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Tosolini AP, Abatecola F, Negro S, Sleigh JN, Schiavo G. The node of Ranvier influences the in vivo axonal transport of mitochondria and signaling endosomes. iScience 2024; 27:111158. [PMID: 39524336 PMCID: PMC11544082 DOI: 10.1016/j.isci.2024.111158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2024] [Revised: 09/15/2024] [Accepted: 10/09/2024] [Indexed: 11/16/2024] Open
Abstract
Efficient long-range axonal transport is essential for maintaining neuronal function, and perturbations in this process underlie severe neurological diseases. Nodes of Ranvier (NoR) are short, specialized unmyelinated axonal domains with a unique molecular and structural composition. Currently, it remains unresolved how the distinct molecular structures of the NoR impact axonal transport dynamics. Using intravital time-lapse microscopy of sciatic nerves in live, anesthetized mice, we reveal (1) similar morphologies of the NoR in fast and slow motor axons, (2) signaling endosomes and mitochondria accumulate specifically at the distal node, and (3) unique axonal transport profiles of signaling endosomes and mitochondria transiting through the NoR. Collectively, these findings provide important insights into the fundamental physiology of peripheral nerve axons, motor neuron subtypes, and diverse organelle dynamics at the NoR. Furthermore, this work has relevance for several pathologies affecting peripheral nerves and the NoR.
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Affiliation(s)
- Andrew P. Tosolini
- Department of Neuromuscular Diseases and UCL Queen Square Motor Neuron Disease Centre, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD 4067, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, St Lucia, QLD 4067, Australia
| | - Federico Abatecola
- Department of Neuromuscular Diseases and UCL Queen Square Motor Neuron Disease Centre, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
| | - Samuele Negro
- Department of Biomedical Sciences, University of Padua, 35131 Padua, Italy
- U.O.C. Clinica Neurologica, Azienda Ospedale, University of Padua, 35128 Padua, Italy
| | - James N. Sleigh
- Department of Neuromuscular Diseases and UCL Queen Square Motor Neuron Disease Centre, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
- UK Dementia Research Institute, University College London, London WC1E 6BT, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases and UCL Queen Square Motor Neuron Disease Centre, Queen Square Institute of Neurology, University College London, London WC1N 3BG, UK
- UK Dementia Research Institute, University College London, London WC1E 6BT, UK
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2
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Nishio H, Niba ETE, Saito T, Okamoto K, Lee T, Takeshima Y, Awano H, Lai PS. Clinical and Genetic Profiles of 5q- and Non-5q-Spinal Muscular Atrophy Diseases in Pediatric Patients. Genes (Basel) 2024; 15:1294. [PMID: 39457418 PMCID: PMC11506990 DOI: 10.3390/genes15101294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2024] [Revised: 09/25/2024] [Accepted: 09/27/2024] [Indexed: 10/28/2024] Open
Abstract
BACKGROUND Spinal muscular atrophy (SMA) is a genetic disease characterized by loss of motor neurons in the spinal cord and lower brainstem. The term "SMA" usually refers to the most common form, 5q-SMA, which is caused by biallelic mutations in SMN1 (located on chromosome 5q13). However, long before the discovery of SMN1, it was known that other forms of SMA existed. Therefore, SMA is currently divided into two groups: 5q-SMA and non-5q-SMA. This is a simple and practical classification, and therapeutic drugs have only been developed for 5q-SMA (nusinersen, onasemnogene abeparvovec, risdiplam) and not for non-5q-SMA disease. METHODS We conducted a non-systematic critical review to identify the characteristics of each SMA disease. RESULTS Many of the non-5q-SMA diseases have similar symptoms, making DNA analysis of patients essential for accurate diagnosis. Currently, genetic analysis technology using next-generation sequencers is rapidly advancing, opening up the possibility of elucidating the pathology and treating non-5q-SMA. CONCLUSION Based on accurate diagnosis and a deeper understanding of the pathology of each disease, treatments for non-5q-SMA diseases may be developed in the near future.
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Affiliation(s)
- Hisahide Nishio
- Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan
| | - Emma Tabe Eko Niba
- Laboratory of Molecular and Biochemical Research, Biomedical Research Core Facilities, Graduate School of Medicine, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan;
| | - Toshio Saito
- Department of Neurology, National Hospital Organization Osaka Toneyama Medical Center, 5-1-1 Toneyama, Toyonaka 560-8552, Japan;
| | - Kentaro Okamoto
- Department of Pediatrics, Ehime Prefectural Imabari Hospital, 4-5-5 Ishi-cho, Imabari 794-0006, Japan;
| | - Tomoko Lee
- Department of Pediatrics, Hyogo Medical University, 1-1 Mukogawacho, Nishinomiya 663-8501, Japan; (T.L.); (Y.T.)
| | - Yasuhiro Takeshima
- Department of Pediatrics, Hyogo Medical University, 1-1 Mukogawacho, Nishinomiya 663-8501, Japan; (T.L.); (Y.T.)
| | - Hiroyuki Awano
- Organization for Research Initiative and Promotion, Research Initiative Center, Tottori University, 86 Nishi-cho, Yonago 683-8503, Japan;
| | - Poh-San Lai
- Department of Pediatrics, National University of Singapore, 1E Lower Kent Ridge Road, Singapore 119228, Singapore;
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3
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Zufiría M, Pikatza-Menoio O, Garciandia-Arcelus M, Bengoetxea X, Jiménez A, Elicegui A, Levchuk M, Arnold-García O, Ondaro J, Iruzubieta P, Rodríguez-Gómez L, Fernández-Pelayo U, Muñoz-Oreja M, Aiastui A, García-Verdugo JM, Herranz-Pérez V, Zulaica M, Poza JJ, Ruiz-Onandi R, Fernández-Torrón R, Espinal JB, Bonilla M, Lersundi A, Fernández-Eulate G, Riancho J, Vallejo-Illarramendi A, Holt IJ, Sáenz A, Malfatti E, Duguez S, Blázquez L, López de Munain A, Gerenu G, Gil-Bea F, Alonso-Martín S. Dysregulated FOXO1 activity drives skeletal muscle intrinsic dysfunction in amyotrophic lateral sclerosis. Acta Neuropathol 2024; 148:43. [PMID: 39283487 PMCID: PMC11405449 DOI: 10.1007/s00401-024-02794-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2024] [Revised: 08/07/2024] [Accepted: 08/19/2024] [Indexed: 09/22/2024]
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a multisystemic neurodegenerative disorder, with accumulating evidence indicating metabolic disruptions in the skeletal muscle preceding disease symptoms, rather than them manifesting as a secondary consequence of motor neuron (MN) degeneration. Hence, energy homeostasis is deeply implicated in the complex physiopathology of ALS and skeletal muscle has emerged as a key therapeutic target. Here, we describe intrinsic abnormalities in ALS skeletal muscle, both in patient-derived muscle cells and in muscle cell lines with genetic knockdown of genes related to familial ALS, such as TARDBP (TDP-43) and FUS. We found a functional impairment of myogenesis that parallels defects of glucose oxidation in ALS muscle cells. We identified FOXO1 transcription factor as a key mediator of these metabolic and functional features in ALS muscle, via gene expression profiling and biochemical surveys in TDP-43 and FUS-silenced muscle progenitors. Strikingly, inhibition of FOXO1 mitigated the impaired myogenesis in both the genetically modified and the primary ALS myoblasts. In addition, specific in vivo conditional knockdown of TDP-43 or FUS orthologs (TBPH or caz) in Drosophila muscle precursor cells resulted in decreased innervation and profound dysfunction of motor nerve terminals and neuromuscular synapses, accompanied by motor abnormalities and reduced lifespan. Remarkably, these phenotypes were partially corrected by foxo inhibition, bolstering the potential pharmacological management of muscle intrinsic abnormalities associated with ALS. The findings demonstrate an intrinsic muscle dysfunction in ALS, which can be modulated by targeting FOXO factors, paving the way for novel therapeutic approaches that focus on the skeletal muscle as complementary target tissue.
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Grants
- CB06/05/1126 Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas
- PI2020/08-1 Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas
- P18/01066 Instituto de Salud Carlos III
- PI19/00175 Instituto de Salud Carlos III
- PI21/00153 Instituto de Salud Carlos III
- PI22/00433 Instituto de Salud Carlos III
- IJC2019-039965-I Instituto de Salud Carlos III
- 2020-CIEN-000057-01 Diputación Foral de Gipuzkoa
- 2021-CIEN-000020-01 Diputación Foral de Gipuzkoa
- 2019-FELL-000010-01 Diputación Foral de Gipuzkoa
- 2020-FELL-000016-02-01 Diputación Foral de Gipuzkoa
- 2021-FELL-000013-02-01 Diputación Foral de Gipuzkoa
- BIO17/ND/023/BD EiTB Maratoia
- 2015111122 Osasun Saila, Eusko Jaurlaritzako
- 2017222027 Osasun Saila, Eusko Jaurlaritzako
- 2018111042 Osasun Saila, Eusko Jaurlaritzako
- 2019222020 Osasun Saila, Eusko Jaurlaritzako
- 2020111032 Osasun Saila, Eusko Jaurlaritzako
- 2020333043 Osasun Saila, Eusko Jaurlaritzako
- 2021333050 Osasun Saila, Eusko Jaurlaritzako
- PRE_2015_1_0023 Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza
- PRE_2019_1_0339 Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza
- PRE_2020_1_0122 Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza
- PRE_2020_1_0191 Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza
- PRE_2020_1_0119 Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza
- PRE_2018_1_0095 Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza
- PRE_2021_1_0125 Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza
- PRE_2018_1_0253 Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza
- NEURODEGENPROT Hezkuntza, Hizkuntza Politika Eta Kultura Saila, Eusko Jaurlaritza
- PIF18/317 Euskal Herriko Unibertsitatea
- RYC2018-024397-I Spanish National Plan for Scientific and Technical Research and Innovation
- RF/2019/001 Ikerbasque, Basque Foundation for Science
- RF/2023/010 Ikerbasque, Basque Foundation for Science
- PP/2022/003 Ikerbasque, Basque Foundation for Science
- BIO19/ROCHE/017/BD Roche España
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Affiliation(s)
- Mónica Zufiría
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Oihane Pikatza-Menoio
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Stem Cells and Aging Group, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
| | | | - Xabier Bengoetxea
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
| | - Andrés Jiménez
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Amaia Elicegui
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Stem Cells and Aging Group, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
| | - María Levchuk
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
| | - Olatz Arnold-García
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Jon Ondaro
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Pablo Iruzubieta
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Department of Neurology, Donostialdea Integrated Health Organization, Osakidetza Basque Health Service, 20014, Donostia/San Sebastian, Spain
| | - Laura Rodríguez-Gómez
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
| | - Uxoa Fernández-Pelayo
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
| | - Mikel Muñoz-Oreja
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Department of Pediatrics, Faculty of Medicine and Nursery, University of the Basque Country UPV/EHU, 20014, Donostia/San Sebastian, Spain
| | - Ana Aiastui
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Cell Culture Platform, Biodonostia Health Research Institute, 20014, Donostia/San Sebastian, Spain
| | - José Manuel García-Verdugo
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Laboratory of Comparative Neurobiology, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, 46980, Paterna, Spain
- Department of Cell Biology, Functional Biology and Physical Anthropology, University of Valencia, 46100, Burjassot, Spain
| | - Vicente Herranz-Pérez
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Laboratory of Comparative Neurobiology, Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, 46980, Paterna, Spain
- Department of Cell Biology, Functional Biology and Physical Anthropology, University of Valencia, 46100, Burjassot, Spain
| | - Miren Zulaica
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Juan José Poza
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Department of Neurology, Donostialdea Integrated Health Organization, Osakidetza Basque Health Service, 20014, Donostia/San Sebastian, Spain
| | - Rebeca Ruiz-Onandi
- Department of Pathological Anatomy, Galdakao-Usansolo University Hospital, Osakidetza Basque Health Service, 48960, Galdakao, Spain
- Department of Medical-Surgical Specialties, Faculty of Medicine and Nursery, University of the Basque Country UPV/EHU, 48940, Leioa, Spain
| | - Roberto Fernández-Torrón
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Department of Neurology, Donostialdea Integrated Health Organization, Osakidetza Basque Health Service, 20014, Donostia/San Sebastian, Spain
| | - Juan Bautista Espinal
- Department of Neurology, Donostialdea Integrated Health Organization, Osakidetza Basque Health Service, 20014, Donostia/San Sebastian, Spain
| | - Mario Bonilla
- Department of Traumatology and Orthopedic Surgery, Donostialdea Integrated Health Organization, Osakidetza Basque Health Service, 20014, Donostia/San Sebastian, Spain
| | - Ana Lersundi
- Department of Traumatology and Orthopedic Surgery, Donostialdea Integrated Health Organization, Osakidetza Basque Health Service, 20014, Donostia/San Sebastian, Spain
- Department of Surgery, Faculty of Medicine and Nursery, University of the Basque Country UPV/EHU, 20014, Donostia/San Sebastián, Spain
| | - Gorka Fernández-Eulate
- Department of Neurology, Donostialdea Integrated Health Organization, Osakidetza Basque Health Service, 20014, Donostia/San Sebastian, Spain
- Nord/Est/Ile-de-France Neuromuscular Reference Center, Institut de Myologie, Pitié-Salpêtrière Hospital, 75012, Paris, France
- Institut Necker-Enfants Malades, INSERM U1151, BioSPC (ED562), Université Paris Cité, 75015, Paris, France
| | - Javier Riancho
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Department of Neurology, Hospital de Sierrallana-IDIVAL, 39300, Torrelavega, Cantabria, Spain
- Department of Psychiatry and Medicine, Faculty of Medicine, University of Cantabria, 39011, Santander, Spain
| | - Ainara Vallejo-Illarramendi
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Department of Pediatrics, Faculty of Medicine and Nursery, University of the Basque Country UPV/EHU, 20014, Donostia/San Sebastian, Spain
| | - Ian James Holt
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- IKERBASQUE - Basque Foundation for Science, 48009, Bilbao, Spain
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Royal Free Campus, London, NW3 2PF, UK
| | - Amets Sáenz
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
| | - Edoardo Malfatti
- Université Paris Est Créteil, INSERM, IMRB, 94010, Créteil, France
- Hôpital Henri-Mondor, 94010, Créteil, France
- Paris Reference Center for Neuromuscular Disorders, APHP Henri Mondor University Hospital, 94010, Créteil, France
| | - Stéphanie Duguez
- Personalised Medicine Centre, School of Medicine, Ulster University, Derry, BT47 6SB, UK
- Northern Ireland Center for Stratified Medicine, Biomedical Sciences Research Institute, Londonderry, UK
| | - Lorea Blázquez
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- IKERBASQUE - Basque Foundation for Science, 48009, Bilbao, Spain
| | - Adolfo López de Munain
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- Department of Neurology, Donostialdea Integrated Health Organization, Osakidetza Basque Health Service, 20014, Donostia/San Sebastian, Spain
- Department of Neurosciences, Faculty of Medicine and Nursery, University of the Basque Country UPV/EHU, 20014, Donostia/San Sebastian, Spain
- Department of Medicine, Faculty of Health Sciences, University of Deusto, 48007, Bilbao, Spain
- Biodonostia Health Research Institute, 20014, Donostia/San Sebastian, Spain
| | - Gorka Gerenu
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- IKERBASQUE - Basque Foundation for Science, 48009, Bilbao, Spain
- Department of Physiology, Faculty of Medicine and Nursery, University of the Basque Country UPV/EHU, 48940, Leioa, Spain
| | - Francisco Gil-Bea
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain
- IKERBASQUE - Basque Foundation for Science, 48009, Bilbao, Spain
- Department of Health Sciences, Public University of Navarra (UPNA), 31006, Pamplona, Spain
| | - Sonia Alonso-Martín
- Neurosciences Area, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain.
- CIBERNED, ISCIII (CIBER, Carlos III Institute, Spanish Ministry of Sciences and Innovation), 28031, Madrid, Spain.
- Stem Cells and Aging Group, Biogipuzkoa Health Research Institute, 20014, Donostia/San Sebastian, Spain.
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4
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Zhao X, Quintremil S, Rodriguez Castro ED, Cui H, Moraga D, Wang T, Vallee RB, Solmaz SR. Molecular mechanism for recognition of the cargo adapter Rab6 GTP by the dynein adapter BicD2. Life Sci Alliance 2024; 7:e202302430. [PMID: 38719748 PMCID: PMC11077774 DOI: 10.26508/lsa.202302430] [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: 10/11/2023] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 05/12/2024] Open
Abstract
Rab6 is a key modulator of protein secretion. The dynein adapter Bicaudal D2 (BicD2) recruits the motors cytoplasmic dynein and kinesin-1 to Rab6GTP-positive vesicles for transport; however, it is unknown how BicD2 recognizes Rab6. Here, we establish a structural model for recognition of Rab6GTP by BicD2, using structure prediction and mutagenesis. The binding site of BicD2 spans two regions of Rab6 that undergo structural changes upon the transition from the GDP- to GTP-bound state, and several hydrophobic interface residues are rearranged, explaining the increased affinity of the active GTP-bound state. Mutations of Rab6GTP that abolish binding to BicD2 also result in reduced co-migration of Rab6GTP/BicD2 in cells, validating our model. These mutations also severely diminished the motility of Rab6-positive vesicles in cells, highlighting the importance of the Rab6GTP/BicD2 interaction for overall motility of the multi-motor complex that contains both kinesin-1 and dynein. Our results provide insights into trafficking of secretory and Golgi-derived vesicles and will help devise therapies for diseases caused by BicD2 mutations, which selectively affect the affinity to Rab6 and other cargoes.
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Affiliation(s)
- Xiaoxin Zhao
- Department of Chemistry, Binghamton University, Binghamton, NY, USA
| | - Sebastian Quintremil
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | | | - Heying Cui
- Department of Chemistry, Binghamton University, Binghamton, NY, USA
| | - David Moraga
- Department of Chemistry, Binghamton University, Binghamton, NY, USA
| | - Tingyao Wang
- Department of Chemistry, Binghamton University, Binghamton, NY, USA
| | - Richard B Vallee
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Sozanne R Solmaz
- Department of Chemistry, Binghamton University, Binghamton, NY, USA
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5
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Park JG, Jeon H, Hwang KY, Cha SS, Han RT, Cho H, Lee IG. Cargo specificity, regulation, and therapeutic potential of cytoplasmic dynein. Exp Mol Med 2024; 56:827-835. [PMID: 38556551 PMCID: PMC11059388 DOI: 10.1038/s12276-024-01200-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 01/05/2024] [Accepted: 01/10/2024] [Indexed: 04/02/2024] Open
Abstract
Intracellular retrograde transport in eukaryotic cells relies exclusively on the molecular motor cytoplasmic dynein 1. Unlike its counterpart, kinesin, dynein has a single isoform, which raises questions about its cargo specificity and regulatory mechanisms. The precision of dynein-mediated cargo transport is governed by a multitude of factors, including temperature, phosphorylation, the microtubule track, and interactions with a family of activating adaptor proteins. Activating adaptors are of particular importance because they not only activate the unidirectional motility of the motor but also connect a diverse array of cargoes with the dynein motor. Therefore, it is unsurprising that dysregulation of the dynein-activating adaptor transport machinery can lead to diseases such as spinal muscular atrophy, lower extremity, and dominant. Here, we discuss dynein motor motility within cells and in in vitro, and we present several methodologies employed to track the motion of the motor. We highlight several newly identified activating adaptors and their roles in regulating dynein. Finally, we explore the potential therapeutic applications of manipulating dynein transport to address diseases linked to dynein malfunction.
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Affiliation(s)
- Jin-Gyeong Park
- Biomedical Research Division, Korea Institute of Science and Technology, Seoul, 02792, South Korea
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, South Korea
| | - Hanul Jeon
- Biomedical Research Division, Korea Institute of Science and Technology, Seoul, 02792, South Korea
- Department of Chemistry & Nanoscience, Ewha Womans University, Seoul, 03760, South Korea
| | - Kwang Yeon Hwang
- Department of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841, South Korea
| | - Sun-Shin Cha
- Department of Chemistry & Nanoscience, Ewha Womans University, Seoul, 03760, South Korea
| | - Rafael T Han
- Biomedical Research Division, Korea Institute of Science and Technology, Seoul, 02792, South Korea
- KHU-KIST Department of Converging Science and Technology, Kyunghee University, Seoul, 02447, South Korea
| | - Hyesung Cho
- Extreme Materials Research Center, Korea Institute of Science and Technology, Seoul, 02792, South Korea
| | - In-Gyun Lee
- Biomedical Research Division, Korea Institute of Science and Technology, Seoul, 02792, South Korea.
- Department of Biological Chemistry, University of Science and Technology, Daejeon, 34113, South Korea.
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6
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Della Marina A, Hentschel A, Czech A, Schara-Schmidt U, Preusse C, Laner A, Abicht A, Ruck T, Weis J, Choueiri C, Lochmüller H, Kölbel H, Roos A. Novel Genetic and Biochemical Insights into the Spectrum of NEFL-Associated Phenotypes. J Neuromuscul Dis 2024; 11:625-645. [PMID: 38578900 PMCID: PMC11091643 DOI: 10.3233/jnd-230230] [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] [Accepted: 03/06/2024] [Indexed: 04/07/2024]
Abstract
Background NEFL encodes for the neurofilament light chain protein. Pathogenic variants in NEFL cause demyelinating, axonal and intermediate forms of Charcot-Marie-Tooth disease (CMT) which present with a varying degree of severity and somatic mutations have not been described yet. Currently, 34 different CMT-causing pathogenic variants in NEFL in 174 patients have been reported. Muscular involvement was also described in CMT2E patients mostly as a secondary effect. Also, there are a few descriptions of a primary muscle vulnerability upon pathogenic NEFL variants. Objectives To expand the current knowledge on the genetic landscape, clinical presentation and muscle involvement in NEFL-related neurological diseases by retrospective case study and literature review. Methods We applied in-depth phenotyping of new and already reported cases, molecular genetic testing, light-, electron- and Coherent Anti-Stokes Raman Scattering-microscopic studies and proteomic profiling in addition to in silico modelling of NEFL-variants. Results We report on a boy with a muscular phenotype (weakness, myalgia and cramps, Z-band alterations and mini-cores in some myofibers) associated with the heterozygous p.(Phe104Val) NEFL-variant, which was previously described in a neuropathy case. Skeletal muscle proteomics findings indicated affection of cytoskeletal proteins. Moreover, we report on two further neuropathic patients (16 years old girl and her father) both carrying the heterozygous p.(Pro8Ser) variant, which has been identified as 15% somatic mosaic in the father. While the daughter presented with altered neurophysiology,neurogenic clump feet and gait disturbances, the father showed clinically only feet deformities. As missense variants affecting proline at amino acid position 8 are leading to neuropathic manifestations of different severities, in silico modelling of these different amino acid substitutions indicated variable pathogenic impact correlating with disease onset. Conclusions Our findings provide new morphological and biochemical insights into the vulnerability of denervated muscle (upon NEFL-associated neuropathy) as well as novel genetic findings expanding the current knowledge on NEFL-related neuromuscular phenotypes and their clinical manifestations. Along this line, our data show that even subtle expression of somatic NEFL variants can lead to neuromuscular symptoms.
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Affiliation(s)
- Adela Della Marina
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany
| | - Artur Czech
- Leibniz-Institut für Analytische Wissenschaften -ISAS- e.V., Dortmund, Germany
| | - Ulrike Schara-Schmidt
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Corinna Preusse
- Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health (BIH), Berlin, Germany
| | | | - Angela Abicht
- Medical Genetics Center, Munich, Germany
- Friedrich-Baur Institute, Ludwig Maximilian University, Munich, Germany
| | - Tobias Ruck
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Catherine Choueiri
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
| | - Hanns Lochmüller
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
- Division of Neurology, Department of Medicine, The Ottawa Hospital, Ottawa, Canada
- Brain and Mind Research Institute, University of Ottawa, Ottawa, Canada
| | - Heike Kölbel
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
| | - Andreas Roos
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, Essen, Germany
- Department of Neurology, Medical Faculty, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON, Canada
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7
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Sasazawa Y, Hattori N, Saiki S. JNK-interacting protein 4 is a central molecule for lysosomal retrograde trafficking. Bioessays 2023; 45:e2300052. [PMID: 37559169 DOI: 10.1002/bies.202300052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/31/2023] [Accepted: 08/02/2023] [Indexed: 08/11/2023]
Abstract
Lysosomal positioning is an important factor in regulating cellular responses, including autophagy. Because proteins encoded by disease-responsible genes are involved in lysosomal trafficking, proper intracellular lysosomal trafficking is thought to be essential for cellular homeostasis. In the past few years, the mechanisms of lysosomal trafficking have been elucidated with a focus on adapter proteins linking motor proteins to lysosomes. Here, we outline recent findings on the mechanisms of lysosomal trafficking by focusing on adapter protein c-Jun NH2 -terminal kinase-interacting protein (JIP) 4, which plays a central role in this process, and other JIP4 functions and JIP family proteins. Additionally, we discuss neuronal diseases associated with aberrance in the JIP family protein. Accumulating evidence suggests that chemical manipulation of lysosomal positioning may be a therapeutic approach for these neuronal diseases.
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Affiliation(s)
- Yukiko Sasazawa
- Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, Japan
- Department of Neurology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Nobutaka Hattori
- Department of Neurology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
| | - Shinji Saiki
- Department of Neurology, Juntendo University Faculty of Medicine, Bunkyo-ku, Tokyo, Japan
- Department of Neurology, Institute of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
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8
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Esteller D, Morrow J, Alonso-Pérez J, Reyes D, Carbayo A, Bisogni G, Cateruccia M, Monforte M, Tasca G, Alangary A, Marini-Bettolo C, Sabatelli M, Laura M, Ramdharry G, Bolaño-Díaz C, Turon-Sans J, Töpf A, Guglieri M, Rossor AM, Olive M, Bertini E, Straub V, Reilly MM, Rojas-García R, Díaz-Manera J. Muscle magnetic resonance imaging of a large cohort of distal hereditary motor neuropathies reveals characteristic features useful for diagnosis. Neuromuscul Disord 2023; 33:744-753. [PMID: 37704504 DOI: 10.1016/j.nmd.2023.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 08/16/2023] [Accepted: 08/22/2023] [Indexed: 09/15/2023]
Abstract
Distal motor neuropathies (dHMN) are an heterogenous group of diseases characterized by progressive muscle weakness affecting predominantly the distal muscles of the lower and upper limbs. Our aim was to study the imaging features and pattern of muscle involvement in muscle magnetic resonance imaging (MRI) in dHMN patients of suspected genetic origin (dHMN). We conducted a retrospective study collecting clinical, genetic and muscle imaging data. Muscle MRI included T1-weighted and T2 weighted Short Tau Inversion Recovery images (STIR-T2w) sequences. Muscle replacement by fat was quantified using the Mercuri score. Identification of selective patterns of involvement was performed using hierarchical clustering. Eighty-four patients with diagnosis of dHMN were studied. Fat replacement was predominant in the distal lower leg muscles (82/84 cases), although also affected thigh and pelvis muscles. Asymmetric involvement was present in 29% of patients. The superficial posterior compartment of the leg, including the soleus and gastrocnemius muscles, was the most affected area (77/84). We observed a reticular pattern of fatty replacement progressing towards what is commonly known as "muscle islands" in 79.8%. Hyperintensities in STIR-T2w were observed in 78.6% patients mainly in distal leg muscles. Besides features common to all individuals, we identified and describe a pattern of muscle fat replacement characteristic of BICD2, HSPB1 and DYNC1H1 patients. We conclude that muscle MRI of patients with suspected dHMN reveals common features helpful in diagnosis process.
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Affiliation(s)
- Diana Esteller
- Neurology Department Hospital Clinic de Barcelona Universitat de Barcelona, Barcelona Spain
| | - Jasper Morrow
- Centre for Neuromuscular Diseases, Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology and the National Hospital of Neurology and Neurosurgery, London, United Kingdom
| | - Jorge Alonso-Pérez
- Neuromuscular Disease Unit Neurology Department Hospital Universitario Nuestra Señora de Candelaria Fundación Canaria Instituto de Investigación Sanitaria de Canarias (FIISC) Tenerife Spain
| | - David Reyes
- Neuromuscular Disorders Unit, Motor Neuron Diseases Clinic, Neurology Department Hospital de la Santa Creu i Sant Pau Universitat Autònoma de Barcelona IIB Sant Pau Barcelona Spain
| | - Alvaro Carbayo
- Neuromuscular Disorders Unit, Motor Neuron Diseases Clinic, Neurology Department Hospital de la Santa Creu i Sant Pau Universitat Autònoma de Barcelona IIB Sant Pau Barcelona Spain
| | | | - Michela Cateruccia
- Unit of Muscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Childrens' Research Hospital, Rome, Italy
| | - Mauro Monforte
- UOC di Neurologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Giorgio Tasca
- John Walton Muscular Dystrophy Research Centre Newcastle University Translational and Clinical Research Institute and Newcastle Hospitals NHS Foundation Trust Newcastle upon Tyne United Kingdom
| | - Aljwhara Alangary
- Centre for Neuromuscular Diseases, Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology and the National Hospital of Neurology and Neurosurgery, London, United Kingdom
| | - Chiara Marini-Bettolo
- John Walton Muscular Dystrophy Research Centre Newcastle University Translational and Clinical Research Institute and Newcastle Hospitals NHS Foundation Trust Newcastle upon Tyne United Kingdom
| | - Mario Sabatelli
- UOC di Neurologia, Fondazione Policlinico Universitario A. Gemelli IRCCS, Rome, Italy
| | - Matilde Laura
- Centre for Neuromuscular Diseases, Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology and the National Hospital of Neurology and Neurosurgery, London, United Kingdom
| | - Gita Ramdharry
- Centre for Neuromuscular Diseases, Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology and the National Hospital of Neurology and Neurosurgery, London, United Kingdom
| | - Carla Bolaño-Díaz
- John Walton Muscular Dystrophy Research Centre Newcastle University Translational and Clinical Research Institute and Newcastle Hospitals NHS Foundation Trust Newcastle upon Tyne United Kingdom
| | - Janina Turon-Sans
- Neuromuscular Disorders Unit, Motor Neuron Diseases Clinic, Neurology Department Hospital de la Santa Creu i Sant Pau Universitat Autònoma de Barcelona IIB Sant Pau Barcelona Spain
| | - Ana Töpf
- John Walton Muscular Dystrophy Research Centre Newcastle University Translational and Clinical Research Institute and Newcastle Hospitals NHS Foundation Trust Newcastle upon Tyne United Kingdom
| | - Michella Guglieri
- John Walton Muscular Dystrophy Research Centre Newcastle University Translational and Clinical Research Institute and Newcastle Hospitals NHS Foundation Trust Newcastle upon Tyne United Kingdom
| | - Alexander M Rossor
- Centre for Neuromuscular Diseases, Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology and the National Hospital of Neurology and Neurosurgery, London, United Kingdom
| | - Montse Olive
- Neuromuscular Disorders Unit, Motor Neuron Diseases Clinic, Neurology Department Hospital de la Santa Creu i Sant Pau Universitat Autònoma de Barcelona IIB Sant Pau Barcelona Spain
| | - Enrico Bertini
- Unit of Muscular and Neurodegenerative Diseases, IRCCS Bambino Gesù Childrens' Research Hospital, Rome, Italy
| | - Volker Straub
- John Walton Muscular Dystrophy Research Centre Newcastle University Translational and Clinical Research Institute and Newcastle Hospitals NHS Foundation Trust Newcastle upon Tyne United Kingdom
| | - Mary M Reilly
- Centre for Neuromuscular Diseases, Department of Neuromuscular Disease, UCL Queen Square Institute of Neurology and the National Hospital of Neurology and Neurosurgery, London, United Kingdom
| | - Ricard Rojas-García
- Neuromuscular Disorders Unit, Motor Neuron Diseases Clinic, Neurology Department Hospital de la Santa Creu i Sant Pau Universitat Autònoma de Barcelona IIB Sant Pau Barcelona Spain; Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER) Barcelona Spain.
| | - Jordi Díaz-Manera
- John Walton Muscular Dystrophy Research Centre Newcastle University Translational and Clinical Research Institute and Newcastle Hospitals NHS Foundation Trust Newcastle upon Tyne United Kingdom; Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER) Barcelona Spain; Institut de Recerca de l'Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
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9
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Gibson JM, Zhao X, Ali MY, Solmaz SR, Wang C. A Structural Model for the Core Nup358-BicD2 Interface. Biomolecules 2023; 13:1445. [PMID: 37892127 PMCID: PMC10604712 DOI: 10.3390/biom13101445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/08/2023] [Accepted: 09/19/2023] [Indexed: 10/29/2023] Open
Abstract
Dynein motors facilitate the majority of minus-end-directed transport events on microtubules. The dynein adaptor Bicaudal D2 (BicD2) recruits the dynein machinery to several cellular cargo for transport, including Nup358, which facilitates a nuclear positioning pathway that is essential for the differentiation of distinct brain progenitor cells. Previously, we showed that Nup358 forms a "cargo recognition α-helix" upon binding to BicD2; however, the specifics of the BicD2-Nup358 interface are still not well understood. Here, we used AlphaFold2, complemented by two additional docking programs (HADDOCK and ClusPro) as well as mutagenesis, to show that the Nup358 cargo-recognition α-helix binds to BicD2 between residues 747 and 774 in an anti-parallel manner, forming a helical bundle. We identified two intermolecular salt bridges that are important to stabilize the interface. In addition, we uncovered a secondary interface mediated by an intrinsically disordered region of Nup358 that is directly N-terminal to the cargo-recognition α-helix and binds to BicD2 between residues 774 and 800. This is the same BicD2 domain that binds to the competing cargo adapter Rab6, which is important for the transport of Golgi-derived and secretory vesicles. Our results establish a structural basis for cargo recognition and selection by the dynein adapter BicD2, which facilitates transport pathways that are important for brain development.
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Affiliation(s)
- James M. Gibson
- Department of Biological Sciences, Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA
| | - Xiaoxin Zhao
- Department of Chemistry, Binghamton University, P.O. Box 6000, Binghamton, NY 13902, USA;
| | - M. Yusuf Ali
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA;
| | - Sozanne R. Solmaz
- Department of Chemistry, Binghamton University, P.O. Box 6000, Binghamton, NY 13902, USA;
| | - Chunyu Wang
- Department of Biological Sciences, Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, 110 8th Street, Troy, NY 12180, USA
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10
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Borg R, Herrera P, Purkiss A, Cacciottolo R, Cauchi RJ. Reduced levels of ALS gene DCTN1 induce motor defects in Drosophila. Front Neurosci 2023; 17:1164251. [PMID: 37360176 PMCID: PMC10289029 DOI: 10.3389/fnins.2023.1164251] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Accepted: 05/16/2023] [Indexed: 06/28/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a rapidly progressive neuromuscular disease that has a strong genetic component. Deleterious variants in the DCTN1 gene are known to be a cause of ALS in diverse populations. DCTN1 encodes the p150 subunit of the molecular motor dynactin which is a key player in the bidirectional transport of cargos within cells. Whether DCTN1 mutations lead to the disease through either a gain or loss of function mechanism remains unresolved. Moreover, the contribution of non-neuronal cell types, especially muscle tissue, to ALS phenotypes in DCTN1 carriers is unknown. Here we show that gene silencing of Dctn1, the Drosophila main orthologue of DCTN1, either in neurons or muscles is sufficient to cause climbing and flight defects in adult flies. We also identify Dred, a protein with high homology to Drosophila Dctn1 and human DCTN1, that on loss of function also leads to motoric impairments. A global reduction of Dctn1 induced a significant reduction in the mobility of larvae and neuromuscular junction (NMJ) deficits prior to death at the pupal stage. RNA-seq and transcriptome profiling revealed splicing alterations in genes required for synapse organisation and function, which may explain the observed motor dysfunction and synaptic defects downstream of Dctn1 ablation. Our findings support the possibility that loss of DCTN1 function can lead to ALS and underscore an important requirement for DCTN1 in muscle in addition to neurons.
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Affiliation(s)
- Rebecca Borg
- Centre for Molecular Medicine and Biobanking, Biomedical Sciences Building, University of Malta, Msida, Malta
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Paul Herrera
- Centre for Molecular Medicine and Biobanking, Biomedical Sciences Building, University of Malta, Msida, Malta
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Angie Purkiss
- Centre for Molecular Medicine and Biobanking, Biomedical Sciences Building, University of Malta, Msida, Malta
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Rebecca Cacciottolo
- Centre for Molecular Medicine and Biobanking, Biomedical Sciences Building, University of Malta, Msida, Malta
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
| | - Ruben J. Cauchi
- Centre for Molecular Medicine and Biobanking, Biomedical Sciences Building, University of Malta, Msida, Malta
- Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta, Msida, Malta
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11
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Unger A, Roos A, Gangfuß A, Hentschel A, Gläser D, Krause K, Doering K, Schara-Schmidt U, Hoffjan S, Vorgerd M, Güttsches AK. Microscopic and Biochemical Hallmarks of BICD2-Associated Muscle Pathology toward the Evaluation of Novel Variants. Int J Mol Sci 2023; 24:ijms24076808. [PMID: 37047781 PMCID: PMC10095373 DOI: 10.3390/ijms24076808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/02/2023] [Accepted: 04/03/2023] [Indexed: 04/08/2023] Open
Abstract
BICD2 variants have been linked to neurodegenerative disorders like spinal muscular atrophy with lower extremity predominance (SMALED2) or hereditary spastic paraplegia (HSP). Recently, mutations in BICD2 were implicated in myopathies. Here, we present one patient with a known and six patients with novel BICD2 missense variants, further characterizing the molecular landscape of this heterogenous neurological disorder. A total of seven patients were genotyped and phenotyped. Skeletal muscle biopsies were analyzed by histology, electron microscopy, and protein profiling to define pathological hallmarks and pathogenicity markers with consecutive validation using fluorescence microscopy. Clinical and MRI-features revealed a typical pattern of distal paresis of the lower extremities as characteristic features of a BICD2-associated disorder. Histological evaluation showed myopathic features of varying severity including fiber size variation, lipofibromatosis, and fiber splittings. Proteomic analysis with subsequent fluorescence analysis revealed an altered abundance and localization of thrombospondin-4 and biglycan. Our combined clinical, histopathological, and proteomic approaches provide new insights into the pathophysiology of BICD2-associated disorders, confirming a primary muscle cell vulnerability. In this context, biglycan and thrombospondin-4 have been identified, may serve as tissue pathogenicity markers, and might be linked to perturbed protein secretion based on an impaired vesicular transportation.
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Affiliation(s)
- Andreas Unger
- Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH), University Hospital Münster, 48149 Münster, Germany
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Andreas Roos
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr University Bochum, 44789 Bochum, Germany
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, 45122 Essen, Germany
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
| | - Andrea Gangfuß
- Children’s Hospital of Eastern Ontario Research Institute, Ottawa, ON K1H 8L1, Canada
| | - Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., 44139 Dortmund, Germany
| | - Dieter Gläser
- Genetikum, Center for Human Genetics, 89231 Neu-Ulm, Germany
| | - Karsten Krause
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr University Bochum, 44789 Bochum, Germany
| | - Kristina Doering
- Department of Human Genetics, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Ulrike Schara-Schmidt
- Department of Pediatric Neurology, Centre for Neuromuscular Disorders, Centre for Translational Neuro- and Behavioral Sciences, University Duisburg-Essen, 45122 Essen, Germany
| | - Sabine Hoffjan
- Department of Human Genetics, Ruhr-University Bochum, 44801 Bochum, Germany
| | - Matthias Vorgerd
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr University Bochum, 44789 Bochum, Germany
| | - Anne-Katrin Güttsches
- Department of Neurology, Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr University Bochum, 44789 Bochum, Germany
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12
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Yi J, Zhao X, Noell CR, Helmer P, Solmaz SR, Vallee RB. Role of Nesprin-2 and RanBP2 in BICD2-associated brain developmental disorders. PLoS Genet 2023; 19:e1010642. [PMID: 36930595 PMCID: PMC10022797 DOI: 10.1371/journal.pgen.1010642] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 01/28/2023] [Indexed: 03/18/2023] Open
Abstract
Bicaudal D2 (BICD2) is responsible for recruiting cytoplasmic dynein to diverse forms of subcellular cargo for their intracellular transport. Mutations in the human BICD2 gene have been found to cause an autosomal dominant form of spinal muscular atrophy (SMA-LED2), and brain developmental defects. Whether and how the latter mutations are related to roles we and others have identified for BICD2 in brain development remains little understood. BICD2 interacts with the nucleoporin RanBP2 to recruit dynein to the nuclear envelope (NE) of Radial Glial Progenitor cells (RGPs) to mediate their well-known but mysterious cell-cycle-regulated interkinetic nuclear migration (INM) behavior, and their subsequent differentiation to form cortical neurons. We more recently found that BICD2 also mediates NE dynein recruitment in migrating post-mitotic neurons, though via a different interactor, Nesprin-2. Here, we report that Nesprin-2 and RanBP2 compete for BICD2-binding in vitro. To test the physiological implications of this behavior, we examined the effects of known BICD2 mutations using in vitro biochemical and in vivo electroporation-mediated brain developmental assays. We find a clear relationship between the ability of BICD2 to bind RanBP2 vs. Nesprin-2 in controlling of nuclear migration and neuronal migration behavior. We propose that mutually exclusive RanBP2-BICD2 vs. Nesprin-2-BICD2 interactions at the NE play successive, critical roles in INM behavior in RGPs and in post-mitotic neuronal migration and errors in these processes contribute to specific human brain malformations.
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Affiliation(s)
- Julie Yi
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, United States of America
| | - Xiaoxin Zhao
- Department of Chemistry, Binghamton University, Binghamton, New York, New York, United States of America
| | - Crystal R. Noell
- Department of Chemistry, Binghamton University, Binghamton, New York, New York, United States of America
| | - Paige Helmer
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, United States of America
| | - Sozanne R. Solmaz
- Department of Chemistry, Binghamton University, Binghamton, New York, New York, United States of America
| | - Richard B. Vallee
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York, United States of America
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13
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Zambon AA, Pini V, Bosco L, Falzone YM, Munot P, Muntoni F, Previtali SC. Early onset hereditary neuronopathies: an update on non-5q motor neuron diseases. Brain 2022; 146:806-822. [PMID: 36445400 PMCID: PMC9976982 DOI: 10.1093/brain/awac452] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 10/21/2022] [Accepted: 11/12/2022] [Indexed: 11/30/2022] Open
Abstract
Hereditary motor neuropathies (HMN) were first defined as a group of neuromuscular disorders characterized by lower motor neuron dysfunction, slowly progressive length-dependent distal muscle weakness and atrophy, without sensory involvement. Their cumulative estimated prevalence is 2.14/100 000 and, to date, around 30 causative genes have been identified with autosomal dominant, recessive,and X-linked inheritance. Despite the advances of next generation sequencing, more than 60% of patients with HMN remain genetically uncharacterized. Of note, we are increasingly aware of the broad range of phenotypes caused by pathogenic variants in the same gene and of the considerable clinical and genetic overlap between HMN and other conditions, such as Charcot-Marie-Tooth type 2 (axonal), spinal muscular atrophy with lower extremities predominance, neurogenic arthrogryposis multiplex congenita and juvenile amyotrophic lateral sclerosis. Considering that most HMN present during childhood, in this review we primarily aim to summarize key clinical features of paediatric forms, including recent data on novel phenotypes, to help guide differential diagnosis and genetic testing. Second, we describe newly identified causative genes and molecular mechanisms, and discuss how the discovery of these is changing the paradigm through which we approach this group of conditions.
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Affiliation(s)
- Alberto A Zambon
- Correspondence to: Alberto A. Zambon Neuromuscular Repair Unit InSpe and Division of Neuroscience IRCCS Ospedale San Raffaele, Milan, Italy E-mail:
| | - Veronica Pini
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital, London, WC1N 1EH, UK
| | - Luca Bosco
- Neuromuscular Repair Unit, Institute of Experimental Neurology (InSpe), Division of Neuroscience, IRCCS Ospedale San Raffaele, 20132 Milan, Italy
| | - Yuri M Falzone
- Neuromuscular Repair Unit, Institute of Experimental Neurology (InSpe), Division of Neuroscience, IRCCS Ospedale San Raffaele, 20132 Milan, Italy
| | - Pinki Munot
- NIHR Great Ormond Street Hospital Biomedical Research Centre, London, WC1N 1EH, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital, London, WC1N 1EH, UK,NIHR Great Ormond Street Hospital Biomedical Research Centre, London, WC1N 1EH, UK
| | - Stefano C Previtali
- Neuromuscular Repair Unit, Institute of Experimental Neurology (InSpe), Division of Neuroscience, IRCCS Ospedale San Raffaele, 20132 Milan, Italy
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14
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Chin HL, Huynh S, Ashkani J, Castaldo M, Dixon K, Selby K, Shen Y, Wright M, Boerkoel CF, Hendson G, Jones SJM. An infant with congenital respiratory insufficiency and diaphragmatic paralysis: A novel BICD2 phenotype? Am J Med Genet A 2021; 188:926-930. [PMID: 34825470 DOI: 10.1002/ajmg.a.62578] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 09/09/2021] [Accepted: 11/06/2021] [Indexed: 11/06/2022]
Abstract
Monoallelic pathogenic variants in BICD2 are associated with autosomal dominant Spinal Muscular Atrophy Lower Extremity Predominant 2A and 2B (SMALED2A, SMALED2B). As part of the cellular vesicular transport, complex BICD2 facilitates the flow of constitutive secretory cargoes from the trans-Golgi network, and its dysfunction results in motor neuron loss. The reported phenotypes among patients with SMALED2A and SMALED2B range from a congenital onset disorder of respiratory insufficiency, arthrogryposis, and proximal or distal limb weakness to an adult-onset disorder of limb weakness and contractures. We report an infant with congenital respiratory insufficiency requiring mechanical ventilation, congenital diaphragmatic paralysis, decreased lung volume, and single finger camptodactyly. The infant displayed appropriate antigravity limb movements but had radiological, electrophysiological, and histopathological evidence of myopathy. Exome sequencing and long-read whole-genome sequencing detected a novel de novo BICD2 variant (NM_001003800.1:c.[1543G>A];[=]). This is predicted to encode p.(Glu515Lys); p.Glu515 is located in the coiled-coil 2 mutation hotspot. We hypothesize that this novel phenotype of diaphragmatic paralysis without clear appendicular muscle weakness and contractures of large joints is a presentation of BICD2-related disease.
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Affiliation(s)
- Hui-Lin Chin
- Department of Medical Genetics and Provincial Medical Genetics Program, University of British Columbia and Women's Hospital of British Columbia, Vancouver, British Columbia, Canada.,Khoo Teck Puat-National University Children's Medical Institute, National University Hospital, Singapore, Singapore
| | - Stephanie Huynh
- Department of Medical Genetics and Provincial Medical Genetics Program, University of British Columbia and Women's Hospital of British Columbia, Vancouver, British Columbia, Canada
| | - Jahanshah Ashkani
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, British Columbia, Canada
| | - Michael Castaldo
- Division of Neonatology, Department of Pediatrics, University of British Columbia and Women's Hospital of British Columbia, Vancouver, British Columbia, Canada
| | - Katherine Dixon
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, British Columbia, Canada
| | - Kathryn Selby
- Division of Neurology, Department of Pediatrics, University of British Columbia and Children's Hospital of British Columbia, Vancouver, British Columbia, Canada
| | - Yaoqing Shen
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, British Columbia, Canada
| | - Marie Wright
- Division of Respirology, Department of Pediatrics, University of British Columbia and Children's Hospital of British Columbia, Vancouver, British Columbia, Canada
| | - Cornelius F Boerkoel
- Department of Medical Genetics and Provincial Medical Genetics Program, University of British Columbia and Women's Hospital of British Columbia, Vancouver, British Columbia, Canada
| | - Glenda Hendson
- Department of Pathology, BC Children's Hospital, BC Women's Hospital and Health Centre, Vancouver, British Columbia, Canada
| | - Steven J M Jones
- Department of Medical Genetics and Provincial Medical Genetics Program, University of British Columbia and Women's Hospital of British Columbia, Vancouver, British Columbia, Canada.,Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, British Columbia, Canada
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15
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Neurogenic arthrogryposis and the power of phenotyping. Neuromuscul Disord 2021; 31:1062-1069. [PMID: 34736627 DOI: 10.1016/j.nmd.2021.07.399] [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: 07/12/2021] [Revised: 07/22/2021] [Accepted: 07/27/2021] [Indexed: 11/23/2022]
Abstract
In this article we review the commonest cause of neurogenic arthrogryposis, termed Spinal Muscular Atrophy Lower Extremity Dominant (SMALED), due to variants in DYNC1H1 and BICD2. We discuss the characteristic clinical and radiological phenotype of this disorder and how this has facilitated the identification of the genetic cause of SMALED2. We also review the similarities and differences between the human SMALED phenotype and mouse models and how this has informed our understanding of the potential mechanisms governing motor neuron loss in these disorders.
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16
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Villarroel-Campos D, Schiavo G, Sleigh JN. Dissection, in vivo imaging and analysis of the mouse epitrochleoanconeus muscle. J Anat 2021; 241:1108-1119. [PMID: 34121181 PMCID: PMC9558155 DOI: 10.1111/joa.13478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 05/07/2021] [Accepted: 05/18/2021] [Indexed: 12/25/2022] Open
Abstract
Analysis of rodent muscles affords an opportunity to glean key insights into neuromuscular development and the detrimental impact of disease‐causing genetic mutations. Muscles of the distal leg, for instance the gastrocnemius and tibialis anterior, are commonly used in such studies with mice and rats. However, thin and flat muscles, which can be dissected, processed and imaged without major disruption to muscle fibres and nerve‐muscle contacts, are more suitable for accurate and detailed analyses of the peripheral motor nervous system. One such wholemount muscle is the predominantly fast twitch epitrochleoanconeus (ETA), which is located in the upper forelimb, innervated by the radial nerve, and contains relatively large and uniformly flat neuromuscular junctions (NMJs). To facilitate incorporation of the ETA into the experimental toolkit of the neuromuscular disease field, here, we describe a simple method for its rapid isolation (<5 min), supported by high‐resolution videos and step‐by‐step images. Furthermore, we outline how the ETA can be imaged in live, anaesthetised mice, to enable examination of dynamic cellular processes occurring at the NMJ and within intramuscular axons, including transport of organelles, such as mitochondria and signalling endosomes. Finally, we present reference data on wild‐type ETA fibre‐type composition in young adult, male C57BL6/J mice. Comparative neuroanatomical studies of different muscles in rodent models of disease can generate critical insights into pathogenesis and pathology; dissection of the wholemount ETA provides the possibility to diversify the repertoire of muscles analysed for this endeavour.
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Affiliation(s)
- David Villarroel-Campos
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK
| | - James N Sleigh
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK
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17
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Guarnieri AR, Anthony SR, Gozdiff A, Green LC, Fleifil SM, Slone S, Nieman ML, Alam P, Benoit JB, Owens AP, Kanisicak O, Tranter M. Adipocyte-specific deletion of HuR induces spontaneous cardiac hypertrophy and fibrosis. Am J Physiol Heart Circ Physiol 2021; 321:H228-H241. [PMID: 34018851 DOI: 10.1152/ajpheart.00957.2020] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Adipose tissue homeostasis plays a central role in cardiovascular physiology, and the presence of thermogenically active brown adipose tissue (BAT) has recently been associated with cardiometabolic health. We have previously shown that adipose tissue-specific deletion of HuR (Adipo-HuR-/-) reduces BAT-mediated adaptive thermogenesis, and the goal of this work was to identify the cardiovascular impacts of Adipo-HuR-/-. We found that Adipo-HuR-/- mice exhibit a hypercontractile phenotype that is accompanied by increased left ventricle wall thickness and hypertrophic gene expression. Furthermore, hearts from Adipo-HuR-/- mice display increased fibrosis via picrosirius red staining and periostin expression. To identify underlying mechanisms, we applied both RNA-seq and weighted gene coexpression network analysis (WGCNA) across both cardiac and adipose tissue to define HuR-dependent changes in gene expression as well as significant relationships between adipose tissue gene expression and cardiac fibrosis. RNA-seq results demonstrated a significant increase in proinflammatory gene expression in both cardiac and subcutaneous white adipose tissue (scWAT) from Adipo-HuR-/- mice that is accompanied by an increase in serum levels of both TNF-α and IL-6. In addition to inflammation-related genes, WGCNA identified a significant enrichment in extracellular vesicle-mediated transport and exosome-associated genes in scWAT, whose expression most significantly associated with the degree of cardiac fibrosis observed in Adipo-HuR-/- mice, implicating these processes as a likely adipose-to-cardiac paracrine mechanism. These results are significant in that they demonstrate the spontaneous onset of cardiovascular pathology in an adipose tissue-specific gene deletion model and contribute to our understanding of how disruptions in adipose tissue homeostasis may mediate cardiovascular disease.NEW & NOTEWORTHY The presence of functional brown adipose tissue in humans is known to be associated with cardiovascular health. Here, we show that adipocyte-specific deletion of the RNA binding protein HuR, which we have previously shown to reduce BAT-mediated thermogenesis, is sufficient to mediate a spontaneous development of cardiac hypertrophy and fibrosis. These results may have implications on the mechanisms by which BAT function and adipose tissue homeostasis directly mediate cardiovascular disease.
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Affiliation(s)
- Adrienne R Guarnieri
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Sarah R Anthony
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Anamarie Gozdiff
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Lisa C Green
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Salma M Fleifil
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Sam Slone
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Michelle L Nieman
- Department of Pharmacology & Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Perwez Alam
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Joshua B Benoit
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio
| | - A Phillip Owens
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Onur Kanisicak
- Department of Pathology and Laboratory Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Michael Tranter
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio
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18
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Tumurkhuu M, Batbuyan U, Yuzawa S, Munkhsaikhan Y, Batmunkh G, Nishimura W. A novel BICD2 mutation of a patient with Spinal Muscular Atrophy Lower Extremity Predominant 2. Intractable Rare Dis Res 2021; 10:102-108. [PMID: 33996355 PMCID: PMC8122317 DOI: 10.5582/irdr.2021.01004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The bicaudal D homolog 2 (BICD2) gene encodes a protein required for the stable complex of dynein and dynactin, which functions as a motor protein working along the microtubule cytoskeleton. Both inherited and de novo variants of BICD2 are reported with autosomal dominant spinal muscular atrophy with lower extremity predominance (SMALED2). Here, we report a male patient with a novel mutation in the BICD2 gene caused by a heterozygous substitution of arginine with cysteine at residue 162 (Arg162Cys); inherited from his asymptomatic mother. The patient showed typical clinical symptoms of SMALED2, which was genetically confirmed by sequencing. The Arg162Cys mutant clusters with four previously reported variants (c.361C>G, p.Leu121Val; c.581A>G, p.Gln194Arg; c.320C>T, p.Ser107Leu; c.565A>T, p.Ile189Phe) in a region that binds to the dynein-dynactin complex (DDC). The BICD2 domain structures were predicted and the Arg162Cys mutation was localized in the N-terminus coiled-coil segment 1 (CC1) domain. Protein modeling of BICD2's CC1 domain predicted that the Arg162Cys missense variant disrupted interactions with dynein cytoplasmic 1 heavy chain 1 within the DDC. The mutant did this by either changing the electrostatic surface potential or making a broader hydrophobic unit with the neighboring residues. This hereditary case supports the complex and broad genotype-phenotype correlation of BICD2 mutations, which could be explained by incomplete penetrance or variable expressivity in the next generation.
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Affiliation(s)
- Munkhtuya Tumurkhuu
- Department of Molecular Biology, International University of Health and Welfare, School of Medicine, Narita, Chiba, Japan
- Department of Genetics and Molecular Biology, School of Bio-Medicine, Mongolian National University of Medical Sciences, Mongolia
- Address correspondence to:Munkhtuya Tumurkhuu, Department of Molecular Biology, School of Medicine, International University of Health and Welfare, 4-3 Kozunomori, Narita, Chiba 286-8686, Japan. E-mail: , munkhtuya.tumurkhuu@ gmail.com
| | - Uranchimeg Batbuyan
- Department of Genetics and Molecular Biology, School of Bio-Medicine, Mongolian National University of Medical Sciences, Mongolia
| | - Satoru Yuzawa
- Department of Biochemistry, International University of Health and Welfare, School of Medicine, Narita, Chiba, Japan
| | - Yanjinlkham Munkhsaikhan
- Department of Genetics and Molecular Biology, School of Bio-Medicine, Mongolian National University of Medical Sciences, Mongolia
| | - Ganbayar Batmunkh
- Laboratory of Medical Genetics, National Center of Maternal and Child Health, Mongolia
| | - Wataru Nishimura
- Department of Molecular Biology, International University of Health and Welfare, School of Medicine, Narita, Chiba, Japan
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19
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Marchionni E, Agolini E, Mastromoro G, Guadagnolo D, Coppola G, Roggini M, Riminucci M, Novelli A, Giancotti A, Corsi A, Pizzuti A. Fetal early motor neuron disruption and prenatal molecular diagnosis in a severe BICD2-opathy. Am J Med Genet A 2021; 185:1509-1514. [PMID: 33547725 DOI: 10.1002/ajmg.a.62111] [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: 08/09/2020] [Revised: 01/09/2021] [Accepted: 01/22/2021] [Indexed: 12/15/2022]
Abstract
BICD2 (BICD Cargo Adaptor 2, MIM*609797) mutations are associated with severe prenatal-onset forms of spinal muscular atrophy, lower extremity-predominant 2B (SMALED2B MIM 618291) or milder forms with childhood-onset (SMALED2A MIM 615290). Etiopathogenesis is not fully clarified and a wide spectrum of phenotypic presentations is reported, ranging from extreme prenatal forms with adverse outcome, to slow progressive late-onset forms. We report a fetus at 22 gestational weeks with evidence of Arthrogryposis Multiplex Congenita on ultrasound, presenting with fixed extended lower limbs and flexed upper limbs, bilateral clubfoot and absent fetal movements. A trio-based prenatal Exome Sequencing was performed, disclosing a de novo heterozygous pathogenic in frame deletion (NM_015250.3: c.1636_1638delAAT; p.Asn546del) in BICD2. After pregnancy termination, quantitative analysis on NeuN immunostained spinal cord sections of the ventral horns, revealed that neuronal density was markedly reduced compared to the one of an age-matched normal fetus and an age-matched type-I Spinal Muscular Atrophy sample, used as a comparative model. The present case, the first prenatally diagnosed and neuropathologically characterized, showed an early motor neuron loss in SMALED2B, providing further insight into the pathological basis of BICD2-opathies.
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Affiliation(s)
- Enrica Marchionni
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Emanuele Agolini
- Laboratory of Medical Genetics, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Gioia Mastromoro
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Daniele Guadagnolo
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy
| | - Giulia Coppola
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Mario Roggini
- Department of Pediatrics and Child Neuropsychiatry, Sapienza University of Rome, Rome, Italy
| | - Mara Riminucci
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Antonella Giancotti
- Department of Maternal and Child Health and Urologic Science, Sapienza University of Rome, Rome, Italy
| | - Alessandro Corsi
- Department of Molecular Medicine, Sapienza University of Rome, Rome, Italy
| | - Antonio Pizzuti
- Department of Experimental Medicine, Sapienza University of Rome, Rome, Italy.,Clinical Genomics Unit, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo (FG), Italy
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20
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Abstract
The muscle spindle is an important sense organ for motor control and proprioception. Specialized intrafusal fibers are innervated by both stretch sensitive afferents and γ motor neurons that control the length of the spindle and tune the sensitivity of the muscle spindle afferents to both dynamic movement and static length. γ motor neurons share many similarities with other skeletal motor neurons, making it challenging to identify and specifically record or stimulate them. This short review will discuss recent advances in genetic and molecular biology techniques, electrophysiological recording, optical imaging, computer modelling, and stem cell culture techniques that have the potential to help answer important questions about fusimotor function in motor control and disease.
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21
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Gene expression in urinary incontinence and pelvic organ prolapse: a review of literature. Curr Opin Obstet Gynecol 2020; 32:441-448. [DOI: 10.1097/gco.0000000000000661] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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22
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Zhang X, Wang X, Xue Z, Zhan G, Ito Y, Guo Z. Prevention properties on cerebral ischemia reperfusion of medicine food homologous Dioscorea yam-derived diosgenin based on mediation of potential targets. Food Chem 2020; 345:128672. [PMID: 33352403 DOI: 10.1016/j.foodchem.2020.128672] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 10/27/2020] [Accepted: 11/15/2020] [Indexed: 10/23/2022]
Abstract
I/R (cerebral ischemia reperfusion injury) is the secondary complication of ischemic stroke patients that are immediately treated with drug thrombolysis or vascular recanalization in clinic. Diosgenin (DIO) purified from medicine food homologous (MFH) Dioscorea yam source is served as a fatal starting material to synthesize multifarious steroidal anti-inflammatory drugs in medicinal field, and has previously been demonstrated the potential prevention of I/R. However, the detailed mechanisms of neuroprotective effects against I/R remain elusively understood. Here, a global proteomic dynamics of rat right hemisphere brains was executed to investigate the protein expression patterns with a quantitative LC-MSn. In total, 5043 proteins were identified and 418 ones were determined to be significantly dysregulated DEPs (differentially expressed proteins) in comparison of Sham verse I/R and I/R verse DIO after onset stage of I/R, among which 5 DEPs namely BICD2, HNRNPK, CEP41, PPM1K, and ARL2BP, whose biological functions were mainly clustered into the mediation of nervous system, were selected for further validation in vitro and in vivo, and the change tendency expectedly supported the proteomic findings. Additionally, the AUC value of the combined ROC of these 5 DEPs was 0.988 with P < 0.0001, higher than every single one. Collectively, these scientific findings attributed to a typical investigation of dietary Dioscorea-enriched diosgenin in MFH research, suggesting that diosgenin or its derivatives were potential to be developed into food supplements or healthy food products to reveal healthy benefits in natural prevention and reduction risk of I/R. This work also promoted reasonable consumption of Dioscorea yams and contributed to the function of diosgenin-derived products and their applications in food industry.
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Affiliation(s)
- Xinxin Zhang
- College of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China; Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, Qinghai, China
| | - Xingbin Wang
- College of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China
| | - Zhaowei Xue
- College of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China
| | - Guanqun Zhan
- College of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China
| | - Yoichiro Ito
- Laboratory of Bio-separation Technologies, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Zengjun Guo
- College of Pharmacy, Xi'an Jiaotong University, Xi'an 710061, China.
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23
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Reilly MM, Rossor AM. Humans: the ultimate animal models. J Neurol Neurosurg Psychiatry 2020; 91:1132-1136. [PMID: 32769113 PMCID: PMC7415072 DOI: 10.1136/jnnp-2020-323016] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 06/19/2020] [Indexed: 12/13/2022]
Affiliation(s)
- Mary M Reilly
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Alexander M Rossor
- MRC Centre for Neuromuscular Diseases, UCL Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
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24
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Pedersen AF, Meyer DN, Petriv AMV, Soto AL, Shields JN, Akemann C, Baker BB, Tsou WL, Zhang Y, Baker TR. Nanoplastics impact the zebrafish (Danio rerio) transcriptome: Associated developmental and neurobehavioral consequences. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 266:115090. [PMID: 32693326 PMCID: PMC7492438 DOI: 10.1016/j.envpol.2020.115090] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/05/2020] [Accepted: 06/22/2020] [Indexed: 05/20/2023]
Abstract
Microplastics (MPs) are a ubiquitous pollutant detected not only in marine and freshwater bodies, but also in tap and bottled water worldwide. While MPs have been extensively studied, the toxicity of their smaller counterpart, nanoplastics (NPs), is not well documented. Despite likely large-scale human and animal exposure to NPs, the associated health risks remain unclear, especially during early developmental stages. To address this, we investigated the health impacts of exposures to both 50 and 200 nm polystyrene NPs in larval zebrafish. From 6 to 120 h post-fertilization (hpf), developing zebrafish were exposed to a range of fluorescent NPs (10-10,000 parts per billion). Dose-dependent increases in accumulation were identified in exposed larval fish, potentially coinciding with an altered behavioral response as evidenced through swimming hyperactivity. Notably, exposures did not impact mortality, hatching rate, or deformities; however, transcriptomic analysis suggests neurodegeneration and motor dysfunction at both high and low concentrations. Furthermore, results of this study suggest that NPs can accumulate in the tissues of larval zebrafish, alter their transcriptome, and affect behavior and physiology, potentially decreasing organismal fitness in contaminated ecosystems. The uniquely broad scale of this study during a critical window of development provides crucial multidimensional characterization of NP impacts on human and animal health.
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Affiliation(s)
- Adam F Pedersen
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Danielle N Meyer
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA; Department of Pharmacology - School of Medicine, Wayne State University, 540 E Canfield, Detroit, MI, 28201, USA
| | - Anna-Maria V Petriv
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Abraham L Soto
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Jeremiah N Shields
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Camille Akemann
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA; Department of Pharmacology - School of Medicine, Wayne State University, 540 E Canfield, Detroit, MI, 28201, USA
| | - Bridget B Baker
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA
| | - Wei-Ling Tsou
- Department of Pharmacology - School of Medicine, Wayne State University, 540 E Canfield, Detroit, MI, 28201, USA
| | - Yongli Zhang
- College of Engineering, Wayne State University, 5050 Anthony Wayne Dr, Detroit, MI, 28201, USA
| | - Tracie R Baker
- Institute of Environmental Health Sciences, Wayne State University, 6135 Woodward Ave, Detroit, MI, 48202, USA; Department of Pharmacology - School of Medicine, Wayne State University, 540 E Canfield, Detroit, MI, 28201, USA.
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25
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Mendoza-Ferreira N, Karakaya M, Cengiz N, Beijer D, Brigatti KW, Gonzaga-Jauregui C, Fuhrmann N, Hölker I, Thelen MP, Zetzsche S, Rombo R, Puffenberger EG, De Jonghe P, Deconinck T, Zuchner S, Strauss KA, Carson V, Schrank B, Wunderlich G, Baets J, Wirth B. De Novo and Inherited Variants in GBF1 are Associated with Axonal Neuropathy Caused by Golgi Fragmentation. Am J Hum Genet 2020; 107:763-777. [PMID: 32937143 PMCID: PMC7491385 DOI: 10.1016/j.ajhg.2020.08.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 08/19/2020] [Indexed: 01/18/2023] Open
Abstract
Distal hereditary motor neuropathies (HMNs) and axonal Charcot-Marie-Tooth neuropathy (CMT2) are clinically and genetically heterogeneous diseases characterized primarily by motor neuron degeneration and distal weakness. The genetic cause for about half of the individuals affected by HMN/CMT2 remains unknown. Here, we report the identification of pathogenic variants in GBF1 (Golgi brefeldin A-resistant guanine nucleotide exchange factor 1) in four unrelated families with individuals affected by sporadic or dominant HMN/CMT2. Genomic sequencing analyses in seven affected individuals uncovered four distinct heterozygous GBF1 variants, two of which occurred de novo. Other known HMN/CMT2-implicated genes were excluded. Affected individuals show HMN/CMT2 with slowly progressive distal muscle weakness and musculoskeletal deformities. Electrophysiological studies confirmed axonal damage with chronic neurogenic changes. Three individuals had additional distal sensory loss. GBF1 encodes a guanine-nucleotide exchange factor that facilitates the activation of members of the ARF (ADP-ribosylation factor) family of small GTPases. GBF1 is mainly involved in the formation of coatomer protein complex (COPI) vesicles, maintenance and function of the Golgi apparatus, and mitochondria migration and positioning. We demonstrate that GBF1 is present in mouse spinal cord and muscle tissues and is particularly abundant in neuropathologically relevant sites, such as the motor neuron and the growth cone. Consistent with the described role of GBF1 in Golgi function and maintenance, we observed marked increase in Golgi fragmentation in primary fibroblasts derived from all affected individuals in this study. Our results not only reinforce the existing link between Golgi fragmentation and neurodegeneration but also demonstrate that pathogenic variants in GBF1 are associated with HMN/CMT2.
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26
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Sleigh JN, Mech AM, Aktar T, Zhang Y, Schiavo G. Altered Sensory Neuron Development in CMT2D Mice Is Site-Specific and Linked to Increased GlyRS Levels. Front Cell Neurosci 2020; 14:232. [PMID: 32848623 PMCID: PMC7431706 DOI: 10.3389/fncel.2020.00232] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/01/2020] [Indexed: 12/18/2022] Open
Abstract
Dominant, missense mutations in the widely and constitutively expressed GARS1 gene cause peripheral neuropathy that usually begins in adolescence and principally impacts the upper limbs. Caused by a toxic gain-of-function in the encoded glycyl-tRNA synthetase (GlyRS) enzyme, the neuropathology appears to be independent of the canonical role of GlyRS in aminoacylation. Patients display progressive, life-long weakness and wasting of muscles in hands followed by feet, with frequently associated deficits in sensation. When dysfunction is observed in motor and sensory nerves, there is a diagnosis of Charcot-Marie-Tooth disease type 2D (CMT2D), or distal hereditary motor neuropathy type V if the symptoms are purely motor. The cause of this varied sensory involvement remains unresolved, as are the pathomechanisms underlying the selective neurodegeneration characteristic of the disease. We have previously identified in CMT2D mice that neuropathy-causing Gars mutations perturb sensory neuron fate and permit mutant GlyRS to aberrantly interact with neurotrophin receptors (Trks). Here, we extend this work by interrogating further the anatomy and function of the CMT2D sensory nervous system in mutant Gars mice, obtaining several key results: (1) sensory pathology is restricted to neurons innervating the hindlimbs; (2) perturbation of sensory development is not common to all mouse models of neuromuscular disease; (3) in vitro axonal transport of signaling endosomes is not impaired in afferent neurons of all CMT2D mouse models; and (4) Gars expression is selectively elevated in a subset of sensory neurons and linked to sensory developmental defects. These findings highlight the importance of comparative neurological assessment in mouse models of disease and shed light on key proposed neuropathogenic mechanisms in GARS1-linked neuropathy.
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Affiliation(s)
- James N. Sleigh
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
- UK Dementia Research Institute, University College London, London, United Kingdom
| | - Aleksandra M. Mech
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Tahmina Aktar
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Yuxin Zhang
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
- UK Dementia Research Institute, University College London, London, United Kingdom
- Discoveries Centre for Regenerative and Precision Medicine, University College London Campus, London, United Kingdom
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Tsai MH, Cheng HY, Nian FS, Liu C, Chao NH, Chiang KL, Chen SF, Tsai JW. Impairment in dynein-mediated nuclear translocation by BICD2 C-terminal truncation leads to neuronal migration defect and human brain malformation. Acta Neuropathol Commun 2020; 8:106. [PMID: 32665036 PMCID: PMC7362644 DOI: 10.1186/s40478-020-00971-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 06/19/2020] [Indexed: 02/06/2023] Open
Abstract
During brain development, the nucleus of migrating neurons follows the centrosome and translocates into the leading process. Defects in these migratory events, which affect neuronal migration, cause lissencephaly and other neurodevelopmental disorders. However, the mechanism of nuclear translocation remains elusive. Using whole exome sequencing (WES), we identified a novel nonsense BICD2 variant p.(Lys775Ter) (K775X) from a lissencephaly patient. Interestingly, most BICD2 missense variants have been associated with human spinal muscular atrophy (SMA) without obvious brain malformations. By in utero electroporation, we showed that BicD2 knockdown in mouse embryos inhibited neuronal migration. Surprisingly, we observed severe blockage of neuronal migration in cells overexpressing K775X but not in those expressing wild-type BicD2 or SMA-associated missense variants. The centrosome of the mutant was, on average, positioned farther away from the nucleus, indicating a failure in nuclear translocation without affecting the centrosome movement. Furthermore, BicD2 localized at the nuclear envelope (NE) through its interaction with NE protein Nesprin-2. K775X variant disrupted this interaction and further interrupted the NE recruitment of BicD2 and dynein. Remarkably, fusion of BicD2-K775X with NE-localizing domain KASH resumed neuronal migration. Our results underscore impaired nuclear translocation during neuronal migration as an important pathomechanism of lissencephaly.
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Sleigh JN, West SJ, Schiavo G. A video protocol for rapid dissection of mouse dorsal root ganglia from defined spinal levels. BMC Res Notes 2020; 13:302. [PMID: 32580748 PMCID: PMC7313212 DOI: 10.1186/s13104-020-05147-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 06/18/2020] [Indexed: 12/23/2022] Open
Abstract
OBJECTIVE Dorsal root ganglia (DRG) are heterogeneous assemblies of assorted sensory neuron cell bodies found in bilateral pairs at every level of the spinal column. Pseudounipolar afferent neurons convert external stimuli from the environment into electrical signals that are retrogradely transmitted to the spinal cord dorsal horn. To do this, they extend single axons from their DRG-resident somas that then bifurcate and project both centrally and distally. DRG can be dissected from mice at embryonic stages and any age post-natally, and have been extensively used to study sensory neuron development and function, response to injury, and pathological processes in acquired and genetic diseases. We have previously published a step-by-step dissection method for the rapid isolation of post-natal mouse DRG. Here, the objective is to extend the protocol by providing training videos that showcase the dissection in fine detail and permit the extraction of ganglia from defined spinal levels. RESULTS By following this method, the reader will be able to swiftly and accurately isolate specific lumbar, thoracic, and cervical DRG from mice. Dissected ganglia can then be used for RNA/protein analyses, subjected to immunohistochemical examination, and cultured as explants or dissociated primary neurons, for in-depth investigations of sensory neuron biology.
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Affiliation(s)
- James N. Sleigh
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG UK
- UK Dementia Research Institute, University College London, London, WC1E 6BT UK
| | - Steven J. West
- Sainsbury Wellcome Centre, University College London, London, W1T 4JG UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3BG UK
- UK Dementia Research Institute, University College London, London, WC1E 6BT UK
- Discoveries Centre for Regenerative and Precision Medicine, University College London Campus, London, WC1N 3BG UK
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Mech AM, Brown AL, Schiavo G, Sleigh JN. Morphological variability is greater at developing than mature mouse neuromuscular junctions. J Anat 2020; 237:603-617. [PMID: 32533580 PMCID: PMC7495279 DOI: 10.1111/joa.13228] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 05/04/2020] [Accepted: 05/07/2020] [Indexed: 12/18/2022] Open
Abstract
The neuromuscular junction (NMJ) is the highly specialised peripheral synapse formed between lower motor neuron terminals and muscle fibres. Post‐synaptic acetylcholine receptors (AChRs), which are found in high density in the muscle membrane, bind to acetylcholine released into the synaptic cleft of the NMJ, thereby enabling the conversion of motor action potentials to muscle contractions. NMJs have been studied for many years as a general model for synapse formation, development and function, and are known to be early sites of pathological changes in many neuromuscular diseases. However, information is limited on the diversity of NMJs in different muscles, how synaptic morphology changes during development, and the relevance of these parameters to neuropathology. Here, this crucial gap was addressed using a robust and standardised semi‐automated workflow called NMJ‐morph to quantify features of pre‐ and post‐synaptic NMJ architecture in an unbiased manner. Five wholemount muscles from wild‐type mice were dissected and compared at immature (post‐natal day, P7) and early adult (P31−32) timepoints. The inter‐muscular variability was greater in mature post‐synaptic AChR morphology than that of the pre‐synaptic motor neuron terminal. Moreover, the developing NMJ showed greater differences across muscles than the mature synapse, perhaps due to the observed distinctions in synaptic growth between muscles. Nevertheless, the amount of nerve to muscle contact was consistent, suggesting that pathological denervation can be reliably compared across different muscles in mouse models of neurodegeneration. Additionally, mature post‐synaptic endplate diameters correlated with fibre type, independently of muscle fibre diameter. Altogether, this work provides detailed information on healthy pre‐ and post‐synaptic NMJ morphology from five anatomically and functionally distinct mouse muscles, delivering useful reference data for future comparison with neuromuscular disease models.
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Affiliation(s)
- Aleksandra M Mech
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Anna-Leigh Brown
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Giampietro Schiavo
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK.,Discoveries Centre for Regenerative and Precision Medicine, University College London Campus, London, UK
| | - James N Sleigh
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, UK.,UK Dementia Research Institute, University College London, London, UK
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