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Younger DS. On the path to evidence-based therapy in neuromuscular disorders. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:315-358. [PMID: 37562877 DOI: 10.1016/b978-0-323-98818-6.00007-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Neuromuscular disorders encompass a diverse group of acquired and genetic diseases characterized by loss of motor functionality. Although cure is the goal, many therapeutic strategies have been envisioned and are being studied in randomized clinical trials and entered clinical practice. As in all scientific endeavors, the successful clinical translation depends on the quality and translatability of preclinical findings and on the predictive value and feasibility of the clinical models. This chapter focuses on five exemplary diseases: childhood spinal muscular atrophy (SMA), Charcot-Marie-Tooth (CMT) disorders, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), acquired autoimmune myasthenia gravis (MG), and Duchenne muscular dystrophy (DMD), to illustrate the progress made on the path to evidenced-based therapy.
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Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
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2
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Younger DS. Neurogenetic motor disorders. HANDBOOK OF CLINICAL NEUROLOGY 2023; 195:183-250. [PMID: 37562870 DOI: 10.1016/b978-0-323-98818-6.00003-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/12/2023]
Abstract
Advances in the field of neurogenetics have practical applications in rapid diagnosis on blood and body fluids to extract DNA, obviating the need for invasive investigations. The ability to obtain a presymptomatic diagnosis through genetic screening and biomarkers can be a guide to life-saving disease-modifying therapy or enzyme replacement therapy to compensate for the deficient disease-causing enzyme. The benefits of a comprehensive neurogenetic evaluation extend to family members in whom identification of the causal gene defect ensures carrier detection and at-risk counseling for future generations. This chapter explores the many facets of the neurogenetic evaluation in adult and pediatric motor disorders as a primer for later chapters in this volume and a roadmap for the future applications of genetics in neurology.
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Affiliation(s)
- David S Younger
- Department of Clinical Medicine and Neuroscience, CUNY School of Medicine, New York, NY, United States; Department of Medicine, Section of Internal Medicine and Neurology, White Plains Hospital, White Plains, NY, United States.
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3
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Gu Y, Guerra F, Hu M, Pope A, Sung K, Yang W, Jetha S, Shoff TA, Gunatilake T, Dahlkamp O, Shi LZ, Manganelli F, Nolano M, Zhou Y, Ding J, Bucci C, Wu C. Mitochondria dysfunction in Charcot Marie Tooth 2B Peripheral Sensory Neuropathy. Commun Biol 2022; 5:717. [PMID: 35851620 PMCID: PMC9293960 DOI: 10.1038/s42003-022-03632-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 06/23/2022] [Indexed: 11/21/2022] Open
Abstract
Rab7 GTPase regulates mitochondrial morphology and function. Missense mutation(s) of Rab7 underlies the pathogenesis of Charcot Marie Tooth 2B (CMT2B) peripheral neuropathy. Herein, we investigate how mitochondrial morphology and function are impacted by the CMT2B associated Rab7V162M mutation. In contrast to recent studies of using heterologous overexpression systems, our results demonstrate significant mitochondrial fragmentation in both human CMT2B patient fibroblasts and CMT2B embryonic fibroblasts (MEFs). Primary cultured E18 dorsal root ganglion (DRG) sensory neurons also show mitochondrial fragmentation and altered axonal mitochondrial movement. In addition, we demonstrate that inhibitors to either the mitochondrial fission protein Drp1 or to the nucleotide binding to Rab7 normalize the mitochondrial deficits in both MEFs and E18 cultured DRG neurons. Our study reveals, for the first time, that expression of CMT2B Rab7 mutation at the physiological level enhances Drp1 activity to promote mitochondrial fission, potentially underlying selective vulnerability of peripheral sensory neurons in CMT2B pathogenesis. The Rab7V162M mutation associated with Charcot Marie Tooth 2B peripheral neuropathy causes mitochondrial fragmentation in patient-derived fibroblasts and primary cultured dorsal root ganglion sensory neurons from E18 mouse embryos.
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Affiliation(s)
- Yingli Gu
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA.,Department of Neurology, the Fourth Hospital of Harbin Medical University, Harbin, 150001, Heilongjiang, China
| | - Flora Guerra
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), Università del Salento, Via Provinciale Lecce-Monteroni n. 165, 73100, Lecce, Italy
| | - Mingzheng Hu
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA
| | - Alexander Pope
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA
| | - Kijung Sung
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA
| | - Wanlin Yang
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA.,Department of Neurology, Zhujiang Hospital of Southern Medical University Guangzhou, Guangzhou, 510280, Guangdong Sheng, China
| | - Simone Jetha
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA
| | - Thomas A Shoff
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA
| | - Tessanya Gunatilake
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA
| | - Owen Dahlkamp
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA
| | - Linda Zhixia Shi
- Department of Bioengineering, University of California San Diego, La Jolla, 92093, CA, USA
| | - Fiore Manganelli
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples "Federico II", Via Sergio Pansini 5, 80131, Naples, Italy
| | - Maria Nolano
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples "Federico II", Via Sergio Pansini 5, 80131, Naples, Italy
| | - Yue Zhou
- School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai, 200030, China
| | - Jianqing Ding
- Institute of Neurology, Ruijin Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA), Università del Salento, Via Provinciale Lecce-Monteroni n. 165, 73100, Lecce, Italy.
| | - Chengbiao Wu
- Department of Neurosciences, University of California San Diego, La Jolla, 92093, CA, USA.
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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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5
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Systematic Identification of circRNAs in Alzheimer's Disease. Genes (Basel) 2021; 12:genes12081258. [PMID: 34440432 PMCID: PMC8391980 DOI: 10.3390/genes12081258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/25/2021] [Accepted: 08/10/2021] [Indexed: 12/13/2022] Open
Abstract
Mammalian circRNAs are covalently closed circular RNAs often generated through backsplicing of precursor linear RNAs. Although their functions are largely unknown, they have been found to influence gene expression at different levels and in a wide range of biological processes. Here, we investigated if some circRNAs may be differentially abundant in Alzheimer’s Disease (AD). We identified and analyzed publicly available RNA-sequencing data from the frontal lobe, temporal cortex, hippocampus, and plasma samples reported from persons with AD and persons who were cognitively normal, focusing on circRNAs shared across these datasets. We identified an overlap of significantly changed circRNAs among AD individuals in the various brain datasets, including circRNAs originating from genes strongly linked to AD pathology such as DOCK1, NTRK2, APC (implicated in synaptic plasticity and neuronal survival) and DGL1/SAP97, TRAPPC9, and KIF1B (implicated in vesicular traffic). We further predicted the presence of circRNA isoforms in AD using specialized statistical analysis packages to create approximations of entire circRNAs. We propose that the catalog of differentially abundant circRNAs can guide future investigation on the expression and splicing of the host transcripts, as well as the possible roles of these circRNAs in AD pathogenesis.
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Dagher R, Massie R, Gentil BJ. MTP deficiency caused by HADHB mutations: Pathophysiology and clinical manifestations. Mol Genet Metab 2021; 133:1-7. [PMID: 33744096 DOI: 10.1016/j.ymgme.2021.03.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 12/17/2022]
Abstract
Mutations in the HADHB gene lead to Mitochondrial Trifunctional Protein (MTP) deficiency. MTP deficiency is a rare autosomal recessive disorder affecting long-chain fatty acid oxidation. Patients affected by MTP deficiency are unable to metabolize long-chain fatty-acids and suffer a variety of symptoms exacerbated during fasting. The three phenotypes associated with complete MTP deficiency are an early-onset cardiomyopathy and early death, an intermediate form with recurrent hypoketotic hypoglycemia and a sensorimotor neuropathy with episodic rhabdomyolysis with small amount of residual enzyme activities. This review aims to discuss the pathophysiological mechanisms and clinical manifestations of each phenotype, which appears different and linked to HADHB expression levels. Notably, the pathophysiology of the sensorimotor neuropathy is relatively unknown and we provide a hypothesis on the qualitative aspect of the role of acylcarnitine buildup in Schwann cells in MTP deficiency patients. We propose that acylcarnitine may exit the Schwann cell and alter membrane properties of nearby axons leading to axonal degeneration based on recent findings in different metabolic disorders.
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Affiliation(s)
- Robin Dagher
- Department of Kinesiology and Physical Education, McGill University, Montreal, QC H3A 2B4, Canada
| | - Rami Massie
- Department of Neurology/Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada
| | - Benoit J Gentil
- Department of Kinesiology and Physical Education, McGill University, Montreal, QC H3A 2B4, Canada; Department of Neurology/Neurosurgery, McGill University, Montreal, QC H3A 2B4, Canada.
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Moutaoufik MT, Tanguay RM. Analysis of insect nuclear small heat shock proteins and interacting proteins. Cell Stress Chaperones 2021; 26:265-274. [PMID: 32888179 PMCID: PMC7736433 DOI: 10.1007/s12192-020-01156-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/13/2020] [Accepted: 08/19/2020] [Indexed: 10/23/2022] Open
Abstract
The small heat shock proteins (sHsps) are a ubiquitous family of ATP-independent stress proteins found in all domains of life. Drosophila melanogaster Hsp27 (DmHsp27) is the only known nuclear sHsp in insect. Here analyzing sequences from HMMER, we identified 56 additional insect sHsps with conserved arginine-rich nuclear localization signal (NLS) in the N-terminal region. At this time, the exact role of nuclear sHsps remains unknown. DmHsp27 protein-protein interaction analysis from iRefIndex database suggests that this protein, in addition to a putative role of molecular chaperone, is likely involved in other nuclear processes (i.e., chromatin remodeling and transcription). Identification of DmHsp27 interactors should provide key insights on the cellular and molecular functions of this nuclear chaperone.
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Affiliation(s)
- Mohamed Taha Moutaoufik
- Lab of Cell & Developmental Genetics, Department of Cellular and Molecular Biology, Medical Biochemistry & Pathology, Medical School, Université Laval, Quebec, G1K 7P4, Canada
- Department of Biochemistry, University of Regina, Regina, SK, S4S 0A2, Canada
| | - Robert M Tanguay
- Lab of Cell & Developmental Genetics, Department of Cellular and Molecular Biology, Medical Biochemistry & Pathology, Medical School, Université Laval, Quebec, G1K 7P4, Canada.
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8
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Rönkkö J, Molchanova S, Revah‐Politi A, Pereira EM, Auranen M, Toppila J, Kvist J, Ludwig A, Neumann J, Bultynck G, Humblet‐Baron S, Liston A, Paetau A, Rivera C, Harms MB, Tyynismaa H, Ylikallio E. Dominant mutations in ITPR3 cause Charcot-Marie-Tooth disease. Ann Clin Transl Neurol 2020; 7:1962-1972. [PMID: 32949214 PMCID: PMC7545616 DOI: 10.1002/acn3.51190] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 08/24/2020] [Accepted: 08/24/2020] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVE ITPR3, encoding inositol 1,4,5-trisphosphate receptor type 3, was previously reported as a potential candidate disease gene for Charcot-Marie-Tooth neuropathy. Here, we present genetic and functional evidence that ITPR3 is a Charcot-Marie-Tooth disease gene. METHODS Whole-exome sequencing of four affected individuals in an autosomal dominant family and one individual who was the only affected individual in his family was used to identify disease-causing variants. Skin fibroblasts from two individuals of the autosomal dominant family were analyzed functionally by western blotting, quantitative reverse transcription PCR, and Ca2+ imaging. RESULTS Affected individuals in the autosomal dominant family had onset of symmetrical neuropathy with demyelinating and secondary axonal features at around age 30, showing signs of gradual progression with severe distal leg weakness and hand involvement in the proband at age 64. Exome sequencing identified a heterozygous ITPR3 p.Val615Met variant segregating with the disease. The individual who was the only affected in his family had disease onset at age 4 with demyelinating neuropathy. His condition was progressive, leading to severe muscle atrophy below knees and atrophy of proximal leg and hand muscles by age 16. Trio exome sequencing identified a de novo ITPR3 variant p.Arg2524Cys. Altered Ca2+ -transients in p.Val615Met patient fibroblasts suggested that the variant has a dominant-negative effect on inositol 1,4,5-trisphosphate receptor type 3 function. INTERPRETATION Together with two previously identified variants, our report adds further evidence that ITPR3 is a disease-causing gene for CMT and indicates altered Ca2+ homeostasis in disease pathogenesis.
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Affiliation(s)
- Julius Rönkkö
- Stem Cells and Metabolism Research ProgramFaculty of MedicineUniversity of HelsinkiHelsinkiFinland
| | - Svetlana Molchanova
- Stem Cells and Metabolism Research ProgramFaculty of MedicineUniversity of HelsinkiHelsinkiFinland
- Molecular and Integrative Biosciences Research ProgramFaculty of Bio‐ and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | - Anya Revah‐Politi
- Institute for Genomic MedicineColumbia University Medical CenterNew YorkNew YorkUSA
- Precision Genomics LaboratoryColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Elaine M. Pereira
- Department of PediatricsColumbia University Irving Medical CenterNew YorkNew YorkUSA
| | - Mari Auranen
- Clinical NeurosciencesNeurologyUniversity of Helsinki and Helsinki University HospitalHelsinkiFinland
| | - Jussi Toppila
- Department of Clinical NeurophysiologyMedical Imaging CenterHelsinki University Central HospitalHelsinkiFinland
| | - Jouni Kvist
- Stem Cells and Metabolism Research ProgramFaculty of MedicineUniversity of HelsinkiHelsinkiFinland
| | - Anastasia Ludwig
- Neuroscience CenterHelsinki Institute of Life ScienceUniversity of HelsinkiHelsinkiFinland
| | - Julika Neumann
- Department of Microbiology and ImmunologyLaboratory of Adaptive ImmunityKU LeuvenLeuvenBelgium
- VIB‐KU Leuven Center for Brain and Disease ResearchLeuvenBelgium
| | - Geert Bultynck
- Laboratory of Molecular and Cellular SignalingDepartment of Cellular and Molecular Medicine & Leuven Kanker InstituutKU LeuvenLeuvenBelgium
| | | | - Adrian Liston
- Department of Microbiology and ImmunologyLaboratory of Adaptive ImmunityKU LeuvenLeuvenBelgium
- VIB‐KU Leuven Center for Brain and Disease ResearchLeuvenBelgium
- Laboratory of Lymphocyte Signalling and DevelopmentBabraham InstituteCambridgeUnited Kingdom
| | - Anders Paetau
- Department of PathologyHUSLAB and University of HelsinkiHelsinkiFinland
| | - Claudio Rivera
- Neuroscience CenterHelsinki Institute of Life ScienceUniversity of HelsinkiHelsinkiFinland
- Institut de Neurobiologie de la Méditerranée INMED UMR901MarseilleFrance
| | | | - Henna Tyynismaa
- Stem Cells and Metabolism Research ProgramFaculty of MedicineUniversity of HelsinkiHelsinkiFinland
- Neuroscience CenterHelsinki Institute of Life ScienceUniversity of HelsinkiHelsinkiFinland
- Department of Medical and Clinical GeneticsUniversity of HelsinkiHelsinkiFinland
| | - Emil Ylikallio
- Stem Cells and Metabolism Research ProgramFaculty of MedicineUniversity of HelsinkiHelsinkiFinland
- Clinical NeurosciencesNeurologyUniversity of Helsinki and Helsinki University HospitalHelsinkiFinland
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Giudetti AM, Guerra F, Longo S, Beli R, Romano R, Manganelli F, Nolano M, Mangini V, Santoro L, Bucci C. An altered lipid metabolism characterizes Charcot-Marie-Tooth type 2B peripheral neuropathy. Biochim Biophys Acta Mol Cell Biol Lipids 2020; 1865:158805. [PMID: 32829064 DOI: 10.1016/j.bbalip.2020.158805] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 07/20/2020] [Accepted: 08/17/2020] [Indexed: 12/12/2022]
Abstract
Charcot-Marie Tooth type 2B (CMT2B) is a rare inherited peripheral neuropathy caused by five missense mutations in the RAB7A gene, which encodes a small GTPase of the RAB family. Currently, no cure is available for this disease. In this study, we approached the disease by comparing the lipid metabolism of CMT2B-derived fibroblasts to that of healthy controls. We found that CMT2B cells showed increased monounsaturated fatty acid level and increased expression of key enzymes of monounsaturated and polyunsaturated fatty acid synthesis. Moreover, in CMT2B cells a higher expression of acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), key enzymes of de novo fatty acid synthesis, with a concomitantly increased [1-14C]acetate incorporation into fatty acids, was observed. The expression of diacylglycerol acyltransferase 2, a rate-limiting enzyme in triacylglycerol synthesis, as well as triacylglycerol levels were increased in CMT2B compared to control cells. In addition, as RAB7A controls lipid droplet breakdown and lipid droplet dynamics have been linked to diseases, we analyzed these organelles and showed that in CMT2B cells there is a strong accumulation of lipid droplets compared to control cells, thus reinforcing our data on abnormal lipid metabolism in CMT2B. Furthermore, we demonstrated that ACC and FAS expression levels changed upon RAB7 silencing or overexpression in HeLa cells, thus suggesting that metabolic modifications observed in CMT2B-derived fibroblasts can be, at least in part, related to RAB7 mutations.
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Affiliation(s)
- Anna Maria Giudetti
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni n. 165, 73100 Lecce, Italy.
| | - Flora Guerra
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni n. 165, 73100 Lecce, Italy
| | - Serena Longo
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni n. 165, 73100 Lecce, Italy
| | - Raffaella Beli
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni n. 165, 73100 Lecce, Italy
| | - Roberta Romano
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni n. 165, 73100 Lecce, Italy
| | - Fiore Manganelli
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples "Federico II", Via Sergio Pansini 5, 80131, Naples, Italy
| | - Maria Nolano
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples "Federico II", Via Sergio Pansini 5, 80131, Naples, Italy; Istituti Clinici Scientifici Maugeri IRCCS, Department of Neurology of Telese Terme Institute, 82037 Telese Terme, Benevento, Italy
| | - Vincenzo Mangini
- Center for Biomolecular Nanotechnologies@UniLe, Istituto Italiano di Tecnologia, 73010 Arnesano (LE), Italy
| | - Lucio Santoro
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples "Federico II", Via Sergio Pansini 5, 80131, Naples, Italy
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Monteroni n. 165, 73100 Lecce, Italy.
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Muranova LK, Sudnitsyna MV, Strelkov SV, Gusev NB. Mutations in HspB1 and hereditary neuropathies. Cell Stress Chaperones 2020; 25:655-665. [PMID: 32301006 PMCID: PMC7332652 DOI: 10.1007/s12192-020-01099-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2020] [Indexed: 12/12/2022] Open
Abstract
Charcot-Marie-Tooth (CMT) disease is major hereditary neuropathy. CMT has been linked to mutations in a range of proteins, including the small heat shock protein HspB1. Here we review the properties of several HspB1 mutants associated with CMT. In vitro, mutations in the N-terminal domain lead to a formation of larger HspB1 oligomers when compared with the wild-type (WT) protein. These mutants are resistant to phosphorylation-induced dissociation and reveal lower chaperone-like activity than the WT on a range of model substrates. Mutations in the α-crystallin domain lead to the formation of yet larger HspB1 oligomers tending to dissociate at low protein concentration and having variable chaperone-like activity. Mutations in the conservative IPV motif within the C-terminal domain induce the formation of very large oligomers with low chaperone-like activity. Most mutants interact with a partner small heat shock protein, HspB6, in a manner different from that of the WT protein. The link between the altered physico-chemical properties and the pathological CMT phenotype is a subject of discussion. Certain HspB1 mutations appear to have an effect on cytoskeletal elements such as intermediate filaments and/or microtubules, and by this means damage the axonal transport. In addition, mutations of HspB1 can affect the metabolism in astroglia and indirectly modulate the viability of motor neurons. While the mechanisms of pathological mutations in HspB1 are likely to vary greatly across different mutations, further in vitro and in vivo studies are required for a better understanding of the CMT disease at molecular level.
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Affiliation(s)
- Lydia K Muranova
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation, 119991
| | - Maria V Sudnitsyna
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation, 119991
| | - Sergei V Strelkov
- Department of Pharmaceutical and Pharmacological Sciences, Laboratory for Biocrystallography, KU Leuven, 3000, Leuven, Belgium
| | - Nikolai B Gusev
- Department of Biochemistry, School of Biology, Moscow State University, Moscow, Russian Federation, 119991.
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11
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Rudenok M, Alieva A, Starovatykh J, Nesterov M, Stanishevskaya V, Kolacheva A, Ugryumov M, Slominsky P, Shadrina M. Expression analysis of genes involved in mitochondrial biogenesis in mice with MPTP-induced model of Parkinson's disease. Mol Genet Metab Rep 2020; 23:100584. [PMID: 32280590 PMCID: PMC7139113 DOI: 10.1016/j.ymgmr.2020.100584] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 03/23/2020] [Accepted: 03/24/2020] [Indexed: 01/23/2023] Open
Abstract
The mitochondrion is an extremely important organelle that performs various functions in the cell: e.g. energy production, regulation of respiration processes and maintenance of calcium homeostasis. Disruption of the biogenesis and functioning of this organelle can lead to cell damage and cell death. Mitochondrial dysfunction has been shown to possibly be involved in the pathogenesis of Parkinson's disease. However, the role of genes associated with mitochondrial biogenesis in the early stages of disease remains poorly understood. The objective of the present study was to analyze changes in the expression of activator (Nrf1, Ppargc1a, Prkn, and Kif1b) and repressor (Zfp746 and Mybbp1a) genes of mitochondrial biogenesis in the early stages of the development of neurodegeneration in an MPTP-induced model of presymptomatic and early symptomatic stages of PD. Statistically significant changes in expression at the mRNA level were detected for all studied genes. There was mainly a decrease in the expression of activator genes (Nrf1, Ppargc1a, Prkn, and Kif1b) at all stages of neurodegeneration, which seemed to be associated with impaired mitochondrial biogenesis and the development of neurodegeneration processes. A predominant decrease in the expression was detected for the Zfp746 and Mybbp1a repressor genes of mitochondrial biogenesis. However, in this case, it was associated with the emergence of compensatory mechanisms during the development of Parkinson's disease. The largest number of statistically significant changes was detected for the Nrf1 activator gene and the Mybbp1a repressor gene. Apparently, these two genes play the most important role in this disease.
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Affiliation(s)
- M.M. Rudenok
- Laboratory of Molecular Genetics of Hereditary Diseases, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - A.Kh. Alieva
- Laboratory of Molecular Genetics of Hereditary Diseases, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - J.S. Starovatykh
- Laboratory of Molecular Genetics of Hereditary Diseases, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - M.S. Nesterov
- Bioanalytical Research Laboratory, Scientific Center of Biomedical Technologies of the Federal Medical and Biological Agency of Russia, Moscow, Russia
| | - V.A. Stanishevskaya
- Laboratory of Molecular Genetics of Hereditary Diseases, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - A.A. Kolacheva
- Laboratory of Nervous and Neuro-endocrine Regulations, Koltsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia
| | - M.V. Ugryumov
- Laboratory of Nervous and Neuro-endocrine Regulations, Koltsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia
| | - P.A. Slominsky
- Laboratory of Molecular Genetics of Hereditary Diseases, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - M.I. Shadrina
- Laboratory of Molecular Genetics of Hereditary Diseases, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
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Sancho P, Bartesaghi L, Miossec O, García-García F, Ramírez-Jiménez L, Siddell A, Åkesson E, Hedlund E, Laššuthová P, Pascual-Pascual SI, Sevilla T, Kennerson M, Lupo V, Chrast R, Espinós C. Characterization of molecular mechanisms underlying the axonal Charcot-Marie-Tooth neuropathy caused by MORC2 mutations. Hum Mol Genet 2020; 28:1629-1644. [PMID: 30624633 DOI: 10.1093/hmg/ddz006] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 12/27/2018] [Accepted: 01/01/2019] [Indexed: 12/20/2022] Open
Abstract
Mutations in MORC2 lead to an axonal form of Charcot-Marie-Tooth (CMT) neuropathy type 2Z. To date, 31 families have been described with mutations in MORC2, indicating that this gene is frequently involved in axonal CMT cases. While the genetic data clearly establish the causative role of MORC2 in CMT2Z, the impact of its mutations on neuronal biology and their phenotypic consequences in patients remains to be clarified. We show that the full-length form of MORC2 is highly expressed in both embryonic and adult human neural tissues and that Morc2 expression is dynamically regulated in both the developing and the maturing murine nervous system. To determine the effect of the most common MORC2 mutations, p.S87L and p.R252W, we used several in vitro cell culture paradigms. Both mutations induced transcriptional changes in patient-derived fibroblasts and when expressed in rodent sensory neurons. These changes were more pronounced and accompanied by abnormal axonal morphology, in neurons expressing the MORC2 p.S87L mutation, which is associated with a more severe clinical phenotype. These data provide insight into the neuronal specificity of the mutated MORC2-mediated phenotype and highlight the importance of neuronal cell models to study the pathophysiology of CMT2Z.
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Affiliation(s)
- Paula Sancho
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Luca Bartesaghi
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Olivia Miossec
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Francisco García-García
- Unit of Bioinformatics and Biostatistics, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Laura Ramírez-Jiménez
- Department of Genomics and Translational Genetics, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Anna Siddell
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Concord NSW, Australia.,Sydney Medical School, University of Sydney, Sydney NSW, Australia
| | - Elisabet Åkesson
- Division of Neurodegeneration, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden.,The R&D Unit, Stiftelsen Stockholms Sjukhemm, 14152, Sweden
| | - Eva Hedlund
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Petra Laššuthová
- Department of Pediatric Neurology, DNA Laboratory, 2nd Faculty of Medicine, Charles University in Prague and University Hospital Motol, Prague, Czech Republic
| | | | - Teresa Sevilla
- Department of Neurology, Hospital Universitari i Politècnic La Fe, and CIBER of Rare Diseases (CIBERER), Valencia, Spain.,Department of Medicine, University of Valencia, Valencia, Spain
| | - Marina Kennerson
- Northcott Neuroscience Laboratory, ANZAC Research Institute, Concord NSW, Australia.,Sydney Medical School, University of Sydney, Sydney NSW, Australia.,Molecular Medicine Laboratory, Concord Hospital, Concord NSW, Australia
| | - Vincenzo Lupo
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.,Department of Genomics and Translational Genetics, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.,INCLIVA & IIS-La Fe Rare Diseases Joint Units, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Roman Chrast
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Neuroscience, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Carmen Espinós
- Unit of Genetics and Genomics of Neuromuscular and Neurodegenerative Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.,Department of Genomics and Translational Genetics, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain.,INCLIVA & IIS-La Fe Rare Diseases Joint Units, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
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13
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Whole exome sequencing reveals a broader variant spectrum of Charcot-Marie-Tooth disease type 2. Neurogenetics 2019; 21:79-86. [PMID: 31832804 DOI: 10.1007/s10048-019-00591-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 09/12/2019] [Indexed: 12/21/2022]
Abstract
Charcot-Marie-Tooth disease type 2 (CMT2) is a clinically and genetically heterogeneous inherited neuropathy. Although new causative and disease-associated genes have been identified for CMT2 in recent years, molecular diagnoses are still lacking for a majority of patients. We here studied a cohort of 35 CMT2 patients of Chinese descent, using whole exome sequencing to investigate gene mutations and then explored relationships among genotypes, clinical features, and mitochondrial DNA levels in blood as assessed by droplet digital PCR. We identified pathogenic variants in 57% of CMT2 patients. The most common genetic causes in the cohort were MFN2 mutations. Two patients with typical CMT phenotype and neuromyotonia were detected to harbor compound heterozygous variations in the HINT1 gene. In conclusion, our work supports that the molecular diagnostic rate of CMT2 patients can be increased via whole exome sequencing, and our data suggest that assessment of possible HINT1 mutations should be undertaken for CMT2 patients with neuromyotonia.
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Charcot-Marie-Tooth 2F (Hsp27 mutations): A review. Neurobiol Dis 2019; 130:104505. [PMID: 31212070 DOI: 10.1016/j.nbd.2019.104505] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 06/11/2019] [Accepted: 06/13/2019] [Indexed: 12/13/2022] Open
Abstract
Charcot-Marie-Tooth disease is a commonly inherited form of neuropathy. Although named over 100 years ago, identification of subtypes of Charcot-Marie-Tooth has rapidly expanded in the preceding decades with the advancement of genetic sequencing, including type 2F (CMT2F), due to mutations in heat shock protein 27 (Hsp27). However, despite CMT being one of the most common inherited neurological diseases, definitive mechanistic models of pathology and effective treatments for CMT2F are lacking. This review extensively profiles the published literature on CMT2F and distal hereditary motor neuropathy II (dHMN II), a similar neuropathy with exclusively motor symptoms that is also due to mutations in Hsp27. This includes a review of case reports and sequencing studies detailing disease course. Included are tables listing of all known published mutations of Hsp27 that cause symptoms of CMT2F and dHMN II. Furthermore, pathological mechanisms are assessed. While many groups have established pathologies relating to defective chaperone function, cellular neurofilament and microtubule structure and function, and mitochondrial and metabolic dysfunction, there are still discrepancies in results between different model systems. Moreover, initial mouse models have also produced promising results with similar phenotypes to humans, however discrepancies still exist. Both patient-focused and scientific studies have demonstrated variability in phenotypes even considering specific mutations. Given the clinical heterogeneity in presentation, CMT2F and dHMN II likely result from similar pathological mechanisms of the same general disease process that may present distinctly due to other genetic and environment influences. Determining how these influences exert their effects to produce pathology contributing to the disease phenotype will be a major future challenge ahead in the field.
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15
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Jia W, Zhu J, Fu W, Zhu S, Deng F, Xia H, Liu GC, He J. Association of NEFL Gene Polymorphisms with Wilms' Tumor Susceptibility in Chinese Children. JOURNAL OF ONCOLOGY 2019; 2019:3518149. [PMID: 31057612 PMCID: PMC6463584 DOI: 10.1155/2019/3518149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 02/13/2019] [Indexed: 02/07/2023]
Abstract
Wilms' tumor is renal tumor of childhood, characterized by the appearance of embryonic renal tissue and other kidney malformations. The genetic etiology of sporadic Wilms' tumor remains largely unknown. Neurofilament light (NEFL) is a tumor suppressor. We evaluated the association between three NEFL gene polymorphisms (rs11994014 G>A, rs2979704 T>C and rs1059111 A>T) and Wilms' tumor susceptibility in a Chinese population consisting of 145 cases and 531 controls. In the single locus analysis, rs2979704 CC variant genotype was associated with a decreased risk of Wilms' tumor [CC vs. TT: adjusted odds ratio (OR)=0.48, 95% confidence interval (CI)=0.24-0.94; CC vs. TT+CT: adjusted OR=0.51, 95% CI=0.27-0.97]. We also observed that carriers of the three protective genotypes had significantly decreased risk of Wilms' tumor when compared to those with 0-2 protective genotypes (adjusted OR=0.49, 95% CI=0.25-0.95). The association between rs11994014 G>A or rs1059111 A>T polymorphisms and Wilms' tumor susceptibility did not reach statistical significance. No significant association was detected in the stratified analyses. Our findings suggested that the NEFL rs2979704 T>C polymorphism may be associated with Wilms' tumor susceptibility in the Chinese population.
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Affiliation(s)
- Wei Jia
- 1Department of Pediatric Urology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, Guangdong, China
| | - Jinhong Zhu
- 2Department of Clinical Laboratory, Molecular Epidemiology Laboratory, Harbin Medical University Cancer Hospital, Harbin 150040, Heilongjiang, China
| | - Wen Fu
- 1Department of Pediatric Urology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, Guangdong, China
| | - Shibo Zhu
- 1Department of Pediatric Urology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, Guangdong, China
| | - Fuming Deng
- 1Department of Pediatric Urology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, Guangdong, China
| | - Huimin Xia
- 3Department of Pediatric Surgery, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, Guangdong, China
| | - Guo-Chang Liu
- 1Department of Pediatric Urology, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, Guangdong, China
| | - Jing He
- 3Department of Pediatric Surgery, Guangzhou Institute of Pediatrics, Guangzhou Women and Children's Medical Center, Guangzhou Medical University, Guangzhou 510623, Guangdong, China
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16
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Miller DJ, Fort PE. Heat Shock Proteins Regulatory Role in Neurodevelopment. Front Neurosci 2018; 12:821. [PMID: 30483047 PMCID: PMC6244093 DOI: 10.3389/fnins.2018.00821] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/22/2018] [Indexed: 01/20/2023] Open
Abstract
Heat shock proteins (Hsps) are a large family of molecular chaperones that are well-known for their roles in protein maturation, re-folding and degradation. While some Hsps are constitutively expressed in certain regions, others are rapidly upregulated in the presence of stressful stimuli. Numerous stressors, including hyperthermia and hypoxia, can induce the expression of Hsps, which, in turn, interact with client proteins and co-chaperones to regulate cell growth and survival. Such interactions must be tightly regulated, especially at critical points during embryonic and postnatal development. Hsps exhibit specific patterns of expression consistent with a spatio-temporally regulated role in neurodevelopment. There is also growing evidence that Hsps may promote or inhibit neurodevelopment through specific pathways regulating cell differentiation, neurite outgrowth, cell migration, or angiogenesis. This review will examine the regulatory role that these individual chaperones may play in neurodevelopment, and will focus specifically on the signaling pathways involved in the maturation of neuronal and glial cells as well as the underlying vascular network.
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Affiliation(s)
- David J Miller
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, United States.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
| | - Patrice E Fort
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI, United States.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, United States
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17
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Kalmar B, Innes A, Wanisch K, Kolaszynska AK, Pandraud A, Kelly G, Abramov AY, Reilly MM, Schiavo G, Greensmith L. Mitochondrial deficits and abnormal mitochondrial retrograde axonal transport play a role in the pathogenesis of mutant Hsp27-induced Charcot Marie Tooth Disease. Hum Mol Genet 2018; 26:3313-3326. [PMID: 28595321 PMCID: PMC5808738 DOI: 10.1093/hmg/ddx216] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 05/25/2017] [Indexed: 11/26/2022] Open
Abstract
Mutations in the small heat shock protein Hsp27, encoded by the HSPB1 gene, have been shown to cause Charcot Marie Tooth Disease type 2 (CMT-2) or distal hereditary motor neuropathy (dHMN). Protein aggregation and axonal transport deficits have been implicated in the disease. In this study, we conducted analysis of bidirectional movements of mitochondria in primary motor neuron axons expressing wild type and mutant Hsp27. We found significantly slower retrograde transport of mitochondria in Ser135Phe, Pro39Leu and Arg140Gly mutant Hsp27 expressing motor neurons than in wild type Hsp27 neurons, although anterograde movement velocities remained normal. Retrograde transport of other important cargoes, such as the p75 neurotrophic factor receptor was minimally altered in mutant Hsp27 neurons, implicating that axonal transport deficits primarily affect mitochondria and the axonal transport machinery itself is less affected. Investigation of mitochondrial function revealed a decrease in mitochondrial membrane potential in mutant Hsp27 expressing motor axons, as well as a reduction in mitochondrial complex 1 activity, increased vulnerability of mitochondria to mitochondrial stressors, leading to elevated superoxide release and reduced mitochondrial glutathione (GSH) levels, although cytosolic GSH remained normal. This mitochondrial redox imbalance in mutant Hsp27 motor neurons is likely to cause low level of oxidative stress, which in turn will contribute to, and indeed may be the underlying cause of the deficits in mitochondrial axonal transport. Together, these findings suggest that the mitochondrial abnormalities in mutant Hsp27-induced neuropathies may be a primary cause of pathology, leading to further deficits in the mitochondrial axonal transport and onset of disease.
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Affiliation(s)
| | - Amy Innes
- Sobell Department of Motor Neuroscience and Movement Disorders.,MRC Centre for Neuromuscular Diseases
| | - Klaus Wanisch
- Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square House, Queen Square, London WC1N 3BG, UK
| | | | - Amelie Pandraud
- MRC Centre for Neuromuscular Diseases.,Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square House, Queen Square, London WC1N 3BG, UK
| | - Gavin Kelly
- Bioinformatics and Biostatistics Science Technology Platform, The Francis Crick Institute, London NW1?1AT, UK
| | | | - Mary M Reilly
- MRC Centre for Neuromuscular Diseases.,Department of Molecular Neuroscience, UCL Institute of Neurology, Queen Square House, Queen Square, London WC1N 3BG, UK
| | | | - Linda Greensmith
- Sobell Department of Motor Neuroscience and Movement Disorders.,MRC Centre for Neuromuscular Diseases
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18
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Terenzio M, Schiavo G, Fainzilber M. Compartmentalized Signaling in Neurons: From Cell Biology to Neuroscience. Neuron 2017; 96:667-679. [PMID: 29096079 DOI: 10.1016/j.neuron.2017.10.015] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 09/27/2017] [Accepted: 10/09/2017] [Indexed: 12/18/2022]
Abstract
Neurons are the largest known cells, with complex and highly polarized morphologies. As such, neuronal signaling is highly compartmentalized, requiring sophisticated transfer mechanisms to convey and integrate information within and between sub-neuronal compartments. Here, we survey different modes of compartmentalized signaling in neurons, highlighting examples wherein the fundamental cell biological processes of protein synthesis and degradation, membrane trafficking, and organelle transport are employed to enable the encoding and integration of information, locally and globally within a neuron. Comparisons to other cell types indicate that neurons accentuate widely shared mechanisms, providing invaluable models for the compartmentalization and transfer mechanisms required and used by most eukaryotic cells.
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Affiliation(s)
- Marco Terenzio
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Giampietro Schiavo
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London WC1N 3BG, UK; Discoveries Centre for Regenerative and Precision Medicine at UCL, London WC1N 3BG, UK; UK Dementia Research Institute at UCL, London WC1E 6BT, UK
| | - Mike Fainzilber
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.
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19
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Prior R, Van Helleputte L, Benoy V, Van Den Bosch L. Defective axonal transport: A common pathological mechanism in inherited and acquired peripheral neuropathies. Neurobiol Dis 2017; 105:300-320. [DOI: 10.1016/j.nbd.2017.02.009] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 01/29/2017] [Accepted: 02/20/2017] [Indexed: 12/29/2022] Open
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20
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Axonal transport deficits in multiple sclerosis: spiraling into the abyss. Acta Neuropathol 2017; 134:1-14. [PMID: 28315956 PMCID: PMC5486629 DOI: 10.1007/s00401-017-1697-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/13/2017] [Accepted: 03/14/2017] [Indexed: 12/16/2022]
Abstract
The transport of mitochondria and other cellular components along the axonal microtubule cytoskeleton plays an essential role in neuronal survival. Defects in this system have been linked to a large number of neurological disorders. In multiple sclerosis (MS) and associated models such as experimental autoimmune encephalomyelitis (EAE), alterations in axonal transport have been shown to exist before neurodegeneration occurs. Genome-wide association (GWA) studies have linked several motor proteins to MS susceptibility, while neuropathological studies have shown accumulations of proteins and organelles suggestive for transport deficits. A reduced effectiveness of axonal transport can lead to neurodegeneration through inhibition of mitochondrial motility, disruption of axoglial interaction or prevention of remyelination. In MS, demyelination leads to dysregulation of axonal transport, aggravated by the effects of TNF-alpha, nitric oxide and glutamate on the cytoskeleton. The combined effect of all these pathways is a vicious cycle in which a defective axonal transport system leads to an increase in ATP consumption through loss of membrane organization and a reduction in available ATP through inhibition of mitochondrial transport, resulting in even further inhibition of transport. The persistent activity of this positive feedback loop contributes to neurodegeneration in MS.
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21
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Moutaoufik MT, Morrow G, Maaroufi H, Férard C, Finet S, Tanguay RM. Oligomerization and chaperone-like activity of Drosophila melanogaster small heat shock protein DmHsp27 and three arginine mutants in the alpha-crystallin domain. Cell Stress Chaperones 2017; 22:455-466. [PMID: 27933579 PMCID: PMC5465024 DOI: 10.1007/s12192-016-0748-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/09/2016] [Accepted: 11/10/2016] [Indexed: 11/30/2022] Open
Abstract
The small Hsp DmHsp27 from Drosophila melanogaster is one of the few small heat shock proteins (sHsps) found within the nucleus. We report that its dimerization is independent of disulfide bond formation and seems to rely on salt bridges. Unlike metazoan sHsps, DmHsp27 forms two populations of oligomers not in equilibrium. Mutations at highly conserved arginine residues in mammalian sHsps have been reported to be associated with protein conformational defects and intracellular aggregation. Independent mutation of three highly conserved arginines (R122, R131, and R135) to glycine in DmHsp27 results in only one population of higher molecular weight form. In vitro, the chaperone-like activity of wild-type DmHsp27 was comparable with that of its two isolated populations and to the single population of the R122G, R131G, and R135G using luciferase as substrate. However, using insulin, the chaperone-like activity of wild-type DmHsp27 was lower than that of R122G and R131G mutants. Altogether, the results characterize wild-type DmHsp27 and its alpha-crystallin domain (ACD) arginine mutants and may give insight into protection mechanism of sHsps.
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Affiliation(s)
- Mohamed Taha Moutaoufik
- Laboratoire de génétique cellulaire et développementale, Département de biologie moléculaire, de biochimie médicale et de pathologie, Institut de biologie intégrative et des systèmes (IBIS) and PROTEO, Université Laval, Québec, G1V 0A6, Canada
| | - Geneviève Morrow
- Laboratoire de génétique cellulaire et développementale, Département de biologie moléculaire, de biochimie médicale et de pathologie, Institut de biologie intégrative et des systèmes (IBIS) and PROTEO, Université Laval, Québec, G1V 0A6, Canada
| | - Halim Maaroufi
- Plate-forme de bio-informatique, Institut de biologie intégrative et des systèmes (IBIS), Université Laval, Québec, G1V 0A6, Canada
| | - Céline Férard
- IMPMC UMR7590, CNRS, UPMC Paris 6, 4 place Jussieu, Paris, France
| | - Stéphanie Finet
- IMPMC UMR7590, CNRS, UPMC Paris 6, 4 place Jussieu, Paris, France
| | - Robert M Tanguay
- Laboratoire de génétique cellulaire et développementale, Département de biologie moléculaire, de biochimie médicale et de pathologie, Institut de biologie intégrative et des systèmes (IBIS) and PROTEO, Université Laval, Québec, G1V 0A6, Canada.
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22
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23
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HDAC6 Inhibitors Rescued the Defective Axonal Mitochondrial Movement in Motor Neurons Derived from the Induced Pluripotent Stem Cells of Peripheral Neuropathy Patients with HSPB1 Mutation. Stem Cells Int 2016; 2016:9475981. [PMID: 28105056 PMCID: PMC5220520 DOI: 10.1155/2016/9475981] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 11/11/2016] [Accepted: 11/22/2016] [Indexed: 12/21/2022] Open
Abstract
The Charcot-Marie-Tooth disease 2F (CMT2F) and distal hereditary motor neuropathy 2B (dHMN2B) are caused by autosomal dominantly inherited mutations of the heat shock 27 kDa protein 1 (HSPB1) gene and there are no specific therapies available yet. Here, we assessed the potential therapeutic effect of HDAC6 inhibitors on peripheral neuropathy with HSPB1 mutation using in vitro model of motor neurons derived from induced pluripotent stem cells (iPSCs) of CMT2F and dHMN2B patients. The absolute velocity of mitochondrial movements and the percentage of moving mitochondria in axons were lower both in CMT2F-motor neurons and in dHMN2B-motor neurons than those in controls, and the severity of the defective mitochondrial movement was different between the two disease models. CMT2F-motor neurons and dHMN2B-motor neurons also showed reduced α-tubulin acetylation compared with controls. The newly developed HDAC6 inhibitors, CHEMICAL X4 and CHEMICAL X9, increased acetylation of α-tubulin and reversed axonal movement defects of mitochondria in CMT2F-motor neurons and dHMN2B-motor neurons. Our results suggest that the neurons derived from patient-specific iPSCs can be used in drug screening including HDAC6 inhibitors targeting peripheral neuropathy.
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24
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Lupo V, Aguado C, Knecht E, Espinós C. Chaperonopathies: Spotlight on Hereditary Motor Neuropathies. Front Mol Biosci 2016; 3:81. [PMID: 28018906 PMCID: PMC5155517 DOI: 10.3389/fmolb.2016.00081] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 11/29/2016] [Indexed: 12/18/2022] Open
Abstract
Distal hereditary motor neuropathies (dHMN) are a group of rare hereditary neuromuscular disorders characterized by an atrophy that affects peroneal muscles in the absence of sensory symptoms. To date, 23 genes are thought to be responsible for dHMN, four of which encode chaperones: DNAJB2, which encodes a member of the HSP40/DNAJ co-chaperone family; and HSPB1, HSPB3, and HSPB8, encoding three members of the small heat shock protein family. While around 30 different mutations in HSPB1 have been identified, the remaining three genes are altered in many fewer cases. Indeed, a mutation of HSPB3 has only been described in one case, whereas a few cases have been reported carrying mutations in DNAJB2 and HSPB8, most of them caused by a founder c.352+1G>A mutation in DNAJB2 and by mutations affecting the K141 residue in the HSPB8 chaperone. Hence, their rare occurrence makes it difficult to understand the pathological mechanisms driven by such mutations in this neuropathy. Chaperones can assemble into multi-chaperone complexes that form an integrated chaperone network within the cell. Such complexes fulfill relevant roles in a variety of processes, such as the correct folding of newly synthesized proteins, in which chaperones escort them to precise cellular locations, and as a response to protein misfolding, which includes the degradation of proteins that fail to refold properly. Despite this range of functions, mutations in some of these chaperones lead to diseases with a similar clinical profile, suggesting common pathways. This review provides an overview of the genetics of those dHMNs that share a common disease mechanism and that are caused by mutations in four genes encoding chaperones: DNAJB2, HSPB1, HSPB3, and HSPB8.
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Affiliation(s)
- Vincenzo Lupo
- Molecular Basis of Human Diseases Program, Centro de Investigación Príncipe FelipeValencia, Spain; INCLIVA & IIS La Fe Rare Diseases Joint UnitsValencia, Spain
| | - Carmen Aguado
- Molecular Basis of Human Diseases Program, Centro de Investigación Príncipe FelipeValencia, Spain; INCLIVA & IIS La Fe Rare Diseases Joint UnitsValencia, Spain; Centro de Investigación Biomédica en RedValencia, Spain
| | - Erwin Knecht
- Molecular Basis of Human Diseases Program, Centro de Investigación Príncipe FelipeValencia, Spain; INCLIVA & IIS La Fe Rare Diseases Joint UnitsValencia, Spain; Centro de Investigación Biomédica en RedValencia, Spain
| | - Carmen Espinós
- Molecular Basis of Human Diseases Program, Centro de Investigación Príncipe FelipeValencia, Spain; INCLIVA & IIS La Fe Rare Diseases Joint UnitsValencia, Spain
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25
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Nefedova VV, Muranova LK, Sudnitsyna MV, Ryzhavskaya AS, Gusev NB. Small Heat Shock Proteins and Distal Hereditary Neuropathies. BIOCHEMISTRY (MOSCOW) 2016; 80:1734-47. [PMID: 26878578 DOI: 10.1134/s000629791513009x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Classification of small heat shock proteins (sHsp) is presented and processes regulated by sHsp are described. Symptoms of hereditary distal neuropathy are described and the genes whose mutations are associated with development of this congenital disease are listed. The literature data and our own results concerning physicochemical properties of HspB1 mutants associated with Charcot-Marie-Tooth disease are analyzed. Mutations of HspB1, associated with hereditary motor neuron disease, can be accompanied by change of the size of HspB1 oligomers, by decreased stability under unfavorable conditions, by changes in the interaction with protein partners, and as a rule by decrease of chaperone-like activity. The largest part of these mutations is accompanied by change of oligomer stability (that can be either increased or decreased) or by change of intermonomer interaction inside an oligomer. Data on point mutation of HspB3 associated with axonal neuropathy are presented. Data concerning point mutations of Lys141 of HspB8 and those associated with hereditary neuropathy and different forms of Charcot-Marie-Tooth disease are analyzed. It is supposed that point mutations of sHsp associated with distal neuropathies lead either to loss of function (for instance, decrease of chaperone-like activity) or to gain of harmful functions (for instance, increase of interaction with certain protein partners).
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Affiliation(s)
- V V Nefedova
- Lomonosov Moscow State University, Faculty of Biology, Moscow, 119991, Russia.
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Bertholet AM, Delerue T, Millet AM, Moulis MF, David C, Daloyau M, Arnauné-Pelloquin L, Davezac N, Mils V, Miquel MC, Rojo M, Belenguer P. Mitochondrial fusion/fission dynamics in neurodegeneration and neuronal plasticity. Neurobiol Dis 2015; 90:3-19. [PMID: 26494254 DOI: 10.1016/j.nbd.2015.10.011] [Citation(s) in RCA: 252] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 09/16/2015] [Accepted: 10/13/2015] [Indexed: 12/17/2022] Open
Abstract
Mitochondria are dynamic organelles that continually move, fuse and divide. The dynamic balance of fusion and fission of mitochondria determines their morphology and allows their immediate adaptation to energetic needs, keeps mitochondria in good health by restoring or removing damaged organelles or precipitates cells in apoptosis in cases of severe defects. Mitochondrial fusion and fission are essential in mammals and their disturbances are associated with several diseases. However, while mitochondrial fusion/fission dynamics, and the proteins that control these processes, are ubiquitous, associated diseases are primarily neurological disorders. Accordingly, inactivation of the main actors of mitochondrial fusion/fission dynamics is associated with defects in neuronal development, plasticity and functioning, both ex vivo and in vivo. Here, we present the central actors of mitochondrial fusion and fission and review the role of mitochondrial dynamics in neuronal physiology and pathophysiology. Particular emphasis is placed on the three main actors of these processes i.e. DRP1,MFN1-2, and OPA1 as well as on GDAP1, a protein of the mitochondrial outer membrane preferentially expressed in neurons. This article is part of a Special Issue entitled: Mitochondria & Brain.
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Affiliation(s)
- A M Bertholet
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - T Delerue
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - A M Millet
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - M F Moulis
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - C David
- CNRS, Institut de Biochimie et Génétique Cellulaires (IBGC), UMR5095, Bordeaux, France; Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires (IBGC), UMR5095, Bordeaux, France
| | - M Daloyau
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - L Arnauné-Pelloquin
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - N Davezac
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - V Mils
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - M C Miquel
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France
| | - M Rojo
- CNRS, Institut de Biochimie et Génétique Cellulaires (IBGC), UMR5095, Bordeaux, France; Université de Bordeaux, Institut de Biochimie et Génétique Cellulaires (IBGC), UMR5095, Bordeaux, France.
| | - P Belenguer
- Université de Toulouse, Centre de Biologie du Développement, CNRS, UMR5547/Université Paul Sabatier, Toulouse, France; CNRS, Centre de Biologie du Développement, UMR5547/Université Paul Sabatier, Toulouse, France.
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Kevenaar JT, Hoogenraad CC. The axonal cytoskeleton: from organization to function. Front Mol Neurosci 2015; 8:44. [PMID: 26321907 PMCID: PMC4536388 DOI: 10.3389/fnmol.2015.00044] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/31/2015] [Indexed: 01/20/2023] Open
Abstract
The axon is the single long fiber that extends from the neuron and transmits electrical signals away from the cell body. The neuronal cytoskeleton, composed of microtubules (MTs), actin filaments and neurofilaments, is not only required for axon formation and axonal transport but also provides the structural basis for several specialized axonal structures, such as the axon initial segment (AIS) and presynaptic boutons. Emerging evidence suggest that the unique cytoskeleton organization in the axon is essential for its structure and integrity. In addition, the increasing number of neurodevelopmental and neurodegenerative diseases linked to defect in actin- and microtubule-dependent processes emphasizes the importance of a properly regulated cytoskeleton for normal axonal functioning. Here, we provide an overview of the current understanding of actin and microtubule organization within the axon and discuss models for the functional role of the cytoskeleton at specialized axonal structures.
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Affiliation(s)
- Josta T. Kevenaar
- Cell Biology, Faculty of Science, Utrecht UniversityUtrecht, Netherlands
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29
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Midbrain dopamine neurons in Parkinson's disease exhibit a dysregulated miRNA and target-gene network. Brain Res 2015; 1618:111-21. [PMID: 26047984 DOI: 10.1016/j.brainres.2015.05.021] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Revised: 05/09/2015] [Accepted: 05/15/2015] [Indexed: 11/21/2022]
Abstract
The degeneration of substantia nigra (SN) dopamine (DA) neurons in sporadic Parkinson׳s disease (PD) is characterized by disturbed gene expression networks. Micro(mi)RNAs are post-transcriptional regulators of gene expression and we recently provided evidence that these molecules may play a functional role in the pathogenesis of PD. Here, we document a comprehensive analysis of miRNAs in SN DA neurons and PD, including sex differences. Our data show that miRNAs are dysregulated in disease-affected neurons and differentially expressed between male and female samples with a trend of more up-regulated miRNAs in males and more down-regulated miRNAs in females. Unbiased Ingenuity Pathway Analysis (IPA) revealed a network of miRNA/target-gene associations that is consistent with dysfunctional gene and signaling pathways in PD pathology. Our study provides evidence for a general association of miRNAs with the cellular function and identity of SN DA neurons, and with deregulated gene expression networks and signaling pathways related to PD pathogenesis that may be sex-specific.
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Watila MM, Balarabe SA. Molecular and clinical features of inherited neuropathies due to PMP22 duplication. J Neurol Sci 2015; 355:18-24. [PMID: 26076881 DOI: 10.1016/j.jns.2015.05.037] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 04/30/2015] [Accepted: 05/25/2015] [Indexed: 02/06/2023]
Abstract
PMP22 is a transmembrane glycoprotein component of myelin, important for myelin functioning. Mutation of PMP22 gene which encodes for the production of PMP22 glycoprotein is associated with a variety of inherited neuropathies. This literature review sought to review the molecular mechanism and clinical features of inherited neuropathies caused by PMP22 duplication. PMP22 duplication causes CMT1A which accounts for more than half of all CMT cases and about 70% of CMT1 cases. It manifests with muscle weakness, depressed reflexes, impaired distal sensation, hand and foot deformities, slowing of NCV and onion bulbs. With no specific treatment available, it is managed conservatively. Future treatment may be based on the molecular genetics of the disease.
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Affiliation(s)
- M M Watila
- Department of Medicine, University of Maiduguri Teaching Hospital, PMB 1414 Maiduguri, Borno State, Nigeria.
| | - S A Balarabe
- Department of Medicine, Usman DanFodio University Teaching Hospital, Sokoto, Sokoto State, Nigeria
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[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] [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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Capasso M, Diskin S, Cimmino F, Acierno G, Totaro F, Petrosino G, Pezone L, Diamond M, McDaniel L, Hakonarson H, Iolascon A, Devoto M, Maris JM. Common genetic variants in NEFL influence gene expression and neuroblastoma risk. Cancer Res 2014; 74:6913-24. [PMID: 25312269 DOI: 10.1158/0008-5472.can-14-0431] [Citation(s) in RCA: 73] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The genetic etiology of sporadic neuroblastoma is still largely obscure. In a genome-wide association study, we identified single-nucleotide polymorphisms (SNP) associated with neuroblastoma at the CASC15, BARD1, LMO1, DUSP12, HSD17B12, HACE1, and LIN28B gene loci, but these explain only a small fraction of neuroblastoma heritability. Other neuroblastoma susceptibility genes are likely hidden among signals discarded by the multiple testing corrections. In this study, we evaluated eight additional genes selected as candidates for further study based on proven involvement in neuroblastoma differentiation. SNPs at these candidate genes were tested for association with disease susceptibility in 2,101 cases and 4,202 controls, with the associations found replicated in an independent cohort of 459 cases and 809 controls. Replicated associations were further studied for cis-effect using gene expression, transient overexpression, silencing, and cellular differentiation assays. The neurofilament gene NEFL harbored three SNPs associated with neuroblastoma (rs11994014: Pcombined = 0.0050; OR, 0.88; rs2979704: Pcombined = 0.0072; OR, 0.87; rs1059111: Pcombined = 0.0049; OR, 0.86). The protective allele of rs1059111 correlated with increased NEFL expression. Biologic investigations showed that ectopic overexpression of NEFL inhibited cell growth specifically in neuroblastoma cells carrying the protective allele. NEFL overexpression also enhanced differentiation and impaired the proliferation and anchorage-independent growth of cells with protective allele and basal NEFL expression, while impairing invasiveness and proliferation of cells homozygous for the risk genotype. Clinically, high levels of NEFL expression in primary neuroblastoma specimens were associated with better overall survival (P = 0.03; HR, 0.68). Our results show that common variants of NEFL influence neuroblastoma susceptibility and they establish that NEFL expression influences disease initiation and progression.
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Affiliation(s)
- Mario Capasso
- Università degli Studi di Napoli Federico II, Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Naples, Italy. CEINGE Biotecnolgie Avanzate, Naples, Italy.
| | - Sharon Diskin
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Genomics and Computational Biology, Biomedical Graduate Studies, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Flora Cimmino
- Università degli Studi di Napoli Federico II, Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Naples, Italy. CEINGE Biotecnolgie Avanzate, Naples, Italy
| | - Giovanni Acierno
- Università degli Studi di Napoli Federico II, Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Naples, Italy. CEINGE Biotecnolgie Avanzate, Naples, Italy
| | - Francesca Totaro
- Università degli Studi di Napoli Federico II, Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Naples, Italy
| | - Giuseppe Petrosino
- Università degli Studi di Napoli Federico II, Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Naples, Italy
| | | | - Maura Diamond
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Lee McDaniel
- Abramson Family Cancer Research Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. Genomics and Computational Biology, Biomedical Graduate Studies, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Hakon Hakonarson
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. The Center for Applied Genomics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. Division of Genetics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Achille Iolascon
- Università degli Studi di Napoli Federico II, Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Naples, Italy. CEINGE Biotecnolgie Avanzate, Naples, Italy
| | - Marcella Devoto
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Division of Genetics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. Department of Molecular Medicine, University of Rome "La Sapienza," Rome, Italy. Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - John M Maris
- Division of Oncology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania. Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania. Abramson Family Cancer Research Institute, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania. Genomics and Computational Biology, Biomedical Graduate Studies, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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The role of rab proteins in neuronal cells and in the trafficking of neurotrophin receptors. MEMBRANES 2014; 4:642-77. [PMID: 25295627 PMCID: PMC4289860 DOI: 10.3390/membranes4040642] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 08/27/2014] [Accepted: 09/16/2014] [Indexed: 12/11/2022]
Abstract
Neurotrophins are a family of proteins that are important for neuronal development, neuronal survival and neuronal functions. Neurotrophins exert their role by binding to their receptors, the Trk family of receptor tyrosine kinases (TrkA, TrkB, and TrkC) and p75NTR, a member of the tumor necrosis factor (TNF) receptor superfamily. Binding of neurotrophins to receptors triggers a complex series of signal transduction events, which are able to induce neuronal differentiation but are also responsible for neuronal maintenance and neuronal functions. Rab proteins are small GTPases localized to the cytosolic surface of specific intracellular compartments and are involved in controlling vesicular transport. Rab proteins, acting as master regulators of the membrane trafficking network, play a central role in both trafficking and signaling pathways of neurotrophin receptors. Axonal transport represents the Achilles' heel of neurons, due to the long-range distance that molecules, organelles and, in particular, neurotrophin-receptor complexes have to cover. Indeed, alterations of axonal transport and, specifically, of axonal trafficking of neurotrophin receptors are responsible for several human neurodegenerative diseases, such as Huntington's disease, Alzheimer's disease, amyotrophic lateral sclerosis and some forms of Charcot-Marie-Tooth disease. In this review, we will discuss the link between Rab proteins and neurotrophin receptor trafficking and their influence on downstream signaling pathways.
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Zhang R, Zhang F, Li X, Huang S, Zi X, Liu T, Liu S, Li X, Xia K, Pan Q, Tang B. A novel transgenic mouse model of Chinese Charcot-Marie-Tooth disease type 2L. Neural Regen Res 2014; 9:413-9. [PMID: 25206829 PMCID: PMC4146190 DOI: 10.4103/1673-5374.128248] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2014] [Indexed: 12/31/2022] Open
Abstract
We previously found that the K141N mutation in heat shock protein B8 (HSPB8) was responsible for Charcot-Marie-Tooth disease type 2L in a large Chinese family. The objective of the present study was to generate a transgenic mouse model bearing the K141N mutation in the human HSPB8 gene, and to determine whether this K141NHSPB8 transgenic mouse model would manifest the clinical phenotype of Charcot-Marie-Tooth disease type 2L, and consequently be suitable for use in studies of disease pathogenesis. Transgenic mice overexpressing K141NHSPB8 were generated using K141N mutant HSPB8 cDNA cloned into a pCAGGS plasmid driven by a human cytomegalovirus expression system. PCR and western blot analysis confirmed integration of the K141NHSPB8 gene and widespread expression in tissues of the transgenic mice. The K141NHSPB8 transgenic mice exhibited decreased muscle strength in the hind limbs and impaired motor coordination, but no obvious sensory disturbance at 6 months of age by behavioral assessment. Electrophysiological analysis showed that the compound motor action potential amplitude in the sciatic nerve was significantly decreased, but motor nerve conduction velocity remained normal at 6 months of age. Pathological analysis of the sciatic nerve showed reduced myelinated fiber density, notable axonal edema and vacuolar degeneration in K141NHSPB8 transgenic mice, suggesting axonal involvement in the peripheral nerve damage in these animals. These findings indicate that the K141NHSPB8 transgenic mouse successfully models Charcot-Marie-Tooth disease type 2L and can be used to study the pathogenesis of the disease.
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Affiliation(s)
- Ruxu Zhang
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Fufeng Zhang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Xiaobo Li
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Shunxiang Huang
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Xiaohong Zi
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Ting Liu
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Sanmei Liu
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Xuning Li
- Department of Neurology, Third Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Kun Xia
- National Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan Province, China
| | - Qian Pan
- National Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan Province, China
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan Province, China ; National Key Laboratory of Medical Genetics, Central South University, Changsha, Hunan Province, China
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Maximino JR, de Oliveira GP, Alves CJ, Chadi G. Deregulated expression of cytoskeleton related genes in the spinal cord and sciatic nerve of presymptomatic SOD1(G93A) Amyotrophic Lateral Sclerosis mouse model. Front Cell Neurosci 2014; 8:148. [PMID: 24904291 PMCID: PMC4033281 DOI: 10.3389/fncel.2014.00148] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 05/08/2014] [Indexed: 12/11/2022] Open
Abstract
Early molecular events related to cytoskeleton are poorly described in Amyotrophic Lateral Sclerosis (ALS), especially in the Schwann cell (SC), which offers strong trophic support to motor neurons. Database for Annotation, Visualization and Integrated Discovery (DAVID) tool identified cytoskeleton-related genes by employing the Cellular Component Ontology (CCO) in a large gene profiling of lumbar spinal cord and sciatic nerve of presymptomatic SOD1(G93A) mice. One and five CCO terms related to cytoskeleton were described from the spinal cord deregulated genes of 40 days (actin cytoskeleton) and 80 days (microtubule cytoskeleton, cytoskeleton part, actin cytoskeleton, neurofilament cytoskeleton, and cytoskeleton) old transgene mice, respectively. Also, four terms were depicted from the deregulated genes of sciatic nerve of 60 days old transgenes (actin cytoskeleton, cytoskeleton part, microtubule cytoskeleton and cytoskeleton). Kif1b was the unique deregulated gene in more than one studied region or presymptomatic age. The expression of Kif1b [quantitative polymerase chain reaction (qPCR)] elevated in the lumbar spinal cord (40 days old) and decreased in the sciatic nerve (60 days old) of presymptomatic ALS mice, results that were in line to microarray findings. Upregulation (24.8 fold) of Kif1b was seen in laser microdissected enriched immunolabeled motor neurons from the spinal cord of 40 days old presymptomatic SOD1(G93A) mice. Furthermore, Kif1b was dowregulated in the sciatic nerve Schwann cells of presymptomatic ALS mice (60 days old) that were enriched by means of cell microdissection (6.35 fold), cell sorting (3.53 fold), and primary culture (2.70 fold) technologies. The gene regulation of cytoskeleton molecules is an important occurrence in motor neurons and Schwann cells in presymptomatic stages of ALS and may be relevant in the dying back mechanisms of neuronal death. Furthermore, a differential regulation of Kif1b in the spinal cord and sciatic nerve cells emerged as key event in ALS.
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Affiliation(s)
- Jessica R Maximino
- Department of Neurology, Neuroregeneration Research Center, University of São Paulo School of Medicine São Paulo, Brazil
| | - Gabriela P de Oliveira
- Department of Neurology, Neuroregeneration Research Center, University of São Paulo School of Medicine São Paulo, Brazil
| | - Chrystian J Alves
- Department of Neurology, Neuroregeneration Research Center, University of São Paulo School of Medicine São Paulo, Brazil
| | - Gerson Chadi
- Department of Neurology, Neuroregeneration Research Center, University of São Paulo School of Medicine São Paulo, Brazil
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Harel T, Lupski J. Charcot-Marie-Tooth disease and pathways to molecular based therapies. Clin Genet 2014; 86:422-31. [DOI: 10.1111/cge.12393] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 03/27/2014] [Accepted: 03/28/2014] [Indexed: 01/31/2023]
Affiliation(s)
- T. Harel
- Department of Molecular and Human Genetics; Baylor College of Medicine; Houston TX USA
| | - J.R. Lupski
- Department of Molecular and Human Genetics; Baylor College of Medicine; Houston TX USA
- Department of Pediatrics; Baylor College of Medicine; Houston TX USA
- Texas Children's Hospital; Houston TX USA
- Human Genome Sequencing Center; Baylor College of Medicine; Houston TX USA
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37
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DaRe JT, Vasta V, Penn J, Tran NTB, Hahn SH. Targeted exome sequencing for mitochondrial disorders reveals high genetic heterogeneity. BMC MEDICAL GENETICS 2013; 14:118. [PMID: 24215330 PMCID: PMC3827825 DOI: 10.1186/1471-2350-14-118] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 11/06/2013] [Indexed: 12/11/2022]
Abstract
Background Mitochondrial disorders are difficult to diagnose due to extreme genetic and phenotypic heterogeneities. Methods We explored the utility of targeted next-generation sequencing for the diagnosis of mitochondrial disorders in 148 patients submitted for clinical testing. A panel of 447 nuclear genes encoding mitochondrial respiratory chain complexes, and other genes inducing secondary mitochondrial dysfunction or that cause diseases which mimic mitochondrial disorders were tested. Results We identified variants considered to be possibly disease-causing based on family segregation data and/or variants already known to cause disease in twelve genes in thirteen patients. Rare or novel variants of unknown significance were identified in 45 additional genes for various metabolic, genetic or neurogenetic disorders. Conclusions Primary mitochondrial defects were confirmed only in four patients indicating that majority of patients with suspected mitochondrial disorders are presumably not the result of direct impairment of energy production. Our results support that clinical and routine laboratory ascertainment for mitochondrial disorders are challenging due to significant overlapping non-specific clinical symptoms and lack of specific biomarkers. While next-generation sequencing shows promise for diagnosing suspected mitochondrial disorders, the challenges remain as the underlying genetic heterogeneity may be greater than suspected and it is further confounded by the similarity of symptoms with other conditions as we report here.
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Affiliation(s)
| | | | | | | | - Si Houn Hahn
- Seattle Children's Hospital Research Institute, 1900 9th Ave, Seattle, WA 98101, USA.
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38
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Ylikallio E, Pöyhönen R, Zimon M, De Vriendt E, Hilander T, Paetau A, Jordanova A, Lönnqvist T, Tyynismaa H. Deficiency of the E3 ubiquitin ligase TRIM2 in early-onset axonal neuropathy. Hum Mol Genet 2013; 22:2975-83. [PMID: 23562820 DOI: 10.1093/hmg/ddt149] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Inherited peripheral neuropathies are a heterogeneous group of disorders that can affect patients of all ages. Children with inherited neuropathy often develop severe disability, but the genetic causes of recessive early-onset axonal neuropathies are not fully known. We have taken a whole-exome sequencing approach to identify causative disease mutations in single patients with early-onset axonal neuropathy. Here, we report compound heterozygous mutations in the tripartite motif containing 2 (TRIM2) gene in a patient with childhood-onset axonal neuropathy, low weight and small muscle mass. We show that the patient fibroblasts are practically devoid of TRIM2, through mRNA and protein instability caused by the mutations. TRIM2 is an E3 ubiquitin ligase that ubiquitinates neurofilament light chain, a component of the intermediate filament in axons. Resembling the findings in our patient's sural nerve biopsy, Trim2-gene trap mice showed axonopathy with accumulations of neurofilaments inside axons. Our results suggest that loss-of-function mutations in TRIM2 are a cause of axonal neuropathy, which we propose to develop as a consequence of axonal accumulation of neurofilaments, secondary to lack of its ubiquitination by TRIM2.
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Affiliation(s)
- Emil Ylikallio
- Research Programs Unit, Molecular Neurology, Biomedicum Helsinki, Finland
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Franker MAM, Hoogenraad CC. Microtubule-based transport - basic mechanisms, traffic rules and role in neurological pathogenesis. J Cell Sci 2013; 126:2319-29. [PMID: 23729742 DOI: 10.1242/jcs.115030] [Citation(s) in RCA: 156] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Microtubule-based transport is essential for neuronal function because of the large distances that must be traveled by various building blocks and cellular materials. Recent studies in various model systems have unraveled several regulatory mechanisms and traffic rules that control the specificity, directionality and delivery of neuronal cargos. Local microtubule cues, opposing motor activity and cargo-adaptors that regulate motor activity control microtubule-based transport in neurons. Impairment of intracellular transport is detrimental to neurons and has emerged as a common factor in several neurological disorders. Genetic approaches have revealed strong links between intracellular transport processes and the pathogenesis of neurological diseases in both the central and peripheral nervous system. This Commentary highlights recent advances in these areas and discusses the transport defects that are associated with the development of neurological diseases.
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Affiliation(s)
- Mariella A M Franker
- Cell Biology, Faculty of Science, Utrecht University, 3584 CH Utrecht, The Netherlands
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Datskevich PN, Nefedova VV, Sudnitsyna MV, Gusev NB. Mutations of small heat shock proteins and human congenital diseases. BIOCHEMISTRY (MOSCOW) 2013; 77:1500-14. [DOI: 10.1134/s0006297912130081] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Abstract
CMT2B (Charcot–Marie–Tooth type 2B) disease is an autosomal dominant peripheral neuropathy whose onset is in the second or third decade of life, thus in adolescence or young adulthood. CMT2B is clinically characterized by severe symmetric distal sensory loss, reduced tendon reflexes at ankles, weakness in the lower limbs and muscle atrophy, complicated by ulcerations that often lead to amputations. Four missense mutations in the gene encoding the small GTPase Rab7 cause the CMT2B neuropathy. Rab7 is a ubiquitous protein that regulates transport to late endosomes and lysosomes in the endocytic pathway. In neurons, Rab7 is important for endosomal trafficking and signalling of neurotrophins, and for retrograde axonal transport. Recent data on CMT2B-causing Rab7 mutant proteins show that these proteins exhibit altered koff rates and, as a consequence, they are mainly in the GTP-bound state and bind more strongly to Rab7 effector proteins. Notably, expression of CMT2B-causing Rab7 mutant proteins strongly inhibit neurite outgrowth in several cells lines and alter NGF (nerve growth factor) trafficking and signalling. These data indicate that Rab7 plays an essential role in neuronal cells and that CMT2B-causing Rab7 mutant proteins alter neuronal specific pathways, but do not fully explain why only peripheral neurons are affected in CMT2B. In the present paper, we discuss the current understanding of the molecular and cellular mechanisms underlying CMT2B, and we consider possible hypotheses in order to explain how alterations of Rab7 function lead to CMT2B.
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Azzedine H, Senderek J, Rivolta C, Chrast R. Molecular genetics of charcot-marie-tooth disease: from genes to genomes. Mol Syndromol 2012; 3:204-14. [PMID: 23293578 DOI: 10.1159/000343487] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT) is a heterogeneous group of disorders of the peripheral nervous system, mainly characterized by distal muscle weakness and atrophy leading to motor handicap. With an estimated prevalence of 1 in 2,500, this condition is one of the most commonly inherited neurological disorders. Mutations in more than 30 genes affecting glial and/or neuronal functions have been associated with different forms of CMT leading to a substantial improvement in diagnostics of the disease and in the understanding of implicated pathophysiological mechanisms. However, recent data from systematic genetic screening performed in large cohorts of CMT patients indicated that molecular diagnosis could be established only in ∼50-70% of them, suggesting that additional genes are involved in this disease. In addition to providing an overview of genetic and functional data concerning various CMT forms, this review focuses on recent data generated through the use of highly parallel genetic technologies (SNP chips, sequence capture and next-generation DNA sequencing) in CMT families, and the current and future impact of these technologies on gene discovery and diagnostics of CMTs.
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Affiliation(s)
- H Azzedine
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
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Azzedine H, Senderek J, Rivolta C, Chrast R. Molecular genetics of charcot-marie-tooth disease: from genes to genomes. Mol Syndromol 2012. [PMID: 23293578 DOI: 10.1159/000343487/msy-0003-0204] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Charcot-Marie-Tooth disease (CMT) is a heterogeneous group of disorders of the peripheral nervous system, mainly characterized by distal muscle weakness and atrophy leading to motor handicap. With an estimated prevalence of 1 in 2,500, this condition is one of the most commonly inherited neurological disorders. Mutations in more than 30 genes affecting glial and/or neuronal functions have been associated with different forms of CMT leading to a substantial improvement in diagnostics of the disease and in the understanding of implicated pathophysiological mechanisms. However, recent data from systematic genetic screening performed in large cohorts of CMT patients indicated that molecular diagnosis could be established only in ∼50-70% of them, suggesting that additional genes are involved in this disease. In addition to providing an overview of genetic and functional data concerning various CMT forms, this review focuses on recent data generated through the use of highly parallel genetic technologies (SNP chips, sequence capture and next-generation DNA sequencing) in CMT families, and the current and future impact of these technologies on gene discovery and diagnostics of CMTs.
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Affiliation(s)
- H Azzedine
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
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