1
|
Salzer J, Feltri ML, Jacob C. Schwann Cell Development and Myelination. Cold Spring Harb Perspect Biol 2024; 16:a041360. [PMID: 38503507 PMCID: PMC11368196 DOI: 10.1101/cshperspect.a041360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Glial cells in the peripheral nervous system (PNS), which arise from the neural crest, include axon-associated Schwann cells (SCs) in nerves, synapse-associated SCs at the neuromuscular junction, enteric glia, perikaryon-associated satellite cells in ganglia, and boundary cap cells at the border between the central nervous system (CNS) and the PNS. Here, we focus on axon-associated SCs. These SCs progress through a series of formative stages, which culminate in the generation of myelinating SCs that wrap large-caliber axons and of nonmyelinating (Remak) SCs that enclose multiple, small-caliber axons. In this work, we describe SC development, extrinsic signals from the axon and extracellular matrix (ECM) and the intracellular signaling pathways they activate that regulate SC development, and the morphogenesis and organization of myelinating SCs and the myelin sheath. We review the impact of SCs on the biology and integrity of axons and their emerging role in regulating peripheral nerve architecture. Finally, we explain how transcription and epigenetic factors control and fine-tune SC development and myelination.
Collapse
Affiliation(s)
- James Salzer
- Neuroscience Institute, New York University Grossman School of Medicine, New York, New York 10016, USA
| | - M Laura Feltri
- Institute for Myelin and Glia Exploration, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York 14203, USA
- IRCCS Neurological Institute Carlo Besta, Milano 20133, Italy
- Department of Biotechnology and Translational Sciences, Universita' Degli Studi di Milano, Milano 20133, Italy
| | - Claire Jacob
- Faculty of Biology, Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz 55128, Germany
| |
Collapse
|
2
|
Chen Y, Shang T, Sun J, Ji Y, Gong L, Li A, Ding F, Shen M, Zhang Q. Characterization of sciatic nerve myelin sheath during development in C57BL/6 mice. Eur J Neurosci 2024; 60:4503-4517. [PMID: 38951719 DOI: 10.1111/ejn.16457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 06/05/2024] [Accepted: 06/16/2024] [Indexed: 07/03/2024]
Abstract
Myelin sheath plays important roles in information conduction and nerve injury repair in the peripheral nerve system (PNS). Enhancing comprehension of the structure and components of the myelin sheath in the PNS during development would contribute to a more comprehensive understanding of the developmental and regenerative processes. In this research, the structure of sciatic nerve myelin sheath in C57BL/6 mice from embryonic day 14 (E14) to postnatal 12 months (12M) was observed with transmission electron microscopy. Myelin structure appeared in the sciatic nerve as early as E14, and the number and thickness of myelin lamellar gradually increased with the development until 12M. Transcriptome analysis was performed to show the expressions of myelin-associated genes and transcriptional factors involved in myelin formation. The genes encoding myelin proteins (Mag, Pmp22, Mpz, Mbp, Cnp and Prx) showed the same expression pattern, peaking at postnatal day 7 (P7) and P28 after birth, whereas the negative regulators of myelination (c-Jun, Tgfb1, Tnc, Cyr61, Ngf, Egr1, Hgf and Bcl11a) showed an opposite expression pattern. In addition, the expression of myelin-associated proteins and transcriptional factors was measured by Western blot and immunofluorescence staining. The protein expressions of MAG, PMP22, MPZ, CNPase and PRX increased from E20 to P14. The key transcriptional factor c-Jun co-localized with the Schwann cells Marker S100β and decreased after birth, whereas Krox20/Egr2 increased during development. Our data characterized the structure and components of myelin sheath during the early developmental stages, providing insights for further understanding of PNS development.
Collapse
Affiliation(s)
- Yuhan Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Medical School, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
| | - Tongxin Shang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Medical School, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
| | - Junjie Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Medical School, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
| | - Yuhua Ji
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Medical School, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
| | - Leilei Gong
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Medical School, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
- Research and Development Center for E-Learning, Ministry of Education, Beijing, China
| | - Aihong Li
- Department of Neurology, Affiliated Hospital of Nantong University, Medical School, Nantong University, Nantong, China
| | - Fei Ding
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Medical School, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
| | - Mi Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Medical School, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
| | - Qi Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Medical School, Co-innovation Center of Neuroregeneration, NMPA Key Laboratory for Research and Evaluation of Tissue Engineering Technology Products, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, China
| |
Collapse
|
3
|
Aberle T, Walter A, Piefke S, Hillgärtner S, Wüst HM, Wegner M, Küspert M. Sox10 Activity and the Timing of Schwann Cell Differentiation Are Controlled by a Tle4-Dependent Negative Feedback Loop. Int J Mol Sci 2024; 25:5234. [PMID: 38791273 PMCID: PMC11120983 DOI: 10.3390/ijms25105234] [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: 04/17/2024] [Revised: 05/08/2024] [Accepted: 05/08/2024] [Indexed: 05/26/2024] Open
Abstract
The HMG-domain containing transcription factor Sox10 plays a crucial role in regulating Schwann cell survival and differentiation and is expressed throughout the entire Schwann cell lineage. While its importance in peripheral myelination is well established, little is known about its role in the early stages of Schwann cell development. In a search for direct target genes of Sox10 in Schwann cell precursors, the transcriptional co-repressor Tle4 was identified. At least two regions upstream of the Tle4 gene appear involved in mediating the Sox10-dependent activation. Once induced, Tle4 works in tandem with the bHLH transcriptional repressor Hes1 and exerts a dual inhibitory effect on Sox10 by preventing the Sox10 protein from transcriptionally activating maturation genes and by suppressing Sox10 expression through known enhancers of the gene. This mechanism establishes a regulatory barrier that prevents premature activation of factors involved in differentiation and myelin formation by Sox10 in immature Schwann cells. The identification of Tle4 as a critical downstream target of Sox10 sheds light on the gene regulatory network in the early phases of Schwann cell development. It unravels an elaborate regulatory circuitry that fine-tunes the timing and extent of Schwann cell differentiation and myelin gene expression.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Melanie Küspert
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Fahrstrasse 17, 91054 Erlangen, Germany; (T.A.)
| |
Collapse
|
4
|
Bennet BM, Pardo ID, Assaf BT, Buza E, Cramer SD, Crawford LK, Engelhardt JA, Galbreath EJ, Grubor B, Morrison JP, Osborne TS, Sharma AK, Bolon B. Scientific and Regulatory Policy Committee Technical Review: Biology and Pathology of Ganglia in Animal Species Used for Nonclinical Safety Testing. Toxicol Pathol 2023; 51:278-305. [PMID: 38047294 DOI: 10.1177/01926233231213851] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
Dorsal root ganglia (DRG), trigeminal ganglia (TG), other sensory ganglia, and autonomic ganglia may be injured by some test article classes, including anti-neoplastic chemotherapeutics, adeno-associated virus-based gene therapies, antisense oligonucleotides, nerve growth factor inhibitors, and aminoglycoside antibiotics. This article reviews ganglion anatomy, cytology, and pathology (emphasizing sensory ganglia) among common nonclinical species used in assessing product safety for such test articles (TAs). Principal histopathologic findings associated with sensory ganglion injury include neuron degeneration, necrosis, and/or loss; increased satellite glial cell and/or Schwann cell numbers; and leukocyte infiltration and/or inflammation. Secondary nerve fiber degeneration and/or glial reactions may occur in nerves, dorsal spinal nerve roots, spinal cord (dorsal and occasionally lateral funiculi), and sometimes the brainstem. Ganglion findings related to TA administration may result from TA exposure and/or trauma related to direct TA delivery into the central nervous system or ganglia. In some cases, TA-related effects may need to be differentiated from a spectrum of artifactual and/or spontaneous background changes.
Collapse
Affiliation(s)
| | | | | | - Elizabeth Buza
- University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | - James P Morrison
- Charles River Laboratories, Inc., Shrewsbury, Massachusetts, USA
| | | | | | | |
Collapse
|
5
|
Jiravejchakul N, Abe GL, Loza M, Park S, Matangkasombut P, Sasaki JI, Imazato S, Diez D, Standley DM. Intercellular crosstalk in adult dental pulp is mediated by heparin-binding growth factors Pleiotrophin and Midkine. BMC Genomics 2023; 24:184. [PMID: 37024794 PMCID: PMC10077760 DOI: 10.1186/s12864-023-09265-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 03/21/2023] [Indexed: 04/08/2023] Open
Abstract
BACKGROUND In-depth knowledge of the cellular and molecular composition of dental pulp (DP) and the crosstalk between DP cells that drive tissue homeostasis are not well understood. To address these questions, we performed a comparative analysis of publicly available single-cell transcriptomes of healthy adult human DP to 5 other reference tissues: peripheral blood mononuclear cells, bone marrow, adipose tissue, lung, and skin. RESULTS Our analysis revealed that DP resident cells have a unique gene expression profile when compared to the reference tissues, and that DP fibroblasts are the main cell type contributing to this expression profile. Genes coding for pleiotrophin (PTN) and midkine (MDK), homologous heparin-binding growth-factors, possessed the highest differential expression levels in DP fibroblasts. In addition, we identified extensive crosstalk between DP fibroblasts and several other DP resident cells, including Schwann cells, mesenchymal stem cells and odontoblasts, mediated by PTN and MDK. CONCLUSIONS DP fibroblasts emerge as unappreciated players in DP homeostasis, mainly through their crosstalk with glial cells. These findings suggest that fibroblast-derived growth factors possess major regulatory functions and thus have a potential role as dental therapeutic targets.
Collapse
Affiliation(s)
- Natnicha Jiravejchakul
- Department of Genome Informatics, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, 565-0871, Japan
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Gabriela L Abe
- Department of Advanced Functional Materials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, 565-0871, Japan.
| | - Martin Loza
- Laboratory of Functional Analysis in silico, Human Genome Center, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokane-dai, Minato-ku, Tokyo, 108- 8639, Japan
| | - Soyoung Park
- Department of Systems Immunology, Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, 565-0871, Japan
| | - Ponpan Matangkasombut
- Department of Microbiology, Faculty of Science, Mahidol University, Bangkok, 10400, Thailand
| | - Jun-Ichi Sasaki
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, 565-0871, Japan
| | - Satoshi Imazato
- Department of Advanced Functional Materials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, 565-0871, Japan
- Department of Dental Biomaterials, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, 565-0871, Japan
| | - Diego Diez
- Quantitative Immunology Research Unit, Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, 565-0871, Japan
| | - Daron M Standley
- Department of Genome Informatics, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, 565-0871, Japan.
- Department of Systems Immunology, Immunology Frontier Research Center, Osaka University, 3-1 Yamadaoka, Suita, 565-0871, Japan.
| |
Collapse
|
6
|
Zhang X, Lou HE, Gopalan V, Liu Z, Jafarah HM, Lei H, Jones P, Sayers CM, Yohe ME, Chittiboina P, Widemann BC, Thiele CJ, Kelly MC, Hannenhalli S, Shern JF. Single-cell sequencing reveals activation of core transcription factors in PRC2-deficient malignant peripheral nerve sheath tumor. Cell Rep 2022; 40:111363. [PMID: 36130486 PMCID: PMC9585487 DOI: 10.1016/j.celrep.2022.111363] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 05/16/2022] [Accepted: 08/24/2022] [Indexed: 11/26/2022] Open
Abstract
Loss-of-function mutations in the polycomb repressive complex 2 (PRC2) occur frequently in malignant peripheral nerve sheath tumor, an aggressive sarcoma that arises from NF1-deficient Schwann cells. To define the oncogenic mechanisms underlying PRC2 loss, we use engineered cells that dynamically reassemble a competent PRC2 coupled with single-cell sequencing from clinical samples. We discover a two-pronged oncogenic process: first, PRC2 loss leads to remodeling of the bivalent chromatin and enhancer landscape, causing the upregulation of developmentally regulated transcription factors that enforce a transcriptional circuit serving as the cell's core vulnerability. Second, PRC2 loss reduces type I interferon signaling and antigen presentation as downstream consequences of hyperactivated Ras and its cross talk with STAT/IRF transcription factors. Mapping of the transcriptional program of these PRC2-deficient tumor cells onto a constructed developmental trajectory of normal Schwann cells reveals that changes induced by PRC2 loss enforce a cellular profile characteristic of a primitive mesenchymal neural crest stem cell.
Collapse
Affiliation(s)
- Xiyuan Zhang
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hannah E Lou
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Vishaka Gopalan
- Cancer Data Science Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zhihui Liu
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hilda M Jafarah
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Haiyan Lei
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Paige Jones
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Carly M Sayers
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Marielle E Yohe
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Prashant Chittiboina
- Neurosurgery Unit for Pituitary and Inheritable Diseases, National Institute of Neurological Diseases and Stroke, Bethesda, MD 20892, USA
| | - Brigitte C Widemann
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Carol J Thiele
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael C Kelly
- Center for Cancer Research Single Cell Analysis Facility, Cancer Research Technology Program, Frederick National Laboratory, Bethesda, MD 20892, USA
| | - Sridhar Hannenhalli
- Cancer Data Science Laboratory, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jack F Shern
- Pediatric Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
| |
Collapse
|
7
|
Comparative role of SOX10 gene in the gliogenesis of central, peripheral, and enteric nervous systems. Differentiation 2022; 128:13-25. [DOI: 10.1016/j.diff.2022.09.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 09/10/2022] [Accepted: 09/19/2022] [Indexed: 11/17/2022]
|
8
|
Abstract
Schwann cells in the peripheral nervous system (PNS) are essential for the support and myelination of axons, ensuring fast and accurate communication between the central nervous system and the periphery. Schwann cells and related glia accompany innervating axons in virtually all tissues in the body, where they exhibit remarkable plasticity and the ability to modulate pathology in extraordinary, and sometimes surprising, ways. Here, we provide a brief overview of the various glial cell types in the PNS and describe the cornerstone cellular and molecular processes that enable Schwann cells to perform their canonical functions. We then dive into discussing exciting noncanonical functions of Schwann cells and related PNS glia, which include their role in organizing the PNS, in regulating synaptic activity and pain, in modulating immunity, in providing a pool of stem cells for different organs, and, finally, in influencing cancer.
Collapse
Affiliation(s)
- Carla Taveggia
- Axo-Glial Interaction Unit, Division of Neuroscience, IRCCS Ospedale San Raffaele, Milan, Italy;
| | - M. Laura Feltri
- Institute for Myelin and Glia Exploration, Departments of Biochemistry and Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| |
Collapse
|
9
|
Duman M, Jaggi S, Enz LS, Jacob C, Schaeren-Wiemers N. Theophylline Induces Remyelination and Functional Recovery in a Mouse Model of Peripheral Neuropathy. Biomedicines 2022; 10:biomedicines10061418. [PMID: 35740439 PMCID: PMC9219657 DOI: 10.3390/biomedicines10061418] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 06/05/2022] [Accepted: 06/07/2022] [Indexed: 11/16/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT) is a large group of inherited peripheral neuropathies that are primarily due to demyelination and/or axonal degeneration. CMT type 1A (CMT1A), which is caused by the duplication of the peripheral myelin protein 22 (PMP22) gene, is a demyelinating and the most frequent CMT subtype. Hypermyelination, demyelination, and secondary loss of large-caliber axons are hallmarks of CMT1A, and there is currently no cure and no efficient treatment to alleviate the symptoms of the disease. We previously showed that histone deacetylases 1 and 2 (HDAC1/2) are critical for Schwann cell developmental myelination and remyelination after a sciatic nerve crush lesion. We also demonstrated that a short-term treatment with Theophylline, which is a potent activator of HDAC2, enhances remyelination and functional recovery after a sciatic nerve crush lesion in mice. In the present study, we tested whether Theophylline treatment could also lead to (re)myelination in a PMP22-overexpressing mouse line (C22) modeling CMT1A. Indeed, we show here that a short-term treatment with Theophylline in C22 mice increases the percentage of myelinated large-caliber axons and the expression of the major peripheral myelin protein P0 and induces functional recovery. This pilot study suggests that Theophylline treatment could be beneficial to promote myelination and thereby prevent axonal degeneration and enhance functional recovery in CMT1A patients.
Collapse
Affiliation(s)
- Mert Duman
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland;
- Faculty of Biology, Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
| | - Stephanie Jaggi
- Department of Biomedicine, University Hospital Basel, 4031 Basel, Switzerland; (S.J.); (L.S.E.); (N.S.-W.)
| | - Lukas Simon Enz
- Department of Biomedicine, University Hospital Basel, 4031 Basel, Switzerland; (S.J.); (L.S.E.); (N.S.-W.)
| | - Claire Jacob
- Department of Biology, University of Fribourg, 1700 Fribourg, Switzerland;
- Faculty of Biology, Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, 55128 Mainz, Germany
- Correspondence:
| | - Nicole Schaeren-Wiemers
- Department of Biomedicine, University Hospital Basel, 4031 Basel, Switzerland; (S.J.); (L.S.E.); (N.S.-W.)
- Department of Biomedicine, University of Basel, 4058 Basel, Switzerland
| |
Collapse
|
10
|
Park HJ, Tsai E, Huang D, Weaver M, Frick L, Alcantara A, Moran JJ, Patzig J, Melendez-Vasquez CV, Crabtree GR, Feltri M, Svaren J, Casaccia P. ACTL6a coordinates axonal caliber recognition and myelination in the peripheral nerve. iScience 2022; 25:104132. [PMID: 35434551 PMCID: PMC9010646 DOI: 10.1016/j.isci.2022.104132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 01/29/2022] [Accepted: 03/17/2022] [Indexed: 11/12/2022] Open
Abstract
Cells elaborate transcriptional programs in response to external signals. In the peripheral nerves, Schwann cells (SC) sort axons of given caliber and start the process of wrapping their membrane around them. We identify Actin-like protein 6a (ACTL6a), part of SWI/SNF chromatin remodeling complex, as critical for the integration of axonal caliber recognition with the transcriptional program of myelination. Nuclear levels of ACTL6A in SC are increased by contact with large caliber axons or nanofibers, and result in the eviction of repressive histone marks to facilitate myelination. Without Actl6a the SC are unable to coordinate caliber recognition and myelin production. Peripheral nerves in knockout mice display defective radial sorting, hypo-myelination of large caliber axons, and redundant myelin around small caliber axons, resulting in a clinical motor phenotype. Overall, this suggests that ACTL6A is a key component of the machinery integrating external signals for proper myelination of the peripheral nerve.
Collapse
Affiliation(s)
- Hye-Jin Park
- Advanced Science Research Center (ASRC) at The Graduate Center of the City University of New York (CUNY), New York, NY 10031, USA
| | - Eric Tsai
- Advanced Science Research Center (ASRC) at The Graduate Center of the City University of New York (CUNY), New York, NY 10031, USA
- Graduate Program in Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Dennis Huang
- Advanced Science Research Center (ASRC) at The Graduate Center of the City University of New York (CUNY), New York, NY 10031, USA
- Graduate Program in Biology, Graduate Center of CUNY, New York, NY 10016, USA
| | - Michael Weaver
- Hunter James Kelly Research Institute, Departments of Biochemistry and Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
| | - Luciana Frick
- Hunter James Kelly Research Institute, Departments of Biochemistry and Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
| | - Ace Alcantara
- Graduate Program in Biology, Graduate Center of CUNY, New York, NY 10016, USA
- Hunter College, Department of Biological Sciences, New York, NY 10065, USA
| | - John J. Moran
- Waisman Center and Department of Comparative Biosciences, University of Wisconsin, Madison, WI 53705, USA
| | - Julia Patzig
- Advanced Science Research Center (ASRC) at The Graduate Center of the City University of New York (CUNY), New York, NY 10031, USA
| | - Carmen V. Melendez-Vasquez
- Graduate Program in Biology, Graduate Center of CUNY, New York, NY 10016, USA
- Hunter College, Department of Biological Sciences, New York, NY 10065, USA
| | - Gerald R. Crabtree
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - M.L. Feltri
- Hunter James Kelly Research Institute, Departments of Biochemistry and Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA
| | - John Svaren
- Waisman Center and Department of Comparative Biosciences, University of Wisconsin, Madison, WI 53705, USA
| | - Patrizia Casaccia
- Advanced Science Research Center (ASRC) at The Graduate Center of the City University of New York (CUNY), New York, NY 10031, USA
- Graduate Program in Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Graduate Program in Biology, Graduate Center of CUNY, New York, NY 10016, USA
| |
Collapse
|
11
|
Aberle T, Piefke S, Hillgärtner S, Tamm ER, Wegner M, Küspert M. OUP accepted manuscript. Nucleic Acids Res 2022; 50:1951-1968. [PMID: 35137157 PMCID: PMC8887482 DOI: 10.1093/nar/gkac042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 12/21/2021] [Accepted: 01/14/2022] [Indexed: 11/14/2022] Open
Abstract
In oligodendrocytes of the vertebrate central nervous system a complex network of transcriptional regulators is required to ensure correct and timely myelination of neuronal axons. Here we identify Zfp276, the only mammalian ZAD-domain containing zinc finger protein, as a transcriptional regulator of oligodendrocyte differentiation and central myelination downstream of Sox10. In the central nervous system, Zfp276 is exclusively expressed in mature oligodendrocytes. Oligodendroglial deletion of Zfp276 led to strongly reduced expression of myelin genes in the early postnatal mouse spinal cord. Retroviral overexpression of Zfp276 in cultured oligodendrocyte precursor cells induced precocious expression of maturation markers and myelin genes, further supporting its role in oligodendroglial differentiation. On the molecular level, Zfp276 directly binds to and represses Sox10-dependent gene regulatory regions of immaturity factors and functionally interacts with the transcriptional repressor Zeb2 to enable fast transition of oligodendrocytes to the myelinating stage.
Collapse
Affiliation(s)
- Tim Aberle
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Sandra Piefke
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Simone Hillgärtner
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Ernst R Tamm
- Institut für Humananatomie und Embryologie, Universität Regensburg, D-93053, Regensburg, Germany
| | - Michael Wegner
- Institut für Biochemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Melanie Küspert
- To whom correspondence should be addressed. Tel: +49 9131 85 24638; Fax: +49 9131 85 22484;
| |
Collapse
|
12
|
Abstract
Myelin is a key evolutionary specialization and adaptation of vertebrates formed by the plasma membrane of glial cells, which insulate axons in the nervous system. Myelination not only allows rapid and efficient transmission of electric impulses in the axon by decreasing capacitance and increasing resistance but also influences axonal metabolism and the plasticity of neural circuits. In this review, we will focus on Schwann cells, the glial cells which form myelin in the peripheral nervous system. Here, we will describe the main extrinsic and intrinsic signals inducing Schwann cell differentiation and myelination and how myelin biogenesis is achieved. Finally, we will also discuss how the study of human disorders in which molecules and pathways relevant for myelination are altered has enormously contributed to the current knowledge on myelin biology.
Collapse
Affiliation(s)
- Alessandra Bolino
- Human Inherited Neuropathies Unit, Institute of Experimental Neurology INSPE, Division of Neuroscience, IRCCS Ospedale San Raffaele, Via Olgettina 60, 20132, Milan, Italy.
| |
Collapse
|
13
|
Saur AL, Fröb F, Weider M, Wegner M. Formation of the node of Ranvier by Schwann cells is under control of transcription factor Sox10. Glia 2021; 69:1464-1477. [PMID: 33566433 DOI: 10.1002/glia.23973] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 01/21/2021] [Accepted: 01/25/2021] [Indexed: 11/06/2022]
Abstract
The transcription factor Sox10 is an essential regulator of genes that code for structural components of the myelin sheath and for lipid metabolic enzymes in both types of myelinating glia in the central and peripheral nervous systems. In an attempt to characterize additional Sox10 target genes in Schwann cells, we identified in this study a strong influence of Sox10 on the expression of genes associated with adhesion in the MSC80 Schwann cell line. These included the genes for Gliomedin, Neuronal cell adhesion molecule and Neurofascin that together constitute essential Schwann cell contributions to paranode and node of Ranvier. Using bioinformatics and molecular biology techniques we provide evidence that Sox10 directly activates these genes by binding to conserved regulatory regions. For activation, Sox10 cooperates with Krox20, a transcription factor previously identified as the central regulator of Schwann cell myelination. Both the activating function of Sox10 as well as its cooperation with Krox20 were confirmed in vivo. We conclude that the employment of Sox10 and Krox20 as regulators of structural myelin sheath components and genes associated with the node of Ranvier is one way of ensuring a biologically meaningful coordinated formation of both structures during peripheral myelination.
Collapse
Affiliation(s)
- Anna-Lena Saur
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Franziska Fröb
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Matthias Weider
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Zahnklinik 3 - Kieferorthopädie, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| |
Collapse
|
14
|
Chen CZ, Neumann B, Förster S, Franklin RJM. Schwann cell remyelination of the central nervous system: why does it happen and what are the benefits? Open Biol 2021; 11:200352. [PMID: 33497588 PMCID: PMC7881176 DOI: 10.1098/rsob.200352] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 01/07/2021] [Indexed: 12/18/2022] Open
Abstract
Myelin sheaths, by supporting axonal integrity and allowing rapid saltatory impulse conduction, are of fundamental importance for neuronal function. In response to demyelinating injuries in the central nervous system (CNS), oligodendrocyte progenitor cells (OPCs) migrate to the lesion area, proliferate and differentiate into new oligodendrocytes that make new myelin sheaths. This process is termed remyelination. Under specific conditions, demyelinated axons in the CNS can also be remyelinated by Schwann cells (SCs), the myelinating cell of the peripheral nervous system. OPCs can be a major source of these CNS-resident SCs-a surprising finding given the distinct embryonic origins, and physiological compartmentalization of the peripheral and central nervous system. Although the mechanisms and cues governing OPC-to-SC differentiation remain largely undiscovered, it might nevertheless be an attractive target for promoting endogenous remyelination. This article will (i) review current knowledge on the origins of SCs in the CNS, with a particular focus on OPC to SC differentiation, (ii) discuss the necessary criteria for SC myelination in the CNS and (iii) highlight the potential of using SCs for myelin regeneration in the CNS.
Collapse
Affiliation(s)
| | | | | | - Robin J. M. Franklin
- Wellcome-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge Biomedical Campus, Cambridge CB2 0AH, UK
| |
Collapse
|
15
|
Muppirala AN, Limbach LE, Bradford EF, Petersen SC. Schwann cell development: From neural crest to myelin sheath. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2020; 10:e398. [PMID: 33145925 DOI: 10.1002/wdev.398] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/16/2022]
Abstract
Vertebrate nervous system function requires glial cells, including myelinating glia that insulate axons and provide trophic support that allows for efficient signal propagation by neurons. In vertebrate peripheral nervous systems, neural crest-derived glial cells known as Schwann cells (SCs) generate myelin by encompassing and iteratively wrapping membrane around single axon segments. SC gliogenesis and neurogenesis are intimately linked and governed by a complex molecular environment that shapes their developmental trajectory. Changes in this external milieu drive developing SCs through a series of distinct morphological and transcriptional stages from the neural crest to a variety of glial derivatives, including the myelinating sublineage. Cues originate from the extracellular matrix, adjacent axons, and the developing SC basal lamina to trigger intracellular signaling cascades and gene expression changes that specify stages and transitions in SC development. Here, we integrate the findings from in vitro neuron-glia co-culture experiments with in vivo studies investigating SC development, particularly in zebrafish and mouse, to highlight critical factors that specify SC fate. Ultimately, we connect classic biochemical and mutant studies with modern genetic and visualization tools that have elucidated the dynamics of SC development. This article is categorized under: Signaling Pathways > Cell Fate Signaling Nervous System Development > Vertebrates: Regional Development.
Collapse
Affiliation(s)
- Anoohya N Muppirala
- Program in Neuroscience, Harvard Medical School, Boston, Massachusetts, USA.,Department of Neuroscience, Kenyon College, Gambier, Ohio, USA
| | | | | | - Sarah C Petersen
- Department of Neuroscience, Kenyon College, Gambier, Ohio, USA.,Department of Biology, Kenyon College, Gambier, Ohio, USA
| |
Collapse
|
16
|
Yang X, Ji C, Liu X, Zheng C, Zhang Y, Shen R, Zhou Z. The significance of the neuregulin-1/ErbB signaling pathway and its effect on Sox10 expression in the development of terminally differentiated Schwann cells in vitro. Int J Neurosci 2020; 132:171-180. [PMID: 32757877 DOI: 10.1080/00207454.2020.1806266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE The purpose of this study was to explore the significance of the neuregulin-1/ErbB signaling pathway and its effect on Sox10 expression in the course of the differentiation of mouse bone marrow mesenchymal stem cells into Schwann-like cells in vitro. MATERIALS AND METHODS The experiment was conducted with three groups-control, TAK 165, and HRG-off. In the control group, we used the classical induction method of adding β-ME, RA, FSK, b-FGF, PDGF, and neuregulin (HRG); the cells were collected on the 7th day. Using the same basic protocol as the control group, the specific ErbB2 inhibitor mubritinib (TAK 165) was added to block the neuregulin-1/ErbB pathway in the TAK 165 group, while HRG was not added in the HRG-off group. We detected the degree of differentiation of stem cells into Schwann-like cells by using RT-PCR to examine the expression of Sox10, NRG-1, ErbB2, ErbB3, and ErbB4 and by using immunofluorescence staining to examine the Schwann cell marker S100B, Glial Fibrillary Acidic Protein (GFAP) and P75. RESULTS Our results showed that the proliferation of Schwann cells was reduced and apoptosis was increased in the TAK 165 group and the HRG-off group. Sox10 was stably expressed and NRG-1, ErbB2, and ErbB3 increased in the control group. However, the expression of Sox10 in the TAK 165 group was obviously decreased at the end of induced differentiation; meanwhile, the degree of stem cell differentiation also decreased. CONCLUSIONS the neuregulin-1/ErbB signaling pathway plays an important role in the differentiation of bone marrow mesenchymal stem cells into Schwann-like cells and can promote the maintenance of Sox10 。.
Collapse
Affiliation(s)
- Xizhong Yang
- Department of Human Anatomy, Medical College of Qingdao University, Qingdao, P.R China.,Department of Orthopaedics, Jimo people's Hospital, Qingdao, P.R China
| | - Cuijie Ji
- Department of Orthopaedics, Jimo people's Hospital, Qingdao, P.R China
| | - Xinyue Liu
- Department of Human Anatomy, Medical College of Qingdao University, Qingdao, P.R China
| | - Chaoqun Zheng
- Department of Human Anatomy, Medical College of Qingdao University, Qingdao, P.R China
| | - Yanxin Zhang
- Department of Human Anatomy, Medical College of Qingdao University, Qingdao, P.R China
| | - Ruowu Shen
- Department of Human Anatomy, Medical College of Qingdao University, Qingdao, P.R China
| | - Zangong Zhou
- Department of Anesthesiology, Affiliated Hospital of Qingdao University, Qingdao, P.R China
| |
Collapse
|
17
|
SOX10-regulated promoter use defines isoform-specific gene expression in Schwann cells. BMC Genomics 2020; 21:549. [PMID: 32770939 PMCID: PMC7430845 DOI: 10.1186/s12864-020-06963-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/29/2020] [Indexed: 01/12/2023] Open
Abstract
Background Multicellular organisms adopt various strategies to tailor gene expression to cellular contexts including the employment of multiple promoters (and the associated transcription start sites (TSSs)) at a single locus that encodes distinct gene isoforms. Schwann cells—the myelinating cells of the peripheral nervous system (PNS)—exhibit a specialized gene expression profile directed by the transcription factor SOX10, which is essential for PNS myelination. SOX10 regulates promoter elements associated with unique TSSs and gene isoforms at several target loci, implicating SOX10-mediated, isoform-specific gene expression in Schwann cell function. Here, we report on genome-wide efforts to identify SOX10-regulated promoters and TSSs in Schwann cells to prioritize genes and isoforms for further study. Results We performed global TSS analyses and mined previously reported ChIP-seq datasets to assess the activity of SOX10-bound promoters in three models: (i) an adult mammalian nerve; (ii) differentiating primary Schwann cells, and (iii) cultured Schwann cells with ablated SOX10 function. We explored specific characteristics of SOX10-dependent TSSs, which provides confidence in defining them as SOX10 targets. Finally, we performed functional studies to validate our findings at four previously unreported SOX10 target loci: ARPC1A, CHN2, DDR1, and GAS7. These findings suggest roles for the associated SOX10-regulated gene products in PNS myelination. Conclusions In sum, we provide comprehensive computational and functional assessments of SOX10-regulated TSS use in Schwann cells. The data presented in this study will stimulate functional studies on the specific mRNA and protein isoforms that SOX10 regulates, which will improve our understanding of myelination in the peripheral nerve.
Collapse
|
18
|
Zhang Y, Jiang K, Xie G, Ding J, Peng S, Liu X, Sun C, Tang X. FGF21 impedes peripheral myelin development by stimulating p38 MAPK/c-Jun axis. J Cell Physiol 2020; 236:1345-1361. [PMID: 32657446 DOI: 10.1002/jcp.29942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/18/2020] [Accepted: 07/02/2020] [Indexed: 01/13/2023]
Abstract
Fibroblast growth factor 21 (FGF21) as a metabolic stress hormone, is mainly secreted by the liver. In addition to its well-defined roles in energy homeostasis, FGF21 has been shown to promote remyelination after injury in the central nervous system. In the current study, we sought to examine the potential roles of FGF21 in the peripheral nervous system (PNS) myelination. In the PNS myelin development, Fgf21 expression was reversely correlated with myelin gene expression. In cultured primary Schwann cells (SCs), the application of recombinant FGF21 greatly attenuates myelination-associated gene expression, including Oct6, Krox20, Mbp, Mpz, and Pmp22. Accordingly, the injection of FGF21 into neonatal rats markedly mitigates the myelination in sciatic nerves. On the contrary, the infusion of the anti-FGF21 antibody accelerates the myelination. Mechanistically, both extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) were stimulated by FGF21 in SCs and sciatic nerves. Following experiments including pharmaceutical intervention and gene manipulation revealed that the p38 MAPK/c-Jun axis, rather than ERK, is targeted by FGF21 for mediating its repression on myelination in SCs. Taken together, our data provide a new aspect of FGF21 by acting as a negative regulator for the myelin development process in the PNS via activation of p38 MAPK/c-Jun.
Collapse
Affiliation(s)
- Yunzhong Zhang
- Key Laboratory for Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregenetation, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, Jiangsu, China.,School of Medicine, Nantong University, Nantong, Jiangsu, China
| | - Ketao Jiang
- Key Laboratory for Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregenetation, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, Jiangsu, China
| | - Guoqing Xie
- Key Laboratory for Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregenetation, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, Jiangsu, China
| | - Jie Ding
- Key Laboratory for Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregenetation, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, Jiangsu, China
| | - Su Peng
- Key Laboratory for Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregenetation, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, Jiangsu, China
| | - Xiaoyu Liu
- Key Laboratory for Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregenetation, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, Jiangsu, China
| | - Cheng Sun
- Key Laboratory for Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregenetation, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, Jiangsu, China
| | - Xin Tang
- Key Laboratory for Neuroregeneration of Jiangsu Province and Ministry of Education, Co-Innovation Center of Neuroregenetation, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, Jiangsu, China
| |
Collapse
|
19
|
EEF1A1 deacetylation enables transcriptional activation of remyelination. Nat Commun 2020; 11:3420. [PMID: 32647127 PMCID: PMC7347577 DOI: 10.1038/s41467-020-17243-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 06/19/2020] [Indexed: 12/14/2022] Open
Abstract
Remyelination of the peripheral and central nervous systems (PNS and CNS, respectively) is a prerequisite for functional recovery after lesion. However, this process is not always optimal and becomes inefficient in the course of multiple sclerosis. Here we show that, when acetylated, eukaryotic elongation factor 1A1 (eEF1A1) negatively regulates PNS and CNS remyelination. Acetylated eEF1A1 (Ac-eEF1A1) translocates into the nucleus of myelinating cells where it binds to Sox10, a key transcription factor for PNS and CNS myelination and remyelination, to drag Sox10 out of the nucleus. We show that the lysine acetyltransferase Tip60 acetylates eEF1A1, whereas the histone deacetylase HDAC2 deacetylates eEF1A1. Promoting eEF1A1 deacetylation maintains the activation of Sox10 target genes and increases PNS and CNS remyelination efficiency. Taken together, these data identify a major mechanism of Sox10 regulation, which appears promising for future translational studies on PNS and CNS remyelination. The molecular mechanisms regulating remyelination are unclear. Here, the authors show that promoting deacetylation of eEF1A1 prevents the translocation of Sox10 outside the nucleus, contributing to maintaining the expression of Sox10 target genes and increasing remyelination efficiency.
Collapse
|
20
|
Wilson ER, Della-Flora Nunes G, Weaver MR, Frick LR, Feltri ML. Schwann cell interactions during the development of the peripheral nervous system. Dev Neurobiol 2020; 81:464-489. [PMID: 32281247 DOI: 10.1002/dneu.22744] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/14/2020] [Accepted: 04/06/2020] [Indexed: 12/21/2022]
Abstract
Schwann cells play a critical role in the development of the peripheral nervous system (PNS), establishing important relationships both with the extracellular milieu and other cell types, particularly neurons. In this review, we discuss various Schwann cell interactions integral to the proper establishment, spatial arrangement, and function of the PNS. We include signals that cascade onto Schwann cells from axons and from the extracellular matrix, bidirectional signals that help to establish the axo-glial relationship and how Schwann cells in turn support the axon. Further, we speculate on how Schwann cell interactions with other components of the developing PNS ultimately promote the complete construction of the peripheral nerve.
Collapse
Affiliation(s)
- Emma R Wilson
- Hunter James Kelly Research Institute, State University of New York at Buffalo, Buffalo, NY, USA.,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Gustavo Della-Flora Nunes
- Hunter James Kelly Research Institute, State University of New York at Buffalo, Buffalo, NY, USA.,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Michael R Weaver
- Hunter James Kelly Research Institute, State University of New York at Buffalo, Buffalo, NY, USA.,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Luciana R Frick
- Hunter James Kelly Research Institute, State University of New York at Buffalo, Buffalo, NY, USA.,Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - M Laura Feltri
- Hunter James Kelly Research Institute, State University of New York at Buffalo, Buffalo, NY, USA.,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA.,Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| |
Collapse
|
21
|
Modrak M, Talukder MAH, Gurgenashvili K, Noble M, Elfar JC. Peripheral nerve injury and myelination: Potential therapeutic strategies. J Neurosci Res 2019; 98:780-795. [PMID: 31608497 DOI: 10.1002/jnr.24538] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 08/30/2019] [Accepted: 09/16/2019] [Indexed: 12/11/2022]
Abstract
Traumatic peripheral nerve injury represents a major clinical and public health problem that often leads to significant functional impairment and permanent disability. Despite modern diagnostic procedures and advanced microsurgical techniques, functional recovery after peripheral nerve repair is often unsatisfactory. Therefore, there is an unmet need for new therapeutic or adjunctive strategies to promote the functional recovery in nerve injury patients. In contrast to the central nervous system, Schwann cells in the peripheral nervous system play a pivotal role in several aspects of nerve repair such as degeneration, remyelination, and axonal growth. Several non-surgical approaches, including pharmacological, electrical, cell-based, and laser therapies, have been employed to promote myelination and enhance functional recovery after peripheral nerve injury. This review will succinctly discuss the potential therapeutic strategies in the context of myelination following peripheral neurotrauma.
Collapse
Affiliation(s)
- Max Modrak
- School of Medicine & Dentistry, The University of Rochester Medical Center, Rochester, New York, USA
| | - M A Hassan Talukder
- Department of Orthopaedics & Rehabilitation, Penn State Hershey College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA
| | - Khatuna Gurgenashvili
- Department of Neurology, Penn State Hershey College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA
| | - Mark Noble
- Department of Biomedical Genetics, The University of Rochester Medical Center, Rochester, New York, USA
| | - John C Elfar
- Department of Orthopaedics & Rehabilitation, Penn State Hershey College of Medicine, Milton S. Hershey Medical Center, Hershey, Pennsylvania, USA
| |
Collapse
|
22
|
Sock E, Wegner M. Transcriptional control of myelination and remyelination. Glia 2019; 67:2153-2165. [PMID: 31038810 DOI: 10.1002/glia.23636] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Revised: 04/01/2019] [Accepted: 04/11/2019] [Indexed: 12/11/2022]
Abstract
Myelination is an evolutionary recent differentiation program that has been independently acquired in vertebrates by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. Therefore, it is not surprising that regulating transcription factors differ substantially between both cell types. However, overall principles are similar as transcriptional control in Schwann cells and oligodendrocytes combines lineage determining and stage-specific factors in complex regulatory networks. Myelination does not only occur during development, but also as remyelination in the adult. In line with the different conditions during developmental myelination and remyelination and the distinctive properties of Schwann cells and oligodendrocytes, transcriptional regulation of remyelination exhibits unique features and differs between the two cell types. This review gives an overview of the current state in the field.
Collapse
Affiliation(s)
- Elisabeth Sock
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| |
Collapse
|
23
|
Casalenovo MB, Rosa PS, de Faria Bertoluci DF, Barbosa ASAA, do Nascimento DC, de Souza VNB, Nogueira MRS. Myelination key factor krox-20 is downregulated in Schwann cells and murine sciatic nerves infected by Mycobacterium leprae. Int J Exp Pathol 2019; 100:83-93. [PMID: 31090128 PMCID: PMC6540694 DOI: 10.1111/iep.12309] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 01/28/2019] [Accepted: 02/06/2019] [Indexed: 12/14/2022] Open
Abstract
Schwann cells (SCs) critically maintain the plasticity of the peripheral nervous system. Peripheral nerve injuries and infections stimulate SCs in order to retrieve homeostasis in neural tissues. Previous studies indicate that Mycobacterium leprae (ML) regulates the expression of key factors related to SC identity, suggesting that alterations in cell phenotype may be involved in the pathogenesis of neural damage in leprosy. To better understand whether ML restricts the plasticity of peripheral nerves, the present study sought to determine the expression of Krox-20, Sox-10, c-Jun and p75NTR in SC culture and mice sciatic nerves, both infected by ML Thai-53 strain. Primary SC cultures were stimulated with two different multiplicities of infection (MOI 100:1; MOI 50:1) and assessed after 7 and 14 days. Sciatic nerves of nude mice (NU-Foxn1nu ) infected with ML were evaluated after 6 and 9 months. In vitro results demonstrate downregulation of Krox-20 and Sox-10 along with the increase in p75NTR-immunolabelled cells. Concurrently, sciatic nerves of infected mice showed a significant decrease in Krox-20 and increase in p75NTR. Our results corroborate previous findings on the interference of ML in the expression of factors involved in cell maturation, favouring the maintenance of a non-myelinating phenotype in SCs, with possible implications for the repair of adult peripheral nerves.
Collapse
Affiliation(s)
- Mariane Bertolucci Casalenovo
- School of Medicine of BotucatuSão Paulo State UniversityBotucatuBrazil
- Lauro de Souza Lima InstituteSecretariat of Health of São PauloBauruSão PauloBrazil
| | | | | | | | | | - Vânia Nieto Brito de Souza
- School of Medicine of BotucatuSão Paulo State UniversityBotucatuBrazil
- Lauro de Souza Lima InstituteSecretariat of Health of São PauloBauruSão PauloBrazil
| | | |
Collapse
|
24
|
Jessen KR, Mirsky R. Schwann Cell Precursors; Multipotent Glial Cells in Embryonic Nerves. Front Mol Neurosci 2019; 12:69. [PMID: 30971890 PMCID: PMC6443887 DOI: 10.3389/fnmol.2019.00069] [Citation(s) in RCA: 100] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 03/04/2019] [Indexed: 12/20/2022] Open
Abstract
The cells of the neural crest, often referred to as neural crest stem cells, give rise to a number of sub-lineages, one of which is Schwann cells, the glial cells of peripheral nerves. Crest cells transform to adult Schwann cells through the generation of two well defined intermediate stages, the Schwann cell precursors (SCP) in early embryonic nerves, and immature Schwann cells (iSch) in late embryonic and perinatal nerves. SCP are formed when neural crest cells enter nascent nerves and form intimate relationships with axons, a diagnostic feature of glial cells. This involves large-scale changes in gene expression, including the activation of established glial cell markers. Like early glia in the CNS, radial glia, SCP retain developmental multipotency and contribute to other crest-derived lineages during embryonic development. SCP, as well as closely related cells termed boundary cap cells, and later stages of the Schwann cell lineage have all been implicated as the tumor initiating cell in NF1 associated neurofibromas. iSch are formed from SCP in a process that involves the appearance of additional differentiation markers, autocrine survival circuits, cellular elongation, a formation of endoneurial connective tissue and basal lamina. Finally, in peri- and post-natal nerves, iSch are reversibly induced by axon-associated signals to form the myelin and non-myelin Schwann cells of adult nerves. This review article discusses early Schwann cell development in detail and describes a large number of molecular signaling systems that control glial development in embryonic nerves.
Collapse
Affiliation(s)
- Kristjan R Jessen
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| | - Rhona Mirsky
- Department of Cell and Developmental Biology, University College London, London, United Kingdom
| |
Collapse
|
25
|
Tammia M, Mi R, Sluch VM, Zhu A, Chung T, Shinn D, Zack DJ, Höke A, Mao HQ. Egr2 overexpression in Schwann cells increases myelination frequency in vitro. Heliyon 2018; 4:e00982. [PMID: 30761371 PMCID: PMC6275687 DOI: 10.1016/j.heliyon.2018.e00982] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/31/2018] [Accepted: 11/26/2018] [Indexed: 12/20/2022] Open
Abstract
Schwann cells are key players in peripheral nerve regeneration, and are uniquely capable of remyelinating axons in this context. Schwann cells orchestrate this process via a set of transcription factors. While it has been shown that overexpression of specific genes, e.g. Egr2, upregulates myelin-related transcripts, it remains unknown if such manipulation can functionalize the cells and enhance their myelination frequency. The ability to do so could have implications in the use of human stem cell-derived Schwann cells, where myelination is hard to achieve. After screening four candidate transcription factors (Sox10, Oct6, Brn2 and Egr2), we found that overexpression of Egr2 in rat Schwann cells co-cultured with sensory neurons enhanced myelination frequency and reduced cell proliferation. However, in a mouse model of sciatic nerve repair with cells engrafted within a nerve guide, myelination frequency in the engrafted cells was reduced upon Egr2 overexpression. Our results show that while overexpression of Egr2 can enhance the myelination frequency in vitro, it is context-dependent, potentially influenced by the microenvironment, timing of association with axons, expression level, species differences, or other factors.
Collapse
Affiliation(s)
- Markus Tammia
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Materials Science and Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.,Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Ruifa Mi
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Valentin M Sluch
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Allen Zhu
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Tiffany Chung
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Daniel Shinn
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Donald J Zack
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.,Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.,Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Ahmet Höke
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Hai-Quan Mao
- Institute for NanoBioTechnology, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Materials Science and Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.,Translational Tissue Engineering Center, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.,Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| |
Collapse
|
26
|
Weider M, Starost LJ, Groll K, Küspert M, Sock E, Wedel M, Fröb F, Schmitt C, Baroti T, Hartwig AC, Hillgärtner S, Piefke S, Fadler T, Ehrlich M, Ehlert C, Stehling M, Albrecht S, Jabali A, Schöler HR, Winkler J, Kuhlmann T, Wegner M. Nfat/calcineurin signaling promotes oligodendrocyte differentiation and myelination by transcription factor network tuning. Nat Commun 2018; 9:899. [PMID: 29500351 PMCID: PMC5834605 DOI: 10.1038/s41467-018-03336-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Accepted: 02/05/2018] [Indexed: 02/06/2023] Open
Abstract
Oligodendrocytes produce myelin for rapid transmission and saltatory conduction of action potentials in the vertebrate central nervous system. Activation of the myelination program requires several transcription factors including Sox10, Olig2, and Nkx2.2. Functional interactions among them are poorly understood and important components of the regulatory network are still unknown. Here, we identify Nfat proteins as Sox10 targets and regulators of oligodendroglial differentiation in rodents and humans. Overall levels and nuclear fraction increase during differentiation. Inhibition of Nfat activity impedes oligodendrocyte differentiation in vitro and in vivo. On a molecular level, Nfat proteins cooperate with Sox10 to relieve reciprocal repression of Olig2 and Nkx2.2 as precondition for oligodendroglial differentiation and myelination. As Nfat activity depends on calcium-dependent activation of calcineurin signaling, regulatory network and oligodendroglial differentiation become sensitive to calcium signals. NFAT proteins are also detected in human oligodendrocytes, downregulated in active multiple sclerosis lesions and thus likely relevant in demyelinating disease.
Collapse
Affiliation(s)
- Matthias Weider
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Laura Julia Starost
- Institute of Neuropathology, University Hospital Münster, D-48149, Münster, Germany.,Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, D-48149, Münster, Germany
| | - Katharina Groll
- Institute of Neuropathology, University Hospital Münster, D-48149, Münster, Germany
| | - Melanie Küspert
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Elisabeth Sock
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Miriam Wedel
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Franziska Fröb
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Christian Schmitt
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Tina Baroti
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Anna C Hartwig
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Simone Hillgärtner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Sandra Piefke
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Tanja Fadler
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Marc Ehrlich
- Institute of Neuropathology, University Hospital Münster, D-48149, Münster, Germany.,Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, D-48149, Münster, Germany
| | - Corinna Ehlert
- Institute of Neuropathology, University Hospital Münster, D-48149, Münster, Germany
| | - Martin Stehling
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, D-48149, Münster, Germany
| | - Stefanie Albrecht
- Institute of Neuropathology, University Hospital Münster, D-48149, Münster, Germany
| | - Ammar Jabali
- Institute of Neuropathology, University Hospital Münster, D-48149, Münster, Germany
| | - Hans R Schöler
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, D-48149, Münster, Germany
| | - Jürgen Winkler
- Department of Molecular Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany
| | - Tanja Kuhlmann
- Institute of Neuropathology, University Hospital Münster, D-48149, Münster, Germany.
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054, Erlangen, Germany.
| |
Collapse
|
27
|
Abstract
The journey of Schwann cells from their origin in the neural crest to their ensheathment and myelination of peripheral nerves is a remarkable one. Their apparent static function in enabling saltatory conduction of mature nerve is not only vital for long-term health of peripheral nerve but also belies an innate capacity of terminally differentiated Schwann cells to radically alter their differentiation status in the face of nerve injury. The transition from migrating neural crest cells to nerve ensheathment, and then myelination of large diameter axons has been characterized extensively and several of the transcriptional networks have been identified. However, transcription factors must also modify chromatin structure during Schwann cell maturation and this review will focus on chromatin modification machinery that is involved in promoting the transition to, and maintenance of, myelinating Schwann cells. In addition, Schwann cells are known to play important regenerative roles after peripheral nerve injury, and information on epigenomic reprogramming of the Schwann cell genome has emerged. Characterization of epigenomic requirements for myelin maintenance and Schwann cell responses to injury will be vital in understanding how the various Schwann cell functions can be optimized to maintain and repair peripheral nerve function.
Collapse
Affiliation(s)
- Ki H Ma
- 1 Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - John Svaren
- 1 Waisman Center, University of Wisconsin-Madison, Madison, WI, USA.,2 Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| |
Collapse
|
28
|
Marathe HG, Watkins-Chow DE, Weider M, Hoffmann A, Mehta G, Trivedi A, Aras S, Basuroy T, Mehrotra A, Bennett DC, Wegner M, Pavan WJ, de la Serna IL. BRG1 interacts with SOX10 to establish the melanocyte lineage and to promote differentiation. Nucleic Acids Res 2017; 45:6442-6458. [PMID: 28431046 PMCID: PMC5499657 DOI: 10.1093/nar/gkx259] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 04/04/2017] [Indexed: 12/30/2022] Open
Abstract
Mutations in SOX10 cause neurocristopathies which display varying degrees of hypopigmentation. Using a sensitized mutagenesis screen, we identified Smarca4 as a modifier gene that exacerbates the phenotypic severity of Sox10 haplo-insufficient mice. Conditional deletion of Smarca4 in SOX10 expressing cells resulted in reduced numbers of cranial and ventral trunk melanoblasts. To define the requirement for the Smarca4 -encoded BRG1 subunit of the SWI/SNF chromatin remodeling complex, we employed in vitro models of melanocyte differentiation in which induction of melanocyte-specific gene expression is closely linked to chromatin alterations. We found that BRG1 was required for expression of Dct, Tyrp1 and Tyr, genes that are regulated by SOX10 and MITF and for chromatin remodeling at distal and proximal regulatory sites. SOX10 was found to physically interact with BRG1 in differentiating melanocytes and binding of SOX10 to the Tyrp1 distal enhancer temporally coincided with recruitment of BRG1. Our data show that SOX10 cooperates with MITF to facilitate BRG1 binding to distal enhancers of melanocyte-specific genes. Thus, BRG1 is a SOX10 co-activator, required to establish the melanocyte lineage and promote expression of genes important for melanocyte function.
Collapse
Affiliation(s)
- Himangi G Marathe
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Dawn E Watkins-Chow
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-4472, USA
| | - Matthias Weider
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Alana Hoffmann
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Gaurav Mehta
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Archit Trivedi
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Shweta Aras
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Tupa Basuroy
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Aanchal Mehrotra
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| | - Dorothy C Bennett
- Molecular and Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - William J Pavan
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD 20892-4472, USA
| | - Ivana L de la Serna
- Department of Biochemistry and Cancer Biology, University of Toledo College of Medicine and Life Sciences, 3035 Arlington Ave, Toledo, OH 43614, USA
| |
Collapse
|
29
|
Jacob C. Chromatin-remodeling enzymes in control of Schwann cell development, maintenance and plasticity. Curr Opin Neurobiol 2017; 47:24-30. [PMID: 28850819 DOI: 10.1016/j.conb.2017.08.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 06/28/2017] [Accepted: 08/10/2017] [Indexed: 01/06/2023]
Abstract
Gene regulation is essential for cellular differentiation and plasticity. Schwann cells (SCs), the myelinating glia of the peripheral nervous system (PNS), develop from neural crest cells to mature myelinating SCs and can at early developmental stage differentiate into various cell types. After a PNS lesion, SCs can also convert into repair cells that guide and stimulate axonal regrowth, and remyelinate regenerated axons. What controls their development and versatile nature? Several recent studies highlight the key roles of chromatin modifiers in these processes, allowing SCs to regulate their gene expression profile and thereby acquire or change their identity and quickly react to their environment.
Collapse
Affiliation(s)
- Claire Jacob
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland.
| |
Collapse
|
30
|
Martik ML, Bronner ME. Regulatory Logic Underlying Diversification of the Neural Crest. Trends Genet 2017; 33:715-727. [PMID: 28851604 DOI: 10.1016/j.tig.2017.07.015] [Citation(s) in RCA: 115] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 07/24/2017] [Accepted: 07/27/2017] [Indexed: 12/29/2022]
Abstract
The neural crest is a transient, multipotent population of cells that arises at the border of the developing nervous system. After closure of the neural tube, these cells undergo an epithelial-to-mesenchymal transition (EMT) to delaminate and migrate, often to distant locations in the embryo. Neural crest cells give rise to a diverse array of derivatives including neurons and glia of the peripheral nervous system, melanocytes, and bone and cartilage of the face. A gene regulatory network (GRN) controls the specification, delamination, migration, and differentiation of this fascinating cell type. With increasing technological advances, direct linkages within the neural crest GRN are being uncovered. The underlying circuitry is useful for understanding important topics such as reprogramming, evolution, and disease.
Collapse
Affiliation(s)
- Megan L Martik
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| | - Marianne E Bronner
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
| |
Collapse
|
31
|
Brügger V, Duman M, Bochud M, Münger E, Heller M, Ruff S, Jacob C. Delaying histone deacetylase response to injury accelerates conversion into repair Schwann cells and nerve regeneration. Nat Commun 2017; 8:14272. [PMID: 28139683 PMCID: PMC5290322 DOI: 10.1038/ncomms14272] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Accepted: 12/14/2016] [Indexed: 02/02/2023] Open
Abstract
The peripheral nervous system (PNS) regenerates after injury. However, regeneration is often compromised in the case of large lesions, and the speed of axon reconnection to their target is critical for successful functional recovery. After injury, mature Schwann cells (SCs) convert into repair cells that foster axonal regrowth, and redifferentiate to rebuild myelin. These processes require the regulation of several transcription factors, but the driving mechanisms remain partially understood. Here we identify an early response to nerve injury controlled by histone deacetylase 2 (HDAC2), which coordinates the action of other chromatin-remodelling enzymes to induce the upregulation of Oct6, a key transcription factor for SC development. Inactivating this mechanism using mouse genetics allows earlier conversion into repair cells and leads to faster axonal regrowth, but impairs remyelination. Consistently, short-term HDAC1/2 inhibitor treatment early after lesion accelerates functional recovery and enhances regeneration, thereby identifying a new therapeutic strategy to improve PNS regeneration after lesion.
Collapse
Affiliation(s)
- Valérie Brügger
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Mert Duman
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Maëlle Bochud
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Emmanuelle Münger
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Manfred Heller
- Proteomics and Mass Spectrometry Core Facility, Department of Clinical Research, University of Bern, Freiburgstrasse 15, 3010 Bern, Switzerland
| | - Sophie Ruff
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| | - Claire Jacob
- Department of Biology, University of Fribourg, Chemin du Musée 10, 1700 Fribourg, Switzerland
| |
Collapse
|
32
|
Sowa Y, Kishida T, Tomita K, Yamamoto K, Numajiri T, Mazda O. Direct Conversion of Human Fibroblasts into Schwann Cells that Facilitate Regeneration of Injured Peripheral Nerve In Vivo. Stem Cells Transl Med 2017; 6:1207-1216. [PMID: 28186702 PMCID: PMC5442846 DOI: 10.1002/sctm.16-0122] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Accepted: 11/28/2016] [Indexed: 12/18/2022] Open
Abstract
Schwann cells (SCs) play pivotal roles in the maintenance and regeneration of the peripheral nervous system. Although transplantation of SCs enhances repair of experimentally damaged peripheral and central nerve tissues, it is difficult to prepare a sufficient number of functional SCs for transplantation therapy without causing adverse events for the donor. Here, we generated functional SCs by somatic cell reprogramming procedures and demonstrated their capability to promote peripheral nerve regeneration. Normal human fibroblasts were phenotypically converted into SCs by transducing SOX10 and Krox20 genes followed by culturing for 10 days resulting in approximately 43% directly converted Schwann cells (dSCs). The dSCs expressed SC‐specific proteins, secreted neurotrophic factors, and induced neuronal cells to extend neurites. The dSCs also displayed myelin‐forming capability both in vitro and in vivo. Moreover, transplantation of the dSCs into the transected sciatic nerve in mice resulted in significantly accelerated regeneration of the nerve and in improved motor function at a level comparable to that with transplantation of the SCs obtained from a peripheral nerve. The dSCs induced by our procedure may be applicable for novel regeneration therapy for not only peripheral nerve injury but also for central nerve damage and for neurodegenerative disorders related to SC dysfunction. Stem Cells Translational Medicine2017;6:1207–1216
Collapse
Affiliation(s)
- Yoshihiro Sowa
- Department of Immunology, Graduate School of Medical Sciences, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji Kajii-cho 465, Kamigyo-ku, Kyoto, 602-8566, Japan.,Department of Plastic and Reconstructive Surgery, Graduate School of Medical Sciences, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji Kajii-cho 465, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Tsunao Kishida
- Department of Immunology, Graduate School of Medical Sciences, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji Kajii-cho 465, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Koichi Tomita
- Department of Plastic and Reconstructive Surgery, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka Suita, Osaka, 565-0871, Japan
| | - Kenta Yamamoto
- Department of Immunology, Graduate School of Medical Sciences, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji Kajii-cho 465, Kamigyo-ku, Kyoto, 602-8566, Japan.,Department of Dental Medicine, Graduate School of Medical Sciences, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji Kajii-cho 465, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Toshiaki Numajiri
- Department of Plastic and Reconstructive Surgery, Graduate School of Medical Sciences, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji Kajii-cho 465, Kamigyo-ku, Kyoto, 602-8566, Japan
| | - Osam Mazda
- Department of Immunology, Graduate School of Medical Sciences, Kyoto Prefectural University of Medicine, Kawaramachi Hirokoji Kajii-cho 465, Kamigyo-ku, Kyoto, 602-8566, Japan
| |
Collapse
|
33
|
Weider M, Wegner M. SoxE factors: Transcriptional regulators of neural differentiation and nervous system development. Semin Cell Dev Biol 2016; 63:35-42. [PMID: 27552919 DOI: 10.1016/j.semcdb.2016.08.013] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 08/16/2016] [Accepted: 08/18/2016] [Indexed: 12/20/2022]
Abstract
Sox8, Sox9 and Sox10 represent the three vertebrate members of the SoxE subclass of high-mobility-group domain containing Sox transcription factors. They play important roles in the peripheral and central nervous systems as regulators of stemness, specification, survival, lineage progression, glial differentiation and homeostasis. Functions are frequently overlapping, but sometimes antagonistic. SoxE proteins dynamically interact with transcriptional regulators, chromatin changing complexes and components of the transcriptional machinery. By establishing regulatory circuits with other transcription factors and microRNAs, SoxE proteins perform divergent functions in several cell lineages of the vertebrate nervous system, and at different developmental stages in the same cell lineage. The underlying molecular mechanisms are the topic of this review.
Collapse
Affiliation(s)
- Matthias Weider
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054 Erlangen, Germany.
| |
Collapse
|
34
|
Liu X, Zhao Y, Peng S, Zhang S, Wang M, Chen Y, Zhang S, Yang Y, Sun C. BMP7 retards peripheral myelination by activating p38 MAPK in Schwann cells. Sci Rep 2016; 6:31049. [PMID: 27491681 PMCID: PMC4974506 DOI: 10.1038/srep31049] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 07/13/2016] [Indexed: 11/09/2022] Open
Abstract
Schwann cell (SC) myelination is pivotal for the proper physiological functioning of the nervous system, but the underlying molecular mechanism remains less well understood. Here, we showed that the expression of bone morphogenetic protein 7 (BMP7) inversely correlates with myelin gene expression during peripheral myelination, which suggests that BMP7 is likely a negative regulator for myelin gene expression. Our experiments further showed that the application of BMP7 attenuates the cAMP induced myelin gene expression in SCs. Downstream pathway analysis suggested that both p38 MAPK and SMAD are activated by exogenous BMP7 in SCs. The pharmacological intervention and gene silence studies revealed that p38 MAPK, not SMAD, is responsible for BMP7-mediated suppression of myelin gene expression. In addition, c-Jun, a potential negative regulator for peripheral myelination, was up-regulated by BMP7. In vivo experiments showed that BMP7 treatment greatly impaired peripheral myelination in newborn rats. Together, our results established that BMP7 is a negative regulator for peripheral myelin gene expression and that p38 MAPK/c-Jun axis might be the main downstream target of BMP7 in this process.
Collapse
Affiliation(s)
- Xiaoyu Liu
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, P.R. China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Yahong Zhao
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, P.R. China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Su Peng
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, P.R. China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Shuqiang Zhang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, P.R. China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Meihong Wang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, P.R. China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Yeyue Chen
- School of Medicine, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, China
| | - Shan Zhang
- School of Medicine, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, China
| | - Yumin Yang
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, P.R. China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, P.R. China
| | - Cheng Sun
- Jiangsu Key Laboratory of Neuroregeneration, Nantong University, 19 Qixiu Road, Nantong, Jiangsu 226001, P.R. China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, Jiangsu 226001, P.R. China
| |
Collapse
|
35
|
Balakrishnan A, Stykel MG, Touahri Y, Stratton JA, Biernaskie J, Schuurmans C. Temporal Analysis of Gene Expression in the Murine Schwann Cell Lineage and the Acutely Injured Postnatal Nerve. PLoS One 2016; 11:e0153256. [PMID: 27058953 PMCID: PMC4826002 DOI: 10.1371/journal.pone.0153256] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Accepted: 03/26/2016] [Indexed: 01/09/2023] Open
Abstract
Schwann cells (SCs) arise from neural crest cells (NCCs) that first give rise to SC precursors (SCPs), followed by immature SCs, pro-myelinating SCs, and finally, non-myelinating or myelinating SCs. After nerve injury, mature SCs ‘de-differentiate’, downregulating their myelination program while transiently re-activating early glial lineage genes. To better understand molecular parallels between developing and de-differentiated SCs, we characterized the expression profiles of a panel of 12 transcription factors from the onset of NCC migration through postnatal stages, as well as after acute nerve injury. Using Sox10 as a pan-glial marker in co-expression studies, the earliest transcription factors expressed in E9.0 Sox10+ NCCs were Sox9, Pax3, AP2α and Nfatc4. E10.5 Sox10+ NCCs coalescing in the dorsal root ganglia differed slightly, expressing Sox9, Pax3, AP2α and Etv5. E12.5 SCPs continued to express Sox10, Sox9, AP2α and Pax3, as well as initiating Sox2 and Egr1 expression. E14.5 immature SCs were similar to SCPs, except that they lost Pax3 expression. By E18.5, AP2α, Sox2 and Egr1 expression was turned off in the nerve, while Jun, Oct6 and Yy1 expression was initiated in pro-myelinating Sox9+/Sox10+ SCs. Early postnatal and adult SCs continued to express Sox9, Jun, Oct6 and Yy1 and initiated Nfatc4 and Egr2 expression. Notably, at all stages, expression of each marker was observed only in a subset of Sox10+ SCs, highlighting the heterogeneity of the SC pool. Following acute nerve injury, Egr1, Jun, Oct6, and Sox2 expression was upregulated, Egr2 expression was downregulated, while Sox9, Yy1, and Nfatc4 expression was maintained at similar frequencies. Notably, de-differentiated SCs in the injured nerve did not display a transcription factor profile corresponding to a specific stage in the SC lineage. Taken together, we demonstrate that uninjured and injured SCs are heterogeneous and distinct from one another, and de-differentiation recapitulates transcriptional aspects of several different embryonic stages.
Collapse
Affiliation(s)
- Anjali Balakrishnan
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Morgan G. Stykel
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, Alberta Children’s Hospital Research Institute and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Yacine Touahri
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, Alberta Children’s Hospital Research Institute and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Jo Anne Stratton
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, Alberta Children’s Hospital Research Institute and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, Alberta Children’s Hospital Research Institute and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
| | - Jeff Biernaskie
- Department of Comparative Biology and Experimental Medicine, Faculty of Veterinary Medicine, Alberta Children’s Hospital Research Institute and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- * E-mail: (CS); (JB)
| | - Carol Schuurmans
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, Alberta Children’s Hospital Research Institute and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- * E-mail: (CS); (JB)
| |
Collapse
|
36
|
Abstract
Tissue engineering of Schwann cells (SCs) can serve a number of purposes, such as in vitro SC-related disease modeling, treatment of peripheral nerve diseases or peripheral nerve injury, and, potentially, treatment of CNS diseases. SCs can be generated from autologous stem cells in vitro by recapitulating the various stages of in vivo neural crest formation and SC differentiation. In this review, we survey the cellular and molecular mechanisms underlying these in vivo processes. We then focus on the current in vitro strategies for generating SCs from two sources of pluripotent stem cells, namely embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). Different methods for SC engineering from ESCs and iPSCs are reviewed and suggestions are proposed for optimizing the existing protocols. Potential safety issues regarding the clinical application of iPSC-derived SCs are discussed as well. Lastly, we will address future aspects of SC engineering.
Collapse
|
37
|
Stolt CC, Wegner M. Schwann cells and their transcriptional network: Evolution of key regulators of peripheral myelination. Brain Res 2015; 1641:101-110. [PMID: 26423937 DOI: 10.1016/j.brainres.2015.09.025] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 09/18/2015] [Accepted: 09/20/2015] [Indexed: 11/29/2022]
Abstract
As derivatives of the neural crest, Schwann cells represent a vertebrate invention. Their development and differentiation is under control of a newly constructed, vertebrate-specific regulatory network that contains Sox10, Oct6 and Krox20 as cornerstones and central regulators of peripheral myelination. In this review, we discuss the function and relationship of these transcription factors among each other and in the context of their regulatory network, and present ideas of how neofunctionalization may have helped to recruit them to their novel task in Schwann cells. This article is part of a Special Issue entitled SI: Myelin Evolution.
Collapse
Affiliation(s)
- C Claus Stolt
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054 Erlangen, Germany
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Friedrich-Alexander-Universität Erlangen-Nürnberg, D-91054 Erlangen, Germany.
| |
Collapse
|
38
|
Monk KR, Feltri ML, Taveggia C. New insights on Schwann cell development. Glia 2015; 63:1376-93. [PMID: 25921593 PMCID: PMC4470834 DOI: 10.1002/glia.22852] [Citation(s) in RCA: 179] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/13/2015] [Indexed: 12/11/2022]
Abstract
In the peripheral nervous system, Schwann cells are glial cells that are in intimate contact with axons throughout development. Schwann cells generate the insulating myelin sheath and provide vital trophic support to the neurons that they ensheathe. Schwann cell precursors arise from neural crest progenitor cells, and a highly ordered developmental sequence controls the progression of these cells to become mature myelinating or nonmyelinating Schwann cells. Here, we discuss both seminal discoveries and recent advances in our understanding of the molecular mechanisms that drive Schwann cell development and myelination with a focus on cell-cell and cell-matrix signaling events.
Collapse
Affiliation(s)
- Kelly R Monk
- Department of Developmental Biology, Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri
| | - M Laura Feltri
- Department of Biochemistry and Neurology, Hunter James Kelly Research Institute, University at Buffalo, State University of New York, Buffalo, New York
| | - Carla Taveggia
- Division of Neuroscience and INSPE, San Raffaele Scientific Institute, Milan, Italy
| |
Collapse
|
39
|
Bartesaghi L, Arnaud Gouttenoire E, Prunotto A, Médard JJ, Bergmann S, Chrast R. Sox4 participates in the modulation of Schwann cell myelination. Eur J Neurosci 2015; 42:1788-96. [PMID: 25899854 DOI: 10.1111/ejn.12929] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 03/20/2015] [Accepted: 04/20/2015] [Indexed: 11/26/2022]
Abstract
In order to identify new regulators of Schwann cell myelination potentially playing a role in peripheral nervous system (PNS) pathologies, we analysed gene expression profiling data from three mouse models of demyelinating neuropathies and from the developing PNS. This analysis revealed that Sox4, which encodes a member of the Sry-related high-mobility group box protein family, was consistently upregulated in all three analysed models of neuropathy. Moreover, Sox4 showed a peak in its expression during development that corresponded with the onset of myelination. To gain further insights into the role of Sox4 in PNS development, we generated a transgenic mouse that specifically overexpresses Sox4 in Schwann cells. Sox4 overexpression led to a temporary delay in PNS myelination without affecting axonal sorting. Importantly, we observed that, whereas Sox4 mRNA could be efficiently overexpressed, Sox4 protein expression in Schwann cells was strictly regulated. Finally, our data showed that enforced expression of Sox4 in the mouse model for Charcot-Marie-Tooth 4C aggravated its neuropathic phenotype. Together, these observations reveal that Sox4 contributes to the regulation of Schwann cell myelination, and also indicates its involvement in the pathophysiology of peripheral neuropathies.
Collapse
Affiliation(s)
- Luca Bartesaghi
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland.,Department of Neuroscience and Department of Clinical Neuroscience, Karolinska Institutet, Retzius väg 8, 171 77, Stockholm, Sweden
| | | | - Andrea Prunotto
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, University of Lausanne, Lausanne, Switzerland
| | - Jean-Jacques Médard
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
| | - Sven Bergmann
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland.,Swiss Institute of Bioinformatics, University of Lausanne, Lausanne, Switzerland
| | - Roman Chrast
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland.,Department of Neuroscience and Department of Clinical Neuroscience, Karolinska Institutet, Retzius väg 8, 171 77, Stockholm, Sweden
| |
Collapse
|
40
|
Specific marker expression and cell state of Schwann cells during culture in vitro. PLoS One 2015; 10:e0123278. [PMID: 25859851 PMCID: PMC4393255 DOI: 10.1371/journal.pone.0123278] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2014] [Accepted: 02/18/2015] [Indexed: 12/12/2022] Open
Abstract
Schwann cells (SCs) in animals exist in different developmental stages or wound repair phases, distinguished mainly by the expression of SC-specific markers. No study has yet determined SC state under in vitro culture conditions, and the specific markers expressed in SC are obscure as well. In this study, we harvested sciatic nerves from newborn mice and isolated SCs by an enzyme-digestion method, then we examined the expression profiles of ten markers (S100, p75NTR, Sox10, Sox2, GAP43, NCAM, Krox20, Oct6, MBP, and MPZ) at both the RNA and protein levels in in vitro mouse SCs and speculated their relation with in vivo SC stages. We assayed RNA and protein levels of SC specific markers by immunofluorescence, Western Blot, and real-time quantitative RT-PCR. The results show that the expression of most markers (S100, p75NTR, GAP43, NCAM, Krox20, Oct6, MBP and MPZ) was not detectable in all of early stage cultured SCs. The expression of transcription factors Sox10 and Sox2 was, however, detectable in all SCs. After 8 days, the positive expression rate of all markers except GAP43 and Oct6 was almost 100%.These results indicates Sox10 is a necessary marker for SC identification, while S100 is not reliable. SCs cultured in vitro express Sox2, P75NTR, NCAM, GAP43, Oct6, and MPZ, suggesting that they are similar to in vivo undifferentiated iSCs or dedifferentiated iSCs after nerve injury.
Collapse
|
41
|
Hung HA, Sun G, Keles S, Svaren J. Dynamic regulation of Schwann cell enhancers after peripheral nerve injury. J Biol Chem 2015; 290:6937-50. [PMID: 25614629 PMCID: PMC4358118 DOI: 10.1074/jbc.m114.622878] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 12/31/2014] [Indexed: 12/20/2022] Open
Abstract
Myelination of the peripheral nervous system is required for axonal function and long term stability. After peripheral nerve injury, Schwann cells transition from axon myelination to a demyelinated state that supports neuronal survival and ultimately remyelination of axons. Reprogramming of gene expression patterns during development and injury responses is shaped by the actions of distal regulatory elements that integrate the actions of multiple transcription factors. We used ChIP-seq to measure changes in histone H3K27 acetylation, a mark of active enhancers, to identify enhancers in myelinating rat peripheral nerve and their dynamics after demyelinating nerve injury. Analysis of injury-induced enhancers identified enriched motifs for c-Jun, a transcription factor required for Schwann cells to support nerve regeneration. We identify a c-Jun-bound enhancer in the gene for Runx2, a transcription factor induced after nerve injury, and we show that Runx2 is required for activation of other induced genes. In contrast, enhancers that lose H3K27ac after nerve injury are enriched for binding sites of the Sox10 and early growth response 2 (Egr2/Krox20) transcription factors, which are critical determinants of Schwann cell differentiation. Egr2 expression is lost after nerve injury, and many Egr2-binding sites lose H3K27ac after nerve injury. However, the majority of Egr2-bound enhancers retain H3K27ac, indicating that other transcription factors maintain active enhancer status after nerve injury. The global epigenomic changes in H3K27ac deposition pinpoint dynamic changes in enhancers that mediate the effects of transcription factors that control Schwann cell myelination and peripheral nervous system responses to nerve injury.
Collapse
Affiliation(s)
- Holly A Hung
- From the Waisman Center, Cellular and Molecular Pathology Graduate Program, and
| | - Guannan Sun
- Departments of Biostatistics and Medical Informatics and
| | - Sunduz Keles
- Departments of Biostatistics and Medical Informatics and
| | - John Svaren
- From the Waisman Center, Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin 53705
| |
Collapse
|
42
|
Jacob C. Transcriptional control of neural crest specification into peripheral glia. Glia 2015; 63:1883-1896. [PMID: 25752517 DOI: 10.1002/glia.22816] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 01/29/2015] [Accepted: 02/20/2015] [Indexed: 12/20/2022]
Abstract
The neural crest is a transient migratory multipotent cell population that originates from the neural plate border and is formed at the end of gastrulation and during neurulation in vertebrate embryos. These cells give rise to many different cell types of the body such as chondrocytes, smooth muscle cells, endocrine cells, melanocytes, and cells of the peripheral nervous system including different subtypes of neurons and peripheral glia. Acquisition of lineage-specific markers occurs before or during migration and/or at final destination. What are the mechanisms that direct specification of neural crest cells into a specific lineage and how do neural crest cells decide on a specific migration route? Those are fascinating and complex questions that have existed for decades and are still in the research focus of developmental biologists. This review discusses transcriptional events and regulations occurring in neural crest cells and derived lineages, which control specification of peripheral glia, namely Schwann cell precursors that interact with peripheral axons and further differentiate into myelinating or nonmyelinating Schwann cells, satellite cells that remain tightly associated with neuronal cell bodies in sensory and autonomous ganglia, and olfactory ensheathing cells that wrap olfactory axons, both at the periphery in the olfactory mucosa and in the central nervous system in the olfactory bulb. Markers of the different peripheral glia lineages including intermediate multipotent cells such as boundary cap cells, as well as the functions of these specific markers, are also reviewed. Enteric ganglia, another type of peripheral glia, will not be discussed in this review. GLIA 2015;63:1883-1896.
Collapse
Affiliation(s)
- Claire Jacob
- Department of Biology, University of Fribourg, Fribourg, Switzerland
| |
Collapse
|
43
|
Abstract
The zebrafish is a premier vertebrate model system that offers many experimental advantages for in vivo imaging and genetic studies. This review provides an overview of glial cell types in the central and peripheral nervous system of zebrafish. We highlight some recent work that exploited the strengths of the zebrafish system to increase the understanding of the role of Gpr126 in Schwann cell myelination and illuminate the mechanisms controlling oligodendrocyte development and myelination. We also summarize similarities and differences between zebrafish radial glia and mammalian astrocytes and consider the possibility that their distinct characteristics may represent extremes in a continuum of cell identity. Finally, we focus on the emergence of zebrafish as a model for elucidating the development and function of microglia. These recent studies have highlighted the power of the zebrafish system for analyzing important aspects of glial development and function.
Collapse
Affiliation(s)
- David A Lyons
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - William S Talbot
- Department of Developmental Biology, Stanford University, Stanford, California 94305
| |
Collapse
|
44
|
Brewer MH, Ma KH, Beecham GW, Gopinath C, Baas F, Choi BO, Reilly MM, Shy ME, Züchner S, Svaren J, Antonellis A. Haplotype-specific modulation of a SOX10/CREB response element at the Charcot-Marie-Tooth disease type 4C locus SH3TC2. Hum Mol Genet 2014; 23:5171-87. [PMID: 24833716 PMCID: PMC4168306 DOI: 10.1093/hmg/ddu240] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 05/01/2014] [Accepted: 05/12/2014] [Indexed: 12/22/2022] Open
Abstract
Loss-of-function mutations in the Src homology 3 (SH3) domain and tetratricopeptide repeats 2 (SH3TC2) gene cause autosomal recessive demyelinating Charcot-Marie-Tooth neuropathy. The SH3TC2 protein has been implicated in promyelination signaling through axonal neuregulin-1 and the ERBB2 Schwann cell receptor. However, little is known about the transcriptional regulation of the SH3TC2 gene. We performed computational and functional analyses that revealed two cis-acting regulatory elements at SH3TC2-one at the promoter and one ∼150 kb downstream of the transcription start site. Both elements direct reporter gene expression in Schwann cells and are responsive to the transcription factor SOX10, which is essential for peripheral nervous system myelination. The downstream enhancer harbors a single-nucleotide polymorphism (SNP) that causes an ∼80% reduction in enhancer activity. The SNP resides directly within a predicted binding site for the transcription factor cAMP response element binding protein (CREB), and we demonstrate that this regulatory element binds to CREB and is activated by CREB expression. Finally, forskolin induces Sh3tc2 expression in rat primary Schwann cells, indicating that SH3TC2 is a CREB target gene. These findings prompted us to determine if SNP genotypes at SH3TC2 are associated with differential phenotypes in the most common demyelinating peripheral neuropathy, CMT1A. Interestingly, this revealed several associations between SNP alleles and disease severity. In summary, our data indicate that SH3TC2 is regulated by the transcription factors CREB and SOX10, define a regulatory SNP at this disease-associated locus and reveal SH3TC2 as a candidate modifier locus of CMT disease phenotypes.
Collapse
Affiliation(s)
| | - Ki Hwan Ma
- Cellular and Molecular Pathology (CMP) Program
| | - Gary W Beecham
- Dr John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Chetna Gopinath
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Frank Baas
- Department of Genome Analysis, Academic Medical Centre, Amsterdam, The Netherlands
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Gangnam-Gu, Seoul, Korea
| | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology, Queen Square, London, UK
| | - Michael E Shy
- Department of Neurology Department of Pediatrics and Department of Physiology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Stephan Züchner
- Dr John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - John Svaren
- Waisman Center and Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Anthony Antonellis
- Department of Human Genetics Department of Neurology and Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, USA
| |
Collapse
|
45
|
Simon JM, Giresi PG, Davis IJ, Lieb JD. Addendum: Using formaldehyde-assisted isolation of regulatory elements (FAIRE) to isolate active regulatory DNA. Nat Protoc 2014. [DOI: 10.1038/nprot.2014.062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
46
|
Han J, Tan P, Li Z, Wu Y, Li C, Wang Y, Wang B, Zhao S, Liu Y. Fuzi attenuates diabetic neuropathy in rats and protects schwann cells from apoptosis induced by high glucose. PLoS One 2014; 9:e86539. [PMID: 24466139 PMCID: PMC3900563 DOI: 10.1371/journal.pone.0086539] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2013] [Accepted: 12/15/2013] [Indexed: 02/04/2023] Open
Abstract
Radix aconite lateralis preparata (Fuzi), a folk medicine, has long been used for the treatment of diabetes and paralysis in China. We examined the effect of Fuzi alone on diabetic rats and Schwann cells in high glucose and the components responsible for its activity. The major constituents of FZE were identified by HPLC-MS/MS data. Male Sprague Dawley rats (n = 36) were randomly divided into control, diabetic, FZE 1.75 g/kg, FZE 3.50 g/kg, FZE 7.00 g/kg, and methylcobalamin groups. After two weeks treatment, nerve conduction velocity and paw withdrawal latency were measured. In vitro, the Schwann cells were grouped according to exposure: normal glucose (NG), normal glucose plus mannitol (NG+M), high glucose (HG), and HG plus different concentrations of FZE (0.1 µg/ml, 1.0 µg/ml, and 10.0 µg/ml). Oxygen free radicals and apoptosis were evaluated through DCFH2DA, DHE and annexin-PE/7-AAD assay, respectively. Apoptosis factors (Bax, Bcl-2, CytoC, caspase-3, and caspase-9) were analyzed using immunofluorescence. Nine alkaloids were identified. The results from animal model showed that FZE was effective in accelerating nerve conduction velocity and shortening paw withdrawal latency in diabetic rats. And in vitro, FZE was also found to protect Schwann cells against high glucose injury. FZE could significantly decrease the apoptotic ratio, superoxide anion and peroxide level. Furthermore, the apoptosis factors, including Bax, Bcl-2, CytoC, caspase-3, and caspase-9 were ameliorated in FZE treated groups. The HPLC-MSn method is simple and suitable for the identification of alkaloids in Fuzi. FZE has a protective effect in diabetic neuropathic rats, which is probably achieved by the antiapoptotic effect of FZE on Schwann cells. Apoptosis factor data imply that FZE protected Schwann cells through the mitochondria pathway. Alkaloids are major components contributing to the protective effect.
Collapse
Affiliation(s)
- Jing Han
- Beijing University of Chinese Medicine, Beijing, China
| | - Peng Tan
- Beijing University of Chinese Medicine, Beijing, China
| | - Zhiyong Li
- Minzu University of China, Beijing, China
| | - Yan Wu
- Beijing University of Chinese Medicine, Beijing, China
| | - Chun Li
- Beijing University of Chinese Medicine, Beijing, China
| | - Yong Wang
- Beijing University of Chinese Medicine, Beijing, China
| | - Beibei Wang
- Beijing University of Chinese Medicine, Beijing, China
| | - Shuang Zhao
- Beijing University of Chinese Medicine, Beijing, China
| | - Yonggang Liu
- Beijing University of Chinese Medicine, Beijing, China
- * E-mail:
| |
Collapse
|
47
|
Glenn TD, Talbot WS. Signals regulating myelination in peripheral nerves and the Schwann cell response to injury. Curr Opin Neurobiol 2013; 23:1041-8. [PMID: 23896313 PMCID: PMC3830599 DOI: 10.1016/j.conb.2013.06.010] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 06/20/2013] [Accepted: 06/27/2013] [Indexed: 11/23/2022]
Abstract
In peripheral nerves, Schwann cells form myelin, which facilitates the rapid conduction of action potentials along axons in the vertebrate nervous system. Myelinating Schwann cells are derived from neural crest progenitors in a step-wise process that is regulated by extracellular signals and transcription factors. In addition to forming the myelin sheath, Schwann cells orchestrate much of the regenerative response that occurs after injury to peripheral nerves. In response to injury, myelinating Schwann cells dedifferentiate into repair cells that are essential for axonal regeneration, and then redifferentiate into myelinating Schwann cells to restore nerve function. Although this remarkable plasticity has long been recognized, many questions remain unanswered regarding the signaling pathways regulating both myelination and the Schwann cell response to injury.
Collapse
Affiliation(s)
- Thomas D. Glenn
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305
| | - William S. Talbot
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305
| |
Collapse
|
48
|
Affiliation(s)
- Ben Emery
- Department of Anatomy and Neuroscience and Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
- * E-mail:
| |
Collapse
|
49
|
Hornig J, Fröb F, Vogl MR, Hermans-Borgmeyer I, Tamm ER, Wegner M. The transcription factors Sox10 and Myrf define an essential regulatory network module in differentiating oligodendrocytes. PLoS Genet 2013; 9:e1003907. [PMID: 24204311 PMCID: PMC3814293 DOI: 10.1371/journal.pgen.1003907] [Citation(s) in RCA: 161] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 09/03/2013] [Indexed: 01/31/2023] Open
Abstract
Myelin is essential for rapid saltatory conduction and is produced by Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system. In both cell types the transcription factor Sox10 is an essential component of the myelin-specific regulatory network. Here we identify Myrf as an oligodendrocyte-specific target of Sox10 and map a Sox10 responsive enhancer to an evolutionarily conserved element in intron 1 of the Myrf gene. Once induced, Myrf cooperates with Sox10 to implement the myelination program as evident from the physical interaction between both proteins and the synergistic activation of several myelin-specific genes. This is strongly reminiscent of the situation in Schwann cells where Sox10 first induces and then cooperates with Krox20 during myelination. Our analyses indicate that the regulatory network for myelination in oligodendrocytes is organized along similar general principles as the one in Schwann cells, but is differentially implemented.
Collapse
Affiliation(s)
- Julia Hornig
- Institut für Biochemie, Emil-Fischer-Zentrum, Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Franziska Fröb
- Institut für Biochemie, Emil-Fischer-Zentrum, Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Michael R. Vogl
- Institut für Biochemie, Emil-Fischer-Zentrum, Universität Erlangen-Nürnberg, Erlangen, Germany
| | | | - Ernst R. Tamm
- Institut für Humananatomie und Embryologie, Universität Regensburg, Regensburg, Germany
| | - Michael Wegner
- Institut für Biochemie, Emil-Fischer-Zentrum, Universität Erlangen-Nürnberg, Erlangen, Germany
- * E-mail:
| |
Collapse
|
50
|
Bondurand N, Sham MH. The role of SOX10 during enteric nervous system development. Dev Biol 2013; 382:330-43. [DOI: 10.1016/j.ydbio.2013.04.024] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Accepted: 04/24/2013] [Indexed: 12/30/2022]
|