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Eguibar JR, Cortes C, Hernandez VH, Lopez-Juarez A, Piazza V, Carmona D, Kleinert-Altamirano A, Morales-Campos B, Salceda E, Roncagliolo M. 4-aminopyridine improves evoked potentials and ambulation in the taiep rat: A model of hypomyelination with atrophy of basal ganglia and cerebellum. PLoS One 2024; 19:e0298208. [PMID: 38427650 PMCID: PMC10906851 DOI: 10.1371/journal.pone.0298208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 01/21/2024] [Indexed: 03/03/2024] Open
Abstract
The taiep rat is a tubulin mutant with an early hypomyelination followed by progressive demyelination of the central nervous system due to a point mutation in the Tubb4a gene. It shows clinical, radiological, and pathological signs like those of the human leukodystrophy hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC). Taiep rats had tremor, ataxia, immobility episodes, epilepsy, and paralysis; the acronym of these signs given the name to this autosomal recessive trait. The aim of this study was to analyze the characteristics of somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) in adult taiep rats and in a patient suffering from H-ABC. Additionally, we evaluated the effects of 4-aminopyridine (4-AP) on sensory responses and locomotion and finally, we compared myelin loss in the spinal cord of adult taiep and wild type (WT) rats using immunostaining. Our results showed delayed SSEPs in the upper and the absence of them in the lower extremities in a human patient. In taiep rats SSEPs had a delayed second negative evoked responses and were more susceptible to delayed responses with iterative stimulation with respect to WT. MEPs were produced by bipolar stimulation of the primary motor cortex generating a direct wave in WT rats followed by several indirect waves, but taiep rats had fused MEPs. Importantly, taiep SSEPs improved after systemic administration of 4-AP, a potassium channel blocker, and this drug induced an increase in the horizontal displacement measured in a novelty-induced locomotor test. In taiep subjects have a significant decrease in the immunostaining of myelin in the anterior and ventral funiculi of the lumbar spinal cord with respect to WT rats. In conclusion, evoked potentials are useful to evaluate myelin alterations in a leukodystrophy, which improved after systemic administration of 4-AP. Our results have a translational value because our findings have implications in future medical trials for H-ABC patients or with other leukodystrophies.
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Affiliation(s)
- Jose R. Eguibar
- Laboratorio de Neurofisiología de la Conducta y Control Motor, Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla, Pue, México
- Dirección General de Desarrollo Internacional, Benemérita Universidad Autónoma de Puebla, Puebla, Pue, México
| | - Carmen Cortes
- Laboratorio de Neurofisiología de la Conducta y Control Motor, Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, Puebla, Pue, México
| | - Victor H. Hernandez
- Departamento de Ingenierías Química, Electrónica y Biomédica, División de Ciencias e Ingenierías, Universidad de Guanajuato, León, Gto, México
| | - Alejandra Lopez-Juarez
- Departamento de Ingenierías Química, Electrónica y Biomédica, División de Ciencias e Ingenierías, Universidad de Guanajuato, León, Gto, México
| | - Valeria Piazza
- Centro de Investigaciones en Óptica, A.C., León, Gto, México
| | - Diego Carmona
- Departamento de Ingenierías Química, Electrónica y Biomédica, División de Ciencias e Ingenierías, Universidad de Guanajuato, León, Gto, México
- Centro de Investigaciones en Óptica, A.C., León, Gto, México
| | | | - Blanca Morales-Campos
- Departamento de Fisiología, Facultad de Medicina, Benemérita Universidad Autónoma de Puebla, Puebla, Puebla, Pue, México
| | - Emilio Salceda
- Revista Elementos, Benemérita Universidad Autónoma de Puebla, Puebla, Pue, México
| | - Manuel Roncagliolo
- Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso, Chile
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Dhar D, Holla VV, Kumari R, Yadav R, Kamble N, Muthusamy B, Pal PK. Clinical and genetic profile of patients with dystonia: An experience from a tertiary neurology center from India. Parkinsonism Relat Disord 2024; 120:105986. [PMID: 38219528 DOI: 10.1016/j.parkreldis.2023.105986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 12/15/2023] [Accepted: 12/28/2023] [Indexed: 01/16/2024]
Abstract
BACKGROUND The genetics of dystonia have varied across different ethnicities worldwide. Its significance has become more apparent with the advent of deep brain stimulation. OBJECTIVE To study the clinico-genetic profile of patients with probable genetic dystonia using whole exome sequencing (WES). METHODS A prospective, cross-sectional study was conducted from May 2021 to September 2022, enrolling patients with dystonia of presumed genetic etiology for WES. The study compared genetically-determined cases harboring pathogenic/likely-pathogenic variants (P/LP subgroup) with the presumed idiopathic or unsolved cases. RESULTS We recruited 65 patients (males, 69.2%) whose mean age of onset (AAO) and assessment were 25.0 ± 16.6 and 31.7 ± 15.2 years, respectively. Fifteen had pathogenic/likely-pathogenic variants (yield = 23.1%), 16 (24.6%) had variants of uncertain significance (VUS), 2 were heterozygous carriers while the remaining 32 cases tested negative (presumed idiopathic group). The P/LP subgroup had a significantly younger AAO (16.8 ± 12.3 vs 31.3 ± 17.0 years, p = 0.009), longer duration of illness (10.9 ± 10.3 vs 4.8 ± 4.3 years, p = 0.006), higher prevalence of generalized dystonia (n = 12, 80.0% vs n = 10, 31.3%, p = 0.004), lower-limb onset (n = 5, 33.3% vs n = 1, 3.1%, p = 0.009), higher motor (p = 0.035) and disability scores (p = 0.042). The classical DYT genes with pathogenic/likely pathogenic variants included 3 cases each of TOR1A, and KMT2B, and single cases each of SGCE, EIF2AK2, and VPS16. Non-DYT pathogenic/likely-pathogenic cases included PINK1, PANK2, CTSF, POLG, MICU1, and TSPOAP1. CONCLUSIONS The yield of WES was 23.1% among cases of probable genetic dystonia. Pathogenic or likely pathogenic variants in TOR1A, KMT2B, and SGCE genes were commoner. The absence of family history emphasizes the importance of accurate assessment of clinical predictors before genetic testing.
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Affiliation(s)
- Debjyoti Dhar
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru 560029, India
| | - Vikram V Holla
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru 560029, India
| | - Riyanka Kumari
- Institute of Bioinformatics, International Technology Park, Bengaluru 560066, India; Manipal Academy of Higher Education, Manipal 576104, Karnataka, India
| | - Ravi Yadav
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru 560029, India
| | - Nitish Kamble
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru 560029, India
| | - Babylakshmi Muthusamy
- Institute of Bioinformatics, International Technology Park, Bengaluru 560066, India; Manipal Academy of Higher Education, Manipal 576104, Karnataka, India.
| | - Pramod Kumar Pal
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru 560029, India.
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Rogić Vidaković M, Šoda J, Kuluva JE, Bošković B, Dolić K, Gunjača I. Exploring Neurophysiological Mechanisms and Treatment Efficacies in Laryngeal Dystonia: A Transcranial Magnetic Stimulation Approach. Brain Sci 2023; 13:1591. [PMID: 38002550 PMCID: PMC10669610 DOI: 10.3390/brainsci13111591] [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: 10/19/2023] [Revised: 11/14/2023] [Accepted: 11/14/2023] [Indexed: 11/26/2023] Open
Abstract
Laryngeal dystonia (LD), known or termed as spasmodic dysphonia, is a rare movement disorder with an unknown cause affecting the intrinsic laryngeal muscles. Neurophysiological studies point to perturbed inhibitory processes, while conventional genetic studies reveal fragments of genetic architecture in LD. The study's aims are to (1) describe transcranial magnetic stimulation (TMS) methodology for studying the functional integrity of the corticospinal tract by stimulating the primary motor cortex (M1) for laryngeal muscle representation and recording motor evoked potentials (MEPs) from laryngeal muscles; (2) evaluate the results of TMS studies investigating the cortical silent period (cSP) in LD; and (3) present the standard treatments of LD, as well as the results of new theoretical views and treatment approaches like repetitive TMS and laryngeal vibration over the laryngeal muscles as the recent research attempts in treatment of LD. Neurophysiological findings point to a shortened duration of cSP in adductor LD and altered cSP duration in abductor LD individuals. Future TMS studies could further investigate the role of cSP in relation to standard laryngological measures and treatment options. A better understanding of the neurophysiological mechanisms might give new perspectives for the treatment of LD.
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Affiliation(s)
- Maja Rogić Vidaković
- Laboratory for Human and Experimental Neurophysiology, Department of Neuroscience, School of Medicine, University of Split, 21000 Split, Croatia
| | - Joško Šoda
- Signal Processing, Analysis and Advanced Diagnostics Research and Education Laboratory (SPAADREL), Faculty of Maritime Studies, University of Split, 21000 Split, Croatia;
| | | | - Braco Bošković
- Department of Otorhinolaryngology, University Hospital of Split, 21000 Split, Croatia;
| | - Krešimir Dolić
- Department of Interventional and Diagnostic Radiology, University Hospital of Split, 21000 Split, Croatia;
- Department of Radiology, School of Medicine, University of Split, 21000 Split, Croatia
| | - Ivana Gunjača
- Department of Biology and Human Genetics, School of Medicine, University of Split, 21000 Split, Croatia
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4
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Zocchi R, Bellacchio E, Piccione M, Scardigli R, D’Oria V, Petrini S, Baranano K, Bertini E, Sferra A. Novel loss of function mutation in TUBA1A gene compromises tubulin stability and proteostasis causing spastic paraplegia and ataxia. Front Cell Neurosci 2023; 17:1162363. [PMID: 37435044 PMCID: PMC10332271 DOI: 10.3389/fncel.2023.1162363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 06/01/2023] [Indexed: 07/13/2023] Open
Abstract
Microtubules are dynamic cytoskeletal structures involved in several cellular functions, such as intracellular trafficking, cell division and motility. More than other cell types, neurons rely on the proper functioning of microtubules to conduct their activities and achieve complex morphologies. Pathogenic variants in genes encoding for α and β-tubulins, the structural subunits of microtubules, give rise to a wide class of neurological disorders collectively known as "tubulinopathies" and mainly involving a wide and overlapping range of brain malformations resulting from defective neuronal proliferation, migration, differentiation and axon guidance. Although tubulin mutations have been classically linked to neurodevelopmental defects, growing evidence demonstrates that perturbations of tubulin functions and activities may also drive neurodegeneration. In this study, we causally link the previously unreported missense mutation p.I384N in TUBA1A, one of the neuron-specific α-tubulin isotype I, to a neurodegenerative disorder characterized by progressive spastic paraplegia and ataxia. We demonstrate that, in contrast to the p.R402H substitution, which is one of the most recurrent TUBA1A pathogenic variants associated to lissencephaly, the present mutation impairs TUBA1A stability, reducing the abundance of TUBA1A available in the cell and preventing its incorporation into microtubules. We also show that the isoleucine at position 384 is an amino acid residue, which is critical for α-tubulin stability, since the introduction of the p.I384N substitution in three different tubulin paralogs reduces their protein level and assembly into microtubules, increasing their propensity to aggregation. Moreover, we demonstrate that the inhibition of the proteasome degradative systems increases the protein levels of TUBA1A mutant, promoting the formation of tubulin aggregates that, as their size increases, coalesce into inclusions that precipitate within the insoluble cellular fraction. Overall, our data describe a novel pathogenic effect of p.I384N mutation that differs from the previously described substitutions in TUBA1A, and expand both phenotypic and mutational spectrum related to this gene.
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Affiliation(s)
- Riccardo Zocchi
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy
| | - Emanuele Bellacchio
- Molecular Genetics and Functional Genomics Research Unit, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy
| | - Michela Piccione
- Research Laboratories, Bambino Gesù Children’s Hospital, IRCSS, Rome, Italy
| | - Raffaella Scardigli
- Consiglio Nazionale delle Ricerche (CNR), Institute of Translational Pharmacology (IFT), Rome, Italy
- European Brain Research Institute (EBRI) “Rita Levi-Montalcini,” Rome, Italy
| | - Valentina D’Oria
- Research Laboratories, Bambino Gesù Children’s Hospital, IRCSS, Rome, Italy
| | - Stefania Petrini
- Research Laboratories, Bambino Gesù Children’s Hospital, IRCSS, Rome, Italy
| | - Kristin Baranano
- Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Enrico Bertini
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy
| | - Antonella Sferra
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, Rome, Italy
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5
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Almad AA, Garcia L, Takanohashi A, Gagne A, Yang W, Ann McGuire J, French D, Vanderver A. Generation of three induced Pluripotent Stem Cell lines from individuals with Hypomyelination with Atrophy of Basal Ganglia and Cerebellum caused by a c.745G>A (p.D249N) autosomal dominant mutation in TUBB4A. Stem Cell Res 2023; 69:103083. [PMID: 37003180 DOI: 10.1016/j.scr.2023.103083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 02/27/2023] [Accepted: 03/23/2023] [Indexed: 03/28/2023] Open
Abstract
Mutations in tubulin alpha 4a (TUBB4A) result in a spectrum of leukodystrophies, including Hypomyelination with atrophy of basal ganglia and cerebellum (H-ABC), resulting from a recurring mutation p.Asp249Asn (TUBB4AD249N). H-ABC presents with dystonia, motor and cognitive impairment and pathological features of hypomyelination and loss of cerebellar and striatal neurons. We have generated three induced pluripotent stem cell (iPSC) lines from fibroblast and peripheral blood mononuclear cells (PBMCs) of individuals with TUBB4AD249N mutation. The iPSCs were assessed to confirm a normal karyotype, pluripotency, and trilineage differentiation potential. The iPSCs will allow for disease modeling, understanding mechanisms and testing of therapeutic targets.
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Affiliation(s)
- Akshata A Almad
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Luis Garcia
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Asako Takanohashi
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Alyssa Gagne
- Penn Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Wenli Yang
- Penn Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, United States
| | - Jean Ann McGuire
- Department of Pathology and Lab Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Deborah French
- Department of Pathology and Lab Medicine, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
| | - Adeline Vanderver
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, PA, United States
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6
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Garg D, Aggarwal V. DYT-TUBB4A: First Family from India with the Arg2Gly Mutation. Ann Indian Acad Neurol 2023; 26:195-197. [PMID: 37179668 PMCID: PMC10171013 DOI: 10.4103/aian.aian_937_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/05/2023] [Accepted: 01/06/2023] [Indexed: 02/05/2023] Open
Affiliation(s)
- Divyani Garg
- Department of Neurology, Vardhman Mahavir Medical College, Janakpuri, New Delhi, India
| | - Vasundhara Aggarwal
- Department of Neurology, Janakpuri Super Speciality Hospital, Janakpuri, New Delhi, India
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7
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Ganne A, Balasubramaniam M, Ayyadevara H, Kiaei L, Shmookler Reis RJ, Varughese KI, Kiaei M. In silico analysis of TUBA4A mutations in Amyotrophic Lateral Sclerosis to define mechanisms of microtubule disintegration. Sci Rep 2023; 13:2096. [PMID: 36747013 PMCID: PMC9902468 DOI: 10.1038/s41598-023-28381-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 01/18/2023] [Indexed: 02/08/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an inexorably progressive and degenerative disorder of motor neurons with no currently-known cure. Studies to determine the mechanism of neurotoxicity and the impact of ALS-linked mutations (SOD1, FUS, TARDP, C9ORF72, PFN1, TUBA4A and others) have greatly expanded our knowledge of ALS disease mechanisms and have helped to identify potential targets for ALS therapy. Cellular pathologies (e.g., aggregation of mutant forms of SOD1, TDP43, FUS, Ubiqulin2, PFN1, and C9ORF72), mitochondrial dysfunction, neuroinflammation, and oxidative damage are major pathways implicated in ALS. Nevertheless, the selective vulnerability of motor neurons remains unexplained. The importance of tubulins for long-axon infrastructure, and the special morphology and function of motor neurons, underscore the central role of the cytoskeleton. The recent linkage of mutations to the tubulin α chain, TUBA4A, to familial and sporadic cases of ALS provides a new investigative opportunity to shed light on both mechanisms of ALS and the vulnerability of motor neurons. In the current study we investigate TUBA4A, a structural microtubule protein with mutations causal to familial ALS, using molecular-dynamic (MD) modeling of protein structure to predict the effects of each mutation and its overall impact on GTP binding, chain stability, tubulin assembly, and aggregation propensity. These studies predict that each of the reported mutations will cause notable structural changes to the TUBA4A (α chain) tertiary protein structure, adversely affecting its physical properties and functions. Molecular docking and MD simulations indicate certain α chain mutations (e.g. K430N, R215C, and W407X) may cause structural deviations that impair GTP binding, and plausibly prevent or destabilize tubulin polymerization. Furthermore, several mutations (including R320C and K430N) confer a significant increase in predicted aggregation propensity of TUBA4A mutants relative to wild-type. Taken together, these in silico modeling studies predict structural perturbations and disruption of GTP binding, culminating in failure to form a stable tubulin heterocomplex, which may furnish an important pathogenic mechanism to trigger motor neuron degeneration in ALS.
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Affiliation(s)
- Akshatha Ganne
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Meenakshisundaram Balasubramaniam
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.,Central Arkansas Veterans Healthcare Service, McClellan Veterans Medical Center, Little Rock, AR, 72205, USA.,SiBioLead, LLC, Little Rock, AR, 72207, USA
| | | | - Lily Kiaei
- University of California, Los Angeles, Los Angeles, CA, 90095, USA.,RockGen Therapeutics, LLC, Little Rock, AR, 72205, USA
| | - Robert J Shmookler Reis
- Department of Geriatrics, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.,Central Arkansas Veterans Healthcare Service, McClellan Veterans Medical Center, Little Rock, AR, 72205, USA.,SiBioLead, LLC, Little Rock, AR, 72207, USA
| | - Kottayil I Varughese
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Mahmoud Kiaei
- RockGen Therapeutics, LLC, Little Rock, AR, 72205, USA. .,Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA. .,Department of Neurology, University of Arkansas for Medical Sciences, 4301 W. Markham St., Slot 611 (BioMed 1, Rm B-306A), Little Rock, AR, 72205, USA.
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8
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Zocchi R, Compagnucci C, Bertini E, Sferra A. Deciphering the Tubulin Language: Molecular Determinants and Readout Mechanisms of the Tubulin Code in Neurons. Int J Mol Sci 2023; 24:ijms24032781. [PMID: 36769099 PMCID: PMC9917122 DOI: 10.3390/ijms24032781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/17/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Microtubules (MTs) are dynamic components of the cell cytoskeleton involved in several cellular functions, such as structural support, migration and intracellular trafficking. Despite their high similarity, MTs have functional heterogeneity that is generated by the incorporation into the MT lattice of different tubulin gene products and by their post-translational modifications (PTMs). Such regulations, besides modulating the tubulin composition of MTs, create on their surface a "biochemical code" that is translated, through the action of protein effectors, into specific MT-based functions. This code, known as "tubulin code", plays an important role in neuronal cells, whose highly specialized morphologies and activities depend on the correct functioning of the MT cytoskeleton and on its interplay with a myriad of MT-interacting proteins. In recent years, a growing number of mutations in genes encoding for tubulins, MT-interacting proteins and enzymes that post-translationally modify MTs, which are the main players of the tubulin code, have been linked to neurodegenerative processes or abnormalities in neural migration, differentiation and connectivity. Nevertheless, the exact molecular mechanisms through which the cell writes and, downstream, MT-interacting proteins decipher the tubulin code are still largely uncharted. The purpose of this review is to describe the molecular determinants and the readout mechanisms of the tubulin code, and briefly elucidate how they coordinate MT behavior during critical neuronal events, such as neuron migration, maturation and axonal transport.
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Affiliation(s)
- Riccardo Zocchi
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
| | - Claudia Compagnucci
- Molecular Genetics and Functional Genomics, Bambino Gesù Children’s Research Hospital, IRCCS, 00146 Rome, Italy
| | - Enrico Bertini
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
- Correspondence: (E.B.); or (A.S.); Tel.: +39-06-6859-2104 (E.B. & A.S.)
| | - Antonella Sferra
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
- Correspondence: (E.B.); or (A.S.); Tel.: +39-06-6859-2104 (E.B. & A.S.)
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9
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Fink JK. The hereditary spastic paraplegias. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:59-88. [PMID: 37620092 DOI: 10.1016/b978-0-323-98817-9.00022-3] [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: 08/26/2023]
Abstract
The hereditary spastic paraplegias (HSPs) are a group of more than 90 genetic disorders in which lower extremity spasticity and weakness are either the primary neurologic impairments ("uncomplicated HSP") or when accompanied by other neurologic deficits ("complicated HSP"), important features of the clinical syndrome. Various genetic types of HSP are inherited such as autosomal dominant, autosomal recessive, X-linked, and maternal (mitochondrial) traits. Symptoms that begin in early childhood may be nonprogressive and resemble spastic diplegic cerebral palsy. Symptoms that begin later, typically progress insidiously over a number of years. Genetic testing is able to confirm the diagnosis for many subjects. Insights from gene discovery indicate that abnormalities in diverse molecular processes underlie various forms of HSP, including disturbance in axon transport, endoplasmic reticulum morphogenesis, vesicle transport, lipid metabolism, and mitochondrial function. Pathologic studies in "uncomplicated" HSP have shown axon degeneration particularly involving the distal ends of corticospinal tracts and dorsal column fibers. Treatment is limited to symptom reduction including amelioration of spasticity, reducing urinary urgency, proactive physical therapy including strengthening, stretching, balance, and agility exercise.
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Affiliation(s)
- John K Fink
- Department of Neurology, University of Michigan, Ann Arbor, MI, United States.
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10
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Attard TJ, Welburn JPI, Marsh JA. Understanding molecular mechanisms and predicting phenotypic effects of pathogenic tubulin mutations. PLoS Comput Biol 2022; 18:e1010611. [PMID: 36206299 PMCID: PMC9581425 DOI: 10.1371/journal.pcbi.1010611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/19/2022] [Accepted: 09/28/2022] [Indexed: 11/21/2022] Open
Abstract
Cells rely heavily on microtubules for several processes, including cell division and molecular trafficking. Mutations in the different tubulin-α and -β proteins that comprise microtubules have been associated with various diseases and are often dominant, sporadic and congenital. While the earliest reported tubulin mutations affect neurodevelopment, mutations are also associated with other disorders such as bleeding disorders and infertility. We performed a systematic survey of tubulin mutations across all isotypes in order to improve our understanding of how they cause disease, and increase our ability to predict their phenotypic effects. Both protein structural analyses and computational variant effect predictors were very limited in their utility for differentiating between pathogenic and benign mutations. This was even worse for those genes associated with non-neurodevelopmental disorders. We selected tubulin-α and -β disease mutations that were most poorly predicted for experimental characterisation. These mutants co-localise to the mitotic spindle in HeLa cells, suggesting they may exert dominant-negative effects by altering microtubule properties. Our results show that tubulin mutations represent a blind spot for current computational approaches, being much more poorly predicted than mutations in most human disease genes. We suggest that this is likely due to their strong association with dominant-negative and gain-of-function mechanisms.
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Affiliation(s)
- Thomas J. Attard
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Julie P. I. Welburn
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Joseph A. Marsh
- MRC Human Genetics Unit, Institute of Genetics & Cancer, University of Edinburgh, Edinburgh, United Kingdom
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11
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H-ABC tubulinopathy revealed by label-free second harmonic generation microscopy. Sci Rep 2022; 12:14417. [PMID: 36002546 PMCID: PMC9402540 DOI: 10.1038/s41598-022-18370-x] [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: 03/19/2022] [Accepted: 08/10/2022] [Indexed: 11/08/2022] Open
Abstract
Hypomyelination with atrophy of the basal ganglia and cerebellum is a recently described tubulinopathy caused by a mutation in the tubulin beta 4a isoform, expressed in oligodendrocytes. The taiep rat is the only spontaneous tubulin beta 4a mutant available for the study of this pathology. We aimed to identify the effects of the tubulin mutation on freshly collected, unstained samples of the central white matter of taiep rats using second harmonic generation microscopy. Cytoskeletal differences between the central white matter of taiep rats and control animals were found. Nonlinear emissions from the processes and somata of oligodendrocytes in tubulin beta 4a mutant rats were consistently detected, in the shape of elongated structures and cell-like bodies, which were never detected in the controls. This signal represents the second harmonic trademark of the disease. The tissue was also fluorescently labeled and analyzed to corroborate the origin of the nonlinear signal. Besides enabling the description of structural and molecular aspects of H-ABC, our data open the door to the diagnostic use of nonlinear optics in the study of neurodegenerative diseases, with the additional advantage of a label-free approach that preserves tissue morphology and vitality.
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12
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Gandhi SE, Anderson DG, Newman EJ. A Clinical Approach to Focal Dystonias. ADVANCES IN CLINICAL NEUROSCIENCE & REHABILITATION 2022. [DOI: 10.47795/ufdf2068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dystonia is a hyperkinetic movement disorder (HMD), characterised by sustained or intermittent involuntary muscle contractions resulting in abnormal postures and/or movements [1]. Although primary dystonia has an estimated prevalence of 16 per 100,000 [2], the diagnosis may be delayed, due to its clinical heterogeneity, the lack of objective biomarkers and the potential for pseudodystonic conditions to mimic it [1,3]. We provide an overview of the classification and common subtypes of focal dystonia, focusing on the clinical phenomenology and diagnosis.
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13
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Maillard C, Roux CJ, Charbit-Henrion F, Steffann J, Laquerriere A, Quazza F, Buisson NB. Tubulin mutations in human neurodevelopmental disorders. Semin Cell Dev Biol 2022; 137:87-95. [PMID: 35915025 DOI: 10.1016/j.semcdb.2022.07.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 07/22/2022] [Accepted: 07/22/2022] [Indexed: 10/16/2022]
Abstract
Mutations causing dysfunction of tubulins and microtubule-associated proteins, also known as tubulinopathies, are a group of recently described entities that lead to complex brain malformations. Anatomical and functional consequences of the disruption of tubulins include microcephaly, combined with abnormal corticogenesis due to impaired migration or lamination and abnormal growth cone dynamics of projecting and callosal axons. Key imaging features of tubulinopathies are characterized by three major patterns of malformations of cortical development (MCD): lissencephaly, microlissencephaly, and dysgyria. Additional distinctive MRI features include dysmorphism of the basal ganglia, midline commissural structure hypoplasia or agenesis, and cerebellar and brainstem hypoplasia. Tubulinopathies can be diagnosed as early as 21-24 gestational weeks using imaging and neuropathology, with possible extreme microlissencephaly with an extremely thin cortex, lissencephaly with either thick or thin/intermediate cortex, and dysgyria combined with cerebellar hypoplasia, pons hypoplasia and corpus callosum dysgenesis. More than 100 MCD-associated mutations have been reported in TUBA1A, TUBB2B, or TUBB3 genes, whereas fewer than ten are known in other genes such TUBB2A, TUBB or TUBG1. Although these mutations are scattered along the α- and β-tubulin sequences, recurrent mutations are consistently associated with almost identical cortical dysgenesis. Much of the evidence supports that these mutations alter the dynamic properties and functions of microtubules in several fashions. These include diminishing the abundance of functional tubulin heterodimers, altering GTP binding, altering longitudinal and lateral protofilament interactions, and impairing microtubule interactions with kinesin and/or dynein motors or with MAPs. In this review we discuss the recent advances in our understanding of the effects of mutations of tubulins and microtubule-associated proteins on human brain development and the pathogenesis of malformations of cortical development.
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Affiliation(s)
- Camille Maillard
- Université de Paris, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, F-75015 Paris, France; Université de Paris, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, F-75014 Paris, France
| | - Charles Joris Roux
- Pediatric Radiology, Necker Enfants Malades University Hospital, Université de Paris, Paris, France
| | - Fabienne Charbit-Henrion
- Université de Paris, Sorbonne Paris Cité, Imagine INSERM UMR1163, Service de Génétique Moléculaire, Groupe hospitalier Necker-Enfants Malades, AP-HP, France
| | - Julie Steffann
- Université de Paris, Sorbonne Paris Cité, Imagine INSERM UMR1163, Service de Génétique Moléculaire, Groupe hospitalier Necker-Enfants Malades, AP-HP, France
| | - Annie Laquerriere
- Pathology Laboratory, Rouen University Hospital, Rouen, France; NeoVasc Region-Inserm Team ERI28, Laboratory of Microvascular Endothelium and Neonate Brain Lesions, Institute of Research for Innovation in Biomedicine, University of Rouen, Rouen, France
| | - Floriane Quazza
- Pediatric Neurology, Necker Enfants Malades University Hospital, Université de Paris, Paris, France
| | - Nadia Bahi Buisson
- Université de Paris, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, F-75015 Paris, France; Université de Paris, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, F-75014 Paris, France; Pediatric Neurology, Necker Enfants Malades University Hospital, Université de Paris, Paris, France.
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14
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di Biase L, Di Santo A, Caminiti ML, Pecoraro PM, Carbone SP, Di Lazzaro V. Dystonia Diagnosis: Clinical Neurophysiology and Genetics. J Clin Med 2022; 11:jcm11144184. [PMID: 35887948 PMCID: PMC9320296 DOI: 10.3390/jcm11144184] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 07/16/2022] [Indexed: 12/12/2022] Open
Abstract
Dystonia diagnosis is based on clinical examination performed by a neurologist with expertise in movement disorders. Clues that indicate the diagnosis of a movement disorder such as dystonia are dystonic movements, dystonic postures, and three additional physical signs (mirror dystonia, overflow dystonia, and geste antagonists/sensory tricks). Despite advances in research, there is no diagnostic test with a high level of accuracy for the dystonia diagnosis. Clinical neurophysiology and genetics might support the clinician in the diagnostic process. Neurophysiology played a role in untangling dystonia pathophysiology, demonstrating characteristic reduction in inhibition of central motor circuits and alterations in the somatosensory system. The neurophysiologic measure with the greatest evidence in identifying patients affected by dystonia is the somatosensory temporal discrimination threshold (STDT). Other parameters need further confirmations and more solid evidence to be considered as support for the dystonia diagnosis. Genetic testing should be guided by characteristics such as age at onset, body distribution, associated features, and coexistence of other movement disorders (parkinsonism, myoclonus, and other hyperkinesia). The aim of the present review is to summarize the state of the art regarding dystonia diagnosis focusing on the role of neurophysiology and genetic testing.
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Affiliation(s)
- Lazzaro di Biase
- Neurology Unit, Campus Bio-Medico University Hospital Foundation, Via Álvaro del Portillo 200, 00128 Rome, Italy; (A.D.S.); (M.L.C.); (P.M.P.); (S.P.C.); (V.D.L.)
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Campus Bio-Medico University of Rome, Via Álvaro del Portillo 21, 00128 Rome, Italy
- Brain Innovations Lab., Campus Bio-Medico University of Rome, Via Álvaro del Portillo 21, 00128 Rome, Italy
- Correspondence: or ; Tel.: +39-062-2541-1220
| | - Alessandro Di Santo
- Neurology Unit, Campus Bio-Medico University Hospital Foundation, Via Álvaro del Portillo 200, 00128 Rome, Italy; (A.D.S.); (M.L.C.); (P.M.P.); (S.P.C.); (V.D.L.)
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Campus Bio-Medico University of Rome, Via Álvaro del Portillo 21, 00128 Rome, Italy
| | - Maria Letizia Caminiti
- Neurology Unit, Campus Bio-Medico University Hospital Foundation, Via Álvaro del Portillo 200, 00128 Rome, Italy; (A.D.S.); (M.L.C.); (P.M.P.); (S.P.C.); (V.D.L.)
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Campus Bio-Medico University of Rome, Via Álvaro del Portillo 21, 00128 Rome, Italy
| | - Pasquale Maria Pecoraro
- Neurology Unit, Campus Bio-Medico University Hospital Foundation, Via Álvaro del Portillo 200, 00128 Rome, Italy; (A.D.S.); (M.L.C.); (P.M.P.); (S.P.C.); (V.D.L.)
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Campus Bio-Medico University of Rome, Via Álvaro del Portillo 21, 00128 Rome, Italy
| | - Simona Paola Carbone
- Neurology Unit, Campus Bio-Medico University Hospital Foundation, Via Álvaro del Portillo 200, 00128 Rome, Italy; (A.D.S.); (M.L.C.); (P.M.P.); (S.P.C.); (V.D.L.)
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Campus Bio-Medico University of Rome, Via Álvaro del Portillo 21, 00128 Rome, Italy
| | - Vincenzo Di Lazzaro
- Neurology Unit, Campus Bio-Medico University Hospital Foundation, Via Álvaro del Portillo 200, 00128 Rome, Italy; (A.D.S.); (M.L.C.); (P.M.P.); (S.P.C.); (V.D.L.)
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Campus Bio-Medico University of Rome, Via Álvaro del Portillo 21, 00128 Rome, Italy
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15
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Cozzi M, Ferrari V. Autophagy Dysfunction in ALS: from Transport to Protein Degradation. J Mol Neurosci 2022; 72:1456-1481. [PMID: 35708843 PMCID: PMC9293831 DOI: 10.1007/s12031-022-02029-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/17/2022] [Indexed: 01/18/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting upper and lower motor neurons (MNs). Since the identification of the first ALS mutation in 1993, more than 40 genes have been associated with the disorder. The most frequent genetic causes of ALS are represented by mutated genes whose products challenge proteostasis, becoming unable to properly fold and consequently aggregating into inclusions that impose proteotoxic stress on affected cells. In this context, increasing evidence supports the central role played by autophagy dysfunctions in the pathogenesis of ALS. Indeed, in early stages of disease, high levels of proteins involved in autophagy are present in ALS MNs; but at the same time, with neurodegeneration progression, autophagy-mediated degradation decreases, often as a result of the accumulation of toxic protein aggregates in affected cells. Autophagy is a complex multistep pathway that has a central role in maintaining cellular homeostasis. Several proteins are involved in its tight regulation, and importantly a relevant fraction of ALS-related genes encodes products that directly take part in autophagy, further underlining the relevance of this key protein degradation system in disease onset and progression. In this review, we report the most relevant findings concerning ALS genes whose products are involved in the several steps of the autophagic pathway, from phagophore formation to autophagosome maturation and transport and finally to substrate degradation.
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Affiliation(s)
- Marta Cozzi
- Dipartimento Di Scienze Farmacologiche E Biomolecolari, Università Degli Studi Di Milano, 20133, Milan, Italy.
| | - Veronica Ferrari
- Dipartimento Di Scienze Farmacologiche E Biomolecolari, Università Degli Studi Di Milano, 20133, Milan, Italy.
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16
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Xiao H, He H, Wu T, Ni X, Liu F, Yin F, Peng J. Functional Investigation of TUBB4A Variants Associated with Different Clinical Phenotypes. Mol Neurobiol 2022; 59:5056-5069. [PMID: 35668344 DOI: 10.1007/s12035-022-02900-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Accepted: 05/24/2022] [Indexed: 11/26/2022]
Abstract
Dominant TUBB4A variants result in different phenotypes, including hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC), dystonia type 4 (DYT4), and isolated hypomyelination. Here, we report four new patients with a novel TUBB4A variant (p.K324T) and three new patients with previously reported variants (p.Q292K, p.V255I, p.E410K). The individual carrying the novel p.K324T variant exhibits epilepsy of infancy with migrating focal seizures (EIMFS), while the other three have isolated hypomyelination phenotype. We also present a study of the cellular effects of TUBB4A variants responsible for H-ABC (p.D249N), DYT4 (p.R2G), a severe combined phenotype with combination of hypomyelination and EIMFS (p.K324T), and isolated hypomyelination (p.Q292K and p.E410K) on microtubule stability and dynamics, neurite outgrowth, dendritic spine development, and kinesin binding. Cellular-based assays reveal that all variants except p.R2G increase microtubule stability, decrease microtubule polymerization rates, reduce axonal outgrowth, and alter the density and shape of dendritic spines. We also find that the p.K324T and p.E410K variants perturb the binding of TUBB4A to KIF1A, a neuron-specific kinesin required for transport of synaptic vesicle precursors. Taken together, our data suggest that impaired microtubule stability and dynamics, defected axonal growth, and dendritic spine development form the common molecular basis of TUBB4A-related leukodystrophy. Impairment of TUBB4A binding to KIF1A is more likely to be involved in the isolated hypomyelination phenotype, which suggests that alterations in kinesin binding may cause different phenotypes. In conclusion, our study extends the spectrum of TUBB4A mutations and related phenotypes and provides insight into why different TUBB4A variants cause distinct clinical phenotypes.
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Affiliation(s)
- Hui Xiao
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Hailan He
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Tenghui Wu
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Xiaoyuan Ni
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Fangyun Liu
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Xiangya Road 87, Changsha, 410005, Hunan, China.
- Hunan Intellectual and Developmental Disabilities Research Center, Changsha, 410005, China.
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17
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Hashiguchi M, Monden Y, Nozaki Y, Watanabe K, Nakashima M, Saitsu H, Yamagata T, Osaka H. A TUBB4A Met363Thr variant in pediatric hypomyelination without atrophy of the basal ganglia. Hum Genome Var 2022; 9:19. [PMID: 35661708 PMCID: PMC9166743 DOI: 10.1038/s41439-022-00198-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 04/21/2022] [Accepted: 05/02/2022] [Indexed: 01/11/2023] Open
Abstract
TUBB4A gene variants cause dystonia type 4 and hypomyelination with atrophy of the basal ganglia and cerebellum. We report the case of a child with delayed motor development, intellectual disability, and dystonia. Magnetic resonance imaging revealed hypomyelination and progressive cerebellar atrophy without atrophy of the basal ganglia. Whole-exome sequencing revealed a de novo heterozygous variant, c.1088T > C, p.(Met363Thr), in TUBB4A. The present case further supports the vulnerability of the cerebellum in patients with TUBB4A pathogenic variants.
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Affiliation(s)
- Marina Hashiguchi
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Yukifumi Monden
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Yasuyuki Nozaki
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan ,Department of Pediatrics, Shin-Oyama City Hospital, Tochigi, Japan
| | - Kazuki Watanabe
- grid.505613.40000 0000 8937 6696Department of Biochemistry, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Mitsuko Nakashima
- grid.505613.40000 0000 8937 6696Department of Biochemistry, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Hirotomo Saitsu
- grid.505613.40000 0000 8937 6696Department of Biochemistry, Hamamatsu University School of Medicine, Shizuoka, Japan
| | - Takanori Yamagata
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
| | - Hitoshi Osaka
- grid.410804.90000000123090000Department of Pediatrics, Jichi Medical University, Tochigi, Japan
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18
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Bally JF, Kern DS, Fearon C, Camargos S, Pereira da Silva‐Junior F, Barbosa ER, Ozelius LJ, Carvalho Aguiar P, Lang AE. DYT‐TUBB4A
(
DYT4
Dystonia): Clinical Anthology of 11 Cases and Systematized Review. Mov Disord Clin Pract 2022; 9:659-675. [PMID: 35844288 PMCID: PMC9274350 DOI: 10.1002/mdc3.13452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/02/2022] [Accepted: 02/20/2022] [Indexed: 11/25/2022] Open
Abstract
Background DYT‐TUBB4A, formerly known as DYT4, has not been comprehensively described as only one large family and three individual cases have been published. We have recently described an in depth genetic and protein structural analysis of eleven additional cases from four families with four new pathogenic variants. We aim to report on the phenomenology of these cases suffering from DYT‐TUBB4A and to perform a comprehensive review of the clinical presentation and treatment responses of all DYT‐TUBB4A cases reported in the literature. Cases and Literature Review The clinical picture was typically characterized by laryngeal dystonia (more than three quarters of all cases), associated with cervical dystonia, upper limb dystonia and frequent generalization. Extension of the dystonia to the lower limbs, creating the famous “hobby horse” gait, was present in more than 20% of cases (in only one of ours). Globus pallidus pars interna (GPi) deep brain stimulation (DBS), performed in 4 cases, led to a good improvement with greatest benefit in motoric and less benefit in laryngeal symptoms. Medical treatment was generally rather poorly effective, except some benefit from propranolol, tetrabenazine and alcohol intake. Conclusion Laryngeal involvement is a hallmark of DYT‐TUBB4A. Symptomatic treatment with GPi‐DBS led to the greatest benefit in motoric symptoms. Nevertheless, TUBB4A mutations remain an exceedingly rare cause of laryngeal or other isolated dystonia and regular screening of TUBB4A mutations for isolated dystonias has a very low yield.
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Affiliation(s)
- Julien F. Bally
- Service of Neurology, Department of Clinical Neurosciences Lausanne University Hospital and University of Lausanne Lausanne Switzerland
- The Edmond J Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital & University of Toronto Toronto Ontario Canada
| | - Drew S. Kern
- Department of Neurology University of Colorado School of Medicine Aurora Colorado USA
- Department of Neurosurgery University of Colorado School of Medicine Aurora Colorado USA
| | - Conor Fearon
- The Edmond J Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital & University of Toronto Toronto Ontario Canada
| | - Sarah Camargos
- Department of Internal Medicine Universidade Federal de Minas Gerais Belo Horizonte Brazil
| | | | | | - Laurie J. Ozelius
- Department of Neurology Massachusetts General Hospital Boston Massachusetts USA
| | - Patricia Carvalho Aguiar
- Hospital Israelita Albert Einstein Sao Paulo Brazil
- Department of Neurology and Neurosurgery Universidade Federal de Sao Paulo Sao Paulo Brazil
| | - Anthony E. Lang
- The Edmond J Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital & University of Toronto Toronto Ontario Canada
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19
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Krajka V, Vulinovic F, Genova M, Tanzer K, Jijumon AS, Bodakuntla S, Tennstedt S, Mueller-Fielitz H, Meier B, Janke C, Klein C, Rakovic A. H-ABC- and dystonia-causing TUBB4A mutations show distinct pathogenic effects. SCIENCE ADVANCES 2022; 8:eabj9229. [PMID: 35275727 PMCID: PMC8916731 DOI: 10.1126/sciadv.abj9229] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 01/22/2022] [Indexed: 06/14/2023]
Abstract
Mutations in the brain-specific β-tubulin 4A (TUBB4A) gene cause a broad spectrum of diseases, ranging from dystonia (DYT-TUBB4A) to hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC). Currently, the mechanisms of how TUBB4A variants lead to this pleiotropic manifestation remain elusive. Here, we investigated whether TUBB4A mutations causing either DYT-TUBB4A (p.R2G and p.Q424H) or H-ABC (p.R2W and p.D249N) exhibit differential effects at the molecular and cellular levels. Using live-cell imaging of disease-relevant oligodendrocytes and total internal reflection fluorescence microscopy of whole-cell lysates, we observed divergent impact on microtubule polymerization and microtubule integration, partially reflecting the observed pleiotropy. Moreover, in silico simulations demonstrated that the mutants rarely adopted a straight heterodimer conformation in contrast to wild type. In conclusion, for most of the examined variants, we deciphered potential molecular disease mechanisms that may lead to the diverse clinical manifestations and phenotype severity across and within each TUBB4A-related disease.
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Affiliation(s)
- Victor Krajka
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
- Institute of Microtechnology (IMT), Technische Universität Braunschweig, Braunschweig 38124, Germany
| | - Franca Vulinovic
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Mariya Genova
- Institut Curie, Université PSL, CNRS UMR3348, 91401 Orsay, France
- Université Paris-Saclay, CNRS UMR3348, 91401 Orsay, France
| | - Kerstin Tanzer
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - A. S. Jijumon
- Institut Curie, Université PSL, CNRS UMR3348, 91401 Orsay, France
- Université Paris-Saclay, CNRS UMR3348, 91401 Orsay, France
| | - Satish Bodakuntla
- Institut Curie, Université PSL, CNRS UMR3348, 91401 Orsay, France
- Université Paris-Saclay, CNRS UMR3348, 91401 Orsay, France
| | - Stephanie Tennstedt
- Institute for Cardiogenetics, University of Lübeck, 23562 Lübeck, Germany
- DZHK (German Research Centre for Cardiovascular Research), partner site Hamburg/Lübeck/Kiel, 23562 Lübeck, Germany
- University Heart Center Lübeck, 23562 Lübeck, Germany
| | - Helge Mueller-Fielitz
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Germany
| | - Britta Meier
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Carsten Janke
- Institut Curie, Université PSL, CNRS UMR3348, 91401 Orsay, France
- Université Paris-Saclay, CNRS UMR3348, 91401 Orsay, France
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Aleksandar Rakovic
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
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20
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Fertuzinhos S, Legué E, Li D, Liem KF. A dominant tubulin mutation causes cerebellar neurodegeneration in a genetic model of tubulinopathy. SCIENCE ADVANCES 2022; 8:eabf7262. [PMID: 35171680 PMCID: PMC8849301 DOI: 10.1126/sciadv.abf7262] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Mutations in tubulins cause distinct neurodevelopmental and degenerative diseases termed "tubulinopathies"; however, little is known about the functional requirements of tubulins or how mutations cause cell-specific pathologies. Here, we identify a mutation in the gene Tubb4a that causes degeneration of cerebellar granule neurons and myelination defects. We show that the neural phenotypes result from a cell type-specific enrichment of a dominant mutant form of Tubb4a relative to the expression other β-tubulin isotypes. Loss of Tubb4a function does not underlie cellular pathology but is compensated by the transcriptional up-regulation of related tubulin genes in a cell type-specific manner. This work establishes that the expression of a primary tubulin mutation in mature neurons is sufficient to promote cell-autonomous cell death, consistent with a causative association of microtubule dysfunction with neurodegenerative diseases. These studies provide evidence that mutations in tubulins cause specific phenotypes based on expression ratios of tubulin isotype genes.
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Affiliation(s)
- Sofia Fertuzinhos
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Emilie Legué
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Davis Li
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Karel F. Liem
- Vertebrate Developmental Biology Program, Department of Pediatrics, Yale University School of Medicine, New Haven, CT 06520, USA
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21
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Fellner A, Goldberg Y, Lev D, Basel-Salmon L, Shor O, Benninger F. In-silico phenotype prediction by normal mode variant analysis in TUBB4A-related disease. Sci Rep 2022; 12:58. [PMID: 34997144 PMCID: PMC8741991 DOI: 10.1038/s41598-021-04337-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 12/21/2021] [Indexed: 11/09/2022] Open
Abstract
TUBB4A-associated disorder is a rare condition affecting the central nervous system. It displays a wide phenotypic spectrum, ranging from isolated late-onset torsion dystonia to a severe early-onset disease with developmental delay, neurological deficits, and atrophy of the basal ganglia and cerebellum, therefore complicating variant interpretation and phenotype prediction in patients carrying TUBB4A variants. We applied entropy-based normal mode analysis (NMA) to investigate genotype–phenotype correlations in TUBB4A-releated disease and to develop an in-silico approach to assist in variant interpretation and phenotype prediction in this disorder. Variants included in our analysis were those reported prior to the conclusion of data collection for this study in October 2019. All TUBB4A pathogenic missense variants reported in ClinVar and Pubmed, for which associated clinical information was available, and all benign/likely benign TUBB4A missense variants reported in ClinVar, were included in the analysis. Pathogenic variants were divided into five phenotypic subgroups. In-silico point mutagenesis in the wild-type modeled protein structure was performed for each variant. Wild-type and mutated structures were analyzed by coarse-grained NMA to quantify protein stability as entropy difference value (ΔG) for each variant. Pairwise ΔG differences between all variant pairs in each structural cluster were calculated and clustered into dendrograms. Our search yielded 41 TUBB4A pathogenic variants in 126 patients, divided into 11 partially overlapping structural clusters across the TUBB4A protein. ΔG-based cluster analysis of the NMA results revealed a continuum of genotype–phenotype correlation across each structural cluster, as well as in transition areas of partially overlapping structural clusters. Benign/likely benign variants were integrated into the genotype–phenotype continuum as expected and were clearly separated from pathogenic variants. We conclude that our results support the incorporation of the NMA-based approach used in this study in the interpretation of variant pathogenicity and phenotype prediction in TUBB4A-related disease. Moreover, our results suggest that NMA may be of value in variant interpretation in additional monogenic conditions.
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Affiliation(s)
- Avi Fellner
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel. .,Department of Neurology, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.
| | - Yael Goldberg
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel
| | - Dorit Lev
- Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Metabolic-Neurogenetic Clinic, Wolfson Medical Center, 58220, Holon, Israel.,Rina Mor Institute of Medical Genetics, Wolfson Medical Center, 58220, Holon, Israel
| | - Lina Basel-Salmon
- Raphael Recanati Genetics Institute, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Felsenstein Medical Research Center, 49100, Petah Tikva, Israel
| | - Oded Shor
- Department of Neurology, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Felsenstein Medical Research Center, 49100, Petah Tikva, Israel
| | - Felix Benninger
- Department of Neurology, Rabin Medical Center, Beilinson Hospital, 49100, Petah Tikva, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, 69978, Tel-Aviv, Israel.,Felsenstein Medical Research Center, 49100, Petah Tikva, Israel
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22
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Mukherjee A, Sarkar P, Sarkar S, Agrawal R, Dubey S, Pandit A. Adult-onset dystonia with late-onset epilepsy in TUBB4A-Related hypomyelinating leukodystrophy—A new intermediate phenotype. Ann Indian Acad Neurol 2022; 25:562-565. [PMID: 35936629 PMCID: PMC9350765 DOI: 10.4103/aian.aian_952_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 01/02/2022] [Accepted: 01/14/2022] [Indexed: 11/12/2022] Open
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23
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Park K, Hoff KJ, Wethekam L, Stence N, Saenz M, Moore JK. Kinetically Stabilizing Mutations in Beta Tubulins Create Isotype-Specific Brain Malformations. Front Cell Dev Biol 2021; 9:765992. [PMID: 34869359 PMCID: PMC8637541 DOI: 10.3389/fcell.2021.765992] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Accepted: 10/29/2021] [Indexed: 11/13/2022] Open
Abstract
Mutations in the family of genes encoding the tubulin subunits of microtubules are associated with a spectrum of human brain malformations known as tubulinopathies. How these mutations impact tubulin activity to give rise to distinct developmental consequences is poorly understood. Here we report two patients exhibiting brain malformations characteristic of tubulinopathies and heterozygous T178M missense mutations in different β-tubulin genes, TUBB2A or TUBB3. RNAseq analysis indicates that both TUBB2A and TUBB3 are expressed in the brain during development, but only TUBB2A maintains high expression in neurons into adulthood. The T178 residue is highly conserved in β-tubulins and located in the exchangeable GTP-binding pocket of β-tubulin. To determine the impact of T178M on β-tubulin function we created an analogous mutation in the β-tubulin of budding yeast and show that the substitution acts dominantly to produce kinetically stabilized microtubules that assemble and disassemble slowly, with fewer transitions between these states. In vitro experiments with purified mutant tubulin demonstrate that T178M decreases the intrinsic assembly activity of β-tubulin and forms microtubules that rarely transition to disassembly. We provide evidence that the T178M substitution disrupts GTPase-dependent conformational changes in tubulin, providing a mechanistic explanation for kinetic stabilization. Our findings demonstrate the importance of tubulin’s GTPase activity during brain development, and indicate that tubulin isotypes play different, important roles during brain development.
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Affiliation(s)
- Kristen Park
- Department of Pediatrics and Neurology, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Katelyn J Hoff
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Linnea Wethekam
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Nicholas Stence
- Section of Pediatric Radiology, Department of Radiology, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Margarita Saenz
- Section of Genetics, Department of Pediatrics, Children's Hospital Colorado, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Jeffrey K Moore
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
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24
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New perspectives on cytoskeletal dysregulation and mitochondrial mislocalization in amyotrophic lateral sclerosis. Transl Neurodegener 2021; 10:46. [PMID: 34789332 PMCID: PMC8597313 DOI: 10.1186/s40035-021-00272-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Accepted: 10/28/2021] [Indexed: 02/07/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease characterized by selective, early degeneration of motor neurons in the brain and spinal cord. Motor neurons have long axonal projections, which rely on the integrity of neuronal cytoskeleton and mitochondria to regulate energy requirements for maintaining axonal stability, anterograde and retrograde transport, and signaling between neurons. The formation of protein aggregates which contain cytoskeletal proteins, and mitochondrial dysfunction both have devastating effects on the function of neurons and are shared pathological features across several neurodegenerative conditions, including ALS, Alzheimer's disease, Parkinson's disease, Huntington's disease and Charcot-Marie-Tooth disease. Furthermore, it is becoming increasingly clear that cytoskeletal integrity and mitochondrial function are intricately linked. Therefore, dysregulations of the cytoskeletal network and mitochondrial homeostasis and localization, may be common pathways in the initial steps of neurodegeneration. Here we review and discuss known contributors, including variants in genetic loci and aberrant protein activities, which modify cytoskeletal integrity, axonal transport and mitochondrial localization in ALS and have overlapping features with other neurodegenerative diseases. Additionally, we explore some emerging pathways that may contribute to this disruption in ALS.
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25
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Weber R, Chung MY, Keskeny C, Zinnall U, Landthaler M, Valkov E, Izaurralde E, Igreja C. 4EHP and GIGYF1/2 Mediate Translation-Coupled Messenger RNA Decay. Cell Rep 2021; 33:108262. [PMID: 33053355 DOI: 10.1016/j.celrep.2020.108262] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 08/26/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
Current models of mRNA turnover indicate that cytoplasmic degradation is coupled with translation. However, our understanding of the molecular events that coordinate ribosome transit with the mRNA decay machinery is still limited. Here, we show that 4EHP-GIGYF1/2 complexes trigger co-translational mRNA decay. Human cells lacking these proteins accumulate mRNAs with prominent ribosome pausing. They include, among others, transcripts encoding secretory and membrane-bound proteins or tubulin subunits. In addition, 4EHP-GIGYF1/2 complexes fail to reduce mRNA levels in the absence of ribosome stalling or upon disruption of their interaction with the cap structure, DDX6, and ZNF598. We further find that co-translational binding of GIGYF1/2 to the mRNA marks transcripts with perturbed elongation to decay. Our studies reveal how a repressor complex linked to neurological disorders minimizes the protein output of a subset of mRNAs.
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Affiliation(s)
- Ramona Weber
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Min-Yi Chung
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Csilla Keskeny
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Ulrike Zinnall
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 10115 Berlin, Germany; IRI Life Sciences, Institute für Biologie, Humboldt Universität zu Berlin, 10115 Berlin, Germany
| | - Markus Landthaler
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 10115 Berlin, Germany; IRI Life Sciences, Institute für Biologie, Humboldt Universität zu Berlin, 10115 Berlin, Germany
| | - Eugene Valkov
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany.
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26
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Gavazzi F, Charsar BA, Williams C, Shults J, Alves CA, Adang L, Vanderver A. Acquisition of Developmental Milestones in Hypomyelination With Atrophy of the Basal Ganglia and Cerebellum and Other TUBB4A-Related Leukoencephalopathy. J Child Neurol 2021; 36:805-811. [PMID: 34514881 PMCID: PMC8505576 DOI: 10.1177/08830738211000977] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Mutations in TUBB4A are associated with a spectrum of neurologic disorders categorized as TUBB4A-related leukoencephalopathy. Affected children can present with global developmental delay or normal early development, followed by a variable loss of skills over time. Further research is needed to characterize the factors associated with the divergent developmental trajectories in this rare monogenic disorder because this phenotypic spectrum is not fully explained by genotype alone.To characterize early psychomotor features, developmental milestones and age of disease onset were collected from medical records (n=54 individuals). Three subcohorts were identified: individuals with the common p.Asp249Asn variant vs all other genotypes with either early (<12 months of age) or late onset of presentation. Individuals with the p.Asp249Asn variant or those with non-p.Asp249Asn genotypes with later disease onset attained key milestones, including head control, sitting, and independent walking. Subjects with early-onset, non-p.Asp249Asn-associated disease were less likely to achieve developmental milestones. Next, we defined the developmental severity as the percentage of milestones attained by age 2 years. The mild form was defined as attaining at least 75% of key developmental milestones. Among cohort categorized as mild, individuals with p.Asp249Asn variant were more likely to lose acquired abilities when compared with non-p.Asp249Asn individuals.Our results suggest multiple influences on developmental trajectory, including a strong contribution from genotype and age of onset. Further studies are needed to identify additional factors that influence overall outcomes to better counsel families and to design clinical trials with appropriate clinical endpoints.
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Affiliation(s)
- Francesco Gavazzi
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA,Department of Molecular and Translational Medicine, University of Brescia, Italy
| | | | - Catherine Williams
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Justine Shults
- Department of Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA,Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Cesar A. Alves
- Division of Neuroradiology, Children’s Hospital of Philadelphia, Philadelphia, PA
| | - Laura Adang
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA,Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Adeline Vanderver
- Division of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA,Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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27
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Abstract
PURPOSE OF REVIEW The discovery of new disease-causing genes and availability of next-generation sequencing platforms have both progressed rapidly over the last few years. For the practicing neurologist, this presents an increasingly bewildering array both of potential diagnoses and of means to investigate them. We review the latest newly described genetic conditions associated with dystonia, and also address how the changing landscape of gene discovery and genetic testing can best be approached, from both a research and a clinical perspective. RECENT FINDINGS Several new genetic causes for disorders in which dystonia is a feature have been described in the last 2 years, including ZNF142, GSX2, IRF2BPL, DEGS1, PI4K2A, CAMK4, VPS13D and VAMP2. Dystonia has also been a newly described feature or alternative phenotype of several other genetic conditions, notably for genes classically associated with several forms of epilepsy. The DYT system for classifying genetic dystonias, however, last recognized a new gene discovery (KMT2B) in 2016. SUMMARY Gene discovery for dystonic disorders proceeds rapidly, but a high proportion of cases remain undiagnosed. The proliferation of rare disorders means that it is no longer realistic for clinicians to aim for diagnosis to the level of predicting genotype from phenotype in all cases, but rational and adaptive use of available genetic tests can certainly expedite diagnosis.
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28
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Gavazzi F, Charsar BA, Williams C, Shults J, Alves CA, Adang L, Vanderver A. Acquisition of Developmental Milestones in Hypomyelination With Atrophy of the Basal Ganglia and Cerebellum and Other TUBB4A-Related Leukoencephalopathy. J Child Neurol 2021. [PMID: 33843299 DOI: 10.1177/0883073821000977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mutations in TUBB4A are associated with a spectrum of neurologic disorders categorized as TUBB4A-related leukoencephalopathy. Affected children can present with global developmental delay or normal early development, followed by a variable loss of skills over time. Further research is needed to characterize the factors associated with the divergent developmental trajectories in this rare monogenic disorder because this phenotypic spectrum is not fully explained by genotype alone.To characterize early psychomotor features, developmental milestones and age of disease onset were collected from medical records (n=54 individuals). Three subcohorts were identified: individuals with the common p.Asp249Asn variant vs all other genotypes with either early (<12 months of age) or late onset of presentation. Individuals with the p.Asp249Asn variant or those with non-p.Asp249Asn genotypes with later disease onset attained key milestones, including head control, sitting, and independent walking. Subjects with early-onset, non-p.Asp249Asn-associated disease were less likely to achieve developmental milestones. Next, we defined the developmental severity as the percentage of milestones attained by age 2 years. The mild form was defined as attaining at least 75% of key developmental milestones. Among cohort categorized as mild, individuals with p.Asp249Asn variant were more likely to lose acquired abilities when compared with non-p.Asp249Asn individuals.Our results suggest multiple influences on developmental trajectory, including a strong contribution from genotype and age of onset. Further studies are needed to identify additional factors that influence overall outcomes to better counsel families and to design clinical trials with appropriate clinical endpoints.
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Affiliation(s)
- Francesco Gavazzi
- Division of Neurology, 6567Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Brittany A Charsar
- Sidney Kimmel Medical College, 23217Jefferson University, Philadelphia, PA, USA
| | - Catherine Williams
- Division of Neurology, 6567Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Justine Shults
- Department of Pediatrics, 6567Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Biostatistics, Epidemiology and Informatics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Cesar A Alves
- Division of Neuroradiology, 6567Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Laura Adang
- Division of Neurology, 6567Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Adeline Vanderver
- Division of Neurology, 6567Children's Hospital of Philadelphia, Philadelphia, PA, USA.,Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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29
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Yahia A, Stevanin G. The History of Gene Hunting in Hereditary Spinocerebellar Degeneration: Lessons From the Past and Future Perspectives. Front Genet 2021; 12:638730. [PMID: 33833777 PMCID: PMC8021710 DOI: 10.3389/fgene.2021.638730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 03/02/2021] [Indexed: 01/02/2023] Open
Abstract
Hereditary spinocerebellar degeneration (SCD) encompasses an expanding list of rare diseases with a broad clinical and genetic heterogeneity, complicating their diagnosis and management in daily clinical practice. Correct diagnosis is a pillar for precision medicine, a branch of medicine that promises to flourish with the progressive improvements in studying the human genome. Discovering the genes causing novel Mendelian phenotypes contributes to precision medicine by diagnosing subsets of patients with previously undiagnosed conditions, guiding the management of these patients and their families, and enabling the discovery of more causes of Mendelian diseases. This new knowledge provides insight into the biological processes involved in health and disease, including the more common complex disorders. This review discusses the evolution of the clinical and genetic approaches used to diagnose hereditary SCD and the potential of new tools for future discoveries.
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Affiliation(s)
- Ashraf Yahia
- Department of Biochemistry, Faculty of Medicine, University of Khartoum, Khartoum, Sudan
- Department of Biochemistry, Faculty of Medicine, National University, Khartoum, Sudan
- Institut du Cerveau, INSERM U1127, CNRS UMR7225, Sorbonne Université, Paris, France
- Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
| | - Giovanni Stevanin
- Institut du Cerveau, INSERM U1127, CNRS UMR7225, Sorbonne Université, Paris, France
- Ecole Pratique des Hautes Etudes, EPHE, PSL Research University, Paris, France
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30
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Tisch S, Kumar KR. Pallidal Deep Brain Stimulation for Monogenic Dystonia: The Effect of Gene on Outcome. Front Neurol 2021; 11:630391. [PMID: 33488508 PMCID: PMC7820073 DOI: 10.3389/fneur.2020.630391] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 12/09/2020] [Indexed: 11/13/2022] Open
Abstract
Globus pallidus internus deep brain stimulation (GPi DBS) is the most effective intervention for medically refractory segmental and generalized dystonia in both children and adults. Predictive factors for the degree of improvement after GPi DBS include shorter disease duration and dystonia subtype with idiopathic isolated dystonia usually responding better than acquired combined dystonias. Other factors contributing to variability in outcome may include body distribution, pattern of dystonia and DBS related factors such as lead placement and stimulation parameters. The responsiveness to DBS appears to vary between different monogenic forms of dystonia, with some improving more than others. The first observation in this regard was reports of superior DBS outcomes in DYT-TOR1A (DYT1) dystonia, although other studies have found no difference. Recently a subgroup with young onset DYT-TOR1A, more rapid progression and secondary worsening after effective GPi DBS, has been described. Myoclonus dystonia due to DYT-SCGE (DYT11) usually responds well to GPi DBS. Good outcomes following GPi DBS have also been documented in X-linked dystonia Parkinsonism (DYT3). In contrast, poorer, more variable DBS outcomes have been reported in DYT-THAP1 (DYT6) including a recent larger series. The outcome of GPi DBS in other monogenic isolated and combined dystonias including DYT-GNAL (DYT25), DYT-KMT2B (DYT28), DYT-ATP1A3 (DYT12), and DYT-ANO3 (DYT24) have been reported with varying results in smaller numbers of patients. In this article the available evidence for long term GPi DBS outcome between different genetic dystonias is reviewed to reappraise popular perceptions of expected outcomes and revisit whether genetic diagnosis may assist in predicting DBS outcome.
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Affiliation(s)
- Stephen Tisch
- Department of Neurology, St Vincent's Hospital, University of New South Wales, Sydney, NSW, Australia
| | - Kishore Raj Kumar
- Molecular Medicine Laboratory and Neurology Department, Concord Clinical School, Concord Repatriation General Hospital, The University of Sydney, Sydney, NSW, Australia
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
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31
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Microtubule Dysfunction: A Common Feature of Neurodegenerative Diseases. Int J Mol Sci 2020; 21:ijms21197354. [PMID: 33027950 PMCID: PMC7582320 DOI: 10.3390/ijms21197354] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 09/24/2020] [Accepted: 10/01/2020] [Indexed: 12/13/2022] Open
Abstract
Neurons are particularly susceptible to microtubule (MT) defects and deregulation of the MT cytoskeleton is considered to be a common insult during the pathogenesis of neurodegenerative disorders. Evidence that dysfunctions in the MT system have a direct role in neurodegeneration comes from findings that several forms of neurodegenerative diseases are associated with changes in genes encoding tubulins, the structural units of MTs, MT-associated proteins (MAPs), or additional factors such as MT modifying enzymes which modulating tubulin post-translational modifications (PTMs) regulate MT functions and dynamics. Efforts to use MT-targeting therapeutic agents for the treatment of neurodegenerative diseases are underway. Many of these agents have provided several benefits when tested on both in vitro and in vivo neurodegenerative model systems. Currently, the most frequently addressed therapeutic interventions include drugs that modulate MT stability or that target tubulin PTMs, such as tubulin acetylation. The purpose of this review is to provide an update on the relevance of MT dysfunctions to the process of neurodegeneration and briefly discuss advances in the use of MT-targeting drugs for the treatment of neurodegenerative disorders.
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32
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Garcia LM, Hacker JL, Sase S, Adang L, Almad A. Glial cells in the driver seat of leukodystrophy pathogenesis. Neurobiol Dis 2020; 146:105087. [PMID: 32977022 DOI: 10.1016/j.nbd.2020.105087] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 08/16/2020] [Accepted: 09/18/2020] [Indexed: 01/24/2023] Open
Abstract
Glia cells are often viewed as support cells in the central nervous system, but recent discoveries highlight their importance in physiological functions and in neurological diseases. Central to this are leukodystrophies, a group of progressive, neurogenetic disease affecting white matter pathology. In this review, we take a closer look at multiple leukodystrophies, classified based on the primary glial cell type that is affected. While white matter diseases involve oligodendrocyte and myelin loss, we discuss how astrocytes and microglia are affected and impinge on oligodendrocyte, myelin and axonal pathology. We provide an overview of the leukodystrophies covering their hallmark features, clinical phenotypes, diverse molecular pathways, and potential therapeutics for clinical trials. Glial cells are gaining momentum as cellular therapeutic targets for treatment of demyelinating diseases such as leukodystrophies, currently with no treatment options. Here, we bring the much needed attention to role of glia in leukodystrophies, an integral step towards furthering disease comprehension, understanding mechanisms and developing future therapeutics.
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Affiliation(s)
- Luis M Garcia
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Julia L Hacker
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Sunetra Sase
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Laura Adang
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA
| | - Akshata Almad
- Department of Neurology, The Children's Hospital of Philadelphia, PA, Pennsylvania, USA.
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33
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Bally JF, Camargos S, Oliveira Dos Santos C, Kern DS, Lee T, Pereira da Silva-Junior F, Puga RD, Cardoso F, Barbosa ER, Yadav R, Ozelius LJ, de Carvalho Aguiar P, Lang AE. DYT-TUBB4A (DYT4 Dystonia): New Clinical and Genetic Observations. Neurology 2020; 96:e1887-e1897. [PMID: 32943487 DOI: 10.1212/wnl.0000000000010882] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 09/04/2020] [Indexed: 01/06/2023] Open
Abstract
OBJECTIVE To report 4 novel TUBB4A mutations leading to laryngeal and cervical dystonia with frequent generalization. METHODS We screened 4 families including a total of 11 definitely affected members with a clinical picture resembling the original description. RESULTS Four novel variants in the TUBB4A gene have been identified: D295N, R46M, Q424H, and R121W. In silico modeling showed that all variants have characteristics similar to R2G. The variants segregate with the disease in 3 of the families with evidence of incomplete penetrance in 2 of them. All 4 variants would be classified as likely pathogenic. The clinical picture particularly included laryngeal dystonia (often the site of onset), associated with cervical and upper limb dystonia and frequent generalization. Laryngeal dystonia was extremely prevalent (>90%) both in the original cases and in this case series. The hobby horse gait was evident in only 1 patient in this case series. CONCLUSIONS Our interpretation is that laryngeal involvement is a hallmark feature of DYT-TUBB4A. Nevertheless, TUBB4A mutations remain an exceedingly rare cause of laryngeal or other isolated dystonia.
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Affiliation(s)
- Julien F Bally
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Sarah Camargos
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Camila Oliveira Dos Santos
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Drew S Kern
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Teresa Lee
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Francisco Pereira da Silva-Junior
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Renato David Puga
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Francisco Cardoso
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Egberto Reis Barbosa
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Rachita Yadav
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Laurie J Ozelius
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Patricia de Carvalho Aguiar
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Anthony E Lang
- From the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic (J.F.B., A.E.L.), Toronto Western Hospital and University of Toronto, Ontario, Canada; Department of Neurology (J.F.B.), University of Geneva and University Hospitals of Geneva, Switzerland; Department of Internal Medicine (S.C., F.C.), Universidade Federal de Minas Gerais, Belo Horizonte; Hospital Israelita Albert Einstein (C.O.d.S., R.D.P., P.d.C.A.), Sao Paulo, SP, Brazil; Departments of Neurology (D.S.K., T.L.) and Neurosurgery (D.S.K.), University of Colorado School of Medicine; Aurora; Department of Neurology and Neurosurgery (F.P.d.S.-J., E.R.B., P.d.C.A.), Universidade Federal de Sao Paulo, SP, Brazil; and Department of Neurology (R.Y., L.J.O.), Massachusetts General Hospital, Boston. Dr. Bally is currently at Service of Neurology, Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Switzerland.
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Sase S, Almad AA, Boecker CA, Guedes-Dias P, Li JJ, Takanohashi A, Patel A, McCaffrey T, Patel H, Sirdeshpande D, Curiel J, Shih-Hwa Liu J, Padiath Q, Holzbaur EL, Scherer SS, Vanderver A. TUBB4A mutations result in both glial and neuronal degeneration in an H-ABC leukodystrophy mouse model. eLife 2020; 9:52986. [PMID: 32463361 PMCID: PMC7255805 DOI: 10.7554/elife.52986] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 04/13/2020] [Indexed: 12/20/2022] Open
Abstract
Mutations in TUBB4A result in a spectrum of leukodystrophy including Hypomyelination with Atrophy of Basal Ganglia and Cerebellum (H-ABC), a rare hypomyelinating leukodystrophy, often associated with a recurring variant p.Asp249Asn (D249N). We have developed a novel knock-in mouse model harboring heterozygous (Tubb4aD249N/+) and the homozygous (Tubb4aD249N/D249N) mutation that recapitulate the progressive motor dysfunction with tremor, dystonia and ataxia seen in H-ABC. Tubb4aD249N/D249N mice have myelination deficits along with dramatic decrease in mature oligodendrocytes and their progenitor cells. Additionally, a significant loss occurs in the cerebellar granular neurons and striatal neurons in Tubb4aD249N/D249N mice. In vitro studies show decreased survival and dysfunction in microtubule dynamics in neurons from Tubb4aD249N/D249N mice. Thus Tubb4aD249N/D249N mice demonstrate the complex cellular physiology of H-ABC, likely due to independent effects on oligodendrocytes, striatal neurons, and cerebellar granule cells in the context of altered microtubule dynamics, with profound neurodevelopmental deficits.
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Affiliation(s)
- Sunetra Sase
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Akshata A Almad
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - C Alexander Boecker
- Department of Physiology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Pedro Guedes-Dias
- Department of Physiology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Jian J Li
- Department of Neurology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Asako Takanohashi
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Akshilkumar Patel
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Tara McCaffrey
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Heta Patel
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Divya Sirdeshpande
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Julian Curiel
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States
| | - Judy Shih-Hwa Liu
- Department of Neurology, Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, United States
| | - Quasar Padiath
- Department of Human Genetics and Neurobiology, University of Pittsburgh, Pittsburgh, United States
| | - Erika Lf Holzbaur
- Department of Physiology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Steven S Scherer
- Department of Neurology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Adeline Vanderver
- Department of Neurology, The Children's Hospital of Philadelphia, Philadelphia, United States.,Department of Neurology, the Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
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Hausrat TJ, Radwitz J, Lombino FL, Breiden P, Kneussel M. Alpha- and beta-tubulin isotypes are differentially expressed during brain development. Dev Neurobiol 2020; 81:333-350. [PMID: 32293117 DOI: 10.1002/dneu.22745] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/21/2020] [Accepted: 04/08/2020] [Indexed: 12/14/2022]
Abstract
Alpha- and beta-tubulin dimers polymerize into protofilaments that associate laterally to constitute a hollow tube, the microtubule. A dynamic network of interlinking filaments forms the microtubule cytoskeleton, which maintains the structure of cells and is key to various cellular processes including cell division, cell migration, and intracellular transport. Individual microtubules have an identity that depends on the differential integration of specific alpha- and beta-tubulin isotypes and is further specified by a variety of posttranslational modifications (PTMs). It is barely understood to which extent neighboring microtubules differ in their tubulin composition or whether specific tubulin isotypes cluster along the polymer. Furthermore, our knowledge about the spatio-temporal expression patterns of tubulin isotypes is limited, not at least due to the lack of antibodies or antibody cross-reactivities. Here, we asked which alpha- and beta-tubulin mRNAs and proteins are expressed in developing hippocampal neuron cultures and ex vivo brain tissue lysates. Using heterologous expression of GFP-tubulin fusion proteins, we systematically tested antibody-specificities against various tubulin isotypes. Our data provide quantitative information about tubulin expression levels in the mouse brain and classify tubulin isotypes during pre- and postnatal development.
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Affiliation(s)
- Torben J Hausrat
- Department of Molecular Neurogenetics, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Jennifer Radwitz
- Department of Molecular Neurogenetics, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Franco L Lombino
- Department of Molecular Neurogenetics, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Petra Breiden
- Department of Molecular Neurogenetics, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Matthias Kneussel
- Department of Molecular Neurogenetics, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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36
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Stephen CD, Go CL, Acuna P, Sharma N. Phasic Knee Bending Dystonic and Parkinsonian Gait: A Characteristic Finding in X-Linked Dystonia Parkinsonism. Mov Disord Clin Pract 2020; 7:448-452. [PMID: 32373662 DOI: 10.1002/mdc3.12929] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 01/22/2020] [Accepted: 02/26/2020] [Indexed: 11/11/2022] Open
Abstract
Background X-linked dystonia parkinsonism (XDP) is a rare disorder characterized by adult-onset, progressive dystonia that, over time, is combined with or replaced by features of parkinsonism. Gait impairment is common. Methods Case series of 4 XDP patients with a unique gait disorder. Results The patients displayed a characteristic gait disorder with combined dystonic and parkinsonian gait features, with phasic knee bending. Of these patients, all had parkinsonism and three-quarters had prominent dystonic features, but 1 had predominant parkinsonism and subtle dystonic features. Conclusion Although XDP is a classic form of dystonia parkinsonism, some cases can mimic idiopathic Parkinson's disease. We describe a gait disorder which appears unique to XDP, involving phasic dystonic knee bending superimposed on parkinsonian shuffling, and may help clinically differentiate one of our parkinsonian-predominant patients from more-common forms of parkinsonism. The gait is distinct from other complex dystonic disorders with gait involvement.
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Affiliation(s)
- Christopher D Stephen
- Dystonia Clinic and Movement Disorders Unit Department of Neurology, Massachusetts General Hospital and Harvard Medical School Boston MA USA
| | - Criscely L Go
- Department of Behavioral Medicine Jose Reyes Memorial Medical Center Manila Philippines
| | - Patrick Acuna
- Dystonia Clinic and Movement Disorders Unit Department of Neurology, Massachusetts General Hospital and Harvard Medical School Boston MA USA
| | - Nutan Sharma
- Dystonia Clinic and Movement Disorders Unit Department of Neurology, Massachusetts General Hospital and Harvard Medical School Boston MA USA
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Maraldi T, Beretti F, Anselmi L, Franchin C, Arrigoni G, Braglia L, Mandrioli J, Vinceti M, Marmiroli S. Influence of selenium on the emergence of neuro tubule defects in a neuron-like cell line and its implications for amyotrophic lateral sclerosis. Neurotoxicology 2019; 75:209-220. [PMID: 31585128 DOI: 10.1016/j.neuro.2019.09.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 12/13/2022]
Abstract
Impairment of the axonal transport system mediated by intracellular microtubules (MTs) is known to be a major drawback in neurodegenerative processes. Due to a growing interest on the neurotoxic effects of selenium in environmental health, our study aimed to assess the relationship between selenium and MTs perturbation, that may favour disease onset over a genetic predisposition to amyotrophic lateral sclerosis. We treated a neuron-like cell line with sodium selenite, sodium selenate and seleno-methionine and observed that the whole cytoskeleton was affected. We then investigated the protein interactome of cells overexpressing αTubulin-4A (TUBA4A) and found that selenium increases the interaction of TUBA4A with DNA- and RNA-binding proteins. TUBA4A ubiquitination and glutathionylation were also observed, possibly due to a selenium-dependent increase of ROS, leading to perturbation and degradation of MTs. Remarkably, the TUBA4A mutants R320C and A383 T, previously described in ALS patients, showed the same post-translational modifications to a similar extent. In conclusion this study gives insights into a specific mechanism characterizing selenium neurotoxicity.
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Affiliation(s)
- Tullia Maraldi
- Department of Surgical, Medical, Dental and Morphological Sciences with interest in Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, Via Del Pozzo 71, 41124, Modena, Italy.
| | - Francesca Beretti
- Department of Surgical, Medical, Dental and Morphological Sciences with interest in Transplant, Oncology and Regenerative Medicine, University of Modena and Reggio Emilia, Via Del Pozzo 71, 41124, Modena, Italy.
| | - Laura Anselmi
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, 41125, Italy.
| | - Cinzia Franchin
- Department of Biomedical Sciences, University of Padova, via G. Basso 58/B, 35131, Padova, Italy; Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, via G. Orus 2/B, 35129, Padova, Italy.
| | - Giorgio Arrigoni
- Department of Biomedical Sciences, University of Padova, via G. Basso 58/B, 35131, Padova, Italy; Proteomics Center, University of Padova and Azienda Ospedaliera di Padova, via G. Orus 2/B, 35129, Padova, Italy.
| | - Luca Braglia
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, 41125, Italy.
| | - Jessica Mandrioli
- Neurology Unit, Department of Neurosciences, Azienda Ospedaliero Universitaria di Modena, Modena, Italy.
| | - Marco Vinceti
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, 41125, Italy; Department of Epidemiology, Boston University School of Public Health, Boston, Massachusetts, United States.
| | - Sandra Marmiroli
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, 41125, Italy.
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Tubulin heterogeneity regulates functions and dynamics of microtubules and plays a role in the development of drug resistance in cancer. Biochem J 2019; 476:1359-1376. [DOI: 10.1042/bcj20190123] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 04/21/2019] [Accepted: 04/24/2019] [Indexed: 01/01/2023]
Abstract
Abstract
Microtubules, composed of αβ-tubulin heterodimers, exhibit diverse structural and functional properties in different cell types. The diversity in the microtubule structure originates from tubulin heterogeneities, namely tubulin isotypes and their post-translational modifications (PTMs). These heterogeneities confer differential stability to microtubules and provide spatial cues for the functioning of the cell. Furthermore, the altered expressions of tubulin isotypes and PTMs are prominent factors for the development of resistance against some cancer drugs. In this review, we summarize our current knowledge of the tubulin isotypes and PTMs and how, together, they control the cellular functions of the microtubules. We also describe how cancer cells use this tubulin heterogeneity to acquire resistance against clinical agents and discuss existing attempts to counter the developed resistance.
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Vulinovic F, Krajka V, Hausrat TJ, Seibler P, Alvarez-Fischer D, Madoev H, Park JS, Kumar KR, Sue CM, Lohmann K, Kneussel M, Klein C, Rakovic A. Motor protein binding and mitochondrial transport are altered by pathogenic TUBB4A variants. Hum Mutat 2018; 39:1901-1915. [PMID: 30079973 DOI: 10.1002/humu.23602] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 07/05/2018] [Accepted: 07/29/2018] [Indexed: 12/21/2022]
Abstract
Mutations in TUBB4A have been identified to cause a wide phenotypic spectrum of diseases ranging from hereditary generalized dystonia with whispering dysphonia (DYT-TUBB4A) and hereditary spastic paraplegia (HSP) to leukodystrophy hypomyelination with atrophy of the basal ganglia and cerebellum (H-ABC). TUBB4A encodes the brain-specific β-tubulin isotype, β-tubulin 4A. To elucidate the pathogenic mechanisms conferred by TUBB4A mutations leading to the different phenotypes, we functionally characterized three pathogenic TUBB4A variants (c.4C>G,p.R2G; c.745G>A,p.D249N; c.811G>A, p.A271T) as representatives of the mutational and disease spectrum) in human neuroblastoma cells and human induced pluripotent stem cell (iPSC)-derived neurons. We showed that mRNA stability was not affected by any of the TUBB4A variants. Although two mutations (p.R2G and p.D249N) are located at the α/β-tubulin interdimer interface, we confirmed incorporation of all TUBB4A mutants into the microtubule network. However, we showed that the mutations p.D249N and p.A271T interfered with motor protein binding to microtubules and impaired neurite outgrowth and microtubule dynamics. Finally, TUBB4A mutations, as well as heterozygous knockout of TUBB4A, disrupted mitochondrial transport in iPSC-derived neurons. Taken together, our findings suggest that functional impairment of microtubule-associated transport is a shared pathogenic mechanism by which the TUBB4A mutations studied here cause a spectrum of diseases.
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Affiliation(s)
- Franca Vulinovic
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Victor Krajka
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Torben J Hausrat
- Institute of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Philip Seibler
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | | | - Harutyun Madoev
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Jin-Sung Park
- Department of Neurogenetics, Kolling Institute, Royal North Shore Hospital and the University of Sydney, St. Leonards, New South Wales, Australia
| | - Kishore R Kumar
- Department of Neurogenetics, Kolling Institute, Royal North Shore Hospital and the University of Sydney, St. Leonards, New South Wales, Australia
- Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Darlinghurst, Australia
| | - Carolyn M Sue
- Department of Neurogenetics, Kolling Institute, Royal North Shore Hospital and the University of Sydney, St. Leonards, New South Wales, Australia
| | - Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
| | - Matthias Kneussel
- Institute of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Lübeck, Germany
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Clinical and Functional Characterization of the Recurrent TUBA1A p.(Arg2His) Mutation. Brain Sci 2018; 8:brainsci8080145. [PMID: 30087272 PMCID: PMC6119949 DOI: 10.3390/brainsci8080145] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/06/2018] [Accepted: 07/17/2018] [Indexed: 12/25/2022] Open
Abstract
The TUBA1A gene encodes tubulin alpha-1A, a protein that is highly expressed in the fetal brain. Alpha- and beta-tubulin subunits form dimers, which then co-assemble into microtubule polymers: dynamic, scaffold-like structures that perform key functions during neurogenesis, neuronal migration, and cortical organisation. Mutations in TUBA1A have been reported to cause a range of brain malformations. We describe four unrelated patients with the same de novo missense mutation in TUBA1A, c.5G>A, p.(Arg2His), as found by next generation sequencing. Detailed comparison revealed similar brain phenotypes with mild variability. Shared features included developmental delay, microcephaly, hypoplasia of the cerebellar vermis, dysplasia or thinning of the corpus callosum, small pons, and dysmorphic basal ganglia. Two of the patients had bilateral perisylvian polymicrogyria. We examined the effects of the p.(Arg2His) mutation by computer-based protein structure modelling and heterologous expression in HEK-293 cells. The results suggest the mutation subtly impairs microtubule function, potentially by affecting inter-dimer interaction. Based on its sequence context, c.5G>A is likely to be a common recurrent mutation. We propose that the subtle functional effects of p.(Arg2His) may allow for other factors (such as genetic background or environmental conditions) to influence phenotypic outcome, thus explaining the mild variability in clinical manifestations.
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Tubulin genes and malformations of cortical development. Eur J Med Genet 2018; 61:744-754. [PMID: 30016746 DOI: 10.1016/j.ejmg.2018.07.012] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 06/03/2018] [Accepted: 07/12/2018] [Indexed: 01/18/2023]
Abstract
A large number of genes encoding for tubulin proteins are expressed in the developing brain. Each is subject to specific spatial and temporal expression patterns. However, most are highly expressed in post-mitotic neurons during stages of neuronal migration and differentiation. The major tubulin subclasses (alpha- and beta-tubulin) share high sequence and structural homology. These globular proteins form heterodimers and subsequently co-assemble into microtubules. Microtubules are dynamic, cytoskeletal polymers which play key roles in cellular processes crucial for cortical development, including neuronal proliferation, migration and cortical laminar organisation. Mutations in seven genes encoding alpha-tubulin (TUBA1A), beta-tubulin (TUBB2A, TUBB2B, TUBB3, TUBB4A, TUBB) and gamma-tubulin (TUBG1) isoforms have been associated with a wide and overlapping range of brain malformations or "Tubulinopathies". The majority of cortical phenotypes include lissencephaly, polymicrogyria, microlissencephaly and simplified gyration. Well-known hallmarks of the tubulinopathies include dysmorphism of the basal ganglia (fusion of the caudate nucleus and putamen with absence of the anterior limb of the internal capsule), midline commissural structures hypoplasia and/or agenesis (anterior commissure, corpus callosum and fornix), hypoplasia of the oculomotor and optic nerves, cerebellar hypoplasia or dysplasia and dysmorphism of the hind-brain structures. The cortical and extra-cortical brain phenotypes observed are largely dependent on the specific tubulin gene affected. In the present review, all the published data on tubulin family gene mutations and the associated cortical phenotypes are summarized. In addition, the most typical neuroimaging patterns of malformations of cortical development associated with tubulin gene mutations detected on the basis of our own experience are described.
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Meijer IA, Pearson TS. The Twists of Pediatric Dystonia: Phenomenology, Classification, and Genetics. Semin Pediatr Neurol 2018; 25:65-74. [PMID: 29735118 DOI: 10.1016/j.spen.2018.02.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This article aims to provide a practical review of pediatric dystonia from a clinician's perspective. The focus is on the underlying genetic causes, recent findings, and treatable conditions. Dystonia can occur in an isolated fashion or accompanied by other neurological or systemic features. The clinical presentation is often a complex overlap of neurological findings with a large differential diagnosis. We recommend an approach guided by thorough clinical evaluation, brain magnetic resonance imaging (MRI), biochemical analysis, and genetic testing to hone in on the diagnosis. This article highlights the clinical and genetic complexity of pediatric dystonia and underlines the importance of a genetic diagnosis for therapeutic considerations.
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Affiliation(s)
- Inge A Meijer
- Department of Neurology, Mount Sinai Beth Israel, New York, NY; Department of Pediatrics, Neurology division, Université de Montreal, Montreal, Canada
| | - Toni S Pearson
- Department of Neurology, Washington University School of Medicine, Saint Louis, MO.
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Curiel J, Rodríguez Bey G, Takanohashi A, Bugiani M, Fu X, Wolf NI, Nmezi B, Schiffmann R, Bugaighis M, Pierson T, Helman G, Simons C, van der Knaap MS, Liu J, Padiath Q, Vanderver A. TUBB4A mutations result in specific neuronal and oligodendrocytic defects that closely match clinically distinct phenotypes. Hum Mol Genet 2018; 26:4506-4518. [PMID: 28973395 DOI: 10.1093/hmg/ddx338] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/24/2017] [Indexed: 12/16/2022] Open
Abstract
Hypomyelinating leukodystrophies are heritable disorders defined by lack of development of brain myelin, but the cellular mechanisms of hypomyelination are often poorly understood. Mutations in TUBB4A, encoding the tubulin isoform tubulin beta class IVA (Tubb4a), result in the symptom complex of hypomyelination with atrophy of basal ganglia and cerebellum (H-ABC). Additionally, TUBB4A mutations are known to result in a broad phenotypic spectrum, ranging from primary dystonia (DYT4), isolated hypomyelination with spastic quadriplegia, and an infantile onset encephalopathy, suggesting multiple cell types may be involved. We present a study of the cellular effects of TUBB4A mutations responsible for H-ABC (p.Asp249Asn), DYT4 (p.Arg2Gly), a severe combined phenotype with hypomyelination and encephalopathy (p.Asn414Lys), as well as milder phenotypes causing isolated hypomyelination (p.Val255Ile and p.Arg282Pro). We used a combination of histopathological, biochemical and cellular approaches to determine how these different mutations may have variable cellular effects in neurons and/or oligodendrocytes. Our results demonstrate that specific mutations lead to either purely neuronal, combined neuronal and oligodendrocytic or purely oligodendrocytic defects that closely match their respective clinical phenotypes. Thus, the DYT4 mutation that leads to phenotypes attributable to neuronal dysfunction results in altered neuronal morphology, but with unchanged tubulin quantity and polymerization, with normal oligodendrocyte morphology and myelin gene expression. Conversely, mutations associated with isolated hypomyelination (p.Val255Ile and p.Arg282Pro) and the severe combined phenotype (p.Asn414Lys) resulted in normal neuronal morphology but were associated with altered oligodendrocyte morphology, myelin gene expression, and microtubule dysfunction. The H-ABC mutation (p.Asp249Asn) that exhibits a combined neuronal and myelin phenotype had overlapping cellular defects involving both neuronal and oligodendrocyte cell types in vitro. Only mutations causing hypomyelination phenotypes showed altered microtubule dynamics and acted through a dominant toxic gain of function mechanism. The DYT4 mutation had no impact on microtubule dynamics suggesting a distinct mechanism of action. In summary, the different clinical phenotypes associated with TUBB4A reflect the selective and specific cellular effects of the causative mutations. Cellular specificity of disease pathogenesis is relevant to developing targeted treatments for this disabling condition.
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Affiliation(s)
- Julian Curiel
- Center for Neuroscience Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | | | - Asako Takanohashi
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA.,Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | | | - Xiaoqin Fu
- Center for Neuroscience Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Nicole I Wolf
- VU University Medical Center, Amsterdam, The Netherlands
| | - Bruce Nmezi
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Raphael Schiffmann
- Institute of Metabolic Disease, Baylor Scott & White Research Institute, Dallas, TX 75204, USA
| | - Mona Bugaighis
- Center for Neuroscience Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Tyler Pierson
- Departments of Pediatrics and Neurology, Cedar Sinai Medical Center, Board of Governors Regenerative Medicine Institute, Los Angeles, CA 90048, USA
| | - Guy Helman
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA.,Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia.,Department of Neurology, Children's National Health System, Washington, DC 20010, USA
| | - Cas Simons
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Australia
| | | | - Judy Liu
- Center for Neuroscience Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA
| | - Quasar Padiath
- Department of Human Genetics, University of Pittsburgh, Pittsburgh, PA 15260, USA
| | - Adeline Vanderver
- Center for Genetic Medicine Research, Children's National Health System, Children's Research Institute, Washington, DC 20010, USA.,Division of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA.,Department of Neurology, Children's National Health System, Washington, DC 20010, USA.,Perlman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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Zorzi G, Carecchio M, Zibordi F, Garavaglia B, Nardocci N. Diagnosis and treatment of pediatric onset isolated dystonia. Eur J Paediatr Neurol 2018; 22:238-244. [PMID: 29396174 DOI: 10.1016/j.ejpn.2018.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 12/14/2017] [Accepted: 01/08/2018] [Indexed: 12/14/2022]
Abstract
Isolated dystonia refers to a genetic heterogeneous group of progressive conditions with onset of symptoms during childhood or adolescence, progressive course with frequent generalization and marked functional impairment. There are well-known monogenic forms of isolated dystonia with pediatric onset such as DYT1 and DYT6 transmitted with autosomal dominant inheritance and low penetrance. Genetic findings of the past years have widened the etiological spectrum and the phenotype. The recently discovered genes (GNAL, ANO-3, KTM2B) or variant of already known diseases, such as Ataxia-Teleangectasia, are emerging as another causes of pediatric onset dystonia, sometimes with a more complex phenotype, but their incidence is unknown and still a considerable number of cases remains genetically undetermined. Due to the severe disability of pediatric onset dystonia treatment remains unsatisfactory and still mainly based upon oral pharmacological agents. However, deep brain stimulation is now extensively applied with good to excellent results especially when patients are treated early during the course of the disease.
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Affiliation(s)
- Giovanna Zorzi
- Department of Paediatric Neurology, IRCCS Fondazione C. Besta, Milan, Italy.
| | - Miryam Carecchio
- Department of Paediatric Neurology, IRCCS Fondazione C. Besta, Milan, Italy; Molecular Neurogenetics Unit, IRCCS Fondazione C. Besta, Milan, Italy
| | - Federica Zibordi
- Department of Paediatric Neurology, IRCCS Fondazione C. Besta, Milan, Italy
| | | | - Nardo Nardocci
- Department of Paediatric Neurology, IRCCS Fondazione C. Besta, Milan, Italy
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45
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Hypomyelinating disorders in China: The clinical and genetic heterogeneity in 119 patients. PLoS One 2018; 13:e0188869. [PMID: 29451896 PMCID: PMC5815574 DOI: 10.1371/journal.pone.0188869] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2017] [Accepted: 11/14/2017] [Indexed: 01/08/2023] Open
Abstract
OBJECTIVE Hypomyelinating disorders are a group of clinically and genetically heterogeneous diseases characterized by neurological deterioration with hypomyelination visible on brain MRI scans. This study was aimed to clarify the clinical and genetic features of HMDs in Chinese population. METHODS 119 patients with hypomyelinating disorders in Chinese population were enrolled and evaluated based on their history, clinical manifestation, laboratory examinations, series of brain MRI with follow-up, genetic etiological tests including chromosomal analysis, multiplex ligation probe amplification, Sanger sequencing, targeted enrichment-based next-generation sequencing and whole exome sequencing. RESULTS Clinical and genetic features of hypomyelinating disorders were revealed. Nine different hypomyelinating disorders were identified in 119 patients: Pelizaeus-Merzbacher disease (94, 79%), Pelizaeus-Merzbacher-like disease (10, 8%), hypomyelination with atrophy of the basal ganglia and cerebellum (3, 3%), GM1 gangliosidosis (5, 4%), GM2 gangliosidosis (3, 3%), trichothiodystrophy (1, 1%), Pol III-related leukodystrophy (1, 1%), hypomyelinating leukodystrophy type 9 (1, 1%), and chromosome 18q deletion syndrome (1, 1%). Of the sample, 94% (112/119) of the patients were genetically diagnosed, including 111 with mutations distributing across 9 genes including PLP1, GJC2, TUBB4A, GLB1, HEXA, HEXB, ERCC2, POLR3A, and RARS and 1 with mosaic chromosomal change of 46, XX,del(18)(q21.3)/46,XX,r(18)(p11.32q21.3)/45,XX,-18. Eighteen novel mutations were discovered. Mutations in POLR3A and RARS were first identified in Chinese patients with Pol III-related leukodystrophy and hypomyelinating leukodystrophy, respectively. SIGNIFICANCE This is the first report on clinical and genetic features of hypomyelinating disorders with a large sample of patients in Chinese population, identifying 18 novel mutations especially mutations in POLR3A and RARS in Chinese patients, expanding clinical and genetic spectrums of hypomyelinating disorders.
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46
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Watanabe N, Itakaoka M, Seki Y, Morimoto T, Homma K, Miyamoto Y, Yamauchi J. Dystonia-4 (DYT4)-associated TUBB4A mutants exhibit disorganized microtubule networks and inhibit neuronal process growth. Biochem Biophys Res Commun 2018; 495:346-352. [DOI: 10.1016/j.bbrc.2017.11.038] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 11/06/2017] [Indexed: 10/18/2022]
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Abstract
PURPOSE OF REVIEW Deep brain stimulation (DBS) has recently emerged as an important management option in children with medically refractory dystonia. DBS is most commonly used, best studied, and thought to be most efficacious for a select group of childhood or adolescent onset monogenic dystonias (designated with a standard 'DYT' prefix). We review how to clinically recognize these types of dystonia and the relative efficacy of DBS for key monogenic dystonias. RECENT FINDINGS Though used for dystonia in adults for several years, DBS has only lately been used in children. Recent evidence shows that patients with shorter duration of dystonia often experience greater benefit following DBS. This suggests that early recognition of the appropriate dystonic phenotypes and consideration of DBS in these patients may improve the management of dystonia. SUMMARY DBS should be considered early in patients who have medically refractory dystonia, especially for the monogenic dystonias that have a high response rate to DBS. It is important to differentiate between these monogenic dystonias and dystonias of other causes to properly prognosticate for these patients and to determine whether DBS is an appropriate management option.
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49
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Monies D, Abou Al-Shaar H, Goljan EA, Al-Younes B, Al-Breacan MMA, Al-Saif MM, Wakil SM, Meyer BF, Khabar KSA, Bohlega S. Identification of a novel genetic locus underlying tremor and dystonia. Hum Genomics 2017; 11:25. [PMID: 29110692 PMCID: PMC5674688 DOI: 10.1186/s40246-017-0123-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2017] [Accepted: 10/27/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Five affected individuals with syndromic tremulous dystonia, spasticity, and white matter disease from a consanguineous extended family covering a period of over 24 years are presented. A positional cloning approach utilizing genome-wide linkage, homozygozity mapping and whole exome sequencing was used for genetic characterization. The impact of a calmodulin-binding transcription activator 2, (CAMTA2) isoform 2, hypomorphic mutation on mRNA and protein abundance was studied using fluorescent reporter expression cassettes. Human brain sub-region cDNA libraries were used to study the expression pattern of CAMTA2 transcript variants. RESULTS Linkage analysis and homozygozity mapping localized the disease allele to a 2.1 Mb interval on chromosome 17 with a LOD score of 4.58. Whole exome sequencing identified a G>A change in the transcript variant 2 5'UTR of CAMTA2 that was only 6 bases upstream of the translation start site (c.-6G > A) (NM_001171166.1) and segregated with disease in an autosomal recessive manner. Transfection of wild type and mutant 5'UTR-linked fluorescent reporters showed no impact upon mRNA levels but a significant reduction in the protein fluorescent activity implying translation inhibition. CONCLUSIONS Mutation of CAMTA2 resulting in post-transcriptional inhibition of its own gene activity likely underlies a novel syndromic tremulous dystonia.
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Affiliation(s)
- Dorota Monies
- Department of Genetics, King Faisal Specialist Hospital, and Research Centre, PO Box 3354, Riyadh, 11211, Saudi Arabia. .,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.
| | - Hussam Abou Al-Shaar
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh, 11211, Saudi Arabia
| | - Ewa A Goljan
- Department of Genetics, King Faisal Specialist Hospital, and Research Centre, PO Box 3354, Riyadh, 11211, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Banan Al-Younes
- Department of Genetics, King Faisal Specialist Hospital, and Research Centre, PO Box 3354, Riyadh, 11211, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | | | - Maher Mohammed Al-Saif
- Biomolecular Medicine, Research Centre, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Salma M Wakil
- Department of Genetics, King Faisal Specialist Hospital, and Research Centre, PO Box 3354, Riyadh, 11211, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Brian F Meyer
- Department of Genetics, King Faisal Specialist Hospital, and Research Centre, PO Box 3354, Riyadh, 11211, Saudi Arabia.,Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Khalid S A Khabar
- Biomolecular Medicine, Research Centre, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Saeed Bohlega
- Saudi Human Genome Program, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia. .,Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, PO Box 3354, Riyadh, 11211, Saudi Arabia.
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Breuss MW, Nguyen T, Srivatsan A, Leca I, Tian G, Fritz T, Hansen AH, Musaev D, McEvoy-Venneri J, James KN, Rosti RO, Scott E, Tan U, Kolodner RD, Cowan NJ, Keays DA, Gleeson JG. Uner Tan syndrome caused by a homozygous TUBB2B mutation affecting microtubule stability. Hum Mol Genet 2017; 26:258-269. [PMID: 28013290 DOI: 10.1093/hmg/ddw383] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 11/03/2016] [Indexed: 01/07/2023] Open
Abstract
The integrity and dynamic properties of the microtubule cytoskeleton are indispensable for the development of the mammalian brain. Consequently, mutations in the genes that encode the structural component (the α/β-tubulin heterodimer) can give rise to severe, sporadic neurodevelopmental disorders. These are commonly referred to as the tubulinopathies. Here we report the addition of recessive quadrupedalism, also known as Uner Tan syndrome (UTS), to the growing list of diseases caused by tubulin variants. Analysis of a consanguineous UTS family identified a biallelic TUBB2B mutation, resulting in a p.R390Q amino acid substitution. In addition to the identifying quadrupedal locomotion, all three patients showed severe cerebellar hypoplasia. None, however, displayed the basal ganglia malformations typically associated with TUBB2B mutations. Functional analysis of the R390Q substitution revealed that it did not affect the ability of β-tubulin to fold or become assembled into the α/β-heterodimer, nor did it influence the incorporation of mutant-containing heterodimers into microtubule polymers. The 390Q mutation in S. cerevisiae TUB2 did not affect growth under basal conditions, but did result in increased sensitivity to microtubule-depolymerizing drugs, indicative of a mild impact of this mutation on microtubule function. The TUBB2B mutation described here represents an unusual recessive mode of inheritance for missense-mediated tubulinopathies and reinforces the sensitivity of the developing cerebellum to microtubule defects.
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Affiliation(s)
- Martin W Breuss
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Thai Nguyen
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Anjana Srivatsan
- Ludwig Institute for Cancer Research, University of California School of Medicine, San Diego, La Jolla, CA, USA
| | - Ines Leca
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Guoling Tian
- Department of Biochemistry and Molecular Pharmacology, New York University Langone Medical Center, New York, NY, USA
| | - Tanja Fritz
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Andi H Hansen
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Damir Musaev
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Jennifer McEvoy-Venneri
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Kiely N James
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Rasim O Rosti
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Eric Scott
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
| | - Uner Tan
- Department of Physiology, Medical School, Cukurova University, Adana, Turkey and
| | - Richard D Kolodner
- Ludwig Institute for Cancer Research, University of California School of Medicine, San Diego, La Jolla, CA, USA.,Department of Cellular and Molecular Medicine, Institute for Genomic Medicine and Moores-UCSD Cancer Center, San Diego, La Jolla, CA, USA
| | - Nicholas J Cowan
- Department of Biochemistry and Molecular Pharmacology, New York University Langone Medical Center, New York, NY, USA
| | - David A Keays
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Joseph G Gleeson
- Department of Neurosciences, Howard Hughes Medical Institute, University of California, San Diego, La Jolla, CA, USA.,Rady Children's Institute for Genomic Medicine, San Diego, CA, USA
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