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Dansu DK, Sauma S, Huang D, Li M, Moyon S, Casaccia P. The epigenetic landscape of oligodendrocyte progenitors changes with time. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.06.579145. [PMID: 38501119 PMCID: PMC10946295 DOI: 10.1101/2024.02.06.579145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
SUMMARY Dansu et al. identify distinct histone H4 modifications as potential mechanism underlying the functional differences between adult and neonatal progenitors. While H4K8ac favors the expression of differentiation genes, their expression is halted by H4K20me3. Adult oligodendrocyte progenitors (aOPCs) generate myelinating oligodendrocytes, like neonatal progenitors (nOPCs), but they also display unique functional features. Here, using RNA-sequencing, unbiased histone proteomics analysis and ChIP-sequencing, we define the transcripts and histone marks underlying the unique properties of aOPCs. We describe the lower proliferative capacity and higher levels of expression of oligodendrocyte specific genes in aOPCs compared to nOPCs, as well as the greater levels of H4 histone marks. We also report increased occupancy of the H4K8ac mark at chromatin locations corresponding to oligodendrocyte-specific transcription factors and lipid metabolism genes. Pharmacological inhibition of H4K8ac deposition reduces the levels of these transcripts in aOPCs, rendering their transcriptome more similar to nOPCs. The repressive H4K20me3 mark is also higher in aOPCs compared to nOPCs and pharmacological inhibition of its deposition results in increased levels of genes related to the mature oligodendrocyte state. Overall, this study identifies two histone marks which are important for the unique transcriptional and functional identity of aOPCs.
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2
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Ferreira-Peralta P, França B, Murtinheira F, Rodrigues MS, Herrera F. Is spastic ataxia 8 a protein misfolding disorder? Biochim Biophys Acta Mol Basis Dis 2024; 1870:166882. [PMID: 37696463 DOI: 10.1016/j.bbadis.2023.166882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 09/03/2023] [Accepted: 09/04/2023] [Indexed: 09/13/2023]
Affiliation(s)
- Pedro Ferreira-Peralta
- BioISI - Instituto de Biosistemas e Ciências integrativas, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisbon, Portugal
| | - Brenda França
- BioISI - Instituto de Biosistemas e Ciências integrativas, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisbon, Portugal
| | - Fernanda Murtinheira
- BioISI - Instituto de Biosistemas e Ciências integrativas, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisbon, Portugal; MOSTMICRO Research Unit, Instituto de Tecnologia Química e Biológica (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mario S Rodrigues
- BioISI - Instituto de Biosistemas e Ciências integrativas, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisbon, Portugal
| | - Federico Herrera
- BioISI - Instituto de Biosistemas e Ciências integrativas, Faculdade de Ciências da Universidade de Lisboa, 1749-016 Lisbon, Portugal.
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3
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Ghosh S, Bhatti GK, Sharma PK, Kandimalla R, Mastana SS, Bhatti JS. Potential of Nano-Engineered Stem Cells in the Treatment of Multiple Sclerosis: A Comprehensive Review. Cell Mol Neurobiol 2023; 44:6. [PMID: 38104307 DOI: 10.1007/s10571-023-01434-5] [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: 06/12/2023] [Accepted: 11/06/2023] [Indexed: 12/19/2023]
Abstract
Multiple sclerosis (MS) is a chronic and degrading autoimmune disorder mainly targeting the central nervous system, leading to progressive neurodegeneration, demyelination, and axonal damage. Current treatment options for MS are limited in efficacy, generally linked to adverse side effects, and do not offer a cure. Stem cell therapies have emerged as a promising therapeutic strategy for MS, potentially promoting remyelination, exerting immunomodulatory effects and protecting against neurodegeneration. Therefore, this review article focussed on the potential of nano-engineering in stem cells as a therapeutic approach for MS, focusing on the synergistic effects of combining stem cell biology with nanotechnology to stimulate the proliferation of oligodendrocytes (OLs) from neural stem cells and OL precursor cells, by manipulating neural signalling pathways-PDGF, BMP, Wnt, Notch and their essential genes such as Sox, bHLH, Nkx. Here we discuss the pathophysiology of MS, the use of various types of stem cells in MS treatment and their mechanisms of action. In the context of nanotechnology, we present an overview of its applications in the medical and research field and discuss different methods and materials used to nano-engineer stem cells, including surface modification, biomaterials and scaffolds, and nanoparticle-based delivery systems. We further elaborate on nano-engineered stem cell techniques, such as nano script, nano-exosome hybrid, nano-topography and their potentials in MS. The article also highlights enhanced homing, engraftment, and survival of nano-engineered stem cells, targeted and controlled release of therapeutic agents, and immunomodulatory and tissue repair effects with their challenges and limitations. This visual illustration depicts the process of utilizing nano-engineering in stem cells and exosomes for the purpose of delivering more accurate and improved treatments for Multiple Sclerosis (MS). This approach targets specifically the creation of oligodendrocytes, the breakdown of which is the primary pathological factor in MS.
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Affiliation(s)
- Sushruta Ghosh
- Laboratory of Translational Medicine and Nanotherapeutics, Department of Human Genetics and Molecular Medicine, School of Health Sciences Central, University of Punjab, Bathinda, India
| | - Gurjit Kaur Bhatti
- Department of Medical Lab Technology, University Institute of Applied Health Sciences, Chandigarh University, Mohali, India
| | - Pushpender Kumar Sharma
- Amity Institute of Biotechnology, Amity University, Rajasthan, India
- Amity Centre for Nanobiotechnology and Nanomedicine, Amity University, Rajasthan, India
| | - Ramesh Kandimalla
- Department of Biochemistry, Kakatiya Medical College, Warangal, Telangana, India
- Department of Applied Biology, CSIR-Indian Institute of Technology, Hyderabad, India
| | - Sarabjit Singh Mastana
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - Jasvinder Singh Bhatti
- Laboratory of Translational Medicine and Nanotherapeutics, Department of Human Genetics and Molecular Medicine, School of Health Sciences Central, University of Punjab, Bathinda, India.
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4
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NKX6-2 Disease in Two Unrelated Patients with Early Onset Spastic Quadriplegia and Diffuse Hypomyelinating Leukodystrophy. BRAIN DISORDERS 2023. [DOI: 10.1016/j.dscb.2023.100069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
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5
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Anne A, Saxena S, Mohan KN. Genome-wide methylation analysis of post-mortem cerebellum samples supports the role of peroxisomes in autism spectrum disorder. Epigenomics 2022; 14:1015-1027. [PMID: 36154275 DOI: 10.2217/epi-2022-0184] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: We tested the hypothesis that a subset of patients with autism spectrum disorder (ASD) contains candidate genes with high DNA methylation differences (effective values) that potentially affect one of the two alleles. Materials & methods: Genome-wide DNA methylation comparisons were made on cerebellum samples from 30 patients and 45 controls. Results: 12 genes with high effective values, including GSDMD, MMACHC, SLC6A5 and NKX6-2, implicated in ASD and other neuropsychiatric disorders were identified. Monoallelic promoter methylation and downregulation were observed for SERHL (serine hydrolase-like) and CAT (catalase) genes associated with peroxisome function. Conclusion: These data are consistent with the hypothesis implicating impaired peroxisome function/biogenesis for ASD. A similar approach holds promise for identifying rare epimutations in ASD and other complex disorders.
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Affiliation(s)
- Anuhya Anne
- Molecular Biology and Genetics Laboratory, Department of Biological Sciences, Birla Institute of Technology & Science, Pilani - Hyderabad Campus, 500 078, India.,Centre for Human Disease Research, Birla Institute of Technology & Science, Pilani - Hyderabad Campus, 500 078, India
| | - Sonal Saxena
- Molecular Biology and Genetics Laboratory, Department of Biological Sciences, Birla Institute of Technology & Science, Pilani - Hyderabad Campus, 500 078, India
| | - Kommu Naga Mohan
- Molecular Biology and Genetics Laboratory, Department of Biological Sciences, Birla Institute of Technology & Science, Pilani - Hyderabad Campus, 500 078, India.,Centre for Human Disease Research, Birla Institute of Technology & Science, Pilani - Hyderabad Campus, 500 078, India
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6
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Nowacki JC, Fields AM, Fu MM. Emerging cellular themes in leukodystrophies. Front Cell Dev Biol 2022; 10:902261. [PMID: 36003149 PMCID: PMC9393611 DOI: 10.3389/fcell.2022.902261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Leukodystrophies are a broad spectrum of neurological disorders that are characterized primarily by deficiencies in myelin formation. Clinical manifestations of leukodystrophies usually appear during childhood and common symptoms include lack of motor coordination, difficulty with or loss of ambulation, issues with vision and/or hearing, cognitive decline, regression in speech skills, and even seizures. Many cases of leukodystrophy can be attributed to genetic mutations, but they have diverse inheritance patterns (e.g., autosomal recessive, autosomal dominant, or X-linked) and some arise from de novo mutations. In this review, we provide an updated overview of 35 types of leukodystrophies and focus on cellular mechanisms that may underlie these disorders. We find common themes in specialized functions in oligodendrocytes, which are specialized producers of membranes and myelin lipids. These mechanisms include myelin protein defects, lipid processing and peroxisome dysfunction, transcriptional and translational dysregulation, disruptions in cytoskeletal organization, and cell junction defects. In addition, non-cell-autonomous factors in astrocytes and microglia, such as autoimmune reactivity, and intercellular communication, may also play a role in leukodystrophy onset. We hope that highlighting these themes in cellular dysfunction in leukodystrophies may yield conceptual insights on future therapeutic approaches.
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7
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Paes de Faria J, Vale-Silva RS, Fässler R, Werner HB, Relvas JB. Pinch2 regulates myelination in the mouse central nervous system. Development 2022; 149:275524. [DOI: 10.1242/dev.200597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 05/16/2022] [Indexed: 11/20/2022]
Abstract
ABSTRACT
The extensive morphological changes of oligodendrocytes during axon ensheathment and myelination involve assembly of the Ilk-Parvin-Pinch (IPP) heterotrimeric complex of proteins to relay essential mechanical and biochemical signals between integrins and the actin cytoskeleton. Binding of Pinch1 and Pinch2 isoforms to Ilk is mutually exclusive and allows the formation of distinct IPP complexes with specific signaling properties. Using tissue-specific conditional gene ablation in mice, we reveal an essential role for Pinch2 during central nervous system myelination. Unlike Pinch1 gene ablation, loss of Pinch2 in oligodendrocytes results in hypermyelination and in the formation of pathological myelin outfoldings in white matter regions. These structural changes concur with inhibition of Rho GTPase RhoA and Cdc42 activities and phenocopy aspects of myelin pathology observed in corresponding mouse mutants. We propose a dual role for Pinch2 in preventing an excess of myelin wraps through RhoA-dependent control of membrane growth and in fostering myelin stability via Cdc42-dependent organization of cytoskeletal septins. Together, these findings indicate that IPP complexes containing Pinch2 act as a crucial cell-autonomous molecular hub ensuring synchronous control of key signaling networks during developmental myelination.
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Affiliation(s)
- Joana Paes de Faria
- Department of Neurobiology and Neurological Disease, Glial Cell Biology Laboratory, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto 1 , 4200-135 Porto , Portugal
- Department of Neurobiology and Neurological Disease, Glial Cell Biology Laboratory, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto 2 , 4200-135 Porto , Portugal
| | - Raquel S. Vale-Silva
- Department of Neurobiology and Neurological Disease, Glial Cell Biology Laboratory, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto 1 , 4200-135 Porto , Portugal
- Department of Neurobiology and Neurological Disease, Glial Cell Biology Laboratory, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto 2 , 4200-135 Porto , Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto 3 , 4050-313 Porto , Portugal
| | - Reinhard Fässler
- Department of Molecular Medicine, Max Planck Institute of Biochemistry 4 , 82152 Martinsried , Germany
| | - Hauke B. Werner
- Max Planck Institute of Experimental Medicine 5 Department of Neurogenetics , , D-37075 Gottingen , Germany
| | - João B. Relvas
- Department of Neurobiology and Neurological Disease, Glial Cell Biology Laboratory, Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto 1 , 4200-135 Porto , Portugal
- Department of Neurobiology and Neurological Disease, Glial Cell Biology Laboratory, Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto 2 , 4200-135 Porto , Portugal
- Faculty of Medicine, Universidade do Porto 6 Department of Biomedicine , , 4200-319 Porto , Portugal
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8
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Meschkat M, Steyer AM, Weil MT, Kusch K, Jahn O, Piepkorn L, Agüi-Gonzalez P, Phan NTN, Ruhwedel T, Sadowski B, Rizzoli SO, Werner HB, Ehrenreich H, Nave KA, Möbius W. White matter integrity in mice requires continuous myelin synthesis at the inner tongue. Nat Commun 2022; 13:1163. [PMID: 35246535 PMCID: PMC8897471 DOI: 10.1038/s41467-022-28720-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 01/24/2022] [Indexed: 12/18/2022] Open
Abstract
Myelin, the electrically insulating sheath on axons, undergoes dynamic changes over time. However, it is composed of proteins with long lifetimes. This raises the question how such a stable structure is renewed. Here, we study the integrity of myelinated tracts after experimentally preventing the formation of new myelin in the CNS of adult mice, using an inducible Mbp null allele. Oligodendrocytes survive recombination, continue to express myelin genes, but they fail to maintain compacted myelin sheaths. Using 3D electron microscopy and mass spectrometry imaging we visualize myelin-like membranes failing to incorporate adaxonally, most prominently at juxta-paranodes. Myelinoid body formation indicates degradation of existing myelin at the abaxonal side and the inner tongue of the sheath. Thinning of compact myelin and shortening of internodes result in the loss of about 50% of myelin and axonal pathology within 20 weeks post recombination. In summary, our data suggest that functional axon-myelin units require the continuous incorporation of new myelin membranes. Myelin is formed of proteins of long half-lives. The mechanisms of renewal of such a stable structure are unclear. Here, the authors show that myelin integrity requires continuous myelin synthesis at the inner tongue, contributing to the maintenance of a functional axon-myelin unit.
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Affiliation(s)
- Martin Meschkat
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Göttingen Graduate Center for Neurosciences, Biophysics, and Molecular Biosciences (GGNB), Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Abberior Instruments GmbH, Göttingen, Germany
| | - Anna M Steyer
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Imaging Centre, European Molecular Biology Laboratory (EMBL), Heidelberg, Germany
| | - Marie-Theres Weil
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, Göttingen, Germany
| | - Olaf Jahn
- DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Lars Piepkorn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Paola Agüi-Gonzalez
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany
| | - Nhu Thi Ngoc Phan
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.,Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
| | - Torben Ruhwedel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Boguslawa Sadowski
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Silvio O Rizzoli
- DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Center for Biostructural Imaging of Neurodegeneration, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Hannelore Ehrenreich
- DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany.,Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany. .,Electron Microscopy Core Unit, Max Planck Institute of Experimental Medicine, Göttingen, Germany. .,DFG Research Center for Nanoscale Microscopy and Molecular Physiology of the Brain (CNMPB), Göttingen, Germany. .,Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.
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9
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Sock E, Wegner M. Using the lineage determinants Olig2 and Sox10 to explore transcriptional regulation of oligodendrocyte development. Dev Neurobiol 2021; 81:892-901. [PMID: 34480425 DOI: 10.1002/dneu.22849] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/30/2021] [Accepted: 08/31/2021] [Indexed: 02/02/2023]
Abstract
The transcription factors Olig2 and Sox10 jointly define oligodendroglial identity. Because of their continuous presence during development and in the differentiated state they shape the oligodendroglial regulatory network at all times. In this review, we exploit their eminent role and omnipresence to elaborate the central principles that organize the gene regulatory network in oligodendrocytes in such a way that it preserves its identity, but at the same time allows defined and stimulus-dependent changes that result in an ordered lineage progression, differentiation, and myelination. For this purpose, we outline the multiple functional and physical interactions and intricate cross-regulatory relationships with other transcription factors, such as Hes5, Id, and SoxD proteins, in oligodendrocyte precursors and Tcf7l2, Sip1, Nkx2.2, Zfp24, and Myrf during differentiation and myelination, and interpret them in the context of the regulatory network.
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Affiliation(s)
- Elisabeth Sock
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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10
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Ning K, Duffy BA, Franklin M, Matloff W, Zhao L, Arzouni N, Sun F, Toga AW. Improving brain age estimates with deep learning leads to identification of novel genetic factors associated with brain aging. Neurobiol Aging 2021; 105:199-204. [PMID: 34098431 PMCID: PMC9004720 DOI: 10.1016/j.neurobiolaging.2021.03.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 03/24/2021] [Accepted: 03/25/2021] [Indexed: 11/17/2022]
Abstract
To study genetic factors associated with brain aging, we first need to quantify brain aging. Statistical models have been created for estimating the apparent age of the brain, or predicted brain age (PBA), using imaging data. Recent studies have refined these models to obtain a more accurate PBA, but research has yet to demonstrate the scientific value of doing so. Here, we show that a more accurate PBA leads to better characterization of genetic factors associated with brain aging. We trained a convolutional neural network (CNN) model on 16,998 UK Biobank subjects to derive PBA, then conducted a genome-wide association study on the PBA, in which we identified single nucleotide polymorphisms from four independent loci significantly associated with brain aging, three of which were novel. By comparing association results based on the CNN-derived PBA to those based on a linear regression-derived PBA, we concluded that a more accurate PBA enables the discovery of novel genetic associations. Our results may be valuable for identifying other lifestyle factors associated with brain aging.
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Affiliation(s)
- Kaida Ning
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA; Molecular and Computational Biology Program, University of Southern California, Los Angeles, CA, USA
| | - Ben A Duffy
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - Meredith Franklin
- Department of Preventive Medicine, University of Southern California, Los Angeles, CA, USA
| | - Will Matloff
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA; Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, USA
| | - Lu Zhao
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA
| | - Nibal Arzouni
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA; Molecular and Computational Biology Program, University of Southern California, Los Angeles, CA, USA
| | - Fengzhu Sun
- Molecular and Computational Biology Program, University of Southern California, Los Angeles, CA, USA
| | - Arthur W Toga
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of University of Southern California, Los Angeles, CA, USA.
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11
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Kohnke S, Buller S, Nuzzaci D, Ridley K, Lam B, Pivonkova H, Bentsen MA, Alonge KM, Zhao C, Tadross J, Holmqvist S, Shimizu T, Hathaway H, Li H, Macklin W, Schwartz MW, Richardson WD, Yeo GSH, Franklin RJM, Karadottir RT, Rowitch DH, Blouet C. Nutritional regulation of oligodendrocyte differentiation regulates perineuronal net remodeling in the median eminence. Cell Rep 2021; 36:109362. [PMID: 34260928 PMCID: PMC8293628 DOI: 10.1016/j.celrep.2021.109362] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/26/2021] [Accepted: 06/17/2021] [Indexed: 12/13/2022] Open
Abstract
The mediobasal hypothalamus (MBH; arcuate nucleus of the hypothalamus [ARH] and median eminence [ME]) is a key nutrient sensing site for the production of the complex homeostatic feedback responses required for the maintenance of energy balance. Here, we show that refeeding after an overnight fast rapidly triggers proliferation and differentiation of oligodendrocyte progenitors, leading to the production of new oligodendrocytes in the ME specifically. During this nutritional paradigm, ME perineuronal nets (PNNs), emerging regulators of ARH metabolic functions, are rapidly remodeled, and this process requires myelin regulatory factor (Myrf) in oligodendrocyte progenitors. In genetically obese ob/ob mice, nutritional regulations of ME oligodendrocyte differentiation and PNN remodeling are blunted, and enzymatic digestion of local PNN increases food intake and weight gain. We conclude that MBH PNNs are required for the maintenance of energy balance in lean mice and are remodeled in the adult ME by the nutritional control of oligodendrocyte differentiation.
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Affiliation(s)
- Sara Kohnke
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Sophie Buller
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Danae Nuzzaci
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Katherine Ridley
- Department of Paediatrics and Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Brian Lam
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Helena Pivonkova
- Wellcome-MRC Cambridge Stem Cell Institute, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - Marie A Bentsen
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Kimberly M Alonge
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA, USA
| | - Chao Zhao
- Wellcome-MRC Cambridge Stem Cell Institute, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - John Tadross
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Staffan Holmqvist
- Department of Paediatrics and Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
| | - Takahiro Shimizu
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Hannah Hathaway
- Department of Cell & Developmental Biology and Program in Neuroscience, University of Colorado School of Medicine, Aurora, CO, USA
| | - Huiliang Li
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Wendy Macklin
- Department of Cell & Developmental Biology and Program in Neuroscience, University of Colorado School of Medicine, Aurora, CO, USA
| | - Michael W Schwartz
- University of Washington Medicine Diabetes Institute, Department of Medicine, University of Washington, Seattle, WA, USA
| | - William D Richardson
- Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Giles S H Yeo
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
| | - Robin J M Franklin
- Wellcome-MRC Cambridge Stem Cell Institute, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Ragnhildur T Karadottir
- Wellcome-MRC Cambridge Stem Cell Institute, Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | - David H Rowitch
- Department of Paediatrics and Wellcome-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK; Wolfson Institute for Biomedical Research, University College London, London, UK
| | - Clemence Blouet
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, WT-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK.
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12
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Vallejo R, Kelley CA, Gupta A, Smith WJ, Vallejo A, Cedeño DL. Modulation of neuroglial interactions using differential target multiplexed spinal cord stimulation in an animal model of neuropathic pain. Mol Pain 2021; 16:1744806920918057. [PMID: 32290778 PMCID: PMC7160773 DOI: 10.1177/1744806920918057] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The development and maintenance of chronic neuropathic pain involves distorted
neuroglial interactions, which result in prolonged perturbations of immune and
inflammatory response, as well as disrupted synapses and cellular interactions.
Spinal cord stimulation (SCS) has proven effective and safe for more than
40 years, but comprehensive understanding of its mode of action remains elusive.
Previous work in our laboratory provided evidence that conventional SCS
parameters modulate biological processes associated with neuropathic pain in
animals. This inspired the development of differential target multiplexed
programming (DTMP) in which multiple electrical signals are used for modulating
glial cells and neurons in order to rebalance their interactions. This work
compares DTMP with both low rate and high rate programming using an animal model
of neuropathic pain. The spared nerve injury model was implemented in 48 rats
equally randomized into four experimental groups: No-SCS, DTMP, low rate, and
high rate. Naive animals (N = 7) served as a reference control. SCS was applied
continuously for 48 h and pain-related behavior assessed before and after SCS.
RNA from the spinal cord exposed to SCS was sequenced to determine changes in
gene expression as a result of injury (No-SCS vs. naïve) and as a result of SCS
(SCS vs. No-SCS). Bioinformatics tools (Weighted Gene Co-expression Network
Analysis and Gene Ontology Enrichment Analysis) were used to evaluate the
significance of the results. All three therapies significantly reduced
mechanical hypersensitivity, although DTMP provided statistically better results
overall. DTMP also reduced thermal hypersensitivity significantly.
RNA-sequencing corroborated the complex effects of nerve injury on the
transcriptome. In addition, DTMP provided significantly more effective
modulation of genes associated with pain-related processes in returning their
expression toward levels observed in naïve, noninjured animals. DTMP provides a
more effective way of modulating the expression of genes involved in
pain-relevant biological processes associated with neuroglial interactions.
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Affiliation(s)
- Ricardo Vallejo
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Courtney A Kelley
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Ashim Gupta
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA.,Department of Research, South Texas Orthopaedic Research Institute, Laredo, TX, USA
| | - William J Smith
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Alejandro Vallejo
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA
| | - David L Cedeño
- Department of Basic Science, Millennium Pain Center, Bloomington, IL, USA.,Department of Psychology, Illinois Wesleyan University, Bloomington, IL, USA
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13
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Chung HH, Lee CT, Hu JM, Chou YC, Lin YW, Shih YL. NKX6.1 Represses Tumorigenesis, Metastasis, and Chemoresistance in Colorectal Cancer. Int J Mol Sci 2020; 21:ijms21145106. [PMID: 32707737 PMCID: PMC7404324 DOI: 10.3390/ijms21145106] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/14/2020] [Accepted: 07/16/2020] [Indexed: 12/28/2022] Open
Abstract
Accumulating evidence suggests that NKX6.1 (NK homeobox 1) plays a role in various types of cancer. In our previous studies, we identified NKX6.1 hypermethylation as a promising marker and demonstrated that the NKX6.1 gene functions as a metastasis suppressor through the epigenetic regulation of the epithelial-to-mesenchymal transition (EMT) in cervical cancer. More recently, we have demonstrated that NKX6.1 methylation is related to the chemotherapy response in colorectal cancer (CRC). Nevertheless, the biological function of NKX6.1 in the tumorigenesis of CRC remains unclear. In this study, we showed that NKX6.1 suppresses tumorigenic and metastatic ability both in vitro and in vivo. NKX6.1 represses cell invasion partly through the modulation of EMT. The overexpression of NKX6.1 enhances chemosensitivity in CRC cells. To further explore how NKX6.1 exerts its tumor-suppressive function, we used RNA sequencing technology for comprehensive analysis. The results showed that differentially expressed genes (DEGs) were mainly related to cell migration, response to drug, transcription factor activity, and growth factor activity, suggesting that these DEGs are involved in the function of NKX6.1 suppressing cancer invasion and metastasis. Our results demonstrated that NKX6.1 functions as a tumor suppressor partly by repressing EMT and enhancing chemosensitivity in CRC, making it a potential therapeutic target.
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Affiliation(s)
- Hsin-Hua Chung
- Graduate Institute of Medical Sciences, National Defense Medical Center, No.161, Sec.6, Minquan East Rd., Neihu District, Taipei 11490, Taiwan; (H.-H.C.); (J.-M.H.); (Y.-W.L.)
| | - Chun-Te Lee
- Division of Urological Surgery, Department of Surgery, Tri-Service General Hospital Songshan Branch, No.131, Jiankang Rd., Songshan District, Taipei 10581, Taiwan;
| | - Je-Ming Hu
- Graduate Institute of Medical Sciences, National Defense Medical Center, No.161, Sec.6, Minquan East Rd., Neihu District, Taipei 11490, Taiwan; (H.-H.C.); (J.-M.H.); (Y.-W.L.)
- Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, No.325, Sec.2, Chenggong Rd., Neihu District, Taipei 11490, Taiwan
| | - Yu-Ching Chou
- School of Public Health, National Defense Medical Center, No.161, Sec.6, Minquan East Rd., Neihu District, Taipei 11490, Taiwan;
| | - Ya-Wen Lin
- Graduate Institute of Medical Sciences, National Defense Medical Center, No.161, Sec.6, Minquan East Rd., Neihu District, Taipei 11490, Taiwan; (H.-H.C.); (J.-M.H.); (Y.-W.L.)
- Department and Graduate Institute of Microbiology and Immunology, National Defense Medical Center, No.161, Sec.6, Minquan East Rd., Neihu District, Taipei 11490, Taiwan
- Graduate Institute of Life Sciences, National Defense Medical Center, No.161, Sec.6, Minquan East Rd., Neihu District, Taipei 11490, Taiwan
| | - Yu-Lueng Shih
- Graduate Institute of Medical Sciences, National Defense Medical Center, No.161, Sec.6, Minquan East Rd., Neihu District, Taipei 11490, Taiwan; (H.-H.C.); (J.-M.H.); (Y.-W.L.)
- Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sec. 2, Chenggong Rd., Neihu District, Taipei 11490, Taiwan
- Correspondence: ; Tel./Fax: +886-2-87917654
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14
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Almatrafi A, Umair M, Eldardear A, Al-Luqmani M, Hashmi JA, Albalawi AM, Alfadhel M, Ramzan K, Basit S. A homozygous missense variant in the homeobox domain of the NKX6-2 results in progressive spastic ataxia type 8 associated with lower limb weakness and neurological manifestations. J Gene Med 2020; 22:e3196. [PMID: 32246862 DOI: 10.1002/jgm.3196] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Revised: 03/24/2020] [Accepted: 03/25/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Progressive spastic ataxia is a heterogeneous disorder characterized by cerebellar ataxia and limb spasticity associated with other severe neurological complications. Spastic ataxia is classified into pure and complex types, inherited in both an autosomal recessive and autosomal dominant manner. It is caused by pathogenic variants in at least eight different genes, including NKX6-2 (MIM 607063) located on chromosome 10q26.3. The present study aimed to identify the genetic variant(s) underlying progressive spastic ataxia and to establish the genotype-phenotype correlation. METHODS We collected a large consanguineous family having four affected individuals segregating progressive spastic ataxia in an autosomal recessive manner. To investigate the molecular cause of the disease, genomic DNA of three affected individuals underwent whole exome sequencing. RESULTS All of the affected individuals showed progressive clinical features such as spastic ataxia, lower limb weakness and other mild neurological abnormalities. Whole exome sequencing data were analyzed using different filters. Filtering of rare and shared homozygous variants revealed a novel homozygous missense variant (c.545C>T; p.Ala182Val) in a highly conserved homeobox domain of the NKX6-2 protein. CONCLUSIONS The findings of the present study add a novel variant to the NKX6-2 mutation spectrum and provide evidence that homozygous variants in the NKX6-2 cause progressive spastic ataxia associated with other abnormalities.
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Affiliation(s)
- Ahmad Almatrafi
- Department of Biology, College of Science, Taibah University, Almadinah Almunawwarah, Saudi Arabia
| | - Muhammad Umair
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia
| | - Amr Eldardear
- College of Medicine, Taibah University, Almadinah Almunawwarah, Saudi Arabia
| | - Majid Al-Luqmani
- College of Medicine, Taibah University, Almadinah Almunawwarah, Saudi Arabia
| | - Jamil A Hashmi
- Center for Genetics and Inherited Diseases, Taibah University, Medina, Saudi Arabia
| | - Alia M Albalawi
- Center for Genetics and Inherited Diseases, Taibah University, Medina, Saudi Arabia.,Department of Biology, College of Science, King Abdulaziz University Jeddah, Jeddah, Saudi Arabia
| | - Majid Alfadhel
- Medical Genomics Research Department, King Abdullah International Medical Research Center (KAIMRC), King Saud Bin Abdulaziz University for Health Sciences, Ministry of National Guard-Health Affairs (MNGHA), Riyadh, Saudi Arabia.,Division of Genetics, Department of Pediatrics, King Abdullah Specialized Children's Hospital (KASCH), King Abdulaziz Medical City, Riyadh, Saudi Arabia
| | - Khushnooda Ramzan
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Sulman Basit
- Center for Genetics and Inherited Diseases, Taibah University, Medina, Saudi Arabia
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15
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Expanding the clinical and neuroimaging features of NKX6-2-related hereditary spastic ataxia type 8. Eur J Med Genet 2020; 63:103868. [PMID: 32004679 DOI: 10.1016/j.ejmg.2020.103868] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 01/08/2020] [Accepted: 01/25/2020] [Indexed: 12/30/2022]
Abstract
Pathogenic variants in NKX6-2 gene causing autosomal recessive spastic ataxia type 8 with hypomyelinating leukodystrophy have been reported in few families around the world. In this study, we performed Whole Exome Sequencing and identified a novel missense variant, c.501C > G; p.(Phe167Leu), in two affected siblings with main manifestations of global developmental delay, motor regression, hypotonia, clonus in lower limbs and muscle bulk atrophy especially in the upper limbs, spasticity and contracture, scoliosis, hip dislocation, oculomotor apraxia, horizontal and vertical nystagmus. In addition, wrist and foot drop due to peripheral axonal neuropathy were observed in these patients as a new clinical finding and cerebellar white matter involvement in brain Magnetic Resonance Imaging (MRI) as new imaging finding. Therefore, we expanded the manifestations of NKX6-2-related disorders in this manuscript.
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16
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Toch M, Harris A, Schakman O, Kondratskaya E, Boulland JL, Dauguet N, Debrulle S, Baudouin C, Hidalgo-Figueroa M, Mu X, Gow A, Glover JC, Tissir F, Clotman F. Onecut-dependent Nkx6.2 transcription factor expression is required for proper formation and activity of spinal locomotor circuits. Sci Rep 2020; 10:996. [PMID: 31969659 PMCID: PMC6976625 DOI: 10.1038/s41598-020-57945-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 01/09/2020] [Indexed: 11/26/2022] Open
Abstract
In the developing spinal cord, Onecut transcription factors control the diversification of motor neurons into distinct neuronal subsets by ensuring the maintenance of Isl1 expression during differentiation. However, other genes downstream of the Onecut proteins and involved in motor neuron diversification have remained unidentified. In the present study, we generated conditional mutant embryos carrying specific inactivation of Onecut genes in the developing motor neurons, performed RNA-sequencing to identify factors downstream of Onecut proteins in this neuron population, and employed additional transgenic mouse models to assess the role of one specific Onecut-downstream target, the transcription factor Nkx6.2. Nkx6.2 expression was up-regulated in Onecut-deficient motor neurons, but strongly downregulated in Onecut-deficient V2a interneurons, indicating an opposite regulation of Nkx6.2 by Onecut factors in distinct spinal neuron populations. Nkx6.2-null embryos, neonates and adult mice exhibited alterations of locomotor pattern and spinal locomotor network activity, likely resulting from defective survival of a subset of limb-innervating motor neurons and abnormal migration of V2a interneurons. Taken together, our results indicate that Nkx6.2 regulates the development of spinal neuronal populations and the formation of the spinal locomotor circuits downstream of the Onecut transcription factors.
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Affiliation(s)
- Mathilde Toch
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Neural Differentiation, Brussels, Belgium
| | - Audrey Harris
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Neural Differentiation, Brussels, Belgium
| | - Olivier Schakman
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Cell Physiology, Brussels, Belgium
| | - Elena Kondratskaya
- Laboratory for Neural Development and Optical Recording (NDEVOR), Section for Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Jean-Luc Boulland
- Norwegian Center for Stem Cell Research, Department of Immunology and Transfusion Medicine, Oslo University Hospital, Oslo, Norway
| | - Nicolas Dauguet
- Université catholique de Louvain, de Duve Institute, Flow cytometry and cell sorting facility (CYTF), Brussels, Belgium
| | - Stéphanie Debrulle
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Neural Differentiation, Brussels, Belgium
| | - Charlotte Baudouin
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Neural Differentiation, Brussels, Belgium
| | - Maria Hidalgo-Figueroa
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Neural Differentiation, Brussels, Belgium.,CIBER de Salud Mental (CIBERSAM), Madrid, Spain.,University of Cadiz, Cadiz, Spain
| | - Xiuqian Mu
- Department of Ophthalmology/Ross Eye Institute, New York State Center of Excellence in Bioinformatics and Life Sciences, University at Buffalo, Buffalo, NY, 14203, USA
| | - Alexander Gow
- Wayne state University, Center for Molecular Medicine and Genetics, Carman and Ann Adams Department of Pediatrics, Department of Neurology, Detroit, Michigan, USA
| | - Joel C Glover
- Laboratory for Neural Development and Optical Recording (NDEVOR), Section for Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.,Norwegian Center for Stem Cell Research, Department of Immunology and Transfusion Medicine, Oslo University Hospital, Oslo, Norway
| | - Fadel Tissir
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Developmental Neurobiology, Brussels, Belgium
| | - Frédéric Clotman
- Université catholique de Louvain, Institute of Neuroscience, Laboratory of Neural Differentiation, Brussels, Belgium.
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17
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Baldi C, Bertoli-Avella AM, Al-Sannaa N, Alfadhel M, Al-Thihli K, Alameer S, Elmonairy AA, Al Shamsi AM, Abdelrahman HA, Al-Gazali L, Shawli A, Al-Hakami F, Yavuz H, Kandaswamy KK, Rolfs A, Brandau O, Bauer P. Expanding the clinical and genetic spectra of NKX6-2-related disorder. Clin Genet 2019; 93:1087-1092. [PMID: 29388673 DOI: 10.1111/cge.13221] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 01/26/2018] [Accepted: 01/26/2018] [Indexed: 11/29/2022]
Abstract
Hypomyelinating leukodystrophies (HLDs) affect the white matter of the central nervous system and manifest as neurological disorders. They are genetically heterogeneous. Very recently, biallelic variants in NKX6-2 have been suggested to cause a novel form of autosomal recessive HLD. Using whole-exome or whole-genome sequencing, we identified the previously reported c.196delC and c.487C>G variants in NKX6-2 in 3 and 2 unrelated index cases, respectively; the novel c.608G>A variant was identified in a sixth patient. All variants were homozygous in affected family members only. Our patients share a primary diagnosis of psychomotor delay, and they show spastic quadriparesis, nystagmus and hypotonia. Seizures and dysmorphic features (observed in 2 families each) represent an addition to the phenotype, while developmental regression (observed in 3 families) appears to be a notable and previously underestimated clinical feature. Our findings extend the clinical and mutational spectra associated with this novel form of HLD. Comparative analysis of our 10 patients and the 15 reported previously did, however, not reveal clear evidence for a genotype-phenotype correlation.
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Affiliation(s)
- C Baldi
- Centogene AG, Rostock, Germany
| | | | - N Al-Sannaa
- John Hopkins Aramco Health Care, Pediatric Services, Dhahran, Saudi Arabia
| | - M Alfadhel
- King Abdullah International Medical Research Centre, King Saud Bin Abdulaziz University for Health Sciences, Division of Genetics, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (NGHA), Riyadh, Saudi Arabia
| | - K Al-Thihli
- Department of Genetics, Sultan Qaboos University Hospital, Muscat, Oman
| | - S Alameer
- King Saud Bin Abdulaziz University for Health Sciences, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (NGHA), Jeddah, Saudi Arabia
| | | | - A M Al Shamsi
- Department of Paediatrics, Tawam Hospital, Al-Ain, United Arab Emirates
| | - H A Abdelrahman
- Department of Pathology, College of Medicine and Health Sciences, United Arab Emirates University Al Ain, Al-Ain, United Arab Emirates
| | - L Al-Gazali
- Department of Pediatrics, College of Medicine and Health Sciences, United Arab Emirates University Al Ain, United Arab Emirates
| | - A Shawli
- King Saud Bin Abdulaziz University for Health Sciences, Department of Pediatrics, King Abdulaziz Medical City, Ministry of National Guard Health Affairs (NGHA), Jeddah, Saudi Arabia.,Molecular Medicine Section, King Saud Bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia
| | - F Al-Hakami
- Molecular Medicine Section, King Saud Bin Abdulaziz University for Health Sciences, Jeddah, Saudi Arabia.,Molecular Medicine Section, King Abdulaziz Medical City-WR, Jeddah, Saudi Arabia
| | - H Yavuz
- Centogene AG, Rostock, Germany
| | | | - A Rolfs
- Centogene AG, Rostock, Germany.,Albrecht-Kossel-Institute for Neuroregeneration, Medical University Rostock, Rostock, Germany
| | | | - P Bauer
- Centogene AG, Rostock, Germany
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18
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Kim T, Valera E, Desplats P. Alterations in Striatal microRNA-mRNA Networks Contribute to Neuroinflammation in Multiple System Atrophy. Mol Neurobiol 2019; 56:7003-7021. [PMID: 30968343 DOI: 10.1007/s12035-019-1577-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 03/20/2019] [Indexed: 10/27/2022]
Abstract
Multiple systems atrophy (MSA) is a rare neurodegenerative disorder characterized by the accumulation of α-synuclein in glial cells and neurodegeneration in the striatum, substantia nigra, and cerebellum. Aberrant miRNA regulation has been associated with neurodegeneration, including alterations of specific miRNAs in brain tissue, serum, and cerebrospinal fluid from MSA patients. Still, a causal link between deregulation of miRNA networks and pathological changes in the transcriptome remains elusive. We profiled ~ 800 miRNAs in the striatum of MSA patients in comparison to healthy individuals to identify specific miRNAs altered in MSA. In addition, we performed a parallel screening of 700 transcripts associated with neurodegeneration to determine the impact of miRNA deregulation on the transcriptome. We identified 60 miRNAs with abnormal levels in MSA brains that are involved in extracellular matrix receptor interactions, prion disease, inflammation, ubiquitin-mediated proteolysis, and addiction pathways. Using the correlation between miRNA expression and the abundance of their known targets, miR-124-3p, miR-19a-3p, miR-27b-3p, and miR-29c-3p were identified as key regulators altered in MSA, mainly contributing to neuroinflammation. Finally, our study also uncovered a potential link between Alzheimer's disease (AD) and MSA pathologies that involves miRNAs and deregulation of BACE1. Our results provide a comprehensive appraisal of miRNA alterations in MSA and their effect on the striatal transcriptome, supporting that aberrant miRNA expression is highly correlated with changes in gene transcription associated with MSA neuropathology, in particular those driving inflammation, disrupting myelination, and potentially impacting α-synuclein accumulation via deregulation of autophagy and prion mechanisms.
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Affiliation(s)
- Taeyeon Kim
- Department of Neuroscience, University of California San Diego, 9500 Gilman Dr., MTF 344 MC0624, La Jolla, CA, 92093-0624, USA
| | - Elvira Valera
- Department of Neuroscience, University of California San Diego, 9500 Gilman Dr., MTF 344 MC0624, La Jolla, CA, 92093-0624, USA
| | - Paula Desplats
- Department of Neuroscience, University of California San Diego, 9500 Gilman Dr., MTF 344 MC0624, La Jolla, CA, 92093-0624, USA. .,Department of Pathology, University of California San Diego, 9500 Gilman Dr., MTF 344 MC0624, La Jolla, CA, 92093-0624, USA.
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19
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Manso C, Querol L, Lleixà C, Poncelet M, Mekaouche M, Vallat JM, Illa I, Devaux JJ. Anti-Neurofascin-155 IgG4 antibodies prevent paranodal complex formation in vivo. J Clin Invest 2019; 129:2222-2236. [PMID: 30869655 DOI: 10.1172/jci124694] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Neurofascin-155 (Nfasc155) is an essential glial cell adhesion molecule expressed in paranodal septate-like junctions of peripheral and central myelinated axons. The genetic deletion of Nfasc155 results in the loss of septate-like junctions and in conduction slowing. In humans, IgG4 antibodies against Nfasc155 are implicated in the pathogenesis of chronic inflammatory demyelinating polyneuropathy (CIDP). These antibodies are associated with an aggressive onset, a refractoriness to intravenous immunoglobulin, and tremor of possible cerebellar origin. Here, we examined the pathogenic effects of patient-derived anti-Nfasc155 IgG4. These antibodies did not inhibit the ability of Nfasc155 to complex with its axonal partners contactin-1/CASPR1 or induce target internalization. Passive transfer experiments revealed that IgG4 antibodies target Nfasc155 on Schwann cell surface, and diminished Nfasc155 protein levels and prevented paranodal complex formation in neonatal animals. In adult animals, chronic intrathecal infusions of antibodies also induced the loss of Nfasc155 and of paranodal specialization and resulted in conduction alterations in motor nerves. These results indicate that anti-Nfasc155 IgG4 perturb conduction in absence of demyelination, validating the existence of paranodopathy. These results also shed light on the mechanisms regulating protein insertion at paranodes.
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Affiliation(s)
- Constance Manso
- Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France.,Université de Bordeaux, Interdisciplinary Institute for Neuroscience, UMR5297, Bordeaux, France
| | - Luis Querol
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain.,Centro para la Investigación en Red en Enfermedades Raras (CIBERER), Madrid, Spain
| | - Cinta Lleixà
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain.,Centro para la Investigación en Red en Enfermedades Raras (CIBERER), Madrid, Spain
| | - Mallory Poncelet
- Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier University, Hopital Gui de Chauliac, Montpellier, France
| | - Mourad Mekaouche
- Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France.,Aix Marseille Université, CNRS, INP UMR7051, Marseille, France
| | - Jean-Michel Vallat
- National Reference Center for "rare peripheral neuropathies" and Department of Neurology, University Hospital, Limoges, France
| | - Isabel Illa
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain.,Centro para la Investigación en Red en Enfermedades Raras (CIBERER), Madrid, Spain
| | - Jérôme J Devaux
- Aix Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France.,Institute for Neurosciences of Montpellier, INSERM U1051, Montpellier University, Hopital Gui de Chauliac, Montpellier, France
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20
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Elbaz B, Popko B. Molecular Control of Oligodendrocyte Development. Trends Neurosci 2019; 42:263-277. [PMID: 30770136 DOI: 10.1016/j.tins.2019.01.002] [Citation(s) in RCA: 150] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/07/2019] [Accepted: 01/15/2019] [Indexed: 12/27/2022]
Abstract
Myelin is a multilayer lipid membrane structure that wraps and insulates axons, allowing for the efficient propagation of action potentials. During developmental myelination of the central nervous system (CNS), oligodendrocyte progenitor cells (OPCs) proliferate and migrate to their final destination, where they terminally differentiate into mature oligodendrocytes and myelinate axons. Lineage progression and terminal differentiation of oligodendrocyte lineage cells are under tight transcriptional and post-transcriptional control. The characterization of several recently identified regulatory factors that govern these processes, which are the focus of this review, has greatly increased our understanding of oligodendrocyte development and function. These insights are critical to facilitate efforts to enhance OPC differentiation in neurological disorders that disrupt CNS myelin.
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Affiliation(s)
- Benayahu Elbaz
- The Center for Peripheral Neuropathy, The Department of Neurology, University of Chicago, Chicago, IL, USA
| | - Brian Popko
- The Center for Peripheral Neuropathy, The Department of Neurology, University of Chicago, Chicago, IL, USA.
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21
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Graciarena M, Seiffe A, Nait-Oumesmar B, Depino AM. Hypomyelination and Oligodendroglial Alterations in a Mouse Model of Autism Spectrum Disorder. Front Cell Neurosci 2019; 12:517. [PMID: 30687009 PMCID: PMC6338056 DOI: 10.3389/fncel.2018.00517] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/12/2018] [Indexed: 01/22/2023] Open
Abstract
Autism spectrum disorders (ASDs) are neuropsychiatric diseases characterized by impaired social interaction, communication deficits, and repetitive and stereotyped behaviors. ASD etiology is unknown, and both genetic and environmental causes have been proposed. Different brain structures are believed to play a role in ASD-related behaviors, including medial prefrontal cortex (mPFC), hippocampus, piriform cortex (Pir), basolateral amygdala (BLA) and Cerebellum. Compelling evidence suggests a link between white matter modifications and ASD symptoms in patients. Besides, an hypomyelination of the mPFC has been associated in rodents to social behavior impairment, one of the main symptoms of ASD. However, a comparative analysis of myelination as well as oligodendroglial (OL)-lineage cells in brain regions associated to social behaviors in animal models of ASD has not been performed so far. Here, we investigated whether OL-lineage cells and myelination are altered in a murine model of ASD induced by the prenatal exposure to valproic acid (VPA). We showed an hypomyelination in the BLA and Pir of adult VPA-exposed mice. These results were accompanied by a decrease in the number of OL-lineage cells and of mature OLs in the Pir, in addition to the mPFC, where myelination presented no alterations. In these regions the number of oligodendrocyte progenitors (OPCs) remained unaltered. Likewise, activation of histone deacetylases (HDACs) on OL-lineage cells in adulthood showed no differences. Overall, our results reveal OL-lineage cell alterations and hypomyelination as neuropathological hallmarks of ASD that have been overlooked so far.
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Affiliation(s)
- Mariana Graciarena
- Brain and Spine Institute, Inserm U1127, Sorbonne Universités/Université Pierre & Marie Curie UMRS 1127, CNRS UMR 7225, Paris, France.,Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Araceli Seiffe
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Brahim Nait-Oumesmar
- Brain and Spine Institute, Inserm U1127, Sorbonne Universités/Université Pierre & Marie Curie UMRS 1127, CNRS UMR 7225, Paris, France
| | - Amaicha M Depino
- Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.,Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE), CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
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22
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Chang SY, Kuo CC, Wu CC, Hsiao CW, Hu JM, Hsu CH, Chou YC, Shih YL, Lin YW. NKX6.1 hypermethylation predicts the outcome of stage II colorectal cancer patients undergoing chemotherapy. Genes Chromosomes Cancer 2018; 57:268-277. [PMID: 29363224 DOI: 10.1002/gcc.22529] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 01/19/2018] [Accepted: 01/19/2018] [Indexed: 12/16/2022] Open
Abstract
Colorectal cancer (CRC) is a common malignancy worldwide. CRC patients in the same stage often present with dramatically different clinical scenarios. Thus, robust prognostic biomarkers are urgently needed to guide therapies and improve treatment outcomes. The NKX6.1 gene has been identified as a hypermethylation marker in cervical cancer, functioning as a metastasis suppressor by regulating epithelial-mesenchymal transition. Here, we investigated whether hypermethylation of NKX6.1 might be a prognostic biomarker for CRC. By analyzing the methylation and expression of NKX6.1 in CRC tissues and CRC cell lines. We quantitatively examined the NKX6.1 methylation levels in 151 pairs of CRC tissues by using methylation-specific polymerase chain reaction analysis and found that NKX6.1 was hypermethylated in 35 of 151 CRC tissues (23%). NKX6.1 gene expression was inversely correlated with the DNA methylation level in CRC cell lines in vitro. Then, we analyzed the association of NKX6.1 methylation with clinical characteristics of these CRC patients. Our data demonstrated that patients with NKX6.1 methylation presented poorer 5-year overall survival (P = 0.0167) and disease-free survival (P = 0.0083) than patients without NKX6.1 methylation after receiving adjuvant chemotherapy. Most importantly, these data revealed that stage II CRC patients with NKX6.1 methylation had poorer 5-year disease-free survival (P = 0.0322) than patients without NKX6.1 methylation after adjuvant chemotherapy. Our results demonstrate that methylation of NKX6.1 is a novel prognostic biomarker in CRC and that it may be used as a predictor of the response to chemotherapy.
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Affiliation(s)
- Sou-Yi Chang
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China.,Division of Hematology & Oncology, Department of Internal Medicine, Taipei Tzu Chi Hospital, Taipei, Taiwan, Republic of China
| | - Chih-Chi Kuo
- Teaching and Research Office, Tri-Service General Hospital Songshan Branch, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Chang-Chieh Wu
- Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Cheng-Wen Hsiao
- Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Je-Ming Hu
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China.,Division of Colorectal Surgery, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Chih-Hsiung Hsu
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China.,School of Medicine, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Yu-Ching Chou
- School of Public Health, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Yu-Lueng Shih
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China.,Division of Gastroenterology, Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, Republic of China
| | - Ya-Wen Lin
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China.,Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan, Republic of China.,Department and Graduate Institute of Microbiology and Immunology, National Defense Medical Center, Taipei, Taiwan, Republic of China
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23
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Pentón-Rol G, Marín-Prida J, Falcón-Cama V. C-Phycocyanin and Phycocyanobilin as Remyelination Therapies for Enhancing Recovery in Multiple Sclerosis and Ischemic Stroke: A Preclinical Perspective. Behav Sci (Basel) 2018; 8:bs8010015. [PMID: 29346320 PMCID: PMC5791033 DOI: 10.3390/bs8010015] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 01/03/2018] [Accepted: 01/16/2018] [Indexed: 12/21/2022] Open
Abstract
Myelin loss has a crucial impact on behavior disabilities associated to Multiple Sclerosis (MS) and Ischemic Stroke (IS). Although several MS therapies are approved, none of them promote remyelination in patients, limiting their ability for chronic recovery. With no available therapeutic options, enhanced demyelination in stroke survivors is correlated with a poorer behavioral recovery. Here, we show the experimental findings of our group and others supporting the remyelinating effects of C-Phycocyanin (C-PC), the main biliprotein of Spirulina platensis and its linked tetrapyrrole Phycocyanobilin (PCB), in models of these illnesses. C-PC promoted white matter regeneration in rats and mice affected by experimental autoimmune encephalomyelitis. Electron microscopy analysis in cerebral cortex from ischemic rats revealed a potent remyelinating action of PCB treatment after stroke. Among others biological processes, we discussed the role of regulatory T cell induction, the control of oxidative stress and pro-inflammatory mediators, gene expression modulation and COX-2 inhibition as potential mechanisms involved in the C-PC and PCB effects on the recruitment, differentiation and maturation of oligodendrocyte precursor cells in demyelinated lesions. The assembled evidence supports the implementation of clinical trials to demonstrate the recovery effects of C-PC and PCB in these diseases.
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Affiliation(s)
- Giselle Pentón-Rol
- Center for Genetic Engineering and Biotechnology (CIGB), Ave. 31 e/158 y 190, Cubanacan, P.O. Box 6162, Playa, Havana 10600, Cuba.
| | - Javier Marín-Prida
- Center for Research and Biological Evaluations (CEIEB), Institute of Pharmacy and Food, University of Havana, Ave. 23 e/214 y 222, La Lisa, PO Box 430, Havana 13600, Cuba.
| | - Viviana Falcón-Cama
- Center for Genetic Engineering and Biotechnology (CIGB), Ave. 31 e/158 y 190, Cubanacan, P.O. Box 6162, Playa, Havana 10600, Cuba.
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24
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Dorboz I, Aiello C, Simons C, Stone RT, Niceta M, Elmaleh M, Abuawad M, Doummar D, Bruselles A, Wolf NI, Travaglini L, Boespflug-Tanguy O, Tartaglia M, Vanderver A, Rodriguez D, Bertini E. Biallelic mutations in the homeodomain of NKX6-2 underlie a severe hypomyelinating leukodystrophy. Brain 2017; 140:2550-2556. [PMID: 28969374 DOI: 10.1093/brain/awx207] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Accepted: 07/04/2017] [Indexed: 11/14/2022] Open
Abstract
Hypomyelinating leukodystrophies are genetically heterogeneous disorders with overlapping clinical and neuroimaging features reflecting variable abnormalities in myelin formation. We report on the identification of biallelic inactivating mutations in NKX6-2, a gene encoding a transcription factor regulating multiple developmental processes with a main role in oligodendrocyte differentiation and regulation of myelin-specific gene expression, as the cause underlying a previously unrecognized severe variant of hypomyelinating leukodystrophy. Five affected subjects (three unrelated families) were documented to share biallelic inactivating mutations affecting the NKX6-2 homeobox domain. A trio-based whole exome sequencing analysis in the first family detected a homozygous frameshift change [c.606delinsTA; p.(Lys202Asnfs*?)]. In the second family, homozygosity mapping coupled to whole exome sequencing identified a homozygous nucleotide substitution (c.565G>T) introducing a premature stop codon (p.Glu189*). In the third family, whole exome sequencing established compound heterozygosity for a non-conservative missense change affecting a key residue participating in DNA binding (c.599G>A; p.Arg200Gln) and a nonsense substitution (c.589C>T; p.Gln197*), in both affected siblings. The clinical presentation was homogeneous, with four subjects having severe motor delays, nystagmus and absent head control, and one individual showing gross motor delay at the age of 6 months. All exhibited neuroimaging that was consistent with hypomyelination. These findings define a novel, severe form of leukodystrophy caused by impaired NKX6-2 function.
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Affiliation(s)
- Imen Dorboz
- INSERM UMR 1141, DHU PROTECT, Paris Diderot University, Sorbonne Paris Cité, France, Paris 06, Paris, France
| | - Chiara Aiello
- Unit of Neuromuscular and Neurodegnerative Disorders, Laboratory of Molecular Medicine, Bambino Gesu' Children's Hospital, Rome, Italy.,Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Cas Simons
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
| | - Robert Thompson Stone
- Pediatric Multiple Sclerosis and Neuroimmunology Program, University of Rochester, Rochester, USA
| | - Marcello Niceta
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Monique Elmaleh
- AP-HP, Department of Child Radiology, Robert Debré Hospital, Paris, France
| | - Mohammad Abuawad
- INSERM UMR 1141, DHU PROTECT, Paris Diderot University, Sorbonne Paris Cité, France, Paris 06, Paris, France
| | - Diane Doummar
- APHP, Department of Neuropediatrics, National Reference Center for Neurogenetic Disorders, Hôpital Armand-Trousseau, GHUEP, Paris, France.,GRC ConCer-LD, Sorbonne Universités, UPMC Université, Paris, France
| | - Alessandro Bruselles
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, Rome, Italy
| | - Nicole I Wolf
- Department of Child Neurology, VU University Medical Center, Amsterdam, and Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Lorena Travaglini
- Unit of Neuromuscular and Neurodegnerative Disorders, Laboratory of Molecular Medicine, Bambino Gesu' Children's Hospital, Rome, Italy.,Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Odile Boespflug-Tanguy
- INSERM UMR 1141, DHU PROTECT, Paris Diderot University, Sorbonne Paris Cité, France, Paris 06, Paris, France.,AP-HP, Department of Neuropediatrics and Metabolic Diseases, National Reference Center for Leukodystrophies, Robert Debré Hospital, Paris, France
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Adeline Vanderver
- Division of Neurology, Children's Hospital of Philadelphia, USA.,Department of Neurology, University of Pennsylvania, USA
| | - Diana Rodriguez
- APHP, Department of Neuropediatrics, National Reference Center for Neurogenetic Disorders, Hôpital Armand-Trousseau, GHUEP, Paris, France.,GRC ConCer-LD, Sorbonne Universités, UPMC Université, Paris, France
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegnerative Disorders, Laboratory of Molecular Medicine, Bambino Gesu' Children's Hospital, Rome, Italy.,Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
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25
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Overexpression of CHOP in Myelinating Cells Does Not Confer a Significant Phenotype under Normal or Metabolic Stress Conditions. J Neurosci 2017; 36:6803-19. [PMID: 27335410 DOI: 10.1523/jneurosci.1118-15.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 05/23/2016] [Indexed: 01/22/2023] Open
Abstract
UNLABELLED The PKR-like endoplasmic reticulum kinase (PERK) pathway of the unfolded protein response (UPR) is protective against toxic accumulations of misfolded proteins in the endoplasmic reticulum, but is thought to drive cell death via the transcription factor, CHOP. However, in many cell types, CHOP is an obligate step in the PERK pathway, which frames the conundrum of a prosurvival pathway that kills cells. Our laboratory and others have previously demonstrated the prosurvival activity of the PERK pathway in oligodendrocytes. In the current study, we constitutively overexpress CHOP in myelinating cells during development and into adulthood under normal or UPR conditions. We show that this transcription factor does not drive apoptosis. Indeed, we observe no detriment in mice at multiple levels from single cells to mouse behavior and life span. In light of these data and other studies, we reinterpret PERK pathway function in the context of a stochastic vulnerability model, which governs the likelihood that cells undergo cell death upon cessation of UPR protection and while attempting to restore homeostasis. SIGNIFICANCE STATEMENT Herein, we tackle the biggest controversy in the UPR literature: the function of the transcription factor CHOP as a protective or a prodeath factor. This manuscript is timely in light of the 2014 Lasker award for the UPR. Our in vivo data show that CHOP is not a prodeath protein, and we demonstrate that myelinating glial cells function normally in the presence of high CHOP expression from development to adulthood. Further, we propose a simplified view of UPR-mediated cell death after CHOP induction. We anticipate our work may turn the tide of the dogmatic view of CHOP and cause a reinvestigation of its function in different cell types. Accordingly, we believe our work will be a watershed for the UPR field.
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26
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Chelban V, Patel N, Vandrovcova J, Zanetti MN, Lynch DS, Ryten M, Botía JA, Bello O, Tribollet E, Efthymiou S, Davagnanam I, Bashiri FA, Wood NW, Rothman JE, Alkuraya FS, Houlden H, Houlden H. Mutations in NKX6-2 Cause Progressive Spastic Ataxia and Hypomyelination. Am J Hum Genet 2017; 100:969-977. [PMID: 28575651 PMCID: PMC5473715 DOI: 10.1016/j.ajhg.2017.05.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 05/08/2017] [Indexed: 11/29/2022] Open
Abstract
Progressive limb spasticity and cerebellar ataxia are frequently found together in clinical practice and form a heterogeneous group of degenerative disorders that are classified either as pure spastic ataxia or as complex spastic ataxia with additional neurological signs. Inheritance is either autosomal dominant or autosomal recessive. Hypomyelinating features on MRI are sometimes seen with spastic ataxia, but this is usually mild in adults and severe and life limiting in children. We report seven individuals with an early-onset spastic-ataxia phenotype. The individuals come from three families of different ethnic backgrounds. Affected members of two families had childhood onset disease with very slow progression. They are still alive in their 30s and 40s and show predominant ataxia and cerebellar atrophy features on imaging. Affected members of the third family had a similar but earlier-onset presentation associated with brain hypomyelination. Using a combination of homozygozity mapping and exome sequencing, we mapped this phenotype to deleterious nonsense or homeobox domain missense mutations in NKX6-2. NKX6-2 encodes a transcriptional repressor with early high general and late focused CNS expression. Deficiency of its mouse ortholog results in widespread hypomyelination in the brain and optic nerve, as well as in poor motor coordination in a pattern consistent with the observed human phenotype. In-silico analysis of human brain expression and network data provides evidence that NKX6-2 is involved in oligodendrocyte maturation and might act within the same pathways of genes already associated with central hypomyelination. Our results support a non-redundant developmental role of NKX6-2 in humans and imply that NKX6-2 mutations should be considered in the differential diagnosis of spastic ataxia and hypomyelination.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Henry Houlden
- Department of Molecular Neuroscience, University College London, London WC1N 3BG, UK; Neurogenetics Laboratory, The National Hospital for Neurology and Neurosurgery, London WC1N 3BG, UK
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27
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Manso C, Querol L, Mekaouche M, Illa I, Devaux JJ. Contactin-1 IgG4 antibodies cause paranode dismantling and conduction defects. Brain 2016; 139:1700-12. [PMID: 27017186 DOI: 10.1093/brain/aww062] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 01/28/2016] [Indexed: 12/20/2022] Open
Abstract
Paranodal axoglial junctions formed by the association of contactin-1, contactin-associated protein 1, and neurofascin-155, play important functions in nerve impulse propagation along myelinated axons. Autoantibodies to contactin-1 and neurofascin-155 define chronic inflammatory demyelinating polyradiculoneuropathy subsets of patients with specific clinical features. These autoantibodies are mostly of the IgG4 isotype, but their pathogenicity has not been proven. Here, we investigated the mechanisms how IgG subclasses to contactin-1 affect conduction. We show that purified anti-contactin-1 IgG1 and IgG4 bind to paranodes. To determine whether these isotypes can pass the paranodal barrier, we incubated isolated sciatic nerves with the purified antibody or performed intraneural injections. We found that IgG4 diffused into the paranodal regions in vitro or after intraneural injections. IgG4 infiltration was slow and progressive. In 24 h, IgG4 accessed the paranode borders near the nodal lumen, and completely fill the paranodal segments by 3 days. By contrast, control IgG, anti-contactin-1 IgG1, or even anti-contactin-associated-protein-2 IgG4 did not pass the paranodal barrier. To determine whether chronic exposure to these antibodies is pathogenic, we passively transferred anti-contactin-1 IgG1 and IgG4 into Lewis rats immunized with P2 peptide. IgG4 to contactin-1, but not IgG1, induced progressive clinical deteriorations combined with gait ataxia. No demyelination, axonal degeneration, or immune infiltration were observed. Instead, these animals presented a selective loss of the paranodal specialization in motor neurons characterized by the disappearance of the contactin-associated protein 1/contactin-1/neurofascin-155 complex at paranodes. Paranode destruction did not affect nodal specialization, but resulted in a moderate node lengthening. The sensory nerves and dorsal root ganglion were not affected in these animals. Electrophysiological examination further supported these results and revealed strong nerve activity loss affecting predominantly small diameter or slow conducting motor axons. These deficits partly matched with those found in patients: proximal motor involvement, gait ataxia, and a demyelinating neuropathy that showed early axonal features. The animal model thus seemed to replicate the early deteriorations in these patients and pointed out that paranodal loss in mature fibres results in conduction defects, but not conduction slowing. Our findings indicate that IgG4 directed against contactin-1 are pathogenic and are reliable biomarkers of a specific subset of chronic inflammatory demyelinating polyneuropathy patients. These antibodies appear to loosen the paranodal barrier, thereby favouring antibody progression and causing paranodal collapse.
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Affiliation(s)
- Constance Manso
- Aix-Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Luis Querol
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Mourad Mekaouche
- Aix-Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
| | - Isabel Illa
- Neuromuscular Diseases Unit, Hospital de la Santa Creu i Sant Pau, Universitat Autónoma de Barcelona, Barcelona, Spain
| | - Jérôme J Devaux
- Aix-Marseille Université, CNRS, CRN2M-UMR7286, Marseille, France
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28
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Zhu Q, Tan Z, Zhao S, Huang H, Zhao X, Hu X, Zhang Y, Shields CB, Uetani N, Qiu M. Developmental expression and function analysis of protein tyrosine phosphatase receptor type D in oligodendrocyte myelination. Neuroscience 2015; 308:106-14. [PMID: 26341907 PMCID: PMC4600676 DOI: 10.1016/j.neuroscience.2015.08.062] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 08/13/2015] [Accepted: 08/24/2015] [Indexed: 11/22/2022]
Abstract
Receptor protein tyrosine phosphatases (RPTPs) are extensively expressed in the central nervous system (CNS), and have distinct spatial and temporal patterns in different cell types during development. Previous studies have demonstrated possible roles for RPTPs in axon outgrowth, guidance, and synaptogenesis. In the present study, our results revealed that protein tyrosine phosphatase, receptor type D (PTPRD) was initially expressed in mature neurons in embryonic CNS, and later in oligodendroglial cells at postnatal stages when oligodendrocytes undergo active axonal myelination process. In PTPRD mutants, oligodendrocyte differentiation was normal and a transient myelination delay occurred at early postnatal stages, indicating the contribution of PTPRD to the initiation of axonal myelination. Our results also showed that the remyelination process was not affected in the absence of PTPRD function after a cuprizone-induced demyelination in adult animals.
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Affiliation(s)
- Q Zhu
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA
| | - Z Tan
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA; Institute of Developmental and Regenerative Biology, Zhejiang Key Lab of Organ Development and Regeneration, College of Life Sciences, Hangzhou Normal University, China
| | - S Zhao
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA
| | - H Huang
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA; Institute of Developmental and Regenerative Biology, Zhejiang Key Lab of Organ Development and Regeneration, College of Life Sciences, Hangzhou Normal University, China
| | - X Zhao
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA; Institute of Developmental and Regenerative Biology, Zhejiang Key Lab of Organ Development and Regeneration, College of Life Sciences, Hangzhou Normal University, China
| | - X Hu
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA
| | - Y Zhang
- Norton Neuroscience Institute, Norton Healthcare, Louisville, KY 40202, USA
| | - C B Shields
- Norton Neuroscience Institute, Norton Healthcare, Louisville, KY 40202, USA
| | - N Uetani
- McGill Cancer Centre and Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - M Qiu
- Department of Anatomical Sciences and Neurobiology, University of Louisville, Louisville, KY 40292, USA; Institute of Developmental and Regenerative Biology, Zhejiang Key Lab of Organ Development and Regeneration, College of Life Sciences, Hangzhou Normal University, China.
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29
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Küspert M, Wegner M. SomethiNG 2 talk about-Transcriptional regulation in embryonic and adult oligodendrocyte precursors. Brain Res 2015; 1638:167-182. [PMID: 26232072 DOI: 10.1016/j.brainres.2015.07.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 07/14/2015] [Accepted: 07/18/2015] [Indexed: 12/26/2022]
Abstract
Glial cells that express the chondroitin sulfate proteoglycan NG2 represent an inherently heterogeneous population. These so-called NG2-glia are present during development and in the adult CNS, where they are referred to as embryonic oligodendrocyte precursors and adult NG2-glia, respectively. They give rise to myelinating oligodendrocytes at all times of life. Over the years much has been learnt about the transcriptional network in embryonic oligodendrocyte precursors, and several transcription factors from the HLH, HMG-domain, zinc finger and homeodomain protein families have been identified as main constituents. Much less is known about the corresponding network in adult NG2-glia. Here we summarize and discuss current knowledge on functions of each of these transcription factor families in NG2-glia, and where possible compare transcriptional regulation in embryonic oligodendrocyte precursors and adult NG2-glia. This article is part of a Special Issue entitled SI:NG2-glia (Invited only).
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Affiliation(s)
- Melanie Küspert
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Fahrstrasse 17, Erlangen D-91054, Germany.
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Fahrstrasse 17, Erlangen D-91054, Germany.
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30
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Emery B, Lu QR. Transcriptional and Epigenetic Regulation of Oligodendrocyte Development and Myelination in the Central Nervous System. Cold Spring Harb Perspect Biol 2015; 7:a020461. [PMID: 26134004 DOI: 10.1101/cshperspect.a020461] [Citation(s) in RCA: 183] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Central nervous system (CNS) myelination by oligodendrocytes (OLs) is a highly orchestrated process involving well-defined steps from specification of neural stem cells into proliferative OL precursors followed by terminal differentiation and subsequent maturation of these precursors into myelinating OLs. These specification and differentiation processes are mediated by profound global changes in gene expression, which are in turn subject to control by both extracellular signals and regulatory networks intrinsic to the OL lineage. Recently, basic transcriptional mechanisms that control OL differentiation and myelination have begun to be elucidated at the molecular level and on a genome scale. The interplay between transcription factors activated by differentiation-promoting signals and master regulators likely exerts a crucial role in controlling stage-specific progression of the OL lineage. In this review, we describe the current state of knowledge regarding the transcription factors and the epigenetic programs including histone methylation, acetylation, chromatin remodeling, micro-RNAs, and noncoding RNAs that regulate development of OLs and myelination.
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Affiliation(s)
- Ben Emery
- Department of Anatomy and Neurobiology, University of Melbourne, Victoria 3010, Australia Florey Institute of Neuroscience and Mental Health, University of Melbourne, Victoria 3010, Australia
| | - Q Richard Lu
- Department of Pediatrics, Cancer and Blood Diseases Institute, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229
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31
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Mitew S, Hay C, Peckham H, Xiao J, Koenning M, Emery B. Mechanisms regulating the development of oligodendrocytes and central nervous system myelin. Neuroscience 2014; 276:29-47. [DOI: 10.1016/j.neuroscience.2013.11.029] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 11/13/2013] [Accepted: 11/14/2013] [Indexed: 12/29/2022]
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Volman V, Ng LJ. Primary paranode demyelination modulates slowly developing axonal depolarization in a model of axonal injury. J Comput Neurosci 2014; 37:439-57. [PMID: 24986633 DOI: 10.1007/s10827-014-0515-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 06/18/2014] [Accepted: 06/20/2014] [Indexed: 01/12/2023]
Abstract
Neurological sequelae of mild traumatic brain injury are associated with the damage to white matter myelinated axons. In vitro models of axonal injury suggest that the progression to pathological ruin is initiated by the mechanical damage to tetrodotoxin-sensitive voltage-gated sodium channels that breaches the ion balance through alteration in kinetic properties of these channels. In myelinated axons, sodium channels are concentrated at nodes of Ranvier, making these sites vulnerable to mechanical injury. Nodal damage can also be inflicted by injury-induced partial demyelination of paranode/juxtaparanode compartments that flank the nodes and contain high density of voltage-gated potassium channels. Demyelination-induced potassium deregulation can further aggravate axonal damage; however, the role of paranode/juxtaparanode demyelination in immediate impairment of axonal function, and its contribution to the development of axonal depolarization remain elusive. A biophysically realistic computational model of myelinated axon that incorporates ion exchange mechanisms and nodal/paranodal/juxtaparanodal organization was developed and used to study the impact of injury-induced demyelination on axonal signal transmission. Injured axons showed alterations in signal propagation that were consistent with the experimental findings and with the notion of reduced axonal excitability immediately post trauma. Injury-induced demyelination strongly modulated the rate of axonal depolarization, suggesting that trauma-induced damage to paranode myelin can affect axonal transition to degradation. Results of these studies clarify the contribution of paranode demyelination to immediate post trauma alterations in axonal function and suggest that partial paranode demyelination should be considered as another "injury parameter" that is likely to determine the stability of axonal function.
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Affiliation(s)
- Vladislav Volman
- L-3 Applied Technologies/Simulation, Engineering, & Testing, 10770 Wateridge Circle, Suite 200, San Diego, CA, 92121, USA,
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Alsanie WF, Niclis JC, Petratos S. Human embryonic stem cell-derived oligodendrocytes: protocols and perspectives. Stem Cells Dev 2013; 22:2459-76. [PMID: 23621561 PMCID: PMC3760471 DOI: 10.1089/scd.2012.0520] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Accepted: 04/26/2013] [Indexed: 12/19/2022] Open
Abstract
Oligodendrocytes play a fundamental supportive role in the mammalian central nervous system (CNS) as the myelinating-glial cells. Disruption of fast axonal transport mechanisms can occur as a consequence of mature oligodendrocyte loss following spinal cord injury, stroke, or due to neuroinflammatory conditions, such as multiple sclerosis. As a result of the limited remyelination ability in the CNS after injury or disease, human embryonic stem cells (hESCs) may prove to be a promising option for the generation and replacement of mature oligodendrocytes. Moreover, hESC-derived oligodendrocytes may be experimentally utilized to unravel fundamental questions of oligodendrocyte development, along with their therapeutic potential through growth factor support of axons and neurons. However, an intensive characterization and examination of hESC-derived oligodendrocytes prior to preclinical or clinical trials is required to facilitate greater success in their integration following cellular replacement therapy (CRT). Currently, the protocols utilized to derive oligodendrocytes from hESCs consist of significant variations in culture style, time-length of differentiation, and the provision of growth factors in culture. Further, these differing protocols also report disparate patterns in the expression of oligodendroglial markers by these derived oligodendrocytes, throughout their differentiation in culture. We have comprehensively reviewed the published protocols describing the derivation of oligodendrocytes from hESCs and the studies that examine their efficacy to remyelinate, along with the fundamental issues of their safety as a viable CRT. Additionally, this review will highlight particular issues of concern and suggestions for troubleshooting to provide investigators critical information for the future improvement of establishing in vitro hESC-derived oligodendrocytes.
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Affiliation(s)
- Walaa F Alsanie
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Australia.
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Maheras KJ, Gow A. Increased anesthesia time using 2,2,2-tribromoethanol-chloral hydrate with low impact on mouse psychoacoustics. J Neurosci Methods 2013; 219:61-9. [PMID: 23856212 DOI: 10.1016/j.jneumeth.2013.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 06/11/2013] [Accepted: 07/04/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND To examine psychoacoustics in mice, we have used 2,2,2-tribromoethanol anesthesia in multiple studies. We find this drug is fast-acting and yields consistent results, providing 25-30 min of anesthesia. Our recent studies in binaural hearing prompted development of a regimen to anesthesia time to 1h. We tested a novel cocktail using 2,2,2-tribromoethanol coupled with low dose chloral hydrate to extend the effective anesthesia time. NEW METHOD We have established an intraperitoneal dosing regimen for 2,2,2-tribromoethanol-chloral hydrate anesthesia. To measure efficacy of the drug cocktail, we measured auditory brainstem responses (ABRs) at 10 min intervals to determine the effects on hearing thresholds and wave amplitudes and latencies. RESULTS This novel drug combination increases effective anesthesia to 1h. ABR Wave I amplitudes, but not latencies, are marginally suppressed. Additionally, amplitudes of the centrally derived Waves III and V show significant inter-animal variability that is independent of stimulus intensity. These data argue against the systematic suppression of ABRs by the drug cocktail. COMPARISON WITH EXISTING METHODS Using 2,2,2-tribromoethanol-chloral hydrate combination in psychoacoustic studies has several advantages over other drug cocktails, the most important being preservation of latencies from centrally- and peripherally-derived ABR waves. In addition, hearing thresholds are unchanged and wave amplitudes are not systematically suppressed, although they exhibit greater variability. CONCLUSIONS We demonstrate that 375 mg/kg 2,2,2-tribromoethanol followed after 5 min by 200mg/kg chloral hydrate provides an anesthesia time of 60 min, has negligible effects on ABR wave latencies and thresholds and non-systematic effects on amplitudes.
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Affiliation(s)
- Kathleen J Maheras
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, MI 48201, USA
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Zhu Y, Li H, Li K, Zhao X, An T, Hu X, Park J, Huang H, Bin Y, Qiang B, Yuan J, Peng X, Qiu M. Necl-4/SynCAM-4 is expressed in myelinating oligodendrocytes but not required for axonal myelination. PLoS One 2013; 8:e64264. [PMID: 23700466 PMCID: PMC3659047 DOI: 10.1371/journal.pone.0064264] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 04/10/2013] [Indexed: 12/04/2022] Open
Abstract
The timing and progression of axonal myelination are precisely controlled by intercellular interactions between neurons and glia in development. Previous in vitro studies demonstrated that Nectin like 4 (Necl-4, also known as cell adhesion molecule Cadm-4 or SynCAM-4) plays an essential role in axonal myelination by Schwann cells in the peripheral nervous system (PNS). However, the role of Necl-4 protein in axonal myelination in the developing central nervous system (CNS) has remained unknown. In this study, we discovered upregulation of Necl-4 expression in mature oligodendrocytes at perinatal stages when axons undergo active myelination. We generated Necl4 gene knockout mice, but found that disruption of Necl-4 gene did not affect oligodendrocyte differentiation and myelin formation in the CNS. Surprisingly, disruption of Necl-4 had no significant effect on axonal myelination in the PNS either. Therefore, our results demonstrated that Necl-4 is dispensable for axonal myelination in the developing nervous system.
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Affiliation(s)
- Ying Zhu
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Hong Li
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Kehan Li
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaofeng Zhao
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
- Institute of Developmental and Regenerative Biology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Tai An
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xuemei Hu
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Jinsil Park
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Hao Huang
- Institute of Developmental and Regenerative Biology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Yin Bin
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Boqin Qiang
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jiangang Yuan
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiaozhong Peng
- The National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- * E-mail: (XP); (MQ)
| | - Mengsheng Qiu
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
- Institute of Developmental and Regenerative Biology, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
- * E-mail: (XP); (MQ)
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Buttermore ED, Thaxton CL, Bhat MA. Organization and maintenance of molecular domains in myelinated axons. J Neurosci Res 2013; 91:603-22. [PMID: 23404451 DOI: 10.1002/jnr.23197] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 09/19/2012] [Accepted: 11/28/2012] [Indexed: 01/17/2023]
Abstract
Over a century ago, Ramon y Cajal first proposed the idea of a directionality involved in nerve conduction and neuronal communication. Decades later, it was discovered that myelin, produced by glial cells, insulated axons with periodic breaks where nodes of Ranvier (nodes) form to allow for saltatory conduction. In the peripheral nervous system (PNS), Schwann cells are the glia that can either individually myelinate the axon from one neuron or ensheath axons of many neurons. In the central nervous system (CNS), oligodendrocytes are the glia that myelinate axons from different neurons. Review of more recent studies revealed that this myelination created polarized domains adjacent to the nodes. However, the molecular mechanisms responsible for the organization of axonal domains are only now beginning to be elucidated. The molecular domains in myelinated axons include the axon initial segment (AIS), where various ion channels are clustered and action potentials are initiated; the node, where sodium channels are clustered and action potentials are propagated; the paranode, where myelin loops contact with the axolemma; the juxtaparanode (JXP), where delayed-rectifier potassium channels are clustered; and the internode, where myelin is compactly wrapped. Each domain contains a unique subset of proteins critical for the domain's function. However, the roles of these proteins in axonal domain organization are not fully understood. In this review, we highlight recent advances on the molecular nature and functions of some of the components of each axonal domain and their roles in axonal domain organization and maintenance for proper neuronal communication.
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Affiliation(s)
- Elizabeth D Buttermore
- Curriculum in Neurobiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina, USA
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37
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Devaux JJ. Antibodies to gliomedin cause peripheral demyelinating neuropathy and the dismantling of the nodes of Ranvier. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 181:1402-13. [PMID: 22885108 DOI: 10.1016/j.ajpath.2012.06.034] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 06/15/2012] [Accepted: 06/20/2012] [Indexed: 11/18/2022]
Abstract
Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) are conditions that affect peripheral nerves. The mechanisms that underlie demyelination in these neuropathies are unknown. Recently, we demonstrated that the node of Ranvier is the primary site of the immune attack in patients with GBS and CIDP. In particular, GBS patients have antibodies against gliomedin and neurofascin, two adhesion molecules that play a crucial role in the formation of nodes of Ranvier. We demonstrate that immunity toward gliomedin, but not neurofascin, induced a progressive neuropathy in Lewis rats characterized by conduction defects and demyelination in spinal nerves. The clinical symptoms closely followed the titers of anti-gliomedin IgG and were associated with an important deposition of IgG at nodes. Furthermore, passive transfer of antigliomedin IgG induced a severe demyelinating condition and conduction loss. In both active and passive models, the immune attack at nodes occasioned the loss of the nodal clusters for gliomedin, neurofascin-186, and voltage-gated sodium channels. These results indicate that primary immune reaction against gliomedin, a peripheral nervous system adhesion molecule, can be responsible for the initiation or progression of the demyelinating form of GBS. Furthermore, these autoantibodies affect saltatory propagation by dismantling nodal organization and sodium channel clusters. Antibodies reactive against nodal adhesion molecules thus likely participate in the pathologic process of GBS and CIDP.
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MESH Headings
- Animals
- Antibodies/immunology
- Cell Adhesion Molecules, Neuronal/immunology
- Demyelinating Diseases/immunology
- Demyelinating Diseases/pathology
- Humans
- Immunity/immunology
- Immunization
- Immunization, Passive
- Immunoglobulin G/immunology
- Male
- Mice
- Mice, Inbred C57BL
- Neuritis, Autoimmune, Experimental/immunology
- Neuritis, Autoimmune, Experimental/pathology
- Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/immunology
- Polyradiculoneuropathy, Chronic Inflammatory Demyelinating/pathology
- Ranvier's Nodes/immunology
- Ranvier's Nodes/pathology
- Rats
- Rats, Inbred Lew
- Spinal Nerve Roots/pathology
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Affiliation(s)
- Jérôme J Devaux
- National Center for Scientific Research (CNRS), Aix-Marseille University, Marseille, France.
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38
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Wu X, Peppi M, Vengalil MJ, Maheras KJ, Southwood CM, Bradley M, Gow A. Transgene-mediated rescue of spermatogenesis in Cldn11-null mice. Biol Reprod 2012; 86:139, 1-11. [PMID: 22378758 DOI: 10.1095/biolreprod.111.096230] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Claudins comprise a large family of tight junction (TJ) proteins that are often expressed broadly during development and in adult tissues and constitute the physical barriers that occlude the paracellular space in polarized epithelia. In mouse testis, the integrity of TJs is critical to normal spermatogenesis and is dependent on CLDN11 expression. In the current study, we have generated multiple transgenic mouse lines in which steady-state levels of transgene-derived Cldn11 mRNA are up to fourfold greater than endogenous gene expression. Spermatogenesis in all founder mice harboring two copies of the endogenous Cldn11 gene is normal. These animals breed well, indicating that transgene overexpression, at least at the level of mRNA, is well tolerated by Sertoli cells. In addition, we demonstrate that the promoter/enhancer of the transgene, comprising 5 kb of genomic sequence upstream of exon 1 of the mouse Cldn11 gene, is sufficient to rescue azoospermia in Cldn11-null mice. Finally, using transient transgenic mice, we narrow the location of Sertoli cell-specific cis regulatory elements to a 2-kb region upstream of the Cldn11 transcription start site. Together, these data provide essential information for further investigation of the biological regulation of CLDN11 TJs in the testis.
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Affiliation(s)
- Xin Wu
- Center for Molecular Medicine and Genetics, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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39
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Pang Y, Zheng B, Kimberly SL, Cai Z, Rhodes PG, Lin RCS. Neuron-oligodendrocyte myelination co-culture derived from embryonic rat spinal cord and cerebral cortex. Brain Behav 2012; 2:53-67. [PMID: 22574274 PMCID: PMC3343299 DOI: 10.1002/brb3.33] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 12/13/2011] [Accepted: 12/18/2011] [Indexed: 02/07/2023] Open
Abstract
An in vitro myelination model derived from rat central nervous system (CNS) remains to be established. Here, we describe a simple and reproducible myelination culture method using dissociated neuron-oligodendrocyte (OL) co-cultures from either the embryonic day 16 (E16) rat spinal cord or cerebral cortex. The dissociated cells are plated directly on poly-L-lysine-coated cover slips and maintained in a modified myelination medium that supports both OL and neuron differentiation. The spinal cord derived OL progenitor cells develop quickly into myelin basic protein (MBP)+ mature OLs and start to myelinate axons around 17 days in vitro (DIV17). Myelination reaches its peak around six weeks (DIV40) and the typical nodes of Ranvier are revealed by paranodal proteins Caspr and juxaparanodal protein Kv1.2 immunoreactivity. Electron microscopy (EM) shows typical myelination cytoarchitecture and synaptic organization. In contrast, the cortical-derived co-culture requires triiodothyronine (T3) in the culture medium for myelination. Finally, either hypomyelination and/or demyelination can be induced by exposing proinflammatory cytokines or demyelinating agents to the co-culture, suggesting the feasibility of this modified in vitro myelination model for myelin-deficit investigation.
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Affiliation(s)
- Yi Pang
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, Mississippi 39216
| | - Baoying Zheng
- Department of Pathology, University of Mississippi Medical Center, Jackson, Mississippi 39216
| | - Simpson L. Kimberly
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi 39216
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi 39216
| | - Zhengwei Cai
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, Mississippi 39216
| | - Philip G. Rhodes
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, Mississippi 39216
| | - Rick C. S. Lin
- Department of Neurobiology and Anatomical Sciences, University of Mississippi Medical Center, Jackson, Mississippi 39216
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, Mississippi 39216
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40
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Fu H, Kesari S, Cai J. Tcf7l2 is tightly controlled during myelin formation. Cell Mol Neurobiol 2011; 32:345-52. [PMID: 22160878 DOI: 10.1007/s10571-011-9778-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Accepted: 11/29/2011] [Indexed: 12/25/2022]
Abstract
Recent, studies have shown that Tcf7l2, an important transcription factor in Wnt pathway, plays critical roles in oligodendrocyte development. In this article we report a study showing that Tcf7l2 is under tight regulation during myelin formation. We have found that during early development, Tcf7l2 mRNA appears much earlier than the protein, suggesting a regulation at the translational level. We induced demyelination in a mouse model by a dietary toxin, where remyelination followed after a few weeks, and found that Tcf7l2 protein was expressed specifically during the active remyelination phase. Similarly, in human patients with demyelination diseases, Tcf7l2 protein expression was specifically promoted in regions undergoing active remyelination. During remyelination, Tcf7l2 was only expressed in non-dividing oligodendrocyte precursors and was associated with modest levels of nuclear beta-catenin. We also documented that Tcf7l2 could form protein complex with Olig2, but not with Olig1. Our data showed that during myelin formation, Tcf7l2/beta-catenin is regulated temporally, spatially, and also at levels of expression. These data suggest a key role for Tcf7l2 in myelination/remyelination processes via a tightly controlled activation of Wnt/beta-catenin pathway and the interaction with Olig2.
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Affiliation(s)
- Hui Fu
- Department of Physiology, Basic Medical College of Nanchang University, Nanchang, Jiangxi, China.
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41
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Bordner KA, George ED, Carlyle BC, Duque A, Kitchen RR, Lam TT, Colangelo CM, Stone KL, Abbott TB, Mane SM, Nairn AC, Simen AA. Functional genomic and proteomic analysis reveals disruption of myelin-related genes and translation in a mouse model of early life neglect. Front Psychiatry 2011; 2:18. [PMID: 21629843 PMCID: PMC3098717 DOI: 10.3389/fpsyt.2011.00018] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 04/11/2011] [Indexed: 12/13/2022] Open
Abstract
Early life neglect is an important public health problem which can lead to lasting psychological dysfunction. Good animal models are necessary to understand the mechanisms responsible for the behavioral and anatomical pathology that results. We recently described a novel model of early life neglect, maternal separation with early weaning (MSEW), that produces behavioral changes in the mouse that persist into adulthood. To begin to understand the mechanism by which MSEW leads to these changes we applied cDNA microarray, next-generation RNA-sequencing (RNA-seq), label-free proteomics, multiple reaction monitoring (MRM) proteomics, and methylation analysis to tissue samples obtained from medial prefrontal cortex to determine the molecular changes induced by MSEW that persist into adulthood. The results show that MSEW leads to dysregulation of markers of mature oligodendrocytes and genes involved in protein translation and other categories, an apparent downward biasing of translation, and methylation changes in the promoter regions of selected dysregulated genes. These findings are likely to prove useful in understanding the mechanism by which early life neglect affects brain structure, cognition, and behavior.
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Affiliation(s)
- Kelly A Bordner
- Department of Psychiatry, Yale University School of Medicine New Haven, CT, USA
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42
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Transcriptional and post-transcriptional control of CNS myelination. Curr Opin Neurobiol 2010; 20:601-7. [DOI: 10.1016/j.conb.2010.05.005] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 05/21/2010] [Accepted: 05/21/2010] [Indexed: 11/23/2022]
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43
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Moreno-Bravo JA, Perez-Balaguer A, Martinez S, Puelles E. Dynamic expression patterns of Nkx6.1 and Nkx6.2 in the developing mes-diencephalic basal plate. Dev Dyn 2010; 239:2094-101. [PMID: 20549744 DOI: 10.1002/dvdy.22327] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The components of the molecular codes needed to specify the different neuronal populations present in the basal neural tube are being identified. These codes become more intricate as we move to more anterior regions of the central nervous system. The aim of this study is to thoroughly analyze the expression pattern of Nkx6.1, Nkx6.2, and Pou4f1. These three genes are candidates to play an important role in the determination and differentiation of the basal nuclei of the mesencephalon and diencephalon. The results obtained have shown that there is a longitudinal domain positive for both Nkx6.1 and Nkx6.2 that is medial to the Pou4f1-positive red nucleus. This domain could correspond to part of the reticular formation, which extends from the diencephalon and the mesencephalon. The nuclei integrated in this domain would be the rostral interstitial nucleus, the interstitial nucleus of Cajal, and a mesencephalic equivalent to these nuclei.
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Affiliation(s)
- Juan Antonio Moreno-Bravo
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Cientificas, and Universidad Miguel Hernández, Sant Joan d'Alacant, Spain
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44
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Sundberg M, Skottman H, Suuronen R, Narkilahti S. Production and isolation of NG2+ oligodendrocyte precursors from human embryonic stem cells in defined serum-free medium. Stem Cell Res 2010; 5:91-103. [DOI: 10.1016/j.scr.2010.04.005] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Revised: 03/02/2010] [Accepted: 04/20/2010] [Indexed: 12/28/2022] Open
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45
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Bsibsi M, Bajramovic JJ, Vogt MHJ, van Duijvenvoorden E, Baghat A, Persoon-Deen C, Tielen F, Verbeek R, Huitinga I, Ryffel B, Kros A, Gerritsen WH, Amor S, van Noort JM. The microtubule regulator stathmin is an endogenous protein agonist for TLR3. THE JOURNAL OF IMMUNOLOGY 2010; 184:6929-37. [PMID: 20483774 DOI: 10.4049/jimmunol.0902419] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
TLR3 recognizes dsRNAs and is considered of key importance to antiviral host-defense responses. TLR3 also triggers neuroprotective responses in astrocytes and controls the growth of axons and neuronal progenitor cells, suggesting additional roles for TLR3-mediated signaling in the CNS. This prompted us to search for alternative, CNS-borne protein agonists for TLR3. A genome-scale functional screening of a transcript library from brain tumors revealed that the microtubule regulator stathmin is an activator of TLR3-dependent signaling in astrocytes, inducing the same set of neuroprotective factors as the known TLR3 agonist polyinosinic:polycytidylic acid. This activity of stathmin crucially depends on a long, negatively charged alpha helix in the protein. Colocalization of stathmin with TLR3 on astrocytes, microglia, and neurons in multiple sclerosis-affected human brain indicates that as an endogenous TLR3 agonist, stathmin may fulfill previously unsuspected regulatory roles during inflammation and repair in the adult CNS.
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Affiliation(s)
- Malika Bsibsi
- Department of Biomedical Research, TNO Quality of Life, Delta Crystallon, Leiden, The Netherlands
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46
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Abstract
The insulative properties of myelin sheaths in the central and peripheral nervous systems (CNS and PNS) are widely thought to derive from the high resistance and low capacitance of the constituent membranes. Although this view adequately accounts for myelin function in large diameter fibers, it poorly reflects the behavior of small fibers that are prominent in many regions of the CNS. Herein, we develop a computational model to more accurately represent conduction in small fibers. By incorporating structural features that, hitherto, have not been simulated, we demonstrate that myelin tight junctions (TJs) improve saltatory conduction by reducing current flow through the myelin, limiting axonal membrane depolarization and restraining the activation of ion channels beneath the myelin sheath. Accordingly, our simulations provide a novel view of myelin by which TJs minimize charging of the membrane capacitance and lower the membrane time constant to improve the speed and accuracy of transmission in small diameter fibers. This study establishes possible mechanisms whereby TJs affect conduction in the absence of overt perturbations to myelin architecture and may in part explain the tremor and gait abnormalities observed in Claudin 11-null mice.
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47
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Cai J, Zhu Q, Zheng K, Li H, Qi Y, Cao Q, Qiu M. Co-localization of Nkx6.2 and Nkx2.2 homeodomain proteins in differentiated myelinating oligodendrocytes. Glia 2010; 58:458-68. [PMID: 19780200 DOI: 10.1002/glia.20937] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent studies have suggested that Nkx6.2/Gtx and Nkx2.2 homeodomain transcription factors are involved in the regulation of oligodendrocyte maturation and/or myelination which occur predominantly in postnatal stages. However, their cellular specificity in postnatal central nervous system has not been characterized and their dynamic expressional relationship during oligodendrocyte lineage progression has not been determined. Here we report that both Nkx2.2 and Nkx6.2 are selectively expressed in Olig2+ cells of oligodendrocyte lineage in postnatal spinal cords. Although Nkx6.2 is specifically expressed in the APC+ mature oligodendrocytes, Nkx2.2 is initially expressed in differentiating oligodendrocyte precursor cells (OPCs) but quickly down-regulated as OPCs undergo terminal differentiation. Intriguingly, Nkx2.2 expression is up-regulated in mature myelinating oligodendrocytes at later stages. The co-expression of Nkx2.2 and Nkx6.2 transcription factors in myelinating oligodendrocytes suggests their functional interactions in the regulation of myelin sheath formation and/or maintenance.
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Affiliation(s)
- Jun Cai
- Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, Kentucky, USA.
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Pedraza L, Huang JK, Colman D. Disposition of axonal caspr with respect to glial cell membranes: Implications for the process of myelination. J Neurosci Res 2010; 87:3480-91. [PMID: 19170162 DOI: 10.1002/jnr.22004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Neurofascin-155 (NF155) and caspr are transmembrane proteins found at discrete locations early during development of the nervous system. NF155 is present in the oligodendrocyte cell body and processes, whereas caspr is on the axonal surface. In mature nerves, these proteins are clustered at paranodes, flanking the node of Ranvier. To understand how NF155 and caspr become localized to the paranodal regions of myelinated nerves, we have studied their distribution over time in myelinating cultures. Our observations indicate that these two proteins are recruited to the cell surface at the contact zone between axons and oligodendrocytes, where they trans-interact. This association explains the early pattern of caspr distribution, a helical coil that winds around the axon, resembling the turns of the myelin sheath. Caspr, an axonal membrane protein, therefore seems to move in register with the overlying myelinating cell via its interactions with myelin proteins. We suggest that NF155 is the glial cell membrane protein responsible for caspr distribution. The pair act as interacting partners on either side of the axoglial contact area. Most likely, there are other proteins on the axonal surface whose distribution is equally influenced by interaction with the nascent myelin sheath. The fact that caspr follows the movement of the spiraling membrane has a direct affect on the interpretation of the way in which myelin is formed.
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Affiliation(s)
- Liliana Pedraza
- Montreal Neurological Institute, Program in Neuroengineering, McGill University, Montreal, Quebec, Canada.
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Ogawa Y, Rasband MN. Proteomic analysis of optic nerve lipid rafts reveals new paranodal proteins. J Neurosci Res 2010; 87:3502-10. [PMID: 19156860 DOI: 10.1002/jnr.21984] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Neuron-glia interactions at paranodal junctions play important roles in action potential propagation. Among their many functions, they contribute to the passive electrical properties of myelinated nerve fibers and actively regulate the polarized distribution of ion channels along axons. Despite their importance, relatively little is known about the molecules responsible for paranode formation and function. Paranodal junction formation apparently depends on interactions among three cell adhesion molecules: caspr and contactin on the axon and neurofascin 155 (NF-155) on the glial membrane. Using Caspr-null paranodal mutant mice, we demonstrate that loss of paranodal junctions causes failure of NF-155 to partition into lipid rafts, indicating that proteins located at paranodal junctions have biochemical characteristics of lipid raft-associated proteins. Based on this property of paranodal junctions, mass spectrometry of lipid rafts isolated from a pure white matter tract (optic nerve) was used to search for new paranodal proteins. Because we used a relatively crude biochemical preparation, we identified several hundred different proteins. Among these, we found all previously described paranodal proteins. Further analysis based on antibody staining of central and peripheral nerves revealed beta-adducin, septin 2, and sh3p8 as putative paranodal proteins. We describe the localization of these proteins in relation to other markers of nodes, paranodes, and juxtaparanodes in adult and developing nerve fibers. Finally, we describe their distribution in dysmyelinating TremblerJ mice, a model for the peripheral neuropathy Charcot-Marie-Tooth disease.
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Affiliation(s)
- Yasuhiro Ogawa
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
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Li H, He Y, Richardson WD, Casaccia P. Two-tier transcriptional control of oligodendrocyte differentiation. Curr Opin Neurobiol 2009; 19:479-85. [PMID: 19740649 DOI: 10.1016/j.conb.2009.08.004] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Accepted: 08/19/2009] [Indexed: 01/06/2023]
Abstract
Oligodendrocytes (OLs) are the myelin-forming cells of the central nervous system (CNS). They differentiate from proliferative OL precursor cells that migrate from the embryonic neuroepithelium throughout the developing CNS before associating with axons and elaborating myelin. Recent research into the regulation of OL differentiation has uncovered a two-stage mechanism of transcriptional control that combines epigenetic repression of transcriptional inhibitors with direct transcriptional activation of myelin genes. This 'two-pronged' approach creates a fail-safe system of genetic control to ensure orderly and unambiguous expression of the myelination program during development and during repair of demyelinated lesions.
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Affiliation(s)
- Huiliang Li
- Wolfson Institute for Biomedical Research, and Research Department of Cell and Developmental Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom
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