151
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Friedel RH, Kerjan G, Rayburn H, Schüller U, Sotelo C, Tessier-Lavigne M, Chédotal A. Plexin-B2 controls the development of cerebellar granule cells. J Neurosci 2007; 27:3921-32. [PMID: 17409257 PMCID: PMC6672405 DOI: 10.1523/jneurosci.4710-06.2007] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Cerebellar granule cell progenitors proliferate postnatally in the upper part of the external granule cell layer (EGL) of the cerebellum. Postmitotic granule cells differentiate and migrate, tangentially in the EGL and then radially through the molecular and Purkinje cell layers. The molecular control of the transition between proliferation and differentiation in cerebellar granule cells is poorly understood. We show here that the transmembrane receptor Plexin-B2 is expressed by proliferating granule cell progenitors. To study Plexin-B2 function, we generated a targeted mutation of mouse Plexin-B2. Most Plexin-B2(-/-) mutants die at birth as a result of neural tube closure defects. Some mutants survive but their cerebellum cytoarchitecture is profoundly altered. This is correlated with a disorganization of the timing of granule cell proliferation and differentiation in the EGL. Many differentiated granule cells migrate inside the cerebellum and keep proliferating. These results reveal that Plexin-B2 controls the balance between proliferation and differentiation in granule cells.
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Affiliation(s)
- Roland H. Friedel
- Department of Biological Sciences, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305
| | - Géraldine Kerjan
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7102, Université Paris 6, 75005 Paris, France
| | - Helen Rayburn
- Department of Biological Sciences, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305
| | - Ulrich Schüller
- Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts 02115, and
| | - Constantino Sotelo
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7102, Université Paris 6, 75005 Paris, France
- Cátedra de Neurobiología del Desarrollo “Remedios Caro Almela,” Instituto de Neurociencias de Alicante, Universidad Miguel Hernández de Elche, Consejo Superior de Investigaciones Científicas, 03550 San Juan de Alicante, Alicante, Spain
| | - Marc Tessier-Lavigne
- Department of Biological Sciences, Howard Hughes Medical Institute, Stanford University, Stanford, California 94305
| | - Alain Chédotal
- Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7102, Université Paris 6, 75005 Paris, France
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152
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Pasterkamp RJ, Verhaagen J. Semaphorins in axon regeneration: developmental guidance molecules gone wrong? Philos Trans R Soc Lond B Biol Sci 2007; 361:1499-511. [PMID: 16939971 PMCID: PMC1664670 DOI: 10.1098/rstb.2006.1892] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Semaphorins are developmental axon guidance cues that continue to be expressed during adulthood and are regulated by neural injury. During the formation of the nervous system, repulsive semaphorins guide axons to their targets by restricting and channelling their growth. They affect the growth cone cytoskeleton through interactions with receptor complexes that are linked to a complicated intracellular signal transduction network. Following injury, regenerating axons stop growing when they reach the border of the glial-fibrotic scar, in part because they encounter a potent molecular barrier that inhibits growth cone extension. A number of secreted semaphorins are expressed in the glial-fibrotic scar and at least one transmembrane semaphorin is upregulated in oligodendrocytes surrounding the lesion site. Semaphorin receptors, and many of the signal transduction components required for semaphorin signalling, are present in injured central nervous system neurons. Here, we review evidence that supports a critical role for semaphorin signalling in axon regeneration, and highlight a number of challenges that lie ahead with respect to advancing our understanding of semaphorin function in the normal and injured adult nervous system.
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Affiliation(s)
- R. Jeroen Pasterkamp
- Department of Pharmacology and Anatomy, Rudolf Magnus Institute of NeuroscienceUniversity Medical Center Utrecht, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands
- Authors for correspondence () ()
| | - Joost Verhaagen
- Netherlands Institute for NeuroscienceMeibergdreef 33, 1105 AZ, Amsterdam, The Netherlands
- Authors for correspondence () ()
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153
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Toyofuku T, Yabuki M, Kamei J, Kamei M, Makino N, Kumanogoh A, Hori M. Semaphorin-4A, an activator for T-cell-mediated immunity, suppresses angiogenesis via Plexin-D1. EMBO J 2007; 26:1373-84. [PMID: 17318185 PMCID: PMC1817636 DOI: 10.1038/sj.emboj.7601589] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2006] [Accepted: 01/09/2007] [Indexed: 01/13/2023] Open
Abstract
Originally identified as axon guidance molecules, semaphorins are now known to be widely expressed mediators that play significant roles in immune responses and organ morphogenesis. However, not much is known about the signaling pathways via which they exert their organ-specific effects. Here we demonstrate that Sema4A, previously identified as an activator of T-cell-mediated immunity, is expressed in endothelial cells, where it suppresses vascular endothelial growth factor (VEGF)-mediated endothelial cell migration and proliferation in vitro and angiogenesis in vivo. Mice lacking Sema4A exhibit enhanced angiogenesis in response to VEGF or inflammatory stimuli. In addition, binding and functional experiments revealed Plexin-D1 to be a receptor for Sema4A on endothelial cells, indicating that Sema4A exerts organ-specific activities via different receptor-mediated signaling pathways: via Plexin-D1 in the endothelial cells and via T-cell immunoglobulin and mucin domain-2 in T cells. The effects of Sema4A on endothelial cells are dependent on its ability to suppress VEGF-mediated Rac activation and integrin-dependent cell adhesion. It thus appears that Sema4A-Plexin-D1 signaling negatively regulates angiogenesis.
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Affiliation(s)
- Toshihiko Toyofuku
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
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154
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Schmidt EF, Strittmatter SM. The CRMP family of proteins and their role in Sema3A signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 600:1-11. [PMID: 17607942 PMCID: PMC2853248 DOI: 10.1007/978-0-387-70956-7_1] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The CRMP proteins were originally identified as mediators of Sema3A signaling and neuronal differentiation. Much has been learned about the mechanism by which CRMPs regulate cellular responses to Sema3A. In this review, the evidence for CRMP as a component of the Sema3A signaling cascade and the modulation of CRMP by plexin and phosphorylation are considered. In addition, current knowledge of the function of CRMP in a variety of cellular processes, including regulation of the cytoskeleton and endocytosis, is discussed in relationship to the mechanisms of axonal growth cone Sema3A response. The secreted protein Sema3A (collapsin-1) was the first identified vertebrate semaphorin. Sema3A acts primarily as a repulsive axon guidance cue, and can cause a dramatic collapse of the growth cone lamellipodium. This process results from the redistribution of the F-actin cytoskeleton and endocytosis of the growth cone cell membrane. Neuropilin-1 (NP1) and members of the class A plexins (PlexA) form a Sema3A receptor complex, with NP1 serving as a high-affinity ligand binding partner, and PlexA transducing the signal into the cell via its large intracellular domain. Although the effect of Sema3A on growth cones was first described nearly 15 years ago, the intracellular signaling pathways that lead to the cellular effects have only recently begun to be understood. Monomeric G-proteins, various kinases, the redox protein, MICAL, and protein turnover have all been implicated in PlexA transduction. In addition, the collapsin-response-mediator protein (CRMP) family of cytosolic phosphoproteins plays a crucial role in Sema3A/NP1/PlexA signal transduction. Current knowledge regarding CRMP functions are reviewed here.
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Affiliation(s)
| | - Stephen M. Strittmatter
- Corresponding Author: Stephen M. Strittmatter—Department of Neurology, Yale University School of Medicine, New Haven, Connecticut, U.S.A.
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155
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Toyofuku T, Kikutani H. Semaphorin Signaling During Cardiac Development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 600:109-17. [PMID: 17607950 DOI: 10.1007/978-0-387-70956-7_9] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Toshihiko Toyofuku
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
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156
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von Philipsborn A, Bastmeyer M. Mechanisms of Gradient Detection: A Comparison of Axon Pathfinding with Eukaryotic Cell Migration. INTERNATIONAL REVIEW OF CYTOLOGY 2007; 263:1-62. [PMID: 17725964 DOI: 10.1016/s0074-7696(07)63001-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The detection of gradients of chemotactic cues is a common task for migrating cells and outgrowing axons. Eukaryotic gradient detection employs a spatial mechanism, meaning that the external gradient has to be translated into an intracellular signaling gradient, which affects cell polarization and directional movement. The sensitivity of gradient detection is governed by signal amplification and adaptation mechanisms. Comparison of the major signal transduction pathways underlying gradient detection in three exemplary chemotaxing cell types, Dictyostelium, neutrophils, and fibroblasts and in neuronal growth cones, reveals conserved mechanisms such as localized PI3 kinase/PIP3 signaling and a common output, the regulation of the cytoskeleton by Rho GTPases. Local protein translation plays a role in directional movement of both fibroblasts and neuronal growth cones. Ca(2+) signaling is prominently involved in growth cone gradient detection. The diversity of signaling between different cell types and its functional implications make sense in the biological context.
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Affiliation(s)
- Anne von Philipsborn
- Department of Cell Biology and Neurobiology, University of Karlsruhe, D-76131 Karlsruhe, Germany
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157
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Casazza A, Fazzari P, Tamagnone L. Semaphorin signals in cell adhesion and cell migration: functional role and molecular mechanisms. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 600:90-108. [PMID: 17607949 DOI: 10.1007/978-0-387-70956-7_8] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Cell migration is pivotal in embryo development and in the adult. During development a wide range of progenitor cells travel over long distances before undergoing terminal differentiation. Moreover, the morphogenesis of epithelial tissues and of the cardiovascular system involves remodelling compact cell layers and sprouting of new tubular branches. In the adult, cell migration is essential for leucocytes involved in immune response. Furthermore, invasive and metastatic cancer cells have the distinctive ability to overcome normal tissue boundaries, travel in and out of blood vessels, and settle down in heterologous tissues. Cell migration normally follows strict guidance cues, either attractive, or inhibitory and repulsive. Semaphorins are a wide family of signals guiding cell migration during development and in the adult. Recent findings have established that semaphorin receptors, the plexins, govern cell migration by regulating integrin-based cell substrate adhesion and actin cytoskeleton dynamics, via specific monomeric GTPases. Plexins furthermore recruit tyrosine kinases in receptor complexes, which allows switching between multiple signaling pathways and functional outcomes. In this article, we will review the functional role of semaphorins in cell migration and the implicated molecular mechanisms controlling cell adhesion.
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Affiliation(s)
- Andrea Casazza
- University of Turin Medical School, Institute for Cancer Research and Treatment, Str. Prov. 142, I-10060 Candiolo, Torino, Italy
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158
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Abstract
The semaphorin family consists of soluble and membrane-bound proteins originally identified as axonal guidance cues functioning during neuronal development. However, it is becoming increasingly clear that semaphorins play diverse roles in organogenesis, vascular growth, and tumor progression. In addition, emerging evidence indicates that several semaphorins, called "immune semaphorins," play crucial roles also during immune responses. Extensive studies on the immune semaphorins have revealed not only parallels but also differences in the semaphorin functions between the immune and nervous systems, providing unexpected but meaningful insights into the biological activities of these molecules. This chapter focuses on our current understanding of the roles of semaphorins and their receptors in the immune system.
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Affiliation(s)
- Hitoshi Kikutani
- Department of Molecular Immunology and CREST Program of JST, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 5650871, Japan
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159
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Ahmed A, Eickholt BJ. Intracellular Kinases in Semaphorin Signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 600:24-37. [PMID: 17607944 DOI: 10.1007/978-0-387-70956-7_3] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/09/2022]
Abstract
Originally identified as collapse-inducing and repellent proteins for neuronal processes, semaphorins are now implicated in a diverse array of cellular responses, contributing not only to embryonic development, but also to the maintenance of tissue integrity in the adult organism. In addition, semaphorins play a role in the pathological context. Some Semaphorins can act at a distance, facilitating the navigation of cells or axonal process, whilst others evoke responses in a contact-dependent fashion. The intracellular signaling mechanisms employed by the semaphorins are beginning to be determined, and much work in recent years implicates a host of intracellular kinases in mediating Semaphorin function. These include the tyrosine kinase Fyn and the serine/threonine kinases Cdk5, GSK3, MAPK, and LIMK, and the lipid kinase PI3K. What follows is a review of this work with respect to their functions in mediating specific semaphorin-induced responses.
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Affiliation(s)
- Aminul Ahmed
- MRC Centre for Developmental Neurobiology, King's College London, London SE1 1UL, UK
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160
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Kolk SM, Pasterkamp RJ. MICAL flavoprotein monooxygenases: structure, function and role in semaphorin signaling. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2007; 600:38-51. [PMID: 17607945 DOI: 10.1007/978-0-387-70956-7_4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
MICALs (for Molecule Interacting with CasL) form a recently discovered family of evolutionary conserved signal transduction proteins. They contain multiple well-conserved domains known for interactions with the cytoskeleton, cytoskeletal adaptor proteins, and other signaling proteins. In addition to their ability to bind other proteins, MICALs contain a large NADPH-dependent flavoprotein monooxygenase enzymatic domain. Although MICALs have already been implicated in a variety of cellular processes, their function during axonal pathfinding in the Drosophila neuromuscular system has been best characterized. During the establishment of neuromuscular connectivity in the fruit fly, MICAL binds the axon guidance receptor Plexin A and transduces semaphorin-1a-mediated repulsive axon guidance. Intriguingly, mutagenesis and pharmacological inhibitor studies suggest a role for MICAL flavoenzyme redox functions in semaphorin/plexin-mediated axonal pathfinding events. This review summarizes our current understanding of MICALs, with an emphasis on their role in semaphorin signaling.
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Affiliation(s)
- Sharon M Kolk
- Department of Pharmacology and Anatomy, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Universiteitsweg 100, 3584 CG Utrecht, The Netherlands
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161
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Nguyen QD, Rodrigues S, Rodrigue CM, Rivat C, Grijelmo C, Bruyneel E, Emami S, Attoub S, Gespach C. Inhibition of vascular endothelial growth factor (VEGF)-165 and semaphorin 3A-mediated cellular invasion and tumor growth by the VEGF signaling inhibitor ZD4190 in human colon cancer cells and xenografts. Mol Cancer Ther 2006; 5:2070-7. [PMID: 16928828 DOI: 10.1158/1535-7163.mct-06-0044] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We recently showed by DNA microarray analysis that vascular endothelial growth factor (VEGF) receptor (VEGFR) is expressed in HCT8/S11 human colon cancer cells, suggesting that several angiogenic factors may target colon cancer cells themselves. In this study, transcripts encoding the VEGF-165 and semaphorin 3A (Sema3A) receptors and coreceptors Flt-1, KDR/Flk-1, plexin A1, and neuropilins NP-1 and NP-2 were identified by reverse transcription-PCR in the human colon cancer cell lines HCT8/S11, HT29, HCT116, and PCmsrc. Collagen invasion induced by VEGF-165 and Sema3A in HCT8/S11 cells (EC(50), 0.4-1 nmol/L) required p42/44 mitogen-activated protein kinase and signaling through RhoA/Rho-kinase-dependent and -independent pathways, respectively. As expected, the VEGFR signaling inhibitor ZD4190 selectively abrogated the proinvasive activity of VEGF in collagen gels (IC(50), 10 nmol/L) and chick heart fragments. We identify a novel function for VEGF-165 and Sema3A as proinvasive factors for human colorectal cancer cells. Interestingly, oral administration of the single drug ZD4190 to athymic mice (50 mg/kg/d, once daily) inhibited by 70% the growth of HCT8/S11 tumor cell xenografts. Combinations between the src tyrosine kinase inhibitor M475271 and ZD4190 or cisplatin resulted in additive therapeutic activity against LNM35 human lung tumor xenografts. Our data have significant implications for new therapeutic approaches and individualized treatment targeting VEGFR and src signaling pathways in combination with established clinical drugs at primary tumors and distant metastases in colon and lung cancer patients.
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Affiliation(s)
- Quang-Dé Nguyen
- Institut National de la Sante et de la Recherche Medicale U673, Université Pierre et Marie Curie-Paris 6, Molecular and Clinical Oncology of Solid Tumors, Hôpital Saint-Antoine, 75571 Paris Cedex 12, France
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162
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Tarpey P, Thomas S, Sarvananthan N, Mallya U, Lisgo S, Talbot CJ, Roberts EO, Awan M, Surendran M, McLean RJ, Reinecke RD, Langmann A, Lindner S, Koch M, Woodruff G, Gale R, Degg C, Droutsas K, Asproudis I, Zubcov AA, Pieh C, Veal CD, Machado RD, Backhouse OC, Baumber L, Jain S, Constantinescu CS, Brodsky MC, Hunter DG, Hertle RW, Read RJ, Edkins S, O’Meara S, Parker A, Stevens C, Teague J, Wooster R, Futreal PA, Trembath RC, Stratton MR, Raymond FL, Gottlob I. Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus. Nat Genet 2006; 38:1242-4. [PMID: 17013395 PMCID: PMC2592600 DOI: 10.1038/ng1893] [Citation(s) in RCA: 130] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2006] [Accepted: 09/01/2006] [Indexed: 11/09/2022]
Abstract
Idiopathic congenital nystagmus is characterized by involuntary, periodic, predominantly horizontal oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 singleton cases of idiopathic congenital nystagmus (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina, suggesting a specific role in the control of eye movement and gaze stability.
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Affiliation(s)
- P Tarpey
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - S Thomas
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - N Sarvananthan
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - U Mallya
- Cambridge Institute for Medical Research, Addenbrookes Hospital Cambridge CB2 2XY UK
| | - S Lisgo
- Institute of Human Genetics, International Centre for Life, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - CJ Talbot
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - EO Roberts
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - M Awan
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - M Surendran
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - RJ McLean
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
| | - RD Reinecke
- Foerderer Eye Movement Centre for Children, Wills Eye Hospital, Philadelphia, Pennsylvania, 19107 USA
| | - A Langmann
- Medical University Graz, Department of Ophthalmology, Auenbruggerplatz 4, 8036, Graz, Austria
| | - S Lindner
- Medical University Graz, Department of Ophthalmology, Auenbruggerplatz 4, 8036, Graz, Austria
| | - M Koch
- Medical University Graz, Department of Ophthalmology, Auenbruggerplatz 4, 8036, Graz, Austria
| | - G Woodruff
- Royal Preston Hospital, Sharoe Green Lane North, Fulwood, Preston, Lancashire PR2 9HT
| | - R Gale
- Ophthalmology, Leeds General Infirmary, Leeds, LS1 3EX, UK
| | - C Degg
- Department of Medical Physics, University Hospitals of Leicester, Leicester, LE1 5WW, UK
| | - K Droutsas
- Department of Ophthalmology, Justus-Liebig-University, 35392 Giessen, Germany
| | - I Asproudis
- Department of Ophthalmology, Medical Faculty, University Hospital of Ioannina, 45110 Ioannina, Greece
| | - AA Zubcov
- University Eye Hospital, Johann-Wolfgang-Goethe-Universität, Theodor-Stern-Kai 7, 60590 Frankfurt/Main, Germany
| | - C Pieh
- University Eye Hospital, Killianstr. 5, 79106 Freiburg, Germany
| | - CD Veal
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK
| | - RD Machado
- Division of Genetics and Molecular Medicine, King’s College London SE1 9RT, UK
| | - OC Backhouse
- Ophthalmology, Leeds General Infirmary, Leeds, LS1 3EX, UK
| | - L Baumber
- Department of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK
- Division of Genetics and Molecular Medicine, King’s College London SE1 9RT, UK
| | - S Jain
- Royal Preston Hospital, Sharoe Green Lane North, Fulwood, Preston, Lancashire PR2 9HT
| | - CS Constantinescu
- Division of Clinical Neurology, School of Medical and Surgical Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
| | - MC Brodsky
- Arkansas Children’s Hospital, 800 Marshall, Little Rock, Arkansas 72202, UK
| | - DG Hunter
- Department of Ophthalmology, Children’s Hospital Boston, Harvard Medical School, Boston, Mass 02115, USA
| | - RW Hertle
- University of Pittsburgh Medical Centre, Division of Paediatric Ophthalmology, Children’s Hospital of Pittsburgh, 3705 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - RJ Read
- Cambridge Institute for Medical Research, Addenbrookes Hospital Cambridge CB2 2XY UK
| | - S Edkins
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - S O’Meara
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - A Parker
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - C Stevens
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - J Teague
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - R Wooster
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - PA Futreal
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - RC Trembath
- Division of Genetics and Molecular Medicine, King’s College London SE1 9RT, UK
| | - MR Stratton
- Wellcome Trust Sanger Institute, Hinxton Cambridge CB10 1SA UK
| | - FL Raymond
- Cambridge Institute for Medical Research, Addenbrookes Hospital Cambridge CB2 2XY UK
- Joint senior authors and corresponding authors and
| | - I Gottlob
- Ophthalmology Group, School of Medicine, University of Leicester, RKCSB, PO Box 65, Leicester, LE2 7LX, UK
- Joint senior authors and corresponding authors and
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163
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Berndt JD, Halloran MC. Semaphorin 3d promotes cell proliferation and neural crest cell development downstream of TCF in the zebrafish hindbrain. Development 2006; 133:3983-92. [PMID: 16971468 DOI: 10.1242/dev.02583] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Neural crest cells (NCCs) are pluripotent migratory cells that are crucial to the development of the peripheral nervous system, pigment cells and craniofacial cartilage and bone. NCCs are specified within the dorsal ectoderm and undergo an epithelial to mesenchymal transition (EMT) in order to migrate to target destinations where they differentiate. Here we report a role for a member of the semaphorin family of cell guidance molecules in NCC development. Morpholino-mediated knockdown of Sema3d inhibits the proliferation of hindbrain neuroepithelial cells. In addition, Sema3d knockdown reduces markers of migratory NCCs and disrupts NCC-derived tissues. Similarly, expression of a dominant-repressor form of TCF (DeltaTCF) reduces hindbrain cell proliferation and leads to a disruption of migratory NCC markers. Moreover, expression of DeltaTCF downregulates sema3d RNA expression. Finally, Sema3d overexpression rescues reduced proliferation caused by DeltaTCF expression, suggesting that Sema3d lies downstream of Wnt/TCF signaling in the molecular pathway thought to control cell cycle in NCC precursors.
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Affiliation(s)
- Jason D Berndt
- Department of Zoology and Anatomy and Neuroscience Training Program, University of Wisconsin, Madison, WI 53706, USA
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164
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Halloran MC, Wolman MA. Repulsion or adhesion: receptors make the call. Curr Opin Cell Biol 2006; 18:533-40. [PMID: 16930978 DOI: 10.1016/j.ceb.2006.08.010] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2006] [Accepted: 08/04/2006] [Indexed: 12/31/2022]
Abstract
Repulsive signaling plays a prominent role in regulating cell-cell interactions and is fundamental to multiple developmental processes. A proper balance between repulsion from and adhesion to other cells or the extracellular matrix is also important. Semaphorin-Plexin and ephrin-Eph ligand-receptor pairs compose two major repulsive signaling systems. Recent advances have elucidated mechanisms by which Semaphorin-Plexin and ephrin-Eph signaling control repulsion versus adhesion. Semaphorins act through a complex signaling pathway to inhibit integrin-mediated adhesion, allowing cell repulsion. Ephrin-Eph interactions can directly mediate cell adhesion and several mechanisms control whether ephrin-Eph binding and signaling induces repulsion or adhesion.
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165
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Ito Y, Oinuma I, Katoh H, Kaibuchi K, Negishi M. Sema4D/plexin-B1 activates GSK-3beta through R-Ras GAP activity, inducing growth cone collapse. EMBO Rep 2006; 7:704-9. [PMID: 16799460 PMCID: PMC1500830 DOI: 10.1038/sj.embor.7400737] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2005] [Revised: 01/13/2006] [Accepted: 05/24/2006] [Indexed: 11/08/2022] Open
Abstract
Plexins are receptors for the axonal guidance molecules known as semaphorins, and the semaphorin 4D (Sema4D) receptor plexin-B1 induces repulsive responses by functioning as an R-Ras GTPase-activating protein (GAP). Here we characterized the downstream signalling of plexin-B1-mediated R-Ras GAP activity, inducing growth cone collapse. Sema4D suppressed R-Ras activity in hippocampal neurons, in parallel with dephosphorylation of Akt and activation of glycogen synthase kinase (GSK)-3beta. Ectopic expression of the constitutively active mutant of Akt or treatment with GSK-3 inhibitors suppressed the Sema4D-induced growth cone collapse. Constitutive activation of phosphatidylinositol-3-OH kinase (PI(3)K), an upstream kinase of Akt and GSK-3beta, also blocked the growth cone collapse. The R-Ras GAP activity was necessary for plexin-B1-induced dephosphorylation of Akt and activation of GSK-3beta and was also required for phosphorylation of a downstream kinase of GSK-3beta, collapsin response mediator protein-2. Plexin-A1 also induced dephosphorylation of Akt and GSK-3beta through its R-Ras GAP activity. We conclude that plexin-B1 inactivates PI(3)K and dephosphorylates Akt and GSK-3beta through R-Ras GAP activity, inducing growth cone collapse.
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Affiliation(s)
- Yuri Ito
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshida konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Izumi Oinuma
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshida konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Hironori Katoh
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshida konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kozo Kaibuchi
- Department of Cell Pharmacology, Graduate School of Medicine, Nagoya University, 65 Tsurumi, Showa, Nagoya 466-8550, Japan
| | - Manabu Negishi
- Laboratory of Molecular Neurobiology, Graduate School of Biostudies, Kyoto University, Yoshida konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan
- Tel: +81 75 753 4547; Fax: +81 75 753 7688; E-mail:
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Ayoob JC, Terman JR, Kolodkin AL. DrosophilaPlexin B is a Sema-2a receptor required for axon guidance. Development 2006; 133:2125-35. [PMID: 16672342 DOI: 10.1242/dev.02380] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Plexin receptors play a crucial role in the transduction of axonal guidance events elicited by semaphorin proteins. In Drosophila, Plexin A(PlexA) is a receptor for the transmembrane semaphorin semaphorin-1a (Sema-1a)and is required for motor and central nervous system (CNS) axon guidance in the developing embryonic nervous system. However, it remains unknown how PlexB functions during neural development and which ligands serve to activate this receptor. Here, we show that plexB, like plexA, is robustly expressed in the developing CNS and is required for motor and CNS axon pathfinding. PlexB and PlexA serve both distinct and shared neuronal guidance functions. We observe a physical association between these two plexin receptors in vivo and find that they can utilize common downstream signaling mechanisms. PlexB does not directly bind to the cytosolic semaphorin signaling component MICAL (molecule that interacts with CasL), but requires MICAL for certain axonal guidance functions. Ligand binding and genetic analyses demonstrate that PlexB is a receptor for the secreted semaphorin Sema-2a,suggesting that secreted and transmembrane semaphorins in Drosophilause PlexB and PlexA, respectively, for axon pathfinding during neural development. These results establish roles for PlexB in central and peripheral axon pathfinding, define a functional ligand for PlexB, and implicate common signaling events in plexin-mediated axonal guidance.
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Affiliation(s)
- Joseph C Ayoob
- Howard Hughes Medical Institute, Solomon H. Snyder Department of Neuroscience, The Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Morita A, Yamashita N, Sasaki Y, Uchida Y, Nakajima O, Nakamura F, Yagi T, Taniguchi M, Usui H, Katoh-Semba R, Takei K, Goshima Y. Regulation of dendritic branching and spine maturation by semaphorin3A-Fyn signaling. J Neurosci 2006; 26:2971-80. [PMID: 16540575 PMCID: PMC6673984 DOI: 10.1523/jneurosci.5453-05.2006] [Citation(s) in RCA: 132] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A member of semaphorin family, semaphorin3A (Sema3A), acts as a chemorepellent or chemoattractant on a wide variety of axons and dendrites in the development of the nervous systems. We here show that Sema3A induces clustering of both postsynaptic density-95 (PSD-95) and presynaptic synapsin I in cultured cortical neurons without changing the density of spines or filopodia. Neuropilin-1 (NRP-1), a receptor for Sema3A, is present on both axons and dendrites. When the cultured neurons are exposed to Sema3A, the cluster size of PSD-95 is markedly enhanced, and an extensive colocalization of PSD-95 and NRP-1 or actin-rich protrusion is seen. The effects of Sema3A on spine morphology are blocked by PP2, an Src type tyrosine kinase inhibitor, but not by the PP3, the inactive-related compound. In the cultured cortical neurons from fyn(-/-) mice, dendrites bear few spines, and Sema3A does not induce PSD-95 cluster formation on the dendrites. Sema3A and its receptor genes are highly expressed during the synaptogenic period of postnatal days 10 and 15. The cortical neurons in layer V, but not layer III, show a lowered density of synaptic bouton-like structure on dendrites in sema3A- and fyn-deficient mice. The neurons of the double-heterozygous mice show the lowered spine density, whereas those of single heterozygous mice show similar levels of the spine density as the wild type. These findings suggest that the Sema3A signaling pathway plays an important role in the regulation of dendritic spine maturation in the cerebral cortex neurons.
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Abstract
Semaphorins are secreted, transmembrane, and GPI-linked proteins, defined by cysteine-rich semaphorin protein domains, that have important roles in a variety of tissues. Humans have 20 semaphorins, Drosophila has five, and two are known from DNA viruses; semaphorins are also found in nematodes and crustaceans but not in non-animals. They are grouped into eight classes on the basis of phylogenetic tree analyses and the presence of additional protein motifs. The expression of semaphorins has been described most fully in the nervous system, but they are also present in most, or perhaps all, other tissues. Functionally, semaphorins were initially characterized for their importance in the development of the nervous system and in axonal guidance. More recently, they have been found to be important for the formation and functioning of the cardiovascular, endocrine, gastrointestinal, hepatic, immune, musculoskeletal, renal, reproductive, and respiratory systems. A common theme in the mechanisms of semaphorin function is that they alter the cytoskeleton and the organization of actin filaments and the microtubule network. These effects occur primarily through binding of semaphorins to their receptors, although transmembrane semaphorins also serve as receptors themselves. The best characterized receptors for mediating semaphorin signaling are members of the neuropilin and plexin families of transmembrane proteins. Plexins, in particular, are thought to control many of the functional effects of semaphorins; the molecular mechanisms of semaphorin signaling are still poorly understood, however. Given the importance of semaphorins in a wide range of functions, including neural connectivity, angiogenesis, immunoregulation, and cancer, much remains to be learned about these proteins and their roles in pathology and human disease.
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Affiliation(s)
- Umar Yazdani
- Center for Basic Neuroscience, Department of Pharmacology, NA4.301/5323 Harry Hines Blvd, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jonathan R Terman
- Center for Basic Neuroscience, Department of Pharmacology, NA4.301/5323 Harry Hines Blvd, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
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