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Breau MA, Trembleau A. Chemical and mechanical control of axon fasciculation and defasciculation. Semin Cell Dev Biol 2023; 140:72-81. [PMID: 35810068 DOI: 10.1016/j.semcdb.2022.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/14/2022] [Accepted: 06/21/2022] [Indexed: 01/28/2023]
Abstract
Neural networks are constructed through the development of robust axonal projections from individual neurons, which ultimately establish connections with their targets. In most animals, developing axons assemble in bundles to navigate collectively across various areas within the central nervous system or the periphery, before they separate from these bundles in order to find their specific targets. These processes, called fasciculation and defasciculation respectively, were thought for many years to be controlled chemically: while guidance cues may attract or repulse axonal growth cones, adhesion molecules expressed at the surface of axons mediate their fasciculation. Recently, an additional non-chemical parameter, the mechanical longitudinal tension of axons, turned out to play a role in axon fasciculation and defasciculation, through zippering and unzippering of axon shafts. In this review, we present an integrated view of the currently known chemical and mechanical control of axon:axon dynamic interactions. We highlight the facts that the decision to cross or not to cross another axon depends on a combination of chemical, mechanical and geometrical parameters, and that the decision to fasciculate/defasciculate through zippering/unzippering relies on the balance between axon:axon adhesion and their mechanical tension. Finally, we speculate about possible functional implications of zippering-dependent axon shaft fasciculation, in the collective migration of axons, and in the sorting of subpopulations of axons.
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Affiliation(s)
- Marie Anne Breau
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS UMR 7622), Institut de Biologie Paris Seine (IBPS), Developmental Biology Laboratory, Paris, France
| | - Alain Trembleau
- Sorbonne Université, Centre National de la Recherche Scientifique (CNRS UMR8246), Inserm U1130, Institut de Biologie Paris Seine (IBPS), Neuroscience Paris Seine (NPS), Paris, France.
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2
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Kim JH, Kim K, Kim I, Seong S, Koh JT, Kim N. Overexpression of Neurogenin 1 Negatively Regulates Osteoclast and Osteoblast Differentiation. Int J Mol Sci 2022; 23:ijms23126708. [PMID: 35743149 PMCID: PMC9223505 DOI: 10.3390/ijms23126708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 02/05/2023] Open
Abstract
Neurogenin 1 (Ngn1) belongs to the basic helix–loop–helix (bHLH) transcription factor family and plays important roles in specifying neuronal differentiation. The present study aimed to determine whether forced Ngn1 expression contributes to bone homeostasis. Ngn1 inhibited the p300/CREB-binding protein-associated factor (PCAF)-induced acetylation of nuclear factor of activated T cells 1 (NFATc1) and runt-related transcription factor 2 (Runx2) through binding to PCAF, which led to the inhibition of osteoclast and osteoblast differentiation, respectively. In addition, Ngn1 overexpression inhibited the TNF-α- and IL-17A-mediated enhancement of osteoclast differentiation and IL-17A-induced osteoblast differentiation. These findings indicate that Ngn1 can serve as a novel therapeutic agent for treating ankylosing spondylitis with abnormally increased bone formation and resorption.
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Affiliation(s)
- Jung Ha Kim
- Department of Pharmacology, Chonnam National University Medical School, Gwangju 61469, Korea; (J.H.K.); (K.K.); (I.K.); (S.S.)
- Hard-Tissue Biointerface Research Center, School of Dentistry, Chonnam National University, Gwangju 61186, Korea;
| | - Kabsun Kim
- Department of Pharmacology, Chonnam National University Medical School, Gwangju 61469, Korea; (J.H.K.); (K.K.); (I.K.); (S.S.)
| | - Inyoung Kim
- Department of Pharmacology, Chonnam National University Medical School, Gwangju 61469, Korea; (J.H.K.); (K.K.); (I.K.); (S.S.)
| | - Semun Seong
- Department of Pharmacology, Chonnam National University Medical School, Gwangju 61469, Korea; (J.H.K.); (K.K.); (I.K.); (S.S.)
- Hard-Tissue Biointerface Research Center, School of Dentistry, Chonnam National University, Gwangju 61186, Korea;
| | - Jeong-Tae Koh
- Hard-Tissue Biointerface Research Center, School of Dentistry, Chonnam National University, Gwangju 61186, Korea;
- Department of Pharmacology and Dental Therapeutics, School of Dentistry, Chonnam National University, Gwangju 61186, Korea
| | - Nacksung Kim
- Department of Pharmacology, Chonnam National University Medical School, Gwangju 61469, Korea; (J.H.K.); (K.K.); (I.K.); (S.S.)
- Hard-Tissue Biointerface Research Center, School of Dentistry, Chonnam National University, Gwangju 61186, Korea;
- Correspondence: ; Tel.: +82-61-379-2835
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Chu LY, Huang BL, Huang XC, Peng YH, Xie JJ, Xu YW. EFNA1 in gastrointestinal cancer: Expression, regulation and clinical significance. World J Gastrointest Oncol 2022; 14:973-988. [PMID: 35646281 PMCID: PMC9124989 DOI: 10.4251/wjgo.v14.i5.973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 09/17/2021] [Accepted: 04/04/2022] [Indexed: 02/06/2023] Open
Abstract
Ephrin-A1 is a protein that in humans is encoded by the EFNA1 gene. The ephrins and EPH-related receptors comprise the largest subfamily of receptor protein-tyrosine kinases which play an indispensable role in normal growth and development or in the pathophysiology of various tumors. The role of EFNA1 in tumorigenesis and development is complex and depends on the cell type and microenvironment which in turn affect the expression of EFNA1. This article reviews the expression, prognostic value, regulation and clinical significance of EFNA1 in gastrointestinal tumors.
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Affiliation(s)
- Ling-Yu Chu
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong Province, China
| | - Bin-Liang Huang
- Department of Clinical Laboratory Medicine, The Cancer Hospital of Shantou University Medical College, Shantou 515041, Guangdong Province, China
| | - Xu-Chun Huang
- Department of Clinical Laboratory Medicine, The Cancer Hospital of Shantou University Medical College, Shantou 515041, Guangdong Province, China
| | - Yu-Hui Peng
- Department of Clinical Laboratory Medicine, The Cancer Hospital of Shantou University Medical College, Shantou 515041, Guangdong Province, China
- Guangdong Esophageal Cancer Research Institute, The Cancer Hospital of Shantou University Medical College, Shantou 515041, Guangdong Province, China
| | - Jian-Jun Xie
- Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong Province, China
| | - Yi-Wei Xu
- Department of Clinical Laboratory Medicine, The Cancer Hospital of Shantou University Medical College, Shantou 515041, Guangdong Province, China
- Guangdong Esophageal Cancer Research Institute, The Cancer Hospital of Shantou University Medical College, Shantou 515041, Guangdong Province, China
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4
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Moreland T, Poulain FE. To Stick or Not to Stick: The Multiple Roles of Cell Adhesion Molecules in Neural Circuit Assembly. Front Neurosci 2022; 16:889155. [PMID: 35573298 PMCID: PMC9096351 DOI: 10.3389/fnins.2022.889155] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 03/28/2022] [Indexed: 01/02/2023] Open
Abstract
Precise wiring of neural circuits is essential for brain connectivity and function. During development, axons respond to diverse cues present in the extracellular matrix or at the surface of other cells to navigate to specific targets, where they establish precise connections with post-synaptic partners. Cell adhesion molecules (CAMs) represent a large group of structurally diverse proteins well known to mediate adhesion for neural circuit assembly. Through their adhesive properties, CAMs act as major regulators of axon navigation, fasciculation, and synapse formation. While the adhesive functions of CAMs have been known for decades, more recent studies have unraveled essential, non-adhesive functions as well. CAMs notably act as guidance cues and modulate guidance signaling pathways for axon pathfinding, initiate contact-mediated repulsion for spatial organization of axonal arbors, and refine neuronal projections during circuit maturation. In this review, we summarize the classical adhesive functions of CAMs in axonal development and further discuss the increasing number of other non-adhesive functions CAMs play in neural circuit assembly.
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Holt E, Stanton-Turcotte D, Iulianella A. Development of the Vertebrate Trunk Sensory System: Origins, Specification, Axon Guidance, and Central Connectivity. Neuroscience 2021; 458:229-243. [PMID: 33460728 DOI: 10.1016/j.neuroscience.2020.12.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 12/09/2020] [Accepted: 12/31/2020] [Indexed: 12/26/2022]
Abstract
Crucial to an animal's movement through their environment and to the maintenance of their homeostatic physiology is the integration of sensory information. This is achieved by axons communicating from organs, muscle spindles and skin that connect to the sensory ganglia composing the peripheral nervous system (PNS), enabling organisms to collect an ever-constant flow of sensations and relay it to the spinal cord. The sensory system carries a wide spectrum of sensory modalities - from sharp pain to cool refreshing touch - traveling from the periphery to the spinal cord via the dorsal root ganglia (DRG). This review covers the origins and development of the DRG and the cells that populate it, and focuses on how sensory connectivity to the spinal cord is achieved by the diverse developmental and molecular processes that control axon guidance in the trunk sensory system. We also describe convergences and differences in sensory neuron formation among different vertebrate species to gain insight into underlying developmental mechanisms.
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Affiliation(s)
- Emily Holt
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, and Brain Repair Centre, Life Science Research Institute, 1348 Summer Street, Halifax, Nova Scotia B3H-4R2, Canada
| | - Danielle Stanton-Turcotte
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, and Brain Repair Centre, Life Science Research Institute, 1348 Summer Street, Halifax, Nova Scotia B3H-4R2, Canada
| | - Angelo Iulianella
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, and Brain Repair Centre, Life Science Research Institute, 1348 Summer Street, Halifax, Nova Scotia B3H-4R2, Canada.
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Abeynayake N, Arthur A, Gronthos S. Crosstalk between skeletal and neural tissues is critical for skeletal health. Bone 2021; 142:115645. [PMID: 32949783 DOI: 10.1016/j.bone.2020.115645] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 09/09/2020] [Accepted: 09/10/2020] [Indexed: 12/24/2022]
Abstract
Emerging evidence in the literature describes a physical and functional association between the neural and skeletal systems that forms a neuro-osteogenic network. This communication between bone cells and neural tissues within the skeleton is important in facilitating bone skeletal growth, homeostasis and repair. The growth and repair of the skeleton is dependent on correct neural innervation for correct skeletal developmental growth and fracture repair, while pathological conditions such as osteoporosis are accelerated by disruptions to sympathetic innervation. To date, different molecular mechanisms have been reported to mediate communication between bone and neural populations. This review highlights the important role of various cell surface receptors, cytokines and associated ligands as potential regulators of skeletal development, homeostasis, and repair, by mediating interactions between the skeletal and nervous systems. Specifically, this review describes how Bone Morphogenetic Proteins (BMPs), Eph/ephrin, Chemokine CXCL12, Calcitonin Gene-related Peptide (CGRP), Netrins, Neurotrophins (NTs), Slit/Robo and the Semaphorins (Semas) contribute to the cross talk between bone cells and peripheral nerves, and the importance of these interactions in maintaining skeletal health.
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Affiliation(s)
- Nethmi Abeynayake
- Mesenchymal Stem Cell Laboratory, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia; Precision Medicine Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Agnieszka Arthur
- Mesenchymal Stem Cell Laboratory, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia; Precision Medicine Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia
| | - Stan Gronthos
- Mesenchymal Stem Cell Laboratory, Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA, Australia; Precision Medicine Theme, South Australian Health and Medical Research Institute, Adelaide, SA, Australia.
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Suter TACS, Blagburn SV, Fisher SE, Anderson-Keightly HM, D'Elia KP, Jaworski A. TAG-1 Multifunctionality Coordinates Neuronal Migration, Axon Guidance, and Fasciculation. Cell Rep 2020; 30:1164-1177.e7. [PMID: 31995756 PMCID: PMC7049094 DOI: 10.1016/j.celrep.2019.12.085] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 10/25/2019] [Accepted: 12/22/2019] [Indexed: 11/03/2022] Open
Abstract
Neuronal migration, axon fasciculation, and axon guidance need to be closely coordinated for neural circuit assembly. Spinal motor neurons (MNs) face unique challenges during development because their cell bodies reside within the central nervous system (CNS) and their axons project to various targets in the body periphery. The molecular mechanisms that contain MN somata within the spinal cord while allowing their axons to exit the CNS and navigate to their final destinations remain incompletely understood. We find that the MN cell surface protein TAG-1 anchors MN cell bodies in the spinal cord to prevent their emigration, mediates motor axon fasciculation during CNS exit, and guides motor axons past dorsal root ganglia. TAG-1 executes these varied functions in MN development independently of one another. Our results identify TAG-1 as a key multifunctional regulator of MN wiring that coordinates neuronal migration, axon fasciculation, and axon guidance. Suter et al. demonstrate that the motor neuron cell surface molecule TAG-1 confines motor neurons to the central nervous system, promotes motor axon fasciculation, and steers motor axons past inappropriate targets. This study highlights how a single cell adhesion molecule coordinates multiple steps in neuronal wiring through partially divergent mechanisms.
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Affiliation(s)
- Tracey A C S Suter
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA
| | - Sara V Blagburn
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA
| | - Sophie E Fisher
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA
| | | | - Kristen P D'Elia
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Department of Biology, Providence College, Providence, RI 02918, USA
| | - Alexander Jaworski
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912, USA.
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Renthal W, Tochitsky I, Yang L, Cheng YC, Li E, Kawaguchi R, Geschwind DH, Woolf CJ. Transcriptional Reprogramming of Distinct Peripheral Sensory Neuron Subtypes after Axonal Injury. Neuron 2020; 108:128-144.e9. [PMID: 32810432 PMCID: PMC7590250 DOI: 10.1016/j.neuron.2020.07.026] [Citation(s) in RCA: 230] [Impact Index Per Article: 57.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 05/27/2020] [Accepted: 07/22/2020] [Indexed: 12/27/2022]
Abstract
Primary somatosensory neurons are specialized to transmit specific types of sensory information through differences in cell size, myelination, and the expression of distinct receptors and ion channels, which together define their transcriptional and functional identity. By profiling sensory ganglia at single-cell resolution, we find that all somatosensory neuronal subtypes undergo a similar transcriptional response to peripheral nerve injury that both promotes axonal regeneration and suppresses cell identity. This transcriptional reprogramming, which is not observed in non-neuronal cells, resolves over a similar time course as target reinnervation and is associated with the restoration of original cell identity. Injury-induced transcriptional reprogramming requires ATF3, a transcription factor that is induced rapidly after injury and necessary for axonal regeneration and functional recovery. Our findings suggest that transcription factors induced early after peripheral nerve injury confer the cellular plasticity required for sensory neurons to transform into a regenerative state.
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Affiliation(s)
- William Renthal
- Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, 60 Fenwood Rd., Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA.
| | - Ivan Tochitsky
- Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, 3 Blackfan Cir., Boston, MA 02115, USA
| | - Lite Yang
- Department of Neurology, Brigham and Women's Hospital and Harvard Medical School, 60 Fenwood Rd., Boston, MA 02115, USA; Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, 3 Blackfan Cir., Boston, MA 02115, USA
| | - Yung-Chih Cheng
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, 3 Blackfan Cir., Boston, MA 02115, USA
| | - Emmy Li
- Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA
| | - Riki Kawaguchi
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Daniel H Geschwind
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Clifford J Woolf
- Department of Neurobiology, Harvard Medical School, 220 Longwood Ave., Boston, MA 02115, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, 3 Blackfan Cir., Boston, MA 02115, USA.
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Trans-Axonal Signaling in Neural Circuit Wiring. Int J Mol Sci 2020; 21:ijms21145170. [PMID: 32708320 PMCID: PMC7404203 DOI: 10.3390/ijms21145170] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/15/2020] [Accepted: 07/17/2020] [Indexed: 12/24/2022] Open
Abstract
The development of neural circuits is a complex process that relies on the proper navigation of axons through their environment to their appropriate targets. While axon–environment and axon–target interactions have long been known as essential for circuit formation, communication between axons themselves has only more recently emerged as another crucial mechanism. Trans-axonal signaling governs many axonal behaviors, including fasciculation for proper guidance to targets, defasciculation for pathfinding at important choice points, repulsion along and within tracts for pre-target sorting and target selection, repulsion at the target for precise synaptic connectivity, and potentially selective degeneration for circuit refinement. This review outlines the recent advances in identifying the molecular mechanisms of trans-axonal signaling and discusses the role of axon–axon interactions during the different steps of neural circuit formation.
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Kischel A, Audouard C, Fawal MA, Davy A. Ephrin-B2 paces neuronal production in the developing neocortex. BMC DEVELOPMENTAL BIOLOGY 2020; 20:12. [PMID: 32404061 PMCID: PMC7222552 DOI: 10.1186/s12861-020-00215-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 04/19/2020] [Indexed: 01/19/2023]
Abstract
Background During mammalian cerebral cortex development, different types of projection neurons are produced in a precise temporal order and in stereotypical numbers. The mechanisms regulating timely generation of neocortex projection neurons and ensuring production in sufficient numbers of each neuronal identity are only partially understood. Results Here, we show that ephrin-B2, a member of the Eph:ephrin cell-to-cell communication pathway, sets the neurogenic tempo in the neocortex. Indeed, conditional mutant embryos for ephrin-B2 exhibit a transient delay in neurogenesis and acute stimulation of Eph signaling by in utero injection of synthetic ephrin-B2 led to a transient increase in neuronal production. Using genetic approaches we show that ephrin-B2 acts on neural progenitors to control their differentiation in a juxtacrine manner. Unexpectedly, we observed that perinatal neuron numbers recovered following both loss and gain of ephrin-B2, highlighting the ability of neural progenitors to adapt their behavior to the state of the system in order to produce stereotypical numbers of neurons. Conclusions Altogether, our data uncover a role for ephrin-B2 in embryonic neurogenesis and emphasize the plasticity of neuronal production in the neocortex.
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Affiliation(s)
- Anthony Kischel
- Centre de Biologie Intégrative (CBI), Centre de Biologie du Développement (CBD), Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse, France
| | - Christophe Audouard
- Centre de Biologie Intégrative (CBI), Centre de Biologie du Développement (CBD), Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse, France
| | - Mohamad-Ali Fawal
- Centre de Biologie Intégrative (CBI), Centre de Biologie du Développement (CBD), Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse, France
| | - Alice Davy
- Centre de Biologie Intégrative (CBI), Centre de Biologie du Développement (CBD), Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062, Toulouse, France.
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Yip ZC, Heiman MG. Ordered arrangement of dendrites within a C. elegans sensory nerve bundle. eLife 2018; 7:e35825. [PMID: 30117807 PMCID: PMC6133548 DOI: 10.7554/elife.35825] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 08/14/2018] [Indexed: 01/06/2023] Open
Abstract
Biological systems are organized into well-ordered structures and can evolve new patterns when perturbed. To identify principles underlying biological order, we turned to C. elegans for its simple anatomy and powerful genetics. We developed a method to quantify the arrangement of three dendrites in the main sensory nerve bundle, and found that they exhibit a stereotyped arrangement throughout larval growth. Dendrite order does not require prominent features including sensory cilia and glial junctions. In contrast, loss of the cell adhesion molecule (CAM) CDH-4/Fat-like cadherin causes dendrites to be ordered randomly, despite remaining bundled. Loss of the CAMs PTP-3/LAR or SAX-7/L1CAM causes dendrites to adopt an altered order, which becomes increasingly random as animals grow. Misexpression of SAX-7 leads to subtle but reproducible changes in dendrite order. Our results suggest that combinations of CAMs allow dendrites to self-organize into a stereotyped arrangement and can produce altered patterns when perturbed.
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Affiliation(s)
- Zhiqi Candice Yip
- Division of Genetics and GenomicsBoston Children’s HospitalBostonUnited States
- Department of GeneticsHarvard Medical SchoolBostonUnited States
| | - Maxwell G Heiman
- Division of Genetics and GenomicsBoston Children’s HospitalBostonUnited States
- Department of GeneticsHarvard Medical SchoolBostonUnited States
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12
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Guidance of motor axons: where do we stand? CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2018.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
Motor neurons of the spinal cord are responsible for the assembly of neuromuscular connections indispensable for basic locomotion and skilled movements. A precise spatial relationship exists between the position of motor neuron cell bodies in the spinal cord and the course of their axonal projections to peripheral muscle targets. Motor neuron innervation of the vertebrate limb is a prime example of this topographic organization and by virtue of its accessibility and predictability has provided access to fundamental principles of motor system development and neuronal guidance. The seemingly basic binary map established by genetically defined motor neuron subtypes that target muscles in the limb is directed by a surprisingly large number of directional cues. Rather than being simply redundant, these converging signaling pathways are hierarchically linked and cooperate to increase the fidelity of axon pathfinding decisions. A current priority is to determine how multiple guidance signals are integrated by individual growth cones and how they synergize to delineate class-specific axonal trajectories.
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Affiliation(s)
- Dario Bonanomi
- Molecular Neurobiology Laboratory, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy.
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14
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Laussu J, Audouard C, Kischel A, Assis-Nascimento P, Escalas N, Liebl DJ, Soula C, Davy A. Eph/Ephrin Signaling Controls Progenitor Identities In The Ventral Spinal Cord. Neural Dev 2017; 12:10. [PMID: 28595615 PMCID: PMC5463316 DOI: 10.1186/s13064-017-0087-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 05/31/2017] [Indexed: 02/01/2023] Open
Abstract
Background In the vertebrate spinal cord, motor neurons (MN) are generated in stereotypical numbers from a pool of dedicated progenitors (pMN) whose number depends on signals that control their specification but also their proliferation and differentiation rates. Although the initial steps of pMN specification have been extensively studied, how pMN numbers are regulated over time is less well characterized. Results Here, we show that ephrinB2 and ephrinB3 are differentially expressed in progenitor domains in the ventral spinal cord with several Eph receptors more broadly expressed. Genetic loss-of-function analyses show that ephrinB2 and ephrinB3 inversely control pMN numbers and that these changes in progenitor numbers correlate with changes in motor neuron numbers. Detailed phenotypic analyses by immunostaining and genetic interaction studies between ephrinB2 and Shh indicate that changes in pMN numbers in ephrin mutants are due to alteration in progenitor identity at late stages of development. Conclusions Altogether our data reveal that Eph:ephrin signaling is required to control progenitor identities in the ventral spinal cord. Electronic supplementary material The online version of this article (doi:10.1186/s13064-017-0087-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julien Laussu
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France.,Present address: CRBM, 1919 route de Mende, 34293, Montpellier, France
| | - Christophe Audouard
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Anthony Kischel
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Poincyane Assis-Nascimento
- University of Miami Miller School of Medicine, The Miami Project to Cure Paralysis, 1095 NW 14th Terrace, Miami, FL, R-48, USA
| | - Nathalie Escalas
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Daniel J Liebl
- University of Miami Miller School of Medicine, The Miami Project to Cure Paralysis, 1095 NW 14th Terrace, Miami, FL, R-48, USA
| | - Cathy Soula
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France
| | - Alice Davy
- Centre de Biologie du Développement (CBD), Centre de Biologie Intégrative (CBI), Université de Toulouse, CNRS, UPS, 118 Route de Narbonne, 31062, Toulouse, France.
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15
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Lu P, Shih C, Qi H. Ephrin B1-mediated repulsion and signaling control germinal center T cell territoriality and function. Science 2017; 356:science.aai9264. [PMID: 28408722 DOI: 10.1126/science.aai9264] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 01/03/2017] [Accepted: 03/31/2017] [Indexed: 12/11/2022]
Abstract
Follicular T helper (TFH) cells orchestrate the germinal center (GC) reaction locally. Local mechanisms regulating their dynamics and helper functions are not well defined. Here we found that GC-expressed ephrin B1 (EFNB1) repulsively inhibited T cell to B cell adhesion and GC TFH retention by signaling through TFH-expressed EPHB6 receptor. At the same time, EFNB1 promoted interleukin-21 production from GC TFH cells by signaling predominantly through EPHB4. Consequently, EFNB1-null GCs were associated with defective production of plasma cells despite harboring excessive TFH cells. In a competitive GC reaction, EFNB1-deficient B cells more efficiently interacted with TFH cells and produced more bone-marrow plasma cells, likely as a result of gaining more contact-dependent help. Our results reveal a contact-dependent repulsive guidance system that controls GC TFH dynamics and effector functions locally.
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Affiliation(s)
- Peiwen Lu
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China.,Laboratory of Dynamic Immunobiology, Institute for Immunology, Tsinghua University, Beijing 100084, China.,Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Changming Shih
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China.,Laboratory of Dynamic Immunobiology, Institute for Immunology, Tsinghua University, Beijing 100084, China.,Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Hai Qi
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China. .,Laboratory of Dynamic Immunobiology, Institute for Immunology, Tsinghua University, Beijing 100084, China.,Department of Basic Medical Sciences, School of Medicine, Tsinghua University, Beijing 100084, China.,School of Life Sciences, Tsinghua University, Beijing 100084, China
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16
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Bold J, Sakata-Haga H, Fukui Y. Spinal nerve defects in mouse embryos prenatally exposed to valproic acid. Anat Sci Int 2016; 93:35-41. [DOI: 10.1007/s12565-016-0363-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 08/05/2016] [Indexed: 01/01/2023]
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17
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Rundle CH, Xing W, Lau KHW, Mohan S. Bidirectional ephrin signaling in bone. Osteoporos Sarcopenia 2016; 2:65-76. [PMID: 30775469 PMCID: PMC6372807 DOI: 10.1016/j.afos.2016.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 04/27/2016] [Accepted: 05/04/2016] [Indexed: 12/12/2022] Open
Abstract
The interaction between ephrin ligands (efn) and their receptors (Eph) is capable of inducing forward signaling, from ligand to receptor, as well as reverse signaling, from receptor to ligand. The ephrins are widely expressed in many tissues, where they mediate cell migration and adherence, properties that make the efn-Eph signaling critically important in establishing and maintaining tissue boundaries. The efn-Eph system has also received considerable attention in skeletal tissues, as ligand and receptor combinations are predicted to mediate interactions between the different types of cells that regulate bone development and homeostasis. This review summarizes our current understanding of efn-Eph signaling with a particular focus on the expression and functions of ephrins and their receptors in bone.
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Affiliation(s)
- Charles H Rundle
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, 11201 Benton St, Loma Linda, CA 92357, USA.,Department of Medicine, Loma Linda University, Loma Linda, CA 92354, USA
| | - Weirong Xing
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, 11201 Benton St, Loma Linda, CA 92357, USA.,Department of Medicine, Loma Linda University, Loma Linda, CA 92354, USA
| | - Kin-Hing William Lau
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, 11201 Benton St, Loma Linda, CA 92357, USA.,Department of Medicine, Loma Linda University, Loma Linda, CA 92354, USA
| | - Subburaman Mohan
- Musculoskeletal Disease Center, VA Loma Linda Healthcare System, 11201 Benton St, Loma Linda, CA 92357, USA.,Department of Medicine, Loma Linda University, Loma Linda, CA 92354, USA
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18
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Stark DA, Coffey NJ, Pancoast HR, Arnold LL, Walker JPD, Vallée J, Robitaille R, Garcia ML, Cornelison DDW. Ephrin-A3 promotes and maintains slow muscle fiber identity during postnatal development and reinnervation. J Cell Biol 2015; 211:1077-91. [PMID: 26644518 PMCID: PMC4674275 DOI: 10.1083/jcb.201502036] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 10/22/2015] [Indexed: 11/28/2022] Open
Abstract
Each adult mammalian skeletal muscle has a unique complement of fast and slow myofibers, reflecting patterns established during development and reinforced via their innervation by fast and slow motor neurons. Existing data support a model of postnatal "matching" whereby predetermined myofiber type identity promotes pruning of inappropriate motor axons, but no molecular mechanism has yet been identified. We present evidence that fiber type-specific repulsive interactions inhibit innervation of slow myofibers by fast motor axons during both postnatal maturation of the neuromuscular junction and myofiber reinnervation after injury. The repulsive guidance ligand ephrin-A3 is expressed only on slow myofibers, whereas its candidate receptor, EphA8, localizes exclusively to fast motor endplates. Adult mice lacking ephrin-A3 have dramatically fewer slow myofibers in fast and mixed muscles, and misexpression of ephrin-A3 on fast myofibers followed by denervation/reinnervation promotes their respecification to a slow phenotype. We therefore conclude that Eph/ephrin interactions guide the fiber type specificity of neuromuscular interactions during development and adult life.
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Affiliation(s)
- Danny A Stark
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - Nathan J Coffey
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211
| | - Hannah R Pancoast
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211
| | - Laura L Arnold
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - J Peyton D Walker
- Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - Joanne Vallée
- Département de Neurosciences, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Richard Robitaille
- Département de Neurosciences, Université de Montréal, Montréal, Québec H3C 3J7, Canada Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Michael L Garcia
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
| | - D D W Cornelison
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211 Christopher S. Bond Life Sciences Center, University of Missouri, Columbia, MO 65211
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19
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Luxey M, Laussu J, Davy A. EphrinB2 sharpens lateral motor column division in the developing spinal cord. Neural Dev 2015; 10:25. [PMID: 26503288 PMCID: PMC4624581 DOI: 10.1186/s13064-015-0051-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 10/13/2015] [Indexed: 12/25/2022] Open
Abstract
Background During sensori-motor circuit development, the somas of motoneurons (MN) are distributed in a topographic manner in the ventral horn of the neural tube. Indeed, their position within the lateral motor columns (LMC) correlates with axonal trajectories and identity of target limb muscles. The mechanisms by which this topographic distribution is established remains poorly understood. To address this issue, we assessed the role of ephrinB2 in MN topographic organization in the developing mouse spinal cord. Results First, we used a reporter mouse line to establish the spatio-temporal expression pattern of EfnB2 in the developing LMC. We show that early in LMC development, ephrinB2 is differentially expressed in MN of the lateral versus medial LMC, suggesting a possible role in MN sorting and/or migration. We demonstrate that while MN-specific excision of EfnB2 did not perturb specification or migration of MN, conditional loss of ephrinB2 led to the blurring of the LMC divisional boundary and to errors in the selection of LMC axon trajectory in the limb. Conclusions Altogether, our study uncovered a novel cell autonomous role for ephrinB2 in LMC MN thus emphasizing the prevalent role of this ephrin member in maintaining cell population boundaries. Electronic supplementary material The online version of this article (doi:10.1186/s13064-015-0051-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Maëva Luxey
- Centre de Biologie du Développement, CNRS, 118 Route de Narbonne, 31062, Toulouse, France.,Université de Toulouse, Toulouse, France.,Institut de Recherche Clinique de Montréal, 110 avenue des Pins Ouest, Montréal (Québec), H2W 1R7, Canada
| | - Julien Laussu
- Centre de Biologie du Développement, CNRS, 118 Route de Narbonne, 31062, Toulouse, France.,Université de Toulouse, Toulouse, France
| | - Alice Davy
- Centre de Biologie du Développement, CNRS, 118 Route de Narbonne, 31062, Toulouse, France. .,Université de Toulouse, Toulouse, France.
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20
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Sui YP, Zhang XX, Lu JL, Sui F. New Insights into the Roles of Nogo-A in CNS Biology and Diseases. Neurochem Res 2015; 40:1767-85. [PMID: 26266872 DOI: 10.1007/s11064-015-1671-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 07/15/2015] [Accepted: 07/17/2015] [Indexed: 12/22/2022]
Abstract
Nogos have become a hot topic for its well-known number Nogo-A's big role in clinical matters. It has been recognized that the expression of Nogo-A and the receptor NgR1 inhibit the neuron's growth after CNS injuries or the onset of the MS. The piling evidence supports the notion that the Nogo-A is also involved in the synaptic plasticity, which was shown to negatively regulate the strength of synaptic transmission. The occurrence of significant schizophrenia-like behavioral phenotypes in Nogo-A KO rats also added strong proof to this conclusion. This review mainly focuses on the structure of Nogo-A and its corresponding receptor-NgR1, its intra- and extra-cellular signaling, together with its major physiological functions such as regulation of migration and distribution and its related diseases like stroke, AD, ALS and so on.
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Affiliation(s)
- Yun-Peng Sui
- Institute of Chinese Material Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
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21
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Le Duc D, Renaud G, Krishnan A, Almén MS, Huynen L, Prohaska SJ, Ongyerth M, Bitarello BD, Schiöth HB, Hofreiter M, Stadler PF, Prüfer K, Lambert D, Kelso J, Schöneberg T. Kiwi genome provides insights into evolution of a nocturnal lifestyle. Genome Biol 2015; 16:147. [PMID: 26201466 PMCID: PMC4511969 DOI: 10.1186/s13059-015-0711-4] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 07/01/2015] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Kiwi, comprising five species from the genus Apteryx, are endangered, ground-dwelling bird species endemic to New Zealand. They are the smallest and only nocturnal representatives of the ratites. The timing of kiwi adaptation to a nocturnal niche and the genomic innovations, which shaped sensory systems and morphology to allow this adaptation, are not yet fully understood. RESULTS We sequenced and assembled the brown kiwi genome to 150-fold coverage and annotated the genome using kiwi transcript data and non-redundant protein information from multiple bird species. We identified evolutionary sequence changes that underlie adaptation to nocturnality and estimated the onset time of these adaptations. Several opsin genes involved in color vision are inactivated in the kiwi. We date this inactivation to the Oligocene epoch, likely after the arrival of the ancestor of modern kiwi in New Zealand. Genome comparisons between kiwi and representatives of ratites, Galloanserae, and Neoaves, including nocturnal and song birds, show diversification of kiwi's odorant receptors repertoire, which may reflect an increased reliance on olfaction rather than sight during foraging. Further, there is an enrichment of genes influencing mitochondrial function and energy expenditure among genes that are rapidly evolving specifically on the kiwi branch, which may also be linked to its nocturnal lifestyle. CONCLUSIONS The genomic changes in kiwi vision and olfaction are consistent with changes that are hypothesized to occur during adaptation to nocturnal lifestyle in mammals. The kiwi genome provides a valuable genomic resource for future genome-wide comparative analyses to other extinct and extant diurnal ratites.
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Affiliation(s)
- Diana Le Duc
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Johannisallee 30, Leipzig, 04103, Germany.
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany.
| | - Gabriel Renaud
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany.
| | - Arunkumar Krishnan
- Department of Neuroscience, Unit of Functional Pharmacology, Uppsala University, Box 593, Husargatan 3, Uppsala, 751 24, Sweden.
| | - Markus Sällman Almén
- Department of Neuroscience, Unit of Functional Pharmacology, Uppsala University, Box 593, Husargatan 3, Uppsala, 751 24, Sweden.
| | - Leon Huynen
- Griffith School of Environment and School of Biomolecular and Physical Sciences, Griffith University, Nathan, Queensland, 4111, Australia.
| | - Sonja J Prohaska
- Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, 04103, Germany.
| | - Matthias Ongyerth
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany.
| | - Bárbara D Bitarello
- Department of Genetics and Evolutionary Biology, University of São Paulo, São Paulo, SP, 05508-090, Brazil.
| | - Helgi B Schiöth
- Department of Neuroscience, Unit of Functional Pharmacology, Uppsala University, Box 593, Husargatan 3, Uppsala, 751 24, Sweden.
| | - Michael Hofreiter
- Adaptive Evolutionary Genomics, Institute for Biochemistry and Biology, University Potsdam, Potsdam, 14469, Germany.
| | - Peter F Stadler
- Department of Computer Science, and Interdisciplinary Center for Bioinformatics, University of Leipzig, Leipzig, 04103, Germany.
| | - Kay Prüfer
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany.
| | - David Lambert
- Griffith School of Environment and School of Biomolecular and Physical Sciences, Griffith University, Nathan, Queensland, 4111, Australia.
| | - Janet Kelso
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany.
| | - Torsten Schöneberg
- Institute of Biochemistry, Medical Faculty, University of Leipzig, Johannisallee 30, Leipzig, 04103, Germany.
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22
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Cissé M, Checler F. Eph receptors: new players in Alzheimer's disease pathogenesis. Neurobiol Dis 2014; 73:137-49. [PMID: 25193466 DOI: 10.1016/j.nbd.2014.08.028] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Revised: 08/01/2014] [Accepted: 08/22/2014] [Indexed: 12/23/2022] Open
Abstract
Alzheimer's disease (AD) is devastating and leads to permanent losses of memory and other cognitive functions. Although recent genetic evidences strongly argue for a causative role of Aβ in AD onset and progression (Jonsson et al., 2012), its role in AD etiology remains a matter of debate. However, even if not the sole culprit or pathological trigger, genetic and anatomical evidences in conjunction with numerous pharmacological studies, suggest that Aβ peptides, at least contribute to the disease. How Aβ contributes to memory loss remains largely unknown. Soluble Aβ species referred to as Aβ oligomers have been shown to be neurotoxic and induce network failure and cognitive deficits in animal models of the disease. In recent years, several proteins were described as potential Aβ oligomers receptors, amongst which are the receptor tyrosine kinases of Eph family. These receptors together with their natural ligands referred to as ephrins have been involved in a plethora of physiological and pathological processes, including embryonic neurogenesis, learning and memory, diabetes, cancers and anxiety. Here we review recent discoveries on Eph receptors-mediated protection against Aβ oligomers neurotoxicity as well as their potential as therapeutic targets in AD pathogenesis.
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Affiliation(s)
- Moustapha Cissé
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNS, "Labex Distalz", 660 route des Lucioles, 06560, Sophia-Antipolis, Valbonne, France..
| | - Frédéric Checler
- Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275 CNRS/UNS, "Labex Distalz", 660 route des Lucioles, 06560, Sophia-Antipolis, Valbonne, France..
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23
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Behavioral improvement and regulation of molecules related to neuroplasticity in ischemic rat spinal cord treated with PEDF. Neural Plast 2014; 2014:451639. [PMID: 25110592 PMCID: PMC4106224 DOI: 10.1155/2014/451639] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2013] [Revised: 06/04/2014] [Accepted: 06/05/2014] [Indexed: 11/28/2022] Open
Abstract
Pigment epithelium derived factor (PEDF) exerts trophic actions to motoneurons and modulates nonneuronal restorative events, but its effects on neuroplasticity responses after spinal cord (SC) injury are unknown. Rats received a low thoracic SC photothrombotic ischemia and local injection of PEDF and were evaluated behaviorally six weeks later. PEDF actions were detailed in SC ventral horn (motor) in the levels of the lumbar central pattern generator (CPG), far from the injury site. Molecules related to neuroplasticity (MAP-2), those that are able to modulate such event, for instance, neurotrophic factors (NT-3, GDNF, BDNF, and FGF-2), chondroitin sulfate proteoglycans (CSPG), and those associated with angiogenesis and antiapoptosis (laminin and Bcl-2) and Eph (receptor)/ephrin system were evaluated at cellular or molecular levels. PEDF injection improved motor behavioral performance and increased MAP-2 levels and dendritic processes in the region of lumbar CPG. Treatment also elevated GDNF and decreased NT-3, laminin, and CSPG. Injury elevated EphA4 and ephrin-B1 levels, and PEDF treatment increased ephrin A2 and ephrins B1, B2, and B3. Eph receptors and ephrins were found in specific populations of neurons and astrocytes. PEDF treatment to SC injury triggered neuroplasticity in lumbar CPG and regulation of neurotrophic factors, extracellular matrix molecules, and ephrins.
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24
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Iyer AN, Bellon A, Baudet ML. microRNAs in axon guidance. Front Cell Neurosci 2014; 8:78. [PMID: 24672429 PMCID: PMC3953822 DOI: 10.3389/fncel.2014.00078] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2013] [Accepted: 02/23/2014] [Indexed: 01/01/2023] Open
Abstract
Brain wiring is a highly intricate process in which trillions of neuronal connections are established. Its initial phase is particularly crucial in establishing the general framework of neuronal circuits. During this early step, differentiating neurons extend axons, which reach their target by navigating through a complex environment with extreme precision. Research in the past 20 years has unraveled a vast and complex array of chemotropic cues that guide the leading tip of axons, the growth cone, throughout its journey. Tight regulation of these cues, and of their receptors and signaling pathways, is necessary for the high degree of accuracy required during circuit formation. However, little is known about the nature of regulatory molecules or mechanisms fine-tuning axonal cue response. Here we review recent, and somewhat fragmented, research on the possibility that microRNAs (miRNAs) could be key fine-tuning regulatory molecules in axon guidance. miRNAs appear to shape long-range axon guidance, fasciculation and targeting. We also present several lines of evidence suggesting that miRNAs could have a compartmentalized and differential action at the cell soma, and within axons and growth cones.
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Affiliation(s)
- Archana N Iyer
- Center for Integrative Biology, University of Trento Trento, Italy
| | - Anaïs Bellon
- Department of Physiology, Development and Neuroscience, University of Cambridge Cambridge, UK
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