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Bullivant J, Sen A, Page J, Graham RJ, Jungbluth H, Schara-Schmidt U, Lynch O, Bönnemann C, Hollander AD, Lennox A, Moat D, Saegert C, Amburgey K, Buj-Bello A, Dowling JJ, Marini-Bettolo C. The myotubular and centronuclear myopathy patient registry: a multifunctional tool for translational research. Neuromuscul Disord 2024; 35:42-52. [PMID: 38061948 DOI: 10.1016/j.nmd.2023.10.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 09/15/2023] [Accepted: 10/23/2023] [Indexed: 02/09/2024]
Abstract
The Myotubular and Centronuclear Myopathy Registry is an international research database containing key longitudinal data on a diverse and growing cohort of individuals affected by this group of rare and ultra-rare neuromuscular conditions. It can inform and support all areas of translational research including epidemiological and natural history studies, clinical trial feasibility planning, recruitment for clinical trials or other research studies, stand-alone clinical studies, standards of care development, and provision of real-world evidence data. For ten years, it has also served as a valuable communications tool and provided a link between the scientific and patient communities. With the anticipated advent of disease-modifying therapies for these conditions, the registry is a key resource for the generation of post-authorisation data for regulatory decision-making, real world evidence, and patient-reported outcome measures. In this paper we present some key data from the current 444 registered individuals with the following genotype split: MTM1 n=270, DNM2 n=42, BIN1 n=4, TTN n=4, RYR1 n=12, other n=4, unknown n=108. The data presented are consistent with the current literature and the common understanding of a strong genotype/phenotype correlations in CNM, most notably the data supports the current knowledge that XLMTM is typically the most severe form of CNM. Additionally, we outline the ways in which the registry supports research, and, more generally, the importance of continuous investment and development to maintain the relevance of registries for all stakeholders. Further information on the registry and contact details are available on the registry website at www.mtmcnmregistry.org.
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Affiliation(s)
- Joanne Bullivant
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Anando Sen
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Jess Page
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Robert J Graham
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, United States
| | - Heinz Jungbluth
- Department of Paediatric Neurology - Neuromuscular Service, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, United Kingdom; Randall Centre for Cell and Molecular Biophysics, Muscle Signalling Section, Faculty of Life Sciences and Medicine (FoLSM), King's College London, London, United Kingdom
| | - Ulrike Schara-Schmidt
- Department of Pediatric Neurology, Developmental Neurology and Social Pediatrics, University of Duisburg-Essen, Essen, Germany
| | | | - Carsten Bönnemann
- National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, United States
| | | | | | - Dionne Moat
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK
| | | | - Kimberly Amburgey
- Division of Neurology, Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, Canada
| | - Ana Buj-Bello
- Genethon, Evry 91000, France; Université Paris-Saclay, Univ Evry, Inserm, Genethon, Integrare research unit UMR_S951, Evry 91000, France
| | - James J Dowling
- Division of Neurology, Program for Genetics and Genome Biology, Hospital for Sick Children, Toronto, Canada
| | - Chiara Marini-Bettolo
- The John Walton Muscular Dystrophy Research Centre, Translational and Clinical Research Institute, Newcastle University and Newcastle Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.
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2
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Bitoun M. [The dynamin-2-gene related centronuclear myopathy]. Med Sci (Paris) 2023; 39 Hors série n° 1:6-10. [PMID: 37975763 DOI: 10.1051/medsci/2023130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023] Open
Abstract
Autosomal dominant centronuclear myopathy (AD-CNM) is a rare congenital myopathy characterized by muscle weakness and centrally located nuclei in muscle fibers in the absence of any regeneration. AD-CNM is due to mutations in the DNM2 gene encoding dynamin 2 (DNM2), a large GTPase involved in intracellular membrane trafficking and a regulator of actin and microtubule cytoskeletons. DNM2 mutations are associated with a broad clinical spectrum ranging from severe neonatal to less severe late-onset forms. The histopathological signature includes nuclear centralization, predominance and atrophy of type 1 myofibers and radiating sarcoplasmic strands. To explain the muscle dysfunction, several pathophysiological mechanisms affecting key mechanisms of muscle homeostasis have been identified. They include defects in excitation-contraction coupling, muscle regeneration, mitochondria or autophagy. Several therapeutic approaches are under development by modulating the expression of DNM2 in a pan-allelic manner or by allele-specific silencing targeting only the mutated allele, which open the era of clinical trials for this pathology.
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Affiliation(s)
- Marc Bitoun
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, UMRS974, Institut de Myologie, Groupe Hospitalier Pitié-Salpêtrière, 75013 Paris, France
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3
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Giraud Q, Spiegelhalter C, Messaddeq N, Laporte J. MTM1 overexpression prevents and reverts BIN1-related centronuclear myopathy. Brain 2023; 146:4158-4173. [PMID: 37490306 PMCID: PMC10545525 DOI: 10.1093/brain/awad251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 06/30/2023] [Accepted: 07/06/2023] [Indexed: 07/26/2023] Open
Abstract
Centronuclear and myotubular myopathies (CNM) are rare and severe genetic diseases associated with muscle weakness and atrophy as well as intracellular disorganization of myofibres. The main mutated proteins control lipid and membrane dynamics and are the lipid phosphatase myotubularin (MTM1), and the membrane remodelling proteins amphiphysin 2 (BIN1) and dynamin 2 (DNM2). There is no available therapy. Here, to validate a novel therapeutic strategy for BIN1- and DNM2-CNM, we evaluated adeno-associated virus-mediated MTM1 (AAV-MTM1 ) overexpression in relevant mouse models. Early systemic MTM1 overexpression prevented the development of the CNM pathology in Bin1mck-/- mice, while late intramuscular MTM1 expression partially reverted the established phenotypes after only 4 weeks of treatment. However, AAV-MTM1 injection did not change the DNM2-CNM mouse phenotypes. We investigated the mechanism of the rescue of the myopathy in BIN1-CNM and found that the lipid phosphatase activity of MTM1 was essential for the rescue of muscle atrophy and myofibre hypotrophy but dispensable for the rescue of myofibre disorganization including organelle mis-position and T-tubule defects. Furthermore, the improvement of T-tubule organization correlated with normalization of key regulators of T-tubule morphogenesis, dysferlin and caveolin. Overall, these data support the inclusion of BIN1-CNM patients in an AAV-MTM1 clinical trial.
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Affiliation(s)
- Quentin Giraud
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U1258, Université de Strasbourg, 67404, Illkirch, France
| | - Coralie Spiegelhalter
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U1258, Université de Strasbourg, 67404, Illkirch, France
| | - Nadia Messaddeq
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U1258, Université de Strasbourg, 67404, Illkirch, France
| | - Jocelyn Laporte
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U1258, Université de Strasbourg, 67404, Illkirch, France
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4
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Arriagada-Diaz J, Flores-Muñoz C, Gómez-Soto B, Labraña-Allende M, Mattar-Araos M, Prado-Vega L, Hinostroza F, Gajardo I, Guerra-Fernández MJ, Bevilacqua JA, Cárdenas AM, Bitoun M, Ardiles AO, Gonzalez-Jamett AM. A centronuclear myopathy-causing mutation in dynamin-2 disrupts neuronal morphology and excitatory synaptic transmission in a murine model of the disease. Neuropathol Appl Neurobiol 2023; 49:e12918. [PMID: 37317811 DOI: 10.1111/nan.12918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 04/30/2023] [Accepted: 06/02/2023] [Indexed: 06/16/2023]
Abstract
AIMS Dynamin-2 is a large GTPase, a member of the dynamin superfamily that regulates membrane remodelling and cytoskeleton dynamics. Mutations in the dynamin-2 gene (DNM2) cause autosomal dominant centronuclear myopathy (CNM), a congenital neuromuscular disorder characterised by progressive weakness and atrophy of the skeletal muscles. Cognitive defects have been reported in some DNM2-linked CNM patients suggesting that these mutations can also affect the central nervous system (CNS). Here we studied how a dynamin-2 CNM-causing mutation influences the CNS function. METHODS Heterozygous mice harbouring the p.R465W mutation in the dynamin-2 gene (HTZ), the most common causing autosomal dominant CNM, were used as disease model. We evaluated dendritic arborisation and spine density in hippocampal cultured neurons, analysed excitatory synaptic transmission by electrophysiological field recordings in hippocampal slices, and evaluated cognitive function by performing behavioural tests. RESULTS HTZ hippocampal neurons exhibited reduced dendritic arborisation and lower spine density than WT neurons, which was reversed by transfecting an interference RNA against the dynamin-2 mutant allele. Additionally, HTZ mice showed defective hippocampal excitatory synaptic transmission and reduced recognition memory compared to the WT condition. CONCLUSION Our findings suggest that the dynamin-2 p.R465W mutation perturbs the synaptic and cognitive function in a CNM mouse model and support the idea that this GTPase plays a key role in regulating neuronal morphology and excitatory synaptic transmission in the hippocampus.
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Affiliation(s)
- Jorge Arriagada-Diaz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Programa de Magister en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Carolina Flores-Muñoz
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Bárbara Gómez-Soto
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Programa de Magister en Ciencias Médicas, Mención Biología Celular y Molecular, Universidad de Valparaíso, Valparaíso, Chile
| | - Marjorie Labraña-Allende
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Programa de Magister en Ciencias Médicas, Mención Biología Celular y Molecular, Universidad de Valparaíso, Valparaíso, Chile
| | - Michelle Mattar-Araos
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Lorena Prado-Vega
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Programa de Magister en Ciencias, Mención Neurociencia, Universidad de Valparaíso, Valparaíso, Chile
| | - Fernando Hinostroza
- Centro de Investigación de Estudios Avanzados del Maule, CIEAM, Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca, Chile
- Centro de Investigación en Neuropsicología y Neurociencias Cognitivas, Facultad de Ciencias de la Salud, Universidad Católica del Maule, Talca, Chile
- Escuela de Química y Farmacia, Departamento de Medicina Traslacional, Facultad de Medicina, Universidad Católica del Maule, Talca, Chile
| | - Ivana Gajardo
- Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile
| | | | - Jorge A Bevilacqua
- Departamento de Neurología y Neurocirugía, Hospital Clínico Universidad de Chile, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Ana M Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
| | - Marc Bitoun
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, Paris, F-75013, France
| | - Alvaro O Ardiles
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Centro de Neurología Traslacional, Facultad de Medicina, Universidad de Valparaíso, Valparaíso, Chile
- Centro Interdisciplinario de Estudios en Salud, Facultad de Medicina, Universidad de Valparaíso, Viña del Mar, Chile
| | - Arlek M Gonzalez-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Universidad de Valparaíso, Valparaíso, Chile
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso, Chile
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Bouma S, Cobben N, Bouman K, Gaytant M, van de Biggelaar R, van Doorn J, Reumers SFI, Voet NB, Doorduin J, Erasmus CE, Kamsteeg EJ, Jungbluth H, Wijkstra P, Voermans NC. Respiratory features of centronuclear myopathy in the Netherlands. Neuromuscul Disord 2023; 33:580-588. [PMID: 37364426 DOI: 10.1016/j.nmd.2023.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 06/06/2023] [Accepted: 06/09/2023] [Indexed: 06/28/2023]
Abstract
Centronuclear myopathy (CNM) is a heterogeneous group of muscle disorders primarily characterized by muscle weakness and variable degrees of respiratory dysfunction caused by mutations in MTM1, DNM2, RYR1, TTN and BIN1. X-linked myotubular myopathy has been the focus of recent natural history studies and clinical trials. Data on respiratory function for other genotypes is limited. To better understand the respiratory properties of the CNM spectrum, we performed a retrospective study in a non-selective Dutch CNM cohort. Respiratory dysfunction was defined as an FVC below 70% of predicted and/or a daytime pCO2 higher than 6 kPa. We collected results of other pulmonary function values (FEV1/FVC ratio) and treatment data from the home mechanical ventilation centres. Sixty-one CNM patients were included. Symptoms of respiratory weakness were reported by 15/47 (32%) patients. Thirty-three individuals (54%) with different genotypes except autosomal dominant (AD)-BIN1-related CNM showed respiratory dysfunction. Spirometry showed decreased FVC, FEV1 & PEF values in all but two patients. Sixteen patients were using HMV (26%), thirteen of them only during night-time. In conclusion, this study provides insight into the prevalence of respiratory symptoms in four genetic forms of CNM in the Netherlands and offers the basis for future natural history studies.
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Affiliation(s)
- Sietse Bouma
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nicolle Cobben
- Department of Pulmonary Diseases & Home Mechanical Ventilation, Maastricht University Medical Center+, Maastricht, the Netherlands
| | - Karlijn Bouman
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Michael Gaytant
- Center for Home Mechanical Ventilation, Department of Pulmonology, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Ries van de Biggelaar
- Department of Pulmonary Diseases & Home Mechanical Ventilation, Erasmus MC, Rotterdam, the Netherlands
| | - Jeroen van Doorn
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Stacha F I Reumers
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Nicoline Bm Voet
- Department of Rehabilitation, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands; Rehabilitation Center Klimmendaal, Arnhem, the Netherlands
| | - Jonne Doorduin
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Corrie E Erasmus
- Department of Paediatric Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center - Amalia Children's Hospital, Nijmegen, the Netherlands
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK; Randall Centre for Cell and Molecular Biophysics, Muscle Signalling Section, FoLSM, King's College, London, UK
| | - Peter Wijkstra
- Department of Pulmonary Diseases & Home Mechanical Ventilation, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands; Groningen Research Institute for Asthma and COPD (GRIAC), University of Groningen, University Medical Centre Groningen, the Netherlands
| | - Nicol C Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands.
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Bayonés L, Guerra-Fernández MJ, Hinostroza F, Báez-Matus X, Vásquez-Navarrete J, Gallo LI, Parra S, Martínez AD, González-Jamett A, Marengo FD, Cárdenas AM. Gain-of-Function Dynamin-2 Mutations Linked to Centronuclear Myopathy Impair Ca2+-Induced Exocytosis in Human Myoblasts. Int J Mol Sci 2022; 23:ijms231810363. [PMID: 36142275 PMCID: PMC9499313 DOI: 10.3390/ijms231810363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/26/2022] [Accepted: 09/02/2022] [Indexed: 11/16/2022] Open
Abstract
Gain-of-function mutations of dynamin-2, a mechano-GTPase that remodels membrane and actin filaments, cause centronuclear myopathy (CNM), a congenital disease that mainly affects skeletal muscle tissue. Among these mutations, the variants p.A618T and p.S619L lead to a gain of function and cause a severe neonatal phenotype. By using total internal reflection fluorescence microscopy (TIRFM) in immortalized human myoblasts expressing the pH-sensitive fluorescent protein (pHluorin) fused to the insulin-responsive aminopeptidase IRAP as a reporter of the GLUT4 vesicle trafficking, we measured single pHluorin signals to investigate how p.A618T and p.S619L mutations influence exocytosis. We show here that both dynamin-2 mutations significantly reduced the number and durations of pHluorin signals induced by 10 μM ionomycin, indicating that in addition to impairing exocytosis, they also affect the fusion pore dynamics. These mutations also disrupt the formation of actin filaments, a process that reportedly favors exocytosis. This altered exocytosis might importantly disturb the plasmalemma expression of functional proteins such as the glucose transporter GLUT4 in skeletal muscle cells, impacting the physiology of the skeletal muscle tissue and contributing to the CNM disease.
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Affiliation(s)
- Lucas Bayonés
- Instituto de Fisiología, Biología Molecular y Neurociencias, CONICET, Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - María José Guerra-Fernández
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretaña 1111, Valparaíso 2360102, Chile
| | - Fernando Hinostroza
- Centro de Investigación de Estudios Avanzados del Maule (CIEAM), Vicerrectoría de Investigación y Postgrado, Universidad Católica del Maule, Talca 3460000, Chile
- Centro de Investigación en Neuropsicología y Neurociencias Cognitivas (CINPSI Neurocog), Facultad de Ciencias de la Salud, Universidad Católica del Maule, Talca 3460000, Chile
| | - Ximena Báez-Matus
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretaña 1111, Valparaíso 2360102, Chile
| | - Jacqueline Vásquez-Navarrete
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretaña 1111, Valparaíso 2360102, Chile
| | - Luciana I. Gallo
- Instituto de Fisiología, Biología Molecular y Neurociencias, CONICET, Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
| | - Sergio Parra
- Instituto de Fisiología Celular—Neurociencias, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
| | - Agustín D. Martínez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretaña 1111, Valparaíso 2360102, Chile
| | - Arlek González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretaña 1111, Valparaíso 2360102, Chile
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile
| | - Fernando D. Marengo
- Instituto de Fisiología, Biología Molecular y Neurociencias, CONICET, Departamento de Fisiología y Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires 1428, Argentina
- Correspondence: (F.D.M.); (A.M.C.)
| | - Ana M. Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Gran Bretaña 1111, Valparaíso 2360102, Chile
- Correspondence: (F.D.M.); (A.M.C.)
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7
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Fujise K, Noguchi S, Takeda T. Centronuclear Myopathy Caused by Defective Membrane Remodelling of Dynamin 2 and BIN1 Variants. Int J Mol Sci 2022; 23:ijms23116274. [PMID: 35682949 PMCID: PMC9181712 DOI: 10.3390/ijms23116274] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 05/31/2022] [Accepted: 06/01/2022] [Indexed: 02/01/2023] Open
Abstract
Centronuclear myopathy (CNM) is a congenital myopathy characterised by centralised nuclei in skeletal myofibers. T-tubules, sarcolemmal invaginations required for excitation-contraction coupling, are disorganised in the skeletal muscles of CNM patients. Previous studies showed that various endocytic proteins are involved in T-tubule biogenesis and their dysfunction is tightly associated with CNM pathogenesis. DNM2 and BIN1 are two causative genes for CNM that encode essential membrane remodelling proteins in endocytosis, dynamin 2 and BIN1, respectively. In this review, we overview the functions of dynamin 2 and BIN1 in T-tubule biogenesis and discuss how their dysfunction in membrane remodelling leads to CNM pathogenesis.
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Affiliation(s)
- Kenshiro Fujise
- Departments of Neuroscience and Cell Biology, Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, CT 06520-8001, USA;
| | - Satoru Noguchi
- National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Tokyo 187-8502, Japan;
| | - Tetsuya Takeda
- Department of Biochemistry, Faculty of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Shikata-cho 2-5-1, Kita-ku, Okayama 700-8558, Japan
- Correspondence: ; Tel.: +81-86-235-7125; Fax: +81-86-235-7126
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8
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Abstract
Pancreatic β cells operate with a high rate of membrane recycling for insulin secretion, yet endocytosis in these cells is not fully understood. We investigate this process in mature mouse β cells by genetically deleting dynamin GTPase, the membrane fission machinery essential for clathrin-mediated endocytosis. Unexpectedly, the mice lacking all three dynamin genes (DNM1, DNM2, DNM3) in their β cells are viable, and their β cells still contain numerous insulin granules. Endocytosis in these β cells is severely impaired, resulting in abnormal endocytic intermediates on the plasma membrane. Although insulin granules are abundant, their release upon glucose stimulation is blunted in both the first and second phases, leading to hyperglycemia and glucose intolerance in mice. Dynamin triple deletion impairs insulin granule exocytosis and decreases intracellular Ca2+ responses and granule docking. The docking defect is correlated with reduced expression of Munc13-1 and RIM1 and reorganization of cortical F-actin in β cells. Collectively, these findings uncover the role of dynamin in dense-core vesicle endocytosis and secretory capacity. Insulin secretion deficiency in the absence of dynamin-mediated endocytosis highlights the risk of impaired membrane trafficking in endocrine failure and diabetes pathogenesis.
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Affiliation(s)
- Fan Fan
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Yumei Wu
- HHMI, Yale University School of Medicine, New Haven, CT 06510
- Departments of Neuroscience and Cell Biology, Program in Cellular Neuroscience, Neurodegeneration and Repair, Kavli Institute for Neuroscience, Yale University School of Medicine, New Haven, CT 06510
| | - Manami Hara
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Chicago, Chicago, IL 60637
| | - Adam Rizk
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Chicago, Chicago, IL 60637
| | - Chen Ji
- Synapses and Circuits section, National Institute of Neurological Disorders and Stroke, Bethesda, MD 20892
| | - Dan Nerad
- Emergency Medicine, Carl R. Darnall Army Medical Center, Fort Hood, TX 76544
| | - Natalia Tamarina
- Department of Medicine, The Kovler Diabetes Center, University of Chicago, Chicago, IL 60637
| | - Xuelin Lou
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226;
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9
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Fujise K, Okubo M, Abe T, Yamada H, Nishino I, Noguchi S, Takei K, Takeda T. Mutant BIN1-Dynamin 2 complexes dysregulate membrane remodeling in the pathogenesis of centronuclear myopathy. J Biol Chem 2021; 296:100077. [PMID: 33187981 PMCID: PMC7949082 DOI: 10.1074/jbc.ra120.015184] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 11/10/2020] [Accepted: 11/13/2020] [Indexed: 11/08/2022] Open
Abstract
Membrane remodeling is required for dynamic cellular processes such as cell division, polarization, and motility. BAR domain proteins and dynamins are key molecules in membrane remodeling that work together for membrane deformation and fission. In striated muscles, sarcolemmal invaginations termed T-tubules are required for excitation-contraction coupling. BIN1 and DNM2, which encode a BAR domain protein BIN1 and dynamin 2, respectively, have been reported to be causative genes of centronuclear myopathy (CNM), a hereditary degenerative disease of skeletal muscle, and deformation of T-tubules is often observed in the CNM patients. However, it remains unclear how BIN1 and dynamin 2 are implicated in T-tubule biogenesis and how mutations in these molecules cause CNM to develop. Here, using an in cellulo reconstitution assay, we demonstrate that dynamin 2 is required for stabilization of membranous structures equivalent to T-tubules. GTPase activity of wild-type dynamin 2 is suppressed through interaction with BIN1, whereas that of the disease-associated mutant dynamin 2 remains active due to lack of the BIN1-mediated regulation, thus causing aberrant membrane remodeling. Finally, we show that in cellulo aberrant membrane remodeling by mutant dynamin 2 variants is correlated with their enhanced membrane fission activities, and the results can explain severity of the symptoms in patients. Thus, this study provides molecular insights into dysregulated membrane remodeling triggering the pathogenesis of DNM2-related CNM.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adaptor Proteins, Signal Transducing/metabolism
- Adaptor Proteins, Signal Transducing/physiology
- Animals
- Blotting, Western
- Dynamin II/genetics
- Dynamin II/metabolism
- HEK293 Cells
- Humans
- Immunoprecipitation
- Microscopy, Fluorescence
- Muscle, Skeletal/metabolism
- Myopathies, Structural, Congenital/genetics
- Myopathies, Structural, Congenital/metabolism
- Nanotubes/chemistry
- Nuclear Proteins/genetics
- Nuclear Proteins/metabolism
- Tumor Suppressor Proteins/genetics
- Tumor Suppressor Proteins/metabolism
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Affiliation(s)
- Kenshiro Fujise
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Mariko Okubo
- National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan; Department of Pediatrics, The University of Tokyo, Tokyo, Japan
| | - Tadashi Abe
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Hiroshi Yamada
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Ichizo Nishino
- National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan
| | - Satoru Noguchi
- National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo, Japan
| | - Kohji Takei
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
| | - Tetsuya Takeda
- Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
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10
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Gayi E, Neff LA, Massana Muñoz X, Ismail HM, Sierra M, Mercier T, Décosterd LA, Laporte J, Cowling BS, Dorchies OM, Scapozza L. Tamoxifen prolongs survival and alleviates symptoms in mice with fatal X-linked myotubular myopathy. Nat Commun 2018; 9:4848. [PMID: 30451843 PMCID: PMC6243013 DOI: 10.1038/s41467-018-07058-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 10/12/2018] [Indexed: 11/08/2022] Open
Abstract
X-linked myotubular myopathy (XLMTM, also known as XLCNM) is a severe congenital muscular disorder due to mutations in the myotubularin gene, MTM1. It is characterized by generalized hypotonia, leading to neonatal death of most patients. No specific treatment exists. Here, we show that tamoxifen, a well-known drug used against breast cancer, rescues the phenotype of Mtm1-deficient mice. Tamoxifen increases lifespan several-fold while improving overall motor function and preventing disease progression including lower limb paralysis. Tamoxifen corrects functional, histological and molecular hallmarks of XLMTM, with improved force output, myonuclei positioning, myofibrillar structure, triad number, and excitation-contraction coupling. Tamoxifen normalizes the expression level of the XLMTM disease modifiers DNM2 and PI3KC2B, likely contributing to the phenotypic rescue. Our findings demonstrate that tamoxifen is a promising candidate for clinical evaluation in XLMTM patients.
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MESH Headings
- Animals
- Class II Phosphatidylinositol 3-Kinases/genetics
- Class II Phosphatidylinositol 3-Kinases/metabolism
- Disease Models, Animal
- Disease Progression
- Dynamin II/genetics
- Dynamin II/metabolism
- Electric Stimulation
- Excitation Contraction Coupling/drug effects
- Female
- Gene Expression/drug effects
- Genes, Lethal
- Humans
- Longevity/drug effects
- Male
- Mice
- Mice, Knockout
- Motor Activity/drug effects
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Myofibrils/drug effects
- Myofibrils/metabolism
- Myofibrils/ultrastructure
- Myopathies, Structural, Congenital/drug therapy
- Myopathies, Structural, Congenital/genetics
- Myopathies, Structural, Congenital/metabolism
- Myopathies, Structural, Congenital/pathology
- Protective Agents/pharmacology
- Protein Tyrosine Phosphatases, Non-Receptor/deficiency
- Protein Tyrosine Phosphatases, Non-Receptor/genetics
- Tamoxifen/pharmacology
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Affiliation(s)
- Elinam Gayi
- Pharmaceutical Biochemistry Group, School of Pharmaceutical Sciences, University of Lausanne, University of Geneva, CMU 5-6, Rue Michel-Servet 1, Geneva, 1211, Switzerland
| | - Laurence A Neff
- Pharmaceutical Biochemistry Group, School of Pharmaceutical Sciences, University of Lausanne, University of Geneva, CMU 5-6, Rue Michel-Servet 1, Geneva, 1211, Switzerland
| | - Xènia Massana Muñoz
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, 67404, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, 67404, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, 67404, France
- Université de Strasbourg, Illkirch, 67404, France
| | - Hesham M Ismail
- Pharmaceutical Biochemistry Group, School of Pharmaceutical Sciences, University of Lausanne, University of Geneva, CMU 5-6, Rue Michel-Servet 1, Geneva, 1211, Switzerland
| | - Marta Sierra
- Pharmaceutical Biochemistry Group, School of Pharmaceutical Sciences, University of Lausanne, University of Geneva, CMU 5-6, Rue Michel-Servet 1, Geneva, 1211, Switzerland
| | - Thomas Mercier
- Division and Laboratory of Clinical Pharmacology, Service of Biomedicine, Department of Laboratories, Lausanne University Hospital, Lausanne, 1011, Switzerland
| | - Laurent A Décosterd
- Division and Laboratory of Clinical Pharmacology, Service of Biomedicine, Department of Laboratories, Lausanne University Hospital, Lausanne, 1011, Switzerland
| | - Jocelyn Laporte
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, 67404, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, 67404, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, 67404, France
- Université de Strasbourg, Illkirch, 67404, France
| | - Belinda S Cowling
- Department of Translational Medicine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch, 67404, France
- Centre National de la Recherche Scientifique (CNRS), UMR7104, Illkirch, 67404, France
- Institut National de la Santé et de la Recherche Médicale (INSERM), U1258, Illkirch, 67404, France
- Université de Strasbourg, Illkirch, 67404, France
| | - Olivier M Dorchies
- Pharmaceutical Biochemistry Group, School of Pharmaceutical Sciences, University of Lausanne, University of Geneva, CMU 5-6, Rue Michel-Servet 1, Geneva, 1211, Switzerland.
| | - Leonardo Scapozza
- Pharmaceutical Biochemistry Group, School of Pharmaceutical Sciences, University of Lausanne, University of Geneva, CMU 5-6, Rue Michel-Servet 1, Geneva, 1211, Switzerland.
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11
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Maani N, Sabha N, Rezai K, Ramani A, Groom L, Eltayeb N, Mavandadnejad F, Pang A, Russo G, Brudno M, Haucke V, Dirksen RT, Dowling JJ. Tamoxifen therapy in a murine model of myotubular myopathy. Nat Commun 2018; 9:4849. [PMID: 30451841 PMCID: PMC6242823 DOI: 10.1038/s41467-018-07057-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 10/12/2018] [Indexed: 02/07/2023] Open
Abstract
Myotubular myopathy (MTM) is a severe X-linked disease without existing therapies. Here, we show that tamoxifen ameliorates MTM-related histopathological and functional abnormalities in mice, and nearly doubles survival. The beneficial effects of tamoxifen are mediated primarily via estrogen receptor signaling, as demonstrated through in vitro studies and in vivo phenotypic rescue with estradiol. RNA sequencing and protein expression analyses revealed that rescue is mediated in part through post-transcriptional reduction of dynamin-2, a known MTM modifier. These findings demonstrate an unexpected ability of tamoxifen to improve the murine MTM phenotype, providing preclinical evidence to support clinical translation.
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MESH Headings
- Animals
- Disease Models, Animal
- Drug Evaluation, Preclinical
- Dynamin II/genetics
- Dynamin II/metabolism
- Estradiol/metabolism
- Estradiol/pharmacology
- Excitation Contraction Coupling/drug effects
- Female
- Gene Expression/drug effects
- High-Throughput Nucleotide Sequencing
- Humans
- Longevity/drug effects
- Male
- Mice
- Mice, Knockout
- Motor Activity/drug effects
- Muscle, Skeletal/drug effects
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Myofibrils/drug effects
- Myofibrils/metabolism
- Myofibrils/ultrastructure
- Myopathies, Structural, Congenital/drug therapy
- Myopathies, Structural, Congenital/genetics
- Myopathies, Structural, Congenital/metabolism
- Myopathies, Structural, Congenital/pathology
- Protective Agents/pharmacology
- Protein Tyrosine Phosphatases, Non-Receptor/deficiency
- Protein Tyrosine Phosphatases, Non-Receptor/genetics
- Receptors, Estrogen/genetics
- Receptors, Estrogen/metabolism
- Tamoxifen/pharmacology
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Affiliation(s)
- Nika Maani
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Medical Science Building, Room 4386, 1 King's College Cir, Toronto, ON, CAN M5S 1A8, Canada
| | - Nesrin Sabha
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Medical Science Building, Room 4386, 1 King's College Cir, Toronto, ON, CAN M5S 1A8, Canada
- Department of Paediatrics, University of Toronto, Room 1436D, 555 University Avenue, Toronto, ON, CAN M5G 1X8, Canada
| | - Kamran Rezai
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Molecular Genetics, University of Toronto, Medical Science Building, Room 4386, 1 King's College Cir, Toronto, ON, CAN M5S 1A8, Canada
| | - Arun Ramani
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Computer Science, University of Toronto, Pratt Building Room 286C, 6 King's College Rd, Toronto, ON, CAN M5S 3G4, Canada
- Centre for Computational Medicine, The Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Linda Groom
- Department of Pharmacology and Physiology, University of Rochester Medical Center School of Medicine and Dentistry, 601 Elmwood Ave, Box 711, Rochester, NY, 14642, USA
| | - Nadine Eltayeb
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Faranak Mavandadnejad
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Andrea Pang
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Giulia Russo
- Department of Molecular Pharmacology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Michael Brudno
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
- Department of Computer Science, University of Toronto, Pratt Building Room 286C, 6 King's College Rd, Toronto, ON, CAN M5S 3G4, Canada
- Centre for Computational Medicine, The Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada
| | - Volker Haucke
- Department of Molecular Pharmacology and Cell Biology, Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), 13125, Berlin, Germany
| | - Robert T Dirksen
- Department of Pharmacology and Physiology, University of Rochester Medical Center School of Medicine and Dentistry, 601 Elmwood Ave, Box 711, Rochester, NY, 14642, USA
| | - James J Dowling
- Program for Genetics and Genome Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, CAN M5G 0A4, Canada.
- Department of Molecular Genetics, University of Toronto, Medical Science Building, Room 4386, 1 King's College Cir, Toronto, ON, CAN M5S 1A8, Canada.
- Department of Paediatrics, University of Toronto, Room 1436D, 555 University Avenue, Toronto, ON, CAN M5G 1X8, Canada.
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12
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Trochet D, Prudhon B, Beuvin M, Peccate C, Lorain S, Julien L, Benkhelifa-Ziyyat S, Rabai A, Mamchaoui K, Ferry A, Laporte J, Guicheney P, Vassilopoulos S, Bitoun M. Allele-specific silencing therapy for Dynamin 2-related dominant centronuclear myopathy. EMBO Mol Med 2018; 10:239-253. [PMID: 29246969 PMCID: PMC5801507 DOI: 10.15252/emmm.201707988] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 11/14/2017] [Accepted: 11/20/2017] [Indexed: 11/09/2022] Open
Abstract
Rapid advances in allele-specific silencing by RNA interference established a strategy of choice to cure dominant inherited diseases by targeting mutant alleles. We used this strategy for autosomal-dominant centronuclear myopathy (CNM), a rare neuromuscular disorder without available treatment due to heterozygous mutations in the DNM2 gene encoding Dynamin 2. Allele-specific siRNA sequences were developed in order to specifically knock down the human and murine DNM2-mRNA harbouring the p.R465W mutation without affecting the wild-type allele. Functional restoration was achieved in muscle from a knock-in mouse model and in patient-derived fibroblasts, both expressing the most frequently encountered mutation in patients. Restoring either muscle force in a CNM mouse model or DNM2 function in patient-derived cells is an essential breakthrough towards future gene-based therapy for dominant centronuclear myopathy.
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Affiliation(s)
- Delphine Trochet
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Bernard Prudhon
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Maud Beuvin
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Cécile Peccate
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Stéphanie Lorain
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Laura Julien
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Sofia Benkhelifa-Ziyyat
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Aymen Rabai
- Department of Translational Medicine and Neurogenetics, IGBMC, INSERM U964, CNRS UMR7104, Collège de France, University of Strasbourg, Illkirch, France
| | - Kamel Mamchaoui
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Arnaud Ferry
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Jocelyn Laporte
- Department of Translational Medicine and Neurogenetics, IGBMC, INSERM U964, CNRS UMR7104, Collège de France, University of Strasbourg, Illkirch, France
| | - Pascale Guicheney
- Institute of Cardiometabolism and Nutrition (ICAN), INSERM UMR_S1166, UPMC Univ Paris 06, Sorbonne Universités, Paris, France
| | - Stéphane Vassilopoulos
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
| | - Marc Bitoun
- Research Center for Myology, UPMC Univ Paris 06 and INSERM UMRS 974, Institute of Myology, Sorbonne Universités, Paris, France
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13
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Kockx M, Karunakaran D, Traini M, Xue J, Huang KY, Nawara D, Gaus K, Jessup W, Robinson PJ, Kritharides L. Pharmacological inhibition of dynamin II reduces constitutive protein secretion from primary human macrophages. PLoS One 2014; 9:e111186. [PMID: 25347775 PMCID: PMC4210248 DOI: 10.1371/journal.pone.0111186] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Accepted: 09/22/2014] [Indexed: 12/14/2022] Open
Abstract
Dynamins are fission proteins that mediate endocytic and exocytic membrane events and are pharmacological therapeutic targets. These studies investigate whether dynamin II regulates constitutive protein secretion and show for the first time that pharmacological inhibition of dynamin decreases secretion of apolipoprotein E (apoE) and several other proteins constitutively secreted from primary human macrophages. Inhibitors that target recruitment of dynamin to membranes (MiTMABs) or directly target the GTPase domain (Dyngo or Dynole series), dose- and time- dependently reduced the secretion of apoE. SiRNA oligo’s targeting all isoforms of dynamin II confirmed the involvement of dynamin II in apoE secretion. Inhibition of secretion was not mediated via effects on mRNA or protein synthesis. 2D-gel electrophoresis showed that inhibition occurred after apoE was processed and glycosylated in the Golgi and live cell imaging showed that inhibited secretion was associated with reduced post-Golgi movement of apoE-GFP-containing vesicles. The effect was not restricted to macrophages, and was not mediated by the effects of the inhibitors on microtubules. Inhibition of dynamin also altered the constitutive secretion of other proteins, decreasing the secretion of fibronectin, matrix metalloproteinase 9, Chitinase-3-like protein 1 and lysozyme but unexpectedly increasing the secretion of the inflammatory mediator cyclophilin A. We conclude that pharmacological inhibitors of dynamin II modulate the constitutive secretion of macrophage apoE as a class effect, and that their capacity to modulate protein secretion may affect a range of biological processes.
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Affiliation(s)
- Maaike Kockx
- Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, Australia
| | - Denuja Karunakaran
- Centre for Vascular Research, University of New South Wales, Sydney, Australia
- University of Ottawa Heart Institute, Ottawa, Canada
| | - Mathew Traini
- Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, Australia
| | - Jing Xue
- Children’s Medical Research Institute, University of Sydney, Sydney, Australia
| | - Kuan Yen Huang
- Centre for Vascular Research, University of New South Wales, Sydney, Australia
| | - Diana Nawara
- Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, Australia
| | - Katharina Gaus
- Centre for Vascular Research, University of New South Wales, Sydney, Australia
| | - Wendy Jessup
- Atherosclerosis Laboratory, ANZAC Research Institute, University of Sydney, Sydney, Australia
| | - Phillip J. Robinson
- Children’s Medical Research Institute, University of Sydney, Sydney, Australia
| | - Leonard Kritharides
- Department of Cardiology and ANZAC Research Institute, Concord Hospital, University of Sydney, Sydney, Australia
- * E-mail:
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14
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Abstract
Centronuclear myopathy is a lethal muscle disease. The most severe form of the disease, X-linked centronuclear myopathy, is due to mutations in the gene encoding myotubularin (MTM1), while mutations in dynamin 2 (DNM2) and amphiphysin 2/BIN1 (AMPH2) cause milder forms of myopathy. MTM1 is a lipid phosphatase, and mutations that disrupt this activity cause severe muscle wasting. In this issue of the JCI, Cowling and colleagues report on their finding of increased DNM2 levels in human and mouse muscle with MTM1 mutations. Partial reduction of Dnm2 in mice harboring Mtm1 mutations remarkably rescued muscle wasting and lethality, and this effect was muscle specific. DNM2 regulates membrane trafficking through vesicular scission, and it is presumed that reducing this activity accounts for improved outcome in X-linked centronuclear myopathy.
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15
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Cowling BS, Chevremont T, Prokic I, Kretz C, Ferry A, Coirault C, Koutsopoulos O, Laugel V, Romero NB, Laporte J. Reducing dynamin 2 expression rescues X-linked centronuclear myopathy. J Clin Invest 2014; 124:1350-63. [PMID: 24569376 DOI: 10.1172/jci71206] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 11/21/2013] [Indexed: 12/29/2022] Open
Abstract
Centronuclear myopathies (CNM) are congenital disorders associated with muscle weakness and abnormally located nuclei in skeletal muscle. An autosomal dominant form of CNM results from mutations in the gene encoding dynamin 2 (DNM2), and loss-of-function mutations in the gene encoding myotubularin (MTM1) result in X-linked CNM (XLCNM, also called myotubular myopathy), which promotes severe neonatal hypotonia and early death. Currently, no effective treatments exist for XLCNM. Here, we found increased DNM2 levels in XLCNM patients and a mouse model of XLCNM (Mtm1(-/y)). Generation of Mtm1(-/y) mice that were heterozygous for Dnm2 revealed that reduction of DNM2 in XLCNM mice restored life span, whole-body strength, and diaphragm function and increased muscle strength. Additionally, classic CNM-associated histological features, including fiber atrophy and nuclei mispositioning, were absent or reduced. Ultrastructural analysis revealed improvement of sarcomere organization and triad structures. Skeletal muscle-specific decrease of Dnm2 during embryogenesis or in young mice after disease onset revealed that the rescue associated with downregulation of Dnm2 is cell autonomous and is able to stop and potentially revert XLCNM progression. These data indicate that MTM1 and DNM2 regulate muscle organization and force through a common pathway. Furthermore, despite DNM2 being a key mechanoenzyme, its reduction is beneficial for XLCNM and represents a potential therapeutic approach for patients.
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MESH Headings
- Animals
- Diaphragm/physiopathology
- Down-Regulation
- Dynamin II/genetics
- Dynamin II/metabolism
- Female
- Gene Expression
- Humans
- Male
- Mice
- Mice, Knockout
- Muscle Contraction
- Muscle Strength
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Myopathies, Structural, Congenital/metabolism
- Myopathies, Structural, Congenital/pathology
- Myopathies, Structural, Congenital/therapy
- Phenotype
- Protein Tyrosine Phosphatases, Non-Receptor/metabolism
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16
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Abstract
Dynamin proteins are involved in vesicle generation, providing mechanical force to excise newly formed vesicles from membranes of cellular compartments. In the brain, dynamin-1, dynamin-2, and dynamin-3 have been well studied; however, their function in the retina remains elusive. A retina-specific splice variant of dynamin-1 interacts with the photoreceptor-specific protein Tubby-like protein 1 (Tulp1), which when mutated causes an early onset form of autosomal recessive retinitis pigmentosa. Here, we investigated the role of the dynamins in the retina, using immunohistochemistry to localize dynamin-1, dynamin-2, and dynamin-3 and immunoprecipitation followed by mass spectrometry to explore dynamin-1 interacting proteins in mouse retina. Dynamin-2 is primarily confined to the inner segment compartment of photoreceptors, suggesting a role in outer segment protein transport. Dynamin-3 is present in the terminals of photoreceptors and dendrites of second-order neurons but is most pronounced in the inner plexiform layer where second-order neurons relay signals from photoreceptors. Dynamin-1 appears to be the dominant isoform in the retina and is present throughout the retina and in multiple compartments of the photoreceptor cell. This suggests that it may function in multiple cellular pathways. Surprisingly, dynamin-1 expression and localization did not appear to be disrupted in tulp1−/− mice. Immunoprecipitation experiments reveal that dynamin-1 associates primarily with proteins involved in cytoskeletal-based membrane dynamics. This finding is confirmed by western blot analysis. Results further implicate dynamin-1 in vesicular protein transport processes relevant to synaptic and post-Golgi pathways and indicate a possible role in photoreceptor stability.
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Affiliation(s)
- Gregory H Grossman
- Department of Ophthalmic Research, Cleveland Clinic Cole Eye Institute, Cleveland, Ohio
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17
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Razidlo GL, Wang Y, Chen J, Krueger EW, Billadeau DD, McNiven MA. Dynamin 2 potentiates invasive migration of pancreatic tumor cells through stabilization of the Rac1 GEF Vav1. Dev Cell 2013; 24:573-85. [PMID: 23537630 PMCID: PMC3905678 DOI: 10.1016/j.devcel.2013.02.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 01/03/2013] [Accepted: 02/19/2013] [Indexed: 01/03/2023]
Abstract
The large GTPase Dynamin 2 (Dyn2) is markedly upregulated in pancreatic cancer, is a potent activator of metastatic migration, and is required for Rac1-mediated formation of lamellipodia. Here we demonstrate an unexpected mechanism of Dyn2 action in these contexts via direct binding to the Rac1 guanine nucleotide exchange factor (GEF) Vav1. Surprisingly, disruption of the Dyn2-Vav1 interaction targets Vav1 to the lysosome for degradation via an interaction with the cytoplasmic chaperone Hsc70, resulting in a dramatic reduction of Vav1 protein stability. Importantly, a specific mutation in Vav1 near its Dyn2-binding C-terminal Src homology 3 (SH3) domain prevents Hsc70 binding, resulting in a stabilization of Vav1 levels. Dyn2 binding regulates the interaction of Vav1 with Hsc70 to control the stability and subsequent activity of this oncogenic GEF. These findings elucidate how Dyn2 activates Rac1, lamellipod protrusion, and invasive cellular migration and provide insight into how this specific Vav is ectopically expressed in pancreatic tumors.
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Affiliation(s)
- Gina L. Razidlo
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Rochester, Minnesota, 55905 USA
| | - Yu Wang
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Rochester, Minnesota, 55905 USA
| | - Jing Chen
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Rochester, Minnesota, 55905 USA
| | - Eugene W. Krueger
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Rochester, Minnesota, 55905 USA
| | - Daniel D. Billadeau
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Rochester, Minnesota, 55905 USA
| | - Mark A. McNiven
- Department of Biochemistry and Molecular Biology and the Center for Digestive Diseases, Rochester, Minnesota, 55905 USA
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18
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Schudel BR, Harmon B, Abhyankar VV, Pruitt BW, Negrete OA, Singh AK. Microfluidic platforms for RNA interference screening of virus-host interactions. Lab Chip 2013; 13:811-817. [PMID: 23361404 DOI: 10.1039/c2lc41165b] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
RNA interference (RNAi) is a powerful tool for functional genomics with the capacity to comprehensively analyze host-pathogen interactions. High-throughput RNAi screening is used to systematically perturb cellular pathways and discover therapeutic targets, but the method can be tedious and requires extensive capital equipment and expensive reagents. To aid in the development of an inexpensive miniaturized RNAi screening platform, we have developed a two part microfluidic system for patterning and screening gene targets on-chip to examine cellular pathways involved in virus entry and infection. First, a multilayer polydimethylsiloxane (PDMS)-based spotting device was used to array siRNA molecules into 96 microwells targeting markers of endocytosis, along with siRNA controls. By using a PDMS-based spotting device, we remove the need for a microarray printer necessary to perform previously described small scale (e.g. cellular microarrays) and microchip-based RNAi screening, while still minimizing reagent usage tenfold compared to conventional screening. Second, the siRNA spotted array was transferred to a reversibly sealed PDMS-based screening platform containing microchannels designed to enable efficient cell loading and transfection of mammalian cells while preventing cross-contamination between experimental conditions. Validation of the screening platform was examined using Vesicular stomatitis virus and emerging pathogen Rift Valley fever virus, which demonstrated virus entry pathways of clathrin-mediated endocytosis and caveolae-mediated endocytosis, respectively. The techniques here are adaptable to other well-characterized infection pathways with a potential for large scale screening in high containment biosafety laboratories.
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Affiliation(s)
- Benjamin R Schudel
- Sandia National Laboratories, Department of Biotechnology and Bioengineering, Livermore, CA 94551, USA
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19
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Tsai WC, Hsu CC, Pang JHS, Lin MS, Chen YH, Liang FC. Low-level laser irradiation stimulates tenocyte migration with up-regulation of dynamin II expression. PLoS One 2012; 7:e38235. [PMID: 22666495 PMCID: PMC3364209 DOI: 10.1371/journal.pone.0038235] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 05/01/2012] [Indexed: 12/12/2022] Open
Abstract
Low-level laser therapy (LLLT) is commonly used to treat sports-related tendinopathy or tendon injury. Tendon healing requires tenocyte migration to the repair site, followed by proliferation and synthesis of the extracellular matrix. This study was designed to determine the effect of laser on tenocyte migration. Furthermore, the correlation between this effect and expression of dynamin 2, a positive regulator of cell motility, was also investigated. Tenocytes intrinsic to rat Achilles tendon were treated with low-level laser (660 nm with energy density at 1.0, 1.5, and 2.0 J/cm2). Tenocyte migration was evaluated by an in vitro wound healing model and by transwell filter migration assay. The messenger RNA (mRNA) and protein expressions of dynamin 2 were determined by reverse transcription/real-time polymerase chain reaction (real-time PCR) and Western blot analysis respectively. Immunofluorescence staining was used to evaluate the dynamin 2 expression in tenocytes. Tenocytes with or without laser irradiation was treated with dynasore, a dynamin competitor and then underwent transwell filter migration assay. In vitro wound model revealed that more tenocytes with laser irradiation migrated across the wound border to the cell-free zone. Transwell filter migration assay confirmed that tenocyte migration was enhanced dose-dependently by laser. Real-time PCR and Western-blot analysis demonstrated that mRNA and protein expressions of dynamin 2 were up-regulated by laser irradiation dose-dependently. Confocal microscopy showed that laser enhanced the expression of dynamin 2 in cytoplasm of tenocytes. The stimulation effect of laser on tenocytes migration was suppressed by dynasore. In conclusion, low-level laser irradiation stimulates tenocyte migration in a process that is mediated by up-regulation of dynamin 2, which can be suppressed by dynasore.
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Affiliation(s)
- Wen-Chung Tsai
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Taoyuan County, Taiwan
- College of Medicine, Chang Gung University, Taoyuan County, Taiwan
| | - Chih-Chin Hsu
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Taoyuan County, Taiwan
- College of Medicine, Chang Gung University, Taoyuan County, Taiwan
| | - Jong-Hwei S. Pang
- Graduate Institute of Clinical Medical Sciences, Chang Gung University, Taoyuan County, Taiwan
- * E-mail:
| | - Miao-Sui Lin
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Taoyuan County, Taiwan
- College of Medicine, Chang Gung University, Taoyuan County, Taiwan
| | - Ying-Hsun Chen
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Taoyuan County, Taiwan
| | - Fang-Chen Liang
- Department of Physical Medicine and Rehabilitation, Chang Gung Memorial Hospital, Taoyuan County, Taiwan
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20
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Abstract
Congenital myopathies are a genetically heterogeneous group of early-onset myopathies classified according to the predominant histopathological findings in skeletal muscle. During the past years, considerable overlap between different pathological and genetic forms of congenital myopathies has been discovered. In contrast, the pattern of involved muscles seen on muscle imaging is often more specific, providing useful additional information in the differential diagnosis of these diseases. Therefore, muscle imaging can help to target the most appropriate genetic investigations. The aim of this review is to give a comprehensive up-to-date overview of the muscle imaging findings that have recently been described in different genetic congenital myopathies.
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Affiliation(s)
- Susana Quijano-Roy
- APHP, Service de Pédiatrie, Hôpital Universitaire R. Poincaré, Garches, France
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21
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Koutsopoulos OS, Koch C, Tosch V, Böhm J, North KN, Laporte J. Mild functional differences of dynamin 2 mutations associated to centronuclear myopathy and Charcot-Marie Tooth peripheral neuropathy. PLoS One 2011; 6:e27498. [PMID: 22096584 PMCID: PMC3214065 DOI: 10.1371/journal.pone.0027498] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 10/18/2011] [Indexed: 11/18/2022] Open
Abstract
The large GTPase dynamin 2 is a key player in membrane and cytoskeletal dynamics mutated in centronuclear myopathy (CNM) and Charcot-Marie Tooth (CMT) neuropathy, two discrete dominant neuromuscular disorders affecting skeletal muscle and peripheral nerves respectively. The molecular basis for the tissue-specific phenotypes observed and the physiopathological mechanisms linked to dynamin 2 mutations are not well established. In this study, we have analyzed the impact of CNM and CMT implicated dynamin 2 mutants using ectopic expression of four CNM and two CMT mutations, and patient fibroblasts harboring two dynamin 2 CNM mutations in established cellular processes of dynamin 2 action. Wild type and CMT mutants were seen in association with microtubules whereas CNM mutants lacked microtubules association and did not disrupt interphase microtubules dynamics. Most dynamin 2 mutants partially decreased clathrin-mediated endocytosis when ectopically expressed in cultured cells; however, experiments in patient fibroblasts suggested that endocytosis is overall not defective. Furthermore, CNM mutants were seen in association with enlarged clathrin stained structures whereas the CMT mutant constructs were associated with clathrin structures that appeared clustered, similar to the structures observed in Dnm1 and Dnm2 double knock-out cells. Other roles of dynamin 2 including its interaction with BIN1 (amphiphysin 2), and its function in Golgi maintenance and centrosome cohesion were not significantly altered. Taken together, these mild functional defects are suggestive of differences between CMT and CNM disease-causing dynamin 2 mutants and suggest that a slight impairment in clathrin-mediated pathways may accumulate over time to foster the respective human diseases.
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Affiliation(s)
- Olga S. Koutsopoulos
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Catherine Koch
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Valerie Tosch
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Johann Böhm
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
| | - Kathryn N. North
- Institute for Neuroscience and Muscle Research, The Children's Hospital at Westmead, Sydney, Australia
- Discipline of Paediatrics and Child Health, Faculty of Medicine, University of Sydney, Australia
| | - Jocelyn Laporte
- Department of Translational Medecine, IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire), Illkirch, France
- Inserm, U964, Illkirch, France
- CNRS, UMR7104, Illkirch, France
- Université de Strasbourg, Illkirch, France
- * E-mail:
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22
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Ganeff C, Remouchamps C, Boutaffala L, Benezech C, Galopin G, Vandepaer S, Bouillenne F, Ormenese S, Chariot A, Schneider P, Caamaño J, Piette J, Dejardin E. Induction of the alternative NF-κB pathway by lymphotoxin αβ (LTαβ) relies on internalization of LTβ receptor. Mol Cell Biol 2011; 31:4319-34. [PMID: 21896778 PMCID: PMC3209329 DOI: 10.1128/mcb.05033-11] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 08/26/2011] [Indexed: 01/29/2023] Open
Abstract
Several tumor necrosis factor receptor (TNFR) family members activate both the classical and the alternative NF-κB pathways. However, how a single receptor engages these two distinct pathways is still poorly understood. Using lymphotoxin β receptor (LTβR) as a prototype, we showed that activation of the alternative, but not the classical, NF-κB pathway relied on internalization of the receptor. Further molecular analyses revealed a specific cytosolic region of LTβR essential for its internalization, TRAF3 recruitment, and p100 processing. Interestingly, we found that dynamin-dependent, but clathrin-independent, internalization of LTβR appeared to be required for the activation of the alternative, but not the classical, NF-κB pathway. In vivo, ligand-induced internalization of LTβR in mesenteric lymph node stromal cells correlated with induction of alternative NF-κB target genes. Thus, our data shed light on LTβR cellular trafficking as a process required for specific biological functions of NF-κB.
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Affiliation(s)
- Corinne Ganeff
- Unit of Molecular Immunology and Signal Transduction
- Laboratory of Virology and Immunology
| | - Caroline Remouchamps
- Unit of Molecular Immunology and Signal Transduction
- Laboratory of Virology and Immunology
| | - Layla Boutaffala
- Unit of Molecular Immunology and Signal Transduction
- Laboratory of Virology and Immunology
| | - Cécile Benezech
- MRC Centre for Immune Regulation, University of Birmingham, Birmingham, United Kingdom
| | - Géraldine Galopin
- Unit of Molecular Immunology and Signal Transduction
- Laboratory of Virology and Immunology
| | - Sarah Vandepaer
- Unit of Molecular Immunology and Signal Transduction
- Laboratory of Virology and Immunology
| | | | | | - Alain Chariot
- Laboratory of Medical Chemistry, GIGA-Research, University of Liège, Liège, Belgium
| | - Pascal Schneider
- Institute of Biochemistry, University of Lausanne, Lausanne, Switzerland
| | - Jorge Caamaño
- MRC Centre for Immune Regulation, University of Birmingham, Birmingham, United Kingdom
| | | | - Emmanuel Dejardin
- Unit of Molecular Immunology and Signal Transduction
- Laboratory of Virology and Immunology
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23
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Oh JH, Choi BD, Park JJ, Jeong SJ, Kim JS, Kim JD, Lim DS, Kim BH, Cho YI, Jeong MJ. Expression of dynamin II in odontoblast during mouse tooth development. J Nanosci Nanotechnol 2011; 11:7096-7099. [PMID: 22103132 DOI: 10.1166/jnn.2011.4854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Odontoblasts secrete a collagen-based matrix and release numerous membrane-bound matrix vesicles, which are involved in dentin formation during tooth development. Dynamin II is a GTPase protein that contributes a variety of vesicular budding events, such as endocytotic membrane fission, caveolae internalization and protein trafficking in the Golgi apparatus. However, the expression and function of dynamin II in odontoblasts has not been reported. Therefore, this study examined the expression and possible role of dynamin II in odontoblasts during tooth development and mineralization. The levels of mRNA and protein expression in MDPC23 cells were significantly high at the early stages of differentiation and then decreased gradually thereafter. Immunohistochemistry showed that dynamin II was not expressed near the region of the odontoblasts at embryonic day 17 (E17) and E21. However, dynamin II was expressed strongly in the odontoblast layer at postnatal day 1 (PN1) and decreased gradually at PN3 and PN5. In addition, at PN15 in the functional stage, the dynamin II protein was also expressed in the odontoblast process as well as adjacent to the nuclear region. In conclusion, dynamin II may be involved in the transport of vesicles containing collageneous and non-collageneous proteins for dentin formation in odontoblast, suggesting that it is a good nanomolecule as a candidate to regulate the secretion of collagen on the bone and other nano material.
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Affiliation(s)
- Jong-Hwa Oh
- Department of Oral Histology and Developmental Biology, School of Dentistry, Chosun University, Gwangju, 501-759, Korea
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24
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Thibault D, Albert PR, Pineyro G, Trudeau LÉ. Neurotensin triggers dopamine D2 receptor desensitization through a protein kinase C and beta-arrestin1-dependent mechanism. J Biol Chem 2011; 286:9174-84. [PMID: 21233215 PMCID: PMC3059057 DOI: 10.1074/jbc.m110.166454] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 01/12/2011] [Indexed: 11/06/2022] Open
Abstract
The peptide neurotensin (NT) is known to exert a potent excitatory effect on the dopaminergic system by inhibiting D2 dopamine (DA) receptor (D2R) function. This regulation is dependent on activation of PKC, a well known effector of the type 1 NT receptor (NTR1). Because PKC phosphorylation of the D2R has recently been shown to induce its internalization, we hypothesized that NT acts to reduce D2R function through heterologous desensitization of the D2R. In the present study, we first used HEK-293 cells to demonstrate that NT induces PKC-dependent D2R internalization. Furthermore, internalization displayed faster kinetics in cells expressing the D2R short isoform, known to act as an autoreceptor in DA neurons, than in cells expressing the long isoform, known to act as a postsynaptic D2R. In patch clamp experiments on cultured DA neurons, overexpression of a mutant D2S lacking three key PKC phosphorylation sites abrogated the ability of NT to reduce D2R-mediated cell firing inhibition. Short interfering RNA-mediated inhibition of β-arrestin1 and dynamin2, proteins important for receptor desensitization, reduced agonist-induced desensitization of D2R function, but only the inhibition of β-arrestin1 reduced the effect of NT on D2R function. Taken together, our data suggest that NT acutely regulates D2 autoreceptor function and DA neuron excitability through PKC-mediated phosphorylation of the D2R, leading to heterologous receptor desensitization.
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Affiliation(s)
- Dominic Thibault
- From the Department of Pharmacology
- Department of Physiology
- the Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Québec H3C 3J7, Canada
| | - Paul R. Albert
- the Ottawa Hospital Research Institute, University of Ottawa, Ottawa K1H 8M5, Canada
| | - Graciela Pineyro
- From the Department of Pharmacology
- Department of Psychiatry, Faculty of Medicine, and
- the Centre de Recherche du Centre Hospitalier Universitaire Sainte Justine, Université de Montréal, Quebec H3T 1C5, Canada, and
| | - Louis-Éric Trudeau
- From the Department of Pharmacology
- Department of Physiology
- Department of Psychiatry, Faculty of Medicine, and
- the Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, Québec H3C 3J7, Canada
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25
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Toussaint A, Cowling BS, Hnia K, Mohr M, Oldfors A, Schwab Y, Yis U, Maisonobe T, Stojkovic T, Wallgren-Pettersson C, Laugel V, Echaniz-Laguna A, Mandel JL, Nishino I, Laporte J. Defects in amphiphysin 2 (BIN1) and triads in several forms of centronuclear myopathies. Acta Neuropathol 2011; 121:253-66. [PMID: 20927630 DOI: 10.1007/s00401-010-0754-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Revised: 09/24/2010] [Accepted: 09/25/2010] [Indexed: 11/24/2022]
Abstract
Myotubular myopathy and centronuclear myopathies (CNM) are congenital myopathies characterized by generalized muscle weakness and mislocalization of muscle fiber nuclei. Genetically distinct forms exist, and mutations in BIN1 were recently identified in autosomal recessive cases (ARCNM). Amphiphysins have been implicated in membrane remodeling in brain and skeletal muscle. Our objective was to decipher the pathogenetic mechanisms underlying different forms of CNM, with a focus on ARCNM cases. In this study, we compare the histopathological features from patients with X-linked, autosomal recessive, and dominant forms, respectively, mutated in myotubularin (MTM1), amphiphysin 2 (BIN1), and dynamin 2 (DNM2). We further characterize the ultrastructural defects in ARCNM muscles. We demonstrate that the two BIN1 isoforms expressed in skeletal muscle possess the phosphoinositide-binding domain and are specifically targeted to the triads close to the DHPR-RYR1 complex. Cardiac isoforms do not contain this domain, suggesting that splicing of BIN1 regulates its specific function in skeletal muscle. Immunofluorescence analyses of muscles from patients with BIN1 mutations reveal aberrations of BIN1 localization and triad organization. These defects are also observed in X-linked and autosomal dominant forms of CNM and in Mtm1 knockout mice. In addition to previously reported implications of BIN1 in cancer as a tumor suppressor, these findings sustain an important role for BIN1 skeletal muscle isoforms in membrane remodeling and organization of the excitation-contraction machinery. We propose that aberrant BIN1 localization and defects in triad structure are part of a common pathogenetic mechanism shared between the three forms of centronuclear myopathies.
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MESH Headings
- Adaptor Proteins, Signal Transducing/genetics
- Adolescent
- Adult
- Brain/pathology
- Brain/ultrastructure
- Child
- Dynamin II/genetics
- Female
- Humans
- Infant
- Male
- Microscopy, Electron, Transmission/methods
- Muscle, Skeletal/pathology
- Muscle, Skeletal/ultrastructure
- Mutation/genetics
- Myopathies, Structural, Congenital/classification
- Myopathies, Structural, Congenital/genetics
- Nuclear Proteins/genetics
- Protein Tyrosine Phosphatases, Non-Receptor/genetics
- Tumor Suppressor Proteins/genetics
- Young Adult
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Affiliation(s)
- Anne Toussaint
- Department of Neurobiology and Genetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch, France
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26
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Park M, Farrell J, Lemmon K, York DA. Enterostatin alters protein trafficking to inhibit insulin secretion in Beta-TC6 cells. Peptides 2009; 30:1866-73. [PMID: 19563849 PMCID: PMC2755607 DOI: 10.1016/j.peptides.2009.06.021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Revised: 06/19/2009] [Accepted: 06/21/2009] [Indexed: 10/20/2022]
Abstract
Enterostatin is a peptide that regulates dietary fat intake in rodents and inhibits insulin secretion from pancreatic beta cells. Microarray studies of the genomic response of both a human hepatoma cell line (HepG2 cells) and a mouse hypothalamic cell line (GT1-7 cells) to enterostatin suggested that it might regulate protein trafficking. Using semi-quantitative real-time PCR and Western blot analysis, we confirmed that enterostatin upregulated Scamp2 and down regulated Dynamin2 in these cell lines. The receptor for enterostatin is the F1-ATPase beta subunit. We transfected HepG2 cells with either a green fluorescent protein (GFP) tagged F1-ATPase beta subunit or a red fluorescent protein (RFP) tagged F1-ATPase alpha subunit to study the effects of enterostatin on translocation of its own receptor protein. Enterostatin induced movement of GFP-beta subunit to the cell periphery area but did not have any effect on the localization of RFP-alpha subunit protein in HepG2. As Scamp2 is involved in glucose uptake in mouse Beta-TC6 insulinoma cells we tested enterostatin's effect in Beta-TC6 cells. Glucose stimulated insulin release was inhibited by enterostatin as reported previously. Using siRNA to Scamp2 did not change glucose stimulated insulin release but siRNA to Dynamin2 and dominant negative Dynamin2 (Dyn K44A) inhibited glucose stimulated insulin release and abolished the response to enterostatin. This suggests enterostatin inhibits glucose stimulated insulin release in pancreatic beta cells through down regulation of Dynamin2. This study also suggests that enterostatin might have a more generalized effect on protein trafficking in various cells.
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Affiliation(s)
- Miejung Park
- Center for Advanced Nutrition, Utah State University, 4715 Old Main Hill, Logan, UT 84322-4715, USA
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27
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Hamao K, Morita M, Hosoya H. New function of the proline rich domain in dynamin-2 to negatively regulate its interaction with microtubules in mammalian cells. Exp Cell Res 2009; 315:1336-45. [PMID: 19331814 DOI: 10.1016/j.yexcr.2009.01.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2008] [Revised: 12/29/2008] [Accepted: 01/24/2009] [Indexed: 11/19/2022]
Abstract
Microtubule reorganization is necessary for many cellular functions such as cell migration, cell polarity and cell division. Dynamin was originally identified as a microtubule-binding protein. Previous limited digestion experiment revealed that C-terminal 100-amino acids proline rich domain (PRD) of dynamin is responsible for microtubule binding in vitro. However, as obvious localization of dynamin along microtubules is only observed at the spindle midzone during mitosis but not in interphase cells, it remains unclear how dynamin interacts with microtubules in vivo. Here, we report that GFP-dynamin-2-(1-786), a truncated mutant lacking a C-terminal portion of the PRD, localized along microtubules in interphase HeLa cells. GFP-dynamin-2-wild type (WT) and GFP-dynamin-2-(1-745), a construct that was further truncated to remove the entire PRD, localized in discrete punctate structures but not along microtubules. These data suggest that the N-terminal (residues 746-786) but not the entire PRD is necessary for the interaction of dynamin-2 with microtubules in the cell and that the C-terminus of PRD (787-870) negatively regulate this interaction. Microtubules in cells expressing GFP-dynamin-2-(1-786) were stabilized against exposure to cold. These results provide a first evidence for a regulated interaction of dynamin-2 with microtubules in cultured mammalian cells.
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Affiliation(s)
- Kozue Hamao
- Department of Biological Science, Graduate School of Science, Hiroshima University, Higashi-Hiroshima, 739-8526, Japan
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28
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Liu YW, Surka MC, Schroeter T, Lukiyanchuk V, Schmid SL. Isoform and splice-variant specific functions of dynamin-2 revealed by analysis of conditional knock-out cells. Mol Biol Cell 2008; 19:5347-59. [PMID: 18923138 PMCID: PMC2592655 DOI: 10.1091/mbc.e08-08-0890] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Revised: 10/01/2008] [Accepted: 10/03/2008] [Indexed: 01/05/2023] Open
Abstract
Dynamin (Dyn) is a multifunctional GTPase implicated in several cellular events, including endocytosis, intracellular trafficking, cell signaling, and cytokinesis. The mammalian genome encodes three isoforms, Dyn1, Dyn2, and Dyn3, and several splice variants of each, leading to the suggestion that distinct isoforms and/or distinct splice variants might mediate distinct cellular functions. We generated a conditional Dyn2 KO cell line and performed knockout and reconstitution experiments to explore the isoform- and splice variant specific cellular functions of ubiquitously expressed Dyn2. We find that Dyn2 is required for clathrin-mediated endocytosis (CME), p75 export from the Golgi, and PDGF-stimulated macropinocytosis and cytokinesis, but not for other endocytic pathways. Surprisingly, CME and p75 exocytosis were efficiently rescued by reintroduction of Dyn2, but not Dyn1, suggesting that these two isoforms function differentially in vesicular trafficking in nonneuronal cells. Both isoforms rescued macropinocytosis and cytokinesis, suggesting that dynamin function in these processes might be mechanistically distinct from its role in CME. Although all four Dyn2 splice variants could equally restore CME, Dyn2ba and -bb were more effective at restoring p75 exocytosis. This splice variant specificity correlated with their differential targeting to the Golgi. These studies reveal isoform and splice-variant specific functions for Dyn2.
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Affiliation(s)
- Ya-Wen Liu
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Mark C. Surka
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Thomas Schroeter
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Vasyl Lukiyanchuk
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
| | - Sandra L. Schmid
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037
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Echaniz-Laguna A, Nicot AS, Carré S, Franques J, Tranchant C, Dondaine N, Biancalana V, Mandel JL, Laporte J. Subtle central and peripheral nervous system abnormalities in a family with centronuclear myopathy and a novel dynamin 2 gene mutation. Neuromuscul Disord 2007; 17:955-9. [PMID: 17825552 DOI: 10.1016/j.nmd.2007.06.467] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2007] [Revised: 06/06/2007] [Accepted: 06/28/2007] [Indexed: 11/25/2022]
Abstract
Mutations in dynamin 2 (DNM2), an ubiquitously-expressed large GTPase, cause autosomal dominant centronuclear myopathy (DNM2-CNM) and AD Charcot-Marie-Tooth disease type 2B (DNM2-CMT2B). We report a series of 5 patients from the same family who all presented with dominant centronuclear myopathy, mild cognitive impairment, mild axonal peripheral nerve involvement, and the novel E368Q mutation in the DNM2 gene. This study suggests that the phenotypes of dynamin 2 related centronuclear myopathy and Charcot-Marie-Tooth disease overlap and that DNM2 mutations may alter cerebral function. This report extends the clinical knowledge of DNM2-centronuclear myopathy and shows that the role of DNM2 mutations in the central nervous system should be further studied.
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Affiliation(s)
- Andoni Echaniz-Laguna
- Département de Neurologie, Hôpital Civil de Strasbourg, 1 Place de l'Hôpital, BP426, 67091 Strasbourg, France.
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30
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Bernatchez PN, Acevedo L, Fernandez-Hernando C, Murata T, Chalouni C, Kim J, Erdjument-Bromage H, Shah V, Gratton JP, McNally EM, Tempst P, Sessa WC. Myoferlin regulates vascular endothelial growth factor receptor-2 stability and function. J Biol Chem 2007; 282:30745-53. [PMID: 17702744 DOI: 10.1074/jbc.m704798200] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myoferlin and dysferlin are members of the ferlin family of membrane proteins. Recent studies have shown that mutation or genetic disruption of myoferlin or dysferlin promotes muscular dystrophy-related phenotypes in mice, which are the result of impaired plasma membrane integrity. However, no biological functions have been ascribed to myoferlin in non-muscle tissues. Herein, using a proteomic analysis of endothelial cell (EC) caveolae/lipid raft microdomains we identified myoferlin in these domains and show that myoferlin is highly expressed in ECs and vascular tissues. The loss of myoferlin results in lack of proliferation, migration, and nitric oxide (NO) release in response to vascular endothelial growth factor (VEGF). Western blotting and surface biotinylation experiments show that loss of myoferlin reduces the expression level and autophosphorylation of VEGF receptor-2 (VEGFR-2) in native ECs. In a reconstituted cell system, transfection of myoferlin increases VEGFR-2 membrane expression and autophosphorylation in response to VEGF. In vivo, VEGFR-2 levels and VEGF-induced permeability are impaired in myoferlin-deficient mice. Mechanistically, myoferlin forms a complex with dynamin-2 and VEGFR-2, which prevents CBL-dependent VEGFR-2 polyubiquitination and proteasomal degradation. These data are the first to report novel biological activities for myoferlin and reveal the role of membrane integrity to VEGF signaling.
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Affiliation(s)
- Pascal N Bernatchez
- Department of Pharmacology and Vascular Biology & Transplantation Program, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut 06536, USA
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31
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Singleton PA, Salgia R, Moreno-Vinasco L, Moitra J, Sammani S, Mirzapoiazova T, Garcia JGN. CD44 regulates hepatocyte growth factor-mediated vascular integrity. Role of c-Met, Tiam1/Rac1, dynamin 2, and cortactin. J Biol Chem 2007; 282:30643-57. [PMID: 17702746 DOI: 10.1074/jbc.m702573200] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The preservation of vascular endothelial cell (EC) barrier integrity is critical to normal vessel homeostasis, with barrier dysfunction being a feature of inflammation, tumor angiogenesis, atherosclerosis, and acute lung injury. Therefore, agents that preserve or restore vascular integrity have important therapeutic implications. In this study, we explored the regulation of hepatocyte growth factor (HGF)-mediated enhancement of EC barrier function via CD44 isoforms. We observed that HGF promoted c-Met association with CD44v10 and recruitment of c-Met into caveolin-enriched microdomains (CEM) containing CD44s (standard form). Treatment of EC with CD44v10-blocking antibodies inhibited HGF-mediated c-Met phosphorylation and c-Met recruitment to CEM. Silencing CD44 expression (small interfering RNA) attenuated HGF-induced recruitment of c-Met, Tiam1 (a Rac1 exchange factor), cortactin (an actin cytoskeletal regulator), and dynamin 2 (a vesicular regulator) to CEM as well as HGF-induced trans-EC electrical resistance. In addition, silencing Tiam1 or dynamin 2 reduced HGF-induced Rac1 activation, cortactin recruitment to CEM, and EC barrier regulation. We observed that both HGF- and high molecular weight hyaluronan (CD44 ligand)-mediated protection from lipopolysaccharide-induced pulmonary vascular hyperpermeability was significantly reduced in CD44 knock-out mice, thus validating these in vitro findings in an in vivo murine model of inflammatory lung injury. Taken together, these results suggest that CD44 is an important regulator of HGF/c-Met-mediated in vitro and in vivo barrier enhancement, a process with essential involvement of Tiam1, Rac1, dynamin 2, and cortactin.
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Affiliation(s)
- Patrick A Singleton
- Department of Medicine, Pritzker School of Medicine, University of Chicago, Chicago, Illinois 60637, USA
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32
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Atapattu DN, Czuprynski CJ. Mannheimia haemolytica leukotoxin binds to lipid rafts in bovine lymphoblastoid cells and is internalized in a dynamin-2- and clathrin-dependent manner. Infect Immun 2007; 75:4719-27. [PMID: 17682044 PMCID: PMC2044511 DOI: 10.1128/iai.00534-07] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mannheimia haemolytica is the principal bacterial pathogen of the bovine respiratory disease complex. Its most important virulence factor is a leukotoxin (LKT), which is a member of the RTX family of exotoxins produced by many gram-negative bacteria. Previous studies demonstrated that LKT binds to the beta(2)-integrin LFA-1 (CD11a/CD18) on bovine leukocytes, resulting in cell death. In this study, we demonstrated that depletion of lipid rafts significantly decreases LKT-induced bovine lymphoblastoid cell (BL-3) death. After binding to BL-3 cells, some of the LKT relocated to lipid rafts in an LFA-1-independent manner. We hypothesized that after binding to LFA-1 on BL-3 cells, LKT moves to lipid rafts and clathrin-coated pits via a dynamic process that results in LKT internalization and cytotoxicity. Knocking down dynamin-2 by small interfering RNA reduced both LKT internalization and cytotoxicity. Similarly, expression of dominant negative Eps15 protein expression, which is required for clathrin coat formation, reduced LKT internalization and LKT-mediated cytotoxicity to BL-3 cells. Finally, we demonstrated that inhibiting actin polymerization reduced both LKT internalization and LKT-mediated cytotoxicity. These results suggest that both lipid rafts and clathrin-mediated mechanisms are important for LKT internalization and cytotoxicity in BL-3 cells and illustrate the complex nature of LKT internalization by the cytoskeletal network.
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Affiliation(s)
- Dhammika N Atapattu
- Department of Pathobiological Sciences, University of Wisconsin, 2015, Linden Drive, West, Madison, WI 53706, USA
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33
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Nicot AS, Toussaint A, Tosch V, Kretz C, Wallgren-Pettersson C, Iwarsson E, Kingston H, Garnier JM, Biancalana V, Oldfors A, Mandel JL, Laporte J. Mutations in amphiphysin 2 (BIN1) disrupt interaction with dynamin 2 and cause autosomal recessive centronuclear myopathy. Nat Genet 2007; 39:1134-9. [PMID: 17676042 DOI: 10.1038/ng2086] [Citation(s) in RCA: 296] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2006] [Accepted: 05/31/2007] [Indexed: 11/09/2022]
Abstract
Centronuclear myopathies are characterized by muscle weakness and abnormal centralization of nuclei in muscle fibers not secondary to regeneration. The severe neonatal X-linked form (myotubular myopathy) is due to mutations in the phosphoinositide phosphatase myotubularin (MTM1), whereas mutations in dynamin 2 (DNM2) have been found in some autosomal dominant cases. By direct sequencing of functional candidate genes, we identified homozygous mutations in amphiphysin 2 (BIN1) in three families with autosomal recessive inheritance. Two missense mutations affecting the BAR (Bin1/amphiphysin/RVS167) domain disrupt its membrane tubulation properties in transfected cells, and a partial truncation of the C-terminal SH3 domain abrogates the interaction with DNM2 and its recruitment to the membrane tubules. Our results suggest that mutations in BIN1 cause centronuclear myopathy by interfering with remodeling of T tubules and/or endocytic membranes, and that the functional interaction between BIN1 and DNM2 is necessary for normal muscle function and positioning of nuclei.
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Affiliation(s)
- Anne-Sophie Nicot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Department of Molecular Pathology, F-67400 Illkirch, France
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34
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Abstract
BACKGROUND Recently, mutations affecting different domains of dynamin-2 (DNM2) were associated alternatively with autosomal dominant centronuclear myopathy or dominant intermediate (demyelinating and axonal) Charcot-Marie-Tooth disease (CMT) type B. OBJECTIVE To assess the etiologic role of DNM2 in CMT. METHODS We performed a mutational screening of DNM2 exons 13 through 16 encoding the pleckstrin homology domain in a large series of CMT patients with a broad range of nerve conduction velocities and without mutations in more common genes. RESULTS We identified two novel DNM2 mutations that cosegregated with purely axonal CMT in two pedigrees without clinical evidence of primary myopathy. CONCLUSION Patients with axonal Charcot-Marie-Tooth disease type 2 neuropathy without mutations in more common genes should undergo investigation for DNM2 pleckstrin homology.
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Affiliation(s)
- G M Fabrizi
- Section of Clinical Neurology, Department of Neurological and Visual Sciences, University of Verona, Verona, Italy.
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35
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Xu F, Mukhopadhyay S, Sehgal PB. Live cell imaging of interleukin-6-induced targeting of "transcription factor" STAT3 to sequestering endosomes in the cytoplasm. Am J Physiol Cell Physiol 2007; 293:C1374-82. [PMID: 17670892 DOI: 10.1152/ajpcell.00220.2007] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Signal transducer and activator of transcription (STAT) family transcription factors are classically viewed as transducing cytokine- and growth factor-activated signals from the plasma membrane to the cell nucleus for the purpose of activating transcription. We report live cell imaging studies of fluorescently labeled STAT3 expressed in Hep3B hepatocytes that reveal interleukin (IL)-6-activated targeting of STAT3 and PY-STAT3 to relatively long-lived sequestering endosomes in the cytoplasm. This targeting was rapid but transient, required phosphorylation and integrity of Tyr 705 in STAT3, and was blocked by nocodazole, geldanamycin, and indirubin E804 and by overexpression of wild-type caveolin-1. Strikingly, overexpression of the dominant-negative (DN) mutant K44A of the GTPase dynamin II led to marked constitutive accumulation of STAT3 in the endocytic compartment with depletion of the STAT3 nuclear pool. Subsets of the native and K44A-generated STAT3- and PY-STAT3-sequestering endosomes colocalized with MyD88, an adapter protein that integrates pathways of Toll-like receptor and IL-1 transcriptional signaling and stabilization of mRNAs. These data provide direct evidence for the cytokine-induced "signal transduction" by STAT3 from the plasma membrane to a cytoplasmic membrane destination for yet to be elucidated function(s) in the cytoplasm including prolongation of signaling and/or cross talk.
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Affiliation(s)
- Fang Xu
- Department of Cell Biology & Anatomy, New York Medical College, Valhalla, NY 10595, USA
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36
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Kang-Decker N, Cao S, Chatterjee S, Yao J, Egan LJ, Semela D, Mukhopadhyay D, Shah V. Nitric oxide promotes endothelial cell survival signaling through S-nitrosylation and activation of dynamin-2. J Cell Sci 2007; 120:492-501. [PMID: 17251380 DOI: 10.1242/jcs.03361] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Endothelial cell-based angiogenesis requires activation of survival signals that generate resistance to external apoptotic stimuli, such as tumor necrosis factor-alpha (TNF-alpha), during pathobiologic settings. Mechanisms by which this is achieved are not fully defined. Here, we use a model in which the multifunctional cytokine nitric oxide counterbalances TNF-alpha-induced apoptosis, to define a role for membrane trafficking in the process of endothelial cell survival signaling. By perturbing dynamin GTPase function, we identify a key role of dynamin for ensuing downstream endothelial cell survival signals and vascular tube formation. Furthermore, nitric oxide is directly demonstrated to promote dynamin function through specific cysteine residue nitrosylation, which promotes endocytosis and endothelial cell survival signaling. Thus, these studies identify a novel role for dynamin as a survival factor in endothelial cells, through a mechanism by which dynamin S-nitrosylation regulates the counterbalances of TNF-alpha-induced apoptosis and nitric oxide-dependent survival signals, with implications highly relevant to angiogenesis.
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Affiliation(s)
- Ningling Kang-Decker
- GI Research Unit, Department of Physiology and Tumor Biology Program, Mayo Clinic, Rochester, MN 55903, USA
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37
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Foye PM. Myopathic (not neuropathic) electrophysiological abnormalities in dynamin 2-related centronuclear myopathy. Brain 2007; 130:e63; author reply e64. [PMID: 17235117 DOI: 10.1093/brain/awl186] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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38
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Pénisson-Besnier I, Biancalana V, Reynier P, Cossée M, Dubas F. Diagnosis of myotubular myopathy in the oldest known manifesting female carrier: a clinical and genetic study. Neuromuscul Disord 2007; 17:180-5. [PMID: 17251023 DOI: 10.1016/j.nmd.2006.10.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 09/26/2006] [Accepted: 10/27/2006] [Indexed: 10/23/2022]
Abstract
X-linked myotubular myopathy is a congenital myopathy due to mutation in the MTM1 gene, encoding myotubularin. Most of the affected male neonates die early of respiratory failure. The female carriers are usually asymptomatic. The authors report a novel MTM1 mutation in a 77-year-old woman. She presented with progressive ptosis since childhood, proximal limb weakness, and a severe restrictive respiratory dysfunction with a hemidiaphragmatic paresis, leading to death at 84 years of age. The muscle biopsy showed centrally nucleated fibers and mitochondrial abnormalities. A stop mutation Leu498X in MTM1 gene was identified in the proband and in her two healthy daughters. The X-inactivation pattern was random in the proband's blood and muscle DNA, and in blood DNA from her two unaffected MTM1 mutation carrier daughters. Two large heteroplasmic deletions were also detected in the muscle mitochondrial DNA of the propositus, raising the question of their putative impact on the phenotype.
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MESH Headings
- Aged, 80 and over
- Blepharoptosis/etiology
- Blepharoptosis/genetics
- Blotting, Southern
- Chromosomes, Human, X
- Creatine Kinase/blood
- DNA/genetics
- Dynamin II/genetics
- Female
- Heterozygote
- Humans
- Lactic Acid/blood
- Muscle, Skeletal/diagnostic imaging
- Muscle, Skeletal/pathology
- Myopathies, Structural, Congenital/diagnosis
- Myopathies, Structural, Congenital/genetics
- Myopathies, Structural, Congenital/pathology
- Pedigree
- Phenotype
- Protein Tyrosine Phosphatases/genetics
- Protein Tyrosine Phosphatases, Non-Receptor
- Respiratory Paralysis/genetics
- Respiratory Paralysis/pathology
- Reverse Transcriptase Polymerase Chain Reaction
- Tomography, X-Ray Computed
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Affiliation(s)
- Isabelle Pénisson-Besnier
- Centre de référence Maladies Neuromusculaires rares Nantes-Angers, Centre Hospitalier Universitaire d'Angers, 4 rue Larrey, F-49033 Angers, France.
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39
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40
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Schessl J, Medne L, Hu Y, Zou Y, Brown MJ, Huse JT, Torigian DA, Jungbluth H, Goebel HH, Bönnemann CG. MRI in DNM2-related centronuclear myopathy: evidence for highly selective muscle involvement. Neuromuscul Disord 2006; 17:28-32. [PMID: 17134899 DOI: 10.1016/j.nmd.2006.09.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Revised: 08/15/2006] [Accepted: 09/04/2006] [Indexed: 11/18/2022]
Abstract
Dynamin 2 has recently been recognized as a causative gene for the autosomal dominant form of centronuclear myopathy (dominant centronuclear myopathy). Here we report an affected father and daughter with dynamin 2 related AD CNM with predominantly distal onset of weakness. In addition to the diagnostic central location of myonuclei the muscle biopsy also showed core-like structures. Muscle MRI in the lower leg revealed prominent involvement of the soleus, but also of the gastrocnemius and the tibialis anterior whereas in the thigh there was a consistent pattern of selective involvement of adductor longus, semimembranosus, biceps femoris, rectus femoris, and vastus intermedius with relative sparing of vastus lateralis and medialis, sartorius, gracilis, and partly of the semitendinosus. These characteristic findings on muscle MRI confirm similar findings reported for CT imaging in dynamin 2 related dominant centronuclear myopathy and may help to differentiate this disorder from central core disease and other myopathies.
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Affiliation(s)
- Joachim Schessl
- Division of Neurology, The Children's Hospital of Philadelphia, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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41
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Soulet F, Schmid SL, Damke H. Domain requirements for an endocytosis-independent, isoform-specific function of dynamin-2. Exp Cell Res 2006; 312:3539-45. [PMID: 16938290 DOI: 10.1016/j.yexcr.2006.07.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2006] [Accepted: 07/27/2006] [Indexed: 11/20/2022]
Abstract
Endocytosis is inhibited by overexpression of either dynamin-1 or dynamin-2 mutants because both isoforms form heterotetramers with endogenous dynamin-2 and interfere with its function. By contrast, other phenotypes, which are specifically triggered by overexpression of dynamin-2, but not dynamin-1 are likely to reflect endocytosis-independent, dynamin-2-specific functions and/or interactions. Using Dyn2/Dyn1 chimeras, we explored the structural requirements for a readily quantifiable, isoform-specific function of dynamin-2, the activation of caspase-3 to trigger apoptosis. Strikingly, swapping the highly homologous GTPase domain of dynamin-2 into dynamin-1 was sufficient to confer caspase-3 activation. Moreover, assembly-defective mutations in GED, dynamin's GAP/assembly domain, that inhibit endocytosis enhance caspase-3 activation. Thus, this dynamin-2-specific function is mechanistically distinct from and independent of its role in endocytosis. These findings have important implications for interpreting dynamin-2 dependent phenotypes in overexpression studies.
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Affiliation(s)
- Fabienne Soulet
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
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42
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Abstract
We show here that the GTPase RhoG is involved in caveolar trafficking. Wild-type RhoG moves sequentially to the plasma membrane, intracellular vesicles, and the Golgi apparatus along markers of this endocytic pathway. Such translocation is associated with changes in RhoG GDP/GTP levels and is highly dependent on lipid raft integrity and on the function of the GTPase dynamin2. In addition, the constitutively active RhoG(Q61L) mutant is preferentially located in endocytic vesicles that can be decorated with markers of the caveola-derived endocytic pathway. RhoG(Q61L), but not the analogous Rac1 mutant protein, affects caveola internalization and the subsequent delivery of endocytic vesicles to the Golgi apparatus. The expression of RhoG/Rac1 chimeric proteins and RhoG(Q61L) effector mutants in cells induces alterations in the internalization of caveolae and severe changes in vesicle structure, respectively. However, the knockdown of endogenous rhoG transcripts using small interfering RNAs does not affect significantly the trafficking of caveola-derived vesicles, suggesting that RhoG function is dispensable for this endocytic process or, alternatively, that its function is compensated by other molecules. Taken together, these observations assign a novel function to RhoG and suggest that caveolar trafficking, as previously shown for other endocytic routes, is modulated by GTPases of the Ras superfamily.
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Affiliation(s)
| | | | - XR Bustelo
- Correspondence: Dr XR Bustelo, Centro de Investigación del Cáncer, Instituto de Biología Molecular y Celular del Cáncer (IBMCC), and Red Temática Cooperativa de Centros de Cáncer, CSIC-University of Salamanca, Campus Unamuno, E-37007 Salamanca, Spain. E-mail:
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Massol RH, Boll W, Griffin AM, Kirchhausen T. A burst of auxilin recruitment determines the onset of clathrin-coated vesicle uncoating. Proc Natl Acad Sci U S A 2006; 103:10265-10270. [PMID: 16798879 PMCID: PMC1502446 DOI: 10.1073/pnas.0603369103] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Clathrin-coated pits assemble on a membrane and pinch off as coated vesicles. The released vesicles then rapidly lose their clathrin coats in a process mediated by the ATPase Hsc70, recruited by auxilin, a J-domain-containing cofactor. How is the uncoating process regulated? We find that during coat assembly small and variable amounts of auxilin are recruited transiently but that a much larger burst of association occurs after the peak of dynamin signal, during the transition between membrane constriction and vesicle budding. We show that the auxilin burst depends on domains of the protein likely to interact with lipid head groups. We conclude that the timing of auxilin recruitment determines the onset of uncoating. We propose that, when a diffusion barrier is established at the constricting neck of a fully formed coated pit and immediately after vesicle budding, accumulation of a specific lipid can recruit sufficient auxilin molecules to trigger uncoating.
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Affiliation(s)
- Ramiro H Massol
- Department of Cell Biology and CBR Institute for Biomedical Research, Harvard Medical School, 200 Longwood Ave, Boston, MA 02115
| | - Werner Boll
- Department of Cell Biology and CBR Institute for Biomedical Research, Harvard Medical School, 200 Longwood Ave, Boston, MA 02115
| | - April M Griffin
- Department of Cell Biology and CBR Institute for Biomedical Research, Harvard Medical School, 200 Longwood Ave, Boston, MA 02115
| | - Tomas Kirchhausen
- Department of Cell Biology and CBR Institute for Biomedical Research, Harvard Medical School, 200 Longwood Ave, Boston, MA 02115
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44
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Kessels MM, Dong J, Leibig W, Westermann P, Qualmann B. Complexes of syndapin II with dynamin II promote vesicle formation at the trans-Golgi network. J Cell Sci 2006; 119:1504-16. [PMID: 16551695 DOI: 10.1242/jcs.02877] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The role of dynamin and so-called accessory proteins in endocytosis is well established. However, molecular details of the function(s) of dynamin II at the Golgi are largely unclear. We demonstrate that the ubiquitously expressed syndapin II isoform interacts with the proline-rich domain (PRD) of dynamin II through its Src-homology 3 (SH3) domain. Co-immunoprecipitation of endogenous syndapin II and dynamin II, and successful reconstitutions of such complexes at membranes in COS-7 cells, show the in vivo relevance of the interaction. Syndapin II can associate with Golgi membranes and this association increases upon Golgi exit block. Brefeldin A treatment clearly shows that the observed perinuclear localization of syndapin II co-localizing with syntaxin 6 reflects the Golgi complex and that it requires functional integrity of the Golgi. Syndapins are crucial for Golgi vesicle formation because anti-syndapin antibodies, used either in in vitro reconstitutions or in living cells, inhibited this process. Both types of assays additionally revealed the essential role of syndapin II SH3 interactions with the dynamin II PRD in vesicle formation. An excess of the syndapin SH3 domain strongly inhibited budding from Golgi membranes in vitro. Likewise, overexpression of the syndapin SH3 domain or of a dynamin II variant incapable of associating with syndapin II (dynamin IIΔPRD) impaired trafficking of vesicular stomatitis virus glycoprotein (VSVG)-GFP in vivo. By contrast, full-length syndapin II-l had no negative effect, and instead promoted VSVG-GFP export from the Golgi. Importantly, a cytosolic fraction containing endogenous syndapin-dynamin complexes was sufficient to promote vesicle formation from Golgi membranes in a syndapin-dependent manner. Thus, syndapin-dynamin complexes are crucial and sufficient to promote vesicle formation from the trans-Golgi network.
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Affiliation(s)
- Michael M Kessels
- Department of Neurochemistry and Molecular Biology, AG Membrane Trafficking and Cytoskeleton, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany
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Fischer D, Herasse M, Bitoun M, Barragán-Campos HM, Chiras J, Laforêt P, Fardeau M, Eymard B, Guicheney P, Romero NB. Characterization of the muscle involvement in dynamin 2-related centronuclear myopathy. Brain 2006; 129:1463-9. [PMID: 16585051 DOI: 10.1093/brain/awl071] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Centronuclear myopathy (CNM) is a slowly progressive congenital myopathy characterized by abnormal centrally located nuclei in a large number of muscle fibres. Recently, different missense mutations affecting the middle domain of the dynamin 2 (DNM2) have been shown to cause autosomal dominant CNM. In order to better define the phenotype of DNM2-related CNM, we report here on the clinical and muscle imaging findings of 10 patients harbouring DNM2 mutations. DNM2-CNM is characterized by slowly progressive muscular weakness usually beginning in adolescence or early adulthood. In addition to bilateral ptosis, our data show that distal muscle weakness often exceeds proximal involvement. Furthermore, electrophysiological investigations frequently demonstrated signs of mild axonal peripheral nerve involvement, and electromyographical examination may show neuropathic changes in addition to the predominant myopathic changes. These features overlap with findings seen in the phenotype of DNM2-related autosomal dominant Charcot-Marie-Tooth disease type 2B. In all 10 DNM2-CNM patients, muscle computer tomography assessment showed a consistent pattern of muscular involvement and a characteristic temporal course with early and predominant distal muscle involvement, and later affection of the posterior thigh compartment and gluteus minimus muscles. The recognition of this specific imaging pattern of muscle involvement--distinct to the reported patterns in other congenital myopathies--may enable a better selection for direct genetic testing.
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MESH Headings
- Adolescent
- Adult
- Aged
- Biopsy
- Child
- Dynamin II/genetics
- Humans
- Middle Aged
- Muscle Weakness/diagnostic imaging
- Muscle Weakness/genetics
- Muscle Weakness/pathology
- Muscle, Skeletal/diagnostic imaging
- Muscle, Skeletal/pathology
- Mutation, Missense
- Myopathies, Structural, Congenital/diagnostic imaging
- Myopathies, Structural, Congenital/genetics
- Myopathies, Structural, Congenital/pathology
- Myopathies, Structural, Congenital/physiopathology
- Phenotype
- Tomography, X-Ray Computed
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Affiliation(s)
- Dirk Fischer
- Institut National de la Santé et de la Recherche Médicale U582, Institut de Myologie IFR14, Groupe Hospitalier Pitié-Salpêtrière, Paris, France
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Tsujita K, Suetsugu S, Sasaki N, Furutani M, Oikawa T, Takenawa T. Coordination between the actin cytoskeleton and membrane deformation by a novel membrane tubulation domain of PCH proteins is involved in endocytosis. ACTA ACUST UNITED AC 2006; 172:269-79. [PMID: 16418535 PMCID: PMC2063556 DOI: 10.1083/jcb.200508091] [Citation(s) in RCA: 298] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The conserved FER-CIP4 homology (FCH) domain is found in the pombe Cdc15 homology (PCH) protein family members, including formin-binding protein 17 (FBP17). However, the amino acid sequence homology extends beyond the FCH domain. We have termed this region the extended FC (EFC) domain. We found that FBP17 coordinated membrane deformation with actin cytoskeleton reorganization during endocytosis. The EFC domains of FBP17, CIP4, and other PCH protein family members show weak homology to the Bin-amphiphysin-Rvs (BAR) domain. The EFC domains bound strongly to phosphatidylserine and phosphatidylinositol 4,5-bisphosphate and deformed the plasma membrane and liposomes into narrow tubules. Most PCH proteins possess an SH3 domain that is known to bind to dynamin and that recruited and activated neural Wiskott-Aldrich syndrome protein (N-WASP) at the plasma membrane. FBP17 and/or CIP4 contributed to the formation of the protein complex, including N-WASP and dynamin-2, in the early stage of endocytosis. Furthermore, knockdown of endogenous FBP17 and CIP4 impaired endocytosis. Our data indicate that PCH protein family members couple membrane deformation to actin cytoskeleton reorganization in various cellular processes.
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Affiliation(s)
- Kazuya Tsujita
- Department of Biochemistry, Institute of Medical Science, University of Tokyo, Shirokanedai, Minato-ku, Tokyo, 108-8639 Japan
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Niemann A, Berger P, Suter U. Pathomechanisms of mutant proteins in Charcot-Marie-Tooth disease. Neuromolecular Med 2006; 8:217-42. [PMID: 16775378 DOI: 10.1385/nmm:8:1-2:217] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Revised: 11/10/2005] [Accepted: 11/18/2005] [Indexed: 12/22/2022]
Abstract
We review the putative functions and malfunctions of proteins encoded by genes mutated in Charcot-Marie-Tooth disease (CMT; inherited motor and sensory neuropathies) in normal and affected peripheral nerves. Some proteins implicated in demyelinating CMT, peripheral myelin protein 22, protein zero (P0), and connexin32 (Cx32/GJB1) are crucial components of myelin. Periaxin is involved in connecting myelin to the surrounding basal lamina. Early growth response 2 (EGR2) and Sox10 are transcriptional regulators of myelin genes. Mutations in the small integral membrane protein of lysosome/late endosome, the myotubularin-related protein 2 (MTMR2), and MTMR13/set-binding factor 2 are involved in vesicle and membrane transport and the regulation of protein degradation. Pathomechanisms related to alterations of these processes are a widespread phenomenon in demyelinating neuropathies because mutations of myelin components may also affect protein biosynthesis, transport, and/or degradation. Related disease mechanisms are also involved in axonal neuropathies although there is considerably more functional heterogeneity. Some mutations, most notably in P0, GJB1, ganglioside-induced differentiation-associated protein 1 (GDAP1), neurofilament light chain (NF-L), and dynamin 2 (DNM2), can result in demyelinating or axonal neuropathies introducing additional complexity in the pathogenesis. Often, this relates to the intimate connection between Schwann cells and neurons/axons leading to axonal damage even if the mutation-caused defect is Schwann-cell-autonomous. This mechanism is likely for P0 and Cx32 mutations and provides the basis for the unifying hypothesis that also demyelinating neuropathies develop into functional axonopathies. In GDAP1 and DNM2 mutants, both Schwann cells and axons/neurons might be directly affected. NF-L mutants have a primary neuronal defect but also cause demyelination. The major challenge ahead lies in determining the individual contributions by neurons and Schwann cells to the pathology over time and to delineate the detailed molecular functions of the proteins associated with CMT in health and disease.
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Affiliation(s)
- Axel Niemann
- Institute of Cell Biology, Department of Biology, Swiss Federal Institute of Technology, ETH-Hönggerberg, CH-8093 Zürich, Switzerland
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Bitoun M, Maugenre S, Jeannet PY, Lacène E, Ferrer X, Laforêt P, Martin JJ, Laporte J, Lochmüller H, Beggs AH, Fardeau M, Eymard B, Romero NB, Guicheney P. Mutations in dynamin 2 cause dominant centronuclear myopathy. Nat Genet 2005; 37:1207-9. [PMID: 16227997 DOI: 10.1038/ng1657] [Citation(s) in RCA: 302] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Accepted: 08/23/2005] [Indexed: 11/09/2022]
Abstract
Autosomal dominant centronuclear myopathy is a rare congenital myopathy characterized by delayed motor milestones and muscular weakness. In 11 families affected by centronuclear myopathy, we identified recurrent and de novo missense mutations in the gene dynamin 2 (DNM2, 19p13.2), which encodes a protein involved in endocytosis and membrane trafficking, actin assembly and centrosome cohesion. The transfected mutants showed reduced labeling in the centrosome, suggesting that DNM2 mutations might cause centronuclear myopathy by interfering with centrosome function.
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Affiliation(s)
- Marc Bitoun
- INSERM U582, Institute of Myology, IFR14, Groupe Hospitalier Pitié-Salpêtrière, UPMC, 47 Boulevard de l'Hôpital, 75651 Paris Cedex 13, France
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Abstract
Specific viral targeting into intrahepatic tumors remains critical for adenovirus gene therapy in liver cancer. We previously showed that ionizing radiation increases adenovirus uptake and transgene expression in cells and colon cancer xenografts. Here, we tested whether radiation induces viral uptake through virus-cell membrane interaction. We found that radiation (8 Gy) induced adenoviral gene transfer in rat hepatocytes (WB) and human colon carcinoma cells (LoVo). This induction (24.4- and 6.5-fold, respectively) and viral uptake were significantly diminished by preincubation with antibody for Dynamin 2 but not for Coxsackie adenovirus receptor or for integrin alpha(v). Radiation-induced Dynamin 2 expression was detected by immunohistochemical staining and by increased mRNA levels for Dynamin 2 in WB (1.5-fold) and LoVo (2.2-fold) cells. Specific small interference RNA (siRNA) transfection significantly inhibited Dynamin 2 expression in various tumor cell lines (LoVo, D54, and MCF-7) and abolished the radiation induction of Dynamin 2. Likewise, radiation-induced viral gene transfer in these cells (6.5-, 5.5-, and 9.0-fold, respectively) was significantly reduced in siRNA-transfected cells (2.7-, 3.7-, and 5.0-fold, respectively). Moreover, viral uptake in LoVo tumor xenografts was significantly increased in s.c. tumors (10.9-fold) when adenovirus was given i.v. at 24 hours after tumor irradiation, coincident with an elevated Dynamin 2 expression in irradiated tumors. These data suggest that ionizing radiation induces adenovirus gene transfer in cells and tumor xenografts by regulating viral uptake, potentially through interaction with cellular Dynamin 2 and thus should provide insight into improving adenovirus targeting in tumors.
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Affiliation(s)
- Jun Qian
- Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor, Michigan 48109, USA
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