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Ludwig K, Volpe A, Guzzardo V, Santoro L, Midrio P, Gamba P, Alaggio R. Anti-Glypican 3, a Novel Ancillary Maker in the Histological Assessment of Hirschsprung's Disease. J Pediatr Gastroenterol Nutr 2016; 62:692-7. [PMID: 26513623 DOI: 10.1097/mpg.0000000000001020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVES Hirschsprung's disease (HSCR) results from a malformation of the enteric nervous system. A congenital absence of intrinsic ganglion cells from the distal rectum and a variable length of the contiguous bowel is the required diagnostic feature of Hirschsprung's disease and total colonic aganglionosis (TCA). We evaluated the utility of a monoclonal antibody directed against glypican 3 (GPC-3), a membrane bound protein involved in regulation of the signaling of Wingless-types (WNTs), Hedgehogs (Hh), Fibroblast Growth Factors (FGFs), and Bone Morphogenetic Proteins (BMPs), in the detection of ganglion cells in formalin-fixed, paraffin-embedded tissue sections. METHODS The presence/absence of ganglion cells was evaluated retrospectively by immunohistochemical staining for calretinin and GPC-3 in tissue specimens; a total of 15 patients who underwent colectomy (total or sub-total) for histologically proven aganglionosis (14 HSCR, 1 TCA) and 5 rectal suction biopsies (4HSCR-B, 1 TCA-B) were considered. Of the 20 considered cases, a total of 60 tissue specimens (3 for each patient) were selected. A total of 30 additional normal (N) colonic mucosa biopsy samples were also included. RESULTS GPC-3 constantly identified ganglion cell bodies in all but 2 normal biopsies (with normal presentation of ganglion cells on hematoxylin and eosin (H&E) stain), and was negative in all 60 aganglionotic biopsies; these results were reflective of calretinin staining pattern. CONCLUSIONS The present study indicates that monoclonal anti-GPC-3 might prove to be useful immunohistochemical marker in the identification of ganglion cells in paraffin-embedded rectal tissue specimens and suction biopsies. Further studies in larger series will contribute to demonstrate its utility as an ancillary marker in the histological assessment of HSCR aganglionosis.
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Affiliation(s)
- Kathrin Ludwig
- *Department of Medicine (DIMED), Surgical Pathology & Cytopathology Unit, University of Padua, Padua †Division of Pediatric Surgery, Department of Pediatrics Salus Pueri, University of Padova, Padova, Italy
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152
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Corredor M, Bonet R, Moure A, Domingo C, Bujons J, Alfonso I, Pérez Y, Messeguer À. Cationic Peptides and Peptidomimetics Bind Glycosaminoglycans as Potential Sema3A Pathway Inhibitors. Biophys J 2016; 110:1291-303. [PMID: 27028639 PMCID: PMC4816699 DOI: 10.1016/j.bpj.2016.01.033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 01/29/2016] [Accepted: 01/29/2016] [Indexed: 12/28/2022] Open
Abstract
Semaphorin3A (Sema3A) is a vertebrate-secreted protein that was initially characterized as a repulsive-guidance cue. Semaphorins have crucial roles in several diseases; therefore, the development of Sema3A inhibitors is of therapeutic interest. Sema3A interacts with glycosaminoglycans (GAGs), presumably through its C-terminal basic region. We used different biophysical techniques (i.e., NMR, surface plasmon resonance, isothermal titration calorimetry, fluorescence, and UV-visible spectroscopy) to characterize the binding of two Sema3A C-terminus-derived basic peptides (FS2 and NFS3) to heparin and chondroitin sulfate A. We found that these peptides bind to both GAGs with affinities in the low-micromolar range. On the other hand, a peptoid named SICHI (semaphorin-induced chemorepulsion inhibitor), which is positively charged at physiological pH, was first identified by our group as being able to block Sema3A chemorepulsion and growth-cone collapse in axons at the extracellular level. To elucidate the direct target for the reported SICHI inhibitory effect in the Sema3A signaling pathway, we looked first to the protein-protein interaction between secreted Sema3A and the Nrp1 receptor. However, our results show that SICHI does not bind directly to the Sema3A sema domain or to Nrp1 extracellular domains. We evaluated a new, to our knowledge, hypothesis, according to which SICHI binds to GAGs, thereby perturbing the Sema3A-GAG interaction. By using the above-mentioned techniques, we observed that SICHI binds to GAGs and competes with Sema3A C-terminus-derived basic peptides for binding to GAGs. These data support the ability of SICHI to block the biologically relevant interaction between Sema3A and GAGs, thus revealing SICHI as a new, to our knowledge, class of inhibitors that target the GAG-protein interaction.
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Affiliation(s)
- Miriam Corredor
- Departamento de Química Biológica y Modelización Molecular, Instituto de Química Avanzada de Catalunya, IQAC-CSIC, Barcelona, Spain
| | - Roman Bonet
- Departamento de Química Biológica y Modelización Molecular, Instituto de Química Avanzada de Catalunya, IQAC-CSIC, Barcelona, Spain
| | - Alejandra Moure
- Departamento de Química Biológica y Modelización Molecular, Instituto de Química Avanzada de Catalunya, IQAC-CSIC, Barcelona, Spain
| | - Cecilia Domingo
- Departamento de Química Biológica y Modelización Molecular, Instituto de Química Avanzada de Catalunya, IQAC-CSIC, Barcelona, Spain
| | - Jordi Bujons
- Departamento de Química Biológica y Modelización Molecular, Instituto de Química Avanzada de Catalunya, IQAC-CSIC, Barcelona, Spain
| | - Ignacio Alfonso
- Departamento de Química Biológica y Modelización Molecular, Instituto de Química Avanzada de Catalunya, IQAC-CSIC, Barcelona, Spain
| | - Yolanda Pérez
- Servicio de Resonancia Magnética Nuclear, Instituto de Química Avanzada de Catalunya, IQAC-CSIC, Barcelona, Spain.
| | - Àngel Messeguer
- Departamento de Química Biológica y Modelización Molecular, Instituto de Química Avanzada de Catalunya, IQAC-CSIC, Barcelona, Spain.
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153
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Doody KM, Stanford SM, Sacchetti C, Svensson MND, Coles CH, Mitakidis N, Kiosses WB, Bartok B, Fos C, Cory E, Sah RL, Liu-Bryan R, Boyle DL, Arnett HA, Mustelin T, Corr M, Esko JD, Tremblay ML, Firestein GS, Aricescu AR, Bottini N. Targeting phosphatase-dependent proteoglycan switch for rheumatoid arthritis therapy. Sci Transl Med 2016; 7:288ra76. [PMID: 25995222 DOI: 10.1126/scitranslmed.aaa4616] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Despite the availability of several therapies for rheumatoid arthritis (RA) that target the immune system, a large number of RA patients fail to achieve remission. Joint-lining cells, called fibroblast-like synoviocytes (FLS), become activated during RA and mediate joint inflammation and destruction of cartilage and bone. We identify RPTPσ, a transmembrane tyrosine phosphatase, as a therapeutic target for FLS-directed therapy. RPTPσ is reciprocally regulated by interactions with chondroitin sulfate or heparan sulfate containing extracellular proteoglycans in a mechanism called the proteoglycan switch. We show that the proteoglycan switch regulates FLS function. Incubation of FLS with a proteoglycan-binding RPTPσ decoy protein inhibited cell invasiveness and attachment to cartilage by disrupting a constitutive interaction between RPTPσ and the heparan sulfate proteoglycan syndecan-4. RPTPσ mediated the effect of proteoglycans on FLS signaling by regulating the phosphorylation and cytoskeletal localization of ezrin. Furthermore, administration of the RPTPσ decoy protein ameliorated in vivo human FLS invasiveness and arthritis severity in the K/BxN serum transfer model of RA. Our data demonstrate that FLS are regulated by an RPTPσ-dependent proteoglycan switch in vivo, which can be targeted for RA therapy. We envision that therapies targeting the proteoglycan switch or its intracellular pathway in FLS could be effective as a monotherapy or in combination with currently available immune-targeted agents to improve control of disease activity in RA patients.
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Affiliation(s)
- Karen M Doody
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Stephanie M Stanford
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Cristiano Sacchetti
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Mattias N D Svensson
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Charlotte H Coles
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Nikolaos Mitakidis
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - William B Kiosses
- Core Microscopy, Scripps Research Institute, La Jolla, CA 92037, USA
| | - Beatrix Bartok
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Camille Fos
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA
| | - Esther Cory
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Robert L Sah
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ru Liu-Bryan
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA. Veterans Affairs San Diego Healthcare System, Department of Medicine, University of California, San Diego, San Diego, CA 92161, USA
| | - David L Boyle
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA
| | | | - Tomas Mustelin
- Research, MedImmune, AstraZeneca, One Medimmune Way, Gaithersburg, MD 20878, USA
| | - Maripat Corr
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA
| | - Jeffrey D Esko
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michel L Tremblay
- Rosalind and Morris Goodman Cancer Research Centre, McGill University, Montréal, Québec H3A 1A3, Canada. Department of Biochemistry, McGill University, Montréal, Québec H3A 1A3, Canada. Department of Medicine, Division of Experimental Medicine, McGill University, Montréal, Québec H3A 1A3, Canada
| | - Gary S Firestein
- Division of Rheumatology, Allergy and Immunology, University of California, San Diego School of Medicine, La Jolla, CA 92093, USA
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Nunzio Bottini
- Division of Cellular Biology, La Jolla Institute for Allergy and Immunology, La Jolla, CA 92037, USA.
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154
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Hamasaki H, Fujitani M, Yamashita T. NME2 associates with PTPσ to transduce signals from chondroitin sulfate proteoglycans. Biochem Biophys Res Commun 2016; 471:522-7. [PMID: 26896769 DOI: 10.1016/j.bbrc.2016.02.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 02/11/2016] [Indexed: 11/18/2022]
Abstract
Chondroitin sulfate proteoglycans (CSPGs) are a major component of glial scars, inhibiting axonal growth in the central nervous system. Protein tyrosine phosphatase, receptor type S (PTPσ) has been identified as a receptor for CSPGs, whereas its downstream signaling pathway remains to be fully understood. Here, we report that nucleoside diphosphate kinase 2 (NME2) interacts with PTPσ. We screened proteins associated with PTPσ by mass spectrometry, and obtained NME2. Immunoprecipitation analysis revealed that NME2 associated with the PTPσ intracellular domain in HEK-293T cells. NME2 was expressed in the cytoplasm and nucleus of cortical neurons, and knockdown of NME2 in the cortical neurons completely rescued neurite outgrowth inhibition induced by CSPGs. These results demonstrate that NME2 associates with PTPσ to elicit neurite outgrowth inhibition in response to CSPGs.
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Affiliation(s)
- Hajime Hamasaki
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan; JST, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo, 102-0075, Japan; Faculty of Medicine, MD Scientist Training Program, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0872, Japan
| | - Masashi Fujitani
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan; JST, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo, 102-0075, Japan; Molecular Research Center for Children's Mental Development, United Graduate School of Child Development, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0872, Japan; Department of Anatomy and Neuroscience, Hyogo College of Medicine, 1-1, Mukogawa-cho, Nishinomiya, Hyogo, 663-8501, Japan.
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan; JST, CREST, 5, Sanbancho, Chiyoda-ku, Tokyo, 102-0075, Japan.
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155
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Han KA, Jeon S, Um JW, Ko J. Emergent Synapse Organizers: LAR-RPTPs and Their Companions. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2016; 324:39-65. [PMID: 27017006 DOI: 10.1016/bs.ircmb.2016.01.002] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Leukocyte common antigen-related receptor tyrosine phosphatases (LAR-RPTPs) have emerged as key players that organize various aspects of neuronal development, including axon guidance, neurite extension, and synapse formation and function. Recent research has highlighted the roles of LAR-RPTPs at neuronal synapses in mediating distinct synaptic adhesion pathways through interactions with a host of extracellular ligands and in governing a variety of intracellular signaling cascades through binding to various scaffolds and signaling proteins. In this chapter, we review and update current research progress on the extracellular ligands of LAR-RPTPs, regulation of their extracellular interactions by alternative splicing and heparan sulfates, and their intracellular signaling machineries. In particular, we review structural insights on complexes of LAR-RPTPs with their various ligands. These studies lend support to general molecular mechanisms underlying LAR-RPTP-mediated synaptic adhesion and signaling pathways.
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Affiliation(s)
- K A Han
- Department of Physiology and BK21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - S Jeon
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea
| | - J W Um
- Department of Physiology and BK21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, South Korea
| | - J Ko
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, South Korea.
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156
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Distribution of N-Acetylgalactosamine-Positive Perineuronal Nets in the Macaque Brain: Anatomy and Implications. Neural Plast 2016; 2016:6021428. [PMID: 26881119 PMCID: PMC4735937 DOI: 10.1155/2016/6021428] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/17/2015] [Accepted: 08/26/2015] [Indexed: 11/17/2022] Open
Abstract
Perineuronal nets (PNNs) are extracellular molecules that form around neurons near the end of critical periods during development. They surround neuronal cell bodies and proximal dendrites. PNNs inhibit the formation of new connections and may concentrate around rapidly firing inhibitory interneurons. Previous work characterized the important role of perineuronal nets in plasticity in the visual system, amygdala, and spinal cord of rats. In this study, we use immunohistochemistry to survey the distribution of perineuronal nets in representative areas of the primate brain. We also document changes in PNN prevalence in these areas in animals of different ages. We found that PNNs are most prevalent in the cerebellar nuclei, surrounding >90% of the neurons there. They are much less prevalent in cerebral cortex, surrounding less than 10% of neurons in every area that we examined. The incidence of perineuronal nets around parvalbumin-positive neurons (putative fast-spiking interneurons) varies considerably between different areas in the brain. Our survey indicates that the presence of PNNs may not have a simple relationship with neural plasticity and may serve multiple functions in the central nervous system.
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157
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Abstract
Receptor protein tyrosine phosphatases (RPTPs) form a group of over 20 enzymes in vertebrates, each with unique ectodomains subject to potential extracellular interactions with ligands. It has recently become clear that a remarkably diverse range of ligands exist, including homophilic binders, adhesion molecules, neurotrophin receptors, and proteoglycans. Individual RPTPs can bind several ligands, and vice versa, suggesting that complex cell signaling networks exist. The identification of RPTP ligands and where they are located in tissues remains a challenge for a large number of these enzymes. Here we describe some powerful methods that have proved successful for several research groups, leading to our improved understanding of RPTP-ligand interactions and functional regulation.
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Affiliation(s)
- Andrew William Stoker
- UCL Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK.
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158
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Lee HS, Ku B, Park TH, Park H, Choi JK, Chang KT, Kim CH, Ryu SE, Kim SJ. Identification of novel protein tyrosine phosphatase sigma inhibitors promoting neurite extension. Bioorg Med Chem Lett 2015; 26:87-93. [PMID: 26602279 DOI: 10.1016/j.bmcl.2015.11.026] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 10/26/2015] [Accepted: 11/09/2015] [Indexed: 10/22/2022]
Abstract
Protein tyrosine phosphatase sigma (PTPσ) is a potential target for the therapeutic treatment of neurological deficits associated with impaired neuronal recovery, as this protein is the receptor for chondroitin sulfate proteoglycan (CSPG), which is known to inhibit neuronal regeneration. Through a high-throughput screening approach started from 6400 representative compounds in the Korea Chemical Bank chemical library, we identified 11 novel PTPσ inhibitors that can be classified as flavonoid derivatives or analogs, with IC50 values ranging from 0.5 to 17.5μM. Biochemical assays and structure-based active site-docking simulation indicate that our inhibitors are accommodated at the catalytic active site of PTPσ as surrogates for the phosphotyrosine group. Treatments of these compounds on PC-12 neuronal cells led to the recovery of neurite extension attenuated by CSPG treatment, demonstrating their potential as antineurodegenerative agents.
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Affiliation(s)
- Hye Seon Lee
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea; Department of Biology, Chungnam National University, Daejeon 305-764, Republic of Korea
| | - Bonsu Ku
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea
| | - Tae Hyun Park
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul 133-791, Republic of Korea
| | - Hwangseo Park
- Department of Bioscience and Biotechnology, Sejong University, Seoul 143-747, Republic of Korea
| | - Joong-Kwon Choi
- Korea Chemical Bank, Korea Research Institute of Chemical Technology, Daejeon 305-600, Republic of Korea
| | - Kyu-Tae Chang
- National Primate Research Center, Korea Research Institute of Bioscience and Biotechnology, Cheongju 363-883, Republic of Korea
| | - Cheol-Hee Kim
- Department of Biology, Chungnam National University, Daejeon 305-764, Republic of Korea
| | - Seong Eon Ryu
- Department of Bioengineering, College of Engineering, Hanyang University, Seoul 133-791, Republic of Korea
| | - Seung Jun Kim
- Functional Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea.
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159
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160
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Haftchenary S, Jouk AO, Aubry I, Lewis AM, Landry M, Ball DP, Shouksmith AE, Collins CV, Tremblay ML, Gunning PT. Identification of Bidentate Salicylic Acid Inhibitors of PTP1B. ACS Med Chem Lett 2015; 6:982-6. [PMID: 26396684 DOI: 10.1021/acsmedchemlett.5b00171] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/22/2015] [Indexed: 12/13/2022] Open
Abstract
PTP1B is a master regulator in the insulin and leptin metabolic pathways. Hyper-activated PTP1B results in insulin resistance and is viewed as a key factor in the onset of type II diabetes and obesity. Moreover, inhibition of PTP1B expression in cancer cells dramatically inhibits cell growth in vitro and in vivo. Herein, we report the computationally guided optimization of a salicylic acid-based PTP1B inhibitor 6, identifying new and more potent bidentate PTP1B inhibitors, such as 20h, which exhibited a > 4-fold improvement in activity. In CHO-IR cells, 20f, 20h, and 20j suppressed PTP1B activity and restored insulin receptor phosphorylation levels. Notably, 20f, which displayed a 5-fold selectivity for PTP1B over the closely related PTPσ protein, showed no inhibition of PTP-LAR, PRL2 A/S, MKPX, or papain. Finally, 20i and 20j displayed nanomolar inhibition of PTPσ, representing interesting lead compounds for further investigation.
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Affiliation(s)
- Sina Haftchenary
- Department
of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Andriana O. Jouk
- Department
of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Isabelle Aubry
- McGill
Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Andrew M. Lewis
- Department
of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Melissa Landry
- McGill
Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Daniel P. Ball
- Department
of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Andrew E. Shouksmith
- Department
of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Catherine V. Collins
- Department
of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
| | - Michel L. Tremblay
- McGill
Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Patrick T. Gunning
- Department
of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON L5L 1C6, Canada
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161
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Miller GM, Hsieh-Wilson LC. Sugar-dependent modulation of neuronal development, regeneration, and plasticity by chondroitin sulfate proteoglycans. Exp Neurol 2015; 274:115-25. [PMID: 26315937 DOI: 10.1016/j.expneurol.2015.08.015] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2015] [Revised: 08/14/2015] [Accepted: 08/19/2015] [Indexed: 01/08/2023]
Abstract
Chondroitin sulfate proteoglycans (CSPGs) play important roles in the developing and mature nervous system, where they guide axons, maintain stable connections, restrict synaptic plasticity, and prevent axon regeneration following CNS injury. The chondroitin sulfate glycosaminoglycan (CS GAG) chains that decorate CSPGs are essential for their functions. Through these sugar chains, CSPGs are able to bind and regulate the activity of a diverse range of proteins. CSPGs have been found both to promote and inhibit neuronal growth. They can promote neurite outgrowth by binding to various growth factors such as midkine (MK), pleiotrophin (PTN), brain-derived neurotrophic factor (BDNF) and other neurotrophin family members. CSPGs can also inhibit neuronal growth and limit plasticity by interacting with transmembrane receptors such as protein tyrosine phosphatase σ (PTPσ), leukocyte common antigen-related (LAR) receptor protein tyrosine phosphatase, and the Nogo receptors 1 and 3 (NgR1 and NgR3). These CS-protein interactions depend on specific sulfation patterns within the CS GAG chains, and accordingly, particular CS sulfation motifs are upregulated during development, in the mature nervous system, and in response to CNS injury. Thus, spatiotemporal regulation of CS GAG biosynthesis may provide an important mechanism to control the functions of CSPGs and to modulate intracellular signaling pathways. Here, we will discuss these sulfation-dependent processes and highlight how the CS sugars on CSPGs contribute to neuronal growth, axon guidance, and plasticity in the nervous system.
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Affiliation(s)
- Gregory M Miller
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA
| | - Linda C Hsieh-Wilson
- Division of Chemistry and Chemical Engineering, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125, USA.
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162
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Bunin A, Sisirak V, Ghosh HS, Grajkowska LT, Hou ZE, Miron M, Yang C, Ceribelli M, Uetani N, Chaperot L, Plumas J, Hendriks W, Tremblay ML, Häcker H, Staudt LM, Green PH, Bhagat G, Reizis B. Protein Tyrosine Phosphatase PTPRS Is an Inhibitory Receptor on Human and Murine Plasmacytoid Dendritic Cells. Immunity 2015; 43:277-88. [PMID: 26231120 PMCID: PMC4547994 DOI: 10.1016/j.immuni.2015.07.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 05/01/2015] [Accepted: 05/29/2015] [Indexed: 12/15/2022]
Abstract
Plasmacytoid dendritic cells (pDCs) are primary producers of type I interferon (IFN) in response to viruses. The IFN-producing capacity of pDCs is regulated by specific inhibitory receptors, yet none of the known receptors are conserved in evolution. We report that within the human immune system, receptor protein tyrosine phosphatase sigma (PTPRS) is expressed specifically on pDCs. Surface PTPRS was rapidly downregulated after pDC activation, and only PTPRS(-) pDCs produced IFN-α. Antibody-mediated PTPRS crosslinking inhibited pDC activation, whereas PTPRS knockdown enhanced IFN response in a pDC cell line. Similarly, murine Ptprs and the homologous receptor phosphatase Ptprf were specifically co-expressed in murine pDCs. Haplodeficiency or DC-specific deletion of Ptprs on Ptprf-deficient background were associated with enhanced IFN response of pDCs, leukocyte infiltration in the intestine and mild colitis. Thus, PTPRS represents an evolutionarily conserved pDC-specific inhibitory receptor, and is required to prevent spontaneous IFN production and immune-mediated intestinal inflammation.
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Affiliation(s)
- Anna Bunin
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA; Celiac Disease Center, Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - Vanja Sisirak
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Pathology and Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Hiyaa S Ghosh
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Lucja T Grajkowska
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Pathology and Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA
| | - Z Esther Hou
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Michelle Miron
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Cliff Yang
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA
| | - Michele Ceribelli
- Lymphoid Malignancy Branch, Center for Cancer Research, National Cancer Institute, Rockville, MD 20852, USA
| | - Noriko Uetani
- Goodman Cancer Centre, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Laurence Chaperot
- R&D Laboratory, EFS Rhone-Alpes Grenoble, La Tronche F-38701, France
| | - Joel Plumas
- R&D Laboratory, EFS Rhone-Alpes Grenoble, La Tronche F-38701, France
| | - Wiljan Hendriks
- Department of Cell Biology, Radboud University, 6525 GA Nijmegen Medical Center, Nijmegen, The Netherlands
| | - Michel L Tremblay
- Goodman Cancer Centre, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Hans Häcker
- Department of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Louis M Staudt
- Lymphoid Malignancy Branch, Center for Cancer Research, National Cancer Institute, Rockville, MD 20852, USA
| | - Peter H Green
- Celiac Disease Center, Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA
| | - Govind Bhagat
- Celiac Disease Center, Department of Medicine, Columbia University Medical Center, New York, NY 10032, USA; Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - Boris Reizis
- Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY 10032, USA; Department of Pathology and Department of Medicine, New York University Langone Medical Center, New York, NY 10016, USA.
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163
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Smith PD, Coulson-Thomas VJ, Foscarin S, Kwok JCF, Fawcett JW. "GAG-ing with the neuron": The role of glycosaminoglycan patterning in the central nervous system. Exp Neurol 2015; 274:100-14. [PMID: 26277685 DOI: 10.1016/j.expneurol.2015.08.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2015] [Revised: 07/17/2015] [Accepted: 08/06/2015] [Indexed: 01/17/2023]
Abstract
Proteoglycans (PGs) are a diverse family of proteins that consist of one or more glycosaminoglycan (GAG) chains, covalently linked to a core protein. PGs are major components of the extracellular matrix (ECM) and play critical roles in development, normal function and damage-response of the central nervous system (CNS). GAGs are classified based on their disaccharide subunits, into the following major groups: chondroitin sulfate (CS), heparan sulfate (HS), heparin (HEP), dermatan sulfate (DS), keratan sulfate (KS) and hyaluronic acid (HA). All except HA are modified by sulfation, giving GAG chains specific charged structures and binding properties. While significant neuroscience research has focused on the role of one PG family member, chondroitin sulfate proteoglycan (CSPG), there is ample evidence in support of a role for the other PGs in regulating CNS function in normal and pathological conditions. This review discusses the role of all the identified PG family members (CS, HS, HEP, DS, KS and HA) in normal CNS function and in the context of pathology. Understanding the pleiotropic roles of these molecules in the CNS may open the door to novel therapeutic strategies for a number of neurological conditions.
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Affiliation(s)
- Patrice D Smith
- John van Geest Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK; Department of Neuroscience, Carleton University, Ottawa, ON, Canada.
| | - Vivien J Coulson-Thomas
- John van Geest Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK
| | - Simona Foscarin
- John van Geest Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK
| | - Jessica C F Kwok
- John van Geest Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK
| | - James W Fawcett
- John van Geest Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge, UK.
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164
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Abstract
Proteoglycans (PGs) regulate diverse functions in the central nervous system (CNS) by interacting with a number of growth factors, matrix proteins, and cell surface molecules. Heparan sulfate (HS) and chondroitin sulfate (CS) are two major glycosaminoglycans present in the PGs of the CNS. The functionality of these PGs is to a large extent dictated by the fine sulfation patterns present on their glycosaminoglycan (GAG) chains. In the past 15 years, there has been a significant expansion in our knowledge on the role of HS and CS chains in various neurological processes, such as neuronal growth, regeneration, plasticity, and pathfinding. However, defining the relation between distinct sulfation patterns of the GAGs and their functionality has thus far been difficult. With the emergence of novel tools for the synthesis of defined GAG structures, and techniques for their characterization, we are now in a better position to explore the structure-function relation of GAGs in the context of their sulfation patterns. In this review, we discuss the importance of GAGs on CNS development, injury, and disorders with an emphasis on their sulfation patterns. Finally, we outline several GAG-based therapeutic strategies to exploit GAG chains for ameliorating various CNS disorders.
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Affiliation(s)
- Vimal P Swarup
- Department of Bioengineering, University of Utah, Salt Lake City, 84112 UT , USA
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165
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Baldwin KT, Giger RJ. Insights into the physiological role of CNS regeneration inhibitors. Front Mol Neurosci 2015; 8:23. [PMID: 26113809 PMCID: PMC4462676 DOI: 10.3389/fnmol.2015.00023] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 05/26/2015] [Indexed: 12/14/2022] Open
Abstract
The growth inhibitory nature of injured adult mammalian central nervous system (CNS) tissue constitutes a major barrier to robust axonal outgrowth and functional recovery following trauma or disease. Prototypic CNS regeneration inhibitors are broadly expressed in the healthy and injured brain and spinal cord and include myelin-associated glycoprotein (MAG), the reticulon family member NogoA, oligodendrocyte myelin glycoprotein (OMgp), and chondroitin sulfate proteoglycans (CSPGs). These structurally diverse molecules strongly inhibit neurite outgrowth in vitro, and have been most extensively studied in the context of nervous system injury in vivo. The physiological role of CNS regeneration inhibitors in the naïve, or uninjured, CNS remains less well understood, but has received growing attention in recent years and is the focus of this review. CNS regeneration inhibitors regulate myelin development and axon stability, consolidate neuronal structure shaped by experience, and limit activity-dependent modification of synaptic strength. Altered function of CNS regeneration inhibitors is associated with neuropsychiatric disorders, suggesting crucial roles in brain development and health.
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Affiliation(s)
- Katherine T Baldwin
- Department of Cell and Developmental Biology, University of Michigan School of Medicine Ann Arbor, MI, USA ; Cellular and Molecular Biology Graduate Program, University of Michigan School of Medicine Ann Arbor, MI, USA
| | - Roman J Giger
- Department of Cell and Developmental Biology, University of Michigan School of Medicine Ann Arbor, MI, USA ; Department of Neurology, University of Michigan School of Medicine Ann Arbor, MI, USA
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166
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The role of neuronal versus astrocyte-derived heparan sulfate proteoglycans in brain development and injury. Biochem Soc Trans 2015; 42:1263-9. [PMID: 25233401 DOI: 10.1042/bst20140166] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Astrocytes modulate many aspects of neuronal function, including synapse formation and the response to injury. Heparan sulfate proteoglycans (HSPGs) mediate some of the effects of astrocytes on synaptic function, and participate in the astrocyte-mediated brain injury response. HSPGs are a highly conserved class of proteoglycans, with variable heparan sulfate (HS) chains that play a major role in determining the function of these proteins, such as binding to growth factors and receptors. Expression of both the core proteins and their HS chains can vary depending on cellular origin, thus the functional impact of HSPGs may be determined by the cell type in which they are expressed. In the brain, HSPGs are expressed by both neurons and astrocytes; however, the specific contribution of neuronal HSPGs compared with astrocyte-derived HSPGs to development and the injury response is largely unknown. The present review examines the current evidence regarding the roles of HSPGs in the brain, describes the cellular origins of HSPGs, and interrogates the roles of HSPGs from astrocytes and neurons in synaptogenesis and injury. The importance of considering cell-type-specific expression of HSPGs when studying brain function is discussed.
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167
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Yamagata A, Sato Y, Goto-Ito S, Uemura T, Maeda A, Shiroshima T, Yoshida T, Fukai S. Structure of Slitrk2-PTPδ complex reveals mechanisms for splicing-dependent trans-synaptic adhesion. Sci Rep 2015; 5:9686. [PMID: 25989451 PMCID: PMC4437028 DOI: 10.1038/srep09686] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 03/16/2015] [Indexed: 01/07/2023] Open
Abstract
Selective binding between pre- and postsynaptic adhesion molecules can induce synaptic differentiation. Here we report the crystal structure of a synaptogenic trans-synaptic adhesion complex between Slit and Trk-like family member 2 (Slitrk2) and receptor protein tyrosine phosphatase (RPTP) δ. The structure and site-directed mutational analysis revealed the structural basis of splicing-dependent adhesion between Slitrks and type IIa RPTPs for inducing synaptic differentiation.
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Affiliation(s)
- Atsushi Yamagata
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Yusuke Sato
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Sakurako Goto-Ito
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Takeshi Uemura
- CREST, JST, Saitama 332-0012, Japan,Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Nagano 390-8621, Japan,Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano 390-8621, Japan
| | - Asami Maeda
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Tomoko Shiroshima
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan,PRESTO, JST, Saitama 332-0012, Japan,
| | - Shuya Fukai
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan,CREST, JST, Saitama 332-0012, Japan,
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168
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Dyck SM, Alizadeh A, Santhosh KT, Proulx EH, Wu CL, Karimi-Abdolrezaee S. Chondroitin Sulfate Proteoglycans Negatively Modulate Spinal Cord Neural Precursor Cells by Signaling Through LAR and RPTPσ and Modulation of the Rho/ROCK Pathway. Stem Cells 2015; 33:2550-63. [PMID: 25703008 DOI: 10.1002/stem.1979] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 01/20/2015] [Indexed: 12/27/2022]
Abstract
Multipotent adult neural precursor cells (NPCs) have tremendous intrinsic potential to repair the damaged spinal cord. However, evidence shows that the regenerative capabilities of endogenous and transplanted NPCs are limited in the microenvironment of spinal cord injury (SCI). We previously demonstrated that injury-induced upregulation of matrix chondroitin sulfate proteoglycans (CSPGs) restricts the survival, migration, integration, and differentiation of NPCs following SCI. CSPGs are long-lasting components of the astroglial scar that are formed around the lesion. Our recent in vivo studies demonstrated that removing CSPGs from the SCI environment enhances the potential of transplanted and endogenous adult NPCs for spinal cord repair; however, the mechanisms by which CSPGs regulate NPCs remain unclear. In this study, using in vitro models recapitulating the extracellular matrix of SCI, we investigated the direct role of CSPGs in modulating the properties of adult spinal cord NPCs. We show that CSPGs significantly decrease NPCs growth, attachment, survival, proliferation, and oligodendrocytes differentiation. Moreover, using genetic models, we show that CSPGs regulate NPCs by signaling on receptor protein tyrosine phosphate sigma (RPTPσ) and leukocyte common antigen-related phosphatase (LAR). Intracellularly, CSPGs inhibitory effects are mediated through Rho/ROCK pathway and inhibition of Akt and Erk1/2 phosphorylation. Downregulation of RPTPσ and LAR and blockade of ROCK in NPCs attenuates the inhibitory effects of CSPGS. Our work provide novel evidence uncovering how upregulation of CSPGs challenges the response of NPCs in their post-SCI niche and identifies new therapeutic targets for enhancing NPC-based therapies for SCI repair.
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Affiliation(s)
- Scott M Dyck
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Arsalan Alizadeh
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Kallivalappil T Santhosh
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Evan H Proulx
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Chia-Lun Wu
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Soheila Karimi-Abdolrezaee
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.,Department of Biochemistry and Medical Genetics and Children's Hospital Research Institute of Manitoba, Winnipeg, Manitoba, Canada
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169
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Bartesaghi A, Merk A, Banerjee S, Matthies D, Wu X, Milne JLS, Subramaniam S. 2.2 Å resolution cryo-EM structure of β-galactosidase in complex with a cell-permeant inhibitor. Science 2015; 348:1147-51. [PMID: 25953817 DOI: 10.1126/science.aab1576] [Citation(s) in RCA: 324] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 04/29/2015] [Indexed: 01/21/2023]
Abstract
Cryo-electron microscopy (cryo-EM) is rapidly emerging as a powerful tool for protein structure determination at high resolution. Here we report the structure of a complex between Escherichia coli β-galactosidase and the cell-permeant inhibitor phenylethyl β-D-thiogalactopyranoside (PETG), determined by cryo-EM at an average resolution of ~2.2 angstroms (Å). Besides the PETG ligand, we identified densities in the map for ~800 water molecules and for magnesium and sodium ions. Although it is likely that continued advances in detector technology may further enhance resolution, our findings demonstrate that preparation of specimens of adequate quality and intrinsic protein flexibility, rather than imaging or image-processing technologies, now represent the major bottlenecks to routinely achieving resolutions close to 2 Å using single-particle cryo-EM.
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Affiliation(s)
- Alberto Bartesaghi
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Alan Merk
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Soojay Banerjee
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Doreen Matthies
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiongwu Wu
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jacqueline L S Milne
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sriram Subramaniam
- Laboratory of Cell Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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170
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Hartin SN, Hudson ML, Yingling C, Ackley BD. A Synthetic Lethal Screen Identifies a Role for Lin-44/Wnt in C. elegans Embryogenesis. PLoS One 2015; 10:e0121397. [PMID: 25938228 PMCID: PMC4418752 DOI: 10.1371/journal.pone.0121397] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 01/31/2015] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND The C. elegans proteins PTP-3/LAR-RPTP and SDN-1/Syndecan are conserved cell adhesion molecules. Loss-of-function (LOF) mutations in either ptp-3 or sdn-1 result in low penetrance embryonic developmental defects. Work from other systems has shown that syndecans can function as ligands for LAR receptors in vivo. We used double mutant analysis to test whether ptp-3 and sdn-1 function in a linear genetic pathway during C. elegans embryogenesis. RESULTS We found animals with LOF in both sdn-1 and ptp-3 exhibited a highly penetrant synthetic lethality (SynLet), with only a small percentage of animals surviving to adulthood. Analysis of the survivors demonstrated that these animals had a synergistic increase in the penetrance of embryonic developmental defects. Together, these data strongly suggested PTP-3 and SDN-1 function in parallel during embryogenesis. We subsequently used RNAi to knockdown ~3,600 genes predicted to encode secreted and/or transmembrane molecules to identify genes that interacted with ptp-3 or sdn-1. We found that the Wnt ligand, lin-44, was SynLet with sdn-1, but not ptp-3. We used 4-dimensional time-lapse analysis to characterize the interaction between lin-44 and sdn-1. We found evidence that loss of lin-44 caused defects in the polarization and migration of endodermal precursors during gastrulation, a previously undescribed role for lin-44 that is strongly enhanced by the loss of sdn-1. CONCLUSIONS PTP-3 and SDN-1 function in compensatory pathways during C. elegans embryonic and larval development, as simultaneous loss of both genes has dire consequences for organismal survival. The Wnt ligand lin-44 contributes to the early stages of gastrulation in parallel to sdn-1, but in a genetic pathway with ptp-3. Overall, the SynLet phenotype provides a robust platform to identify ptp-3 and sdn-1 interacting genes, as well as other genes that function in development, yet might be missed in traditional forward genetic screens.
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Affiliation(s)
- Samantha N. Hartin
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States of America
| | - Martin L. Hudson
- Department of Biology and Physics, Kennesaw State University, Kennesaw, GA, United States of America
| | - Curtis Yingling
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States of America
| | - Brian D. Ackley
- Department of Molecular Biosciences, University of Kansas, Lawrence, KS, United States of America
- * E-mail:
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171
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Yamagata A, Yoshida T, Sato Y, Goto-Ito S, Uemura T, Maeda A, Shiroshima T, Iwasawa-Okamoto S, Mori H, Mishina M, Fukai S. Mechanisms of splicing-dependent trans-synaptic adhesion by PTPδ-IL1RAPL1/IL-1RAcP for synaptic differentiation. Nat Commun 2015; 6:6926. [PMID: 25908590 PMCID: PMC4423211 DOI: 10.1038/ncomms7926] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 03/16/2015] [Indexed: 01/07/2023] Open
Abstract
Synapse formation is triggered through trans-synaptic interaction between pairs of pre- and postsynaptic adhesion molecules, the specificity of which depends on splice inserts known as 'splice-insert signaling codes'. Receptor protein tyrosine phosphatase δ (PTPδ) can bidirectionally induce pre- and postsynaptic differentiation of neurons by trans-synaptically binding to interleukin-1 receptor accessory protein (IL-1RAcP) and IL-1RAcP-like-1 (IL1RAPL1) in a splicing-dependent manner. Here, we report crystal structures of PTPδ in complex with IL1RAPL1 and IL-1RAcP. The first immunoglobulin-like (Ig) domain of IL1RAPL1 directly recognizes the first splice insert, which is critical for binding to IL1RAPL1. The second splice insert functions as an adjustable linker that positions the Ig2 and Ig3 domains of PTPδ for simultaneously interacting with the Ig1 domain of IL1RAPL1 or IL-1RAcP. We further identified the IL1RAPL1-specific interaction, which appears coupled to the first-splice-insert-mediated interaction. Our results thus reveal the decoding mechanism of splice-insert signaling codes for synaptic differentiation induced by trans-synaptic adhesion between PTPδ and IL1RAPL1/IL-1RAcP.
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Affiliation(s)
- Atsushi Yamagata
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Tomoyuki Yoshida
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan,Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan,PRESTO, JST, Saitama 332-0012, Japan,
| | - Yusuke Sato
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Sakurako Goto-Ito
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan
| | - Takeshi Uemura
- CREST, JST, Saitama 332-0012, Japan,Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan,Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Nagano 390-8621, Japan,Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research, Shinshu University, Nagano 390-8621, Japan
| | - Asami Maeda
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Tomoko Shiroshima
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,CREST, JST, Saitama 332-0012, Japan
| | - Shiho Iwasawa-Okamoto
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan,PRESTO, JST, Saitama 332-0012, Japan
| | - Hisashi Mori
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Masayoshi Mishina
- Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan,Brain Science Laboratory, The Research Organization of Science and Technology, Ritsumeikan University, Shiga 525-8577, Japan
| | - Shuya Fukai
- Structural Biology Laboratory, Life Science Division, Synchrotron Radiation Research Organization and Institute of Molecular and Cellular Biosciences, The University of Tokyo, Tokyo 113-0032, Japan,Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8501, Japan,CREST, JST, Saitama 332-0012, Japan,
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172
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Dyck SM, Karimi-Abdolrezaee S. Chondroitin sulfate proteoglycans: Key modulators in the developing and pathologic central nervous system. Exp Neurol 2015; 269:169-87. [PMID: 25900055 DOI: 10.1016/j.expneurol.2015.04.006] [Citation(s) in RCA: 123] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Revised: 04/11/2015] [Accepted: 04/14/2015] [Indexed: 12/15/2022]
Abstract
Chondroitin Sulfate Proteoglycans (CSPGs) are a major component of the extracellular matrix in the central nervous system (CNS) and play critical role in the development and pathophysiology of the brain and spinal cord. Developmentally, CSPGs provide guidance cues for growth cones and contribute to the formation of neuronal boundaries in the developing CNS. Their presence in perineuronal nets plays a crucial role in the maturation of synapses and closure of critical periods by limiting synaptic plasticity. Following injury to the CNS, CSPGs are dramatically upregulated by reactive glia which form a glial scar around the lesion site. Increased level of CSPGs is a hallmark of all CNS injuries and has been shown to limit axonal plasticity, regeneration, remyelination, and conduction after injury. Additionally, CSPGs create a non-permissive milieu for cell replacement activities by limiting cell migration, survival and differentiation. Mounting evidence is currently shedding light on the potential benefits of manipulating CSPGs in combination with other therapeutic strategies to promote spinal cord repair and regeneration. Moreover, the recent discovery of multiple receptors for CSPGs provides new therapeutic targets for targeted interventions in blocking the inhibitory properties of CSPGs following injury. Here, we will provide an in depth discussion on the impact of CSPGs in normal and pathological CNS. We will also review the recent preclinical therapies that have been developed to target CSPGs in the injured CNS.
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Affiliation(s)
- Scott M Dyck
- Regenerative Medicine Program, Department of Physiology and the Spinal Cord Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Soheila Karimi-Abdolrezaee
- Regenerative Medicine Program, Department of Physiology and the Spinal Cord Research Centre, University of Manitoba, Winnipeg, Manitoba, Canada.
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173
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Maeda N. Proteoglycans and neuronal migration in the cerebral cortex during development and disease. Front Neurosci 2015; 9:98. [PMID: 25852466 PMCID: PMC4369650 DOI: 10.3389/fnins.2015.00098] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 03/07/2015] [Indexed: 12/13/2022] Open
Abstract
Chondroitin sulfate proteoglycans and heparan sulfate proteoglycans are major constituents of the extracellular matrix and the cell surface in the brain. Proteoglycans bind with many proteins including growth factors, chemokines, axon guidance molecules, and cell adhesion molecules through both the glycosaminoglycan and the core protein portions. The functions of proteoglycans are flexibly regulated due to the structural variability of glycosaminoglycans, which are generated by multiple glycosaminoglycan synthesis and modifying enzymes. Neuronal cell surface proteoglycans such as PTPζ, neuroglycan C and syndecan-3 function as direct receptors for heparin-binding growth factors that induce neuronal migration. The lectican family, secreted chondroitin sulfate proteoglycans, forms large aggregates with hyaluronic acid and tenascins, in which many signaling molecules and enzymes including matrix proteases are preserved. In the developing cerebrum, secreted chondroitin sulfate proteoglycans such as neurocan, versican and phosphacan are richly expressed in the areas that are strategically important for neuronal migration such as the striatum, marginal zone, subplate and subventricular zone in the neocortex. These proteoglycans may anchor various attractive and/or repulsive cues, regulating the migration routes of inhibitory neurons. Recent studies demonstrated that the genes encoding proteoglycan core proteins and glycosaminoglycan synthesis and modifying enzymes are associated with various psychiatric and intellectual disorders, which may be related to the defects of neuronal migration.
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Affiliation(s)
- Nobuaki Maeda
- Neural Network Project, Department of Brain Development and Neural Regeneration, Tokyo Metropolitan Institute of Medical Science Setagaya, Japan
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174
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Hatzihristidis T, Desai N, Hutchins AP, Meng TC, Tremblay ML, Miranda-Saavedra D. A Drosophila-centric view of protein tyrosine phosphatases. FEBS Lett 2015; 589:951-66. [PMID: 25771859 DOI: 10.1016/j.febslet.2015.03.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Revised: 03/02/2015] [Accepted: 03/02/2015] [Indexed: 12/30/2022]
Abstract
Most of our knowledge on protein tyrosine phosphatases (PTPs) is derived from human pathologies and mouse knockout models. These models largely correlate well with human disease phenotypes, but can be ambiguous due to compensatory mechanisms introduced by paralogous genes. Here we present the analysis of the PTP complement of the fruit fly and the complementary view that PTP studies in Drosophila will accelerate our understanding of PTPs in physiological and pathological conditions. With only 44 PTP genes, Drosophila represents a streamlined version of the human complement. Our integrated analysis places the Drosophila PTPs into evolutionary and functional contexts, thereby providing a platform for the exploitation of the fly for PTP research and the transfer of knowledge onto other model systems.
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Affiliation(s)
- Teri Hatzihristidis
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue, Montreal, Québec H3A 1A3, Canada; Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada
| | - Nikita Desai
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue, Montreal, Québec H3A 1A3, Canada; Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Andrew P Hutchins
- Key Laboratory of Regenerative Biology and Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, Guangdong 510530, China
| | - Tzu-Ching Meng
- Taiwan International Graduate Program, Academia Sinica, Taipei, Taiwan; Institute of Biochemical Sciences, National Taiwan University, Taipei, Taiwan; Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Michel L Tremblay
- Goodman Cancer Research Centre, McGill University, 1160 Pine Avenue, Montreal, Québec H3A 1A3, Canada; Department of Medicine, Division of Experimental Medicine, McGill University, Montreal, Quebec, Canada; Department of Biochemistry, McGill University, Montreal, Quebec, Canada.
| | - Diego Miranda-Saavedra
- World Premier International (WPI) Immunology Frontier Research Center (IFReC), Osaka University, 3-1 Yamadaoka, Suita 565-0871, Osaka, Japan; Centro de Biología Molecular Severo Ochoa, CSIC/Universidad Autónoma de Madrid, 28049 Madrid, Spain; IE Business School, IE University, María de Molina 31 bis, 28006 Madrid, Spain.
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175
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Rowlands D, Sugahara K, Kwok JCF. Glycosaminoglycans and glycomimetics in the central nervous system. Molecules 2015; 20:3527-48. [PMID: 25706756 PMCID: PMC6272379 DOI: 10.3390/molecules20033527] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 02/09/2015] [Accepted: 02/13/2015] [Indexed: 01/05/2023] Open
Abstract
With recent advances in the construction of synthetic glycans, selective targeting of the extracellular matrix (ECM) as a potential treatment for a wide range of diseases has become increasingly popular. The use of compounds that mimic the structure or bioactive function of carbohydrate structures has been termed glycomimetics. These compounds are mostly synthetic glycans or glycan-binding constructs which manipulate cellular interactions. Glycosaminoglycans (GAGs) are major components of the ECM and exist as a diverse array of differentially sulphated disaccharide units. In the central nervous system (CNS), they are expressed by both neurons and glia and are crucial for brain development and brain homeostasis. The inherent diversity of GAGs make them an essential biological tool for regulating a complex range of cellular processes such as plasticity, cell interactions and inflammation. They are also involved in the pathologies of various neurological disorders, such as glial scar formation and psychiatric illnesses. It is this diversity of functions and potential for selective interventions which makes GAGs a tempting target. In this review, we shall describe the molecular make-up of GAGs and their incorporation into the ECM of the CNS. We shall highlight the different glycomimetic strategies that are currently being used in the nervous system. Finally, we shall discuss some possible targets in neurological disorders that may be addressed using glycomimetics.
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Affiliation(s)
- Dáire Rowlands
- John van Geest Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge CB2 0PY, UK.
| | - Kazuyuki Sugahara
- Proteoglycan Signaling and Therapeutics Research Group, Graduate School of Life Science, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan.
| | - Jessica C F Kwok
- John van Geest Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge CB2 0PY, UK.
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176
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PTPσ functions as a presynaptic receptor for the glypican-4/LRRTM4 complex and is essential for excitatory synaptic transmission. Proc Natl Acad Sci U S A 2015; 112:1874-9. [PMID: 25624497 DOI: 10.1073/pnas.1410138112] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Leukocyte common antigen-related receptor protein tyrosine phosphatases--comprising LAR, PTPδ, and PTPσ--are synaptic adhesion molecules that organize synapse development. Here, we identify glypican 4 (GPC-4) as a ligand for PTPσ. GPC-4 showed strong (nanomolar) affinity and heparan sulfate (HS)-dependent interaction with the Ig domains of PTPσ. PTPσ bound only to proteolytically cleaved GPC-4 and formed additional complex with leucine-rich repeat transmembrane protein 4 (LRRTM4) in rat brains. Moreover, single knockdown (KD) of PTPσ, but not LAR, in cultured neurons significantly reduced the synaptogenic activity of LRRTM4, a postsynaptic ligand of GPC-4, in heterologous synapse-formation assays. Finally, PTPσ KD dramatically decreased both the frequency and amplitude of excitatory synaptic transmission. This effect was reversed by wild-type PTPσ, but not by a HS-binding-defective PTPσ mutant. Our results collectively suggest that presynaptic PTPσ, together with GPC-4, acts in a HS-dependent manner to maintain excitatory synapse development and function.
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177
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Murray PB, Lax I, Reshetnyak A, Ligon GF, Lillquist JS, Natoli EJ, Shi X, Folta-Stogniew E, Gunel M, Alvarado D, Schlessinger J. Heparin is an activating ligand of the orphan receptor tyrosine kinase ALK. Sci Signal 2015; 8:ra6. [PMID: 25605972 DOI: 10.1126/scisignal.2005916] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Anaplastic lymphoma kinase (ALK) is one of the few remaining "orphan" receptor tyrosine kinases (RTKs) in which the ligands are unknown. Ligand-mediated activation of RTKs is important throughout development. ALK is particularly relevant to the development of the nervous system. Increased activation of RTKs by mutation, genetic amplification, or signals from the stroma contributes to disease progression and acquired drug resistance in cancer. Aberrant activation of ALK occurs in subsets of lung adenocarcinoma, neuroblastoma, and other cancers. We found that heparin is a ligand that binds specifically to the ALK extracellular domain. Whereas heparins with short chain lengths bound to ALK in a monovalent manner and did not activate the receptor, longer heparin chains induced ALK dimerization and activation in cultured neuroblastoma cells. Heparin lacking N- and O-linked sulfate groups or other glycosaminoglycans with sulfation patterns different than heparin failed to activate ALK. Moreover, antibodies that bound to the extracellular domain of ALK interfered with heparin binding and prevented heparin-mediated activation of ALK. Thus, heparin and perhaps related glycosaminoglycans function as ligands for ALK, revealing a potential mechanism for the regulation of ALK activity in vivo and suggesting an approach for developing ALK-targeted therapies for cancer.
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Affiliation(s)
- Phillip B Murray
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Irit Lax
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Andrey Reshetnyak
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | | | | | | | - Xiarong Shi
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Ewa Folta-Stogniew
- Keck Foundation Biotechnology Resource Laboratory, Yale University, New Haven, CT 06520, USA
| | - Murat Gunel
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT 06520, USA. Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | | | - Joseph Schlessinger
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06520, USA.
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178
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Coles CH, Jones EY, Aricescu AR. Extracellular regulation of type IIa receptor protein tyrosine phosphatases: mechanistic insights from structural analyses. Semin Cell Dev Biol 2015; 37:98-107. [PMID: 25234613 PMCID: PMC4765084 DOI: 10.1016/j.semcdb.2014.09.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 09/02/2014] [Accepted: 09/05/2014] [Indexed: 01/06/2023]
Abstract
The receptor protein tyrosine phosphatases (RPTPs) exhibit a wide repertoire of cellular signalling functions. In particular, type IIa RPTP family members have recently been highlighted as hubs for extracellular interactions in neurons, regulating neuronal extension and guidance, as well as synaptic organisation. In this review, we will discuss the recent progress of structural biology investigations into the architecture of type IIa RPTP ectodomains and their interactions with extracellular ligands. Structural insights, in combination with biophysical and cellular studies, allow us to begin to piece together molecular mechanisms for the transduction and integration of type IIa RPTP signals and to propose hypotheses for future experimental validation.
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Affiliation(s)
- Charlotte H Coles
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany.
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
| | - A Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
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179
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Proteoglycans of reactive rat cortical astrocyte cultures: abundance of N-unsubstituted glucosamine-enriched heparan sulfate. Matrix Biol 2014; 41:8-18. [PMID: 25483985 DOI: 10.1016/j.matbio.2014.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 11/15/2014] [Accepted: 11/16/2014] [Indexed: 11/22/2022]
Abstract
"Reactive" astrocytes and other glial cells in the injured CNS produce an altered extracellular matrix (ECM) that influences neuronal regeneration. We have profiled the glycosaminoglycan (GAG) component of proteoglycans (PGs) produced by reactive neonatal rat cortical astrocytes, and have quantified their neurite-outgrowth inhibitory activity. PGs extracted from cell layers and medium were fractionated on DEAE-Sephacel with a gradient of NaCl from 0.15 to 1.0 M. Monosaccharide analysis of the major peaks eluting at 0.6 M NaCl indicated an excess of GlcNH₂ to GalNH₂, suggesting an approximate HS/CS ratio of 6.2 in the cell layer and 4.2 in the medium. Chondroitinase ABC-generated disaccharide analysis of cell and medium PGs showed a >5-fold excess of chondroitin 4-sulfate over chondroitin 6-sulfate. Heparin lyase-generated disaccharides characteristic of the highly sulfated S-domain regions within HS were more abundant in cell layer than medium-derived PGs. Cell layer and medium HS disaccharides contained ~20% and ~40% N-unsubstituted glucosamine respectively, which is normally rare in HS isolated from most tissues. NGF-stimulated neurite outgrowth assays using NS-1 (PC12) neuronal cells on adsorbed substrata of PGs isolated from reactive astrocyte medium showed pronounced inhibition of neurite outgrowth, and aggregation of NS-1 cells. Cell layer PGs from DEAE-Sephacel pooled fractions having high charge density permitted greater NGF-stimulated outgrowth than PGs with lower charge density. Our results indicate the synthesis of both inhibitory and permissive PGs by activated astrocytes that may correlate with sulfation patterns and HS/CS ratios.
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180
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Quarmyne M, Doan PL, Himburg HA, Yan X, Nakamura M, Zhao L, Chao NJ, Chute JP. Protein tyrosine phosphatase-σ regulates hematopoietic stem cell-repopulating capacity. J Clin Invest 2014; 125:177-82. [PMID: 25415437 DOI: 10.1172/jci77866] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 10/24/2014] [Indexed: 01/06/2023] Open
Abstract
Hematopoietic stem cell (HSC) function is regulated by activation of receptor tyrosine kinases (RTKs). Receptor protein tyrosine phosphatases (PTPs) counterbalance RTK signaling; however, the functions of receptor PTPs in HSCs remain incompletely understood. We found that a receptor PTP, PTPσ, was substantially overexpressed in mouse and human HSCs compared with more mature hematopoietic cells. Competitive transplantation of bone marrow cells from PTPσ-deficient mice revealed that the loss of PTPσ substantially increased long-term HSC-repopulating capacity compared with BM cells from control mice. While HSCs from PTPσ-deficient mice had no apparent alterations in cell-cycle status, apoptosis, or homing capacity, these HSCs exhibited increased levels of activated RAC1, a RhoGTPase that regulates HSC engraftment capacity. shRNA-mediated silencing of PTPσ also increased activated RAC1 levels in wild-type HSCs. Functionally, PTPσ-deficient BM cells displayed increased cobblestone area-forming cell (CAFC) capacity and augmented transendothelial migration capacity, which was abrogated by RAC inhibition. Specific selection of human cord blood CD34⁺CD38⁻CD45RA⁻lin⁻ PTPσ⁻ cells substantially increased the repopulating capacity of human HSCs compared with CD34⁺CD38⁻CD45RA⁻lin⁻ cells and CD34⁺CD38⁻CD45RA⁻lin⁻PTPσ⁺ cells. Our results demonstrate that PTPσ regulates HSC functional capacity via RAC1 inhibition and suggest that selecting for PTPσ-negative human HSCs may be an effective strategy for enriching human HSCs for transplantation.
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181
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Um JW, Kim KH, Park BS, Choi Y, Kim D, Kim CY, Kim SJ, Kim M, Ko JS, Lee SG, Choii G, Nam J, Heo WD, Kim E, Lee JO, Ko J, Kim HM. Structural basis for LAR-RPTP/Slitrk complex-mediated synaptic adhesion. Nat Commun 2014; 5:5423. [PMID: 25394468 DOI: 10.1038/ncomms6423] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2014] [Accepted: 09/29/2014] [Indexed: 01/08/2023] Open
Abstract
Synaptic adhesion molecules orchestrate synaptogenesis. The presynaptic leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs) regulate synapse development by interacting with postsynaptic Slit- and Trk-like family proteins (Slitrks), which harbour two extracellular leucine-rich repeats (LRR1 and LRR2). Here we identify the minimal regions of the LAR-RPTPs and Slitrks, LAR-RPTPs Ig1-3 and Slitrks LRR1, for their interaction and synaptogenic function. Subsequent crystallographic and structure-guided functional analyses reveal that the splicing inserts in LAR-RPTPs are key molecular determinants for Slitrk binding and synapse formation. Moreover, structural comparison of the two Slitrk1 LRRs reveal that unique properties on the concave surface of Slitrk1 LRR1 render its specific binding to LAR-RPTPs. Finally, we demonstrate that lateral interactions between adjacent trans-synaptic LAR-RPTPs/Slitrks complexes observed in crystal lattices are critical for Slitrk1-induced lateral assembly and synaptogenic activity. Thus, we propose a model in which Slitrks mediate synaptogenic functions through direct binding to LAR-RPTPs and the subsequent lateral assembly of LAR-RPTPs/Slitrks complexes.
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Affiliation(s)
- Ji Won Um
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Kee Hun Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Beom Seok Park
- Department of Biomedical Laboratory Science, College of Health Science, Eulji University, Seongnam 461-713, Korea
| | - Yeonsoo Choi
- 1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea [2] Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Doyoun Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Cha Yeon Kim
- Graduate School of Nanoscience and Technology, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
| | - Soo Jin Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Minhye Kim
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Ji Seung Ko
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Seong-Gyu Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Gayoung Choii
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Jungyong Nam
- 1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea [2] Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Won Do Heo
- 1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea [2] Center for Cognition and Sociality, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Eunjoon Kim
- 1] Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea [2] Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Jie-Oh Lee
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Jaewon Ko
- 1] Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea [2] Department of Psychiatry, Yonsei University College of Medicine, Seoul 120-751, Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea
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182
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Coles CH, Mitakidis N, Zhang P, Elegheert J, Lu W, Stoker AW, Nakagawa T, Craig AM, Jones EY, Aricescu AR. Structural basis for extracellular cis and trans RPTPσ signal competition in synaptogenesis. Nat Commun 2014; 5:5209. [PMID: 25385546 PMCID: PMC4239663 DOI: 10.1038/ncomms6209] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 09/09/2014] [Indexed: 01/26/2023] Open
Abstract
Receptor protein tyrosine phosphatase sigma (RPTPσ) regulates neuronal extension and acts as a presynaptic nexus for multiple protein and proteoglycan interactions during synaptogenesis. Unknown mechanisms govern the shift in RPTPσ function, from outgrowth promotion to synaptic organization. Here, we report crystallographic, electron microscopic and small-angle X-ray scattering analyses, which reveal sufficient inter-domain flexibility in the RPTPσ extracellular region for interaction with both cis (same cell) and trans (opposite cell) ligands. Crystal structures of RPTPσ bound to its postsynaptic ligand TrkC detail an interaction surface partially overlapping the glycosaminoglycan-binding site. Accordingly, heparan sulphate and heparin oligomers compete with TrkC for RPTPσ binding in vitro and disrupt TrkC-dependent synaptic differentiation in neuronal co-culture assays. We propose that transient RPTPσ ectodomain emergence from the presynaptic proteoglycan layer allows capture by TrkC to form a trans-synaptic complex, the consequent reduction in RPTPσ flexibility potentiating interactions with additional ligands to orchestrate excitatory synapse formation.
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Affiliation(s)
- Charlotte H. Coles
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Nikolaos Mitakidis
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Peng Zhang
- Brain Research Centre and Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada V6T 2B5
| | - Jonathan Elegheert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Weixian Lu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Andrew W. Stoker
- Cancer Section, Institute of Child Health, University College London, 30 Guilford Street, London WC1N 1EH, UK
| | - Terunaga Nakagawa
- Department of Molecular Physiology and Biophysics, Vanderbilt University, School of Medicine, 702 Light Hall (0615), Nashville, Tennessee 37232-0615, USA
| | - Ann Marie Craig
- Brain Research Centre and Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada V6T 2B5
| | - E. Yvonne Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - A. Radu Aricescu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
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183
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Miyata S, Kitagawa H. Mechanisms for modulation of neural plasticity and axon regeneration by chondroitin sulphate. J Biochem 2014; 157:13-22. [PMID: 25381371 DOI: 10.1093/jb/mvu067] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Chondroitin sulphate proteoglycans (CSPGs), consisting of core proteins linked to one or more chondroitin sulphate (CS) chains, are major extracellular matrix (ECM) components of the central nervous system (CNS). Multi-functionality of CSPGs can be explained by the diversity in structure of CS chains that undergo dynamic changes during development and under pathological conditions. CSPGs, together with other ECM components, form mesh-like structures called perineuronal nets around a subset of neurons. Enzymatic digestion or genetic manipulation of CSPGs reactivates neural plasticity in the adult brain and improves regeneration of damaged axons after CNS injury. Recent studies have shown that CSPGs not only act as non-specific physical barriers that prevent rearrangement of synaptic connections but also regulate neural plasticity through specific interaction of CS chains with its binding partners in a manner that depends on the structure of the CS chain.
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Affiliation(s)
- Shinji Miyata
- Department of Biochemistry, Kobe Pharmaceutical University, Kobe 658-8558, Japan; and Institute for Advanced Research, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan Department of Biochemistry, Kobe Pharmaceutical University, Kobe 658-8558, Japan; and Institute for Advanced Research, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
| | - Hiroshi Kitagawa
- Department of Biochemistry, Kobe Pharmaceutical University, Kobe 658-8558, Japan; and Institute for Advanced Research, Nagoya University, Chikusa-ku, Nagoya 464-8601, Japan
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184
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Abstract
The complex, branched morphology of dendrites is a cardinal feature of neurons and has been used as a criterion for cell type identification since the beginning of neurobiology. Regulated dendritic outgrowth and branching during development form the basis of receptive fields for neurons and are essential for the wiring of the nervous system. The cellular and molecular mechanisms of dendritic morphogenesis have been an intensely studied area. In this review, we summarize the major experimental systems that have contributed to our understandings of dendritic development as well as the intrinsic and extrinsic mechanisms that instruct the neurons to form cell type-specific dendritic arbors.
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185
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Joy MT, Vrbova G, Dhoot GK, Anderson PN. Sulf1 and Sulf2 expression in the nervous system and its role in limiting neurite outgrowth in vitro. Exp Neurol 2014; 263:150-60. [PMID: 25448158 DOI: 10.1016/j.expneurol.2014.10.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Revised: 10/10/2014] [Accepted: 10/14/2014] [Indexed: 01/30/2023]
Abstract
Sulf1 and Sulf2 are endosulfatases that cleave 6-O-sulphate groups from Heparan Sulphate Proteoglycans (HSPGs). Sulfation levels of HSPGs are critical for their role in modulating the activity of various growth factor receptors. Sulf1 and Sulf2 mRNAs were found to be widely expressed in the rodent nervous system and their full-length proteins were found in many types of neuronal perikarya and axons in the cerebral cortex, cerebellum, spinal cord and dorsal root ganglia (DRG) of adult rats. Sulf1/2 were also strongly expressed by cultured DRG neurons. To determine if blocking Sulf1 or Sulf2 activity affected neurite outgrowth in vitro, cultured DRG neurons were treated with neutralising antibodies to Sulf1 or Sulf2. Blocking Sulf1 and Sulf2 activity did not affect neurite outgrowth from cultured DRG neurons grown on a laminin/polylysine substrate but ameliorated the inhibitory effects of chondroitin sulphate proteoglycans (CSPGs) on neurite outgrowth. Blocking epidermal growth factor receptor (ErbB1) activity also improved neurite outgrowth in the presence of CSPGs, but the effects of ErbB1 antagonists and blocking SULFs were not additive. It is proposed that Sulf1, Sulf2 and ErbB1 are involved in the signalling pathway from CSPGs that leads to inhibition of neurite outgrowth and may regulate structural plasticity and regeneration in the nervous system.
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Affiliation(s)
- Mary T Joy
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Gerta Vrbova
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 OTU, UK
| | - Gurtej K Dhoot
- Department of Comparative Biomedical Sciences, The Royal Veterinary College, Royal College Street, London NW1 OTU, UK.
| | - Patrick N Anderson
- Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, UK
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186
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Seiradake E, del Toro D, Nagel D, Cop F, Härtl R, Ruff T, Seyit-Bremer G, Harlos K, Border EC, Acker-Palmer A, Jones EY, Klein R. FLRT structure: balancing repulsion and cell adhesion in cortical and vascular development. Neuron 2014; 84:370-85. [PMID: 25374360 PMCID: PMC4210639 DOI: 10.1016/j.neuron.2014.10.008] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/02/2014] [Indexed: 11/03/2022]
Abstract
FLRTs are broadly expressed proteins with the unique property of acting as homophilic cell adhesion molecules and as heterophilic repulsive ligands of Unc5/Netrin receptors. How these functions direct cell behavior and the molecular mechanisms involved remain largely unclear. Here we use X-ray crystallography to reveal the distinct structural bases for FLRT-mediated cell adhesion and repulsion in neurons. We apply this knowledge to elucidate FLRT functions during cortical development. We show that FLRTs regulate both the radial migration of pyramidal neurons, as well as their tangential spread. Mechanistically, radial migration is controlled by repulsive FLRT2-Unc5D interactions, while spatial organization in the tangential axis involves adhesive FLRT-FLRT interactions. Further, we show that the fundamental mechanisms of FLRT adhesion and repulsion are conserved between neurons and vascular endothelial cells. Our results reveal FLRTs as powerful guidance factors with structurally encoded repulsive and adhesive surfaces.
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Affiliation(s)
- Elena Seiradake
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, OX3 7BN Oxford, UK
| | - Daniel del Toro
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Daniel Nagel
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany; Graduate School of Systemic Neurosciences, Ludwig-Maximilians-University Munich, Großhaderner Str. 2, 82152 Planegg-Martinsried, Germany
| | - Florian Cop
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany; Focus Program Translational Neurosciences, Johannes Gutenberg University Mainz, Saarstr. 21, 55122 Mainz, Germany
| | - Ricarda Härtl
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany; Focus Program Translational Neurosciences, Johannes Gutenberg University Mainz, Saarstr. 21, 55122 Mainz, Germany
| | - Tobias Ruff
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Gönül Seyit-Bremer
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Karl Harlos
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, OX3 7BN Oxford, UK
| | - Ellen Clare Border
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, OX3 7BN Oxford, UK
| | - Amparo Acker-Palmer
- Institute of Cell Biology and Neuroscience and Buchmann Institute for Molecular Life Sciences, Goethe University Frankfurt, Max-von-Laue-Str. 15, 60438 Frankfurt am Main, Germany; Focus Program Translational Neurosciences, Johannes Gutenberg University Mainz, Saarstr. 21, 55122 Mainz, Germany
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, OX3 7BN Oxford, UK.
| | - Rüdiger Klein
- Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), 80336 Munich, Germany.
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187
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Noborn F, Gomez Toledo A, Sihlbom C, Lengqvist J, Fries E, Kjellén L, Nilsson J, Larson G. Identification of chondroitin sulfate linkage region glycopeptides reveals prohormones as a novel class of proteoglycans. Mol Cell Proteomics 2014; 14:41-9. [PMID: 25326458 DOI: 10.1074/mcp.m114.043703] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Vertebrates produce various chondroitin sulfate proteoglycans (CSPGs) that are important structural components of cartilage and other connective tissues. CSPGs also contribute to the regulation of more specialized processes such as neurogenesis and angiogenesis. Although many aspects of CSPGs have been studied extensively, little is known of where the CS chains are attached on the core proteins and so far, only a limited number of CSPGs have been identified. Obtaining global information on glycan structures and attachment sites would contribute to our understanding of the complex proteoglycan structures and may also assist in assigning CSPG specific functions. In the present work, we have developed a glycoproteomics approach that characterizes CS linkage regions, attachment sites, and identities of core proteins. CSPGs were enriched from human urine and cerebrospinal fluid samples by strong-anion-exchange chromatography, digested with chondroitinase ABC, a specific CS-lyase used to reduce the CS chain lengths and subsequently analyzed by nLC-MS/MS with a novel glycopeptide search algorithm. The protocol enabled the identification of 13 novel CSPGs, in addition to 13 previously established CSPGs, demonstrating that this approach can be routinely used to characterize CSPGs in complex human samples. Surprisingly, five of the identified CSPGs are traditionally defined as prohormones (cholecystokinin, chromogranin A, neuropeptide W, secretogranin-1, and secretogranin-3), typically stored and secreted from granules of endocrine cells. We hypothesized that the CS side chain may influence the assembly and structural organization of secretory granules and applied surface plasmon resonance spectroscopy to show that CS actually promotes the assembly of chromogranin A core proteins in vitro. This activity required mild acidic pH and suggests that the CS-side chains may also influence the self-assembly of chromogranin A in vivo giving a possible explanation to previous observations that chromogranin A has an inherent property to assemble in the acidic milieu of secretory granules.
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Affiliation(s)
- Fredrik Noborn
- From the ‡Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, University of Gothenburg, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Alejandro Gomez Toledo
- From the ‡Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, University of Gothenburg, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Carina Sihlbom
- §Proteomics Core Facility, Sahlgrenska Academy, University of Gothenburg, Box 413, SE-405 30, Sweden
| | - Johan Lengqvist
- §Proteomics Core Facility, Sahlgrenska Academy, University of Gothenburg, Box 413, SE-405 30, Sweden
| | - Erik Fries
- ¶Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Lena Kjellén
- ¶Department of Medical Biochemistry and Microbiology, Uppsala University, SE-751 23 Uppsala, Sweden
| | - Jonas Nilsson
- From the ‡Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, University of Gothenburg, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden
| | - Göran Larson
- From the ‡Department of Clinical Chemistry and Transfusion Medicine, Institute of Biomedicine, University of Gothenburg, Sahlgrenska University Hospital, SE-413 45 Gothenburg, Sweden;
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188
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Stoker AW. RPTPs in axons, synapses and neurology. Semin Cell Dev Biol 2014; 37:90-7. [PMID: 25234542 DOI: 10.1016/j.semcdb.2014.09.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 09/04/2014] [Accepted: 09/05/2014] [Indexed: 01/06/2023]
Abstract
Receptor-like protein tyrosine phosphatases represent a large protein family related to cell adhesion molecules, with diverse roles throughout neural development in vertebrates and invertebrates. This review focuses on their roles in axon growth, guidance and repair, as well as more recent findings demonstrating their key roles in pre-synaptic and post-synaptic maturation and function. These enzymes have been linked to memory and neuropsychiatric defects in loss-of-function rodent models, highlighting their potential as future drug targets.
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Affiliation(s)
- Andrew W Stoker
- Institute of Child Health, University College London, United Kingdom.
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189
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Abstract
Proteoglycans in the central nervous system play integral roles as "traffic signals" for the direction of neurite outgrowth. This attribute of proteoglycans is a major factor in regeneration of the injured central nervous system. In this review, the structures of proteoglycans and the evidence suggesting their involvement in the response following spinal cord injury are presented. The review further describes the methods routinely used to determine the effect proteoglycans have on neurite outgrowth. The effects of proteoglycans on neurite outgrowth are not completely understood as there is disagreement on what component of the molecule is interacting with growing neurites and this ambiguity is chronicled in an historical context. Finally, the most recent findings suggesting possible receptors, interactions, and sulfation patterns that may be important in eliciting the effect of proteoglycans on neurite outgrowth are discussed. A greater understanding of the proteoglycan-neurite interaction is necessary for successfully promoting regeneration in the injured central nervous system.
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Affiliation(s)
- Justin A Beller
- Spinal Cord and Brain Injury Research Center, The University of Kentucky, Lexington, KY, USA
| | - Diane M Snow
- Spinal Cord and Brain Injury Research Center, The University of Kentucky, Lexington, KY, USA
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190
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Chen M, Zheng B. Axon plasticity in the mammalian central nervous system after injury. Trends Neurosci 2014; 37:583-93. [PMID: 25218468 DOI: 10.1016/j.tins.2014.08.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2014] [Revised: 08/19/2014] [Accepted: 08/21/2014] [Indexed: 12/31/2022]
Abstract
It is widely recognized that severed axons in the adult central nervous system (CNS) have limited capacity to regenerate. However, mounting evidence from studies of CNS injury response and repair is challenging the prevalent view that the adult mammalian CNS is incapable of structural reorganization to adapt to an altered environment. Animal studies demonstrate the potential to achieve significant anatomical repair and functional recovery following CNS injury by manipulating axon growth regulators alone or in combination with activity-dependent strategies. With a growing understanding of the cellular and molecular mechanisms regulating axon plasticity, and the availability of new experimental tools to map detour circuits of functional importance, directing circuit rewiring to promote functional recovery may be achieved.
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Affiliation(s)
- Meifan Chen
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, MC 0691, La Jolla, CA 92093-0691, USA
| | - Binhai Zheng
- Department of Neurosciences, University of California, San Diego, 9500 Gilman Drive, MC 0691, La Jolla, CA 92093-0691, USA.
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191
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Ohtake Y, Li S. Molecular mechanisms of scar-sourced axon growth inhibitors. Brain Res 2014; 1619:22-35. [PMID: 25192646 DOI: 10.1016/j.brainres.2014.08.064] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/21/2014] [Indexed: 12/29/2022]
Abstract
Astrogliosis is a defense response of the CNS to minimize primary damage and to repair injured tissues, but it ultimately generates harmful effects by upregulating inhibitory molecules to suppress neuronal elongation and forming potent barriers to axon regeneration. Chondroitin sulfate proteoglycans (CSPGs) are highly expressed by reactive scars and are potent contributors to the non-permissive environment in mature CNS. Surmounting strong inhibition by CSPG-rich scar is an important therapeutic goal for achieving functional recovery after CNS injuries. Currently, enzymatic digestion of CSPGs with locally applied chondroitinase ABC is the main in vivo approach to overcome scar inhibition, but several disadvantages may prevent using this bacterial enzyme as a therapeutic option for patients. A better understanding of molecular mechanisms underlying CSPG function may facilitate development of new effective therapies to overcome scar-mediated inhibition. Previous studies support that CSPGs act by non-specifically hindering the binding of matrix molecules to their cell surface receptors through steric interactions, but two members of the leukocyte common antigen related (LAR) phosphatase subfamily, protein tyrosine phosphatase σ and LAR, are functional receptors that bind CSPGs with high affinity and mediate CSPG inhibition. CSPGs may also act by binding two receptors for myelin-associated growth inhibitors, Nogo receptors 1 and 3. Thus, CSPGs inhibit axon growth through multiple mechanisms, making them especially potent and difficult therapeutic targets. Identification of CSPG receptors is not only important for understanding the scar-mediated growth suppression, but also for developing novel and selective therapies to promote axon sprouting and/or regeneration after CNS injuries. This article is part of a Special Issue entitled SI: Spinal cord injury.
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Affiliation(s)
- Yosuke Ohtake
- Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500N. Broad Street, Philadelphia 19140, PA, USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center and Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500N. Broad Street, Philadelphia 19140, PA, USA.
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192
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Targeting RPTPσ with lentiviral shRNA promotes neurites outgrowth of cortical neurons and improves functional recovery in a rat spinal cord contusion model. Brain Res 2014; 1586:46-63. [PMID: 25152470 DOI: 10.1016/j.brainres.2014.08.048] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Revised: 08/09/2014] [Accepted: 08/16/2014] [Indexed: 01/01/2023]
Abstract
After spinal cord injury (SCI), the rapidly upregulated chondroitin sulfate proteoglycans (CSPGs), the prominent chemical constituents and main repulsive factors of the glial scar, play an important role in the extremely limited ability to regenerate in adult mammals. Although many methods to overcome the inhibition have been tested, no successful method with clinical feasibility has been devised to date. It was recently discovered that receptor protein tyrosine phosphatase sigma (RPTPσ) is a functional receptor for CSPGs-mediated inhibition. In view of the potential clinical application of RNA interference (RNAi), here we investigated whether silencing RPTPσ via lentivirus-mediated RNA interference can promote axon regeneration and functional recovery after SCI. Neurites of primary rat cerebral cortical neurons with depleted RPTPσ exhibited a significant enhancement in elongation and crossing ability when they encountered CSPGs in vitro. A contusion model of spinal cord injury in Wistar rats (the New York University (NYU) impactor) was used for in vivo experiments. Local injection of lentivirus encoding RPTPσ shRNA at the lesion site promoted axon regeneration and synapse formation, but did not affect the scar formation. Meanwhile, in vivo functional recovery (motor and sensory) was also enhanced after RPTPσ depletion. Therefore, strategies directed at silencing RPTPσ by RNAi may prove to be a beneficial, efficient and valuable approach for the treatment of SCI.
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193
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Roll L, Faissner A. Influence of the extracellular matrix on endogenous and transplanted stem cells after brain damage. Front Cell Neurosci 2014; 8:219. [PMID: 25191223 PMCID: PMC4137450 DOI: 10.3389/fncel.2014.00219] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 07/18/2014] [Indexed: 01/07/2023] Open
Abstract
The limited regeneration capacity of the adult central nervous system (CNS) requires strategies to improve recovery of patients. In this context, the interaction of endogenous as well as transplanted stem cells with their environment is crucial. An understanding of the molecular mechanisms could help to improve regeneration by targeted manipulation. In the course of reactive gliosis, astrocytes upregulate Glial fibrillary acidic protein (GFAP) and start, in many cases, to proliferate. Beside GFAP, subpopulations of these astroglial cells coexpress neural progenitor markers like Nestin. Although cells express these markers, the proportion of cells that eventually give rise to neurons is limited in many cases in vivo compared to the situation in vitro. In the first section, we present the characteristics of endogenous progenitor-like cells and discuss the differences in their neurogenic potential in vitro and in vivo. As the environment plays an important role for survival, proliferation, migration, and other processes, the second section of the review describes changes in the extracellular matrix (ECM), a complex network that contains numerous signaling molecules. It appears that signals in the damaged CNS lead to an activation and de-differentiation of astrocytes, but do not effectively promote neuronal differentiation of these cells. Factors that influence stem cells during development are upregulated in the damaged brain as part of an environment resembling a stem cell niche. We give a general description of the ECM composition, with focus on stem cell-associated factors like the glycoprotein Tenascin-C (TN-C). Stem cell transplantation is considered as potential treatment strategy. Interaction of transplanted stem cells with the host environment is critical for the outcome of stem cell-based therapies. Possible mechanisms involving the ECM by which transplanted stem cells might improve recovery are discussed in the last section.
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Affiliation(s)
- Lars Roll
- Department of Cell Morphology and Molecular Neurobiology, Ruhr-University Bochum Bochum, Germany ; International Graduate School of Neuroscience, Ruhr-University Bochum Bochum, Germany
| | - Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology, Ruhr-University Bochum Bochum, Germany ; International Graduate School of Neuroscience, Ruhr-University Bochum Bochum, Germany
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194
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Pantazaka E, Papadimitriou E. Chondroitin sulfate-cell membrane effectors as regulators of growth factor-mediated vascular and cancer cell migration. Biochim Biophys Acta Gen Subj 2014; 1840:2643-50. [DOI: 10.1016/j.bbagen.2014.01.009] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2013] [Revised: 01/02/2014] [Accepted: 01/03/2014] [Indexed: 12/18/2022]
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195
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Lang BT, Wang J, Filous AR, Au NPB, Ma CHE, Shen Y. Pleiotropic molecules in axon regeneration and neuroinflammation. Exp Neurol 2014; 258:17-23. [DOI: 10.1016/j.expneurol.2014.04.031] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Revised: 04/21/2014] [Accepted: 04/29/2014] [Indexed: 12/20/2022]
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196
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Chondroitin sulphate N-acetylgalactosaminyl-transferase-1 inhibits recovery from neural injury. Nat Commun 2014; 4:2740. [PMID: 24220492 PMCID: PMC3831297 DOI: 10.1038/ncomms3740] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Accepted: 10/10/2013] [Indexed: 12/20/2022] Open
Abstract
Extracellular factors that inhibit axon growth and intrinsic factors that promote it affect neural regeneration. Therapies targeting any single gene have not yet simultaneously optimized both types of factors. Chondroitin sulphate (CS), a glycosaminoglycan, is the most abundant extracellular inhibitor of axon growth. Here we show that mice carrying a gene knockout for CS N-acetylgalactosaminyltransferase-1 (T1), a key enzyme in CS biosynthesis, recover more completely from spinal cord injury than wild-type mice and even chondroitinase ABC-treated mice. Notably, synthesis of heparan sulphate (HS), a glycosaminoglycan promoting axonal growth, is also upregulated in TI knockout mice because HS-synthesis enzymes are induced in the mutant neurons. Moreover, chondroitinase ABC treatment never induces HS upregulation. Taken together, our results indicate that regulation of a single gene, T1, mediates excellent recovery from spinal cord injury by optimizing counteracting effectors of axon regeneration—an extracellular inhibitor of CS and intrinsic promoters, namely, HS-synthesis enzymes. The glycosaminoglycan chondroitin sulphate inhibits axon growth. Here the authors show that mice deficient in chondroitin sulphate biosynthesis have increased levels of heparan sulphate, which is more efficient than chondroitinase in supporting recovery from spinal cord injury.
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197
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Mechanisms of axon regeneration and its inhibition: roles of sulfated glycans. Arch Biochem Biophys 2014; 558:36-41. [PMID: 24951877 DOI: 10.1016/j.abb.2014.06.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 06/05/2014] [Accepted: 06/09/2014] [Indexed: 12/25/2022]
Abstract
Axons in the peripheral nervous system can regenerate after injury, whereas axons in the central nervous system (CNS) do not readily regenerate. Intrinsic regenerating capacity and emerging inhibitors could explain these contrasting phenotypes. Among the inhibitors, sulfated sugar chains including chondroitin sulfate and keratan sulfate have recently attracted attention, since these sugar chains strongly inhibit axon regeneration and also induce dystrophic endball formation, a hallmark of injured axons in the adult mammalian CNS. In addition, chondroitin sulfate is a negative regulator of synaptic plasticity. To overcome the inability of CNS axons to regenerate, a comprehensive understanding of both the positive and negative regulations of axon regeneration is required. These may include signaling waves from the injury site to the nucleus, intracellular signals for growth cone formation and axon regeneration, intracellular signals for the inhibition of axon regeneration, and extracellular inhibitory signals and their receptors. This review addresses these issues, with a focus on the roles of chondroitin sulfate and keratan sulfate.
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198
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Cukkemane N, Bikker FJ, Nazmi K, Brand HS, Veerman EC. Identification and characterization of a salivary-pellicle-binding peptide by phage display. Arch Oral Biol 2014; 59:448-54. [DOI: 10.1016/j.archoralbio.2014.02.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 01/10/2014] [Accepted: 02/10/2014] [Indexed: 12/01/2022]
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199
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Silver L, Michael JV, Goldfinger LE, Gallo G. Activation of PI3K and R-Ras signaling promotes the extension of sensory axons on inhibitory chondroitin sulfate proteoglycans. Dev Neurobiol 2014; 74:918-33. [PMID: 24578264 DOI: 10.1002/dneu.22174] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 02/24/2014] [Indexed: 12/22/2022]
Abstract
Chondroitin sulfate proteoglycans (CSPGs) are extracellular inhibitors of axon extension and plasticity, and cause growth cones to exhibit dystrophic behaviors. Phosphoinositide 3-kinase (PI3K) is a lipid kinase activated by axon growth promoting signals. In this study, we used embryonic chicken dorsal root ganglion neurons to determine if CSPGs impair signaling through PI3K. We report that CSPGs inhibit PI3K signaling in axons and growth cones, as evidenced by decreased levels of phosphorylated downstream kinases (Akt and S6). Direct activation of PI3K signaling, using a cell permeable phosphopeptide (PI3Kpep), countered the effects of CSPGs on growth cones and axon extension. Both overnight and acute treatment with PI3Kpep promoted axon extension on CSPG-coated substrates. The R-Ras GTPase is an upstream positive regulator of PI3K signaling. Expression of constitutively active R-Ras promoted axon extension and growth cone elaboration on CSPGs and permissive substrata. In contrast, an N-terminus-deleted constitutively active R-Ras, deficient in PI3K activation, promoted axon extension but not growth cone elaboration on CSPGs and permissive substrata. These data indicate that activation of R-Ras-PI3K signaling may be a viable approach for manipulating axon extension on CSPGs.
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Affiliation(s)
- Lee Silver
- Department of Anatomy and Cell Biology, Temple University School of Medicine, 3500 North Broad St., Philadelphia, Pennsylvania, 19140; Shriners Hospitals Pediatric Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania, 19140
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200
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Abstract
Numerous proteins, including cytokines and chemokines, enzymes and enzyme inhibitors, extracellular matrix proteins, and membrane receptors, bind heparin. Although they are traditionally classified as heparin-binding proteins, under normal physiological conditions these proteins actually interact with the heparan sulfate chains of one or more membrane or extracellular proteoglycans. Thus, they are more appropriately classified as heparan sulfate-binding proteins (HSBPs). This review provides an overview of the various modes of interaction between heparan sulfate and HSBPs, emphasizing biochemical and structural insights that improve our understanding of the many biological functions of heparan sulfate.
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Affiliation(s)
- Ding Xu
- Department of Cellular and Molecular Medicine, Glycobiology Research and Training Center, University of California, San Diego, La Jolla, California 92093; ,
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