1
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Jamecna D, Höglinger D. The use of click chemistry in sphingolipid research. J Cell Sci 2024; 137:jcs261388. [PMID: 38488070 DOI: 10.1242/jcs.261388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024] Open
Abstract
Sphingolipid dysregulation is involved in a range of rare and fatal diseases as well as common pathologies including cancer, infectious diseases or neurodegeneration. Gaining insights into how sphingolipids are involved in these diseases would contribute much to our understanding of human physiology, as well as the pathology mechanisms. However, scientific progress is hampered by a lack of suitable tools that can be used in intact systems. To overcome this, efforts have turned to engineering modified lipids with small clickable tags and to harnessing the power of click chemistry to localize and follow these minimally modified lipid probes in cells. We hope to inspire the readers of this Review to consider applying existing click chemistry tools for their own aspects of sphingolipid research. To this end, we focus here on different biological applications of clickable lipids, mainly to follow metabolic conversions, their visualization by confocal or superresolution microscopy or the identification of their protein interaction partners. Finally, we describe recent approaches employing organelle-targeted and clickable lipid probes to accurately follow intracellular sphingolipid transport with organellar precision.
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Affiliation(s)
- Denisa Jamecna
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69118 Heidelberg, Germany
| | - Doris Höglinger
- Heidelberg University Biochemistry Center, Im Neuenheimer Feld 328, 69118 Heidelberg, Germany
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2
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Sternstein C, Böhm TM, Fink J, Meyr J, Lüdemann M, Krug M, Kriukov K, Gurdap CO, Sezgin E, Ebert R, Seibel J. Development of an Effective Functional Lipid Anchor for Membranes (FLAME) for the Bioorthogonal Modification of the Lipid Bilayer of Mesenchymal Stromal Cells. Bioconjug Chem 2023; 34:1221-1233. [PMID: 37328799 DOI: 10.1021/acs.bioconjchem.3c00091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The glycosylation of cellular membranes is crucial for the survival and communication of cells. As our target is the engineering of the glycocalyx, we designed a functionalized lipid anchor for the introduction into cellular membranes called Functional Lipid Anchor for MEmbranes (FLAME). Since cholesterol incorporates very effectively into membranes, we developed a twice cholesterol-substituted anchor in a total synthesis by applying protecting group chemistry. We labeled the compound with a fluorescent dye, which allows cell visualization. FLAME was successfully incorporated in the membranes of living human mesenchymal stromal cells (hMSC), acting as a temporary, nontoxic marker. The availability of an azido function─a bioorthogonal reacting group within the compound─enables the convenient coupling of alkyne-functionalized molecules, such as fluorophores or saccharides. After the incorporation of FLAME into the plasma membrane of living hMSC, we were able to successfully couple our molecule with an alkyne-tagged fluorophore via click reaction. This suggests that FLAME is useful for the modification of the membrane surface. Coupling FLAME with a galactosamine derivative yielded FLAME-GalNAc, which was incorporated into U2OS cells as well as in giant unilamellar vesicles (GUVs) and cell-derived giant plasma membrane vesicles (GPMVs). With this, we have shown that FLAME-GalNAc is a useful tool for studying the partitioning in the liquid-ordered (Lo) and the liquid-disordered (Ld) phases. The molecular tool can also be used to analyze the diffusion behavior in the model and the cell membranes by fluorescence correlation spectroscopy (FCS).
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Affiliation(s)
- Christine Sternstein
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Theresa-Maria Böhm
- Department of Musculoskeletal Tissue Regeneration, Orthopedic Clinic König-Ludwig Haus, University of Würzburg, Friedrich-Bergius-Ring 15, 97076 Würzburg, Germany
| | - Julian Fink
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Jessica Meyr
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Martin Lüdemann
- Department of Orthopaedic Surgery, König-Ludwig-Haus, University of Würzburg, Brettreichstr. 11, 97074 Würzburg, Germany
| | - Melanie Krug
- Department of Musculoskeletal Tissue Regeneration, Orthopedic Clinic König-Ludwig Haus, University of Würzburg, Friedrich-Bergius-Ring 15, 97076 Würzburg, Germany
| | - Kirill Kriukov
- Department of Musculoskeletal Tissue Regeneration, Orthopedic Clinic König-Ludwig Haus, University of Würzburg, Friedrich-Bergius-Ring 15, 97076 Würzburg, Germany
| | - Cenk O Gurdap
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden
| | - Erdinc Sezgin
- Science for Life Laboratory, Department of Women's and Children's Health, Karolinska Institutet, 17165 Solna, Sweden
| | - Regina Ebert
- Department of Musculoskeletal Tissue Regeneration, Orthopedic Clinic König-Ludwig Haus, University of Würzburg, Friedrich-Bergius-Ring 15, 97076 Würzburg, Germany
| | - Jürgen Seibel
- Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074 Würzburg, Germany
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3
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Synthesis and Characterization of Ceramide-Containing Liposomes as Membrane Models for Different T Cell Subpopulations. J Funct Biomater 2022; 13:jfb13030111. [PMID: 35997449 PMCID: PMC9397063 DOI: 10.3390/jfb13030111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 12/01/2022] Open
Abstract
A fine balance of regulatory (Treg) and conventional CD4+ T cells (Tconv) is required to prevent harmful immune responses, while at the same time ensuring the development of protective immunity against pathogens. As for many cellular processes, sphingolipid metabolism also crucially modulates the Treg/Tconv balance. However, our understanding of how sphingolipid metabolism is involved in T cell biology is still evolving and a better characterization of the tools at hand is required to advance the field. Therefore, we established a reductionist liposomal membrane model system to imitate the plasma membrane of mouse Treg and Tconv with regards to their ceramide content. We found that the capacity of membranes to incorporate externally added azide-functionalized ceramide positively correlated with the ceramide content of the liposomes. Moreover, we studied the impact of the different liposomal preparations on primary mouse splenocytes in vitro. The addition of liposomes to resting, but not activated, splenocytes maintained viability with liposomes containing high amounts of C16-ceramide being most efficient. Our data thus suggest that differences in ceramide post-incorporation into Treg and Tconv reflect differences in the ceramide content of cellular membranes.
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Peters S, Fohmann I, Rudel T, Schubert-Unkmeir A. A Comprehensive Review on the Interplay between Neisseria spp. and Host Sphingolipid Metabolites. Cells 2021; 10:cells10113201. [PMID: 34831424 PMCID: PMC8623382 DOI: 10.3390/cells10113201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 02/01/2023] Open
Abstract
Sphingolipids represent a class of structural related lipids involved in membrane biology and various cellular processes including cell growth, apoptosis, inflammation and migration. Over the past decade, sphingolipids have become the focus of intensive studies regarding their involvement in infectious diseases. Pathogens can manipulate the sphingolipid metabolism resulting in cell membrane reorganization and receptor recruitment to facilitate their entry. They may recruit specific host sphingolipid metabolites to establish a favorable niche for intracellular survival and proliferation. In contrast, some sphingolipid metabolites can also act as a first line defense against bacteria based on their antimicrobial activity. In this review, we will focus on the strategies employed by pathogenic Neisseria spp. to modulate the sphingolipid metabolism and hijack the sphingolipid balance in the host to promote cellular colonization, invasion and intracellular survival. Novel techniques and innovative approaches will be highlighted that allow imaging of sphingolipid derivatives in the host cell as well as in the pathogen.
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Affiliation(s)
- Simon Peters
- Institute for Hygiene and Microbiology, University of Wuerzburg, 97080 Wuerzburg, Germany; (S.P.); (I.F.)
| | - Ingo Fohmann
- Institute for Hygiene and Microbiology, University of Wuerzburg, 97080 Wuerzburg, Germany; (S.P.); (I.F.)
| | - Thomas Rudel
- Chair of Microbiology, University of Wuerzburg, 97080 Wuerzburg, Germany;
| | - Alexandra Schubert-Unkmeir
- Institute for Hygiene and Microbiology, University of Wuerzburg, 97080 Wuerzburg, Germany; (S.P.); (I.F.)
- Correspondence: ; Tel.: +49-931-31-46721; Fax: +49-931-31-46445
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5
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Canals D, Clarke CJ. Compartmentalization of Sphingolipid metabolism: Implications for signaling and therapy. Pharmacol Ther 2021; 232:108005. [PMID: 34582834 DOI: 10.1016/j.pharmthera.2021.108005] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 09/13/2021] [Accepted: 09/23/2021] [Indexed: 12/12/2022]
Abstract
Sphingolipids (SLs) are a family of bioactive lipids implicated in a variety of cellular processes, and whose levels are controlled by an interlinked network of enzymes. While the spatial distribution of SL metabolism throughout the cell has been understood for some time, the implications of this for SL signaling and biological outcomes have only recently begun to be fully explored. In this review, we outline the compartmentalization of SL metabolism and describe advances in tools for investigating and probing compartment-specific SL functions. We also briefly discuss the implications of SL compartmentalization for cell signaling and therapeutic approaches to targeting the SL network.
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Affiliation(s)
- Daniel Canals
- Department of Medicine and the Cancer Center, Stony Brook University, Stony Brook, NY, USA.
| | - Christopher J Clarke
- Department of Medicine and the Cancer Center, Stony Brook University, Stony Brook, NY, USA.
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6
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Fink J, Schumacher F, Schlegel J, Stenzel P, Wigger D, Sauer M, Kleuser B, Seibel J. Azidosphinganine enables metabolic labeling and detection of sphingolipid de novo synthesis. Org Biomol Chem 2021; 19:2203-2212. [PMID: 33496698 DOI: 10.1039/d0ob02592e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Here were report the combination of biocompatible click chemistry of ω-azidosphinganine with fluorescence microscopy and mass spectrometry as a powerful tool to elaborate the sphingolipid metabolism. The azide probe was efficiently synthesized over 13 steps starting from l-serine in an overall yield of 20% and was used for live-cell fluorescence imaging of the endoplasmic reticulum in living cells by bioorthogonal click reaction with a DBCO-labeled fluorophore revealing that the incorporated analogue is mainly localized in the endoplasmic membrane like the endogenous species. A LC-MS(/MS)-based microsomal in vitro assay confirmed that ω-azidosphinganine mimics the natural species enabling the identification and analysis of metabolic breakdown products of sphinganine as a key starting intermediate in the complex sphingolipid biosynthetic pathways. Furthermore, the sphinganine-fluorophore conjugate after click reaction was enzymatically tolerated to form its dihydroceramide and ceramide metabolites. Thus, ω-azidosphinganine represents a useful biofunctional tool for metabolic investigations both by in vivo fluorescence imaging of the sphingolipid subcellular localization in the ER and by in vitro high-resolution mass spectrometry analysis. This should reveal novel insights of the molecular mechanisms sphingolipids and their processing enzymes have e.g. in infection.
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Affiliation(s)
- Julian Fink
- Institute of Organic Chemistry, Julius-Maximilians University Würzburg, Am Hubland C1, 97074 Würzburg, Germany.
| | - Fabian Schumacher
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany. and Institute of Nutritional Science, Department of Toxicology, University of Potsdam, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Jan Schlegel
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians University Würzburg, 97074 Würzburg, Germany.
| | - Philipp Stenzel
- Institute of Organic Chemistry, Julius-Maximilians University Würzburg, Am Hubland C1, 97074 Würzburg, Germany.
| | - Dominik Wigger
- Institute of Nutritional Science, Department of Toxicology, University of Potsdam, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians University Würzburg, 97074 Würzburg, Germany.
| | - Burkhard Kleuser
- Institute of Pharmacy, Freie Universität Berlin, Königin-Luise-Str. 2+4, 14195 Berlin, Germany. and Institute of Nutritional Science, Department of Toxicology, University of Potsdam, Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany
| | - Jürgen Seibel
- Institute of Organic Chemistry, Julius-Maximilians University Würzburg, Am Hubland C1, 97074 Würzburg, Germany.
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7
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Wiese T, Dennstädt F, Hollmann C, Stonawski S, Wurst C, Fink J, Gorte E, Mandasari P, Domschke K, Hommers L, Vanhove B, Schumacher F, Kleuser B, Seibel J, Rohr J, Buttmann M, Menke A, Schneider-Schaulies J, Beyersdorf N. Inhibition of acid sphingomyelinase increases regulatory T cells in humans. Brain Commun 2021; 3:fcab020. [PMID: 33898989 PMCID: PMC8054263 DOI: 10.1093/braincomms/fcab020] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 11/11/2020] [Accepted: 12/15/2020] [Indexed: 12/27/2022] Open
Abstract
Genetic deficiency for acid sphingomyelinase or its pharmacological inhibition has been shown to increase Foxp3+ regulatory T-cell frequencies among CD4+ T cells in mice. We now investigated whether pharmacological targeting of the acid sphingomyelinase, which catalyzes the cleavage of sphingomyelin to ceramide and phosphorylcholine, also allows to manipulate relative CD4+ Foxp3+ regulatory T-cell frequencies in humans. Pharmacological acid sphingomyelinase inhibition with antidepressants like sertraline, but not those without an inhibitory effect on acid sphingomyelinase activity like citalopram, increased the frequency of Foxp3+ regulatory T cell among human CD4+ T cells in vitro. In an observational prospective clinical study with patients suffering from major depression, we observed that acid sphingomyelinase-inhibiting antidepressants induced a stronger relative increase in the frequency of CD4+ Foxp3+ regulatory T cells in peripheral blood than acid sphingomyelinase-non- or weakly inhibiting antidepressants. This was particularly true for CD45RA− CD25high effector CD4+ Foxp3+ regulatory T cells. Mechanistically, our data indicate that the positive effect of acid sphingomyelinase inhibition on CD4+ Foxp3+ regulatory T cells required CD28 co-stimulation, suggesting that enhanced CD28 co-stimulation was the driver of the observed increase in the frequency of Foxp3+ regulatory T cells among human CD4+ T cells. In summary, the widely induced pharmacological inhibition of acid sphingomyelinase activity in patients leads to an increase in Foxp3+ regulatory T-cell frequencies among CD4+ T cells in humans both in vivo and in vitro.
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Affiliation(s)
- Teresa Wiese
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg 97078, Germany
| | - Fabio Dennstädt
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg 97078, Germany
| | - Claudia Hollmann
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg 97078, Germany
| | - Saskia Stonawski
- Department of Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health, University Hospital of Würzburg, Würzburg 97080, Germany
| | - Catherina Wurst
- Department of Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health, University Hospital of Würzburg, Würzburg 97080, Germany
| | - Julian Fink
- Institute of Organic Chemistry, University of Würzburg, Würzburg 97074, Germany
| | - Erika Gorte
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg 97078, Germany
| | - Putri Mandasari
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg 97078, Germany
| | - Katharina Domschke
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg 79104, Germany
| | - Leif Hommers
- Department of Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health, University Hospital of Würzburg, Würzburg 97080, Germany.,Comprehensive Heart Failure Center, University Hospital of Würzburg, Würzburg 97080, Germany.,Interdisciplinary Center for Clinical Research, University of Würzburg, Würzburg 97080, Germany
| | - Bernard Vanhove
- Centre de Recherche en Transplantation et Immunologie UMR 1064, INSERM, Université de Nantes, Nantes, France.,Institut de Transplantation Urologie Néphrologie (ITUN), CHU Nantes, Nantes, France.,OSE Immunotherapeutics S.A., Nantes, France
| | - Fabian Schumacher
- Institute of Nutritional Science, University of Potsdam, Nuthetal D-14558, Germany
| | - Burkhard Kleuser
- Institute of Nutritional Science, University of Potsdam, Nuthetal D-14558, Germany
| | - Jürgen Seibel
- Institute of Organic Chemistry, University of Würzburg, Würzburg 97074, Germany
| | - Jan Rohr
- Center for Chronic Immunodeficiency (CCI), Medical Center-University of Freiburg, Freiburg 79106, Germany
| | - Mathias Buttmann
- Department of Neurology, Caritas Hospital, Bad Mergentheim 97980, Germany.,Department of Neurology, University Hospital Würzburg, Würzburg 97080, Germany
| | - Andreas Menke
- Department of Psychiatry, Psychosomatics and Psychotherapy, Center of Mental Health, University Hospital of Würzburg, Würzburg 97080, Germany.,Comprehensive Heart Failure Center, University Hospital of Würzburg, Würzburg 97080, Germany.,Interdisciplinary Center for Clinical Research, University of Würzburg, Würzburg 97080, Germany.,Medical Park Chiemseeblick, Bernau-Felden 83233, Germany
| | | | - Niklas Beyersdorf
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg 97078, Germany
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8
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Peters S, Kaiser L, Fink J, Schumacher F, Perschin V, Schlegel J, Sauer M, Stigloher C, Kleuser B, Seibel J, Schubert-Unkmeir A. Click-correlative light and electron microscopy (click-AT-CLEM) for imaging and tracking azido-functionalized sphingolipids in bacteria. Sci Rep 2021; 11:4300. [PMID: 33619350 PMCID: PMC7900124 DOI: 10.1038/s41598-021-83813-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 02/05/2021] [Indexed: 11/21/2022] Open
Abstract
Sphingolipids, including ceramides, are a diverse group of structurally related lipids composed of a sphingoid base backbone coupled to a fatty acid side chain and modified terminal hydroxyl group. Recently, it has been shown that sphingolipids show antimicrobial activity against a broad range of pathogenic microorganisms. The antimicrobial mechanism, however, remains so far elusive. Here, we introduce ‘click-AT-CLEM’, a labeling technique for correlated light and electron microscopy (CLEM) based on the super-resolution array tomography (srAT) approach and bio-orthogonal click chemistry for imaging of azido-tagged sphingolipids to directly visualize their interaction with the model Gram-negative bacterium Neisseria meningitidis at subcellular level. We observed ultrastructural damage of bacteria and disruption of the bacterial outer membrane induced by two azido-modified sphingolipids by scanning electron microscopy and transmission electron microscopy. Click-AT-CLEM imaging and mass spectrometry clearly revealed efficient incorporation of azido-tagged sphingolipids into the outer membrane of Gram-negative bacteria as underlying cause of their antimicrobial activity.
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Affiliation(s)
- Simon Peters
- Institute for Hygiene and Microbiology, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Lena Kaiser
- Institute for Hygiene and Microbiology, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Julian Fink
- Institute for Organic Chemistry, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Fabian Schumacher
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany.,Department of Toxicology, University of Potsdam, Nuthetal, Germany.,Institute of Molecular Biology, University of Duisburg-Essen, Essen, Germany
| | - Veronika Perschin
- Imaging Core Facility, Biocenter, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Jan Schlegel
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Christian Stigloher
- Imaging Core Facility, Biocenter, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Burkhard Kleuser
- Institute of Pharmacy, Freie Universität Berlin, Berlin, Germany.,Department of Toxicology, University of Potsdam, Nuthetal, Germany
| | - Jürgen Seibel
- Institute for Organic Chemistry, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
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9
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Götz R, Kunz TC, Fink J, Solger F, Schlegel J, Seibel J, Kozjak-Pavlovic V, Rudel T, Sauer M. Nanoscale imaging of bacterial infections by sphingolipid expansion microscopy. Nat Commun 2020; 11:6173. [PMID: 33268771 PMCID: PMC7710728 DOI: 10.1038/s41467-020-19897-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 11/05/2020] [Indexed: 12/20/2022] Open
Abstract
Expansion microscopy (ExM) enables super-resolution imaging of proteins and nucleic acids on conventional microscopes. However, imaging of details of the organization of lipid bilayers by light microscopy remains challenging. We introduce an unnatural short-chain azide- and amino-modified sphingolipid ceramide, which upon incorporation into membranes can be labeled by click chemistry and linked into hydrogels, followed by 4× to 10× expansion. Confocal and structured illumination microscopy (SIM) enable imaging of sphingolipids and their interactions with proteins in the plasma membrane and membrane of intracellular organelles with a spatial resolution of 10–20 nm. As our functionalized sphingolipids accumulate efficiently in pathogens, we use sphingolipid ExM to investigate bacterial infections of human HeLa229 cells by Neisseria gonorrhoeae, Chlamydia trachomatis and Simkania negevensis with a resolution so far only provided by electron microscopy. In particular, sphingolipid ExM allows us to visualize the inner and outer membrane of intracellular bacteria and determine their distance to 27.6 ± 7.7 nm. Imaging of lipid bilayers using light microscopy is challenging. Here the authors label cells using a short chain click-compatible ceramide to visualize mammalian and bacterial membranes with expansion microscopy.
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Affiliation(s)
- Ralph Götz
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Tobias C Kunz
- Department of Microbiology, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Julian Fink
- Institute for Organic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Franziska Solger
- Department of Microbiology, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Jan Schlegel
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Jürgen Seibel
- Institute for Organic Chemistry, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Vera Kozjak-Pavlovic
- Department of Microbiology, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Thomas Rudel
- Department of Microbiology, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Biocenter, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany.
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10
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De Lira MN, Raman SJ, Schulze A, Schneider-Schaulies S, Avota E. Neutral Sphingomyelinase-2 (NSM 2) Controls T Cell Metabolic Homeostasis and Reprogramming During Activation. Front Mol Biosci 2020; 7:217. [PMID: 33088808 PMCID: PMC7498697 DOI: 10.3389/fmolb.2020.00217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 08/04/2020] [Indexed: 12/15/2022] Open
Abstract
Neutral sphingomyelinase-2 (NSM2) is a member of a superfamily of enzymes responsible for conversion of sphingomyelin into phosphocholine and ceramide at the cytosolic leaflet of the plasma membrane. Upon specific ablation of NSM2, T cells proved to be hyper-responsive to CD3/CD28 co-stimulation, indicating that the enzyme acts to dampen early overshooting activation of these cells. It remained unclear whether hyper-reactivity of NSM2-deficient T cells is supported by a deregulated metabolic activity in these cells. Here, we demonstrate that ablation of NSM2 activity affects metabolism of the quiescent CD4+ T cells which accumulate ATP in mitochondria and increase basal glycolytic activity. This supports enhanced production of total ATP and metabolic switch early after TCR/CD28 stimulation. Most interestingly, increased metabolic activity in resting NSM2-deficient T cells does not support sustained response upon stimulation. While elevated under steady-state conditions in NSM2-deficient CD4+ T cells, the mTORC1 pathway regulating mitochondria size, oxidative phosphorylation, and ATP production is impaired after 24 h of stimulation. Taken together, the absence of NSM2 promotes a hyperactive metabolic state in unstimulated CD4+ T cells yet fails to support sustained T cell responses upon antigenic stimulation.
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Affiliation(s)
| | | | - Almut Schulze
- Division of Tumor Metabolism and Microenvironment, German Cancer Research Center, Heidelberg, Germany
| | | | - Elita Avota
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg, Germany
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11
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Detection of Functionalized Sphingolipid Analogs in Detergent-Resistant Membranes of Immune Cells. Methods Mol Biol 2020. [PMID: 32770515 DOI: 10.1007/978-1-0716-0814-2_18] [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
The analysis of protein enrichment in the detergent-resistant membranes (DRMs) isolated from immune cells enables us to analyze a link between the membrane lipid dynamics and cell activation. Here, we describe the fractionation of detergent-resistant membranes and the correlative analysis of the enrichment of T cell receptor (TCR) and ω-azido-modified synthetic ceramide in those fractions upon TCR stimulation.
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12
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Böll S, Ziemann S, Ohl K, Klemm P, Rieg AD, Gulbins E, Becker KA, Kamler M, Wagner N, Uhlig S, Martin C, Tenbrock K, Verjans E. Acid sphingomyelinase regulates T H 2 cytokine release and bronchial asthma. Allergy 2020; 75:603-615. [PMID: 31494944 DOI: 10.1111/all.14039] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 08/01/2019] [Accepted: 08/19/2019] [Indexed: 12/16/2022]
Abstract
BACKGROUND Allergic diseases and especially allergic asthma are widespread diseases with high prevalence in childhood, but also in adults. Acid sphingomyelinase (ASM) is a key regulator of the sphingolipid pathway. Previous studies defined the association of ASM with the pathogenesis of TH 1-directed lung diseases like cystic fibrosis and acute lung injury. Here, we define the role of ASM in TH 2-regulated allergic bronchial asthma. METHODS To determine the role of Asm under baseline conditions, wild-type (WT) and Asm-/- mice were ventilated with a flexiVent setup and bronchial hyperresponsiveness was determined using acetylcholine. Flow cytometry and cytokine measurements in bronchoalveolar lavage fluid and lung tissue were followed by in vitro TH 2 differentiations with cells from WT and Asm-/- mice and blockade of Asm with amitriptyline. As proof of principle, we conducted an ovalbumin-induced model of asthma in WT- and Asm-/- mice. RESULTS At baseline, Asm-/- mice showed better lung mechanics, but unaltered bronchial hyperresponsiveness. Higher numbers of Asm-/- T cells in bronchoalveolar lavage fluid released lower levels of IL-4 and IL-5, and these results were paralleled by decreased production of typical TH 2 cytokines in Asm-/- T lymphocytes in vitro. This phenotype could be imitated by incubation of T cells with amitriptyline. In the ovalbumin asthma model, Asm-/- animals were protected from high disease activity and showed better lung functions and lower levels of eosinophils and TH 2 cytokines. CONCLUSION Asm deficiency could induce higher numbers of TH 2 cells in the lung, but those cells release decreased TH 2 cytokine levels. Hereby, Asm-/- animals are protected from bronchial asthma, which possibly offers novel therapeutic strategies, for example, with ASM blockade.
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Affiliation(s)
- Svenja Böll
- Department of Pediatrics Medical Faculty RWTH Aachen University University Hospital Aachen Aachen Germany
- Institute of Pharmacology and Toxicology RWTH Aachen University University Hospital Aachen Aachen Germany
| | - Sebastian Ziemann
- Institute of Pharmacology and Toxicology RWTH Aachen University University Hospital Aachen Aachen Germany
- Department of Anaesthesiology Medical Faculty RWTH Aachen University University Hospital Aachen Aachen Germany
| | - Kim Ohl
- Department of Pediatrics Medical Faculty RWTH Aachen University University Hospital Aachen Aachen Germany
| | - Patricia Klemm
- Department of Pediatrics Medical Faculty RWTH Aachen University University Hospital Aachen Aachen Germany
| | - Annette D. Rieg
- Institute of Pharmacology and Toxicology RWTH Aachen University University Hospital Aachen Aachen Germany
- Department of Anaesthesiology Medical Faculty RWTH Aachen University University Hospital Aachen Aachen Germany
| | - Erich Gulbins
- Department of Molecular Biology University Hospital Essen University of Duisburg‐Essen Essen Germany
- Department of Surgery University of Cincinnati Cincinnati OH USA
| | - Katrin Anne Becker
- Department of Molecular Biology University Hospital Essen University of Duisburg‐Essen Essen Germany
| | - Markus Kamler
- Thoracic Transplantation Thoracic and Cardiovascular Surgery University Hospital Essen University of Duisburg‐Essen Essen Germany
| | - Norbert Wagner
- Department of Pediatrics Medical Faculty RWTH Aachen University University Hospital Aachen Aachen Germany
| | - Stefan Uhlig
- Institute of Pharmacology and Toxicology RWTH Aachen University University Hospital Aachen Aachen Germany
| | - Christian Martin
- Institute of Pharmacology and Toxicology RWTH Aachen University University Hospital Aachen Aachen Germany
| | - Klaus Tenbrock
- Department of Pediatrics Medical Faculty RWTH Aachen University University Hospital Aachen Aachen Germany
| | - Eva Verjans
- Department of Pediatrics Medical Faculty RWTH Aachen University University Hospital Aachen Aachen Germany
- Institute of Pharmacology and Toxicology RWTH Aachen University University Hospital Aachen Aachen Germany
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13
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Börtlein C, Schumacher F, Kleuser B, Dölken L, Avota E. Role of Neutral Sphingomyelinase-2 (NSM 2) in the Control of T Cell Plasma Membrane Lipid Composition and Cholesterol Homeostasis. Front Cell Dev Biol 2019; 7:226. [PMID: 31681760 PMCID: PMC6803391 DOI: 10.3389/fcell.2019.00226] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 09/24/2019] [Indexed: 12/12/2022] Open
Abstract
The activity of neutral sphingomyelinase-2 (NSM2) to catalyze the conversion of sphingomyelin (SM) to ceramide and phosphocholine at the cytosolic leaflet of plasma membrane (PM) is important in T cell receptor (TCR) signaling. We recently identified PKCζ as a major NSM2 downstream effector which regulates microtubular polarization. It remained, however, unclear to what extent NSM2 activity affected overall composition of PM lipids and downstream effector lipids in antigen stimulated T cells. Here, we provide a detailed lipidomics analyses on PM fractions isolated from TCR stimulated wild type and NSM2 deficient (ΔNSM) Jurkat T cells. This revealed that in addition to that of sphingolipids, NSM2 depletion also affected concentrations of many other lipids. In particular, NSM2 ablation resulted in increase of lyso-phosphatidylcholine (LPC) and lyso-phosphatidylethanolamine (LPE) which both govern PM biophysical properties. Crucially, TCR dependent upregulation of the important T cell signaling lipid diacylglycerol (DAG), which is fundamental for activation of conventional and novel PKCs, was abolished in ΔNSM cells. Moreover, NSM2 activity was found to play an important role in PM cholesterol transport to the endoplasmic reticulum (ER) and production of cholesteryl esters (CE) there. Most importantly, CE accumulation was essential to sustain human T cell proliferation. Accordingly, inhibition of CE generating enzymes, the cholesterol acetyltransferases ACAT1/SOAT1 and ACAT2/SOAT2, impaired TCR driven expansion of both CD4+ and CD8+ T cells. In summary, our study reveals an important role of NSM2 in regulating T cell functions by its multiple effects on PM lipids and cholesterol homeostasis.
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Affiliation(s)
- Charlene Börtlein
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg, Germany
| | - Fabian Schumacher
- Department of Toxicology, Institute of Nutritional Science, Faculty of Mathematics and Natural Science, University of Potsdam, Nuthetal, Germany.,Department of Molecular Biology, University of Duisburg-Essen, Essen, Germany
| | - Burkhard Kleuser
- Department of Toxicology, Institute of Nutritional Science, Faculty of Mathematics and Natural Science, University of Potsdam, Nuthetal, Germany
| | - Lars Dölken
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg, Germany
| | - Elita Avota
- Institute for Virology and Immunobiology, University of Würzburg, Würzburg, Germany
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14
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Avota E, de Lira MN, Schneider-Schaulies S. Sphingomyelin Breakdown in T Cells: Role of Membrane Compartmentalization in T Cell Signaling and Interference by a Pathogen. Front Cell Dev Biol 2019; 7:152. [PMID: 31457008 PMCID: PMC6700246 DOI: 10.3389/fcell.2019.00152] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 07/22/2019] [Indexed: 12/15/2022] Open
Abstract
Sphingolipids are major components of cellular membranes, and at steady-state level, their metabolic fluxes are tightly controlled. On challenge by external signals, they undergo rapid turnover, which substantially affects the biophysical properties of membrane lipid and protein compartments and, consequently, signaling and morphodynamics. In T cells, external cues translate into formation of membrane microdomains where proximal signaling platforms essential for metabolic reprograming and cytoskeletal reorganization are organized. This review will focus on sphingomyelinases, which mediate sphingomyelin breakdown and ensuing ceramide release that have been implicated in T-cell viability and function. Acting at the sphingomyelin pool at the extrafacial or cytosolic leaflet of cellular membranes, acid and neutral sphingomyelinases organize ceramide-enriched membrane microdomains that regulate T-cell homeostatic activity and, upon stimulation, compartmentalize receptors, membrane proximal signaling complexes, and cytoskeletal dynamics as essential for initiating T-cell motility and interaction with endothelia and antigen-presenting cells. Prominent examples to be discussed in this review include death receptor family members, integrins, CD3, and CD28 and their associated signalosomes. Progress made with regard to experimental tools has greatly aided our understanding of the role of bioactive sphingolipids in T-cell biology at a molecular level and of targets explored by a model pathogen (measles virus) to specifically interfere with their physiological activity.
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Affiliation(s)
- Elita Avota
- Institute for Virology and Immunobiology, Julius Maximilian University of Würzburg, Würzburg, Germany
| | - Maria Nathalia de Lira
- Institute for Virology and Immunobiology, Julius Maximilian University of Würzburg, Würzburg, Germany
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15
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Activity-based proteomic profiling: The application of photoaffinity probes in the target identification of bioactive molecules. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2019.03.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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16
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Collenburg L, Schneider-Schaulies S, Avota E. The neutral sphingomyelinase 2 in T cell receptor signaling and polarity. Biol Chem 2019; 399:1147-1155. [PMID: 29337691 DOI: 10.1515/hsz-2017-0280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 12/31/2017] [Indexed: 01/13/2023]
Abstract
By hydrolyzing its substrate sphingomyelin at the cytosolic leaflet of cellular membranes, the neutral sphingomyelinase 2 (NSM2) generates microdomains which serve as docking sites for signaling proteins and thereby, functions to regulate signal relay. This has been particularly studied in cellular stress responses while the regulatory role of this enzyme in the immune cell compartment has only recently emerged. In T cells, phenotypic polarization by co-ordinated cytoskeletal remodeling is central to motility and interaction with endothelial or antigen-presenting cells during tissue recruitment or immune synapse formation, respectively. This review highlights studies adressing the role of NSM2 in T cell polarity in which the enzyme plays a major role in regulating cytoskeletal dynamics.
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Affiliation(s)
- Lena Collenburg
- Institute for Virology and Immunobiology, University of Würzburg, Versbacher Str. 7, D-97078 Würzburg, Germany
| | - Sibylle Schneider-Schaulies
- Institute for Virology and Immunobiology, University of Würzburg, Versbacher Str. 7, D-97078 Würzburg, Germany
| | - Elita Avota
- Institute for Virology and Immunobiology, University of Würzburg, Versbacher Str. 7, D-97078 Würzburg, Germany
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17
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Fink J, Seibel J. Click reactions with functional sphingolipids. Biol Chem 2019; 399:1157-1168. [PMID: 29908120 DOI: 10.1515/hsz-2018-0169] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 04/15/2018] [Indexed: 12/17/2022]
Abstract
Sphingolipids and glycosphingolipids can regulate cell recognition and signalling. Ceramide and sphingosine-1-phosphate are major players in the sphingolipid pathways and are involved in the initiation and regulation of signalling, apoptosis, stress responses and infection. Specific chemically synthesised sphingolipid derivatives containing small functionalities like azide or alkyne can mimic the biological properties of natural lipid species, which turns them into useful tools for the investigation of the highly complex sphingolipid metabolism by rapid and selective 'click chemistry' using sensitive tags like fluorophores. Subsequent analysis by various fluorescence microscopy techniques or mass spectrometry allows the identification and quantification of the corresponding sphingolipid metabolites as well as the research of associated enzymes. Here we present an overview of recent advances in the synthesis of ceramide and sphingosine analogues for bioorthogonal click reactions to study biosynthetic pathways and localization of sphingolipids for the development of novel therapeutics against lipid-dependent diseases.
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Affiliation(s)
- Julian Fink
- University of Würzburg, Institute of Organic Chemistry, Am Hubland, D-97074 Würzburg, Germany
| | - Jürgen Seibel
- University of Würzburg, Institute of Organic Chemistry, Am Hubland, D-97074 Würzburg, Germany
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18
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Mohamed ZH, Rhein C, Saied EM, Kornhuber J, Arenz C. FRET probes for measuring sphingolipid metabolizing enzyme activity. Chem Phys Lipids 2018; 216:152-161. [DOI: 10.1016/j.chemphyslip.2018.09.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 09/21/2018] [Indexed: 12/31/2022]
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19
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Bumpus TW, Baskin JM. Greasing the Wheels of Lipid Biology with Chemical Tools. Trends Biochem Sci 2018; 43:970-983. [PMID: 30472989 DOI: 10.1016/j.tibs.2018.09.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 08/31/2018] [Accepted: 09/19/2018] [Indexed: 02/06/2023]
Abstract
Biological lipids are a structurally diverse and historically vexing group of hydrophobic metabolites. Here, we review recent advances in chemical imaging techniques that reveal changes in lipid biosynthesis, metabolism, dynamics, and interactions. We highlight tools for tagging many lipid classes via metabolic incorporation of bioorthogonally functionalized precursors, detectable via click chemistry, and photocaged, photoswitchable, and photocrosslinkable variants of different lipids. Certain lipid probes can supplant traditional protein-based markers of organelle membranes in super-resolution microscopy, and emerging vibrational imaging methods, such as stimulated Raman spectroscopy (SRS), enable simultaneous imaging of more than a dozen different types of target molecule, including lipids. Collectively, these chemical imaging techniques will illuminate, in living color, previously hidden aspects of lipid biology.
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Affiliation(s)
- Timothy W Bumpus
- Department of Chemistry and Chemical Biology and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA
| | - Jeremy M Baskin
- Department of Chemistry and Chemical Biology and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA.
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20
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Click chemistry in sphingolipid research. Chem Phys Lipids 2018; 215:71-83. [DOI: 10.1016/j.chemphyslip.2018.07.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 07/13/2018] [Accepted: 07/16/2018] [Indexed: 01/17/2023]
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21
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Börtlein C, Draeger A, Schoenauer R, Kuhlemann A, Sauer M, Schneider-Schaulies S, Avota E. The Neutral Sphingomyelinase 2 Is Required to Polarize and Sustain T Cell Receptor Signaling. Front Immunol 2018; 9:815. [PMID: 29720981 PMCID: PMC5915489 DOI: 10.3389/fimmu.2018.00815] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/04/2018] [Indexed: 01/02/2023] Open
Abstract
By promoting ceramide release at the cytosolic membrane leaflet, the neutral sphingomyelinase 2 (NSM) is capable of organizing receptor and signalosome segregation. Its role in T cell receptor (TCR) signaling remained so far unknown. We now show that TCR-driven NSM activation is dispensable for TCR clustering and initial phosphorylation, but of crucial importance for further signal amplification. In particular, at low doses of TCR stimulatory antibodies, NSM is required for Ca2+ mobilization and T cell proliferation. NSM-deficient T cells lack sustained CD3ζ and ZAP-70 phosphorylation and are unable to polarize and stabilize their microtubular system. We identified PKCζ as the key NSM downstream effector in this second wave of TCR signaling supporting dynamics of microtubule-organizing center (MTOC). Ceramide supplementation rescued PKCζ membrane recruitment and MTOC translocation in NSM-deficient cells. These findings identify the NSM as essential in TCR signaling when dynamic cytoskeletal reorganization promotes continued lateral and vertical supply of TCR signaling components: CD3ζ, Zap70, and PKCζ, and functional immune synapses are organized and stabilized via MTOC polarization.
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Affiliation(s)
- Charlene Börtlein
- Institute for Virology and Immunobiology, University of Wuerzburg, Wuerzburg, Germany
| | - Annette Draeger
- Department of Cell Biology, Institute for Anatomy, University of Bern, Bern, Switzerland
| | - Roman Schoenauer
- Department of Cell Biology, Institute for Anatomy, University of Bern, Bern, Switzerland
| | - Alexander Kuhlemann
- Department of Biotechnology and Biophysics, University of Wuerzburg, Wuerzburg, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, University of Wuerzburg, Wuerzburg, Germany
| | | | - Elita Avota
- Institute for Virology and Immunobiology, University of Wuerzburg, Wuerzburg, Germany
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22
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Walter T, Schlegel J, Burgert A, Kurz A, Seibel J, Sauer M. Incorporation studies of clickable ceramides in Jurkat cell plasma membranes. Chem Commun (Camb) 2018; 53:6836-6839. [PMID: 28597878 DOI: 10.1039/c7cc01220a] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The incorporation properties of ceramide analogues for click chemistry in Jurkat T cells were investigated. The analogues varied in the acyl chain length and the position of the functional group for click chemistry. Fluorescence microscopy studies including anisotropy and quenching experiments showed significant differences in the accessibility of the functional group indicating different incorporation properties into the plasma membrane.
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Affiliation(s)
- T Walter
- Institute for Organic Chemistry, Julius-Maximilians University Würzburg, Am Hubland C1, 97074 Würzburg, Germany.
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23
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Becam J, Walter T, Burgert A, Schlegel J, Sauer M, Seibel J, Schubert-Unkmeir A. Antibacterial activity of ceramide and ceramide analogs against pathogenic Neisseria. Sci Rep 2017; 7:17627. [PMID: 29247204 PMCID: PMC5732201 DOI: 10.1038/s41598-017-18071-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 12/01/2017] [Indexed: 12/29/2022] Open
Abstract
Certain fatty acids and sphingoid bases found at mucosal surfaces are known to have antibacterial activity and are thought to play a more direct role in innate immunity against bacterial infections. Herein, we analysed the antibacterial activity of sphingolipids, including the sphingoid base sphingosine as well as short-chain C6 and long-chain C16-ceramides and azido-functionalized ceramide analogs against pathogenic Neisseriae. Determination of the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) demonstrated that short-chain ceramides and a ω-azido-functionalized C6-ceramide were active against Neisseria meningitidis and N. gonorrhoeae, whereas they were inactive against Escherichia coli and Staphylococcus aureus. Kinetic assays showed that killing of N. meningitidis occurred within 2 h with ω–azido-C6-ceramide at 1 X the MIC. Of note, at a bactericidal concentration, ω–azido-C6-ceramide had no significant toxic effect on host cells. Moreover, lipid uptake and localization was studied by flow cytometry and confocal laser scanning microscopy (CLSM) and revealed a rapid uptake by bacteria within 5 min. CLSM and super-resolution fluorescence imaging by direct stochastic optical reconstruction microscopy demonstrated homogeneous distribution of ceramide analogs in the bacterial membrane. Taken together, these data demonstrate the potent bactericidal activity of sphingosine and synthetic short-chain ceramide analogs against pathogenic Neisseriae.
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Affiliation(s)
- Jérôme Becam
- Institute of Hygiene and Microbiology, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Tim Walter
- Institute for Organic Chemistry, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Anne Burgert
- Department of Biotechnology and Biophysics, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Jan Schlegel
- Department of Biotechnology and Biophysics, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Markus Sauer
- Department of Biotechnology and Biophysics, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
| | - Jürgen Seibel
- Institute for Organic Chemistry, Julius-Maximilian University Wuerzburg, Wuerzburg, Germany
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Lizardo DY, Parisi LR, Li N, Atilla-Gokcumen GE. Noncanonical Roles of Lipids in Different Cellular Fates. Biochemistry 2017; 57:22-29. [DOI: 10.1021/acs.biochem.7b00862] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Darleny Y. Lizardo
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Laura R. Parisi
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Nasi Li
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - G. Ekin Atilla-Gokcumen
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
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25
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Acid sphingomyelinase mediates human CD4 + T-cell signaling: potential roles in T-cell responses and diseases. Cell Death Dis 2017; 8:e2963. [PMID: 28749465 PMCID: PMC5550889 DOI: 10.1038/cddis.2017.360] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 06/11/2017] [Accepted: 06/14/2017] [Indexed: 12/13/2022]
Abstract
Acid sphingomyelinase (ASM) is a lipid hydrolase. By generating ceramide, ASM had been reported to have an important role in regulating immune cell functions inclusive of macrophages, NK cells, and CD8+ T cells, whereas the role of ASM bioactivity in regulation of human CD4+ T-cell functions remained uncertain. Recent studies have provided novel findings in this field. Upon stimulation of CD3 and/or CD28, ASM-dependent ceramide signaling mediates intracellular downstream signal cascades of CD3 and CD28, and regulates CD4+ T-cell activation and proliferation. Meanwhile, CD39 and CD161 have direct interactions with ASM, which mediates downstream signals inclusive of STAT3 and mTOR and thus defines human Th17 cells. Intriguingly, ASM mediates Th1 responses, but negatively regulates Treg functions. In this review, we summarized the pivotal roles of ASM in regulation of human CD4+ T-cell activation and responses. ASM/sphingolipid signaling may be a novel target for the therapy of human autoimmune diseases.
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