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC)/Sphingomyelin (SM)/Cholesterol (Chol) mixtures with, respectively, low and high Chol/SM levels were prepared. The effect of Sph on membrane permeability and biophysical properties was evaluated by fluorescence spectroscopy, electrophoretic and dynamic light scattering. The results showed that overall Sph has the ability to cause a shift in vesicle surface charge, increase membrane order and promote a rapid increase in membrane permeability. These effects are enhanced in NPC1- LMVs. The results suggest that lysosomal accumulation of these lipids, as observed under pathological conditions, might significantly affect lysosomal membrane structure and integrity, and therefore contribute to the impairment of cell function.
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9
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Characterization of cholesterol homeostasis in sphingosine-1-phosphate lyase-deficient fibroblasts reveals a Niemann-Pick disease type C-like phenotype with enhanced lysosomal Ca 2+ storage. Sci Rep 2017; 7:43575. [PMID: 28262793 PMCID: PMC5337937 DOI: 10.1038/srep43575] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Accepted: 01/25/2017] [Indexed: 02/08/2023] Open
Abstract
Sphingosine-1-phosphate (S1P) lyase irreversibly cleaves S1P, thereby catalysing the ultimate step of sphingolipid degradation. We show here that embryonic fibroblasts from S1P lyase-deficient mice (Sgpl1−/−-MEFs), in which S1P and sphingosine accumulate, have features of Niemann-Pick disease type C (NPC) cells. In the presence of serum, overall cholesterol content was elevated in Sgpl1−/−-MEFs, due to upregulation of the LDL receptor and enhanced cholesterol uptake. Despite this, activation of sterol regulatory element-binding protein-2 was increased in Sgpl1−/−-MEFs, indicating a local lack of cholesterol at the ER. Indeed, free cholesterol was retained in NPC1-containing vesicles, which is a hallmark of NPC. Furthermore, upregulation of amyloid precursor protein in Sgpl1−/−-MEFs was mimicked by an NPC1 inhibitor in Sgpl1+/+-MEFs and reduced by overexpression of NPC1. Lysosomal pH was not altered by S1P lyase deficiency, similar to NPC. Interestingly, lysosomal Ca2+ content and bafilomycin A1-induced [Ca2+]i increases were enhanced in Sgpl1−/−-MEFs, contrary to NPC. These results show that both a primary defect in cholesterol trafficking and S1P lyase deficiency cause overlapping phenotypic alterations, and challenge the present view on the role of sphingosine in lysosomal Ca2+ homeostasis.
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10
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Trifunctional lipid probes for comprehensive studies of single lipid species in living cells. Proc Natl Acad Sci U S A 2017; 114:1566-1571. [PMID: 28154130 DOI: 10.1073/pnas.1611096114] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Lipid-mediated signaling events regulate many cellular processes. Investigations of the complex underlying mechanisms are difficult because several different methods need to be used under varying conditions. Here we introduce multifunctional lipid derivatives to study lipid metabolism, lipid-protein interactions, and intracellular lipid localization with a single tool per target lipid. The probes are equipped with two photoreactive groups to allow photoliberation (uncaging) and photo-cross-linking in a sequential manner, as well as a click-handle for subsequent functionalization. We demonstrate the versatility of the design for the signaling lipids sphingosine and diacylglycerol; uncaging of the probe for these two species triggered calcium signaling and intracellular protein translocation events, respectively. We performed proteomic screens to map the lipid-interacting proteome for both lipids. Finally, we visualized a sphingosine transport deficiency in patient-derived Niemann-Pick disease type C fibroblasts by fluorescence as well as correlative light and electron microscopy, pointing toward the diagnostic potential of such tools. We envision that this type of probe will become important for analyzing and ultimately understanding lipid signaling events in a comprehensive manner.
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11
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Zhou K, Blom T. Trafficking and Functions of Bioactive Sphingolipids: Lessons from Cells and Model Membranes. Lipid Insights 2015; 8:11-20. [PMID: 26715852 PMCID: PMC4685176 DOI: 10.4137/lpi.s31615] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/08/2015] [Accepted: 11/10/2015] [Indexed: 12/15/2022] Open
Abstract
Ceramide and sphingosine and their phosphorylated counterparts are recognized as "bioactive sphingolipids" and modulate membrane integrity, the activity of enzymes, or act as ligands of G protein-coupled receptors. The subcellular distribution of the bioactive sphingolipids is central to their function as the same lipid can mediate diametrically opposite effects depending on its location. To ensure that these lipids are present in the right amount and in the appropriate organelles, cells employ selective lipid transport and compartmentalize sphingolipid-metabolizing enzymes to characteristic subcellular sites. Our knowledge of key mechanisms involved in sphingolipid signaling and trafficking has increased substantially in the past decades-thanks to advances in biochemical and cell biological methods. In this review, we focus on the bioactive sphingolipids and discuss how the combination of studies in cells and in model membranes have contributed to our understanding of how they behave and function in living organisms.
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Affiliation(s)
- Kecheng Zhou
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Tomas Blom
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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12
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Höglinger D, Haberkant P, Aguilera-Romero A, Riezman H, Porter FD, Platt FM, Galione A, Schultz C. Intracellular sphingosine releases calcium from lysosomes. eLife 2015; 4:e10616. [PMID: 26613410 PMCID: PMC4744193 DOI: 10.7554/elife.10616] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/27/2015] [Indexed: 12/15/2022] Open
Abstract
To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endosomes and lysosomes. Further, uncaging of Sph leads to the translocation of the autophagy-relevant transcription factor EB (TFEB) to the nucleus specifically after lysosomal calcium release. We confirm that Sph accumulates in late endosomes and lysosomes of cells derived from Niemann-Pick disease type C (NPC) patients and demonstrate a greatly reduced calcium release upon Sph uncaging. We conclude that sphingosine is a positive regulator of calcium release from acidic stores and that understanding the interplay between Sph homeostasis, calcium signaling and autophagy will be crucial in developing new therapies for lipid storage disorders such as NPC.
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Affiliation(s)
- Doris Höglinger
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Per Haberkant
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | | | - Howard Riezman
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Forbes D Porter
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, United States
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Antony Galione
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Carsten Schultz
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
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A reflection of the lasting contributions from Dr. Robert Bittman to sterol trafficking, sphingolipid and phospholipid research. Prog Lipid Res 2015; 61:19-29. [PMID: 26584871 DOI: 10.1016/j.plipres.2015.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 10/21/2015] [Accepted: 10/28/2015] [Indexed: 10/22/2022]
Abstract
With the passing of Dr. Robert Bittman from pancreatic cancer on the 1st October 2014, the lipid research field lost one of the most influential and significant personalities. Robert Bittman's genius was in chemical design and his contribution to the lipid research field was truly immense. The reagents and chemicals he designed and synthesised allowed interrogation of the role of lipids in constituting complex biophysical membranes, sterol transfer and in cellular communication networks. Here we provide a review of these works which serve as a lasting memory to his life.
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Ikonen E, Blom T. Lipoprotein-mediated delivery of BODIPY-labeled sterol and sphingolipid analogs reveals lipid transport mechanisms in mammalian cells. Chem Phys Lipids 2015; 194:29-36. [PMID: 26343174 DOI: 10.1016/j.chemphyslip.2015.08.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/17/2015] [Accepted: 08/18/2015] [Indexed: 01/29/2023]
Abstract
Lipids are often introduced into cell membranes directly from solvent or from lipophilic artificial carriers, such as cyclodextrins. A physiological lipid entry route into mammalian cells is via lipoprotein mediated uptake. In this review, we discuss the introduction of BODIPY-labeled sterol and sphingolipid analogs into mammalian cells via high- or low-density lipoproteins, and the novel findings made by using this strategy. Lipoprotein mediated delivery favors endocytic uptake and initial incorporation of the lipid into membranes of the endosomal compartments. This routing can therefore highlight physiological mechanisms of lipid entry into and exit from the endo-lysosomal membrane system. The underlying principles are of key importance for instance in controlling plasma cholesterol levels and in the development and regression of lysosomal lipid storage diseases. A common denominator for the BODIPY-labeled lipid analogs discussed in this review is that they were synthesized by late Robert Bittman, whose scientific impact radiates far beyond his lifework in organic chemistry.
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Affiliation(s)
- Elina Ikonen
- Dept of Anatomy, Faculty of Medicine, University of Helsinki and Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Tomas Blom
- Dept of Anatomy, Faculty of Medicine, University of Helsinki and Minerva Foundation Institute for Medical Research, Helsinki, Finland.
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LAPTM4B facilitates late endosomal ceramide export to control cell death pathways. Nat Chem Biol 2015; 11:799-806. [DOI: 10.1038/nchembio.1889] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 07/09/2015] [Indexed: 12/31/2022]
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16
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Vanier MT. Complex lipid trafficking in Niemann-Pick disease type C. J Inherit Metab Dis 2015; 38:187-99. [PMID: 25425283 DOI: 10.1007/s10545-014-9794-4] [Citation(s) in RCA: 184] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 10/31/2014] [Accepted: 11/09/2014] [Indexed: 10/24/2022]
Abstract
Niemann-Pick disease type C (NPC) is an atypical lysosomal storage disease resulting from mutations in one of two genes, either NPC1 or NPC2. Although a neurovisceral disorder, it is above all a neurodegenerative disease in the vast majority of patients. Not an enzyme deficiency, it is currently conceived as a lipid trafficking disorder. Impaired egress of cholesterol from the late endosomal/lysosomal (LE/L) compartment is a specific and key element of the pathogenesis, but other lipids, more specially sphingolipids, are also involved, and there are indications for further abnormalities. The full function of the NPC1 and NPC2 proteins is still unclear. This review provides a reappraisal of lipid storage and lysosomal enzymes activities in tissues/cells from NPC patients and animal models. It summarizes the current knowledge on the NPC1 and NPC2 proteins and their function in transport of cholesterol within the late endosomal-lysosomal compartment, with emphasis on differences between systemic organs and the brain; it also discusses regulation by membrane lipids of the NPC2-mediated cholesterol trafficking, interplay between cholesterol and sphingomyelin, the metabolic origin of glycosphingolipids stored in brain, and the putative role of free sphingoid bases in pathogenesis. Brief mention is finally made of diseases affecting other genes that were very recently shown to impact the "NPC pathway".
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Affiliation(s)
- Marie T Vanier
- Institut National de la Santé et de la Recherche Médicale U820, Université Lyon-1 EA4611, Faculté de Médecine Lyon-Est, 7 Rue G. Paradin, 69008, Lyon, France,
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Pathological roles of the VEGF/SphK pathway in Niemann-Pick type C neurons. Nat Commun 2014; 5:5514. [PMID: 25417698 PMCID: PMC4263144 DOI: 10.1038/ncomms6514] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 10/08/2014] [Indexed: 12/14/2022] Open
Abstract
Sphingosine is a major storage compound in Niemann–Pick type C disease (NP–C), although the pathological role(s) of this accumulation have not been fully characterized. Here we found that sphingosine kinase (SphK) activity is reduced in NP–C patient fibroblasts and NP–C mouse Purkinje neurons (PNs) due to defective vascular endothelial growth factor (VEGF) levels. Sphingosine accumulation due to inactivation of VEGF/SphK pathway led to PNs loss via inhibition of autophagosome–lysosome fusion in NP–C mice. VEGF activates SphK by binding to VEGFR2, resulting in decreased sphingosine storage as well as improved PNs survival and clinical outcomes in NP–C cells and mice. We also show that induced pluripotent stem cell (iPSC)-derived human NP–C neurons are generated and the abnormalities caused by VEGF/SphK inactivity in these cells are corrected by replenishment of VEGF. Overall, these results reveal a pathogenic mechanism in NP–C neurons where defective SphK activity is due to impaired VEGF levels. Sphingosine is abnormally accumulated in Niemann–Pick type C disease (NP–C), but the causes of this accumulation have not been fully characterized. Here the authors show that sphingosine kinase activity is reduced in NP–C patient fibroblasts and NP–C mouse neurons due to defective vascular endothelial growth factor levels, suggesting therapeutic avenues.
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Pietiäinen V, Vassilev B, Blom T, Wang W, Nelson J, Bittman R, Bäck N, Zelcer N, Ikonen E. NDRG1 functions in LDL receptor trafficking by regulating endosomal recycling and degradation. J Cell Sci 2013; 126:3961-71. [PMID: 23813961 DOI: 10.1242/jcs.128132] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
N-myc downstream-regulated gene 1 (NDRG1) mutations cause Charcot-Marie-Tooth disease type 4D (CMT4D). However, the cellular function of NDRG1 and how it causes CMT4D are poorly understood. We report that NDRG1 silencing in epithelial cells results in decreased uptake of low-density lipoprotein (LDL) due to reduced LDL receptor (LDLR) abundance at the plasma membrane. This is accompanied by the accumulation of LDLR in enlarged EEA1-positive endosomes that contain numerous intraluminal vesicles and sequester ceramide. Concomitantly, LDLR ubiquitylation is increased but its degradation is reduced and ESCRT (endosomal sorting complex required for transport) proteins are downregulated. Co-depletion of IDOL (inducible degrader of the LDLR), which ubiquitylates the LDLR and promotes its degradation, rescues plasma membrane LDLR levels and LDL uptake. In murine oligodendrocytes, Ndrg1 silencing not only results in reduced LDL uptake but also in downregulation of the oligodendrocyte differentiation factor Olig2. Both phenotypes are rescued by co-silencing of Idol, suggesting that ligand uptake through LDLR family members controls oligodendrocyte differentiation. These findings identify NDRG1 as a novel regulator of multivesicular body formation and endosomal LDLR trafficking. The deficiency of functional NDRG1 in CMT4D might impair lipid processing and differentiation of myelinating cells.
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Affiliation(s)
- Vilja Pietiäinen
- Institute of Biomedicine, Anatomy, University of Helsinki, Helsinki, Finland.
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Albinet V, Bats ML, Bedia C, Sabourdy F, Garcia V, Ségui B, Andrieu-Abadie N, Hornemann T, Levade T. Genetic disorders of simple sphingolipid metabolism. Handb Exp Pharmacol 2013:127-152. [PMID: 23579453 DOI: 10.1007/978-3-7091-1368-4_7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A better understanding of the functions sphingolipids play in living organisms can be achieved by analyzing the biochemical and physiological changes that result from genetic alterations of sphingolipid metabolism. This review summarizes the current knowledge gained from studies both on human patients and mutant animals (mice, cats, dogs, and cattle) with genetic disorders of sphingolipid metabolism. Genetic alterations affecting the biosynthesis, transport, or degradation of simple sphingolipids are discussed.
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Affiliation(s)
- Virginie Albinet
- Institut National de la Santé et de la Recherche Médicale UMR1037, Centre de Recherches en Cancérologie de Toulouse, Team n°4, Université de Toulouse, CHU Rangueil, 84225, Toulouse Cedex 4, 31432, France
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