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Okechukwu NG, Klein C, Jamann H, Maitre M, Patte-Mensah C, Mensah-Nyagan AG. Monomeric Amyloid Peptide-induced Toxicity in Human Oligodendrocyte Cell Line and Mouse Brain Primary Mixed-glial Cell Cultures: Evidence for a Neuroprotective Effect of Neurosteroid 3α-O-allyl-allopregnanolone. Neurotox Res 2024; 42:37. [PMID: 39102123 DOI: 10.1007/s12640-024-00715-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 04/18/2024] [Accepted: 07/22/2024] [Indexed: 08/06/2024]
Abstract
Amyloid-peptide (Aβ) monomeric forms (ABM) occurring in presymptomatic Alzheimer's disease (AD) brain are thought to be devoid of neurotoxicity while the transition/aggregation of ABM into oligomers is determinant for Aβ-induced toxicity since Aβ is predominantly monomeric up to 3 µM and aggregates over this concentration. However, recent imaging and/or histopathological investigations revealed alterations of myelin in prodromal AD brain in absence of aggregated Aβ oligomers, suggesting that ABM may induce toxicity in myelin-producing cells in early AD-stages. To check this hypothesis, here we studied ABM effects on the viability of the Human oligodendrocyte cell line (HOG), a reliable oligodendrocyte model producing myelin proteins. Furthermore, to mimic closely interactions between oligodendrocytes and other glial cells regulating myelination, we investigated also ABM effects on mouse brain primary mixed-glial cell cultures. Various methods were combined to show that ABM concentrations (600 nM-1 µM), extremely lower than 3 µM, significantly decreased HOG cell and mouse brain primary mixed-glial cell survival. Interestingly, flow-cytometry studies using specific cell-type markers demonstrated that oligodendrocytes represent the most vulnerable glial cell population affected by ABM toxicity. Our work also shows that the neurosteroid 3α-O-allyl-allopregnanolone BR351 (250 and 500 nM) efficiently prevented ABM-induced HOG and brain primary glial cell toxicity. Bicuculline (50-100 nM), the GABA-A-receptor antagonist, was unable to block/reduce BR351 effect against ABM-induced HOG and primary glial cell toxicity, suggesting that BR351-evoked neuroprotection of these cells may not depend on GABA-A-receptor allosterically modulated by neurosteroids. Altogether, our results suggest that further exploration of BR351 therapeutic potential may offer interesting perspectives to develop effective neuroprotective strategies.
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Affiliation(s)
- Nwife Getrude Okechukwu
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
| | - Christian Klein
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France
| | - Hélène Jamann
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France
| | - Michel Maitre
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France
| | - Christine Patte-Mensah
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France
| | - Ayikoé-Guy Mensah-Nyagan
- Biopathologie de la Myéline, Neuroprotection et Stratégies Thérapeutiques, INSERM U1119, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Bâtiment CRBS de la Faculté de Médecine, 1 rue Eugène Boeckel, 67 000, Strasbourg, France.
- Centre d'Investigation Clinique de Strasbourg (CIC), Equipe CIC-Recherche Translationnelle Neuro, INSERM 1434, Université de Strasbourg, Bâtiment CRBS, 1 rue Eugène Boeckel, 67000, Strasbourg, France.
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2
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Logue J, Melville VM, Ardanuy J, Frieman MB. CNP blocks mitochondrial depolarization and inhibits SARS-CoV-2 replication in vitro and in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.09.544327. [PMID: 37333151 PMCID: PMC10274905 DOI: 10.1101/2023.06.09.544327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
The COVID-19 pandemic has claimed over 6.5 million lives worldwide and continues to have lasting impacts on the world's healthcare and economic systems. Several approved and emergency authorized therapeutics that inhibit early stages of the virus replication cycle have been developed however, effective late-stage therapeutical targets have yet to be identified. To that end, our lab identified that 2',3' cyclic-nucleotide 3'-phosphodiesterase (CNP) inhibits SARS-CoV-2 virion assembly. We show that CNP inhibits the generation of new SARS-CoV-2 virions, reducing intracellular titers without inhibiting viral structural protein translation. Additionally, we show that targeting of CNP to mitochondria is necessary for inhibition, blocking mitochondrial depolarization and implicating CNP's proposed role as an inhibitor of the mitochondrial permeabilization transition pore (mPTP) as the mechanism of virion assembly inhibition. We also demonstrate that an adenovirus expressing virus expressing both human ACE2 and CNP inhibits SARS-CoV-2 titers to undetectable levels in lungs of mice. Collectively, this work shows the potential of CNP to be a new SARS-CoV-2 antiviral target.
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Affiliation(s)
- James Logue
- The Department of Microbiology and Immunology, The University of Maryland School of Medicine, Baltimore,Maryland, USA
- Center for Pathogen Research, The University of Maryland School of Medicine, Baltimore,Maryland, USA
| | - Victoria M. Melville
- The Department of Microbiology and Immunology, The University of Maryland School of Medicine, Baltimore,Maryland, USA
- Center for Pathogen Research, The University of Maryland School of Medicine, Baltimore,Maryland, USA
| | - Jeremy Ardanuy
- The Department of Microbiology and Immunology, The University of Maryland School of Medicine, Baltimore,Maryland, USA
- Center for Pathogen Research, The University of Maryland School of Medicine, Baltimore,Maryland, USA
| | - Matthew B. Frieman
- The Department of Microbiology and Immunology, The University of Maryland School of Medicine, Baltimore,Maryland, USA
- Center for Pathogen Research, The University of Maryland School of Medicine, Baltimore,Maryland, USA
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3
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Logue J, Melville VM, Ardanuy J, Frieman MB. CNP blocks mitochondrial depolarization and inhibits SARS-CoV-2 replication in vitro and in vivo. PLoS Pathog 2023; 19:e1011870. [PMID: 38117830 PMCID: PMC10766180 DOI: 10.1371/journal.ppat.1011870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 01/04/2024] [Accepted: 11/28/2023] [Indexed: 12/22/2023] Open
Abstract
The COVID-19 pandemic has claimed over 6.5 million lives worldwide and continues to have lasting impacts on the world's healthcare and economic systems. Several approved and emergency authorized therapeutics that inhibit early stages of the virus replication cycle have been developed however, effective late-stage therapeutical targets have yet to be identified. To that end, our lab identified that 2',3' cyclic-nucleotide 3'-phosphodiesterase (CNP) inhibits SARS-CoV-2 virion assembly. We show that CNP inhibits the generation of new SARS-CoV-2 virions, reducing intracellular titers without inhibiting viral structural protein translation. Additionally, we show that targeting of CNP to mitochondria is necessary for inhibition, blocking mitochondrial depolarization and implicating CNP's proposed role as an inhibitor of the mitochondrial permeabilization transition pore (mPTP) as the mechanism of virion assembly inhibition. We also demonstrate that an adenovirus expressing virus expressing both human ACE2 and CNP inhibits SARS-CoV-2 titers to undetectable levels in lungs of mice. Collectively, this work shows the potential of CNP to be a new SARS-CoV-2 antiviral target.
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Affiliation(s)
- James Logue
- The Department of Microbiology and Immunology, The University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Center for Pathogen Research, The University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Victoria M. Melville
- The Department of Microbiology and Immunology, The University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Center for Pathogen Research, The University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Jeremy Ardanuy
- The Department of Microbiology and Immunology, The University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Center for Pathogen Research, The University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Matthew B. Frieman
- The Department of Microbiology and Immunology, The University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Center for Pathogen Research, The University of Maryland School of Medicine, Baltimore, Maryland, United States of America
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4
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Sharifi M, Farahani MK, Salehi M, Atashi A, Alizadeh M, Kheradmandi R, Molzemi S. Exploring the Physicochemical, Electroactive, and Biodelivery Properties of Metal Nanoparticles on Peripheral Nerve Regeneration. ACS Biomater Sci Eng 2023; 9:106-138. [PMID: 36545927 DOI: 10.1021/acsbiomaterials.2c01216] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Despite the advances in the regeneration/rehabilitation field of damaged tissues, the functional recovery of peripheral nerves (PNs), especially in a long gap injury, is considered a great medical challenge. Recent progress in nanomedicine has provided great hope for PN regeneration through the strategy of controlling cell behavior by metal nanoparticles individually or loaded on scaffolds/conduits. Despite the confirmed toxicity of metal nanoparticles due to long-term accumulation in nontarget tissues, they play a role in the damaged PN regeneration based on the topography modification of scaffolds/conduits, enhancing neurotrophic factor secretion, the ion flow improvement, and the regulation of electrical signals. Determining the fate of neural progenitor cells would be a major achievement in PN regeneration, which seems to be achievable by metal nanoparticles through altering cell vital approaches and controlling their functions. Therefore, in this literature, an attempt was made to provide an overview of the effective activities of metal nanoparticles on the PN regeneration, until the vital clues of the PN regeneration and how they are changed by metal nanoparticles are revealed to the researcher.
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Affiliation(s)
- Majid Sharifi
- Student Research Committee, School of Medicine, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran.,Department of Tissue Engineering, School of Medicine, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran
| | - Mohammad Kamalabadi Farahani
- Department of Tissue Engineering, School of Medicine, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran
| | - Majid Salehi
- Department of Tissue Engineering, School of Medicine, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran.,Tissue Engineering and Stem Cells Research Center, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran
| | - Amir Atashi
- Stem Cell and Tissue Engineering Research Center, Faculty of Allied Medical Sciences, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran
| | - Morteza Alizadeh
- Department of Tissue Engineering, School of Medicine, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran
| | - Rasoul Kheradmandi
- Student Research Committee, School of Medicine, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran.,Department of Tissue Engineering, School of Medicine, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran
| | - Sahar Molzemi
- Student Research Committee, School of Medicine, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran.,Department of Tissue Engineering, School of Medicine, Shahroud University of Medical Sciences, Shahroud, 3614773955, Iran
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5
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Buscham TJ, Eichel-Vogel MA, Steyer AM, Jahn O, Strenzke N, Dardawal R, Memhave TR, Siems SB, Müller C, Meschkat M, Sun T, Ruhwedel T, Möbius W, Krämer-Albers EM, Boretius S, Nave KA, Werner HB. Progressive axonopathy when oligodendrocytes lack the myelin protein CMTM5. eLife 2022; 11:75523. [PMID: 35274615 PMCID: PMC8916772 DOI: 10.7554/elife.75523] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 02/27/2022] [Indexed: 11/26/2022] Open
Abstract
Oligodendrocytes facilitate rapid impulse propagation along the axons they myelinate and support their long-term integrity. However, the functional relevance of many myelin proteins has remained unknown. Here, we find that expression of the tetraspan-transmembrane protein CMTM5 (chemokine-like factor-like MARVEL-transmembrane domain containing protein 5) is highly enriched in oligodendrocytes and central nervous system (CNS) myelin. Genetic disruption of the Cmtm5 gene in oligodendrocytes of mice does not impair the development or ultrastructure of CNS myelin. However, oligodendroglial Cmtm5 deficiency causes an early-onset progressive axonopathy, which we also observe in global and tamoxifen-induced oligodendroglial Cmtm5 mutants. Presence of the WldS mutation ameliorates the axonopathy, implying a Wallerian degeneration-like pathomechanism. These results indicate that CMTM5 is involved in the function of oligodendrocytes to maintain axonal integrity rather than myelin biogenesis.
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Affiliation(s)
- Tobias J Buscham
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Maria A Eichel-Vogel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 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
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Translational Neuroproteomics Group, Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Georg-August-University, Göttingen, Germany
| | - Nicola Strenzke
- Institute for Auditory Neuroscience, University Medicine Göttingen, Göttingen, Germany
| | - Rakshit Dardawal
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Tor R Memhave
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Sophie B Siems
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Christina Müller
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz, Germany
| | - Martin Meschkat
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Abberior Instruments Gmbh, Göttingen, Germany
| | - Ting Sun
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - 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
| | - 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
| | - Eva-Maria Krämer-Albers
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University, Mainz, Germany
| | - Susann Boretius
- Functional Imaging Laboratory, German Primate Center, Leibniz Institute for Primate Research, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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6
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Chesnut M, Paschoud H, Repond C, Smirnova L, Hartung T, Zurich MG, Hogberg HT, Pamies D. Human IPSC-Derived Model to Study Myelin Disruption. Int J Mol Sci 2021; 22:9473. [PMID: 34502381 PMCID: PMC8430601 DOI: 10.3390/ijms22179473] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/27/2021] [Accepted: 08/28/2021] [Indexed: 12/15/2022] Open
Abstract
Myelin is of vital importance to the central nervous system and its disruption is related to a large number of both neurodevelopmental and neurodegenerative diseases. The differences observed between human and rodent oligodendrocytes make animals inadequate for modeling these diseases. Although developing human in vitro models for oligodendrocytes and myelinated axons has been a great challenge, 3D cell cultures derived from iPSC are now available and able to partially reproduce the myelination process. We have previously developed a human iPSC-derived 3D brain organoid model (also called BrainSpheres) that contains a high percentage of myelinated axons and is highly reproducible. Here, we have further refined this technology by applying multiple readouts to study myelination disruption. Myelin was assessed by quantifying immunostaining/confocal microscopy of co-localized myelin basic protein (MBP) with neurofilament proteins as well as proteolipid protein 1 (PLP1). Levels of PLP1 were also assessed by Western blot. We identified compounds capable of inducing developmental neurotoxicity by disrupting myelin in a systematic review to evaluate the relevance of our BrainSphere model for the study of the myelination/demyelination processes. Results demonstrated that the positive reference compound (cuprizone) and two of the three potential myelin disruptors tested (Bisphenol A, Tris(1,3-dichloro-2-propyl) phosphate, but not methyl mercury) decreased myelination, while ibuprofen (negative control) had no effect. Here, we define a methodology that allows quantification of myelin disruption and provides reference compounds for chemical-induced myelin disruption.
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Affiliation(s)
- Megan Chesnut
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
| | - Hélène Paschoud
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland; (H.P.); (C.R.); (M.-G.Z.)
| | - Cendrine Repond
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland; (H.P.); (C.R.); (M.-G.Z.)
| | - Lena Smirnova
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
| | - Thomas Hartung
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
- Center for Alternative to Animla Testing Europe, University of Konstanz, 78464 Konstanz, Germany
| | - Marie-Gabrielle Zurich
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland; (H.P.); (C.R.); (M.-G.Z.)
- Swiss Centre for Applied Human Toxicology (SCAHT), 4055 Basel, Switzerland
| | - Helena T. Hogberg
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
| | - David Pamies
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, 615 N Wolfe St., Baltimore, MD 21205, USA; (M.C.); (L.S.); (T.H.)
- Department of Biomedical Sciences, University of Lausanne, CH-1005 Lausanne, Switzerland; (H.P.); (C.R.); (M.-G.Z.)
- Swiss Centre for Applied Human Toxicology (SCAHT), 4055 Basel, Switzerland
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7
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Chesnut M, Hartung T, Hogberg H, Pamies D. Human Oligodendrocytes and Myelin In Vitro to Evaluate Developmental Neurotoxicity. Int J Mol Sci 2021; 22:7929. [PMID: 34360696 PMCID: PMC8347131 DOI: 10.3390/ijms22157929] [Citation(s) in RCA: 9] [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: 06/09/2021] [Revised: 07/14/2021] [Accepted: 07/21/2021] [Indexed: 01/01/2023] Open
Abstract
Neurodevelopment is uniquely sensitive to toxic insults and there are concerns that environmental chemicals are contributing to widespread subclinical developmental neurotoxicity (DNT). Increased DNT evaluation is needed due to the lack of such information for most chemicals in common use, but in vivo studies recommended in regulatory guidelines are not practical for the large-scale screening of potential DNT chemicals. It is widely acknowledged that developmental neurotoxicity is a consequence of disruptions to basic processes in neurodevelopment and that testing strategies using human cell-based in vitro systems that mimic these processes could aid in prioritizing chemicals with DNT potential. Myelination is a fundamental process in neurodevelopment that should be included in a DNT testing strategy, but there are very few in vitro models of myelination. Thus, there is a need to establish an in vitro myelination assay for DNT. Here, we summarize the routes of myelin toxicity and the known models to study this particular endpoint.
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Affiliation(s)
- Megan Chesnut
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (M.C.); (T.H.)
| | - Thomas Hartung
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (M.C.); (T.H.)
- Center for Alternatives to Animal Testing (CAAT-Europe), University of Konstanz, 78464 Konstanz, Germany
| | - Helena Hogberg
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (M.C.); (T.H.)
| | - David Pamies
- Center for Alternatives to Animal Testing (CAAT), Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (M.C.); (T.H.)
- Department of Physiology, University of Lausanne, 1005 Lausanne, Switzerland
- Swiss Centre for Applied Human Toxicology (SCAHT), 4055 Basel, Switzerland
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8
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Liu W, Rohlman AR, Vetreno R, Crews FT. Expression of Oligodendrocyte and Oligoprogenitor Cell Proteins in Frontal Cortical White and Gray Matter: Impact of Adolescent Development and Ethanol Exposure. Front Pharmacol 2021; 12:651418. [PMID: 34025418 PMCID: PMC8134748 DOI: 10.3389/fphar.2021.651418] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 04/12/2021] [Indexed: 12/15/2022] Open
Abstract
Adolescent development of prefrontal cortex (PFC) parallels maturation of executive functions as well as increasing white matter and myelination. Studies using MRI and other methods find that PFC white matter increases across adolescence into adulthood in both humans and rodents. Adolescent binge drinking is common and has been found to alter adult behaviors and PFC functions. This study examines development of oligoprogenitor (OPC) and oligodendrocytes (OLs) in Wistar rats from adolescence to adulthood within PFC white matter, corpus callosum forceps minor (fmi), PFC gray matter, and the neurogenic subventricular zone (SVZ) using immunohistochemistry for marker proteins. In addition, the effects of adolescent intermittent ethanol exposure [AIE; 5.0 g/kg/day, intragastric, 2 days on/2 days off on postnatal day (P)25-54], which is a weekend binge drinking model, were determined. OPC markers NG2+, PDGFRα+ and Olig2+IHC were differentially impacted by both age and PFC region. In both fmi and SVZ, NG2+IHC cells declined from adolescence to adulthood with AIE increasing adult NG2+IHC cells and their association with microglial marker Iba1. PFC gray matter decline in NG2+IHC in adulthood was not altered by AIE. Both adult maturation and AIE impacted OL expression of PLP+, MBP+, MAG+, MOG+, CNPase+, Olig1+, and Olig2+IHC in all three PFC regions, but in region- and marker-specific patterns. These findings are consistent with PFC region-specific changes in OPC and OL markers from adolescence to adulthood as well as following AIE that could contribute to lasting changes in PFC function.
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Affiliation(s)
| | | | | | - Fulton T. Crews
- Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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9
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Siems SB, Jahn O, Hoodless LJ, Jung RB, Hesse D, Möbius W, Czopka T, Werner HB. Proteome Profile of Myelin in the Zebrafish Brain. Front Cell Dev Biol 2021; 9:640169. [PMID: 33898427 PMCID: PMC8060510 DOI: 10.3389/fcell.2021.640169] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/05/2021] [Indexed: 12/14/2022] Open
Abstract
The velocity of nerve conduction along vertebrate axons depends on their ensheathment with myelin. Myelin membranes comprise specialized proteins well characterized in mice. Much less is known about the protein composition of myelin in non-mammalian species. Here, we assess the proteome of myelin biochemically purified from the brains of adult zebrafish (Danio rerio), considering its increasing popularity as model organism for myelin biology. Combining gel-based and gel-free proteomic approaches, we identified > 1,000 proteins in purified zebrafish myelin, including all known constituents. By mass spectrometric quantification, the predominant Ig-CAM myelin protein zero (MPZ/P0), myelin basic protein (MBP), and the short-chain dehydrogenase 36K constitute 12%, 8%, and 6% of the total myelin protein, respectively. Comparison with previously established mRNA-abundance profiles shows that expression of many myelin-related transcripts coincides with the maturation of zebrafish oligodendrocytes. Zebrafish myelin comprises several proteins that are not present in mice, including 36K, CLDNK, and ZWI. However, a surprisingly large number of ortholog proteins is present in myelin of both species, indicating partial evolutionary preservation of its constituents. Yet, the relative abundance of CNS myelin proteins can differ markedly as exemplified by the complement inhibitor CD59 that constitutes 5% of the total zebrafish myelin protein but is a low-abundant myelin component in mice. Using novel transgenic reporter constructs and cryo-immuno electron microscopy, we confirm the incorporation of CD59 into myelin sheaths. These data provide the first proteome resource of zebrafish CNS myelin and demonstrate both similarities and heterogeneity of myelin composition between teleost fish and rodents.
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Affiliation(s)
- Sophie B Siems
- Department of Neurogenetics, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Laura J Hoodless
- Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Dörte Hesse
- Proteomics Group, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute for Experimental Medicine, Göttingen, Germany.,Electron Microscopy Core Unit, Max Planck Institute for Experimental Medicine, Göttingen, Germany
| | - Tim Czopka
- Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Experimental Medicine, Göttingen, Germany
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10
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Martins-de-Souza D, Guest PC, Reis-de-Oliveira G, Schmitt A, Falkai P, Turck CW. An overview of the human brain myelin proteome and differences associated with schizophrenia. World J Biol Psychiatry 2021; 22:271-287. [PMID: 32602824 DOI: 10.1080/15622975.2020.1789217] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVES Disturbances in the myelin sheath drive disruptions in neural transmission and brain connectivity as seen in schizophrenia. Here, the myelin proteome was characterised in schizophrenia patients and healthy controls to visualise differences in proteomic profiles. METHODS A liquid chromatography tandem mass spectrometry-based shotgun proteomic analysis was performed of a myelin-enriched fraction of postmortem brain samples from schizophrenia patients (n = 12) and mentally healthy controls (n = 8). In silico pathway analyses were performed on the resulting data. RESULTS The present characterisation of the human myelinome led to the identification of 480 non-redundant proteins, of which 102 proteins are newly annotated to be associated with the myelinome. Levels of 172 of these proteins were altered between schizophrenia patients and controls. These proteins were mainly associated with glial cell differentiation, metabolism/energy, synaptic vesicle function and neurodegeneration. The hub proteins with the highest degree of connectivity in the network included multiple kinases and synaptic vesicle transport proteins. CONCLUSIONS Together these findings suggest disruptive effects on synaptic activity and therefore neural transmission and connectivity, consistent with the dysconnectivity hypothesis of schizophrenia. Further studies on these proteins may lead to the identification of potential drug targets related to the synaptic dysconnectivity in schizophrenia and other psychiatric and neurodegenerative disorders.
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Affiliation(s)
- Daniel Martins-de-Souza
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil.,Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBION) Conselho Nacional de Desenvolvimento Científico e Tecnológico, São Paulo, Brazil.,Experimental Medicine Research Cluster (EMRC), University of Campinas, Campinas, Brazil.,D'Or Institute for Research and Education (IDOR), São Paulo, Brazil
| | - Paul C Guest
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Guilherme Reis-de-Oliveira
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, Brazil
| | - Andrea Schmitt
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Peter Falkai
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Christoph W Turck
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, Munich, Germany
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11
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Möbius W, Hümmert S, Ruhwedel T, Kuzirian A, Gould R. New Species Can Broaden Myelin Research: Suitability of Little Skate, Leucoraja erinacea. Life (Basel) 2021; 11:136. [PMID: 33670172 PMCID: PMC7916940 DOI: 10.3390/life11020136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/02/2021] [Accepted: 02/06/2021] [Indexed: 02/06/2023] Open
Abstract
Although myelinated nervous systems are shared among 60,000 jawed vertebrates, studies aimed at understanding myelination have focused more and more on mice and zebrafish. To obtain a broader understanding of the myelination process, we examined the little skate, Leucoraja erinacea. The reasons behind initiating studies at this time include: the desire to study a species belonging to an out group of other jawed vertebrates; using a species with embryos accessible throughout development; the availability of genome sequences; and the likelihood that mammalian antibodies recognize homologs in the chosen species. We report that the morphological features of myelination in a skate hatchling, a stage that supports complex behavioral repertoires needed for survival, are highly similar in terms of: appearances of myelinating oligodendrocytes (CNS) and Schwann cells (PNS); the way their levels of myelination conform to axon caliber; and their identity in terms of nodal and paranodal specializations. These features provide a core for further studies to determine: axon-myelinating cell communication; the structures of the proteins and lipids upon which myelinated fibers are formed; the pathways used to transport these molecules to sites of myelin assembly and maintenance; and the gene regulatory networks that control their expressions.
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Affiliation(s)
- Wiebke Möbius
- Electron Microscopy Core Unit, Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, 37075 Göttingen, Germany; (W.M.); (S.H.); (T.R.)
- Cluster of Excellence Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells (MBExC), University of Göttingen, 37073 Göttingen, Germany
| | - Sophie Hümmert
- Electron Microscopy Core Unit, Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, 37075 Göttingen, Germany; (W.M.); (S.H.); (T.R.)
| | - Torben Ruhwedel
- Electron Microscopy Core Unit, Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, 37075 Göttingen, Germany; (W.M.); (S.H.); (T.R.)
| | - Alan Kuzirian
- Eugene Bell Center for Regenerative Biology and Tissue Engineering, Marine Biological Laboratory, Woods Hole, MA 02540, USA;
| | - Robert Gould
- Whitman Science Center, Marin Biological Laboratory, Woods Hole, MA 02540, USA
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12
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Oudejans E, Luchicchi A, Strijbis EMM, Geurts JJG, van Dam AM. Is MS affecting the CNS only? Lessons from clinic to myelin pathophysiology. NEUROLOGY-NEUROIMMUNOLOGY & NEUROINFLAMMATION 2020; 8:8/1/e914. [PMID: 33234720 PMCID: PMC7803330 DOI: 10.1212/nxi.0000000000000914] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 09/23/2020] [Indexed: 01/27/2023]
Abstract
MS is regarded as a disease of the CNS where a combination of demyelination, inflammation, and axonal degeneration results in neurologic disability. However, various studies have also shown that the peripheral nervous system (PNS) can be involved in MS, expanding the consequences of this disorder outside the brain and spinal cord, and providing food for thought to the still unanswered questions about MS origin and treatment. Here, we review the emerging concept of PNS involvement in MS by looking at it from a clinical, molecular, and biochemical point of view. Clinical, pathologic, electrophysiologic, and imaging studies give evidence that the PNS is functionally affected during MS and suggest that the disease might be part of a spectrum of demyelinating disorders instead of being a distinct entity. At the molecular level, similarities between the anatomic structure of the myelin and its interaction with axons in CNS and PNS are evident. In addition, a number of biochemical alterations that affect the myelin during MS can be assumed to be shared between CNS and PNS. Involvement of the PNS as a relevant disease target in MS pathology may have consequences for reaching the diagnosis and for therapeutic approaches of patients with MS. Hence, future MS studies should pay attention to the involvement of the PNS, i.e., its myelin, in MS pathogenesis, which could advance MS research.
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Affiliation(s)
- Ellen Oudejans
- From the Department of Anatomy and Neurosciences (E.O., A.L., J.J.G.G., A.-M.v.D.), Department of Neurology (E.M.M.S.), and Department of Child Neurology (E.O.), Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, the Netherlands
| | - Antonio Luchicchi
- From the Department of Anatomy and Neurosciences (E.O., A.L., J.J.G.G., A.-M.v.D.), Department of Neurology (E.M.M.S.), and Department of Child Neurology (E.O.), Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, the Netherlands
| | - Eva M M Strijbis
- From the Department of Anatomy and Neurosciences (E.O., A.L., J.J.G.G., A.-M.v.D.), Department of Neurology (E.M.M.S.), and Department of Child Neurology (E.O.), Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, the Netherlands
| | - Jeroen J G Geurts
- From the Department of Anatomy and Neurosciences (E.O., A.L., J.J.G.G., A.-M.v.D.), Department of Neurology (E.M.M.S.), and Department of Child Neurology (E.O.), Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, the Netherlands
| | - Anne-Marie van Dam
- From the Department of Anatomy and Neurosciences (E.O., A.L., J.J.G.G., A.-M.v.D.), Department of Neurology (E.M.M.S.), and Department of Child Neurology (E.O.), Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, the Netherlands.
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13
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Hardt R, Jordans S, Winter D, Gieselmann V, Wang-Eckhardt L, Eckhardt M. Decreased turnover of the CNS myelin protein Opalin in a mouse model of hereditary spastic paraplegia 35. Hum Mol Genet 2020; 29:3616-3630. [PMID: 33215680 DOI: 10.1093/hmg/ddaa246] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 02/07/2023] Open
Abstract
Spastic paraplegia 35 (SPG35) (OMIM: 612319) or fatty acid hydroxylase-associated neurodegeneration (FAHN) is caused by deficiency of fatty acid 2-hydroxylase (FA2H). This enzyme synthesizes sphingolipids containing 2-hydroxylated fatty acids, which are particularly abundant in myelin. Fa2h-deficient (Fa2h-/-) mice develop symptoms reminiscent of the human disease and therefore serve as animal model of SPG35. In order to understand further the pathogenesis of SPG35, we compared the proteome of purified CNS myelin isolated from wild type and Fa2h-/- mice at different time points of disease progression using tandem mass tag labeling. Data analysis with a focus on myelin membrane proteins revealed a significant increase of the oligodendrocytic myelin paranodal and inner loop protein (Opalin) in Fa2h-/- mice, whereas the concentration of other major myelin proteins was not significantly changed. Western blot analysis revealed an almost 6-fold increase of Opalin in myelin of Fa2h-/- mice aged 21-23 months. A concurrent unaltered Opalin gene expression suggested a decreased turnover of the Opalin protein in Fa2h-/- mice. Supporting this hypothesis, Opalin protein half-life was reduced significantly when expressed in CHO cells synthesizing 2-hydroxylated sulfatide, compared to cells synthesizing only non-hydroxylated sulfatide. Degradation of Opalin was inhibited by inhibitors of lysosomal degradation but unaffected by proteasome inhibitors. Taken together, these results reveal a new function of 2-hydroxylated sphingolipids namely affecting the turnover of a myelin membrane protein. This may play a role in the pathogenesis of SPG35.
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Affiliation(s)
- Robert Hardt
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn 53115, Germany
| | - Silvia Jordans
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn 53115, Germany
| | - Dominic Winter
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn 53115, Germany
| | - Volkmar Gieselmann
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn 53115, Germany
| | - Lihua Wang-Eckhardt
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn 53115, Germany
| | - Matthias Eckhardt
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn 53115, Germany
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14
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Valenzuela A, Meservey L, Nguyen H, Fu MM. Golgi Outposts Nucleate Microtubules in Cells with Specialized Shapes. Trends Cell Biol 2020; 30:792-804. [PMID: 32863092 DOI: 10.1016/j.tcb.2020.07.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 07/11/2020] [Accepted: 07/15/2020] [Indexed: 12/16/2022]
Abstract
Classically, animal cells nucleate or form new microtubules off the perinuclear centrosome. In recent years, the Golgi outpost has emerged as a satellite organelle that can function as an acentrosomal microtubule-organizing center (MTOC), nucleating new microtubules at distances far from the nucleus or cell body. Golgi outposts can nucleate new microtubules in specialized cells with unique cytoarchitectures, including Drosophila neurons, mouse muscle cells, and rodent oligodendrocytes. This review compares and contrasts topics of functional relevance, including Golgi outpost heterogeneity, formation and transport, as well as regulation of microtubule polarity and branching. Golgi outposts have also been implicated in the pathology of diseases including muscular dystrophy, and neurodegenerative diseases, such as Parkinson's disease (PD). Since Golgi outposts are relatively understudied, many outstanding questions regarding their function and roles in disease remain.
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Affiliation(s)
- Alex Valenzuela
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lindsey Meservey
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Huy Nguyen
- Department of Neurology, Stanford University School of Medicine, Stanford, CA, USA
| | - Meng-Meng Fu
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA; National Institute of Neurological Disorders and Stroke, Bethesda, MD, USA.
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15
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Jahn O, Siems SB, Kusch K, Hesse D, Jung RB, Liepold T, Uecker M, Sun T, Werner HB. The CNS Myelin Proteome: Deep Profile and Persistence After Post-mortem Delay. Front Cell Neurosci 2020; 14:239. [PMID: 32973451 PMCID: PMC7466725 DOI: 10.3389/fncel.2020.00239] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 07/07/2020] [Indexed: 12/14/2022] Open
Abstract
Myelin membranes are dominated by lipids while the complexity of their protein composition has long been considered to be low. However, numerous additional myelin proteins have been identified since. Here we revisit the proteome of myelin biochemically purified from the brains of healthy c56Bl/6N-mice utilizing complementary proteomic approaches for deep qualitative and quantitative coverage. By gel-free, label-free mass spectrometry, the most abundant myelin proteins PLP, MBP, CNP, and MOG constitute 38, 30, 5, and 1% of the total myelin protein, respectively. The relative abundance of myelin proteins displays a dynamic range of over four orders of magnitude, implying that PLP and MBP have overshadowed less abundant myelin constituents in initial gel-based approaches. By comparisons with published datasets we evaluate to which degree the CNS myelin proteome correlates with the mRNA and protein abundance profiles of myelin and oligodendrocytes. Notably, the myelin proteome displays only minor changes if assessed after a post-mortem delay of 6 h. These data provide the most comprehensive proteome resource of CNS myelin so far and a basis for addressing proteomic heterogeneity of myelin in mouse models and human patients with white matter disorders.
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Affiliation(s)
- Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Sophie B. Siems
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Dörte Hesse
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ramona B. Jung
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Thomas Liepold
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Marina Uecker
- Proteomics Group, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ting Sun
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Hauke B. Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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16
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Domingues HS, Urbanski MM, Macedo-Ribeiro S, Almaktari A, Irfan A, Hernandez Y, Wang H, Relvas JB, Rubinstein B, Melendez-Vasquez CV, Pinto IM. Pushing myelination - developmental regulation of myosin expression drives oligodendrocyte morphological differentiation. J Cell Sci 2020; 133:jcs232264. [PMID: 32620697 PMCID: PMC7426197 DOI: 10.1242/jcs.232264] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 06/24/2020] [Indexed: 01/26/2023] Open
Abstract
Oligodendrocytes are the central nervous system myelin-forming cells providing axonal electrical insulation and higher-order neuronal circuitry. The mechanical forces driving the differentiation of oligodendrocyte precursor cells into myelinating oligodendrocytes are largely unknown, but likely require the spatiotemporal regulation of the architecture and dynamics of the actin and actomyosin cytoskeletons. In this study, we analyzed the expression pattern of myosin motors during oligodendrocyte development. We report that oligodendrocyte differentiation is regulated by the synchronized expression and non-uniform distribution of several members of the myosin network, particularly non-muscle myosins 2B and 2C, which potentially operate as nanomechanical modulators of cell tension and myelin membrane expansion at different cell stages.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Helena Sofia Domingues
- International Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135 Porto, Portugal
| | - Mateusz M Urbanski
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - Sandra Macedo-Ribeiro
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135 Porto, Portugal
| | - Amr Almaktari
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - Azka Irfan
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - Yamely Hernandez
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - Haibo Wang
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
| | - João Bettencourt Relvas
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, 4200-135 Porto, Portugal
- Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, 4200-135 Porto, Portugal
| | - Boris Rubinstein
- Stowers Institute for Medical Research, Kansas City, MO 64110, USA
| | - Carmen V Melendez-Vasquez
- Department of Biological Sciences, Hunter College City University of New York, New York, NY 10065, USA
- The Graduate Center, City University of New York (CUNY), New York, NY 10016, USA
| | - Inês Mendes Pinto
- International Iberian Nanotechnology Laboratory (INL), 4715-330 Braga, Portugal
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17
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Raasakka A, Kursula P. How Does Protein Zero Assemble Compact Myelin? Cells 2020; 9:E1832. [PMID: 32759708 PMCID: PMC7465998 DOI: 10.3390/cells9081832] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 07/21/2020] [Accepted: 07/30/2020] [Indexed: 02/06/2023] Open
Abstract
Myelin protein zero (P0), a type I transmembrane protein, is the most abundant protein in peripheral nervous system (PNS) myelin-the lipid-rich, periodic structure of membrane pairs that concentrically encloses long axonal segments. Schwann cells, the myelinating glia of the PNS, express P0 throughout their development until the formation of mature myelin. In the intramyelinic compartment, the immunoglobulin-like domain of P0 bridges apposing membranes via homophilic adhesion, forming, as revealed by electron microscopy, the electron-dense, double "intraperiod line" that is split by a narrow, electron-lucent space corresponding to the extracellular space between membrane pairs. The C-terminal tail of P0 adheres apposing membranes together in the narrow cytoplasmic compartment of compact myelin, much like myelin basic protein (MBP). In mouse models, the absence of P0, unlike that of MBP or P2, severely disturbs myelination. Therefore, P0 is the executive molecule of PNS myelin maturation. How and when P0 is trafficked and modified to enable myelin compaction, and how mutations that give rise to incurable peripheral neuropathies alter the function of P0, are currently open questions. The potential mechanisms of P0 function in myelination are discussed, providing a foundation for the understanding of mature myelin development and how it derails in peripheral neuropathies.
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Affiliation(s)
- Arne Raasakka
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, NO-5009 Bergen, Norway;
| | - Petri Kursula
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, NO-5009 Bergen, Norway;
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Aapistie 7A, FI-90220 Oulu, Finland
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18
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Salas IH, Burgado J, Allen NJ. Glia: victims or villains of the aging brain? Neurobiol Dis 2020; 143:105008. [PMID: 32622920 DOI: 10.1016/j.nbd.2020.105008] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 06/14/2020] [Accepted: 06/29/2020] [Indexed: 12/11/2022] Open
Abstract
Aging is the strongest risk factor for metabolic, vascular and neurodegenerative diseases. Aging alone is associated with a gradual decline of cognitive and motor functions. Considering an increasing elderly population in the last century, understanding the cellular and molecular mechanisms contributing to brain aging is of vital importance. Recent genetic and transcriptomic findings strongly suggest that glia are the first cells changing with aging. Glial cells constitute around 50% of the total cells in the brain and play key roles regulating brain homeostasis in health and disease. Their essential functions include providing nutritional support to neurons, activation of immune responses, and regulation of synaptic transmission and plasticity. In this review we discuss how glia are altered in the aging brain and whether these alterations are protective or contribute to the age-related pathological cascade. We focus on the major morphological, transcriptional and functional changes affecting glia in a range of systems, including human, non-human primates, and rodents. We also highlight future directions for investigating the roles of glia in brain aging.
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Affiliation(s)
- Isabel H Salas
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jillybeth Burgado
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Nicola J Allen
- Salk Institute for Biological Studies, Molecular Neurobiology Laboratory, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA.
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19
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Sampaio-Baptista C, Vallès A, Khrapitchev AA, Akkermans G, Winkler AM, Foxley S, Sibson NR, Roberts M, Miller K, Diamond ME, Martens GJM, De Weerd P, Johansen-Berg H. White matter structure and myelin-related gene expression alterations with experience in adult rats. Prog Neurobiol 2020; 187:101770. [PMID: 32001310 PMCID: PMC7086231 DOI: 10.1016/j.pneurobio.2020.101770] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 12/19/2019] [Accepted: 01/24/2020] [Indexed: 11/30/2022]
Abstract
White matter (WM) plasticity during adulthood is a recently described phenomenon by which experience can shape brain structure. It has been observed in humans using diffusion tensor imaging (DTI) and myelination has been suggested as a possible mechanism. Here, we set out to identify molecular and cellular changes associated with WM plasticity measured by DTI. We combined DTI, immunohistochemistry and mRNA expression analysis and examined the effects of somatosensory experience in adult rats. First, we observed experience-induced DTI differences in WM and in grey matter structure. C-Fos mRNA expression, a marker of cortical activity, in the barrel cortex correlated with the MRI WM metrics, indicating that molecular correlates of cortical activity relate to macroscale measures of WM structure. Analysis of myelin-related genes revealed higher myelin basic protein (MBP) mRNA expression. Higher MBP protein expression was also found via immunohistochemistry in WM. Finally, unbiased RNA sequencing analysis identified 134 differentially expressed genes encoding proteins involved in functions related to cell proliferation and differentiation, regulation of myelination and neuronal activity modulation. In conclusion, macroscale measures of WM plasticity are supported by both molecular and cellular evidence and confirm that myelination is one of the underlying mechanisms.
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Affiliation(s)
- Cassandra Sampaio-Baptista
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK.
| | - Astrid Vallès
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behaviour, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, 6525 GA Nijmegen, The Netherlands; Department of Neurocognition, Faculty of Psychology and Neurosciences, Maastricht University, 6200 MD Maastricht, The Netherlands
| | - Alexandre A Khrapitchev
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Churchill Hospital, Oxford OX3 7LE, UK
| | - Guus Akkermans
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behaviour, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, 6525 GA Nijmegen, The Netherlands
| | - Anderson M Winkler
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Sean Foxley
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Nicola R Sibson
- Cancer Research UK and Medical Research Council Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Churchill Hospital, Oxford OX3 7LE, UK
| | - Mark Roberts
- Department of Neurocognition, Faculty of Psychology and Neurosciences, Maastricht University, 6200 MD Maastricht, The Netherlands
| | - Karla Miller
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
| | - Mathew E Diamond
- Tactile Perception and Learning Lab, International School for Advanced Studies (SISSA), 34136 Trieste, Italy
| | - Gerard J M Martens
- Department of Molecular Animal Physiology, Donders Institute for Brain, Cognition and Behaviour, Radboud Institute for Molecular Life Sciences (RIMLS), Radboud University Nijmegen, 6525 GA Nijmegen, The Netherlands
| | - Peter De Weerd
- Department of Neurocognition, Faculty of Psychology and Neurosciences, Maastricht University, 6200 MD Maastricht, The Netherlands; Department of Cognitive Neuroscience, Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, 6500 HB Nijmegen, The Netherlands; Maastricht Centre for Systems Biology (MaCSBio), Maastricht University, 6229 ER Maastricht, The Netherlands
| | - Heidi Johansen-Berg
- Wellcome Centre for Integrative Neuroimaging, FMRIB, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford OX3 9DU, UK
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20
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Siems SB, Jahn O, Eichel MA, Kannaiyan N, Wu LMN, Sherman DL, Kusch K, Hesse D, Jung RB, Fledrich R, Sereda MW, Rossner MJ, Brophy PJ, Werner HB. Proteome profile of peripheral myelin in healthy mice and in a neuropathy model. eLife 2020; 9:e51406. [PMID: 32130108 PMCID: PMC7056269 DOI: 10.7554/elife.51406] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 02/19/2020] [Indexed: 02/07/2023] Open
Abstract
Proteome and transcriptome analyses aim at comprehending the molecular profiles of the brain, its cell-types and subcellular compartments including myelin. Despite the relevance of the peripheral nervous system for normal sensory and motor capabilities, analogous approaches to peripheral nerves and peripheral myelin have fallen behind evolving technical standards. Here we assess the peripheral myelin proteome by gel-free, label-free mass-spectrometry for deep quantitative coverage. Integration with RNA-Sequencing-based developmental mRNA-abundance profiles and neuropathy disease genes illustrates the utility of this resource. Notably, the periaxin-deficient mouse model of the neuropathy Charcot-Marie-Tooth 4F displays a highly pathological myelin proteome profile, exemplified by the discovery of reduced levels of the monocarboxylate transporter MCT1/SLC16A1 as a novel facet of the neuropathology. This work provides the most comprehensive proteome resource thus far to approach development, function and pathology of peripheral myelin, and a straightforward, accurate and sensitive workflow to address myelin diversity in health and disease.
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Affiliation(s)
- Sophie B Siems
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Maria A Eichel
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Nirmal Kannaiyan
- Department of Psychiatry and Psychotherapy, University Hospital, LMU MunichMunichGermany
| | - Lai Man N Wu
- Centre for Discovery Brain Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Diane L Sherman
- Centre for Discovery Brain Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Dörte Hesse
- Proteomics Group, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
| | - Robert Fledrich
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
- Institute of Anatomy, University of LeipzigLeipzigGermany
| | - Michael W Sereda
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
- Department of Clinical Neurophysiology, University Medical CenterGöttingenGermany
| | - Moritz J Rossner
- Department of Psychiatry and Psychotherapy, University Hospital, LMU MunichMunichGermany
| | - Peter J Brophy
- Centre for Discovery Brain Sciences, University of EdinburghEdinburghUnited Kingdom
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental MedicineGöttingenGermany
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21
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Raasakka A, Kursula P. Flexible Players within the Sheaths: The Intrinsically Disordered Proteins of Myelin in Health and Disease. Cells 2020; 9:cells9020470. [PMID: 32085570 PMCID: PMC7072810 DOI: 10.3390/cells9020470] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 02/16/2020] [Accepted: 02/16/2020] [Indexed: 02/07/2023] Open
Abstract
Myelin ensheathes selected axonal segments within the nervous system, resulting primarily in nerve impulse acceleration, as well as mechanical and trophic support for neurons. In the central and peripheral nervous systems, various proteins that contribute to the formation and stability of myelin are present, which also harbor pathophysiological roles in myelin disease. Many myelin proteins have common attributes, including small size, hydrophobic segments, multifunctionality, longevity, and regions of intrinsic disorder. With recent advances in protein biophysical characterization and bioinformatics, it has become evident that intrinsically disordered proteins (IDPs) are abundant in myelin, and their flexible nature enables multifunctionality. Here, we review known myelin IDPs, their conservation, molecular characteristics and functions, and their disease relevance, along with open questions and speculations. We place emphasis on classifying the molecular details of IDPs in myelin, and we correlate these with their various functions, including susceptibility to post-translational modifications, function in protein–protein and protein–membrane interactions, as well as their role as extended entropic chains. We discuss how myelin pathology can relate to IDPs and which molecular factors are potentially involved.
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Affiliation(s)
- Arne Raasakka
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, NO-5009 Bergen, Norway;
| | - Petri Kursula
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, NO-5009 Bergen, Norway;
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Aapistie 7A, FI-90220 Oulu, Finland
- Correspondence:
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22
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Joseph S, Werner HB, Stegmüller J. Gallyas Silver Impregnation of Myelinated Nerve Fibers. Bio Protoc 2019; 9:e3436. [PMID: 33654932 DOI: 10.21769/bioprotoc.3436] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/31/2019] [Accepted: 11/26/2019] [Indexed: 12/18/2022] Open
Abstract
In the nervous system of vertebrates, nerve impulse propagation is accelerated by the ensheathment of neuronal axons with myelin. Myelin sheaths are molecularly specialized, lipid-rich plasma membrane extensions of Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system (CNS). To visualize myelinated nerve fibers and to allow for the morphological analyses of myelin in the brain and the spinal cord, an efficient method for silver impregnation of myelin has originally been developed by Ferenc Gallyas in 1979, referred to as Gallyas silver impregnation. Gallyas' method is based on the agyrophilic characteristic of myelin to form and bind silver particles, while this process is suppressed in tissues other than myelin. The silver particles are finally enhanced in a developing step ("physical developer"). The main advantage of this method is that it efficiently visualizes both large myelinated fiber tracts and individual myelinated axons. Here we provide our laboratory protocol that is suitable for paraffin embedded sections and the use of light microscopy based on Gallyas' original protocol and subsequent modifications by Pistorio and colleagues.
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Affiliation(s)
- Sabitha Joseph
- Department of Neurology, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Hermann Rein Strasse 3, 37075 Göttingen
| | - Judith Stegmüller
- Department of Neurology, RWTH Aachen University Hospital, Pauwelsstrasse 30, 52074 Aachen, Germany.,Research Training Group 2416 MultiSenses-MultiScales, RWTH Aachen University, 52074 Aachen, Germany
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23
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Scalia F, Marino Gammazza A, Conway de Macario E, Macario AJL, Cappello F. Myelin Pathology: Involvement of Molecular Chaperones and the Promise of Chaperonotherapy. Brain Sci 2019; 9:brainsci9110297. [PMID: 31671529 PMCID: PMC6896170 DOI: 10.3390/brainsci9110297] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/23/2019] [Accepted: 10/27/2019] [Indexed: 11/27/2022] Open
Abstract
The process of axon myelination involves various proteins including molecular chaperones. Myelin alteration is a common feature in neurological diseases due to structural and functional abnormalities of one or more myelin proteins. Genetic proteinopathies may occur either in the presence of a normal chaperoning system, which is unable to assist the defective myelin protein in its folding and migration, or due to mutations in chaperone genes, leading to functional defects in assisting myelin maturation/migration. The latter are a subgroup of genetic chaperonopathies causing demyelination. In this brief review, we describe some paradigmatic examples pertaining to the chaperonins Hsp60 (HSPD1, or HSP60, or Cpn60) and CCT (chaperonin-containing TCP-1). Our aim is to make scientists and physicians aware of the possibility and advantages of classifying patients depending on the presence or absence of a chaperonopathy. In turn, this subclassification will allow the development of novel therapeutic strategies (chaperonotherapy) by using molecular chaperones as agents or targets for treatment.
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Affiliation(s)
- Federica Scalia
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy.
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy.
| | - Antonella Marino Gammazza
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy.
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy.
| | - Everly Conway de Macario
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy.
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore-Institute of Marine and Environmental Technology (IMET), Baltimore, MD 21202, USA.
| | - Alberto J L Macario
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy.
- Department of Microbiology and Immunology, School of Medicine, University of Maryland at Baltimore-Institute of Marine and Environmental Technology (IMET), Baltimore, MD 21202, USA.
| | - Francesco Cappello
- Department of Biomedicine, Neuroscience and Advanced Diagnostics (BIND), University of Palermo, 90127 Palermo, Italy.
- Euro-Mediterranean Institute of Science and Technology (IEMEST), 90139 Palermo, Italy.
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24
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Altered distribution, aggregation, and protease resistance of cellular prion protein following intracranial inoculation. PLoS One 2019; 14:e0219457. [PMID: 31291644 PMCID: PMC6620108 DOI: 10.1371/journal.pone.0219457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 06/24/2019] [Indexed: 11/19/2022] Open
Abstract
Prion protein (PrPC) is a protease-sensitive and soluble cell surface glycoprotein expressed in almost all mammalian cell types. PrPSc, a protease-resistant and insoluble form of PrPC, is the causative agent of prion diseases, fatal and transmissible neurogenerative diseases of mammals. Prion infection is initiated via either ingestion or inoculation of PrPSc or when host PrPC stochastically refolds into PrPSc. In either instance, the early events that occur during prion infection remain poorly understood. We have used transgenic mice expressing mouse PrPC tagged with a unique antibody epitope to monitor the response of host PrPC to prion inoculation. Following intracranial inoculation of either prion-infected or uninfected brain homogenate, we show that host PrPC can accumulate both intra-axonally and within the myelin membrane of axons suggesting that it may play a role in axonal loss following brain injury. Moreover, in response to the inoculation host PrPC exhibits an increased insolubility and protease resistance similar to that of PrPSc, even in the absence of infectious prions. Thus, our results raise the possibility that damage to the brain may be one trigger by which PrPC stochastically refolds into pathogenic PrPSc leading to productive prion infection.
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25
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Schoor C, Brocke-Ahmadinejad N, Gieselmann V, Winter D. Investigation of Oligodendrocyte Precursor Cell Differentiation by Quantitative Proteomics. Proteomics 2019; 19:e1900057. [PMID: 31216117 DOI: 10.1002/pmic.201900057] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 06/02/2019] [Indexed: 01/20/2023]
Abstract
Oligodendrocytes, the myelinating cells of the central nervous system, are essential for correct brain function. They originate from oligodendrocyte precursor cells through a differentiation process which is only incompletely understood and impaired in a variety of demyelinating diseases. Better knowledge of this differentiation holds the promise to develop novel therapies for these disorders. The differentiation of rat oligodendrocyte precursor cells to oligodendrocytes in vitro is investigated. After confirmation of differentiation by immunohistochemical analysis using cell type-specific marker proteins, a quantitative proteomics study using tandem mass tags (TMT) is conducted. Four time points of differentiation covering early, intermediate, and late stages are investigated. Data analysis by Mascot and MaxQuant identified 5259 protein groups of which 471 are not described in the context of cells of the oligodendroglial lineage before. Quantitative analysis of the dataset revealed distinct regulation patterns for proteins of different functional categories including metabolic processes, regulation of the cell cycle, and transcriptional control of protein expression. The present data confirm a significant number of proteins known to play a role in oligodendrocytes and myelination. Furthermore, novel candidate proteins are identified which may play an important role in this differentiation process providing a valuable resource for oligodendrocyte research.
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Affiliation(s)
- Carmen Schoor
- Institute for Biochemistry and Molecular Biology, University of Bonn, 53115, Bonn, Germany
| | | | - Volkmar Gieselmann
- Institute for Biochemistry and Molecular Biology, University of Bonn, 53115, Bonn, Germany
| | - Dominic Winter
- Institute for Biochemistry and Molecular Biology, University of Bonn, 53115, Bonn, Germany
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26
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Raasakka A, Linxweiler H, Brophy PJ, Sherman DL, Kursula P. Direct Binding of the Flexible C-Terminal Segment of Periaxin to β4 Integrin Suggests a Molecular Basis for CMT4F. Front Mol Neurosci 2019; 12:84. [PMID: 31024253 PMCID: PMC6465933 DOI: 10.3389/fnmol.2019.00084] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/19/2019] [Indexed: 11/13/2022] Open
Abstract
The process of myelination in the nervous system requires a coordinated formation of both transient and stable supramolecular complexes. Myelin-specific proteins play key roles in these assemblies, which may link membranes to each other or connect the myelinating cell cytoskeleton to the extracellular matrix. The myelin protein periaxin is known to play an important role in linking the Schwann cell cytoskeleton to the basal lamina through membrane receptors, such as the dystroglycan complex. Mutations that truncate periaxin from the C terminus cause demyelinating peripheral neuropathy, Charcot-Marie-Tooth (CMT) disease type 4F, indicating a function for the periaxin C-terminal region in myelination. We identified the cytoplasmic domain of β4 integrin as a specific high-affinity binding partner for periaxin. The C-terminal region of periaxin remains unfolded and flexible when bound to the third fibronectin type III domain of β4 integrin. Our data suggest that periaxin is able to link the Schwann cell cytoplasm to the basal lamina through a two-pronged interaction via different membrane protein complexes, which bind close to the N and C terminus of this elongated, flexible molecule.
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Affiliation(s)
- Arne Raasakka
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | | | - Peter J. Brophy
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Diane L. Sherman
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Petri Kursula
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
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27
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Lüders KA, Nessler S, Kusch K, Patzig J, Jung RB, Möbius W, Nave KA, Werner HB. Maintenance of high proteolipid protein level in adult central nervous system myelin is required to preserve the integrity of myelin and axons. Glia 2019; 67:634-649. [PMID: 30637801 DOI: 10.1002/glia.23549] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/24/2018] [Accepted: 10/01/2018] [Indexed: 12/20/2022]
Abstract
Proteolipid protein (PLP) is the most abundant integral membrane protein in central nervous system (CNS) myelin. Expression of the Plp-gene in oligodendrocytes is not essential for the biosynthesis of myelin membranes but required to prevent axonal pathology. This raises the question whether the exceptionally high level of PLP in myelin is required later in life, or whether high-level PLP expression becomes dispensable once myelin has been assembled. Both models require a better understanding of the turnover of PLP in myelin in vivo. Thus, we generated and characterized a novel line of tamoxifen-inducible Plp-mutant mice that allowed us to determine the rate of PLP turnover after developmental myelination has been completed, and to assess the possible impact of gradually decreasing amounts of PLP for myelin and axonal integrity. We found that 6 months after targeting the Plp-gene the abundance of PLP in CNS myelin was about halved, probably reflecting that myelin is slowly turned over in the adult brain. Importantly, this reduction by 50% was sufficient to cause the entire spectrum of neuropathological changes previously associated with the developmental lack of PLP, including myelin outfoldings, lamellae splittings, and axonal spheroids. In comparison to axonopathy and gliosis, the infiltration of cytotoxic T-cells was temporally delayed, suggesting a corresponding chronology also in the genetic disorders of PLP-deficiency. High-level abundance of PLP in myelin throughout adult life emerges as a requirement for the preservation of white matter integrity.
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Affiliation(s)
- Katja A Lüders
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Göttingen Graduate School for Neurosciences, Biophysics and Molecular Biosciences, Göttingen, Germany
| | - Stefan Nessler
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Julia Patzig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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28
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Erwig MS, Hesse D, Jung RB, Uecker M, Kusch K, Tenzer S, Jahn O, Werner HB. Myelin: Methods for Purification and Proteome Analysis. Methods Mol Biol 2019; 1936:37-63. [PMID: 30820892 DOI: 10.1007/978-1-4939-9072-6_3] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Molecular characterization of myelin is a prerequisite for understanding the normal structure of the axon/myelin-unit in the healthy nervous system and abnormalities in myelin-related disorders. However, reliable molecular profiles necessitate very pure myelin membranes, in particular when considering the power of highly sensitive "omics"-data acquisition methods. Here, we recapitulate the history and recent applications of myelin purification. We then provide our laboratory protocols for the biochemical isolation of a highly pure myelin-enriched fraction from mouse brains and for its proteomic analysis. We also supply methodological modifications when investigating posttranslational modifications, RNA, or myelin from peripheral nerves. Notably, technical advancements in solubilizing myelin are beneficial for gel-based and gel-free myelin proteome analyses. We conclude this article by exemplifying the exceptional power of label-free proteomics in the mass-spectrometric quantification of myelin proteins.
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Affiliation(s)
- Michelle S Erwig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Dörte Hesse
- Proteomics Group, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Marina Uecker
- Proteomics Group, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental Medicine, Goettingen, Germany.
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany.
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29
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Baburina Y, Odinokova I, Azarashvili T, Akatov V, Sotnikova L, Krestinina O. Possible Involvement of 2',3'-Cyclic Nucleotide-3'-Phosphodiesterase in the Protein Phosphorylation-Mediated Regulation of the Permeability Transition Pore. Int J Mol Sci 2018; 19:ijms19113499. [PMID: 30405014 PMCID: PMC6274948 DOI: 10.3390/ijms19113499] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/04/2018] [Accepted: 11/05/2018] [Indexed: 12/31/2022] Open
Abstract
Calcium as a secondary messenger regulates the phosphorylation of several membrane-bound proteins in brain and liver mitochondria. Regulation of the activity of different protein kinases and phosphatases by Ca2+ occurs through its binding with calmodulin. The protein phosphorylation is strongly dependent on the Ca2+-induced mitochondrial permeability transition pore (mPTP) opening. 2′,3′-Cyclic nucleotide-3′-phosphodiesterase (CNPase) was phosphorylated by protein kinases A and C. CNPase and melatonin (MEL) might interact with calmodulin. The effects of the calmodulin antagonist calmidazolium and the inhibitor of protein kinase A H89 on mPTP opening in rat brain mitochondria of male Wistar rats were investigated. In addition, the role of CNPase, serine/threonine kinases, and MEL in the mPTP opening was examined. The anti-CNPase antibody added to rat brain mitochondria (RBM) reduced the content of CNPase in mitochondria. The threshold [Ca2+] decreased, and mitochondrial swelling was accelerated in the presence of the anti-CNPase antibody. H89 enhanced the effect of anti-CNPase antibody and accelerated the swelling of mitochondria, while CmZ abolished the effect of anti-CNPase antibody under mPTP opening. The levels of phospho-Akt and phospho-GSK3β increased, while the MEL content did not change. It can be assumed that CNPase may be involved in the regulation of these kinases, which in turn plays an important role in mPTP functioning.
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Affiliation(s)
- Yulia Baburina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia.
| | - Irina Odinokova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia.
| | - Tamara Azarashvili
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia.
| | - Vladimir Akatov
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia.
| | - Linda Sotnikova
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia.
| | - Olga Krestinina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Russia.
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30
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Ferrer I. Oligodendrogliopathy in neurodegenerative diseases with abnormal protein aggregates: The forgotten partner. Prog Neurobiol 2018; 169:24-54. [DOI: 10.1016/j.pneurobio.2018.07.004] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 07/24/2018] [Accepted: 07/27/2018] [Indexed: 12/31/2022]
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31
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Barry AM, Sondermann JR, Sondermann JH, Gomez-Varela D, Schmidt M. Region-Resolved Quantitative Proteome Profiling Reveals Molecular Dynamics Associated With Chronic Pain in the PNS and Spinal Cord. Front Mol Neurosci 2018; 11:259. [PMID: 30154697 PMCID: PMC6103001 DOI: 10.3389/fnmol.2018.00259] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/10/2018] [Indexed: 12/27/2022] Open
Abstract
To obtain a thorough understanding of chronic pain, large-scale molecular mapping of the pain axis at the protein level is necessary, but has not yet been achieved. We applied quantitative proteome profiling to build a comprehensive protein compendium of three regions of the pain neuraxis in mice: the sciatic nerve (SN), the dorsal root ganglia (DRG), and the spinal cord (SC). Furthermore, extensive bioinformatics analysis enabled us to reveal unique protein subsets which are specifically enriched in the peripheral nervous system (PNS) and SC. The immense value of these datasets for the scientific community is highlighted by validation experiments, where we monitored protein network dynamics during neuropathic pain. Here, we resolved profound region-specific differences and distinct changes of PNS-enriched proteins under pathological conditions. Overall, we provide a unique and validated systems biology proteome resource (summarized in our online database painproteome.em.mpg.de), which facilitates mechanistic insights into somatosensory biology and chronic pain—a prerequisite for the identification of novel therapeutic targets.
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Affiliation(s)
- Allison M Barry
- Max-Planck Institute of Experimental Medicine, Somatosensory Signaling and Systems Biology Group, Goettingen, Germany
| | - Julia R Sondermann
- Max-Planck Institute of Experimental Medicine, Somatosensory Signaling and Systems Biology Group, Goettingen, Germany
| | - Jan-Hendrik Sondermann
- Max-Planck Institute of Experimental Medicine, Somatosensory Signaling and Systems Biology Group, Goettingen, Germany
| | - David Gomez-Varela
- Max-Planck Institute of Experimental Medicine, Somatosensory Signaling and Systems Biology Group, Goettingen, Germany
| | - Manuela Schmidt
- Max-Planck Institute of Experimental Medicine, Somatosensory Signaling and Systems Biology Group, Goettingen, Germany
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32
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33
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McKenzie AT, Moyon S, Wang M, Katsyv I, Song WM, Zhou X, Dammer EB, Duong DM, Aaker J, Zhao Y, Beckmann N, Wang P, Zhu J, Lah JJ, Seyfried NT, Levey AI, Katsel P, Haroutunian V, Schadt EE, Popko B, Casaccia P, Zhang B. Multiscale network modeling of oligodendrocytes reveals molecular components of myelin dysregulation in Alzheimer's disease. Mol Neurodegener 2017; 12:82. [PMID: 29110684 PMCID: PMC5674813 DOI: 10.1186/s13024-017-0219-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 10/17/2017] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Oligodendrocytes (OLs) and myelin are critical for normal brain function and have been implicated in neurodegeneration. Several lines of evidence including neuroimaging and neuropathological data suggest that Alzheimer's disease (AD) may be associated with dysmyelination and a breakdown of OL-axon communication. METHODS In order to understand this phenomenon on a molecular level, we systematically interrogated OL-enriched gene networks constructed from large-scale genomic, transcriptomic and proteomic data obtained from human AD postmortem brain samples. We then validated these networks using gene expression datasets generated from mice with ablation of major gene expression nodes identified in our AD-dysregulated networks. RESULTS The robust OL gene coexpression networks that we identified were highly enriched for genes associated with AD risk variants, such as BIN1 and demonstrated strong dysregulation in AD. We further corroborated the structure of the corresponding gene causal networks using datasets generated from the brain of mice with ablation of key network drivers, such as UGT8, CNP and PLP1, which were identified from human AD brain data. Further, we found that mice with genetic ablations of Cnp mimicked aspects of myelin and mitochondrial gene expression dysregulation seen in brain samples from patients with AD, including decreased protein expression of BIN1 and GOT2. CONCLUSIONS This study provides a molecular blueprint of the dysregulation of gene expression networks of OL in AD and identifies key OL- and myelination-related genes and networks that are highly associated with AD.
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Affiliation(s)
- Andrew T. McKenzie
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
- Medical Scientist Training Program, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Sarah Moyon
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
- Neuroscience Initiative, The City University of New York, Advanced Science Research Center, 85 St. Nicholas Terrace, New York, NY 10031 USA
| | - Minghui Wang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Igor Katsyv
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
- Medical Scientist Training Program, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Won-Min Song
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Xianxiao Zhou
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Eric B. Dammer
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Duc M. Duong
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322 USA
- Integrated Proteomics Core Facility, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Joshua Aaker
- Department of Neurology, The University of Chicago Pritzker School of Medicine, 5841 S. Maryland Avenue, Chicago, IL 60637 USA
| | - Yongzhong Zhao
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Noam Beckmann
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Pei Wang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Jun Zhu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - James J. Lah
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322 USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Nicholas T. Seyfried
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322 USA
- Integrated Proteomics Core Facility, Emory University School of Medicine, Atlanta, GA 30322 USA
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Allan I. Levey
- Department of Neurology, Emory University School of Medicine, Atlanta, GA 30322 USA
- Center for Neurodegenerative Disease, Emory University School of Medicine, Atlanta, GA 30322 USA
| | - Pavel Katsel
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Vahram Haroutunian
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
- Mental Illness Research, Education, and Clinical Center (VISN 3), James J. Peters VA Medical Center, Bronx, NY 10468 USA
| | - Eric E. Schadt
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
| | - Brian Popko
- Department of Neurology, The University of Chicago Pritzker School of Medicine, 5841 S. Maryland Avenue, Chicago, IL 60637 USA
| | - Patrizia Casaccia
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
- Neuroscience Initiative, The City University of New York, Advanced Science Research Center, 85 St. Nicholas Terrace, New York, NY 10031 USA
| | - Bin Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, 1470 Madison Avenue, Room S8-111, New York, NY 10029 USA
- Icahn Institute of Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029 USA
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34
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Lüders KA, Patzig J, Simons M, Nave KA, Werner HB. Genetic dissection of oligodendroglial and neuronalPlp1function in a novel mouse model of spastic paraplegia type 2. Glia 2017; 65:1762-1776. [DOI: 10.1002/glia.23193] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 06/28/2017] [Accepted: 06/29/2017] [Indexed: 12/12/2022]
Affiliation(s)
- Katja A. Lüders
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
| | - Julia Patzig
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
| | - Mikael Simons
- Cellular Neuroscience; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
| | - Hauke B. Werner
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Göttingen 37075 Germany
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35
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Prasad A, Teh DBL, Blasiak A, Chai C, Wu Y, Gharibani PM, Yang IH, Phan TT, Lim KL, Yang H, Liu X, All AH. Static Magnetic Field Stimulation Enhances Oligodendrocyte Differentiation and Secretion of Neurotrophic Factors. Sci Rep 2017; 7:6743. [PMID: 28751716 PMCID: PMC5532210 DOI: 10.1038/s41598-017-06331-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Accepted: 06/12/2017] [Indexed: 02/02/2023] Open
Abstract
The cellular-level effects of low/high frequency oscillating magnetic field on excitable cells such as neurons are well established. In contrast, the effects of a homogeneous, static magnetic field (SMF) on Central Nervous System (CNS) glial cells are less investigated. Here, we have developed an in vitro SMF stimulation set-up to investigate the genomic effects of SMF exposure on oligodendrocyte differentiation and neurotrophic factors secretion. Human oligodendrocytes precursor cells (OPCs) were stimulated with moderate intensity SMF (0.3 T) for a period of two weeks (two hours/day). The differential gene expression of cell activity marker (c-fos), early OPC (Olig1, Olig2. Sox10), and mature oligodendrocyte markers (CNP, MBP) were quantified. The enhanced myelination capacity of the SMF stimulated oligodendrocytes was validated in a dorsal root ganglion microfluidics chamber platform. Additionally, the effects of SMF on the gene expression and secretion of neurotrophic factors- BDNF and NT3 was quantified. We also report that SMF stimulation increases the intracellular calcium influx in OPCs as well as the gene expression of L-type channel subunits-CaV1.2 and CaV1.3. Our findings emphasize the ability of glial cells such as OPCs to positively respond to moderate intensity SMF stimulation by exhibiting enhanced differentiation, functionality as well as neurotrophic factor release.
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Affiliation(s)
- Ankshita Prasad
- Department of Biomedical Engineering, National University of Singapore, E4, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Daniel B Loong Teh
- Singapore Institute of Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, 5-COR, Singapore, 117456, Singapore
| | - Agata Blasiak
- Singapore Institute of Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, 5-COR, Singapore, 117456, Singapore
| | - Chou Chai
- National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Yang Wu
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Payam M Gharibani
- Department of Biomedical Engineering, John Hopkins School of Medicine, 701C Rutland Avenue 720, Baltimore, MD, 21205, USA
| | - In Hong Yang
- Singapore Institute of Neurotechnology (SINAPSE), National University of Singapore, 28 Medical Drive, 5-COR, Singapore, 117456, Singapore.,Department of Biomedical Engineering, John Hopkins School of Medicine, 701C Rutland Avenue 720, Baltimore, MD, 21205, USA
| | - Thang T Phan
- Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore
| | - Kah Leong Lim
- National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.,Department of Physiology, 2 Medical Drive, MD9, National University of Singapore, 117593, Singapore, Singapore.,Duke-NUS Medical School. 8 College Road, 169857, Singapore, Singapore
| | - Hyunsoo Yang
- Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore, 117583, Singapore
| | - Xiaogang Liu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore, 117543, Singapore.
| | - Angelo H All
- Department of Biomedical Engineering, John Hopkins School of Medicine, 701C Rutland Avenue 720, Baltimore, MD, 21205, USA. .,Department of Neurology, John Hopkins School of Medicine, 701C Rutland Avenue 720, Baltimore, MD, 21205, USA.
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36
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Bessonov K, Vassall KA, Harauz G. Docking and molecular dynamics simulations of the Fyn-SH3 domain with free and phospholipid bilayer-associated 18.5-kDa myelin basic protein (MBP)-Insights into a noncanonical and fuzzy interaction. Proteins 2017; 85:1336-1350. [PMID: 28380689 DOI: 10.1002/prot.25295] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 03/03/2017] [Accepted: 03/27/2017] [Indexed: 01/06/2023]
Abstract
The molecular details of the association between the human Fyn-SH3 domain, and the fragment of 18.5-kDa myelin basic protein (MBP) spanning residues S38-S107 (denoted as xα2-peptide, murine sequence numbering), were studied in silico via docking and molecular dynamics over 50-ns trajectories. The results show that interaction between the two proteins is energetically favorable and heavily dependent on the MBP proline-rich region (P93-P98) in both aqueous and membrane environments. In aqueous conditions, the xα2-peptide/Fyn-SH3 complex adopts a "sandwich""-like structure. In the membrane context, the xα2-peptide interacts with the Fyn-SH3 domain via the proline-rich region and the β-sheets of Fyn-SH3, with the latter wrapping around the proline-rich region in a form of a clip. Moreover, the simulations corroborate prior experimental evidence of the importance of upstream segments beyond the canonical SH3-ligand. This study thus provides a more-detailed glimpse into the context-dependent interaction dynamics and importance of the β-sheets in Fyn-SH3 and proline-rich region of MBP. Proteins 2017; 85:1336-1350. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Kyrylo Bessonov
- Systems and Modeling Unit, Montefiore Institute, Université de Liège, Quartier Polytech 1, Allée de la Découverte 10, Liège, 4000, Belgium
| | - Kenrick A Vassall
- Department of Molecular and Cellular Biology, Biophysics Interdepartmental Group, and Collaborative Program in Neuroscience, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
| | - George Harauz
- Department of Molecular and Cellular Biology, Biophysics Interdepartmental Group, and Collaborative Program in Neuroscience, University of Guelph, 50 Stone Road East, Guelph, Ontario, N1G 2W1, Canada
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37
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Ishimoto T, Ninomiya K, Inoue R, Koike M, Uchiyama Y, Mori H. Mice lacking BCAS1, a novel myelin-associated protein, display hypomyelination, schizophrenia-like abnormal behaviors, and upregulation of inflammatory genes in the brain. Glia 2017; 65:727-739. [PMID: 28230289 DOI: 10.1002/glia.23129] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 01/30/2017] [Accepted: 02/01/2017] [Indexed: 12/22/2022]
Abstract
The abnormal expression and function of myelin-related proteins contribute to nervous system dysfunction associated with neuropsychiatric disorders; however, the underlying mechanism of this remains unclear. We found here that breast carcinoma amplified sequence 1 (BCAS1), a basic protein abundant in the brain, was expressed specifically in oligodendrocytes and Schwann cells, and that its expression level was decreased by demyelination. This suggests that BCAS1 is a novel myelin-associated protein. BCAS1 knockout mice displayed schizophrenia-like behavioral abnormalities and a tendency toward reduced anxiety-like behaviors. Moreover, we found that the loss of BCAS1 specifically induced hypomyelination and the expression of inflammation-related genes in the brain. These observations provide a novel insight into the functional link between oligodendrocytes and inflammation and/or abnormal behaviors.
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Affiliation(s)
- Tetsuya Ishimoto
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Kensuke Ninomiya
- Department of Anatomy and Developmental Biology, Graduate School of Medicine, Kyoto University, Yoshida-Konoe-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Ran Inoue
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
| | - Masato Koike
- Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Yasuo Uchiyama
- Department of Cell Biology and Neuroscience, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Hisashi Mori
- Department of Molecular Neuroscience, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
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38
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Partial Immunoblotting of 2D-Gels: A Novel Method to Identify Post-Translationally Modified Proteins Exemplified for the Myelin Acetylome. Proteomes 2017; 5:proteomes5010003. [PMID: 28248254 PMCID: PMC5372224 DOI: 10.3390/proteomes5010003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 12/23/2016] [Accepted: 01/04/2017] [Indexed: 11/17/2022] Open
Abstract
Post-translational modifications (PTMs) play a key role in regulating protein function, yet their identification is technically demanding. Here, we present a straightforward workflow to systematically identify post-translationally modified proteins based on two-dimensional gel electrophoresis. Upon colloidal Coomassie staining the proteins are partially transferred, and the investigated PTMs are immunodetected. This strategy allows tracking back the immunopositive antigens to the corresponding spots on the original gel, from which they are excised and mass spectrometrically identified. Candidate proteins are validated on the same membrane by immunodetection using a second fluorescence channel. We exemplify the power of partial immunoblotting with the identification of lysine-acetylated proteins in myelin, the oligodendroglial membrane that insulates neuronal axons. The excellent consistency of the detected fluorescence signals at all levels allows the differential comparison of PTMs across multiple conditions. Beyond PTM screening, our multi-level workflow can be readily adapted to clinical applications such as identifying auto-immune antigens or host-pathogen interactions.
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39
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Turcotte R, Rutledge DJ, Bélanger E, Dill D, Macklin WB, Côté DC. Intravital assessment of myelin molecular order with polarimetric multiphoton microscopy. Sci Rep 2016; 6:31685. [PMID: 27538357 PMCID: PMC4990840 DOI: 10.1038/srep31685] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Accepted: 07/25/2016] [Indexed: 11/22/2022] Open
Abstract
Myelin plays an essential role in the nervous system and its disruption in diseases such as multiple sclerosis may lead to neuronal death, thus causing irreversible functional impairments. Understanding myelin biology is therefore of fundamental and clinical importance, but no tools currently exist to describe the fine spatial organization of myelin sheaths in vivo. Here we demonstrate intravital quantification of the myelin molecular structure using a microscopy method based on polarization-resolved coherent Raman scattering. Developmental myelination was imaged noninvasively in live zebrafish. Longitudinal imaging of individual axons revealed changes in myelin organization beyond the diffraction limit. Applied to promyelination drug screening, the method uniquely enabled the identification of focal myelin regions with differential architectures. These observations indicate that the study of myelin biology and the identification of therapeutic compounds will largely benefit from a method to quantify the myelin molecular organization in vivo.
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Affiliation(s)
- Raphaël Turcotte
- Centre de recherche de l'Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, QC G1J 2G3, Canada
| | - Danette J Rutledge
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Erik Bélanger
- Centre de recherche de l'Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, QC G1J 2G3, Canada
| | - Dorothy Dill
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Wendy B Macklin
- Department of Cell and Developmental Biology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Daniel C Côté
- Centre de recherche de l'Institut Universitaire en Santé Mentale de Québec, Université Laval, Québec, QC G1J 2G3, Canada.,Centre d'Optique, Photonique et Laser, Université Laval, Québec, QC G1V 0A6, Canada
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40
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Patzig J, Erwig MS, Tenzer S, Kusch K, Dibaj P, Möbius W, Goebbels S, Schaeren-Wiemers N, Nave KA, Werner HB. Septin/anillin filaments scaffold central nervous system myelin to accelerate nerve conduction. eLife 2016; 5. [PMID: 27504968 PMCID: PMC4978525 DOI: 10.7554/elife.17119] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 07/13/2016] [Indexed: 12/15/2022] Open
Abstract
Myelination of axons facilitates rapid impulse propagation in the nervous system. The axon/myelin-unit becomes impaired in myelin-related disorders and upon normal aging. However, the molecular cause of many pathological features, including the frequently observed myelin outfoldings, remained unknown. Using label-free quantitative proteomics, we find that the presence of myelin outfoldings correlates with a loss of cytoskeletal septins in myelin. Regulated by phosphatidylinositol-(4,5)-bisphosphate (PI(4,5)P2)-levels, myelin septins (SEPT2/SEPT4/SEPT7/SEPT8) and the PI(4,5)P2-adaptor anillin form previously unrecognized filaments that extend longitudinally along myelinated axons. By confocal microscopy and immunogold-electron microscopy, these filaments are localized to the non-compacted adaxonal myelin compartment. Genetic disruption of these filaments in Sept8-mutant mice causes myelin outfoldings as a very specific neuropathology. Septin filaments thus serve an important function in scaffolding the axon/myelin-unit, evidently a late stage of myelin maturation. We propose that pathological or aging-associated diminishment of the septin/anillin-scaffold causes myelin outfoldings that impair the normal nerve conduction velocity. DOI:http://dx.doi.org/10.7554/eLife.17119.001 Normal communication within the brain or between the brain and other parts of the body requires information to flow quickly around the nervous system. This information travels along nerve cells in the form of electrical signals. To speed up the signals, a part of the nerve cell called the axon is frequently wrapped in an electrically insulating sheath made up of a membrane structure called myelin. The myelin sheath becomes impaired as a result of disease or ageing. In order to understand what might produce these changes, Patzig et al. have used biochemical and microscopy techniques to study mice that had similar defects in their myelin sheaths. The study reveals that forming a normal myelin sheath around an axon requires a newly identified ‘scaffold’ made of a group of proteins called the septins. Combining with another protein called anillin, septins assemble into filaments in the myelin sheath. These filaments then knit together into a scaffold that grows lengthways along the myelin-wrapped axon. Without this scaffold, the myelin sheath grew defects known as outfoldings. Axons transmitted electrical signals much more slowly than normal when the septin scaffold was missing from the myelin sheath. Future studies are needed to understand the factors that control how the septin scaffold forms. This could help to reveal ways of reversing the changes that alter the myelin sheath during ageing and disease. DOI:http://dx.doi.org/10.7554/eLife.17119.002
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Affiliation(s)
- Julia Patzig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Michelle S Erwig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Stefan Tenzer
- Institute of Immunology, University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Payam Dibaj
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Sandra Goebbels
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
| | | | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, Germany
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41
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Kangas SM, Ohlmeier S, Sormunen R, Jouhilahti EM, Peltonen S, Peltonen J, Heape AM. An approach to comprehensive genome and proteome expression analyses in Schwann cells and neurons during peripheral nerve myelin formation. J Neurochem 2016; 138:830-44. [PMID: 27364987 DOI: 10.1111/jnc.13722] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Revised: 06/09/2016] [Accepted: 06/27/2016] [Indexed: 12/01/2022]
Abstract
Peripheral nerve myelination is a complex event resulting from spatially and temporally regulated reciprocal interactions between the neuron and myelin-forming Schwann cells. The dynamic process and the protein functional modules and networks that operate throughout the myelination process are poorly understood because of a lack of methodologies suitable for observing specific changes in the Schwann cell/neuron-unit. The identification of the precise roles for the proteins participating in the functional modules and networks that participate in the myelination process is hindered by the cellular and molecular complexity of the nervous tissue itself. We have developed an approach based on a myelinating dorsal root ganglion explant model that allows distinguishing clear, reproducible and predictable differences between the biochemical properties and the genomic and proteomic expression profiles of both cellular components of the Schwann cell/neuron unit at different stages of the myelination process. This model, derived from E13.5 C57BL/6J mouse embryos, is sufficiently robust for use in identifying the protein functional networks and modules related to peripheral nerve myelin formation. The genomic expression profiles of the selected neuronal, Schwann cell and myelin-specific proteins in the cultures reflect in vivo profiles reported in the literature, and the structural and ultrastructural properties of the myelin, as well as the myelination schedule of the cultures, closely resemble those observed in peripheral nerves in situ. The RNA expression data set is available through NCBI gene expression omnibus accession GSE60345. We have developed a reproducible and robust cell culture-based approach, accompanied by a genome-wide expression data set, which allows studying myelination in the peripheral nervous system at the proteomic and transcriptomic levels in Schwann cells and neurons. Myelinating dorsal root explant cultures, prepared from C57BL/6J mouse embryos, present distinct developmental stages comparable to those observed in a peripheral nerve in situ. This model can be used for identifying the protein functional networks and modules related to peripheral nerve myelin formation.
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Affiliation(s)
- Salla M Kangas
- Cancer and Translational Medicine Research Unit (Anatomy and Cell Biology), University of Oulu, Oulu, Finland.
| | - Steffen Ohlmeier
- Proteomics Core Facility, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Raija Sormunen
- Biocenter Oulu and Departments of Pathology, University of Oulu, Oulu, Finland
| | - Eeva-Mari Jouhilahti
- Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Sirkku Peltonen
- Department of Dermatology, University of Turku and Turku University Hospital, Turku, Finland
| | - Juha Peltonen
- Department of Cell Biology and Anatomy, Institute of Biomedicine, University of Turku, Turku, Finland
| | - Anthony M Heape
- Cancer and Translational Medicine Research Unit (Anatomy and Cell Biology), University of Oulu, Oulu, Finland.
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42
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Thakurela S, Garding A, Jung RB, Müller C, Goebbels S, White R, Werner HB, Tiwari VK. The transcriptome of mouse central nervous system myelin. Sci Rep 2016; 6:25828. [PMID: 27173133 PMCID: PMC4865983 DOI: 10.1038/srep25828] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 04/21/2016] [Indexed: 01/03/2023] Open
Abstract
Rapid nerve conduction in the CNS is facilitated by insulation of axons with myelin, a specialized oligodendroglial compartment distant from the cell body. Myelin is turned over and adapted throughout life; however, the molecular and cellular basis of myelin dynamics remains elusive. Here we performed a comprehensive transcriptome analysis (RNA-seq) of myelin biochemically purified from mouse brains at various ages and find a surprisingly large pool of transcripts enriched in myelin. Further computational analysis showed that the myelin transcriptome is closely related to the myelin proteome but clearly distinct from the transcriptomes of oligodendrocytes and brain tissues, suggesting a highly selective incorporation of mRNAs into the myelin compartment. The mRNA-pool in myelin displays maturation-dependent dynamic changes of composition, abundance, and functional associations; however ageing-dependent changes after 6 months were minor. We suggest that this transcript pool enables myelin turnover and the local adaptation of individual pre-existing myelin sheaths.
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Affiliation(s)
| | - Angela Garding
- Institute of Molecular Biology (IMB), 55128 Mainz, Germany
| | - Ramona B. Jung
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Christina Müller
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University, 55128 Mainz, Germany
| | - Sandra Goebbels
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Robin White
- Institute of Physiology, University Medical Center of the Johannes Gutenberg-University, 55128 Mainz, Germany
| | - Hauke B. Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
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Sub-Chronic Neuropathological and Biochemical Changes in Mouse Visual System after Repetitive Mild Traumatic Brain Injury. PLoS One 2016; 11:e0153608. [PMID: 27088355 PMCID: PMC4835061 DOI: 10.1371/journal.pone.0153608] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 03/31/2016] [Indexed: 11/29/2022] Open
Abstract
Repetitive mild traumatic brain injury (r-mTBI) results in neuropathological and biochemical consequences in the human visual system. Using a recently developed mouse model of r-mTBI, with control mice receiving repetitive anesthesia alone (r-sham) we assessed the effects on the retina and optic nerve using histology, immunohistochemistry, proteomic and lipidomic analyses at 3 weeks post injury. Retina tissue was used to determine retinal ganglion cell (RGC) number, while optic nerve tissue was examined for cellularity, myelin content, protein and lipid changes. Increased cellularity and areas of demyelination were clearly detectable in optic nerves in r-mTBI, but not in r-sham. These changes were accompanied by a ~25% decrease in the total number of Brn3a-positive RGCs. Proteomic analysis of the optic nerves demonstrated various changes consistent with a negative effect of r-mTBI on major cellular processes like depolymerization of microtubules, disassembly of filaments and loss of neurons, manifested by decrease of several proteins, including neurofilaments (NEFH, NEFM, NEFL), tubulin (TUBB2A, TUBA4A), microtubule-associated proteins (MAP1A, MAP1B), collagen (COL6A1, COL6A3) and increased expression of other proteins, including heat shock proteins (HSP90B1, HSPB1), APOE and cathepsin D. Lipidomic analysis showed quantitative changes in a number of phospholipid species, including a significant increase in the total amount of lysophosphatidylcholine (LPC), including the molecular species 16:0, a known demyelinating agent. The overall amount of some ether phospholipids, like ether LPC, ether phosphatidylcholine and ether lysophosphatidylethanolamine were also increased, while the majority of individual molecular species of ester phospholipids, like phosphatidylcholine and phosphatidylethanolamine, were decreased. Results from the biochemical analysis correlate well with changes detected by histological and immunohistochemical methods and indicate the involvement of several important molecular pathways. This will allow future identification of therapeutic targets for improving the visual consequences of r-mTBI.
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Möbius W, Nave KA, Werner HB. Electron microscopy of myelin: Structure preservation by high-pressure freezing. Brain Res 2016; 1641:92-100. [PMID: 26920467 DOI: 10.1016/j.brainres.2016.02.027] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 02/16/2016] [Indexed: 10/24/2022]
Abstract
Electron microscopic visualization of nervous tissue morphology is crucial when aiming to understand the biogenesis and structure of myelin in healthy and pathological conditions. However, accurate interpretation of electron micrographs requires excellent tissue preservation. In this short review we discuss the recent utilization of tissue fixation by high-pressure freezing and freeze-substitution, which now supplements aldehyde fixation in the preparation of samples for electron microscopy of myelin. Cryofixation has proven well suited to yield both, improved contrast and excellent preservation of structural detail of the axon/myelin-unit in healthy and mutant mice and can also be applied to other model organisms, including aquatic species. This article is part of a Special Issue entitled SI: Myelin Evolution.
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Affiliation(s)
- Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany; Center for Nanoscale Microscopy and Molecular Physiology of the Brain, 37075 Göttingen, Germany.
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany.
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany.
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45
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Tikka S, Monogioudi E, Gotsopoulos A, Soliymani R, Pezzini F, Scifo E, Uusi-Rauva K, Tyynelä J, Baumann M, Jalanko A, Simonati A, Lalowski M. Proteomic Profiling in the Brain of CLN1 Disease Model Reveals Affected Functional Modules. Neuromolecular Med 2015; 18:109-33. [PMID: 26707855 DOI: 10.1007/s12017-015-8382-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 12/15/2015] [Indexed: 02/06/2023]
Abstract
Neuronal ceroid lipofuscinoses (NCL) are the most commonly inherited progressive encephalopathies of childhood. Pathologically, they are characterized by endolysosomal storage with different ultrastructural features and biochemical compositions. The molecular mechanisms causing progressive neurodegeneration and common molecular pathways linking expression of different NCL genes are largely unknown. We analyzed proteome alterations in the brains of a mouse model of human infantile CLN1 disease-palmitoyl-protein thioesterase 1 (Ppt1) gene knockout and its wild-type age-matched counterpart at different stages: pre-symptomatic, symptomatic and advanced. For this purpose, we utilized a combination of laser capture microdissection-based quantitative liquid chromatography tandem mass spectrometry (MS) and matrix-assisted laser desorption/ionization time-of-flight MS imaging to quantify/visualize the changes in protein expression in disease-affected brain thalamus and cerebral cortex tissue slices, respectively. Proteomic profiling of the pre-symptomatic stage thalamus revealed alterations mostly in metabolic processes and inhibition of various neuronal functions, i.e., neuritogenesis. Down-regulation in dynamics associated with growth of plasma projections and cellular protrusions was further corroborated by findings from RNA sequencing of CLN1 patients' fibroblasts. Changes detected at the symptomatic stage included: mitochondrial functions, synaptic vesicle transport, myelin proteome and signaling cascades, such as RhoA signaling. Considerable dysregulation of processes related to mitochondrial cell death, RhoA/Huntington's disease signaling and myelin sheath breakdown were observed at the advanced stage of the disease. The identified changes in protein levels were further substantiated by bioinformatics and network approaches, immunohistochemistry on brain tissues and literature knowledge, thus identifying various functional modules affected in the CLN1 childhood encephalopathy.
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Affiliation(s)
- Saara Tikka
- Medicum, Biochemistry/Developmental Biology, Meilahti Clinical Proteomics Core Facility, University of Helsinki, P.O. Box 63 (Haartmaninkatu 8), Room C214a, 00014, Helsinki, Finland.,Folkhälsan Institute of Genetics, 00014, Helsinki, Finland
| | - Evanthia Monogioudi
- Folkhälsan Institute of Genetics, 00014, Helsinki, Finland.,Joint Research Centre, Directorate D-Institute for Reference Materials and Measurements, Standards for Innovation and Sustainable Development, Geel, Belgium
| | - Athanasios Gotsopoulos
- Brain and Mind Laboratory, Department of Biomedical Engineering and Computational Science (BECS), Aalto University School of Science, 02150, Espoo, Finland
| | - Rabah Soliymani
- Medicum, Biochemistry/Developmental Biology, Meilahti Clinical Proteomics Core Facility, University of Helsinki, P.O. Box 63 (Haartmaninkatu 8), Room C214a, 00014, Helsinki, Finland
| | - Francesco Pezzini
- Department of Neurological and Movement Sciences, University of Verona, 37134, Verona, Italy
| | - Enzo Scifo
- Medicum, Biochemistry/Developmental Biology, Meilahti Clinical Proteomics Core Facility, University of Helsinki, P.O. Box 63 (Haartmaninkatu 8), Room C214a, 00014, Helsinki, Finland.,Doctoral Program Brain & Mind, University of Helsinki, Helsinki, Finland.,Campbell Family Mental Health Research Institute, CAMH, University of Toronto, Toronto, Canada
| | - Kristiina Uusi-Rauva
- Folkhälsan Institute of Genetics, 00014, Helsinki, Finland.,Genomics and Biomarkers, National Institute for Health and Welfare (THL), P.O. Box 30, 00271, Helsinki, Finland
| | - Jaana Tyynelä
- Medicum, Biochemistry/Developmental Biology, Meilahti Clinical Proteomics Core Facility, University of Helsinki, P.O. Box 63 (Haartmaninkatu 8), Room C214a, 00014, Helsinki, Finland
| | - Marc Baumann
- Medicum, Biochemistry/Developmental Biology, Meilahti Clinical Proteomics Core Facility, University of Helsinki, P.O. Box 63 (Haartmaninkatu 8), Room C214a, 00014, Helsinki, Finland
| | - Anu Jalanko
- Institute for Molecular Medicine (FIMM), University of Helsinki, 00014, Helsinki, Finland.,Genomics and Biomarkers, National Institute for Health and Welfare (THL), P.O. Box 30, 00271, Helsinki, Finland
| | - Alessandro Simonati
- Department of Neurological and Movement Sciences, University of Verona, 37134, Verona, Italy
| | - Maciej Lalowski
- Medicum, Biochemistry/Developmental Biology, Meilahti Clinical Proteomics Core Facility, University of Helsinki, P.O. Box 63 (Haartmaninkatu 8), Room C214a, 00014, Helsinki, Finland. .,Folkhälsan Institute of Genetics, 00014, Helsinki, Finland.
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46
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Raasakka A, Myllykoski M, Laulumaa S, Lehtimäki M, Härtlein M, Moulin M, Kursula I, Kursula P. Determinants of ligand binding and catalytic activity in the myelin enzyme 2',3'-cyclic nucleotide 3'-phosphodiesterase. Sci Rep 2015; 5:16520. [PMID: 26563764 PMCID: PMC4643303 DOI: 10.1038/srep16520] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 10/13/2015] [Indexed: 12/11/2022] Open
Abstract
2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) is an enzyme highly abundant in the central nervous system myelin of terrestrial vertebrates. The catalytic domain of CNPase belongs to the 2H phosphoesterase superfamily and catalyzes the hydrolysis of nucleoside 2',3'-cyclic monophosphates to nucleoside 2'-monophosphates. The detailed reaction mechanism and the essential catalytic amino acids involved have been described earlier, but the roles of many amino acids in the vicinity of the active site have remained unknown. Here, several CNPase catalytic domain mutants were studied using enzyme kinetics assays, thermal stability experiments, and X-ray crystallography. Additionally, the crystal structure of a perdeuterated CNPase catalytic domain was refined at atomic resolution to obtain a detailed view of the active site and the catalytic mechanism. The results specify determinants of ligand binding and novel essential residues required for CNPase catalysis. For example, the aromatic side chains of Phe235 and Tyr168 are crucial for substrate binding, and Arg307 may affect active site electrostatics and regulate loop dynamics. The β5-α7 loop, unique for CNPase in the 2H phosphoesterase family, appears to have various functions in the CNPase reaction mechanism, from coordinating the nucleophilic water molecule to providing a binding pocket for the product and being involved in product release.
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Affiliation(s)
- Arne Raasakka
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Helmholtz Centre for Infection Research at German Electron Synchrotron (DESY), Hamburg, Germany
| | - Matti Myllykoski
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
| | - Saara Laulumaa
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
- Helmholtz Centre for Infection Research at German Electron Synchrotron (DESY), Hamburg, Germany
- European Spallation Source (ESS), Lund, Sweden
| | - Mari Lehtimäki
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | | | | | - Inari Kursula
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Helmholtz Centre for Infection Research at German Electron Synchrotron (DESY), Hamburg, Germany
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- Biocenter Oulu, University of Oulu, Oulu, Finland
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Helmholtz Centre for Infection Research at German Electron Synchrotron (DESY), Hamburg, Germany
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47
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Patzig J, Kusch K, Fledrich R, Eichel MA, Lüders KA, Möbius W, Sereda MW, Nave KA, Martini R, Werner HB. Proteolipid protein modulates preservation of peripheral axons and premature death when myelin protein zero is lacking. Glia 2015; 64:155-74. [PMID: 26393339 DOI: 10.1002/glia.22922] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/04/2015] [Indexed: 12/23/2022]
Abstract
Protein zero (P0) is the major structural component of peripheral myelin. Lack of this adhesion protein from Schwann cells causes a severe dysmyelinating neuropathy with secondary axonal degeneration in humans with the neuropathy Dejerine-Sottas syndrome (DSS) and in the corresponding mouse model (P0(null)-mice). In the mammalian CNS, the tetraspan-membrane protein PLP is the major structural myelin constituent and required for the long-term preservation of myelinated axons, which fails in hereditary spastic paraplegia (SPG type-2) and the relevant mouse model (Plp(null)-mice). The Plp-gene is also expressed in Schwann cells but PLP is of very low abundance in normal peripheral myelin; its function has thus remained enigmatic. Here we show that the abundance of PLP but not of other tetraspan myelin proteins is strongly increased in compact peripheral myelin of P0(null)-mice. To determine the functional relevance of PLP expression in the absence of P0, we generated P0(null)*Plp(null)-double-mutant mice. Compared with either single-mutant, P0(null)*Plp(null)-mice display impaired nerve conduction, reduced motor functions, and premature death. At the morphological level, axonal segments were frequently non-myelinated but in a one-to-one relationship with a hypertrophic Schwann cell. Importantly, axonal numbers were reduced in the vital phrenic nerve of P0(null)*Plp(null)-mice. In the absence of P0, thus, PLP also contributes to myelination by Schwann cells and to the preservation of peripheral axons. These data provide a link between the Schwann cell-dependent support of peripheral axons and the oligodendrocyte-dependent support of central axons.
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Affiliation(s)
- Julia Patzig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Robert Fledrich
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Maria A Eichel
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Katja A Lüders
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Michael W Sereda
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany.,Department of Clinical Neurophysiology, University Medical Center, Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Rudolf Martini
- Department of Neurology, Developmental Neurobiology, University Hospital, Würzburg, Germany
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
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48
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Myllykoski M, Seidel L, Muruganandam G, Raasakka A, Torda AE, Kursula P. Structural and functional evolution of 2',3'-cyclic nucleotide 3'-phosphodiesterase. Brain Res 2015; 1641:64-78. [PMID: 26367445 DOI: 10.1016/j.brainres.2015.09.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Revised: 09/02/2015] [Accepted: 09/03/2015] [Indexed: 02/06/2023]
Abstract
2',3'-cyclic nucleotide 3'-phosphodiesterase (CNPase) is an abundant membrane-associated enzyme within the vertebrate myelin sheath. While the physiological function of CNPase still remains to be characterized in detail, it is known - in addition to its in vitro enzymatic activity - to interact with other proteins, small molecules, and membrane surfaces. From an evolutionary point of view, it can be deduced that CNPase is not restricted to myelin-forming cells or vertebrate tissues. Its evolution has involved gene fusion, addition of other small segments with distinct functions, such as membrane attachment, and possibly loss of function at the polynucleotide kinase-like domain. Currently, it is unclear whether the enzymatic function of the conserved phosphodiesterase domain in vertebrate myelin has a physiological role, or if CNPase could actually function - like many other classical myelin proteins - in a more structural role. This article is part of a Special Issue entitled SI: Myelin Evolution.
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Affiliation(s)
- Matti Myllykoski
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Aapistie 7, 90220 Oulu, Finland
| | - Leonie Seidel
- Centre for Bioinformatics, University of Hamburg, Bundesstraße 43, 20146 Hamburg, Germany
| | | | - Arne Raasakka
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Aapistie 7, 90220 Oulu, Finland; Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Andrew E Torda
- Centre for Bioinformatics, University of Hamburg, Bundesstraße 43, 20146 Hamburg, Germany
| | - Petri Kursula
- Faculty of Biochemistry and Molecular Medicine & Biocenter Oulu, University of Oulu, Aapistie 7, 90220 Oulu, Finland; German Electron Synchrotron, Notkestraße 85, 22607 Hamburg, Germany; Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway.
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49
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Müller C, Schäfer I, Luhmann HJ, White R. Oligodendroglial Argonaute protein Ago2 associates with molecules of the Mbp mRNA localization machinery and is a downstream target of Fyn kinase. Front Cell Neurosci 2015; 9:328. [PMID: 26379499 PMCID: PMC4548153 DOI: 10.3389/fncel.2015.00328] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 08/10/2015] [Indexed: 01/10/2023] Open
Abstract
Oligodendrocytes myelinate neuronal axons in the central nervous system (CNS) facilitating rapid transmission of action potentials by saltatory conduction. Myelin basic protein (MBP) is an essential component of myelin and its absence results in severe hypomyelination in the CNS of rodents. Mbp mRNA is not translated immediately after exit from the nucleus in the cytoplasm, but is transported to the plasma membrane in RNA transport granules in a translationally silenced state. We have previously identified the small non-coding RNA 715 (sncRNA715) as an inhibitor of Mbp translation associated with RNA granules. Argonaute (Ago) proteins and small RNAs form the minimal core of the RNA induced silencing complex and together recognize target mRNAs to be translationally inhibited or degraded. Recently, tyrosine phosphorylation of Ago2 was reported to be a regulator of small RNA binding. The oligodendroglial non-receptor tyrosine kinase Fyn is activated by neuronal signals and stimulates the translation of Mbp mRNA at the axon-glial contact site. Here we analyzed the expression of Ago proteins in oligodendrocytes, if they associate with Mbp mRNA transport granules and are tyrosine phosphorylated by Fyn. We show that all Ago proteins (Ago1-4) are expressed by oligodendrocytes and that Ago2 colocalizes with hnRNP A2 in granular cytoplasmic structures. Ago2 associates with hnRNP A2, Mbp mRNA, sncRNA715 and Fyn kinase and is tyrosine phosphorylated in response to Fyn activity. Our findings suggest an involvement of Ago2 in the translational regulation of Mbp. The identification of Ago proteins as Fyn targets will foster further research to understand in more molecular detail how Fyn activity regulates Mbp translation.
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Affiliation(s)
| | | | | | - Robin White
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University, MainzGermany
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50
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Differential activation of ER stress pathways in myelinating cerebellar tracts. Int J Dev Neurosci 2015; 47:347-60. [PMID: 26297908 DOI: 10.1016/j.ijdevneu.2015.08.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 08/12/2015] [Accepted: 08/13/2015] [Indexed: 11/22/2022] Open
Abstract
Myelin production during brain development requires an increase in membrane protein and lipid production in oligodendrocytes and this primarily occurs in the endoplasmic reticulum (ER), an organelle which initiates the Unfolded Protein Response (UPR) when under stress. We hypothesise that the UPR is activated in white matter tracts during myelination in order to expand the ER capacity of oligodendrocytes. Using early and late stage markers, critical myelination time points were identified by immunohistochemistry in developing rat cerebellum. These were correlated to peaks in ER stress signalling by staining for activated UPR transducers (pIRE1, ATF6 and pPERK) and associated downstream molecules (peIF2α, PDI, GRP78, GRP94, CHOP and calreticulin) in cerebellar tracts III and IV. Gene expression in developing cerebellum was assessed by qPCR. Actively myelinating tracts were shown to have differential expression of pIRE1, PERK and ATF6 as well as UPR targets GRP94, GRP78 and PDI. Activated pIRE1-positive cells were widespread at P14 and P17 and at significantly higher numbers during myelination than at other stages. Nuclear-localised ATF6 (indicative of the active transcription factor) peaked at P10, concurrent with the initial phase of myelination. The percentage of cells positive for pPERK was less than 1% at postnatal ages but increased significantly in adult tissue. The downstream targets GRP78, GRP94 and PDI were significantly up-regulated at P17 compared to P7 and remained significantly elevated in adults. The majority of cells positive for these markers and ATF6 were oligodendrocytes as confirmed by dual-labelling. Although gene expression in the cerebellum for GRP78, GRP94 and PDI did not change significantly over time, ATF6 and XBP1s both showed significant fold changes between early and late timepoints. This data helps promote understanding of events occurring during developmental myelination and may have implications for the development of reparative treatments in diseases such as multiple sclerosis.
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