1
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Bessa P, Newman AG, Yan K, Schaub T, Dannenberg R, Lajkó D, Eilenberger J, Brunet T, Textoris-Taube K, Kemmler E, Deng P, Banerjee P, Ravindran E, Preissner R, Rosário M, Tarabykin V. Semaphorin heterodimerization in cis regulates membrane targeting and neocortical wiring. Nat Commun 2024; 15:7059. [PMID: 39152101 PMCID: PMC11329519 DOI: 10.1038/s41467-024-51009-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 07/22/2024] [Indexed: 08/19/2024] Open
Abstract
Disruption of neocortical circuitry and architecture in humans causes numerous neurodevelopmental disorders. Neocortical cytoarchitecture is orchestrated by various transcription factors such as Satb2 that control target genes during strict time windows. In humans, mutations of SATB2 cause SATB2 Associated Syndrome (SAS), a multisymptomatic syndrome involving epilepsy, intellectual disability, speech delay, and craniofacial defects. Here we show that Satb2 controls neuronal migration and callosal axonal outgrowth during murine neocortical development by inducing the expression of the GPI-anchored protein, Semaphorin 7A (Sema7A). We find that Sema7A exerts this biological activity by heterodimerizing in cis with the transmembrane semaphorin, Sema4D. We could also observe that heterodimerization with Sema7A promotes targeting of Sema4D to the plasma membrane in vitro. Finally, we report an epilepsy-associated de novo mutation in Sema4D (Q497P) that inhibits normal glycosylation and plasma membrane localization of Sema4D-associated complexes. These results suggest that neuronal use of semaphorins during neocortical development is heteromeric, and a greater signaling complexity exists than was previously thought.
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Affiliation(s)
- Paraskevi Bessa
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Andrew G Newman
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Kuo Yan
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Theres Schaub
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Rike Dannenberg
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Denis Lajkó
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Julia Eilenberger
- Department of Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Theresa Brunet
- Department of Pediatric Neurology and Developmental Medicine and Ludwig Maximilians University Center for Children with Medical Complexity, Dr. von Hauner Children's Hospital, Ludwig Maximilians University Hospital, Ludwig Maximilians University, Munich, Germany
- Institute of Human Genetics, Klinikum rechts der Isar, School of Medicine, Technical University of Munich, Munich, Germany
| | - Kathrin Textoris-Taube
- Institute of Biochemistry, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Philippstrasse 12, 10115, Berlin, Germany
- Core Facility - High-Throughput Mass Spectrometry, Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Core Facility - High-Throughput Mass Spectrometry, Am Charitéplatz 1, Berlin, Germany
| | - Emanuel Kemmler
- Institute of Physiology, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Philippstrasse 12, 10115, Berlin, Germany
| | - Penghui Deng
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Priyanka Banerjee
- Institute of Physiology, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Philippstrasse 12, 10115, Berlin, Germany
| | - Ethiraj Ravindran
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Robert Preissner
- Institute of Physiology, Charité -Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Philippstrasse 12, 10115, Berlin, Germany
| | - Marta Rosário
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany
| | - Victor Tarabykin
- Institute of Cell Biology and Neurobiology, Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, 10117, Berlin, Germany.
- Institute of Neuroscience, Lobachevsky University of Nizhny Novgorod, Nizhny Novgorod, 603950, Russian Federation.
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2
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Dumas CM, St Clair RM, Lasseigne AM, Ballif BA, Ebert AM. The intracellular domain of Sema6A is essential for development of the zebrafish retina. J Cell Sci 2024; 137:jcs261469. [PMID: 38963001 DOI: 10.1242/jcs.261469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 06/24/2024] [Indexed: 07/05/2024] Open
Abstract
Semaphorin6A (Sema6A) is a repulsive guidance molecule that plays many roles in central nervous system, heart and bone development, as well as immune system responses and cell signaling in cancer. Loss of Sema6A or its receptor PlexinA2 in zebrafish leads to smaller eyes and improper retinal patterning. Here, we investigate a potential role for the Sema6A intracellular domain in zebrafish eye development and dissect which phenotypes rely on forward signaling and which rely on reverse signaling. We performed rescue experiments on zebrafish Sema6A morphants with either full-length Sema6A (Sema6A-FL) or Sema6A lacking its intracellular domain (Sema6A-ΔC). We identified that the intracellular domain is not required for eye size and retinal patterning, however it is required for retinal integrity, the number and end feet strength of Müller glia and protecting against retinal cell death. This novel function for the intracellular domain suggests a role for Sema6A reverse signaling in zebrafish eye development.
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Affiliation(s)
- Caroline M Dumas
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Riley M St Clair
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | | | - Bryan A Ballif
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
| | - Alicia M Ebert
- Department of Biology, University of Vermont, Burlington, VT 05405, USA
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3
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Bustillo ME, Douthit J, Astigarraga S, Treisman JE. Two distinct mechanisms of Plexin A function in Drosophila optic lobe lamination and morphogenesis. Development 2024; 151:dev202237. [PMID: 38738602 PMCID: PMC11190435 DOI: 10.1242/dev.202237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 04/28/2024] [Indexed: 05/14/2024]
Abstract
Visual circuit development is characterized by subdivision of neuropils into layers that house distinct sets of synaptic connections. We find that, in the Drosophila medulla, this layered organization depends on the axon guidance regulator Plexin A. In Plexin A null mutants, synaptic layers of the medulla neuropil and arborizations of individual neurons are wider and less distinct than in controls. Analysis of semaphorin function indicates that Semaphorin 1a, acting in a subset of medulla neurons, is the primary partner for Plexin A in medulla lamination. Removal of the cytoplasmic domain of endogenous Plexin A has little effect on the formation of medulla layers; however, both null and cytoplasmic domain deletion mutations of Plexin A result in an altered overall shape of the medulla neuropil. These data suggest that Plexin A acts as a receptor to mediate morphogenesis of the medulla neuropil, and as a ligand for Semaphorin 1a to subdivide it into layers. Its two independent functions illustrate how a few guidance molecules can organize complex brain structures by each playing multiple roles.
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Affiliation(s)
- Maria E. Bustillo
- Department of Cell Biology, New York University Grossman School of Medicine, 435 E. 30th Street, New York, NY 10016, USA
| | - Jessica Douthit
- Department of Cell Biology, New York University Grossman School of Medicine, 435 E. 30th Street, New York, NY 10016, USA
| | - Sergio Astigarraga
- Department of Cell Biology, New York University Grossman School of Medicine, 435 E. 30th Street, New York, NY 10016, USA
| | - Jessica E. Treisman
- Department of Cell Biology, New York University Grossman School of Medicine, 435 E. 30th Street, New York, NY 10016, USA
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4
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Fries M, Brown TW, Jolicoeur C, Boulan B, Boudreau-Pinsonneault C, Javed A, Abram P, Cayouette M. Pou3f1 orchestrates a gene regulatory network controlling contralateral retinogeniculate projections. Cell Rep 2023; 42:112985. [PMID: 37590135 DOI: 10.1016/j.celrep.2023.112985] [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: 07/07/2022] [Revised: 05/26/2023] [Accepted: 08/01/2023] [Indexed: 08/19/2023] Open
Abstract
The balance of contralateral and ipsilateral retinogeniculate projections is critical for binocular vision, but the transcriptional programs regulating this process remain ill defined. Here we show that the Pou class homeobox protein POU3F1 is expressed in nascent mouse contralateral retinal ganglion cells (cRGCs) but not ipsilateral RGCs (iRGCs). Upon Pou3f1 inactivation, the proportion of cRGCs is reduced in favor of iRGCs, leading to abnormal projection ratios at the optic chiasm. Conversely, misexpression of Pou3f1 in progenitors increases the production of cRGCs. Using CUT&RUN and RNA sequencing in gain- and loss-of-function assays, we demonstrate that POU3F1 regulates expression of several key members of the cRGC gene regulatory network. Finally, we report that POU3F1 is sufficient to induce RGC-like cell production, even in late-stage retinal progenitors of Atoh7 knockout mice. This work uncovers POU3F1 as a regulator of the cRGC transcriptional program, opening possibilities for optic nerve regenerative therapies.
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Affiliation(s)
- Michel Fries
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada; Molecular Biology Program, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Thomas W Brown
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada; Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 1A1, Canada
| | - Christine Jolicoeur
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
| | - Benoit Boulan
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
| | - Camille Boudreau-Pinsonneault
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada; Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 1A1, Canada
| | - Awais Javed
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada; Molecular Biology Program, Université de Montréal, Montreal, QC H3C 3J7, Canada
| | - Pénélope Abram
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
| | - Michel Cayouette
- Cellular Neurobiology Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada; Molecular Biology Program, Université de Montréal, Montreal, QC H3C 3J7, Canada; Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 1A1, Canada; Department of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada.
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5
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Bustillo ME, Douthit J, Astigarraga S, Treisman JE. Two distinct mechanisms of Plexin A function in Drosophila optic lobe lamination and morphogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.07.552282. [PMID: 37609142 PMCID: PMC10441316 DOI: 10.1101/2023.08.07.552282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Visual circuit development is characterized by subdivision of neuropils into layers that house distinct sets of synaptic connections. We find that in the Drosophila medulla, this layered organization depends on the axon guidance regulator Plexin A. In plexin A null mutants, synaptic layers of the medulla neuropil and arborizations of individual neurons are wider and less distinct than in controls. Analysis of Semaphorin function indicates that Semaphorin 1a, provided by cells that include Tm5 neurons, is the primary partner for Plexin A in medulla lamination. Removal of the cytoplasmic domain of endogenous Plexin A does not disrupt the formation of medulla layers; however, both null and cytoplasmic domain deletion mutations of plexin A result in an altered overall shape of the medulla neuropil. These data suggest that Plexin A acts as a receptor to mediate morphogenesis of the medulla neuropil, and as a ligand for Semaphorin 1a to subdivide it into layers. Its two independent functions illustrate how a few guidance molecules can organize complex brain structures by each playing multiple roles. Summary statement The axon guidance molecule Plexin A has two functions in Drosophila medulla development; morphogenesis of the neuropil requires its cytoplasmic domain, but establishing synaptic layers through Semaphorin 1a does not.
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6
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Chen Y, Yang X, Yan X, Shen L, Guo J, Xu Q. A novel SEMA6B variant causes adult-onset progressive myoclonic epilepsy-11 in a Chinese family: A case report and literature review. Front Genet 2023; 14:1110310. [PMID: 36873942 PMCID: PMC9974634 DOI: 10.3389/fgene.2023.1110310] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 01/26/2023] [Indexed: 02/17/2023] Open
Abstract
This study describes a patient with progressive myoclonic epilepsy-11 (EPM-11), which follows autosomal dominant inheritance caused by a novel SEMA6B variant. Most patients develop this disease during infancy or adolescence with action myoclonus, generalized tonic-clonic seizures (GTCS), and progressive neurological deterioration. No cases of adult-onset EPM-11 have been reported yet. Here, we present one case of adult-onset EPM-11 who experienced gait instability, seizures, and cognitive impairment, and harbored a novel missense variant, c.432C>G (p.C144W). Our findings provide a foundation for a better understanding of the phenotypic and genotypic profiles of EPM-11. Further functional studies are recommended to elucidate the pathogenesis of this disease.
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Affiliation(s)
- Yirao Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Xingyan Yang
- Department of Neurology, Central Hospital, Bai Yin, China
| | - Xinxiang Yan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Lu Shen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China.,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China.,Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China.,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, China
| | - Jifeng Guo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China.,Centre for Medical Genetics and Hunan Key Laboratory of Medical Genetics, School of Life Sciences, Central South University, Changsha, China.,Hunan International Scientific and Technological Cooperation Base of Neurodegenerative and Neurogenetic Diseases, Changsha, China.,Engineering Research Center of Hunan Province in Cognitive Impairment Disorders, Central South University, Changsha, China
| | - Qian Xu
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, China.,Key Laboratory of Hunan Province in Neurodegenerative Disorders, Central South University, Changsha, China
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7
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Suzuki M, Nukazuka A, Kamei Y, Yuba S, Oda Y, Takagi S. Mosaic gene expression analysis of semaphorin-plexin interactions in Caenorhabditis elegans using the IR-LEGO single-cell gene induction system. Dev Growth Differ 2022; 64:230-242. [PMID: 35596523 DOI: 10.1111/dgd.12793] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 02/17/2022] [Accepted: 03/14/2022] [Indexed: 12/16/2022]
Abstract
Genetic mosaic analysis is a powerful means of addressing the sites of gene action in multicellular organisms. In conventional genetic analysis, the generation of desired mosaic patterns is difficult to control due to the randomness of generating the genetic mosaic which often renders the analysis laborious and time consuming. The infrared laser-evoked gene operator (IR-LEGO) microscope system facilitates genetic mosaic analysis by enabling gene induction in targeted single cells in a living organism. However, the level of gene induction is not controllable due to the usage of a heat-shock promoter. Here, we applied IR-LEGO to examine the cell-cell interactions mediated by semaphoring-plexin signaling in Caenorhabditis elegans by inducing wild-type semaphorin/plexin in single cells within the population of mutant cells lacking the relevant proteins. We found that the cell contact-dependent termination of the extension of vulval precursor cells is elicited by the forward signaling mediated by the semaphorin receptor, PLX-1, but not by the reverse signaling via the transmembrane semaphorin, SMP-1. By utilizing Cre/loxP recombination coupled with the IR-LEGO system to induce SMP-1 at a physiological level, we found that SMP-1 interacts with PLX-1 only in trans upon contact between vulval precursor cells. In contrast, when overexpressed, SMP-1 exhibits the ability to cis-interact with PLX-1 on a single cell. These results indicate that mosaic analysis with IR-LEGO, especially when combined with an in vivo recombination system, efficiently complements conventional methods.
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Affiliation(s)
- Motoshi Suzuki
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Akira Nukazuka
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Yasuhiro Kamei
- Laboratory for Biothermology, National Institute of Basic Biology, Okazaki, Aichi, Japan
| | - Shunsuke Yuba
- Research Institute for Cell Engineering, National Institute of Advanced and Industrial Science and Technology, Ikeda, Osaka, Japan
| | - Yoichi Oda
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Shin Takagi
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
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8
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Cordovado A, Schaettin M, Jeanne M, Panasenkava V, Denommé-Pichon AS, Keren B, Mignot C, Doco-Fenzy M, Rodan L, Ramsey K, Narayanan V, Jones JR, Prijoles EJ, Mitchell WG, Ozmore JR, Juliette K, Torti E, Normand EA, Granger L, Petersen AK, Au MG, Matheny JP, Phornphutkul C, Chambers MK, Fernández-Ramos JA, López-Laso E, Kruer MC, Bakhtiari S, Zollino M, Morleo M, Marangi G, Mei D, Pisano T, Guerrini R, Louie RJ, Childers A, Everman DB, Isidor B, Audebert-Bellanger S, Odent S, Bonneau D, Gilbert-Dussardier B, Redon R, Bézieau S, Laumonnier F, Stoeckli ET, Toutain A, Vuillaume ML. SEMA6B variants cause intellectual disability and alter dendritic spine density and axon guidance. Hum Mol Genet 2022; 31:3325-3340. [PMID: 35604360 DOI: 10.1093/hmg/ddac114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/25/2022] [Accepted: 05/12/2022] [Indexed: 11/14/2022] Open
Abstract
Intellectual disability is a neurodevelopmental disorder frequently caused by monogenic defects. In this study, we collected 14 SEMA6B heterozygous variants in 16 unrelated patients referred for intellectual disability to different centres. Whereas until now SEMA6B variants have mainly been reported in patients with progressive myoclonic epilepsy, our study indicates that the clinical spectrum is wider, and also includes non-syndromic intellectual disability without epilepsy or myoclonus. To assess the pathogenicity of these variants, selected mutated forms of Sema6b were overexpressed in HEK293T cells and in primary neuronal cultures. shRNAs targeting Sema6b were also used in neuronal cultures to measure the impact of the decreased Sema6b expression on morphogenesis and synaptogenesis. The overexpression of some variants leads to a subcellular mislocalisation of SEMA6B protein in HEK293T cells and to a reduced spine density due to loss of mature spines in neuronal cultures. Sema6b knock-down also impairs spine density and spine maturation. In addition, we conducted in vivo rescue experiments in chicken embryos with the selected mutated forms of Sema6b expressed in commissural neurons after knock-down of endogenous SEMA6B. We observed that expression of these variants in commissural neurons fails to rescue the normal axon pathway. In conclusion, identification of SEMA6B variants in patients presenting with an overlapping phenotype with intellectual disability, and functional studies highlight the important role of SEMA6B in neuronal development, notably in spine formation and maturation, and in axon guidance. This study adds SEMA6B to the list of intellectual disability-related genes.
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Affiliation(s)
- Amélie Cordovado
- UMR 1253, iBrain, University of Tours, Inserm, 37032 Tours, France
| | - Martina Schaettin
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich 8057, Switzerland
| | - Médéric Jeanne
- UMR 1253, iBrain, University of Tours, Inserm, 37032 Tours, France.,Genetics Department, University Hospital of Tours, 37044 Tours, France
| | | | - Anne-Sophie Denommé-Pichon
- Functional Unit in Innovative Genomic Diagnosis of Rare Diseases, FHU-TRANSLAD, Dijon-Bourgogne University Hospital, Dijon, France.,UMR1231 GAD, Inserm - Bourgogne-Franche Comté University, Dijon, France
| | - Boris Keren
- Genetics Department, Pitié-Salpêtrière Hospital, AP-HP. Sorbonne University, 75651 Paris, France
| | - Cyril Mignot
- Genetics Department, Pitié-Salpêtrière Hospital, AP-HP. Sorbonne University, 75651 Paris, France
| | - Martine Doco-Fenzy
- University Hospital Reims, AMH2, Genetics Division, SFR CAP santé EA3801, Reims, France
| | - Lance Rodan
- Division of Genetics and Genomics, Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Keri Ramsey
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, USA
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, USA
| | - Julie R Jones
- Molecular Diagnostic Laboratory, Greenwood Genetic Center, Greenwood, SC, USA
| | | | - Wendy G Mitchell
- Neurology Division, Keck School of Medicine, University of Southern California, Children's Hospital Los Angeles, USA
| | | | - Kali Juliette
- Gillette Children's Specialty Healthcare: Neurology Department, St Paul, MN 55101, USA
| | | | | | - Leslie Granger
- Genetics Division, Department of Pediatric Development and Rehabilitation, Randall Children's Hospital, Portland, OR 97227, USA
| | - Andrea K Petersen
- Genetics Division, Department of Pediatric Development and Rehabilitation, Randall Children's Hospital, Portland, OR 97227, USA
| | - Margaret G Au
- University of Kentucky: Department of Genetics and Metabolism, Lexington, KY 40536, USA
| | - Juliann P Matheny
- University of Kentucky: Department of Genetics and Metabolism, Lexington, KY 40536, USA
| | - Chanika Phornphutkul
- Division of Human Genetics, Department of Pediatrics, Warren Alpert Medical School of Brown University, Hasbro Children's Hospital, Providence, RI 02903, USA
| | - Mary-Kathryn Chambers
- Division of Genetics, Rhode Island Hospital, Hasbro Children's Hospital, Providence, RI 02903, USA
| | | | - Eduardo López-Laso
- Pediatric Neurology Unit, department of Pediatrics, University Hospital Reina Sofía, IMIBIC and CIBERER, Córdoba, Spain
| | - Michael C Kruer
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA.,Departments of Child Health, Neurology, and Cellular & Molecular Medicine, and Program in Genetics, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Somayeh Bakhtiari
- Pediatric Movement Disorders Program, Division of Pediatric Neurology, Barrow Neurological Institute, Phoenix Children's Hospital, Phoenix, AZ, USA.,Departments of Child Health, Neurology, and Cellular & Molecular Medicine, and Program in Genetics, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Marcella Zollino
- Università Cattolica Sacro Cuore, Dipartimento Scienze della Vita e Sanità Pubblica, Sezione di Medicina Genomica, Roma, Italy.,Fondazione Policlinico A. Gemelli IRCCS, U. O. C. Genetica Medica, Roma, Italy
| | - Manuela Morleo
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli, Naples, Italy.,Department of Precision Medicine, University of Campania "Luigi Vanvitelli", Naples 80138, Italy
| | - Giuseppe Marangi
- Università Cattolica Sacro Cuore, Dipartimento Scienze della Vita e Sanità Pubblica, Sezione di Medicina Genomica, Roma, Italy.,Fondazione Policlinico A. Gemelli IRCCS, U. O. C. Genetica Medica, Roma, Italy
| | - Davide Mei
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Meyer Children's Hospital, Member of ERN Epicare, University of Florence, Florence, Italy
| | - Tiziana Pisano
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Meyer Children's Hospital, Member of ERN Epicare, University of Florence, Florence, Italy
| | - Renzo Guerrini
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Meyer Children's Hospital, Member of ERN Epicare, University of Florence, Florence, Italy
| | - Raymond J Louie
- Molecular Diagnostic Laboratory, Greenwood Genetic Center, Greenwood, SC, USA
| | - Anna Childers
- Molecular Diagnostic Laboratory, Greenwood Genetic Center, Greenwood, SC, USA
| | - David B Everman
- Molecular Diagnostic Laboratory, Greenwood Genetic Center, Greenwood, SC, USA
| | - Betrand Isidor
- Medical Genetics Service, Clinical Genetics Unit, University Hospital of Nantes, Hôtel Dieu, 44093 Nantes, France
| | | | - Sylvie Odent
- Clinical Genetics Service, University Hospital, Genetic and Development Institute of Rennes IGDR, UMR 6290 University of Rennes, ITHACA ERN, 35203 Rennes, France
| | - Dominique Bonneau
- Department of Medical Genetics, University Hospital of Angers and Mitovasc INSERM 1083, CNRS 6015, 49000 Angers, France
| | | | - Richard Redon
- INSERM, CNRS, UNIV Nantes, Thorax Institute, 44007 Nantes, France
| | - Stéphane Bézieau
- INSERM, CNRS, UNIV Nantes, Thorax Institute, 44007 Nantes, France.,University Hospital of Nantes, Medical Genetics Service 44093 Nantes, France
| | | | - Esther T Stoeckli
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich 8057, Switzerland
| | - Annick Toutain
- UMR 1253, iBrain, University of Tours, Inserm, 37032 Tours, France.,Genetics Department, University Hospital of Tours, 37044 Tours, France
| | - Marie-Laure Vuillaume
- UMR 1253, iBrain, University of Tours, Inserm, 37032 Tours, France.,Genetics Department, University Hospital of Tours, 37044 Tours, France
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9
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Vaccaro G, Dumoulin A, Zuñiga NR, Bandtlow CE, Stoeckli ET. The Nogo-66 Receptors NgR1 and NgR3 Are Required for Commissural Axon Pathfinding. J Neurosci 2022; 42:4087-4100. [PMID: 35437280 PMCID: PMC9121835 DOI: 10.1523/jneurosci.1390-21.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 11/30/2022] Open
Abstract
Nogo-66 receptors (NgR1-3) are glycosylphosphatidyl inositol-linked proteins that belong to the leucine-rich repeat superfamily. Through binding to myelin-associated inhibitors, NgRs contribute to the inhibition of axonal regeneration after spinal cord injury. Their role in limiting synaptic plasticity and axonal outgrowth in the adult CNS has been described previously, but not much is known about their role during the development of the nervous system. Here, we show that NgR1 and NgR3 mRNAs are expressed during spinal cord development of the chicken embryo. In particular, they are expressed in the dI1 subpopulation of commissural neurons during the time when their axons navigate toward and across the floorplate, the ventral midline of the spinal cord. To assess a potential role of NgR1 and NgR3 in axon guidance, we downregulated them using in ovo RNAi and analyzed the trajectory of commissural axons by tracing them in open-book preparations of spinal cords. Our results show that loss of either NgR1 or NgR3 causes axons to stall in the midline area and to interfere with the rostral turn of postcrossing axons. In addition, we also show that NgR1, but not NgR3, requires neuronal PlexinA2 for the regulation of commissural axon guidance.SIGNIFICANCE STATEMENT Over the last decades, many studies have focused on the role of NgRs, particularly NgR1, in axonal regeneration in the injured adult CNS. Here, we show a physiological role of NgRs in guiding commissural axons during early development of the chicken spinal cord in vivo Both NgR1 and NgR3 are required for midline crossing and subsequent turning of postcrossing axons into the longitudinal axis of the spinal cord. NgR1, but not NgR3, forms a receptor complex with PlexinA2 during axon guidance. Overall, these findings provide a link between neural regenerative mechanisms and developmental processes.
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Affiliation(s)
- Giuseppe Vaccaro
- Institute of Neurobiochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, 6020, Austria
- Department of Molecular Life Sciences, Neuroscience Center Zurich, Zurich, 8057, Switzerland
| | - Alexandre Dumoulin
- Department of Molecular Life Sciences, Neuroscience Center Zurich, Zurich, 8057, Switzerland
| | - Nikole R Zuñiga
- Department of Molecular Life Sciences, Neuroscience Center Zurich, Zurich, 8057, Switzerland
| | - Christine E Bandtlow
- Institute of Neurobiochemistry, Biocenter, Medical University of Innsbruck, Innsbruck, 6020, Austria
| | - Esther T Stoeckli
- Department of Molecular Life Sciences, Neuroscience Center Zurich, Zurich, 8057, Switzerland
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10
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Zhang S, Chen S, Wang Y, Zhan Y, Li J, Nong X, Gao B. Association of a Novel Prognosis Model with Tumor Mutation Burden and Tumor-Infiltrating Immune Cells in Thyroid Carcinoma. Front Genet 2022; 12:744304. [PMID: 34976004 PMCID: PMC8718762 DOI: 10.3389/fgene.2021.744304] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 11/25/2021] [Indexed: 12/25/2022] Open
Abstract
Although immunotherapy has recently demonstrated a substantial promise in treating advanced thyroid carcinoma (THCA), it is not appropriate for all THCA patients. As a result, this study aims to identify biomarkers for predicting immunotherapy efficacy and prognosis in THCA patients based on a constructed prognostic model. The transcriptomic and corresponding clinical data of THCA patients were obtained from the Cancer Genome Atlas (TCGA) database. We identified differentially expressed genes (DEGs) between THCA and normal samples and performed an intersection analysis of DEGs with immune-related genes (IRGs) downloaded from the ImmPort database. Functional enrichment analysis was performed on the chosen immune-related DEGs. Subsequently, Cox and LASSO regression analyses were conducted to obtain three hub immune-related DEGs, including PPBP, SEMA6B, and GCGR. Following that, a prognostic risk model was established and validated based on PPBP, SEMA6B, and GCGR genes to predict immunotherapy efficacy and THCA prognosis. Finally, we investigated the association between the constructed risk model and tumor mutational burden (TMB), abundance of tumor-infiltrating immune cells (TICs) as well as immunotherapeutic targets (PDL-1, PD-1, and CTLA4) in THCA. THCA patients in the high-risk score (RS) group showed higher TMB levels and worse prognosis than the low RS group. Patients in the high-RS group had higher proportions of monocytes, M2 macrophages, and activated dendritic cells, whereas those in the low-RS group exhibited higher numbers of M1 macrophages and dendritic resting cells. Our data implied that the constructed THCA prognostic model was sound and we concluded that the THCA patients having high TMB and low PD-L1 expression levels might respond poorly to immunotherapy. Taken together, we constructed a novel prognostic model for THCA patients to predict their prognosis and immunotherapy efficacy, providing a viable option for the future management of THCA patients in the clinic.
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Affiliation(s)
- Siqin Zhang
- College of Stomatology, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, China
| | - Shaoyong Chen
- College of Stomatology, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, China
| | - Yuchen Wang
- College of Stomatology, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, China
| | - Yuxiang Zhan
- College of Stomatology, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, China
| | - Jiarui Li
- College of Stomatology, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, China
| | - Xiaolin Nong
- College of Stomatology, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, China
| | - Biyun Gao
- College of Stomatology, Guangxi Medical University, Nanning, China.,Guangxi Key Laboratory of Oral and Maxillofacial Surgery Disease Treatment, Nanning, China
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11
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Duan J, Chen Y, Hu Z, Ye Y, Zhang T, Li C, Zeng Q, Zhao X, Mai J, Sun Y, Liu C, Zheng W, Xiao Y, Liao J, Chen L. Non-convulsive Status Epilepticus in SEMA6B-Related Progressive Myoclonic Epilepsy: A Case Report With Literature Review. Front Pediatr 2022; 10:859183. [PMID: 35573939 PMCID: PMC9096209 DOI: 10.3389/fped.2022.859183] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/06/2022] [Indexed: 11/13/2022] Open
Abstract
Progressive myoclonic epilepsy (PME) is a group of rare diseases characterized by progressive myoclonus, cognitive impairment, ataxia, and other neurologic deficits. PME has high genetic heterogeneity, and more than 40 genes are reportedly associated with this disorder. SEMA6B encodes a member of the semaphorin family and was first reported to cause PME in 2020. Herein, we present a rare case of PME due to a novel SEMA6B gene mutation in a 6-year-old boy born to healthy non-consanguineous Chinese parents. His developmental milestones were delayed, and he developed recurrent atonic seizures and myoclonic seizures without fever at 3 years and 11 months of age. He experienced recurrent myoclonic seizures, non-convulsive status epilepticus (NCSE), atonic seizures, and atypical absence seizures during the last 2 years. At different time points since onset, valproic acid, levetiracetam, piracetam, and clobazam were used to control the intractable seizures. Notably, NCSE was controlled by a combination of piracetam with clobazam and valproic acid instead of intravenous infusion of midazolam and phenobarbital. Due to the limited number of cases reported to date, the clinical description of our case provides a better understanding of the genotype-phenotype correlations associated with PME and indicate that piracetam may be effective against NCSE in patients with SEMA6B-related PME.
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Affiliation(s)
- Jing Duan
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Yan Chen
- Department of Epilepsy Surgery, Shenzhen Children’s Hospital, Shenzhen, China
| | - Zhanqi Hu
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Yuanzhen Ye
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Tian Zhang
- Department of Epilepsy Surgery, Shenzhen Children’s Hospital, Shenzhen, China
| | - Cong Li
- Department of Epilepsy Surgery, Shenzhen Children’s Hospital, Shenzhen, China
| | - Qi Zeng
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Xia Zhao
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Jiahui Mai
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Yang Sun
- Department of Epilepsy Surgery, Shenzhen Children’s Hospital, Shenzhen, China
| | - Chao Liu
- Department of Bioinformatics, Berry Genomics Co., Ltd., Beijing, China
| | - Wenxin Zheng
- Department of Bioinformatics, Berry Genomics Co., Ltd., Beijing, China
| | - Yuhan Xiao
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Jianxiang Liao
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
| | - Li Chen
- Department of Neurology, Shenzhen Children’s Hospital, Shenzhen, China
- *Correspondence: Li Chen,
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12
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A De Novo SEMA6B Variant in a Chinese Patient with Progressive Myoclonic Epilepsy-11 and Review of the Literature. J Mol Neurosci 2021; 71:1944-1950. [PMID: 34218423 DOI: 10.1007/s12031-021-01880-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/21/2021] [Indexed: 10/20/2022]
Abstract
Progressive myoclonic epilepsy is a group of neurodegenerative diseases with complex clinical and genetic heterogeneity, which is associated with spontaneous or action-induced myoclonus and progressive neurodegeneration. Since 2020, 4 families with progressive myoclonic epilepsy-11 [OMIM#618876] have been reported with a very limited spectrum of SEMA6B pathogenic variants. In our study, whole-exome sequencing was used in a proband from a nonconsanguineous Chinese family presenting with growth retardation and recurrent atonic seizures. A deletion mutation (c.1960_1978del, p.Leu654Argfs*25) in the last exon of SEMA6B was detected, which is a de novo variant and pathogenic. The new genetic evidence we reported here strengthened the gene-disease relationship, and the gene curation level between SEMA6B and progressive myoclonic epilepsy-11 became "strong" following the ClinGen SOP. Therefore, the results of this study broaden the mutation spectrum of SEMA6B in different ethnic groups and strengthen the gene-disease relationship between SEMA6B and progressive myoclonic epilepsy-11.
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13
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Shu L, Xu Y, Tian Q, Chen Y, Wang Y, Xi H, Wang H, Xiao N, Mao X. A Frameshift Variant in the SEMA6B Gene Causes Global Developmental Delay and Febrile Seizures. Neurosci Bull 2021; 37:1357-1360. [PMID: 34110594 DOI: 10.1007/s12264-021-00717-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 02/10/2021] [Indexed: 11/29/2022] Open
Affiliation(s)
- Li Shu
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, 410008, China.,National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, China.,School of Life Sciences, Central South University, Changsha, 410013, China
| | - Yuchen Xu
- Department of Neurology, Xiangya Hospital, Changsha, 410008, China
| | - Qi Tian
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, 410008, China
| | - Yuanyuan Chen
- Center for Reproductive Medicine, Maternal and Child Health Hospital of Hunan Province, Changsha, 410008, China
| | - Yaqin Wang
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, 410013, China
| | - Hui Xi
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, 410008, China
| | - Hua Wang
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, 410008, China.,National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, China
| | - Neng Xiao
- Department of Pediatric Neurology, Chenzhou First People's Hospital, Chenzhou, 423000, China.
| | - Xiao Mao
- Department of Medical Genetics, Maternal and Child Health Hospital of Hunan Province, Changsha, 410008, China. .,National Health Commission Key Laboratory of Birth Defects Research, Prevention and Treatment, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, China.
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14
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Xiaozhen S, Fan Y, Fang Y, Xiaoping L, Jia J, Wuhen X, Xiaojun T, Jun S, Yucai C, Hong Z, Guang H, Shengnan W. Novel Truncating and Missense Variants in SEMA6B in Patients With Early-Onset Epilepsy. Front Cell Dev Biol 2021; 9:633819. [PMID: 34017830 PMCID: PMC8129541 DOI: 10.3389/fcell.2021.633819] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 03/17/2021] [Indexed: 11/13/2022] Open
Abstract
Progressive myoclonic epilepsy (PME) is a rare neurodegenerative disease, characterized by myoclonic seizures and tonic clonic seizures, with genetical and phenotypical heterogeneity. The semaphorin 6B (SEMA6B) gene has been recently reported a causal gene of PME. Independent studies are warranted to further support these findings. Here we report that one nonsense variant in NM_032108.3 exon17 c.2056C > T (p.Gln686∗) and one missense variant in exon14 c.1483G > T (p.Gly495Trp) of SEMA6B, both occurring de novo, underlie early-onset epilepsy with variable severity and different response to treatment in two patients. In vitro analyses have demonstrated that the nonsense variant, p.Gln686∗, results in a truncated protein with remarkably increased expression compared to that of the wild type. The truncated protein presented more homogeneous and failed to locate in the plasma membrane. The missense variant p.Gly495Trp affects evolutionarily conserved amino acid and is located in the sema domain, a key functional domain of SEMA6B. It was predicted to perturb the SEMA6B function by altering the tertiary structure of mutant protein, although neither change of protein length and expression nor difference of cellular distribution was observed. Co-immunoprecipitation studies have demonstrated that both variants influence protein binding of SEMA6B and PlxnA2 with varying degrees. Our results provide further evidence to support the initial findings of SEMA6B being causal to epilepsy and indicate that mediating Semaphorin/Plexin signaling is the potential mechanism of the SEMA6B-related disease.
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Affiliation(s)
- Song Xiaozhen
- Laboratory of Molecular Diagnosis, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Yuan Fan
- Bio-X Institute, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Institute of Mental Health, Shanghai Jiao Tong University, Shanghai, China
| | - Yuan Fang
- Department of Neurology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Lan Xiaoping
- Laboratory of Molecular Diagnosis, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Jia Jia
- Fuxiang Gene Engineering Research Institute, Shanghai, China
| | - Xu Wuhen
- Laboratory of Molecular Diagnosis, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Tang Xiaojun
- Laboratory of Molecular Diagnosis, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Shen Jun
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, United States
| | - Chen Yucai
- Department of Neurology, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Zhang Hong
- Laboratory of Molecular Diagnosis, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - He Guang
- Bio-X Institute, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Institute of Mental Health, Shanghai Jiao Tong University, Shanghai, China
| | - Wu Shengnan
- Laboratory of Molecular Diagnosis, Shanghai Children's Hospital, Shanghai Jiao Tong University, Shanghai, China
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15
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Yusifov E, Dumoulin A, Stoeckli ET. Investigating Primary Cilia during Peripheral Nervous System Formation. Int J Mol Sci 2021; 22:3176. [PMID: 33804711 PMCID: PMC8003989 DOI: 10.3390/ijms22063176] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 03/16/2021] [Accepted: 03/16/2021] [Indexed: 12/22/2022] Open
Abstract
The primary cilium plays a pivotal role during the embryonic development of vertebrates. It acts as a somatic signaling hub for specific pathways, such as Sonic Hedgehog signaling. In humans, mutations in genes that cause dysregulation of ciliogenesis or ciliary function lead to severe developmental disorders called ciliopathies. Beyond its role in early morphogenesis, growing evidence points towards an essential function of the primary cilium in neural circuit formation in the central nervous system. However, very little is known about a potential role in the formation of the peripheral nervous system. Here, we investigate the presence of the primary cilium in neural crest cells and their derivatives in the trunk of developing chicken embryos in vivo. We found that neural crest cells, sensory neurons, and boundary cap cells all bear a primary cilium during key stages of early peripheral nervous system formation. Moreover, we describe differences in the ciliation of neuronal cultures of different populations from the peripheral and central nervous systems. Our results offer a framework for further in vivo and in vitro investigations on specific roles that the primary cilium might play during peripheral nervous system formation.
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Affiliation(s)
| | | | - Esther T. Stoeckli
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland; (E.Y.); (A.D.)
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16
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Baeriswyl T, Dumoulin A, Schaettin M, Tsapara G, Niederkofler V, Helbling D, Avilés E, Frei JA, Wilson NH, Gesemann M, Kunz B, Stoeckli ET. Endoglycan plays a role in axon guidance by modulating cell adhesion. eLife 2021; 10:64767. [PMID: 33650489 PMCID: PMC7946425 DOI: 10.7554/elife.64767] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 02/25/2021] [Indexed: 01/27/2023] Open
Abstract
Axon navigation depends on the interactions between guidance molecules along the trajectory and specific receptors on the growth cone. However, our in vitro and in vivo studies on the role of Endoglycan demonstrate that in addition to specific guidance cue – receptor interactions, axon guidance depends on fine-tuning of cell-cell adhesion. Endoglycan, a sialomucin, plays a role in axon guidance in the central nervous system of chicken embryos, but it is neither an axon guidance cue nor a receptor. Rather, Endoglycan acts as a negative regulator of molecular interactions based on evidence from in vitro experiments demonstrating reduced adhesion of growth cones. In the absence of Endoglycan, commissural axons fail to properly navigate the midline of the spinal cord. Taken together, our in vivo and in vitro results support the hypothesis that Endoglycan acts as a negative regulator of cell-cell adhesion in commissural axon guidance.
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Affiliation(s)
- Thomas Baeriswyl
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Alexandre Dumoulin
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Martina Schaettin
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Georgia Tsapara
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Vera Niederkofler
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Denise Helbling
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Evelyn Avilés
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Jeannine A Frei
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Nicole H Wilson
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Matthias Gesemann
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Beat Kunz
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Esther T Stoeckli
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
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17
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Klein R, Pasterkamp RJ. Recent advances in inter-cellular interactions during neural circuit assembly. Curr Opin Neurobiol 2021; 69:25-32. [PMID: 33383489 DOI: 10.1016/j.conb.2020.12.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/02/2020] [Accepted: 12/07/2020] [Indexed: 12/12/2022]
Abstract
Neural circuit assembly is regulated by inter-cellular interactions involving secreted and surface-tethered guidance molecules. Here, we review recent progress in our understanding of their mechanisms-of-action and biological effects. We discuss mechanisms through which the secreted cue Netrin-1 regulates neuron migration and highlight novel roles for axon-derived secreted guidance cues. We cover recent structural work at atomic resolution that provides new insights into the activation mechanisms of axon guidance receptors and into protein complexes containing cell adhesion molecules, such as Teneurin (Ten), Latrophilin (Lphn) and FLRT. Ten-Ten homophilic, Ten-Lphn heterophilic, and Ten-Lphn-FLRT tripartite complexes seem to elicit distinct context-dependent cellular responses. Seemingly opposite responses can also be triggered by the Eph/ephrin signaling system. Here, recent work provides a simple mechanism for the decision of forming a new synapse versus rejection of the pre-synaptic partner. These studies identify novel regulatory mechanisms and biological functions that will apply generally in developing neural systems.
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Affiliation(s)
- Rüdiger Klein
- Department Molecules-Signaling-Development, Max Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Martinsried, Germany.
| | - Ronald Jeroen Pasterkamp
- Department of Translational Neuroscience, University Medical Center (UMC) Utrecht Brain Center, Utrecht University, Universiteitsweg 100, 3584 CG, Utrecht, The Netherlands.
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18
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Alvarez S, Varadarajan SG, Butler SJ. Dorsal commissural axon guidance in the developing spinal cord. Curr Top Dev Biol 2020; 142:197-231. [PMID: 33706918 DOI: 10.1016/bs.ctdb.2020.10.009] [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] [Indexed: 01/04/2023]
Abstract
Commissural axons have been a key model system for identifying axon guidance signals in vertebrates. This review summarizes the current thinking about the molecular and cellular mechanisms that establish a specific commissural neural circuit: the dI1 neurons in the developing spinal cord. We assess the contribution of long- and short-range signaling while sequentially following the developmental timeline from the birth of dI1 neurons, to the extension of commissural axons first circumferentially and then contralaterally into the ventral funiculus.
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Affiliation(s)
- Sandy Alvarez
- Department of Neurobiology, University of California, Los Angeles, CA, United States; Molecular Biology Interdepartmental Doctoral Program, University of California, Los Angeles, CA, United States
| | | | - Samantha J Butler
- Department of Neurobiology, University of California, Los Angeles, CA, United States; Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, CA, United States.
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19
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Rozbesky D, Verhagen MG, Karia D, Nagy GN, Alvarez L, Robinson RA, Harlos K, Padilla‐Parra S, Pasterkamp RJ, Jones EY. Structural basis of semaphorin-plexin cis interaction. EMBO J 2020; 39:e102926. [PMID: 32500924 PMCID: PMC7327498 DOI: 10.15252/embj.2019102926] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 04/22/2020] [Accepted: 04/23/2020] [Indexed: 01/05/2023] Open
Abstract
Semaphorin ligands interact with plexin receptors to contribute to functions in the development of myriad tissues including neurite guidance and synaptic organisation within the nervous system. Cell-attached semaphorins interact in trans with plexins on opposing cells, but also in cis on the same cell. The interplay between trans and cis interactions is crucial for the regulated development of complex neural circuitry, but the underlying molecular mechanisms are uncharacterised. We have discovered a distinct mode of interaction through which the Drosophila semaphorin Sema1b and mouse Sema6A mediate binding in cis to their cognate plexin receptors. Our high-resolution structural, biophysical and in vitro analyses demonstrate that monomeric semaphorins can mediate a distinctive plexin binding mode. These findings suggest the interplay between monomeric vs dimeric states has a hereto unappreciated role in semaphorin biology, providing a mechanism by which Sema6s may balance cis and trans functionalities.
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Affiliation(s)
- Daniel Rozbesky
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Marieke G Verhagen
- Department of Translational NeuroscienceUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Dimple Karia
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Gergely N Nagy
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Luis Alvarez
- Cellular ImagingWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Ross A Robinson
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Present address:
Immunocore LtdAbingdonUK
| | - Karl Harlos
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Sergi Padilla‐Parra
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Cellular ImagingWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
- Present address:
Department of Infectious DiseasesFaculty of Life Sciences & MedicineKing's College LondonLondonUK
- Present address:
Randall Centre for Cell and Molecular BiophysicsKing's College LondonLondonUK
| | - R Jeroen Pasterkamp
- Department of Translational NeuroscienceUMC Utrecht Brain CenterUniversity Medical Center UtrechtUtrecht UniversityUtrechtThe Netherlands
| | - Edith Yvonne Jones
- Division of Structural BiologyWellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
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20
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De Novo Truncating Variants in the Last Exon of SEMA6B Cause Progressive Myoclonic Epilepsy. Am J Hum Genet 2020; 106:549-558. [PMID: 32169168 DOI: 10.1016/j.ajhg.2020.02.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/19/2020] [Indexed: 12/22/2022] Open
Abstract
De novo variants (DNVs) cause many genetic diseases. When DNVs are examined in the whole coding regions of genes in next-generation sequencing analyses, pathogenic DNVs often cluster in a specific region. One such region is the last exon and the last 50 bp of the penultimate exon, where truncating DNVs cause escape from nonsense-mediated mRNA decay [NMD(-) region]. Such variants can have dominant-negative or gain-of-function effects. Here, we first developed a resource of rates of truncating DNVs in NMD(-) regions under the null model of DNVs. Utilizing this resource, we performed enrichment analysis of truncating DNVs in NMD(-) regions in 346 developmental and epileptic encephalopathy (DEE) trios. We observed statistically significant enrichment of truncating DNVs in semaphorin 6B (SEMA6B) (p value: 2.8 × 10-8; exome-wide threshold: 2.5 × 10-6). The initial analysis of the 346 individuals and additional screening of 1,406 and 4,293 independent individuals affected by DEE and developmental disorders collectively identified four truncating DNVs in the SEMA6B NMD(-) region in five individuals who came from unrelated families (p value: 1.9 × 10-13) and consistently showed progressive myoclonic epilepsy. RNA analysis of lymphoblastoid cells established from an affected individual showed that the mutant allele escaped NMD, indicating stable production of the truncated protein. Importantly, heterozygous truncating variants in the NMD(+) region of SEMA6B are observed in general populations, and SEMA6B is most likely loss-of-function tolerant. Zebrafish expressing truncating variants in the NMD(-) region of SEMA6B orthologs displayed defective development of brain neurons and enhanced pentylenetetrazole-induced seizure behavior. In summary, we show that truncating DNVs in the final exon of SEMA6B cause progressive myoclonic epilepsy.
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21
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St Clair RM, Dumas CM, Williams KS, Goldstein MT, Stant EA, Ebert AM, Ballif BA. PKC induces release of a functional ectodomain of the guidance cue semaphorin6A. FEBS Lett 2019; 593:3015-3028. [PMID: 31378926 DOI: 10.1002/1873-3468.13561] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 07/16/2019] [Accepted: 07/25/2019] [Indexed: 01/06/2023]
Abstract
Semaphorins (Semas) are a family of secreted and transmembrane proteins that play critical roles in development. Interestingly, several vertebrate transmembrane Sema classes are capable of producing functional soluble ectodomains. However, little is known of soluble Sema6 ectodomains in the nervous system. Herein, we show that the soluble Sema6A ectodomain, sSema6A, exhibits natural and protein kinase C (PKC)-induced release. We show that PKC mediates Sema6A phosphorylation at specific sites and while this phosphorylation is not the primary mechanism regulating sSema6A production, we found that the intracellular domain confers resistance to ectodomain release. Finally, sSema6A is functional as it promotes the cohesion of zebrafish early eye field explants. This suggests that in addition to its canonical contact-mediated functions, Sema6A may have regulated, long-range, forward-signaling capacity.
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Affiliation(s)
- Riley M St Clair
- Department of Biology, University of Vermont, Burlington, VT, USA
| | - Caroline M Dumas
- Department of Biology, University of Vermont, Burlington, VT, USA
| | - Kori S Williams
- Department of Biology, University of Vermont, Burlington, VT, USA
| | | | | | - Alicia M Ebert
- Department of Biology, University of Vermont, Burlington, VT, USA
| | - Bryan A Ballif
- Department of Biology, University of Vermont, Burlington, VT, USA
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22
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Ye X, Qiu Y, Gao Y, Wan D, Zhu H. A Subtle Network Mediating Axon Guidance: Intrinsic Dynamic Structure of Growth Cone, Attractive and Repulsive Molecular Cues, and the Intermediate Role of Signaling Pathways. Neural Plast 2019; 2019:1719829. [PMID: 31097955 PMCID: PMC6487106 DOI: 10.1155/2019/1719829] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/25/2019] [Accepted: 03/06/2019] [Indexed: 01/01/2023] Open
Abstract
A fundamental feature of both early nervous system development and axon regeneration is the guidance of axonal projections to their targets in order to assemble neural circuits that control behavior. In the navigation process where the nerves grow toward their targets, the growth cones, which locate at the tips of axons, sense the environment surrounding them, including varies of attractive or repulsive molecular cues, then make directional decisions to adjust their navigation journey. The turning ability of a growth cone largely depends on its highly dynamic skeleton, where actin filaments and microtubules play a very important role in its motility. In this review, we summarize some possible mechanisms underlying growth cone motility, relevant molecular cues, and signaling pathways in axon guidance of previous studies and discuss some questions regarding directions for further studies.
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Affiliation(s)
- Xiyue Ye
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, China
- Chongqing Engineering Research Center for Pharmacological Evaluation, Chongqing 400715, China
- Engineering Research Center for Chongqing Pharmaceutical Process and Quality Control, Chongqing 400715, China
| | - Yan Qiu
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, China
- Chongqing Engineering Research Center for Pharmacological Evaluation, Chongqing 400715, China
- Engineering Research Center for Chongqing Pharmaceutical Process and Quality Control, Chongqing 400715, China
| | - Yuqing Gao
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, China
- Chongqing Engineering Research Center for Pharmacological Evaluation, Chongqing 400715, China
- Engineering Research Center for Chongqing Pharmaceutical Process and Quality Control, Chongqing 400715, China
| | - Dong Wan
- Department of Emergency, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China
| | - Huifeng Zhu
- College of Pharmaceutical Sciences and Traditional Chinese Medicine, Southwest University, Chongqing 400715, China
- Chongqing Engineering Research Center for Pharmacological Evaluation, Chongqing 400715, China
- Engineering Research Center for Chongqing Pharmaceutical Process and Quality Control, Chongqing 400715, China
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23
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He M, Lin Y, Xu Y. Identification of prognostic biomarkers in colorectal cancer using a long non-coding RNA-mediated competitive endogenous RNA network. Oncol Lett 2019; 17:2687-2694. [PMID: 30854042 PMCID: PMC6365949 DOI: 10.3892/ol.2019.9936] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 12/05/2018] [Indexed: 02/07/2023] Open
Abstract
Colorectal cancer (CRC) is a highly malignant gastrointestinal tumor accompanied by poor prognosis. Long non-coding RNA (lncRNA) plays an important role in the progression and physiology of tumors as it competes with endogenous RNAs, including miRNA and mRNA. In the present study, a multi-step computational method was used to build a CRC-related functional lncRNA-mediated competitive endogenous RNA (ceRNA) network (LMCN). lncRNAs with more degrees and betweenness centrality (BC) were screened out as hub lncRNAs. Then functional enrichment analyses of lncRNAs were carried out from the Gene Ontology (GO) and Reactome pathway databases based on the 'guilt by association' principle. As a result, lncRNAs in the LMCN displayed specific topological characteristics in accordance with the regulatory correlation of coding mRNAs in CRC pathology. HCP5, EPB41L4A-AS1, SNHG12, and LINC00649 were screened out as hub lncRNAs which were more significantly related to the development and prognosis of CRC. The hub lncRNAs in CRC were obviously involved in functions of cell cycle arrest, vacuolar transport, histone modification, and in pathways of GPCR, signaling by Rho GTPases, axon guidance pathways, meaning that they might be potential biomarkers for diagnosis, evaluation and gene-targeted therapy of CRC. Thus, the LMCN construction method could accelerate lncRNA discovery and therapeutic development in CRC.
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Affiliation(s)
- Minjie He
- Department of Medical Oncology, The First Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650000, P.R. China
| | - Yan Lin
- Department of Oncology, The Affiliated Traditional Chinese Medical Hospital of Xinjiang Medical University, Urumqi, Xinjiang 830000, P.R. China
| | - Yuzhen Xu
- Department of Gastrointestinal Surgery, Xuzhou Hospital Affiliated to Medical School of Southeast University, Xuzhou, Jiangsu 221009, P.R. China
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24
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Melrose J. Keratan sulfate (KS)-proteoglycans and neuronal regulation in health and disease: the importance of KS-glycodynamics and interactive capability with neuroregulatory ligands. J Neurochem 2019; 149:170-194. [PMID: 30578672 DOI: 10.1111/jnc.14652] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 11/26/2018] [Accepted: 12/13/2018] [Indexed: 12/18/2022]
Abstract
Compared to the other classes of glycosaminoglycans (GAGs), that is, chondroitin/dermatan sulfate, heparin/heparan sulfate and hyaluronan, keratan sulfate (KS), have the least known of its interactive properties. In the human body, the cornea and the brain are the two most abundant tissue sources of KS. Embryonic KS is synthesized as a linear poly-N-acetyllactosamine chain of d-galactose-GlcNAc repeat disaccharides which become progressively sulfated with development, sulfation of GlcNAc is more predominant than galactose. KS contains multi-sulfated high-charge density, monosulfated and non-sulfated poly-N-acetyllactosamine regions and thus is a heterogeneous molecule in terms of chain length and charge distribution. A recent proteomics study on corneal KS demonstrated its interactivity with members of the Slit-Robbo and Ephrin-Ephrin receptor families and proteins which regulate Rho GTPase signaling and actin polymerization/depolymerization in neural development and differentiation. KS decorates a number of peripheral nervous system/CNS proteoglycan (PG) core proteins. The astrocyte KS-PG abakan defines functional margins of the brain and is up-regulated following trauma. The chondroitin sulfate/KS PG aggrecan forms perineuronal nets which are dynamic neuroprotective structures with anti-oxidant properties and roles in neural differentiation, development and synaptic plasticity. Brain phosphacan a chondroitin sulfate, KS, HNK-1 PG have roles in neural development and repair. The intracellular microtubule and synaptic vesicle KS-PGs MAP1B and SV2 have roles in metabolite transport, storage, and export of neurotransmitters and cytoskeletal assembly. MAP1B has binding sites for tubulin and actin through which it promotes cytoskeletal development in growth cones and is highly expressed during neurite extension. The interactive capability of KS with neuroregulatory ligands indicate varied roles for KS-PGs in development and regenerative neural processes.
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Affiliation(s)
- James Melrose
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, St. Leonards, New South Wales, Australia.,Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia.,Sydney Medical School, Northern Campus, Royal North Shore Hospital, The University of Sydney, New South Wales, Australia.,Faculty of Medicine and Health, Royal North Shore Hospital, The University of Sydney, St. Leonards, New South Wales, Australia
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25
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Ducuing H, Gardette T, Pignata A, Tauszig-Delamasure S, Castellani V. Commissural axon navigation in the spinal cord: A repertoire of repulsive forces is in command. Semin Cell Dev Biol 2019; 85:3-12. [DOI: 10.1016/j.semcdb.2017.12.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Revised: 12/11/2017] [Accepted: 12/11/2017] [Indexed: 01/31/2023]
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26
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Han Q, Sun YA, Zong Y, Chen C, Wang HF, Tan L. Common Variants in PLXNA4 and Correlation to CSF-related Phenotypes in Alzheimer's Disease. Front Neurosci 2018; 12:946. [PMID: 30618575 PMCID: PMC6305543 DOI: 10.3389/fnins.2018.00946] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 11/29/2018] [Indexed: 01/21/2023] Open
Abstract
The Plexin-A 4 (PLXNA4) gene, has recently been identified in genome wide association studies (GWAS), as a novel genetic player associated with Alzheimer's disease (AD). Additionally, PLXNA4 genetic variations were also found to increase AD risk by tau pathology in vitro. However, the potential roles of PLXNA4 variants in the amyloid-β (Aβ) pathology, were not evaluated. Five targeted loci capturing the top common variations in PLXNA4, were extracted using tagger methods. Multiple linear regression models were used to explore whether these variations can affect the cerebrospinal fluid (CSF) (Aβ1−42, T-tau, and P-tau) phenotypes in the Alzheimer's disease Neuroimaging Initiative (ADNI) dataset. We detected that two loci (rs6467431, rs67468325) were significantly associated with CSF Aβ1−42 levels in the hybrid population (rs6467431: P = 0.01376, rs67468325: P = 0.006536) and the significance remained after false discovery rate (FDR) correction (rs6467431: Pc = 0.03441, rs67468325: Pc = 0.03268). In the subgroup analysis, we further confirmed the association of rs6467431 in the cognitively normal (CN) subgroup (P = 0.01904, Pc = 0.04761). Furthermore, rs6467431-A carriers and rs67468325-G carriers showed higher CSF Aβ1−42 levels than non-carriers. Nevertheless, we did not detect any significant relationships between the levels of T-tau, P-tau and these PLXNA4 loci. Our findings provided preliminary evidence that PLXNA4 variants can confer AD risk through modulating the Aβ deposition.
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Affiliation(s)
- Qiu Han
- Department of Neurology, Qingdao Clinical Medical School, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China.,Department of Neurology, The Affiliated Huaian Hosipital of Xuzhou Medical University, Huai'an, China
| | - Yong-An Sun
- Department of Neurology, Qingdao Clinical Medical School, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China.,Department of Neurology, First Affiliated Hospital of Kangda School, Nanjing Medical University, Lianyungang, China
| | - Yu Zong
- Department of Neurology, School of Medicine, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Chun Chen
- Department of Neurology, Qingdao Clinical Medical School, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China.,Department of Neurology, Hongze Huai'an District People's Hospital, Huai'an, China
| | - Hui-Fu Wang
- Department of Neurology, School of Medicine, Qingdao Municipal Hospital, Qingdao University, Qingdao, China
| | - Lan Tan
- Department of Neurology, Qingdao Clinical Medical School, Qingdao Municipal Hospital, Nanjing Medical University, Qingdao, China
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27
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Finney AC, Orr AW. Guidance Molecules in Vascular Smooth Muscle. Front Physiol 2018; 9:1311. [PMID: 30283356 PMCID: PMC6157320 DOI: 10.3389/fphys.2018.01311] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/30/2018] [Indexed: 12/21/2022] Open
Abstract
Several highly conserved families of guidance molecules, including ephrins, Semaphorins, Netrins, and Slits, play conserved and distinct roles in tissue remodeling during tissue patterning and disease pathogenesis. Primarily, these guidance molecules function as either secreted or surface-bound ligands that interact with their receptors to activate a variety of downstream effects, including cell contractility, migration, adhesion, proliferation, and inflammation. Vascular smooth muscle cells, contractile cells comprising the medial layer of the vessel wall and deriving from the mural population, regulate vascular tone and blood pressure. While capillaries lack a medial layer of vascular smooth muscle, mural-derived pericytes contribute similarly to capillary tone to regulate blood flow in various tissues. Furthermore, pericyte coverage is critical in vascular development, as perturbations disrupt vascular permeability and viability. During cardiovascular disease, smooth muscle cells play a more dynamic role in which suppression of contractile markers, enhanced proliferation, and migration lead to the progression of aberrant vascular remodeling. Since many types of guidance molecules are expressed in vascular smooth muscle and pericytes, these may contribute to blood vessel formation and aberrant remodeling during vascular disease. While vascular development is a large focus of the existing literature, studies emerged to address post-developmental roles for guidance molecules in pathology and are of interest as novel therapeutic targets. In this review, we will discuss the roles of guidance molecules in vascular smooth muscle and pericyte function in development and disease.
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Affiliation(s)
- Alexandra Christine Finney
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
| | - Anthony Wayne Orr
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
- Department of Molecular and Cellular Physiology, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
- Department of Pathology and Translational Medicine, Louisiana State University Health Sciences Center Shreveport, Shreveport, LA, United States
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28
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Ros O, Barrecheguren PJ, Cotrufo T, Schaettin M, Roselló-Busquets C, Vílchez-Acosta A, Hernaiz-Llorens M, Martínez-Marmol R, Ulloa F, Stoeckli ET, Araújo SJ, Soriano E. A conserved role for Syntaxin-1 in pre- and post-commissural midline axonal guidance in fly, chick, and mouse. PLoS Genet 2018; 14:e1007432. [PMID: 29912942 PMCID: PMC6029812 DOI: 10.1371/journal.pgen.1007432] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 07/03/2018] [Accepted: 05/18/2018] [Indexed: 02/03/2023] Open
Abstract
Axonal growth and guidance rely on correct growth cone responses to guidance cues. Unlike the signaling cascades that link axonal growth to cytoskeletal dynamics, little is known about the crosstalk mechanisms between guidance and membrane dynamics and turnover. Recent studies indicate that whereas axonal attraction requires exocytosis, chemorepulsion relies on endocytosis. Indeed, our own studies have shown that Netrin-1/Deleted in Colorectal Cancer (DCC) signaling triggers exocytosis through the SNARE Syntaxin-1 (STX1). However, limited in vivo evidence is available about the role of SNARE proteins in axonal guidance. To address this issue, here we systematically deleted SNARE genes in three species. We show that loss-of-function of STX1 results in pre- and post-commissural axonal guidance defects in the midline of fly, chick, and mouse embryos. Inactivation of VAMP2, Ti-VAMP, and SNAP25 led to additional abnormalities in axonal guidance. We also confirmed that STX1 loss-of-function results in reduced sensitivity of commissural axons to Slit-2 and Netrin-1. Finally, genetic interaction studies in Drosophila show that STX1 interacts with both the Netrin-1/DCC and Robo/Slit pathways. Our data provide evidence of an evolutionarily conserved role of STX1 and SNARE proteins in midline axonal guidance in vivo, by regulating both pre- and post-commissural guidance mechanisms. Syntaxin-1 is a core factor in tethering synaptic vesicles and mediating their fusion to the cell membrane at the synapse. Thus, Syntaxin-1 mediates neurotransmission in the adult nervous system. Here we show that this protein is also involved in axonal guidance in the CNS of vertebrates and invertebrates during the development of the nervous system: our systematic analysis of the phenotypes in the nervous system midline of fly, chick, and mouse embryos mutant for Syntaxin-1 unveils an evolutionarily conserved role for this protein in midline axonal guidance. Further, we also dissect the contribution of other proteins regulating neuronal exocytosis in axonal development. We propose that the coupling of the guidance molecule machinery to proteins that regulate exocytosis is a general mechanism linking chemotropism to axonal growth.
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Affiliation(s)
- Oriol Ros
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology and Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
| | - Pablo José Barrecheguren
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology and Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Institut de Recerca Biomedica de Barcelona (IRB Barcelona), Parc Cientific de Barcelona, Barcelona, Spain
| | - Tiziana Cotrufo
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology and Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
| | - Martina Schaettin
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Cristina Roselló-Busquets
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology and Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
| | - Alba Vílchez-Acosta
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology and Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
| | - Marc Hernaiz-Llorens
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology and Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
| | - Ramón Martínez-Marmol
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology and Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
| | - Fausto Ulloa
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology and Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
| | - Esther T. Stoeckli
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
- * E-mail: (ETS); (SJA); (ES)
| | - Sofia J. Araújo
- Institut de Recerca Biomedica de Barcelona (IRB Barcelona), Parc Cientific de Barcelona, Barcelona, Spain
- Institut de Biologia Molecular de Barcelona (IBMB-CSIC), Parc Cientific de Barcelona, Barcelona, Spain
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
- * E-mail: (ETS); (SJA); (ES)
| | - Eduardo Soriano
- Department of Cell Biology, Physiology and Immunology, Faculty of Biology and Institute of Neurosciences, University of Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), ISCIII, Madrid, Spain
- Vall d´Hebron Institute of Research (VHIR), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- * E-mail: (ETS); (SJA); (ES)
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29
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Abstract
During nervous system development, neurons extend axons to reach their targets and form functional circuits. The faulty assembly or disintegration of such circuits results in disorders of the nervous system. Thus, understanding the molecular mechanisms that guide axons and lead to neural circuit formation is of interest not only to developmental neuroscientists but also for a better comprehension of neural disorders. Recent studies have demonstrated how crosstalk between different families of guidance receptors can regulate axonal navigation at choice points, and how changes in growth cone behaviour at intermediate targets require changes in the surface expression of receptors. These changes can be achieved by a variety of mechanisms, including transcription, translation, protein-protein interactions, and the specific trafficking of proteins and mRNAs. Here, I review these axon guidance mechanisms, highlighting the most recent advances in the field that challenge the textbook model of axon guidance.
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Affiliation(s)
- Esther T Stoeckli
- University of Zurich, Institute of Molecular Life Sciences, Neuroscience Center Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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30
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Cherif H, Duhamel F, Cécyre B, Bouchard A, Quintal A, Chemtob S, Bouchard JF. Receptors of intermediates of carbohydrate metabolism, GPR91 and GPR99, mediate axon growth. PLoS Biol 2018; 16:e2003619. [PMID: 29771909 PMCID: PMC5976209 DOI: 10.1371/journal.pbio.2003619] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 05/30/2018] [Accepted: 05/01/2018] [Indexed: 01/23/2023] Open
Abstract
During the development of the visual system, high levels of energy are expended propelling axons from the retina to the brain. However, the role of intermediates of carbohydrate metabolism in the development of the visual system has been overlooked. Here, we report that the carbohydrate metabolites succinate and α-ketoglutarate (α-KG) and their respective receptor-GPR91 and GPR99-are involved in modulating retinal ganglion cell (RGC) projections toward the thalamus during visual system development. Using ex vivo and in vivo approaches, combined with pharmacological and genetic analyses, we revealed that GPR91 and GPR99 are expressed on axons of developing RGCs and have complementary roles during RGC axon growth in an extracellular signal-regulated kinases 1 and 2 (ERK1/2)-dependent manner. However, they have no effects on axon guidance. These findings suggest an important role for these receptors during the establishment of the visual system and provide a foundational link between carbohydrate metabolism and axon growth.
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Affiliation(s)
- Hosni Cherif
- School of Optometry, Université de Montréal, Montreal, Quebec, Canada
| | - François Duhamel
- Department of Pediatrics, Research Center-CHU Sainte-Justine, Montreal, Quebec, Canada
- Department of Pharmacology, Université de Montréal, Montreal, Quebec, Canada
| | - Bruno Cécyre
- School of Optometry, Université de Montréal, Montreal, Quebec, Canada
| | - Alex Bouchard
- School of Optometry, Université de Montréal, Montreal, Quebec, Canada
| | - Ariane Quintal
- School of Optometry, Université de Montréal, Montreal, Quebec, Canada
| | - Sylvain Chemtob
- Department of Pediatrics, Research Center-CHU Sainte-Justine, Montreal, Quebec, Canada
- Department of Pharmacology, Université de Montréal, Montreal, Quebec, Canada
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31
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Hernandez-Fleming M, Rohrbach EW, Bashaw GJ. Sema-1a Reverse Signaling Promotes Midline Crossing in Response to Secreted Semaphorins. Cell Rep 2017; 18:174-184. [PMID: 28052247 DOI: 10.1016/j.celrep.2016.12.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 11/21/2016] [Accepted: 12/08/2016] [Indexed: 11/26/2022] Open
Abstract
Commissural axons must cross the midline to form functional midline circuits. In the invertebrate nerve cord and vertebrate spinal cord, midline crossing is mediated in part by Netrin-dependent chemoattraction. Loss of crossing, however, is incomplete in mutants for Netrin or its receptor Frazzled/DCC, suggesting the existence of additional pathways. We identified the transmembrane Semaphorin, Sema-1a, as an important regulator of midline crossing in the Drosophila CNS. We show that in response to the secreted Semaphorins Sema-2a and Sema-2b, Sema-1a functions as a receptor to promote crossing independently of Netrin. In contrast to other examples of reverse signaling where Sema1a triggers repulsion through activation of Rho in response to Plexin binding, in commissural neurons Sema-1a acts independently of Plexins to inhibit Rho to promote attraction to the midline. These findings suggest that Sema-1a reverse signaling can elicit distinct axonal responses depending on differential engagement of distinct ligands and signaling effectors.
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Affiliation(s)
- Melissa Hernandez-Fleming
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, 415 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Ethan W Rohrbach
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, 415 Curie Boulevard, Philadelphia, PA 19104, USA
| | - Greg J Bashaw
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, 415 Curie Boulevard, Philadelphia, PA 19104, USA.
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32
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Fanfone D, Despretz N, Stanicki D, Rubio-Magnieto J, Fossépré M, Surin M, Rorive S, Salmon I, Vander Elst L, Laurent S, Muller RN, Saussez S, Burtea C. Toward a new and noninvasive diagnostic method of papillary thyroid cancer by using peptide vectorized contrast agents targeted to galectin-1. Med Oncol 2017; 34:184. [PMID: 28986753 DOI: 10.1007/s12032-017-1042-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 09/21/2017] [Indexed: 11/24/2022]
Abstract
The incidence of papillary thyroid cancer has increased these last decades due to a better detection. High prevalence of nodules combined with the low incidence of thyroid cancers constitutes an important diagnostic challenge. We propose to develop an alternative diagnostic method to reduce the number of useless and painful thyroidectomies using a vectorized contrast agent for magnetic resonance imaging. Galectin-1 (gal-1), a protein overexpressed in well-differentiated thyroid cancer, has been targeted with a randomized linear 12-mer peptide library using the phage display technique. Selected peptides have been conjugated to ultrasmall superparamagnetic particles of iron oxide (USPIO). Peptides and their corresponding contrast agents have been tested in vitro for their specific binding and toxicity. Two peptides (P1 and P7) were selected according to their affinity toward gal-1. Their binding has been revealed by immunohistochemistry on human thyroid cancer biopsies, and they were co-localized with gal-1 by immunofluorescence on TPC-1 cell line. Both peptides induce a decrease in TPC-1 cells' adhesion to gal-1 immobilized on culture plates. After coupling to USPIO, the peptides preserved their affinity toward gal-1. Their specific binding has been corroborated by co-localization with gal-1 expressed by TPC-1 cells and by their ability to compete with anti-gal-1 antibody. The peptides and their USPIO derivatives produce no toxicity in HepaRG cells as determined by MTT assay. The vectorized contrast agents are potential imaging probes for thyroid cancer diagnosis. Moreover, the two gal-1-targeted peptides prevent cancer cell adhesion by interacting with the carbohydrate-recognition domain of gal-1.
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Affiliation(s)
- Deborah Fanfone
- Department of General, Organic and Biomedical Chemistry, University of Mons, Avenue Victor Maistriau 19, 7000, Mons, Belgium
| | - Nadège Despretz
- Department of General, Organic and Biomedical Chemistry, University of Mons, Avenue Victor Maistriau 19, 7000, Mons, Belgium
| | - Dimitri Stanicki
- Department of General, Organic and Biomedical Chemistry, University of Mons, Avenue Victor Maistriau 19, 7000, Mons, Belgium
| | - Jenifer Rubio-Magnieto
- Laboratory for Chemistry of Novel Materials, Center for Innovation in Materials and Polymers, University of Mons, Avenue Victor Maistriau, 19, 7000, Mons, Belgium
| | - Mathieu Fossépré
- Laboratory for Chemistry of Novel Materials, Center for Innovation in Materials and Polymers, University of Mons, Avenue Victor Maistriau, 19, 7000, Mons, Belgium
| | - Mathieu Surin
- Laboratory for Chemistry of Novel Materials, Center for Innovation in Materials and Polymers, University of Mons, Avenue Victor Maistriau, 19, 7000, Mons, Belgium
| | - Sandrine Rorive
- Department of Pathology, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik 808, 1070, Brussels, Belgium.,DIAPath, Center for Microscopy and Molecular Imaging, Rue Adrienne Bolland, 8, 6041, Charleroi, Belgium
| | - Isabelle Salmon
- Department of Pathology, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik 808, 1070, Brussels, Belgium.,DIAPath, Center for Microscopy and Molecular Imaging, Rue Adrienne Bolland, 8, 6041, Charleroi, Belgium
| | - Luce Vander Elst
- Department of General, Organic and Biomedical Chemistry, University of Mons, Avenue Victor Maistriau 19, 7000, Mons, Belgium
| | - Sophie Laurent
- Department of General, Organic and Biomedical Chemistry, University of Mons, Avenue Victor Maistriau 19, 7000, Mons, Belgium.,Center for Microscopy and Molecular Imaging, Rue Adrienne Bolland, 8, 6041, Charleroi, Belgium
| | - Robert N Muller
- Department of General, Organic and Biomedical Chemistry, University of Mons, Avenue Victor Maistriau 19, 7000, Mons, Belgium.,Center for Microscopy and Molecular Imaging, Rue Adrienne Bolland, 8, 6041, Charleroi, Belgium
| | - Sven Saussez
- Laboratory of Human Anatomy and Experimental Oncology, University of Mons, Avenue du Champ de Mars, 6, 7000, Mons, Belgium
| | - Carmen Burtea
- Department of General, Organic and Biomedical Chemistry, University of Mons, Avenue Victor Maistriau 19, 7000, Mons, Belgium.
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Varicose and cheerio collaborate with pebble to mediate semaphorin-1a reverse signaling in Drosophila. Proc Natl Acad Sci U S A 2017; 114:E8254-E8263. [PMID: 28894005 DOI: 10.1073/pnas.1713010114] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The transmembrane semaphorin Sema-1a acts as both a ligand and a receptor to regulate axon-axon repulsion during neural development. Pebble (Pbl), a Rho guanine nucleotide exchange factor, mediates Sema-1a reverse signaling through association with the N-terminal region of the Sema-1a intracellular domain (ICD), resulting in cytoskeletal reorganization. Here, we uncover two additional Sema-1a interacting proteins, varicose (Vari) and cheerio (Cher), each with neuronal functions required for motor axon pathfinding. Vari is a member of the membrane-associated guanylate kinase (MAGUK) family of proteins, members of which can serve as scaffolds to organize signaling complexes. Cher is related to actin filament cross-linking proteins that regulate actin cytoskeleton dynamics. The PDZ domain binding motif found in the most C-terminal region of the Sema-1a ICD is necessary for interaction with Vari, but not Cher, indicative of distinct binding modalities. Pbl/Sema-1a-mediated repulsive guidance is potentiated by both vari and cher Genetic analyses further suggest that scaffolding functions of Vari and Cher play an important role in Pbl-mediated Sema-1a reverse signaling. These results define intracellular components critical for signal transduction from the Sema-1a receptor to the cytoskeleton and provide insight into mechanisms underlying semaphorin-induced localized changes in cytoskeletal organization.
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Mitsogiannis MD, Little GE, Mitchell KJ. Semaphorin-Plexin signaling influences early ventral telencephalic development and thalamocortical axon guidance. Neural Dev 2017; 12:6. [PMID: 28438183 PMCID: PMC5402653 DOI: 10.1186/s13064-017-0083-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Accepted: 04/12/2017] [Indexed: 12/22/2022] Open
Abstract
Background Sensory processing relies on projections from the thalamus to the neocortex being established during development. Information from different sensory modalities reaching the thalamus is segregated into specialized nuclei, whose neurons then send inputs to cognate cortical areas through topographically defined axonal connections. Developing thalamocortical axons (TCAs) normally approach the cortex by extending through the subpallium; here, axonal navigation is aided by distributed guidance cues and discrete cell populations, such as the corridor neurons and the internal capsule (IC) guidepost cells. In mice lacking Semaphorin-6A, axons from the dorsal lateral geniculate nucleus (dLGN) bypass the IC and extend aberrantly in the ventral subpallium. The functions normally mediated by Semaphorin-6A in this system remain unknown, but might depend on interactions with Plexin-A2 and Plexin-A4, which have been implicated in other neurodevelopmental processes. Methods We performed immunohistochemical and neuroanatomical analyses of thalamocortical wiring and subpallial development in Sema6a and Plxna2; Plxna4 null mutant mice and analyzed the expression of these genes in relevant structures. Results In Plxna2; Plxna4 double mutants we discovered TCA pathfinding defects that mirrored those observed in Sema6a mutants, suggesting that Semaphorin-6A − Plexin-A2/Plexin-A4 signaling might mediate dLGN axon guidance at subpallial level. In order to understand where and when Semaphorin-6A, Plexin-A2 and Plexin-A4 may be required for proper subpallial TCA guidance, we then characterized their spatiotemporal expression dynamics during early TCA development. We observed that the thalamic neurons whose axons are misrouted in these mutants normally express Semaphorin-6A but not Plexin-A2 or Plexin-A4. By contrast, all three proteins are expressed in corridor cells and other structures in the developing basal ganglia. This finding could be consistent with an hypothetical action of Plexins as guidance signals through Sema6A as a receptor on dLGN axons, and/or with their indirect effect on TCA guidance due to functions in the morphogenesis of subpallial intermediate targets. In support of the latter possibility, we observed that in both Plxna2; Plxna4 and Sema6a mutants some IC guidepost cells abnormally localize in correspondence of the ventral path misrouted TCAs elongate into. Conclusions These findings implicate Semaphorin-6A − Plexin-A2/Plexin-A4 interactions in dLGN axon guidance and in the spatiotemporal organization of guidepost cell populations in the mammalian subpallium. Electronic supplementary material The online version of this article (doi:10.1186/s13064-017-0083-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Manuela D Mitsogiannis
- Smurfit Institute of Genetics, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland
| | - Graham E Little
- Smurfit Institute of Genetics, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland.,MRC Clinical Sciences Centre, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London, W12 0NN, United Kingdom
| | - Kevin J Mitchell
- Smurfit Institute of Genetics, School of Genetics and Microbiology, Trinity College Dublin, Dublin 2, Ireland. .,Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland. .,Developmental Neurogenetics, Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland.
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Jongbloets BC, Lemstra S, Schellino R, Broekhoven MH, Parkash J, Hellemons AJCGM, Mao T, Giacobini P, van Praag H, De Marchis S, Ramakers GMJ, Pasterkamp RJ. Stage-specific functions of Semaphorin7A during adult hippocampal neurogenesis rely on distinct receptors. Nat Commun 2017; 8:14666. [PMID: 28281529 PMCID: PMC5353663 DOI: 10.1038/ncomms14666] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/23/2017] [Indexed: 02/06/2023] Open
Abstract
The guidance protein Semaphorin7A (Sema7A) is required for the proper development of the immune and nervous systems. Despite strong expression in the mature brain, the role of Sema7A in the adult remains poorly defined. Here we show that Sema7A utilizes different cell surface receptors to control the proliferation and differentiation of neural progenitors in the adult hippocampal dentate gyrus (DG), one of the select regions of the mature brain where neurogenesis occurs. PlexinC1 is selectively expressed in early neural progenitors in the adult mouse DG and mediates the inhibitory effects of Sema7A on progenitor proliferation. Subsequently, during differentiation of adult-born DG granule cells, Sema7A promotes dendrite growth, complexity and spine development through β1-subunit-containing integrin receptors. Our data identify Sema7A as a key regulator of adult hippocampal neurogenesis, providing an example of how differential receptor usage spatiotemporally controls and diversifies the effects of guidance cues in the adult brain.
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Affiliation(s)
- Bart C. Jongbloets
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Suzanne Lemstra
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Roberta Schellino
- Dipartimento di Scienze della Vita e Biologia dei Sistemi and Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10100 Torino, Italy
| | - Mark H. Broekhoven
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Jyoti Parkash
- Centre for Animal Sciences, School of Basic and Applied Sciences, Central University Punjab, City Campus, Mansa Road, Bathinda 151001, India
| | - Anita J. C. G. M. Hellemons
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - Tianyi Mao
- Vollum Institute, Oregon Health & Science University, Portland, Oregon 97239, USA
| | - Paolo Giacobini
- Inserm, Laboratory of Development and Plasticity of the Neuroendocrine Brain, Jean-Pierre Aubert Research Centre, U1172, 59045 Lille, France
- University of Lille, 59045 Lille, France
| | - Henriette van Praag
- Neuroplasticity and Behavior Unit, Laboratory of Neurosciences, Intramural Research Program, National Institute on Aging, National Institutes of Health, Baltimore, Maryland 21224, USA
| | - Silvia De Marchis
- Dipartimento di Scienze della Vita e Biologia dei Sistemi and Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10100 Torino, Italy
| | - Geert M. J. Ramakers
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
| | - R. Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, 3584 CG Utrecht, The Netherlands
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Abstract
During neural circuit formation, axons need to navigate to their target cells in a complex, constantly changing environment. Although we most likely have identified most axon guidance cues and their receptors, we still cannot explain the molecular background of pathfinding for any subpopulation of axons. We lack mechanistic insight into the regulation of interactions between guidance receptors and their ligands. Recent developments in the field of axon guidance suggest that the regulation of surface expression of guidance receptors comprises transcriptional, translational, and post-translational mechanisms, such as trafficking of vesicles with specific cargos, protein-protein interactions, and specific proteolysis of guidance receptors. Not only axon guidance molecules but also the regulatory mechanisms that control their spatial and temporal expression are involved in synaptogenesis and synaptic plasticity. Therefore, it is not surprising that genes associated with axon guidance are frequently found in genetic and genomic studies of neurodevelopmental disorders.
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Affiliation(s)
- Esther Stoeckli
- Department of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
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37
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MiR-218 targets MeCP2 and inhibits heroin seeking behavior. Sci Rep 2017; 7:40413. [PMID: 28074855 PMCID: PMC5225456 DOI: 10.1038/srep40413] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 12/06/2016] [Indexed: 11/09/2022] Open
Abstract
MicroRNAs (miRNAs) are a class of evolutionarily conserved, 18-25 nucleotide non-coding sequences that post-transcriptionally regulate gene expression. Recent studies implicated their roles in the regulation of neuronal functions, such as learning, cognition and memory formation. Here we report that miR-218 inhibits heroin-induced behavioral plasticity. First, network propagation-based method was used to predict candidate miRNAs that played potential key roles in regulating drug addiction-related genes. Microarray screening was also carried out to identify miRNAs responding to chronic heroin administration in the nucleus accumbens (NAc). Among the collapsed miRNAs, top-ranked miR-218 was decreased after chronic exposure to heroin. Lentiviral overexpression of miR-218 in NAc could inhibit heroin-induced reinforcement in both conditioned place preference (CPP) test and heroin self-administration experiments. Luciferase activity assay indicated that miR-218 could regulate 3' untranslated regions (3' UTR) of multiple neuroplasticity-related genes and directly target methyl CpG binding protein 2 (Mecp2). Consistently, Mecp2308/y mice exhibited reduced heroin seeking behavior in CPP test. These data reveal a functional role of miR-218 and its target, MeCP2, in the regulation of heroin-induced behavioral plasticity.
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38
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Sun T, Yang L, Kaur H, Pestel J, Looso M, Nolte H, Krasel C, Heil D, Krishnan RK, Santoni MJ, Borg JP, Bünemann M, Offermanns S, Swiercz JM, Worzfeld T. A reverse signaling pathway downstream of Sema4A controls cell migration via Scrib. J Cell Biol 2016; 216:199-215. [PMID: 28007914 PMCID: PMC5223600 DOI: 10.1083/jcb.201602002] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 09/30/2016] [Accepted: 11/13/2016] [Indexed: 11/22/2022] Open
Abstract
Semaphorins comprise a large family of ligands that regulate key cellular functions through their receptors, plexins. In this study, we show that the transmembrane semaphorin 4A (Sema4A) can also function as a receptor, rather than a ligand, and transduce signals triggered by the binding of Plexin-B1 through reverse signaling. Functionally, reverse Sema4A signaling regulates the migration of various cancer cells as well as dendritic cells. By combining mass spectrometry analysis with small interfering RNA screening, we identify the polarity protein Scrib as a downstream effector of Sema4A. We further show that binding of Plexin-B1 to Sema4A promotes the interaction of Sema4A with Scrib, thereby removing Scrib from its complex with the Rac/Cdc42 exchange factor βPIX and decreasing the activity of the small guanosine triphosphatase Rac1 and Cdc42. Our data unravel a role for Plexin-B1 as a ligand and Sema4A as a receptor and characterize a reverse signaling pathway downstream of Sema4A, which controls cell migration.
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Affiliation(s)
- Tianliang Sun
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Lida Yang
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Harmandeep Kaur
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Jenny Pestel
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Mario Looso
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Hendrik Nolte
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Cornelius Krasel
- Institute of Pharmacology and Clinical Pharmacy, Biochemical-Pharmacological Center, University of Marburg, 35043 Marburg, Germany
| | - Daniel Heil
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Ramesh K Krishnan
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Marie-Josée Santoni
- Cell Polarity, Cell Signaling and Cancer, Equipe labellisée Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale, U1068, 13009 Marseille, France.,Institut Paoli-Calmettes, 13009 Marseille, France.,Aix-Marseille Université, 13284 Marseille, France.,Centre National de la Recherche Scientifique, UMR7258, 13273 Marseille, France
| | - Jean-Paul Borg
- Cell Polarity, Cell Signaling and Cancer, Equipe labellisée Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale, U1068, 13009 Marseille, France.,Institut Paoli-Calmettes, 13009 Marseille, France.,Aix-Marseille Université, 13284 Marseille, France.,Centre National de la Recherche Scientifique, UMR7258, 13273 Marseille, France
| | - Moritz Bünemann
- Institute of Pharmacology and Clinical Pharmacy, Biochemical-Pharmacological Center, University of Marburg, 35043 Marburg, Germany
| | - Stefan Offermanns
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany.,Medical Faculty, University of Frankfurt, 60590 Frankfurt am Main, Germany
| | - Jakub M Swiercz
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany
| | - Thomas Worzfeld
- Max Planck Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany .,Institute of Pharmacology, Biochemical-Pharmacological Center, University of Marburg, 35043 Marburg, Germany
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de Castro-Miró M, Tonda R, Escudero-Ferruz P, Andrés R, Mayor-Lorenzo A, Castro J, Ciccioli M, Hidalgo DA, Rodríguez-Ezcurra JJ, Farrando J, Pérez-Santonja JJ, Cormand B, Marfany G, Gonzàlez-Duarte R. Novel Candidate Genes and a Wide Spectrum of Structural and Point Mutations Responsible for Inherited Retinal Dystrophies Revealed by Exome Sequencing. PLoS One 2016; 11:e0168966. [PMID: 28005958 PMCID: PMC5179108 DOI: 10.1371/journal.pone.0168966] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 12/09/2016] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND NGS-based genetic diagnosis has completely revolutionized the human genetics field. In this study, we have aimed to identify new genes and mutations by Whole Exome Sequencing (WES) responsible for inherited retinal dystrophies (IRD). METHODS A cohort of 33 pedigrees affected with a variety of retinal disorders was analysed by WES. Initial prioritization analysis included around 300 IRD-associated genes. In non-diagnosed families a search for pathogenic mutations in novel genes was undertaken. RESULTS Genetic diagnosis was attained in 18 families. Moreover, a plausible candidate is proposed for 10 more cases. Two thirds of the mutations were novel, including 4 chromosomal rearrangements, which expand the IRD allelic heterogeneity and highlight the contribution of private mutations. Our results prompted clinical re-evaluation of some patients resulting in assignment to a syndromic instead of non-syndromic IRD. Notably, WES unveiled four new candidates for non-syndromic IRD: SEMA6B, CEP78, CEP250, SCLT1, the two latter previously associated to syndromic disorders. We provide functional data supporting that missense mutations in CEP250 alter cilia formation. CONCLUSION The diagnostic efficiency of WES, and strictly following the ACMG/AMP criteria is 55% in reported causative genes or functionally supported new candidates, plus 30% families in which likely pathogenic or VGUS/VUS variants were identified in plausible candidates. Our results highlight the clinical utility of WES for molecular diagnosis of IRD, provide a wider spectrum of mutations and concomitant genetic variants, and challenge our view on syndromic vs non-syndromic, and causative vs modifier genes.
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Affiliation(s)
- Marta de Castro-Miró
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
| | - Raul Tonda
- CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Paula Escudero-Ferruz
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
| | - Rosa Andrés
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
| | | | - Joaquín Castro
- Servicio de Oftalmología, Unidad de Retina, Hospital Universitario Central de Asturias, Oviedo, Spain
| | | | - Daniel A. Hidalgo
- Hospital Interzonal General de Agudos Eva Perón, Buenos Aires, Argentina
| | | | - Jorge Farrando
- Institut Oftalmològic Quirón Barcelona, Barcelona, Spain
| | - Juan J. Pérez-Santonja
- Department of Ophthalmology, Alicante University General Hospital, Alicante Institute for Health and Biomedical Research (ISABIAL-FISABIO Foundation), Alicante, Spain
| | - Bru Cormand
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
| | - Gemma Marfany
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
| | - Roser Gonzàlez-Duarte
- Departament de Genètica, Microbiologia i Estadística, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Barcelona, Spain
- Institut de Biomedicina (IBUB), Universitat de Barcelona, Barcelona, Spain
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de Ramon Francàs G, Zuñiga NR, Stoeckli ET. The spinal cord shows the way - How axons navigate intermediate targets. Dev Biol 2016; 432:43-52. [PMID: 27965053 DOI: 10.1016/j.ydbio.2016.12.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 11/26/2016] [Accepted: 12/01/2016] [Indexed: 12/13/2022]
Abstract
Functional neural circuits depend on the establishment of specific connections between neurons and their target cells. To this end, many axons have to travel long distances to reach their target cells during development. Studies addressing the molecular mechanisms of axon guidance have to overcome the complexity of subpopulation-specific requirements with respect to pathways, guidance cues, and target recognition. Compared to the brain, the relatively simple structure of the spinal cord provides an advantage for experimental studies of axon guidance mechanisms. Therefore, the so far best understood model for axon guidance is the dI1 population of dorsal interneurons of the spinal cord. They extend their axons ventrally towards the floor plate. After midline crossing, they turn rostrally along the contralateral floor-plate border. Despite the fact that the trajectory of dI1 axons seems to be rather simple, the number of axon guidance molecules involved in the decisions taken by these axons is bewildering. Because guidance molecules and mechanisms are conserved throughout the developing nervous system, we can generalize what we have learned about the navigation of the floor plate as an intermediate target for commissural axons to the brain.
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Affiliation(s)
- Gemma de Ramon Francàs
- University of Zurich, Department of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Nikole R Zuñiga
- University of Zurich, Department of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Esther T Stoeckli
- University of Zurich, Department of Molecular Life Sciences and Neuroscience Center Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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41
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Madsen MB, Kogelman LJA, Kadarmideen HN, Rasmussen HB. Systems genetics analysis of pharmacogenomics variation during antidepressant treatment. THE PHARMACOGENOMICS JOURNAL 2016; 18:144-152. [PMID: 27752142 DOI: 10.1038/tpj.2016.68] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 06/17/2016] [Accepted: 08/25/2016] [Indexed: 12/24/2022]
Abstract
Selective serotonin reuptake inhibitors (SSRIs) are the most widely used antidepressants, but the efficacy of the treatment varies significantly among individuals. It is believed that complex genetic mechanisms play a part in this variation. We have used a network based approach to unravel the involved genetic components. Moreover, we investigated the potential difference in the genetic interaction networks underlying SSRI treatment response over time. We found four hub genes (ASCC3, PPARGC1B, SCHIP1 and TMTC2) with different connectivity in the initial SSRI treatment period (baseline to week 4) compared with the subsequent period (4-8 weeks after initiation), suggesting that different genetic networks are important at different times during SSRI treatment. The strongest interactions in the initial SSRI treatment period involved genes encoding transcriptional factors, and in the subsequent period genes involved in calcium homeostasis. In conclusion, we suggest a difference in genetic interaction networks between initial and subsequent SSRI response.
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Affiliation(s)
- M B Madsen
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Capital Region of Denmark, Roskilde, Denmark.,iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Denmark
| | - L J A Kogelman
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - H N Kadarmideen
- Department of Large Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - H B Rasmussen
- Institute of Biological Psychiatry, Mental Health Centre Sct. Hans, Capital Region of Denmark, Roskilde, Denmark.,iPSYCH, The Lundbeck Foundation Initiative for Integrative Psychiatric Research, Denmark
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Yang DS, Roh S, Jeong S. The axon guidance function of Rap1 small GTPase is independent of PlexA RasGAP activity in Drosophila. Dev Biol 2016; 418:258-67. [DOI: 10.1016/j.ydbio.2016.08.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 07/25/2016] [Accepted: 08/22/2016] [Indexed: 12/20/2022]
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Frei JA, Stoeckli ET. SynCAMs - From axon guidance to neurodevelopmental disorders. Mol Cell Neurosci 2016; 81:41-48. [PMID: 27594578 DOI: 10.1016/j.mcn.2016.08.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 08/28/2016] [Accepted: 08/31/2016] [Indexed: 12/22/2022] Open
Abstract
Many cell adhesion molecules are located at synapses but only few of them can be considered synaptic cell adhesion molecules in the strict sense. Besides the Neurexins and Neuroligins, the LRRTMs (leucine rich repeat transmembrane proteins) and the SynCAMs/CADMs can induce synapse formation when expressed in non-neuronal cells and therefore are true synaptic cell adhesion molecules. SynCAMs (synaptic cell adhesion molecules) are a subfamily of the immunoglobulin superfamily of cell adhesion molecules. As suggested by their name, they were first identified as cell adhesion molecules at the synapse which were sufficient to trigger synapse formation. They also contribute to myelination by mediating axon-glia cell contacts. More recently, their role in earlier stages of neural circuit formation was demonstrated, as they also guide axons both in the peripheral and in the central nervous system. Mutations in SynCAM genes were found in patients diagnosed with autism spectrum disorders. The diverse functions of SynCAMs during development suggest that neurodevelopmental disorders are not only due to defects in synaptic plasticity. Rather, early steps of neural circuit formation are likely to contribute.
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Affiliation(s)
- Jeannine A Frei
- Hussman Institute for Autism, 801 W Baltimore Street, Baltimore, MD 20201, United States
| | - Esther T Stoeckli
- Dept of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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Pignata A, Ducuing H, Castellani V. Commissural axon navigation: Control of midline crossing in the vertebrate spinal cord by the semaphorin 3B signaling. Cell Adh Migr 2016; 10:604-617. [PMID: 27532244 PMCID: PMC5160037 DOI: 10.1080/19336918.2016.1212804] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The mechanisms governing the navigation of commissural axons during embryonic development have been extensively investigated in the past years, often using the drosophila ventral nerve cord and the spinal cord as model systems. Similarities but also specificities in the general strategies, the molecular signals as well as in the regulatory pathways controlling the response of commissural axons to the guidance cues have been found between species. Whether the semaphorin signaling contributes to midline crossing in the fly nervous system remains unknown, while in contrast, it does play a prominent contribution in vertebrates. In this review we discuss the functions of the semaphorins during commissural axon guidance in the developing spinal cord, focusing on the family member semaphorin 3B (Sema3B) in the context of midline crossing in the spinal cord.
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Affiliation(s)
- Aurora Pignata
- a University of Lyon, Université Claude Bernard Lyon 1, NeuroMyogene Institute (INMG), UMR CNRS 5310, INSERM U1217 Lyon , France
| | - Hugo Ducuing
- a University of Lyon, Université Claude Bernard Lyon 1, NeuroMyogene Institute (INMG), UMR CNRS 5310, INSERM U1217 Lyon , France
| | - Valérie Castellani
- a University of Lyon, Université Claude Bernard Lyon 1, NeuroMyogene Institute (INMG), UMR CNRS 5310, INSERM U1217 Lyon , France
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Kong Y, Janssen BJC, Malinauskas T, Vangoor VR, Coles CH, Kaufmann R, Ni T, Gilbert RJC, Padilla-Parra S, Pasterkamp RJ, Jones EY. Structural Basis for Plexin Activation and Regulation. Neuron 2016; 91:548-60. [PMID: 27397516 PMCID: PMC4980550 DOI: 10.1016/j.neuron.2016.06.018] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2014] [Revised: 05/11/2016] [Accepted: 06/07/2016] [Indexed: 12/17/2022]
Abstract
Class A plexins (PlxnAs) act as semaphorin receptors and control diverse aspects of nervous system development and plasticity, ranging from axon guidance and neuron migration to synaptic organization. PlxnA signaling requires cytoplasmic domain dimerization, but extracellular regulation and activation mechanisms remain unclear. Here we present crystal structures of PlxnA (PlxnA1, PlxnA2, and PlxnA4) full ectodomains. Domains 1-9 form a ring-like conformation from which the C-terminal domain 10 points away. All our PlxnA ectodomain structures show autoinhibitory, intermolecular "head-to-stalk" (domain 1 to domain 4-5) interactions, which are confirmed by biophysical assays, live cell fluorescence microscopy, and cell-based and neuronal growth cone collapse assays. This work reveals a 2-fold role of the PlxnA ectodomains: imposing a pre-signaling autoinhibitory separation for the cytoplasmic domains via intermolecular head-to-stalk interactions and supporting dimerization-based PlxnA activation upon ligand binding. More generally, our data identify a novel molecular mechanism for preventing premature activation of axon guidance receptors.
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Affiliation(s)
- Youxin Kong
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Bert J C Janssen
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Tomas Malinauskas
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Vamshidhar R Vangoor
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Charlotte H Coles
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Rainer Kaufmann
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom; Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Tao Ni
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Robert J C Gilbert
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Sergi Padilla-Parra
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, The Netherlands.
| | - E Yvonne Jones
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom.
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Perez-Branguli F, Zagar Y, Shanley DK, Graef IA, Chédotal A, Mitchell KJ. Reverse Signaling by Semaphorin-6A Regulates Cellular Aggregation and Neuronal Morphology. PLoS One 2016; 11:e0158686. [PMID: 27392094 PMCID: PMC4938514 DOI: 10.1371/journal.pone.0158686] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 06/20/2016] [Indexed: 12/28/2022] Open
Abstract
The transmembrane semaphorin, Sema6A, has important roles in axon guidance, cell migration and neuronal connectivity in multiple regions of the nervous system, mediated by context-dependent interactions with plexin receptors, PlxnA2 and PlxnA4. Here, we demonstrate that Sema6A can also signal cell-autonomously, in two modes, constitutively, or in response to higher-order clustering mediated by either PlxnA2-binding or chemically induced multimerisation. Sema6A activation stimulates recruitment of Abl to the cytoplasmic domain of Sema6A and phos¡phorylation of this cytoplasmic tyrosine kinase, as well as phosphorylation of additional cytoskeletal regulators. Sema6A reverse signaling affects the surface area and cellular complexity of non-neuronal cells and aggregation and neurite formation of primary neurons in vitro. Sema6A also interacts with PlxnA2 in cis, which reduces binding by PlxnA2 of Sema6A in trans but not vice versa. These experiments reveal the complex nature of Sema6A biochemical functions and the molecular logic of the context-dependent interactions between Sema6A and PlxnA2.
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Affiliation(s)
- Francesc Perez-Branguli
- Smurfit Institute of Genetics and Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Yvrick Zagar
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMR_S968, CNRS_UMR7210, Institut de la Vision, Paris, France
| | - Daniel K. Shanley
- Smurfit Institute of Genetics and Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
| | - Isabella A. Graef
- Department of Pathology, Stanford University Medical School, Stanford, California, United States of America
| | - Alain Chédotal
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMR_S968, CNRS_UMR7210, Institut de la Vision, Paris, France
| | - Kevin J. Mitchell
- Smurfit Institute of Genetics and Institute of Neuroscience, Trinity College Dublin, Dublin 2, Ireland
- * E-mail:
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Gurrapu S, Tamagnone L. Transmembrane semaphorins: Multimodal signaling cues in development and cancer. Cell Adh Migr 2016; 10:675-691. [PMID: 27295627 DOI: 10.1080/19336918.2016.1197479] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Semaphorins constitute a large family of membrane-bound and secreted proteins that provide guidance cues for axon pathfinding and cell migration. Although initially discovered as repelling cues for axons in nervous system, they have been found to regulate cell adhesion and motility, angiogenesis, immune function and tumor progression. Notably, semaphorins are bifunctional cues and for instance can mediate both repulsive and attractive functions in different contexts. While many studies focused so far on the function of secreted family members, class 1 semaphorins in invertebrates and class 4, 5 and 6 in vertebrate species comprise around 14 transmembrane semaphorin molecules with emerging functional relevance. These can signal in juxtacrine, paracrine and autocrine fashion, hence mediating long and short range repulsive and attractive guidance cues which have a profound impact on cellular morphology and functions. Importantly, transmembrane semaphorins are capable of bidirectional signaling, acting both in "forward" mode via plexins (sometimes in association with receptor tyrosine kinases), and in "reverse" manner through their cytoplasmic domains. In this review, we will survey known molecular mechanisms underlying the functions of transmembrane semaphorins in development and cancer.
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Affiliation(s)
- Sreeharsha Gurrapu
- a Department of Oncology , University of Torino c/o IRCCS , Candiolo ( TO ), Italy.,b Candiolo Cancer Institute, IRCCS-FPO , Candiolo ( TO ), Italy
| | - Luca Tamagnone
- a Department of Oncology , University of Torino c/o IRCCS , Candiolo ( TO ), Italy.,b Candiolo Cancer Institute, IRCCS-FPO , Candiolo ( TO ), Italy
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Battistini C, Tamagnone L. Transmembrane semaphorins, forward and reverse signaling: have a look both ways. Cell Mol Life Sci 2016; 73:1609-22. [PMID: 26794845 PMCID: PMC11108563 DOI: 10.1007/s00018-016-2137-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 01/07/2016] [Accepted: 01/11/2016] [Indexed: 01/06/2023]
Abstract
Semaphorins are signaling molecules playing pivotal roles not only as axon guidance cues, but are also involved in the regulation of a range of biological processes, such as immune response, angiogenesis and invasive tumor growth. The main functional receptors for semaphorins are plexins, which are large single-pass transmembrane molecules. Semaphorin signaling through plexins-the "classical" forward signaling-affects cytoskeletal remodeling and integrin-dependent adhesion, consequently influencing cell migration. Intriguingly, semaphorins and plexins can interact not only in trans, but also in cis, leading to differentiated and highly regulated signaling outputs. Moreover, transmembrane semaphorins can also mediate a so-called "reverse" signaling, by acting not as ligands but rather as receptors, and initiate a signaling cascade through their own cytoplasmic domains. Semaphorin reverse signaling has been clearly demonstrated in fruit fly Sema1a, which is required to control motor axon defasciculation and target recognition during neuromuscular development. Sema1a invertebrate semaphorin is most similar to vertebrate class-6 semaphorins, and examples of semaphorin reverse signaling in mammalians have been described for these family members. Reverse signaling is also reported for other vertebrate semaphorin subsets, e.g. class-4 semaphorins, which bear potential PDZ-domain interaction motifs in their cytoplasmic regions. Therefore, thanks to their various signaling abilities, transmembrane semaphorins can play multifaceted roles both in developmental processes and in physiological as well as pathological conditions in the adult.
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Affiliation(s)
- Chiara Battistini
- Department of Oncology, University of Torino c/o IRCCS, Str. Prov. 142, 10060, Candiolo (TO), Italy
- Candiolo Cancer Institute, IRCCS-FPO, Str. Prov. 142, 10060, Candiolo (TO), Italy
| | - Luca Tamagnone
- Department of Oncology, University of Torino c/o IRCCS, Str. Prov. 142, 10060, Candiolo (TO), Italy.
- Candiolo Cancer Institute, IRCCS-FPO, Str. Prov. 142, 10060, Candiolo (TO), Italy.
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Alther TA, Domanitskaya E, Stoeckli ET. Calsyntenin1-mediated trafficking of axon guidance receptors regulates the switch in axonal responsiveness at a choice point. Development 2016; 143:994-1004. [DOI: 10.1242/dev.127449] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Accepted: 01/26/2016] [Indexed: 02/04/2023]
Abstract
Axon guidance at choice points depends on the precise regulation of guidance receptors on the growth cone surface. Upon arrival at the intermediate target or choice point, a switch from attraction to repulsion is required for the axon to move on. Dorsal commissural (dI1) axons crossing the ventral midline of the spinal cord in the floor plate represent a convenient model for the analysis of the molecular mechanism underlying the switch in axonal behavior.
We identified a role of Calsyntenin1 in the regulation of vesicular trafficking of guidance receptors in dI1 axons at choice points. In cooperation with RabGDI, Calsyntenin1 shuttles Rab11-positive vesicles containing Robo1 to the growth cone surface in a precisely regulated manner. In contrast, Calsyntenin1-mediated trafficking of Frizzled3, a guidance receptor in the Wnt pathway, is independent of RabGDI. Thus, tightly regulated insertion of guidance receptors, which is required for midline crossing and the subsequent turn into the longitudinal axis, is achieved by specific trafficking.
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Affiliation(s)
- Tobias A. Alther
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Elena Domanitskaya
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
| | - Esther T. Stoeckli
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland
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50
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Avilés EC, Stoeckli ET. Canonical wnt signaling is required for commissural axon guidance. Dev Neurobiol 2015; 76:190-208. [PMID: 26014644 PMCID: PMC4755210 DOI: 10.1002/dneu.22307] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Revised: 05/20/2015] [Accepted: 05/20/2015] [Indexed: 12/20/2022]
Abstract
Morphogens have been identified as guidance cues for postcrossing commissural axons in the spinal cord. Shh has a dual effect on postcrossing commissural axons: a direct repellent effect mediated by Hhip as a receptor, and an indirect effect by shaping a Wnt activity gradient. Wnts were shown to be attractants for postcrossing commissural axons in both chicken and mouse embryos. In mouse, the effects of Wnts on axon guidance were concluded to depend on the planar cell polarity (PCP) pathway. Canonical Wnt signaling was excluded based on the absence of axon guidance defects in mice lacking Lrp6 which is an obligatory coreceptor for Fzd in canonical Wnt signaling. In the loss-of-function studies reported here, we confirmed a role for the PCP pathway in postcrossing commissural axon guidance also in the chicken embryo. However, taking advantage of the precise temporal control of gene silencing provided by in ovo RNAi, we demonstrate that canonical Wnt signaling is also required for proper guidance of postcrossing commissural axons in the developing spinal cord. Thus, axon guidance does not seem to depend on any one of the classical Wnt signaling pathways but rather involve a network of Wnt receptors and downstream components.
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Affiliation(s)
- Evelyn C Avilés
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Esther T Stoeckli
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
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