1
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Schengrund CL. The Ying and Yang of Ganglioside Function in Cancer. Cancers (Basel) 2023; 15:5362. [PMID: 38001622 PMCID: PMC10670608 DOI: 10.3390/cancers15225362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/23/2023] [Accepted: 10/28/2023] [Indexed: 11/26/2023] Open
Abstract
The plethora of information about the expression of cancer cell-associated gangliosides, their role(s) in signal transduction, and their potential usefulness in the development of cancer treatments makes this an appropriate time to review these enigmatic glycosphingolipids. Evidence, reflecting the work of many, indicates that (1) expression of specific gangliosides, not generally found in high concentrations in most normal human cells, can be linked to certain types of cancer. (2) Gangliosides can affect the ability of cells to interact either directly or indirectly with growth factor receptors, thereby changing such things as a cell's mobility, rate of proliferation, and metastatic ability. (3) Anti-ganglioside antibodies have been tested, with some success, as potential treatments for certain cancers. (4) Cancer-associated gangliosides shed into the circulation can (a) affect immune cell responsiveness either positively or negatively, (b) be considered as diagnostic markers, and (c) be used to look for recurrence. (5) Cancer registries enable investigators to evaluate data from sufficient numbers of patients to obtain information about potential therapies. Despite advances that have been made, a discussion of possible approaches to identifying additional treatment strategies to inhibit metastasis, responsible for the majority of deaths of cancer patients, as well as for treating therapy-resistant tumors, is included.
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Affiliation(s)
- Cara-Lynne Schengrund
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
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2
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Wang Y, Peng Y, Long R, Shi P, Zhang Y, Kong DX, Zheng J, Wang X. Sequence variety in the CC' loop of Siglec-8/9/3 determines the recognitions to sulfated oligosaccharides. Comput Struct Biotechnol J 2023; 21:4159-4171. [PMID: 37675287 PMCID: PMC10477811 DOI: 10.1016/j.csbj.2023.08.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/18/2023] [Accepted: 08/18/2023] [Indexed: 09/08/2023] Open
Abstract
Siglecs are important lectins found in different types of immune cells and function as regulatory molecules by recognizing self-associated glycans and converting extracellular interactions into signals for inhibiting immune cell functions. Although many Siglecs have been found to show broad specificities and recognize different types of sulfated oligosaccharides, Siglec-8 and Siglec-9 displayed a high degree of specificity for sialyl N-acetyllactosamine (sLacNAc) with sulfations at O6-positions of the galactose (6'-sulfation) and N-acetylglucosamine (6-sulfation), respectively. Siglec-3 was recently discovered to bind sLacNAc both sulfations. In addition to a conserved arginine residue for binding to sialic acid residue, the sequence variety in the CC' loop may provide binding specificities to sulfated oligosaccharides in Siglecs. Thus, the present study employed molecular models to study the impact of different residues in the CC' loops of Siglec-8/9/3 to the recognitions of 6-sulfations in Gal and/or GlcNAc of sLacNAc. The negatively charged residues in the CC' loop of Siglec-9 formed unfavorable electrostatic repulsions with the 6-sulfate in Gal and resulted no recognitions, in contrast to the favorable interactions formed between the positively charged residues in the CC' loop of Siglec-8 and the 6-sulfate in Gal resulting strong specificity. A two-state binding model was proposed for Siglec-3 recognizing 6-sulfations in Gal and GlcNAc of sLacNAc, as the neutral residues in the CC' loop of Siglec-3 could not form strong favorable interactions to lock the 6-sulfate in Gal within a single binding pose or strong unfavorable interactions to repel the 6-sulfate in Gal. The oligosaccharide adopted two distinctive binding poses and oriented the sulfate groups to form interactions with residues in the CC' loop and G-strand. The present study provided a structural mechanism for the sequence variety in the CC' loop of Siglec-8/9/3 determining the recognitions to the sulfated oligosaccharides and offered insights into the binding specificities for Siglecs.
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Affiliation(s)
- Yucheng Wang
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yujie Peng
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Rui Long
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Peiting Shi
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Yinghao Zhang
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - De-Xin Kong
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Jinshui Zheng
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
- National Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Xiaocong Wang
- Hubei Key Laboratory of Agricultural Bioinformatics, College of Informatics, Huazhong Agricultural University, Wuhan, Hubei 430070, China
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3
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Schmidt EN, Lamprinaki D, McCord KA, Joe M, Sojitra M, Waldow A, Nguyen J, Monyror J, Kitova EN, Mozaneh F, Guo XY, Jung J, Enterina JR, Daskhan GC, Han L, Krysler AR, Cromwell CR, Hubbard BP, West LJ, Kulka M, Sipione S, Klassen JS, Derda R, Lowary TL, Mahal LK, Riddell MR, Macauley MS. Siglec-6 mediates the uptake of extracellular vesicles through a noncanonical glycolipid binding pocket. Nat Commun 2023; 14:2327. [PMID: 37087495 PMCID: PMC10122656 DOI: 10.1038/s41467-023-38030-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Accepted: 04/12/2023] [Indexed: 04/24/2023] Open
Abstract
Immunomodulatory Siglecs are controlled by their glycoprotein and glycolipid ligands. Siglec-glycolipid interactions are often studied outside the context of a lipid bilayer, missing the complex behaviors of glycolipids in a membrane. Through optimizing a liposomal formulation to dissect Siglec-glycolipid interactions, it is shown that Siglec-6 can recognize glycolipids independent of its canonical binding pocket, suggesting that Siglec-6 possesses a secondary binding pocket tailored for recognizing glycolipids in a bilayer. A panel of synthetic neoglycolipids is used to probe the specificity of this glycolipid binding pocket on Siglec-6, leading to the development of a neoglycolipid with higher avidity for Siglec-6 compared to natural glycolipids. This neoglycolipid facilitates the delivery of liposomes to Siglec-6 on human mast cells, memory B-cells and placental syncytiotrophoblasts. A physiological relevance for glycolipid recognition by Siglec-6 is revealed for the binding and internalization of extracellular vesicles. These results demonstrate a unique and physiologically relevant ability of Siglec-6 to recognize glycolipids in a membrane.
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Affiliation(s)
- Edward N Schmidt
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | | | - Kelli A McCord
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Maju Joe
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Mirat Sojitra
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Ayk Waldow
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Jasmine Nguyen
- Department of Obstetrics & Gynaecology and Physiology University of Alberta, Edmonton, AB, Canada
| | - John Monyror
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - Elena N Kitova
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Fahima Mozaneh
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Xue Yan Guo
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Jaesoo Jung
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Jhon R Enterina
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
| | - Gour C Daskhan
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Ling Han
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Amanda R Krysler
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | | | - Basil P Hubbard
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Lori J West
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
- Department of Pediatrics, University of Alberta, Edmonton, AB, Canada
- Department of Surgery, University of Alberta, Edmonton, AB, Canada
| | - Marianne Kulka
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada
- National Research Council, Edmonton, AB, Canada
| | - Simonetta Sipione
- Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada
| | - John S Klassen
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Ratmir Derda
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Todd L Lowary
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
- Institute of Biological Chemistry, Academia Sinica, Nangang, Taipei, Taiwan
- Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan
| | - Lara K Mahal
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada
| | - Meghan R Riddell
- Department of Obstetrics & Gynaecology and Physiology University of Alberta, Edmonton, AB, Canada
| | - Matthew S Macauley
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada.
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, AB, Canada.
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, Canada.
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4
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Schnaar RL. Gangliosides as Siglec ligands. Glycoconj J 2023; 40:159-167. [PMID: 36701102 PMCID: PMC11000168 DOI: 10.1007/s10719-023-10101-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/09/2023] [Accepted: 01/13/2023] [Indexed: 01/27/2023]
Abstract
The structure of a sialoglycan can be translated into to a biological response when it binds to a specific endogenous lectin. Among endogenous sialic acid-binding lectins in humans are those comprising the 15-member Siglec family, most of which are expressed on overlapping sets of immune cells. Endogenous Siglec ligands are sialoglycolipids (gangliosides) and/or sialoglycoproteins, on cell surfaces or in the extracellular milieu, that bind to and initiate signaling by cell surface Siglecs. In the nervous system, where gangliosides are the predominant sialoglycans, Siglec-4 (myelin-associated glycoprotein) on myelinating cells binds to gangliosides GD1a and GT1b on nerve cell axons to ensure stable and productive axon-myelin interactions. In the immune system, Siglec-7 on natural killer cells binds to gangliosides GD3 and GD2 to inhibit immune signaling. Expression of GD3 and GD2 on cancer cells can lead to tumor immune evasion. Siglec-1 (sialoadhesin, CD169) on macrophages binds to gangliosides on tumors and enveloped viruses. This may enhance antigen presentation in some cases, or increase viral distribution in others. Several other Siglecs bind to gangliosides in vitro, the biological significance of which has yet to be fully established. Gangliosides, which are found on all human cells and tissues in cell-specific distributions, are functional Siglec ligands with varied roles driving Siglec-mediated signaling.
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Affiliation(s)
- Ronald L Schnaar
- Department of Pharmacology and Molecular Sciences, Department of Neuroscience, Johns Hopkins University School of Medicine, 725 N Wolfe St, Baltimore, MD, 21205, USA.
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5
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Prenzler S, Rudrawar S, Waespy M, Kelm S, Anoopkumar-Dukie S, Haselhorst T. The role of sialic acid-binding immunoglobulin-like-lectin-1 (siglec-1) in immunology and infectious disease. Int Rev Immunol 2023; 42:113-138. [PMID: 34494938 DOI: 10.1080/08830185.2021.1931171] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
Siglec-1, also known as Sialoadhesin (Sn) and CD169 is highly conserved among vertebrates and with 17 immunoglobulin-like domains is Siglec-1 the largest member of the Siglec family. Expression of Siglec-1 is found primarily on dendritic cells (DCs), macrophages and interferon induced monocyte. The structure of Siglec-1 is unique among siglecs and its function as a receptor is also different compared to other receptors in this class as it contains the most extracellular domains out of all the siglecs. However, the ability of Siglec-1 to internalize antigens and to pass them on to lymphocytes by allowing dendritic cells and macrophages to act as antigen presenting cells, is the main reason that has granted Siglec-1's key role in multiple human disease states including atherosclerosis, coronary artery disease, autoimmune diseases, cell-cell signaling, immunology, and more importantly bacterial and viral infections. Enveloped viruses for example have been shown to manipulate Siglec-1 to increase their virulence by binding to sialic acids present on the virus glycoproteins allowing them to spread or evade immune response. Siglec-1 mediates dissemination of HIV-1 in activated tissues enhancing viral spread via infection of DC/T-cell synapses. Overall, the ability of Siglec-1 to bind a variety of target cells within the immune system such as erythrocytes, B-cells, CD8+ granulocytes and NK cells, highlights that Siglec-1 is a unique player in these essential processes.
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Affiliation(s)
- Shane Prenzler
- School of Pharmacy and Medical Sciences, Griffith University, Gold Coast, Queensland, Australia.,Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Santosh Rudrawar
- School of Pharmacy and Medical Sciences, Griffith University, Gold Coast, Queensland, Australia.,Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Mario Waespy
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen, Bremen, Germany
| | - Sørge Kelm
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen, Bremen, Germany
| | - Shailendra Anoopkumar-Dukie
- School of Pharmacy and Medical Sciences, Griffith University, Gold Coast, Queensland, Australia.,Menzies Health Institute Queensland, Griffith University, Gold Coast, Queensland, Australia
| | - Thomas Haselhorst
- Institute for Glycomics, Griffith University, Gold Coast, Queensland, Australia
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6
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Cooper O, Waespy M, Chen D, Kelm S, Li Q, Haselhorst T, Tiralongo J. Sugar-decorated carbon dots: a novel tool for targeting immunomodulatory receptors. NANOSCALE ADVANCES 2022; 4:5355-5364. [PMID: 36540112 PMCID: PMC9729803 DOI: 10.1039/d2na00364c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 10/14/2022] [Indexed: 06/17/2023]
Abstract
Interactions between sialic acid (Sia) and sialic acid-binding immunoglobulin-like lectins (siglecs) regulate the immune system, with aberrations contributing to pathologies such as autoimmunity, infectious disease and cancer. Over the last decade, several multivalent Sia ligands have been synthesized to modulate the Sia-binding affinity of proteins/lectins. Here, we report a novel class of multivalent siglec probes through the decoration of α(2,6)-sialyllactose ligands on inherently fluorescent carbon dots (CD). We show that the preference of α(2,3)-linked Sia for siglec-1 can be altered by increasing the multivalence of Sia ligands present on the CD, and that a locally high glycan concentration can have a direct effect on linkage specificity. Additionally, micromolar (IC50 ∼ 70 μM) interaction of α(2,6)-sialyllactose-CD (6-CD) with siglec-2 (CD22) revealed it was capable of generating a significant cytotoxic effect on Burkitt's Lymphoma (BL) Daudi B cells. This phenonomen was attributed to 6-CD's ability to form trans interactions with CD22 on masked BL Daudi cells as a direct result of clustering of the Sia moiety on the CD surface. Overall, our glycoengineered carbon dots represent a novel high affinity molecular probe with multiple applications in sialoglycoscience and medicine.
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Affiliation(s)
- Oren Cooper
- Institute for Glycomics, Gold Coast Campus, Griffith University Queensland 4222 Australia
| | - Mario Waespy
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen 28334 Bremen Germany
| | - Dechao Chen
- School of Engineering and Built Environment, Nathan Campus, Griffith University QLD 4111 Australia
| | - Sørge Kelm
- Centre for Biomolecular Interactions Bremen, Department of Biology and Chemistry, University of Bremen 28334 Bremen Germany
| | - Qin Li
- School of Engineering and Built Environment, Nathan Campus, Griffith University QLD 4111 Australia
- Queensland Micro- and Nanotechnology Centre, Australia, Nathan Campus, Griffith University QLD 4111 Australia
| | - Thomas Haselhorst
- Institute for Glycomics, Gold Coast Campus, Griffith University Queensland 4222 Australia
| | - Joe Tiralongo
- Institute for Glycomics, Gold Coast Campus, Griffith University Queensland 4222 Australia
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7
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Petitpas K, Habibabady Z, Ritchie V, Connolly MR, Burdorf L, Qin W, Kan Y, Layer JV, Crabtree JN, Youd ME, Westlin WF, Magnani DM, Pierson RN, Azimzadeh AM. Genetic modifications designed for xenotransplantation attenuate sialoadhesin-dependent binding of human erythrocytes to porcine macrophages. Xenotransplantation 2022; 29:e12780. [PMID: 36125388 PMCID: PMC10152518 DOI: 10.1111/xen.12780] [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] [Received: 06/05/2022] [Revised: 08/11/2022] [Accepted: 09/01/2022] [Indexed: 01/15/2023]
Abstract
The phenomenon of diminishing hematocrit after in vivo liver and lung xenotransplantation and during ex vivo liver xenoperfusion has largely been attributed to action by resident liver porcine macrophages, which bind and destroy human erythrocytes. Porcine sialoadhesin (siglec-1) was implicated previously in this interaction. This study examines the effect of porcine genetic modifications, including knockout of the CMAH gene responsible for expression of Neu5Gc sialic acid, on the adhesion of human red blood cells (RBCs) to porcine macrophages. Wild-type (WT) porcine macrophages and macrophages from several strains of genetically engineered pigs, including CMAH gene knockout and several human transgenes (TKO+hTg), were incubated with human RBCs and "rosettes" (≥3 erythrocytes bound to one macrophage) were quantified by microscopy. Our results show that TKO+hTg genetic modifications significantly reduced rosette formation. The monoclonal antibody 1F1, which blocks porcine sialoadhesin, significantly reduced rosette formation by WT and TKO+hTg macrophages compared with an isotype control antibody. Further, desialation of human RBCs with neuraminidase before addition to WT or TKO+hTg macrophages resulted in near-complete abrogation of rosette formation, to a level not significantly different from porcine RBC rosette formation on porcine macrophages. These observations are consistent with rosette formation being mediated by binding of sialic acid on human RBCs to sialoadhesin on porcine macrophages. In conclusion, the data predict that TKO+hTg genetic modifications, coupled with targeting of porcine sialoadhesin by the 1F1 mAb, will attenuate erythrocyte sequestration and anemia during ex vivo xenoperfusion and following in vivo liver, lung, and potentially other organ xenotransplantation.
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Affiliation(s)
- Kaitlyn Petitpas
- MGH, Center for Transplantation Sciences, Boston, Massachusetts, USA
| | - Zahra Habibabady
- MGH, Center for Transplantation Sciences, Boston, Massachusetts, USA
| | - Veronica Ritchie
- MGH, Center for Transplantation Sciences, Boston, Massachusetts, USA
| | | | - Lars Burdorf
- MGH, Center for Transplantation Sciences, Boston, Massachusetts, USA
| | - Wenning Qin
- eGenesis Inc., Cambridge, Massachusetts, USA
| | - Yinan Kan
- eGenesis Inc., Cambridge, Massachusetts, USA
| | | | | | | | | | | | - Richard N Pierson
- MGH, Center for Transplantation Sciences, Boston, Massachusetts, USA
| | - Agnes M Azimzadeh
- MGH, Center for Transplantation Sciences, Boston, Massachusetts, USA
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8
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Olona A, Hateley C, Muralidharan S, Wenk MR, Torta F, Behmoaras J. Sphingolipid metabolism during Toll-like receptor 4 (TLR4)-mediated macrophage activation. Br J Pharmacol 2021; 178:4575-4587. [PMID: 34363204 DOI: 10.1111/bph.15642] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 06/18/2021] [Accepted: 07/27/2021] [Indexed: 12/14/2022] Open
Abstract
Macrophage activation in response to stimulation of Toll-like receptor 4 (TLR4) provides a paradigm for investigating energy metabolism that regulates the inflammatory response. TLR4-mediated pro-inflammatory macrophage activation is characterized by increased glycolysis and altered mitochondrial metabolism, supported by selective amino acid uptake and/or usage. Fatty acid metabolism remains as a highly complex rewiring that accompanies classical macrophage activation. TLR4 activation leads to de novo synthesis of fatty acids, which flux into sphingolipids, complex lipids that form the building blocks of eukaryotic cell membranes and regulate cell function. Here, we review the importance of TLR4-mediated de novo synthesis of membrane sphingolipids in macrophages. We first highlight fatty acid metabolism during TLR4-driven macrophage immunometabolism. We then focus on the temporal dynamics of sphingolipid biosynthesis and emphasize the modulatory role of some sphingolipid species (i.e. sphingomyelins, ceramides and glycosphingolipids) on the pro-inflammatory and pro-resolution phases of LPS/TLR4 activation in macrophages.
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Affiliation(s)
- Antoni Olona
- Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK
| | - Charlotte Hateley
- Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK
| | | | - Markus R Wenk
- SLING, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Federico Torta
- SLING, Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Jacques Behmoaras
- Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, UK.,Programme in Cardiovascular and Metabolic Disorders and Centre for Computational Biology, Duke-NUS Medical School Singapore, Republic of Singapore
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9
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Grabowska J, Affandi AJ, van Dinther D, Nijen Twilhaar MK, Olesek K, Hoogterp L, Ambrosini M, Heijnen DAM, Klaase L, Hidalgo A, Asano K, Crocker PR, Storm G, van Kooyk Y, den Haan JMM. Liposome induction of CD8 + T cell responses depends on CD169 + macrophages and Batf3-dependent dendritic cells and is enhanced by GM3 inclusion. J Control Release 2021; 331:309-320. [PMID: 33493613 DOI: 10.1016/j.jconrel.2021.01.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 01/16/2021] [Accepted: 01/19/2021] [Indexed: 02/07/2023]
Abstract
Cancer vaccines aim to efficiently prime cytotoxic CD8+ T cell responses which can be achieved by vaccine targeting to dendritic cells. CD169+ macrophages have been shown to transfer antigen to dendritic cells and could act as an alternative target for cancer vaccines. Here, we evaluated liposomes containing the CD169/Siglec-1 binding ligand, ganglioside GM3, and the non-binding ligand, ganglioside GM1, for their capacity to target antigens to CD169+ macrophages and to induce immune responses. CD169+ macrophages demonstrated specific uptake of GM3 liposomes in vitro and in vivo that was dependent on a functional CD169 receptor. Robust antigen-specific CD8+ and CD4+ T and B cell responses were observed upon intravenous administration of GM3 liposomes containing the model antigen ovalbumin in the presence of adjuvant. Immunization of B16-OVA tumor bearing mice with all liposomes resulted in delayed tumor growth and improved survival. The absence of CD169+ macrophages, functional CD169 molecules, and cross-presenting Batf3-dependent dendritic cells (cDC1s) significantly impaired CD8+ T cell responses, while B cell responses were less affected. In conclusion, we demonstrate that inclusion of GM3 in liposomes enhance immune responses and that splenic CD169+ macrophages and cDC1s are required for induction of CD8+ T cell immunity after liposomal vaccination.
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Affiliation(s)
- J Grabowska
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - A J Affandi
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - D van Dinther
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - M K Nijen Twilhaar
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - K Olesek
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - L Hoogterp
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - M Ambrosini
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - D A M Heijnen
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - L Klaase
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - A Hidalgo
- Area of Cell and Developmental Biology, Centro Nacional de Investigaciones Cardiovasculares Carlos III, Madrid, Spain
| | - K Asano
- Laboratory of Immune Regulation, School of Life Science, Tokyo University of Pharmacy and Life Sciences, Tokyo 192-0392, Japan
| | - P R Crocker
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dundee, UK
| | - G Storm
- Department of Pharmaceutics, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584, CG, Utrecht, the Netherlands; Department of Biomaterials, Science and Technology, Faculty of Science and Technology, University of Twente, Enschede, the Netherlands; Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, 117597, Singapore
| | - Y van Kooyk
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands
| | - J M M den Haan
- Department of Molecular Cell Biology and Immunology, Amsterdam University Medical Center, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Vrije Universiteit Amsterdam, Amsterdam, Netherlands.
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10
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Nowack L, Teschers CS, Albrecht S, Gilmour R. Oligodendroglial glycolipids in (Re)myelination: implications for multiple sclerosis research. Nat Prod Rep 2021; 38:890-904. [PMID: 33575689 DOI: 10.1039/d0np00093k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Covering: up to 2020 This short review surveys aspects of glycolipid-based natural products and their biological relevance in multiple sclerosis (MS). The role of isolated gangliosides in disease models is discussed together with an overview of ganglioside-inspired small molecule drugs and imaging probes. The discussion is extended to neurodegeneration in a more general context and addresses the need for more efficient synthetic methods to generate (glyco)structures that are of therapeutic relevance.
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Affiliation(s)
- Luise Nowack
- Institute for Organic Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149 Münster, Germany. and Institute of Neuropathology, University Hospital Münster, Pottkamp 2, 48149 Münster, Germany.
| | - Charlotte S Teschers
- Institute for Organic Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149 Münster, Germany.
| | - Stefanie Albrecht
- Institute of Neuropathology, University Hospital Münster, Pottkamp 2, 48149 Münster, Germany.
| | - Ryan Gilmour
- Institute for Organic Chemistry, Westfälische Wilhelms-Universität Münster, Corrensstraße 36, 48149 Münster, Germany.
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11
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Current Status on Therapeutic Molecules Targeting Siglec Receptors. Cells 2020; 9:cells9122691. [PMID: 33333862 PMCID: PMC7765293 DOI: 10.3390/cells9122691] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/09/2020] [Accepted: 12/12/2020] [Indexed: 12/15/2022] Open
Abstract
The sialic acid-binding immunoglobulin-type of lectins (Siglecs) are receptors that recognize sialic acid-containing glycans. In the majority of the cases, Siglecs are expressed on immune cells and play a critical role in regulating immune cell signaling. Over the years, it has been shown that the sialic acid-Siglec axis participates in immunological homeostasis, and that any imbalance can trigger different pathologies, such as autoimmune diseases or cancer. For all this, different therapeutics have been developed that bind to Siglecs, either based on antibodies or being smaller molecules. In this review, we briefly introduce the Siglec family and we compile a description of glycan-based molecules and antibody-based therapies (including CAR-T and bispecific antibodies) that have been designed to therapeutically targeting Siglecs.
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12
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Optimization of Liposomes for Antigen Targeting to Splenic CD169 + Macrophages. Pharmaceutics 2020; 12:pharmaceutics12121138. [PMID: 33255564 PMCID: PMC7760819 DOI: 10.3390/pharmaceutics12121138] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/20/2020] [Accepted: 11/23/2020] [Indexed: 12/21/2022] Open
Abstract
Despite promising progress in cancer vaccination, therapeutic effectiveness is often insufficient. Cancer vaccine effectiveness could be enhanced by targeting vaccine antigens to antigen-presenting cells, thereby increasing T-cell activation. CD169-expressing splenic macrophages efficiently capture particulate antigens from the blood and transfer these antigens to dendritic cells for the activation of CD8+ T cells. In this study, we incorporated a physiological ligand for CD169, the ganglioside GM3, into liposomes to enhance liposome uptake by CD169+ macrophages. We assessed how variation in the amount of GM3, surface-attached PEG and liposomal size affected the binding to, and uptake by, CD169+ macrophages in vitro and in vivo. As a proof of concept, we prepared GM3-targeted liposomes containing a long synthetic ovalbumin peptide and tested the capacity of these liposomes to induce CD8+ and CD4+ T-cell responses compared to control liposomes or soluble peptide. The data indicate that the delivery of liposomes to splenic CD169+ macrophages can be optimized by the selection of liposomal constituents and liposomal size. Moreover, optimized GM3-mediated liposomal targeting to CD169+ macrophages induces potent immune responses and therefore presents as an interesting delivery strategy for cancer vaccination.
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13
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Affandi AJ, Grabowska J, Olesek K, Lopez Venegas M, Barbaria A, Rodríguez E, Mulder PPG, Pijffers HJ, Ambrosini M, Kalay H, O'Toole T, Zwart ES, Kazemier G, Nazmi K, Bikker FJ, Stöckl J, van den Eertwegh AJM, de Gruijl TD, Storm G, van Kooyk Y, den Haan JMM. Selective tumor antigen vaccine delivery to human CD169 + antigen-presenting cells using ganglioside-liposomes. Proc Natl Acad Sci U S A 2020; 117:27528-27539. [PMID: 33067394 PMCID: PMC7959579 DOI: 10.1073/pnas.2006186117] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Priming of CD8+ T cells by dendritic cells (DCs) is crucial for the generation of effective antitumor immune responses. Here, we describe a liposomal vaccine carrier that delivers tumor antigens to human CD169/Siglec-1+ antigen-presenting cells using gangliosides as targeting ligands. Ganglioside-liposomes specifically bound to CD169 and were internalized by in vitro-generated monocyte-derived DCs (moDCs) and macrophages and by ex vivo-isolated splenic macrophages in a CD169-dependent manner. In blood, high-dimensional reduction analysis revealed that ganglioside-liposomes specifically targeted CD14+ CD169+ monocytes and Axl+ CD169+ DCs. Liposomal codelivery of tumor antigen and Toll-like receptor ligand to CD169+ moDCs and Axl+ CD169+ DCs led to cytokine production and robust cross-presentation and activation of tumor antigen-specific CD8+ T cells. Finally, Axl+ CD169+ DCs were present in cancer patients and efficiently captured ganglioside-liposomes. Our findings demonstrate a nanovaccine platform targeting CD169+ DCs to drive antitumor T cell responses.
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Affiliation(s)
- Alsya J Affandi
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Joanna Grabowska
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Katarzyna Olesek
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Miguel Lopez Venegas
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
- DC4U, 3621 ZA Breukelen, The Netherlands
| | - Arnaud Barbaria
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Ernesto Rodríguez
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Patrick P G Mulder
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Helen J Pijffers
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Martino Ambrosini
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Hakan Kalay
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Tom O'Toole
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
| | - Eline S Zwart
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
- Department of Surgery, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Geert Kazemier
- Department of Surgery, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Kamran Nazmi
- Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam and University of Amsterdam, 1081 LA Amsterdam, The Netherlands
| | - Floris J Bikker
- Department of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), Vrije Universiteit Amsterdam and University of Amsterdam, 1081 LA Amsterdam, The Netherlands
| | - Johannes Stöckl
- Institute of Immunology, Centre for Pathophysiology, Infectiology and Immunology, Medical University of Vienna, 1090 Vienna, Austria
| | - Alfons J M van den Eertwegh
- Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Tanja D de Gruijl
- Department of Medical Oncology, Cancer Center Amsterdam, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HV Amsterdam, The Netherlands
| | - Gert Storm
- Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3508 TB Utrecht, The Netherlands
- Department of Biomaterials, Science and Technology, Faculty of Science and Technology, University of Twente, 7522 NB Enschede, The Netherlands
| | - Yvette van Kooyk
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands
- DC4U, 3621 ZA Breukelen, The Netherlands
| | - Joke M M den Haan
- Department of Molecular Cell Biology and Immunology, Cancer Center Amsterdam, Amsterdam Infection and Immunity Institute, Amsterdam UMC, Vrije Universiteit Amsterdam, 1081 HZ Amsterdam, The Netherlands;
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Stadelmann C, Timmler S, Barrantes-Freer A, Simons M. Myelin in the Central Nervous System: Structure, Function, and Pathology. Physiol Rev 2019; 99:1381-1431. [PMID: 31066630 DOI: 10.1152/physrev.00031.2018] [Citation(s) in RCA: 283] [Impact Index Per Article: 56.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Oligodendrocytes generate multiple layers of myelin membrane around axons of the central nervous system to enable fast and efficient nerve conduction. Until recently, saltatory nerve conduction was considered the only purpose of myelin, but it is now clear that myelin has more functions. In fact, myelinating oligodendrocytes are embedded in a vast network of interconnected glial and neuronal cells, and increasing evidence supports an active role of oligodendrocytes within this assembly, for example, by providing metabolic support to neurons, by regulating ion and water homeostasis, and by adapting to activity-dependent neuronal signals. The molecular complexity governing these interactions requires an in-depth molecular understanding of how oligodendrocytes and axons interact and how they generate, maintain, and remodel their myelin sheaths. This review deals with the biology of myelin, the expanded relationship of myelin with its underlying axons and the neighboring cells, and its disturbances in various diseases such as multiple sclerosis, acute disseminated encephalomyelitis, and neuromyelitis optica spectrum disorders. Furthermore, we will highlight how specific interactions between astrocytes, oligodendrocytes, and microglia contribute to demyelination in hereditary white matter pathologies.
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Affiliation(s)
- Christine Stadelmann
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Sebastian Timmler
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Alonso Barrantes-Freer
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Mikael Simons
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
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15
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Wei M, Wang PG. Desialylation in physiological and pathological processes: New target for diagnostic and therapeutic development. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 162:25-57. [PMID: 30905454 DOI: 10.1016/bs.pmbts.2018.12.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Desialylation is a pivotal part of sialic acid metabolism, which initiates the catabolism of glycans by removing the terminal sialic acid residues on glycans, thereby modulating the structure and functions of glycans, glycoproteins, or glycolipids. The functions of sialic acids have been well recognized, whereas the function of desialylation process is underappreciated or largely ignored. However, accumulating evidence demonstrates that desialylation plays an important role in a variety of physiological and pathological processes. This chapter summarizes the current knowledge pertaining to desialylation in a variety of physiological and pathological processes, with a focus on the underlying molecular mechanisms. The potential of targeting desialylation process for diagnostic and therapeutic development is also discussed.
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Affiliation(s)
- Mohui Wei
- Department of Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, United States.
| | - Peng George Wang
- Department of Chemistry, Center for Diagnostics and Therapeutics, Georgia State University, Atlanta, GA, United States
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16
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Angata T. Possible Influences of Endogenous and Exogenous Ligands on the Evolution of Human Siglecs. Front Immunol 2018; 9:2885. [PMID: 30564250 PMCID: PMC6288428 DOI: 10.3389/fimmu.2018.02885] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 11/23/2018] [Indexed: 12/25/2022] Open
Abstract
Sialic acids, a group of acidic sugars abundantly expressed in the tissues of deuterostome animals but rarely found in microbes, serve as a "signature of self" for these animals. Cognate sensors for sialic acids include Siglecs, a family of transmembrane lectins of vertebrate immune systems that recognize glycans containing sialic acids. A type of sialic acid called N-glycolylneuraminic acid (Neu5Gc) is abundant in many mammalian lineages including great apes, the closest extant relatives of modern human, but was lost in the lineage leading to modern human via the pseudogenization of the CMAH gene encoding the enzyme that converts N-acetylneuraminic acid (Neu5Ac) to Neu5Gc. Loss of Neu5Gc appears to have influenced the evolution of human Siglecs, such as the adjustment of sialic acid binding preferences and the inactivation of at least one Siglec. In addition, various mechanistic studies using model systems and genetic association studies have revealed that some human Siglecs interact with pathogens and influence the outcome of infections, and these pathogens in turn likely influence the evolution of these Siglecs. By understanding the evolutionary forces affecting Siglecs, we shall achieve a better appreciation of Siglec functions, and by understanding Siglec functions, we can obtain deeper insight into the evolutionary processes driving Siglec evolution.
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Affiliation(s)
- Takashi Angata
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
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17
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Abstract
Gangliosides comprise a varied family of glycosphingolipid structures bearing one or more sialic acid residues. They are found in all mammalian tissues but are most abundant in the brain, where they represent the quantitatively major class of sialoglycans. As prominent molecular determinants on cell surfaces, they function as molecular-recognition partners for diverse glycan-binding proteins ranging from bacterial toxins to endogenous cell-cell adhesion molecules. Gangliosides also regulate the activity of plasma membrane proteins, including protein tyrosine kinases, by lateral association in the same membranes in which they reside. Their roles in molecular recognition and membrane protein regulation implicate gangliosides in human physiology and pathology, including infectious diseases, diabetes, cancer, and neurodegeneration. The varied structures and biosynthetic pathways of gangliosides are presented here, along with representative examples of their biological functions in health and disease.
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18
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Yoshihara T, Satake H, Nishie T, Okino N, Hatta T, Otani H, Naruse C, Suzuki H, Sugihara K, Kamimura E, Tokuda N, Furukawa K, Fururkawa K, Ito M, Asano M. Lactosylceramide synthases encoded by B4galt5 and 6 genes are pivotal for neuronal generation and myelin formation in mice. PLoS Genet 2018; 14:e1007545. [PMID: 30114188 PMCID: PMC6095488 DOI: 10.1371/journal.pgen.1007545] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Accepted: 07/06/2018] [Indexed: 01/10/2023] Open
Abstract
It is uncertain which β4-galactosyltransferase (β4GalT; gene name, B4galt), β4GalT-5 and/or β4GalT-6, is responsible for the production of lactosylceramide (LacCer) synthase, which functions in the initial step of ganglioside biosynthesis. Here, we generated conditional B4galt5 knockout (B4galt5 cKO) mice, using Nestin-Cre mice, and crossed these with B4galt6 KO mice to generate B4galt5 and 6 double KO (DKO) mice in the central nervous system (CNS). LacCer synthase activity and major brain gangliosides were completely absent in brain homogenates from the DKO mice, although LacCer synthase activity was about half its normal level in B4galt5 cKO mice and B4galt6 KO mice. The DKO mice were born normally but they showed growth retardation and motor deficits at 2 weeks and died by 4 weeks of age. Histological analyses showed that myelin-associated proteins were rarely found localized in axons in the cerebral cortex, and axonal and myelin formation were remarkably impaired in the spinal cords of the DKO mice. Neuronal cells, differentiated from neurospheres that were prepared from the DKO mice, showed impairments in neurite outgrowth and branch formation, which can be explained by the fact that neurospheres from DKO mice could weakly interact with laminin due to lack of gangliosides, such as GM1a. Furthermore, the neurons were immature and perineuronal nets (PNNs) were poorly formed in DKO cerebral cortices. Our results indicate that LacCer synthase is encoded by B4galt5 and 6 genes in the CNS, and that gangliosides are indispensable for neuronal maturation, PNN formation, and axonal and myelin formation. Gangliosides are membrane-bound glycosphingolipids that contain sialic acid residues and are abundant in the mammalian nervous system, suggesting that they play pivotal roles in neural functions. We generated conditional β4-galactosyltransferase-5 (B4galt5) knockout (KO) and double B4galt5/B4galt6 KO (DKO) mice to completely ablate lactosylceramide (LacCer) synthase in the central nervous system (CNS). LacCer functions in the initial step of ganglioside biosynthesis. DKO mice were born normally but showed growth retardation and motor deficits at 2 weeks and died by 4 weeks of age. Myelin-associated proteins were rarely found localized in axons in the cerebral cortex, and axonal and myelin formation were remarkably impaired in the spinal cords of DKO mice. Neurospheres prepared from DKO mice could weakly interact with laminin, probably due to the lack of gangliosides in these mice. This defect might have caused the impaired neurite outgrowth in neuronal cells from DKO mice and poor formation of perineuronal nets (PNNs) with immature neurons in the cerebral cortices of DKO mice. Our results indicate pivotal roles for gangliosides in the CNS, including neuronal maturation, PNN formation, and axonal and myelin formation.
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Affiliation(s)
- Toru Yoshihara
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Division of Transgenic Animal Science, Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Hiroyuki Satake
- Division of Transgenic Animal Science, Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Toshikazu Nishie
- Division of Transgenic Animal Science, Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Nozomu Okino
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan
| | - Toshihisa Hatta
- Department of Molecular and Cell Structural Science, Kanazawa Medical University, Uchinada, Japan
| | - Hiroki Otani
- Department of Developmental Biology, Faculty of Medicine, Shimane University, Izumo, Japan
| | - Chie Naruse
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Division of Transgenic Animal Science, Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Hiroshi Suzuki
- Division of Transgenic Animal Science, Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Kazushi Sugihara
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Division of Transgenic Animal Science, Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Eikichi Kamimura
- Division of Transgenic Animal Science, Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
| | - Noriyo Tokuda
- Department of Biochemistry II, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Keiko Furukawa
- Department of Biomedical Sciences, Chubu University College of Life and Health Sciences, Kasugai, Japan
| | - Koichi Fururkawa
- Department of Biochemistry II, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Department of Biomedical Sciences, Chubu University College of Life and Health Sciences, Kasugai, Japan
| | - Makoto Ito
- Department of Bioscience and Biotechnology, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan
| | - Masahide Asano
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto, Japan
- Division of Transgenic Animal Science, Advanced Science Research Center, Kanazawa University, Kanazawa, Japan
- * E-mail:
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19
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Pshezhetsky AV, Ashmarina M. Keeping it trim: roles of neuraminidases in CNS function. Glycoconj J 2018; 35:375-386. [PMID: 30088207 PMCID: PMC6182584 DOI: 10.1007/s10719-018-9837-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/25/2018] [Accepted: 07/27/2018] [Indexed: 12/11/2022]
Abstract
The sialylated glyconjugates (SGC) are found in abundance on the surface of brain cells, where they form a dense array of glycans mediating cell/cell and cell/protein recognition in numerous physiological and pathological processes. Metabolic genetic blocks in processing and catabolism of SGC result in development of severe storage disorders, dominated by CNS involvement including marked neuroinflammation and neurodegeneration, the pathophysiological mechanisms of which are still discussed. SGC patterns in the brain are cell and organelle-specific, dynamic and maintained by highly coordinated processes of their biosynthesis, trafficking, processing and catabolism. The changes in the composition of SGC during development and aging of the brain cannot be explained based solely on the regulation of the SGC-synthesizing enzymes, sialyltransferases, suggesting that neuraminidases (sialidases) hydrolysing the removal of terminal sialic acid residues also play an essential role. In the current review we summarize the roles of three mammalian neuraminidases: neuraminidase 1, neuraminidase 3 and neuraminidase 4 in processing brain SGC. Emerging data demonstrate that these enzymes with different, yet overlapping expression patterns, intracellular localization and substrate specificity play essential roles in the physiology of the CNS.
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Affiliation(s)
- Alexey V Pshezhetsky
- Sainte-Justine Hospital Research Center, Department of Paediatrics, University of Montreal, CHU Ste-Justine, Centre de recherche, 3175 Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, H3A0C7, Canada.
| | - Mila Ashmarina
- Sainte-Justine Hospital Research Center, Department of Paediatrics, University of Montreal, CHU Ste-Justine, Centre de recherche, 3175 Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada
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20
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Lopez PH, Báez BB. Gangliosides in Axon Stability and Regeneration. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 156:383-412. [DOI: 10.1016/bs.pmbts.2018.03.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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21
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Higuero AM, Díez-Revuelta N, Abad-Rodríguez J. The sugar code in neuronal physiology. Histochem Cell Biol 2016; 147:257-267. [PMID: 27999993 DOI: 10.1007/s00418-016-1519-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2016] [Indexed: 10/20/2022]
Abstract
Carbohydrate-related interactions are necessary for the correct development and function of the nervous system. As we illustrate with several examples, those interactions are controlled by carbohydrate-modifying enzymes and by carbohydrate-binding proteins that regulate a plethora of complex axonal processes. Among others, glycan-related proteins as sialidase Neu3 or galectins-1, -3, and -4 play central roles in the determination of axonal fate, axon growth, guidance and regeneration, as well as in polarized axonal glycoprotein transport. In addition, myelination is also highly dependent on glycans, and the stabilization of myelin architecture requires the interaction of the myelin-associated glycoprotein (siglec-4) with gangliosides in the axonal membrane. The roles of glycans in neuroscience are far from being completely understood, though the cases presented here underscore the importance and potential of carbohydrates to establish with precision key molecular mechanisms of the physiology of the nervous system. New specific applications in diagnosis as well as the definition of new molecular targets to treat neurological diseases related to lectins and/or glycans are envisioned in the future.
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Affiliation(s)
- Alonso M Higuero
- Membrane Biology and Axonal Repair Laboratory, National Hospital for Paraplegics (SESCAM), Finca La Peraleda s/n, 45071, Toledo, Spain
| | - Natalia Díez-Revuelta
- Membrane Biology and Axonal Repair Laboratory, National Hospital for Paraplegics (SESCAM), Finca La Peraleda s/n, 45071, Toledo, Spain
| | - José Abad-Rodríguez
- Membrane Biology and Axonal Repair Laboratory, National Hospital for Paraplegics (SESCAM), Finca La Peraleda s/n, 45071, Toledo, Spain.
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22
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Lertkiatmongkol P, Paddock C, Newman DK, Zhu J, Thomas MJ, Newman PJ. The Role of Sialylated Glycans in Human Platelet Endothelial Cell Adhesion Molecule 1 (PECAM-1)-mediated Trans Homophilic Interactions and Endothelial Cell Barrier Function. J Biol Chem 2016; 291:26216-26225. [PMID: 27793989 DOI: 10.1074/jbc.m116.756502] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/12/2016] [Indexed: 11/06/2022] Open
Abstract
Platelet Endothelial Cell Adhesion Molecule 1 (PECAM-1) is a major component of the endothelial cell intercellular junction. Previous studies have shown that PECAM-1 homophilic interactions, mediated by amino-terminal immunoglobulin homology domain 1, contribute to maintenance of the vascular permeability barrier and to its re-establishment following inflammatory or thrombotic insult. PECAM-1 glycans account for ∼30% of its molecular mass, and the newly solved crystal structure of human PECAM-1 immunoglobulin homology domain 1 reveals that a glycan emanating from the asparagine residue at position 25 (Asn-25) is located within the trans homophilic-binding interface, suggesting a role for an Asn-25-associated glycan in PECAM-1 homophilic interactions. In support of this possibility, unbiased molecular docking studies revealed that negatively charged α2,3 sialic acid moieties bind tightly to a groove within the PECAM-1 homophilic interface in an orientation that favors the formation of an electrostatic bridge with positively charged Lys-89, mutation of which has been shown previously to disrupt PECAM-1-mediated homophilic binding. To verify the contribution of the Asn-25 glycan to endothelial barrier function, we generated an N25Q mutant form of PECAM-1 that is not glycosylated at this position and examined its ability to contribute to vascular integrity in endothelial cell-like REN cells. Confocal microscopy showed that although N25Q PECAM-1 concentrates normally at cell-cell junctions, the ability of this mutant form of PECAM-1 to support re-establishment of a permeability barrier following disruption with thrombin was significantly compromised. Taken together, these data suggest that a sialic acid-containing glycan emanating from Asn-25 reinforces dynamic endothelial cell-cell interactions by stabilizing the PECAM-1 homophilic binding interface.
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Affiliation(s)
- Panida Lertkiatmongkol
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, Wisconsin 53201, and.,the Departments of Pharmacology
| | - Cathy Paddock
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, Wisconsin 53201, and
| | - Debra K Newman
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, Wisconsin 53201, and.,the Departments of Pharmacology
| | - Jieqing Zhu
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, Wisconsin 53201, and.,Biochemistry, and
| | | | - Peter J Newman
- From the Blood Research Institute, BloodCenter of Wisconsin, Milwaukee, Wisconsin 53201, and .,the Departments of Pharmacology.,Cell Biology, Medical College of Wisconsin, Milwaukee, Wisconsin 53226
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Preparation of legionaminic acid analogs of sialo-glycoconjugates by means of mammalian sialyltransferases. Glycoconj J 2015; 32:729-34. [DOI: 10.1007/s10719-015-9624-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 09/20/2015] [Accepted: 09/22/2015] [Indexed: 12/16/2022]
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24
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Schwarz F, Fong JJ, Varki A. Human-specific evolutionary changes in the biology of siglecs. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 842:1-16. [PMID: 25408333 DOI: 10.1007/978-3-319-11280-0_1] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Flavio Schwarz
- Departments of Medicine, and Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California San Diego, La Jolla, CA, USA,
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25
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Cecioni S, Imberty A, Vidal S. Glycomimetics versus Multivalent Glycoconjugates for the Design of High Affinity Lectin Ligands. Chem Rev 2014; 115:525-61. [DOI: 10.1021/cr500303t] [Citation(s) in RCA: 381] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Samy Cecioni
- CERMAV, Université Grenoble Alpes and CNRS, BP 53, F-38041 Grenoble Cedex 9, France
- Institut
de Chimie et Biochimie Moléculaires et Supramoléculaires,
Laboratoire de Chimie Organique 2 - Glycochimie, UMR 5246, Université Lyon 1 and CNRS, 43 Boulevard du 11 Novembre 1918, F-69622, Villeurbanne, France
| | - Anne Imberty
- CERMAV, Université Grenoble Alpes and CNRS, BP 53, F-38041 Grenoble Cedex 9, France
| | - Sébastien Vidal
- Institut
de Chimie et Biochimie Moléculaires et Supramoléculaires,
Laboratoire de Chimie Organique 2 - Glycochimie, UMR 5246, Université Lyon 1 and CNRS, 43 Boulevard du 11 Novembre 1918, F-69622, Villeurbanne, France
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Schnaar RL, Gerardy-Schahn R, Hildebrandt H. Sialic acids in the brain: gangliosides and polysialic acid in nervous system development, stability, disease, and regeneration. Physiol Rev 2014; 94:461-518. [PMID: 24692354 DOI: 10.1152/physrev.00033.2013] [Citation(s) in RCA: 489] [Impact Index Per Article: 48.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Every cell in nature carries a rich surface coat of glycans, its glycocalyx, which constitutes the cell's interface with its environment. In eukaryotes, the glycocalyx is composed of glycolipids, glycoproteins, and proteoglycans, the compositions of which vary among different tissues and cell types. Many of the linear and branched glycans on cell surface glycoproteins and glycolipids of vertebrates are terminated with sialic acids, nine-carbon sugars with a carboxylic acid, a glycerol side-chain, and an N-acyl group that, along with their display at the outmost end of cell surface glycans, provide for varied molecular interactions. Among their functions, sialic acids regulate cell-cell interactions, modulate the activities of their glycoprotein and glycolipid scaffolds as well as other cell surface molecules, and are receptors for pathogens and toxins. In the brain, two families of sialoglycans are of particular interest: gangliosides and polysialic acid. Gangliosides, sialylated glycosphingolipids, are the most abundant sialoglycans of nerve cells. Mouse genetic studies and human disorders of ganglioside metabolism implicate gangliosides in axon-myelin interactions, axon stability, axon regeneration, and the modulation of nerve cell excitability. Polysialic acid is a unique homopolymer that reaches >90 sialic acid residues attached to select glycoproteins, especially the neural cell adhesion molecule in the brain. Molecular, cellular, and genetic studies implicate polysialic acid in the control of cell-cell and cell-matrix interactions, intermolecular interactions at cell surfaces, and interactions with other molecules in the cellular environment. Polysialic acid is essential for appropriate brain development, and polymorphisms in the human genes responsible for polysialic acid biosynthesis are associated with psychiatric disorders including schizophrenia, autism, and bipolar disorder. Polysialic acid also appears to play a role in adult brain plasticity, including regeneration. Together, vertebrate brain sialoglycans are key regulatory components that contribute to proper development, maintenance, and health of the nervous system.
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27
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Angata T. Associations of genetic polymorphisms of Siglecs with human diseases. Glycobiology 2014; 24:785-93. [PMID: 24841380 DOI: 10.1093/glycob/cwu043] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Genetic polymorphism studies in humans provide unique opportunities to understand human biology and the mechanisms of diseases. Correlations between polymorphisms in the genes encoding human Siglecs and various diseases have been reported. Leading examples, such as the CD33 polymorphism associated with late-onset Alzheimer's disease, are well supported by genetic replication and mechanistic studies, while some others (such as SIGLEC8 polymorphism associated with bronchial asthma and SIGLEC14 polymorphism associated with exacerbation of chronic obstructive pulmonary disease) may benefit reinforcement by independent genetic replication or mechanistic studies. In a few cases, such as MAG polymorphism associated with psychological disorder and CD22 polymorphism associated with autoimmune disease, the phenotype associated with a genetic polymorphism of a Siglec gene and that of an enzyme gene involved in the biosynthesis of Siglec ligand show some overlap, providing indirect support for the observed genotype-phenotype association. Although studies using engineered mutant mice have provided invaluable insights into the biological functions and mechanisms of diseases, it is not always possible to develop appropriate mouse model to replicate human situations because of significant species-to-species differences, which can be a major obstacle in understanding the biology of some of human CD33/Siglec-3-related Siglecs. Further studies in genetic polymorphisms of human Siglecs, combined with appropriate functional studies, may reveal unexpected biological roles of human Siglecs, and identify possible targets for prevention and/or treatment of certain diseases.
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Affiliation(s)
- Takashi Angata
- Institute of Biological Chemistry, Academia Sinica, 128 Academia Road, Section 2, Nankang District, Taipei 11529, Taiwan
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Harlalka GV, Lehman A, Chioza B, Baple EL, Maroofian R, Cross H, Sreekantan-Nair A, Priestman DA, Al-Turki S, McEntagart ME, Proukakis C, Royle L, Kozak RP, Bastaki L, Patton M, Wagner K, Coblentz R, Price J, Mezei M, Schlade-Bartusiak K, Platt FM, Hurles ME, Crosby AH. Mutations in B4GALNT1 (GM2 synthase) underlie a new disorder of ganglioside biosynthesis. ACTA ACUST UNITED AC 2013; 136:3618-24. [PMID: 24103911 PMCID: PMC3859217 DOI: 10.1093/brain/awt270] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glycosphingolipids are ubiquitous constituents of eukaryotic plasma membranes, and their sialylated derivatives, gangliosides, are the major class of glycoconjugates expressed by neurons. Deficiencies in their catabolic pathways give rise to a large and well-studied group of inherited disorders, the lysosomal storage diseases. Although many glycosphingolipid catabolic defects have been defined, only one proven inherited disease arising from a defect in ganglioside biosynthesis is known. This disease, because of defects in the first step of ganglioside biosynthesis (GM3 synthase), results in a severe epileptic disorder found at high frequency amongst the Old Order Amish. Here we investigated an unusual neurodegenerative phenotype, most commonly classified as a complex form of hereditary spastic paraplegia, present in families from Kuwait, Italy and the Old Order Amish. Our genetic studies identified mutations in B4GALNT1 (GM2 synthase), encoding the enzyme that catalyzes the second step in complex ganglioside biosynthesis, as the cause of this neurodegenerative phenotype. Biochemical profiling of glycosphingolipid biosynthesis confirmed a lack of GM2 in affected subjects in association with a predictable increase in levels of its precursor, GM3, a finding that will greatly facilitate diagnosis of this condition. With the description of two neurological human diseases involving defects in two sequentially acting enzymes in ganglioside biosynthesis, there is the real possibility that a previously unidentified family of ganglioside deficiency diseases exist. The study of patients and animal models of these disorders will pave the way for a greater understanding of the role gangliosides play in neuronal structure and function and provide insights into the development of effective treatment therapies.
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Affiliation(s)
- Gaurav V Harlalka
- 1 Institute of Biomedical and Clinical Science, University of Exeter Medical School, St. Luke's Campus, Heavitree Road, EX1 2LU, Exeter, Devon, UK
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29
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30
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Schwardt O, Kelm S, Ernst B. SIGLEC-4 (MAG) Antagonists: From the Natural Carbohydrate Epitope to Glycomimetics. Top Curr Chem (Cham) 2013; 367:151-200. [DOI: 10.1007/128_2013_498] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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31
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Abstract
Sialic acids are a diverse family of monosaccharides widely expressed on all cell surfaces of vertebrates and so-called "higher" invertebrates, and on certain bacteria that interact with vertebrates. This overview surveys examples of biological roles of sialic acids in immunity, with emphasis on an evolutionary perspective. Given the breadth of the subject, the treatment of individual topics is brief. Subjects discussed include biophysical effects regulation of factor H; modulation of leukocyte trafficking via selectins; Siglecs in immune cell activation; sialic acids as ligands for microbes; impact of microbial and endogenous sialidases on immune cell responses; pathogen molecular mimicry of host sialic acids; Siglec recognition of sialylated pathogens; bacteriophage recognition of microbial sialic acids; polysialic acid modulation of immune cells; sialic acids as pathogen decoys or biological masks; modulation of immunity by sialic acid O-acetylation; sialic acids as antigens and xeno-autoantigens; antisialoglycan antibodies in reproductive incompatibility; and sialic-acid-based blood groups.
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Affiliation(s)
- Ajit Varki
- Glycobiology Research and Training Center, Department of Medicine, University of California at San Diego, La Jolla, 92093-0687, USA.
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32
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Sturgill ER, Aoki K, Lopez PHH, Colacurcio D, Vajn K, Lorenzini I, Majić S, Yang WH, Heffer M, Tiemeyer M, Marth JD, Schnaar RL. Biosynthesis of the major brain gangliosides GD1a and GT1b. Glycobiology 2012; 22:1289-301. [PMID: 22735313 DOI: 10.1093/glycob/cws103] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Gangliosides-sialylated glycosphingolipids-are the major glycoconjugates of nerve cells. The same four structures-GM1, GD1a, GD1b and GT1b-comprise the great majority of gangliosides in mammalian brains. They share a common tetrasaccharide core (Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1'Cer) with one or two sialic acids on the internal galactose and zero (GM1 and GD1b) or one (GD1a and GT1b) α2-3-linked sialic acid on the terminal galactose. Whereas the genes responsible for the sialylation of the internal galactose are known, those responsible for terminal sialylation have not been established in vivo. We report that St3gal2 and St3gal3 are responsible for nearly all the terminal sialylation of brain gangliosides in the mouse. When brain ganglioside expression was analyzed in adult St3gal1-, St3gal2-, St3gal3- and St3gal4-null mice, only St3gal2-null mice differed significantly from wild type, expressing half the normal amount of GD1a and GT1b. St3gal1/2-double-null mice were no different than St3gal2-single-null mice; however, St3gal2/3-double-null mice were >95% depleted in gangliosides GD1a and GT1b. Total ganglioside expression (lipid-bound sialic acid) in the brains of St3gal2/3-double-null mice was equivalent to that in wild-type mice, whereas total protein sialylation was reduced by half. St3gal2/3-double-null mice were small, weak and short lived. They were half the weight of wild-type mice at weaning and displayed early hindlimb dysreflexia. We conclude that the St3gal2 and St3gal3 gene products (ST3Gal-II and ST3Gal-III sialyltransferases) are largely responsible for ganglioside terminal α2-3 sialylation in the brain, synthesizing the major brain gangliosides GD1a and GT1b.
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Affiliation(s)
- Elizabeth R Sturgill
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Zou Z, Chastain A, Moir S, Ford J, Trandem K, Martinelli E, Cicala C, Crocker P, Arthos J, Sun PD. Siglecs facilitate HIV-1 infection of macrophages through adhesion with viral sialic acids. PLoS One 2011; 6:e24559. [PMID: 21931755 PMCID: PMC3169630 DOI: 10.1371/journal.pone.0024559] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 08/14/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Human immunodeficiency virus type 1 (HIV-1) infects macrophages effectively, despite relatively low levels of cell surface-expressed CD4. Although HIV-1 infections are defined by viral tropisms according to chemokine receptor usage (R5 and X4), variations in infection are common within both R5- and X4-tropic viruses, indicating additional factors may contribute to viral tropism. METHODOLOGY AND PRINCIPAL FINDINGS Using both solution and cell surface binding experiments, we showed that R5- and X4-tropic HIV-1 gp120 proteins recognized a family of I-type lectin receptors, the Sialic acid-binding immunoglobulin-like lectins (Siglec). The recognition was through envelope-associated sialic acids that promoted viral adhesion to macrophages. The sialic acid-mediated viral-host interaction facilitated both R5-tropic pseudovirus and HIV-1(BaL) infection of macrophages. The high affinity Siglec-1 contributed the most to HIV-1 infection and the variation in Siglec-1 expression on primary macrophages from different donors was associated statistically with sialic acid-facilitated viral infection. Furthermore, envelope-associated sialoglycan variations on various strains of R5-tropic viruses also affected infection. CONCLUSIONS AND SIGNIFICANCE OF THE FINDINGS Our study showed that sialic acids on the viral envelope facilitated HIV-1 infection of macrophages through interacting with Siglec receptors, and the expression of Siglec-1 correlated with viral sialic acid-mediated host attachment. This glycan-mediated viral adhesion underscores the importance of viral sialic acids in HIV infection and pathogenesis, and suggests a novel class of antiviral compounds targeting Siglec receptors.
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Affiliation(s)
- Zhongcheng Zou
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Ashley Chastain
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Susan Moir
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Jennifer Ford
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Kathryn Trandem
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
| | - Elena Martinelli
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Claudia Cicala
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Paul Crocker
- Cell Biology and Immunology, College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - James Arthos
- Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Peter D. Sun
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, Maryland, United States of America
- * E-mail:
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Abstract
Glycosylation is the most common post-translational modification of proteins. Protein sequence data suggested that more than half of all proteins produced in mammalian cells are glycoproteins. Recent studies showed that glycans of secreted glycoproteins affect many protein properties, such as solubility, stability, protease sensitivity and polarity, whereas glycans on cell-surface glycoproteins are involved in various cellular functions, including cell-cell communication. Accordingly, the investigation of glycoprotein changes caused by aging is expected to help understand the aging process and to elucidate age-associated diseases. The present review will summarize our current knowledge of changes found in brain glycoproteins resulting from the aging process.
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Affiliation(s)
- Yuji Sato
- Molecular Glycobiology, Research Team for Mechanism of Aging, Tokyo Metropolitan Institute of Gerontology, Itabashi-ku, Tokyo, Japan
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35
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Abstract
Axons fail to regenerate in the injured spinal cord, limiting motor and autonomic recovery and contributing to long-term morbidity. Endogenous inhibitors, including those on residual myelin, contribute to regeneration failure. One inhibitor, myelin-associated glycoprotein (MAG), binds to sialoglycans and other receptors on axons. MAG inhibition of axon outgrowth in some neurons is reversed by treatment with sialidase, an enzyme that hydrolyzes sialic acids and eliminates MAG-sialoglycan binding. We delivered recombinant sialidase intrathecally to rats following a spinal cord contusive injury. Sialidase (or saline solution) was infused to the injury site continuously for 2 wk and then motor behavior, autonomic physiology, and anatomic outcomes were determined 3 wk later. Sialidase treatment significantly enhanced hindlimb motor function, improved bulbospinally mediated autonomic reflexes, and increased axon sprouting. These findings validate sialoglycans as therapeutic targets and sialidase as a candidate therapy for spinal cord injury.
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36
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Schnaar RL, Lopez PHH. Myelin-associated glycoprotein and its axonal receptors. J Neurosci Res 2010; 87:3267-76. [PMID: 19156870 DOI: 10.1002/jnr.21992] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Myelin-associated glycoprotein (MAG) is expressed on the innermost myelin membrane wrap, directly apposed to the axon surface. Although it is not required for myelination, MAG enhances long-term axon-myelin stability, helps to structure nodes of Ranvier, and regulates the axon cytoskeleton. In addition to its role in axon-myelin stabilization, MAG inhibits axon regeneration after injury; MAG and a discrete set of other molecules on residual myelin membranes at injury sites actively signal axons to halt elongation. Both the stabilizing and the axon outgrowth inhibitory effects of MAG are mediated by complementary MAG receptors on the axon surface. Two MAG receptor families have been described, sialoglycans (specifically gangliosides GD1a and GT1b) and Nogo receptors (NgRs). Controversies remain about which receptor(s) mediates which of MAG's biological effects. Here we review the findings and challenges in associating MAG's biological effects with specific receptors.
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Affiliation(s)
- Ronald L Schnaar
- Department of Pharmacology, The Johns Hopkins School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205, USA.
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Mesch S, Moser D, Strasser DS, Kelm A, Cutting B, Rossato G, Vedani A, Koliwer-Brandl H, Wittwer M, Rabbani S, Schwardt O, Kelm S, Ernst B. Low Molecular Weight Antagonists of the Myelin-Associated Glycoprotein: Synthesis, Docking, and Biological Evaluation. J Med Chem 2010; 53:1597-615. [DOI: 10.1021/jm901517k] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Stefanie Mesch
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Delia Moser
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Daniel S. Strasser
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Antje Kelm
- Department of Physiological Biochemistry, University of Bremen, D-28334 Bremen, Germany
| | - Brian Cutting
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Gianluca Rossato
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Angelo Vedani
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | | | - Matthias Wittwer
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Said Rabbani
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Oliver Schwardt
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
| | - Soerge Kelm
- Department of Physiological Biochemistry, University of Bremen, D-28334 Bremen, Germany
| | - Beat Ernst
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland
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Abstract
AbstractGangliosides are membrane glycosphingolipids bearing sialic acid residues. Within membranes, gangliosides are specifically enriched in highly organized domains, lipid rafts, and are attributed with diverse functions such as intercellular interactions, cell recognition, neurotransmission, and signal transduction. The highest concentration and variability of ganglioside structures are found in the human brain. Specific temporal and regional distribution of brain gangliosides has been reported; moreover, gangliosides may serve as markers of neurodevelopmental stages, aging and neurodegeneration. Brain ganglioside content and composition as well as ganglioside metabolism are altered in Alzheimer’s disease. It appears that the alterations of ganglioside metabolism leading to changes in membrane physico-chemical properties are not merely a consequence of primary pathology, but may also be involved in the early pathogenesis of Alzheimer’s disease through documented effects on APP proteolytic processing and amyloid aggregation. Investigations of glycolipid metabolic alterations which accompany neurodegenerative disorders provide insight into pathogenetic mechanisms and enable recognition of diagnostic markers as well as molecular structures acting as therapeutic tools interfering with cascade of pathological events.
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Schnaar RL. Brain gangliosides in axon-myelin stability and axon regeneration. FEBS Lett 2009; 584:1741-7. [PMID: 19822144 DOI: 10.1016/j.febslet.2009.10.011] [Citation(s) in RCA: 116] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 10/02/2009] [Accepted: 10/05/2009] [Indexed: 01/21/2023]
Abstract
Gangliosides, sialic acid-bearing glycosphingolipids, are expressed at high abundance and complexity in the brain. Altered ganglioside expression results in neural disorders, including seizures and axon degeneration. Brain gangliosides function, in part, by interacting with a ganglioside-binding lectin, myelin-associated glycoprotein (MAG). MAG, on the innermost wrap of the myelin sheath, binds to gangliosides GD1a and GT1b on axons. MAG-ganglioside binding ensures optimal axon-myelin cell-cell interactions, enhances long-term axon-myelin stability and inhibits axon outgrowth after injury. Knowledge of the molecular interactions of brain gangliosides may improve understanding of axon-myelin stability and provide opportunities to enhance recovery after nerve injury.
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Affiliation(s)
- Ronald L Schnaar
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins School of Medicine, Baltimore, MD 21205, USA.
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Cao Z, Gao Y, Deng K, Williams G, Doherty P, Walsh FS. Receptors for myelin inhibitors: Structures and therapeutic opportunities. Mol Cell Neurosci 2009; 43:1-14. [PMID: 19619659 DOI: 10.1016/j.mcn.2009.07.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2009] [Revised: 05/28/2009] [Accepted: 07/10/2009] [Indexed: 11/19/2022] Open
Abstract
Many studies have indicated that the inability of adult mammalian central nervous system (CNS) to regenerate after injury is partly due to the existence of growth-inhibitory molecules associated with CNS myelin. Studies over the years have led to the identification of multiple myelin-associated inhibitors, among which Nogo, myelin-associated glycoprotein (MAG) and oligodendrocyte-myelin glycoprotein (Omgp) represent potentially major contributors to CNS axon regeneration failure. Here we review in vitro and in vivo investigations into these inhibitory ligands and their functional mechanisms, focusing particularly on the neuronal receptors that mediate the inhibitory signals from these myelin molecules. A better understanding of the receptors for myelin-associated inhibitors could provide opportunities to decipher the mechanism of restriction in CNS regeneration, and lead to the development of potential therapeutic targets in neurodegenerative diseases and neurological injury. We will discuss the structures of the receptors and therapeutic opportunities that might arise based on this information.
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Affiliation(s)
- Zixuan Cao
- Neuroscience Discovery, Wyeth Research, Princeton, NJ 08543, USA
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Molecular basis of the interactions of the Nogo-66 receptor and its homolog NgR2 with myelin-associated glycoprotein: development of NgROMNI-Fc, a novel antagonist of CNS myelin inhibition. J Neurosci 2009; 29:5768-83. [PMID: 19420245 DOI: 10.1523/jneurosci.4935-08.2009] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Myelin-associated glycoprotein (MAG) is a sialic acid-binding Ig-family lectin that functions in neuronal growth inhibition and stabilization of axon-glia interactions. The ectodomain of MAG is comprised of five Ig-like domains and uses neuronal cell-type-specific mechanisms to signal growth inhibition. We show that the first three Ig-like domains of MAG bind with high affinity and in a sialic acid-dependent manner to the Nogo-66 receptor-1 (NgR1) and its homolog NgR2. Domains Ig3-Ig5 of MAG are sufficient to inhibit neurite outgrowth but fail to associate with NgR1 or NgR2. Nogo receptors are sialoglycoproteins comprised of 8.5 canonical leucine-rich repeats (LRR) flanked by LRR N-terminal (NT) and C-terminal (CT)-cap domains. The LRR cluster is connected through a stalk region to a membrane lipid anchor. The CT-cap domain and stalk region of NgR2, but not NgR1, are sufficient for MAG binding, and when expressed in neurons, exhibit constitutive growth inhibitory activity. The LRR cluster of NgR1 supports binding of Nogo-66, OMgp, and MAG. Deletion of disulfide loop Cys(309)-Cys(336) of NgR1 selectively increases its affinity for Nogo-66 and OMgp. A chimeric Nogo receptor variant (NgR(OMNI)) in which Cys(309)-Cys(336) is deleted and followed by a 13 aa MAG-binding motif of the NgR2 stalk, shows superior binding of OMgp, Nogo-66, and MAG compared with wild-type NgR1 or NgR2. Soluble NgR(OMNI) (NgR(OMNI)-Fc) binds strongly to membrane-bound inhibitors and promotes neurite outgrowth on both MAG and CNS myelin substrates. Thus, NgR(OMNI)-Fc may offer therapeutic opportunities following nervous system injury or disease where myelin inhibits neuronal regeneration.
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Bhunia A, Schwardt O, Gäthje H, Gao GP, Kelm S, Benie AJ, Hricovini M, Peters T, Ernst B. Consistent bioactive conformation of the Neu5Acalpha(2-->3)Gal epitope upon lectin binding. Chembiochem 2009; 9:2941-5. [PMID: 18850605 DOI: 10.1002/cbic.200800458] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Anirban Bhunia
- Institute of Chemistry, University of Luebeck, Luebeck, Germany
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Shin SY, Gäthje H, Schwardt O, Gao GP, Ernst B, Kelm S, Meyer B. Binding epitopes of gangliosides to their neuronal receptor, myelin-associated glycoprotein, from saturation transfer difference NMR. Chembiochem 2009; 9:2946-9. [PMID: 19040245 DOI: 10.1002/cbic.200800485] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- So-Young Shin
- Department of Chemistry, University of Hamburg, Hamburg, Germany
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Schwardt O, Gäthje H, Vedani A, Mesch S, Gao GP, Spreafico M, von Orelli J, Kelm S, Ernst B. Examination of the Biological Role of the α(2→6)-Linked Sialic Acid in Gangliosides Binding to the Myelin-Associated Glycoprotein (MAG). J Med Chem 2009; 52:989-1004. [DOI: 10.1021/jm801058n] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Oliver Schwardt
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland, Institute for Physiological Biochemistry, University Bremen, D-28334 Bremen, Germany
| | - Heiko Gäthje
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland, Institute for Physiological Biochemistry, University Bremen, D-28334 Bremen, Germany
| | - Angelo Vedani
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland, Institute for Physiological Biochemistry, University Bremen, D-28334 Bremen, Germany
| | - Stefanie Mesch
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland, Institute for Physiological Biochemistry, University Bremen, D-28334 Bremen, Germany
| | - Gan-Pan Gao
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland, Institute for Physiological Biochemistry, University Bremen, D-28334 Bremen, Germany
| | - Morena Spreafico
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland, Institute for Physiological Biochemistry, University Bremen, D-28334 Bremen, Germany
| | - Johannes von Orelli
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland, Institute for Physiological Biochemistry, University Bremen, D-28334 Bremen, Germany
| | - Sørge Kelm
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland, Institute for Physiological Biochemistry, University Bremen, D-28334 Bremen, Germany
| | - Beat Ernst
- Institute of Molecular Pharmacy, Pharmacenter, University of Basel, Klingelbergstrasse 50, CH-4056 Basel, Switzerland, Institute for Physiological Biochemistry, University Bremen, D-28334 Bremen, Germany
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Abstract
SUMMARYInfection with parasitic helminths takes a heavy toll on the health and well-being of humans and their domestic livestock, concomitantly resulting in major economic losses. Analyses have consistently revealed bioactive molecules in extracts of helminths or in their excretory/secretory products that modulate the immune response of the host. It is our view that parasitic helminths are an untapped source of immunomodulatory substances that, in pure form, could become new drugs (or models for drug design) to treat disease. Here, we illustrate the range of immunomodulatory molecules in selected parasitic trematodes, cestodes and nematodes, their impact on the immune cells in the host and how the host may recognize these molecules. There are many examples of the partial characterization of helminth-derived immunomodulatory molecules, but these have not yet translated into new drugs, reflecting the difficulty of isolating and fully characterizing proteins, glycoproteins and lipid-based molecules from small amounts of parasite material. However, this should not deter the investigator, since analytical techniques are now being used to accrue considerable structural information on parasite-derived molecules, even when only minute quantities of tissue are available. With the introduction of methodologies to purify and structurally-characterize molecules from small amounts of tissue and the application of high throughput immunological assays, one would predict that an assessment of parasitic helminths will yield a variety of novel drug candidates in the coming years.
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DeMarco ML, Woods RJ. Atomic-resolution conformational analysis of the GM3 ganglioside in a lipid bilayer and its implications for ganglioside-protein recognition at membrane surfaces. Glycobiology 2008; 19:344-55. [PMID: 19056784 DOI: 10.1093/glycob/cwn137] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Eukaryotic cells depend on external surface markers, such as gangliosides, to recognize and bind various other molecules as part of normal growth and maturation. The localization of gangliosides in the outer leaflet of the plasma membrane, also make them targets for pathogens trying to invade the host cells. Since ganglioside-mediated interactions are critical to both beneficial and pathological processes, much effort has been directed at determining the 3D structures of their carbohydrate head groups; however, technical difficulties have generally prevented the characterization of the head group in intact membrane-bound gangliosides. Determining the 3D structure and presentation of gangliosides at the surface of membranes is important in understanding how cells interact with their local environment. Here, we employ all-atom explicit solvent molecular dynamics (MD) simulations, using the GLYCAM06 force field, to model the conformation and dynamics of ganglioside G(M3) (alpha-Neu5Ac-(2-3)-beta-Gal-(1-4)-beta-Glc-ceramide) in a DMPC lipid bilayer. By comparison with MD simulations of the carbohydrate head-group fragment of G(M3) alone, it was possible to quantify and characterize the extent of changes in head-group presentation and dynamics associated with membrane anchoring. The accuracy of data from the MD simulations was determined by comparison to NMR and crystallographic data for the head group in solution and for G(M3) in membrane-mimicking environments. The experimentally consistent model of G(M3), in a lipid bilayer, was then used to model the recognition of G(M3) at the cell surface by known protein receptors.
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Affiliation(s)
- Mari L DeMarco
- Complex Carbohydrate Research Center, University of Georgia, Athens, GA 30602-4712, USA
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Manor T, Barbiro-Michaely E, Rogatsky G, Mayevsky A. Real-time multi-site multi-parametric monitoring of rat brain subjected to traumatic brain injury. Neurol Res 2008; 30:1075-83. [PMID: 18826757 DOI: 10.1179/174313208x346107] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
INTRODUCTION Traumatic brain injury (TBI) is one of the major causes of death in the world, with at least ten million serious traumatic brain injuries occurring annually; nevertheless, the pathophysiologic events taking place immediately after the injury are not yet fully known. OBJECTIVE To study the effects of TBI on brain hemodynamic, metabolic and ionic homeostasis using the multi-parametric monitoring system. This system enables real-time monitoring of cerebral blood flow (CBF), mitochondrial NADH redox state, extracellular levels of K+, H+, DC potential, ECoG and ICP. METHODS In order to find the best brain location for the monitoring device in relation to the fluid percussion injury site, we used the multi-site multi-parametric monitoring system. Two groups of rats were connected to four monitoring probes at four different locations near the injury site, two in each hemisphere. We monitored CBF, NADH redox state, tissue reflectance and DC steady potential in each of the four sites. RESULTS Under anoxia, the initial CBF decrease was followed by an increase, NADH level increased, the reflectance decreased and dc potential showed a biphasic response, in all 4 locations. However, following fluid percussion injury, there was a significant variability in the responses in each of the 4 monitored locations. CONCLUSION The advantage of the multi-parametric-monitoring approach for enhanced understanding of the injured brain was indicated. Moreover, we showed that contralateral monitoring of the injured brain gives good indication for the events taking place following fluid percussion brain injury.
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Affiliation(s)
- Tami Manor
- Mina and Everard Goodman Faculty of Life Sciences and The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat-Gan 52900, Israel
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Lopez PHH, Zhang G, Bianchet MA, Schnaar RL, Sheikh KA. Structural requirements of anti-GD1a antibodies determine their target specificity. Brain 2008; 131:1926-39. [PMID: 18487279 DOI: 10.1093/brain/awn074] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The acute motor axonal neuropathy (AMAN) variant of Guillain-Barré syndrome (GBS) is associated with anti-GD1a and anti-GM1 IgG antibodies. The basis of preferential motor nerve injury in this disease is not clear, however, because biochemical studies demonstrate that sensory and motor nerves express similar quantities of GD1a and GM1 gangliosides. To elucidate the pathophysiology of AMAN, we have developed several monoclonal antibodies (mAbs) with GD1a reactivity and reported that one mAb, GD1a-1, preferentially stained motor axons in human and rodent nerves. To understand the basis of this preferential motor axon staining, several derivatives of GD1a were generated by various chemical modifications of N-acetylneuraminic (sialic) acid residues (GD1a NeuAc 1-amide, GD1a NeuAc ethyl ester, GD1a NeuAc 1-alcohol, GD1a NeuAc 1-methyl ester, GD1a NeuAc 7-alcohol, GD1a NeuAc 7-aldehyde) on this ganglioside. Binding of anti-GD1a mAbs and AMAN sera with anti-GD1a Abs to these derivatives was examined. Our results indicate that mAbs with selective motor axon staining had a distinct pattern of reactivity with GD1a-derivatives compared to mAbs that stain both motor and sensory axons. The fine specificity of the anti-GD1a antibodies determines their motor selectivity, which was validated by cloning a new mAb (GD1a-E6) with a chemical and immunocytochemical binding pattern similar to that of GD1a-1 but with two orders of magnitude higher affinity. Control studies indicate that selective binding of mAbs to motor nerves is not due to differences in antibody affinity or ceramide structural specificity. Since GD1a-reactive mAb with preferential motor axon staining showed similar binding to sensory- and motor nerve-derived GD1a in a solid phase assay, we generated computer models of GD1a based on binding patterns of different GD1a-reactive mAbs to different GD1a-derivatives. These modelling studies suggest that critical GD1a epitopes recognized by mAbs are differentially expressed in motor and sensory nerves. The GD1a-derivative binding patterns of AMAN sera resembled those with motor-specific mAbs. On the basis of these findings we postulate that both the fine specificity and ganglioside orientation/exposure in the tissues contribute to target recognition by anti-ganglioside antibodies and this observation provides one explanation for preferential motor axon injury in AMAN.
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Affiliation(s)
- Pablo H H Lopez
- Department of Neurology, Johns Hopkins Hospital, Baltimore, MD 21287, USA
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Affiliation(s)
- Heather E. Murrey
- Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California 91125
| | - Linda C. Hsieh-Wilson
- Division of Chemistry and Chemical Engineering and Howard Hughes Medical Institute, California Institute of Technology, Pasadena, California 91125
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Varki A. Loss of N-glycolylneuraminic acid in humans: Mechanisms, consequences, and implications for hominid evolution. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2008. [PMID: 11786991 PMCID: PMC7159735 DOI: 10.1002/ajpa.10018] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The surface of all mammalian cells is covered with a dense and complex array of sugar chains, which are frequently terminated by members of a family of molecules called sialic acids. One particular sialic acid called N‐glycolylneuraminic acid (Neu5Gc) is widely expressed on most mammalian tissues, but is not easily detectable on human cells. In fact, it provokes an immune response in adult humans. The human deficiency of Neu5Gc is explained by an inactivating mutation in the gene encoding CMP‐N‐acetylneuraminic acid hydroxylase, the rate‐limiting enzyme in generating Neu5Gc in cells of other mammals. This deficiency also results in an excess of the precursor sialic acid N‐acetylneuraminic acid (Neu5Ac) in humans. This mutation appears universal to modern humans, occurred sometime after our last common ancestor with the great apes, and happens to be one of the first known human‐great ape genetic differences with an obvious biochemical readout. While the original selection mechanisms and major biological consequences of this human‐specific mutation remain uncertain, several interesting clues are currently being pursued. First, there is evidence that the human condition can explain differences in susceptibility or resistance to certain microbial pathogens. Second, the functions of some endogenous receptors for sialic acids in the immune system may be altered by this difference. Third, despite the lack of any obvious alternate pathway for synthesis, Neu5Gc has been reported in human tumors and possibly in human fetal tissues, and traces have even been detected in normal human tissues. One possible explanation is that this represents accumulation of Neu5Gc from dietary sources of animal origin. Finally, a markedly reduced expression of hydroxylase in the brains of other mammals raises the possibility that the human‐specific mutation of this enzyme could have played a role in human brain evolution. Yrbk Phys Anthropol 44:54–69, 2001. © 2001 Wiley‐Liss, Inc.
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Affiliation(s)
- A Varki
- Glycobiology Research and Training Center and Department of Medicine and University of California, San Diego, La Jolla, California 92093, USA
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