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Heller DT, Kolson DR, Brandebura AN, Amick EM, Wan J, Ramadan J, Holcomb PS, Liu S, Deerinck TJ, Ellisman MH, Qian J, Mathers PH, Spirou GA. Astrocyte ensheathment of calyx-forming axons of the auditory brainstem precedes accelerated expression of myelin genes and myelination by oligodendrocytes. J Comp Neurol 2024; 532:e25552. [PMID: 37916792 PMCID: PMC10922096 DOI: 10.1002/cne.25552] [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: 02/28/2023] [Revised: 09/22/2023] [Accepted: 10/17/2023] [Indexed: 11/03/2023]
Abstract
Early postnatal brain development involves complex interactions among maturing neurons and glial cells that drive tissue organization. We previously analyzed gene expression in tissue from the mouse medial nucleus of the trapezoid body (MNTB) during the first postnatal week to study changes that surround rapid growth of the large calyx of Held (CH) nerve terminal. Here, we present genes that show significant changes in gene expression level during the second postnatal week, a developmental timeframe that brackets the onset of airborne sound stimulation and the early stages of myelination. Gene Ontology analysis revealed that many of these genes are related to the myelination process. Further investigation of these genes using a previously published cell type-specific bulk RNA-Seq data set in cortex and our own single-cell RNA-Seq data set in the MNTB revealed enrichment of these genes in the oligodendrocyte lineage (OL) cells. Combining the postnatal day (P)6-P14 microarray gene expression data with the previously published P0-P6 data provided fine temporal resolution to investigate the initiation and subsequent waves of gene expression related to OL cell maturation and the process of myelination. Many genes showed increasing expression levels between P2 and P6 in patterns that reflect OL cell maturation. Correspondingly, the first myelin proteins were detected by P4. Using a complementary, developmental series of electron microscopy 3D image volumes, we analyzed the temporal progression of axon wrapping and myelination in the MNTB. By employing a combination of established ultrastructural criteria to classify reconstructed early postnatal glial cells in the 3D volumes, we demonstrated for the first time that astrocytes within the mouse MNTB extensively wrap the axons of the growing CH terminal prior to OL cell wrapping and compaction of myelin. Our data revealed significant expression of several myelin genes and enrichment of multiple genes associated with lipid metabolism in astrocytes, which may subserve axon wrapping in addition to myelin formation. The transition from axon wrapping by astrocytes to OL cells occurs rapidly between P4 and P9 and identifies a potential new role of astrocytes in priming calyceal axons for subsequent myelination.
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Affiliation(s)
| | - Douglas R. Kolson
- WVU Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV
- Otolaryngology HNS, West Virginia University School of Medicine, Morgantown, WV
| | - Ashley N. Brandebura
- WVU Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV
- Biochemistry, West Virginia University School of Medicine, Morgantown, WV
| | - Emily M. Amick
- Medical Engineering, University of South Florida, Tampa, FL
| | - Jun Wan
- Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Jad Ramadan
- Otolaryngology HNS, West Virginia University School of Medicine, Morgantown, WV
| | - Paul S. Holcomb
- WVU Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV
| | - Sheng Liu
- Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN
| | - Thomas J. Deerinck
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA
- Department of Neuroscience, University of California, San Diego, CA
| | - Mark H. Ellisman
- National Center for Microscopy and Imaging Research, University of California, San Diego, CA
- Department of Neuroscience, University of California, San Diego, CA
| | - Jiang Qian
- Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Peter H. Mathers
- WVU Rockefeller Neuroscience Institute, West Virginia University School of Medicine, Morgantown, WV
- Otolaryngology HNS, West Virginia University School of Medicine, Morgantown, WV
- Biochemistry, West Virginia University School of Medicine, Morgantown, WV
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2
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Walker BL, Nie Q. NeST: nested hierarchical structure identification in spatial transcriptomic data. Nat Commun 2023; 14:6554. [PMID: 37848426 PMCID: PMC10582109 DOI: 10.1038/s41467-023-42343-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 10/06/2023] [Indexed: 10/19/2023] Open
Abstract
Spatial gene expression in tissue is characterized by regions in which particular genes are enriched or depleted. Frequently, these regions contain nested inside them subregions with distinct expression patterns. Segmentation methods in spatial transcriptomic (ST) data extract disjoint regions maximizing similarity over the greatest number of genes, typically on a particular spatial scale, thus lacking the ability to find region-within-region structure. We present NeST, which extracts spatial structure through coexpression hotspots-regions exhibiting localized spatial coexpression of some set of genes. Coexpression hotspots identify structure on any spatial scale, over any possible subset of genes, and are highly explainable. NeST also performs spatial analysis of cell-cell interactions via ligand-receptor, identifying active areas de novo without restriction of cell type or other groupings, in both two and three dimensions. Through application on ST datasets of varying type and resolution, we demonstrate the ability of NeST to reveal a new level of biological structure.
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Affiliation(s)
- Benjamin L Walker
- The NSF-Simons Center for Multiscale Cell Fate Research, University of California Irvine, Irvine, CA, 92627, USA
- Department of Mathematics, University of California Irvine, Irvine, CA, 92627, USA
| | - Qing Nie
- The NSF-Simons Center for Multiscale Cell Fate Research, University of California Irvine, Irvine, CA, 92627, USA.
- Department of Mathematics, University of California Irvine, Irvine, CA, 92627, USA.
- Department of Developmental and Cell Biology, University of California Irvine, Irvine, CA, 92627, USA.
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3
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Ament SA, Poulopoulos A. The brain's dark transcriptome: Sequencing RNA in distal compartments of neurons and glia. Curr Opin Neurobiol 2023; 81:102725. [PMID: 37196598 PMCID: PMC10524153 DOI: 10.1016/j.conb.2023.102725] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/22/2023] [Accepted: 04/02/2023] [Indexed: 05/19/2023]
Abstract
Transcriptomic approaches are powerful strategies to map the molecular diversity of cells in the brain. Single-cell genomic atlases have now been compiled for entire mammalian brains. However, complementary techniques are only just beginning to map the subcellular transcriptomes from distal cellular compartments. We review single-cell datasets alongside subtranscriptome data from the mammalian brain to explore the development of cellular and subcellular diversity. We discuss how single-cell RNA-seq misses transcripts localized away from cell bodies, which form the 'dark transcriptome' of the brain: a collection of subtranscriptomes in dendrites, axons, growth cones, synapses, and endfeet with important roles in brain development and function. Recent advances in subcellular transcriptome sequencing are beginning to reveal these elusive pools of RNA. We outline the success stories to date in uncovering the constituent subtranscriptomes of neurons and glia, as well as present the emerging toolkit that is accelerating the pace of subtranscriptome discovery.
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Affiliation(s)
- Seth A Ament
- Department of Psychiatry, UM-MIND, and Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Alexandros Poulopoulos
- Department of Pharmacology and UM-MIND, University of Maryland School of Medicine, Baltimore, MD, USA.
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4
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Krämer-Albers EM, Werner HB. Mechanisms of axonal support by oligodendrocyte-derived extracellular vesicles. Nat Rev Neurosci 2023:10.1038/s41583-023-00711-y. [PMID: 37258632 DOI: 10.1038/s41583-023-00711-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2023] [Indexed: 06/02/2023]
Abstract
Extracellular vesicles (EVs) have recently emerged as versatile elements of cell communication in the nervous system, mediating tissue homeostasis. EVs influence the physiology of their target cells via horizontal transfer of molecular cargo between cells and by triggering signalling pathways. In this Review, we discuss recent work revealing that EVs mediate interactions between oligodendrocytes and neurons, which are relevant for maintaining the structural integrity of axons. In response to neuronal activity, myelinating oligodendrocytes release EVs, which are internalized by neurons and provide axons with key factors that improve axonal transport, stress resistance and energy homeostasis. Glia-to-neuron transfer of EVs is thus a crucial facet of axonal preservation. When glial support is impaired, axonal integrity is progressively lost, as observed in myelin-related disorders, other neurodegenerative diseases and with normal ageing. We highlight the mechanisms that oligodendroglial EVs use to sustain axonal integrity and function.
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Affiliation(s)
- Eva-Maria Krämer-Albers
- Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany.
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
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5
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Gould R, Brady S. Identifying mRNAs Residing in Myelinating Oligodendrocyte Processes as a Basis for Understanding Internode Autonomy. Life (Basel) 2023; 13:life13040945. [PMID: 37109474 PMCID: PMC10142070 DOI: 10.3390/life13040945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/28/2023] [Accepted: 03/31/2023] [Indexed: 04/07/2023] Open
Abstract
In elaborating and maintaining myelin sheaths on multiple axons/segments, oligodendrocytes distribute translation of some proteins, including myelin basic protein (MBP), to sites of myelin sheath assembly, or MSAS. As mRNAs located at these sites are selectively trapped in myelin vesicles during tissue homogenization, we performed a screen to identify some of these mRNAs. To confirm locations, we used real-time quantitative polymerase chain reaction (RT-qPCR), to measure mRNA levels in myelin (M) and ‘non-myelin’ pellet (P) fractions, and found that five (LPAR1, TRP53INP2, TRAK2, TPPP, and SH3GL3) of thirteen mRNAs were highly enriched in myelin (M/P), suggesting residences in MSAS. Because expression by other cell-types will increase p-values, some MSAS mRNAs might be missed. To identify non-oligodendrocyte expression, we turned to several on-line resources. Although neurons express TRP53INP2, TRAK2 and TPPP mRNAs, these expressions did not invalidate recognitions as MSAS mRNAs. However, neuronal expression likely prevented recognition of KIF1A and MAPK8IP1 mRNAs as MSAS residents and ependymal cell expression likely prevented APOD mRNA assignment to MSAS. Complementary in situ hybridization (ISH) is recommended to confirm residences of mRNAs in MSAS. As both proteins and lipids are synthesized in MSAS, understanding myelination should not only include efforts to identify proteins synthesized in MSAS, but also the lipids.
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Affiliation(s)
- Robert Gould
- Whitman Research Center, Marine Biology Laboratory, Woods Hole, MA 02543, USA
| | - Scott Brady
- Departments of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL 60612, USA
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6
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Stair MI, Winn CB, Burns MA, Holcombe H, Artim SC, Ge Z, Shen Z, Wang TC, Muthupalani S, Franco-Mahecho O, Ennis K, Georgieff MK, Fox JG. Effects of chronic Helicobacter pylori strain PMSS1 infection on whole brain and gastric iron homeostasis in male INS-GAS mice. Microbes Infect 2023; 25:105045. [PMID: 36162750 DOI: 10.1016/j.micinf.2022.105045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 09/09/2022] [Accepted: 09/18/2022] [Indexed: 02/03/2023]
Abstract
Iron deficiency, the most common micronutrient deficiency in humans, is associated with long-term deficits in cognition and memory if left untreated. Infection with the gastric pathogen Helicobacter pylori has been linked to iron deficiency anemia (IDA). The H. pylori virulence factor cytotoxin-associated gene A (cagA) is proposed to be especially pertinent in iron deficiency. Male INS-GAS/FVB mice were infected with the CagA+ strain pre-murine Sydney strain 1 (PMSS1) for 12-13 or 27-29 weeks to investigate the role of chronic H. pylori infection in iron deficiency and neurological sequelae. Mice at both timepoints demonstrated significantly elevated gastric histopathology scores and inflammatory cytokines compared to sham-dosed controls. However, only mice at 27-29 weeks post infection had changes in hematological parameters, with significantly decreased erythrocyte count, hematocrit, serum hemoglobin, and increased serum total iron binding capacity. Gastric transcription of iron-regulatory genes Hamp and Bmp4 were significantly downregulated at both timepoints. In the brain, iron-dependent myelingergic and synaptic markers were significantly downregulated at 27-29 weeks. These results indicated that long-term infection of the CagA + PMSS1 strain of H. pylori in this study caused anemia, altered gastric iron homeostasis, and neurological changes similar to those reported in other rodent H. pylori CagA- strain infection models.
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Affiliation(s)
- Melissa I Stair
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States; Animal Resource Program, Atrium Health Wake Forest Baptist, Winston Salem, NC, United States
| | - Caroline Bodi Winn
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Comparative Medicine, Worldwide Research, Development, and Medical, Pfizer, Cambridge, MA, United States
| | - Monika A Burns
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States; Novartis Institutes for BioMedical Research, Cambridge, MA, United States
| | - Hilda Holcombe
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Stephen C Artim
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States; Merck Research Laboratories, Merck, South San Francisco, CA, United States
| | - Zhongming Ge
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Zeli Shen
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Timothy C Wang
- Department of Medicine, Columbia University, New York, NY, United States
| | - Sureshkumar Muthupalani
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Olga Franco-Mahecho
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Kathleen Ennis
- Division of Neonatology, Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Michael K Georgieff
- Division of Neonatology, Department of Pediatrics, University of Minnesota Medical School, Minneapolis, MN, United States
| | - James G Fox
- Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.
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7
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Gala DS, Titlow JS, Teodoro RO, Davis I. Far from home: the role of glial mRNA localization in synaptic plasticity. RNA (NEW YORK, N.Y.) 2023; 29:153-169. [PMID: 36442969 PMCID: PMC9891262 DOI: 10.1261/rna.079422.122] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Neurons and glia are highly polarized cells, whose distal cytoplasmic functional subdomains require specific proteins. Neurons have axonal and dendritic cytoplasmic extensions containing synapses whose plasticity is regulated efficiently by mRNA transport and localized translation. The principles behind these mechanisms are equally attractive for explaining rapid local regulation of distal glial cytoplasmic projections, independent of their cell nucleus. However, in contrast to neurons, mRNA localization has received little experimental attention in glia. Nevertheless, there are many functionally diverse glial subtypes containing extensive networks of long cytoplasmic projections with likely localized regulation that influence neurons and their synapses. Moreover, glia have many other neuron-like properties, including electrical activity, secretion of gliotransmitters and calcium signaling, influencing, for example, synaptic transmission, plasticity and axon pruning. Here, we review previous studies concerning glial transcripts with important roles in influencing synaptic plasticity, focusing on a few cases involving localized translation. We discuss a variety of important questions about mRNA transport and localized translation in glia that remain to be addressed, using cutting-edge tools already available for neurons.
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Affiliation(s)
- Dalia S Gala
- Department of Biochemistry, The University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Joshua S Titlow
- Department of Biochemistry, The University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Rita O Teodoro
- iNOVA4Health, NOVA Medical School-Faculdade de Ciências Médicas, Universidade Nova de Lisboa, Lisboa 1169-056, Portugal
| | - Ilan Davis
- Department of Biochemistry, The University of Oxford, Oxford OX1 3QU, United Kingdom
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8
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Giuditta A, Zucconi GG, Sadile A. Brain Metabolic DNA: A Long Story and Some Conclusions. Mol Neurobiol 2022; 60:228-234. [PMID: 36251232 DOI: 10.1007/s12035-022-03030-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 09/09/2022] [Indexed: 11/26/2022]
Abstract
We have previously outlined the main properties of brain metabolic DNA (BMD) and its involvement in circadian oscillations, learning, and post-trial sleep. The presence of BMD in certain subcellular fractions and their behavior in cesium gradients have suggested that BMD originates from cytoplasmic reverse transcription and subsequently acquires a double-stranded configuration. More recently, it has been reported that some DNA sequences of cytoplasmic BMD in learning mice are different from that of the control animals. Furthermore, BMD is located in vicinity of the genes involved in different modifications of synaptic activity, suggesting that BMD may contribute to the brain's response to the changing environment. The present review outlines recent data with a special emphasis on reverse transcription of BMD that may recapitulate the molecular events at the time of the "RNA world" by activating mitochondrial telomerase and generating RNA templates from mitochondrial transcripts. The latter unexpected role of mitochondria is likely to promote a better understanding of mitochondrial contribution to cellular interactions and eukaryotic evolution. An initial step regards the role of human mitochondria in embryonic BMD synthesis, which is exclusively of maternal origin. In addition, mitochondrial transcripts involved in reverse transcription of BMD might possibly reveal unexpected features elucidating mitochondrial involvement in cancer events and neurodegenerative disorders.
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Affiliation(s)
- Antonio Giuditta
- Accademia Di Scienze Fisiche E Matematiche, Via Mezzocannone 8, 80134, Napoli, Italy.
| | | | - Adolfo Sadile
- Dept Experimental Medicine, Medical School, University Campania "L. Vanvitelli", Via S. Andrea delle Dame 7, 80138, Naples, Italy
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9
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Cheng N, Li G, Kanchwala M, Evers BM, Xing C, Yu H. STAG2 promotes the myelination transcriptional programin oligodendrocytes. eLife 2022; 11:77848. [PMID: 35959892 PMCID: PMC9439679 DOI: 10.7554/elife.77848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 08/11/2022] [Indexed: 11/13/2022] Open
Abstract
Cohesin folds chromosomes via DNA loop extrusion. Cohesin-mediated chromosome loops regulate transcription by shaping long-range enhancer-promoter interactions, among other mechanisms. Mutations of cohesin subunits and regulators cause human developmental diseases termed cohesinopathy. Vertebrate cohesin consists of SMC1, SMC3, RAD21, and either STAG1 or STAG2. To probe the physiological functions of cohesin, we created conditional knockout (cKO) mice with Stag2 deleted in the nervous system. Stag2 cKO mice exhibit growth retardation, neurological defects, and premature death, in part due to insufficient myelination of nerve fibers. Stag2 cKO oligodendrocytes exhibit delayed maturation and downregulation of myelination-related genes. Stag2 loss reduces promoter-anchored loops at downregulated genes in oligodendrocytes. Thus, STAG2-cohesin generates promoter-anchored loops at myelination-promoting genes to facilitate their transcription. Our study implicates defective myelination as a contributing factor to cohesinopathy and establishes oligodendrocytes as a relevant cell type to explore the mechanisms by which cohesin regulates transcription.
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Affiliation(s)
- Ningyan Cheng
- Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Guanchen Li
- School of Life Sciences, Westlake University, Hangzhou, China
| | - Mohammed Kanchwala
- Eugene McDermott Center for Human Growth and Development, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Bret M Evers
- Division of Neuropathology, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Chao Xing
- Eugene McDermott Center for Human Growth and Development, The University of Texas Southwestern Medical Center, Dallas, United States
| | - Hongtao Yu
- Westlake Laboratory of Life Sciences and Biomedicine, Westlake University, Hangzhou, Zhejiang Province, China
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10
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Nowacki JC, Fields AM, Fu MM. Emerging cellular themes in leukodystrophies. Front Cell Dev Biol 2022; 10:902261. [PMID: 36003149 PMCID: PMC9393611 DOI: 10.3389/fcell.2022.902261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 06/30/2022] [Indexed: 11/18/2022] Open
Abstract
Leukodystrophies are a broad spectrum of neurological disorders that are characterized primarily by deficiencies in myelin formation. Clinical manifestations of leukodystrophies usually appear during childhood and common symptoms include lack of motor coordination, difficulty with or loss of ambulation, issues with vision and/or hearing, cognitive decline, regression in speech skills, and even seizures. Many cases of leukodystrophy can be attributed to genetic mutations, but they have diverse inheritance patterns (e.g., autosomal recessive, autosomal dominant, or X-linked) and some arise from de novo mutations. In this review, we provide an updated overview of 35 types of leukodystrophies and focus on cellular mechanisms that may underlie these disorders. We find common themes in specialized functions in oligodendrocytes, which are specialized producers of membranes and myelin lipids. These mechanisms include myelin protein defects, lipid processing and peroxisome dysfunction, transcriptional and translational dysregulation, disruptions in cytoskeletal organization, and cell junction defects. In addition, non-cell-autonomous factors in astrocytes and microglia, such as autoimmune reactivity, and intercellular communication, may also play a role in leukodystrophy onset. We hope that highlighting these themes in cellular dysfunction in leukodystrophies may yield conceptual insights on future therapeutic approaches.
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OCT4-induced oligodendrocyte progenitor cells promote remyelination and ameliorate disease. NPJ Regen Med 2022; 7:4. [PMID: 35027563 PMCID: PMC8758684 DOI: 10.1038/s41536-021-00199-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 11/30/2021] [Indexed: 12/23/2022] Open
Abstract
The generation of human oligodendrocyte progenitor cells (OPCs) may be therapeutically valuable for human demyelinating diseases such as multiple sclerosis. Here, we report the direct reprogramming of human somatic cells into expandable induced OPCs (iOPCs) using a combination of OCT4 and a small molecule cocktail. This method enables generation of A2B5+ (an early marker for OPCs) iOPCs within 2 weeks retaining the ability to differentiate into MBP-positive mature oligodendrocytes. RNA-seq analysis revealed that the transcriptome of O4+ iOPCs was similar to that of O4+ OPCs and ChIP-seq analysis revealed that putative OCT4-binding regions were detected in the regulatory elements of CNS development-related genes. Notably, engrafted iOPCs remyelinated the brains of adult shiverer mice and experimental autoimmune encephalomyelitis mice with MOG-induced 14 weeks after transplantation. In conclusion, our study may contribute to the development of therapeutic approaches for neurological disorders, as well as facilitate the understanding of the molecular mechanisms underlying glial development.
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12
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Panganiban CH, Barth JL, Tan J, Noble KV, McClaskey CM, Howard BA, Jafri SH, Dias JW, Harris KC, Lang H. Two distinct types of nodes of Ranvier support auditory nerve function in the mouse cochlea. Glia 2021; 70:768-791. [DOI: 10.1002/glia.24138] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 11/12/2021] [Accepted: 12/17/2021] [Indexed: 11/09/2022]
Affiliation(s)
- Clarisse H. Panganiban
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
- Wolfson Centre for Age‐Related Diseases King's College London London UK
| | - Jeremy L. Barth
- Department of Regenerative Medicine and Cell Biology Medical University of South Carolina Charleston South Carolina USA
| | - Junying Tan
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
| | - Kenyaria V. Noble
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
| | - Carolyn M. McClaskey
- Department of Otolaryngology & Head and Neck Surgery Medical University of South Carolina Charleston South Carolina USA
| | - Blake A. Howard
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
| | - Shabih H. Jafri
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
| | - James W. Dias
- Department of Otolaryngology & Head and Neck Surgery Medical University of South Carolina Charleston South Carolina USA
| | - Kelly C. Harris
- Department of Otolaryngology & Head and Neck Surgery Medical University of South Carolina Charleston South Carolina USA
| | - Hainan Lang
- Department of Pathology and Laboratory Medicine Medical University of South Carolina Charleston South Carolina USA
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13
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Edgar JM, McGowan E, Chapple KJ, Möbius W, Lemgruber L, Insall RH, Nave K, Boullerne A. Río-Hortega's drawings revisited with fluorescent protein defines a cytoplasm-filled channel system of CNS myelin. J Anat 2021; 239:1241-1255. [PMID: 34713444 PMCID: PMC8602028 DOI: 10.1111/joa.13577] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 10/10/2021] [Accepted: 10/11/2021] [Indexed: 01/13/2023] Open
Abstract
A century ago this year, Pío del Río-Hortega (1921) coined the term 'oligodendroglia' for the 'interfascicular glia' with very few processes, launching an extensive discovery effort on his new cell type. One hundred years later, we review his original contributions to our understanding of the system of cytoplasmic channels within myelin in the context of what we observe today using light and electron microscopy of genetically encoded fluorescent reporters and immunostaining. We use the term myelinic channel system to describe the cytoplasm-delimited spaces associated with myelin; being the paranodal loops, inner and outer tongues, cytoplasm-filled spaces through compact myelin and further complex motifs associated to the sheath. Using a central nervous system myelinating cell culture model that contains all major neural cell types and produces compact myelin, we find that td-tomato fluorescent protein delineates the myelinic channel system in a manner reminiscent of the drawings of adult white matter by Río-Hortega, despite that he questioned whether some cytoplasmic figures he observed represented artefact. Together, these data lead us to propose a slightly revised model of the 'unrolled' sheath. Further, we show that the myelinic channel system, while relatively stable, can undergo subtle dynamic shape changes over days. Importantly, we capture an under-appreciated complexity of the myelinic channel system in mature myelin sheaths.
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Affiliation(s)
- Julia M. Edgar
- Axo‐Glial GroupInstitute of Infection, Immunity and InflammationCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
- Department of NeurogeneticsMax Planck Institute of Experimental MedicineGöttingenGermany
| | - Eleanor McGowan
- Axo‐Glial GroupInstitute of Infection, Immunity and InflammationCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Katie J. Chapple
- Axo‐Glial GroupInstitute of Infection, Immunity and InflammationCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Wiebke Möbius
- Department of NeurogeneticsMax Planck Institute of Experimental MedicineGöttingenGermany
- Electron Microscopy Core UnitMax Planck Institute of Experimental MedicineGöttingenGermany
| | - Leandro Lemgruber
- Glasgow Imaging FacilityInstitute of Infection, Immunity and InflammationCollege of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | | | - Klaus‐Armin Nave
- Department of NeurogeneticsMax Planck Institute of Experimental MedicineGöttingenGermany
| | - Anne Boullerne
- Department of AnesthesiologyUniversity of Illinois at ChicagoChicagoIllinoisUSA
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The Akt-mTOR Pathway Drives Myelin Sheath Growth by Regulating Cap-Dependent Translation. J Neurosci 2021; 41:8532-8544. [PMID: 34475201 DOI: 10.1523/jneurosci.0783-21.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 08/24/2021] [Accepted: 08/27/2021] [Indexed: 11/21/2022] Open
Abstract
In the vertebrate CNS, oligodendrocytes produce myelin, a specialized membrane, to insulate and support axons. Individual oligodendrocytes wrap multiple axons with myelin sheaths of variable lengths and thicknesses. Myelin grows at the distal ends of oligodendrocyte processes, and multiple lines of work have provided evidence that mRNAs and RNA binding proteins localize to myelin, together supporting a model where local translation controls myelin sheath growth. What signal transduction mechanisms could control this? One strong candidate is the Akt-mTOR pathway, a major cellular signaling hub that coordinates transcription, translation, metabolism, and cytoskeletal organization. Here, using zebrafish as a model system, we found that Akt-mTOR signaling promotes myelin sheath growth and stability during development. Through cell-specific manipulations to oligodendrocytes, we show that the Akt-mTOR pathway drives cap-dependent translation to promote myelination and that restoration of cap-dependent translation is sufficient to rescue myelin deficits in mTOR loss-of-function animals. Moreover, an mTOR-dependent translational regulator was phosphorylated and colocalized with mRNA encoding a canonically myelin-translated protein in vivo, and bioinformatic investigation revealed numerous putative translational targets in the myelin transcriptome. Together, these data raise the possibility that Akt-mTOR signaling in nascent myelin sheaths promotes sheath growth via translation of myelin-resident mRNAs during development.SIGNIFICANCE STATEMENT In the brain and spinal cord, oligodendrocytes extend processes that tightly wrap axons with myelin, a protein- and lipid-rich membrane that increases electrical impulses and provides trophic support. Myelin membrane grows dramatically following initial axon wrapping in a process that demands protein and lipid synthesis. How protein and lipid synthesis is coordinated with the need for myelin to be generated in certain locations remains unknown. Our study reveals that the Akt-mTOR signaling pathway promotes myelin sheath growth by regulating protein translation. Because we found translational regulators of the Akt-mTOR pathway in myelin, our data raise the possibility that Akt-mTOR activity regulates translation in myelin sheaths to deliver myelin on demand to the places it is needed.
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15
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Vacher CM, Lacaille H, O'Reilly JJ, Salzbank J, Bakalar D, Sebaoui S, Liere P, Clarkson-Paredes C, Sasaki T, Sathyanesan A, Kratimenos P, Ellegood J, Lerch JP, Imamura Y, Popratiloff A, Hashimoto-Torii K, Gallo V, Schumacher M, Penn AA. Placental endocrine function shapes cerebellar development and social behavior. Nat Neurosci 2021; 24:1392-1401. [PMID: 34400844 PMCID: PMC8481124 DOI: 10.1038/s41593-021-00896-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/23/2021] [Indexed: 02/07/2023]
Abstract
Compromised placental function or premature loss has been linked to diverse neurodevelopmental disorders. Here we show that placenta allopregnanolone (ALLO), a progesterone-derived GABA-A receptor (GABAAR) modulator, reduction alters neurodevelopment in a sex-linked manner. A new conditional mouse model, in which the gene encoding ALLO's synthetic enzyme (akr1c14) is specifically deleted in trophoblasts, directly demonstrated that placental ALLO insufficiency led to cerebellar white matter abnormalities that correlated with autistic-like behavior only in male offspring. A single injection of ALLO or muscimol, a GABAAR agonist, during late gestation abolished these alterations. Comparison of male and female human preterm infant cerebellum also showed sex-linked myelination marker alteration, suggesting similarities between mouse placental ALLO insufficiency and human preterm brain development. This study reveals a new role for a placental hormone in shaping brain regions and behaviors in a sex-linked manner. Placental hormone replacement might offer novel therapeutic opportunities to prevent later neurobehavioral disorders.
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Affiliation(s)
- Claire-Marie Vacher
- Department of Pediatrics, Columbia University, New York-Presbyterian Morgan Stanley Children's Hospital, New York, NY, USA.
| | - Helene Lacaille
- Department of Pediatrics, Columbia University, New York-Presbyterian Morgan Stanley Children's Hospital, New York, NY, USA
| | - Jiaqi J O'Reilly
- Department of Pediatrics, Columbia University, New York-Presbyterian Morgan Stanley Children's Hospital, New York, NY, USA
| | - Jacquelyn Salzbank
- Department of Pediatrics, Columbia University, New York-Presbyterian Morgan Stanley Children's Hospital, New York, NY, USA
| | - Dana Bakalar
- National Institutes of Health, Bethesda, MD, USA
| | - Sonia Sebaoui
- Center for Neuroscience Research, Children's National Health System, Washington, DC, USA
| | - Philippe Liere
- U1195 INSERM, Paris-Saclay University, Le Kremlin-Bicêtre Cedex, France
| | | | - Toru Sasaki
- Center for Neuroscience Research, Children's National Health System, Washington, DC, USA
| | - Aaron Sathyanesan
- Center for Neuroscience Research, Children's National Health System, Washington, DC, USA
| | - Panagiotis Kratimenos
- Center for Neuroscience Research, Children's National Health System, Washington, DC, USA
- The George Washington University School of Medicine and Health Sciences, Pediatrics, Washington, DC, USA
| | - Jacob Ellegood
- Mouse Imaging Centre (MICe), Hospital for Sick Children, Toronto, ON, Canada
| | - Jason P Lerch
- Mouse Imaging Centre (MICe), Hospital for Sick Children, Toronto, ON, Canada
- Wellcome Centre for Integrative Neuroimaging (WIN), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Yuka Imamura
- Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Pittsburgh, PA, USA
| | - Anastas Popratiloff
- The George Washington University, Nanofabrication and Imaging Center, Washington, DC, USA
- The George Washington University, SMHS, Anatomy & Cell Biology, Washington, DC, USA
| | - Kazue Hashimoto-Torii
- Center for Neuroscience Research, Children's National Health System, Washington, DC, USA
- The George Washington University School of Medicine and Health Sciences, Pediatrics, Washington, DC, USA
| | - Vittorio Gallo
- Center for Neuroscience Research, Children's National Health System, Washington, DC, USA
- The George Washington University School of Medicine and Health Sciences, Pediatrics, Washington, DC, USA
| | | | - Anna A Penn
- Department of Pediatrics, Columbia University, New York-Presbyterian Morgan Stanley Children's Hospital, New York, NY, USA.
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16
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Swire M, Assinck P, McNaughton PA, Lyons DA, Ffrench-Constant C, Livesey MR. Oligodendrocyte HCN2 Channels Regulate Myelin Sheath Length. J Neurosci 2021; 41:7954-7964. [PMID: 34341156 PMCID: PMC8460148 DOI: 10.1523/jneurosci.2463-20.2021] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 06/16/2021] [Accepted: 07/06/2021] [Indexed: 11/21/2022] Open
Abstract
Oligodendrocytes generate myelin sheaths vital for the formation, health, and function of the CNS. Myelin sheath length is a key property that determines axonal conduction velocity and is known to be variable across the CNS. Myelin sheath length can be modified by neuronal activity, suggesting that dynamic regulation of sheath length might contribute to the functional plasticity of neural circuits. Although the mechanisms that establish and refine myelin sheath length are important determinants of brain function, our understanding of these remains limited. In recent years, the membranes of myelin sheaths have been increasingly recognized to contain ion channels and transporters that are associated with specific important oligodendrocyte functions, including metabolic support of axons and the regulation of ion homeostasis, but none have been shown to influence sheath architecture. In this study, we determined that hyperpolarization-activated, cyclic nucleotide-gated (HCN) ion channels, typically associated with neuronal and cardiac excitability, regulate myelin sheath length. Using both in vivo and in vitro approaches, we show that oligodendrocytes abundantly express functional, predominantly HCN2 subunit-containing ion channels. These HCN ion channels retain key pharmacological and biophysical features and regulate the resting membrane potential of myelinating oligodendrocytes. Further, reduction of their function via pharmacological blockade or generation of transgenic mice with two independent oligodendrocyte-specific HCN2 knock-out strategies reduced myelin sheath length. We conclude that HCN2 ion channels are key determinants of myelin sheath length in the CNS.SIGNIFICANCE STATEMENT Myelin sheath length is a critical determinant of axonal conduction velocity, but the signaling mechanisms responsible for determining sheath length are poorly understood. Here we find that oligodendrocytes express functional hyperpolarization-activated, cyclic nucleotide-gated 2 (HCN2) ion channels that regulate the length of myelin sheaths formed by oligodendrocytes in myelinating cultures and in the mouse brain and spinal cord. These results suggest that the regulation of HCN2 channel activity is well placed to refine sheath length and conduction along myelinated axons, providing a potential mechanism for alterations in conduction velocity and circuit function in response to axonal signals such as those generated by increased activity.
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Affiliation(s)
- Matthew Swire
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Wolfson Institute for Biomedical Research, University College London, London WC1E 6BT, United Kingdom
| | - Peggy Assinck
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Peter A McNaughton
- Wolfson Centre for Age-Related Diseases, King's College London, London WC2R 2LS, United Kingdom
| | - David A Lyons
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
| | - Charles Ffrench-Constant
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Matthew R Livesey
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, United Kingdom
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield S10 2HQ, United Kingdom
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17
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Hudson KM, Shiver E, Yu J, Mehta S, Jima DD, Kane MA, Patisaul HB, Cowley M. Transcriptomic, proteomic, and metabolomic analyses identify candidate pathways linking maternal cadmium exposure to altered neurodevelopment and behavior. Sci Rep 2021; 11:16302. [PMID: 34381081 PMCID: PMC8357970 DOI: 10.1038/s41598-021-95630-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 07/28/2021] [Indexed: 02/07/2023] Open
Abstract
Cadmium (Cd) is a ubiquitous toxic heavy metal of major public concern. Despite inefficient placental transfer, maternal Cd exposure impairs fetal growth and development. Increasing evidence from animal models and humans suggests maternal Cd exposure negatively impacts neurodevelopment; however, the underlying molecular mechanisms are unclear. To address this, we utilized multiple -omics approaches in a mouse model of maternal Cd exposure to identify pathways altered in the developing brain. Offspring maternally exposed to Cd presented with enlarged brains proportional to body weights at birth and altered behavior at adulthood. RNA-seq in newborn brains identified exposure-associated increases in Hox gene and myelin marker expression and suggested perturbed retinoic acid (RA) signaling. Proteomic analysis showed altered levels of proteins involved in cellular energy pathways, hypoxic response, and RA signaling. Consistent with transcriptomic and proteomic analyses, we identified increased levels of retinoids in maternally-exposed newborn brains. Metabolomic analyses identified metabolites with significantly altered abundance, supportive of changes to cellular energy pathways and hypoxia. Finally, maternal Cd exposure reduced mitochondrial DNA levels in newborn brains. The identification of multiple pathways perturbed in the developing brain provides a basis for future studies determining the mechanistic links between maternal Cd exposure and altered neurodevelopment and behavior.
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Affiliation(s)
- Kathleen M Hudson
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA
| | - Emily Shiver
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA
| | - Jianshi Yu
- School of Pharmacy Mass Spectrometry Center, Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD, 21201, USA
| | - Sanya Mehta
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA
| | - Dereje D Jima
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, 27695, USA
| | - Maureen A Kane
- School of Pharmacy Mass Spectrometry Center, Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD, 21201, USA
| | - Heather B Patisaul
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA
| | - Michael Cowley
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, 27695, USA.
- Center for Human Health and the Environment, North Carolina State University, Raleigh, NC, 27695, USA.
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18
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Hughes AN. Glial Cells Promote Myelin Formation and Elimination. Front Cell Dev Biol 2021; 9:661486. [PMID: 34046407 PMCID: PMC8144722 DOI: 10.3389/fcell.2021.661486] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 04/07/2021] [Indexed: 12/13/2022] Open
Abstract
Building a functional nervous system requires the coordinated actions of many glial cells. In the vertebrate central nervous system (CNS), oligodendrocytes myelinate neuronal axons to increase conduction velocity and provide trophic support. Myelination can be modified by local signaling at the axon-myelin interface, potentially adapting sheaths to support the metabolic needs and physiology of individual neurons. However, neurons and oligodendrocytes are not wholly responsible for crafting the myelination patterns seen in vivo. Other cell types of the CNS, including microglia and astrocytes, modify myelination. In this review, I cover the contributions of non-neuronal, non-oligodendroglial cells to the formation, maintenance, and pruning of myelin sheaths. I address ways that these cell types interact with the oligodendrocyte lineage throughout development to modify myelination. Additionally, I discuss mechanisms by which these cells may indirectly tune myelination by regulating neuronal activity. Understanding how glial-glial interactions regulate myelination is essential for understanding how the brain functions as a whole and for developing strategies to repair myelin in disease.
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Affiliation(s)
- Alexandria N Hughes
- Section of Developmental Biology, Department of Pediatrics, University of Colorado, Aurora, Aurora, CO, United States
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19
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Meservey LM, Topkar VV, Fu MM. mRNA Transport and Local Translation in Glia. Trends Cell Biol 2021; 31:419-423. [PMID: 33840591 DOI: 10.1016/j.tcb.2021.03.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/06/2021] [Accepted: 03/08/2021] [Indexed: 11/26/2022]
Abstract
Though mRNA transport and local translation are extensively studied in neurons, emerging evidence supports that these cellular processes are also abundant in non-neuronal glial cells. Here, we explore mechanisms of mRNA transport and local translation in oligodendrocytes, astrocytes, microglia, radial glia, and their functions in development, structure, and intercellular interactions.
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Affiliation(s)
| | - Ved V Topkar
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA, USA
| | - Meng-Meng Fu
- National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, MD, USA.
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20
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Abstract
Myelination of axons provides the structural basis for rapid saltatory impulse propagation along vertebrate fiber tracts, a well-established neurophysiological concept. However, myelinating oligodendrocytes and Schwann cells serve additional functions in neuronal energy metabolism that are remarkably similar to those of axon-ensheathing glial cells in unmyelinated invertebrates. Here we discuss myelin evolution and physiological glial functions, beginning with the role of ensheathing glia in preventing ephaptic coupling, axoglial metabolic support, and eliminating oxidative radicals. In both vertebrates and invertebrates, axoglial interactions are bidirectional, serving to regulate cell fate, nerve conduction, and behavioral performance. One key step in the evolution of compact myelin in the vertebrate lineage was the emergence of the open reading frame for myelin basic protein within another gene. Several other proteins were neofunctionalized as myelin constituents and help maintain a healthy nervous system. Myelination in vertebrates became a major prerequisite of inhabiting new ecological niches.
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Affiliation(s)
- Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany; ,
| | - Hauke B Werner
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany; ,
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21
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RNA Localization and Local Translation in Glia in Neurological and Neurodegenerative Diseases: Lessons from Neurons. Cells 2021; 10:cells10030632. [PMID: 33809142 PMCID: PMC8000831 DOI: 10.3390/cells10030632] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 03/03/2021] [Accepted: 03/09/2021] [Indexed: 12/11/2022] Open
Abstract
Cell polarity is crucial for almost every cell in our body to establish distinct structural and functional domains. Polarized cells have an asymmetrical morphology and therefore their proteins need to be asymmetrically distributed to support their function. Subcellular protein distribution is typically achieved by localization peptides within the protein sequence. However, protein delivery to distinct cellular compartments can rely, not only on the transport of the protein itself but also on the transport of the mRNA that is then translated at target sites. This phenomenon is known as local protein synthesis. Local protein synthesis relies on the transport of mRNAs to subcellular domains and their translation to proteins at target sites by the also localized translation machinery. Neurons and glia specially depend upon the accurate subcellular distribution of their proteome to fulfil their polarized functions. In this sense, local protein synthesis has revealed itself as a crucial mechanism that regulates proper protein homeostasis in subcellular compartments. Thus, deregulation of mRNA transport and/or of localized translation can lead to neurological and neurodegenerative diseases. Local translation has been more extensively studied in neurons than in glia. In this review article, we will summarize the state-of-the art research on local protein synthesis in neuronal function and dysfunction, and we will discuss the possibility that local translation in glia and deregulation thereof contributes to neurological and neurodegenerative diseases.
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22
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Holzmann C, Witt M, Rolfs A, Antipova V, Wree A. Gender-Specific Effects of Two Treatment Strategies in a Mouse Model of Niemann-Pick Disease Type C1. Int J Mol Sci 2021; 22:ijms22052539. [PMID: 33802605 PMCID: PMC7962008 DOI: 10.3390/ijms22052539] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/16/2022] Open
Abstract
In a mouse model of Niemann-Pick disease type C1 (NPC1), a combination therapy (COMBI) of miglustat (MIGLU), the neurosteroid allopregnanolone (ALLO) and the cyclic oligosaccharide 2-hydroxypropyl-β-cyclodextrin (HPßCD) has previously resulted in, among other things, significantly improved motor function. The present study was designed to compare the therapeutic effects of the COMBI therapy with that of MIGLU or HPßCD alone on body and brain weight and the behavior of NPC1−/− mice in a larger cohort, with special reference to gender differences. A total of 117 NPC1−/− and 123 NPC1+/+ mice underwent either COMBI, MIGLU only, HPßCD only, or vehicle treatment (Sham), or received no treatment at all (None). In male and female NPC1−/− mice, all treatments led to decreased loss of body weight and, partly, brain weight. Concerning motor coordination, as revealed by the accelerod test, male NPC1−/− mice benefited from COMBI treatment, whereas female mice benefited from COMBI, MIGLU, and HPßCD treatment. As seen in the open field test, the reduced locomotor activity of male and female NPC1−/− mice was not significantly ameliorated in either treatment group. Our results suggest that in NPC1−/− mice, each drug treatment scheme had a beneficial effect on at least some of the parameters evaluated compared with Sham-treated mice. Only in COMBI-treated male and female NPC+/+ mice were drug effects seen in reduced body and brain weights. Upon COMBI treatment, the increased dosage of drugs necessary for anesthesia in Sham-treated male and female NPC1−/− mice was almost completely reduced only in the female groups.
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Affiliation(s)
- Carsten Holzmann
- Institute of Medical Genetics, Rostock University Medical Center, D-18057 Rostock, Germany;
- Centre of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany;
| | - Martin Witt
- Centre of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany;
- Institute of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany;
| | - Arndt Rolfs
- Centogene AG, Rostock, Am Strande 7, 18055 Rostock, Germany;
- University of Rostock, 18055 Rostock, Germany
| | - Veronica Antipova
- Institute of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany;
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Macroscopic and Clinical Anatomy, Medical University of Graz, A-8010 Graz, Austria
| | - Andreas Wree
- Centre of Transdisciplinary Neuroscience Rostock, D-18147 Rostock, Germany;
- Institute of Anatomy, Rostock University Medical Center, D-18057 Rostock, Germany;
- Correspondence: ; Tel.: +49-381-494-8429
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23
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Dyakin VV, Wisniewski TM, Lajtha A. Racemization in Post-Translational Modifications Relevance to Protein Aging, Aggregation and Neurodegeneration: Tip of the Iceberg. Symmetry (Basel) 2021; 13:455. [PMID: 34350031 PMCID: PMC8330555 DOI: 10.3390/sym13030455] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Homochirality of DNA and prevalent chirality of free and protein-bound amino acids in a living organism represents the challenge for modern biochemistry and neuroscience. The idea of an association between age-related disease, neurodegeneration, and racemization originated from the studies of fossils and cataract disease. Under the pressure of new results, this concept has a broader significance linking protein folding, aggregation, and disfunction to an organism's cognitive and behavioral functions. The integrity of cognitive function is provided by a delicate balance between the evolutionarily imposed molecular homo-chirality and the epigenetic/developmental impact of spontaneous and enzymatic racemization. The chirality of amino acids is the crucial player in the modulation the structure and function of proteins, lipids, and DNA. The collapse of homochirality by racemization is the result of the conformational phase transition. The racemization of protein-bound amino acids (spontaneous and enzymatic) occurs through thermal activation over the energy barrier or by the tunnel transfer effect under the energy barrier. The phase transition is achieved through the intermediate state, where the chirality of alpha carbon vanished. From a thermodynamic consideration, the system in the homo-chiral (single enantiomeric) state is characterized by a decreased level of entropy. The oscillating protein chirality is suggesting its distinct significance in the neurotransmission and flow of perceptual information, adaptive associative learning, and cognitive laterality. The common pathological hallmarks of neurodegenerative disorders include protein misfolding, aging, and the deposition of protease-resistant protein aggregates. Each of the landmarks is influenced by racemization. The brain region, cell type, and age-dependent racemization critically influence the functions of many intracellular, membrane-bound, and extracellular proteins including amyloid precursor protein (APP), TAU, PrP, Huntingtin, α-synuclein, myelin basic protein (MBP), and collagen. The amyloid cascade hypothesis in Alzheimer's disease (AD) coexists with the failure of amyloid beta (Aβ) targeting drug therapy. According to our view, racemization should be considered as a critical factor of protein conformation with the potential for inducing order, disorder, misfolding, aggregation, toxicity, and malfunctions.
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Affiliation(s)
- Victor V. Dyakin
- Virtual Reality Perception Lab (VRPL), The Nathan S. Kline Institute for Psychiatric Research (NKI), Orangeburg, NY 10962, USA
| | - Thomas M. Wisniewski
- Departments of Neurology, Pathology and Psychiatry, Center for Cognitive Neurology, New York University School of Medicine, New York, NY 10016, USA
| | - Abel Lajtha
- Center for Neurochemistry, The Nathan S. Kline Institute for Psychiatric Research (NKI), Orangeburg, NY 10962, USA
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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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25
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Yergert KM, Doll CA, O’Rouke R, Hines JH, Appel B. Identification of 3' UTR motifs required for mRNA localization to myelin sheaths in vivo. PLoS Biol 2021; 19:e3001053. [PMID: 33439856 PMCID: PMC7837478 DOI: 10.1371/journal.pbio.3001053] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 01/26/2021] [Accepted: 12/22/2020] [Indexed: 12/20/2022] Open
Abstract
Myelin is a specialized membrane produced by oligodendrocytes that insulates and supports axons. Oligodendrocytes extend numerous cellular processes, as projections of the plasma membrane, and simultaneously wrap multiple layers of myelin membrane around target axons. Notably, myelin sheaths originating from the same oligodendrocyte are variable in size, suggesting local mechanisms regulate myelin sheath growth. Purified myelin contains ribosomes and hundreds of mRNAs, supporting a model that mRNA localization and local protein synthesis regulate sheath growth and maturation. However, the mechanisms by which mRNAs are selectively enriched in myelin sheaths are unclear. To investigate how mRNAs are targeted to myelin sheaths, we tested the hypothesis that transcripts are selected for myelin enrichment through consensus sequences in the 3' untranslated region (3' UTR). Using methods to visualize mRNA in living zebrafish larvae, we identified candidate 3' UTRs that were sufficient to localize mRNA to sheaths and enriched near growth zones of nascent membrane. We bioinformatically identified motifs common in 3' UTRs from 3 myelin-enriched transcripts and determined that these motifs are required and sufficient in a context-dependent manner for mRNA transport to myelin sheaths. Finally, we show that 1 motif is highly enriched in the myelin transcriptome, suggesting that this sequence is a global regulator of mRNA localization during developmental myelination.
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Affiliation(s)
- Katie M. Yergert
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Caleb A. Doll
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Rebecca O’Rouke
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Jacob H. Hines
- Department of Biology, Winona State University, Winona, Minnesota, United States of America
| | - Bruce Appel
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
- * E-mail:
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26
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Giuditta A, Grassi Zucconi G, Sadile A. Brain metabolic DNA: recent evidence for a mitochondrial connection. Rev Neurosci 2020; 32:/j/revneuro.ahead-of-print/revneuro-2020-0050/revneuro-2020-0050.xml. [PMID: 32866135 DOI: 10.1515/revneuro-2020-0050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 07/18/2020] [Indexed: 02/24/2024]
Abstract
This review highlights recent data concerning the synthesis of brain metabolic DNA (BMD) by cytoplasmic reverse transcription and the prompt acquisition of the double-stranded configuration that allows its partial transfer to nuclei. BMD prevails in the mitochondrial fraction and is present in presynaptic regions and astroglial processes where it undergoes a turnover lasting a few weeks. Additional data demonstrate that BMD sequences are modified by learning, thus indicating that the modified synaptic activity allowing proper brain responses is encoded in learning BMD. In addition, several converging observations regarding the origin of BMD strongly suggest that BMD is reverse transcribed by mitochondrial telomerase.
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Affiliation(s)
- Antonio Giuditta
- Accademia di Scienze Fisiche e Matematiche, Via Mezzocannone 8, Naples, I-80134,Italy
| | | | - Adolfo Sadile
- Department of Experimental Medicine, L. Vanvitelli Medical School, University Campania, Via S. Andrea delle dame 7, Naples, I-80138,Italy
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27
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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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28
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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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29
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Mukherjee C, Kling T, Russo B, Miebach K, Kess E, Schifferer M, Pedro LD, Weikert U, Fard MK, Kannaiyan N, Rossner M, Aicher ML, Goebbels S, Nave KA, Krämer-Albers EM, Schneider A, Simons M. Oligodendrocytes Provide Antioxidant Defense Function for Neurons by Secreting Ferritin Heavy Chain. Cell Metab 2020; 32:259-272.e10. [PMID: 32531201 PMCID: PMC7116799 DOI: 10.1016/j.cmet.2020.05.019] [Citation(s) in RCA: 84] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/25/2020] [Accepted: 05/26/2020] [Indexed: 12/28/2022]
Abstract
An evolutionarily conserved function of glia is to provide metabolic and structural support for neurons. To identify molecules generated by glia and with vital functions for neurons, we used Drosophila melanogaster as a screening tool, and subsequently translated the findings to mice. We found that a cargo receptor operating in the secretory pathway of glia was essential to maintain axonal integrity by regulating iron buffering. Ferritin heavy chain was identified as the critical secretory cargo, required for the protection against iron-mediated ferroptotic axonal damage. In mice, ferritin heavy chain is highly expressed by oligodendrocytes and secreted by employing an unconventional secretion pathway involving extracellular vesicles. Disrupting the release of extracellular vesicles or the expression of ferritin heavy chain in oligodendrocytes causes neuronal loss and oxidative damage in mice. Our data point to a role of oligodendrocytes in providing an antioxidant defense system to support neurons against iron-mediated cytotoxicity.
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Affiliation(s)
- Chaitali Mukherjee
- Institute of Neuronal Cell Biology, Technical University Munich, 80802 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - Tina Kling
- Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Belisa Russo
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Kerstin Miebach
- Institute of Developmental Biology and Neurobiology (IDN), University of Mainz, 55128 Mainz, Germany
| | - Eva Kess
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
| | - Martina Schifferer
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - Liliana D Pedro
- Institute of Neuronal Cell Biology, Technical University Munich, 80802 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - Ulrich Weikert
- Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Maryam K Fard
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany
| | - Nirmal Kannaiyan
- Department of Psychiatry, Ludwig-Maximillian University, 80336 Munich, Germany
| | - Moritz Rossner
- Department of Psychiatry, Ludwig-Maximillian University, 80336 Munich, Germany
| | - Marie-Louise Aicher
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Sandra Goebbels
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Eva-Maria Krämer-Albers
- Institute of Developmental Biology and Neurobiology (IDN), University of Mainz, 55128 Mainz, Germany
| | - Anja Schneider
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany; Department of Neurodegenerative Diseases and Geriatric Psychiatry, University Bonn, 53127 Bonn, Germany.
| | - Mikael Simons
- Institute of Neuronal Cell Biology, Technical University Munich, 80802 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany; Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany; Munich Cluster of Systems Neurology (SyNergy), 81377 Munich, Germany.
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30
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Weigel M, Wang L, Fu MM. Microtubule organization and dynamics in oligodendrocytes, astrocytes, and microglia. Dev Neurobiol 2020; 81:310-320. [PMID: 32324338 DOI: 10.1002/dneu.22753] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 01/16/2020] [Accepted: 04/20/2020] [Indexed: 12/16/2022]
Abstract
Though much is known about microtubule organization and microtubule-based transport in neurons, the development and function of microtubules in glia are more enigmatic. In this review, we provide an overview of the literature on microtubules in ramified brain cells, including oligodendrocytes, astrocytes, and microglia. We focus on normal cell biology-how structure relates to function in these cells. In oligodendrocytes, microtubules are important for extension of processes that contact axons and for elongating the myelin sheath. Recent studies demonstrate that new microtubules can form outside of the oligodendrocyte cell body off of Golgi outpost organelles. In astrocytes and microglia, changes in cell shape and ramification can be influenced by neighboring cells and the extracellular milieu. Finally, we highlight key papers implicating glial microtubule defects in neurological injury and disease and discuss how microtubules may contribute to invasiveness in gliomas. Thus, future research on the mechanisms underlying microtubule organization in normal glial cell function may yield valuable insights on neurological disease pathology.
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Affiliation(s)
- Maya Weigel
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lin Wang
- Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | - Meng-Meng Fu
- Department of Neurobiology, Stanford University School of Medicine, Stanford, CA, USA
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31
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Farias J, Holt CE, Sotelo JR, Sotelo-Silveira JR. Axon microdissection and transcriptome profiling reveals the in vivo RNA content of fully differentiated myelinated motor axons. RNA (NEW YORK, N.Y.) 2020; 26:595-612. [PMID: 32051223 PMCID: PMC7161357 DOI: 10.1261/rna.073700.119] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/31/2020] [Indexed: 05/23/2023]
Abstract
Axonal protein synthesis has been shown to play a role in developmental and regenerative growth, as well as in the maintenance of the axoplasm in a steady state. Recent studies have begun to identify the mRNAs localized in axons, which could be translated locally under different conditions. Despite that by now hundreds or thousands of mRNAs have been shown to be localized into the axonal compartment of cultured neurons in vitro, knowledge of which mRNAs are localized in mature myelinated axons is quite limited. With the purpose of characterizing the transcriptome of mature myelinated motor axons of peripheral nervous systems, we modified the axon microdissection method devised by Koenig, enabling the isolation of the axoplasm RNA to perform RNA-seq analysis. The transcriptome analysis indicates that the number of RNAs detected in mature axons is lower in comparison with in vitro data, depleted of glial markers, and enriched in neuronal markers. The mature myelinated axons are enriched for mRNAs related to cytoskeleton, translation, and oxidative phosphorylation. Moreover, it was possible to define core genes present in axons when comparing our data with transcriptomic data of axons grown in different conditions. This work provides evidence that axon microdissection is a valuable method to obtain genome-wide data from mature and myelinated axons of the peripheral nervous system, and could be especially useful for the study of axonal involvement in neurodegenerative pathologies of motor neurons such as amyotrophic lateral sclerosis (ALS) and spinal muscular atrophies (SMA).
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Affiliation(s)
- Joaquina Farias
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, 11600, Uruguay
- Departamento de Proteínas y Ácidos Nucléicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, 11600, Uruguay
| | - Christine E Holt
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, CB2 3DY, United Kingdom
| | - José R Sotelo
- Departamento de Proteínas y Ácidos Nucléicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, 11600, Uruguay
| | - José R Sotelo-Silveira
- Departamento de Genómica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, 11600, Uruguay
- Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, 11400, Uruguay
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32
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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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33
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Spencer SA, Suárez-Pozos E, Escalante M, Myo YP, Fuss B. Sodium-Calcium Exchangers of the SLC8 Family in Oligodendrocytes: Functional Properties in Health and Disease. Neurochem Res 2020; 45:1287-1297. [PMID: 31927687 DOI: 10.1007/s11064-019-02949-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Revised: 12/20/2019] [Accepted: 12/23/2019] [Indexed: 12/30/2022]
Abstract
The solute carrier 8 (SLC8) family of sodium-calcium exchangers (NCXs) functions as an essential regulatory system that couples opposite fluxes of sodium and calcium ions across plasmalemmal membranes. NCXs, thereby, play key roles in maintaining an ion homeostasis that preserves cellular integrity. Hence, alterations in NCX expression and regulation have been found to lead to ionic imbalances that are often associated with intracellular calcium overload and cell death. On the other hand, intracellular calcium has been identified as a key driver for a multitude of downstream signaling events that are crucial for proper functioning of biological systems, thus highlighting the need for a tightly controlled balance. In the CNS, NCXs have been primarily characterized in the context of synaptic transmission and ischemic brain damage. However, a much broader picture is emerging. NCXs are expressed by virtually all cells of the CNS including oligodendrocytes (OLGs), the cells that generate the myelin sheath. With a growing appreciation of dynamic calcium signals in OLGs, NCXs are becoming increasingly recognized for their crucial roles in shaping OLG function under both physiological and pathophysiological conditions. In order to provide a current update, this review focuses on the importance of NCXs in cells of the OLG lineage. More specifically, it provides a brief introduction into plasmalemmal NCXs and their modes of activity, and it discusses the roles of OLG expressed NCXs in regulating CNS myelination and in contributing to CNS pathologies associated with detrimental effects on OLG lineage cells.
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Affiliation(s)
- Samantha A Spencer
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA
| | - Edna Suárez-Pozos
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA
| | - Miguel Escalante
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA.,Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Yu Par Myo
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA
| | - Babette Fuss
- Department of Anatomy and Neurobiology, Virginia Commonwealth University School of Medicine, Box 980709, Richmond, VA, 23298, USA.
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34
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Xu H, Dzhashiashvili Y, Shah A, Kunjamma RB, Weng YL, Elbaz B, Fei Q, Jones JS, Li YI, Zhuang X, Ming GL, He C, Popko B. m 6A mRNA Methylation Is Essential for Oligodendrocyte Maturation and CNS Myelination. Neuron 2019; 105:293-309.e5. [PMID: 31901304 DOI: 10.1016/j.neuron.2019.12.013] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 10/15/2019] [Accepted: 12/09/2019] [Indexed: 12/21/2022]
Abstract
The molecular mechanisms that govern the maturation of oligodendrocyte lineage cells remain unclear. Emerging studies have shown that N6-methyladenosine (m6A), the most common internal RNA modification of mammalian mRNA, plays a critical role in various developmental processes. Here, we demonstrate that oligodendrocyte lineage progression is accompanied by dynamic changes in m6A modification on numerous transcripts. In vivo conditional inactivation of an essential m6A writer component, METTL14, results in decreased oligodendrocyte numbers and CNS hypomyelination, although oligodendrocyte precursor cell (OPC) numbers are normal. In vitro Mettl14 ablation disrupts postmitotic oligodendrocyte maturation and has distinct effects on OPC and oligodendrocyte transcriptomes. Moreover, the loss of Mettl14 in oligodendrocyte lineage cells causes aberrant splicing of myriad RNA transcripts, including those that encode the essential paranodal component neurofascin 155 (NF155). Together, our findings indicate that dynamic RNA methylation plays an important regulatory role in oligodendrocyte development and CNS myelination.
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Affiliation(s)
- Huan Xu
- Center for Peripheral Neuropathy and Department of Neurology, University of Chicago, Chicago, IL 60637, USA
| | - Yulia Dzhashiashvili
- Center for Peripheral Neuropathy and Department of Neurology, University of Chicago, Chicago, IL 60637, USA
| | - Ankeeta Shah
- Committee on Genetics, Genomics, and Systems Biology, University of Chicago, Chicago, IL 60637, USA; Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Rejani B Kunjamma
- Center for Peripheral Neuropathy and Department of Neurology, University of Chicago, Chicago, IL 60637, USA
| | - Yi-Lan Weng
- Department of Neuroscience and Mahoney Institute for Neurosciences, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Benayahu Elbaz
- Center for Peripheral Neuropathy and Department of Neurology, University of Chicago, Chicago, IL 60637, USA
| | - Qili Fei
- Department of Chemistry and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA
| | - Joshua S Jones
- Center for Peripheral Neuropathy and Department of Neurology, University of Chicago, Chicago, IL 60637, USA
| | - Yang I Li
- Section of Genetic Medicine, Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | - Xiaoxi Zhuang
- Department of Neurobiology, University of Chicago, Chicago, IL 60637, USA
| | - Guo-Li Ming
- Department of Neuroscience and Mahoney Institute for Neurosciences, Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Chuan He
- Department of Chemistry and Institute for Biophysical Dynamics, University of Chicago, Chicago, IL 60637, USA
| | - Brian Popko
- Center for Peripheral Neuropathy and Department of Neurology, University of Chicago, Chicago, IL 60637, USA.
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35
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Prospective administration of anti-nerve growth factor treatment effectively suppresses functional connectivity alterations after cancer-induced bone pain in mice. Pain 2019; 160:151-159. [PMID: 30161041 DOI: 10.1097/j.pain.0000000000001388] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cancer-induced bone pain is abundant among advanced-stage cancer patients and arises from a primary tumor in the bone or skeletal metastasis of common cancer types such as breast, lung, or prostate cancer. Recently, antibodies targeting nerve growth factor (NGF) have been shown to effectively relieve neuropathic and inflammatory pain states in mice and in humans. Although efficacy has been shown in mice on a behavioral level, effectiveness in preventing pain-induced functional rearrangements in the central nervous system has not been shown. Therefore, we assessed longitudinal whole-brain functional connectivity using resting-state functional magnetic resonance imaging in a mouse model of cancer-induced bone pain. We found functional connectivity between major hubs of ascending and descending pain pathways such as the periaqueductal gray, amygdala, thalamus, and cortical somatosensory regions to be affected by a developing cancer pain state. These changes could be successfully prevented through prospective administration of a monoclonal anti-NGF antibody (mAb911). This indicates efficacy of anti-NGF treatment to prevent pain-induced adaptations in brain functional networks after persistent nociceptive input from cancer-induced bone pain. In addition, it highlights the suitability of resting-state functional magnetic resonance imaging readouts as an indicator of treatment response on the basis of longitudinal functional network changes.
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36
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Yun W, Hong W, Son D, Liu HW, Kim SS, Park M, Kim IY, Kim DS, Song G, You S. Generation of Anterior Hindbrain-Specific, Glial-Restricted Progenitor-Like Cells from Human Pluripotent Stem Cells. Stem Cells Dev 2019; 28:633-648. [PMID: 30880587 DOI: 10.1089/scd.2019.0033] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Engraftment of oligodendrocyte progenitor cells (OPCs), which form myelinating oligodendrocytes, has the potential to treat demyelinating diseases such as multiple sclerosis. However, conventional strategies for generating oligodendrocytes have mainly focused on direct differentiation into forebrain- or spinal cord-restricted oligodendrocytes without establishing or amplifying stem/progenitor cells. Taking advantage of a recently established culture system, we generated expandable EN1- and GBX2-positive glial-restricted progenitor-like cells (GPLCs) near the anterior hindbrain. These cells expressed PDGFRα, CD9, S100β, and SOX10 and mostly differentiated into GFAP-positive astrocytes and MBP-positive oligodendrocytes. RNA-seq analysis revealed that the transcriptome of GPLCs was similar to that of O4-positive OPCs, but distinct from that of rosette-type neural stem cells. Notably, engrafted GPLCs not only differentiated into GFAP-positive astrocytes but also myelinated the brains of adult shiverer mice 8 weeks after transplantation. Our strategy for establishing anterior hindbrain-specific GPLCs with gliogenic potency will facilitate their use in the treatment of demyelinating diseases and studies of the molecular mechanisms underlying glial development in the hindbrain.
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Affiliation(s)
- Wonjin Yun
- 1 Laboratory of Cell Function Regulation, Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.,2 Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
| | - Wonjun Hong
- 1 Laboratory of Cell Function Regulation, Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.,2 Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
| | - Daryeon Son
- 1 Laboratory of Cell Function Regulation, Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.,2 Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
| | - Hui-Wen Liu
- 2 Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea.,3 Laboratory of Reprogramming & Differentiation, Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Seung-Soo Kim
- 2 Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
| | - Minji Park
- 1 Laboratory of Cell Function Regulation, Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea
| | - In Yong Kim
- 1 Laboratory of Cell Function Regulation, Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.,4 Department of Neurosurgery, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Dae-Sung Kim
- 2 Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea.,3 Laboratory of Reprogramming & Differentiation, Department of Biotechnology, College of Life Science and Biotechnology, Korea University, Seoul, Republic of Korea
| | - Gwonhwa Song
- 5 Department of Biotechnology, Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
| | - Seungkwon You
- 1 Laboratory of Cell Function Regulation, Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, Republic of Korea.,2 Institute of Animal Molecular Biotechnology, Korea University, Seoul, Republic of Korea
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37
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Intrinsic mutant HTT-mediated defects in oligodendroglia cause myelination deficits and behavioral abnormalities in Huntington disease. Proc Natl Acad Sci U S A 2019; 116:9622-9627. [PMID: 31015293 DOI: 10.1073/pnas.1818042116] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
White matter abnormalities are a nearly universal pathological feature of neurodegenerative disorders including Huntington disease (HD). A long-held assumption is that this white matter pathology is simply a secondary outcome of the progressive neuronal loss that manifests with advancing disease. Using a mouse model of HD, here we show that white matter and myelination abnormalities are an early disease feature appearing before the manifestation of any behavioral abnormalities or neuronal loss. We further show that selective inactivation of mutant huntingtin (mHTT) in the NG2+ oligodendrocyte progenitor cell population prevented myelin abnormalities and certain behavioral deficits in HD mice. Strikingly, the improvements in behavioral outcomes were seen despite the continued expression of mHTT in nonoligodendroglial cells including neurons, astrocytes, and microglia. Using RNA-seq and ChIP-seq analyses, we implicate a pathogenic mechanism that involves enhancement of polycomb repressive complex 2 (PRC2) activity by mHTT in the intrinsic oligodendroglial dysfunction and myelination deficits observed in HD. Our findings challenge the long-held dogma regarding the etiology of white matter pathology in HD and highlight the contribution of epigenetic mechanisms to the observed intrinsic oligodendroglial dysfunction. Our results further suggest that ameliorating white matter pathology and oligodendroglial dysfunction may be beneficial for HD.
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38
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Hoch-Kraft P, Trotter J, Gonsior C. Missing in Action: Dysfunctional RNA Metabolism in Oligodendroglial Cells as a Contributor to Neurodegenerative Diseases? Neurochem Res 2019; 45:566-579. [PMID: 30843138 DOI: 10.1007/s11064-019-02763-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 02/22/2019] [Accepted: 02/23/2019] [Indexed: 12/14/2022]
Abstract
The formation of myelin around axons by oligodendrocytes (OL) poses an enormous synthetic and energy challenge for the glial cell. Local translation of transcripts, including the mRNA for the essential myelin protein Myelin Basic Protein (MBP) at the site of myelin deposition has been recognised as an efficient mechanism to assure proper myelin sheath assembly. Oligodendroglial precursor cells (OPCs) form synapses with neurons and may localise many additional mRNAs in a similar fashion to synapses between neurons. In some diseases in which demyelination occurs, an abundance of OPCs is present but there is a failure to efficiently remyelinate and to synthesise MBP. This compromises axonal survival and function. OPCs are especially sensitive to cellular stress as occurring in neurodegenerative diseases, which can impinge on their ability to translate mRNAs into protein. Stress causes the build up of cytoplasmic stress granules (SG) in which many RNAs are sequestered and translationally stalled until the stress ceases. Chronic stress in particular could convert this initially protective reaction of the cell into damage, as persistence of SG may lead to pathological aggregate formation or long-term translation block of SG-associated RNAs. The recent recognition that many neurodegenerative diseases often exhibit an early white matter pathology with a proliferation of surviving OPCs, renders a study of the stress-associated processes in oligodendrocytes and OPCs especially relevant. Here, we discuss a potential dysfunction of RNA regulation in myelin diseases such as Multiple Sclerosis (MS) and Vanishing white matter disease (VWM) and potential contributions of OL dysfunction to neurodegenerative diseases such as Amyotrophic lateral sclerosis (ALS), Alzheimer's disease (AD) and Fragile X syndrome (FXS).
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Affiliation(s)
- Peter Hoch-Kraft
- Cellular Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128, Mainz, Germany
| | - Jacqueline Trotter
- Cellular Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128, Mainz, Germany
| | - Constantin Gonsior
- Cellular Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128, Mainz, Germany.
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39
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Elbaz B, Popko B. Molecular Control of Oligodendrocyte Development. Trends Neurosci 2019; 42:263-277. [PMID: 30770136 DOI: 10.1016/j.tins.2019.01.002] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/07/2019] [Accepted: 01/15/2019] [Indexed: 12/27/2022]
Abstract
Myelin is a multilayer lipid membrane structure that wraps and insulates axons, allowing for the efficient propagation of action potentials. During developmental myelination of the central nervous system (CNS), oligodendrocyte progenitor cells (OPCs) proliferate and migrate to their final destination, where they terminally differentiate into mature oligodendrocytes and myelinate axons. Lineage progression and terminal differentiation of oligodendrocyte lineage cells are under tight transcriptional and post-transcriptional control. The characterization of several recently identified regulatory factors that govern these processes, which are the focus of this review, has greatly increased our understanding of oligodendrocyte development and function. These insights are critical to facilitate efforts to enhance OPC differentiation in neurological disorders that disrupt CNS myelin.
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Affiliation(s)
- Benayahu Elbaz
- The Center for Peripheral Neuropathy, The Department of Neurology, University of Chicago, Chicago, IL, USA
| | - Brian Popko
- The Center for Peripheral Neuropathy, The Department of Neurology, University of Chicago, Chicago, IL, USA.
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40
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Erwig MS, Patzig J, Steyer AM, Dibaj P, Heilmann M, Heilmann I, Jung RB, Kusch K, Möbius W, Jahn O, Nave KA, Werner HB. Anillin facilitates septin assembly to prevent pathological outfoldings of central nervous system myelin. eLife 2019; 8:43888. [PMID: 30672734 PMCID: PMC6344079 DOI: 10.7554/elife.43888] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/11/2019] [Indexed: 12/15/2022] Open
Abstract
Myelin serves as an axonal insulator that facilitates rapid nerve conduction along axons. By transmission electron microscopy, a healthy myelin sheath comprises compacted membrane layers spiraling around the cross-sectioned axon. Previously we identified the assembly of septin filaments in the innermost non-compacted myelin layer as one of the latest steps of myelin maturation in the central nervous system (CNS) (Patzig et al., 2016). Here we show that loss of the cytoskeletal adaptor protein anillin (ANLN) from oligodendrocytes disrupts myelin septin assembly, thereby causing the emergence of pathological myelin outfoldings. Since myelin outfoldings are a poorly understood hallmark of myelin disease and brain aging we assessed axon/myelin-units in Anln-mutant mice by focused ion beam-scanning electron microscopy (FIB-SEM); myelin outfoldings were three-dimensionally reconstructed as large sheets of multiple compact membrane layers. We suggest that anillin-dependent assembly of septin filaments scaffolds mature myelin sheaths, facilitating rapid nerve conduction in the healthy CNS.
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Affiliation(s)
- Michelle S Erwig
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Julia Patzig
- 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.,Center for Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Payam Dibaj
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Mareike Heilmann
- Department of Cellular Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Ingo Heilmann
- Department of Cellular Biochemistry, Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle, Germany
| | - Ramona B Jung
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Kathrin Kusch
- Department of Neurogenetics, 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
| | - Olaf Jahn
- Proteomics Group, Max Planck Institute of Experimental Medicine, 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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41
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Abstract
Neural plasticity in the adult central nervous system involves the adaptation of myelination, including the formation of novel myelin sheaths by adult-born oligodendrocytes. Yet, mature oligodendrocytes slowly but constantly turn over their pre-existing myelin sheaths, thereby establishing an equilibrium of replenishment and degradation that may also be subject to adaptation with consequences for nerve conduction velocity. In this short review we highlight selected approaches to the normal turnover of adult myelin in vivo, from injecting radioactive precursors of myelin constituents in the 1960s to current strategies involving isotope labeling and tamoxifen-induced gene targeting.
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Affiliation(s)
- Tobias J Buscham
- 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
| | - Sophie B Siems
- 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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42
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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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43
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Marques S, van Bruggen D, Vanichkina DP, Floriddia EM, Munguba H, Väremo L, Giacomello S, Falcão AM, Meijer M, Björklund ÅK, Hjerling-Leffler J, Taft RJ, Castelo-Branco G. Transcriptional Convergence of Oligodendrocyte Lineage Progenitors during Development. Dev Cell 2018; 46:504-517.e7. [PMID: 30078729 PMCID: PMC6104814 DOI: 10.1016/j.devcel.2018.07.005] [Citation(s) in RCA: 156] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 05/23/2018] [Accepted: 07/03/2018] [Indexed: 01/31/2023]
Abstract
Pdgfra+ oligodendrocyte precursor cells (OPCs) arise in distinct specification waves during embryogenesis in the central nervous system (CNS). It is unclear whether there is a correlation between these waves and different oligodendrocyte (OL) states at adult stages. Here, we present bulk and single-cell transcriptomics resources providing insights on how transitions between these states occur. We found that post-natal OPCs from brain and spinal cord present similar transcriptional signatures. Moreover, post-natal OPC progeny of E13.5 Pdgfra+ cells present electrophysiological and transcriptional profiles similar to OPCs derived from subsequent specification waves, indicating that Pdgfra+ pre-OPCs rewire their transcriptional network during development. Single-cell RNA-seq and lineage tracing indicates that a subset of E13.5 Pdgfra+ cells originates cells of the pericyte lineage. Thus, our results indicate that embryonic Pdgfra+ cells in the CNS give rise to distinct post-natal cell lineages, including OPCs with convergent transcriptional profiles in different CNS regions. OPCs arising from different parts of the CNS are highly similar to one another Pre-OPCs converge into similar transcriptional and electrophysiological OPC states E13.5 Pdgfra+ cells give rise mainly to OPCs in the post-natal CNS E13.5 Pdgfra+ cells also give rise to cells of the pericyte lineage
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Affiliation(s)
- Sueli Marques
- Laboratory of Molecular Neurobiology, Department Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, Stockholm 17177, Sweden
| | - David van Bruggen
- Laboratory of Molecular Neurobiology, Department Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, Stockholm 17177, Sweden
| | - Darya Pavlovna Vanichkina
- Gene and Stem Cell Therapy Program, Centenary Institute, University of Sydney, Camperdown, NSW 2050, Australia; Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4067, Australia
| | - Elisa Mariagrazia Floriddia
- Laboratory of Molecular Neurobiology, Department Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, Stockholm 17177, Sweden
| | - Hermany Munguba
- Laboratory of Molecular Neurobiology, Department Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, Stockholm 17177, Sweden
| | - Leif Väremo
- Science for Life Laboratory, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, Göteborg 412 96, Sweden
| | - Stefania Giacomello
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Box 1031, 17121 Solna, Sweden
| | - Ana Mendanha Falcão
- Laboratory of Molecular Neurobiology, Department Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, Stockholm 17177, Sweden
| | - Mandy Meijer
- Laboratory of Molecular Neurobiology, Department Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, Stockholm 17177, Sweden
| | - Åsa Kristina Björklund
- Science for Life Laboratory, Department of Cell and Molecular Biology, Uppsala University, Husargatan 3, 75237 Uppsala, Sweden
| | - Jens Hjerling-Leffler
- Laboratory of Molecular Neurobiology, Department Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, Stockholm 17177, Sweden
| | - Ryan James Taft
- Institute for Molecular Bioscience, University of Queensland, St Lucia, QLD 4067, Australia; Illumina, Inc., San Diego, CA 92122, USA
| | - Gonçalo Castelo-Branco
- Laboratory of Molecular Neurobiology, Department Medical Biochemistry and Biophysics, Biomedicum, Karolinska Institutet, Stockholm 17177, Sweden.
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44
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Cathomas F, Azzinnari D, Bergamini G, Sigrist H, Buerge M, Hoop V, Wicki B, Goetze L, Soares S, Kukelova D, Seifritz E, Goebbels S, Nave KA, Ghandour MS, Seoighe C, Hildebrandt T, Leparc G, Klein H, Stupka E, Hengerer B, Pryce CR. Oligodendrocyte gene expression is reduced by and influences effects of chronic social stress in mice. GENES BRAIN AND BEHAVIOR 2018; 18:e12475. [DOI: 10.1111/gbb.12475] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 03/18/2018] [Accepted: 03/19/2018] [Indexed: 12/16/2022]
Affiliation(s)
- F. Cathomas
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
- Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
| | - D. Azzinnari
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
- Neuroscience Center Zurich; University of Zurich and ETH Zurich; Zurich Switzerland
| | - G. Bergamini
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
- Neuroscience Center Zurich; University of Zurich and ETH Zurich; Zurich Switzerland
| | - H. Sigrist
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
| | - M. Buerge
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
| | - V. Hoop
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
- Institute of Human Movement Sciences and Sport; ETH Zurich; Zurich Switzerland
| | - B. Wicki
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
| | - L. Goetze
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
| | - S. Soares
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
| | - D. Kukelova
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
| | - E. Seifritz
- Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
| | - S. Goebbels
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Goettingen Germany
| | - K.-A. Nave
- Department of Neurogenetics; Max Planck Institute of Experimental Medicine; Goettingen Germany
| | - M. S. Ghandour
- Center of Neurochemistry, University of Strasbourg, UMR 7357; Strasbourg France
- Department of Anatomy and Neurobiology; Virginia Commonwealth University; Richmond Virginia
| | - C. Seoighe
- School of Mathematics, Statistics & Applied Mathematics; National University of Ireland; Galway Ireland
| | - T. Hildebrandt
- Target Discovery Germany; Boehringer Ingelheim Pharma GmbH & Co. KG.; Biberach Germany
| | - G. Leparc
- Target Discovery Germany; Boehringer Ingelheim Pharma GmbH & Co. KG.; Biberach Germany
| | - H. Klein
- Target Discovery Germany; Boehringer Ingelheim Pharma GmbH & Co. KG.; Biberach Germany
| | - E. Stupka
- Target Discovery Germany; Boehringer Ingelheim Pharma GmbH & Co. KG.; Biberach Germany
| | - B. Hengerer
- CNS Diseases Research Germany; Boehringer Ingelheim Pharma GmbH & Co. KG.; Biberach Germany
| | - C. R. Pryce
- Preclinical Laboratory for Translational Research into Affective Disorders, Department of Psychiatry, Psychotherapy and Psychosomatics; Psychiatric Hospital, University of Zurich; Zurich Switzerland
- Neuroscience Center Zurich; University of Zurich and ETH Zurich; Zurich Switzerland
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45
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Fröhlich D, Suchowerska AK, Voss C, He R, Wolvetang E, von Jonquieres G, Simons C, Fath T, Housley GD, Klugmann M. Expression Pattern of the Aspartyl-tRNA Synthetase DARS in the Human Brain. Front Mol Neurosci 2018; 11:81. [PMID: 29615866 PMCID: PMC5869200 DOI: 10.3389/fnmol.2018.00081] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 03/01/2018] [Indexed: 12/21/2022] Open
Abstract
Translation of mRNA into protein is an evolutionarily conserved, fundamental process of life. A prerequisite for translation is the accurate charging of tRNAs with their cognate amino acids, a reaction catalyzed by specific aminoacyl-tRNA synthetases. One of these enzymes is the aspartyl-tRNA synthetase DARS, which pairs aspartate with its corresponding tRNA. Missense mutations of the gene encoding DARS result in the leukodystrophy hypomyelination with brainstem and spinal cord involvement and leg spasticity (HBSL) with a distinct pattern of hypomyelination, motor abnormalities, and cognitive impairment. A thorough understanding of the DARS expression domains in the central nervous system is essential for the development of targeted therapies to treat HBSL. Here, we analyzed endogenous DARS expression on the mRNA and protein level in different brain regions and cell types of human post mortem brain tissue as well as in human stem cell derived neurons, oligodendrocytes, and astrocytes. DARS expression is significantly enriched in the cerebellum, a region affected in HBSL patients and important for motor control. Although obligatorily expressed in all cells, DARS shows a distinct expression pattern with enrichment in neurons but only low abundance in oligodendrocytes, astrocytes, and microglia. Our results reveal little homogeneity across the different cell types, largely matching previously published data in the murine brain. This human gene expression study will significantly contribute to the understanding of DARS gene function and HBSL pathology and will be instrumental for future development of animal models and targeted therapies. In particular, we anticipate high benefit from a gene replacement approach in neurons of HBSL mouse models, given the abundant endogenous DARS expression in this lineage cell.
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Affiliation(s)
- Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Alexandra K Suchowerska
- Neurodegenerative and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Carola Voss
- Stem Cell Engineering Group, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Ruojie He
- Stem Cell Engineering Group, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia.,Department of Neurology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Ernst Wolvetang
- Stem Cell Engineering Group, Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD, Australia
| | - Georg von Jonquieres
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Cas Simons
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Thomas Fath
- Neurodegenerative and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Gary D Housley
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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46
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Transcriptomic characterization of MRI contrast with focus on the T1-w/T2-w ratio in the cerebral cortex. Neuroimage 2018; 174:504-517. [PMID: 29567503 PMCID: PMC6450807 DOI: 10.1016/j.neuroimage.2018.03.027] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Revised: 03/12/2018] [Accepted: 03/14/2018] [Indexed: 01/24/2023] Open
Abstract
Magnetic resonance (MR) images of the brain are of immense clinical and research utility. At the atomic and subatomic levels, the sources of MR signals are well understood. However, we lack a comprehensive understanding of the macromolecular correlates of MR signal contrast. To address this gap, we used genome-wide measurements to correlate gene expression with MR signal intensity across the cerebral cortex in the Allen Human Brain Atlas (AHBA). We focused on the ratio of T1-weighted and T2-weighted intensities (T1-w/T2-w ratio image), which is considered to be a useful proxy for myelin content. As expected, we found enrichment of positive correlations between myelin-associated genes and the ratio image, supporting its use as a myelin marker. Genome-wide, there was an association with protein mass, with genes coding for heavier proteins expressed in regions with high T1-w/T2-w values. Oligodendrocyte gene markers were strongly correlated with the T1-w/T2-w ratio, but this was not driven by myelin-associated genes. Mitochondrial genes exhibit the strongest relationship, showing higher expression in regions with low T1-w/T2-w ratio. This may be due to the pH gradient in mitochondria as genes up-regulated by pH in the brain were also highly correlated with the ratio. While we corroborate associations with myelin and synaptic plasticity, differences in the T1-w/T2-w ratio across the cortex are more strongly linked to molecule size, oligodendrocyte markers, mitochondria, and pH. We evaluate correlations between AHBA transcriptomic measurements and a group averaged T1-w/T2-w ratio image, showing agreement with in-sample results. Expanding our analysis to the whole brain results in strong positive T1-w/T2-w correlations for immune system, inflammatory disease, and microglia marker genes. Genes with negative correlations were enriched for neuron markers and synaptic plasticity genes. Lastly, our findings are similar when performed on T1-w or inverted T2-w intensities alone. These results provide a molecular characterization of MR contrast that will aid interpretation of future MR studies of the brain.
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47
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Noise-Induced Dysregulation of Quaking RNA Binding Proteins Contributes to Auditory Nerve Demyelination and Hearing Loss. J Neurosci 2018; 38:2551-2568. [PMID: 29437856 DOI: 10.1523/jneurosci.2487-17.2018] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 01/22/2018] [Accepted: 01/29/2018] [Indexed: 11/21/2022] Open
Abstract
Noise exposure causes auditory nerve (AN) degeneration and hearing deficiency, though the proximal biological consequences are not entirely understood. Most AN fibers and spiral ganglion neurons are ensheathed by myelinating glia that provide insulation and ensure rapid transmission of nerve impulses from the cochlea to the brain. Here we show that noise exposure administered to mice of either sex rapidly affects myelinating glial cells, causing molecular and cellular consequences that precede nerve degeneration. This response is characterized by demyelination, inflammation, and widespread expression changes in myelin-related genes, including the RNA splicing regulator Quaking (QKI) and numerous QKI target genes. Analysis of mice deficient in QKI revealed that QKI production in cochlear glial cells is essential for proper myelination of spiral ganglion neurons and AN fibers, and for normal hearing. Our findings implicate QKI dysregulation as a critical early component in the noise response, influencing cochlear glia function that leads to AN demyelination and, ultimately, to hearing deficiency.SIGNIFICANCE STATEMENT Auditory glia cells ensheath a majority of spiral ganglion neurons with myelin, protect auditory neurons, and allow for fast conduction of electrical impulses along the auditory nerve. Here we show that noise exposure causes glial dysfunction leading to myelin abnormality and altered expression of numerous genes in the auditory nerve, including QKI, a gene implicated in regulating myelination. Study of a conditional mouse model that specifically depleted QKI in glia showed that QKI deficiency alone was sufficient to elicit myelin-related abnormality and auditory functional declines. These results establish QKI as a key molecular target in the noise response and a causative agent in hearing loss.
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Bechler ME, Swire M, ffrench‐Constant C. Intrinsic and adaptive myelination-A sequential mechanism for smart wiring in the brain. Dev Neurobiol 2018; 78:68-79. [PMID: 28834358 PMCID: PMC5813148 DOI: 10.1002/dneu.22518] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/28/2017] [Accepted: 08/19/2017] [Indexed: 12/15/2022]
Abstract
The concept of adaptive myelination-myelin plasticity regulated by activity-is an important advance for the field. What signals set up the adaptable pattern in the first place? Here we review work that demonstrates an intrinsic pathway within oligodendrocytes requiring only an axon-shaped substrate to generate multilayered and compacted myelin sheaths of a physiological length. Based on this, we discuss a model we proposed in 2015 which argues that myelination has two phases-intrinsic and then adaptive-which together generate "smart wiring," in which active axons become more myelinated. This model explains why prior studies have failed to identify a signal necessary for central nervous system myelination and argues that myelination, like synapses, might contribute to learning by the activity-dependent modification of an initially hard-wired pattern. © 2017 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 78: 68-79, 2018.
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Affiliation(s)
- Marie E. Bechler
- MRC Centre for Regenerative Medicine and MS Society Edinburgh Centre for MS Research, The University of Edinburgh, 5 Little France DriveEdinburghEH16 4UUUnited Kingdom
| | - Matthew Swire
- MRC Centre for Regenerative Medicine and MS Society Edinburgh Centre for MS Research, The University of Edinburgh, 5 Little France DriveEdinburghEH16 4UUUnited Kingdom
| | - Charles ffrench‐Constant
- MRC Centre for Regenerative Medicine and MS Society Edinburgh Centre for MS Research, The University of Edinburgh, 5 Little France DriveEdinburghEH16 4UUUnited Kingdom
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Hoch-Kraft P, White R, Tenzer S, Krämer-Albers EM, Trotter J, Gonsior C. Dual role of the RNA helicase DDX5 in post-transcriptional regulation of Myelin Basic Protein in oligodendrocytes. J Cell Sci 2018; 131:jcs.204750. [DOI: 10.1242/jcs.204750] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 03/28/2018] [Indexed: 01/11/2023] Open
Abstract
In the central nervous system, oligodendroglial expression of Myelin Basic Protein (MBP) is crucial for the assembly and structure of the myelin sheath. MBP synthesis is tightly regulated in space and time, particularly on the post-transcriptional level. We have identified the DEAD-box RNA helicase DDX5 (alias p68) in a complex with Mbp mRNA in oligodendroglial cells. Expression of DDX5 is highest in progenitor cells and immature oligodendrocytes, where it localizes to heterogeneous populations of cytoplasmic ribonucleoprotein (RNP) complexes associated with Mbp mRNA in the cell body and processes. Manipulation of DDX5 protein amounts inversely affects levels of MBP protein. We present evidence that DDX5 is involved in post-transcriptional regulation of MBP protein synthesis, with implications for oligodendroglial development. In addition, DDX5 knockdown results in an increased abundance of MBP exon 2-positive isoforms in immature oligodendrocytes, most likely by regulating alternative splicing of Mbp. Our findings contribute to the understanding of the complex nature of MBP post-transcriptional control in immature oligodendrocytes where DDX5 appears to affect the abundance of MBP proteins via distinct but converging mechanisms.
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Affiliation(s)
- Peter Hoch-Kraft
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
| | - Robin White
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
- Institute of Physiology and Pathophysiology, University Medical Center of the Johannes Gutenberg-University, Duesbergweg 6, 55128 Mainz, Germany
| | - Stefan Tenzer
- Institute for Immunology, University Medical Center Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Eva-Maria Krämer-Albers
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
| | - Jacqueline Trotter
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
| | - Constantin Gonsior
- Molecular Cell Biology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University of Mainz, Anselm-Franz-von-Bentzelweg 3, 55128 Mainz, Germany
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Darr AJ, Danzi MC, Brady L, Emig-Agius D, Hackett A, Golshani R, Warner N, Lee J, Lemmon VP, Tsoulfas P. Identification of genome-wide targets of Olig2 in the adult mouse spinal cord using ChIP-Seq. PLoS One 2017; 12:e0186091. [PMID: 29049317 PMCID: PMC5648140 DOI: 10.1371/journal.pone.0186091] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 09/25/2017] [Indexed: 11/19/2022] Open
Abstract
In jawed vertebrates, oligodendrocytes (OLs) are the myelin-producing glial cells responsible for ensheathment of axons within the central nervous system and are also crucial for remyelination following injury or disease. Olig2 is a crucial factor in the specification and differentiation of oligodendrocyte precursor cells (OPCs) that give rise to mature, myelin-producing OLs in the developing and postnatal CNS; however, its role in adulthood is less well understood. To investigate the role Olig2 plays in regulating gene expression in the adult OL lineage in a physiologically-relevant context, we performed chromatin immunoprecipitation followed by next generation sequencing analysis (ChIP-Seq) using whole spinal cord tissue harvested from adult mice. We found that many of the Olig2-bound sites were associated with genes with biological processes corresponding to OL differentiation (Nkx2.2, Nkx6.2, and Sip1), myelination and ensheathment (Mbp, Cldn11, and Mobp), as well as cell cycle and cytoskeletal regulation. This suggests Olig2 continues to play a critical role in processes related to OL differentiation and myelination well into adulthood.
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Affiliation(s)
- Andrew J. Darr
- The Miami Project to Cure Paralysis, Miami, Florida, United States of America
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Matt C. Danzi
- The Miami Project to Cure Paralysis, Miami, Florida, United States of America
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Center for Computational Science, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Lee Brady
- Illumina, Inc., San Diego, California, United States of America
| | | | - Amber Hackett
- The Miami Project to Cure Paralysis, Miami, Florida, United States of America
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | | | - Nikita Warner
- Illumina, Inc., San Diego, California, United States of America
| | - Jae Lee
- The Miami Project to Cure Paralysis, Miami, Florida, United States of America
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Vance P. Lemmon
- The Miami Project to Cure Paralysis, Miami, Florida, United States of America
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- Center for Computational Science, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Pantelis Tsoulfas
- The Miami Project to Cure Paralysis, Miami, Florida, United States of America
- Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, Florida, United States of America
- * E-mail:
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