1
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Lee JY, Gala DS, Kiourlappou M, Olivares-Abril J, Joha J, Titlow JS, Teodoro RO, Davis I. Murine glial protrusion transcripts predict localized Drosophila glial mRNAs involved in plasticity. J Cell Biol 2024; 223:e202306152. [PMID: 39037431 PMCID: PMC11262410 DOI: 10.1083/jcb.202306152] [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: 06/30/2023] [Revised: 06/14/2024] [Accepted: 07/03/2024] [Indexed: 07/23/2024] Open
Abstract
The polarization of cells often involves the transport of specific mRNAs and their localized translation in distal projections. Neurons and glia are both known to contain long cytoplasmic processes, while localized transcripts have only been studied extensively in neurons, not glia, especially in intact nervous systems. Here, we predict 1,740 localized Drosophila glial transcripts by extrapolating from our meta-analysis of seven existing studies characterizing the localized transcriptomes and translatomes of synaptically associated mammalian glia. We demonstrate that the localization of mRNAs in mammalian glial projections strongly predicts the localization of their high-confidence Drosophila homologs in larval motor neuron-associated glial projections and are highly statistically enriched for genes associated with neurological diseases. We further show that some of these localized glial transcripts are specifically required in glia for structural plasticity at the nearby neuromuscular junction synapses. We conclude that peripheral glial mRNA localization is a common and conserved phenomenon and propose that it is likely to be functionally important in disease.
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Affiliation(s)
- Jeffrey Y. Lee
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Dalia S. Gala
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | | | - Jana Joha
- Department of Biochemistry, University of Oxford, Oxford, UK
| | | | - Rita O. Teodoro
- iNOVA4Health, NOVA Medical School | Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa, Portugal
| | - Ilan Davis
- School of Molecular Biosciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
- Department of Biochemistry, University of Oxford, Oxford, UK
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2
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Brandão-Teles C, Antunes ASLM, de Moraes Vrechi TA, Martins-de-Souza D. The Roles of hnRNP Family in the Brain and Brain-Related Disorders. Mol Neurobiol 2024; 61:3578-3595. [PMID: 37999871 DOI: 10.1007/s12035-023-03747-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Accepted: 10/25/2023] [Indexed: 11/25/2023]
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) belong to a complex family of RNA-binding proteins that are essential to control alternative splicing, mRNA trafficking, synaptic plasticity, stress granule formation, cell cycle regulation, and axonal transport. Over the past decade, hnRNPs have been associated with different brain disorders such as Alzheimer's disease, multiple sclerosis, and schizophrenia. Given their essential role in maintaining cell function and integrity, it is not surprising that dysregulated hnRNP levels lead to neurological implications. This review aims to explore the primary functions of hnRNPs in neurons, oligodendrocytes, microglia, and astrocytes, and their roles in brain disorders. We also discuss proteomics and other technologies and their potential for studying and evaluating hnRNPs in brain disorders, including the discovery of new therapeutic targets and possible pharmacological interventions.
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Affiliation(s)
- Caroline Brandão-Teles
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil.
| | - André S L M Antunes
- Brazilian Biosciences National Laboratory (LNBio), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Talita Aparecida de Moraes Vrechi
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Daniel Martins-de-Souza
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil.
- D'Or Institute for Research and Education (IDOR), São Paulo, Brazil.
- Experimental Medicine Research Cluster (EMRC), University of Campinas, Campinas, SP, 13083-862, Brazil.
- INCT in Modelling Human Complex Diseases with 3D Platforms (Model3D), São Paulo, Brazil.
- Conselho Nacional de Desenvolvimento Científico e Tecnológico, Instituto Nacional de Biomarcadores em Neuropsiquiatria, São Paulo, Brazil.
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3
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Lu J, Ge P, Sawaya MR, Hughes MP, Boyer DR, Cao Q, Abskharon R, Cascio D, Tayeb-Fligelman E, Eisenberg DS. Cryo-EM structures of the D290V mutant of the hnRNPA2 low-complexity domain suggests how D290V affects phase separation and aggregation. J Biol Chem 2024; 300:105531. [PMID: 38072051 PMCID: PMC10844680 DOI: 10.1016/j.jbc.2023.105531] [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: 08/16/2023] [Revised: 11/08/2023] [Accepted: 11/20/2023] [Indexed: 02/02/2024] Open
Abstract
Heterogeneous nuclear ribonucleoprotein A2 (hnRNPA2) is a human ribonucleoprotein that transports RNA to designated locations for translation via its ability to phase separate. Its mutated form, D290V, is implicated in multisystem proteinopathy known to afflict two families, mainly with myopathy and Paget's disease of bone. Here, we investigate this mutant form of hnRNPA2 by determining cryo-EM structures of the recombinant D290V low complexity domain. We find that the mutant form of hnRNPA2 differs from the WT fibrils in four ways. In contrast to the WT fibrils, the PY-nuclear localization signals in the fibril cores of all three mutant polymorphs are less accessible to chaperones. Also, the mutant fibrils are more stable than WT fibrils as judged by phase separation, thermal stability, and energetic calculations. Similar to other pathogenic amyloids, the mutant fibrils are polymorphic. Thus, these structures offer evidence to explain how a D-to-V missense mutation diverts the assembly of reversible, functional amyloid-like fibrils into the assembly of pathogenic amyloid, and may shed light on analogous conversions occurring in other ribonucleoproteins that lead to neurological diseases such as amyotrophic lateral sclerosis and frontotemporal dementia.
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Affiliation(s)
- Jiahui Lu
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, California, USA
| | - Peng Ge
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, California, USA
| | - Michael R Sawaya
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, California, USA
| | - Michael P Hughes
- Department of Cell and Molecular Biology, St Jude Children's Research Hospital, Memphis, Tennessee, USA
| | - David R Boyer
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, California, USA
| | - Qin Cao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China
| | - Romany Abskharon
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, California, USA
| | - Duilio Cascio
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, California, USA
| | - Einav Tayeb-Fligelman
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, California, USA
| | - David S Eisenberg
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, California, USA; UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, California, USA.
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4
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Fekete CD, Horning RZ, Doron MS, Nishiyama A. Cleavage of VAMP2/3 Affects Oligodendrocyte Lineage Development in the Developing Mouse Spinal Cord. J Neurosci 2023; 43:6592-6608. [PMID: 37620160 PMCID: PMC10538588 DOI: 10.1523/jneurosci.2206-21.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 10/20/2022] [Accepted: 08/15/2023] [Indexed: 08/26/2023] Open
Abstract
In the developing and adult CNS, new oligodendrocytes (OLs) are generated from a population of cells known as oligodendrocyte precursor cells (OPCs). As they begin to differentiate, OPCs undergo a series of highly regulated changes to morphology, gene expression, and membrane organization. This stage represents a critical bottleneck in oligodendrogliogenesis, and the regulatory program that guides it is still not fully understood. Here, we show that in vivo toxin-mediated cleavage of the vesicle associated SNARE proteins VAMP2/3 in the OL lineage of both male and female mice impairs the ability of early OLs to mature into functional, myelinating OLs. In the developing mouse spinal cord, many VAMP2/3-cleaved OLs appeared to stall in the premyelinating, early OL stage, resulting in an overall loss of both myelin density and OL number. The Src kinase Fyn, a key regulator of oligodendrogliogenesis and myelination, is highly expressed among premyelinating OLs, but its expression decreases as OLs mature. We found that OLs with cleaved VAMP2/3 in the spinal cord white matter showed significantly higher expression of Fyn compared with neighboring control cells, potentially because of an extended premyelinating stage. Overall, our results show that functional VAMP2/3 in OL lineage cells is essential for proper myelin formation and plays a major role in controlling the maturation and terminal differentiation of premyelinating OLs.SIGNIFICANCE STATEMENT The production of mature oligodendrocytes (OLs) is essential for CNS myelination during development, myelin remodeling in adulthood, and remyelination following injury or in demyelinating disease. Before myelin sheath formation, newly formed OLs undergo a series of highly regulated changes during a stage of their development known as the premyelinating, or early OL stage. This stage acts as a critical checkpoint in OL development, and much is still unknown about the dynamic regulatory processes involved. In this study, we show that VAMP2/3, SNARE proteins involved in vesicular trafficking and secretion play an essential role in regulating premyelinating OL development and are required for healthy myelination in the developing mouse spinal cord.
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Affiliation(s)
- Christopher D Fekete
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269
| | - Robert Z Horning
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269
| | - Matan S Doron
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269
| | - Akiko Nishiyama
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269
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5
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Zhang T, Alonzo I, Stubben C, Geng Y, Herdman C, Chandler N, Doane KP, Pluimer BR, Trauger SA, Peterson RT. A zebrafish model of combined saposin deficiency identifies acid sphingomyelinase as a potential therapeutic target. Dis Model Mech 2023; 16:dmm049995. [PMID: 37183607 PMCID: PMC10320721 DOI: 10.1242/dmm.049995] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 04/26/2023] [Indexed: 05/16/2023] Open
Abstract
Sphingolipidoses are a subcategory of lysosomal storage diseases (LSDs) caused by mutations in enzymes of the sphingolipid catabolic pathway. Like many LSDs, neurological involvement in sphingolipidoses leads to early mortality with limited treatment options. Given the role of myelin loss as a major contributor toward LSD-associated neurodegeneration, we investigated the pathways contributing to demyelination in a CRISPR-Cas9-generated zebrafish model of combined saposin (psap) deficiency. psap knockout (KO) zebrafish recapitulated major LSD pathologies, including reduced lifespan, reduced lipid storage, impaired locomotion and severe myelin loss; loss of myelin basic protein a (mbpa) mRNA was progressive, with no changes in additional markers of oligodendrocyte differentiation. Brain transcriptomics revealed dysregulated mTORC1 signaling and elevated neuroinflammation, where increased proinflammatory cytokine expression preceded and mTORC1 signaling changes followed mbpa loss. We examined pharmacological and genetic rescue strategies via water tank administration of the multiple sclerosis drug monomethylfumarate (MMF), and crossing the psap KO line into an acid sphingomyelinase (smpd1) deficiency model. smpd1 mutagenesis, but not MMF treatment, prolonged lifespan in psap KO zebrafish, highlighting the modulation of acid sphingomyelinase activity as a potential path toward sphingolipidosis treatment.
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Affiliation(s)
- Tejia Zhang
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Ivy Alonzo
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Chris Stubben
- Bioinformatic Analysis Shared Resource, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT 84112, USA
| | - Yijie Geng
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Chelsea Herdman
- Department of Neurobiology and Molecular Medicine Program, University of Utah School of Medicine, Salt Lake City, UT 84112, USA
| | - Nancy Chandler
- Electron Microscopy Core Laboratory, University of Utah, Salt Lake City, UT 84112, USA
| | - Kim P. Doane
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Brock R. Pluimer
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
| | - Sunia A. Trauger
- Harvard Center for Mass Spectrometry, Harvard University, Cambridge, MA 02138, USA
| | - Randall T. Peterson
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA
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6
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Krämer-Albers EM, Werner HB. Mechanisms of axonal support by oligodendrocyte-derived extracellular vesicles. Nat Rev Neurosci 2023:10.1038/s41583-023-00711-y. [PMID: 37258632 DOI: 10.1038/s41583-023-00711-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2023] [Indexed: 06/02/2023]
Abstract
Extracellular vesicles (EVs) have recently emerged as versatile elements of cell communication in the nervous system, mediating tissue homeostasis. EVs influence the physiology of their target cells via horizontal transfer of molecular cargo between cells and by triggering signalling pathways. In this Review, we discuss recent work revealing that EVs mediate interactions between oligodendrocytes and neurons, which are relevant for maintaining the structural integrity of axons. In response to neuronal activity, myelinating oligodendrocytes release EVs, which are internalized by neurons and provide axons with key factors that improve axonal transport, stress resistance and energy homeostasis. Glia-to-neuron transfer of EVs is thus a crucial facet of axonal preservation. When glial support is impaired, axonal integrity is progressively lost, as observed in myelin-related disorders, other neurodegenerative diseases and with normal ageing. We highlight the mechanisms that oligodendroglial EVs use to sustain axonal integrity and function.
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Affiliation(s)
- Eva-Maria Krämer-Albers
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany.
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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7
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Rocha DN, Carvalho ED, Pires LR, Gardin C, Zanolla I, Szewczyk PK, Machado C, Fernandes R, Stachewicz U, Zavan B, Relvas JB, Pêgo AP. It takes two to remyelinate: A bioengineered platform to study astrocyte-oligodendrocyte crosstalk and potential therapeutic targets in remyelination. BIOMATERIALS ADVANCES 2023; 151:213429. [PMID: 37148597 DOI: 10.1016/j.bioadv.2023.213429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 03/21/2023] [Accepted: 04/12/2023] [Indexed: 05/08/2023]
Abstract
The loss of the myelin sheath insulating axons is the hallmark of demyelinating diseases. These pathologies often lead to irreversible neurological impairment and patient disability. No effective therapies are currently available to promote remyelination. Several elements contribute to the inadequacy of remyelination, thus understanding the intricacies of the cellular and signaling microenvironment of the remyelination niche might help us to devise better strategies to enhance remyelination. Here, using a new in vitro rapid myelinating artificial axon system based on engineered microfibres, we investigated how reactive astrocytes influence oligodendrocyte (OL) differentiation and myelination ability. This artificial axon culture system enables the effective uncoupling of molecular cues from the biophysical properties of the axons, allowing the detailed study of the astrocyte-OL crosstalk. Oligodendrocyte precursor cells (OPCs) were cultured on poly(trimethylene carbonate-co-ε-caprolactone) copolymer electrospun microfibres that served as surrogate axons. This platform was then combined with a previously established tissue engineered glial scar model of astrocytes embedded in 1 % (w/v) alginate matrices, in which astrocyte reactive phenotype was acquired using meningeal fibroblast conditioned medium. OPCs were shown to adhere to uncoated engineered microfibres and differentiate into myelinating OL. Reactive astrocytes were found to significantly impair OL differentiation ability, after six and eight days in a co-culture system. Differentiation impairment was seen to be correlated with astrocytic miRNA release through exosomes. We found significantly reduction on the expression of pro-myelinating miRNAs (miR-219 and miR-338) and an increase in anti-myelinating miRNA (miR-125a-3p) content between reactive and quiescent astrocytes. Additionally, we show that OPC differentiation inhibition could be reverted by rescuing the activated astrocytic phenotype with ibuprofen, a chemical inhibitor of the small rhoGTPase RhoA. Overall, these findings show that modulating astrocytic function might be an interesting therapeutic avenue for demyelinating diseases. The use of these engineered microfibres as an artificial axon culture system will enable the screening for potential therapeutic agents that promote OL differentiation and myelination while providing valuable insight on the myelination/remyelination processes.
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Affiliation(s)
- Daniela N Rocha
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Engenharia Biomédica (INEB), Universidade do Porto, 4200-135 Porto, Portugal; Faculdade de Engenharia da Universidade do Porto (FEUP), 4200-465 Porto, Portugal
| | - Eva D Carvalho
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Engenharia Biomédica (INEB), Universidade do Porto, 4200-135 Porto, Portugal; Faculdade de Engenharia da Universidade do Porto (FEUP), 4200-465 Porto, Portugal
| | - Liliana R Pires
- Instituto de Engenharia Biomédica (INEB), Universidade do Porto, 4200-135 Porto, Portugal; Faculdade de Engenharia da Universidade do Porto (FEUP), 4200-465 Porto, Portugal
| | - Chiara Gardin
- Maria Cecilia Hospital, GVM Care & Research, Cotignola, 48033 Ravenna, Italy
| | - Ilaria Zanolla
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Piotr K Szewczyk
- Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, 30-059 Krakow, Poland
| | - Cláudia Machado
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Rui Fernandes
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Urszula Stachewicz
- Faculty of Metals Engineering and Industrial Computer Science, AGH University of Science and Technology, 30-059 Krakow, Poland
| | - Barbara Zavan
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - João B Relvas
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135 Porto, Portugal; Department of Biomedicine, Faculty of Medicine, Universidade do Porto, 4200-319 Porto, Portugal
| | - Ana P Pêgo
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Engenharia Biomédica (INEB), Universidade do Porto, 4200-135 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, 4050-343 Porto, Portugal.
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8
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Zhao X, Jacob C. Mechanisms of Demyelination and Remyelination Strategies for Multiple Sclerosis. Int J Mol Sci 2023; 24:ijms24076373. [PMID: 37047344 PMCID: PMC10093908 DOI: 10.3390/ijms24076373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 03/19/2023] [Accepted: 03/25/2023] [Indexed: 03/31/2023] Open
Abstract
All currently licensed medications for multiple sclerosis (MS) target the immune system. Albeit promising preclinical results demonstrated disease amelioration and remyelination enhancement via modulating oligodendrocyte lineage cells, most drug candidates showed only modest or no effects in human clinical trials. This might be due to the fact that remyelination is a sophistically orchestrated process that calls for the interplay between oligodendrocyte lineage cells, neurons, central nervous system (CNS) resident innate immune cells, and peripheral immune infiltrates and that this process may somewhat differ in humans and rodent models used in research. To ensure successful remyelination, the recruitment and activation/repression of each cell type should be regulated in a highly organized spatio–temporal manner. As a result, drug candidates targeting one single pathway or a single cell population have difficulty restoring the optimal microenvironment at lesion sites for remyelination. Therefore, when exploring new drug candidates for MS, it is instrumental to consider not only the effects on all CNS cell populations but also the optimal time of administration during disease progression. In this review, we describe the dysregulated mechanisms in each relevant cell type and the disruption of their coordination as causes of remyelination failure, providing an overview of the complex cell interplay in CNS lesion sites.
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9
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Bregalda A, Carducci C, Viscomi MT, Pierigè F, Biagiotti S, Menotta M, Biancucci F, Pascucci T, Leuzzi V, Magnani M, Rossi L. Myelin basic protein recovery during PKU mice lifespan and the potential role of microRNAs on its regulation. Neurobiol Dis 2023; 180:106093. [PMID: 36948260 DOI: 10.1016/j.nbd.2023.106093] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/10/2023] [Accepted: 03/17/2023] [Indexed: 03/24/2023] Open
Abstract
Untreated phenylketonuria (PKU) patients and PKU animal models show hypomyelination in the central nervous system and white matter damages, which are accompanied by myelin basic protein (MBP) impairment. Despite many assumptions, the primary explanation of the mentioned cerebral outcomes remains elusive. In this study, MBP protein and mRNA expression on brains of wild type (WT) and phenylketonuric (ENU2) mice were analyzed throughout mice lifespan (14-60-180-270-360-540 post-natal days, PND). The results confirmed the low MBP expression at first PND times, while revealed an unprecedented progressive MBP protein expression recovery in aged ENU2 mice. Unexpectedly, unaltered MBP mRNA expression between WT and ENU2 was always observed. Additionally, for the same time intervals, a significant decrease of the phenylalanine concentration in the peripheral blood and brain of ENU2 mice was detected, to date, for the first time. In this scenario, a translational hindrance of MBP during initial and late cerebral development in ENU2 mice was hypothesized, leading to the execution of a microRNA microarray analysis on 60 PND brains, which was followed by a proteomic assay on 60 and 360 PND brains in order to validate in silico miRNA-target predictions. Taken together, miR-218 - 1-3p, miR - 1231-3p and miR-217-5p were considered as the most impactful microRNAs, since a downregulation of their potential targets (MAG, CNTNAP2 and ANLN, respectively) can indirectly lead to a low MBP protein expression. These miRNAs, in addition, follow an opposite expression trend compared to MBP during adulthood, and their target proteins revealed a complete normalization in aged ENU2 mice. In conclusion, these results provide a new perspective on the PKU pathophysiology understanding and on a possible treatment, emphasizing the potential modulating role of differentially expressed microRNAs in MBP expression on PKU brains during PKU mouse lifespan.
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Affiliation(s)
- Alessandro Bregalda
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy.
| | - Claudia Carducci
- Department of Experimental Medicine, Sapienza University, viale del Policlinico 155, 00161 Rome, Italy
| | - Maria Teresa Viscomi
- Department of Life Sciences and Public Health, Sect. Histology and Embryology, Università Cattolica del S. Cuore, Largo F. Vito 1, 00168 Rome, Italy; Fondazione Policlinico Universitario "Agostino Gemelli", IRCCS, 00168 Rome, Italy
| | - Francesca Pierigè
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy
| | - Sara Biagiotti
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy
| | - Michele Menotta
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy
| | - Federica Biancucci
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy
| | - Tiziana Pascucci
- Fondazione Santa Lucia IRCCS, via Ardeatina 306, 00142 Rome, Italy; Department of Psychology and Centro "Daniel Bovet", Sapienza University, via dei Marsi 78, 00185 Rome, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Sapienza University, via dei Sabelli 108, 00185 Rome, Italy
| | - Mauro Magnani
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy; EryDel SpA, via Antonio Meucci 3, 20091 Bresso, Milan, Italy
| | - Luigia Rossi
- Department of Biomolecular Sciences, University of Urbino "Carlo Bo", via Saffi 2, 61029 Urbino, PU, Italy; EryDel SpA, via Antonio Meucci 3, 20091 Bresso, Milan, Italy
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10
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Yu P, Zhang G, Hou B, Song E, Wen J, Ba Y, Zhu D, Wang G, Qin F. Effects of ECM proteins (laminin, fibronectin, and type IV collagen) on the biological behavior of Schwann cells and their roles in the process of remyelination after peripheral nerve injury. Front Bioeng Biotechnol 2023; 11:1133718. [PMID: 37034260 PMCID: PMC10080002 DOI: 10.3389/fbioe.2023.1133718] [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: 12/29/2022] [Accepted: 03/15/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction: It is important to note that complete myelination and formation of myelinated fibers are essential for functional nerve regeneration after peripheral nerve injury (PNI). However, suboptimal myelin regeneration is common and can hinder ideal nerve regeneration. Therefore, it is important to closely monitor and support myelin regeneration in patients with PNI to achieve optimal outcomes. Methods: This study analyzed the effects of three extracellular matrix (ECM) proteins on Schwann cells (SCs) in the nerve regeneration environment, including their adhesion, proliferation, and migration. The study also explored the use of composite sodium alginate hydrogel neural scaffolds with ECM components and investigated the effects of ECM proteins on remyelination following peripheral nerve injury. Results: The results showed that laminin (LN), fibronectin (FN), and collagen Ⅳ (type IV Col) promoted the early adhesion of SCs in 2-dimensional culture but the ratios of early cell adhesion were quite different and the maintenance of cells' morphology by different ECM proteins were significantly different. In transwell experiment, the ability of LN and FN to induce the migration of SCs was obviously higher than that of type IV Col. An vitro co-culture model of SCs and dorsal root ganglia (DRG) neurons showed that LN promoted the transition of SCs to a myelinated state and the maturation of the myelin sheath, and increased the thickness of neurofilaments. Animal experiments showed that LN had superior effects in promoting myelin sheath formation, axon repair, and reaching an ideal G-ratio after injury compared to FN and Col IV. The situation of gastrocnemius atrophy was significantly better in the LN group. Notably, the thickness of the regenerated myelin sheaths in the type IV Col group was the thickest. Conclusion: In this experiment, we analyzed and compared the effects of LN, FN, and type IV Col on the biological behavior of SCs and their effects on remyelination after PNI and further clarified their unique roles in the process of remyelination. Further research is necessary to explore the underlying mechanisms.
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Affiliation(s)
- Peng Yu
- Department of Neurosurgery, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Guanhua Zhang
- Department of Cerebrovascular Surgery, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Bo Hou
- Department of Neurosurgery, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Enpeng Song
- Department of Neurosurgery, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Jiaming Wen
- Department of Obstetrics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yueyang Ba
- Department of Neurosurgery, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Donglin Zhu
- Department of Clinical Laboratory, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
- *Correspondence: Donglin Zhu, ; Gangwei Wang, ; Feng Qin,
| | - Gangwei Wang
- Department of Emergency, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong, China
- *Correspondence: Donglin Zhu, ; Gangwei Wang, ; Feng Qin,
| | - Feng Qin
- Department of Neurosurgery, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
- *Correspondence: Donglin Zhu, ; Gangwei Wang, ; Feng Qin,
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11
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Di Liegro CM, Schiera G, Schirò G, Di Liegro I. RNA-Binding Proteins as Epigenetic Regulators of Brain Functions and Their Involvement in Neurodegeneration. Int J Mol Sci 2022; 23:ijms232314622. [PMID: 36498959 PMCID: PMC9739182 DOI: 10.3390/ijms232314622] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/18/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022] Open
Abstract
A central aspect of nervous system development and function is the post-transcriptional regulation of mRNA fate, which implies time- and site-dependent translation, in response to cues originating from cell-to-cell crosstalk. Such events are fundamental for the establishment of brain cell asymmetry, as well as of long-lasting modifications of synapses (long-term potentiation: LTP), responsible for learning, memory, and higher cognitive functions. Post-transcriptional regulation is in turn dependent on RNA-binding proteins that, by recognizing and binding brief RNA sequences, base modifications, or secondary/tertiary structures, are able to control maturation, localization, stability, and translation of the transcripts. Notably, most RBPs contain intrinsically disordered regions (IDRs) that are thought to be involved in the formation of membrane-less structures, probably due to liquid-liquid phase separation (LLPS). Such structures are evidenced as a variety of granules that contain proteins and different classes of RNAs. The other side of the peculiar properties of IDRs is, however, that, under altered cellular conditions, they are also prone to form aggregates, as observed in neurodegeneration. Interestingly, RBPs, as part of both normal and aggregated complexes, are also able to enter extracellular vesicles (EVs), and in doing so, they can also reach cells other than those that produced them.
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Affiliation(s)
- Carlo Maria Di Liegro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Gabriella Schiera
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies (Dipartimento di Scienze e Tecnologie Biologiche, Chimiche e Farmaceutiche) (STEBICEF), University of Palermo, 90128 Palermo, Italy
| | - Giuseppe Schirò
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
| | - Italia Di Liegro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics (Dipartimento di Biomedicina, Neuroscienze e Diagnostica Avanzata) (Bi.N.D.), University of Palermo, 90127 Palermo, Italy
- Correspondence: ; Tel.: +39-091-238-97 (ext. 415/446)
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12
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Fekete CD, Nishiyama A. Presentation and integration of multiple signals that modulate oligodendrocyte lineage progression and myelination. Front Cell Neurosci 2022; 16:1041853. [PMID: 36451655 PMCID: PMC9701731 DOI: 10.3389/fncel.2022.1041853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 10/17/2022] [Indexed: 11/15/2022] Open
Abstract
Myelination is critical for fast saltatory conduction of action potentials. Recent studies have revealed that myelin is not a static structure as previously considered but continues to be made and remodeled throughout adulthood in tune with the network requirement. Synthesis of new myelin requires turning on the switch in oligodendrocytes (OL) to initiate the myelination program that includes synthesis and transport of macromolecules needed for myelin production as well as the metabolic and other cellular functions needed to support this process. A significant amount of information is available regarding the individual intrinsic and extrinsic signals that promote OL commitment, expansion, terminal differentiation, and myelination. However, it is less clear how these signals are made available to OL lineage cells when needed, and how multiple signals are integrated to generate the correct amount of myelin that is needed in a given neural network state. Here we review the pleiotropic effects of some of the extracellular signals that affect myelination and discuss the cellular processes used by the source cells that contribute to the variation in the temporal and spatial availability of the signals, and how the recipient OL lineage cells might integrate the multiple signals presented to them in a manner dialed to the strength of the input.
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Affiliation(s)
| | - Akiko Nishiyama
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, United States
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13
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Emerging roles of hnRNP A2B1 in cancer and inflammation. Int J Biol Macromol 2022; 221:1077-1092. [PMID: 36113587 DOI: 10.1016/j.ijbiomac.2022.09.104] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 08/27/2022] [Accepted: 09/11/2022] [Indexed: 11/05/2022]
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) are a group of RNA-binding proteins with important roles in multiple aspects of nucleic acid metabolism, including the packaging of nascent transcripts, alternative splicing, transactivation of gene expression, and regulation of protein translation. As a core component of the hnRNP complex in mammalian cells, heterogeneous nuclear ribonucleoprotein A2B1 (hnRNP A2B1) participates in and coordinates various molecular events. Given its regulatory role in inflammation and cancer progression, hnRNP A2B1 has become a novel player in immune response, inflammation, and cancer development. Concomitant with these new roles, a surprising number of mechanisms deemed to regulate hnRNP A2B1 functions have been identified, including post-translational modifications, changes in subcellular localization, direct interactions with multiple DNAs, RNAs, and proteins or the formation of complexes with them, which have gradually made hnRNP A2B1 a molecular target for multiple drugs. In light of the rising interest in the intersection between cancer and inflammation, this review will focus on recent knowledge of the biological roles of hnRNP A2B1 in cancer, immune response, and inflammation.
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14
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A Proposed Role for Interactions between Argonautes, miRISC, and RNA Binding Proteins in the Regulation of Local Translation in Neurons and Glia. J Neurosci 2022; 42:3291-3301. [PMID: 35444007 PMCID: PMC9034781 DOI: 10.1523/jneurosci.2391-21.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/04/2022] [Accepted: 03/08/2022] [Indexed: 11/21/2022] Open
Abstract
The first evidence of local translation in the CNS appeared nearly 40 years ago, when electron microscopic studies showed polyribosomes localized to the base of dendritic spines. Since then, local translation has been established as an important regulatory mechanism for gene expression in polarized or functionally compartmentalized cells. While much attention has been placed on characterizing the local transcriptome and regulatory "grammar" directing mRNA localization in neurons and glia, less is understood about how these cells subsequently de-repress mRNA translation in their peripheral processes to produce a rapid translational response to stimuli. MicroRNA-mediated translation regulation offers a possible solution to this question. Not only do miRNAs provide the specificity needed for targeted gene regulation, but association and dynamic interactions between Argonaute (AGO) with sequence-specific RNA-binding proteins may provide a molecular switch to allow for de-repression of target mRNAs. Here, we review the expression and activity of different AGO proteins in miRNA-induced silencing complexes in neurons and glia and discuss known pathways of miRNA-mediated regulation, including activity-dependent pre-miRNA maturation in dendrites. We further detail work on AGO and RNA-binding protein interactions that allow for the reversal of miRNA-mediated translational silencing, and we propose a model for how intercellular communication may play a role in the regulation of local translation.
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15
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Sołtys K, Ożyhar A. Transcription Regulators and Membraneless Organelles Challenges to Investigate Them. Int J Mol Sci 2021; 22:12758. [PMID: 34884563 PMCID: PMC8657783 DOI: 10.3390/ijms222312758] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/19/2021] [Accepted: 11/23/2021] [Indexed: 12/13/2022] Open
Abstract
Eukaryotic cells are composed of different bio-macromolecules that are divided into compartments called organelles providing optimal microenvironments for many cellular processes. A specific type of organelles is membraneless organelles. They are formed via a process called liquid-liquid phase separation that is driven by weak multivalent interactions between particular bio-macromolecules. In this review, we gather crucial information regarding different classes of transcription regulators with the propensity to undergo liquid-liquid phase separation and stress the role of intrinsically disordered regions in this phenomenon. We also discuss recently developed experimental systems for studying formation and properties of membraneless organelles.
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Affiliation(s)
- Katarzyna Sołtys
- Department of Biochemistry, Molecular Biology and Biotechnology, Faculty of Chemistry, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wroclaw, Poland;
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16
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Smirnova EV, Rakitina TV, Ziganshin RH, Arapidi GP, Saratov GA, Kudriaeva AA, Belogurov AA. Comprehensive Atlas of the Myelin Basic Protein Interaction Landscape. Biomolecules 2021; 11:1628. [PMID: 34827627 PMCID: PMC8615356 DOI: 10.3390/biom11111628] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 10/27/2021] [Accepted: 10/29/2021] [Indexed: 12/22/2022] Open
Abstract
Intrinsically disordered myelin basic protein (MBP) is one of the key autoantigens in autoimmune neurodegeneration and multiple sclerosis particularly. MBP is highly positively charged and lacks distinct structure in solution and therefore its intracellular partners are still mostly enigmatic. Here we used combination of formaldehyde-induced cross-linking followed by immunoprecipitation and liquid chromatography-tandem mass spectrometry (LC-MS/MS) to elucidate the interaction network of MBP in mammalian cells and provide the list of potential MBP interacting proteins. Our data suggest that the largest group of MBP-interacting proteins belongs to cellular proteins involved in the protein translation machinery, as well as in the spatial and temporal regulation of translation. MBP interacts with core ribosomal proteins, RNA helicase Ddx28 and RNA-binding proteins STAU1, TDP-43, ADAR-1 and hnRNP A0, which are involved in various stages of RNA biogenesis and processing, including specific maintaining MBP-coding mRNA. Among MBP partners we identified CTNND1, which has previously been shown to be necessary for myelinating Schwann cells for cell-cell interactions and the formation of a normal myelin sheath. MBP binds proteins MAGEB2/D2 associated with neurotrophin receptor p75NTR, involved in pathways that promote neuronal survival and neuronal death. Finally, we observed that MBP interacts with RNF40-a component of heterotetrameric Rnf40/Rnf20 E3 ligase complex, recruited by Egr2, which is the central transcriptional regulator of peripheral myelination. Concluding, our data suggest that MBP may be more actively involved in myelination not only as a main building block but also as a self-regulating element.
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Affiliation(s)
- Evgeniya V. Smirnova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.S.); (T.V.R.); (R.H.Z.); (G.P.A.); (G.A.S.); (A.A.K.)
| | - Tatiana V. Rakitina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.S.); (T.V.R.); (R.H.Z.); (G.P.A.); (G.A.S.); (A.A.K.)
| | - Rustam H. Ziganshin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.S.); (T.V.R.); (R.H.Z.); (G.P.A.); (G.A.S.); (A.A.K.)
| | - Georgij P. Arapidi
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.S.); (T.V.R.); (R.H.Z.); (G.P.A.); (G.A.S.); (A.A.K.)
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 119435 Moscow, Russia
- Moscow Institute of Physics and Technology, National Research University, 141701 Dolgoprudny, Moscow Region, Russia
| | - George A. Saratov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.S.); (T.V.R.); (R.H.Z.); (G.P.A.); (G.A.S.); (A.A.K.)
- Moscow Institute of Physics and Technology, National Research University, 141701 Dolgoprudny, Moscow Region, Russia
| | - Anna A. Kudriaeva
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.S.); (T.V.R.); (R.H.Z.); (G.P.A.); (G.A.S.); (A.A.K.)
| | - Alexey A. Belogurov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (E.V.S.); (T.V.R.); (R.H.Z.); (G.P.A.); (G.A.S.); (A.A.K.)
- Department of Fundamental Medicine, Lomonosov Moscow State University, 117192 Moscow, Russia
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17
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Mompeán M, Oroz J, Laurents DV. Do polyproline II helix associations modulate biomolecular condensates? FEBS Open Bio 2021; 11:2390-2399. [PMID: 33934561 PMCID: PMC8409303 DOI: 10.1002/2211-5463.13163] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Revised: 03/29/2021] [Accepted: 04/09/2021] [Indexed: 12/22/2022] Open
Abstract
Biomolecular condensates are microdroplets that form inside cells and serve to selectively concentrate proteins, RNAs and other molecules for a variety of physiological functions, but can contribute to cancer, neurodegenerative diseases and viral infections. The formation of these condensates is driven by weak, transient interactions between molecules. These weak associations can operate at the level of whole protein domains, elements of secondary structure or even moieties composed of just a few atoms. Different types of condensates do not generally combine to form larger microdroplets, suggesting that each uses a distinct class of attractive interactions. Here, we address whether polyproline II (PPII) helices mediate condensate formation. By combining with PPII-binding elements such as GYF, WW, profilin, SH3 or OCRE domains, PPII helices help form lipid rafts, nuclear speckles, P-body-like neuronal granules, enhancer complexes and other condensates. The number of PPII helical tracts or tandem PPII-binding domains can strongly influence condensate stability. Many PPII helices have a low content of proline residues, which hinders their identification. Recently, we characterized the NMR spectral properties of a Gly-rich, Pro-poor protein composed of six PPII helices. Based on those results, we predicted that many Gly-rich segments may form PPII helices and interact with PPII-binding domains. This prediction is being tested and could join the palette of verified interactions contributing to biomolecular condensate formation.
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Affiliation(s)
- Miguel Mompeán
- Departamento de Química Física BiológicaInstituto de Química Física RocasolanoCSICMadridEspaña
| | - Javier Oroz
- Departamento de Química Física BiológicaInstituto de Química Física RocasolanoCSICMadridEspaña
| | - Douglas V. Laurents
- Departamento de Química Física BiológicaInstituto de Química Física RocasolanoCSICMadridEspaña
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18
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Sams E. Oligodendrocytes in the aging brain. Neuronal Signal 2021; 5:NS20210008. [PMID: 34290887 PMCID: PMC8264650 DOI: 10.1042/ns20210008] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 12/22/2022] Open
Abstract
More than half of the human brain volume is made up of white matter: regions where axons are coated in myelin, which primarily functions to increase the conduction speed of axon potentials. White matter volume significantly decreases with age, correlating with cognitive decline. Much research in the field of non-pathological brain aging mechanisms has taken a neuron-centric approach, with relatively little attention paid to other neural cells. This review discusses white matter changes, with focus on oligodendrocyte lineage cells and their ability to produce and maintain myelin to support normal brain homoeostasis. Improved understanding of intrinsic cellular changes, general senescence mechanisms, intercellular interactions and alterations in extracellular environment which occur with aging and impact oligodendrocyte cells is paramount. This may lead to strategies to support oligodendrocytes in aging, for example by supporting myelin synthesis, protecting against oxidative stress and promoting the rejuvenation of the intrinsic regenerative potential of progenitor cells. Ultimately, this will enable the protection of white matter integrity thus protecting cognitive function into the later years of life.
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Affiliation(s)
- Eleanor Catherine Sams
- Blizard Institute, Barts and The London School of Medicine and Dentistry Centre for Neuroscience, Surgery and Trauma, Blizard Institute, 4 Newark Street, Whitechapel E1 2AT, London
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19
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Guglietti B, Sivasankar S, Mustafa S, Corrigan F, Collins-Praino LE. Fyn Kinase Activity and Its Role in Neurodegenerative Disease Pathology: a Potential Universal Target? Mol Neurobiol 2021; 58:5986-6005. [PMID: 34432266 DOI: 10.1007/s12035-021-02518-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Accepted: 08/03/2021] [Indexed: 12/14/2022]
Abstract
Fyn is a non-receptor tyrosine kinase belonging to the Src family of kinases (SFKs) which has been implicated in several integral functions throughout the central nervous system (CNS), including myelination and synaptic transmission. More recently, Fyn dysfunction has been associated with pathological processes observed in neurodegenerative diseases, such as multiple sclerosis (MS), Alzheimer's disease (AD) and Parkinson's disease (PD). Neurodegenerative diseases are amongst the leading cause of death and disability worldwide and, due to the ageing population, prevalence is predicted to rise in the coming years. Symptoms across neurodegenerative diseases are both debilitating and degenerative in nature and, concerningly, there are currently no disease-modifying therapies to prevent their progression. As such, it is important to identify potential new therapeutic targets. This review will outline the role of Fyn in normal/homeostatic processes, as well as degenerative/pathological mechanisms associated with neurodegenerative diseases, such as demyelination, pathological protein aggregation, neuroinflammation and cognitive dysfunction.
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Affiliation(s)
- Bianca Guglietti
- Department of Medical Sciences, University of Adelaide, SG31, Helen Mayo South, Adelaide, SA, 5005, Australia
| | - Srisankavi Sivasankar
- Department of Medical Sciences, University of Adelaide, SG31, Helen Mayo South, Adelaide, SA, 5005, Australia
| | - Sanam Mustafa
- Department of Medical Sciences, University of Adelaide, SG31, Helen Mayo South, Adelaide, SA, 5005, Australia.,ARC Centre of Excellence for Nanoscale BioPhotonics, University of Adelaide, Adelaide, Australia
| | - Frances Corrigan
- Department of Medical Sciences, University of Adelaide, SG31, Helen Mayo South, Adelaide, SA, 5005, Australia
| | - Lyndsey E Collins-Praino
- Department of Medical Sciences, University of Adelaide, SG31, Helen Mayo South, Adelaide, SA, 5005, Australia. .,ARC Centre of Excellence for Nanoscale BioPhotonics, University of Adelaide, Adelaide, Australia.
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20
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Thibault PA, Ganesan A, Kalyaanamoorthy S, Clarke JPWE, Salapa HE, Levin MC. hnRNP A/B Proteins: An Encyclopedic Assessment of Their Roles in Homeostasis and Disease. BIOLOGY 2021; 10:biology10080712. [PMID: 34439945 PMCID: PMC8389229 DOI: 10.3390/biology10080712] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 07/16/2021] [Accepted: 07/21/2021] [Indexed: 12/13/2022]
Abstract
The hnRNP A/B family of proteins is canonically central to cellular RNA metabolism, but due to their highly conserved nature, the functional differences between hnRNP A1, A2/B1, A0, and A3 are often overlooked. In this review, we explore and identify the shared and disparate homeostatic and disease-related functions of the hnRNP A/B family proteins, highlighting areas where the proteins have not been clearly differentiated. Herein, we provide a comprehensive assembly of the literature on these proteins. We find that there are critical gaps in our grasp of A/B proteins' alternative splice isoforms, structures, regulation, and tissue and cell-type-specific functions, and propose that future mechanistic research integrating multiple A/B proteins will significantly improve our understanding of how this essential protein family contributes to cell homeostasis and disease.
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Affiliation(s)
- Patricia A. Thibault
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Medicine, Neurology Division, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada
| | - Aravindhan Ganesan
- ArGan’s Lab, School of Pharmacy, Faculty of Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
| | - Subha Kalyaanamoorthy
- Department of Chemistry, Faculty of Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada;
| | - Joseph-Patrick W. E. Clarke
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Health Sciences, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
| | - Hannah E. Salapa
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Medicine, Neurology Division, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada
| | - Michael C. Levin
- Office of the Saskatchewan Multiple Sclerosis Clinical Research Chair, University of Saskatchewan, Saskatoon, SK S7K 0M7, Canada; (P.A.T.); (J.-P.W.E.C.); (H.E.S.)
- Department of Medicine, Neurology Division, University of Saskatchewan, Saskatoon, SK S7N 0X8, Canada
- Department of Health Sciences, College of Medicine, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Department of Anatomy, Physiology and Pharmacology, University of Saskatchewan, Saskatoon, SK S7N 5E5, Canada
- Correspondence:
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21
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Mueller RL, Combs B, Alhadidy MM, Brady ST, Morfini GA, Kanaan NM. Tau: A Signaling Hub Protein. Front Mol Neurosci 2021; 14:647054. [PMID: 33815057 PMCID: PMC8017207 DOI: 10.3389/fnmol.2021.647054] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Accepted: 02/23/2021] [Indexed: 12/23/2022] Open
Abstract
Over four decades ago, in vitro experiments showed that tau protein interacts with and stabilizes microtubules in a phosphorylation-dependent manner. This observation fueled the widespread hypotheses that these properties extend to living neurons and that reduced stability of microtubules represents a major disease-driving event induced by pathological forms of tau in Alzheimer’s disease and other tauopathies. Accordingly, most research efforts to date have addressed this protein as a substrate, focusing on evaluating how specific mutations, phosphorylation, and other post-translational modifications impact its microtubule-binding and stabilizing properties. In contrast, fewer efforts were made to illuminate potential mechanisms linking physiological and disease-related forms of tau to the normal and pathological regulation of kinases and phosphatases. Here, we discuss published work indicating that, through interactions with various kinases and phosphatases, tau may normally act as a scaffolding protein to regulate phosphorylation-based signaling pathways. Expanding on this concept, we also review experimental evidence linking disease-related tau species to the misregulation of these pathways. Collectively, the available evidence supports the participation of tau in multiple cellular processes sustaining neuronal and glial function through various mechanisms involving the scaffolding and regulation of selected kinases and phosphatases at discrete subcellular compartments. The notion that the repertoire of tau functions includes a role as a signaling hub should widen our interpretation of experimental results and increase our understanding of tau biology in normal and disease conditions.
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Affiliation(s)
- Rebecca L Mueller
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Benjamin Combs
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States
| | - Mohammed M Alhadidy
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, East Lansing, MI, United States
| | - Scott T Brady
- Department of Anatomy and Cell Biology, The University of Illinois at Chicago, Chicago, IL, United States.,Marine Biological Laboratory, Woods Hole, MA, United States
| | - Gerardo A Morfini
- Department of Anatomy and Cell Biology, The University of Illinois at Chicago, Chicago, IL, United States.,Marine Biological Laboratory, Woods Hole, MA, United States
| | - Nicholas M Kanaan
- Department of Translational Neuroscience, Michigan State University, Grand Rapids, MI, United States.,Neuroscience Program, Michigan State University, East Lansing, MI, United States.,Hauenstein Neuroscience Center, Mercy Health Saint Mary's, Grand Rapids, MI, United States
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22
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Balestri S, Del Giovane A, Sposato C, Ferrarelli M, Ragnini-Wilson A. The Current Challenges for Drug Discovery in CNS Remyelination. Int J Mol Sci 2021; 22:ijms22062891. [PMID: 33809224 PMCID: PMC8001072 DOI: 10.3390/ijms22062891] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022] Open
Abstract
The myelin sheath wraps around axons, allowing saltatory currents to be transmitted along neurons. Several genetic, viral, or environmental factors can damage the central nervous system (CNS) myelin sheath during life. Unless the myelin sheath is repaired, these insults will lead to neurodegeneration. Remyelination occurs spontaneously upon myelin injury in healthy individuals but can fail in several demyelination pathologies or as a consequence of aging. Thus, pharmacological intervention that promotes CNS remyelination could have a major impact on patient’s lives by delaying or even preventing neurodegeneration. Drugs promoting CNS remyelination in animal models have been identified recently, mostly as a result of repurposing phenotypical screening campaigns that used novel oligodendrocyte cellular models. Although none of these have as yet arrived in the clinic, promising candidates are on the way. Many questions remain. Among the most relevant is the question if there is a time window when remyelination drugs should be administrated and why adult remyelination fails in many neurodegenerative pathologies. Moreover, a significant challenge in the field is how to reconstitute the oligodendrocyte/axon interaction environment representative of healthy as well as disease microenvironments in drug screening campaigns, so that drugs can be screened in the most appropriate disease-relevant conditions. Here we will provide an overview of how the field of in vitro models developed over recent years and recent biological findings about how oligodendrocytes mature after reactivation of their staminal niche. These data have posed novel questions and opened new views about how the adult brain is repaired after myelin injury and we will discuss how these new findings might change future drug screening campaigns for CNS regenerative drugs.
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23
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RNA Localization and Local Translation in Glia in Neurological and Neurodegenerative Diseases: Lessons from Neurons. Cells 2021; 10:cells10030632. [PMID: 33809142 PMCID: PMC8000831 DOI: 10.3390/cells10030632] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/03/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022] Open
Abstract
Cell polarity is crucial for almost every cell in our body to establish distinct structural and functional domains. Polarized cells have an asymmetrical morphology and therefore their proteins need to be asymmetrically distributed to support their function. Subcellular protein distribution is typically achieved by localization peptides within the protein sequence. However, protein delivery to distinct cellular compartments can rely, not only on the transport of the protein itself but also on the transport of the mRNA that is then translated at target sites. This phenomenon is known as local protein synthesis. Local protein synthesis relies on the transport of mRNAs to subcellular domains and their translation to proteins at target sites by the also localized translation machinery. Neurons and glia specially depend upon the accurate subcellular distribution of their proteome to fulfil their polarized functions. In this sense, local protein synthesis has revealed itself as a crucial mechanism that regulates proper protein homeostasis in subcellular compartments. Thus, deregulation of mRNA transport and/or of localized translation can lead to neurological and neurodegenerative diseases. Local translation has been more extensively studied in neurons than in glia. In this review article, we will summarize the state-of-the art research on local protein synthesis in neuronal function and dysfunction, and we will discuss the possibility that local translation in glia and deregulation thereof contributes to neurological and neurodegenerative diseases.
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24
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Ryan VH, Perdikari TM, Naik MT, Saueressig CF, Lins J, Dignon GL, Mittal J, Hart AC, Fawzi NL. Tyrosine phosphorylation regulates hnRNPA2 granule protein partitioning and reduces neurodegeneration. EMBO J 2021; 40:e105001. [PMID: 33349959 PMCID: PMC7849316 DOI: 10.15252/embj.2020105001] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 10/14/2020] [Accepted: 11/03/2020] [Indexed: 12/12/2022] Open
Abstract
mRNA transport in neurons requires formation of transport granules containing many protein components, and subsequent alterations in phosphorylation status can release transcripts for translation. Further, mutations in a structurally disordered domain of the transport granule protein hnRNPA2 increase its aggregation and cause hereditary proteinopathy of neurons, myocytes, and bone. We examine in vitro hnRNPA2 granule component phase separation, partitioning specificity, assembly/disassembly, and the link to neurodegeneration. Transport granule components hnRNPF and ch-TOG interact weakly with hnRNPA2 yet partition specifically into liquid phase droplets with the low complexity domain (LC) of hnRNPA2, but not FUS LC. In vitro hnRNPA2 tyrosine phosphorylation reduces hnRNPA2 phase separation, prevents partitioning of hnRNPF and ch-TOG into hnRNPA2 LC droplets, and decreases aggregation of hnRNPA2 disease variants. The expression of chimeric hnRNPA2 D290V in Caenorhabditis elegans results in stress-induced glutamatergic neurodegeneration; this neurodegeneration is rescued by loss of tdp-1, suggesting gain-of-function toxicity. The expression of Fyn, a tyrosine kinase that phosphorylates hnRNPA2, reduces neurodegeneration associated with chimeric hnRNPA2 D290V. These data suggest a model where phosphorylation alters LC interaction specificity, aggregation, and toxicity.
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Affiliation(s)
- Veronica H Ryan
- Neuroscience Graduate ProgramBrown UniversityProvidenceRIUSA
| | | | - Mandar T Naik
- Department of Molecular Pharmacology, Physiology, and BiotechnologyBrown UniversityProvidenceRIUSA
| | | | - Jeremy Lins
- Department of NeuroscienceBrown UniversityProvidenceRIUSA
| | - Gregory L Dignon
- Department of Chemical and Biomolecular EngineeringLehigh UniversityBethlehemPAUSA
| | - Jeetain Mittal
- Department of Chemical and Biomolecular EngineeringLehigh UniversityBethlehemPAUSA
| | - Anne C Hart
- Department of NeuroscienceBrown UniversityProvidenceRIUSA
| | - Nicolas L Fawzi
- Department of Molecular Pharmacology, Physiology, and BiotechnologyBrown UniversityProvidenceRIUSA
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25
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Ehinger Y, Morisot N, Phamluong K, Sakhai SA, Soneja D, Adrover MF, Alvarez VA, Ron D. cAMP-Fyn signaling in the dorsomedial striatum direct pathway drives excessive alcohol use. Neuropsychopharmacology 2021; 46:334-342. [PMID: 32417851 PMCID: PMC7852539 DOI: 10.1038/s41386-020-0712-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 05/11/2020] [Indexed: 12/19/2022]
Abstract
Fyn kinase in the dorsomedial striatum (DMS) of rodents plays a central role in mechanisms underlying excessive alcohol intake. The DMS is comprised of medium spiny neurons (MSNs) that project directly (dMSNs) or indirectly (iMSNs) to the substantia nigra. Here, we examined the cell-type specificity of Fyn's actions in alcohol use. First, we knocked down Fyn selectively in DMS dMSNs or iMSNs of mice and measured the level of alcohol consumption. We found that downregulation of Fyn in dMSNs, but not in iMSNs, reduces excessive alcohol but not saccharin intake. D1Rs are coupled to Gαs/olf, which activate cAMP signaling. To examine whether Fyn's actions are mediated through cAMP signaling, DMS dMSNs were infected with GαsDREADD, and the activation of Fyn signaling was measured following CNO treatment. We found that remote stimulation of cAMP signaling in DMS dMSNs activates Fyn and promotes the phosphorylation of the Fyn substrate, GluN2B. In contract, remote activation of GαsDREADD in DLS dMSNs did not alter Fyn signaling. We then tested whether activation of GαsDREADD in DMS dMSNs or iMSNs alters alcohol intake and observed that CNO-dependent activation of GαsDREADD in DMS dMSNs but not iMSNs increases alcohol but not saccharin intake. Finally, we examined the contribution of Fyn to GαsDREADD-dependent increase in alcohol intake, and found that systemic administration of the Fyn inhibitor, AZD0503 blocks GαsDREADD-dependent increase in alcohol consumption. Our results suggest that the cAMP-Fyn axis in the DMS dMSNs is a molecular transducer of mechanisms underlying the development of excessive alcohol consumption.
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Affiliation(s)
- Yann Ehinger
- grid.266102.10000 0001 2297 6811Department of Neurology, University of California San Francisco (UCSF), San Francisco, CA 94143 USA
| | - Nadege Morisot
- grid.266102.10000 0001 2297 6811Department of Neurology, University of California San Francisco (UCSF), San Francisco, CA 94143 USA ,Present Address: Nkarta Therapeutics, San Francisco, CA USA
| | - Khanhky Phamluong
- grid.266102.10000 0001 2297 6811Department of Neurology, University of California San Francisco (UCSF), San Francisco, CA 94143 USA
| | - Samuel A. Sakhai
- grid.266102.10000 0001 2297 6811Department of Neurology, University of California San Francisco (UCSF), San Francisco, CA 94143 USA ,grid.476678.c0000 0004 5913 664XPresent Address: Sage Therapeutics, San Francisco, CA USA
| | - Drishti Soneja
- grid.266102.10000 0001 2297 6811Department of Neurology, University of California San Francisco (UCSF), San Francisco, CA 94143 USA
| | - Martin F. Adrover
- grid.94365.3d0000 0001 2297 5165National Institutes of Alcohol Abuse and Alcoholism, National Institute of Health, Bethesda, MD 20892 USA ,grid.423606.50000 0001 1945 2152Present Address: INGEBI, CONICET, Buenos Aires, Argentina
| | - Veronica A. Alvarez
- grid.94365.3d0000 0001 2297 5165National Institutes of Alcohol Abuse and Alcoholism, National Institute of Health, Bethesda, MD 20892 USA ,grid.94365.3d0000 0001 2297 5165Center on Compulsive Behaviors, Intramural Research Program, National Institute of Health, Bethesda, MD 20892 USA
| | - Dorit Ron
- Department of Neurology, University of California San Francisco (UCSF), San Francisco, CA, 94143, USA.
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26
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Schieweck R, Ninkovic J, Kiebler MA. RNA-binding proteins balance brain function in health and disease. Physiol Rev 2020; 101:1309-1370. [PMID: 33000986 DOI: 10.1152/physrev.00047.2019] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Posttranscriptional gene expression including splicing, RNA transport, translation, and RNA decay provides an important regulatory layer in many if not all molecular pathways. Research in the last decades has positioned RNA-binding proteins (RBPs) right in the center of posttranscriptional gene regulation. Here, we propose interdependent networks of RBPs to regulate complex pathways within the central nervous system (CNS). These are involved in multiple aspects of neuronal development and functioning, including higher cognition. Therefore, it is not sufficient to unravel the individual contribution of a single RBP and its consequences but rather to study and understand the tight interplay between different RBPs. In this review, we summarize recent findings in the field of RBP biology and discuss the complex interplay between different RBPs. Second, we emphasize the underlying dynamics within an RBP network and how this might regulate key processes such as neurogenesis, synaptic transmission, and synaptic plasticity. Importantly, we envision that dysfunction of specific RBPs could lead to perturbation within the RBP network. This would have direct and indirect (compensatory) effects in mRNA binding and translational control leading to global changes in cellular expression programs in general and in synaptic plasticity in particular. Therefore, we focus on RBP dysfunction and how this might cause neuropsychiatric and neurodegenerative disorders. Based on recent findings, we propose that alterations in the entire regulatory RBP network might account for phenotypic dysfunctions observed in complex diseases including neurodegeneration, epilepsy, and autism spectrum disorders.
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Affiliation(s)
- Rico Schieweck
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Jovica Ninkovic
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
| | - Michael A Kiebler
- Biomedical Center (BMC), Department for Cell Biology and Anatomy, Medical Faculty, Ludwig-Maximilians-University, Planegg-Martinsried, Germany
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27
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Lu J, Cao Q, Hughes MP, Sawaya MR, Boyer DR, Cascio D, Eisenberg DS. CryoEM structure of the low-complexity domain of hnRNPA2 and its conversion to pathogenic amyloid. Nat Commun 2020; 11:4090. [PMID: 32796831 PMCID: PMC7427792 DOI: 10.1038/s41467-020-17905-y] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 07/14/2020] [Indexed: 01/02/2023] Open
Abstract
hnRNPA2 is a human ribonucleoprotein (RNP) involved in RNA metabolism. It forms fibrils both under cellular stress and in mutated form in neurodegenerative conditions. Previous work established that the C-terminal low-complexity domain (LCD) of hnRNPA2 fibrillizes under stress, and missense mutations in this domain are found in the disease multisystem proteinopathy (MSP). However, little is known at the atomic level about the hnRNPA2 LCD structure that is involved in those processes and how disease mutations cause structural change. Here we present the cryo-electron microscopy (cryoEM) structure of the hnRNPA2 LCD fibril core and demonstrate its capability to form a reversible hydrogel in vitro containing amyloid-like fibrils. Whereas these fibrils, like pathogenic amyloid, are formed from protein chains stacked into β-sheets by backbone hydrogen bonds, they display distinct structural differences: the chains are kinked, enabling non-covalent cross-linking of fibrils and disfavoring formation of pathogenic steric zippers. Both reversibility and energetic calculations suggest these fibrils are less stable than pathogenic amyloid. Moreover, the crystal structure of the disease-mutation-containing segment (D290V) of hnRNPA2 suggests that the replacement fundamentally alters the fibril structure to a more stable energetic state. These findings illuminate how molecular interactions promote protein fibril networks and how mutation can transform fibril structure from functional to a pathogenic form. hnRNPA2 is involved in RNA metabolism and can form both functional amyloid-like fibrils in membraneless organelles, and pathogenic fibrils in neurodegenerative conditions. Here, the authors present the cryo-EM fibril structure of the wild-type hnRNPA2 low-complexity domain (LCD) and the crystal structure of a LCD segment with the disease causing D290V variant and discuss how mutations can transform fibril structure from a functional to a pathogenic form.
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Affiliation(s)
- Jiahui Lu
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, USA.,UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, CA, USA
| | - Qin Cao
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, USA.,UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, CA, USA
| | - Michael P Hughes
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, USA.,UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, CA, USA.,Department of Cell and Molecular Biology, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Michael R Sawaya
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, USA.,UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, CA, USA
| | - David R Boyer
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, USA.,UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, CA, USA
| | - Duilio Cascio
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, USA.,UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, CA, USA
| | - David S Eisenberg
- Departments of Chemistry and Biochemistry and Biological Chemistry, University of California, Los Angeles, Los Angeles, CA, USA. .,UCLA-DOE Institute, Molecular Biology Institute, Howard Hughes Medical Institute, Los Angeles, CA, USA.
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28
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Bassetti D, Hammann J, Luhmann HJ, White R, Kirischuk S. Ryanodine receptor- and sodium-calcium exchanger-mediated spontaneous calcium activity in immature oligodendrocytes in cultures. Neurosci Lett 2020; 732:134913. [PMID: 32482568 DOI: 10.1016/j.neulet.2020.134913] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 03/03/2020] [Accepted: 03/12/2020] [Indexed: 11/17/2022]
Abstract
Myelination in the central nervous system depends on interactions between axons and oligodendrocyte precursor cells (OPCs). Action potentials in an axon can be followed by release of biologically active substances, like glutamate, which can instruct OPCs to start myelination. Myelin Basic Protein (MBP) is an "executive molecule of myelin" required for the formation of compact myelin. As cells of the oligodendrocyte lineage (OLCs) are capable of producing MBP in pure oligodendrocyte cultures, i.e. without neurons, we investigated Ca2+ signaling in developing OLCs in cultures. We show that spontaneous Ca2+ transients (CTs) occur at very low frequency in both bipolar OPCs and mature oligodendrocytes. In contrast immature OLCs (imOLCs), cells with several thick processes, demonstrate a relatively high frequency of CTs. Moreover, CT frequency in imOLC processes is much higher as compared with the somatic CT frequency. Somatic CTs are almost completely blocked by thapsigargin, an antagonist of sarco-(endo-) plasmic reticulum Ca2+ ATPase, and ryanodine, a blocker of ryanodine receptors, indicating an involvement of Ca2+ release from the endoplasmic reticulum. Ryanodine strongly reduces CT frequency in imOLC processes. Ouabain, an antagonist of Na+, K+-ATPase (NKA), applied at low concentration increases CT frequency, while KB-R7943, a blocker of reverse mode of Na+, Ca2+ exchanger (NCX), decreases CT frequency. We suggest that local RyR-NCX-(NKA?) interaction might underlie the generation of CTs in imOLC in the absence of neurons, and this activity influences oligodendrocyte maturation.
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Affiliation(s)
- Davide Bassetti
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jens Hammann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Robin White
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Sergei Kirischuk
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany.
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29
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Liu Y, Shi SL. The roles of hnRNP A2/B1 in RNA biology and disease. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1612. [PMID: 32588964 DOI: 10.1002/wrna.1612] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Revised: 05/25/2020] [Accepted: 05/26/2020] [Indexed: 12/12/2022]
Abstract
The RNA-binding protein hnRNPA2/B1 is a member of the hnRNPs family and is widely expressed in various tissues. hnRNPA2/B1 recognizes and binds specific RNA substrates and DNA motifs and is involved in the transcription, splicing processing, transport, stability, and translation regulation of a variety of RNA molecules and in regulating the expression of a large number of genes. hnRNPA2/B1 is also involved in telomere maintenance and DNA repair, while its expression changes and mutations are involved in the development of various tumors and neurodegenerative and autoimmune diseases. This paper reviews the role and mechanism of hnRNPA2/B1 in RNA metabolism, tumors, and neurodegenerative and autoimmune diseases. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease.
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Affiliation(s)
- Yu Liu
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China.,School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Song-Lin Shi
- Cancer Research Center, School of Medicine, Xiamen University, Xiamen, China
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30
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Fyn Tyrosine Kinase as Harmonizing Factor in Neuronal Functions and Dysfunctions. Int J Mol Sci 2020; 21:ijms21124444. [PMID: 32580508 PMCID: PMC7352836 DOI: 10.3390/ijms21124444] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/19/2020] [Accepted: 06/20/2020] [Indexed: 12/25/2022] Open
Abstract
Fyn is a non-receptor or cytoplasmatic tyrosine kinase (TK) belonging to the Src family kinases (SFKs) involved in multiple transduction pathways in the central nervous system (CNS) including synaptic transmission, myelination, axon guidance, and oligodendrocyte formation. Almost one hundred years after the original description of Fyn, this protein continues to attract extreme interest because of its multiplicity of actions in the molecular signaling pathways underlying neurodevelopmental as well as neuropathologic events. This review highlights and summarizes the most relevant recent findings pertinent to the role that Fyn exerts in the brain, emphasizing aspects related to neurodevelopment and synaptic plasticity. Fyn is a common factor in healthy and diseased brains that targets different proteins and shapes different transduction signals according to the neurological conditions. We will primarily focus on Fyn-mediated signaling pathways involved in neuronal differentiation and plasticity that have been subjected to considerable attention lately, opening the fascinating scenario to target Fyn TK for the development of potential therapeutic interventions for the treatment of CNS injuries and certain neurodegenerative disorders like Alzheimer’s disease.
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31
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Farias J, Holt CE, Sotelo JR, Sotelo-Silveira JR. Axon microdissection and transcriptome profiling reveals the in vivo RNA content of fully differentiated myelinated motor axons. RNA (NEW YORK, N.Y.) 2020; 26:595-612. [PMID: 32051223 PMCID: PMC7161357 DOI: 10.1261/rna.073700.119] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/31/2020] [Indexed: 05/23/2023]
Abstract
Axonal protein synthesis has been shown to play a role in developmental and regenerative growth, as well as in the maintenance of the axoplasm in a steady state. Recent studies have begun to identify the mRNAs localized in axons, which could be translated locally under different conditions. Despite that by now hundreds or thousands of mRNAs have been shown to be localized into the axonal compartment of cultured neurons in vitro, knowledge of which mRNAs are localized in mature myelinated axons is quite limited. With the purpose of characterizing the transcriptome of mature myelinated motor axons of peripheral nervous systems, we modified the axon microdissection method devised by Koenig, enabling the isolation of the axoplasm RNA to perform RNA-seq analysis. The transcriptome analysis indicates that the number of RNAs detected in mature axons is lower in comparison with in vitro data, depleted of glial markers, and enriched in neuronal markers. The mature myelinated axons are enriched for mRNAs related to cytoskeleton, translation, and oxidative phosphorylation. Moreover, it was possible to define core genes present in axons when comparing our data with transcriptomic data of axons grown in different conditions. This work provides evidence that axon microdissection is a valuable method to obtain genome-wide data from mature and myelinated axons of the peripheral nervous system, and could be especially useful for the study of axonal involvement in neurodegenerative pathologies of motor neurons such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophies (SMA).
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Affiliation(s)
- Joaquina Farias
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, 11600, Uruguay
- Departamento de Proteínas y Ácidos Nucléicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, 11600, Uruguay
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3DY, United Kingdom
| | - José R Sotelo
- Departamento de Proteínas y Ácidos Nucléicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, 11600, Uruguay
| | - José R Sotelo-Silveira
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, 11600, Uruguay
- Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, 11400, Uruguay
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32
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de Jong CGHM, Gabius HJ, Baron W. The emerging role of galectins in (re)myelination and its potential for developing new approaches to treat multiple sclerosis. Cell Mol Life Sci 2020; 77:1289-1317. [PMID: 31628495 PMCID: PMC7113233 DOI: 10.1007/s00018-019-03327-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 09/27/2019] [Accepted: 09/30/2019] [Indexed: 12/12/2022]
Abstract
Multiple sclerosis (MS) is an inflammatory, demyelinating and neurodegenerative disease of the central nervous system with unknown etiology. Currently approved disease-modifying treatment modalities are immunomodulatory or immunosuppressive. While the applied drugs reduce the frequency and severity of the attacks, their efficacy to regenerate myelin membranes and to halt disease progression is limited. To achieve such therapeutic aims, understanding biological mechanisms of remyelination and identifying factors that interfere with remyelination in MS can give respective directions. Such a perspective is given by the emerging functional profile of galectins. They form a family of tissue lectins, which are potent effectors in processes as diverse as adhesion, apoptosis, immune mediator release or migration. This review focuses on endogenous and exogenous roles of galectins in glial cells such as oligodendrocytes, astrocytes and microglia in the context of de- and (re)myelination and its dysregulation in MS. Evidence is arising for a cooperation among family members so that timed expression and/or secretion of galectins-1, -3 and -4 result in modifying developmental myelination, (neuro)inflammatory processes, de- and remyelination. Dissecting the mechanisms that underlie the distinct activities of galectins and identifying galectins as target or tool to modulate remyelination have the potential to contribute to the development of novel therapeutic strategies for MS.
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Affiliation(s)
- Charlotte G H M de Jong
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University of Groningen, University Medical Center Groningen, A. Deusinglaan 1, 9713 AV, Groningen, The Netherlands
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Wia Baron
- Department of Biomedical Sciences of Cells & Systems, Section Molecular Neurobiology, University of Groningen, University Medical Center Groningen, A. Deusinglaan 1, 9713 AV, Groningen, The Netherlands.
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33
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Mechanistic Target of Rapamycin Regulates the Oligodendrocyte Cytoskeleton during Myelination. J Neurosci 2020; 40:2993-3007. [PMID: 32139584 DOI: 10.1523/jneurosci.1434-18.2020] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 02/23/2020] [Accepted: 02/26/2020] [Indexed: 12/22/2022] Open
Abstract
During differentiation, oligodendrocyte precursor cells (OPCs) extend a network of processes that make contact with axons and initiate myelination. Recent studies revealed that actin polymerization is required for initiation of myelination whereas actin depolymerization promotes myelin wrapping. Here, we used primary OPCs in culture isolated from neonatal rat cortices of both sexes and young male and female mice with oligodendrocyte-specific deletion of mechanistic target of rapamycin (mTOR) to demonstrate that mTOR regulates expression of specific cytoskeletal targets and actin reorganization in oligodendrocytes during developmental myelination. Loss or inhibition of mTOR reduced expression of profilin2 and ARPC3, actin polymerizing factors, and elevated levels of active cofilin, which mediates actin depolymerization. The deficits in actin polymerization were revealed in reduced phalloidin and deficits in oligodendrocyte cellular branching complexity at the peak of morphologic differentiation and a delay in initiation of myelination. We further show a critical role for mTOR in expression and localization of myelin basic protein (Mbp) mRNA and MBP protein to the cellular processes where it is necessary at the myelin membrane for axon wrapping. Mbp mRNA transport deficits were confirmed by single molecule RNA FISH. Moreover, expression of the kinesin family member 1B, an Mbp mRNA transport protein, was reduced in CC1+ cells in the mTOR cKO and in mTOR inhibited oligodendrocytes undergoing differentiation in vitro These data support the conclusion that mTOR regulates both initiation of myelination and axon wrapping by targeting cytoskeletal reorganization and MBP localization to oligodendrocyte processes.SIGNIFICANCE STATEMENT Myelination is essential for normal CNS development and adult axon preservation and function. The mechanistic target of rapamycin (mTOR) signaling pathway has been implicated in promoting CNS myelination; however, there is a gap in our understanding of the mechanisms by which mTOR promotes developmental myelination through regulating specific downstream targets. Here, we present evidence that mTOR promotes the initiation of myelination through regulating specific cytoskeletal targets and cellular process expansion by oligodendrocyte precursor cells as well as expression and cellular localization of myelin basic protein.
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Liu G, Thangavel R, Rysted J, Kim Y, Francis MB, Adams E, Lin Z, Taugher RJ, Wemmie JA, Usachev YM, Lee G. Loss of tau and Fyn reduces compensatory effects of MAP2 for tau and reveals a Fyn-independent effect of tau on calcium. J Neurosci Res 2019; 97:1393-1413. [PMID: 31452242 PMCID: PMC6850396 DOI: 10.1002/jnr.24517] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 07/31/2019] [Accepted: 08/01/2019] [Indexed: 12/18/2022]
Abstract
Microtubule-associated protein tau associates with Src family tyrosine kinase Fyn and is tyrosine phosphorylated by Fyn. The presence of tyrosine phosphorylated tau in AD and the involvement of Fyn in AD has drawn attention to the tau-Fyn complex. In this study, a tau-Fyn double knockout (DKO) mouse was generated to investigate the role of the complex. DKO mice resembled Fyn KO in novel object recognition and contextual fear conditioning tasks and resembled tau KO mice in the pole test and protection from pentylenetetrazole-induced seizures. In glutamate-induced Ca2+ response, Fyn KO was decreased relative to WT and DKO had a greater reduction relative to Fyn KO, suggesting that tau may have a Fyn-independent role. Since tau KO resembled WT in its Ca2+ response, we investigated whether microtubule-associated protein 2 (MAP2) served to compensate for tau, since the MAP2 level was increased in tau KO but decreased in DKO mice. We found that like tau, MAP2 increased Fyn activity. Moreover, tau KO neurons had increased density of dendritic MAP2-Fyn complexes relative to WT neurons. Therefore, we hypothesize that in the tau KO, the absence of tau would be compensated by MAP2, especially in the dendrites, where tau-Fyn complexes are of critical importance. In the DKO, decreased levels of MAP2 made compensation more difficult, thus revealing the effect of tau in the Ca2+ response.
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Affiliation(s)
- Guanghao Liu
- Interdisciplinary Program in Neuroscience, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Ramasamy Thangavel
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Jacob Rysted
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Yohan Kim
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Meghan B Francis
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Eric Adams
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Zhihong Lin
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Rebecca J Taugher
- Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - John A Wemmie
- Department of Psychiatry, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Yuriy M Usachev
- Department of Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
| | - Gloria Lee
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA
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de Jong CGHM, Stancic M, Pinxterhuis TH, van Horssen J, van Dam AM, Gabius HJ, Baron W. Galectin-4, a Negative Regulator of Oligodendrocyte Differentiation, Is Persistently Present in Axons and Microglia/Macrophages in Multiple Sclerosis Lesions. J Neuropathol Exp Neurol 2019; 77:1024-1038. [PMID: 30252090 DOI: 10.1093/jnen/nly081] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Neuron-derived molecules are potent regulators of oligodendrocyte differentiation and myelination during brain development and upon demyelination. Their analysis will thus contribute to understanding remyelination failure in demyelinating diseases, such as multiple sclerosis (MS). Previously, we have identified neuronal galectin-4 as a novel negative soluble regulator in the timing of developmental myelination. Here, we investigated whether galectin-4 is re-expressed in axons upon demyelination to regulate the timing of remyelination. Our findings revealed that galectin-4 is transiently localized to axons in demyelinated areas upon cuprizone-induced demyelination. In contrast, in chronic demyelinated MS lesions, where remyelination fails, galectin-4 is permanently present on axons. Remarkably, microglia/macrophages in cuprizone-demyelinated areas also harbor galectin-4, as also observed in activated microglia/macrophages that are present in active MS lesions and in inflammatory infiltrates in chronic-relapsing experimental autoimmune encephalomyelitis. In vitro analysis showed that galectin-4 is effectively endocytosed by macrophages, and may scavenge galectin-4 from oligodendrocytes, and that endogenous galectin-4 levels are increased in alternatively interleukin-4-activated macrophages and microglia. Hence, similar to developmental myelination, the (re)expressed galectin-4 upon demyelination may act as factor in the timing of oligodendrocyte differentiation, while the persistent presence of galectin-4 on demyelinated axons may disrupt this fine-tuning of remyelination.
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Affiliation(s)
- Charlotte G H M de Jong
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Mirjana Stancic
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Tineke H Pinxterhuis
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Anne-Marie van Dam
- Department of Anatomy and Neurosciences, VU University Medical Center, Amsterdam, The Netherlands
| | - Hans-Joachim Gabius
- Institute of Physiological Chemistry, Faculty of Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Wia Baron
- Department of Cell Biology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
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36
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Ryan VH, Fawzi NL. Physiological, Pathological, and Targetable Membraneless Organelles in Neurons. Trends Neurosci 2019; 42:693-708. [PMID: 31493925 PMCID: PMC6779520 DOI: 10.1016/j.tins.2019.08.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2019] [Revised: 07/03/2019] [Accepted: 08/05/2019] [Indexed: 12/20/2022]
Abstract
Neurons require unique subcellular compartmentalization to function efficiently. Formed from proteins and RNAs through liquid-liquid phase separation, membraneless organelles (MLOs) have emerged as one way in which cells form distinct, specialized compartments in the absence of lipid membranes. We first discuss MLOs that are common to many cell types as well as those that are specific to neurons. Interestingly, many proteins associated with neurodegenerative disease are found in MLOs, particularly in stress and transport granules. We next review possible links between neurodegeneration and MLOs, and the hypothesis that the protein and RNA inclusions formed in disease are related to the functional complexes occurring inside these MLOs. Finally, we discuss the hypothesis that protein post-translational modifications (PTMs), which can alter phase separation, can modulate MLO formation and provide potential new therapeutic strategies for currently untreatable neurodegenerative diseases.
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Affiliation(s)
- Veronica H Ryan
- Neuroscience Graduate Program, Brown University, Providence, RI 02912, USA
| | - Nicolas L Fawzi
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912, USA.
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37
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Stadelmann C, Timmler S, Barrantes-Freer A, Simons M. Myelin in the Central Nervous System: Structure, Function, and Pathology. Physiol Rev 2019; 99:1381-1431. [PMID: 31066630 DOI: 10.1152/physrev.00031.2018] [Citation(s) in RCA: 292] [Impact Index Per Article: 58.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Oligodendrocytes generate multiple layers of myelin membrane around axons of the central nervous system to enable fast and efficient nerve conduction. Until recently, saltatory nerve conduction was considered the only purpose of myelin, but it is now clear that myelin has more functions. In fact, myelinating oligodendrocytes are embedded in a vast network of interconnected glial and neuronal cells, and increasing evidence supports an active role of oligodendrocytes within this assembly, for example, by providing metabolic support to neurons, by regulating ion and water homeostasis, and by adapting to activity-dependent neuronal signals. The molecular complexity governing these interactions requires an in-depth molecular understanding of how oligodendrocytes and axons interact and how they generate, maintain, and remodel their myelin sheaths. This review deals with the biology of myelin, the expanded relationship of myelin with its underlying axons and the neighboring cells, and its disturbances in various diseases such as multiple sclerosis, acute disseminated encephalomyelitis, and neuromyelitis optica spectrum disorders. Furthermore, we will highlight how specific interactions between astrocytes, oligodendrocytes, and microglia contribute to demyelination in hereditary white matter pathologies.
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Affiliation(s)
- Christine Stadelmann
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Sebastian Timmler
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Alonso Barrantes-Freer
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
| | - Mikael Simons
- Institute of Neuropathology, University Medical Center Göttingen , Göttingen , Germany ; Institute of Neuronal Cell Biology, Technical University Munich , Munich , Germany ; German Center for Neurodegenerative Diseases (DZNE), Munich , Germany ; Department of Neuropathology, University Medical Center Leipzig , Leipzig , Germany ; Munich Cluster of Systems Neurology (SyNergy), Munich , Germany ; and Max Planck Institute of Experimental Medicine, Göttingen , Germany
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38
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Lee H, Li C, Zhang Y, Zhang D, Otterbein LE, Jin Y. Caveolin-1 selectively regulates microRNA sorting into microvesicles after noxious stimuli. J Exp Med 2019; 216:2202-2220. [PMID: 31235510 PMCID: PMC6719430 DOI: 10.1084/jem.20182313] [Citation(s) in RCA: 133] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 04/23/2019] [Accepted: 05/31/2019] [Indexed: 12/23/2022] Open
Abstract
Emerging evidence suggests that extracellular vesicle (EV)-containing miRNAs mediate intercellular communications in response to noxious stimuli. It remains unclear how a cell selectively sorts the cellular miRNAs into EVs. We report that caveolin-1 (cav-1) is essential for sorting of selected miRNAs into microvesicles (MVs), a main type of EVs generated by outward budding of the plasma membrane. We found that cav-1 tyrosine 14 (Y14)-phosphorylation leads to interactions between cav-1 and hnRNPA2B1, an RNA-binding protein. The cav-1/hnRNPA2B1 complex subsequently traffics together into MVs. Oxidative stress induces O-GlcNAcylation of hnRNPA2B1, resulting in a robustly altered hnRNPA2B1-bound miRNA repertoire. Notably, cav-1 pY14 also promotes hnRNPA2B1 O-GlcNAcylation. Functionally, macrophages serve as the principal recipient of epithelial MVs in the lung. MV-containing cav-1/hnRNPA2B1 complex-bound miR-17/93 activate tissue macrophages. Collectively, cav-1 is the first identified membranous protein that directly guides RNA-binding protein into EVs. Our work delineates a novel mechanism by which oxidative stress compels epithelial cells to package and secrete specific miRNAs and elicits an innate immune response.
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Affiliation(s)
- Heedoo Lee
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Boston University Medical Campus, Boston, MA
| | - Chunhua Li
- Department of Computational Medicine and Bioinformatics Department of Biological Chemistry, The University of Michigan, Ann Arbor, MI
| | - Yang Zhang
- Department of Computational Medicine and Bioinformatics Department of Biological Chemistry, The University of Michigan, Ann Arbor, MI
| | - Duo Zhang
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Boston University Medical Campus, Boston, MA
| | - Leo E Otterbein
- Department of Surgery, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA
| | - Yang Jin
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Boston University Medical Campus, Boston, MA
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39
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Nocita E, Del Giovane A, Tiberi M, Boccuni L, Fiorelli D, Sposato C, Romano E, Basoli F, Trombetta M, Rainer A, Traversa E, Ragnini-Wilson A. EGFR/ErbB Inhibition Promotes OPC Maturation up to Axon Engagement by Co-Regulating PIP2 and MBP. Cells 2019; 8:cells8080844. [PMID: 31390799 PMCID: PMC6721729 DOI: 10.3390/cells8080844] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/04/2019] [Accepted: 08/05/2019] [Indexed: 12/11/2022] Open
Abstract
Remyelination in the adult brain relies on the reactivation of the Neuronal Precursor Cell (NPC) niche and differentiation into Oligodendrocyte Precursor Cells (OPCs) as well as on OPC maturation into myelinating oligodendrocytes (OLs). These two distinct phases in OL development are defined by transcriptional and morphological changes. How this differentiation program is controlled remains unclear. We used two drugs that stimulate myelin basic protein (MBP) expression (Clobetasol and Gefitinib) alone or combined with epidermal growth factor receptor (EGFR) or Retinoid X Receptor gamma (RXRγ) gene silencing to decode the receptor signaling required for OPC differentiation in myelinating OLs. Electrospun polystyrene (PS) microfibers were used as synthetic axons to study drug efficacy on fiber engagement. We show that EGFR inhibition per se stimulates MBP expression and increases Clobetasol efficacy in OPC differentiation. Consistent with this, Clobetasol and Gefitinib co-treatment, by co-regulating RXRγ, MBP and phosphatidylinositol 4,5-bisphosphate (PIP2) levels, maximizes synthetic axon engagement. Conversely, RXRγ gene silencing reduces the ability of the drugs to promote MBP expression. This work provides a view of how EGFR/ErbB inhibition controls OPC differentiation and indicates the combination of Clobetasol and Gefitinib as a potent remyelination-enhancing treatment.
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Affiliation(s)
- Emanuela Nocita
- NeurotechIT Laboratory, Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Alice Del Giovane
- NeurotechIT Laboratory, Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Marta Tiberi
- NeurotechIT Laboratory, Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Laura Boccuni
- NeurotechIT Laboratory, Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Denise Fiorelli
- NeurotechIT Laboratory, Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Carola Sposato
- NeurotechIT Laboratory, Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Elena Romano
- Advanced Microscopy Center, Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy
| | - Francesco Basoli
- Department of Engineering, Università Campus Bio-Medico di Roma, 00128 Rome, Italy
| | - Marcella Trombetta
- Department of Engineering, Università Campus Bio-Medico di Roma, 00128 Rome, Italy
| | - Alberto Rainer
- Department of Engineering, Università Campus Bio-Medico di Roma, 00128 Rome, Italy
| | - Enrico Traversa
- School of Materials and Energy, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Antonella Ragnini-Wilson
- NeurotechIT Laboratory, Department of Biology, University of Rome "Tor Vergata", 00133 Rome, Italy.
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40
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Quintela-López T, Ortiz-Sanz C, Serrano-Regal MP, Gaminde-Blasco A, Valero J, Baleriola J, Sánchez-Gómez MV, Matute C, Alberdi E. Aβ oligomers promote oligodendrocyte differentiation and maturation via integrin β1 and Fyn kinase signaling. Cell Death Dis 2019; 10:445. [PMID: 31171765 PMCID: PMC6554322 DOI: 10.1038/s41419-019-1636-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/17/2019] [Accepted: 05/08/2019] [Indexed: 12/13/2022]
Abstract
Alzheimer´s disease (AD) is characterized by a progressive cognitive decline that correlates with the levels of amyloid β-peptide (Aβ) oligomers. Strong evidences connect changes of oligodendrocyte function with the onset of neurodegeneration in AD. However, the mechanisms controlling oligodendrocyte responses to Aβ are still elusive. Here, we tested the role of Aβ in oligodendrocyte differentiation, maturation, and survival in isolated oligodendrocytes and in organotypic cerebellar slices. We found that Aβ peptides specifically induced local translation of 18.5-kDa myelin basic protein (MBP) isoform in distal cell processes concomitant with an increase of process complexity of MBP-expressing oligodendrocytes. Aβ oligomers required integrin β1 receptor, Src-family kinase Fyn and Ca2+/CaMKII as effectors to modulate MBP protein expression. The pharmacological inhibition of Fyn kinase also attenuated oligodendrocyte differentiation and survival induced by Aβ oligomers. Similarly, using ex vivo organotypic cerebellar slices Aβ promoted MBP upregulation through Fyn kinase, and modulated oligodendrocyte population dynamics by inducing cell proliferation and differentiation. Importantly, application of Aβ to cerebellar organotypic slices enhanced remyelination and oligodendrocyte lineage recovery in lysolecithin (LPC)-induced demyelination. These data reveal an important role of Aβ in oligodendrocyte lineage function and maturation, which may be relevant to AD pathogenesis.
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Affiliation(s)
- Tania Quintela-López
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Carolina Ortiz-Sanz
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Mari Paz Serrano-Regal
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Adhara Gaminde-Blasco
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Jorge Valero
- Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain
| | - Jimena Baleriola
- Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,IKERBASQUE Basque Foundation for Science, Bilbao, Spain.,Department of Cell Biology and Histology, UPV/EHU, Leioa, 48940, Spain
| | - Maria Victoria Sánchez-Gómez
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain.,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain.,CIBERNED, Leioa, 48940, Spain
| | - Carlos Matute
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain. .,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain. .,CIBERNED, Leioa, 48940, Spain.
| | - Elena Alberdi
- Department of Neuroscience, University of Basque Country (UPV/EHU), Leioa, 48940, Spain. .,Achucarro Basque Center for Neuroscience, Leioa, 48940, Spain. .,CIBERNED, Leioa, 48940, Spain.
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41
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Barton SK, Gregory JM, Chandran S, Turner BJ. Could an Impairment in Local Translation of mRNAs in Glia be Contributing to Pathogenesis in ALS? Front Mol Neurosci 2019; 12:124. [PMID: 31164803 PMCID: PMC6536688 DOI: 10.3389/fnmol.2019.00124] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 04/26/2019] [Indexed: 12/13/2022] Open
Abstract
One of the key pathways implicated in amyotrophic lateral sclerosis (ALS) pathogenesis is abnormal RNA processing. Studies to date have focussed on defects in RNA stability, splicing, and translation, but this review article will focus on the largely overlooked RNA processing mechanism of RNA trafficking, with particular emphasis on the importance of glia. In the central nervous system (CNS), oligodendrocytes can extend processes to myelinate and metabolically support up to 50 axons and astrocytes can extend processes to cover up to 100,000 synapses, all with differing local functional requirements. Furthermore, many of the proteins required in these processes are large, aggregation-prone proteins which would be difficult to transport in their fully translated, terminally-folded state. This, therefore, highlights a critical requirement in these cells for local control of protein translation, which is achieved through specific trafficking of mRNAs to each process and local translation therein. Given that a large number of RNA-binding proteins have been implicated in ALS, and RNA-binding proteins are essential for trafficking mRNAs from the nucleus to glial processes for local translation, RNA misprocessing in glial cells is a likely source of cellular dysfunction in ALS. To date, neurons have been the focus of ALS research, but an intrinsic deficit in glia, namely astrocytes and oligodendrocytes, could have an additive effect on declining neuronal function in ALS. This review article aims to highlight the key evidence that supports the contention that RNA trafficking deficits in astrocytes and oligodendrocytes may contribute to in ALS.
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Affiliation(s)
- Samantha K Barton
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia.,Euan MacDonald Centre for MND Research, University of Edinburgh, Edinburgh, United Kingdom.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Jenna M Gregory
- Euan MacDonald Centre for MND Research, University of Edinburgh, Edinburgh, United Kingdom.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.,UK Dementia Research Institute at University of Edinburgh, Edinburgh, United Kingdom
| | - Siddharthan Chandran
- Euan MacDonald Centre for MND Research, University of Edinburgh, Edinburgh, United Kingdom.,Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.,UK Dementia Research Institute at University of Edinburgh, Edinburgh, United Kingdom
| | - Bradley J Turner
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
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42
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Zakaria M, Ferent J, Hristovska I, Laouarem Y, Zahaf A, Kassoussi A, Mayeur ME, Pascual O, Charron F, Traiffort E. The Shh receptor Boc is important for myelin formation and repair. Development 2019; 146:146/9/dev172502. [PMID: 31048318 DOI: 10.1242/dev.172502] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2018] [Accepted: 03/28/2019] [Indexed: 12/25/2022]
Abstract
Myelination leads to the formation of myelin sheaths surrounding neuronal axons and is crucial for function, plasticity and repair of the central nervous system (CNS). It relies on the interaction of the axons and the oligodendrocytes: the glial cells producing CNS myelin. Here, we have investigated the role of a crucial component of the Sonic hedgehog (Shh) signalling pathway, the co-receptor Boc, in developmental and repairing myelination. During development, Boc mutant mice display a transient decrease in oligodendroglial cell density together with delayed myelination. Despite recovery of oligodendroglial cells at later stages, adult mutants still exhibit a lower production of myelin basic protein correlated with a significant decrease in the calibre of callosal axons and a reduced amount of the neurofilament NF-M. During myelin repair, the altered OPC differentiation observed in the mutant is reminiscent of the phenotype observed after blockade of Shh signalling. In addition, Boc mutant microglia/macrophages unexpectedly exhibit the apparent inability to transition from a highly to a faintly ramified morphology in vivo Altogether, these results identify Boc as an important component of myelin formation and repair.
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Affiliation(s)
- Mary Zakaria
- INSERM-University Paris-Sud/Paris-Saclay; Diseases and Hormones of the Nervous System, U1195, 80 rue du Général Leclerc, F-94276, Le Kremlin-Bicêtre, France
| | - Julien Ferent
- IRCM, Molecular Biology of Neural Development, 110 Pine Avenue West, Montreal, Quebec H2W 1R7, Canada; Department of Medicine, University of Montreal, Montreal, Quebec, Canada; McGill University, Montreal, Quebec, Canada
| | - Ines Hristovska
- Institut NeuroMyoGène CNRS UMR 5310-INSERM U1217-Université Claude Bernard Lyon 1, Faculté de Médecine et de Pharmacie 69008 Lyon, France
| | - Yousra Laouarem
- INSERM-University Paris-Sud/Paris-Saclay; Diseases and Hormones of the Nervous System, U1195, 80 rue du Général Leclerc, F-94276, Le Kremlin-Bicêtre, France
| | - Amina Zahaf
- INSERM-University Paris-Sud/Paris-Saclay; Diseases and Hormones of the Nervous System, U1195, 80 rue du Général Leclerc, F-94276, Le Kremlin-Bicêtre, France
| | - Abdelmoumen Kassoussi
- INSERM-University Paris-Sud/Paris-Saclay; Diseases and Hormones of the Nervous System, U1195, 80 rue du Général Leclerc, F-94276, Le Kremlin-Bicêtre, France
| | - Marie-Eve Mayeur
- Institut NeuroMyoGène CNRS UMR 5310-INSERM U1217-Université Claude Bernard Lyon 1, Faculté de Médecine et de Pharmacie 69008 Lyon, France
| | - Olivier Pascual
- Institut NeuroMyoGène CNRS UMR 5310-INSERM U1217-Université Claude Bernard Lyon 1, Faculté de Médecine et de Pharmacie 69008 Lyon, France
| | - Frederic Charron
- IRCM, Molecular Biology of Neural Development, 110 Pine Avenue West, Montreal, Quebec H2W 1R7, Canada; Department of Medicine, University of Montreal, Montreal, Quebec, Canada; McGill University, Montreal, Quebec, Canada
| | - Elisabeth Traiffort
- INSERM-University Paris-Sud/Paris-Saclay; Diseases and Hormones of the Nervous System, U1195, 80 rue du Général Leclerc, F-94276, Le Kremlin-Bicêtre, France
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43
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Linneberg C, Toft CLF, Kjaer-Sorensen K, Laursen LS. L1cam-mediated developmental processes of the nervous system are differentially regulated by proteolytic processing. Sci Rep 2019; 9:3716. [PMID: 30842511 PMCID: PMC6403279 DOI: 10.1038/s41598-019-39884-x] [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: 06/06/2018] [Accepted: 11/08/2018] [Indexed: 11/09/2022] Open
Abstract
Normal brain development depends on tight temporal and spatial regulation of connections between cells. Mutations in L1cam, a member of the immunoglobulin (Ig) superfamily that mediate cell-cell contacts through homo- and heterophilic interactions, are associated with several developmental abnormalities of the nervous system, including mental retardation, limb spasticity, hydrocephalus, and corpus callosum aplasia. L1cam has been reported to be shed from the cell surface, but the significance of this during different phases of brain development is unknown. We here show that ADAM10-mediated shedding of L1cam is regulated by its fibronectin type III (FNIII) domains. Specifically, the third FNIII domain is important for maintaining a conformation where access to a membrane proximal cleavage site is restricted. To define the role of ADAM10/17/BACE1-mediated shedding of L1cam during brain development, we used a zebrafish model system. Knockdown of the zebrafish, l1camb, caused hydrocephalus, defects in axonal outgrowth, and myelination abnormalities. Rescue experiments with proteinase-resistant and soluble L1cam variants showed that proteolytic cleavage is not required for normal axonal outgrowth and development of the ventricular system. In contrast, metalloproteinase-mediated shedding is required for efficient myelination, and only specific fragments are able to mediate this stimulatory function of the shedded L1cam.
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Affiliation(s)
- Cecilie Linneberg
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000, Aarhus C, Denmark
| | - Christian Liebst Frisk Toft
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000, Aarhus C, Denmark
| | - Kasper Kjaer-Sorensen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000, Aarhus C, Denmark
| | - Lisbeth S Laursen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, 8000, Aarhus C, Denmark.
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44
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Hoch-Kraft P, Trotter J, Gonsior C. Missing in Action: Dysfunctional RNA Metabolism in Oligodendroglial Cells as a Contributor to Neurodegenerative Diseases? Neurochem Res 2019; 45:566-579. [PMID: 30843138 DOI: 10.1007/s11064-019-02763-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 02/22/2019] [Accepted: 02/23/2019] [Indexed: 12/14/2022]
Abstract
The formation of myelin around axons by oligodendrocytes (OL) poses an enormous synthetic and energy challenge for the glial cell. Local translation of transcripts, including the mRNA for the essential myelin protein Myelin Basic Protein (MBP) at the site of myelin deposition has been recognised as an efficient mechanism to assure proper myelin sheath assembly. Oligodendroglial precursor cells (OPCs) form synapses with neurons and may localise many additional mRNAs in a similar fashion to synapses between neurons. In some diseases in which demyelination occurs, an abundance of OPCs is present but there is a failure to efficiently remyelinate and to synthesise MBP. This compromises axonal survival and function. OPCs are especially sensitive to cellular stress as occurring in neurodegenerative diseases, which can impinge on their ability to translate mRNAs into protein. Stress causes the build up of cytoplasmic stress granules (SG) in which many RNAs are sequestered and translationally stalled until the stress ceases. Chronic stress in particular could convert this initially protective reaction of the cell into damage, as persistence of SG may lead to pathological aggregate formation or long-term translation block of SG-associated RNAs. The recent recognition that many neurodegenerative diseases often exhibit an early white matter pathology with a proliferation of surviving OPCs, renders a study of the stress-associated processes in oligodendrocytes and OPCs especially relevant. Here, we discuss a potential dysfunction of RNA regulation in myelin diseases such as Multiple Sclerosis (MS) and Vanishing white matter disease (VWM) and potential contributions of OL dysfunction to neurodegenerative diseases such as Amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD) and Fragile X syndrome (FXS).
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Affiliation(s)
- Peter Hoch-Kraft
- Cellular Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128, Mainz, Germany
| | - Jacqueline Trotter
- Cellular Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128, Mainz, Germany
| | - Constantin Gonsior
- Cellular Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128, Mainz, Germany.
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45
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Mayya VK, Duchaine TF. Ciphers and Executioners: How 3'-Untranslated Regions Determine the Fate of Messenger RNAs. Front Genet 2019; 10:6. [PMID: 30740123 PMCID: PMC6357968 DOI: 10.3389/fgene.2019.00006] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 01/07/2019] [Indexed: 12/29/2022] Open
Abstract
The sequences and structures of 3'-untranslated regions (3'UTRs) of messenger RNAs govern their stability, localization, and expression. 3'UTR regulatory elements are recognized by a wide variety of trans-acting factors that include microRNAs (miRNAs), their associated machinery, and RNA-binding proteins (RBPs). In turn, these factors instigate common mechanistic strategies to execute the regulatory programs encoded by 3'UTRs. Here, we review classes of factors that recognize 3'UTR regulatory elements and the effector machineries they guide toward mRNAs to dictate their expression and fate. We outline illustrative examples of competitive, cooperative, and coordinated interplay such as mRNA localization and localized translation. We further review the recent advances in the study of mRNP granules and phase transition, and their possible significance for the functions of 3'UTRs. Finally, we highlight some of the most recent strategies aimed at deciphering the complexity of the regulatory codes of 3'UTRs, and identify some of the important remaining challenges.
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Affiliation(s)
| | - Thomas F. Duchaine
- Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, QC, Canada
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46
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Weil MT, Schulz-Ëberlin G, Mukherjee C, Kuo-Elsner WP, Schäfer I, Müller C, Simons M. Isolation and Culture of Oligodendrocytes. Methods Mol Biol 2019; 1936:79-95. [PMID: 30820894 DOI: 10.1007/978-1-4939-9072-6_5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Primary cultures of brain-derived rodent cells are widely used to study molecular and cellular mechanisms in neurobiology. In this chapter, we describe methods of purifying and culturing oligodendroglial cells from mouse perinatal brains. In addition, we describe methods of coculturing the purified oligodendrocytes with neurons. When prepared and cultured according to these protocols, many essential aspects of the biology of oligodendrocytes, such as their proliferation, differentiation, and myelination, can be studied in culture.
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Affiliation(s)
- Marie-Theres Weil
- Max Planck Institute of Experimental Medicine, Goettingen, Germany
- Center Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Goettingen, Germany
- AbbVie Germany GmbH & Co. KG, Knollstrasse, Ludwigshafen, Germany
| | | | - Chaitali Mukherjee
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany
- German Center for Neurodegenerative Disease (DZNE), Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Wen Ping Kuo-Elsner
- Department of Biology, Molecular Cell Biology, Johannes Gutenberg University, Mainz, Germany
| | - Isabelle Schäfer
- Institute of Physiology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Christina Müller
- Institute of Physiology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Mikael Simons
- Max Planck Institute of Experimental Medicine, Goettingen, Germany.
- Institute of Neuronal Cell Biology, Technical University Munich, Munich, Germany.
- German Center for Neurodegenerative Disease (DZNE), Munich, Germany.
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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47
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Amaya J, Ryan VH, Fawzi NL. The SH3 domain of Fyn kinase interacts with and induces liquid-liquid phase separation of the low-complexity domain of hnRNPA2. J Biol Chem 2018; 293:19522-19531. [PMID: 30397184 DOI: 10.1074/jbc.ra118.005120] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/27/2018] [Indexed: 11/06/2022] Open
Abstract
Liquid-liquid phase separation of proteins and nucleic acids into membraneless organelles (MLOs) spatially organizes cellular components and reactions. The RNA-binding protein heterogeneous nuclear ribonucleoprotein A2 (hnRNPA2) carries mRNA targets in MLOs called transport granules in neurons and oligodendrocytes. At sites of local translation, hnRNPA2 is phosphorylated by the tyrosine protein kinase Fyn, releasing the mRNA for translation. Fyn recognizes targets through its SH3 domain (Fyn-SH3). However, hnRNPA2 lacks canonical SH3-binding sequences, raising the question of how Fyn-SH3 binds hnRNPA2 in phase-separated transport granules. Here, we characterize the structural details of the interaction of the hnRNPA2 low-complexity domain (LC) with Fyn-SH3 and the effect of Fyn-SH3 on hnRNPA2 phase separation. We combined in vitro microscopy and solution NMR spectroscopy to evaluate assembly of hnRNPA2 and Fyn-SH3 into in vitro phase-separated granules and probe the structural details of their interaction. We observed that Fyn-SH3 induces hnRNPA2 LC phase separation and that Fyn-SH3 is incorporated into in vitro hnRNPA2 LC granules. Moreover, we identified hnRNPA2 LC interaction sites on the surface of Fyn-SH3. Our data offer a structural view of how hnRNPA2 LC may interact with Fyn. To our knowledge, our study provides the first example of a single globular domain inducing phase separation of a disordered MLO scaffold protein.
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Affiliation(s)
- Joshua Amaya
- From the Department of Molecular Pharmacology, Physiology, and Biotechnology and
| | - Veronica H Ryan
- the Graduate Program in Neuroscience, Brown University, Providence, Rhode Island 02912
| | - Nicolas L Fawzi
- From the Department of Molecular Pharmacology, Physiology, and Biotechnology and
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48
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Götz J, Halliday G, Nisbet RM. Molecular Pathogenesis of the Tauopathies. ANNUAL REVIEW OF PATHOLOGY-MECHANISMS OF DISEASE 2018; 14:239-261. [PMID: 30355155 DOI: 10.1146/annurev-pathmechdis-012418-012936] [Citation(s) in RCA: 143] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The tauopathies constitute a group of diseases that have Tau inclusions in neurons or glia as their common denominator. In this review, we describe the biochemical and histological differences in Tau pathology that are characteristic of the spectrum of frontotemporal lobar degeneration as primary tauopathies and of Alzheimer's disease as a secondary tauopathy, as well as the commonalities and differences between the familial and sporadic forms. Furthermore, we discuss selected advances in transgenic animal models in delineating the different pathomechanisms of Tau.
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Affiliation(s)
- Jürgen Götz
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St. Lucia Campus, Brisbane, Queensland 4072, Australia;
| | - Glenda Halliday
- Brain and Mind Centre and Central Clinical School, Sydney Medical School, University of Sydney, New South Wales 2006, Australia
| | - Rebecca M Nisbet
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, St. Lucia Campus, Brisbane, Queensland 4072, Australia;
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49
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Torvund-Jensen J, Steengaard J, Askebjerg LB, Kjaer-Sorensen K, Laursen LS. The 3'UTRs of Myelin Basic Protein mRNAs Regulate Transport, Local Translation and Sensitivity to Neuronal Activity in Zebrafish. Front Mol Neurosci 2018; 11:185. [PMID: 29946237 PMCID: PMC6006989 DOI: 10.3389/fnmol.2018.00185] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 05/14/2018] [Indexed: 02/04/2023] Open
Abstract
Formation of functional myelin sheaths within the central nervous system depends on expression of myelin basic protein (MBP). Following process extension and wrapping around axonal segments, this highly basic protein is required for compaction of the multi-layered membrane sheath produced by oligodendrocytes. MBP is hypothesized to be targeted to the membrane sheath by mRNA transport and local translation, which ensures that its expression is temporally and spatially restricted. The mechanistic details of how this might be regulated are still largely unknown, in particular because a model system that allows this process to be studied in vivo is lacking. We here show that the expression of the zebrafish MBP orthologs, mbpa and mbpb, is developmentally regulated, and that expression of specific mbpa isoforms is restricted to the peripheral nervous system. By analysis of transgenic zebrafish, which express a fluorescent reporter protein specifically in myelinating oligodendrocytes, we demonstrate that both mbpa and mbpb include a 3’UTR sequence, by which mRNA transport and translation is regulated in vivo. Further functional analysis suggests that: (1) the 3’UTRs delay the onset of protein expression; and that (2) several regulatory elements contribute to targeting of the mbp mRNA to the myelin sheath. Finally, we show that a pharmacological compound known to enhance neuronal activity stimulates the translation of Mbp in zebrafish in a 3’UTR-dependent manner. A similar effect was obtained following stimulation with a TrkB receptor agonist, and cell-based assays further confirmed that the receptor ligand, BDNF, in combination with other signals reversed the inhibitory effect of the 3’UTR on translation.
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Affiliation(s)
- Julie Torvund-Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jes Steengaard
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | | | | | - Lisbeth S Laursen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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50
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Hammann J, Bassetti D, White R, Luhmann HJ, Kirischuk S. α2 isoform of Na +,K +-ATPase via Na +,Ca 2+ exchanger modulates myelin basic protein synthesis in oligodendrocyte lineage cells in vitro. Cell Calcium 2018; 73:1-10. [PMID: 29880193 DOI: 10.1016/j.ceca.2018.03.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 03/05/2018] [Accepted: 03/25/2018] [Indexed: 11/26/2022]
Abstract
Oligodendrocytes in the CNS myelinate neuronal axons, facilitating rapid propagation of action potentials. Myelin basic protein (MBP) is an essential component of myelin and its absence results in severe hypomyelination. In oligodendrocyte lineage cell (OLC) monocultures MBP synthesis starts at DIV4. Ouabain (10 nM), a Na+,K+-ATPase (NKA) blocker, stimulates MBP synthesis. As OLCs express the α2 isoform of NKA (α2-NKA) that has a high affinity for ouabain, we hypothesized that α2-NKA mediates this effect. Knockdown of α2-NKA with small interfering (si)RNA (α2-siRNA) significantly potentiated MBP synthesis at DIV4 and 5. This effect was completely blocked by KB-R7943 (1 μM), a Na+,Ca2+ exchanger (NCX) antagonist. α2-NKA ablation increased the frequency of NCX-mediated spontaneous Ca2+ transients ([Ca2+]t) at DIV4, whereas in control OLC cultures comparable frequency of [Ca2+]t was observed at DIV5. At DIV6 almost no [Ca2+]t were observed either in control or in α2-siRNA-treated cultures. Immunocytochemical analyses showed that α2-NKA co-localizes with MBP in proximal processes of immature OLCs but is only weakly present in MBP-enriched membrane sheets. Knockdown of α2-NKA in cortical slice cultures did not change MBP levels but reduced co-localization of neurofilament- and MBP-positive compartments. We conclude that α2-NKA activity in OLCs affects NCX-mediated [Ca2+]t and the onset of MBP synthesis. We suggest therefore that neuronal activity, presumably in form of local extracellular [K+] changes, might locally influence NCX-mediated [Ca2+]t in OLC processes thus triggering local MBP synthesis in the vicinity of an active axon.
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Affiliation(s)
- Jens Hammann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Davide Bassetti
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Robin White
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany
| | - Sergei Kirischuk
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, D-55128 Mainz, Germany.
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