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Kim SH, Nichols KD, Anderson EN, Liu Y, Ramesh N, Jia W, Kuerbis CJ, Scalf M, Smith LM, Pandey UB, Tibbetts RS. Axon guidance genes modulate neurotoxicity of ALS-associated UBQLN2. eLife 2023; 12:e84382. [PMID: 37039476 PMCID: PMC10147378 DOI: 10.7554/elife.84382] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 04/06/2023] [Indexed: 04/12/2023] Open
Abstract
Mutations in the ubiquitin (Ub) chaperone Ubiquilin 2 (UBQLN2) cause X-linked forms of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) through unknown mechanisms. Here, we show that aggregation-prone, ALS-associated mutants of UBQLN2 (UBQLN2ALS) trigger heat stress-dependent neurodegeneration in Drosophila. A genetic modifier screen implicated endolysosomal and axon guidance genes, including the netrin receptor, Unc-5, as key modulators of UBQLN2 toxicity. Reduced gene dosage of Unc-5 or its coreceptor Dcc/frazzled diminished neurodegenerative phenotypes, including motor dysfunction, neuromuscular junction defects, and shortened lifespan, in flies expressing UBQLN2ALS alleles. Induced pluripotent stem cells (iPSCs) harboring UBQLN2ALS knockin mutations exhibited lysosomal defects while inducible motor neurons (iMNs) expressing UBQLN2ALS alleles exhibited cytosolic UBQLN2 inclusions, reduced neurite complexity, and growth cone defects that were partially reversed by silencing of UNC5B and DCC. The combined findings suggest that altered growth cone dynamics are a conserved pathomechanism in UBQLN2-associated ALS/FTD.
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Affiliation(s)
- Sang Hwa Kim
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Kye D Nichols
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Eric N Anderson
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical CenterPittsburghUnited States
| | - Yining Liu
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Nandini Ramesh
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical CenterPittsburghUnited States
| | - Weiyan Jia
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Connor J Kuerbis
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
| | - Mark Scalf
- Department of Chemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin-MadisonMadisonUnited States
| | - Udai Bhan Pandey
- Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical CenterPittsburghUnited States
| | - Randal S Tibbetts
- Department of Human Oncology, University of Wisconsin School of Medicine and Public HealthMadisonUnited States
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2
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Guidance landscapes unveiled by quantitative proteomics to control reinnervation in adult visual system. Nat Commun 2022; 13:6040. [PMID: 36229455 PMCID: PMC9561644 DOI: 10.1038/s41467-022-33799-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 09/30/2022] [Indexed: 12/24/2022] Open
Abstract
In the injured adult central nervous system (CNS), activation of pro-growth molecular pathways in neurons leads to long-distance regeneration. However, most regenerative fibers display guidance defects, which prevent reinnervation and functional recovery. Therefore, the molecular characterization of the proper target regions of regenerative axons is essential to uncover the modalities of adult reinnervation. In this study, we use mass spectrometry (MS)-based quantitative proteomics to address the proteomes of major nuclei of the adult visual system. These analyses reveal that guidance-associated molecules are expressed in adult visual targets. Moreover, we show that bilateral optic nerve injury modulates the expression of specific proteins. In contrast, the expression of guidance molecules remains steady. Finally, we show that regenerative axons are able to respond to guidance cues ex vivo, suggesting that these molecules possibly interfere with brain target reinnervation in adult. Using a long-distance regeneration model, we further demonstrate that the silencing of specific guidance signaling leads to rerouting of regenerative axons in vivo. Altogether, our results suggest ways to modulate axon guidance of regenerative neurons to achieve circuit repair in adult.
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3
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Moreland T, Poulain FE. To Stick or Not to Stick: The Multiple Roles of Cell Adhesion Molecules in Neural Circuit Assembly. Front Neurosci 2022; 16:889155. [PMID: 35573298 PMCID: PMC9096351 DOI: 10.3389/fnins.2022.889155] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 03/28/2022] [Indexed: 01/02/2023] Open
Abstract
Precise wiring of neural circuits is essential for brain connectivity and function. During development, axons respond to diverse cues present in the extracellular matrix or at the surface of other cells to navigate to specific targets, where they establish precise connections with post-synaptic partners. Cell adhesion molecules (CAMs) represent a large group of structurally diverse proteins well known to mediate adhesion for neural circuit assembly. Through their adhesive properties, CAMs act as major regulators of axon navigation, fasciculation, and synapse formation. While the adhesive functions of CAMs have been known for decades, more recent studies have unraveled essential, non-adhesive functions as well. CAMs notably act as guidance cues and modulate guidance signaling pathways for axon pathfinding, initiate contact-mediated repulsion for spatial organization of axonal arbors, and refine neuronal projections during circuit maturation. In this review, we summarize the classical adhesive functions of CAMs in axonal development and further discuss the increasing number of other non-adhesive functions CAMs play in neural circuit assembly.
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Lu C, Wei F, He X, Yao X, Yu C. LncRNA expression in idiopathic achalasia: New insight and preliminary exploration into pathogenesis. Open Med (Wars) 2022; 17:732-740. [PMID: 35509690 PMCID: PMC9007103 DOI: 10.1515/med-2022-0473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 03/18/2022] [Accepted: 03/21/2022] [Indexed: 11/15/2022] Open
Abstract
Idiopathic achalasia is a primary esophageal motility disorder characterized by the absence of esophageal peristalsis and impaired relaxation of the lower esophageal sphincter (LES). However, the pathogenesis of idiopathic achalasia remains unclear. To further understand the pathogenesis, we conducted lncRNA and mRNA microarray analyses. LES specimens from 5 patients and 4 controls were used for microarray. Potential target genes with significantly changed lncRNA and mRNA were predicted using cis/trans-regulatory algorithms, followed by the Gene Ontology and KEGG pathway enrichment analysis to understand the biophysical effect. Finally, 7,133 significantly dysregulated mRNAs (3,136 increased and 3,997 decreased), along with 6,892 significantly dysregulated lncRNAs (4,900 increased and 1,992 decreased). Biophysical function analysis revealed that the cell adhesion molecule (CAM) pathway was a common pathway. The predicted lncRNA targets of NRXN1 (Down FC: 9.07), NTNG2 (UP FC: 2.75), CADM1 (Down FC: 2.26), NLGN1 (Down FC: 4.60), NEGR1 (Down FC: 2.335), CD22 (Down FC: 5.62), HLA-DQB1 (Down FC: 5.06), and HLA-DOA (Down FC: 2.31) were inputted in this pathway, which was mainly located in the synapse part of the neural system and immune system. Our study demonstrates the lncRNAs and corresponding mRNAs that may play important roles in idiopathic achalasia.
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Affiliation(s)
- Chao Lu
- Department of Gastroenterology, The First Affiliated Hospital, Zhejiang University School of Medicine , Hangzhou , 310003 , China
| | - Furong Wei
- Department of Gastroenterology, The First Affiliated Hospital, Zhejiang University School of Medicine , Hangzhou , 310003 , China
| | - Xinjue He
- Department of Gastroenterology, The First Affiliated Hospital, Zhejiang University School of Medicine , Hangzhou , 310003 , China
| | - Xin Yao
- Department of Gastroenterology, The First Affiliated Hospital, Zhejiang University School of Medicine , Hangzhou , 310003 , China
| | - Chaohui Yu
- Department of Gastroenterology, The First Affiliated Hospital, Zhejiang University School of Medicine , Hangzhou , 310003 , China
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5
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Eijsbouts C, Zheng T, Kennedy NA, Bonfiglio F, Anderson CA, Moutsianas L, Holliday J, Shi J, Shringarpure S, Voda AI, Farrugia G, Franke A, Hübenthal M, Abecasis G, Zawistowski M, Skogholt AH, Ness-Jensen E, Hveem K, Esko T, Teder-Laving M, Zhernakova A, Camilleri M, Boeckxstaens G, Whorwell PJ, Spiller R, McVean G, D'Amato M, Jostins L, Parkes M. Genome-wide analysis of 53,400 people with irritable bowel syndrome highlights shared genetic pathways with mood and anxiety disorders. Nat Genet 2021; 53:1543-1552. [PMID: 34741163 PMCID: PMC8571093 DOI: 10.1038/s41588-021-00950-8] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 09/08/2021] [Indexed: 12/19/2022]
Abstract
Irritable bowel syndrome (IBS) results from disordered brain-gut interactions. Identifying susceptibility genes could highlight the underlying pathophysiological mechanisms. We designed a digestive health questionnaire for UK Biobank and combined identified cases with IBS with independent cohorts. We conducted a genome-wide association study with 53,400 cases and 433,201 controls and replicated significant associations in a 23andMe panel (205,252 cases and 1,384,055 controls). Our study identified and confirmed six genetic susceptibility loci for IBS. Implicated genes included NCAM1, CADM2, PHF2/FAM120A, DOCK9, CKAP2/TPTE2P3 and BAG6. The first four are associated with mood and anxiety disorders, expressed in the nervous system, or both. Mirroring this, we also found strong genome-wide correlation between the risk of IBS and anxiety, neuroticism and depression (rg > 0.5). Additional analyses suggested this arises due to shared pathogenic pathways rather than, for example, anxiety causing abdominal symptoms. Implicated mechanisms require further exploration to help understand the altered brain-gut interactions underlying IBS.
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Affiliation(s)
- Chris Eijsbouts
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
- Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Tenghao Zheng
- Center for Molecular Medicine & Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - Nicholas A Kennedy
- IBD Pharmacogenetics, College of Medicine and Health, University of Exeter, Exeter, UK
| | - Ferdinando Bonfiglio
- Center for Molecular Medicine & Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia
| | - Carl A Anderson
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK
| | - Loukas Moutsianas
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, UK
- William Harvey Research Institute, Barts & The London School of Medicine & Dentistry, Queen Mary University of London, London, UK
| | - Joanne Holliday
- Nuffield Department of Population Health, University of Oxford, Oxford, UK
| | | | | | - Alexandru-Ioan Voda
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK
- Saint Edmund Hall, University of Oxford, Oxford, UK
| | - Gianrico Farrugia
- Enteric NeuroScience Program, Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Andre Franke
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Matthias Hübenthal
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany
- Department of Dermatology, Quincke Research Center, University Hospital Schleswig-Holstein, Kiel, Germany
| | - Gonçalo Abecasis
- Department of Biostatistics, University of Michigan, School of Public Health, Ann Arbor, MI, USA
| | - Matthew Zawistowski
- Department of Biostatistics, University of Michigan, School of Public Health, Ann Arbor, MI, USA
| | - Anne Heidi Skogholt
- Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Public Health and Nursing, Norwegian University of Science and Technology, Trondheim, Norway
| | - Eivind Ness-Jensen
- Department of Public Health and Nursing, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Medicine, Levanger Hospital, Nord-Trøndelag Hospital Trust, Levanger, Norway
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Kristian Hveem
- Department of Public Health and Nursing, Norwegian University of Science and Technology, Trondheim, Norway
| | - Tõnu Esko
- Estonian Genome Center, Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Maris Teder-Laving
- Estonian Genome Center, Institute of Genomics, University of Tartu, Tartu, Estonia
| | - Alexandra Zhernakova
- Department of Genetics, University Medical Center Groningen, Groningen, the Netherlands
| | - Michael Camilleri
- Clinical Enteric Neuroscience Translational and Epidemiological Research and Division of Gastroenterology and Hepatology, Department of Medicine, Mayo Clinic, Rochester, MN, USA
| | - Guy Boeckxstaens
- David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Peter J Whorwell
- Neurogastroenterology Unit, Wythenshawe Hospital, Centre for Gastrointestinal Sciences, University of Manchester, Manchester, UK
| | - Robin Spiller
- Nottingham Digestive Diseases Centre, National Institute for Health Research Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - Gil McVean
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK
| | - Mauro D'Amato
- Center for Molecular Medicine & Clinical Epidemiology Unit, Department of Medicine Solna, Karolinska Institutet, Stockholm, Sweden.
- School of Biological Sciences, Monash University, Clayton, Victoria, Australia.
- Institute of Clinical Molecular Biology, Christian-Albrechts-University of Kiel, Kiel, Germany.
- Biodonostia Health Research Institute, San Sebastian, Spain.
- Gastrointestinal Genetics Lab, CIC bioGUNE - Basque Research and Technology Alliance, Derio, Spain.
- IKERBASQUE, The Basque Science Foundation, Bilbao, Spain.
| | - Luke Jostins
- Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, UK.
- Kennedy Institute of Rheumatology, University of Oxford, Oxford, UK.
- Christ Church, University of Oxford, Oxford, UK.
| | - Miles Parkes
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge, UK.
- Department of Gastroenterology, Cambridge University Hospital, Cambridge, UK.
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6
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Mencer S, Kartawy M, Lendenfeld F, Soluh H, Tripathi MK, Khaliulin I, Amal H. Proteomics of autism and Alzheimer's mouse models reveal common alterations in mTOR signaling pathway. Transl Psychiatry 2021; 11:480. [PMID: 34535637 PMCID: PMC8448888 DOI: 10.1038/s41398-021-01578-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/03/2021] [Accepted: 08/20/2021] [Indexed: 12/14/2022] Open
Abstract
Autism spectrum disorder (ASD) and Alzheimer's disease (AD) are two different neurological disorders that share common clinical features, such as language impairment, executive functions, and motor problems. A genetic convergence has been proposed as well. However, the molecular mechanisms of these pathologies are still not well understood. Protein S-nitrosylation (SNO), the nitric oxide (NO)-mediated posttranslational modification, targets key proteins implicated in synaptic and neuronal functions. Previously, we have shown that NO and SNO are involved in the InsG3680(+/+) ASD and P301S AD mouse models. Here, we performed large-scale computational biology analysis of the SNO-proteome followed by biochemical validation to decipher the shared mechanisms between the pathologies. This analysis pointed to the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway as one of the shared molecular mechanisms. Activation of mTOR in the cortex of both mouse models was confirmed by western blots that showed increased phosphorylation of RPS6, a major substrate of mTORC1. Other molecular alterations affected by SNO and shared between the two mouse models, such as synaptic-associated processes, PKA signaling, and cytoskeleton-related processes were also detected. This is the first study to decipher the SNO-related shared mechanisms between SHANK3 and MAPT mutations. Understanding the involvement of SNO in neurological disorders and its intersection between ASD and AD might help developing an effective novel therapy for both neuropathologies.
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Affiliation(s)
- Shira Mencer
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Maryam Kartawy
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Felix Lendenfeld
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Huda Soluh
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Manish Kumar Tripathi
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Igor Khaliulin
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Haitham Amal
- Institute for Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel.
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7
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Thorpe HHA, Talhat MA, Khokhar JY. High genes: Genetic underpinnings of cannabis use phenotypes. Prog Neuropsychopharmacol Biol Psychiatry 2021; 106:110164. [PMID: 33152387 DOI: 10.1016/j.pnpbp.2020.110164] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 09/25/2020] [Accepted: 10/29/2020] [Indexed: 12/19/2022]
Abstract
Cannabis is one of the most widely used substances across the globe and its use has a substantial heritable component. However, the heritability of cannabis use varies according to substance use phenotype, suggesting that a unique profile of gene variants may contribute to the different stages of use, such as age of use onset, lifetime use, cannabis use disorder, and withdrawal and craving during abstinence. Herein, we review a subset of genes identified by candidate gene, family-based linkage, and genome-wide association studies related to these cannabis use phenotypes. We also describe their relationships with other substances, and their functions at the neurobiological, cognitive, and behavioral levels to hypothesize the role of these genes in cannabis use risk. Delineating genetic risk factors in the various stages of cannabis use will provide insight into the biological mechanisms related to cannabis use and highlight points of intervention prior to and following the development of dependence, as well as identify targets to aid drug development for treating problematic cannabis use.
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Affiliation(s)
- Hayley H A Thorpe
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | | | - Jibran Y Khokhar
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada.
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8
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Kim HY, Um JW, Ko J. Proper synaptic adhesion signaling in the control of neural circuit architecture and brain function. Prog Neurobiol 2021; 200:101983. [PMID: 33422662 DOI: 10.1016/j.pneurobio.2020.101983] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/23/2020] [Accepted: 12/22/2020] [Indexed: 12/17/2022]
Abstract
Trans-synaptic cell-adhesion molecules are critical for governing various stages of synapse development and specifying neural circuit properties via the formation of multifarious signaling pathways. Recent studies have pinpointed the putative roles of trans-synaptic cell-adhesion molecules in mediating various cognitive functions. Here, we review the literature on the roles of a diverse group of central synaptic organizers, including neurexins (Nrxns), leukocyte common antigen-related receptor protein tyrosine phosphatases (LAR-RPTPs), and their associated binding proteins, in regulating properties of specific type of synapses and neural circuits. In addition, we highlight the findings that aberrant synaptic adhesion signaling leads to alterations in the structures, transmission, and plasticity of specific synapses across diverse brain areas. These results seem to suggest that proper trans-synaptic signaling pathways by Nrxns, LAR-RPTPs, and their interacting network is likely to constitute central molecular complexes that form the basis for cognitive functions, and that these complexes are heterogeneously and complexly disrupted in many neuropsychiatric and neurodevelopmental disorders.
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Affiliation(s)
- Hee Young Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea; Core Protein Resources Center, DGIST, Daegu, 42988, South Korea.
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, 42988, South Korea.
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9
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Differential Contribution of Cadm1-Cadm3 Cell Adhesion Molecules to Peripheral Myelinated Axons. J Neurosci 2021; 41:1393-1400. [PMID: 33397712 DOI: 10.1523/jneurosci.2736-20.2020] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 11/18/2020] [Indexed: 12/14/2022] Open
Abstract
Cell adhesion proteins of the Cadm (SynCAM/Necl) family regulate myelination and the organization of myelinated axons. In the peripheral nervous system (PNS), intercellular contact between Schwann cells and their underlying axons is believed to be mediated by binding of glial Cadm4 to axonal Cadm3 or Cadm2. Nevertheless, given that distinct neurons express different combinations of the Cadm proteins, the identity of the functional axonal ligand for Cadm4 remains to be determined. Here, we took a genetic approach to compare the phenotype of Cadm4 null mice, which exhibit abnormal distribution of Caspr and Kv1 potassium channels, with mice lacking different combinations of Cadm1-Cadm3 genes. We show that in contrast to mice lacking the single Cadm1, Cadm2, or Cadm3 genes, genetic ablation of all three phenocopies the abnormalities detected in the absence of Cadm4. Similar defects were observed in double mutant mice lacking Cadm3 and Cadm2 (i.e., Cadm3 -/- /Cadm2 -/-) or Cadm3 and Cadm1 (i.e., Cadm3 -/- /Cadm1 -/-), but not in mice lacking Cadm1 and Cadm2 (i.e., Cadm1 -/- /Cadm2 -/-). Furthermore, axonal organization abnormalities were also detected in Cadm3 null mice that were heterozygous for the two other axonal Cadms. Our results identify Cadm3 as the main axonal ligand for glial Cadm4, and reveal that its absence could be compensated by the combined action of Cadm2 and Cadm1.SIGNIFICANCE STATEMENT Myelination by Schwann cells enables fast conduction of action potentials along motor and sensory axons. In these nerves, Schwann cell-axon contact is mediated by cell adhesion molecules of the Cadm family. Cadm4 in Schwann cells regulates axonal ensheathment and myelin wrapping, as well as the organization of the axonal membrane, but the identity of its axonal ligands is not clear. Here, we reveal that Cadm mediated axon-glia interactions depend on a hierarchical adhesion code that involves multiple family members. Our results provide important insights into the molecular mechanisms of axon-glia communication, and the function of Cadm proteins in PNS myelin.
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10
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Chou VT, Johnson SA, Van Vactor D. Synapse development and maturation at the drosophila neuromuscular junction. Neural Dev 2020; 15:11. [PMID: 32741370 PMCID: PMC7397595 DOI: 10.1186/s13064-020-00147-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/14/2020] [Indexed: 12/12/2022] Open
Abstract
Synapses are the sites of neuron-to-neuron communication and form the basis of the neural circuits that underlie all animal cognition and behavior. Chemical synapses are specialized asymmetric junctions between a presynaptic neuron and a postsynaptic target that form through a series of diverse cellular and subcellular events under the control of complex signaling networks. Once established, the synapse facilitates neurotransmission by mediating the organization and fusion of synaptic vesicles and must also retain the ability to undergo plastic changes. In recent years, synaptic genes have been implicated in a wide array of neurodevelopmental disorders; the individual and societal burdens imposed by these disorders, as well as the lack of effective therapies, motivates continued work on fundamental synapse biology. The properties and functions of the nervous system are remarkably conserved across animal phyla, and many insights into the synapses of the vertebrate central nervous system have been derived from studies of invertebrate models. A prominent model synapse is the Drosophila melanogaster larval neuromuscular junction, which bears striking similarities to the glutamatergic synapses of the vertebrate brain and spine; further advantages include the simplicity and experimental versatility of the fly, as well as its century-long history as a model organism. Here, we survey findings on the major events in synaptogenesis, including target specification, morphogenesis, and the assembly and maturation of synaptic specializations, with a emphasis on work conducted at the Drosophila neuromuscular junction.
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Affiliation(s)
- Vivian T Chou
- Department of Cell Biology and Program in Neuroscience, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Seth A Johnson
- Department of Cell Biology and Program in Neuroscience, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
| | - David Van Vactor
- Department of Cell Biology and Program in Neuroscience, Blavatnik Institute, Harvard Medical School, Boston, MA, 02115, USA.
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11
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Trans-Axonal Signaling in Neural Circuit Wiring. Int J Mol Sci 2020; 21:ijms21145170. [PMID: 32708320 PMCID: PMC7404203 DOI: 10.3390/ijms21145170] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/15/2020] [Accepted: 07/17/2020] [Indexed: 12/24/2022] Open
Abstract
The development of neural circuits is a complex process that relies on the proper navigation of axons through their environment to their appropriate targets. While axon–environment and axon–target interactions have long been known as essential for circuit formation, communication between axons themselves has only more recently emerged as another crucial mechanism. Trans-axonal signaling governs many axonal behaviors, including fasciculation for proper guidance to targets, defasciculation for pathfinding at important choice points, repulsion along and within tracts for pre-target sorting and target selection, repulsion at the target for precise synaptic connectivity, and potentially selective degeneration for circuit refinement. This review outlines the recent advances in identifying the molecular mechanisms of trans-axonal signaling and discusses the role of axon–axon interactions during the different steps of neural circuit formation.
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12
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Emerging Roles of Synapse Organizers in the Regulation of Critical Periods. Neural Plast 2019; 2019:1538137. [PMID: 31565044 PMCID: PMC6745111 DOI: 10.1155/2019/1538137] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/09/2019] [Accepted: 07/25/2019] [Indexed: 01/10/2023] Open
Abstract
Experience remodels cortical connectivity during developmental windows called critical periods. Experience-dependent regulation of synaptic strength during these periods establishes circuit functions that are stabilized as critical period plasticity wanes. These processes have been extensively studied in the developing visual cortex, where critical period opening and closure are orchestrated by the assembly, maturation, and strengthening of distinct synapse types. The synaptic specificity of these processes points towards the involvement of distinct molecular pathways. Attractive candidates are pre- and postsynaptic transmembrane proteins that form adhesive complexes across the synaptic cleft. These synapse-organizing proteins control synapse development and maintenance and modulate structural and functional properties of synapses. Recent evidence suggests that they have pivotal roles in the onset and closure of the critical period for vision. In this review, we describe roles of synapse-organizing adhesion molecules in the regulation of visual critical period plasticity and we discuss the potential they offer to restore circuit functions in amblyopia and other neurodevelopmental disorders.
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13
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Greenbaum L, Ravona-Springer R, Livny A, Shelly S, Sharvit-Ginon I, Ganmore I, Alkelai A, Heymann A, Schnaider Beeri M. The CADM2 gene is associated with processing speed performance - evidence among elderly with type 2 diabetes. World J Biol Psychiatry 2019; 20:577-583. [PMID: 28797215 DOI: 10.1080/15622975.2017.1366055] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Objectives: Recent large-scale meta-analysis of genome-wide association studies (GWAS) from multiple cohorts, demonstrated the association of the single nucleotide polymorphism (SNP) rs17518584, with processing speed (measured by the Digit Symbol Substitution Test (DSST) or the Letter Digit Substitution Test (LDST)), at GWAS significance level. This SNP is located within the cell adhesion molecule 2 (CADM2) gene. We aimed to validate this finding in our sample of 944 cognitively normal Jewish elderly individuals with type 2 diabetes (T2D), a population which is at risk for cognitive decline and dementia.Methods: Using linear regression, we studied the association of rs17518584 with DSST performance, adjusting for demographic, T2D-related characteristics and cardiovascular factors. In secondary analyses, associations with performance in four cognitive domains (episodic memory, language/semantic categorisation, attention/working memory and executive function) and overall cognition were examined.Results: Controlling for sex, age at cognitive assessment, years of education and ancestry, we found a significant association of rs17518584 with DSST performance (P = 0.013), consistent with the originally reported effect direction. Results remained significant even when the additional covariates (T2D-related and cardiovascular factors) were included in the analysis (P = 0.034). Moreover, this SNP was significantly associated with performance in the cognitive domains of language/semantic categorisation and executive function, as well as overall cognition.Conclusions: Taken together, irrespective of T2D-related characteristics and cardiovascular factors, our findings provide independent support for the association of CADM2 SNP rs17518584 with processing speed (and demonstrate association with additional cognitive phenotypes), among cognitively normal elderly individuals with T2D.
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Affiliation(s)
- Lior Greenbaum
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel.,The Danek Gertner Institute of Human Genetics, Sheba Medical Center, Tel Hashomer, Israel.,Department of Neurology, Sheba Medical Center, Tel Hashomer, Israel
| | - Ramit Ravona-Springer
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel.,Memory Clinic, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Abigail Livny
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel.,Department of Diagnostic Imaging, Sheba Medical Center, Tel Hashomer, affiliated to Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shahar Shelly
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel.,Department of Neurology, Sheba Medical Center, Tel Hashomer, Israel
| | - Inbal Sharvit-Ginon
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel.,Department of Psychology, Bar-Ilan University, Ramat Gan, Israel
| | - Ithamar Ganmore
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel.,Department of Neurology, Sheba Medical Center, Tel Hashomer, Israel
| | - Anna Alkelai
- Institute for Genomic Medicine, Columbia University, New York, NY, USA
| | - Anthony Heymann
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Maccabi Healthcare Services, Tel Aviv, Israel
| | - Michal Schnaider Beeri
- The Joseph Sagol Neuroscience Center, Sheba Medical Center, Tel Hashomer, Israel.,Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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14
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Xu F, Si X, Du J, Xu F, Yang A, Zhang C, Zhang X, Yang Y. Downregulating SynCAM and MPP6 expression is associated with ovarian cancer progression. Oncol Lett 2019; 18:2477-2483. [PMID: 31402947 PMCID: PMC6676726 DOI: 10.3892/ol.2019.10542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 05/17/2019] [Indexed: 12/13/2022] Open
Abstract
Synaptic cell adhesion molecules (SynCAMs) are single transmembrane proteins that belong to the immunoglobulin superfamily of cell adhesion molecules. In the present study, a decrease in SynCAM levels in ovarian tumor tissues compared with normal tissues is reported; the downregulation was accompanied by the grade malignancy. The observations suggested that SynCAM may be essential for important novel functions in ovarian cancer. Further experiments showed that low SynCAM expression inhibited membrane palmitoylated protein 6 (MPP6) expression, a member of the palmitoylated membrane protein subfamily of peripheral membrane-associated guanylate kinases. In addition, low levels of MPP6 in ovarian tumor tissues correlated with shorter patient survival. A SynCAM-regulated pathway may provide molecular targets for the treatment of ovarian cancer and novel biomarkers to be used in clinical diagnosis.
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Affiliation(s)
- Feixue Xu
- Department of Gynecology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
| | - Xiaoqiang Si
- Department of Plastic Surgery, The Gansu Provincial Hospital, Lanzhou, Gansu 730000, P.R. China
| | - Jingran Du
- Department of Gynecology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
| | - Feihua Xu
- Department of Labor and Environmental Health, The School of Public Health of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
| | - Aihong Yang
- Department of Gynecology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
| | - Caixia Zhang
- Department of Gynecology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
| | - Xiucai Zhang
- Department of Gynecology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
| | - Yongxiu Yang
- Department of Gynecology, The First Hospital of Lanzhou University, Lanzhou, Gansu 730000, P.R. China
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15
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Magadmi R, Meszaros J, Damanhouri ZA, Seward EP. Secretion of Mast Cell Inflammatory Mediators Is Enhanced by CADM1-Dependent Adhesion to Sensory Neurons. Front Cell Neurosci 2019; 13:262. [PMID: 31275114 PMCID: PMC6591473 DOI: 10.3389/fncel.2019.00262] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 05/24/2019] [Indexed: 01/05/2023] Open
Abstract
Neuroimmune interactions are important in the pathophysiology of many chronic inflammatory diseases, particularly those associated with alterations in sensory processing and pain. Mast cells and sensory neuron nerve endings are found in areas of the body exposed to the external environment, both are specialized to sense potential damage by injury or pathogens and signal to the immune system and nervous system, respectively, to elicit protective responses. Cell adhesion molecule 1 (CADM1), also known as SynCAM1, has previously been identified as an adhesion molecule which may couple mast cells to sensory neurons however, whether this molecule exerts a functional as well as structural role in neuroimmune cross-talk is unknown. Here we show, using a newly developed in vitro co-culture system consisting of murine bone marrow derived mast cells (BMMC) and adult sensory neurons isolated from dorsal root ganglions (DRG), that CADM1 is expressed in mast cells and adult sensory neurons and mediates strong adhesion between the two cell types. Non-neuronal cells in the DRG cultures did not express CADM1, and mast cells did not adhere to them. The interaction of BMMCs with sensory neurons was found to induce mast cell degranulation and IL-6 secretion and to enhance responses to antigen stimulation and activation of FcεRI receptors. Secretion of TNFα in contrast was not affected, nor was secretion evoked by compound 48/80. Co-cultures of BMMCs with HEK 293 cells, which also express CADM1, while also leading to adhesion did not replicate the effects of sensory neurons on mast cells, indicative of a neuron-specific interaction. Application of a CADM1 blocking peptide or knockdown of CADM1 in BMMCs significantly decreased BMMC attachment to sensory neurites and abolished the enhanced secretory responses of mast cells. In conclusion, CADM1 is necessary and sufficient to drive mast cell-sensory neuron adhesion and promote the development of a microenvironment in which neurons enhance mast cell responsiveness to antigen, this interaction could explain why the incidence of painful neuroinflammatory disorders such as irritable bowel syndrome (IBS) are increased in atopic patients.
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Affiliation(s)
- Rania Magadmi
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom.,Department of Pharmacology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Judit Meszaros
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Zoheir A Damanhouri
- Department of Pharmacology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Elizabeth P Seward
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
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16
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Genetic variation in CADM2 as a link between psychological traits and obesity. Sci Rep 2019; 9:7339. [PMID: 31089183 PMCID: PMC6517397 DOI: 10.1038/s41598-019-43861-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 05/02/2019] [Indexed: 12/12/2022] Open
Abstract
CADM2 has been associated with a range of behavioural and metabolic traits, including physical activity, risk-taking, educational attainment, alcohol and cannabis use and obesity. Here, we set out to determine whether CADM2 contributes to mechanisms shared between mental and physical health disorders. We assessed genetic variants in the CADM2 locus for association with phenotypes in the UK Biobank, IMPROVE, PROCARDIS and SCARFSHEEP studies, before performing meta-analyses. A wide range of metabolic phenotypes were meta-analysed. Psychological phenotypes analysed in UK Biobank only were major depressive disorder, generalised anxiety disorder, bipolar disorder, neuroticism, mood instability and risk-taking behaviour. In UK Biobank, four, 88 and 172 genetic variants were significantly (p < 1 × 10−5) associated with neuroticism, mood instability and risk-taking respectively. In meta-analyses of 4 cohorts, we identified 362, 63 and 11 genetic variants significantly (p < 1 × 10−5) associated with BMI, SBP and CRP respectively. Genetic effects on BMI, CRP and risk-taking were all positively correlated, and were consistently inversely correlated with genetic effects on SBP, mood instability and neuroticism. Conditional analyses suggested an overlap in the signals for physical and psychological traits. Many significant variants had genotype-specific effects on CADM2 expression levels in adult brain and adipose tissues. CADM2 variants influence a wide range of both psychological and metabolic traits, suggesting common biological mechanisms across phenotypes via regulation of CADM2 expression levels in adipose tissue. Functional studies of CADM2 are required to fully understand mechanisms connecting mental and physical health conditions.
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17
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Kimura R, Yoneshige A, Hagiyama M, Otani T, Inoue T, Shiraishi N, Yanagihara K, Wakayama T, Ito A. Expression of cell adhesion molecule 1 in gastric neck and base glandular cells: Possible involvement in peritoneal dissemination of signet ring cells. Life Sci 2018; 213:206-213. [PMID: 30312702 DOI: 10.1016/j.lfs.2018.10.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2018] [Revised: 09/22/2018] [Accepted: 10/08/2018] [Indexed: 01/27/2023]
Abstract
AIMS To determine cellular distribution of cell adhesion molecule 1 (CADM1), an immunoglobulin superfamily member, in the human oxyntic gastric mucosa, and to explore possible involvement in the development and peritoneal dissemination of signet ring cell (SRC) gastric carcinoma, which often develops in the oxyntic mucosa. MAIN METHODS Immunohistochemistry and double immunofluorescence were conducted on surgical specimens of normal and SRC-bearing stomachs and peritoneal metastatic foci of SRCs. KATO-III (lacking CADM1) and HSC-43 (expressing CADM1) SRC cell lines were cocultured on a Met-5A mesothelial or TIG-1 fibroblastic cell monolayer. KEY FINDINGS In the oxyntic gland, some neck and nearly all base glandular cells were CADM1-positive, and mucin 5AC-positive cells were CADM1-negative, while some mucin 6-positive neck cells were CADM1-positive. Foveolar-epithelial, parietal, and endocrine cells were CADM1-negative. CADM1 was negative in all SRC carcinomas that were confined within the submucosa (n = 11) and all but one of those invading deeper (n = 15). In contrast, peritoneal metastatic foci of SRCs were CADM1-positive in five out of eleven cases (P < 0.01). In the cocultures, exogenous CADM1 made KATO-III cells adhere more and grow faster on a Met-5A monolayer, not on TIG-1 monolayers. HSC-43 cells adhered more and grew faster on Met-5A than on TIG-1 monolayers, which were partly counteracted by a function-neutralizing anti-CADM1 antibody. SIGNIFICANCE Nearly all chief cells and a part of mucous neck cells express CADM1. SRC gastric carcinoma appears to emerge as a CADM1-negative tumor, but CADM1 may help SRCs develop peritoneal dissemination through promoting their adhesion and growth in the serosal tissue.
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Affiliation(s)
- Ryuichiro Kimura
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Azusa Yoneshige
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Man Hagiyama
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Tomoyuki Otani
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Takao Inoue
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Naoki Shiraishi
- Hospital Pathology, Faculty of Medicine, Kindai University, Osaka, Japan
| | - Kazuyoshi Yanagihara
- Division of Biomarker Discovery, Exploratory Oncology Research & Clinical Trial Center, National Cancer Center, Chiba, Japan
| | - Tomohiko Wakayama
- Department of Histology, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Akihiko Ito
- Department of Pathology, Faculty of Medicine, Kindai University, Osaka, Japan.
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18
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Dumoulin A, Dagane A, Dittmar G, Rathjen FG. S-palmitoylation Is Required for the Control of Growth Cone Morphology of DRG Neurons by CNP-Induced cGMP Signaling. Front Mol Neurosci 2018; 11:345. [PMID: 30319353 PMCID: PMC6166100 DOI: 10.3389/fnmol.2018.00345] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Accepted: 09/04/2018] [Indexed: 12/24/2022] Open
Abstract
Genetic investigations have demonstrated that a specific form of axonal branching - the bifurcation of afferents from dorsal root ganglia (DRG), cranial sensory ganglia (CSG) and mesencephalic trigeminal neurons (MTN) – is regulated by a cGMP-dependent signaling pathway. This cascade is composed of the ligand C-type natriuretic peptide (CNP), the receptor guanylyl cyclase Npr2, and the cGMP-dependent protein kinase Iα (cGKIα). In the absence of any one of these components, axons no longer bifurcate, instead they turn in either an ascending or a descending direction. To gain further mechanistic insights into the process of axon bifurcation we applied different cell culture approaches to decipher downstream activities of cGKI in somatosensory growth cones. We demonstrate that CNP induces an enlargement of DRG growth cones via cGKI which is considered as the priming step of axon bifurcation in the spinal cord. This growth cone remodeling was both blocked by pharmacological inhibitors of S-palmitoylation and potentiated by blocking de-palmitoylation. cGKI colocalizes with the palmitoylome and vesicular structures including the endoplasmic reticulum, early endosomes, lysosomes primarily in the central domain of the growth cone as well as with the Golgi apparatus at the level of the soma. Interestingly, an acyl-biotin-exchange chemistry-based screen indicated that 8pCPT-cGMP-induced signaling induces S-palmitoylation of a restricted pool of proteins in the DRG-derived cell line F11. Overall, our data indicate that CNP-induced cGMP signaling via cGKI affects growth cone morphology of somatosensory afferents. Moreover, it also suggests that S-palmitoylation might play a role in this process.
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Affiliation(s)
| | - Alina Dagane
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
| | - Gunnar Dittmar
- Max Delbrück Center for Molecular Medicine, Berlin, Germany
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19
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Carruthers RD, Ahmed SU, Ramachandran S, Strathdee K, Kurian KM, Hedley A, Gomez-Roman N, Kalna G, Neilson M, Gilmour L, Stevenson KH, Hammond EM, Chalmers AJ. Replication Stress Drives Constitutive Activation of the DNA Damage Response and Radioresistance in Glioblastoma Stem-like Cells. Cancer Res 2018; 78:5060-5071. [PMID: 29976574 PMCID: PMC6128404 DOI: 10.1158/0008-5472.can-18-0569] [Citation(s) in RCA: 105] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 05/25/2018] [Accepted: 06/28/2018] [Indexed: 11/16/2022]
Abstract
Glioblastoma (GBM) is a lethal primary brain tumor characterized by treatment resistance and inevitable tumor recurrence, both of which are driven by a subpopulation of GBM cancer stem-like cells (GSC) with tumorigenic and self-renewal properties. Despite having broad implications for understanding GSC phenotype, the determinants of upregulated DNA-damage response (DDR) and subsequent radiation resistance in GSC are unknown and represent a significant barrier to developing effective GBM treatments. In this study, we show that constitutive DDR activation and radiation resistance are driven by high levels of DNA replication stress (RS). CD133+ GSC exhibited reduced DNA replication velocity and a higher frequency of stalled replication forks than CD133- non-GSC in vitro; immunofluorescence studies confirmed these observations in a panel of orthotopic xenografts and human GBM specimens. Exposure of non-GSC to low-level exogenous RS generated radiation resistance in vitro, confirming RS as a novel determinant of radiation resistance in tumor cells. GSC exhibited DNA double-strand breaks, which colocalized with "replication factories" and RNA: DNA hybrids. GSC also demonstrated increased expression of long neural genes (>1 Mbp) containing common fragile sites, supporting the hypothesis that replication/transcription collisions are the likely cause of RS in GSC. Targeting RS by combined inhibition of ATR and PARP (CAiPi) provided GSC-specific cytotoxicity and complete abrogation of GSC radiation resistance in vitro These data identify RS as a cancer stem cell-specific target with significant clinical potential.Significance: These findings shed new light on cancer stem cell biology and reveal novel therapeutics with the potential to improve clinical outcomes by overcoming inherent radioresistance in GBM. Cancer Res; 78(17); 5060-71. ©2018 AACR.
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Affiliation(s)
- Ross D Carruthers
- Institute of Cancer Sciences, Wolfson Wohl Cancer Research Centre, University of Glasgow, Glasgow, United Kingdom.
| | - Shafiq U Ahmed
- School of Pharmacy and Pharmaceutical Sciences, Faculty of Health Sciences and Wellbeing, University of Sunderland, Sunderland, United Kingdom
| | - Shaliny Ramachandran
- Cancer Research UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Karen Strathdee
- Institute of Cancer Sciences, Wolfson Wohl Cancer Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Kathreena M Kurian
- Department of Neuropathology, Brain Tumour Research Group, Frenchay Hospital, North Bristol NHS Trust Bristol, Bristol, United Kingdom
| | - Ann Hedley
- Cancer Research UK Beatson Institute, Glasgow, United Kingdom
| | - Natividad Gomez-Roman
- Institute of Cancer Sciences, Wolfson Wohl Cancer Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Gabriela Kalna
- Cancer Research UK Beatson Institute, Glasgow, United Kingdom
| | - Mathew Neilson
- Cancer Research UK Beatson Institute, Glasgow, United Kingdom
| | - Lesley Gilmour
- Institute of Cancer Sciences, Wolfson Wohl Cancer Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Katrina H Stevenson
- Institute of Cancer Sciences, Wolfson Wohl Cancer Research Centre, University of Glasgow, Glasgow, United Kingdom
| | - Ester M Hammond
- Cancer Research UK/MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Anthony J Chalmers
- Institute of Cancer Sciences, Wolfson Wohl Cancer Research Centre, University of Glasgow, Glasgow, United Kingdom
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20
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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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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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22
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Zagajewska K, Piątkowska M, Goryca K, Bałabas A, Kluska A, Paziewska A, Pośpiech E, Grabska-Liberek I, Hennig EE. GWAS links variants in neuronal development and actin remodeling related loci with pseudoexfoliation syndrome without glaucoma. Exp Eye Res 2018; 168:138-148. [DOI: 10.1016/j.exer.2017.12.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 12/05/2017] [Accepted: 12/20/2017] [Indexed: 01/13/2023]
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23
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Singh K, Loreth D, Pöttker B, Hefti K, Innos J, Schwald K, Hengstler H, Menzel L, Sommer CJ, Radyushkin K, Kretz O, Philips MA, Haas CA, Frauenknecht K, Lilleväli K, Heimrich B, Vasar E, Schäfer MKE. Neuronal Growth and Behavioral Alterations in Mice Deficient for the Psychiatric Disease-Associated Negr1 Gene. Front Mol Neurosci 2018; 11:30. [PMID: 29479305 PMCID: PMC5811522 DOI: 10.3389/fnmol.2018.00030] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 01/23/2018] [Indexed: 12/11/2022] Open
Abstract
Neuronal growth regulator 1 (NEGR1), a member of the immunoglobulin superfamily cell adhesion molecule subgroup IgLON, has been implicated in neuronal growth and connectivity. In addition, genetic variants in or near the NEGR1 locus have been associated with obesity and more recently with learning difficulties, intellectual disability and psychiatric disorders. However, experimental evidence is lacking to support a possible link between NEGR1, neuronal growth and behavioral abnormalities. Initial expression analysis of NEGR1 mRNA in C57Bl/6 wildtype (WT) mice by in situ hybridization demonstrated marked expression in the entorhinal cortex (EC) and dentate granule cells. In co-cultures of cortical neurons and NSC-34 cells overexpressing NEGR1, neurite growth of cortical neurons was enhanced and distal axons occupied an increased area of cells overexpressing NEGR1. Conversely, in organotypic slice co-cultures, Negr1-knockout (KO) hippocampus was less permissive for axons grown from EC of β-actin-enhanced green fluorescent protein (EGFP) mice compared to WT hippocampus. Neuroanatomical analysis revealed abnormalities of EC axons in the hippocampal dentate gyrus (DG) of Negr1-KO mice including increased numbers of axonal projections to the hilus. Neurotransmitter receptor ligand binding densities, a proxy of functional neurotransmitter receptor abundance, did not show differences in the DG of Negr1-KO mice but altered ligand binding densities to NMDA receptor and muscarinic acetylcholine receptors M1 and M2 were found in CA1 and CA3. Activity behavior, anxiety-like behavior and sensorimotor gating were not different between genotypes. However, Negr1-KO mice exhibited impaired social behavior compared to WT littermates. Moreover, Negr1-KO mice showed reversal learning deficits in the Morris water maze and increased susceptibility to pentylenetetrazol (PTZ)-induced seizures. Thus, our results from neuronal growth assays, neuroanatomical analyses and behavioral assessments provide first evidence that deficiency of the psychiatric disease-associated Negr1 gene may affect neuronal growth and behavior. These findings might be relevant to further evaluate the role of NEGR1 in cognitive and psychiatric disorders.
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Affiliation(s)
- Katyayani Singh
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.,Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Desirée Loreth
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Bruno Pöttker
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Kyra Hefti
- Institute of Neuropathology, University Medical Center, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Jürgen Innos
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.,Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Kathrin Schwald
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Heidi Hengstler
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Lutz Menzel
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany
| | - Clemens J Sommer
- Institute of Neuropathology, University Medical Center, Johannes Gutenberg-University of Mainz, Mainz, Germany.,Focus Program Translational Neurosciences, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Konstantin Radyushkin
- Focus Program Translational Neurosciences, Johannes Gutenberg-University of Mainz, Mainz, Germany.,Mouse Behavioral Unit, Johannes Gutenberg-University of Mainz, Mainz, Germany
| | - Oliver Kretz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Mari-Anne Philips
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.,Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Carola A Haas
- Experimental Epilepsy Research, Department of Neurosurgery, Medical Center-University of Freiburg, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Katrin Frauenknecht
- Institute of Neuropathology, University Medical Center, Johannes Gutenberg-University of Mainz, Mainz, Germany.,Institute of Neuropathology, University Hospital Zurich, Zurich, Switzerland
| | - Kersti Lilleväli
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.,Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Bernd Heimrich
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Eero Vasar
- Department of Physiology, Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia.,Centre of Excellence in Genomics and Translational Medicine, University of Tartu, Tartu, Estonia
| | - Michael K E Schäfer
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Mainz, Germany.,Focus Program Translational Neurosciences, Johannes Gutenberg-University of Mainz, Mainz, Germany
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24
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Kawada K, Mimori S. Implication of Endoplasmic Reticulum Stress in Autism Spectrum Disorder. Neurochem Res 2017; 43:147-152. [PMID: 28770435 DOI: 10.1007/s11064-017-2370-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/23/2017] [Accepted: 07/29/2017] [Indexed: 12/31/2022]
Abstract
Autism spectrum disorder (ASD) is categorized as a neurodevelopmental disorder according to the Diagnostic and Statistical Manual of Disorders, Fifth Edition and is defined as a congenital impairment of the central nervous system. ASD may be caused by a chromosomal abnormality or gene mutation. However, these etiologies are insufficient to account for the pathogenesis of ASD. Therefore, we propose that the etiology and pathogenesis of ASD are related to the stress of the endoplasmic reticulum (ER). ER stress, induced by valproic acid, increased in ASD mouse model, characterized by an unfolded protein response that is activated by this stress. The inhibition of neurite outgrowth and expression of synaptic factors are observed in ASD. Similarly, ER stress suppresses the neurite outgrowth and expression of synaptic factors. Additionally, hyperplasia of the brain is observed in patients with ASD. ER stress also enhances neuronal differentiation. Synaptic factors, such as cell adhesion molecule and shank, play important roles in the formation of neural circuits. Thus, ER stress is associated with the abnormalities of neuronal differentiation, neurite outgrowth, and synaptic protein expression. ER stress elevates the expression of the ubiquitin-protein ligase HRD1 for the degradation of unfolded proteins. HRD1 expression significantly increased in the middle frontal cortex in the postmortem of patients with ASD. Moreover, HRD1 silencing improved the abnormalities induced by ER stress. Because other ubiquitin ligases are related with neurite outgrowth, ER stress may be related to the pathogenesis of neuronal developmental diseases via abnormalities of neuronal differentiation or maturation.
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Affiliation(s)
- Koichi Kawada
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Chiba Institute of Science, 15-8 Shiomi-cho, Choshi, Chiba, 288-0025, Japan.
| | - Seisuke Mimori
- Department of Clinical Medicine, Faculty of Pharmaceutical Sciences, Chiba Institute of Science, Choshi, Chiba, 288-0025, Japan
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25
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Fowler DK, Peters JH, Williams C, Washbourne P. Redundant Postsynaptic Functions of SynCAMs 1-3 during Synapse Formation. Front Mol Neurosci 2017; 10:24. [PMID: 28197078 PMCID: PMC5281628 DOI: 10.3389/fnmol.2017.00024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 01/17/2017] [Indexed: 01/13/2023] Open
Abstract
Investigating the roles of synaptogenic adhesion molecules during synapse formation has proven challenging, often due to compensatory functions between additional family members. The synaptic cell adhesion molecules 1–3 (SynCAM1–3) are expressed both pre- and postsynaptically, share highly homologous domains and are synaptogenic when ectopically presented to neurons; yet their endogenous functions during synaptogenesis are unclear. Here we report that SynCAM1–3 are functionally redundant and collectively necessary for synapse formation in cultured hippocampal neurons. Only triple knockdown (KD) of SynCAM1–3 using highly efficient, chained artificial microRNAs (amiRNAs) reduced synapse density and increased synapse area. Electrophysiological recordings of quantal release events supported an increase in synapse size caused by SynCAM1–3 depletion. Furthermore, a combinatorial, mosaic lentiviral approach comparing wild type (WT) and SynCAM1–3 KD neurons in the same culture demonstrate that SynCAM1–3 set synapse number and size through postsynaptic mechanisms. The results demonstrate that the redundancy between SynCAM1–3 has concealed their synaptogenic function at the postsynaptic terminal.
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Affiliation(s)
- Daniel K Fowler
- Department of Biology, Institute of Neuroscience, University of OregonEugene, OR, USA; Department of Integrative Physiology and Neuroscience, Washington State UniversityPullman, WA, USA
| | - James H Peters
- Department of Integrative Physiology and Neuroscience, Washington State University Pullman, WA, USA
| | - Carly Williams
- Department of Biology, Institute of Neuroscience, University of Oregon Eugene, OR, USA
| | - Philip Washbourne
- Department of Biology, Institute of Neuroscience, University of Oregon Eugene, OR, USA
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26
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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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27
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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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28
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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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29
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Park KA, Ribic A, Laage Gaupp FM, Coman D, Huang Y, Dulla CG, Hyder F, Biederer T. Excitatory Synaptic Drive and Feedforward Inhibition in the Hippocampal CA3 Circuit Are Regulated by SynCAM 1. J Neurosci 2016; 36:7464-75. [PMID: 27413156 PMCID: PMC4945666 DOI: 10.1523/jneurosci.0189-16.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 06/01/2016] [Accepted: 06/02/2016] [Indexed: 01/24/2023] Open
Abstract
UNLABELLED Select adhesion proteins control the development of synapses and modulate their structural and functional properties. Despite these important roles, the extent to which different synapse-organizing mechanisms act across brain regions to establish connectivity and regulate network properties is incompletely understood. Further, their functional roles in different neuronal populations remain to be defined. Here, we applied diffusion tensor imaging (DTI), a modality of magnetic resonance imaging (MRI), to map connectivity changes in knock-out (KO) mice lacking the synaptogenic cell adhesion protein SynCAM 1. This identified reduced fractional anisotropy in the hippocampal CA3 area in absence of SynCAM 1. In agreement, mossy fiber refinement in CA3 was impaired in SynCAM 1 KO mice. Mossy fibers make excitatory inputs onto postsynaptic specializations of CA3 pyramidal neurons termed thorny excrescences and these structures were smaller in the absence of SynCAM 1. However, the most prevalent targets of mossy fibers are GABAergic interneurons and SynCAM 1 loss unexpectedly reduced the number of excitatory terminals onto parvalbumin (PV)-positive interneurons in CA3. SynCAM 1 KO mice additionally exhibited lower postsynaptic GluA1 expression in these PV-positive interneurons. These synaptic imbalances in SynCAM 1 KO mice resulted in CA3 disinhibition, in agreement with reduced feedforward inhibition in this network in the absence of SynCAM 1-dependent excitatory drive onto interneurons. In turn, mice lacking SynCAM 1 were impaired in memory tasks involving CA3. Our results support that SynCAM 1 modulates excitatory mossy fiber inputs onto both interneurons and principal neurons in the hippocampal CA3 area to balance network excitability. SIGNIFICANCE STATEMENT This study advances our understanding of synapse-organizing mechanisms on two levels. First, the data support that synaptogenic proteins guide connectivity and can function in distinct brain regions even if they are expressed broadly. Second, the results demonstrate that a synaptogenic process that controls excitatory inputs to both pyramidal neurons and interneurons can balance excitation and inhibition. Specifically, the study reveals that hippocampal CA3 connectivity is modulated by the synapse-organizing adhesion protein SynCAM 1 and identifies a novel, SynCAM 1-dependent mechanism that controls excitatory inputs onto parvalbumin-positive interneurons. This enables SynCAM 1 to regulate feedforward inhibition and set network excitability. Further, we show that diffusion tensor imaging is sensitive to these cellular refinements affecting neuronal connectivity.
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Affiliation(s)
- Kellie A Park
- Department of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut 06520
| | - Adema Ribic
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Fabian M Laage Gaupp
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians-University, 80539 Munich, Germany
| | - Daniel Coman
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, and
| | - Yuegao Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, and
| | - Chris G Dulla
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111
| | - Fahmeed Hyder
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut 06520, and Department of Biomedical Engineering, Yale University, School of Engineering and Applied Science, New Haven, Connecticut 06520
| | - Thomas Biederer
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111,
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30
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Genome-wide association study of cognitive functions and educational attainment in UK Biobank (N=112 151). Mol Psychiatry 2016; 21:758-67. [PMID: 27046643 PMCID: PMC4879186 DOI: 10.1038/mp.2016.45] [Citation(s) in RCA: 235] [Impact Index Per Article: 29.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 01/14/2016] [Accepted: 02/11/2016] [Indexed: 12/13/2022]
Abstract
People's differences in cognitive functions are partly heritable and are associated with important life outcomes. Previous genome-wide association (GWA) studies of cognitive functions have found evidence for polygenic effects yet, to date, there are few replicated genetic associations. Here we use data from the UK Biobank sample to investigate the genetic contributions to variation in tests of three cognitive functions and in educational attainment. GWA analyses were performed for verbal-numerical reasoning (N=36 035), memory (N=112 067), reaction time (N=111 483) and for the attainment of a college or a university degree (N=111 114). We report genome-wide significant single-nucleotide polymorphism (SNP)-based associations in 20 genomic regions, and significant gene-based findings in 46 regions. These include findings in the ATXN2, CYP2DG, APBA1 and CADM2 genes. We report replication of these hits in published GWA studies of cognitive function, educational attainment and childhood intelligence. There is also replication, in UK Biobank, of SNP hits reported previously in GWA studies of educational attainment and cognitive function. GCTA-GREML analyses, using common SNPs (minor allele frequency>0.01), indicated significant SNP-based heritabilities of 31% (s.e.m.=1.8%) for verbal-numerical reasoning, 5% (s.e.m.=0.6%) for memory, 11% (s.e.m.=0.6%) for reaction time and 21% (s.e.m.=0.6%) for educational attainment. Polygenic score analyses indicate that up to 5% of the variance in cognitive test scores can be predicted in an independent cohort. The genomic regions identified include several novel loci, some of which have been associated with intracranial volume, neurodegeneration, Alzheimer's disease and schizophrenia.
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31
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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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32
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Frei JA, Andermatt I, Gesemann M, Stoeckli ET. The SynCAM synaptic cell adhesion molecules are involved in sensory axon pathfinding by regulating axon-axon contacts. Development 2015. [DOI: 10.1242/dev.120535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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