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Taruta A, Hiyoshi T, Harada A, Nakashima M. Electrical impedance myography detects progressive pathological alterations in the hindlimb muscle of the PMP22-C3 mice, an animal model of CMT1A. Exp Neurol 2025; 385:115111. [PMID: 39667653 DOI: 10.1016/j.expneurol.2024.115111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2024] [Revised: 11/26/2024] [Accepted: 12/08/2024] [Indexed: 12/14/2024]
Abstract
Charcot-Marie-Tooth type 1A (CMT1A) is the most common inherited peripheral dysmyelinating neuropathy. Although lower limb muscle weakness is the most important factor affecting the quality of life of patients with CMT1A, existing clinical measures for its evaluation have limitations, including low sensitivity in detecting disease progression. Electrical impedance myography (EIM) is a newer tool that enables noninvasive evaluation of muscle state by measuring muscle composition, and potentially supports the evaluation of neuromuscular disease progression and treatment effects. To determine the potential of EIM as a CMT1A biomarker, we obtained natural history data for EIM from the gastrocnemius muscle of the PMP22-C3 mice, an animal model of CMT1A. Alterations in the EIM parameters, weak hindlimb grip strength, decreased muscle fiber size, and changes in the mRNA expression of genes related to neuromuscular junction dysfunction were found. These changes were more pronounced at later stages (12 and 18 weeks of age) than at earlier stage (6 weeks of age), indicating that EIM can detect disease progression in PMP22-C3 mice. Our preclinical findings support the use of EIM as a potential translational biomarker for assessing progressive changes in the pathological muscle state in CMT1A.
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Affiliation(s)
- Atsuki Taruta
- Neuroscience Translational Medicine, Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Tetsuaki Hiyoshi
- Neuroscience Translational Medicine, Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Akina Harada
- Muscular Disease and Neuropathy Unit, Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan
| | - Masato Nakashima
- Neuroscience Translational Medicine, Neuroscience Drug Discovery Unit, Research, Takeda Pharmaceutical Company Limited, 26-1, Muraoka-Higashi 2-chome, Fujisawa, Kanagawa 251-8555, Japan.
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2
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Schepers M, Vangansewinkel T, Libberecht K, Jeurissen H, Jacobs D, Piccart E, Prior R, Ricciarelli R, Brullo C, Fedele E, Bruno O, Prickaerts J, Lambrichts I, Van Den Bosch L, Vanmierlo T, Wolfs E. Phosphodiesterase 4D inhibition improves the functional and molecular outcome in a mouse and human model of Charcot Marie Tooth disease 1 A. Biomed Pharmacother 2025; 183:117828. [PMID: 39823724 DOI: 10.1016/j.biopha.2025.117828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2024] [Revised: 01/03/2025] [Accepted: 01/09/2025] [Indexed: 01/20/2025] Open
Abstract
Charcot-Marie-Tooth disease type 1A (CMT1A) is an inherited peripheral neuropathy caused by a duplication of the peripheral myelin protein 22 (PMP22) gene. It is primarily marked by Schwann cell dedifferentiation and demyelination, leading to motor and sensory deficits. Cyclic adenosine monophosphate (cAMP) is crucial for Schwann cell differentiation and maturation. Therefore, increasing cAMP by inhibiting its degraders, phosphodiesterases (PDE), is a potential therapeutic strategy for CMT1A. This study investigated the therapeutic potential of the specific PDE4D inhibitor Gebr32a using the C3-PMP22 mouse model for CMT1A and patient-induced Pluripotent Stem Cell (iPSC)-derived Schwann cells. C3-PMP22 mice, injected subcutaneously with Gebr32a twice a day for 10 weeks, showed significantly increased nerve conduction in sciatic nerves compared to vehicle-injected controls, indicating improved myelination. Additionally, Gebr32a-treated C3-PMP22 mice exhibited improved sensorimotor functions. Grip strength analysis revealed significantly increased strength in all limbs of Gebr32a-treated C3-PMP22 mice. Post-mortem histological and ultrastructural analysis confirmed enhanced myelination in the sciatic nerve of treated mice compared to controls. In primary mouse CMT1A Schwann cells, Gebr32a dose-dependently increased the expression of pro-myelinating genes such as oct6, Krox20, Mbp, Mpz, and Plp, while downregulating the dedifferentiation marker c-Jun and human PMP22. Similar effects on gene expression were observed in iPSC-derived Schwann cells from a CMT1A patient, highlighting the clinical relevance of our findings. In conclusion, inhibition of PDE4D with Gebr32a improves the functional and molecular outcomes in mouse and human models of CMT1A, highlighting its potential as a new therapeutic strategy for CMT1A disease management.
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Affiliation(s)
- Melissa Schepers
- NIC&R - Neuro-Immune Connection & Repair, BIOMED, Department of Neuroscience, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience - Division Translational Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Tim Vangansewinkel
- Laboratory for Functional Imaging & Research on Stem Cells, BIOMED, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven , Belgium
| | - Karen Libberecht
- Laboratory for Functional Imaging & Research on Stem Cells, BIOMED, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven , Belgium
| | - Hanne Jeurissen
- Laboratory for Functional Imaging & Research on Stem Cells, BIOMED, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Darren Jacobs
- NIC&R - Neuro-Immune Connection & Repair, BIOMED, Department of Neuroscience, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; Laboratory for Functional Imaging & Research on Stem Cells, BIOMED, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Elisabeth Piccart
- NIC&R - Neuro-Immune Connection & Repair, BIOMED, Department of Neuroscience, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Robert Prior
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven , Belgium; Department of Ophthalmology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Roberta Ricciarelli
- IRCCS Ospedale Policlinico San Martino, Genova 16100, Italy; Department of Experimental Medicine, Section of General Pathology, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy
| | - Chiara Brullo
- Department of Pharmacy, Section of Medicinal Chemistry, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy
| | - Ernesto Fedele
- IRCCS Ospedale Policlinico San Martino, Genova 16100, Italy; Department of Pharmacy, Section of Pharmacology and Toxicology, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy
| | - Olga Bruno
- Department of Pharmacy, Section of Medicinal Chemistry, School of Medical and Pharmaceutical Sciences, University of Genoa, Genoa, Italy
| | | | - Ivo Lambrichts
- Laboratory for Functional Imaging & Research on Stem Cells, BIOMED, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium
| | - Ludo Van Den Bosch
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven , Belgium
| | - Tim Vanmierlo
- NIC&R - Neuro-Immune Connection & Repair, BIOMED, Department of Neuroscience, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium; Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience - Division Translational Neuroscience, Maastricht University, Maastricht, the Netherlands.
| | - Esther Wolfs
- Laboratory for Functional Imaging & Research on Stem Cells, BIOMED, Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.
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Grønnebæk TS, Haahr‐Lillevang H, Skov M, Kelly K, Kerr NR, Viteri JA, Jaworek A, Bartlett A, Bold J, Hutchison J, Quiroz J, Tankisi H, Pedersen TH, Andersen H, Arnold WD. Neuromuscular transmission deficits in patients with CMT and ClC-1 inhibition in CMT animal models. Ann Clin Transl Neurol 2025; 12:320-331. [PMID: 39670429 PMCID: PMC11822784 DOI: 10.1002/acn3.52252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2024] [Revised: 10/26/2024] [Accepted: 10/29/2024] [Indexed: 12/14/2024] Open
Abstract
OBJECTIVE Charcot-Marie Tooth (CMT) is a hereditary neuropathy characterized by muscle weakness and fatigue with no approved therapies. Preclinical studies implicate neuromuscular junction (NMJ) transmission deficits in muscle dysfunction in CMT. This study aimed to evaluate NMJ function in patients with CMT types 1 and 2, and to determine whether enhancing NMJ transmission can improve muscle function in preclinical CMT models. METHODS First, an observational study involving single fiber electromyography (SFEMG) and clinical testing in patients with CMT 1 and 2 and healthy controls (HC) was conducted. Next, preclinical studies examined muscle function, specifically nerve-stimulated muscle force after partially inhibiting ClC-1 chloride channels with the novel small molecule NMD670. RESULTS Twenty-one CMT patients (46.4 ± 14.4 years) and 10 HC (43.3 ± 12.7 years) were enrolled. SFEMG jitter (NMJ variability) was higher [median (range)] in the CMT patients [56 μs (35; 197 μs)] vs. HC [29 μs (19; 36 μs)], (p < 0.05). Blocking (NMJ failure) was higher in the CMT patients (13.4% (0.0; 90.9%)) vs. HC (0.0% (0.0; 4.5%)), (p < 0.05). In CMT, jitter and blocking correlated inversely with muscle strength, mobility, balance, and endurance. In CMT 1A and 2D mice, NMD670 increased both peak force and contractile endurance in vivo. INTERPRETATION Our study suggests that NMJ dysfunction contributes to muscle dysfunction in patients with CMT 1 and 2. Furthermore, our preclinical data provide proof-of-mechanism for recovery of muscle function with ClC-1 inhibition in CMT mouse models. Collectively, these findings suggest that targeting NMJ dysfunction with ClC-1 inhibitors could enhance muscle function in CMT patients, warranting further clinical trials.
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Affiliation(s)
| | | | | | - Kristina Kelly
- NextGen Precision HealthUniversity of MissouriColumbiaMissouriUSA
- Department of Physical Medicine and RehabilitationUniversity of MissouriColumbiaMissouriUSA
| | - Nathan R. Kerr
- NextGen Precision HealthUniversity of MissouriColumbiaMissouriUSA
- Department of Physical Medicine and RehabilitationUniversity of MissouriColumbiaMissouriUSA
| | - Jose A. Viteri
- NextGen Precision HealthUniversity of MissouriColumbiaMissouriUSA
- Department of Physical Medicine and RehabilitationUniversity of MissouriColumbiaMissouriUSA
| | - Andrea Jaworek
- Department of NeurologyThe Ohio State UniversityColumbusOHUSA
| | - Amy Bartlett
- Department of NeurologyThe Ohio State UniversityColumbusOHUSA
| | | | | | | | - Hatice Tankisi
- Department of NeurologyAarhus University HospitalAarhusDenmark
| | - Thomas Holm Pedersen
- NMD Pharma A/SAarhusDenmark
- Department of BiomedicineAarhus UniversityAarhusDenmark
| | | | - William David Arnold
- NextGen Precision HealthUniversity of MissouriColumbiaMissouriUSA
- Department of Physical Medicine and RehabilitationUniversity of MissouriColumbiaMissouriUSA
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Moore SM, Gawron J, Stevens M, Marziali LN, Buys ES, Milne GT, Feltri ML, VerPlank JJS. Pharmacologically increasing cGMP improves proteostasis and reduces neuropathy in mouse models of CMT1. Cell Mol Life Sci 2024; 81:434. [PMID: 39400753 PMCID: PMC11473742 DOI: 10.1007/s00018-024-05463-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2024] [Revised: 08/27/2024] [Accepted: 09/23/2024] [Indexed: 10/15/2024]
Abstract
Increasing cyclic GMP activates 26S proteasomes via phosphorylation by Protein Kinase G and stimulates the intracellular degradation of misfolded proteins. Therefore, agents that raise cGMP may be useful therapeutics against neurodegenerative diseases and other diseases in which protein degradation is reduced and misfolded proteins accumulate, including Charcot Marie Tooth 1A and 1B peripheral neuropathies, for which there are no treatments. Here we increased cGMP in the S63del mouse model of CMT1B by treating for three weeks with either the phosphodiesterase 5 inhibitor tadalafil, or the brain-penetrant soluble guanylyl cyclase stimulator CYR119. Both molecules activated proteasomes in the affected peripheral nerves, reduced polyubiquitinated proteins, and improved myelin thickness and nerve conduction. CYR119 increased cGMP more than tadalafil in the peripheral nerves of S63del mice and elicited greater biochemical and functional improvements. To determine whether raising cGMP could be beneficial in other neuropathies, we first showed that polyubiquitinated proteins and the disease-causing protein accumulate in the sciatic nerves of the C3 mouse model of CMT1A. Treatment of these mice with CYR119 reduced the levels of polyubiquitinated proteins and the disease-causing protein, presumably by increasing their degradation, and improved myelination, nerve conduction, and motor coordination. Thus, pharmacological agents that increase cGMP are promising treatments for CMT1 neuropathies and may be useful against other proteotoxic and neurodegenerative diseases.
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Affiliation(s)
- Seth M Moore
- Department of Biochemistry, Institute for Myelin and Glia Exploration, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Joseph Gawron
- Department of Biochemistry, Institute for Myelin and Glia Exploration, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Mckayla Stevens
- Department of Anatomy, Physiology, and Genetics, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Leandro N Marziali
- Department of Biochemistry, Institute for Myelin and Glia Exploration, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
| | - Emmanuel S Buys
- Cyclerion Therapeutics, 245 First Street Riverview II, 18th floor, Cambridge, MA, 02142, USA
| | - G Todd Milne
- Cyclerion Therapeutics, 245 First Street Riverview II, 18th floor, Cambridge, MA, 02142, USA
| | - Maria Laura Feltri
- Department of Biochemistry, Institute for Myelin and Glia Exploration, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA
- IRCCS Neurological institute 'Carlo Besta', Milano, Italy
- Department of Medical Biotechnology and Translational Medicine, Universita' degli Studi di Milano, Milano, Italy
| | - Jordan J S VerPlank
- Department of Biochemistry, Institute for Myelin and Glia Exploration, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, 14203, USA.
- Department of Anatomy, Physiology, and Genetics, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
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5
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Cassinotti LR, Ji L, Yuk MC, Desai AS, Cass ND, Amir ZA, Corfas G. Hidden hearing loss in a Charcot-Marie-Tooth type 1A mouse model. JCI Insight 2024; 9:e180315. [PMID: 39178128 PMCID: PMC11466197 DOI: 10.1172/jci.insight.180315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 08/15/2024] [Indexed: 08/25/2024] Open
Abstract
Hidden hearing loss (HHL), a recently described auditory neuropathy characterized by normal audiometric thresholds but reduced sound-evoked cochlear compound action potentials, has been proposed to contribute to hearing difficulty in noisy environments in people with normal hearing thresholds and has become a widespread complaint. While most studies on HHL pathogenesis have focused on inner hair cell (IHC) synaptopathy, we recently showed that transient auditory nerve (AN) demyelination also causes HHL in mice. To test the effect of myelinopathy on hearing in a clinically relevant model, we studied a mouse model of Charcot-Marie-Tooth type 1A (CMT1A), the most prevalent hereditary peripheral neuropathy in humans. CMT1A mice exhibited the functional hallmarks of HHL together with disorganization of AN heminodes near the IHCs with minor loss of AN fibers. These results support the hypothesis that mild disruptions of AN myelination can cause HHL and that heminodal defects contribute to the alterations in the sound-evoked cochlear compound action potentials seen in this mouse model. Furthermore, these findings suggest that patients with CMT1A or other mild peripheral neuropathies are likely to suffer from HHL. Furthermore, these results suggest that studies of hearing in patients with CMT1A might help develop robust clinical tests for HHL, which are currently lacking.
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6
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Prior R, Silva A, Vangansewinkel T, Idkowiak J, Tharkeshwar AK, Hellings TP, Michailidou I, Vreijling J, Loos M, Koopmans B, Vlek N, Agaser C, Kuipers TB, Michiels C, Rossaert E, Verschoren S, Vermeire W, de Laat V, Dehairs J, Eggermont K, van den Biggelaar D, Bademosi AT, Meunier FA, vandeVen M, Van Damme P, Mei H, Swinnen JV, Lambrichts I, Baas F, Fluiter K, Wolfs E, Van Den Bosch L. PMP22 duplication dysregulates lipid homeostasis and plasma membrane organization in developing human Schwann cells. Brain 2024; 147:3113-3130. [PMID: 38743588 PMCID: PMC11370802 DOI: 10.1093/brain/awae158] [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: 12/06/2023] [Revised: 04/08/2024] [Accepted: 04/19/2024] [Indexed: 05/16/2024] Open
Abstract
Charcot-Marie-Tooth disease type 1A (CMT1A) is the most common inherited peripheral neuropathy caused by a 1.5 Mb tandem duplication of chromosome 17 harbouring the PMP22 gene. This dose-dependent overexpression of PMP22 results in disrupted Schwann cell myelination of peripheral nerves. To obtain better insights into the underlying pathogenic mechanisms in CMT1A, we investigated the role of PMP22 duplication in cellular homeostasis in CMT1A mouse models and in patient-derived induced pluripotent stem cells differentiated into Schwann cell precursors (iPSC-SCPs). We performed lipidomic profiling and bulk RNA sequencing (RNA-seq) on sciatic nerves of two developing CMT1A mouse models and on CMT1A patient-derived iPSC-SCPs. For the sciatic nerves of the CMT1A mice, cholesterol and lipid metabolism was downregulated in a dose-dependent manner throughout development. For the CMT1A iPSC-SCPs, transcriptional analysis unveiled a strong suppression of genes related to autophagy and lipid metabolism. Gene ontology enrichment analysis identified disturbances in pathways related to plasma membrane components and cell receptor signalling. Lipidomic analysis confirmed the severe dysregulation in plasma membrane lipids, particularly sphingolipids, in CMT1A iPSC-SCPs. Furthermore, we identified reduced lipid raft dynamics, disturbed plasma membrane fluidity and impaired cholesterol incorporation and storage, all of which could result from altered lipid storage homeostasis in the patient-derived CMT1A iPSC-SCPs. Importantly, this phenotype could be rescued by stimulating autophagy and lipolysis. We conclude that PMP22 duplication disturbs intracellular lipid storage and leads to a more disordered plasma membrane owing to an alteration in the lipid composition, which might ultimately lead to impaired axo-glial interactions. Moreover, targeting lipid handling and metabolism could hold promise for the treatment of patients with CMT1A.
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Affiliation(s)
- Robert Prior
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
- Department of Ophthalmology, Medical Faculty, University of Bonn, Bonn 53127, Germany
| | - Alessio Silva
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
| | - Tim Vangansewinkel
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
- UHasselt—Hasselt University, Biomedical Research Institute, Diepenbeek 3590, Belgium
| | - Jakub Idkowiak
- Laboratory of Lipid Metabolism and Cancer, Department of Oncology, KU Leuven, Leuven 3000, Belgium
- Department of Analytical Chemistry, Faculty of Chemical Technology, University of Pardubice, Pardubice 532 10, Czech Republic
| | - Arun Kumar Tharkeshwar
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
| | - Tom P Hellings
- Department of Clinical Genetics, Leiden University Medical Center, Leiden 2333 ZA, The Netherlands
| | - Iliana Michailidou
- Department of Clinical Genetics, Leiden University Medical Center, Leiden 2333 ZA, The Netherlands
| | - Jeroen Vreijling
- Department of Clinical Genetics, Leiden University Medical Center, Leiden 2333 ZA, The Netherlands
| | - Maarten Loos
- InnoSer Nederland B.V., 2333 CK Leiden, The Netherlands
| | | | - Nina Vlek
- InnoSer Nederland B.V., 2333 CK Leiden, The Netherlands
| | - Cedrick Agaser
- Department of Biomedical Data Sciences, Sequencing Analysis Support Core, Leiden University Medical Center, Leiden 2333 ZA, The Netherlands
| | - Thomas B Kuipers
- Department of Biomedical Data Sciences, Sequencing Analysis Support Core, Leiden University Medical Center, Leiden 2333 ZA, The Netherlands
| | - Christine Michiels
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
| | - Elisabeth Rossaert
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
| | - Stijn Verschoren
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
| | - Wendy Vermeire
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
| | - Vincent de Laat
- Laboratory of Lipid Metabolism and Cancer, Department of Oncology, KU Leuven, Leuven 3000, Belgium
| | - Jonas Dehairs
- Laboratory of Lipid Metabolism and Cancer, Department of Oncology, KU Leuven, Leuven 3000, Belgium
| | - Kristel Eggermont
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
| | - Diede van den Biggelaar
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
| | - Adekunle T Bademosi
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Frederic A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Martin vandeVen
- UHasselt—Hasselt University, Biomedical Research Institute, Diepenbeek 3590, Belgium
| | - Philip Van Damme
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
- Department of Neurology, University Hospitals Leuven, Leuven 3000, Belgium
| | - Hailiang Mei
- Department of Biomedical Data Sciences, Sequencing Analysis Support Core, Leiden University Medical Center, Leiden 2333 ZA, The Netherlands
| | - Johannes V Swinnen
- Laboratory of Lipid Metabolism and Cancer, Department of Oncology, KU Leuven, Leuven 3000, Belgium
| | - Ivo Lambrichts
- UHasselt—Hasselt University, Biomedical Research Institute, Diepenbeek 3590, Belgium
| | - Frank Baas
- Department of Clinical Genetics, Leiden University Medical Center, Leiden 2333 ZA, The Netherlands
| | - Kees Fluiter
- Department of Clinical Genetics, Leiden University Medical Center, Leiden 2333 ZA, The Netherlands
| | - Esther Wolfs
- UHasselt—Hasselt University, Biomedical Research Institute, Diepenbeek 3590, Belgium
| | - Ludo Van Den Bosch
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven—University of Leuven, Leuven 3000, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Leuven 3000, Belgium
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7
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Cassinotti LR, Ji L, Yuk MC, Desai AS, Cass ND, Amir ZA, Corfas G. Hidden hearing loss in a Charcot-Marie-Tooth type 1A mouse model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.14.571732. [PMID: 38168255 PMCID: PMC10760174 DOI: 10.1101/2023.12.14.571732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Hidden hearing loss (HHL), a recently described auditory neuropathy characterized by normal audiometric thresholds but reduced sound-evoked cochlear compound action potentials, has been proposed to contribute to hearing difficulty in noisy environments in people with normal hearing thresholds, a widespread complaint. While most studies on HHL pathogenesis have focused on inner hair cell (IHC) synaptopathy, we recently showed that transient auditory nerve (AN) demyelination also causes HHL in mice. To test the impact of myelinopathy on hearing in a clinically relevant model, we studied a mouse model of Charcot-Marie-Tooth type 1A (CMT1A), the most prevalent hereditary peripheral neuropathy in humans. CMT1A mice exhibited the functional hallmarks of HHL together with disorganization of AN heminodes near the IHCs with minor loss of AN fibers. These results support the hypothesis that mild disruptions of AN myelination can cause HHL, and that heminodal defects contribute to the alterations in the sound-evoked cochlear compound action potentials seen in this mouse model. Also, these findings suggest that patients with CMT1A or other mild peripheral neuropathies are likely to suffer from HHL. Furthermore, these results suggest that studies of hearing in CMT1A patients might help develop robust clinical tests for HHL, which are currently lacking.
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8
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Fernandez-Fuente G, Farrugia MA, Peng Y, Schneider A, Svaren J, Puglielli L. Spatial selectivity of ATase inhibition in mouse models of Charcot-Marie-Tooth disease. Brain Commun 2024; 6:fcae232. [PMID: 39035418 PMCID: PMC11258571 DOI: 10.1093/braincomms/fcae232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/30/2024] [Accepted: 07/08/2024] [Indexed: 07/23/2024] Open
Abstract
The endoplasmic reticulum acetylation machinery has emerged as a new branch of the larger endoplasmic reticulum quality control system. It regulates the selection of correctly folded polypeptides as well as reticulophagy-mediated removal of toxic protein aggregates with the former being a particularly important aspect of the proteostatic functions of endoplasmic reticulum acetylation. Essential to this function is the Nε-lysine acetyltransferase activity of acetyltransferase 1 and acetyltransferase 2, which regulates the induction of endoplasmic reticulum-specific autophagy through the acetylation of the autophagy-related protein 9A. Here, we used three mouse models of Charcot-Marie-Tooth disease, peripheral myelin protein 22/Tr-J, C3-peripheral myelin protein 22 and myelin protein zero/ttrr, to study spatial and translational selectivity of endoplasmic reticulum acetyltransferase inhibitors. The results show that inhibition of the endoplasmic reticulum acetyltransferases selectively targets misfolding/pro-aggregating events occurring in the lumen of the organelle. Therefore, they establish acetyltransferase 1 and acetyltransferase 2 as the first proven targets for disease-causing proteotoxic states that initiate within the lumen of the endoplasmic reticulum/secretory pathway.
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Affiliation(s)
- Gonzalo Fernandez-Fuente
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Mark A Farrugia
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Yajing Peng
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Andrew Schneider
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - John Svaren
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Luigi Puglielli
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
- Waisman Center, University of Wisconsin-Madison, Madison, WI 53705, USA
- Geriatric Research Education Clinical Center, Veterans Affairs Medical Center, Madison, WI 53705, USA
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9
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Yoon BA, Kim YH, Nam SH, Lee HJ, Oh SI, Kim N, Kim KH, Jo YR, Kim JK, Choi BO, Park HT. p62/sequestosome-1 as a severity-reflecting plasma biomarker in Charcot-Marie-Tooth disease type 1A. Sci Rep 2024; 14:10972. [PMID: 38745059 PMCID: PMC11094036 DOI: 10.1038/s41598-024-61794-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Accepted: 05/09/2024] [Indexed: 05/16/2024] Open
Abstract
Autophagy is a self-degradation system for recycling to maintain homeostasis. p62/sequestosome-1 (p62) is an autophagy receptor that accumulates in neuroglia in neurodegenerative diseases. The objective of this study was to determine the elevation of plasma p62 protein levels in patients with Charcot-Marie-Tooth disease 1A (CMT1A) for its clinical usefulness to assess disease severity. We collected blood samples from 69 CMT1A patients and 59 healthy controls. Plasma concentrations of p62 were analyzed by ELISA, and we compared them with Charcot-Marie-Tooth neuropathy score version 2 (CMTNSv2). A mouse CMT1A model (C22) was employed to determine the source and mechanism of plasma p62 elevation. Plasma p62 was detected in healthy controls with median value of 1978 pg/ml, and the levels were significantly higher in CMT1A (2465 pg/ml, p < 0.001). The elevated plasma p62 levels were correlated with CMTNSv2 (r = 0.621, p < 0.0001), motor nerve conduction velocity (r = - 0.490, p < 0.0001) and disease duration (r = 0.364, p < 0.01). In C22 model, increased p62 expression was observed not only in pathologic Schwann cells but also in plasma. Our findings indicate that plasma p62 measurement could be a valuable tool for evaluating CMT1A severity and Schwann cell pathology.
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Affiliation(s)
- Byeol-A Yoon
- Peripheral Neuropathy Research Center (PNRC), Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, 49201, Republic of Korea
- Department of Neurology, Dong-A University College of Medicine, Busan, 49201, Republic of Korea
| | - Young Hee Kim
- Peripheral Neuropathy Research Center (PNRC), Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, 49201, Republic of Korea
- Department of Molecular Neuroscience and Translational Biomedical Sciences, Dong-A University College of Medicine, Busan, 49201, Republic of Korea
| | - Soo Hyun Nam
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, Republic of Korea
| | - Hye-Jin Lee
- Peripheral Neuropathy Research Center (PNRC), Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, 49201, Republic of Korea
- Department of Molecular Neuroscience and Translational Biomedical Sciences, Dong-A University College of Medicine, Busan, 49201, Republic of Korea
| | - Seong-Il Oh
- Department of Neurology, Kyung Hee University Hospital, Kyung Hee University College of Medicine, Seoul, 02447, Republic of Korea
| | - Namhee Kim
- Department of Laboratory Medicine, Dong-A University College of Medicine, Busan, 49201, Republic of Korea
| | - Kyeong-Hee Kim
- Department of Laboratory Medicine, Dong-A University College of Medicine, Busan, 49201, Republic of Korea
| | - Young Rae Jo
- Department of Molecular Neuroscience and Translational Biomedical Sciences, Dong-A University College of Medicine, Busan, 49201, Republic of Korea
| | - Jong Kuk Kim
- Peripheral Neuropathy Research Center (PNRC), Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, 49201, Republic of Korea
- Department of Neurology, Dong-A University College of Medicine, Busan, 49201, Republic of Korea
| | - Byung-Ok Choi
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, Republic of Korea.
- Department of Neurology, Samsung Medical Center, 81 Irwon-Ro, Gangnam-Gu, Seoul, 06351, Republic of Korea.
| | - Hwan Tae Park
- Peripheral Neuropathy Research Center (PNRC), Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, 49201, Republic of Korea.
- Department of Molecular Neuroscience and Translational Biomedical Sciences, Dong-A University College of Medicine, Busan, 49201, Republic of Korea.
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10
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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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11
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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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12
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Libberecht K, Vangansewinkel T, Van Den Bosch L, Lambrichts I, Wolfs E. Proteostasis plays an important role in demyelinating Charcot Marie Tooth disease. Biochem Pharmacol 2023; 216:115760. [PMID: 37604292 DOI: 10.1016/j.bcp.2023.115760] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 08/23/2023]
Abstract
Type 1 Charcot-Marie-Tooth disease (CMT1) is the most common demyelinating peripheral neuropathy. Patients suffer from progressive muscle weakness and sensory problems. The underlying disease mechanisms of CMT1 are still unclear and no therapy is currently available, hence patients completely rely on supportive care. Balancing protein levels is a complex multistep process fundamental to maintain cells in their healthy state and a disrupted proteostasis is a hallmark of several neurodegenerative diseases. When protein misfolding occurs, protein quality control systems are activated such as chaperones, the lysosomal-autophagy system and proteasomal degradation to ensure proper degradation. However, in pathological circumstances, these mechanisms are overloaded and thereby become inefficient to clear the load of misfolded proteins. Recent evidence strongly indicates that a disbalance in proteostasis plays an important role in several forms of CMT1. In this review, we present an overview of the protein quality control systems, their role in CMT1, and potential treatment strategies to restore proteostasis.
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Affiliation(s)
- Karen Libberecht
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Functional Imaging & Research on Stem Cells (FIERCELab), Diepenbeek, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium.
| | - Tim Vangansewinkel
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Functional Imaging & Research on Stem Cells (FIERCELab), Diepenbeek, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium; UHasselt, Biomedical Research Institute (BIOMED), Lab for Histology and Regeneration (HISTOREGEN Lab), Diepenbeek, Belgium
| | - Ludo Van Den Bosch
- KU Leuven, Department of Neurosciences, Experimental Neurology, and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Ivo Lambrichts
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Histology and Regeneration (HISTOREGEN Lab), Diepenbeek, Belgium
| | - Esther Wolfs
- UHasselt, Biomedical Research Institute (BIOMED), Lab for Functional Imaging & Research on Stem Cells (FIERCELab), Diepenbeek, Belgium.
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13
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Lassetter AP, Corty MM, Barria R, Sheehan AE, Hill JQ, Aicher SA, Fox AN, Freeman MR. Glial TGFβ activity promotes neuron survival in peripheral nerves. J Cell Biol 2023; 222:e202111053. [PMID: 36399182 PMCID: PMC9679965 DOI: 10.1083/jcb.202111053] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 09/06/2022] [Accepted: 10/26/2022] [Indexed: 11/19/2022] Open
Abstract
Maintaining long, energetically demanding axons throughout the life of an animal is a major challenge for the nervous system. Specialized glia ensheathe axons and support their function and integrity throughout life, but glial support mechanisms remain poorly defined. Here, we identified a collection of secreted and transmembrane molecules required in glia for long-term axon survival in vivo. We showed that the majority of components of the TGFβ superfamily are required in glia for sensory neuron maintenance but not glial ensheathment of axons. In the absence of glial TGFβ signaling, neurons undergo age-dependent degeneration that can be rescued either by genetic blockade of Wallerian degeneration or caspase-dependent death. Blockade of glial TGFβ signaling results in increased ATP in glia that can be mimicked by enhancing glial mitochondrial biogenesis or suppressing glial monocarboxylate transporter function. We propose that glial TGFβ signaling supports axon survival and suppresses neurodegeneration through promoting glial metabolic support of neurons.
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Affiliation(s)
| | - Megan M. Corty
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Romina Barria
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Amy E. Sheehan
- Vollum Institute, Oregon Health & Science University, Portland, OR
| | - Jo Q. Hill
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR
| | - Sue A. Aicher
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR
| | - A. Nicole Fox
- University of Massachusetts Medical School, Worcester, MA
| | - Marc R. Freeman
- Vollum Institute, Oregon Health & Science University, Portland, OR
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14
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Michailidou I, Vreijling J, Rumpf M, Loos M, Koopmans B, Vlek N, Straat N, Agaser C, Kuipers TB, Mei H, Baas F, Fluiter K. The systemic inhibition of the terminal complement system reduces neuroinflammation but does not improve motor function in mouse models of CMT1A with overexpressed PMP22. CURRENT RESEARCH IN NEUROBIOLOGY 2023; 4:100077. [PMID: 36926597 PMCID: PMC10011818 DOI: 10.1016/j.crneur.2023.100077] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 12/13/2022] [Accepted: 01/27/2023] [Indexed: 02/07/2023] Open
Abstract
Charcot-Marie-Tooth disease type 1A (CMT1A) is the most prevalent hereditary demyelinating neuropathy. This autosomal, dominantly inherited disease is caused by a duplication on chromosome 17p which includes the peripheral myelin protein 22 (PMP22) gene. There is clinical evidence that the disability in CMT1A is to a large extend due to axonal damage rather than demyelination. Over-expression of PMP22 is recently thought to impede cholesterol trafficking causing a total shutdown of local cholesterol and lipid synthesis in the Schwann cells, thus disturbing their ability to remyelinate. But there is a large variety in disease burden between CMT1A patients with the same genetic defect, indicating the presence of modifying factors that affect disease severity. One of these potential factors is the immune system. Several reports have described patients with co-occurrence of CMT1A with chronic inflammatory demyelinating disease or Guillain-Barré syndrome. We have previously shown in multiple animal models that the innate immune system and specifically the terminal complement system is a driver of inflammatory demyelination. To test the contribution of the terminal complement system to neuroinflammation and disease progression in CMT1A, we inhibited systemic complement C6 in two transgenic mouse models for CMT1A, the C3-PMP22 and C3-PMP22 c-JunP0Cre models. Both models over-express human PMP22, and one (C3-PMP22 c-JunP0Cre) also has a Schwann cell-specific knockout of c-Jun, a crucial regulator of myelination controlling autophagy. We found that systemic inhibition of C6 using antisense oligonucleotides affects the neuroinflammation, Rho GTPase and ERK/MAPK signalling pathways in the CMT1A mouse models. The cholesterol synthesis pathway remained unaffected. Analysis of motor function during treatment with C6 antisense oligonucleotides did not reveal any significant improvement in the CMT1A mouse models. This study shows that the contribution of the terminal complement system to progressive loss of motor function in the CMT1A mouse models tested is limited.
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Affiliation(s)
- Iliana Michailidou
- Dept of Clinical Genetics, LUMC, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Jeroen Vreijling
- Dept of Clinical Genetics, LUMC, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Matthijs Rumpf
- Dept of Clinical Genetics, LUMC, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Maarten Loos
- Sylics (Synaptologics B.V.), Bilthoven, the Netherlands
| | | | - Nina Vlek
- Sylics (Synaptologics B.V.), Bilthoven, the Netherlands
| | - Nina Straat
- Sylics (Synaptologics B.V.), Bilthoven, the Netherlands
| | - Cedrick Agaser
- Sequencing Analysis Support Core, Department of Biomedical Data Sciences LUMC, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Thomas B Kuipers
- Sequencing Analysis Support Core, Department of Biomedical Data Sciences LUMC, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Hailiang Mei
- Sequencing Analysis Support Core, Department of Biomedical Data Sciences LUMC, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Frank Baas
- Dept of Clinical Genetics, LUMC, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
| | - Kees Fluiter
- Dept of Clinical Genetics, LUMC, Albinusdreef 2, 2333 ZA Leiden, the Netherlands
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15
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Nguyen NP, Lopez S, Smith CL, Lever TE, Nichols NL, Bunyak F. Axon and Myelin Sheath Segmentation in Electron Microscopy Images using Meta Learning. IEEE APPLIED IMAGERY PATTERN RECOGNITION WORKSHOP : [PROCEEDINGS]. IEEE APPLIED IMAGERY PATTERN RECOGNITION WORKSHOP 2022; 2022:10.1109/aipr57179.2022.10092238. [PMID: 37214276 PMCID: PMC10197949 DOI: 10.1109/aipr57179.2022.10092238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Various neurological diseases affect the morphology of myelinated axons. Quantitative analysis of these structures and changes occurring due to neurodegeneration or neuroregeneration is of great importance for characterization of disease state and treatment response. This paper proposes a robust, meta-learning based pipeline for segmentation of axons and surrounding myelin sheaths in electron microscopy images. This is the first step towards computation of electron microscopy related bio-markers of hypoglossal nerve degeneration/regeneration. This segmentation task is challenging due to large variations in morphology and texture of myelinated axons at different levels of degeneration and very limited availability of annotated data. To overcome these difficulties, the proposed pipeline uses a meta learning-based training strategy and a U-net like encoder decoder deep neural network. Experiments on unseen test data collected at different magnification levels (i.e, trained on 500X and 1200X images, and tested on 250X and 2500X images) showed improved segmentation performance by 5% to 7% compared to a regularly trained, comparable deep learning network.
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Affiliation(s)
- Nguyen P. Nguyen
- Department of Electrical Engineering and Computer Science, University of Missouri-Columbia, MO, USA
| | - Stephanie Lopez
- Department of Biomedical Sciences, Department of Otolaryngology-Head and Neck Surgery, University of Missouri-Columbia, MO, USA
| | - Catherine L. Smith
- Department of Biomedical Sciences, Department of Otolaryngology-Head and Neck Surgery, University of Missouri-Columbia, MO, USA
| | - Teresa E. Lever
- Department of Biomedical Sciences, Department of Otolaryngology-Head and Neck Surgery, University of Missouri-Columbia, MO, USA
| | - Nicole L. Nichols
- Department of Biomedical Sciences, Department of Otolaryngology-Head and Neck Surgery, University of Missouri-Columbia, MO, USA
| | - Filiz Bunyak
- Department of Electrical Engineering and Computer Science, University of Missouri-Columbia, MO, USA
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16
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Prior R, Verschoren S, Vints K, Jaspers T, Rossaert E, Klingl YE, Silva A, Hersmus N, Van Damme P, Van Den Bosch L. HDAC3 Inhibition Stimulates Myelination in a CMT1A Mouse Model. Mol Neurobiol 2022; 59:3414-3430. [PMID: 35320455 PMCID: PMC9148289 DOI: 10.1007/s12035-022-02782-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 02/07/2022] [Indexed: 12/02/2022]
Abstract
Charcot-Marie-Tooth disease (CMT) is the most common inherited peripheral neuropathy, with currently no effective treatment or cure. CMT1A is caused by a duplication of the PMP22 gene, which leads to Schwann cell differentiation defects and dysmyelination of the peripheral nerves. The epigenetic regulator histone deacetylase 3 (HDAC3) has been shown to negatively regulate myelination as well as its associated signaling pathways, PI3K-AKT and MAPK-ERK. We showed that these signaling pathways are indeed downregulated in the C3-PMP22 mouse model, similar to what has been shown in the CMT1A rat model. We confirmed that early postnatal defects are present in the peripheral nerves of the C3-PMP22 mouse model, which led to a progressive reduction in axon caliber size and myelination. The aim of this study was to investigate whether pharmacological HDAC3 inhibition could be a valuable therapeutic approach for this CMT1A mouse model. We demonstrated that early treatment of CMT1A mice with the selective HDAC3 inhibitor RGFP966 increased myelination and myelin g-ratios, which was associated with improved electrophysiological recordings. However, a high dose of RGFP966 caused a decline in rotarod performance and a decline in overall grip strength. Additionally, macrophage presence in peripheral nerves was increased in RGFP966 treated CMT1A mice. We conclude that HDAC3 does not only play a role in regulating myelination but is also important in the neuroimmune modulation. Overall, our results indicate that correct dosing of HDAC3 inhibitors is of crucial importance if translated to a clinical setting for demyelinating forms of CMT or other neurological disorders.
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Affiliation(s)
- Robert Prior
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium.
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Campus Gasthuisberg O&N5, Herestraat 49, box 602, B-3000, Leuven, Belgium.
| | - Stijn Verschoren
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Campus Gasthuisberg O&N5, Herestraat 49, box 602, B-3000, Leuven, Belgium
| | - Katlijn Vints
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium
- Electron Microscopy Platform & VIB BioImaging Core, Herestraat 49, B-3000, Leuven, Belgium
| | - Tom Jaspers
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Campus Gasthuisberg O&N5, Herestraat 49, box 602, B-3000, Leuven, Belgium
| | - Elisabeth Rossaert
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Campus Gasthuisberg O&N5, Herestraat 49, box 602, B-3000, Leuven, Belgium
| | - Yvonne E Klingl
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Campus Gasthuisberg O&N5, Herestraat 49, box 602, B-3000, Leuven, Belgium
| | - Alessio Silva
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Campus Gasthuisberg O&N5, Herestraat 49, box 602, B-3000, Leuven, Belgium
| | - Nicole Hersmus
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Campus Gasthuisberg O&N5, Herestraat 49, box 602, B-3000, Leuven, Belgium
| | - Philip Van Damme
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Campus Gasthuisberg O&N5, Herestraat 49, box 602, B-3000, Leuven, Belgium
- Neurology, University Hospitals Leuven, B-3000, Leuven, Belgium
| | - Ludo Van Den Bosch
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), KU Leuven - University of Leuven, B-3000, Leuven, Belgium.
- Laboratory of Neurobiology, VIB, Center for Brain & Disease Research, Campus Gasthuisberg O&N5, Herestraat 49, box 602, B-3000, Leuven, Belgium.
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17
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Stavrou M, Kagiava A, Choudury SG, Jennings MJ, Wallace LM, Fowler AM, Heslegrave A, Richter J, Tryfonos C, Christodoulou C, Zetterberg H, Horvath R, Harper SQ, Kleopa KA. A translatable RNAi-driven gene therapy silences PMP22/Pmp22 genes and improves neuropathy in CMT1A mice. J Clin Invest 2022; 132:159814. [PMID: 35579942 PMCID: PMC9246392 DOI: 10.1172/jci159814] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 05/12/2022] [Indexed: 11/17/2022] Open
Abstract
Charcot-Marie-Tooth disease type 1A (CMT1A), the most common inherited demyelinating peripheral neuropathy, is caused by PMP22 gene duplication. Overexpression of WT PMP22 in Schwann cells destabilizes the myelin sheath, leading to demyelination and ultimately to secondary axonal loss and disability. No treatments currently exist that modify the disease course. The most direct route to CMT1A therapy will involve reducing PMP22 to normal levels. To accomplish this, we developed a gene therapy strategy to reduce PMP22 using artificial miRNAs targeting human PMP22 and mouse Pmp22 mRNAs. Our lead therapeutic miRNA, miR871, was packaged into an adeno-associated virus 9 (AAV9) vector and delivered by lumbar intrathecal injection into C61-het mice, a model of CMT1A. AAV9-miR871 efficiently transduced Schwann cells in C61-het peripheral nerves and reduced human and mouse PMP22 mRNA and protein levels. Treatment at early and late stages of the disease significantly improved multiple functional outcome measures and nerve conduction velocities. Furthermore, myelin pathology in lumbar roots and femoral motor nerves was ameliorated. The treated mice also showed reductions in circulating biomarkers of CMT1A. Taken together, our data demonstrate that AAV9-miR871–driven silencing of PMP22 rescues a CMT1A model and provides proof of principle for treating CMT1A using a translatable gene therapy approach.
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Affiliation(s)
- Marina Stavrou
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Alexia Kagiava
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Sarah G Choudury
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, United States of America
| | - Matthew J Jennings
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Lindsay M Wallace
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, United States of America
| | - Allison M Fowler
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, United States of America
| | - Amanda Heslegrave
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, London, United Kingdom
| | - Jan Richter
- Department of Molecular Virology, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Christina Tryfonos
- Department of Molecular Virology, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Christina Christodoulou
- Department of Molecular Virology, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Henrik Zetterberg
- Institute of Laboratory Medicine, Göteborgs University, Göteborg, Sweden
| | - Rita Horvath
- Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Scott Q Harper
- Center for Gene Therapy, The Research Institute at Nationwide Children's Hospital, Columbus, United States of America
| | - Kleopas A Kleopa
- Neuroscience Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
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18
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Bai Y, Treins C, Volpi VG, Scapin C, Ferri C, Mastrangelo R, Touvier T, Florio F, Bianchi F, Del Carro U, Baas FF, Wang D, Miniou P, Guedat P, Shy ME, D'Antonio M. Treatment with IFB-088 Improves Neuropathy in CMT1A and CMT1B Mice. Mol Neurobiol 2022; 59:4159-4178. [PMID: 35501630 PMCID: PMC9167212 DOI: 10.1007/s12035-022-02838-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 04/09/2022] [Indexed: 11/24/2022]
Abstract
Charcot-Marie-Tooth disease type 1A (CMT1A), caused by duplication of the peripheral myelin protein 22 (PMP22) gene, and CMT1B, caused by mutations in myelin protein zero (MPZ) gene, are the two most common forms of demyelinating CMT (CMT1), and no treatments are available for either. Prior studies of the MpzSer63del mouse model of CMT1B have demonstrated that protein misfolding, endoplasmic reticulum (ER) retention and activation of the unfolded protein response (UPR) contributed to the neuropathy. Heterozygous patients with an arginine to cysteine mutation in MPZ (MPZR98C) develop a severe infantile form of CMT1B which is modelled by MpzR98C/ + mice that also show ER stress and an activated UPR. C3-PMP22 mice are considered to effectively model CMT1A. Altered proteostasis, ER stress and activation of the UPR have been demonstrated in mice carrying Pmp22 mutations. To determine whether enabling the ER stress/UPR and readjusting protein homeostasis would effectively treat these models of CMT1B and CMT1A, we administered Sephin1/IFB-088/icerguestat, a UPR modulator which showed efficacy in the MpzS63del model of CMT1B, to heterozygous MpzR98C and C3-PMP22 mice. Mice were analysed by behavioural, neurophysiological, morphological and biochemical measures. Both MpzR98C/ + and C3-PMP22 mice improved in motor function and neurophysiology. Myelination, as demonstrated by g-ratios and myelin thickness, improved in CMT1B and CMT1A mice and markers of UPR activation returned towards wild-type values. Taken together, our results demonstrate the capability of IFB-088 to treat a second mouse model of CMT1B and a mouse model of CMT1A, the most common form of CMT. Given the recent benefits of IFB-088 treatment in amyotrophic lateral sclerosis and multiple sclerosis animal models, these data demonstrate its potential in managing UPR and ER stress for multiple mutations in CMT1 as well as in other neurodegenerative diseases.
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Affiliation(s)
- Yunhong Bai
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | | | - Vera G Volpi
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute DIBIT, 20132, Milan, Italy
| | - Cristina Scapin
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute DIBIT, 20132, Milan, Italy
| | - Cinzia Ferri
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute DIBIT, 20132, Milan, Italy
| | - Rosa Mastrangelo
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute DIBIT, 20132, Milan, Italy
| | - Thierry Touvier
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute DIBIT, 20132, Milan, Italy
| | - Francesca Florio
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute DIBIT, 20132, Milan, Italy
| | - Francesca Bianchi
- Division of Neuroscience, San Raffaele Scientific Institute DIBIT, 20132, Milan, Italy
| | - Ubaldo Del Carro
- Division of Neuroscience, San Raffaele Scientific Institute DIBIT, 20132, Milan, Italy
| | - Frank F Baas
- Department of Clinical Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - David Wang
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | | | | | - Michael E Shy
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, 52242, USA
| | - Maurizio D'Antonio
- Division of Genetics and Cell Biology, San Raffaele Scientific Institute DIBIT, 20132, Milan, Italy.
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19
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Moss KR, Johnson AE, Bopp TS, Yu ATY, Perry K, Chung T, Höke A. SARM1 knockout does not rescue neuromuscular phenotypes in a Charcot-Marie-Tooth disease Type 1A mouse model. J Peripher Nerv Syst 2022; 27:58-66. [PMID: 35137510 PMCID: PMC8940700 DOI: 10.1111/jns.12483] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 01/25/2022] [Accepted: 02/02/2022] [Indexed: 11/28/2022]
Abstract
Charcot-Marie-Tooth disease Type 1A (CMT1A) is caused by duplication of the PMP22 gene and is the most common inherited peripheral neuropathy. Although CMT1A is a dysmyelinating peripheral neuropathy, secondary axon degeneration has been suggested to drive functional deficits in patients. Given that SARM1 knockout is a potent inhibitor of the programmed axon degeneration pathway, we asked whether SARM1 knockout rescues neuromuscular phenotypes in CMT1A model (C3-PMP) mice. CMT1A mice were bred with SARM1 knockout mice to generate CMT1A/SARM1-/- mice. A series of behavioral assays were employed to evaluate motor and sensorimotor function. Electrophysiological and histological studies of the tibial branch of the sciatic nerve were performed. Additionally, gastrocnemius and soleus muscle morphology were evaluated histologically. Although clear behavioral and electrophysiological deficits were observed in CMT1A model mice, genetic deletion of SARM1 conferred no significant improvement. Nerve morphometry revealed predominantly myelin deficits in CMT1A model mice and SARM1 knockout yielded no improvement in all nerve morphometry measures. Similarly, muscle morphometry deficits in CMT1A model mice were not improved by SARM1 knockout. Our findings demonstrate that programmed axon degeneration pathway inhibition does not provide therapeutic benefit in C3-PMP CMT1A model mice. Our results indicate that the clinical phenotypes observed in CMT1A mice are likely caused primarily by prolonged dysmyelination, motivate further investigation into mechanisms of dysmyelination in these mice and necessitate the development of improved CMT1A rodent models that recapitulate the secondary axon degeneration observed in patients.
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Affiliation(s)
- Kathryn R. Moss
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD
| | - Anna E. Johnson
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD
| | - Taylor S. Bopp
- Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, Baltimore, MD
| | - Andrew T-Y. Yu
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD
| | - Ken Perry
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD
| | - Tae Chung
- Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, Baltimore, MD
| | - Ahmet Höke
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD,Department of Neuroscience, Johns Hopkins School of Medicine, Baltimore, MD,Corresponding Author: Ahmet Höke MD, PhD, Johns Hopkins School of Medicine, 855 N. Wolfe St., Baltimore, MD 21205, Tel: 410-955-2227, Fax: 410-502-5459,
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20
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Abstract
Demyelinating forms of Charcot-Marie-Tooth disease (CMT) are genetically and phenotypically heterogeneous and result from highly diverse biological mechanisms including gain of function (including dominant negative effects) and loss of function. While no definitive treatment is currently available, rapid advances in defining the pathomechanisms of demyelinating CMT have led to promising pre-clinical studies, as well as emerging clinical trials. Especially promising are the recently completed pre-clinical genetic therapy studies in PMP-22, GJB1, and SH3TC2-associated neuropathies, particularly given the success of similar approaches in humans with spinal muscular atrophy and transthyretin familial polyneuropathy. This article focuses on neuropathies related to mutations in PMP-22, MPZ, and GJB1, which together comprise the most common forms of demyelinating CMT, as well as on select rarer forms for which promising treatment targets have been identified. Clinical characteristics and pathomechanisms are reviewed in detail, with emphasis on therapeutically targetable biological pathways. Also discussed are the challenges facing the CMT research community in its efforts to advance the rapidly evolving biological insights to effective clinical trials. These considerations include the limitations of currently available animal models, the need for personalized medicine approaches/allele-specific interventions for select forms of demyelinating CMT, and the increasing demand for optimal clinical outcome assessments and objective biomarkers.
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Affiliation(s)
- Vera Fridman
- Department of Neurology, University of Colorado Anschutz Medical Campus, 12631 E 17th Avenue, Mailstop B185, Room 5113C, Aurora, CO, 80045, USA.
| | - Mario A Saporta
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, USA
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21
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Bosco L, Falzone YM, Previtali SC. Animal Models as a Tool to Design Therapeutical Strategies for CMT-like Hereditary Neuropathies. Brain Sci 2021; 11:1237. [PMID: 34573256 PMCID: PMC8465478 DOI: 10.3390/brainsci11091237] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 09/05/2021] [Accepted: 09/07/2021] [Indexed: 02/07/2023] Open
Abstract
Since ancient times, animal models have provided fundamental information in medical knowledge. This also applies for discoveries in the field of inherited peripheral neuropathies (IPNs), where they have been instrumental for our understanding of nerve development, pathogenesis of neuropathy, molecules and pathways involved and to design potential therapies. In this review, we briefly describe how animal models have been used in ancient medicine until the use of rodents as the prevalent model in present times. We then travel along different examples of how rodents have been used to improve our understanding of IPNs. We do not intend to describe all discoveries and animal models developed for IPNs, but just to touch on a few arbitrary and paradigmatic examples, taken from our direct experience or from literature. The idea is to show how strategies have been developed to finally arrive to possible treatments for IPNs.
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Affiliation(s)
| | | | - Stefano Carlo Previtali
- Institute of Experimental Neurology (INSPE), Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy; (L.B.); (Y.M.F.)
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22
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Carozzi VA, Bolino A, D'Antonio M, Quattrini A, Cavaletti G. Nerve pathology in animal models of neuropathies. J Peripher Nerv Syst 2021; 26 Suppl 2:S61-S68. [PMID: 34498774 DOI: 10.1111/jns.12463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 04/21/2021] [Accepted: 08/24/2021] [Indexed: 11/27/2022]
Abstract
To understand the pathology of axonal degeneration and demyelination in peripheral neuropathy, histological investigations in different animal models that mimic some aspects of human peripheral neuropathy are needed. Thus, in the following section of this special issue, the main pathological features of experimental autoimmune neuritis, animal models of chemotherapy-induced peripheral neuropath and of human inherited peripheral neuropathies (IPNs) will be illustrated. When possible, micrographs from animal models and selected human biopsy will be shown side by side.
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Affiliation(s)
- Valentina Alda Carozzi
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
| | - Alessandra Bolino
- Human Inherited Neuropathies Unit, Division of Neuroscience, Institute of Experimental Neurology (INSPE), IRCCS Ospedale San Raffaele, Milan, Italy
| | - Maurizio D'Antonio
- Biology of Myelin Unit, Division of Genetics and Cell Biology, San Raffaele Scientific Institute, Milan, Italy
| | - Angelo Quattrini
- Experimental Neuropathology Unit, Institute of Experimental Neurology (INSPE), Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Guido Cavaletti
- Experimental Neurology Unit, School of Medicine and Surgery, University of Milano-Bicocca, Monza, Italy
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23
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Martinez NJ, Braisted JC, Dranchak PK, Moran JJ, Larson H, Queme B, Pak E, Dutra A, Rai G, Cheng KCC, Svaren J, Inglese J. Genome-Edited Coincidence and PMP22-HiBiT Fusion Reporter Cell Lines Enable an Artifact-Suppressive Quantitative High-Throughput Screening Strategy for PMP22 Gene-Dosage Disorder Drug Discovery. ACS Pharmacol Transl Sci 2021; 4:1422-1436. [PMID: 34423274 DOI: 10.1021/acsptsci.1c00110] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Indexed: 12/23/2022]
Abstract
Charcot-Marie-Tooth 1A (CMT1A) is the most common form of hereditary peripheral neuropathies, characterized by genetic duplication of the critical myelin gene Peripheral Myelin Protein 22 (PMP22). PMP22 overexpression results in abnormal Schwann cell differentiation, leading to axonal loss and muscle wasting. Since regulation of PMP22 expression is a major target of therapeutic discovery for CMT1A, we sought to establish unbiased approaches that allow the identification of therapeutic agents for this disease. Using genome editing, we generated a coincidence reporter assay that accurately monitors Pmp22 transcript levels in the S16 rat Schwann cell line, while reducing reporter-based false positives. A quantitative high-throughput screen (qHTS) of 42 577 compounds using this assay revealed diverse novel chemical classes that reduce endogenous Pmp22 transcript levels. Moreover, some of these classes show pharmacological specificity in reducing Pmp22 over another major myelin-associated gene, Mpz (Myelin protein zero). Finally, to investigate whether compound-mediated reduction of Pmp22 transcripts translates to reduced PMP22 protein levels, we edited the S16 genome to generate a reporter assay that expresses a PMP22-HiBiT fusion protein using CRISPR/Cas9. Overall, we present a screening platform that combines genome edited cell lines encoding reporters that monitor transcriptional and post-translational regulation of PMP22 with titration-based screening (e.g., qHTS), which could be efficiently incorporated into drug discovery campaigns for CMT1A.
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Affiliation(s)
- Natalia J Martinez
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - John C Braisted
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Patricia K Dranchak
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - John J Moran
- Department of Comparative Biosciences, and Waisman Center, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - Hunter Larson
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Bryan Queme
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Evgenia Pak
- National Human Genome Research Institute, National Institute of Health, Bethesda, Maryland 20817, United States
| | - Amalia Dutra
- National Human Genome Research Institute, National Institute of Health, Bethesda, Maryland 20817, United States
| | - Ganesha Rai
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - Ken Chih-Chien Cheng
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States
| | - John Svaren
- Department of Comparative Biosciences, and Waisman Center, University of Wisconsin, Madison, Wisconsin 53705, United States
| | - James Inglese
- National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, Maryland 20850, United States.,National Human Genome Research Institute, National Institute of Health, Bethesda, Maryland 20817, United States
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24
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Kohrman D, Borges BC, Cassinotti L, Ji L, Corfas G. Axon-glia interactions in the ascending auditory system. Dev Neurobiol 2021; 81:546-567. [PMID: 33561889 PMCID: PMC9004231 DOI: 10.1002/dneu.22813] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 11/25/2020] [Accepted: 02/05/2021] [Indexed: 11/09/2022]
Abstract
The auditory system detects and encodes sound information with high precision to provide a high-fidelity representation of the environment and communication. In mammals, detection occurs in the peripheral sensory organ (the cochlea) containing specialized mechanosensory cells (hair cells) that initiate the conversion of sound-generated vibrations into action potentials in the auditory nerve. Neural activity in the auditory nerve encodes information regarding the intensity and frequency of sound stimuli, which is transmitted to the auditory cortex through the ascending neural pathways. Glial cells are critical for precise control of neural conduction and synaptic transmission throughout the pathway, allowing for the precise detection of the timing, frequency, and intensity of sound signals, including the sub-millisecond temporal fidelity is necessary for tasks such as sound localization, and in humans, for processing complex sounds including speech and music. In this review, we focus on glia and glia-like cells that interact with hair cells and neurons in the ascending auditory pathway and contribute to the development, maintenance, and modulation of neural circuits and transmission in the auditory system. We also discuss the molecular mechanisms of these interactions, their impact on hearing and on auditory dysfunction associated with pathologies of each cell type.
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Affiliation(s)
- David Kohrman
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Beatriz C. Borges
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Luis Cassinotti
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Lingchao Ji
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
| | - Gabriel Corfas
- Kresge Hearing Research Institute and Department of Otolaryngology - Head and Neck Surgery, University of Michigan, 1150 West. Medical Center Dr., Ann Arbor, MI 48109, USA
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25
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Miniou P, Fontes M. Therapeutic Development in Charcot Marie Tooth Type 1 Disease. Int J Mol Sci 2021; 22:ijms22136755. [PMID: 34201736 PMCID: PMC8268813 DOI: 10.3390/ijms22136755] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 01/04/2023] Open
Abstract
Charcot–Marie–Tooth disease (CMT) is the most frequent hereditary peripheral neuropathies. It is subdivided in two main groups, demyelinating (CMT1) and axonal (CMT2). CMT1 forms are the most frequent. The goal of this review is to present published data on 1—cellular and animal models having opened new potential therapeutic approaches. 2—exploration of these tracks, including clinical trials. The first conclusion is the great increase of publications on CMT1 subtypes since 2000. We discussed two points that should be considered in the therapeutic development toward a regulatory-approved therapy to be proposed to patients. The first point concerns long term safety if treatments will be a long-term process. The second point relates to the evaluation of treatment efficiency. Degradation of CMT clinical phenotype is not linear and progressive.
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Affiliation(s)
- Pierre Miniou
- InFlectis BioScience SAS, 21 Rue La Noue Bras de Fer, 44200 Nantes, France;
| | - Michel Fontes
- Centre de recherche en CardioVasculaire et Nutrition, Aix-Marseille Université, INRA 1260—INSERM 1263, 13005 Marseille, France
- Repositioning SAS, 8 Rue Napoleon, 20210 Calenzana, France
- Correspondence:
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26
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Moss KR, Bopp TS, Johnson AE, Höke A. New evidence for secondary axonal degeneration in demyelinating neuropathies. Neurosci Lett 2021; 744:135595. [PMID: 33359733 PMCID: PMC7852893 DOI: 10.1016/j.neulet.2020.135595] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Revised: 10/31/2020] [Accepted: 12/19/2020] [Indexed: 12/28/2022]
Abstract
Development of peripheral nervous system (PNS) myelin involves a coordinated series of events between growing axons and the Schwann cell (SC) progenitors that will eventually ensheath them. Myelin sheaths have evolved out of necessity to maintain rapid impulse propagation while accounting for body space constraints. However, myelinating SCs perform additional critical functions that are required to preserve axonal integrity including mitigating energy consumption by establishing the nodal architecture, regulating axon caliber by organizing axonal cytoskeleton networks, providing trophic and potentially metabolic support, possibly supplying genetic translation materials and protecting axons from toxic insults. The intermediate steps between the loss of these functions and the initiation of axon degeneration are unknown but the importance of these processes provides insightful clues. Prevalent demyelinating diseases of the PNS include the inherited neuropathies Charcot-Marie-Tooth Disease, Type 1 (CMT1) and Hereditary Neuropathy with Liability to Pressure Palsies (HNPP) and the inflammatory diseases Acute Inflammatory Demyelinating Polyneuropathy (AIDP) and Chronic Inflammatory Demyelinating Polyneuropathy (CIDP). Secondary axon degeneration is a common feature of demyelinating neuropathies and this process is often correlated with clinical deficits and long-lasting disability in patients. There is abundant electrophysiological and histological evidence for secondary axon degeneration in patients and rodent models of PNS demyelinating diseases. Fully understanding the involvement of secondary axon degeneration in these diseases is essential for expanding our knowledge of disease pathogenesis and prognosis, which will be essential for developing novel therapeutic strategies.
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Affiliation(s)
- Kathryn R Moss
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Taylor S Bopp
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Anna E Johnson
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States
| | - Ahmet Höke
- Department of Neurology, Neuromuscular Division, Johns Hopkins School of Medicine, Baltimore, MD, United States.
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27
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Boutary S, Echaniz-Laguna A, Adams D, Loisel-Duwattez J, Schumacher M, Massaad C, Massaad-Massade L. Treating PMP22 gene duplication-related Charcot-Marie-Tooth disease: the past, the present and the future. Transl Res 2021; 227:100-111. [PMID: 32693030 DOI: 10.1016/j.trsl.2020.07.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 07/02/2020] [Accepted: 07/15/2020] [Indexed: 12/30/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is the most frequent inherited neuropathy, affecting 1/1500 to 1/10000. CMT1A represents 60%-70% of all CMT and is caused by a duplication on chromosome 17p11.2 leading to an overexpression of the Peripheral Myelin Protein 22 (PMP22). PMP22 gene is under tight regulation and small changes in its expression influences myelination and affect motor and sensory functions. To date, CMT1A treatment is symptomatic and classic pharmacological options have been disappointing. Here, we review the past, present, and future treatment options for CMT1A, with a special emphasis on the highly promising potential of PMP22-targeted small interfering RNA and antisense oligonucleotides.
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Affiliation(s)
- Suzan Boutary
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France
| | - Andoni Echaniz-Laguna
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | - David Adams
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | - Julien Loisel-Duwattez
- U 1195, INSERM and Paris-Saclay University, Le Kremlin-Bicêtre, France; Neurology Department, AP-HP, Paris-Saclay Universityand French Referent Center for Familial Amyloid Polyneuropathy and Other Rare Peripheral Neuropathies (CRMR-NNERF), Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | | | - Charbel Massaad
- Faculty of Basic and Biomedical Sciences, Paris Descartes University, INSERM UMRS 1124, Paris, France
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Electron Microscopy Analysis of Sciatic Nerve Fibers in C57BL/6 Transgenic Mice. NEUROPHYSIOLOGY+ 2020. [DOI: 10.1007/s11062-020-09857-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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29
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Zhou Y, Borchelt D, Bauson JC, Fazio S, Miles JR, Tavori H, Notterpek L. Subcellular diversion of cholesterol by gain- and loss-of-function mutations in PMP22. Glia 2020; 68:2300-2315. [PMID: 32511821 DOI: 10.1002/glia.23840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Revised: 03/22/2020] [Accepted: 04/24/2020] [Indexed: 12/13/2022]
Abstract
Abnormalities of the peripheral myelin protein 22 (PMP22) gene, including duplication, deletion and point mutations are a major culprit in Type 1 Charcot-Marie-Tooth (CMT) diseases. The complete absence of PMP22 alters cholesterol metabolism in Schwann cells, which likely contributes to myelination deficits. Here, we examined the subcellular trafficking of cholesterol in distinct models of PMP22-linked neuropathies. In Schwann cells from homozygous Trembler J (TrJ) mice carrying a Leu16Pro mutation, cholesterol was retained with TrJ-PMP22 in the Golgi, alongside a corresponding reduction in its plasma membrane level. PMP22 overexpression, which models CMT1A caused by gene duplication, triggered cholesterol sequestration to lysosomes, and reduced ATP-binding cassette transporter-dependent cholesterol efflux. Conversely, lysosomal targeting of cholesterol by U18666A treatment increased wild type (WT)-PMP22 levels in lysosomes. Mutagenesis of a cholesterol recognition motif, or CRAC domain, in human PMP22 lead to increased levels of PMP22 in the ER and Golgi compartments, along with higher cytosolic, and lower membrane-associated cholesterol. Importantly, cholesterol trafficking defects observed in PMP22-deficient Schwann cells were rescued by WT but not CRAC-mutant-PMP22. We also observed that myelination deficits in dorsal root ganglia explants from heterozygous PMP22-deficient mice were improved by cholesterol supplementation. Collectively, these findings indicate that PMP22 is critical in cholesterol metabolism, and this mechanism is likely a contributing factor in PMP22-linked hereditary neuropathies. Our results provide a basis for understanding how altered expression of PMP22 impacts cholesterol metabolism.
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Affiliation(s)
- Ye Zhou
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - David Borchelt
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Jodi C Bauson
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Sergio Fazio
- Department of Medicine, Knight Cardiovascular Institute, Center for Preventive Cardiology, Oregon Health and Science University, Oregon, Portland, USA
| | - Joshua R Miles
- Department of Medicine, Knight Cardiovascular Institute, Center for Preventive Cardiology, Oregon Health and Science University, Oregon, Portland, USA
| | - Hagai Tavori
- Department of Medicine, Knight Cardiovascular Institute, Center for Preventive Cardiology, Oregon Health and Science University, Oregon, Portland, USA
| | - Lucia Notterpek
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA.,Department of Neurology, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
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30
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Lee JS, Lee JY, Song DW, Bae HS, Doo HM, Yu HS, Lee KJ, Kim HK, Hwang H, Kwak G, Kim D, Kim S, Hong YB, Lee JM, Choi BO. Targeted PMP22 TATA-box editing by CRISPR/Cas9 reduces demyelinating neuropathy of Charcot-Marie-Tooth disease type 1A in mice. Nucleic Acids Res 2020; 48:130-140. [PMID: 31713617 PMCID: PMC7145652 DOI: 10.1093/nar/gkz1070] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 12/26/2022] Open
Abstract
Charcot-Marie-Tooth 1A (CMT1A) is the most common inherited neuropathy without a known therapy, which is caused by a 1.4 Mb duplication on human chromosome 17, which includes the gene encoding the peripheral myelin protein of 22 kDa (PMP22). Overexpressed PMP22 protein from its gene duplication is thought to cause demyelination and subsequently axonal degeneration in the peripheral nervous system (PNS). Here, we targeted TATA-box of human PMP22 promoter to normalize overexpressed PMP22 level in C22 mice, a mouse model of CMT1A harboring multiple copies of human PMP22. Direct local intraneural delivery of CRISPR/Cas9 designed to target TATA-box of PMP22 before the onset of disease, downregulates gene expression of PMP22 and preserves both myelin and axons. Notably, the same approach was effective in partial rescue of demyelination even after the onset of disease. Collectively, our data present a proof-of-concept that CRISPR/Cas9-mediated targeting of TATA-box can be utilized to treat CMT1A.
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Affiliation(s)
- Ji-Su Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, Korea
| | | | | | | | - Hyun M Doo
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, Korea
| | - Ho S Yu
- ToolGen, Inc., Seoul, 08501, Korea
| | | | - Hee K Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea
| | - Hyun Hwang
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea
| | - Geon Kwak
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, Korea
| | - Daesik Kim
- Center for Genome Engineering, Institute for Basic Science (IBS), Seoul, 08826, Korea
- Department of Chemistry, Seoul National University, Seoul, 08826, Korea
| | | | - Young B Hong
- Department of Biochemistry, College of Medicine, Dong-A University, Busan 49201, Korea
| | - Jung M Lee
- School of Life Science, Handong Global University, Pohang 37554, Korea
| | - Byung-Ok Choi
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, 06351, Korea
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, 06351, Korea
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31
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Chittoor-Vinod VG, Bazick H, Todd AG, Falk D, Morelli KH, Burgess RW, Foster TC, Notterpek L. HSP90 Inhibitor, NVP-AUY922, Improves Myelination in Vitro and Supports the Maintenance of Myelinated Axons in Neuropathic Mice. ACS Chem Neurosci 2019; 10:2890-2902. [PMID: 31017387 PMCID: PMC6588339 DOI: 10.1021/acschemneuro.9b00105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
![]()
Hereditary
demyelinating neuropathies linked to peripheral myelin
protein 22 (PMP22) involve the disruption of normal protein trafficking
and are therefore relevant targets for chaperone therapy. Using a
small molecule HSP90 inhibitor, EC137, in cell culture models, we
previously validated the chaperone pathway as a viable target for
therapy development. Here, we tested five commercially available inhibitors
of HSP90 and identified BIIB021 and AUY922 to support Schwann cell
viability and enhance chaperone expression. AUY922 showed higher efficacy,
compared to BIIB021, in enhancing myelin synthesis in dorsal root
ganglion explant cultures from neuropathic mice. For in vivo testing,
we randomly assigned 2–3 month old C22 and 6 week old Trembler
J (TrJ) mice to receive two weekly injections of either vehicle or
AUY922 (2 mg/kg). By the intraperitoneal (i.p.) route, the drug was
well-tolerated by all mice over the 5 month long study, without influence
on body weight or general grooming behavior. AUY922 improved the maintenance
of myelinated nerves of both neuropathic models and attenuated the
decline in rotarod performance and peak muscle force production in
C22 mice. These studies highlight the significance of proteostasis
in neuromuscular function and further validate the HSP90 pathway as
a therapeutic target for hereditary neuropathies.
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Affiliation(s)
- Vinita G. Chittoor-Vinod
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
| | - Hannah Bazick
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
| | - Adrian G. Todd
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida 32611, United States
| | - Darin Falk
- Department of Pediatrics, Powell Gene Therapy Center, University of Florida, Gainesville, Florida 32611, United States
| | - Kathryn H. Morelli
- The Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine 04469, United States
- The Jackson Laboratory, Bar Harbor, Maine 04609, United States
| | - Robert W. Burgess
- The Graduate School of Biomedical Science and Engineering, University of Maine, Orono, Maine 04469, United States
- The Jackson Laboratory, Bar Harbor, Maine 04609, United States
| | - Thomas C. Foster
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
| | - Lucia Notterpek
- Departments of Neuroscience and Neurology, College of Medicine, McKnight Brain Institute, 1149 Newell Drive, Box 100244, Gainesville, Florida 32610-0244, United States
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32
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Lee JS, Kwak G, Kim HJ, Park HT, Choi BO, Hong YB. miR-381 Attenuates Peripheral Neuropathic Phenotype Caused by Overexpression of PMP22. Exp Neurobiol 2019; 28:279-288. [PMID: 31138995 PMCID: PMC6526106 DOI: 10.5607/en.2019.28.2.279] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 04/05/2019] [Accepted: 04/11/2019] [Indexed: 12/21/2022] Open
Abstract
Charcot-Marie Tooth disease type 1A (CMT1A), the major type of CMT, is caused by duplication of peripheral myelin protein 22 (PMP22) gene whose overexpression causes structural and functional abnormalities in myelination. We investigated whether miRNA-mediated regulation of PMP22 expression could reduce the expression level of PMP22, thereby alleviating the demyelinating neuropathic phenotype of CMT1A. We found that several miRNAs were down-regulated in C22 mouse, a CMT1A mouse model. Among them, miR-381 could target 3′ untranslated region (3′UTR) of PMP22 in vitro based on Western botting and quantitative Real Time-PCR (qRT-PCR) results. In vivo efficacy of miR-381 was assessed by administration of LV-miR-381, an miR-381 expressing lentiviral vector, into the sciatic nerve of C22 mice by a single injection at postnatal day 6 (p6). Administration of LV-miR-381 reduced expression level of PMP22 along with elevated level of miR-381 in the sciatic nerve. Rotarod performance analysis revealed that locomotor coordination of LV-miR-381 administered C22 mice was significantly enhanced from 8 weeks post administration. Electrophysiologically, increased motor nerve conduction velocity was observed in treated mice. Histologically, toluidine blue staining and electron microscopy revealed that structural abnormalities of myelination were improved in sciatic nerves of LV-miR-381 treated mice. Therefore, delivery of miR-381 ameliorated the phenotype of peripheral neuropathy in CMT1A mouse model by down-regulating PMP22 expression. These data suggest that miRNA can be used as a potent therapeutic strategy to control diseases with copy number variations such as CMT1A.
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Affiliation(s)
- Ji-Su Lee
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
| | - Geon Kwak
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
| | - Hye Jin Kim
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
| | - Hwan-Tae Park
- Department of Physiology, College of Medicine, Dong-A University, Busan 49201, Korea
| | - Byung-Ok Choi
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea.,Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea
| | - Young Bin Hong
- Department of Biochemistry, College of Medicine, Dong-A University, Busan 49201, Korea
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33
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Tadenev ALD, Burgess RW. Model validity for preclinical studies in precision medicine: precisely how precise do we need to be? Mamm Genome 2019; 30:111-122. [PMID: 30953144 PMCID: PMC6606658 DOI: 10.1007/s00335-019-09798-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 03/27/2019] [Indexed: 12/15/2022]
Abstract
The promise of personalized medicine is that each patient’s treatment can be optimally tailored to their disease. In turn, their disease, as well as their response to the treatment, is determined by their genetic makeup and the “environment,” which relates to their general health, medical history, personal habits, and surroundings. Developing such optimized treatment strategies is an admirable goal and success stories include examples such as switching chemotherapy agents based on a patient’s tumor genotype. However, it remains a challenge to apply precision medicine to diseases for which there is no known effective treatment. Such diseases require additional research, often using experimentally tractable models. Presumably, models that recapitulate as much of the human pathophysiology as possible will be the most predictive. Here we will discuss the considerations behind such “precision models.” What sort of precision is required and under what circumstances? How can the predictive validity of such models be improved? Ultimately, there is no perfect model, but our continually improving ability to genetically engineer a variety of systems allows the generation of more and more precise models. Furthermore, our steadily increasing awareness of risk alleles, genetic background effects, multifactorial disease processes, and gene by environment interactions also allows increasingly sophisticated models that better reproduce patients’ conditions. In those cases where the research has progressed sufficiently far, results from these models appear to often be translating to effective treatments for patients.
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Affiliation(s)
- Abigail L D Tadenev
- The Center for Precision Genetics, The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA
| | - Robert W Burgess
- The Center for Precision Genetics, The Jackson Laboratory, 600 Main Street, Bar Harbor, ME, 04609, USA.
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34
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Park S, Jung N, Myung S, Choi Y, Chung KW, Choi BO, Jung SC. Differentiation of Human Tonsil-Derived Mesenchymal Stem Cells into Schwann-Like Cells Improves Neuromuscular Function in a Mouse Model of Charcot-Marie-Tooth Disease Type 1A. Int J Mol Sci 2018; 19:ijms19082393. [PMID: 30110925 PMCID: PMC6121309 DOI: 10.3390/ijms19082393] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/06/2018] [Accepted: 08/10/2018] [Indexed: 01/18/2023] Open
Abstract
Charcot-Marie-Tooth disease type 1A (CMT1A) is the most common inherited motor and sensory neuropathy, and is caused by duplication of PMP22, alterations of which are a characteristic feature of demyelination. The clinical phenotype of CMT1A is determined by the degree of axonal loss, and patients suffer from progressive muscle weakness and impaired sensation. Therefore, we investigated the potential of Schwann-like cells differentiated from human tonsil-derived stem cells (T-MSCs) for use in neuromuscular regeneration in trembler-J (Tr-J) mice, a model of CMT1A. After differentiation, we confirmed the increased expression of Schwann cell (SC) markers, including glial fibrillary acidic protein (GFAP), nerve growth factor receptor (NGFR), S100 calcium-binding protein B (S100B), glial cell-derived neurotrophic factor (GDNF), and brain-derived neurotrophic factor (BDNF), which suggests the differentiation of T-MSCs into SCs (T-MSC-SCs). To test their functional efficiency, the T-MSC-SCs were transplanted into the caudal thigh muscle of Tr-J mice. Recipients’ improved locomotive activity on a rotarod test, and their sciatic function index, which suggests that transplanted T-MSC-SCs ameliorated demyelination and atrophy of nerve and muscle in Tr-J mice. Histological and molecular analyses showed the possibility of in situ remyelination by T-MSC-SCs transplantation. These findings demonstrate that the transplantation of heterologous T-MSC-SCs induced neuromuscular regeneration in mice and suggest they could be useful for the therapeutic treatment of patients with CMT1A disease.
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Affiliation(s)
- Saeyoung Park
- Department of Biochemistry, College of Medicine, Ewha Womans University, Seoul 07985, Korea.
| | - Namhee Jung
- Department of Biochemistry, College of Medicine, Ewha Womans University, Seoul 07985, Korea.
| | - Seoha Myung
- Department of Biochemistry, College of Medicine, Ewha Womans University, Seoul 07985, Korea.
| | - Yoonyoung Choi
- Department of Biochemistry, College of Medicine, Ewha Womans University, Seoul 07985, Korea.
| | - Ki Wha Chung
- Department of Biological Sciences, Kongju National University, Gongju 32588, Korea.
| | - Byung-Ok Choi
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea.
| | - Sung-Chul Jung
- Department of Biochemistry, College of Medicine, Ewha Womans University, Seoul 07985, Korea.
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35
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Pharmacodynamics and Pharmacokinetics of Lidocaine in a Rodent Model of Diabetic Neuropathy. Anesthesiology 2018; 128:609-619. [DOI: 10.1097/aln.0000000000002035] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Abstract
Background
Clinical and experimental data show that peripheral nerve blocks last longer in the presence of diabetic neuropathy. This may occur because diabetic nerve fibers are more sensitive to local anesthetics or because the local anesthetic concentration decreases more slowly in the diabetic nerve. The aim of this study was to investigate both hypotheses in a rodent model of neuropathy secondary to type 2 diabetes.
Methods
We performed a series of sciatic nerve block experiments in 25 Zucker Diabetic Fatty rats aged 20 weeks with a neuropathy component confirmed by neurophysiology and control rats. We determined in vivo the minimum local anesthetic dose of lidocaine for sciatic nerve block. To investigate the pharmacokinetic hypothesis, we determined concentrations of radiolabeled (14C) lidocaine up to 90 min after administration. Last, dorsal root ganglia were excised for patch clamp measurements of sodium channel activity.
Results
First, in vivo minimum local anesthetic dose of lidocaine for sciatic nerve motor block was significantly lower in diabetic (0.9%) as compared to control rats (1.4%). Second, at 60 min after nerve block, intraneural lidocaine was higher in the diabetic animals. Third, single cell measurements showed a lower inhibitory concentration of lidocaine for blocking sodium currents in neuropathic as compared to control neurons.
Conclusions
We demonstrate increased sensitivity of the diabetic neuropathic nerve toward local anesthetics, and prolonged residence time of local anesthetics in the diabetic neuropathic nerve. In this rodent model of neuropathy, both pharmacodynamic and pharmacokinetic mechanisms contribute to prolonged nerve block duration.
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36
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Kiepura AJ, Kochański A. Charcot-Marie-Tooth type 1A drug therapies: role of adenylyl cyclase activity and G-protein coupled receptors in disease pathomechanism. Acta Neurobiol Exp (Wars) 2018. [DOI: 10.21307/ane-2018-018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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37
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Fazal SV, Gomez-Sanchez JA, Wagstaff LJ, Musner N, Otto G, Janz M, Mirsky R, Jessen KR. Graded Elevation of c-Jun in Schwann Cells In Vivo: Gene Dosage Determines Effects on Development, Remyelination, Tumorigenesis, and Hypomyelination. J Neurosci 2017; 37:12297-12313. [PMID: 29109239 PMCID: PMC5729195 DOI: 10.1523/jneurosci.0986-17.2017] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 09/22/2017] [Accepted: 10/08/2017] [Indexed: 11/21/2022] Open
Abstract
Schwann cell c-Jun is implicated in adaptive and maladaptive functions in peripheral nerves. In injured nerves, this transcription factor promotes the repair Schwann cell phenotype and regeneration and promotes Schwann-cell-mediated neurotrophic support in models of peripheral neuropathies. However, c-Jun is associated with tumor formation in some systems, potentially suppresses myelin genes, and has been implicated in demyelinating neuropathies. To clarify these issues and to determine how c-Jun levels determine its function, we have generated c-Jun OE/+ and c-Jun OE/OE mice with graded expression of c-Jun in Schwann cells and examined these lines during development, in adulthood, and after injury using RNA sequencing analysis, quantitative electron microscopic morphometry, Western blotting, and functional tests. Schwann cells are remarkably tolerant of elevated c-Jun because the nerves of c-Jun OE/+ mice, in which c-Jun is elevated ∼6-fold, are normal with the exception of modestly reduced myelin thickness. The stronger elevation of c-Jun in c-Jun OE/OE mice is, however, sufficient to induce significant hypomyelination pathology, implicating c-Jun as a potential player in demyelinating neuropathies. The tumor suppressor P19ARF is strongly activated in the nerves of these mice and, even in aged c-Jun OE/OE mice, there is no evidence of tumors. This is consistent with the fact that tumors do not form in injured nerves, although they contain proliferating Schwann cells with strikingly elevated c-Jun. Furthermore, in crushed nerves of c-Jun OE/+ mice, where c-Jun levels are overexpressed sufficiently to accelerate axonal regeneration, myelination and function are restored after injury.SIGNIFICANCE STATEMENT In injured and diseased nerves, the transcription factor c-Jun in Schwann cells is elevated and variously implicated in controlling beneficial or adverse functions, including trophic Schwann cell support for neurons, promotion of regeneration, tumorigenesis, and suppression of myelination. To analyze the functions of c-Jun, we have used transgenic mice with graded elevation of Schwann cell c-Jun. We show that high c-Jun elevation is a potential pathogenic mechanism because it inhibits myelination. Conversely, we did not find a link between c-Jun elevation and tumorigenesis. Modest c-Jun elevation, which is beneficial for regeneration, is well tolerated during Schwann cell development and in the adult and is compatible with restoration of myelination and nerve function after injury.
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Affiliation(s)
- Shaline V Fazal
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | - Jose A Gomez-Sanchez
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | - Laura J Wagstaff
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom
| | | | - Georg Otto
- University College London Great Ormond Street Institute of Child Health, London WC1N1EH, United Kingdom, and
| | - Martin Janz
- Max Delbrück Center for Molecular Medicine and Charité, University Hospital Berlin, Campus Benjamin Franklin, 13092 Berlin, Germany
| | - Rhona Mirsky
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom,
| | - Kristján R Jessen
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, United Kingdom,
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38
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Zhao HT, Damle S, Ikeda-Lee K, Kuntz S, Li J, Mohan A, Kim A, Hung G, Scheideler MA, Scherer SS, Svaren J, Swayze EE, Kordasiewicz HB. PMP22 antisense oligonucleotides reverse Charcot-Marie-Tooth disease type 1A features in rodent models. J Clin Invest 2017; 128:359-368. [PMID: 29202483 DOI: 10.1172/jci96499] [Citation(s) in RCA: 106] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 10/03/2017] [Indexed: 11/17/2022] Open
Abstract
Charcot-Marie-Tooth disease type 1A (CMT1A) is caused by duplication of peripheral myelin protein 22 (PMP22) and is the most common hereditary peripheral neuropathy. CMT1A is characterized by demyelination and axonal loss, which underlie slowed motor nerve conduction velocity (MNCV) and reduced compound muscle action potentials (CMAP) in patients. There is currently no known treatment for this disease. Here, we show that antisense oligonucleotides (ASOs) effectively suppress PMP22 mRNA in affected nerves in 2 murine CMT1A models. Notably, initiation of ASO treatment after disease onset restored myelination, MNCV, and CMAP almost to levels seen in WT animals. In addition to disease-associated gene expression networks that were restored with ASO treatment, we also identified potential disease biomarkers through transcriptomic profiling. Furthermore, we demonstrated that reduction of PMP22 mRNA in skin biopsies from ASO-treated rats is a suitable biomarker for evaluating target engagement in response to ASO therapy. These results support the use of ASOs as a potential treatment for CMT1A and elucidate potential disease and target engagement biomarkers for use in future clinical trials.
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Affiliation(s)
| | - Sagar Damle
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
| | | | - Steven Kuntz
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
| | - Jian Li
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Apoorva Mohan
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
| | - Aneeza Kim
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
| | - Gene Hung
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
| | | | - Steven S Scherer
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - John Svaren
- Waisman Center and Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Eric E Swayze
- Ionis Pharmaceuticals Inc., Carlsbad, California, USA
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39
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Ji ZH, Liu ZJ, Liu ZT, Zhao W, Williams BA, Zhang HF, Li L, Xu SY. Diphenyleneiodonium Mitigates Bupivacaine-Induced Sciatic Nerve Damage in a Diabetic Neuropathy Rat Model by Attenuating Oxidative Stress. Anesth Analg 2017; 125:653-661. [PMID: 28682956 DOI: 10.1213/ane.0000000000002186] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Increased oxidative stress has been linked to local anesthetic-induced nerve injury in a diabetic neuropathy (DN) rat model. The current study explores the effects of diphenyleneiodonium (DPI) chloride, an NADPH oxidase (NOX) inhibitor, on bupivacaine-induced sciatic nerve injury in DN rats. METHODS A rat DN model was established through high-fat diet feeding and streptozotocin injection. The model was confirmed via testing (i) blood glucose, (ii) hindpaw allodynia responses to von Frey (VF) monofilaments, (iii) paw withdrawal thermal latency (PWTL), and (iv) nerve conduction velocity (NCV). Bupivacaine (Bup, 0.2 mL, 5 mg/mL) was used to block the right sciatic nerve. DPI (1 mg/kg) was injected subcutaneously 24 hours and 30 minutes before the sciatic block. At 24 hours after the block, NCV, various reactive oxygen species, and Caspase-3 were evaluated to determine the extent of sciatic nerve injury. RESULTS The DN rat model was successfully established. Compared with the DN control group, the postblock values of VF responses (DN-Con, 16.5 ± 1.3 g; DN + Bup, 19.1 ± 1.5 g, P < .001) and PWTL significantly increased (DN-Con, 13.3 ± 1.1 seconds; DN + Bup, 14.6 ± 1.1 seconds, P = .028); the NCV of sciatic nerve was significantly reduced (DN-Con, 38.8 ± 2.4 m/s, DN + Bup, 30.5 ± 2.0 m/s, P = .003), and sciatic nerve injury (as indicated by axonal area) was more severe in the bupivacaine-treated DN group (DN-Con, 11.6 ± 0.3 μm, DN + Bup, 7.5 ± 0.3 μm, P < .001). In addition, DPI treatment significantly improved nerve function (VF responses, 17.3 ± 1.3 g; PWTL, 13.4 ± 1.1 seconds; NCV, 35.6 ± 3.1 m/s) and mitigated loss of axonal area (9.6 ± 0.3 μm). Compared to the DN + Bup group (without DPI), the levels of lipid peroxides and hydroperoxides, as well as the protein expression of NOX2, NOX4, and Caspase-3, were significantly reduced in the DN + Bup + DPI group (P < .05). CONCLUSIONS Subcutaneous injection of DPI appears to protect against the functional and neurohistological damage of bupivacaine-blocked sciatic nerves in a high-fat diet/streptozotocin-induced DN model.
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Affiliation(s)
- Zhong-Hua Ji
- From the *Department of Anesthesiology, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China; and †Department of Anesthesiology, University of Pittsburgh, Pittsburgh, Pennsylvania
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Manganelli F, Pisciotta C, Reilly MM, Tozza S, Schenone A, Fabrizi GM, Cavallaro T, Vita G, Padua L, Gemignani F, Laurà M, Hughes RAC, Solari A, Pareyson D, Santoro L. Nerve conduction velocity in CMT1A: what else can we tell? Eur J Neurol 2016; 23:1566-71. [PMID: 27412484 DOI: 10.1111/ene.13079] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 06/09/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND PURPOSE Charcot-Marie-Tooth disease (CMT) type 1A is characterized by uniformly reduced nerve conduction velocity (NCV) that is fully penetrant since the first years of life, remains fairly stable through the life and does not correlate with disability whereas compound muscular action potential (CMAP) amplitude does. The aim of the present study was to analyze the large amount of electrophysiological data collected in the ascorbic acid trial in Italy and the UK (CMT-TRIAAL/CMT-TRAUK) and to use these data to gain insights into the pathophysiology of NCV in CMT1A. METHODS Baseline electrophysiological data from 271 patients were analysed. Electrophysiological recordings were taken from the motor ulnar, median and peroneal nerves and the sensory ulnar nerve. Distal motor latency (DML), motor (MNCV) and sensory (SNCV) nerve conduction velocity, and amplitudes of CMAPs and sensory action potentials were assessed. Electrophysiological findings were correlated with age of patients at examination and the Charcot-Marie-Tooth Examination Score (CMTES). RESULTS NCV was markedly and uniformly reduced. CMAP amplitudes were overall reduced but more severely in lower limbs. DML decreased and MNCV and SNCV increased with age of the patients, whereas CMAP amplitudes worsened with age and also correlated with CMTES. CONCLUSIONS This is the largest sample of electrophysiological data obtained so far from CMT1A patients. Axonal degeneration as assessed by means of CMAP amplitude reflected clinical impairment and was consistent with a slowly progressive length-dependent neuropathy. All patients typically had markedly slowed NCV that did, however, slightly increase with age of the patients. The improvement of NCV might depend on myelin thickness remodelling that occurs during the adult life of CMT1A patients.
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Affiliation(s)
- F Manganelli
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University Federico II of Naples, Naples, Italy.
| | - C Pisciotta
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University Federico II of Naples, Naples, Italy
| | - M M Reilly
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - S Tozza
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University Federico II of Naples, Naples, Italy
| | - A Schenone
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics and Maternal Infantile Sciences, University of Genoa, Genoa, Italy
| | - G M Fabrizi
- Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - T Cavallaro
- Department of Neuroscience, AOUI, Verona, Italy
| | - G Vita
- Department of Clinical and Experimental Medicine, School of Neurosciences, University of Messina, Messina, Italy
| | - L Padua
- Department of Geriatrics, Neurosciences and Orthopaedics, Università Cattolica del Sacro Cuore, Rome, Italy.,Don Carlo Gnocchi Foundation, Milan, Italy
| | - F Gemignani
- Department of Neurosciences, University of Parma, Parma, Italy
| | - M Laurà
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - R A C Hughes
- MRC Centre for Neuromuscular Diseases, Institute of Neurology, University College London, London, UK
| | - A Solari
- Carlo Besta Neurological Institute, IRCCS Foundation, Milan, Italy
| | - D Pareyson
- Carlo Besta Neurological Institute, IRCCS Foundation, Milan, Italy
| | - L Santoro
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University Federico II of Naples, Naples, Italy
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Gomez-Sanchez JA, Carty L, Iruarrizaga-Lejarreta M, Palomo-Irigoyen M, Varela-Rey M, Griffith M, Hantke J, Macias-Camara N, Azkargorta M, Aurrekoetxea I, De Juan VG, Jefferies HBJ, Aspichueta P, Elortza F, Aransay AM, Martínez-Chantar ML, Baas F, Mato JM, Mirsky R, Woodhoo A, Jessen KR. Schwann cell autophagy, myelinophagy, initiates myelin clearance from injured nerves. J Cell Biol 2015; 210:153-68. [PMID: 26150392 PMCID: PMC4494002 DOI: 10.1083/jcb.201503019] [Citation(s) in RCA: 336] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 06/03/2015] [Indexed: 02/07/2023] Open
Abstract
Although Schwann cell myelin breakdown is the universal outcome of a remarkably wide range of conditions that cause disease or injury to peripheral nerves, the cellular and molecular mechanisms that make Schwann cell-mediated myelin digestion possible have not been established. We report that Schwann cells degrade myelin after injury by a novel form of selective autophagy, myelinophagy. Autophagy was up-regulated by myelinating Schwann cells after nerve injury, myelin debris was present in autophagosomes, and pharmacological and genetic inhibition of autophagy impaired myelin clearance. Myelinophagy was positively regulated by the Schwann cell JNK/c-Jun pathway, a central regulator of the Schwann cell reprogramming induced by nerve injury. We also present evidence that myelinophagy is defective in the injured central nervous system. These results reveal an important role for inductive autophagy during Wallerian degeneration, and point to potential mechanistic targets for accelerating myelin clearance and improving demyelinating disease.
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Affiliation(s)
- Jose A Gomez-Sanchez
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, England, UK
| | - Lucy Carty
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, England, UK
| | - Marta Iruarrizaga-Lejarreta
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Marta Palomo-Irigoyen
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Marta Varela-Rey
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Megan Griffith
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, England, UK
| | - Janina Hantke
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, England, UK
| | - Nuria Macias-Camara
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Mikel Azkargorta
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain ProteoRed-ISCIII
| | - Igor Aurrekoetxea
- Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain Biocruces Health Research Institute, 48903 Barakaldo, Spain
| | - Virginia Gutiérrez De Juan
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Harold B J Jefferies
- The Francis Crick Institute, Lincoln's Inn Fields Laboratory, London WC2A 3LY, England, UK
| | - Patricia Aspichueta
- Department of Physiology, Faculty of Medicine and Dentistry, University of the Basque Country (UPV/EHU), 48940 Leioa, Spain Biocruces Health Research Institute, 48903 Barakaldo, Spain
| | - Félix Elortza
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain ProteoRed-ISCIII
| | - Ana M Aransay
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - María L Martínez-Chantar
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), E-48080 Bilbao, Spain
| | - Frank Baas
- Department of Genome Analysis, Academic Medical Centre, 1105 AZ Amsterdam, Netherlands
| | - José M Mato
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain
| | - Rhona Mirsky
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, England, UK
| | - Ashwin Woodhoo
- CIC bioGUNE, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), 48160 Derio, Bizkaia, Spain Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain
| | - Kristján R Jessen
- Department of Cell and Developmental Biology, University College London, London WC1E 6BT, England, UK
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Hantke J, Carty L, Wagstaff LJ, Turmaine M, Wilton DK, Quintes S, Koltzenburg M, Baas F, Mirsky R, Jessen KR. c-Jun activation in Schwann cells protects against loss of sensory axons in inherited neuropathy. ACTA ACUST UNITED AC 2014; 137:2922-37. [PMID: 25216747 DOI: 10.1093/brain/awu257] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Charcot-Marie-Tooth disease type 1A is the most frequent inherited peripheral neuropathy. It is generally due to heterozygous inheritance of a partial chromosomal duplication resulting in over-expression of PMP22. A key feature of Charcot-Marie-Tooth disease type 1A is secondary death of axons. Prevention of axonal loss is therefore an important target of clinical intervention. We have previously identified a signalling mechanism that promotes axon survival and prevents neuron death in mechanically injured peripheral nerves. This work suggested that Schwann cells respond to injury by activating/enhancing trophic support for axons through a mechanism that depends on upregulation of the transcription factor c-Jun in Schwann cells, resulting in the sparing of axons that would otherwise die. As c-Jun orchestrates Schwann cell support for distressed neurons after mechanical injury, we have now asked: do Schwann cells also activate a c-Jun dependent neuron-supportive programme in inherited demyelinating disease? We tested this by using the C3 mouse model of Charcot-Marie-Tooth disease type 1A. In line with our previous findings in humans with Charcot-Marie-Tooth disease type 1A, we found that Schwann cell c-Jun was elevated in (uninjured) nerves of C3 mice. We determined the impact of this c-Jun activation by comparing C3 mice with double mutant mice, namely C3 mice in which c-Jun had been conditionally inactivated in Schwann cells (C3/Schwann cell-c-Jun(-/-) mice), using sensory-motor tests and electrophysiological measurements, and by counting axons in proximal and distal nerves. The results indicate that c-Jun elevation in the Schwann cells of C3 nerves serves to prevent loss of myelinated sensory axons, particularly in distal nerves, improve behavioural symptoms, and preserve F-wave persistence. This suggests that Schwann cells have two contrasting functions in Charcot-Marie-Tooth disease type 1A: on the one hand they are the genetic source of the disease, on the other, they respond to it by mounting a c-Jun-dependent response that significantly reduces its impact. Because axonal death is a central feature of much nerve pathology it will be important to establish whether an axon-supportive Schwann cell response also takes place in other conditions. Amplification of this axon-supportive mechanism constitutes a novel target for clinical intervention that might be useful in Charcot-Marie-Tooth disease type 1A and other neuropathies that involve axon loss.
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Affiliation(s)
- Janina Hantke
- 1 Department of Cell and Developmental Biology, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Lucy Carty
- 1 Department of Cell and Developmental Biology, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Laura J Wagstaff
- 1 Department of Cell and Developmental Biology, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Mark Turmaine
- 1 Department of Cell and Developmental Biology, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Daniel K Wilton
- 1 Department of Cell and Developmental Biology, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Susanne Quintes
- 1 Department of Cell and Developmental Biology, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | | | - Frank Baas
- 3 Department of Genome Analysis, Academic Medical Centre, Amsterdam, The Netherlands
| | - Rhona Mirsky
- 1 Department of Cell and Developmental Biology, University College London (UCL), Gower Street, London WC1E 6BT, UK
| | - Kristján R Jessen
- 1 Department of Cell and Developmental Biology, University College London (UCL), Gower Street, London WC1E 6BT, UK
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Lirk P, Verhamme C, Boeckh R, Stevens MF, ten Hoope W, Gerner P, Blumenthal S, de Girolami U, van Schaik IN, Hollmann MW, Picardi S. Effects of early and late diabetic neuropathy on sciatic nerve block duration and neurotoxicity in Zucker diabetic fatty rats. Br J Anaesth 2014; 114:319-26. [PMID: 25145353 DOI: 10.1093/bja/aeu270] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The neuropathy of type II diabetes mellitus (DM) is increasing in prevalence worldwide. We aimed to test the hypothesis that in a rodent model of type II DM, neuropathy would lead to increased neurotoxicity and block duration after lidocaine-induced sciatic nerve block when compared with control animals. METHODS Experiments were carried out in Zucker diabetic fatty rats aged 10 weeks (early diabetic) or 18 weeks (late diabetic, with or without insulin 3 units per day), and age-matched healthy controls. Left sciatic nerve block was performed using 0.2 ml lidocaine 2%. Nerve conduction velocity (NCV) and F-wave latency were used to quantify nerve function before, and 1 week after nerve block, after which sciatic nerves were used for neurohistopathology. RESULTS Early diabetic animals did not show increased signs of nerve dysfunction after nerve block. In late diabetic animals without insulin vs control animals, NCV was 34.8 (5.0) vs 41.1 (4.1) ms s(-1) (P<0.01), and F-wave latency was 7.7 (0.5) vs 7.0 (0.2) ms (P<0.01), respectively. Motor nerve block duration was prolonged in late diabetic animals, but neurotoxicity was not. Late diabetic animals receiving insulin showed intermediate results. CONCLUSIONS In a rodent type II DM model, nerves have increased sensitivity for short-acting local anaesthetics without adjuvants in vivo, as evidenced by prolonged block duration. This sensitivity appears to increase with the progression of neuropathy. Our results do not support the hypothesis that neuropathy due to type II DM increases the risk of nerve injury after nerve block.
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Affiliation(s)
- P Lirk
- Department of Anaesthesiology and Laboratory of Experimental Anaesthesiology and Intensive Care (LEICA), University of Amsterdam, Amsterdam, The Netherlands
| | - C Verhamme
- Department of Neurology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - R Boeckh
- Department of Anesthesiology, University of Heidelberg, Heidelberg, Germany
| | - M F Stevens
- Department of Anaesthesiology and Laboratory of Experimental Anaesthesiology and Intensive Care (LEICA), University of Amsterdam, Amsterdam, The Netherlands
| | - W ten Hoope
- Department of Anaesthesiology and Laboratory of Experimental Anaesthesiology and Intensive Care (LEICA), University of Amsterdam, Amsterdam, The Netherlands
| | - P Gerner
- Department of Anesthesiology, Perioperative and Critical Care Medicine, Paracelsus Medical University, Salzburg, Austria
| | - S Blumenthal
- Department of Anaesthesiology and Intensive Care Medicine, Triemli Hospital, Zurich, Switzerland
| | - U de Girolami
- Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - I N van Schaik
- Department of Neurology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - M W Hollmann
- Department of Anaesthesiology and Laboratory of Experimental Anaesthesiology and Intensive Care (LEICA), University of Amsterdam, Amsterdam, The Netherlands
| | - S Picardi
- Department of Anaesthesiology and Laboratory of Experimental Anaesthesiology and Intensive Care (LEICA), University of Amsterdam, Amsterdam, The Netherlands Department of Anesthesiology, University of Heidelberg, Heidelberg, Germany
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van Paassen BW, van der Kooi AJ, van Spaendonck-Zwarts KY, Verhamme C, Baas F, de Visser M. PMP22 related neuropathies: Charcot-Marie-Tooth disease type 1A and Hereditary Neuropathy with liability to Pressure Palsies. Orphanet J Rare Dis 2014; 9:38. [PMID: 24646194 PMCID: PMC3994927 DOI: 10.1186/1750-1172-9-38] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 03/06/2014] [Indexed: 12/18/2022] Open
Abstract
PMP22 related neuropathies comprise (1) PMP22 duplications leading to Charcot-Marie-Tooth disease type 1A (CMT1A), (2) PMP22 deletions, leading to Hereditary Neuropathy with liability to Pressure Palsies (HNPP), and (3) PMP22 point mutations, causing both phenotypes. Overall prevalence of CMT is usually reported as 1:2,500, epidemiological studies show that 20-64% of CMT patients carry the PMP22 duplication. The prevalence of HNPP is not well known. CMT1A usually presents in the first two decades with difficulty walking or running. Distal symmetrical muscle weakness and wasting and sensory loss is present, legs more frequently and more severely affected than arms. HNPP typically leads to episodic, painless, recurrent, focal motor and sensory peripheral neuropathy, preceded by minor compression on the affected nerve. Electrophysiological evaluation is needed to determine whether the polyneuropathy is demyelinating. Sonography of the nerves can be useful. Diagnosis is confirmed by finding respectively a PMP22 duplication, deletion or point mutation. Differential diagnosis includes other inherited neuropathies, and acquired polyneuropathies. The mode of inheritance is autosomal dominant and de novo mutations occur. Offspring of patients have a chance of 50% to inherit the mutation from their affected parent. Prenatal testing is possible; requests for prenatal testing are not common. Treatment is currently symptomatic and may include management by a rehabilitation physician, physiotherapist, occupational therapist and orthopaedic surgeon. Adult CMT1A patients show slow clinical progression of disease, which seems to reflect a process of normal ageing. Life expectancy is normal.
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Affiliation(s)
- Barbara W van Paassen
- Department of Clinical Genetics, Academic Medical Center, Meibergdreef 9, 1105 AZ, Amsterdam, the Netherlands.
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Bouhy D, Timmerman V. Animal models and therapeutic prospects for Charcot-Marie-Tooth disease. Ann Neurol 2013; 74:391-6. [PMID: 23913540 DOI: 10.1002/ana.23987] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Revised: 07/04/2013] [Accepted: 07/29/2013] [Indexed: 12/14/2022]
Abstract
Charcot-Marie-Tooth (CMT) neuropathies are inherited neuromuscular disorders caused by a length-dependent neurodegeneration of peripheral nerves. More than 900 mutations in 60 different genes are causative of the neuropathy. Despite significant progress in therapeutic strategies, the disease remains incurable. The increasing number of genes linked to the disease, and their considerable clinical and genetic heterogeneity render the development of these strategies particularly challenging. In this context, cellular and animals models provide powerful tools. Efficient motor and sensory tests have been developed to assess the behavioral phenotype in transgenic animal models (rodent and fly). When these models reproduce a phenotype comparable to CMT, they allow therapeutic approaches and the discovery of modifiers and biomarkers. In this review, we describe the most convincing transgenic rodent and fly models of CMT and how they can lead to clinical trial. We also discuss the challenges that the research, the clinic, and the pharmaceutical industry will face in developing efficient and accessible treatment for CMT patients.
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Affiliation(s)
- Delphine Bouhy
- Peripheral Neuropathy Group, Department of Molecular Genetics, Flanders Interuniversity Institute for Biotechnology, Institute Born Bunge, University of Antwerp, Antwerp, Belgium
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Biochemical characterization of protein quality control mechanisms during disease progression in the C22 mouse model of CMT1A. ASN Neuro 2013; 5:e00128. [PMID: 24175617 PMCID: PMC3848555 DOI: 10.1042/an20130024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Charcot–Marie–Tooth disease type 1A (CMT1A) is a hereditary demyelinating neuropathy linked with duplication of the peripheral myelin protein 22 (PMP22) gene. Transgenic C22 mice, a model of CMT1A, display many features of the human disease, including slowed nerve conduction velocity and demyelination of peripheral nerves. How overproduction of PMP22 leads to compromised myelin and axonal pathology is not fully understood, but likely involves subcellular alterations in protein homoeostatic mechanisms within affected Schwann cells. The subcellular response to abnormally localized PMP22 includes the recruitment of the ubiquitin–proteasome system (UPS), autophagosomes and heat-shock proteins (HSPs). Here we assessed biochemical markers of these protein homoeostatic pathways in nerves from PMP22-overexpressing neuropathic mice between the ages of 2 and 12 months to ascertain their potential contribution to disease progression. In nerves of 3-week-old mice, using endoglycosidases and Western blotting, we found altered processing of the exogenous human PMP22, an abnormality that becomes more prevalent with age. Along with the ongoing accrual of misfolded PMP22, the activity of the proteasome becomes compromised and proteins required for autophagy induction and lysosome biogenesis are up-regulated. Moreover, cytosolic chaperones are consistently elevated in nerves from neuropathic mice, with the most prominent change in HSP70. The gradual alterations in protein homoeostatic response are accompanied by Schwann cell de-differentiation and macrophage infiltration. Together, these results show that while subcellular protein quality control mechanisms respond appropriately to the presence of the overproduced PMP22, with aging they are unable to prevent the accrual of misfolded proteins. In peripheral nerves of neuropathic C22 mice the frequency of cytosolic PMP22 aggregates increases with age, which elicits a response from protein quality control mechanisms. The combined effects of aging and neuropathic genotype exacerbate disease progression leading to nerve defects.
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Bouhy D, Timmerman V. Modèles animaux dans la maladie de Charcot-Marie-Tooth et applications de la compréhension de la maladie chez l’homme. Rev Neurol (Paris) 2013; 169:971-7. [DOI: 10.1016/j.neurol.2013.07.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2013] [Revised: 07/25/2013] [Accepted: 07/26/2013] [Indexed: 11/26/2022]
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Lee SM, Sha D, Mohammed AA, Asress S, Glass JD, Chin LS, Li L. Motor and sensory neuropathy due to myelin infolding and paranodal damage in a transgenic mouse model of Charcot-Marie-Tooth disease type 1C. Hum Mol Genet 2013; 22:1755-70. [PMID: 23359569 DOI: 10.1093/hmg/ddt022] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Charcot-Marie-Tooth disease type 1C (CMT1C) is a dominantly inherited motor and sensory neuropathy. Despite human genetic evidence linking missense mutations in SIMPLE to CMT1C, the in vivo role of CMT1C-linked SIMPLE mutations remains undetermined. To investigate the molecular mechanism underlying CMT1C pathogenesis, we generated transgenic mice expressing either wild-type or CMT1C-linked W116G human SIMPLE. Mice expressing mutant, but not wild type, SIMPLE develop a late-onset motor and sensory neuropathy that recapitulates key clinical features of CMT1C disease. SIMPLE mutant mice exhibit motor and sensory behavioral impairments accompanied by decreased motor and sensory nerve conduction velocity and reduced compound muscle action potential amplitude. This neuropathy phenotype is associated with focally infolded myelin loops that protrude into the axons at paranodal regions and near Schmidt-Lanterman incisures of peripheral nerves. We find that myelin infolding is often linked to constricted axons with signs of impaired axonal transport and to paranodal defects and abnormal organization of the node of Ranvier. Our findings support that SIMPLE mutation disrupts myelin homeostasis and causes peripheral neuropathy via a combination of toxic gain-of-function and dominant-negative mechanisms. The results from this study suggest that myelin infolding and paranodal damage may represent pathogenic precursors preceding demyelination and axonal degeneration in CMT1C patients.
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Affiliation(s)
- Samuel M Lee
- Department of Pharmacology, Emory University School of Medicine, Atlanta, GA 30322, USA
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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: 181] [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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Fledrich R, Stassart RM, Sereda MW. Murine therapeutic models for Charcot-Marie-Tooth (CMT) disease. Br Med Bull 2012; 102:89-113. [PMID: 22551516 DOI: 10.1093/bmb/lds010] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
INTRODUCTION OR BACKGROUND Charcot-Marie-Tooth (CMT) disease represents a broad group of inherited motor and sensory neuropathies which can originate from various genetic aberrations, e.g. mutations, deletions and duplications. SOURCES OF DATA We performed a literature review on murine animal models of CMT disease with regard to experimental therapeutic approaches. Hereby, we focussed on the demyelinating subforms of CMT (CMT1). PubMed items were CMT, animal model, demyelination and therapy. AREAS OF AGREEMENT Patients affected by CMT suffer from slowly progressive, distally pronounced muscle atrophy caused by an axonal loss. The disease severity is highly variable and impairments may result in wheelchair boundness. No therapy is available yet. AREAS OF CONTROVERSY Numerous rodent models for the various CMT subtypes are available today. The selection of the correct animal model for the specific CMT subtype provides an important prerequisite for the successful translation of experimental findings in patients. GROWING POINTS Despite more than 20 years of remarkable progress in CMT research, the disease is still left untreatable. There is a growing number of experimental therapeutic strategies that may be translated into future clinical trials in patients with CMT. AREAS TIMELY FOR DEVELOPING RESEARCH The slow disease progression and insensitive outcome measures hamper clinical therapy trials in CMT. Biomarkers may provide powerful tools to monitor therapeutic efficacy. Recently, we have shown that transcriptional profiling can be utilized to assess and predict the disease severity in a transgenic rat model and in affected humans.
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Affiliation(s)
- Robert Fledrich
- Research Group 'Molecular and Translational Neurology', Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
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