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Cisneros-Mejorado AJ, Ordaz RP, Garay E, Arellano RO. β-carbolines that enhance GABA A receptor response expressed in oligodendrocytes promote remyelination in an in vivo rat model of focal demyelination. Front Cell Neurosci 2024; 18:1369730. [PMID: 38694535 PMCID: PMC11061515 DOI: 10.3389/fncel.2024.1369730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 04/09/2024] [Indexed: 05/04/2024] Open
Abstract
Demyelination is typically followed by a remyelination process through mature oligodendrocytes (OLs) differentiated from precursor cells (OPCs) recruited into the lesioned areas, however, this event usually results in uncompleted myelination. Potentiation of the remyelination process is an important target for designing effective therapeutic strategies against white matter loss. Here, it was evaluated the remyelinating effect of different β-carbolines that present differential allosteric modulation on the GABAA receptor expressed in OLs. For this, we used a focalized demyelination model in the inferior cerebellar peduncle (i.c.p.) of rats (DRICP model), in which, demyelination by ethidium bromide (0.05%) stereotaxic injection was confirmed histologically by staining with Black-Gold II (BGII) and toluidine blue. In addition, a longitudinal analysis with diffusion-weighted magnetic resonance imaging (dMRI) was made by computing fractional anisotropy (FA), apparent diffusion coefficient (ADC) and diffusivity parameters to infer i.c.p. microstructural changes. First, dMRI analysis revealed FA decreases together with ADC and radial diffusivity (RD) increases after demyelination, which correlates with histological BGII observations. Then, we evaluated the effect produced by three allosteric GABAA receptor modulators, the N-butyl-β-carboline-3-carboxylate (β-CCB), ethyl 9H-pyrido [3,4-b]indole-3-carboxylate (β-CCE), and 4-ethyl-6,7-dimethoxy-9H-pyrido [3,4-b]indole-3-carboxylic acid methyl ester (DMCM). The results indicated that daily systemic β-CCB (1 mg/Kg) or β-CCE (1 mg/Kg) administration for 2 weeks, but not DMCM (0.35 mg/Kg), in lesioned animals increased FA and decreased ADC or RD, suggesting myelination improvement. This was supported by BGII staining analysis that showed a recovery of myelin content. Also, it was quantified by immunohistochemistry both NG2+ and CC1+ cellular population in the different experimental sceneries. Data indicated that either β-CCB or β-CCE, but not DMCM, produced an increase in the population of CC1+ cells in the lesioned area. Finally, it was also calculated the g-ratio of myelinated axons and observed a similar value in those lesioned animals treated with β-CCB or β-CCE compared to controls. Thus, using the DRICP model, it was observed that either β-CCB or β-CCE, positive modulators of the GABAA receptor in OLs, had a potent promyelinating effect.
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Affiliation(s)
| | | | | | - Rogelio O. Arellano
- Instituto de Neurobiología, Laboratorio de Neurofisiología Celular, Universidad Nacional Autónoma de México, Juriquilla, Mexico
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2
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Li J, Miramontes TG, Czopka T, Monk KR. Synaptic input and Ca 2+ activity in zebrafish oligodendrocyte precursor cells contribute to myelin sheath formation. Nat Neurosci 2024; 27:219-231. [PMID: 38216650 DOI: 10.1038/s41593-023-01553-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Accepted: 12/13/2023] [Indexed: 01/14/2024]
Abstract
In the nervous system, only one type of neuron-glial synapse is known to exist: that between neurons and oligodendrocyte precursor cells (OPCs), yet their composition, assembly, downstream signaling and in vivo functions remain largely unclear. Here, we address these questions using in vivo microscopy in zebrafish spinal cord and identify postsynaptic molecules PSD-95 and gephyrin in OPCs. The puncta containing these molecules in OPCs increase during early development and decrease upon OPC differentiation. These puncta are highly dynamic and frequently assemble at 'hotspots'. Gephyrin hotspots and synapse-associated Ca2+ activity in OPCs predict where a subset of myelin sheaths forms in differentiated oligodendrocytes. Further analyses reveal that spontaneous synaptic release is integral to OPC Ca2+ activity, while evoked synaptic release contributes only in early development. Finally, disruption of the synaptic genes dlg4a/dlg4b, gphnb and nlgn3b impairs OPC differentiation and myelination. Together, we propose that neuron-OPC synapses are dynamically assembled and can predetermine myelination patterns through Ca2+ signaling.
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Affiliation(s)
- Jiaxing Li
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA.
| | | | - Tim Czopka
- Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Kelly R Monk
- Vollum Institute, Oregon Health & Science University, Portland, OR, USA.
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3
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Gakare SG, Bhatt JM, Narasimhan KKS, Dravid SM. Glutamate delta-1 receptor regulates oligodendrocyte progenitor cell differentiation and myelination in normal and demyelinating conditions. PLoS One 2023; 18:e0294583. [PMID: 37983226 PMCID: PMC10659214 DOI: 10.1371/journal.pone.0294583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 11/05/2023] [Indexed: 11/22/2023] Open
Abstract
In this study, we investigated the role of glutamate delta 1 receptor (GluD1) in oligodendrocyte progenitor cell (OPC)-mediated myelination during basal (development) and pathophysiological (cuprizone-induced demyelination) conditions. Initially, we sought to determine the expression pattern of GluD1 in OPCs and found a significant colocalization of GluD1 puncta with neuron-glial antigen 2 (NG2, OPC marker) in the motor cortex and dorsal striatum. Importantly, we found that the ablation of GluD1 led to an increase in the number of myelin-associated glycoprotein (MAG+) cells in the corpus callosum and motor cortex at P40 without affecting the number of NG2+ OPCs, suggesting that GluD1 loss selectively facilitates OPC differentiation rather than proliferation. Further, deletion of GluD1 enhanced myelination in the corpus callosum and motor cortex, as indicated by increased myelin basic protein (MBP) staining at P40, suggesting that GluD1 may play an essential role in the developmental regulation of myelination during the critical window period. In contrast, in cuprizone-induced demyelination, we observed reduced MBP staining in the corpus callosum of GluD1 KO mice. Furthermore, cuprizone-fed GluD1 KO mice showed more robust motor deficits. Collectively, our results demonstrate that GluD1 plays a critical role in OPC regulation and myelination in normal and demyelinating conditions.
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Affiliation(s)
- Sukanya G. Gakare
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE, United States of America
| | - Jay M. Bhatt
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE, United States of America
| | - Kishore Kumar S. Narasimhan
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE, United States of America
| | - Shashank M. Dravid
- Department of Pharmacology and Neuroscience, Creighton University School of Medicine, Omaha, NE, United States of America
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4
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Messina A, Crescimanno C, Cuccì G, Caraci F, Signorelli MS. Cell adhesion molecules in the pathogenesis of the schizophrenia. Folia Med (Plovdiv) 2023; 65:707-712. [PMID: 38351751 DOI: 10.3897/folmed.65.e101356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 03/16/2023] [Indexed: 02/16/2024] Open
Abstract
The causes of schizophrenia remain obscure and complex to identify. Alterations in dopaminergic and serotonergic neurotransmission are, to date, the primary pharmacological targets in treatment. Underlying abnormalities in neural networks have been identified as cell adhesion molecules (CAMs) involved in synaptic remodeling and interplay between neurons-neurons and neurons-glial cells. Among the CAMs, several families have been identified, such as integrins, selectins, cadherins, immunoglobulins, nectins, and the neuroligin-neurexin complex. In this paper, cell adhesion molecules involved in the pathogenesis of schizophrenia will be described.
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5
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Zhao W, Johnston KG, Ren H, Xu X, Nie Q. Inferring neuron-neuron communications from single-cell transcriptomics through NeuronChat. Nat Commun 2023; 14:1128. [PMID: 36854676 PMCID: PMC9974942 DOI: 10.1038/s41467-023-36800-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 02/15/2023] [Indexed: 03/02/2023] Open
Abstract
Neural communication networks form the fundamental basis for brain function. These communication networks are enabled by emitted ligands such as neurotransmitters, which activate receptor complexes to facilitate communication. Thus, neural communication is fundamentally dependent on the transcriptome. Here we develop NeuronChat, a method and package for the inference, visualization and analysis of neural-specific communication networks among pre-defined cell groups using single-cell expression data. We incorporate a manually curated molecular interaction database of neural signaling for both human and mouse, and benchmark NeuronChat on several published datasets to validate its ability in predicting neural connectivity. Then, we apply NeuronChat to three different neural tissue datasets to illustrate its functionalities in identifying interneural communication networks, revealing conserved or context-specific interactions across different biological contexts, and predicting communication pattern changes in diseased brains with autism spectrum disorder. Finally, we demonstrate NeuronChat can utilize spatial transcriptomics data to infer and visualize neural-specific cell-cell communication.
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Affiliation(s)
- Wei Zhao
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA, 92697, USA
| | - Kevin G Johnston
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA, 92697, USA
| | - Honglei Ren
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA, 92697, USA
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA, 92697, USA.,Department of Biomedical Engineering, University of California, Irvine, CA, 92697, USA.,Department of Computer Science, University of California, Irvine, CA, 92697, USA.,The Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA
| | - Qing Nie
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA, 92697, USA. .,Department of Biomedical Engineering, University of California, Irvine, CA, 92697, USA. .,The Center for Neural Circuit Mapping, University of California, Irvine, CA, 92697, USA. .,Department of Developmental and Cell Biology, University of California, Irvine, CA, 92697, USA.
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6
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Neuronal and astrocytic protein connections and associated adhesion molecules. Neurosci Res 2023; 187:14-20. [PMID: 36202350 DOI: 10.1016/j.neures.2022.09.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 08/12/2022] [Accepted: 09/27/2022] [Indexed: 02/11/2023]
Abstract
Astrocytes are morphologically complex, with a myriad of processes which allow contact with other astrocytes, blood vessels, and neurons. Adhesion molecules expressed by these cells regulate this connectivity. Adhesion molecules are required to form and maintain functional neural circuits, but their importance and mechanisms of action, particularly in astrocyte-neuron contact, remain unresolved. Several studies of neuron-astrocyte connections have demonstrated the vital functions of adhesion molecules, including neuron-glia cell adhesion molecules, astrotactins, and protocadherins. In this review, we provide an overview and perspective of astrocyte-neuron contacts mediated by adhesion molecules in developing neural circuits and synapse formation, especially in the cerebellum. We also outline a novel mechanism of interaction between neurons and astrocytes in the tripartite synapses that has been recently found by our group.
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Zhao W, Johnston KG, Ren H, Xu X, Nie Q. Inferring neuron-neuron communications from single-cell transcriptomics through NeuronChat. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.12.523826. [PMID: 36712056 PMCID: PMC9882151 DOI: 10.1101/2023.01.12.523826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Neural communication networks form the fundamental basis for brain function. These communication networks are enabled by emitted ligands such as neurotransmitters, which activate receptor complexes to facilitate communication. Thus, neural communication is fundamentally dependent on the transcriptome. Here we develop NeuronChat, a method and package for the inference, visualization and analysis of neural-specific communication networks among pre-defined cell groups using single-cell expression data. We incorporate a manually curated molecular interaction database of neural signaling for both human and mouse, and benchmark NeuronChat on several published datasets to validate its ability in predicting neural connectivity. Then, we apply NeuronChat to three different neural tissue datasets to illustrate its functionalities in identifying interneural communication networks, revealing conserved or context-specific interactions across different biological contexts, and predicting communication pattern changes in diseased brains with autism spectrum disorder. Finally, we demonstrate NeuronChat can utilize spatial transcriptomics data to infer and visualize neural-specific cell-cell communication.
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Affiliation(s)
- Wei Zhao
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697
| | - Kevin G Johnston
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697
| | - Honglei Ren
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697
| | - Xiangmin Xu
- Department of Anatomy and Neurobiology, School of Medicine, University of California, Irvine, CA 92697.,Department of Biomedical Engineering, University of California, Irvine, CA 92697.,Department of Computer Science, University of California, Irvine, CA 92697.,The Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA 92697.,The Center for Neural Circuit Mapping, University of California, Irvine, CA 92697
| | - Qing Nie
- Department of Mathematics and the NSF-Simons Center for Multiscale Cell Fate Research, University of California, Irvine, CA 92697.,Department of Developmental and Cell Biology, University of California, Irvine, CA 92697.,Department of Biomedical Engineering, University of California, Irvine, CA 92697.,The Center for Neural Circuit Mapping, University of California, Irvine, CA 92697
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8
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Osanai Y, Yamazaki R, Shinohara Y, Ohno N. Heterogeneity and regulation of oligodendrocyte morphology. Front Cell Dev Biol 2022; 10:1030486. [PMID: 36393856 PMCID: PMC9644283 DOI: 10.3389/fcell.2022.1030486] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 10/10/2022] [Indexed: 09/24/2023] Open
Abstract
Oligodendrocytes form multiple myelin sheaths in the central nervous system (CNS), which increase nerve conduction velocity and are necessary for basic and higher brain functions such as sensory function, motor control, and learning. Structures of the myelin sheath such as myelin internodal length and myelin thickness regulate nerve conduction. Various parts of the central nervous system exhibit different myelin structures and oligodendrocyte morphologies. Recent studies supported that oligodendrocytes are a heterogenous population of cells and myelin sheaths formed by some oligodendrocytes can be biased to particular groups of axons, and myelin structures are dynamically modulated in certain classes of neurons by specific experiences. Structures of oligodendrocyte/myelin are also affected in pathological conditions such as demyelinating and neuropsychiatric disorders. This review summarizes our understanding of heterogeneity and regulation of oligodendrocyte morphology concerning central nervous system regions, neuronal classes, experiences, diseases, and how oligodendrocytes are optimized to execute central nervous system functions.
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Affiliation(s)
- Yasuyuki Osanai
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Reiji Yamazaki
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
| | - Yoshiaki Shinohara
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
- Department of Anatomy and Cell Biology, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | - Nobuhiko Ohno
- Department of Anatomy, Division of Histology and Cell Biology, School of Medicine, Jichi Medical University, Shimotsuke, Japan
- Division of Ultrastructural Research, National Institute for Physiological Sciences, Okazaki, Japan
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Liu X, Hua F, Yang D, Lin Y, Zhang L, Ying J, Sheng H, Wang X. Roles of neuroligins in central nervous system development: focus on glial neuroligins and neuron neuroligins. Lab Invest 2022; 20:418. [PMID: 36088343 PMCID: PMC9463862 DOI: 10.1186/s12967-022-03625-y] [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: 07/25/2022] [Accepted: 09/01/2022] [Indexed: 11/10/2022]
Abstract
Neuroligins are postsynaptic cell adhesion molecules that are relevant to many neurodevelopmental disorders. They are differentially enriched at the postsynapse and interact with their presynaptic ligands, neurexins, whose differential binding to neuroligins has been shown to regulate synaptogenesis, transmission, and other synaptic properties. The proper functioning of functional networks in the brain depends on the proper connection between neuronal synapses. Impaired synaptogenesis or synaptic transmission results in synaptic dysfunction, and these synaptic pathologies are the basis for many neurodevelopmental disorders. Deletions or mutations in the neuroligins genes have been found in patients with both autism and schizophrenia. It is because of the important role of neuroligins in synaptic connectivity and synaptic dysfunction that studies on neuroligins in the past have mainly focused on their expression in neurons. As studies on the expression of genes specific to various cells of the central nervous system deepened, neuroligins were found to be expressed in non-neuronal cells as well. In the central nervous system, glial cells are the most representative non-neuronal cells, which can also express neuroligins in large amounts, especially astrocytes and oligodendrocytes, and they are involved in the regulation of synaptic function, as are neuronal neuroligins. This review examines the mechanisms of neuron neuroligins and non-neuronal neuroligins in the central nervous system and also discusses the important role of neuroligins in the development of the central nervous system and neurodevelopmental disorders from the perspective of neuronal neuroligins and glial neuroligins.
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The Intricate Epigenetic and Transcriptional Alterations in Pediatric High-Grade Gliomas: Targeting the Crosstalk as the Oncogenic Achilles’ Heel. Biomedicines 2022; 10:biomedicines10061311. [PMID: 35740334 PMCID: PMC9219798 DOI: 10.3390/biomedicines10061311] [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: 05/11/2022] [Revised: 05/27/2022] [Accepted: 05/28/2022] [Indexed: 02/01/2023] Open
Abstract
Pediatric high-grade gliomas (pHGGs) are a deadly and heterogenous subgroup of gliomas for which the development of innovative treatments is urgent. Advances in high-throughput molecular techniques have shed light on key epigenetic components of these diseases, such as K27M and G34R/V mutations on histone 3. However, modification of DNA compaction is not sufficient by itself to drive those tumors. Here, we review molecular specificities of pHGGs subcategories in the context of epigenomic rewiring caused by H3 mutations and the subsequent oncogenic interplay with transcriptional signaling pathways co-opted from developmental programs that ultimately leads to gliomagenesis. Understanding how transcriptional and epigenetic alterations synergize in each cellular context in these tumors could allow the identification of new Achilles’ heels, thereby highlighting new levers to improve their therapeutic management.
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Mitroi DN, Tian M, Kawaguchi R, Lowry WE, Carmichael ST. Single-nucleus transcriptome analysis reveals disease- and regeneration-associated endothelial cells in white matter vascular dementia. J Cell Mol Med 2022; 26:3183-3195. [PMID: 35543222 PMCID: PMC9170821 DOI: 10.1111/jcmm.17315] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 02/01/2022] [Accepted: 03/12/2022] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Vascular dementia (VaD) is the accumulation of vascular lesions in the subcortical white matter of the brain. These lesions progress and there is no direct medical therapy. AIMS To determine the specific cellular responses in VaD so as to provide molecular targets for therapeutic development. MATERIALS AND METHODS Single-nucleus transcriptome analysis was performed in human periventricular white matter (PVWM) samples of VaD and normal control (NC) subjects. RESULTS Differential analysis shows that cell type-specific transcriptomic changes in VaD are associated with the disruption of specific biological processes, including angiogenesis, immune activation, axonal injury and myelination. Each cell type in the neurovascular unit within white matter has a specific alteration in gene expression in VaD. In a central cell type for this disease, subcluster analysis of endothelial cells (EC) indicates that VaD contains a disease-associated EC subcluster that expresses genes associated with programmed cell death and a response to protein folding. Two other subpopulations of EC in VaD express molecular systems associated with regenerative processes in angiogenesis, and in axonal sprouting and oligodendrocyte progenitor cell maturation. CONCLUSION This comprehensive molecular profiling of brain samples from patients with VaD reveals previously unknown molecular changes in cells of the neurovascular niche, and an attempt at regeneration in injured white matter.
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Affiliation(s)
- Daniel N. Mitroi
- Department of Psychiatry and Biobehavioral SciencesDavid Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
| | - Min Tian
- Department of Psychiatry and Biobehavioral SciencesDavid Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
| | - Riki Kawaguchi
- Department of Psychiatry and Biobehavioral SciencesDavid Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
| | - William E. Lowry
- Department of Molecular, Cell and Developmental BiologyUCLALos AngelesCaliforniaUSA
| | - S. Thomas Carmichael
- Department of Psychiatry and Biobehavioral SciencesDavid Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
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Uchigashima M, Cheung A, Futai K. Neuroligin-3: A Circuit-Specific Synapse Organizer That Shapes Normal Function and Autism Spectrum Disorder-Associated Dysfunction. Front Mol Neurosci 2021; 14:749164. [PMID: 34690695 PMCID: PMC8526735 DOI: 10.3389/fnmol.2021.749164] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 09/06/2021] [Indexed: 01/02/2023] Open
Abstract
Chemical synapses provide a vital foundation for neuron-neuron communication and overall brain function. By tethering closely apposed molecular machinery for presynaptic neurotransmitter release and postsynaptic signal transduction, circuit- and context- specific synaptic properties can drive neuronal computations for animal behavior. Trans-synaptic signaling via synaptic cell adhesion molecules (CAMs) serves as a promising mechanism to generate the molecular diversity of chemical synapses. Neuroligins (Nlgns) were discovered as postsynaptic CAMs that can bind to presynaptic CAMs like Neurexins (Nrxns) at the synaptic cleft. Among the four (Nlgn1-4) or five (Nlgn1-3, Nlgn4X, and Nlgn4Y) isoforms in rodents or humans, respectively, Nlgn3 has a heterogeneous expression and function at particular subsets of chemical synapses and strong association with non-syndromic autism spectrum disorder (ASD). Several lines of evidence have suggested that the unique expression and function of Nlgn3 protein underlie circuit-specific dysfunction characteristic of non-syndromic ASD caused by the disruption of Nlgn3 gene. Furthermore, recent studies have uncovered the molecular mechanism underlying input cell-dependent expression of Nlgn3 protein at hippocampal inhibitory synapses, in which trans-synaptic signaling of specific alternatively spliced isoforms of Nlgn3 and Nrxn plays a critical role. In this review article, we overview the molecular, anatomical, and physiological knowledge about Nlgn3, focusing on the circuit-specific function of mammalian Nlgn3 and its underlying molecular mechanism. This will provide not only new insight into specific Nlgn3-mediated trans-synaptic interactions as molecular codes for synapse specification but also a better understanding of the pathophysiological basis for non-syndromic ASD associated with functional impairment in Nlgn3 gene.
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Affiliation(s)
- Motokazu Uchigashima
- Department of Cellular Neuropathology, Brain Research Institute, Niigata University, Niigata, Japan
| | - Amy Cheung
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, United States
| | - Kensuke Futai
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, MA, United States
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13
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Parmigiani E, Scalera M, Mori E, Tantillo E, Vannini E. Old Stars and New Players in the Brain Tumor Microenvironment. Front Cell Neurosci 2021; 15:709917. [PMID: 34690699 PMCID: PMC8527006 DOI: 10.3389/fncel.2021.709917] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/04/2021] [Indexed: 12/12/2022] Open
Abstract
In recent years, the direct interaction between cancer cells and tumor microenvironment (TME) has emerged as a crucial regulator of tumor growth and a promising therapeutic target. The TME, including the surrounding peritumoral regions, is dynamically modified during tumor progression and in response to therapies. However, the mechanisms regulating the crosstalk between malignant and non-malignant cells are still poorly understood, especially in the case of glioma, an aggressive form of brain tumor. The presence of unique brain-resident cell types, namely neurons and glial cells, and an exceptionally immunosuppressive microenvironment pose additional important challenges to the development of effective treatments targeting the TME. In this review, we provide an overview on the direct and indirect interplay between glioma and neuronal and glial cells, introducing new players and mechanisms that still deserve further investigation. We will focus on the effects of neural activity and glial response in controlling glioma cell behavior and discuss the potential of exploiting these cellular interactions to develop new therapeutic approaches with the aim to preserve proper brain functionality.
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Affiliation(s)
- Elena Parmigiani
- Embryology and Stem Cell Biology, Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Marta Scalera
- Neuroscience Institute, Consiglio Nazionale delle Ricerche (CNR), Pisa, Italy
| | | | - Elena Tantillo
- Neuroscience Institute, Consiglio Nazionale delle Ricerche (CNR), Pisa, Italy
| | - Eleonora Vannini
- Neuroscience Institute, Consiglio Nazionale delle Ricerche (CNR), Pisa, Italy
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14
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Shiota Y, Matsudaira I, Takeuchi H, Ono C, Tomita H, Kawashima R, Taki Y. The influence of NRXN1 on systemizing and the brain structure in healthy adults. Brain Imaging Behav 2021; 16:692-701. [PMID: 34529206 DOI: 10.1007/s11682-021-00530-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/29/2021] [Indexed: 11/24/2022]
Abstract
Certain behavioral characteristics of autism spectrum disorder can be found in otherwise healthy people. Individuals with difficulties in social adaptation may have subclinical autistic traits; however, effective biomarkers of these traits have not yet been established. There is a dire need for objective indices of these traits that combine behavior, brain images, and genetic information. In this study, we examined the association among a single nucleotide polymorphism of NRXN1 (rs858932; C/G), autistic traits, and brain structure in 311 healthy adults. We found that carriers of minor alleles (carriers of the G-allele) had significantly higher systemizing scores than major-allele (C-allele) homozygotes. Furthermore, the regional white matter volume in the right anterior limb of the internal capsule was significantly greater in carriers of the G-allele than in C-allele homozygotes. To the best of our knowledge, this is the first report of NRXN1 rs858932 being involved in systemizing and the brain structure of healthy adults. Our findings provide insight into the effects of genetics on autistic traits and their respective neural substrates.
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Affiliation(s)
- Yuka Shiota
- Department of Nuclear Medicine and Radiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Izumi Matsudaira
- Smart-Aging Research Center, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
| | - Hikaru Takeuchi
- Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Chiaki Ono
- Department of Disaster Psychiatry, International Research Institute of Disaster Science, Tohoku University, Sendai, Japan
| | - Hiroaki Tomita
- Department of Disaster Psychiatry, International Research Institute of Disaster Science, Tohoku University, Sendai, Japan.,Department of Psychiatry, Tohoku University Hospital, Sendai, Japan
| | - Ryuta Kawashima
- Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.,Department of Advanced Brain Science, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.,Smart-Aging Research Center, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Yasuyuki Taki
- Department of Nuclear Medicine and Radiology, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.,Smart-Aging Research Center, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
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15
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Monje M, Káradóttir RT. The bright and the dark side of myelin plasticity: Neuron-glial interactions in health and disease. Semin Cell Dev Biol 2021; 116:10-15. [PMID: 33293232 PMCID: PMC8178421 DOI: 10.1016/j.semcdb.2020.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 12/16/2022]
Abstract
Neuron-glial interactions shape neural circuit establishment, refinement and function. One of the key neuron-glial interactions takes place between axons and oligodendroglial precursor cells. Interactions between neurons and oligodendrocyte precursor cells (OPCs) promote OPC proliferation, generation of new oligodendrocytes and myelination, shaping myelin development and ongoing adaptive myelin plasticity in the brain. Communication between neurons and OPCs can be broadly divided into paracrine and synaptic mechanisms. Following the Nobel mini-symposium "The Dark Side of the Brain" in late 2019 at the Karolinska Institutet, this mini-review will focus on the bright and dark sides of neuron-glial interactions and discuss paracrine and synaptic interactions between neurons and OPCs and their malignant counterparts.
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Affiliation(s)
- Michelle Monje
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA, USA.
| | - Ragnhildur Thóra Káradóttir
- Wellcome - Medical Research Council Cambridge Stem Cell Institute & Department of Veterinary Medicine, University of Cambridge, Cambridge, UK; Department of Physiology, BioMedical Center, Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
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16
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Predicting cell-to-cell communication networks using NATMI. Nat Commun 2020; 11:5011. [PMID: 33024107 PMCID: PMC7538930 DOI: 10.1038/s41467-020-18873-z] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Accepted: 09/16/2020] [Indexed: 12/20/2022] Open
Abstract
Development of high throughput single-cell sequencing technologies has made it cost-effective to profile thousands of cells from diverse samples containing multiple cell types. To study how these different cell types work together, here we develop NATMI (Network Analysis Toolkit for Multicellular Interactions). NATMI uses connectomeDB2020 (a database of 2293 manually curated ligand-receptor pairs with literature support) to predict and visualise cell-to-cell communication networks from single-cell (or bulk) expression data. Using multiple published single-cell datasets we demonstrate how NATMI can be used to identify (i) the cell-type pairs that are communicating the most (or most specifically) within a network, (ii) the most active (or specific) ligand-receptor pairs active within a network, (iii) putative highly-communicating cellular communities and (iv) differences in intercellular communication when profiling given cell types under different conditions. Furthermore, analysis of the Tabula Muris (organism-wide) atlas confirms our previous prediction that autocrine signalling is a major feature of cell-to-cell communication networks, while also revealing that hundreds of ligands and their cognate receptors are co-expressed in individual cells suggesting a substantial potential for self-signalling. Single cell expression data allows for inferring cell-cell communication between cells expressing ligands and those expressing their cognate receptors. Here the authors present an updated and curated database of ligand-receptor pairs and a Python-based toolkit to construct and analyse communication networks from single cell and bulk expression data.
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17
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Sakers K, Eroglu C. Control of neural development and function by glial neuroligins. Curr Opin Neurobiol 2019; 57:163-170. [PMID: 30991196 DOI: 10.1016/j.conb.2019.03.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 11/16/2022]
Abstract
Neuroligins are a family of cell adhesion molecules, which are best known for their functions as postsynaptic components of the trans-synaptic neurexin-neuroligin complexes. Neuroligins are highly conserved across evolution with important roles in the formation, maturation and function of synaptic structures. Mutations in the genes that encode for neuroligins have been linked to a number of neurodevelopmental disorders such as autism and schizophrenia, which stem from synaptic pathologies. Owing to their essential functions in regulating synaptic connectivity and their link to synaptic dysfunction in disease, previous studies on neuroligins have focused on neurons. Yet a recent work reveals that neuroligins are also expressed in the central nervous system by glial cells, such as astrocytes and oligodendrocytes, and perform important roles in controlling synaptic connectivity in a non-cell autonomous manner. In this review, we will highlight these recent findings demonstrating the important roles of glial neuroligins in regulating the development and connectivity of healthy and diseased brains.
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Affiliation(s)
- Kristina Sakers
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, United States
| | - Cagla Eroglu
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, United States; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, United States; Duke Institute for Brain Sciences (DIBS), Durham, NC 27710, United States; Regeneration Next Initiative, Duke University, Durham, NC 27710, United States.
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18
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Uchigashima M, Cheung A, Suh J, Watanabe M, Futai K. Differential expression of neurexin genes in the mouse brain. J Comp Neurol 2019; 527:1940-1965. [PMID: 30761534 DOI: 10.1002/cne.24664] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 01/04/2019] [Accepted: 02/01/2019] [Indexed: 01/22/2023]
Abstract
Synapses, highly specialized membrane junctions between neurons, connect presynaptic neurotransmitter release sites and postsynaptic ligand-gated channels. Neurexins (Nrxns), a family of presynaptic adhesion molecules, have been characterized as major regulators of synapse development and function. Via their extracellular domains, Nrxns bind to different postsynaptic proteins, generating highly diverse functional readouts through their postsynaptic binding partners. Not surprisingly given these versatile protein interactions, mutations and deletions of Nrxn genes have been identified in patients with autism spectrum disorders, intellectual disabilities, and schizophrenia. Therefore, elucidating the expression profiles of Nrxns in the brain is of high significance. Here, using chromogenic and fluorescent in situ hybridization, we characterize the expression patterns of Nrxn isoforms throughout the brain. We found that each Nrxn isoform displays a unique expression profile in a region-, cell type-, and sensory system-specific manner. Interestingly, we also found that αNrxn1 and αNrxn2 mRNAs are expressed in non-neuronal cells, including astrocytes and oligodendrocytes. Lastly, we found diverse expression patterns of genes that encode Nrxn binding proteins, such as Neuroligins (Nlgns), Leucine-rich repeat transmembrane neuronal protein (Lrrtms) and Latrophilins (Adgrls), suggesting that Nrxn proteins can mediate numerous combinations of trans-synaptic interactions. Together, our anatomical profiling of Nrxn gene expression reflects the diverse roles of Nrxn molecules.
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Affiliation(s)
- Motokazu Uchigashima
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts.,Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Amy Cheung
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Julie Suh
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Kensuke Futai
- Department of Neurobiology, Brudnick Neuropsychiatric Research Institute, University of Massachusetts Medical School, Worcester, Massachusetts
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19
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Astrocytic neuroligins control astrocyte morphogenesis and synaptogenesis. Nature 2018; 551:192-197. [PMID: 29120426 PMCID: PMC5796651 DOI: 10.1038/nature24638] [Citation(s) in RCA: 284] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 10/17/2017] [Indexed: 02/07/2023]
Abstract
Astrocytes are highly complex glial cells with numerous fine cellular processes which infiltrate the neuropil to interact with synapses. The mechanisms controlling the establishment of astrocytes’ remarkable morphology and how impairing astrocytic infiltration of the neuropil alters synaptic connectivity are largely unknown. Here we find that cortical astrocyte morphogenesis depends on direct contact with neuronal processes and occurs in tune with the growth and activity of synaptic circuits. Neuroligin (NL) family cell adhesion proteins, NL1, NL2, and NL3, which are expressed by cortical astrocytes, control astrocyte morphogenesis through interactions with neuronal neurexins. Furthermore, in the absence of astrocytic NL2, cortical excitatory synapse formation and function is diminished, whereas inhibitory synaptic function is enhanced. Our findings highlight a novel mechanism of action for NLs and link astrocyte morphogenesis to synaptogenesis. Because NL mutations are implicated in various neurological disorders, these findings also offer an astrocyte-based mechanism of neural pathology.
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20
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Gibson EM, Geraghty AC, Monje M. Bad wrap: Myelin and myelin plasticity in health and disease. Dev Neurobiol 2017; 78:123-135. [PMID: 28986960 DOI: 10.1002/dneu.22541] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 08/31/2017] [Accepted: 10/03/2017] [Indexed: 12/21/2022]
Abstract
Human central nervous system myelin development extends well into the fourth decade of life, and this protracted period underscores the potential for experience to modulate myelination. The concept of myelin plasticity implies adaptability in myelin structure and function in response to experiences during development and beyond. Mounting evidence supports this concept of neuronal activity-regulated changes in myelin-forming cells, including oligodendrocyte precursor cell proliferation, oligodendrogenesis and modulation of myelin microstructure. In healthy individuals, myelin plasticity in associative white matter structures of the brain is implicated in learning and motor function in both rodents and humans. Activity-dependent changes in myelin-forming cells may influence the function of neural networks that depend on the convergence of numerous neural signals on both a temporal and spatial scale. However, dysregulation of myelin plasticity can disadvantageously alter myelin microstructure and result in aberrant circuit function or contribute to pathological cell proliferation. Emerging roles for myelin plasticity in normal neurological function and in disease are discussed. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 123-135, 2018.
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Affiliation(s)
- Erin M Gibson
- Department of Neurology, Stanford University School of Medicine, Stanford, California, 94305
| | - Anna C Geraghty
- Department of Neurology, Stanford University School of Medicine, Stanford, California, 94305
| | - Michelle Monje
- Department of Neurology, Stanford University School of Medicine, Stanford, California, 94305
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21
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Jeong J, Paskus JD, Roche KW. Posttranslational modifications of neuroligins regulate neuronal and glial signaling. Curr Opin Neurobiol 2017; 45:130-138. [PMID: 28577430 DOI: 10.1016/j.conb.2017.05.017] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 05/02/2017] [Accepted: 05/12/2017] [Indexed: 12/29/2022]
Abstract
This review covers the dynamic regulation of neuroligin isoforms, focusing on posttranslational events including phosphorylation, glycosylation and activity-dependent cleavage. There is a growing literature on how phosphorylation confers an isoform-specific level of modulation affecting a variety of protein interactions. In addition, recent studies describe activity-dependent proteolytic cleavage of neuroligins, revealing a broader role for neuroligins than just synaptic 'glue'. Interesting new research implicates the cleaved extracellular fragments of neuroligins in promoting glioma. These reports on cell signaling mediated by the cleavage products of neuroligins suggest novel and important roles for neuroligins in neuro-glial signaling.
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Affiliation(s)
- Jaehoon Jeong
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeremiah D Paskus
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD 20892, USA; Interdisciplinary Program in Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Katherine W Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health, Bethesda, MD 20892, USA.
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22
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Anatomy and Cell Biology of Autism Spectrum Disorder: Lessons from Human Genetics. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2017; 224:1-25. [PMID: 28551748 DOI: 10.1007/978-3-319-52498-6_1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Until recently autism spectrum disorder (ASD) was regarded as a neurodevelopmental condition with unknown causes and pathogenesis. In the footsteps of the revolution of genome technologies and genetics, and with its high degree of heritability, ASD became the first neuropsychiatric disorder for which clues towards molecular and cellular pathogenesis were uncovered by genetic identification of susceptibility genes. Currently several hundreds of risk genes have been assigned, with a recurrence below 1% in the ASD population. The multitude and diversity of known ASD genes has extended the clinical notion that ASD comprises very heterogeneous conditions ranging from severe intellectual disabilities to mild high-functioning forms. The results of genetics have allowed to pinpoint a limited number of cellular and molecular processes likely involved in ASD including protein synthesis, signal transduction, transcription/chromatin remodelling and synaptic function all playing an essential role in the regulation of synaptic homeostasis during brain development. In this context, we highlight the role of protein synthesis as a key process in ASD pathogenesis as it might be central in synaptic deregulation and a potential target for intervention. These current insights should lead to a rational design of interventions in molecular and cellular pathways of ASD pathogenesis that may be applied to affected individuals in the future.
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23
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Baraban M, Mensch S, Lyons DA. Adaptive myelination from fish to man. Brain Res 2016; 1641:149-161. [PMID: 26498877 PMCID: PMC4907128 DOI: 10.1016/j.brainres.2015.10.026] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 10/13/2015] [Accepted: 10/14/2015] [Indexed: 01/06/2023]
Abstract
Myelinated axons with nodes of Ranvier are an evolutionary elaboration common to essentially all jawed vertebrates. Myelin made by Schwann cells in our peripheral nervous system and oligodendrocytes in our central nervous system has been long known to facilitate rapid energy efficient nerve impulse propagation. However, it is now also clear, particularly in the central nervous system, that myelin is not a simple static insulator but that it is dynamically regulated throughout development and life. New myelin sheaths can be made by newly differentiating oligodendrocytes, and mature myelin sheaths can be stimulated to grow again in the adult. Furthermore, numerous studies in models from fish to man indicate that neuronal activity can affect distinct stages of oligodendrocyte development and the process of myelination itself. This begs questions as to how these effects of activity are mediated at a cellular and molecular level and whether activity-driven adaptive myelination is a feature common to all myelinated axons, or indeed all oligodendrocytes, or is specific to cells or circuits with particular functions. Here we review the recent literature on this topic, elaborate on the key outstanding questions in the field, and look forward to future studies that incorporate investigations in systems from fish to man that will provide further insight into this fundamental aspect of nervous system plasticity. This article is part of a Special Issue entitled SI: Myelin Evolution.
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Affiliation(s)
- Marion Baraban
- Centre for Neuroregeneration, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Sigrid Mensch
- Centre for Neuroregeneration, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - David A Lyons
- Centre for Neuroregeneration, University of Edinburgh, 49 Little France Crescent, Edinburgh EH16 4SB, UK.
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24
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Wang LC, Almazan G. Cdon, a cell surface protein, mediates oligodendrocyte differentiation and myelination. Glia 2016; 64:1021-33. [PMID: 26988125 DOI: 10.1002/glia.22980] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/11/2016] [Indexed: 12/13/2022]
Abstract
During central nervous system development, oligodendrocyte progenitors (OLPs) establish multiple branched processes and axonal contacts to initiate myelination. A complete understanding of the molecular signals implicated in cell surface interaction to initiate myelination/remyelination is currently lacking. The objective of our study was to assess whether Cdon, a cell surface protein that was shown to participate in muscle and neuron cell development, is involved in oligodendrocyte (OLG) differentiation and myelination. Here, we demonstrate that endogenous Cdon protein is expressed in OLPs, increasing in the early differentiation stages and decreasing in mature OLGs. Immunocytochemistry of endogenous Cdon showed localization on both OLG cell membranes and cellular processes exhibiting puncta- or varicosity-like structures. Cdon knockdown with siRNA decreased protein levels by 62% as well as two myelin-specific proteins, MBP and MAG. Conversely, overexpression of full-length rat Cdon increased myelin proteins in OLGs. The complexity of OLGs branching and contact point numbers with axons were also increased in Cdon overexpressing cells growing alone or in coculture with dorsal root ganglion neurons (DRGNs). Furthermore, myelination of DRGNs was decreased when OLPs were transfected with Cdon siRNA. Altogether, our results suggest that Cdon participates in OLG differentiation and myelination, most likely in the initial stages of development.
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Affiliation(s)
- Li-Chun Wang
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada, H3G 1Y6
| | - Guillermina Almazan
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada, H3G 1Y6
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25
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Przekwas A, Somayaji MR, Gupta RK. Synaptic Mechanisms of Blast-Induced Brain Injury. Front Neurol 2016; 7:2. [PMID: 26834697 PMCID: PMC4720734 DOI: 10.3389/fneur.2016.00002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 01/04/2016] [Indexed: 01/08/2023] Open
Abstract
Blast wave-induced traumatic brain injury (TBI) is one of the most common injuries to military personnel. Brain tissue compression/tension due to blast-induced cranial deformations and shear waves due to head rotation may generate diffuse micro-damage to neuro-axonal structures and trigger a cascade of neurobiological events culminating in cognitive and neurodegenerative disorders. Although diffuse axonal injury is regarded as a signature wound of mild TBI (mTBI), blast loads may also cause synaptic injury wherein neuronal synapses are stretched and sheared. This synaptic injury may result in temporary disconnect of the neural circuitry and transient loss in neuronal communication. We hypothesize that mTBI symptoms such as loss of consciousness or dizziness, which start immediately after the insult, could be attributed to synaptic injury. Although empirical evidence is beginning to emerge; the detailed mechanisms underlying synaptic injury are still elusive. Coordinated in vitro-in vivo experiments and mathematical modeling studies can shed light into the synaptic injury mechanisms and their role in the potentiation of mTBI symptoms.
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Affiliation(s)
- Andrzej Przekwas
- Computational Medicine and Biology Division, CFD Research Corporation, Huntsville, AL, USA
| | | | - Raj K. Gupta
- Department of Defense Blast Injury Research Program Coordinating Office, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD, USA
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