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Murray GC, Hines TJ, Tadenev ALD, Xu I, Züchner S, Burgess RW. Testing SIPA1L2 as a modifier of CMT1A using mouse models. J Neuropathol Exp Neurol 2024; 83:318-330. [PMID: 38472136 PMCID: PMC11029467 DOI: 10.1093/jnen/nlae020] [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] [Indexed: 03/14/2024] Open
Abstract
Charcot-Marie-Tooth disease type 1A (CMT1A) is a demyelinating peripheral neuropathy caused by the duplication of peripheral myelin protein 22 (PMP22), leading to muscle weakness and loss of sensation in the hands and feet. A recent case-only genome-wide association study of CMT1A patients conducted by the Inherited Neuropathy Consortium identified a strong association between strength of foot dorsiflexion and variants in signal induced proliferation associated 1 like 2 (SIPA1L2), indicating that it may be a genetic modifier of disease. To validate SIPA1L2 as a candidate modifier and to assess its potential as a therapeutic target, we engineered mice with deletion of exon 1 (including the start codon) of the Sipa1l2 gene and crossed them to the C3-PMP22 mouse model of CMT1A. Neuromuscular phenotyping showed that Sipa1l2 deletion in C3-PMP22 mice preserved muscular endurance assayed by inverted wire hang duration and changed femoral nerve axon morphometrics such as myelin thickness. Gene expression changes suggest involvement of Sipa1l2 in cholesterol biosynthesis, a pathway that is also implicated in C3-PMP22 mice. Although Sipa1l2 deletion did impact CMT1A-associated phenotypes, thereby validating a genetic interaction, the overall effect on neuropathy was mild.
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Affiliation(s)
- George C Murray
- The Jackson Laboratory, Bar Harbor, Maine, USA
- The Graduate School of Biomedical Science and Engineering, The University of Maine, Orono, Maine, USA
| | | | | | - Isaac Xu
- Department of Human Genetics and John P Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Stephan Züchner
- Department of Human Genetics and John P Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Robert W Burgess
- The Jackson Laboratory, Bar Harbor, Maine, USA
- The Graduate School of Biomedical Science and Engineering, The University of Maine, Orono, Maine, USA
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Grove M, Kim H, Pang S, Amaya JP, Hu G, Zhou J, Lemay M, Son YJ. TEAD1 is crucial for developmental myelination, Remak bundles, and functional regeneration of peripheral nerves. eLife 2024; 13:e87394. [PMID: 38456457 PMCID: PMC10959528 DOI: 10.7554/elife.87394] [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: 03/15/2023] [Accepted: 03/06/2024] [Indexed: 03/09/2024] Open
Abstract
Previously we showed that the hippo pathway transcriptional effectors, YAP and TAZ, are essential for Schwann cells (SCs) to develop, maintain and regenerate myelin . Although TEAD1 has been implicated as a partner transcription factor, the mechanisms by which it mediates YAP/TAZ regulation of SC myelination are unclear. Here, using conditional and inducible knockout mice, we show that TEAD1 is crucial for SCs to develop and regenerate myelin. It promotes myelination by both positively and negatively regulating SC proliferation, enabling Krox20/Egr2 to upregulate myelin proteins, and upregulating the cholesterol biosynthetic enzymes FDPS and IDI1. We also show stage-dependent redundancy of TEAD1 and that non-myelinating SCs have a unique requirement for TEAD1 to enwrap nociceptive axons in Remak bundles. Our findings establish TEAD1 as a major partner of YAP/TAZ in developmental myelination and functional nerve regeneration and as a novel transcription factor regulating Remak bundle integrity.
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Affiliation(s)
- Matthew Grove
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple UniversityPhiladelphiaUnited States
| | - Hyukmin Kim
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple UniversityPhiladelphiaUnited States
| | - Shuhuan Pang
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple UniversityPhiladelphiaUnited States
| | - Jose Paz Amaya
- Department of Bioengineering, Temple UniversityPhiladelphiaUnited States
| | - Guoqing Hu
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta UniversityAugustaUnited States
| | - Jiliang Zhou
- Department of Pharmacology & Toxicology, Medical College of Georgia, Augusta UniversityAugustaUnited States
| | - Michel Lemay
- Department of Bioengineering, Temple UniversityPhiladelphiaUnited States
| | - Young-Jin Son
- Department of Neural Sciences, Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple UniversityPhiladelphiaUnited States
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Grove M, Kim H, Pang S, Amaya JP, Hu G, Zhou J, Lemay M, Son YJ. TEAD1 is crucial for developmental myelination, Remak bundles, and functional regeneration of peripheral nerves. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.02.27.530298. [PMID: 38293102 PMCID: PMC10827063 DOI: 10.1101/2023.02.27.530298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Previously we showed that the hippo pathway transcriptional effectors, YAP and TAZ, are essential for Schwann cells (SCs) to develop, maintain and regenerate myelin (Grove et al., 2017; Grove, Lee, Zhao, & Son, 2020). Although TEAD1 has been implicated as a partner transcription factor, the mechanisms by which it mediates YAP/TAZ regulation of SC myelination are unclear. Here, using conditional and inducible knockout mice, we show that TEAD1 is crucial for SCs to develop and regenerate myelin. It promotes myelination by both positively and negatively regulating SC proliferation, enabling Krox20/Egr2 to upregulate myelin proteins, and upregulating the cholesterol biosynthetic enzymes FDPS and IDI1. We also show stage-dependent redundancy of TEAD1 and that non-myelinating SCs have a unique requirement for TEAD1 to enwrap nociceptive axons in Remak bundles. Our findings establish TEAD1 as a major partner of YAP/TAZ in developmental myelination and functional nerve regeneration and as a novel transcription factor regulating Remak bundle integrity.
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Cescon M, Gambarotta G, Calabrò S, Cicconetti C, Anselmi F, Kankowski S, Lang L, Basic M, Bleich A, Bolsega S, Steglich M, Oliviero S, Raimondo S, Bizzotto D, Haastert-Talini K, Ronchi G. Gut microbiota depletion delays somatic peripheral nerve development and impairs neuromuscular junction maturation. Gut Microbes 2024; 16:2363015. [PMID: 38845453 PMCID: PMC11164225 DOI: 10.1080/19490976.2024.2363015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 05/29/2024] [Indexed: 06/12/2024] Open
Abstract
Gut microbiota is responsible for essential functions in human health. Several communication axes between gut microbiota and other organs via neural, endocrine, and immune pathways have been described, and perturbation of gut microbiota composition has been implicated in the onset and progression of an emerging number of diseases. Here, we analyzed peripheral nerves, dorsal root ganglia (DRG), and skeletal muscles of neonatal and young adult mice with the following gut microbiota status: a) germ-free (GF), b) gnotobiotic, selectively colonized with 12 specific gut bacterial strains (Oligo-Mouse-Microbiota, OMM12), or c) natural complex gut microbiota (CGM). Stereological and morphometric analyses revealed that the absence of gut microbiota impairs the development of somatic median nerves, resulting in smaller diameter and hypermyelinated axons, as well as in smaller unmyelinated fibers. Accordingly, DRG and sciatic nerve transcriptomic analyses highlighted a panel of differentially expressed developmental and myelination genes. Interestingly, the type III isoform of Neuregulin1 (NRG1), known to be a neuronal signal essential for Schwann cell myelination, was overexpressed in young adult GF mice, with consequent overexpression of the transcription factor Early Growth Response 2 (Egr2), a fundamental gene expressed by Schwann cells at the onset of myelination. Finally, GF status resulted in histologically atrophic skeletal muscles, impaired formation of neuromuscular junctions, and deregulated expression of related genes. In conclusion, we demonstrate for the first time a gut microbiota regulatory impact on proper development of the somatic peripheral nervous system and its functional connection to skeletal muscles, thus suggesting the existence of a novel 'Gut Microbiota-Peripheral Nervous System-axis.'
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Affiliation(s)
- Matilde Cescon
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Giovanna Gambarotta
- Department of Clinical and Biological Sciences & Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano, Italy
| | - Sonia Calabrò
- Department of Molecular Medicine, University of Padova, Padova, Italy
- Department of Biology, University of Padova, Padova, Italy
| | - Chiara Cicconetti
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
| | - Francesca Anselmi
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
| | - Svenja Kankowski
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, Hannover, Lower-Saxony, Germany
| | - Luisa Lang
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, Hannover, Lower-Saxony, Germany
| | - Marijana Basic
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Hannover, Lower-Saxony, Germany
| | - Andre Bleich
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Hannover, Lower-Saxony, Germany
| | - Silvia Bolsega
- Institute for Laboratory Animal Science and Central Animal Facility, Hannover Medical School, Hannover, Lower-Saxony, Germany
| | - Matthias Steglich
- Research Core Unit Genomics, Hannover Medical School, Hannover, Lower-Saxony, Germany
| | - Salvatore Oliviero
- Department of Life Sciences and Systems Biology, University of Torino, Torino, Italy
| | - Stefania Raimondo
- Department of Clinical and Biological Sciences & Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano, Italy
| | - Dario Bizzotto
- Department of Molecular Medicine, University of Padova, Padova, Italy
| | - Kirsten Haastert-Talini
- Institute of Neuroanatomy and Cell Biology, Hannover Medical School, Hannover, Lower-Saxony, Germany
- Centre for Systems Neuroscience (ZSN), Hannover Medical School, Hannover, Lower-Saxony, Germany
| | - Giulia Ronchi
- Department of Clinical and Biological Sciences & Neuroscience Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano, Italy
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Murray GC, Hines TJ, Tadenev ALD, Xu I, Züchner S, Burgess RW. Testing SIPA1L2 as a modifier of CMT1A using mouse models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.30.569428. [PMID: 38076977 PMCID: PMC10705403 DOI: 10.1101/2023.11.30.569428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2023]
Abstract
Charcot-Marie-Tooth 1A is a demyelinating peripheral neuropathy caused by the duplication of peripheral myelin protein 22 (PMP22), which produces muscle weakness and loss of sensation in the hands and feet. A recent case-only genome wide association study by the Inherited Neuropathy Consortium identified a strong association between variants in signal induced proliferation associated 1 like 2 (SIPA1L2) and strength of foot dorsiflexion. To validate SIPA1L2 as a candidate modifier, and to assess its potential as a therapeutic target, we engineered mice with a deletion in SIPA1L2 and crossed them to the C3-PMP22 mouse model of CMT1A. We performed neuromuscular phenotyping and identified an interaction between Sipa1l2 deletion and muscular endurance decrements assayed by wire-hang duration in C3-PMP22 mice, as well as several interactions in femoral nerve axon morphometrics such as myelin thickness. Gene expression changes suggested an involvement of Sipa1l2 in cholesterol biosynthesis, which was also implicated in C3-PMP22 mice. Though several interactions between Sipa1l2 deletion and CMT1A-associated phenotypes were identified, validating a genetic interaction, the overall effect on neuropathy was small.
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Affiliation(s)
- George C Murray
- The Jackson Laboratory, Bar Harbor, ME 04609
- The Graduate School of Biomedical Science and Engineering, The University of Maine, Orono, ME 04469
| | | | | | - Isaac Xu
- Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Stephan Züchner
- Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Robert W Burgess
- The Jackson Laboratory, Bar Harbor, ME 04609
- The Graduate School of Biomedical Science and Engineering, The University of Maine, Orono, ME 04469
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Tang L, Wang Y, Xiang J, Yang D, Zhang Y, Xiang Q, Li J. lncRNA and circRNA expression profiles in the hippocampus of Aβ 25‑35‑induced AD mice treated with Tripterygium glycoside. Exp Ther Med 2023; 26:426. [PMID: 37602300 PMCID: PMC10433443 DOI: 10.3892/etm.2023.12125] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 03/15/2023] [Indexed: 08/22/2023] Open
Abstract
Tripterygium glycosides (TG) have been reported to ameliorate Alzheimer's disease (AD), although the mechanism involved remains to be determined. In the present study, the lncRNA and circRNA expression profiles of an AD mouse model treated with TG were assessed using microarrays. lncRNAs, mRNAs, and circRNAs in the hippocampi of 3 AD+normal saline (NS) mice and 3 AD+TG mice were detected using microarrays. The most differentially expressed lncRNAs, mRNAs, and circRNAs were screened between the AD+NS and AD+TG groups. The differentially expressed lncRNAs and circRNAs were analyzed using GO enrichment and KEGG analyses. Co-expression analysis of lncRNAs, circRNAs, and mRNAs was performed by calculating the correlation coefficients. Protein-protein interaction (PPI) network analysis was performed on mRNAs using STRING. The lncRNA-target-transcription factor (TF) network was analyzed using the Network software. In total, 661 lncRNAs, 64 circRNAs, and 503 mRNAs were found to be differentially expressed in AD mice treated with TG. Pou4f1, Egr2, Mag, and Nr4a1 were the hub genes in the PPI network. The KEGG results showed that the mRNAs that were co-expressed with lncRNAs were enriched in the TNF, PI3K-Akt, and Wnt signaling pathways. LncRNA-target-TF network analysis indicated that TFs, including Cebpa, Zic2, and Rxra, were the most likely to regulate the detected lncRNAs. The circRNA-miRNA interaction network indicated that 275 miRNAs may bind to the 64 circRNAs. In conclusion, these findings provide a novel perspective on AD pathogenesis, and the detected lncRNAs, mRNAs, and circRNAs may serve as novel therapeutic targets for the management of AD.
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Affiliation(s)
- Liang Tang
- Department of Basic Biology, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- Department of Basic Biology, Wuzhou Medical College, Wuzhou, Guangxi Zhuang 543000, P.R. China
- Center for Neuroscience and Behavior, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- The Hunan Provincial University Key Laboratory of The Fundamental and Clinical Research on Functional Nucleic Acid, Changsha Medical College, Changsha, Hunan 410219, P.R. China
| | - Yan Wang
- Department of Basic Biology, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- Department of Basic Biology, Wuzhou Medical College, Wuzhou, Guangxi Zhuang 543000, P.R. China
- Center for Neuroscience and Behavior, Changsha Medical College, Changsha, Hunan 410219, P.R. China
| | - Ju Xiang
- Department of Basic Biology, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- Center for Neuroscience and Behavior, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- The Hunan Provincial University Key Laboratory of The Fundamental and Clinical Research on Functional Nucleic Acid, Changsha Medical College, Changsha, Hunan 410219, P.R. China
| | - Dawei Yang
- Department of Basic Biology, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- Center for Neuroscience and Behavior, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- The Hunan Provincial University Key Laboratory of The Fundamental and Clinical Research on Functional Nucleic Acid, Changsha Medical College, Changsha, Hunan 410219, P.R. China
| | - Yan Zhang
- Department of Basic Biology, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- Center for Neuroscience and Behavior, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- The Hunan Provincial University Key Laboratory of The Fundamental and Clinical Research on Functional Nucleic Acid, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- School of Computer Science and Engineering, Central South University, Changsha, Hunan 410083, P.R. China
| | - Qin Xiang
- Department of Basic Biology, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- Center for Neuroscience and Behavior, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- The Hunan Provincial University Key Laboratory of The Fundamental and Clinical Research on Functional Nucleic Acid, Changsha Medical College, Changsha, Hunan 410219, P.R. China
| | - Jianming Li
- Department of Basic Biology, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- Center for Neuroscience and Behavior, Changsha Medical College, Changsha, Hunan 410219, P.R. China
- The Hunan Provincial University Key Laboratory of The Fundamental and Clinical Research on Functional Nucleic Acid, Changsha Medical College, Changsha, Hunan 410219, P.R. China
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Barnes-Vélez JA, Aksoy Yasar FB, Hu J. Myelin lipid metabolism and its role in myelination and myelin maintenance. Innovation (N Y) 2023; 4:100360. [PMID: 36588745 PMCID: PMC9800635 DOI: 10.1016/j.xinn.2022.100360] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
Myelin is a specialized cell membrane indispensable for rapid nerve conduction. The high abundance of membrane lipids is one of myelin's salient features that contribute to its unique role as an insulator that electrically isolates nerve fibers across their myelinated surface. The most abundant lipids in myelin include cholesterol, glycosphingolipids, and plasmalogens, each playing critical roles in myelin development as well as function. This review serves to summarize the role of lipid metabolism in myelination and myelin maintenance, as well as the molecular determinants of myelin lipid homeostasis, with an emphasis on findings from genetic models. In addition, the implications of myelin lipid dysmetabolism in human diseases are highlighted in the context of hereditary leukodystrophies and neuropathies as well as acquired disorders such as Alzheimer's disease.
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Affiliation(s)
- Joseph A. Barnes-Vélez
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054-1901, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Science, Houston, TX 77225-0334, USA
- University of Puerto Rico Medical Sciences Campus, School of Medicine, San Juan, PR 00936-5067, USA
| | - Fatma Betul Aksoy Yasar
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054-1901, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Science, Houston, TX 77225-0334, USA
| | - Jian Hu
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX 77054-1901, USA
- MD Anderson Cancer Center UTHealth Graduate School of Biomedical Science, Houston, TX 77225-0334, USA
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Buchou C, Laud-Duval K, van der Ent W, Grossetête S, Zaidi S, Gentric G, Corbé M, Müller K, Del Nery E, Surdez D, Delattre O. Upregulation of the Mevalonate Pathway through EWSR1-FLI1/EGR2 Regulatory Axis Confers Ewing Cells Exquisite Sensitivity to Statins. Cancers (Basel) 2022; 14:cancers14092327. [PMID: 35565457 PMCID: PMC9100622 DOI: 10.3390/cancers14092327] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/02/2022] [Accepted: 05/05/2022] [Indexed: 02/04/2023] Open
Abstract
Simple Summary The objective of this project was to search for new dependencies in Ewing sarcoma, a deadly disease for which new therapeutic approaches are urgently needed. A pharmacological screening of off-patent approved drugs (FDA agency) and the investigation of downstream targets of EGR2 were performed. The two approaches showed the MVA pathway as a major dependency in Ewing sarcoma and statin, an inhibitor of this pathway, as a potential new therapeutic agent for the treatment of Ewing sarcoma. Abstract Ewing sarcoma (EwS) is an aggressive primary bone cancer in children and young adults characterized by oncogenic fusions between genes encoding FET-RNA-binding proteins and ETS transcription factors, the most frequent fusion being EWSR1-FLI1. We show that EGR2, an Ewing-susceptibility gene and an essential direct target of EWSR1-FLI1, directly regulates the transcription of genes encoding key enzymes of the mevalonate (MVA) pathway. Consequently, Ewing sarcoma is one of the tumors that expresses the highest levels of mevalonate pathway genes. Moreover, genome-wide screens indicate that MVA pathway genes constitute major dependencies of Ewing cells. Accordingly, the statin inhibitors of HMG-CoA-reductase, a rate-limiting enzyme of the MVA pathway, demonstrate cytotoxicity in EwS. Statins induce increased ROS and lipid peroxidation levels, as well as decreased membrane localization of prenylated proteins, such as small GTP proteins. These metabolic effects lead to an alteration in the dynamics of S-phase progression and to apoptosis. Statin-induced effects can be rescued by downstream products of the MVA pathway. Finally, we further show that statins impair tumor growth in different Ewing PDX models. Altogether, the data show that statins, which are off-patent, well-tolerated, and inexpensive compounds, should be strongly considered in the therapeutic arsenal against this deadly childhood disease.
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Affiliation(s)
- Charlie Buchou
- INSERM U830, Équipe Labellisée LNCC, Diversity & Plasticity of Childhood Tumors Laboratory, PSL Research University, SIREDO Oncology Center, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (C.B.); (K.L.-D.); (W.v.d.E.); (S.G.); (S.Z.); (D.S.)
| | - Karine Laud-Duval
- INSERM U830, Équipe Labellisée LNCC, Diversity & Plasticity of Childhood Tumors Laboratory, PSL Research University, SIREDO Oncology Center, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (C.B.); (K.L.-D.); (W.v.d.E.); (S.G.); (S.Z.); (D.S.)
| | - Wietske van der Ent
- INSERM U830, Équipe Labellisée LNCC, Diversity & Plasticity of Childhood Tumors Laboratory, PSL Research University, SIREDO Oncology Center, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (C.B.); (K.L.-D.); (W.v.d.E.); (S.G.); (S.Z.); (D.S.)
| | - Sandrine Grossetête
- INSERM U830, Équipe Labellisée LNCC, Diversity & Plasticity of Childhood Tumors Laboratory, PSL Research University, SIREDO Oncology Center, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (C.B.); (K.L.-D.); (W.v.d.E.); (S.G.); (S.Z.); (D.S.)
| | - Sakina Zaidi
- INSERM U830, Équipe Labellisée LNCC, Diversity & Plasticity of Childhood Tumors Laboratory, PSL Research University, SIREDO Oncology Center, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (C.B.); (K.L.-D.); (W.v.d.E.); (S.G.); (S.Z.); (D.S.)
| | - Géraldine Gentric
- INSERM U830, Équipe Labellisée LNCC, Stress and Cancer Laboratory, PSL Research University, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France;
| | - Maxime Corbé
- Department of Translational Research, The Biophenics High-Content Screening Laboratory, PSL Research University, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (M.C.); (K.M.); (E.D.N.)
| | - Kévin Müller
- Department of Translational Research, The Biophenics High-Content Screening Laboratory, PSL Research University, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (M.C.); (K.M.); (E.D.N.)
| | - Elaine Del Nery
- Department of Translational Research, The Biophenics High-Content Screening Laboratory, PSL Research University, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (M.C.); (K.M.); (E.D.N.)
| | - Didier Surdez
- INSERM U830, Équipe Labellisée LNCC, Diversity & Plasticity of Childhood Tumors Laboratory, PSL Research University, SIREDO Oncology Center, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (C.B.); (K.L.-D.); (W.v.d.E.); (S.G.); (S.Z.); (D.S.)
- Balgrist University Hospital, University of Zurich, Zurich, Forchstrasse 340, 8008 Zürich, Switzerland
| | - Olivier Delattre
- INSERM U830, Équipe Labellisée LNCC, Diversity & Plasticity of Childhood Tumors Laboratory, PSL Research University, SIREDO Oncology Center, Institut Curie Research Center, 26 rue d’ULM, 75005 Paris, France; (C.B.); (K.L.-D.); (W.v.d.E.); (S.G.); (S.Z.); (D.S.)
- Correspondence:
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Park HJ, Tsai E, Huang D, Weaver M, Frick L, Alcantara A, Moran JJ, Patzig J, Melendez-Vasquez CV, Crabtree GR, Feltri ML, 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] [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. ACTL6a levels in Schwann cells respond to stiffness and caliber of PLA nanofibers ACTL6a integrates axonal caliber recognition signals with Schwann cells transcriptome ACTL6a null mice have thin myelin on large axons and redundant myelin on small axons Mice lacking ACTL6a in Schwann cells show severe clinical symptoms
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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
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10
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Wrestling and Wrapping: A Perspective on SUMO Proteins in Schwann Cells. Biomolecules 2021; 11:biom11071055. [PMID: 34356679 PMCID: PMC8301837 DOI: 10.3390/biom11071055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 11/20/2022] Open
Abstract
Schwann cell development and peripheral nerve myelination are finely orchestrated multistep processes; some of the underlying mechanisms are well described and others remain unknown. Many posttranslational modifications (PTMs) like phosphorylation and ubiquitination have been reported to play a role during the normal development of the peripheral nervous system (PNS) and in demyelinating neuropathies. However, a relatively novel PTM, SUMOylation, has not been studied in these contexts. SUMOylation involves the covalent attachment of one or more small ubiquitin-like modifier (SUMO) proteins to a substrate, which affects the function, cellular localization, and further PTMs of the conjugated protein. SUMOylation also regulates other proteins indirectly by facilitating non-covalent protein–protein interaction via SUMO interaction motifs (SIM). This pathway has important consequences on diverse cellular processes, and dysregulation of this pathway has been reported in several diseases including neurological and degenerative conditions. In this article, we revise the scarce literature on SUMOylation in Schwann cells and the PNS, we propose putative substrate proteins, and we speculate on potential mechanisms underlying the possible involvement of this PTM in peripheral myelination and neuropathies.
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11
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Vashi N, Ackerley C, Post M, Justice MJ. Aberrant lung lipids cause respiratory impairment in a Mecp2-deficient mouse model of Rett syndrome. Hum Mol Genet 2021; 30:2161-2176. [PMID: 34230964 PMCID: PMC8561422 DOI: 10.1093/hmg/ddab182] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Revised: 05/11/2021] [Accepted: 06/28/2021] [Indexed: 11/14/2022] Open
Abstract
Severe respiratory impairment is a prominent feature of Rett syndrome (RTT), an X-linked disorder caused by mutations in methyl CpG-binding protein 2 (MECP2). Despite MECP2's ubiquitous expression, respiratory anomalies are attributed to neuronal dysfunction. Here, we show that neutral lipids accumulate in mouse Mecp2-mutant lungs, while surfactant phospholipids decrease. Conditional deletion of Mecp2 from lipid-producing alveolar epithelial 2 (AE2) cells causes aberrant lung lipids and respiratory symptoms, while deletion of Mecp2 from hindbrain neurons results in distinct respiratory abnormalities. Single-cell RNA sequencing of AE2 cells suggests lipid production and storage increase at the expense of phospholipid synthesis. Lipid production enzymes are confirmed as direct targets of MECP2-directed nuclear receptor corepressor 1/2 (NCOR1/2) transcriptional repression. Remarkably, lipid-lowering fluvastatin improves respiratory anomalies in Mecp2-mutant mice. These data implicate autonomous pulmonary loss of MECP2 in respiratory symptoms for the first time and have immediate impacts on patient care.
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Affiliation(s)
- Neeti Vashi
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A1, Canada.,Genetics and Genome Biology Program, Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5G 0A4, Canada
| | - Cameron Ackerley
- Translational Medicine Program, Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5G 0A4, Canada
| | - Martin Post
- Translational Medicine Program, Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5G 0A4, Canada
| | - Monica J Justice
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S 1A1, Canada.,Genetics and Genome Biology Program, Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, Toronto, ON, M5G 0A4, Canada
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12
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Fornaro M, Marcus D, Rattin J, Goral J. Dynamic Environmental Physical Cues Activate Mechanosensitive Responses in the Repair Schwann Cell Phenotype. Cells 2021; 10:cells10020425. [PMID: 33671410 PMCID: PMC7922665 DOI: 10.3390/cells10020425] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 02/09/2021] [Accepted: 02/11/2021] [Indexed: 01/10/2023] Open
Abstract
Schwann cells plastically change in response to nerve injury to become a newly reconfigured repair phenotype. This cell is equipped to sense and interact with the evolving and unusual physical conditions characterizing the injured nerve environment and activate intracellular adaptive reprogramming as a consequence of external stimuli. Summarizing the literature contributions on this matter, this review is aimed at highlighting the importance of the environmental cues of the regenerating nerve as key factors to induce morphological and functional changes in the Schwann cell population. We identified four different microenvironments characterized by physical cues the Schwann cells sense via interposition of the extracellular matrix. We discussed how the physical cues of the microenvironment initiate changes in Schwann cell behavior, from wrapping the axon to becoming a multifunctional denervated repair cell and back to reestablishing contact with regenerated axons.
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Affiliation(s)
- Michele Fornaro
- Department of Anatomy, College of Graduate Studies (CGS), Midwestern University, Downers Grove, IL 60515, USA;
- Department of Anatomy, Chicago College of Osteopathic Medicine (CCOM), Midwestern University, Downers Grove, IL 60515, USA; (D.M.); (J.R.)
- Correspondence: ; Tel.: +001-630-515-6055
| | - Dominic Marcus
- Department of Anatomy, Chicago College of Osteopathic Medicine (CCOM), Midwestern University, Downers Grove, IL 60515, USA; (D.M.); (J.R.)
| | - Jacob Rattin
- Department of Anatomy, Chicago College of Osteopathic Medicine (CCOM), Midwestern University, Downers Grove, IL 60515, USA; (D.M.); (J.R.)
| | - Joanna Goral
- Department of Anatomy, College of Graduate Studies (CGS), Midwestern University, Downers Grove, IL 60515, USA;
- Department of Anatomy, Chicago College of Osteopathic Medicine (CCOM), Midwestern University, Downers Grove, IL 60515, USA; (D.M.); (J.R.)
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13
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Loverde JR, Tolentino RE, Soteropoulos P, Pfister BJ. Biomechanical Forces Regulate Gene Transcription During Stretch-Mediated Growth of Mammalian Neurons. Front Neurosci 2021; 14:600136. [PMID: 33408609 PMCID: PMC7780124 DOI: 10.3389/fnins.2020.600136] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 11/11/2020] [Indexed: 11/25/2022] Open
Abstract
At birth, there are 100 billion neurons in the human brain, with functional neural circuits extending through the spine to the epidermis of the feet and toes. Following birth, limbs and vertebrae continue to grow by several orders of magnitude, forcing established axons to grow by up to 200 cm in length without motile growth cones. The leading regulatory paradigm suggests that biomechanical expansion of mitotic tissue exerts tensile force on integrated nervous tissue, which synchronizes ongoing growth of spanning axons. Here, we identify unique transcriptional changes in embryonic rat DRG and cortical neurons while the corresponding axons undergo physiological levels of controlled mechanical stretch in vitro. Using bioreactors containing cultured neurons, we recapitulated the peak biomechanical increase in embryonic rat crown-rump-length. Biologically paired sham and “stretch-grown” DRG neurons spanned 4.6- and 17.2-mm in length following static or stretch-induced growth conditions, respectively, which was associated with 456 significant changes in gene transcription identified by genome-wide cDNA microarrays. Eight significant genes found in DRG were cross-validated in stretch-grown cortical neurons by qRT-PCR, which included upregulation of Gpat3, Crem, Hmox1, Hpse, Mt1a, Nefm, Sprr1b, and downregulation of Nrep. The results herein establish a link between biomechanics and gene transcription in mammalian neurons, which elucidates the mechanism underlying long-term growth of axons, and provides a basis for new research in therapeutic axon regeneration.
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Affiliation(s)
- Joseph R Loverde
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials, and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Rosa E Tolentino
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials, and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
| | - Patricia Soteropoulos
- Department of Microbiology, Biochemistry and Molecular Genetics, Genomics Center, Rutgers New Jersey Medical School, Rutgers University, Newark, NJ, United States
| | - Bryan J Pfister
- Department of Biomedical Engineering, Center for Injury Biomechanics, Materials, and Medicine, New Jersey Institute of Technology, Newark, NJ, United States
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14
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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.
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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
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15
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Mayama S, Hamazaki N, Maruyama Y, Matsubara S, Kimura AP. Transcriptional activation of the mouse Scd2 gene by interdependent enhancers and long noncoding RNAs in ovarian granulosa cells. J Reprod Dev 2020; 66:435-444. [PMID: 32507774 PMCID: PMC7593631 DOI: 10.1262/jrd.2019-161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Specific gene expression in granulosa cells is key for the function of ovary, but the molecular mechanism of transcriptional activation is not well studied.
Here we investigated the regulatory mechanism of the mouse stearoyl-CoA desaturase 2 (Scd2) gene encoding an enzyme for lipid metabolism.
Northern blot and in situ hybridization indicated that the mouse Scd2 mRNA was highly expressed in ovarian granulosa cells. We
found four conserved noncoding sequences (CNSs) and two long noncoding RNAs (lncRNAs) transcribed from regions upstream of the Scd2 gene as
candidates of regulatory elements/factors. These lncRNAs were predominantly transcribed in the opposite direction to Scd2 and localized in
nuclei and showed the correlation with Scd2 expression, raising the possibility of their transcriptional regulatory roles. Indeed, knockdown of
both lncRNAs, lncRNA-sc1 and lncRNA-sc2, significantly decreased the Scd2 mRNA level in primary granulosa
cells. Then, we investigated the histone modification pattern at this locus by a chromatin immunoprecipitation assay, and two CNSs, CNS1 and CNS2, were found to
be marked with high levels of histone H3K9/K27 acetylation in primary granulosa cells. By a reporter gene assay, both CNS1 and CNS2 interdependently exhibited
enhancer activity for the Scd2 promoter in primary granulosa cells. These data suggest that the mouse Scd2 gene is activated
by two lncRNAs and interdependent enhancers in ovarian granulosa cells, which provides a new insight into transcriptional activation in granulosa cells.
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Affiliation(s)
- Shota Mayama
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Nobuhiko Hamazaki
- Division of Biology, Department of Biological Sciences, School of Science, Hokkaido University, Sapporo 060-0810, Japan.,Present: Department of Genome Sciences, University of Washington, Seattle, WA, USA
| | - Yuki Maruyama
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Shin Matsubara
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan.,Present: Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto 619-0284, Japan
| | - Atsushi P Kimura
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan.,Division of Biology, Department of Biological Sciences, School of Science, Hokkaido University, Sapporo 060-0810, Japan.,Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
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16
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Igal RA, Sinner DI. Stearoyl-CoA desaturase 5 (SCD5), a Δ-9 fatty acyl desaturase in search of a function. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1866:158840. [PMID: 33049404 DOI: 10.1016/j.bbalip.2020.158840] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/26/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022]
Abstract
A large body of research has demonstrated that human stearoyl-CoA desaturase 1 (SCD1), a universally expressed fatty acid Δ9-desaturase that converts saturated fatty acids (SFA) into monounsaturated fatty acids (MUFA), is a central regulator of metabolic and signaling pathways involved in cell proliferation, differentiation, and survival. Unlike SCD1, stearoyl-CoA desaturase 5 (SCD5), a second SCD isoform found in a variety of vertebrates, including humans, has received considerably less attention but new information on the catalytic properties, regulation and biological functions of this enzyme has begun to emerge. This review will examine the new evidence that supports key metabolic and biological roles for SCD5, as well as the potential implication of this desaturase in the mechanisms of human diseases.
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Affiliation(s)
- R Ariel Igal
- Institute of Human Nutrition and Department of Pediatrics, Columbia University Irving Medical Center, 630 West 168th Street, PH 1501 East, New York City, NY 10032, United States of America.
| | - Débora I Sinner
- Neonatology and Pulmonary Biology, Cincinnati Children's Hospital Medical Center, Lab: R4447, Office: R4445, MLC 7009, 3333 Burnet Ave, Cincinnati, OH 45229, United States of America.
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17
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Pantera H, Hu B, Moiseev D, Dunham C, Rashid J, Moran JJ, Krentz K, Rubinstein CD, Won S, Li J, Svaren J. Pmp22 super-enhancer deletion causes tomacula formation and conduction block in peripheral nerves. Hum Mol Genet 2020; 29:1689-1699. [PMID: 32356557 PMCID: PMC7322568 DOI: 10.1093/hmg/ddaa082] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 04/07/2020] [Accepted: 04/24/2020] [Indexed: 11/12/2022] Open
Abstract
Copy number variation of the peripheral nerve myelin gene Peripheral Myelin Protein 22 (PMP22) causes multiple forms of inherited peripheral neuropathy. The duplication of a 1.4 Mb segment surrounding this gene in chromosome 17p12 (c17p12) causes the most common form of Charcot-Marie-Tooth disease type 1A, whereas the reciprocal deletion of this gene causes a separate neuropathy termed hereditary neuropathy with liability to pressure palsies (HNPP). PMP22 is robustly induced in Schwann cells in early postnatal development, and several transcription factors and their cognate regulatory elements have been implicated in coordinating the gene's proper expression. We previously found that a distal super-enhancer domain was important for Pmp22 expression in vitro, with particular impact on a Schwann cell-specific alternative promoter. Here, we investigate the consequences of deleting this super-enhancer in vivo. We find that loss of the super-enhancer in mice reduces Pmp22 expression throughout development and into adulthood, with greater impact on the Schwann cell-specific promoter. Additionally, these mice display tomacula formed by excessive myelin folding, a pathological hallmark of HNPP, as have been previously observed in heterozygous Pmp22 mice as well as sural biopsies from patients with HNPP. Our findings demonstrate a mechanism by which smaller copy number variations, not including the Pmp22 gene, are sufficient to reduce gene expression and phenocopy a peripheral neuropathy caused by the HNPP-associated deletion encompassing PMP22.
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Affiliation(s)
- Harrison Pantera
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
- Molecular and Cellular Pharmacology Graduate Program, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Bo Hu
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Daniel Moiseev
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Chris Dunham
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - Jibraan Rashid
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - John J Moran
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Kathleen Krentz
- Biotechnology Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - C Dustin Rubinstein
- Biotechnology Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Seongsik Won
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Jun Li
- Department of Neurology and Translational Neuroscience Initiative, Wayne State University School of Medicine, Detroit, MI 48202, USA
| | - John Svaren
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53705, USA
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18
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Chromenopyrimidinone Controls Stemness and Malignancy by suppressing CD133 Expression in Hepatocellular Carcinoma. Cancers (Basel) 2020; 12:cancers12051193. [PMID: 32397206 PMCID: PMC7281429 DOI: 10.3390/cancers12051193] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/17/2020] [Accepted: 04/24/2020] [Indexed: 12/18/2022] Open
Abstract
Hepatocellular carcinoma (HCC) is a highly malignant human cancer that has increasing mortality rates worldwide. Because CD133+ cells control tumor maintenance and progression, compounds that target CD133+ cancer cells could be effective in combating HCC. We found that the administration of chromenopyrimidinone (CPO) significantly decreased spheroid formation and the number of CD133+ cells in mixed HCC cell populations. CPO not only significantly inhibited cell proliferation in HCC cells exhibiting different CD133 expression levels, but also effectively induced apoptosis and increased the expression of LC3-II in HCC cells. CPO also exhibits in vivo therapeutic efficiency in HCC. Specifically, CPO suppressed the expression of CD133 by altering the subcellular localization of CD133 from the membrane to lysosomes in CD133+ HCC cells. Moreover, CPO treatment induced point mutations in the ADRB1, APOB, EGR2, and UBE2C genes and inhibited the expression of these proteins in HCC and the expression of UBE2C is particularly controlled by CD133 expression among those four proteins in HCC. Our results suggested that CPO may suppress stemness and malignancies in vivo and in vitro by decreasing CD133 and UBE2C expression in CD133+ HCC. Our study provides evidence that CPO could act as a novel therapeutic agent for the effective treatment of CD133+ HCC.
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19
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Scapin C, Ferri C, Pettinato E, Zambroni D, Bianchi F, Del Carro U, Belin S, Caruso D, Mitro N, Pellegatta M, Taveggia C, Schwab MH, Nave KA, Feltri ML, Wrabetz L, D'Antonio M. Enhanced axonal neuregulin-1 type-III signaling ameliorates neurophysiology and hypomyelination in a Charcot-Marie-Tooth type 1B mouse model. Hum Mol Genet 2020; 28:992-1006. [PMID: 30481294 DOI: 10.1093/hmg/ddy411] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 10/30/2018] [Accepted: 11/22/2018] [Indexed: 12/11/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) neuropathies are a group of genetic disorders that affect the peripheral nervous system with heterogeneous pathogenesis and no available treatment. Axonal neuregulin 1 type III (Nrg1TIII) drives peripheral nerve myelination by activating downstream signaling pathways such as PI3K/Akt and MAPK/Erk that converge on master transcriptional regulators of myelin genes, such as Krox20. We reasoned that modulating Nrg1TIII activity may constitute a general therapeutic strategy to treat CMTs that are characterized by reduced levels of myelination. Here we show that genetic overexpression of Nrg1TIII ameliorates neurophysiological and morphological parameters in a mouse model of demyelinating CMT1B, without exacerbating the toxic gain-of-function that underlies the neuropathy. Intriguingly, the mechanism appears not to be related to Krox20 or myelin gene upregulation, but rather to a beneficial rebalancing in the stoichiometry of myelin lipids and proteins. Finally, we provide proof of principle that stimulating Nrg1TIII signaling, by pharmacological suppression of the Nrg1TIII inhibitor tumor necrosis factor-alpha-converting enzyme (TACE/ADAM17), also ameliorates the neuropathy. Thus, modulation of Nrg1TIII by TACE/ADAM17 inhibition may represent a general treatment for hypomyelinating neuropathies.
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Affiliation(s)
| | | | | | | | - Francesca Bianchi
- INSPE, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Ubaldo Del Carro
- INSPE, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | | | - Donatella Caruso
- DiSFeB-Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Nico Mitro
- DiSFeB-Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Marta Pellegatta
- INSPE, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Carla Taveggia
- INSPE, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Markus H Schwab
- Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany.,Cellular Neurophysiology, Hannover Medical School, Hannover, Germany
| | - Klaus-Armin Nave
- Max Planck Institute for Experimental Medicine, 37075 Göttingen, Germany
| | - M Laura Feltri
- DIBIT, Divisions of Genetics and Cell Biology.,Hunter James Kelly Research Institute.,Department of Neurology.,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Lawrence Wrabetz
- DIBIT, Divisions of Genetics and Cell Biology.,Hunter James Kelly Research Institute.,Department of Neurology.,Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
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20
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Fröb F, Wegner M. The role of chromatin remodeling complexes in Schwann cell development. Glia 2019; 68:1596-1603. [DOI: 10.1002/glia.23766] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/27/2019] [Accepted: 12/03/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Franziska Fröb
- 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
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21
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Sophie B, Jacob H, Jordan VJS, Yungki P, Laura FM, Yannick P. YAP and TAZ Regulate Cc2d1b and Purβ in Schwann Cells. Front Mol Neurosci 2019; 12:177. [PMID: 31379499 PMCID: PMC6650784 DOI: 10.3389/fnmol.2019.00177] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2019] [Accepted: 07/04/2019] [Indexed: 12/31/2022] Open
Abstract
Schwann cells (SCs) are exquisitely sensitive to the elasticity of their environment and their differentiation and capacity to myelinate depend on the transduction of mechanical stimuli by YAP and TAZ. YAP/TAZ, in concert with other transcription factors, regulate several pathways including lipid and sterol biosynthesis as well as extracellular matrix receptor expressions such as integrins and G-proteins. Yet, the characterization of the signaling downstream YAP/TAZ in SCs is incomplete. Myelin sheath production by SC coincides with rapid up-regulation of numerous transcription factors. Here, we show that ablation of YAP/TAZ alters the expression of transcription regulators known to regulate SC myelin gene transcription and differentiation. Furthermore, we link YAP/TAZ to two DNA binding proteins, Cc2d1b and Purβ, which have no described roles in myelinating glial cells. We demonstrate that silencing of either Cc2d1b or Purβ limits the formation of myelin segments. These data provide a deeper insight into the myelin gene transcriptional network and the role of YAP/TAZ in myelinating glial cells.
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Affiliation(s)
- Belin Sophie
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
| | - Herron Jacob
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
| | - VerPlank J S Jordan
- Department of Cell Biology, Harvard Medical School, Boston, MA, United States
| | - Park Yungki
- Department of Biochemistry, Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, United States
| | - Feltri M Laura
- Department of Biochemistry, Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, United States.,Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
| | - Poitelon Yannick
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, United States
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22
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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.
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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
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23
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Belin S, Ornaghi F, Shackleford G, Wang J, Scapin C, Lopez-Anido C, Silvestri N, Robertson N, Williamson C, Ishii A, Taveggia C, Svaren J, Bansal R, Schwab MH, Nave K, Fratta P, D’Antonio M, Poitelon Y, Feltri ML, Wrabetz L. Neuregulin 1 type III improves peripheral nerve myelination in a mouse model of congenital hypomyelinating neuropathy. Hum Mol Genet 2019; 28:1260-1273. [PMID: 30535360 PMCID: PMC6452193 DOI: 10.1093/hmg/ddy420] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/06/2018] [Accepted: 12/02/2018] [Indexed: 12/13/2022] Open
Abstract
Myelin sheath thickness is precisely regulated and essential for rapid propagation of action potentials along myelinated axons. In the peripheral nervous system, extrinsic signals from the axonal protein neuregulin 1 (NRG1) type III regulate Schwann cell fate and myelination. Here we ask if modulating NRG1 type III levels in neurons would restore myelination in a model of congenital hypomyelinating neuropathy (CHN). Using a mouse model of CHN, we improved the myelination defects by early overexpression of NRG1 type III. Surprisingly, the improvement was independent from the upregulation of Egr2 or essential myelin genes. Rather, we observed the activation of MAPK/ERK and other myelin genes such as peripheral myelin protein 2 and oligodendrocyte myelin glycoprotein. We also confirmed that the permanent activation of MAPK/ERK in Schwann cells has detrimental effects on myelination. Our findings demonstrate that the modulation of axon-to-glial NRG1 type III signaling has beneficial effects and improves myelination defects during development in a model of CHN.
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Affiliation(s)
- Sophie Belin
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - Francesca Ornaghi
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
- SR-TIGET, IRCCS, San Raffaele Scientific Institute, Milan, Italy
| | - Ghjuvan’Ghjacumu Shackleford
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Jie Wang
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Cristina Scapin
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | | | - Nicholas Silvestri
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Neil Robertson
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Courtney Williamson
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
| | - Akihiro Ishii
- Department of Neuroscience, University of Connecticut Medical School, Farmington, CT, USA
| | - Carla Taveggia
- Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - John Svaren
- Waisman Center, University of Wisconsin–Madison, Madison, WI, USA
| | - Rashmi Bansal
- Department of Neuroscience, University of Connecticut Medical School, Farmington, CT, USA
| | - Markus H Schwab
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
- Department of Cellular Neurophysiology, Hannover Medical School, Hannover, Germany
| | - Klaus Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - Pietro Fratta
- Sobell Department of Motor Neuroscience and Movement Disorders, UCL Institute of Neurology, Queen Square, London, UK
| | - Maurizio D’Antonio
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Yannick Poitelon
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, New York, USA
| | - M Laura Feltri
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Lawrence Wrabetz
- Hunter James Kelly Research Institute, University at Buffalo, Buffalo, NY, USA
- Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
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24
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Kim M, Wende H, Walcher J, Kühnemund J, Cheret C, Kempa S, McShane E, Selbach M, Lewin GR, Birchmeier C. Maf links Neuregulin1 signaling to cholesterol synthesis in myelinating Schwann cells. Genes Dev 2018; 32:645-657. [PMID: 29748249 PMCID: PMC6004071 DOI: 10.1101/gad.310490.117] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/16/2018] [Indexed: 11/25/2022]
Abstract
Kim et al. define a crucial role of the transcription factor Maf in myelination and cholesterol biosynthesis and show that Maf acts downstream from Neuregulin1 in myelinating Schwann cells. Cholesterol is a major constituent of myelin membranes, which insulate axons and allow saltatory conduction. Therefore, Schwann cells, the myelinating glia of the peripheral nervous system, need to produce large amounts of cholesterol. Here, we define a crucial role of the transcription factor Maf in myelination and cholesterol biosynthesis and show that Maf acts downstream from Neuregulin1 (Nrg1). Maf expression is induced when Schwann cells begin myelination. Genetic ablation of Maf resulted in hypomyelination that resembled mice with defective Nrg1 signaling. Importantly, loss of Maf or Nrg1 signaling resulted in a down-regulation of the cholesterol synthesis program, and Maf directly binds to enhancers of cholesterol synthesis genes. Furthermore, we identified the molecular mechanisms by which Nrg1 signaling regulates Maf levels. Transcription of Maf depends on calmodulin-dependent kinases downstream from Nrg1, whereas Nrg1–MAPK signaling stabilizes Maf protein. Our results delineate a novel signaling cascade regulating cholesterol synthesis in myelinating Schwann cells.
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Affiliation(s)
- Minchul Kim
- Department of Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Hagen Wende
- Department of Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Jan Walcher
- Department of Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Johannes Kühnemund
- Department of Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Cyril Cheret
- Department of Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Stefan Kempa
- Department of Integrative Proteomics and Metabolomics, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Erik McShane
- Department of Proteome Dynamics, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Matthias Selbach
- Department of Proteome Dynamics, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Gary R Lewin
- Department of Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
| | - Carmen Birchmeier
- Department of Developmental Biology/Signal Transduction, Max Delbrück Center for Molecular Medicine, 13125 Berlin, Germany
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25
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Rodríguez-Molina JF, Lopez-Anido C, Ma KH, Zhang C, Olson T, Muth KN, Weider M, Svaren J. Dual specificity phosphatase 15 regulates Erk activation in Schwann cells. J Neurochem 2017; 140:368-382. [PMID: 27891578 PMCID: PMC5250571 DOI: 10.1111/jnc.13911] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/15/2016] [Accepted: 11/21/2016] [Indexed: 12/20/2022]
Abstract
Schwann cells and oligodendrocytes are the myelinating cells of the peripheral and central nervous system, respectively. Despite having different myelin components and different transcription factors driving their terminal differentiation there are shared molecular mechanisms between the two. Sox10 is one common transcription factor required for several steps in development of myelinating glia. However, other factors are divergent as Schwann cells need the transcription factor early growth response 2/Krox20 and oligodendrocytes require Myrf. Likewise, some signaling pathways, like the Erk1/2 kinases, are necessary in both cell types for proper myelination. Nonetheless, the molecular mechanisms that control this shared signaling pathway in myelinating cells remain only partially characterized. The hypothesis of this study is that signaling pathways that are similarly regulated in both Schwann cells and oligodendrocytes play central roles in coordinating the differentiation of myelinating glia. To address this hypothesis, we have used genome-wide binding data to identify a relatively small set of genes that are similarly regulated by Sox10 in myelinating glia. We chose one such gene encoding Dual specificity phosphatase 15 (Dusp15) for further analysis in Schwann cell signaling. RNA interference and gene deletion by genome editing in cultured RT4 and primary Schwann cells showed Dusp15 is necessary for full activation of Erk1/2 phosphorylation. In addition, we show that Dusp15 represses expression of several myelin genes, including myelin basic protein. The data shown here support a mechanism by which early growth response 2 activates myelin genes, but also induces a negative feedback loop through Dusp15 to limit over-expression of myelin genes.
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Affiliation(s)
- José F. Rodríguez-Molina
- Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Camila Lopez-Anido
- Comparative Biomedical Sciences Graduate Program, University of Wisconsin-Madison, Madison, WI 53705, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Ki H. Ma
- Cellular and Molecular Pathology Graduate Program, University of Wisconsin-Madison, Madison, WI 53705, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Chongyu Zhang
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Tyler Olson
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Katharina N. Muth
- 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
| | - John Svaren
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI 53705, USA
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26
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Poletti S, Aggio V, Bollettini I, Falini A, Colombo C, Benedetti F. SREBF-2 polymorphism influences white matter microstructure in bipolar disorder. Psychiatry Res Neuroimaging 2016; 257:39-46. [PMID: 27771555 DOI: 10.1016/j.pscychresns.2016.10.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 10/13/2016] [Accepted: 10/13/2016] [Indexed: 11/27/2022]
Abstract
The aim of the study is to investigate if gene polymorphisms in sterol regulatory element binding protein transcriptional factors SREBF-1 and SREBF-2, which regulate lipid and cholesterol metabolism, could affect white matter (WM) microstructure, the most recognized structural biomarker of bipolar disorder (BD). In a sample of 93 patients affected by BD, we investigated the effect of SREBF-1 rs11868035, and SREBF-2 rs1052717, on WM microstructure, using diffusion tensor imaging and tract-based spatial statistics. We observed increased radial diffusivity in the rs1052717 A/A genotype compared to A/G and G/G, and reduced fractional anisotropy (FA) in the rs1052717 A/A genotype compared to G carriers in cingulum, corpus callosum, superior and inferior longitudinal fasciculi, and anterior thalamic radiation. These results seem to suggest an involvement of SREBF-2 in the integrity of white matter tracts in BD and therefore a possible role of SREBP pathway in CNS myelination processes.
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Affiliation(s)
- Sara Poletti
- Scientific Institute and University Vita-Salute San Raffaele, Department of Clinical Neurosciences, Milan, Italy; C.E.R.M.A.C. (Centro di Eccellenza Risonanza Magnetica ad Alto Campo), University Vita-Salute San Raffaele, Milan, Italy.
| | - Veronica Aggio
- Scientific Institute and University Vita-Salute San Raffaele, Department of Clinical Neurosciences, Milan, Italy
| | - Irene Bollettini
- Scientific Institute and University Vita-Salute San Raffaele, Department of Clinical Neurosciences, Milan, Italy; C.E.R.M.A.C. (Centro di Eccellenza Risonanza Magnetica ad Alto Campo), University Vita-Salute San Raffaele, Milan, Italy; PhD program in Philosophy and Sciences of Mind; University Vita-Salute San Raffaele, Milan, Italy
| | - Andrea Falini
- C.E.R.M.A.C. (Centro di Eccellenza Risonanza Magnetica ad Alto Campo), University Vita-Salute San Raffaele, Milan, Italy; Scientific Institute and University Vita-Salute San Raffaele, Department of Neuroradiology, Milan, Italy
| | - Cristina Colombo
- Scientific Institute and University Vita-Salute San Raffaele, Department of Clinical Neurosciences, Milan, Italy
| | - Francesco Benedetti
- Scientific Institute and University Vita-Salute San Raffaele, Department of Clinical Neurosciences, Milan, Italy; C.E.R.M.A.C. (Centro di Eccellenza Risonanza Magnetica ad Alto Campo), University Vita-Salute San Raffaele, Milan, Italy
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27
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Monnerie H, Romer M, Jensen BK, Millar JS, Jordan-Sciutto KL, Kim SF, Grinspan JB. Reduced sterol regulatory element-binding protein (SREBP) processing through site-1 protease (S1P) inhibition alters oligodendrocyte differentiation in vitro. J Neurochem 2016; 140:53-67. [PMID: 27385127 DOI: 10.1111/jnc.13721] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 05/24/2016] [Accepted: 06/28/2016] [Indexed: 01/09/2023]
Abstract
The formation of the myelin membrane of the oligodendrocyte in the CNS is a fundamental process requiring the coordinated synthesis of many different components. The myelin membrane is particularly rich in lipids, however, the regulation of this lipid synthesis is not understood. In other cell types, including Schwann cells, the myelin-forming cells of the PNS, lipid synthesis is tightly regulated by the sterol regulatory element-binding protein (SREBP) family of transcription factors, but this has not been previously shown in oligodendrocytes. We investigated SREBPs' role during oligodendrocyte differentiation in vitro. Both SREBP-1 and SREBP-2 were expressed in oligodendrocyte precursor cells and differentiating oligodendrocytes. Using the selective site-1 protease (S1P) inhibitor PF-429242, which inhibits the cleavage of SREBP precursor forms into mature forms, we found that preventing SREBP processing inhibited process growth and reduced the expression level of myelin basic protein, a major component of myelin. Further, process extension deficits could be rescued by the addition of exogenous cholesterol. Blocking SREBP processing reduced mRNA transcription and protein levels of SREBP target genes involved in both the fatty acid and the cholesterol synthetic pathways. Furthermore, de novo levels and total levels of cholesterol synthesis were greatly diminished when SREBP processing was inhibited. Together these results indicate that SREBPs are important regulators of oligodendrocyte maturation and that perturbation of their activity may affect myelin formation and integrity. Cover Image for this issue: doi: 10.1111/jnc.13781.
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Affiliation(s)
- Hubert Monnerie
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Micah Romer
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Brigid K Jensen
- Department of Neuroscience, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - John S Millar
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kelly L Jordan-Sciutto
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sangwon F Kim
- Department of Psychiatry, Center for Neurobiology and Behavior, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Judith B Grinspan
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
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28
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Monnerie H, Romer M, Jensen BK, Millar JS, Jordan-Sciutto KL, Kim SF, Grinspan JB. Reduced sterol regulatory element-binding protein (SREBP) processing through site-1 protease (S1P) inhibition alters oligodendrocyte differentiation in vitro. J Neurochem 2016. [PMID: 27385127 DOI: 10.1111/jnc.13781] [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: 11/27/2022]
Abstract
The formation of the myelin membrane of the oligodendrocyte in the CNS is a fundamental process requiring the coordinated synthesis of many different components. The myelin membrane is particularly rich in lipids, however, the regulation of this lipid synthesis is not understood. In other cell types, including Schwann cells, the myelin-forming cells of the PNS, lipid synthesis is tightly regulated by the sterol regulatory element-binding protein (SREBP) family of transcription factors, but this has not been previously shown in oligodendrocytes. We investigated SREBPs' role during oligodendrocyte differentiation in vitro. Both SREBP-1 and SREBP-2 were expressed in oligodendrocyte precursor cells and differentiating oligodendrocytes. Using the selective site-1 protease (S1P) inhibitor PF-429242, which inhibits the cleavage of SREBP precursor forms into mature forms, we found that preventing SREBP processing inhibited process growth and reduced the expression level of myelin basic protein, a major component of myelin. Further, process extension deficits could be rescued by the addition of exogenous cholesterol. Blocking SREBP processing reduced mRNA transcription and protein levels of SREBP target genes involved in both the fatty acid and the cholesterol synthetic pathways. Furthermore, de novo levels and total levels of cholesterol synthesis were greatly diminished when SREBP processing was inhibited. Together these results indicate that SREBPs are important regulators of oligodendrocyte maturation and that perturbation of their activity may affect myelin formation and integrity. Cover Image for this issue: doi: 10.1111/jnc.13781.
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Affiliation(s)
- Hubert Monnerie
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Micah Romer
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Brigid K Jensen
- Department of Neuroscience, The Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - John S Millar
- Institute of Diabetes, Obesity and Metabolism, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kelly L Jordan-Sciutto
- Department of Pathology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sangwon F Kim
- Department of Psychiatry, Center for Neurobiology and Behavior, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Judith B Grinspan
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
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29
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Niimi N, Yako H, Tsukamoto M, Takaku S, Yamauchi J, Kawakami E, Yanagisawa H, Watabe K, Utsunomiya K, Sango K. Involvement of oxidative stress and impaired lysosomal degradation in amiodarone-induced schwannopathy. Eur J Neurosci 2016; 44:1723-33. [PMID: 27152884 DOI: 10.1111/ejn.13268] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2015] [Revised: 04/28/2016] [Accepted: 04/28/2016] [Indexed: 12/14/2022]
Abstract
Amiodarone hydrochloride (AMD), an anti-arrhythmic agent, has been shown to cause peripheral neuropathy; however, its pathogenesis remains unknown. We examined the toxic effects of AMD on an immortalized adult rat Schwann cell line, IFRS1, and cocultures of IFRS1 cells and adult rat dorsal root ganglion neurons or nerve growth factor-primed PC12 cells. Treatment with AMD (1, 5, and 10 μm) induced time- and dose-dependent cell death, accumulation of phospholipids and neutral lipids, upregulation of the expression of gangliosides, and oxidative stress (increased nuclear factor E2-related factor in nuclear extracts and reduced GSH/GSSG ratios) in IFRS1 cells. It also induced the upregulation of LC3-II and p62 expression, with phosphorylation of p62, suggesting that deficient autolysosomal degradation is involved in AMD-induced IFRS1 cell death. Furthermore, treatment of the cocultures with AMD induced detachment of IFRS1 cells from neurite networks in a time- and dose-dependent manner. These findings suggest that AMD-induced lysosomal storage accompanied by enhanced oxidative stress and impaired lysosomal degradation in Schwann cells might be a cause of demyelination in the peripheral nervous system.
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Affiliation(s)
- Naoko Niimi
- Diabetic Neuropathy Project (Former ALS/Neuropathy Project), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Hideji Yako
- Diabetic Neuropathy Project (Former ALS/Neuropathy Project), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Masami Tsukamoto
- Diabetic Neuropathy Project (Former ALS/Neuropathy Project), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, 156-8506, Japan.,Division of Diabetes, Metabolism & Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Shizuka Takaku
- Diabetic Neuropathy Project (Former ALS/Neuropathy Project), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Junji Yamauchi
- Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo, Japan
| | - Emiko Kawakami
- Diabetic Neuropathy Project (Former ALS/Neuropathy Project), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Hiroko Yanagisawa
- Diabetic Neuropathy Project (Former ALS/Neuropathy Project), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Kazuhiko Watabe
- Diabetic Neuropathy Project (Former ALS/Neuropathy Project), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, 156-8506, Japan
| | - Kazunori Utsunomiya
- Division of Diabetes, Metabolism & Endocrinology, Department of Internal Medicine, Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Kazunori Sango
- Diabetic Neuropathy Project (Former ALS/Neuropathy Project), Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya-ku, Tokyo, 156-8506, Japan
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30
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YAP and TAZ control peripheral myelination and the expression of laminin receptors in Schwann cells. Nat Neurosci 2016; 19:879-87. [PMID: 27273766 PMCID: PMC4925303 DOI: 10.1038/nn.4316] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 05/04/2016] [Indexed: 12/13/2022]
Abstract
Myelination is essential for nervous system function. Schwann cells interact with neurons and the basal lamina to myelinate axons, using known receptors, signals and transcription factors. In contrast, the transcriptional control of axonal sorting and the role of mechanotransduction in myelination are largely unknown. Yap and Taz are effectors of the Hippo pathway that integrate chemical and mechanical signals in cells. We describe a previously unknown role for the Hippo pathway in myelination. Using conditional mutagenesis in mice we show that Taz is required in Schwann cells for radial sorting and myelination, and that Yap is redundant with Taz. Yap/Taz are activated in Schwann cells by mechanical stimuli, and regulate Schwann cell proliferation and transcription of basal lamina receptor genes, both necessary for proper radial sorting of axons and subsequent myelination. These data link transcriptional effectors of the Hippo pathway and of mechanotransduction to myelin formation in Schwann cells.
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31
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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.
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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.
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32
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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.
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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
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mTORC1 is essential for early steps during Schwann cell differentiation of amniotic fluid stem cells and regulates lipogenic gene expression. PLoS One 2014; 9:e107004. [PMID: 25221943 PMCID: PMC4164523 DOI: 10.1371/journal.pone.0107004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 08/04/2014] [Indexed: 01/18/2023] Open
Abstract
Schwann cell development is hallmarked by the induction of a lipogenic profile. Here we used amniotic fluid stem (AFS) cells and focused on the mechanisms occurring during early steps of differentiation along the Schwann cell lineage. Therefore, we initiated Schwann cell differentiation in AFS cells and monitored as well as modulated the activity of the mechanistic target of rapamycin (mTOR) pathway, the major regulator of anabolic processes. Our results show that mTOR complex 1 (mTORC1) activity is essential for glial marker expression and expression of Sterol Regulatory Element-Binding Protein (SREBP) target genes. Moreover, SREBP target gene activation by statin treatment promoted lipogenic gene expression, induced mTORC1 activation and stimulated Schwann cell differentiation. To investigate mTORC1 downstream signaling we expressed a mutant S6K1, which subsequently induced the expression of the Schwann cell marker S100b, but did not affect lipogenic gene expression. This suggests that S6K1 dependent and independent pathways downstream of mTORC1 drive AFS cells to early Schwann cell differentiation and lipogenic gene expression. In conclusion our results propose that future strategies for peripheral nervous system regeneration will depend on ways to efficiently induce the mTORC1 pathway.
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Uggenti C, De Stefano ME, Costantino M, Loreti S, Pisano A, Avallone B, Talora C, Magnaghi V, Tata AM. M2 muscarinic receptor activation regulates Schwann cell differentiation and myelin organization. Dev Neurobiol 2014; 74:676-91. [PMID: 24403178 DOI: 10.1002/dneu.22161] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 12/14/2013] [Accepted: 12/15/2013] [Indexed: 01/01/2023]
Abstract
Glial cells express acetylcholine receptors. In particular, rat Schwann cells express different muscarinic receptor subtypes, the most abundant of which is the M2 subtype. M2 receptor activation causes a reversible arrest of the cell cycle. This negative effect on Schwann cell proliferation suggests that these cells may possibly progress into a differentiating program. In this study we analyzed the in vitro modulation, by the M2 agonist arecaidine, of transcription factors and specific signaling pathways involved in Schwann cell differentiation. The arecaidine-induced M2 receptor activation significantly upregulates transcription factors involved in the promyelinating phase (e.g., Sox10 and Krox20) and downregulates proteins involved in the maintenance of the undifferentiated state (e.g., c-jun, Notch-1, and Jagged-1). Furthermore, arecaidine stimulation significantly increases the expression of myelin proteins, which is accompanied by evident changes in cell morphology, as indicated by electron microscopy analysis, and by substantial cellular re-distribution of actin and cell adhesion molecules. Moreover, ultrastructural and morphometric analyses on sciatic nerves of M2/M4 knockout mice show numerous degenerating axons and clear alterations in myelin organization compared with wild-type mice. Therefore, our data demonstrate that acetylcholine mediates axon-glia cross talk, favoring Schwann cell progression into a differentiated myelinating phenotype and contributing to compact myelin organization.
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Affiliation(s)
- Carolina Uggenti
- Dipartmento di Biologia e Biotecnologie "Charles Darwin,", "Sapienza" Università di Roma, Roma, Italy; Centro di ricerca in Neurobiologia "Daniel Bovet,", "Sapienza" Università di Roma, Roma, Italy
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Cordero P, Campion J, Milagro FI, Martinez JA. Transcriptomic and epigenetic changes in early liver steatosis associated to obesity: effect of dietary methyl donor supplementation. Mol Genet Metab 2013; 110:388-95. [PMID: 24084163 DOI: 10.1016/j.ymgme.2013.08.022] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 08/16/2013] [Accepted: 08/16/2013] [Indexed: 02/06/2023]
Abstract
Non-alcoholic fatty liver disease is a primary hepatic manifestation of obesity and an important adverse metabolic syndrome trait. Animal models of diet-induced obesity promote liver fat accumulation putatively associated with alterations in epigenetic profile. Dietary methyl donor-supplementation may protect against this disturbance during early developmental stages affecting the molecular basis of gene regulation. The aim of this study was to investigate the transcriptomic and epigenetic mechanisms implicated in liver fat accumulation as a result of an obesogenic diet and the putative preventive role of dietary methyl donors. Forty-eight male Wistar rats were assigned into four dietary groups for 8 weeks; control, control methyl-donor-supplemented with a dietary cocktail containing betaine, choline, vitamin B12 and folic acid, high-fat-sucrose and high-fat-sucrose methyl-donor-supplemented. Liver fat accumulation induced by a HFS diet was prevented by methyl donor supplementation in HFS-fed animals. A liver mRNA microarray, subsequently validated by real time-qPCR, showed modifications in some biologically relevant genes involved in obesity development and lipid metabolism (Lepr, Srebf2, Agpat3 and Esr1). Liver global DNA methylation was decreased by methyl donor supplementation in control-fed animals. Methylation levels of specific CpG sites from Srebf2, Agpat3 and Esr1 promoter regions showed changes due to the obesogenic diet and the supplementation with methyl donors. Interestingly, Srebf2 CpG23_24 methylation levels (-167 bp and -156 bp with respect to the transcriptional start site) correlated with HDLc plasma levels, whereas Esr1 CpG14 (-2623 bp) methylation levels were associated with body and liver weights and fat content. Furthermore HFS diet-induced liver fat accumulation was prevented by methyl donor supplementation. In conclusion, both obesogenic diet and methyl donor supplementation modified the mRNA hepatic profile as well as the methylation of specific gene promoters and total DNA.
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Affiliation(s)
- Paul Cordero
- Department of Nutrition, Food Sciences and Physiology, University of Navarra, Irunlarrea 1, 31008 Pamplona, Navarra, Spain.
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Wu SC, Rau CS, Lu TH, Wu CJ, Wu YC, Tzeng SL, Chen YC, Hsieh CH. Knockout of TLR4 and TLR2 impair the nerve regeneration by delayed demyelination but not remyelination. J Biomed Sci 2013; 20:62. [PMID: 23984978 PMCID: PMC3765918 DOI: 10.1186/1423-0127-20-62] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 08/27/2013] [Indexed: 01/09/2023] Open
Abstract
Background Knockout of either toll-like receptor 4 (TLR4) or 2 (TLR2) had been reported to delay the Wallerian degeneration after peripheral nerve injury by deterring the recruitment of the macrophages and clearance of myelin debris. However, the impact on the remyelination process is poorly understood. In this study, the effect of TLR2 and TLR4 knockout on the nerve regeneration and on the remyelination process was studied in a mouse model of sciatic nerve crush injury. Results A standard sciatic nerve crush injury by a No. 5 Jeweler forcep for consistent 30 seconds was performed in Tlr4−/− (B6.B10ScN-Tlr4lps-del/JthJ), Tlr2−/− (B6.129-Tlr2tm1Kir/J) and C57BL/6 mice. One centimeter of nerve segment distal to the crushed site was harvested for western blot analysis of the myelin structure protein myelin protein zero (Mpz) and the remyelination transcription factors Oct6 and Sox10 at day 0, 3, 7, 10, 14, 17, 21, 28. Nerve segment 5-mm distal to injured site from additional groups of mice at day 10 after crush injury were subjected to semi-thin section and toluidine blue stain for a quantitative histomorphometric analysis. With less remyelinated nerves and more nerve debris, the histomorphometric analysis revealed a worse nerve regeneration following the sciatic nerve crush injury in both Tlr4−/− and Tlr2−/− mice than the C57BL/6 mice. Although there was a delayed expression of Sox10 but not Oct6 during remyelination, with an average 4-day delay in the demyelination process, the subsequent complete formation of Mpz during remyelination was also delayed for 4 days, implying that the impaired nerve regeneration was mainly attributed to the delayed demyelination process. Conclusions Both TLR4 and TLR2 are crucial for nerve regeneration after nerve crush injury mainly by delaying the demyelination but not the remyelination process.
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Affiliation(s)
- Shao-Chun Wu
- Department of Plastic and Reconstructive Surgery, Kaohsiung Chang Gung Memorial Hospital and Chang Gung University College of Medicine, No, 123, Ta-Pei Road, Niao-Sung District, Kaohsiung City, 833, Taiwan.
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D'Antonio M, Musner N, Scapin C, Ungaro D, Del Carro U, Ron D, Feltri ML, Wrabetz L. Resetting translational homeostasis restores myelination in Charcot-Marie-Tooth disease type 1B mice. ACTA ACUST UNITED AC 2013; 210:821-38. [PMID: 23547100 PMCID: PMC3620355 DOI: 10.1084/jem.20122005] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Reduction of the CHOP target Gadd34 restores motor function in P0S63del mice with demyelinating neuropathy. P0 glycoprotein is an abundant product of terminal differentiation in myelinating Schwann cells. The mutant P0S63del causes Charcot-Marie-Tooth 1B neuropathy in humans, and a very similar demyelinating neuropathy in transgenic mice. P0S63del is retained in the endoplasmic reticulum of Schwann cells, where it promotes unfolded protein stress and elicits an unfolded protein response (UPR) associated with translational attenuation. Ablation of Chop, a UPR mediator, from S63del mice completely rescues their motor deficit and reduces active demyelination by half. Here, we show that Gadd34 is a detrimental effector of CHOP that reactivates translation too aggressively in myelinating Schwann cells. Genetic or pharmacological limitation of Gadd34 function moderates translational reactivation, improves myelination in S63del nerves, and reduces accumulation of P0S63del in the ER. Resetting translational homeostasis may provide a therapeutic strategy in tissues impaired by misfolded proteins that are synthesized during terminal differentiation.
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Affiliation(s)
- Maurizio D'Antonio
- Division of Genetics and Cell Biology and 2 Division of Neuroscience, San Raffaele Scientific Institute, DIBIT, 20132 Milan, Italy
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Li J, Parker B, Martyn C, Natarajan C, Guo J. The PMP22 gene and its related diseases. Mol Neurobiol 2012; 47:673-98. [PMID: 23224996 DOI: 10.1007/s12035-012-8370-x] [Citation(s) in RCA: 167] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 10/22/2012] [Indexed: 10/27/2022]
Abstract
Peripheral myelin protein-22 (PMP22) is primarily expressed in the compact myelin of the peripheral nervous system. Levels of PMP22 have to be tightly regulated since alterations of PMP22 levels by mutations of the PMP22 gene are responsible for >50 % of all patients with inherited peripheral neuropathies, including Charcot-Marie-Tooth type-1A (CMT1A) with trisomy of PMP22, hereditary neuropathy with liability to pressure palsies (HNPP) with heterozygous deletion of PMP22, and CMT1E with point mutations of PMP22. While overexpression and point-mutations of the PMP22 gene may produce gain-of-function phenotypes, deletion of PMP22 results in a loss-of-function phenotype that reveals the normal physiological functions of the PMP22 protein. In this article, we will review the basic genetics, biochemistry and molecular structure of PMP22, followed by discussion of the current understanding of pathogenic mechanisms involving in the inherited neuropathies with mutations in PMP22 gene.
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Affiliation(s)
- Jun Li
- VA Tennessee Valley Healthcare System, 1310 24th Avenue South, Nashville, TN 37212, USA.
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Promoter analysis of the DHCR24 (3β-hydroxysterol Δ(24)-reductase) gene: characterization of SREBP (sterol-regulatory-element-binding protein)-mediated activation. Biosci Rep 2012; 33:57-69. [PMID: 23050906 PMCID: PMC3522477 DOI: 10.1042/bsr20120095] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
DHCR24 (3β-hydroxysterol Δ24-reductase) catalyses the reduction of the C-24 double bond of sterol intermediates during cholesterol biosynthesis. DHCR24 has also been involved in cell growth, senescence and cellular response to oncogenic and oxidative stress. Despite its important roles, little is known about the transcriptional mechanisms controlling DHCR24 gene expression. We analysed the proximal promoter region and the cholesterol-mediated regulation of DHCR24. A putative SRE (sterol-regulatory element) at −98/−90 bp of the transcription start site was identified. Other putative regulatory elements commonly found in SREBP (SRE-binding protein)-targeted genes were also identified. Sterol responsiveness was analysed by luciferase reporter assays of approximately 1 kb 5′-flanking region of the human DHCR24 gene in HepG2 and SK-N-MC cells. EMSAs (electrophoretic mobility-shift assays) and ChIP (chromatin immunoprecipitation) assays demonstrated cholesterol-dependent recruitment and binding of SREBPs to the putative SRE. Given the presence of several CACCC-boxes in the DHCR24 proximal promoter, we assessed the role of KLF5 (Krüppel-like factor 5) in androgen-regulated DHCR24 expression. DHT (dihydrotestosterone) increased DHCR24 expression synergistically with lovastatin. However, DHT was unable to activate the DHCR24 proximal promoter, whereas KLF5 did, indicating that this mechanism is not involved in the androgen-induced stimulation of DHCR24 expression. The results of the present study allow the elucidation of the mechanism of regulation of the DHCR24 gene by cholesterol availability and identification of other putative cis-acting elements which may be relevant for the regulation of DHCR24 expression.
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Houlden H, Reilly MM. Molecular genetics of autosomal-dominant demyelinating Charcot-Marie-Tooth disease. Neuromolecular Med 2012; 8:43-62. [PMID: 16775366 DOI: 10.1385/nmm:8:1-2:43] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2005] [Revised: 12/15/2005] [Accepted: 01/11/2006] [Indexed: 12/20/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) is a clinically and genetically heterogeneous group of disorders and is the most common inherited neuromuscular disorder, with an estimated overall prevalence of 17-40/10,000. Although there has been major advances in the understanding of the genetic basis of CMT in recent years, the most useful classification is still a neurophysiological classification that divides CMT into type 1 (demyelinating; median motor conduction velocity < 38 m/s) and type 2 (axonal; median motor conduction velocity > 38 m/s). An intermediate type is also increasingly being described. Inheritance can be autosomal-dominant (AD), X-linked, or autosomal-recessive (AR). AD CMT1 is the most common type of CMT and was the first form of CMT in which a causative gene was described. This review provides an up-to-date overview of AD CMT1 concentrating on the molecular genetics as the clinical, neurophysiological, and pathological features have been covered elsewhere. Four genes (PMP22, MPZ, LITAF, and EGR2) have been described in the last 15 yr associated with AD CMTI and a further gene (NEFL), originally described as causing AD CMT2 can also cause AD CMT1 (by neurophysiological criteria). Studies have shown many of these genes, when mutated, can cause a wide range of CMT phenotypes from the relatively mild CMT1 to the more severe Dejerine-Sottas disease and congenital hypomyelinating neuropathy, and even in some cases axonal CMT2. This review discusses what is known about these genes and in particular how they cause a peripheral neuropathy, when mutated.
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Affiliation(s)
- Henry Houlden
- Centre for Neuromuscular Disease and Department of Molecular Neurosciences, National Hospital for Neurology and Neurosurgery and Institute of Neurology, Queen Square, London, WC1N 3BG, UK
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Srinivasan R, Sun G, Keles S, Jones EA, Jang SW, Krueger C, Moran JJ, Svaren J. Genome-wide analysis of EGR2/SOX10 binding in myelinating peripheral nerve. Nucleic Acids Res 2012; 40:6449-60. [PMID: 22492709 PMCID: PMC3413122 DOI: 10.1093/nar/gks313] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Revised: 03/25/2012] [Accepted: 03/26/2012] [Indexed: 11/17/2022] Open
Abstract
Myelin is essential for the rapidity of saltatory nerve conduction, and also provides trophic support for axons to prevent axonal degeneration. Two critical determinants of myelination are SOX10 and EGR2/KROX20. SOX10 is required for specification of Schwann cells from neural crest, and is required at every stage of Schwann cell development. Egr2/Krox20 expression is activated by axonal signals in myelinating Schwann cells, and is required for cell cycle arrest and myelin formation. To elucidate the integrated function of these two transcription factors during peripheral nerve myelination, we performed in vivo ChIP-Seq analysis of myelinating peripheral nerve. Integration of these binding data with loss-of-function array data identified a range of genes regulated by these factors. In addition, although SOX10 itself regulates Egr2/Krox20 expression, leading to coordinate activation of several major myelin genes by the two factors, there is a large subset of genes that are activated independent of EGR2. Finally, the results identify a set of SOX10-dependent genes that are expressed in early Schwann cell development, but become subsequently repressed by EGR2/KROX20.
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Affiliation(s)
- Rajini Srinivasan
- Waisman Center, Department of Statistics, Department of Biostatistics and Medical Informatics, Program in Cellular and Molecular Biology and, Department of Comparative Biosciences, University of Wisconsin, Madison, WI, USA
| | - Guannan Sun
- Waisman Center, Department of Statistics, Department of Biostatistics and Medical Informatics, Program in Cellular and Molecular Biology and, Department of Comparative Biosciences, University of Wisconsin, Madison, WI, USA
| | - Sunduz Keles
- Waisman Center, Department of Statistics, Department of Biostatistics and Medical Informatics, Program in Cellular and Molecular Biology and, Department of Comparative Biosciences, University of Wisconsin, Madison, WI, USA
| | - Erin A. Jones
- Waisman Center, Department of Statistics, Department of Biostatistics and Medical Informatics, Program in Cellular and Molecular Biology and, Department of Comparative Biosciences, University of Wisconsin, Madison, WI, USA
| | - Sung-Wook Jang
- Waisman Center, Department of Statistics, Department of Biostatistics and Medical Informatics, Program in Cellular and Molecular Biology and, Department of Comparative Biosciences, University of Wisconsin, Madison, WI, USA
| | - Courtney Krueger
- Waisman Center, Department of Statistics, Department of Biostatistics and Medical Informatics, Program in Cellular and Molecular Biology and, Department of Comparative Biosciences, University of Wisconsin, Madison, WI, USA
| | - John J. Moran
- Waisman Center, Department of Statistics, Department of Biostatistics and Medical Informatics, Program in Cellular and Molecular Biology and, Department of Comparative Biosciences, University of Wisconsin, Madison, WI, USA
| | - John Svaren
- Waisman Center, Department of Statistics, Department of Biostatistics and Medical Informatics, Program in Cellular and Molecular Biology and, Department of Comparative Biosciences, University of Wisconsin, Madison, WI, USA
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Lengi AJ, Corl BA. Regulation of the bovine SCD5 promoter by EGR2 and SREBP1. Biochem Biophys Res Commun 2012; 421:375-9. [DOI: 10.1016/j.bbrc.2012.04.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Accepted: 04/03/2012] [Indexed: 10/28/2022]
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Abstract
In developing peripheral nerves, differentiating Schwann cells sort individual axons from bundles and ensheath them to generate multiple layers of myelin. In recent years, there has been an increased understanding of the extracellular and intracellular factors that initiate and stimulate Schwann cell myelination, together with a growing appreciation of some of the signaling pathways involved. However, our knowledge of how Schwann cell growth is regulated during myelination is still incomplete. The mammalian target of rapamycin (mTOR) is a core kinase in two major complexes, mTORC1 and mTORC2, that regulate cell growth and differentiation in a variety of mammalian cells. Here we show that elimination of mTOR from murine Schwann cells prevented neither radial sorting nor the initiation of myelination. However, normal postnatal growth of myelinating Schwann cells, both radially and longitudinally, was highly retarded. The myelin sheath in the mutant was much thinner than normal; nevertheless, sheath thickness relative to axon diameter (g-ratio) remained constant in both wild-type and mutant nerves from P14 to P90. Although axon diameters were normal in the mutant at the initiation of myelination, further growth as myelination proceeded was retarded, and this was associated with reduced phosphorylation of neurofilaments. Consistent with thinner axonal diameters and internodal lengths, conduction velocities in mutant quadriceps nerves were also reduced. These data establish a critical role for mTOR signaling in both the longitudinal and radial growth of the myelinating Schwann cell.
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Kim SH, Song JY, Joo EJ, Lee KY, Shin SY, Lee YH, Ahn YM, Kim YS. Genetic association of the EGR2 gene with bipolar disorder in Korea. Exp Mol Med 2012; 44:121-9. [PMID: 22089088 PMCID: PMC3296808 DOI: 10.3858/emm.2012.44.2.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/10/2011] [Indexed: 12/23/2022] Open
Abstract
The early growth response gene 2 (EGR2) is located at chromosome 10q21, one of the susceptibility loci in bipolar disorder (BD). EGR2 is involved in cognitive function, myelination, and signal transduction related to neuregulin-ErbB receptor, Bcl-2 family proteins, and brain-derived neurotrophic factor. This study investigated the genetic association of the EGR2 gene with BD and schizophrenia (SPR) in Korea. In 946 subjects (350 healthy controls, 352 patients with BD, and 244 with SPR), nine single nucleotide polymorphisms (SNPs) in the EGR2 gene region were genotyped. Five SNPs showed nominally significant allelic associations with BD (rs2295814, rs61865882, rs10995315, rs2297488, and rs2297489), and the positive associations of all except rs2297488 remained significant after multiple testing correction. Linkage disequilibrium structure analysis revealed two haplotype blocks. Among the common identified haplotypes (frequency > 5%), 'T-G-A-C-T (block 1)' and 'A-A-G-C (block 2)' haplotypes were over-represented, while 'C-G-G-T-T (block 1)' haplotype was under-represented in BD. In contrast, no significant associations were found with SPR. Although an extended analysis with a larger sample size or independent replication is required, these findings suggest a genetic association of EGR2 with BD. Combined with a plausible biological function of EGR2, the EGR2 gene is a possible susceptibility gene in BD.
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Affiliation(s)
- Se Hyun Kim
- Department of Neuropsychiatry, Seoul National University Hospital, Korea
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45
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Morton PD, Johnstone JT, Ramos AY, Liebl DJ, Bunge MB, Bethea JR. Nuclear factor-κB activation in Schwann cells regulates regeneration and remyelination. Glia 2012; 60:639-50. [PMID: 22275133 DOI: 10.1002/glia.22297] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 01/06/2012] [Indexed: 11/11/2022]
Abstract
Schwann cells (SCs) are crucial for peripheral nerve development and regeneration; however, the intrinsic regulatory mechanisms governing postinjury responses are poorly understood. Activation and deacetylation of nuclear factor-κB (NF- κB) in SCs have been implicated as prerequisites for peripheral nerve myelination. Using GFAP-IκBα-dn mice in which NF- κB transcriptional activation is inhibited in SCs, we found no discernable differences in the quantity or structure of myelinated axons in adult facial nerves. Following crush injury, axonal regeneration was impaired at 31 days and significantly enhanced at 65 days in transgenic animals. Compact remyelination and Remak bundle organization were significantly compromised at 31 days and restored by 65 days post injury. Together, these data indicate that inhibition of NF-κB activation in SCs transiently delays axonal regeneration and compact remyelination. Manipulating the temporal activation of nuclear factor-κB in Schwann cells may offer new therapeutic avenues for PNS and CNS regeneration.
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Affiliation(s)
- Paul D Morton
- The Miami Project To Cure Paralysis, Miller School of Medicine, University of Miami, Miami, Florida 33136, USA
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Gokey NG, Srinivasan R, Lopez-Anido C, Krueger C, Svaren J. Developmental regulation of microRNA expression in Schwann cells. Mol Cell Biol 2012; 32:558-68. [PMID: 22064487 PMCID: PMC3255778 DOI: 10.1128/mcb.06270-11] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2011] [Accepted: 10/30/2011] [Indexed: 01/07/2023] Open
Abstract
Schwann cell differentiation and subsequent myelination of the peripheral nervous system require the action of several transcription factors, including Sox10, which is vital at multiple stages of development. The transition from immature to myelinating Schwann cell is also regulated posttranscriptionally and depends upon Dicer-mediated processing of microRNAs (miRNAs). Although specific miRNA targets have begun to be identified, the mechanisms establishing the dynamic regulation of miRNA expression have not been elucidated. We performed expression profiling studies and identified 225 miRNAs differentially expressed during peripheral myelination. A subset of 9 miRNAs is positively regulated by Sox10, including miR-338 which has been implicated in oligodendrocyte maturation. In vivo chromatin immunoprecipitation (ChIP) of sciatic nerve cells revealed a Sox10 binding site upstream of an alternate promoter within the Aatk gene, which hosts miR-338. Sox10 occupied this site in spinal cord ChIP experiments, suggesting a similar regulatory mechanism in oligodendrocytes. Cancer profiling studies have identified clusters of miRNAs that regulate proliferation, termed "oncomirs." In Schwann cells, the expression of many of these proproliferative miRNAs was reduced in the absence of Sox10. Finally, Schwann cells with reduced Sox10 and oncomir expression have an increase in the CDK inhibitor p21 and a concomitant reduction in cell proliferation.
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Affiliation(s)
| | | | | | | | - John Svaren
- Waisman Center
- Department of Comparative Biosciences, University of Wisconsin—Madison, Madison, Wisconsin, USA
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Valenza M, Cattaneo E. Emerging roles for cholesterol in Huntington's disease. Trends Neurosci 2011; 34:474-86. [DOI: 10.1016/j.tins.2011.06.005] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Revised: 06/04/2011] [Accepted: 06/08/2011] [Indexed: 01/01/2023]
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Gokey NG, Lopez-Anido C, Gillian-Daniel AL, Svaren J. Early growth response 1 (Egr1) regulates cholesterol biosynthetic gene expression. J Biol Chem 2011; 286:29501-10. [PMID: 21712389 DOI: 10.1074/jbc.m111.263509] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The early growth response (EGR) family of transcription factors has been implicated in control of lipid biosynthetic genes. Egr1 is induced by insulin both in vitro and in vivo and is the most highly expressed family member in liver. In this study, we investigated whether Egr1 regulates cholesterol biosynthetic genes in liver. Using an insulin-sensitive liver cell line, we show that localization of Egr1 to cholesterol biosynthetic genes is induced by insulin treatment and that this localization precedes the induction of the genes. Reduction in Egr1 expression using targeted siRNA blunted the insulin-dependent induction of cholesterol genes. A similar reduction in squalene epoxidase expression was also observed in Egr1 null mice. In addition, application of chromatin immunoprecipitation (ChIP) samples to tiled gene microarrays revealed localization of Egr1 in promoter regions of many cholesterol gene loci. In vivo ChIP assays using liver tissue show that Egr1 localization to several cholesterol biosynthetic gene promoters is induced by feeding. Finally, analysis of plasma cholesterol in Egr1(-/-) mice indicated a significant decrease in serum cholesterol when compared with wild-type mice. Together these data point to Egr1 as a modulator of the cholesterol biosynthetic gene family in liver.
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Affiliation(s)
- Nolan G Gokey
- Comparative Biomedical Sciences Graduate Program, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin 53705, USA
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Jang SW, Srinivasan R, Jones EA, Sun G, Keles S, Krueger C, Chang LW, Nagarajan R, Svaren J. Locus-wide identification of Egr2/Krox20 regulatory targets in myelin genes. J Neurochem 2010; 115:1409-20. [PMID: 21044070 PMCID: PMC3260055 DOI: 10.1111/j.1471-4159.2010.07045.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Myelination of peripheral nerves by Schwann cells depends upon a gene regulatory network controlled by early growth response Egr2/Krox20, which is specifically required for Schwann cells to initiate and maintain myelination. To elucidate the mechanism by which Egr2 regulates gene expression during myelination, we have performed chromatin immunoprecipitation analysis on myelinating rat sciatic nerve in vivo. The resulting samples were applied to a tiled microarray consisting of a broad spectrum of genes that are activated or repressed in Egr2-deficient mice. The results show extensive binding within myelin-associated genes, as well as some genes that become repressed in myelinating Schwann cells. Many of the Egr2 peaks coincide with regions of open chromatin, which is a marker of enhancer regions. In addition, further analysis showed that there is substantial colocalization of Egr2 binding with Sox10, a transcription factor required for Schwann cell specification and other stages of Schwann cell development. Finally, we have found that Egr2 binds to promoters of several lipid biosynthetic genes, which is consistent with their dramatic up-regulation during the formation of lipid-rich myelin. Overall, this analysis provides a locus-wide profile of Egr2 binding patterns in major myelin-associated genes using myelinating peripheral nerve.
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Affiliation(s)
- Sung-Wook Jang
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Erin A. Jones
- Program in Cellular and Molecular Biology, University of Wisconsin-Madison, Madison, WI, USA
| | - Guannan Sun
- Department of Statistics, Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, USA
| | - Sunduz Keles
- Department of Statistics, Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI, USA
| | - Courtney Krueger
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Li-Wei Chang
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, USA
| | - Rakesh Nagarajan
- Department of Pathology and Immunology, Washington University School of Medicine, Saint Louis, MO, USA
| | - John Svaren
- Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
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Le Hellard S, Mühleisen TW, Djurovic S, Fernø J, Ouriaghi Z, Mattheisen M, Vasilescu C, Raeder MB, Hansen T, Strohmaier J, Georgi A, Brockschmidt FF, Melle I, Nenadic I, Sauer H, Rietschel M, Nöthen MM, Werge T, Andreassen OA, Cichon S, Steen VM. Polymorphisms in SREBF1 and SREBF2, two antipsychotic-activated transcription factors controlling cellular lipogenesis, are associated with schizophrenia in German and Scandinavian samples. Mol Psychiatry 2010; 15:463-72. [PMID: 18936756 DOI: 10.1038/mp.2008.110] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Several studies have reported structural brain abnormalities, decreased myelination and oligodendrocyte dysfunction in schizophrenia. In the central nervous system, glia-derived de novo synthesized cholesterol is essential for both myelination and synaptogenesis. Previously, we demonstrated in glial cell lines that antipsychotic drugs induce the expression of genes involved in cholesterol and fatty acids biosynthesis through activation of the sterol regulatory element binding protein (SREBP) transcription factors, encoded by the sterol regulatory element binding transcription factor 1 (SREBF1) and sterol regulatory element binding transcription factor 2 (SREBF2) genes. Considering the importance of these factors in the lipid biosynthesis and their possible involvement in antipsychotic drug effects, we hypothesized that genetic variants of SREBF1 and/or SREBF2 could affect schizophrenia susceptibility. We therefore conducted a HapMap-based association study in a large German sample, and identified association between schizophrenia and five markers in SREBF1 and five markers in SREBF2. Follow-up studies in two independent samples of Danish and Norwegian origin (part of the Scandinavian collaboration of psychiatric etiology study, SCOPE) replicated the association for the five SREBF1 markers and for two markers in SREBF2. A combined analysis of all samples resulted in highly significant genotypic P-values of 9 x 10(-4) for SREBF1 (rs11868035, odd ration (OR)=1.26, 95% confidence interval (CI) (1.09-1.45)) and 4 x 10(-5) for SREBF2 (rs1057217, OR=1.39, 95% CI (1.19-1.63)). This finding strengthens the hypothesis that SREBP-controlled cholesterol biosynthesis is involved in the etiology of schizophrenia.
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Affiliation(s)
- S Le Hellard
- Department of Clinical Medicine, Bergen Mental Health Research Center, University of Bergen, Bergen, Norway.
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