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Di Tomaso MV, Vázquez Alberdi L, Olsson D, Cancela S, Fernández A, Rosillo JC, Reyes Ábalos AL, Álvarez Zabaleta M, Calero M, Kun A. Colocalization Analysis of Peripheral Myelin Protein-22 and Lamin-B1 in the Schwann Cell Nuclei of Wt and TrJ Mice. Biomolecules 2022; 12:456. [PMID: 35327648 PMCID: PMC8946543 DOI: 10.3390/biom12030456] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/05/2022] [Accepted: 03/12/2022] [Indexed: 12/19/2022] Open
Abstract
Myelination of the peripheral nervous system requires Schwann cells (SC) differentiation into the myelinating phenotype. The peripheral myelin protein-22 (PMP22) is an integral membrane glycoprotein, expressed in SC. It was initially described as a growth arrest-specific (gas3) gene product, up-regulated by serum starvation. PMP22 mutations were pathognomonic for human hereditary peripheral neuropathies, including the Charcot-Marie-Tooth disease (CMT). Trembler-J (TrJ) is a heterozygous mouse model carrying the same pmp22 point mutation as a CMT1E variant. Mutations in lamina genes have been related to a type of peripheral (CMT2B1) or central (autosomal dominant leukodystrophy) neuropathy. We explore the presence of PMP22 and Lamin B1 in Wt and TrJ SC nuclei of sciatic nerves and the colocalization of PMP22 concerning the silent heterochromatin (HC: DAPI-dark counterstaining), the transcriptionally active euchromatin (EC), and the nuclear lamina (H3K4m3 and Lamin B1 immunostaining, respectively). The results revealed that the number of TrJ SC nuclei in sciatic nerves was greater, and the SC volumes were smaller than those of Wt. The myelin protein PMP22 and Lamin B1 were detected in Wt and TrJ SC nuclei and predominantly in peripheral nuclear regions. The level of PMP22 was higher, and those of Lamin B1 lower in TrJ than in Wt mice. The level of PMP22 was higher, and those of Lamin B1 lower in TrJ than in Wt mice. PMP22 colocalized more with Lamin B1 and with the transcriptionally competent EC, than the silent HC with differences between Wt and TrJ genotypes. The results are discussed regarding the probable nuclear role of PMP22 and the relationship with TrJ neuropathy.
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Affiliation(s)
- María Vittoria Di Tomaso
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
| | - Lucía Vázquez Alberdi
- Laboratorio de Biología Celular del Sistema Nervioso Periférico, Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay;
| | - Daniela Olsson
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
| | - Saira Cancela
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
| | - Anabel Fernández
- Laboratorio de Neurobiología Comparada, Departamento de Neurociencias Integrativas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (A.F.); (J.C.R.)
| | - Juan Carlos Rosillo
- Laboratorio de Neurobiología Comparada, Departamento de Neurociencias Integrativas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (A.F.); (J.C.R.)
| | - Ana Laura Reyes Ábalos
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
- Laboratorio de Neurociencias, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay
| | - Magdalena Álvarez Zabaleta
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
| | - Miguel Calero
- Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Unidad de Microscopía Electrónica de Barrido, Universidad de la República, Montevideo 11400, Uruguay
| | - Alejandra Kun
- Laboratorio de Biología Celular del Sistema Nervioso Periférico, Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay;
- Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Unidad de Encefalopatías Espongiformes (UFIEC), 28029 Madrid, Spain;
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Damián JP, Vázquez Alberdi L, Canclini L, Rosso G, Bravo SO, Martínez M, Uriarte N, Ruiz P, Calero M, Di Tomaso MV, Kun A. Central Alteration in Peripheral Neuropathy of Trembler-J Mice: Hippocampal pmp22 Expression and Behavioral Profile in Anxiety Tests. Biomolecules 2021; 11:biom11040601. [PMID: 33921657 PMCID: PMC8074002 DOI: 10.3390/biom11040601] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 04/15/2021] [Accepted: 04/15/2021] [Indexed: 12/14/2022] Open
Abstract
Charcot–Marie–Tooth (CMT) type 1 disease is the most common human hereditary demyelinating neuropathy. Mutations in pmp22 cause about 70% of all CMT1. Trembler-J (TrJ/+) mice are an animal model of CMT1E, having the same spontaneous pmp22 mutation that is found in humans. We compared the behavior profile of TrJ/+ and +/+ (wild-type) in open-field and elevated-plus-maze anxiety tests. In these tests, TrJ/+ showed an exclusive head shake movement, a lower frequency of rearing, but a greater frequency of grooming. In elevated-plus-maze, TrJ/+ defecate more frequently, performed fewer total entries, and have fewer entries to closed arms. These hippocampus-associated behaviors in TrJ/+ are consistent with increased anxiety levels. The expression of pmp22 and soluble PMP22 were evaluated in E17-hippocampal neurons and adult hippocampus by in situ hybridization and successive immunohistochemistry. Likewise, the expression of pmp22 was confirmed by RT-qPCR in the entire isolated hippocampi of both genotypes. Moreover, the presence of aggregated PMP22 was evidenced in unmasked granular hippocampal adult neurons and shows genotypic differences. We showed for the first time a behavior profile trait associated with anxiety and a differential expression of pmp22/PMP22 in hippocampal neurons of TrJ/+ and +/+ mice, demonstrating the involvement at the central level in an animal model of peripheral neuropathy (CMT1E).
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Affiliation(s)
- Juan Pablo Damián
- Unidad de Bioquímica, Departamento de Biociencias Veterinarias, Facultad de Veterinaria, Universidad de la República, 11600 Montevideo, Uruguay;
| | - Lucia Vázquez Alberdi
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.V.A.); (M.M.)
| | - Lucía Canclini
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.C.); (M.V.D.T.)
| | - Gonzalo Rosso
- Max Planck Institute for the Science of Light, Max-Planck-Zentrum für Physik und Medizin, 91058 Erlangen, Germany;
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Silvia Olivera Bravo
- Neurobiología Celular y Molecular, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay;
| | - Mariana Martínez
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.V.A.); (M.M.)
| | - Natalia Uriarte
- Laboratorio de Neurociencias, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay;
| | - Paul Ruiz
- Unidad de Biofísica, Departamento de Biociencias Veterinarias, Facultad de Veterinaria, Universidad de la República, 11600 Montevideo, Uruguay;
| | - Miguel Calero
- Unidad de Encefalopatías Espongiformes, UFIEC, CIBERNED, CIEN Foundation, Queen Sofia Foundation Alzheimer Center, Instituto de Salud Carlos III, 28031 Madrid, Spain;
| | - María Vittoria Di Tomaso
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.C.); (M.V.D.T.)
| | - Alejandra Kun
- Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, 11600 Montevideo, Uruguay; (L.V.A.); (M.M.)
- Sección Bioquímica, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay
- Correspondence: ; Tel.: +598-2487-1616; Fax: +598-2487-5461
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Wang X, Wen Y, Zhang J, Swanson G, Guo S, Cao C, Krawetz SA, Zhang Z, Yuan S. MFN2 interacts with nuage-associated proteins and is essential for male germ cell development by controlling mRNA fate during spermatogenesis. Development 2021; 148:dev.196295. [PMID: 33674260 DOI: 10.1242/dev.196295] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 02/26/2021] [Indexed: 01/06/2023]
Abstract
Mitochondria play a crucial role in spermatogenesis and are regulated by several mitochondrial fusion proteins. However, their functional importance associated with their structure formation and mRNA fate regulation during spermatogenesis remains unclear. Here, we show that mitofusin 2 (MFN2), a mitochondrial fusion protein, interacts with nuage-associated proteins (including MIWI, DDX4, TDRKH and GASZ) in mice. Conditional mutation of Mfn2 in postnatal germ cells results in male sterility due to germ cell developmental defects. Moreover, MFN2 interacts with MFN1, another mitochondrial fusion protein with a high-sequence similarity to MFN2, in testes to facilitate spermatogenesis. Simultaneous mutation of Mfn1 and Mfn2 in testes causes very severe infertile phenotypes. Importantly, we show that MFN2 is enriched in polysome fractions of testes and interacts with MSY2, a germ cell-specific DNA/RNA-binding protein, to control gamete-specific mRNA (such as Spata19) translational activity during spermatogenesis. Collectively, our findings demonstrate that MFN2 interacts with nuage-associated proteins and MSY2 to regulate male germ cell development by controlling several gamete-specific mRNA fates.
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Affiliation(s)
- Xiaoli Wang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Yujiao Wen
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Jin Zhang
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Grace Swanson
- Department of Obstetrics & Gynecology, Wayne State University, Detroit, MI 48201, USA
| | - Shuangshuang Guo
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Congcong Cao
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Stephen A Krawetz
- Department of Obstetrics & Gynecology, Wayne State University, Detroit, MI 48201, USA
| | - Zhibing Zhang
- Department of Obstetrics & Gynecology, Wayne State University, Detroit, MI 48201, USA.,Department of Physiology, Wayne State University, Detroit, MI 48201, USA
| | - Shuiqiao Yuan
- Institute of Reproductive Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.,Shenzhen Huazhong University of Science and Technology Research Institute, Shenzhen, Guangdong 518057, China
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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: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [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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Abstract
Increasing studies have demonstrated multiple signaling molecules responsible for oligodendrocytes and Schwann cells development such as migration, differentiation, myelination, and axo-glial interaction. However, complicated roles in these events are still poorly understood. This chapter focuses on well established intracellular signaling transduction and recent topics that control myelination and are elucidated from accumulating evidences. The underlying molecular mechanisms, which involved in membrane trafficking through small GTPase Arf6 and its activator cytohesins, demonstrate the crosstalk between well established intracellular signaling transduction and a new finding signaling pathway in glial cells links to physiological phenotype and essential role in peripheral nerve system (PNS). Since Arf family proteins affect the expression levels of myelin protein zero (MPZ) and Krox20, which is a transcription factor regulatory factor in early developmental stages of Schwann cells, Arf proteins likely to be key regulator for Schwann cells development. Herein, we discuss how intracellular signaling transductions in Schwann cells associate with myelination in CNS and PNS.
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Affiliation(s)
- Tomohiro Torii
- Graduate School of Brain Science, Doshisha University, Kyotanabe-shi, Kyoto, Japan
| | - Yuki Miyamoto
- Department of Pharmacology, National Research Institute for Child Health and Development, Setagaya, Tokyo, Japan
| | - Junji Yamauchi
- Laboratory of Molecular Neuroscience and Neurology, Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo, Japan.
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Granger N, Luján Feliu-Pascual A, Spicer C, Ricketts S, Hitti R, Forman O, Hersheson J, Houlden H. Charcot-Marie-Tooth type 4B2 demyelinating neuropathy in miniature Schnauzer dogs caused by a novel splicing SBF2 (MTMR13) genetic variant: a new spontaneous clinical model. PeerJ 2019; 7:e7983. [PMID: 31772832 PMCID: PMC6875392 DOI: 10.7717/peerj.7983] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 10/02/2019] [Indexed: 01/23/2023] Open
Abstract
Background Charcot-Marie-Tooth (CMT) disease is the most common neuromuscular disorder in humans affecting 40 out of 100,000 individuals. In 2008, we described the clinical, electrophysiological and pathological findings of a demyelinating motor and sensory neuropathy in Miniature Schnauzer dogs, with a suspected autosomal recessive mode of inheritance based on pedigree analysis. The discovery of additional cases has followed this work and led to a genome-wide association mapping approach to search for the underlying genetic cause of the disease. Methods For genome wide association screening, genomic DNA samples from affected and unaffected dogs were genotyped using the Illumina CanineHD SNP genotyping array. SBF2 and its variant were sequenced using primers and PCRs. RNA was extracted from muscle of an unaffected and an affected dog and RT-PCR performed. Immunohistochemistry for myelin basic protein was performed on peripheral nerve section specimens. Results The genome-wide association study gave an indicative signal on canine chromosome 21. Although the signal was not of genome-wide significance due to the small number of cases, the SBF2 (also known as MTMR13) gene within the region of shared case homozygosity was a strong positional candidate, as 22 genetic variants in the gene have been associated with demyelinating forms of Charcot-Marie-Tooth disease in humans. Sequencing of SBF2 in cases revealed a splice donor site genetic variant, resulting in cryptic splicing and predicted early termination of the protein based on RNA sequencing results. Conclusions This study reports the first genetic variant in Miniature Schnauzer dogs responsible for the occurrence of a demyelinating peripheral neuropathy with abnormally folded myelin. This discovery establishes a genotype/phenotype correlation in affected Miniature Schnauzers that can be used for the diagnosis of these dogs. It further supports the dog as a natural model of a human disease; in this instance, Charcot-Marie-Tooth disease. It opens avenues to search the biological mechanisms responsible for the disease and to test new therapies in a non-rodent large animal model. In particular, recent gene editing methods that led to the restoration of dystrophin expression in a canine model of muscular dystrophy could be applied to other canine models such as this before translation to humans.
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Affiliation(s)
- Nicolas Granger
- Royal Veterinary College, University of London, Hatfield, United Kingdom.,Bristol Veterinary Specialists, CVS Referrals, Bristol, United Kingdom
| | | | - Charlotte Spicer
- Department of Molecular Neuroscience, UCL Institute of Neurology & National Hospital for Neurology and Neurosurgery & London, London, United Kingdom
| | - Sally Ricketts
- Kennel Club Genetics Centre, Animal Health Trust, Newmarket, United Kingdom
| | - Rebekkah Hitti
- Kennel Club Genetics Centre, Animal Health Trust, Newmarket, United Kingdom
| | - Oliver Forman
- Kennel Club Genetics Centre, Animal Health Trust, Newmarket, United Kingdom
| | - Joshua Hersheson
- Department of Molecular Neuroscience, UCL Institute of Neurology & National Hospital for Neurology and Neurosurgery & London, London, United Kingdom
| | - Henry Houlden
- Department of Molecular Neuroscience, UCL Institute of Neurology & National Hospital for Neurology and Neurosurgery & London, London, United Kingdom
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Weihl CC, Udd B, Hanna M. 234th ENMC International Workshop: Chaperone dysfunction in muscle disease Naarden, The Netherlands, 8-10 December 2017. Neuromuscul Disord 2018; 28:1022-1030. [PMID: 30424919 DOI: 10.1016/j.nmd.2018.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Indexed: 01/13/2023]
Affiliation(s)
- Conrad C Weihl
- Department of Neurology, Washington University School of Medicine, Box 8111, 660 South Euclid Avenue, Saint Louis, MO 63110, USA.
| | - Bjarne Udd
- Tampere Neuromuscular Center and Folkhalsan Genetic Institute, Helsinki, Finland
| | - Michael Hanna
- UCL Institute of Neurology, Queen Square, London, UK
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Juneja M, Azmi A, Baets J, Roos A, Jennings MJ, Saveri P, Pisciotta C, Bernard-Marissal N, Schneider BL, Verfaillie C, Chrast R, Seeman P, Hahn AF, de Jonghe P, Maudsley S, Horvath R, Pareyson D, Timmerman V. PFN2 and GAMT as common molecular determinants of axonal Charcot-Marie-Tooth disease. J Neurol Neurosurg Psychiatry 2018; 89:870-878. [PMID: 29449460 DOI: 10.1136/jnnp-2017-317562] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 01/24/2018] [Accepted: 01/30/2018] [Indexed: 11/04/2022]
Abstract
BACKGROUND Charcot-Marie-Tooth type 2 (CMT2) neuropathy is characterised by a vast clinical and genetic heterogeneity complicating its diagnosis and therapeutic intervention. Identification of molecular signatures that are common to multiple CMT2 subtypes can aid in developing therapeutic strategies and measuring disease outcomes. METHODS A proteomics-based approach was performed on lymphoblasts from CMT2 patients genetically diagnosed with different gene mutations to identify differentially regulated proteins. The candidate proteins were validated through real-time quantitative PCR and western blotting on lymphoblast samples of patients and controls, motor neurons differentiated from patient-derived induced pluripotent stem cells (iPSCs) and sciatic nerves of CMT2 mouse models. RESULTS Proteomic profiling of patient lymphoblasts resulted in the identification of profilin 2 (PFN2) and guanidinoacetate methyltransferase (GAMT) as commonly downregulated proteins in different genotypes compared with healthy controls. This decrease was also observed at the transcriptional level on screening 43 CMT2 patients and 22 controls, respectively. A progressive decrease in PFN2 expression with age was observed in patients, while in healthy controls its expression increased with age. Reduced PFN2 expression was also observed in motor neurons differentiated from CMT2 patient-derived iPSCs and sciatic nerves of CMT2 mice when compared with controls. However, no change in GAMT levels was observed in motor neurons and CMT2 mouse-derived sciatic nerves. CONCLUSIONS We unveil PFN2 and GAMT as molecular determinants of CMT2 with possible indications of the role of PFN2 in the pathogenesis and disease progression. This is the first study describing biomarkers that can boost the development of therapeutic strategies targeting a wider spectrum of CMT2 patients.
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Affiliation(s)
- Manisha Juneja
- Peripheral Neuropathy Research Group, University of Antwerp, Antwerp, Belgium.,Institute Born Bunge, Antwerp, Belgium
| | - Abdelkrim Azmi
- VIB Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium
| | - Jonathan Baets
- Institute Born Bunge, Antwerp, Belgium.,VIB Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium.,Neuromuscular Reference Centre, Department of Neurology, Antwerp University Hospital, Antwerpen, Belgium
| | - Andreas Roos
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK.,Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany
| | - Matthew J Jennings
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Paola Saveri
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, Department of Clinical Neurosciences, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - Chiara Pisciotta
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, Department of Clinical Neurosciences, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - Nathalie Bernard-Marissal
- Aix Marseille University, INSERM, MMG, U1251, Marseille, France.,Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Bernard L Schneider
- Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | | | - Roman Chrast
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Pavel Seeman
- DNA Laboratory, Department of Child Neurology, 2nd Medical School, Charles University and University Hospital Motol, Prague, Czech Republic
| | - Angelika F Hahn
- Department of Clinical Neurological Sciences Centre, University Hospital, Western University, London, Ontario, Canada
| | - Peter de Jonghe
- Institute Born Bunge, Antwerp, Belgium.,VIB Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium
| | - Stuart Maudsley
- VIB Center for Molecular Neurology, University of Antwerp, Antwerp, Belgium
| | - Rita Horvath
- Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Davide Pareyson
- Unit of Rare Neurodegenerative and Neurometabolic Diseases, Department of Clinical Neurosciences, C. Besta Neurological Institute IRCCS Foundation, Milan, Italy
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, University of Antwerp, Antwerp, Belgium.,Institute Born Bunge, Antwerp, Belgium
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Schwartz NU, Linzer RW, Truman JP, Gurevich M, Hannun YA, Senkal CE, Obeid LM. Decreased ceramide underlies mitochondrial dysfunction in Charcot-Marie-Tooth 2F. FASEB J 2018; 32:1716-1728. [PMID: 29133339 DOI: 10.1096/fj.201701067r] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Charcot-Marie-Tooth (CMT) disease is the most commonly inherited neurologic disorder, but its molecular mechanisms remain unclear. One variant of CMT, 2F, is characterized by mutations in heat shock protein 27 (Hsp27). As bioactive sphingolipids have been implicated in neurodegenerative diseases, we sought to determine if their dysregulation is involved in CMT. Here, we show that Hsp27 knockout mice demonstrated decreases in ceramide in peripheral nerve tissue and that the disease-associated Hsp27 S135F mutant demonstrated decreases in mitochondrial ceramide. Given that Hsp27 is a chaperone protein, we examined its role in regulating ceramide synthases (CerSs), an enzyme family responsible for catalyzing generation of the sphingolipid ceramide. We determined that CerSs colocalized with Hsp27, and upon the presence of S135F mutants, CerS1 lost its colocalization with mitochondria suggesting that decreased mitochondrial ceramides result from reduced mitochondrial CerS localization rather than decreased CerS activity. Mitochondria in mutant cells appeared larger with increased interconnectivity. Furthermore, mutant cell lines demonstrated decreased mitochondrial respiratory function and increased autophagic flux. Mitochondrial structural and functional changes were recapitulated by blocking ceramide generation pharmacologically. These results suggest that mutant Hsp27 decreases mitochondrial ceramide levels, producing structural and functional changes in mitochondria leading to neuronal degeneration.-Schwartz, N. U., Linzer, R. W., Truman, J.-P., Gurevich, M., Hannun, Y. A., Senkal, C. E., Obeid, L. M. Decreased ceramide underlies mitochondrial dysfunction in Charcot-Marie-Tooth 2F.
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Affiliation(s)
- Nicholas U Schwartz
- Department of Neurobiology and Behavior, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Ryan W Linzer
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Jean-Philip Truman
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Mikhail Gurevich
- Department of Pharmacology, Stony Brook University School of Medicine, Stony Brook, New York, USA.,Department of Orthopaedics, Stony Brook University School of Medicine, Stony Brook, New York, USA; and
| | - Yusuf A Hannun
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Can E Senkal
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA
| | - Lina M Obeid
- Department of Medicine, Stony Brook University School of Medicine, Stony Brook, New York, USA.,Northport Veterans Affairs Medical Center, Northport, New York, USA
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10
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Chandhok G, Lazarou M, Neumann B. Structure, function, and regulation of mitofusin-2 in health and disease. Biol Rev Camb Philos Soc 2017; 93:933-949. [PMID: 29068134 PMCID: PMC6446723 DOI: 10.1111/brv.12378] [Citation(s) in RCA: 140] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 09/20/2017] [Accepted: 09/22/2017] [Indexed: 12/12/2022]
Abstract
Mitochondria are highly dynamic organelles that constantly migrate, fuse, and divide to regulate their shape, size, number, and bioenergetic function. Mitofusins (Mfn1/2), optic atrophy 1 (OPA1), and dynamin-related protein 1 (Drp1), are key regulators of mitochondrial fusion and fission. Mutations in these molecules are associated with severe neurodegenerative and non-neurological diseases pointing to the importance of functional mitochondrial dynamics in normal cell physiology. In recent years, significant progress has been made in our understanding of mitochondrial dynamics, which has raised interest in defining the physiological roles of key regulators of fusion and fission and led to the identification of additional functions of Mfn2 in mitochondrial metabolism, cell signalling, and apoptosis. In this review, we summarize the current knowledge of the structural and functional properties of Mfn2 as well as its regulation in different tissues, and also discuss the consequences of aberrant Mfn2 expression.
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Affiliation(s)
- Gursimran Chandhok
- Department of Anatomy and Developmental Biology, and Neuroscience Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia
| | - Michael Lazarou
- Department of Biochemistry and Molecular Biology, and Neuroscience Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia
| | - Brent Neumann
- Department of Anatomy and Developmental Biology, and Neuroscience Program, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Victoria 3800, Australia
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11
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Falk DJ, Galatas T, Todd AG, Soto EP, Harris AB, Notterpek L. Locomotor and skeletal muscle abnormalities in trembler J neuropathic mice. Muscle Nerve 2017; 57:664-671. [PMID: 29023846 DOI: 10.1002/mus.25987] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2017] [Indexed: 01/26/2023]
Abstract
INTRODUCTION Patients with hereditary peripheral neuropathies exhibit characteristic deformities of the hands and feet and have difficulty ambulating. To examine to what extent neuropathic animals recapitulate these deficits, we studied trembler J (TrJ) mice, which model early-onset demyelinating neuropathy. METHODS A cohort of 4-month-old female wild type and neuropathic mice were evaluated for locomotor measurements, neuromuscular function, and skeletal muscle proteolysis and morphometry. RESULTS Utilizing the DigiGait imaging system, we identified pronounced alterations in forepaw and hindpaw angles and a decrease in hindpaw area on the treadmill in neuropathic rodents. Torque production by the tibialis anterior (TA) muscle was significantly weakened and was paralleled by a decrease in myofiber cross-sectional area and an increase in muscle tissue proteolysis. DISCUSSION Our findings in TrJ mice reflect the phenotypic presentation of the human neuropathy in which patients exhibit weakness of the TA muscle resulting in foot drop and locomotor abnormalities. Muscle Nerve 57: 664-671, 2018.
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Affiliation(s)
- Darin J Falk
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, 1149 Newell Drive, Box 100244 Gainesville, Florida, 32610-0244, USA.,Department of Pediatrics, College of Medicine, University of Florida, Gainesville, Florida, 32610-0244, USA
| | - Tori Galatas
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, 1149 Newell Drive, Box 100244 Gainesville, Florida, 32610-0244, USA
| | - Adrian G Todd
- Department of Pediatrics, College of Medicine, University of Florida, Gainesville, Florida, 32610-0244, USA
| | - Elliott P Soto
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, 1149 Newell Drive, Box 100244 Gainesville, Florida, 32610-0244, USA
| | - Andrew B Harris
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, 1149 Newell Drive, Box 100244 Gainesville, Florida, 32610-0244, USA
| | - Lucia Notterpek
- Department of Neuroscience, College of Medicine, McKnight Brain Institute, University of Florida, 1149 Newell Drive, Box 100244 Gainesville, Florida, 32610-0244, USA.,Department of Neurology, College of Medicine, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
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12
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Villalón E, Jones MR, Sibigtroth C, Zino SJ, Dale JM, Landayan DS, Shen H, Cornelison DDW, Garcia ML. Muscle spindle alterations precede onset of sensorimotor deficits in Charcot-Marie-Tooth type 2E. Genes Brain Behav 2016; 16:260-270. [PMID: 27643807 DOI: 10.1111/gbb.12341] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/11/2016] [Accepted: 09/14/2016] [Indexed: 02/01/2023]
Abstract
Charcot-Marie-Tooth (CMT) is the most common inherited peripheral neuropathy, affecting approximately 2.8 million people. The CMT leads to distal neuropathy that is characterized by reduced motor nerve conduction velocity, ataxia, muscle atrophy and sensory loss. We generated a mouse model of CMT type 2E (CMT2E) expressing human neurofilament light E396K (hNF-LE396K ), which develops decreased motor nerve conduction velocity, ataxia and muscle atrophy by 4 months of age. Symptomatic hNF-LE396K mice developed phenotypes that were consistent with proprioceptive sensory defects as well as reduced sensitivity to mechanical stimulation, while thermal sensitivity and auditory brainstem responses were unaltered. Progression from presymptomatic to symptomatic included a 50% loss of large diameter sensory axons within the fifth lumbar dorsal root of hNF-LE396K mice. Owing to proprioceptive deficits and loss of large diameter sensory axons, we analyzed muscle spindle morphology in presymptomatic and symptomatic hNF-LE396K and hNF-L control mice. Muscle spindle cross-sectional area and volume were reduced in all hNF-LE396K mice analyzed, suggesting that alterations in muscle spindle morphology occurred prior to the onset of typical CMT pathology. These data suggested that CMT2E pathology initiated in the muscle spindles altering the proprioceptive sensory system. Early sensory pathology in CMT2E could provide a unifying hypothesis for the convergence of pathology observed in CMT.
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Affiliation(s)
- E Villalón
- Division of Biological Sciences, Columbia, MO, USA.,C. S. Bond Life Sciences Center, Columbia, MO, USA
| | - M R Jones
- Division of Biological Sciences, Columbia, MO, USA.,C. S. Bond Life Sciences Center, Columbia, MO, USA
| | - C Sibigtroth
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri-Columbia, Columbia, MO, USA
| | - S J Zino
- Division of Biological Sciences, Columbia, MO, USA.,C. S. Bond Life Sciences Center, Columbia, MO, USA
| | - J M Dale
- Division of Biological Sciences, Columbia, MO, USA.,C. S. Bond Life Sciences Center, Columbia, MO, USA
| | - D S Landayan
- Quantitative and Systems Biology, University of California Merced, Merced, CA, USA
| | - H Shen
- Institute of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - D D W Cornelison
- Division of Biological Sciences, Columbia, MO, USA.,C. S. Bond Life Sciences Center, Columbia, MO, USA
| | - M L Garcia
- Division of Biological Sciences, Columbia, MO, USA.,C. S. Bond Life Sciences Center, Columbia, MO, USA
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13
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Saitoh F, Wakatsuki S, Tokunaga S, Fujieda H, Araki T. Glutamate signals through mGluR2 to control Schwann cell differentiation and proliferation. Sci Rep 2016; 6:29856. [PMID: 27432639 PMCID: PMC4949416 DOI: 10.1038/srep29856] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 06/27/2016] [Indexed: 12/31/2022] Open
Abstract
Rapid saltatory nerve conduction is facilitated by myelin structure, which is produced by Schwann cells (SC) in the peripheral nervous system (PNS). Proper development and degeneration/regeneration after injury requires regulated phenotypic changes of SC. We have previously shown that glutamate can induce SC proliferation in culture. Here we show that glutamate signals through metabotropic glutamate receptor 2 (mGluR2) to induce Erk phosphorylation in SC. mGluR2-elicited Erk phosphorylation requires ErbB2/3 receptor tyrosine kinase phosphorylation to limit the signaling cascade that promotes phosphorylation of Erk, but not Akt. We found that Gβγ and Src are involved in subcellular signaling downstream of mGluR2. We also found that glutamate can transform myelinating SC to proliferating SC, while inhibition of mGluR2 signaling can inhibit demyelination of injured nerves in vivo. These data suggest pathophysiological significance of mGluR2 signaling in PNS and its possible therapeutic importance to combat demyelinating disorders including Charcot-Marie-Tooth disease.
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Affiliation(s)
- Fuminori Saitoh
- Department of Peripheral Nervous System Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan.,Department of Anatomy, School of Medicine, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Shuji Wakatsuki
- Department of Peripheral Nervous System Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan
| | - Shinji Tokunaga
- Department of Peripheral Nervous System Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan
| | - Hiroki Fujieda
- Department of Anatomy, School of Medicine, Tokyo Women's Medical University, Tokyo 162-8666, Japan
| | - Toshiyuki Araki
- Department of Peripheral Nervous System Research National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-higashi, Kodaira, Tokyo 187-8502, Japan
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14
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Kagiava A, Sargiannidou I, Theophilidis G, Karaiskos C, Richter J, Bashiardes S, Schiza N, Nearchou M, Christodoulou C, Scherer SS, Kleopa KA. Intrathecal gene therapy rescues a model of demyelinating peripheral neuropathy. Proc Natl Acad Sci U S A 2016; 113:E2421-9. [PMID: 27035961 DOI: 10.1073/pnas.1522202113] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Inherited demyelinating peripheral neuropathies are progressive incurable diseases without effective treatment. To develop a gene therapy approach targeting myelinating Schwann cells that can be translatable, we delivered a lentiviral vector using a single lumbar intrathecal injection and a myelin-specific promoter. The human gene of interest, GJB1, which is mutated in X-linked Charcot-Marie-Tooth Disease (CMT1X), was delivered intrathecally into adult Gjb1-null mice, a genetically authentic model of CMT1X that develops a demyelinating peripheral neuropathy. We obtained widespread, stable, and cell-specific expression of connexin32 in up to 50% of Schwann cells in multiple lumbar spinal roots and peripheral nerves. Behavioral and electrophysiological analysis revealed significantly improved motor performance, quadriceps muscle contractility, and sciatic nerve conduction velocities. Furthermore, treated mice exhibited reduced numbers of demyelinated and remyelinated fibers and fewer inflammatory cells in lumbar motor roots, as well as in the femoral motor and sciatic nerves. This study demonstrates that a single intrathecal lentiviral gene delivery can lead to Schwann cell-specific expression in spinal roots extending to multiple peripheral nerves. This clinically relevant approach improves the phenotype of an inherited neuropathy mouse model and provides proof of principle for treating inherited demyelinating neuropathies.
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15
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Affiliation(s)
- David Fuhrmann
- Department of Cytobiology and Cytopathobiology, Philipps University of Marburg, Robert-Koch-Strasse 6, 35033 Marburg, Germany
| | - Hans-Peter Elsässer
- Department of Cytobiology and Cytopathobiology, Philipps University of Marburg, Robert-Koch-Strasse 6, 35033 Marburg, Germany
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16
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Groh J, Klein I, Hollmann C, Wettmarshausen J, Klein D, Martini R. CSF-1-activated macrophages are target-directed and essential mediators of Schwann cell dedifferentiation and dysfunction in Cx32-deficient mice. Glia 2015; 63:977-86. [PMID: 25628221 DOI: 10.1002/glia.22796] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 01/08/2015] [Accepted: 01/09/2015] [Indexed: 12/26/2022]
Abstract
We investigated connexin 32 (Cx32)-deficient mice, a model for the X-linked form of Charcot-Marie-Tooth neuropathy (CMT1X), regarding the impact of low-grade inflammation on Schwann cell phenotype. Whereas we previously identified macrophages as amplifiers of the neuropathy, we now explicitly focus on the impact of the phagocytes on Schwann cell dedifferentiation, a so far not-yet addressed disease-related mechanism for CMT1X. Using mice heterozygously deficient for Cx32 and displaying both Cx32-positive and -negative Schwann cells in one and the same nerve, we could demonstrate that macrophage clusters rather than single macrophages precisely associate with mutant but not with Cx32-positive Schwann cells. Similarly, in an advanced stage of Schwann cell perturbation, macrophage clusters were strongly associated with NCAM- and L1-positive, dedifferentiated Schwann cells. To clarify the role of macrophages regarding Schwann cell dedifferentiation, we generated Cx32-deficient mice additionally deficient for the macrophage-directed cytokine colony-stimulating factor (CSF)-1. In the absence of CSF-1, Cx32-deficient Schwann cells not only showed the expected amelioration in myelin preservation but also failed to upregulate the Schwann cell dedifferentiation markers NCAM and L1. Another novel and unexpected finding in the double mutants was the retained activation of ERK signaling, a pathway which is detrimental for Schwann cell homeostasis in myelin mutant models. Our findings demonstrate that increased ERK signaling can be compatible with the maintenance of Schwann cell differentiation and homeostasis in vivo and identifies CSF-1-activated macrophages as crucial mediators of detrimental Schwann cell dedifferentiation in Cx32-deficient mice.
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Affiliation(s)
- Janos Groh
- Department of Neurology, Developmental Neurobiology, University Hospital Wuerzburg, Wuerzburg
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17
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Echaniz-Laguna A. The shifting paradigm of Charcot-Marie-Tooth disease. Rev Neurol (Paris) 2015; 171:498-504. [DOI: 10.1016/j.neurol.2014.12.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 11/11/2014] [Accepted: 12/05/2014] [Indexed: 11/16/2022]
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18
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Grice SJ, Sleigh JN, Motley WW, Liu JL, Burgess RW, Talbot K, Cader MZ. Dominant, toxic gain-of-function mutations in gars lead to non-cell autonomous neuropathology. Hum Mol Genet 2015; 24:4397-406. [PMID: 25972375 PMCID: PMC4492401 DOI: 10.1093/hmg/ddv176] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 05/06/2015] [Indexed: 12/15/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) neuropathies are collectively the most common hereditary neurological condition and a major health burden for society. Dominant mutations in the gene GARS, encoding the ubiquitous enzyme, glycyl-tRNA synthetase (GlyRS), cause peripheral nerve degeneration and lead to CMT disease type 2D. This genetic disorder exemplifies a recurring motif in neurodegeneration, whereby mutations in essential, widely expressed genes have selective deleterious consequences for the nervous system. Here, using novel Drosophila models, we show a potential solution to this phenomenon. Ubiquitous expression of mutant GlyRS leads to motor deficits, progressive neuromuscular junction (NMJ) denervation and pre-synaptic build-up of mutant GlyRS. Intriguingly, neuronal toxicity is, at least in part, non-cell autonomous, as expression of mutant GlyRS in mesoderm or muscle alone results in similar pathology. This mutant GlyRS toxic gain-of-function, which is WHEP domain-dependent, coincides with abnormal NMJ assembly, leading to synaptic degeneration, and, ultimately, reduced viability. Our findings suggest that mutant GlyRS gains access to ectopic sub-compartments of the motor neuron, providing a possible explanation for the selective neuropathology caused by mutations in a widely expressed gene.
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Affiliation(s)
- Stuart J Grice
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, UK
| | - James N Sleigh
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK, The Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK
| | - William W Motley
- Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA and
| | - Ji-Long Liu
- MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, UK
| | | | - Kevin Talbot
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK
| | - M Zameel Cader
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK, The Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK,
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19
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20
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Birouk N. [Review of the recent literature on hereditary neuropathies]. Rev Neurol (Paris) 2014; 170:846-9. [PMID: 25459128 DOI: 10.1016/j.neurol.2014.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Revised: 10/08/2014] [Accepted: 10/08/2014] [Indexed: 11/21/2022]
Abstract
The recent literature included interesting reports on the pathogenic mechanisms of hereditary neuropathies. The axonal traffic and its abnormalities in some forms of Charcot-Marie-Tooth (CMT) disease were particularly reviewed by Bucci et al. Many genes related to CMT disease code for proteins that are involved directly or not in intracellular traffic. KIF1B controls vesicle motility on microtubules. MTMR2, MTMR13 and FIG4 regulate the metabolism of phosphoinositide at the level of endosomes. The HSPs are involved in the proteasomal degradation. GDAP1 and MFN2 regulate the mitochondrial fission and fusion respectively and the mitochondial transport within the axon. Pareyson et al. reported a review on peripheral neuropathies in mitochondrial disorders. They used the term of "mitochondrial CMT" for the forms of CMT with abnormal mitochondrial dynamic or structure. Among the new entities, we can draw the attention to a proximal form of hereditary motor and sensory neuropathy with autosomal dominant inheritance, which is characterized by motor deficit with cramps and fasciculations predominating in proximal muscles. Distal sensory deficit can be present. The gene TFG on chromosome 3 has been recently identified to be responsible for this form. Another rare form of axonal autosomal recessive neuropathy due to HNT1 gene mutation is characterized by the presence of hands myotonia that appears later than neuropathy but constitute an interesting clinical hallmark to orientate the diagnosis of this form. In terms of differential diagnosis, CMT4J due to FIG4 mutation can present with a rapidly progressive and asymmetric weakness that resembles CIDP. Bouhy et al. made an interesting review on the therapeutic trials, animal models and the future therapeutic strategies to be developed in CMT disease.
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21
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Sanz-Moreno A, Fuhrmann D, Zankel A, Reingruber H, Kern L, Meijer D, Niemann A, Elsässer HP. Late onset neuropathy with spontaneous clinical remission in mice lacking the POZ domain of the transcription factor Myc-interacting zinc finger protein 1 (Miz1) in Schwann cells. J Biol Chem 2014; 290:727-43. [PMID: 25416780 DOI: 10.1074/jbc.m114.605931] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The transcription factor Miz1 (Myc-interacting zinc finger 1) is a known regulator of the cell cycle but also has cell cycle-independent functions. Here we analyzed the role of Miz1 in the peripheral nervous system, using an early embryonic conditional knock-out model in which the Miz1 POZ domain is ablated in Schwann cells. Although the development of myelinated nerve fibers was not impaired, Miz1ΔPOZ mice acquired behavioral signs of a peripheral neuropathy at the age of 3 months. At this time, ultrastructural analysis of the sciatic nerve showed de- and dysmyelination of fibers, with massive outfoldings and a focal infiltration of macrophages. Although the expression of genes encoding structural myelin proteins, such as periaxin, myelin basic protein, and myelin protein zero, was decreased, genes associated with a negative regulation of myelination, including c-Jun, Sox2, and Id2, were up-regulated in Miz1ΔPOZ mice compared with controls. In animals older than 4 months, the motor disabilities vanished, and the ultrastructure of the sciatic nerve exhibited numerous tomacula and remyelinated fibers, as indicated by thinner myelin. No second acute attack was observed up to the age of 1 year. Thus, the deletion of the Miz1 POZ domain in Schwann cells induces an acute neuropathy with a subsequent regeneration in which there is ongoing balancing between de- and remyelination. Miz1ΔPOZ mice are impaired in the maintenance of myelinated fibers and are a promising model for studying remyelination in adult peripheral nerves.
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Affiliation(s)
- Adrián Sanz-Moreno
- From the Department of Cytobiology and Cytopathobiology, Philipps University of Marburg, Robert-Koch-Strasse 6, 35033 Marburg, Germany
| | - David Fuhrmann
- From the Department of Cytobiology and Cytopathobiology, Philipps University of Marburg, Robert-Koch-Strasse 6, 35033 Marburg, Germany
| | - Armin Zankel
- Graz University of Technology, 8010 Graz, Austria
| | | | - Lara Kern
- From the Department of Cytobiology and Cytopathobiology, Philipps University of Marburg, Robert-Koch-Strasse 6, 35033 Marburg, Germany
| | - Dies Meijer
- Erasmus Medical Center, 3015GE Rotterdam, Netherlands, and
| | | | - Hans-Peter Elsässer
- From the Department of Cytobiology and Cytopathobiology, Philipps University of Marburg, Robert-Koch-Strasse 6, 35033 Marburg, Germany,
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22
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Nobbio L, Visigalli D, Radice D, Fiorina E, Solari A, Lauria G, Reilly MM, Santoro L, Schenone A, Pareyson D. PMP22 messenger RNA levels in skin biopsies: testing the effectiveness of a Charcot-Marie-Tooth 1A biomarker. Brain 2014; 137:1614-20. [PMID: 24812204 DOI: 10.1093/brain/awu071] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Charcot-Marie-Tooth disease type 1A (CMT1A) is associated with increased gene dosage for PMP22. Therapeutic approaches are currently aiming at correcting PMP22 over-expression. It is unknown whether PMP22 can be used as a biological marker of disease progression and therapy efficacy. We performed quantitative real-time polymerase chain reaction on skin biopsies of 45 patients with CMT1A, obtained at study entry and after 24-months of treatment either with ascorbic acid or placebo. Data of a subgroup of patients were also compared with matched healthy subjects. Finally, we analysed PMP22 messenger RNA levels in sural nerve biopsies. We did not find significant differences in the levels of any known PMP22 transcripts in treated or untreated patients with CMT1A, thus confirming that ascorbic acid does not impact on the molecular features of CMT1A. Most importantly, we did not observe any correlation between PMP22 messenger RNA levels and the different clinical and electrophysiological outcome measures, underscoring the weakness of PMP22 to mirror the phenotypic variability of patients with CMT1A. We did not find increased PMP22 messenger RNA levels in skin and sural nerve biopsies of patients with CMT1A compared with relative controls. In conclusion, this study shows that ascorbic acid does not impact on PMP22 transcriptional regulation and PMP22 is not a suitable biomarker for CMT1A.
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Affiliation(s)
- Lucilla Nobbio
- 1 Department of Neurosciences, Rehabilitation Ophthalmology, Genetics and Maternal-Infantile Sciences (DINOGMI), University of Genoa, Largo P. Daneo 3, 16132 Genoa, Italy
| | - Davide Visigalli
- 1 Department of Neurosciences, Rehabilitation Ophthalmology, Genetics and Maternal-Infantile Sciences (DINOGMI), University of Genoa, Largo P. Daneo 3, 16132 Genoa, Italy
| | - Davide Radice
- 2 Department of Epidemiology and Biostatistics, European Institute of Oncology, Via G. Ripamonti 435, 20141 Milan, Italy
| | - Elisabetta Fiorina
- 1 Department of Neurosciences, Rehabilitation Ophthalmology, Genetics and Maternal-Infantile Sciences (DINOGMI), University of Genoa, Largo P. Daneo 3, 16132 Genoa, Italy
| | - Alessandra Solari
- 3 Unit of Neuroepidemiology, IRCCS Foundation, C. Besta Neurological Institute, Via Celoria 11, 20133 Milan, Italy
| | - Giuseppe Lauria
- 4 Headache and Pain Syndromes Unit, IRCCS Foundation, C. Besta Neurological Institute, Via Celoria 11, 20133 Milan, Italy
| | - Mary M Reilly
- 5 MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Lucio Santoro
- 6 Department of Neurosciences, Reproductive Sciences and Odontostomatology, University "Federico II", Corso Umberto I 40, 80138 Naples, Italy
| | - Angelo Schenone
- 1 Department of Neurosciences, Rehabilitation Ophthalmology, Genetics and Maternal-Infantile Sciences (DINOGMI), University of Genoa, Largo P. Daneo 3, 16132 Genoa, Italy
| | - Davide Pareyson
- 7 Clinic of Central and Peripheral Degenerative Neuropathies Unit, IRCCS Foundation, C. Besta Neurological Institute, Via Celoria 11, 20133 Milan, Italy
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23
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Timmerman V, Strickland AV, Züchner S. Genetics of Charcot-Marie-Tooth (CMT) Disease within the Frame of the Human Genome Project Success. Genes (Basel) 2014; 5:13-32. [PMID: 24705285 DOI: 10.3390/genes5010013] [Citation(s) in RCA: 175] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 01/08/2014] [Accepted: 01/10/2014] [Indexed: 02/06/2023] Open
Abstract
Charcot-Marie-Tooth (CMT) neuropathies comprise a group of monogenic disorders affecting the peripheral nervous system. CMT is characterized by a clinically and genetically heterogeneous group of neuropathies, involving all types of Mendelian inheritance patterns. Over 1,000 different mutations have been discovered in 80 disease-associated genes. Genetic research of CMT has pioneered the discovery of genomic disorders and aided in understanding the effects of copy number variation and the mechanisms of genomic rearrangements. CMT genetic study also unraveled common pathomechanisms for peripheral nerve degeneration, elucidated gene networks, and initiated the development of therapeutic approaches. The reference genome, which became available thanks to the Human Genome Project, and the development of next generation sequencing tools, considerably accelerated gene and mutation discoveries. In fact, the first clinical whole genome sequence was reported in a patient with CMT. Here we review the history of CMT gene discoveries, starting with technologies from the early days in human genetics through the high-throughput application of modern DNA analyses. We highlight the most relevant examples of CMT genes and mutation mechanisms, some of which provide promising treatment strategies. Finally, we propose future initiatives to accelerate diagnosis of CMT patients through new ways of sharing large datasets and genetic variants, and at ever diminishing costs.
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