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Xiong GJ, Sheng ZH. Presynaptic perspective: Axonal transport defects in neurodevelopmental disorders. J Cell Biol 2024; 223:e202401145. [PMID: 38568173 PMCID: PMC10988239 DOI: 10.1083/jcb.202401145] [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: 01/27/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 04/05/2024] Open
Abstract
Disruption of synapse assembly and maturation leads to a broad spectrum of neurodevelopmental disorders. Presynaptic proteins are largely synthesized in the soma, where they are packaged into precursor vesicles and transported into distal axons to ensure precise assembly and maintenance of presynapses. Due to their morphological features, neurons face challenges in the delivery of presynaptic cargos to nascent boutons. Thus, targeted axonal transport is vital to build functional synapses. A growing number of mutations in genes encoding the transport machinery have been linked to neurodevelopmental disorders. Emerging lines of evidence have started to uncover presynaptic mechanisms underlying axonal transport defects, thus broadening the view of neurodevelopmental disorders beyond postsynaptic mechanisms. In this review, we discuss presynaptic perspectives of neurodevelopmental disorders by focusing on impaired axonal transport and disturbed assembly and maintenance of presynapses. We also discuss potential strategies for restoring axonal transport as an early therapeutic intervention.
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Affiliation(s)
- Gui-Jing Xiong
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Zu-Hang Sheng
- Synaptic Function Section, The Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
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2
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Abbaali I, Truong D, Day SD, Mushayeed F, Ganesh B, Haro-Ramirez N, Isles J, Nag H, Pham C, Shah P, Tomar I, Manel-Romero C, Morrissette NS. The tubulin database: Linking mutations, modifications, ligands and local interactions. PLoS One 2023; 18:e0295279. [PMID: 38064432 PMCID: PMC10707541 DOI: 10.1371/journal.pone.0295279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
Microtubules are polymeric filaments, constructed of α-β tubulin heterodimers that underlie critical subcellular structures in eukaryotic organisms. Four homologous proteins (γ-, δ-, ε- and ζ-tubulin) additionally contribute to specialized microtubule functions. Although there is an immense volume of publicly available data pertaining to tubulins, it is difficult to assimilate all potentially relevant information across diverse organisms, isotypes, and categories of data. We previously assembled an extensive web-based catalogue of published missense mutations to tubulins with >1,500 entries that each document a specific substitution to a discrete tubulin, the species where the mutation was described and the associated phenotype with hyperlinks to the amino acid sequence and citation(s) for research. This report describes a significant update and expansion of our online resource (TubulinDB.bio.uci.edu) to nearly 18,000 entries. It now encompasses a cross-referenced catalog of post-translational modifications (PTMs) to tubulin drawn from public datasets, primary literature, and predictive algorithms. In addition, tubulin protein structures were used to define local interactions with bound ligands (GTP, GDP and diverse microtubule-targeting agents) and amino acids at the intradimer interface, within the microtubule lattice and with associated proteins. To effectively cross-reference these datasets, we established a universal tubulin numbering system to map entries into a common framework that accommodates specific insertions and deletions to tubulins. Indexing and cross-referencing permitted us to discern previously unappreciated patterns. We describe previously unlinked observations of loss of PTM sites in the context of cancer cells and tubulinopathies. Similarly, we expanded the set of clinical substitutions that may compromise MAP or microtubule-motor interactions by collecting tubulin missense mutations that alter amino acids at the interface with dynein and doublecortin. By expanding the database as a curated resource, we hope to relate model organism data to clinical findings of pathogenic tubulin variants. Ultimately, we aim to aid researchers in hypothesis generation and design of studies to dissect tubulin function.
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Affiliation(s)
- Izra Abbaali
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Danny Truong
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Shania Deon Day
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Faliha Mushayeed
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Bhargavi Ganesh
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Nancy Haro-Ramirez
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Juliet Isles
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Hindol Nag
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Catherine Pham
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Priya Shah
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Ishaan Tomar
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Carolina Manel-Romero
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
| | - Naomi S. Morrissette
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA, United States of America
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3
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McKenna ED, Sarbanes SL, Cummings SW, Roll-Mecak A. The Tubulin Code, from Molecules to Health and Disease. Annu Rev Cell Dev Biol 2023; 39:331-361. [PMID: 37843925 DOI: 10.1146/annurev-cellbio-030123-032748] [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] [Indexed: 10/18/2023]
Abstract
Microtubules are essential dynamic polymers composed of α/β-tubulin heterodimers. They support intracellular trafficking, cell division, cellular motility, and other essential cellular processes. In many species, both α-tubulin and β-tubulin are encoded by multiple genes with distinct expression profiles and functionality. Microtubules are further diversified through abundant posttranslational modifications, which are added and removed by a suite of enzymes to form complex, stereotyped cellular arrays. The genetic and chemical diversity of tubulin constitute a tubulin code that regulates intrinsic microtubule properties and is read by cellular effectors, such as molecular motors and microtubule-associated proteins, to provide spatial and temporal specificity to microtubules in cells. In this review, we synthesize the rapidly expanding tubulin code literature and highlight limitations and opportunities for the field. As complex microtubule arrays underlie essential physiological processes, a better understanding of how cells employ the tubulin code has important implications for human disease ranging from cancer to neurological disorders.
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Affiliation(s)
- Elizabeth D McKenna
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
| | - Stephanie L Sarbanes
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
| | - Steven W Cummings
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
| | - Antonina Roll-Mecak
- Cell Biology and Biophysics Unit, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, USA;
- Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA
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4
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Li J, Yao J, Qi L. Identification of TUBB2A as a Cancer-Immunity Cycle-Related Therapeutic Target in Triple-Negative Breast Cancer. Mol Biotechnol 2023:10.1007/s12033-023-00880-2. [PMID: 37742297 DOI: 10.1007/s12033-023-00880-2] [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: 07/27/2023] [Accepted: 08/28/2023] [Indexed: 09/26/2023]
Abstract
OBJECTIVE Triple negative breast cancer (TNBC) is a malignant subtype of breast cancer characterized by the absence of ER, PR, and HER2. We aimed to explore target gene from the perspective of cancer-immunity cycle, providing insights into treatment of TNBC. METHODS We obtained TNBC samples from METABRIC database and downloaded 4 datasets from GEO database, as well as an IMvigor210 dataset. WGCNA was applied to screen genes associated with cancer-immunity cycle in TNBC. GO, KEGG and GSEA analyses were performed to explore the target gene's potential functions and pathways. The binding motifs with transcription factors were predicted with FIMO. Immune infiltration analysis was conducted by CIBERSORT. RESULTS TUBB2A was screened out as our target gene which was negatively correlated with T cell recruitment in cancer-immunity cycle. TUBB2A expressed higher in TNBC samples than in normal samples. High expression of TUBB2A was associated with poor prognosis of TNBC. 12 transcription factors and 5 miRNAs might regulate TUBB2A's expression. The infiltration ratios of 7 types of immune cells such as CD8+ T cells, naive CD4+ T cells and activated memory CD4+ T cells were significantly lower in TUBB2A high expression group. TUBB2A was a potential drug target. CONCLUSION We screened a cancer-immunity cycle-related gene TUBB2A which was negatively correlated with T cell recruiting in TNBC. TUBB2A expressed higher in TNBC samples than in normal samples, associated with poor prognosis.
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Affiliation(s)
- Jia Li
- Department of Breast Surgical Oncology, Shanxi Province Cancer Hospital/Shanxi Hospital Affiliated to Cancer Hospital, Chinese Academy of Medical Sciences/Cancer Hospital Affiliated to Shanxi Medical University, Xinghualing District, Taiyuan, 030013, Shanxi Province, People's Republic of China
| | - Jingchun Yao
- Department of Head and Neck, Shanxi Province Cancer Hospital/Shanxi Hospital Affiliated to Cancer Hospital, Chinese Academy of Medical Sciences/Cancer Hospital Affiliated to Shanxi Medical University, Xinghualing District, Taiyuan, 030013, Shanxi Province, People's Republic of China
| | - Liqiang Qi
- Department of Breast Surgical Oncology, Cancer Institute and Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No.17 Panjiayuan, Huawei South Road, Chaoyang District, Beijing, 100021, People's Republic of China.
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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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Zhang L, Tie X, Che F, Wang G, Ge Y, Li B, Yang Y. Novel maternal duplication of 6p22.3-p25.3 with subtelomeric 6p25.3 deletion: new clinical findings and genotype-phenotype correlations. Mol Cytogenet 2023; 16:11. [PMID: 37303060 DOI: 10.1186/s13039-023-00640-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/24/2023] [Indexed: 06/13/2023] Open
Abstract
BACKGROUND Copy-number variants (CNVs) drive many neurodevelopmental-related disorders. Although many neurodevelopmental-related CNVs can give rise to widespread phenotypes, it is necessary to identify the major genes contributing to phenotypic presentation. Copy-number variations in chromosome 6, such as independent 6p deletion and 6p duplication, have been reported in several live-born infants and present widespread abnormalities such as intellectual disability, growth deficiency, developmental delay, and multiple dysmorphic facial features. However, a contiguous deletion and duplication in chromosome 6p regions have been reported in only a few cases. CASE PRESENTATION In this study, we reported the first duplication of chromosome band 6p25.3-p22.3 with deletion of 6p25.3 in a pedigree. This is the first case reported involving CNVs in these chromosomal regions. In this pedigree, we reported a 1-year-old boy with maternal 6p25-pter duplication characterized by chromosome karyotype. Further analysis using CNV-seq revealed a 20.88-Mb duplication at 6p25.3-p22.3 associated with a contiguous 0.66-Mb 6p25.3 deletion. Whole exome sequencing confirmed the deletion/duplication and identified no pathogenic or likely pathogenic variants related with the patient´s phenotype. The proband presented abnormal growth, developmental delay, skeletal dysplasia, hearing loss, and dysmorphic facial features. Additionally, he presented recurrent infection after birth. CNV-seq using the proband´s parental samples showed that the deletion/duplication was inherited from the proband´s mother, who exhibited a similar phenotype to the proband. When compared with other cases, this proband and his mother presented a new clinical finding: forearm bone dysplasia. The major candidate genes contributing to recurrent infection, eye development, hearing loss features, neurodevelopmental development, and congenital bone dysplasia were further discussed. CONCLUSIONS Our results showed a new clinical finding of a contiguous deletion and duplication in chromosome 6p regions and suggested candidate genes associated with phenotypic features, such as FOXC1, SERPINB6, NRN1, TUBB2A, IRF4, and RIPK1.
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Affiliation(s)
- Liyu Zhang
- Shaanxi Institute for Pediatric Diseases, Xi'an Children's Hospital, Xi'an, China
| | - Xiaoling Tie
- Department of Rehabilitation, Xi'an Children's Hospital, Xi'an, China
| | - Fengyu Che
- Shaanxi Institute for Pediatric Diseases, Xi'an Children's Hospital, Xi'an, China
| | - Guoxia Wang
- Shaanxi Institute for Pediatric Diseases, Xi'an Children's Hospital, Xi'an, China
| | - Ying Ge
- The Center Laboratory Medicine, Xi'an Children's Hospital, Xi'an, China
| | - Benchang Li
- Shaanxi Institute for Pediatric Diseases, Xi'an Children's Hospital, Xi'an, China
| | - Ying Yang
- Shaanxi Institute for Pediatric Diseases, Xi'an Children's Hospital, Xi'an, China.
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7
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Tantry MSA, Santhakumar K. Insights on the Role of α- and β-Tubulin Isotypes in Early Brain Development. Mol Neurobiol 2023; 60:3803-3823. [PMID: 36943622 DOI: 10.1007/s12035-023-03302-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 03/05/2023] [Indexed: 03/23/2023]
Abstract
Tubulins are the highly conserved subunit of microtubules which involve in various fundamental functions including brain development. Microtubules help in neuronal proliferation, migration, differentiation, cargo transport along the axons, synapse formation, and many more. Tubulin gene family consisting of multiple isotypes, their differential expression and varied post translational modifications create a whole new level of complexity and diversity in accomplishing manifold neuronal functions. The studies on the relation between tubulin genes and brain development opened a new avenue to understand the role of each tubulin isotype in neurodevelopment. Mutations in tubulin genes are reported to cause brain development defects especially cortical malformations, referred as tubulinopathies. There is an increased need to understand the molecular correlation between various tubulin mutations and the associated brain pathology. Recently, mutations in tubulin isotypes (TUBA1A, TUBB, TUBB1, TUBB2A, TUBB2B, TUBB3, and TUBG1) have been linked to cause various neurodevelopmental defects like lissencephaly, microcephaly, cortical dysplasia, polymicrogyria, schizencephaly, subcortical band heterotopia, periventricular heterotopia, corpus callosum agenesis, and cerebellar hypoplasia. This review summarizes on the microtubule dynamics, their role in neurodevelopment, tubulin isotypes, post translational modifications, and the role of tubulin mutations in causing specific neurodevelopmental defects. A comprehensive list containing all the reported tubulin pathogenic variants associated with brain developmental defects has been prepared to give a bird's eye view on the broad range of tubulin functions.
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Affiliation(s)
- M S Ananthakrishna Tantry
- Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, 603203, India
| | - Kirankumar Santhakumar
- Department of Genetic Engineering, SRM Institute of Science and Technology, Kattankulathur, 603203, India.
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8
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Cushion TD, Leca I, Keays DA. MAPping tubulin mutations. Front Cell Dev Biol 2023; 11:1136699. [PMID: 36875768 PMCID: PMC9975266 DOI: 10.3389/fcell.2023.1136699] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/02/2023] [Indexed: 02/17/2023] Open
Abstract
Microtubules are filamentous structures that play a critical role in a diverse array of cellular functions including, mitosis, nuclear translocation, trafficking of organelles and cell shape. They are composed of α/β-tubulin heterodimers which are encoded by a large multigene family that has been implicated in an umbrella of disease states collectively known as the tubulinopathies. De novo mutations in different tubulin genes are known to cause lissencephaly, microcephaly, polymicrogyria, motor neuron disease, and female infertility. The diverse clinical features associated with these maladies have been attributed to the expression pattern of individual tubulin genes, as well as their distinct Functional repertoire. Recent studies, however, have highlighted the impact of tubulin mutations on microtubule-associated proteins (MAPs). MAPs can be classified according to their effect on microtubules and include polymer stabilizers (e.g., tau, MAP2, doublecortin), destabilizers (e.g., spastin, katanin), plus-end binding proteins (e.g., EB1-3, XMAP215, CLASPs) and motor proteins (e.g., dyneins, kinesins). In this review we analyse mutation-specific disease mechanisms that influence MAP binding and their phenotypic consequences, and discuss methods by which we can exploit genetic variation to identify novel MAPs.
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Affiliation(s)
- Thomas D Cushion
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Ines Leca
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - David A Keays
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom.,Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria.,Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, Munich, Germany
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9
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Generation of an induced pluripotent stem cell line (DHMCi009-A) from an individual with TUBB2A tubulinopathy. Stem Cell Res 2022; 64:102879. [DOI: 10.1016/j.scr.2022.102879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/19/2022] [Accepted: 07/22/2022] [Indexed: 11/21/2022] Open
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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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Neurons: The Interplay between Cytoskeleton, Ion Channels/Transporters and Mitochondria. Cells 2022; 11:cells11162499. [PMID: 36010576 PMCID: PMC9406945 DOI: 10.3390/cells11162499] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/06/2022] [Accepted: 08/09/2022] [Indexed: 11/17/2022] Open
Abstract
Neurons are permanent cells whose key feature is information transmission via chemical and electrical signals. Therefore, a finely tuned homeostasis is necessary to maintain function and preserve neuronal lifelong survival. The cytoskeleton, and in particular microtubules, are far from being inert actors in the maintenance of this complex cellular equilibrium, and they participate in the mobilization of molecular cargos and organelles, thus influencing neuronal migration, neuritis growth and synaptic transmission. Notably, alterations of cytoskeletal dynamics have been linked to alterations of neuronal excitability. In this review, we discuss the characteristics of the neuronal cytoskeleton and provide insights into alterations of this component leading to human diseases, addressing how these might affect excitability/synaptic activity, as well as neuronal functioning. We also provide an overview of the microscopic approaches to visualize and assess the cytoskeleton, with a specific focus on mitochondrial trafficking.
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12
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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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13
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Ragoussis V, Pagnamenta AT, Haines RL, Giacopuzzi E, McClatchey MA, Sampson JR, Suri M, Gardham A, Cobben JM, Osio D, Fry AE, Taylor JC. Using data from the 100,000 Genomes Project to resolve conflicting interpretations of a recurrent TUBB2A mutation. J Med Genet 2022; 59:366-369. [PMID: 33547136 PMCID: PMC8961759 DOI: 10.1136/jmedgenet-2020-107528] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 12/23/2020] [Accepted: 01/10/2021] [Indexed: 01/03/2023]
Affiliation(s)
- Vassilis Ragoussis
- Wellcome Centre for Human Genetics, Oxford University, Oxford, Oxfordshire, UK
- NIHR Biomedical Research Centre, Oxford, UK
| | - Alistair T Pagnamenta
- Wellcome Centre for Human Genetics, Oxford University, Oxford, Oxfordshire, UK
- NIHR Biomedical Research Centre, Oxford, UK
| | - Rebecca L Haines
- East Midlands Regional Molecular Genetics Service, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Edoardo Giacopuzzi
- Wellcome Centre for Human Genetics, Oxford University, Oxford, Oxfordshire, UK
- NIHR Biomedical Research Centre, Oxford, UK
| | - Martin A McClatchey
- Institute of Medical Genetics, University Hospital of Wales, Cardiff, UK
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff, UK
| | - Julian R Sampson
- Institute of Medical Genetics, University Hospital of Wales, Cardiff, UK
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff, UK
| | - Mohnish Suri
- Nottingham Clinical Genetics Service, Nottingham University Hospitals NHS Trust, Nottingham, UK
| | - Alice Gardham
- North West Thames Regional Genetics Service, Northwick Park Hospital, Harrow, London, UK
| | - Jan-Maarten Cobben
- North West Thames Regional Genetics Service, Northwick Park Hospital, Harrow, London, UK
- Department of Pediatrics, Amsterdam University Medical Centres, Duivendrecht, Noord-Holland, Netherlands
| | - Deborah Osio
- West Midlands Regional Clinical Genetics Service and Birmingham Health Partners, Birmingham Women's and Children's Hospitals NHS Foundation Trust, Birmingham, UK
| | - Andrew E Fry
- Institute of Medical Genetics, University Hospital of Wales, Cardiff, UK
- Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff, UK
| | - Jenny C Taylor
- Wellcome Centre for Human Genetics, Oxford University, Oxford, Oxfordshire, UK
- NIHR Biomedical Research Centre, Oxford, UK
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14
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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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15
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Krishnan RK, Halachmi N, Baskar R, Bakhrat A, Zarivach R, Salzberg A, Abdu U. Revisiting the Role of ß-Tubulin in Drosophila Development: β-tubulin60D is not an Essential Gene, and its Novel Pin1 Allele has a Tissue-Specific Dominant-Negative Impact. Front Cell Dev Biol 2022; 9:787976. [PMID: 35111755 PMCID: PMC8802551 DOI: 10.3389/fcell.2021.787976] [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: 10/01/2021] [Accepted: 12/09/2021] [Indexed: 11/19/2022] Open
Abstract
Diversity in cytoskeleton organization and function may be achieved through alternative tubulin isotypes and by a variety of post-translational modifications. The Drosophila genome contains five different β-tubulin paralogs, which may play an isotype tissue-specific function in vivo. One of these genes, the β-tubulin60D gene, which is expressed in a tissue-specific manner, was found to be essential for fly viability and fertility. To further understand the role of the β-tubulin60D gene, we generated new β-tubulin60D null alleles (β-tubulin60DM) using the CRISPR/Cas9 system and found that the homozygous flies were viable and fertile. Moreover, using a combination of genetic complementation tests, rescue experiments, and cell biology analyses, we identified Pin1, an unknown dominant mutant with bristle developmental defects, as a dominant-negative allele of β-tubulin60D. We also found a missense mutation in the Pin1 mutant that results in an amino acid replacement from the highly conserved glutamate at position 75 to lysine (E75K). Analyzing the ß-tubulin structure suggests that this E75K alteration destabilizes the alpha-helix structure and may also alter the GTP-Mg2+ complex binding capabilities. Our results revisited the credence that β-tubulin60D is required for fly viability and revealed for the first time in Drosophila, a novel dominant-negative function of missense β-tubulin60D mutation in bristle morphogenesis.
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Affiliation(s)
| | - Naomi Halachmi
- Department of Genetics and Developmental Biology, Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Raju Baskar
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer’Sheva, Israel
| | - Anna Bakhrat
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer’Sheva, Israel
| | - Raz Zarivach
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer’Sheva, Israel
- National Institute for Biotechnology in the Negev and the Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer Sheva, Israel
| | - Adi Salzberg
- Department of Genetics and Developmental Biology, Rappaport Faculty of Medicine, Technion, Haifa, Israel
| | - Uri Abdu
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer’Sheva, Israel
- *Correspondence: Uri Abdu,
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16
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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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17
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Chen S, Alhassen W, Vakil Monfared R, Vachirakorntong B, Nauli SM, Baldi P, Alachkar A. Dynamic Changes of Brain Cilia Transcriptomes across the Human Lifespan. Int J Mol Sci 2021; 22:10387. [PMID: 34638726 PMCID: PMC8509004 DOI: 10.3390/ijms221910387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 12/27/2022] Open
Abstract
Almost all brain cells contain primary cilia, antennae-like microtubule sensory organelles, on their surface, which play critical roles in brain functions. During neurodevelopmental stages, cilia are essential for brain formation and maturation. In the adult brain, cilia play vital roles as signaling hubs that receive and transduce various signals and regulate cell-to-cell communications. These distinct roles suggest that cilia functions, and probably structures, change throughout the human lifespan. To further understand the age-dependent changes in cilia roles, we identified and analyzed age-dependent patterns of expression of cilia's structural and functional components across the human lifespan. We acquired cilia transcriptomic data for 16 brain regions from the BrainSpan Atlas and analyzed the age-dependent expression patterns using a linear regression model by calculating the regression coefficient. We found that 67% of cilia transcripts were differentially expressed genes with age (DEGAs) in at least one brain region. The age-dependent expression was region-specific, with the highest and lowest numbers of DEGAs expressed in the ventrolateral prefrontal cortex and hippocampus, respectively. The majority of cilia DEGAs displayed upregulation with age in most of the brain regions. The transcripts encoding cilia basal body components formed the majority of cilia DEGAs, and adjacent cerebral cortices exhibited large overlapping pairs of cilia DEGAs. Most remarkably, specific α/β-tubulin subunits (TUBA1A, TUBB2A, and TUBB2B) and SNAP-25 exhibited the highest rates of downregulation and upregulation, respectively, across age in almost all brain regions. α/β-tubulins and SNAP-25 expressions are known to be dysregulated in age-related neurodevelopmental and neurodegenerative disorders. Our results support a role for the high dynamics of cilia structural and functional components across the lifespan in the normal physiology of brain circuits. Furthermore, they suggest a crucial role for cilia signaling in the pathophysiological mechanisms of age-related psychiatric/neurological disorders.
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Affiliation(s)
- Siwei Chen
- Department of Computer Science, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA 92617, USA; (S.C.); (P.B.)
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA 92617, USA
| | - Wedad Alhassen
- Department of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, Irvine, CA 92617, USA; (W.A.); (R.V.M.); (B.V.)
| | - Roudabeh Vakil Monfared
- Department of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, Irvine, CA 92617, USA; (W.A.); (R.V.M.); (B.V.)
| | - Benjamin Vachirakorntong
- Department of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, Irvine, CA 92617, USA; (W.A.); (R.V.M.); (B.V.)
| | - Surya M. Nauli
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University Rinker Health Science Campus, Irvine, CA 92618, USA;
| | - Pierre Baldi
- Department of Computer Science, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA 92617, USA; (S.C.); (P.B.)
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA 92617, USA
| | - Amal Alachkar
- Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA 92617, USA
- Department of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, Irvine, CA 92617, USA; (W.A.); (R.V.M.); (B.V.)
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18
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The Names of Things: The 2018 Bernard Sachs Lecture. Pediatr Neurol 2021; 122:41-49. [PMID: 34330614 DOI: 10.1016/j.pediatrneurol.2021.05.006] [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] [Received: 05/03/2021] [Accepted: 05/05/2021] [Indexed: 11/22/2022]
Abstract
In 2018, I was honored to receive the Bernard Sachs Award for a lifetime of work expanding knowledge of diverse neurodevelopmental disorders. Summarizing work over more than 30 years is difficult but is an opportunity to chronicle the dramatic changes in the medical and scientific world that have transformed the field of Child Neurology over this time, as reflected in my own work. Here I have chosen to highlight five broad themes of my research beginning with my interest in descriptive terms that drive wider understanding and my choice for the title of this review. From there I will go on to contrast the state of knowledge as I entered the field with the state of knowledge today for four human brain malformations-lissencephaly, megalencephaly, cerebellar malformations, and polymicrogyria. For all, the changes have been dramatic.
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19
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Denarier E, Ecklund KH, Berthier G, Favier A, O'Toole ET, Gory-Fauré S, De Macedo L, Delphin C, Andrieux A, Markus SM, Boscheron C. Modeling a disease-correlated tubulin mutation in budding yeast reveals insight into MAP-mediated dynein function. Mol Biol Cell 2021; 32:ar10. [PMID: 34379441 PMCID: PMC8684761 DOI: 10.1091/mbc.e21-05-0237] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mutations in the genes that encode α- and β-tubulin underlie many neurological diseases, most notably malformations in cortical development. In addition to revealing the molecular basis for disease etiology, studying such mutations can provide insight into microtubule function and the role of the large family of microtubule effectors. In this study, we use budding yeast to model one such mutation—Gly436Arg in α-tubulin, which is causative of malformations in cortical development—in order to understand how it impacts microtubule function in a simple eukaryotic system. Using a combination of in vitro and in vivo methodologies, including live cell imaging and electron tomography, we find that the mutant tubulin is incorporated into microtubules, causes a shift in α-tubulin isotype usage, and dramatically enhances dynein activity, which leads to spindle-positioning defects. We find that the basis for the latter phenotype is an impaired interaction between She1—a dynein inhibitor—and the mutant microtubules. In addition to revealing the natural balance of α-tubulin isotype utilization in cells, our results provide evidence of an impaired interaction between microtubules and a dynein regulator as a consequence of a tubulin mutation and sheds light on a mechanism that may be causative of neurodevelopmental diseases.
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Affiliation(s)
- E Denarier
- Univ. Grenoble Alpes, CEA, CNRS, GIN, IBS, Inserm, IRIG, F-38000 Grenoble, France
| | - K H Ecklund
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States
| | - G Berthier
- Univ. Grenoble Alpes, CEA, CNRS, GIN, IBS, Inserm, IRIG, F-38000 Grenoble, France
| | - A Favier
- Univ. Grenoble Alpes, CEA, CNRS, GIN, IBS, Inserm, IRIG, F-38000 Grenoble, France
| | - E T O'Toole
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Boulder, Colorado, United States
| | - S Gory-Fauré
- Univ. Grenoble Alpes, CEA, CNRS, GIN, IBS, Inserm, IRIG, F-38000 Grenoble, France
| | - L De Macedo
- Univ. Grenoble Alpes, CEA, CNRS, GIN, IBS, Inserm, IRIG, F-38000 Grenoble, France
| | - C Delphin
- Univ. Grenoble Alpes, CEA, CNRS, GIN, IBS, Inserm, IRIG, F-38000 Grenoble, France
| | - A Andrieux
- Univ. Grenoble Alpes, CEA, CNRS, GIN, IBS, Inserm, IRIG, F-38000 Grenoble, France
| | - S M Markus
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado, United States
| | - C Boscheron
- Univ. Grenoble Alpes, CEA, CNRS, GIN, IBS, Inserm, IRIG, F-38000 Grenoble, France
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20
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Trakadis Y, Accogli A, Qi B, Bloom D, Joober R, Levy E, Tabbane K. Next-generation gene panel testing in adolescents and adults in a medical neuropsychiatric genetics clinic. Neurogenetics 2021; 22:313-322. [PMID: 34363551 DOI: 10.1007/s10048-021-00664-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 07/21/2021] [Indexed: 01/04/2023]
Abstract
Intellectual disability (ID) encompasses a clinically and genetically heterogeneous group of neurodevelopmental disorders that may present with psychiatric illness in up to 40% of cases. Despite the evidence for clinical utility of genetic panels in pediatrics, there are no published studies in adolescents/adults with ID or autism spectrum disorder (ASD). This study was approved by our institutional research ethics board. We retrospectively reviewed the medical charts of all patients evaluated between January 2017 and December 2019 in our adult neuropsychiatric genetics clinic at the McGill University Health Centre (MUHC), who had undergone a comprehensive ID/ASD gene panel. Thirty-four patients aged > 16 years, affected by ID/ASD and/or other neuropsychiatric/behavioral disorders, were identified. Pathogenic or likely pathogenic variants were identified in one-third of our cohort (32%): 8 single-nucleotide variants in 8 genes (CASK, SHANK3, IQSEC2, CHD2, ZBTB20, TREX1, SON, and TUBB2A) and 3 copy number variants (17p13.3, 16p13.12p13.11, and 9p24.3p24.1). The presence of psychiatric/behavioral disorders, regardless of the co-occurrence of ID, and, at a borderline level, the presence of ID alone were associated with positive genetic findings (p = 0.024 and p = 0.054, respectively). Moreover, seizures were associated with positive genetic results (p = 0.024). One-third of individuals presenting with psychiatric illness who met our red flags for Mendelian diseases have pathogenic or likely pathogenic variants which can be identified using a comprehensive ID/ASD gene panel (~ 2500 genes) performed on an exome backbone.
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Affiliation(s)
- Y Trakadis
- Division of Medical Genetics, Department of Specialized Medicine, Montreal Children's Hospital, McGill University Health Centre (MUHC), Room A04.3140, 1001 Boul. Décarie, Montreal, QC, H4A 3J1, Canada. .,Department of Human Genetics, McGill University, Montreal, QC, Canada. .,Douglas Mental Health Institute/Hospital, Montreal, Canada. .,Department of Psychiatry, McGill University, Montreal, Canada.
| | - A Accogli
- Division of Medical Genetics, Department of Specialized Medicine, Montreal Children's Hospital, McGill University Health Centre (MUHC), Room A04.3140, 1001 Boul. Décarie, Montreal, QC, H4A 3J1, Canada
| | - B Qi
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - D Bloom
- Douglas Mental Health Institute/Hospital, Montreal, Canada.,Department of Psychiatry, McGill University, Montreal, Canada
| | - R Joober
- Department of Human Genetics, McGill University, Montreal, QC, Canada.,Douglas Mental Health Institute/Hospital, Montreal, Canada.,Department of Psychiatry, McGill University, Montreal, Canada
| | - E Levy
- Douglas Mental Health Institute/Hospital, Montreal, Canada.,Department of Psychiatry, McGill University, Montreal, Canada
| | - K Tabbane
- Douglas Mental Health Institute/Hospital, Montreal, Canada.,Department of Psychiatry, McGill University, Montreal, Canada
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21
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Alhassen W, Chen S, Vawter M, Robbins BK, Nguyen H, Myint TN, Saito Y, Schulmann A, Nauli SM, Civelli O, Baldi P, Alachkar A. Patterns of cilia gene dysregulations in major psychiatric disorders. Prog Neuropsychopharmacol Biol Psychiatry 2021; 109:110255. [PMID: 33508383 PMCID: PMC9121176 DOI: 10.1016/j.pnpbp.2021.110255] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 01/06/2021] [Accepted: 01/16/2021] [Indexed: 12/15/2022]
Abstract
Primary cilia function as cells' antennas to detect and transduce external stimuli and play crucial roles in cell signaling and communication. The vast majority of cilia genes that are causally linked with ciliopathies are also associated with neurological deficits, such as cognitive impairments. Yet, the roles of cilia dysfunctions in the pathogenesis of psychiatric disorders have not been studied. Our aim is to identify patterns of cilia gene dysregulation in the four major psychiatric disorders: schizophrenia (SCZ), autism spectrum disorder (ASD), bipolar disorder (BP), and major depressive disorder (MDD). For this purpose, we acquired differentially expressed genes (DEGs) from the largest and most recent publicly available databases. We found that 42%, 24%, 17%, and 15% of brain-expressed cilia genes were significantly differentially expressed in SCZ, ASD, BP, and MDD, respectively. Several genes exhibited cross-disorder overlap, suggesting that typical cilia signaling pathways' dysfunctions determine susceptibility to more than one psychiatric disorder or may partially underlie their pathophysiology. Our study revealed that genes encoding proteins of almost all sub-cilia structural and functional compartments were dysregulated in the four psychiatric disorders. Strikingly, the genes of 75% of cilia GPCRs and 50% of the transition zone proteins were differentially expressed in SCZ. The present study is the first to draw associations between cilia and major psychiatric disorders, and is the first step toward understanding the role that cilia components play in their pathophysiological processes, which may lead to novel therapeutic targets for these disorders.
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Affiliation(s)
- Wedad Alhassen
- Departments of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, CA 92697, USA
| | - Siwei Chen
- Department of Computer Science, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA 92697, USA,Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California-Irvine, CA 92697, USA
| | - Marquis Vawter
- Department of Psychiatry and Human Behavior, School of Medicine, University of California, Irvine, USA
| | - Brianna Kay Robbins
- Departments of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, CA 92697, USA
| | - Henry Nguyen
- Departments of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, CA 92697, USA
| | - Thant Nyi Myint
- Departments of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, CA 92697, USA
| | - Yumiko Saito
- Graduate School of Integrated Arts and Sciences for Life, Hiroshima University, Japan
| | - Anton Schulmann
- Human Genetics Branch, National Institute of Mental Health, BETHESDA MD 20814, USA
| | - Surya M. Nauli
- Department of Biomedical and Pharmaceutical Sciences, School of Pharmacy, Chapman University, Health Science Campus, Chapman University, Irvine, California 92618, USA
| | - Olivier Civelli
- Departments of Pharmaceutical Sciences, School of Pharmacy, University of California-Irvine, CA 92697, USA,Department of Developmental and Cell Biology, School of Biological Sciences, University of California-Irvine, CA 92697, USA
| | - Pierre Baldi
- Department of Computer Science, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA 92697, USA,Institute for Genomics and Bioinformatics, School of Information and Computer Sciences, University of California-Irvine, CA 92697, USA
| | - Amal Alachkar
- Departments of Pharmaceutical Sciences, School of Pharmacy, University of California-, Irvine, CA 92697, USA; Department of Computer Science, School of Information and Computer Sciences, University of California-Irvine, Irvine, CA 92697, USA.
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22
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Sadler B, Wilborn J, Antunes L, Kuensting T, Hale AT, Gannon SR, McCall K, Cruchaga C, Harms M, Voisin N, Reymond A, Cappuccio G, Brunetti-Pierri N, Tartaglia M, Niceta M, Leoni C, Zampino G, Ashley-Koch A, Urbizu A, Garrett ME, Soldano K, Macaya A, Conrad D, Strahle J, Dobbs MB, Turner TN, Shannon CN, Brockmeyer D, Limbrick DD, Gurnett CA, Haller G. Rare and de novo coding variants in chromodomain genes in Chiari I malformation. Am J Hum Genet 2021; 108:100-114. [PMID: 33352116 DOI: 10.1016/j.ajhg.2020.12.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 11/24/2020] [Indexed: 12/16/2022] Open
Abstract
Chiari I malformation (CM1), the displacement of the cerebellum through the foramen magnum into the spinal canal, is one of the most common pediatric neurological conditions. Individuals with CM1 can present with neurological symptoms, including severe headaches and sensory or motor deficits, often as a consequence of brainstem compression or syringomyelia (SM). We conducted whole-exome sequencing (WES) on 668 CM1 probands and 232 family members and performed gene-burden and de novo enrichment analyses. A significant enrichment of rare and de novo non-synonymous variants in chromodomain (CHD) genes was observed among individuals with CM1 (combined p = 2.4 × 10-10), including 3 de novo loss-of-function variants in CHD8 (LOF enrichment p = 1.9 × 10-10) and a significant burden of rare transmitted variants in CHD3 (p = 1.8 × 10-6). Overall, individuals with CM1 were found to have significantly increased head circumference (p = 2.6 × 10-9), with many harboring CHD rare variants having macrocephaly. Finally, haploinsufficiency for chd8 in zebrafish led to macrocephaly and posterior hindbrain displacement reminiscent of CM1. These results implicate chromodomain genes and excessive brain growth in CM1 pathogenesis.
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23
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Schmidt L, Wain KE, Hajek C, Estrada-Veras JI, Guillen Sacoto MJ, Wentzensen IM, Malhotra A, Clause A, Perry D, Moreno-De-Luca A, Bell M. Expanding the Phenotype of TUBB2A-Related Tubulinopathy: Three Cases of a Novel, Heterozygous TUBB2A Pathogenic Variant p.Gly98Arg. Mol Syndromol 2020; 12:33-40. [PMID: 33776625 DOI: 10.1159/000512160] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 10/08/2020] [Indexed: 01/22/2023] Open
Abstract
Tubulinopathies are a group of conditions caused by variants in 6 tubulin genes that present with a spectrum of brain malformations. One of these conditions is TUBB2A-related tubulinopathy. Currently, there are 9 reported individuals with pathogenic variants within the TUBB2A gene, with common manifestations including, but not limited to, global developmental delay, seizures, cortical dysplasia, and dysmorphic corpus callosum. We report 3 patients identified by exome and genome sequencing to have a novel, pathogenic, missense variant in TUBB2A (p.Gly98Arg). They presented similarly with intellectual disability, hypotonia, and global developmental delay and varied with respect to the type of cortical brain malformation, seizure history, diagnosis of autism spectrum disorder, and other features. This case series expands the natural history of TUBB2A-related tubulinopathy while describing the presentation of a novel, pathogenic, missense variant in 3 patients.
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Affiliation(s)
- Lindsey Schmidt
- Sanford Health, Augustana-Sanford Genetic Counseling Program, Sioux Falls, South Dakota, USA
| | - Karen E Wain
- Geisinger Autism & Developmental Medicine Institute, Lewisburg, Pennsylvania, USA
| | | | - Juvianee I Estrada-Veras
- Henry M Jackson Foundation for the Advancement of Military Medicine and Walter Reed National Military Medical Center, Bethesda, Maryland, USA
| | | | | | - Alka Malhotra
- Illumina Clinical Services Laboratory, San Diego, California, USA
| | - Amanda Clause
- Illumina Clinical Services Laboratory, San Diego, California, USA
| | - Denise Perry
- Illumina Clinical Services Laboratory, San Diego, California, USA
| | - Andres Moreno-De-Luca
- Department of Radiology, Geisinger Autism & Developmental Medicine Institute, Genomic Medicine Institute, Lewisburg, Pennsylvania, USA
| | - Megan Bell
- Sanford Health, Sioux Falls, South Dakota, USA
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24
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Leca I, Phillips AW, Hofer I, Landler L, Ushakova L, Cushion TD, Dürnberger G, Stejskal K, Mechtler K, Keays DA. A proteomic survey of microtubule-associated proteins in a R402H TUBA1A mutant mouse. PLoS Genet 2020; 16:e1009104. [PMID: 33137126 PMCID: PMC7660477 DOI: 10.1371/journal.pgen.1009104] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 11/12/2020] [Accepted: 09/08/2020] [Indexed: 11/25/2022] Open
Abstract
Microtubules play a critical role in multiple aspects of neurodevelopment, including the generation, migration and differentiation of neurons. A recurrent mutation (R402H) in the α-tubulin gene TUBA1A is known to cause lissencephaly with cerebellar and striatal phenotypes. Previous work has shown that this mutation does not perturb the chaperone-mediated folding of tubulin heterodimers, which are able to assemble and incorporate into the microtubule lattice. To explore the molecular mechanisms that cause the disease state we generated a new conditional mouse line that recapitulates the R402H variant. We show that heterozygous mutants present with laminar phenotypes in the cortex and hippocampus, as well as a reduction in striatal size and cerebellar abnormalities. We demonstrate that homozygous expression of the R402H allele causes neuronal death and exacerbates a cell intrinsic defect in cortical neuronal migration. Microtubule sedimentation assays coupled with quantitative mass spectrometry demonstrated that the binding and/or levels of multiple microtubule associated proteins (MAPs) are perturbed by the R402H mutation including VAPB, REEP1, EZRIN, PRNP and DYNC1l1/2. Consistent with these data we show that the R402H mutation impairs dynein-mediated transport which is associated with a decoupling of the nucleus to the microtubule organising center. Our data support a model whereby the R402H variant is able to fold and incorporate into microtubules, but acts as a gain of function by perturbing the binding of MAPs. Microtubules are polymers composed of tubulin proteins, which play an important role in the development of the human brain. Genetic mutations in tubulin genes are known to cause neurodevelopmental diseases, including lissencephaly which is characterised by an impairment in the migration of neurons. In this study we investigate how a common mutation (R402H) in TUBA1A causes lissencephaly by generating and characterising a mouse with the same variant. We show that affected animals recapitulate multiple aspects of the human disease; including laminar perturbations in the cortex and hippocampus, attributable to defects in neuronal migration at key developmental time points. To characterize the molecular implications of the R402H mutation we purified microtubules from the developing brain, and analysed the proteins present by mass spectrometry. This revealed that the binding of DYNC1I1/2 to microtubules is altered in mice with the R402H mutation. Our results provide insight into the molecular pathology underlying tubulin related disease states, and provide a foundation for the rational design of therapeutic interventions.
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Affiliation(s)
- Ines Leca
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | | | - Iris Hofer
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Lukas Landler
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
- Institute of Zoology, University of Natural Resources and Life Sciences (BOKU), Vienna, Austria
| | - Lyubov Ushakova
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Thomas David Cushion
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
| | - Gerhard Dürnberger
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Vienna, Austria
| | - Karel Stejskal
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Vienna, Austria
| | - Karl Mechtler
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna Biocenter (VBC), Vienna, Austria
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna Biocenter (VBC), Vienna, Austria
| | - David Anthony Keays
- Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Vienna, Austria
- Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia
- Division of Neurobiology, Department Biology II, Ludwig-Maximilians-University Munich, Planegg-Martinsried 82152, Germany
- * E-mail:
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25
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Schröter J, Döring JH, Garbade SF, Hoffmann GF, Kölker S, Ries M, Syrbe S. Cross-sectional quantitative analysis of the natural history of TUBA1A and TUBB2B tubulinopathies. Genet Med 2020; 23:516-523. [PMID: 33082561 PMCID: PMC7935713 DOI: 10.1038/s41436-020-01001-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/25/2020] [Accepted: 09/28/2020] [Indexed: 11/09/2022] Open
Abstract
Purpose TUBA1A and TUBB2B tubulinopathies are rare neurodevelopmental disorders characterized by cortical and extracortical malformations and heterogenic phenotypes. There is a need for quantitative clinical endpoints that will be beneficial for future diagnostic and therapeutic trials. Methods Quantitative natural history modeling of individuals with TUBA1A and TUBB2B tubulinopathies from clinical reports and database entries of DECIPHER and ClinVar. Main outcome measures were age at disease onset, survival, and diagnostic delay. Phenotypical, neuroradiological, and histopathological features were descriptively illustrated. Results Mean age at disease onset was 4 (TUBA1A) and 6 months (TUBB2B), respectively. Mortality was equally estimated with 7% at 3.2 (TUBA1A) and 8.0 years (TUBB2B). Diagnostic delay was significantly higher in TUBB2B (12.3 years) compared with TUBA1A tubulinopathy (4.2 years). We delineated the isotype-dependent clinical, neuroradiological, and histopathological phenotype of affected individuals and present brain malformations associated with epilepsy and an unfavorable course of disease. Conclusion The natural history of tubulinopathies is defined by the genotype and associated brain malformations. Defined data on estimated survival, diagnostic delay, and disease characteristics of TUBA1A and TUBB2B tubulinopathy will help to raise disease awareness and encourage future clinical trials to optimize genetic testing, family counseling, and supportive care.
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Affiliation(s)
- Julian Schröter
- Division of Pediatric Epileptology, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Jan H Döring
- Division of Pediatric Epileptology, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Sven F Garbade
- Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Georg F Hoffmann
- Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Stefan Kölker
- Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Markus Ries
- Division of Neuropediatrics and Inherited Metabolic Diseases, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany
| | - Steffen Syrbe
- Division of Pediatric Epileptology, Center for Pediatrics and Adolescent Medicine, University Hospital Heidelberg, Heidelberg, Germany.
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26
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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: 57] [Impact Index Per Article: 14.3] [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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27
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Gambino G, Rizzo V, Giglia G, Ferraro G, Sardo P. Microtubule Dynamics and Neuronal Excitability: Advances on Cytoskeletal Components Implicated in Epileptic Phenomena. Cell Mol Neurobiol 2020; 42:533-543. [PMID: 32929563 PMCID: PMC8891195 DOI: 10.1007/s10571-020-00963-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 09/05/2020] [Indexed: 12/14/2022]
Abstract
Extensive researches have deepened knowledge on the role of synaptic components in epileptogenesis, but limited attention has been devoted to the potential implication of the cytoskeleton. The study of the development of epilepsy and hyperexcitability states involves molecular, synaptic, and structural alterations of neuronal bioelectric activity. In this paper we aim to explore the neurobiological targets involved in microtubule functioning and cytoskeletal transport, i.e. how dynamic scaffolding of microtubules can influence neuronal morphology and excitability, in order to suggest a potential role for microtubule dynamics in the processes turning a normal neuronal network in a hyperexcited one. Pathophysiological alterations of microtubule dynamics inducing neurodegeneration, network remodeling and relative impairment on synaptic transmission were overviewed. Recent researches were reported on the phosphorylation state of microtubule-associated proteins such as tau in neurodegenerative diseases and epileptic states, but also on the effect of microtubule-active agents influencing cytoskeleton destabilization in epilepsy models. The manipulation of microtubule polymerization was found effective in the modulation of hyperexcitability. In addition, it was considered the importance of microtubules and related neurotrophic factors during neural development since they are essential for the formation of a properly functional neuronal network. Otherwise, this can lead to cognitive deficits, hyperexcitability phenomena and neurodevelopmental disorders. Lastly, we evaluated the role of microtubule dynamics on neuronal efficiency considering their importance in the transport of mitochondria, cellular elements fulfilling energy requirements for neuronal activity, and a putative influence on cannabinoid-mediated neuroprotection. This review provides novel perspectives for the implication of microtubule dynamics in the development of epileptic phenomena.
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Affiliation(s)
- Giuditta Gambino
- Department of Experimental Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), Sezione Di Fisiologia Umana G. Pagano, University of Palermo, Corso Tukory 129, Palermo, Italy
| | - Valerio Rizzo
- Department of Experimental Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), Sezione Di Fisiologia Umana G. Pagano, University of Palermo, Corso Tukory 129, Palermo, Italy
| | - Giuseppe Giglia
- Department of Experimental Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), Sezione Di Fisiologia Umana G. Pagano, University of Palermo, Corso Tukory 129, Palermo, Italy.
| | - Giuseppe Ferraro
- Department of Experimental Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), Sezione Di Fisiologia Umana G. Pagano, University of Palermo, Corso Tukory 129, Palermo, Italy
| | - Pierangelo Sardo
- Department of Experimental Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), Sezione Di Fisiologia Umana G. Pagano, University of Palermo, Corso Tukory 129, Palermo, Italy
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28
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Gavrilovici C, Jiang Y, Kiroski I, Teskey GC, Rho JM, Nguyen MD. Postnatal Role of the Cytoskeleton in Adult Epileptogenesis. Cereb Cortex Commun 2020; 1:tgaa024. [PMID: 32864616 PMCID: PMC7446231 DOI: 10.1093/texcom/tgaa024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 06/08/2020] [Accepted: 06/11/2020] [Indexed: 02/07/2023] Open
Abstract
Mutations in cytoskeletal proteins can cause early infantile and childhood epilepsies by misplacing newly born neurons and altering neuronal connectivity. In the adult epileptic brain, cytoskeletal disruption is often viewed as being secondary to aberrant neuronal activity and/or death, and hence simply represents an epiphenomenon. Here, we review the emerging evidence collected in animal models and human studies implicating the cytoskeleton as a potential causative factor in adult epileptogenesis. Based on the emerging evidence, we propose that cytoskeletal disruption may be an important pathogenic mechanism in the mature epileptic brain.
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Affiliation(s)
- Cezar Gavrilovici
- Departments of Neurosciences & Pediatrics, University of California San Diego, Rady Children's Hospital San Diego, San Diego, CA 92123, USA
| | - Yulan Jiang
- Departments of Clinical Neurosciences, Cell Biology & Anatomy, and Biochemistry & Molecular Biology, Hotchkiss Brain Institute, Alberta Children Hospital Research Institute, University of Calgary, Calgary T2N 4N1, Canada
| | - Ivana Kiroski
- Departments of Clinical Neurosciences, Cell Biology & Anatomy, and Biochemistry & Molecular Biology, Hotchkiss Brain Institute, Alberta Children Hospital Research Institute, University of Calgary, Calgary T2N 4N1, Canada
| | - G Campbell Teskey
- Department of Cell Biology & Anatomy, Hotchkiss Brain Institute, Alberta Children Hospital Research Institute, University of Calgary, Calgary T2N 4N1, Canada
| | - Jong M Rho
- Departments of Neurosciences & Pediatrics, University of California San Diego, Rady Children's Hospital San Diego, San Diego, CA 92123, USA
| | - Minh Dang Nguyen
- Departments of Clinical Neurosciences, Cell Biology & Anatomy, and Biochemistry & Molecular Biology, Hotchkiss Brain Institute, Alberta Children Hospital Research Institute, University of Calgary, Calgary T2N 4N1, Canada
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29
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Smith SC, Olney AH, Beavers A, Spaulding J, Nelson M, Nielsen S, Sanmann JN. The recurrent TUBB3 Gly98Ser substitution is the first described to inconsistently result in CFEOM3. Am J Med Genet A 2020; 182:2161-2167. [PMID: 32705776 DOI: 10.1002/ajmg.a.61747] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 06/02/2020] [Accepted: 06/05/2020] [Indexed: 11/10/2022]
Abstract
Missense variants in TUBB3 have historically been associated with either congenital fibrosis of the extraocular muscles type 3 (CFEOM3) or malformations of cortical development (MCD). Until a recent report identified two amino acid substitutions in four patients that had clinical features of both disorders, pathogenic variants of TUBB3 were thought distinct to either respective disorder. Three recurrent de novo Gly71Arg TUBB3 substitutions and a single patient with a de novo Gly98Ser substitution blurred the MCD and CFEOM3 phenotypic distinctions. Here we report a second patient with a missense c.292G>A (p.Gly98Ser) substitution, but without CFEOM3, the first reported evidence that even the same TUBB3 substitution can produce a spectrum of TUBB3 syndrome phenotypes. Our patient presented with amblyopia, exotropia, optic disc pallor, and developmental delay. Neuroimaging identified hypoplasia of the corpus callosum, interdigitation of the frontal lobe gyri, and dysplasia or hypoplasia of the optic nerves, basal ganglia, brainstem, and cerebellum. This report identifies the TUBB3 Gly98Ser substitution to be recurrent but inconsistently including CFEOM3, and identifies the absence of joint contractures and the presence of optic disc abnormalities that may be genotype-specific to the TUBB3 Gly98Ser substitution.
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Affiliation(s)
- Scott C Smith
- Human Genetics Laboratory, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Ann Haskins Olney
- Division of Genetic Medicine, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Angela Beavers
- Department of Radiology, Children's Hospital, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Joanna Spaulding
- Human Genetics Laboratory, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Marilu Nelson
- Human Genetics Laboratory, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Shelly Nielsen
- Division of Genetic Medicine, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Jennifer N Sanmann
- Human Genetics Laboratory, Munroe-Meyer Institute for Genetics and Rehabilitation, University of Nebraska Medical Center, Omaha, Nebraska, USA
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30
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Brock S, Vanderhasselt T, Vermaning S, Keymolen K, Régal L, Romaniello R, Wieczorek D, Storm TM, Schaeferhoff K, Hehr U, Kuechler A, Krägeloh-Mann I, Haack TB, Kasteleijn E, Schot R, Mancini GMS, Webster R, Mohammad S, Leventer RJ, Mirzaa G, Dobyns WB, Bahi-Buisson N, Meuwissen M, Jansen AC, Stouffs K. Defining the phenotypical spectrum associated with variants in TUBB2A. J Med Genet 2020; 58:33-40. [PMID: 32571897 PMCID: PMC7803914 DOI: 10.1136/jmedgenet-2019-106740] [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: 11/26/2019] [Revised: 02/05/2020] [Accepted: 03/05/2020] [Indexed: 01/18/2023]
Abstract
BACKGROUND Variants in genes belonging to the tubulin superfamily account for a heterogeneous spectrum of brain malformations referred to as tubulinopathies. Variants in TUBB2A have been reported in 10 patients with a broad spectrum of brain imaging features, ranging from a normal cortex to polymicrogyria, while one patient has been reported with progressive atrophy of the cerebellar vermis. METHODS In order to further refine the phenotypical spectrum associated with TUBB2A, clinical and imaging features of 12 patients with pathogenic TUBB2A variants, recruited via the international network of the authors, were reviewed. RESULTS We report 12 patients with eight novel and one recurrent variants spread throughout the TUBB2A gene but encoding for amino acids clustering at the protein surface. Eleven patients (91.7%) developed seizures in early life. All patients suffered from intellectual disability, and 11 patients had severe motor developmental delay, with 4 patients (36.4 %) being non-ambulatory. The cerebral cortex was normal in five individuals and showed dysgyria of variable severity in seven patients. Associated brain malformations were less frequent in TUBB2A patients compared with other tubulinopathies. None of the patients had progressive cerebellar atrophy. CONCLUSION The imaging phenotype associated with pathogenic variants in TUBB2A is highly variable, ranging from a normal cortex to extensive dysgyria with associated brain malformations. For recurrent variants, no clear genotype-phenotype correlations could be established, suggesting the role of additional modifiers.
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Affiliation(s)
- Stefanie Brock
- Department of Pathology, Universitair Ziekenhuis Brussel, Brussels, Belgium .,Neurogenetics Research Group, Reproduction Genetics and Regenerative Medicine Research Cluster, Vrije Universiteit Brussel, Brussels, Belgium
| | - Tim Vanderhasselt
- Department of Radiology, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Sietske Vermaning
- Belgium Center for Reproduction and Genetics, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Kathelijn Keymolen
- Belgium Center for Reproduction and Genetics, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Luc Régal
- Pediatric Neurology Unit, Department of Pediatrics, Universitair Ziekenhuis, Brussels, Belgium
| | - Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Lecco, Italy
| | - Dagmar Wieczorek
- Institut fuer Humangenetik, Universitaetsklininikum Essen, Essen, Germany.,Institute of Human Genetics, Heinrich Heine University Düsseldorf, Dusseldorf, Nordrhein-Westfalen, Germany
| | - Tim Matthias Storm
- Institut für Humangenetik, Technische Universität München, Munchen, Bayern, Germany
| | - Karin Schaeferhoff
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Baden-Württemberg, Germany
| | - Ute Hehr
- Zentrum für Humangenetik Regensburg, Universitätsklinikum Regensburg, Regensburg, Bayern, Germany
| | - Alma Kuechler
- Institut fuer Humangenetik, Universitaetsklininikum Essen, Essen, Germany
| | - Ingeborg Krägeloh-Mann
- Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital Tübingen, University of Tübingen, Tübingen, Germany
| | - Tobias B Haack
- Institute of Medical Genetics and Applied Genomics, Eberhard-Karls-Universitat Tubingen Medizinische Fakultat, Tübingen, Baden-Württemberg, Germany
| | - Esmee Kasteleijn
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, Zuid-Holland, The Netherlands
| | - Rachel Schot
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, Zuid-Holland, The Netherlands
| | - Grazia Maria Simonetta Mancini
- Department of Clinical Genetics, Erasmus Medical Center, Rotterdam, Zuid-Holland, The Netherlands.,ENCORE Expertise Center for Neurodevelopmental Disorders, Erasmus Medical Center, Rotterdam, Zuid-Holland, The Netherlands
| | - Richard Webster
- Department of Neurology, Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Shekeeb Mohammad
- Department of Neurology, Children's Hospital at Westmead, Westmead, New South Wales, Australia
| | - Richard J Leventer
- Department of Neurology, Murdoch Childrens Research Institute, Melbourne, Victoria, Australia
| | - Ghayda Mirzaa
- Division of Genetic Medicine, Department of Pediatrics, Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - William B Dobyns
- Division of Genetic Medicine, Department of Pediatrics, Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington, USA
| | - Nadia Bahi-Buisson
- Embryology and Genetics of Congenital Malformations, INSERM, Paris, Île-de-France, France
| | - Marije Meuwissen
- Center of Human Genetics, Universiteit Antwerpen, Antwerpen, Belgium
| | - Anna C Jansen
- Neurogenetics Research Group, Reproduction Genetics and Regenerative Medicine Research Cluster, Vrije Universiteit Brussel, Brussels, Belgium.,Pediatric Neurology Unit, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Katrien Stouffs
- Neurogenetics Research Group, Reproduction Genetics and Regenerative Medicine Research Cluster, Vrije Universiteit Brussel, Brussels, Belgium.,Center for Medical Genetics, Universitair Ziekenhuis Brussel, Brussels, Belgium, Brussels, Belgium
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31
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Varderidou-Minasian S, Hinz L, Hagemans D, Posthuma D, Altelaar M, Heine VM. Quantitative proteomic analysis of Rett iPSC-derived neuronal progenitors. Mol Autism 2020; 11:38. [PMID: 32460858 PMCID: PMC7251722 DOI: 10.1186/s13229-020-00344-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/04/2020] [Indexed: 12/12/2022] Open
Abstract
Background Rett syndrome (RTT) is a progressive neurodevelopmental disease that is characterized by abnormalities in cognitive, social, and motor skills. RTT is often caused by mutations in the X-linked gene encoding methyl-CpG binding protein 2 (MeCP2). The mechanism by which impaired MeCP2 induces the pathological abnormalities in the brain is not understood. Both patients and mouse models have shown abnormalities at molecular and cellular level before typical RTT-associated symptoms appear. This implies that underlying mechanisms are already affected during neurodevelopmental stages. Methods To understand the molecular mechanisms involved in disease onset, we used an RTT patient induced pluripotent stem cell (iPSC)-based model with isogenic controls and performed time-series of proteomic analysis using in-depth high-resolution quantitative mass spectrometry during early stages of neuronal development. Results We provide mass spectrometry-based quantitative proteomic data, depth of about 7000 proteins, at neuronal progenitor developmental stages of RTT patient cells and isogenic controls. Our data gives evidence of proteomic alteration at early neurodevelopmental stages, suggesting alterations long before the phase that symptoms of RTT syndrome become apparent. Significant changes are associated with the GO enrichment analysis in biological processes cell-cell adhesion, actin cytoskeleton organization, neuronal stem cell population maintenance, and pituitary gland development, next to protein changes previously associated with RTT, i.e., dendrite morphology and synaptic deficits. Differential expression increased from early to late neural stem cell phases, although proteins involved in immunity, metabolic processes, and calcium signaling were affected throughout all stages analyzed. Limitations The limitation of our study is the number of RTT patients analyzed. As the aim of our study was to investigate a large number of proteins, only one patient was considered, of which 3 different RTT iPSC clones and 3 isogenic control iPSC clones were included. Even though this approach allowed the study of mutation-induced alterations due to the usage of isogenic controls, results should be validated on different RTT patients to suggest common disease mechanisms. Conclusions During early neuronal differentiation, there are consistent and time-point specific proteomic alterations in RTT patient cells carrying exons 3–4 deletion in MECP2. We found changes in proteins involved in pathway associated with RTT phenotypes, including dendrite morphology and synaptogenesis. Our results provide a valuable resource of proteins and pathways for follow-up studies, investigating common mechanisms involved during early disease stages of RTT syndrome.
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Affiliation(s)
- Suzy Varderidou-Minasian
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584, CH, Utrecht, The Netherlands.,Netherlands Proteomics Center, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Lisa Hinz
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Dominique Hagemans
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584, CH, Utrecht, The Netherlands.,Netherlands Proteomics Center, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Danielle Posthuma
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,Child and Youth Psychiatry, Emma Children's Hospital, Amsterdam UMC, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Maarten Altelaar
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, University of Utrecht, Padualaan 8, 3584, CH, Utrecht, The Netherlands.,Netherlands Proteomics Center, Padualaan 8, 3584, CH, Utrecht, The Netherlands
| | - Vivi M Heine
- Department of Complex Trait Genetics, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands. .,Child and Youth Psychiatry, Emma Children's Hospital, Amsterdam UMC, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
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Martínez Anaya D, Fernández Hernández L, González Del Angel A, Alcántara Ortigoza MA, Ulloa Avilés V, Pérez Vera P. Nonmosaic Trisomy 19p13.3p13.2 Resulting from a Rare Unbalanced t(Y;19)(q12;p13.2) Translocation in a Patient with Pachygyria and Polymicrogyria. Cytogenet Genome Res 2020; 160:177-184. [PMID: 32369810 DOI: 10.1159/000507561] [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: 01/21/2020] [Accepted: 03/18/2020] [Indexed: 11/19/2022] Open
Abstract
Nonmosaic trisomy involving 19p13.3p13.2 is a very uncommon abnormality. At present, only 12 cases with this genetic condition have been reported in the literature. However, the size of the trisomic fragment is heterogeneous and thus, the clinical spectrum is variable. Herein, we report the clinical and cytogenetic characterization of a 5-year-old boy with nonmosaic trisomy 19p13.3p13.2 (7.38 Mb), generated by a derivative Y chromosome resulting from a de novo unbalanced translocation t(Y;19)(q12;p13.2). We demonstrated the integrity of the euchromatic regions in the abnormal Y chromosome to confirm the pure trisomy 19p. Our patient shares some clinical features described in other reported patients with pure trisomy 19p, such as craniofacial anomalies, developmental delay, and heart defects. Different to previous reports, our case exhibits frontal pachygyria and polymicrogyria. These additional features contribute to further delineate the clinical spectrum of trisomy 19p13.3p13.2.
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De novo mutations of TUBB2A cause infantile-onset epilepsy and developmental delay. J Hum Genet 2020; 65:601-608. [PMID: 32203252 DOI: 10.1038/s10038-020-0739-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Revised: 02/06/2020] [Accepted: 02/27/2020] [Indexed: 01/20/2023]
Abstract
We analyzed our two new cases of infantile-onset epilepsy with developmental delay with de novo variant in TUBB2A and review the related literatures. Our two probands were both girls with infantile-onset epilepsy and global developmental delay. Case 1 had a novel de novo heterozygous missense variant: c.728C>T [p.Pro243Leu] (NM_001069.2). Her brain magnetic resonance imaging (MRI) showed nonspecific white matter myelination delay and slightly enlarged anterior horn of lateral ventricle. Her epilepsy had been controlled by TPM monotherapy. Case 2 had a reported de novo variant c.743C>T [p.Ala248Val] (NM_001069.2). Her brain MRI showed bilateral microgyria and corpus callosum dysplasia. A total of seven TUBB2A mutations cases had been published previously in five papers, therefore, until now, there were nine patients with TUBB2A mutations. All patients had developmental delay, among them seven cases also with infantile-onset epilepsy, one case with abnormal EEG but without clinical seizures. There are six cases that have different degree of cortical dysplasia, one case with cerebellar vermis atrophy and brainstem sacsinopathy, the rest two cases have no obvious brain structural abnormalities. There was one case with variant c.1249G>A (p.D417N) that had atypical clinical presentation, including prominent progressive spastic ataxia, sensory motor axonal neuropathy, and bilateral optic macular dystrophy, but relatively mild intellectual disability, his MRI showed cerebellar atrophy, thinning of the corpus callosum and pons sacsinopathy, but no cortical malformation. The p.A248V mutation was the most common mutation occurred in three patients (3/9). The clinical phenotypes of these three patients were similar, all of them had global developmental delay with no language and corpus callosum dysplasia, two cases with epilepsy and the other one only have EEG epileptic discharges without clinical seizure, two cases with cortical dysplasia and the other one without obvious brain malformation. In brief, global developmental delay was the most common phenotype of TUBB2A mutation-related disease, most cases also had infantile-onset epilepsy and cortical dysplasia and corpus callosum dysplasia. The region between seventh and eighth alpha-helix of TUBB2A may be a "hot spot" mutation domain.
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Trushina NI, Mulkidjanian AY, Brandt R. The microtubule skeleton and the evolution of neuronal complexity in vertebrates. Biol Chem 2020; 400:1163-1179. [PMID: 31116700 DOI: 10.1515/hsz-2019-0149] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 04/17/2019] [Indexed: 12/21/2022]
Abstract
The evolution of a highly developed nervous system is mirrored by the ability of individual neurons to develop increased morphological complexity. As microtubules (MTs) are crucially involved in neuronal development, we tested the hypothesis that the evolution of complexity is driven by an increasing capacity of the MT system for regulated molecular interactions as it may be implemented by a higher number of molecular players and a greater ability of the individual molecules to interact. We performed bioinformatics analysis on different classes of components of the vertebrate neuronal MT cytoskeleton. We show that the number of orthologs of tubulin structure proteins, MT-binding proteins and tubulin-sequestering proteins expanded during vertebrate evolution. We observed that protein diversity of MT-binding and tubulin-sequestering proteins increased by alternative splicing. In addition, we found that regions of the MT-binding protein tau and MAP6 displayed a clear increase in disorder extent during evolution. The data provide evidence that vertebrate evolution is paralleled by gene expansions, changes in alternative splicing and evolution of coding sequences of components of the MT system. The results suggest that in particular evolutionary changes in tubulin-structure proteins, MT-binding proteins and tubulin-sequestering proteins were prominent drivers for the development of increased neuronal complexity.
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Affiliation(s)
- Nataliya I Trushina
- Department of Neurobiology, University of Osnabrück, Barbarastraße 11, D-49076 Osnabrück, Germany
| | - Armen Y Mulkidjanian
- Department of Physics, University of Osnabrück, Barbarastraße 7, D-49076 Osnabrück, Germany.,A.N. Belozersky Institute of Physico-Chemical Biology and School of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Roland Brandt
- Department of Neurobiology, University of Osnabrück, Barbarastraße 11, D-49076 Osnabrück, Germany.,Center for Cellular Nanoanalytics, University of Osnabrück, Barbarastraße 11, D-49076 Osnabrück, Germany.,Institute of Cognitive Science, University of Osnabrück, Barbarastraße 11, D-49076 Osnabrück, Germany
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Asmaa MJS, Al-Jamal HA, Hussein AR, Yahaya BH, Hassan R, Hussain FA, Shamsuddin S, Johan MF. Transcriptomic Profiles of MV4-11 and Kasumi 1 Acute Myeloid Leukemia Cell Lines Modulated by Epigenetic Modifiers Trichostatin A and 5-Azacytidine. Int J Hematol Oncol Stem Cell Res 2020; 14:72-92. [PMID: 32337016 PMCID: PMC7167603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background: Acute myeloid leukemia (AML) is the most common form of acute leukemias in adults which is clinically and molecularly heterogeneous. Several risk and genetic factors have been widely investigated to characterize AML. However, the concomitant epigenetic factors in controlling the gene expression lead to AML transformation was not fully understood. This study was aimed to identify epigenetically regulated genes in AML cell lines induced by epigenetic modulating agents, Trichostatin A (TSA) and 5-Azacytidine (5-Aza). Materials and Methods: MV4-11 and Kasumi 1 were treated with TSA and/or 5-Aza at IC50 concentration. Gene expression profiling by microarray was utilized using SurePrint G3 Human Gene Expression v3. Gene ontology and KEGG pathway annotations were analyzed by DAVID bioinformatics software using EASE enrichment score. mRNA expression of the differentially expressed genes were verified by quantitative real time PCR. Results: Gene expression analysis revealed a significant changes in the expression of 24,822, 15,720, 15,654 genes in MV4-11 and 12,598, 8828, 18,026 genes in Kasumi 1, in response to TSA, 5-Aza and combination treatments, respectively, compared to non-treated (p<0.05). 7 genes (SOCS3, TUBA1C, CCNA1, MAP3K6, PTPRC, STAT6 and RUNX1) and 4 genes (ANGPTL4, TUBB2A, ADAM12 and PTPN6) shown to be predominantly expressed in MV4-11 and Kasumi 1, respectively (EASE<0.1). The analysis also revealed phagosome pathway commonly activated in both cell lines. Conclusion: Our data showed a distinct optimal biological characteristic and pathway in different types of leukemic cell lines. These finding may help in the identification of cell-specific epigenetic biomarker in the pathogenesis of AML.
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Affiliation(s)
| | | | | | | | - Roslin Hassan
- Department of Hematology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Faezahtul Arbaeyah Hussain
- Department of Pathology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Shaharum Shamsuddin
- School of Health Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia,Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Muhammad Farid Johan
- Department of Hematology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
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Bittermann E, Abdelhamed Z, Liegel RP, Menke C, Timms A, Beier DR, Stottmann RW. Differential requirements of tubulin genes in mammalian forebrain development. PLoS Genet 2019; 15:e1008243. [PMID: 31386652 PMCID: PMC6697361 DOI: 10.1371/journal.pgen.1008243] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 08/16/2019] [Accepted: 06/12/2019] [Indexed: 11/24/2022] Open
Abstract
Tubulin genes encode a series of homologous proteins used to construct microtubules which are essential for multiple cellular processes. Neural development is particularly reliant on functional microtubule structures. Tubulin genes comprise a large family of genes with very high sequence similarity between multiple family members. Human genetics has demonstrated that a large spectrum of cortical malformations are associated with de novo heterozygous mutations in tubulin genes. However, the absolute requirement for many of these genes in development and disease has not been previously tested in genetic loss of function models. Here we directly test the requirement for Tuba1a, Tubb2a and Tubb2b in the mouse by deleting each gene individually using CRISPR-Cas9 genome editing. We show that loss of Tubb2a or Tubb2b does not impair survival but does lead to relatively mild cortical malformation phenotypes. In contrast, loss of Tuba1a is perinatal lethal and leads to significant forebrain dysmorphology. We also present a novel mouse ENU allele of Tuba1a with phenotypes similar to the null allele. This demonstrates the requirements for each of the tubulin genes and levels of functional redundancy are quite different throughout the gene family. The ability of the mouse to survive in the absence of some tubulin genes known to cause disease in humans suggests future intervention strategies for these devastating tubulinopathy diseases.
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Affiliation(s)
- Elizabeth Bittermann
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Zakia Abdelhamed
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- Department of Anatomy and Embryology, Faculty of Medicine (Girl’s Section), Al-Azhar University, Cairo, Egypt
| | - Ryan P. Liegel
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Chelsea Menke
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - Andrew Timms
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, Washington, United States of America
| | - David R. Beier
- Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, Washington, United States of America
- Department of Pediatrics, University of Washington Medical School, Seattle, Washington, United States of America
| | - Rolf W. Stottmann
- Division of Human Genetics, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, United States of America
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Abstract
Mutations causing dysfunction of the tubulins and microtubule-associated proteins, otherwise known as tubulinopathies, are a group of recently described entities, that lead to complex brain malformations. An understanding of the fundamental principles of operation of the cytoskeleton and compounds in particular microtubules, actin, and microtubule-associated proteins, can assist in the interpretation of the imaging findings of tubulinopathies. Somewhat consistent morphological imaging patterns have been described in tubulinopathies such as dysmorphic basal ganglia-the hallmark (found in 75% of cases), callosal dysgenesis, cerebellar hypoplasia/dysplasia, and cortical malformations, most notably lissencephaly. Recognizing the common imaging phenotypes present in tubulinopathies can prove invaluable in directing the genetic workup for a patient with brain malformations.
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Hebebrand M, Hüffmeier U, Trollmann R, Hehr U, Uebe S, Ekici AB, Kraus C, Krumbiegel M, Reis A, Thiel CT, Popp B. The mutational and phenotypic spectrum of TUBA1A-associated tubulinopathy. Orphanet J Rare Dis 2019; 14:38. [PMID: 30744660 PMCID: PMC6371496 DOI: 10.1186/s13023-019-1020-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 02/03/2019] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The TUBA1A-associated tubulinopathy is clinically heterogeneous with brain malformations, microcephaly, developmental delay and epilepsy being the main clinical features. It is an autosomal dominant disorder mostly caused by de novo variants in TUBA1A. RESULTS In three individuals with developmental delay we identified heterozygous de novo missense variants in TUBA1A using exome sequencing. While the c.1307G > A, p.(Gly436Asp) variant was novel, the two variants c.518C > T, p.(Pro173Leu) and c.641G > A, p.(Arg214His) were previously described. We compared the variable phenotype observed in these individuals with a carefully conducted review of the current literature and identified 166 individuals, 146 born and 20 fetuses with a TUBA1A variant. In 107 cases with available clinical information we standardized the reported phenotypes according to the Human Phenotype Ontology. The most commonly reported features were developmental delay (98%), anomalies of the corpus callosum (96%), microcephaly (76%) and lissencephaly (agyria-pachygyria) (70%), although reporting was incomplete in the different studies. We identified a total of 121 specific variants, including 15 recurrent ones. Missense variants cluster in the C-terminal region around the most commonly affected amino acid position Arg402 (13.3%). In a three-dimensional protein model, 38.6% of all disease-causing variants including those in the C-terminal region are predicted to affect the binding of microtubule-associated proteins or motor proteins. Genotype-phenotype analysis for recurrent variants showed an overrepresentation of certain clinical features. However, individuals with these variants are often reported in the same publication. CONCLUSIONS With 166 individuals, we present the most comprehensive phenotypic and genotypic standardized synopsis for clinical interpretation of TUBA1A variants. Despite this considerable number, a detailed genotype-phenotype characterization is limited by large inter-study variability in reporting.
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Affiliation(s)
- Moritz Hebebrand
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 10, 91054, Erlangen, Germany
| | - Ulrike Hüffmeier
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 10, 91054, Erlangen, Germany
| | - Regina Trollmann
- Department of Pediatrics, Division of Neuropediatrics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Ute Hehr
- Institute of Human Genetics, University of Regensburg, Regensburg, Germany
| | - Steffen Uebe
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 10, 91054, Erlangen, Germany
| | - Arif B Ekici
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 10, 91054, Erlangen, Germany
| | - Cornelia Kraus
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 10, 91054, Erlangen, Germany
| | - Mandy Krumbiegel
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 10, 91054, Erlangen, Germany
| | - André Reis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 10, 91054, Erlangen, Germany
| | - Christian T Thiel
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 10, 91054, Erlangen, Germany.
| | - Bernt Popp
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Schwabachanlage 10, 91054, Erlangen, Germany
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The tubulin mutation database: A resource for the cytoskeleton community. Cytoskeleton (Hoboken) 2019; 76:186-191. [DOI: 10.1002/cm.21514] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 12/21/2018] [Accepted: 01/17/2019] [Indexed: 11/07/2022]
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Wang H, Li S, Li S, Jiang N, Guo J, Zhang W, Zhong M, Xie J. De Novo Mutated TUBB2B Associated Pachygyria Diagnosed by Medical Exome Sequencing and Long-Range PCR. Fetal Pediatr Pathol 2019; 38:63-71. [PMID: 30585108 DOI: 10.1080/15513815.2018.1538273] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
INTRODUCTION A range of cerebrocortical development malformations (MCD) ranging from simplified gyral patterns to the complete loss of gyri and sulci is associated with mutations in a cluster of highly homolog β-tublin genes, such as TUBB2A and TUBB2B. CASE REPORT The fetus had pachygyria, asymmetrical perisylvian polymicrogyria, dysplasia of the lateral sulcus and insula, agenesis of the splenium and partial agenesis of the body corpus callosum, cerebellar superior vermian hypoplasia with agenesis of the inferior vermis. Karyotype and microarray were normal. Trio Medical Exome Sequencing detected a de novo novel heterozygous mutation c.862G > A (p.E288K) in the tubulinpathy genes. Long-range PCR and Sanger sequencing specific for TUBB2A and TUBB2B gene detected a heterozygous variant c.862G > A specific to TUBB2B. CONCLUSION The combination of LR-PCR amplification and medical exome sequencing allows mutational assessment in tubulinopathy genes. Our study expands the spectrum of malformations associated with mutations in the β-tubulin gene TUBB2B.
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Affiliation(s)
- Hui Wang
- a Department of Obstetrics and Gynecology , Nanfang Hospital, Southern Medical University , Guangzhou , China.,b Prenatal Diagnosis Center , Shenzhen Maternity and Child Healthcare Hospital , Shenzhen , China
| | - Shaoyuan Li
- c AmCare Genomics Laboratory , International BioIsland , Guangzhou , Shenzhen , China
| | - Shengli Li
- d Ultrasound Department, Shenzhen Maternity and Child Healthcare Hospital , Shenzhen , China
| | - Niping Jiang
- b Prenatal Diagnosis Center , Shenzhen Maternity and Child Healthcare Hospital , Shenzhen , China
| | - Jimin Guo
- e Medical imaging department, Shenzhen Maternity and Child Healthcare Hospital , Shenzhen , China
| | - Wei Zhang
- c AmCare Genomics Laboratory , International BioIsland , Guangzhou , Shenzhen , China
| | - Mei Zhong
- a Department of Obstetrics and Gynecology , Nanfang Hospital, Southern Medical University , Guangzhou , China
| | - Jiansheng Xie
- b Prenatal Diagnosis Center , Shenzhen Maternity and Child Healthcare Hospital , Shenzhen , China
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Yuskaitis CJ, Ruzhnikov MR, Howell KB, Allen IE, Kapur K, Dlugos DJ, Scheffer IE, Poduri A, Sherr EH. Infantile Spasms of Unknown Cause: Predictors of Outcome and Genotype-Phenotype Correlation. Pediatr Neurol 2018; 87:48-56. [PMID: 30174244 PMCID: PMC8188823 DOI: 10.1016/j.pediatrneurol.2018.04.012] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 04/28/2018] [Indexed: 12/14/2022]
Abstract
BACKGROUND No large-scale studies have specifically evaluated the outcomes of infantile spasms (IS) of unknown cause, previously known as cryptogenic or idiopathic. The Epilepsy Phenome/Genome Project aimed to characterize IS of unknown cause by phenotype and genotype analysis. METHODS We undertook a retrospective multicenter observational cohort of 133 individuals within the Epilepsy Phenome/Genome Project database met criteria for IS of unknown cause with at least six months of follow-up data. Clinical medical records, imaging, and electroencephalography were examined. RESULTS Normal development occurred in only 15% of IS of unknown cause. The majority (85%) had clinically documented developmental delay (15% mild, 20% moderate, and 50% severe) at last assessment (median 2.7 years; interquartile interval 1.71-6.25 years). Predictors of positive developmental outcomes included no delay prior to IS (P < 0.001), older age of IS onset (median six months old), and resolution of IS after initial treatment (P < 0.001). Additional seizures after IS occurred in 67%, with predictors being seizures prior to IS (P = 0.018), earlier age of IS onset (median five months old), and refractory IS (P = 0.008). On a research basis, whole exome sequencing identified 15% with de novo variants in known epilepsy genes. Individuals with a genetic finding were more likely to have poor developmental outcomes (P = 0.035). CONCLUSIONS The current study highlights the predominately unfavorable developmental outcomes and that subsequent seizures are common in children with IS of unknown cause. Ongoing genetic evaluation of IS of seemingly unknown cause is likely to yield a diagnosis and provide valuable prognostic information.
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Affiliation(s)
- Christopher J. Yuskaitis
- Department of Neurology and Division of Epilepsy, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts
| | - Maura R.Z. Ruzhnikov
- Division of Medical Genetics and Department of Pediatrics, Stanford University, Stanford, California
| | - Katherine B. Howell
- Department of Neurology, Royal Children’s Hospital, Parkville, Victoria, Australia
| | - I. Elaine Allen
- Department of Epidemiology and Biostatistics/UCSF, University of California San Francisco, San Francisco, California
| | - Kush Kapur
- Department of Neurology and Division of Epilepsy, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts
| | - Dennis J. Dlugos
- The Children’s Hospital of Philadelphia, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ingrid E. Scheffer
- Epilepsy Research Centre, Austin Health, University of Melbourne, Melbourne, Victoria, Australia
| | - Annapurna Poduri
- Department of Neurology and Division of Epilepsy, Boston Children’s Hospital and Harvard Medical School, Boston, Massachusetts
| | - Elliott H. Sherr
- Departments of Neurology and Pediatrics, University of California San Francisco, San Francisco, California,Corresponding author.
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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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Tan AP, Chong WK, Mankad K. Comprehensive genotype-phenotype correlation in lissencephaly. Quant Imaging Med Surg 2018; 8:673-693. [PMID: 30211035 DOI: 10.21037/qims.2018.08.08] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Malformations of cortical development (MCD) are a heterogenous group of disorders with diverse genotypic and phenotypic variations. Lissencephaly is a subtype of MCD caused by defect in neuronal migration, which occurs between 12 and 24 weeks of gestation. The continuous advancement in the field of molecular genetics in the last decade has led to identification of at least 19 lissencephaly-related genes, most of which are related to microtubule structural proteins (tubulin) or microtubule-associated proteins (MAPs). The aim of this review article is to bring together current knowledge of gene mutations associated with lissencephaly and to provide a comprehensive genotype-phenotype correlation. Illustrative cases will be presented to facilitate the understanding of the described genotype-phenotype correlation.
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Affiliation(s)
- Ai Peng Tan
- Department of Diagnostic Imaging, National University Health System, Singapore.,Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore
| | - Wui Khean Chong
- Department of Neuroradiology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
| | - Kshitij Mankad
- Department of Neuroradiology, Great Ormond Street Hospital NHS Foundation Trust, London, UK
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44
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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: 76] [Impact Index Per Article: 12.7] [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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O'Keeffe GW, Sullivan AM. Evidence for dopaminergic axonal degeneration as an early pathological process in Parkinson's disease. Parkinsonism Relat Disord 2018; 56:9-15. [PMID: 29934196 DOI: 10.1016/j.parkreldis.2018.06.025] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 05/21/2018] [Accepted: 06/17/2018] [Indexed: 12/21/2022]
Abstract
Parkinson's disease is a common neurodegenerative disorder presenting with a variety of motor and non-motor symptoms. The motor symptoms manifest as a result of the progressive degeneration of midbrain dopaminergic neurons. The axons of these neurons project to the striatum as the nigrostriatal pathway, which is a crucial part of the basal ganglia circuitry controlling movement. In addition to the neuronal degeneration, abnormal intraneuronal α-synuclein protein inclusions called Lewy bodies and Lewy neurites increase in number and spread throughout the nervous system as the disease progresses. While the loss of midbrain dopaminergic neurons is well-established as being central to motor symptoms, there is an increasing focus on the timing of nigrostriatal degeneration, with preclinical evidence suggesting that early axonal degeneration may play a key role in the early stages of Parkinson's disease. Here we review recent evidence for early midbrain dopaminergic axonal degeneration in patients with Parkinson's disease, and explore the potential role of α-synuclein accumulation in this process, with a focus on studies in human populations at the imaging, post-mortem, cellular and molecular levels. Finally, we discuss the implications of this for neurotrophic factor therapies for Parkinson's disease.
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Affiliation(s)
- Gerard W O'Keeffe
- Department of Anatomy and Neuroscience, Western Gateway Building, University College Cork, Cork, Ireland; Cork Neuroscience Centre, University College Cork, Cork, Ireland.
| | - Aideen M Sullivan
- Department of Anatomy and Neuroscience, Western Gateway Building, University College Cork, Cork, Ireland; Cork Neuroscience Centre, University College Cork, Cork, Ireland.
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Tubulinopathies continued: refining the phenotypic spectrum associated with variants in TUBG1. Eur J Hum Genet 2018; 26:1132-1142. [PMID: 29706637 PMCID: PMC6057922 DOI: 10.1038/s41431-018-0146-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 03/02/2018] [Accepted: 03/13/2018] [Indexed: 12/30/2022] Open
Abstract
Tubulinopathies are a heterogeneous group of conditions with a wide spectrum of clinical severity resulting from variants in genes of the tubulin superfamily. Variants in TUBG1 have been described in three patients with posterior predominant pachygyria and microcephaly. We here report eight additional patients with four novel heterozygous variants in TUBG1 identified by next-generation sequencing (NGS) analysis. All had severe motor and cognitive impairment and all except one developed seizures in early life. The core imaging features included a pachygyric cortex with posterior to anterior gradient, enlarged lateral ventricles most pronounced over the posterior horns, and variable degrees of reduced white matter volume. Basal ganglia, corpus callosum, brainstem, and cerebellum were often normal, in contrast to patients with variants in other tubulin genes where these structures are frequently malformed. The imaging phenotype associated with variants in TUBG1 is therefore more in line with the phenotype resulting from variants in LIS1 (a.k.a. PAFAH1B1). This difference may, at least in part, be explained by gamma-tubulin’s physiological function in microtubule nucleation, which differs from that of alpha and beta-tubulin.
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Han X, Chen H, Huang D, Chen H, Fei L, Cheng C, Huang H, Yuan GC, Guo G. Mapping human pluripotent stem cell differentiation pathways using high throughput single-cell RNA-sequencing. Genome Biol 2018; 19:47. [PMID: 29622030 PMCID: PMC5887227 DOI: 10.1186/s13059-018-1426-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/21/2018] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Human pluripotent stem cells (hPSCs) provide powerful models for studying cellular differentiations and unlimited sources of cells for regenerative medicine. However, a comprehensive single-cell level differentiation roadmap for hPSCs has not been achieved. RESULTS We use high throughput single-cell RNA-sequencing (scRNA-seq), based on optimized microfluidic circuits, to profile early differentiation lineages in the human embryoid body system. We present a cellular-state landscape for hPSC early differentiation that covers multiple cellular lineages, including neural, muscle, endothelial, stromal, liver, and epithelial cells. Through pseudotime analysis, we construct the developmental trajectories of these progenitor cells and reveal the gene expression dynamics in the process of cell differentiation. We further reprogram primed H9 cells into naïve-like H9 cells to study the cellular-state transition process. We find that genes related to hemogenic endothelium development are enriched in naïve-like H9. Functionally, naïve-like H9 show higher potency for differentiation into hematopoietic lineages than primed cells. CONCLUSIONS Our single-cell analysis reveals the cellular-state landscape of hPSC early differentiation, offering new insights that can be harnessed for optimization of differentiation protocols.
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Affiliation(s)
- Xiaoping Han
- Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Institute of Hematology, The 1st Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.,Stem Cell Institute, Zhejiang University, Hangzhou, 310058, China
| | - Haide Chen
- Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China. .,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Hangzhou, 310058, China. .,College of Animal Science, Zhejiang University, Hangzhou, 310058, China.
| | - Daosheng Huang
- Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Stem Cell Institute, Zhejiang University, Hangzhou, 310058, China
| | - Huidong Chen
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Harvard Chan School of Public Health, Boston, MA, 02115, USA.,Department of Computer Science and Technology, Tongji University, Shanghai, 201804, China
| | - Lijiang Fei
- Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China.,Stem Cell Institute, Zhejiang University, Hangzhou, 310058, China
| | - Chen Cheng
- College of Life Sciences, Zhejiang University, Hangzhou, 310058, China
| | - He Huang
- Institute of Hematology, The 1st Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China.,Stem Cell Institute, Zhejiang University, Hangzhou, 310058, China
| | - Guo-Cheng Yuan
- Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Harvard Chan School of Public Health, Boston, MA, 02115, USA.
| | - Guoji Guo
- Center for Stem Cell and Regenerative Medicine, Zhejiang University School of Medicine, Hangzhou, 310058, China. .,Institute of Hematology, The 1st Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310003, China. .,Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cell and Regenerative Medicine, Zhejiang Provincial Key Lab for Tissue Engineering and Regenerative Medicine, Hangzhou, 310058, China. .,Stem Cell Institute, Zhejiang University, Hangzhou, 310058, China.
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48
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Genetics and mechanisms leading to human cortical malformations. Semin Cell Dev Biol 2018; 76:33-75. [DOI: 10.1016/j.semcdb.2017.09.031] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/21/2017] [Accepted: 09/21/2017] [Indexed: 02/06/2023]
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Sferra A, Fattori F, Rizza T, Flex E, Bellacchio E, Bruselles A, Petrini S, Cecchetti S, Teson M, Restaldi F, Ciolfi A, Santorelli FM, Zanni G, Barresi S, Castiglioni C, Tartaglia M, Bertini E. Defective kinesin binding of TUBB2A causes progressive spastic ataxia syndrome resembling sacsinopathy. Hum Mol Genet 2018; 27:1892-1904. [DOI: 10.1093/hmg/ddy096] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2017] [Accepted: 03/12/2018] [Indexed: 12/28/2022] Open
Affiliation(s)
- Antonella Sferra
- Unit of Neuromuscular and Neurodegenerative Disorders, Department Neurosciences, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Fabiana Fattori
- Unit of Neuromuscular and Neurodegenerative Disorders, Department Neurosciences, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Teresa Rizza
- Unit of Neuromuscular and Neurodegenerative Disorders, Department Neurosciences, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Elsabetta Flex
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Emanuele Bellacchio
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Alessandro Bruselles
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Stefania Petrini
- Confocal Microscopy Core Facility, Research Laboratories, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Serena Cecchetti
- Confocal Microscopy Unit, Core Facilities, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Massimo Teson
- Laboratory of Molecular and Cell Biology, Istituto Dermopatico Dell’Immacolata IDI-IRCCS, 00167 Rome, Italy
| | - Fabrizia Restaldi
- Unit of Medical Genetics, Department of Laboratories, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Andrea Ciolfi
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Filippo M Santorelli
- IRCCS Stella Maris, Molecular Medicine and Neuromuscular Disorders, 56128 Pisa, Italy
| | - Ginevra Zanni
- Unit of Neuromuscular and Neurodegenerative Disorders, Department Neurosciences, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Sabina Barresi
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Claudia Castiglioni
- Neurology Unit, Department of Pediatrics, Clínica Las Condes, 7550000 Santiago, Chile
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Enrico Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, Department Neurosciences, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
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50
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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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