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Holzer MT, Uruha A, Roos A, Hentschel A, Schänzer A, Weis J, Claeys KG, Schoser B, Montagnese F, Goebel HH, Huber M, Léonard-Louis S, Kötter I, Streichenberger N, Gallay L, Benveniste O, Schneider U, Preusse C, Krusche M, Stenzel W. Anti-Ku + myositis: an acquired inflammatory protein-aggregate myopathy. Acta Neuropathol 2024; 148:6. [PMID: 39012547 PMCID: PMC11252205 DOI: 10.1007/s00401-024-02765-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 07/07/2024] [Accepted: 07/07/2024] [Indexed: 07/17/2024]
Abstract
Myositis with anti-Ku-autoantibodies is a rare inflammatory myopathy associated with various connective tissue diseases. Histopathological studies have identified inflammatory and necrotizing aspects, but a precise morphological analysis and pathomechanistic disease model are lacking. We therefore aimed to carry out an in-depth morpho-molecular analysis to uncover possible pathomechanisms. Muscle biopsy specimens from 26 patients with anti-Ku-antibodies and unequivocal myositis were analyzed by immunohistochemistry, immunofluorescence, transcriptomics, and proteomics and compared to biopsy specimens of non-disease controls, immune-mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM). Clinical findings and laboratory parameters were evaluated retrospectively and correlated with morphological and molecular features. Patients were mainly female (92%) with a median age of 56.5 years. Isolated myositis and overlap with systemic sclerosis were reported in 31%, respectively. Isolated myositis presented with higher creatine kinase levels and cardiac involvement (83%), whereas systemic sclerosis-overlap patients often had interstitial lung disease (57%). Histopathology showed a wide spectrum from mild to pronounced myositis with diffuse sarcolemmal MHC-class I (100%) and -II (69%) immunoreactivity, myofiber necrosis (88%), endomysial inflammation (85%), thickened capillaries (84%), and vacuoles (60%). Conspicuous sarcoplasmic protein aggregates were p62, BAG3, myotilin, or immunoproteasomal beta5i-positive. Proteomic and transcriptomic analysis identified prominent up-regulation of autophagy, proteasome, and hnRNP-related cell stress. To conclude, Ku + myositis is morphologically characterized by myofiber necrosis, MHC-class I and II positivity, variable endomysial inflammation, and distinct protein aggregation varying from IBM and IMNM, and it can be placed in the spectrum of scleromyositis and overlap myositis. It features characteristic sarcoplasmic protein aggregation on an acquired basis being functionally associated with altered chaperone, proteasome, and autophagy function indicating that Ku + myositis exhibit aspects of an acquired inflammatory protein-aggregate myopathy.
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Affiliation(s)
- Marie-Therese Holzer
- Division of Rheumatology and Systemic Inflammatory Diseases, III, Department of Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany.
- Department of Neuropathology, Charité. Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany.
| | - Akinori Uruha
- Department of Neuropathology, Charité. Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Rheumatology, Charité, Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Tokyo, Japan
| | - Andreas Roos
- Department of Neuropediatrics, Developmental Neurology and Social Pediatrics, Centre for Neuromuscular Disorders in Children, University Children's Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Department of Neurology, Medical Faculty, Heinrich Heine University Dusseldorf, 40225, Dusseldorf, Germany
- Brain and Mind Research Institute, Children's Hospital of Eastern Ontario Research Institute, Ottawa, ON, K1H 8L1, Canada
| | - Andreas Hentschel
- Leibniz-Institut für Analytische Wissenschaften -ISAS- E.V., Dortmund, Germany
| | - Anne Schänzer
- Institute of Neuropathology, Justus-Liebig-University, Gießen, Germany
| | - Joachim Weis
- Medical Faculty, Institute of Neuropathology, RWTH Aachen University, Aachen, Germany
| | - Kristl G Claeys
- Department of Neurology, University Hospitals Leuven, Leuven, Belgium
- Department of Neurosciences, Laboratory for Muscle Diseases and Neuropathies, KU Leuven, and Leuven Brain Institute (LBI), Leuven, Belgium
| | - Benedikt Schoser
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University, Munich, Germany
| | - Federica Montagnese
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University, Munich, Germany
| | - Hans-Hilmar Goebel
- Department of Neuropathology, Charité. Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Melanie Huber
- Department for Rheumatology, Campus Kerckhoff of Justus-Liebig University Gießen, Bad Nauheim, Germany
| | - Sarah Léonard-Louis
- Reference Center of Neuromuscular Pathology Paris-Est, Pitié-Salpêtrière University Hospital, Paris, France
| | - Ina Kötter
- Division of Rheumatology and Systemic Inflammatory Diseases, III, Department of Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Nathalie Streichenberger
- Neuropathologie, Groupement Hospitalier Est, Hospices Civils de Lyon, Université Claude Bernard Lyon 1, Institut NeuroMyogène CNRS UMR 5261- INSERM U1315, Lyon, France
| | - Laure Gallay
- Department of Internal Medicine, Edouard Herriot University Hospital, Hospices Civils de Lyon, Lyon, France
| | - Olivier Benveniste
- Department of Internal Medicine and Clinical Immunology, Assistance Publique Hôpitaux de Paris, Sorbonne Université, Pitié-Salpêtrière University Hospital, Paris, France
| | - Udo Schneider
- Department of Rheumatology, Charité, Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Corinna Preusse
- Department of Neuropathology, Charité. Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
| | - Martin Krusche
- Division of Rheumatology and Systemic Inflammatory Diseases, III, Department of Medicine, University Medical Center Hamburg-Eppendorf, Martinistraße 52, 20246, Hamburg, Germany
| | - Werner Stenzel
- Department of Neuropathology, Charité. Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, Berlin, Germany
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Tapia‐Curimil G, Castro‐Sepulveda M, Zbinden‐Foncea H. Effect of epicatechin consumption on the inflammatory pathway and mitochondria morphology in PBMC from a R350P desminopathy patient: A case report. Physiol Rep 2024; 12:e16020. [PMID: 38658362 PMCID: PMC11043034 DOI: 10.14814/phy2.16020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 04/04/2024] [Accepted: 04/05/2024] [Indexed: 04/26/2024] Open
Abstract
Desminopathy R350P is a human myopathy that is characterized by the progressive loss of muscle fiber organization. This results in the loss of muscle size, mobility, and strength. In desminopathy, inflammation affects muscle homeostasis and repair, and contributes to progressive muscle deterioration. Mitochondria morphology was also suggested to affect desminopathy progression. Epicatechin (Epi)-a natural compound found in cacao-has been proposed to regulate inflammatory signaling and mitochondria morphology in human and animal models. Hence, we hypothesize chronic Epi consumption to improve inflammatory pathway and mitochondria morphology in the peripheral blood mononuclear cells (PBMCs) of a desminopathy R350P patient. We found that 12 weeks of Epi consumption partially restored TRL4 signaling, indicative of inflammatory signaling and mitochondria morphology in the desminopathy patient. Moreover, Epi consumption improved blood health parameters, including reduced HOMA-IR and IL-6 levels in the desminopathy patient. This indicates that Epi consumption could be a useful tool to slow disease progression in desminopathy patients.
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Affiliation(s)
- Germán Tapia‐Curimil
- Exercise Physiology and Metabolism Laboratory, School of Kinesiology, Faculty of MedicineUniversidad Finis TerraeSantiagoChile
- Centro de Salud DeportivaClínica Santa MaríaSantiagoChile
| | - Mauricio Castro‐Sepulveda
- Exercise Physiology and Metabolism Laboratory, School of Kinesiology, Faculty of MedicineUniversidad Finis TerraeSantiagoChile
| | - Hermann Zbinden‐Foncea
- Exercise Physiology and Metabolism Laboratory, School of Kinesiology, Faculty of MedicineUniversidad Finis TerraeSantiagoChile
- Centro de Salud DeportivaClínica Santa MaríaSantiagoChile
- Facultad de Ciencias de la SaludUniversidad Francisco de VitoriaMadridEspaña
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3
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Abayev-Avraham M, Salzberg Y, Gliksberg D, Oren-Suissa M, Rosenzweig R. DNAJB6 mutants display toxic gain of function through unregulated interaction with Hsp70 chaperones. Nat Commun 2023; 14:7066. [PMID: 37923706 PMCID: PMC10624832 DOI: 10.1038/s41467-023-42735-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/19/2023] [Indexed: 11/06/2023] Open
Abstract
Molecular chaperones are essential cellular components that aid in protein folding and preventing the abnormal aggregation of disease-associated proteins. Mutations in one such chaperone, DNAJB6, were identified in patients with LGMDD1, a dominant autosomal disorder characterized by myofibrillar degeneration and accumulations of aggregated protein within myocytes. The molecular mechanisms through which such mutations cause this dysfunction, however, are not well understood. Here we employ a combination of solution NMR and biochemical assays to investigate the structural and functional changes in LGMDD1 mutants of DNAJB6. Surprisingly, we find that DNAJB6 disease mutants show no reduction in their aggregation-prevention activity in vitro, and instead differ structurally from the WT protein, affecting their interaction with Hsp70 chaperones. While WT DNAJB6 contains a helical element regulating its ability to bind and activate Hsp70, in LGMDD1 disease mutants this regulation is disrupted. These variants can thus recruit and hyperactivate Hsp70 chaperones in an unregulated manner, depleting Hsp70 levels in myocytes, and resulting in the disruption of proteostasis. Interfering with DNAJB6-Hsp70 binding, however, reverses the disease phenotype, suggesting future therapeutic avenues for LGMDD1.
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Affiliation(s)
- Meital Abayev-Avraham
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Yehuda Salzberg
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Dar Gliksberg
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Meital Oren-Suissa
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, 761000, Israel
| | - Rina Rosenzweig
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot, 761000, Israel.
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Petry-Schmelzer JN, Abicht A, Barbe MT, Wunderlich G. Myofibrillar myopathy: a rare but important differential diagnosis of camptocormia in a patient with Parkinson's Disease. Neurol Res Pract 2023; 5:26. [PMID: 37287054 PMCID: PMC10249326 DOI: 10.1186/s42466-023-00250-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/20/2023] [Indexed: 06/09/2023] Open
Abstract
Here we report on a patient with Parkinson's Disease and camptocormia due to Myofibrillar Myopathy Type 3. By leading the reader through the clinical reasoning process and highlighting the respective red flags we aim to increase the readers' awareness for the differential diagnosis of camptocormia.
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Affiliation(s)
- Jan Niklas Petry-Schmelzer
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany.
| | - Angela Abicht
- Medizinisch Genetisches Zentrum (MGZ) München, Munich, Germany
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Michael T Barbe
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
| | - Gilbert Wunderlich
- Department of Neurology, Faculty of Medicine and University Hospital, University of Cologne, Kerpener Straße 62, 50937, Cologne, Germany
- Center for Rare Diseases, Faculty of Medicine and University Hospital, University of Cologne, Cologne, Germany
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5
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Onore ME, Savarese M, Picillo E, Passamano L, Nigro V, Politano L. Bi-Allelic DES Gene Variants Causing Autosomal Recessive Myofibrillar Myopathies Affecting Both Skeletal Muscles and Cardiac Function. Int J Mol Sci 2022; 23:ijms232415906. [PMID: 36555543 PMCID: PMC9785402 DOI: 10.3390/ijms232415906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/09/2022] [Accepted: 12/11/2022] [Indexed: 12/15/2022] Open
Abstract
Mutations in the human desmin gene (DES) may cause both autosomal dominant and recessive cardiomyopathies leading to heart failure, arrhythmias and atrio-ventricular blocks, or progressive myopathies. Cardiac conduction disorders, arrhythmias and cardiomyopathies usually associated with progressive myopathy are the main manifestations of autosomal dominant desminopathies, due to mono-allelic pathogenic variants. The recessive forms, due to bi-allelic variants, are very rare and exhibit variable phenotypes in which premature sudden cardiac death could also occur in the first or second decade of life. We describe a further case of autosomal recessive desminopathy in an Italian boy born of consanguineous parents, who developed progressive myopathy at age 12, and dilated cardiomyopathy four years later and died of intractable heart failure at age 17. Next Generation Sequencing (NGS) analysis identified the homozygous loss-of-function variant c.634C>T; p.Arg212*, which was likely inherited from both parents. Furthermore, we performed a comparison of clinical and genetic results observed in our patient with those of cases so far reported in the literature.
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Affiliation(s)
- Maria Elena Onore
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Marco Savarese
- Folkhälsan Research Center, 00280 Helsinki, Finland
- Department of Medical and Clinical Genetics, Medicum, University of Helsinki, 00280 Helsinki, Finland
| | - Esther Picillo
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Luigia Passamano
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
| | - Vincenzo Nigro
- Medical Genetics and Cardiomyology, Department of Precision Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
- Telethon Institute of Genetics and Medicine, 80078 Pozzuoli, Italy
| | - Luisa Politano
- Cardiomyology and Medical Genetics, Department of Experimental Medicine, University of Campania “Luigi Vanvitelli”, 80138 Napoli, Italy
- Correspondence:
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6
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Bhadra AK, Rau MJ, Daw JA, Fitzpatrick JAJ, Weihl CC, True HL. Disease-associated mutations within the yeast DNAJB6 homolog Sis1 slow conformer-specific substrate processing and can be corrected by the modulation of nucleotide exchange factors. Nat Commun 2022; 13:4570. [PMID: 35931773 PMCID: PMC9355953 DOI: 10.1038/s41467-022-32318-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 07/26/2022] [Indexed: 11/09/2022] Open
Abstract
Molecular chaperones, or heat shock proteins (HSPs), protect against the toxic misfolding and aggregation of proteins. As such, mutations or deficiencies within the chaperone network can lead to disease. Dominant mutations within DNAJB6 (Hsp40)-an Hsp70 co-chaperone-lead to a protein aggregation-linked myopathy termed Limb-Girdle Muscular Dystrophy Type D1 (LGMDD1). Here, we used the yeast prion model client in conjunction with in vitro chaperone activity assays to gain mechanistic insights into the molecular basis of LGMDD1. Here, we show how mutations analogous to those found in LGMDD1 affect Sis1 (a functional homolog of human DNAJB6) function by altering the structure of client protein aggregates, interfering with the Hsp70 ATPase cycle, dimerization and substrate processing; poisoning the function of wild-type protein. These results uncover the mechanisms through which LGMDD1-associated mutations alter chaperone activity, and provide insights relevant to potential therapeutic interventions.
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Affiliation(s)
- Ankan K Bhadra
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8228, St. Louis, MO, 63110, USA
| | - Michael J Rau
- Washington University Center for Cellular Imaging (WUCCI), Washington University School of Medicine, St. Louis, MO, USA
| | - Jil A Daw
- Department of Neurology, Hope Center for Neurological Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - James A J Fitzpatrick
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8228, St. Louis, MO, 63110, USA
- Washington University Center for Cellular Imaging (WUCCI), Washington University School of Medicine, St. Louis, MO, USA
- Department of Neuroscience, Washington University School of Medicine, St. Louis, MO, USA
| | - Conrad C Weihl
- Department of Neurology, Hope Center for Neurological Diseases, Washington University School of Medicine, St. Louis, MO, USA
| | - Heather L True
- Department of Cell Biology and Physiology, Washington University School of Medicine, 660 South Euclid Avenue, Campus Box 8228, St. Louis, MO, 63110, USA.
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7
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Kötter S, Krüger M. Protein Quality Control at the Sarcomere: Titin Protection and Turnover and Implications for Disease Development. Front Physiol 2022; 13:914296. [PMID: 35846001 PMCID: PMC9281568 DOI: 10.3389/fphys.2022.914296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 06/10/2022] [Indexed: 11/26/2022] Open
Abstract
Sarcomeres are mainly composed of filament and signaling proteins and are the smallest molecular units of muscle contraction and relaxation. The sarcomere protein titin serves as a molecular spring whose stiffness mediates myofilament extensibility in skeletal and cardiac muscle. Due to the enormous size of titin and its tight integration into the sarcomere, the incorporation and degradation of the titin filament is a highly complex task. The details of the molecular processes involved in titin turnover are not fully understood, but the involvement of different intracellular degradation mechanisms has recently been described. This review summarizes the current state of research with particular emphasis on the relationship between titin and protein quality control. We highlight the involvement of the proteasome, autophagy, heat shock proteins, and proteases in the protection and degradation of titin in heart and skeletal muscle. Because the fine-tuned balance of degradation and protein expression can be disrupted under pathological conditions, the review also provides an overview of previously known perturbations in protein quality control and discusses how these affect sarcomeric proteins, and titin in particular, in various disease states.
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8
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Neonatal myofibrillar myopathy type II associated with biallelic UNC-45B gene novel mutation and perinatal myasthenia as the core phenotype: a case report. Clin Chim Acta 2022; 531:12-16. [DOI: 10.1016/j.cca.2022.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/03/2022] [Indexed: 11/22/2022]
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9
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Zrelski MM, Kustermann M, Winter L. Muscle-Related Plectinopathies. Cells 2021; 10:2480. [PMID: 34572129 PMCID: PMC8466646 DOI: 10.3390/cells10092480] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/06/2021] [Accepted: 09/08/2021] [Indexed: 12/23/2022] Open
Abstract
Plectin is a giant cytoskeletal crosslinker and intermediate filament stabilizing protein. Mutations in the human plectin gene (PLEC) cause several rare diseases that are grouped under the term plectinopathies. The most common disorder is autosomal recessive disease epidermolysis bullosa simplex with muscular dystrophy (EBS-MD), which is characterized by skin blistering and progressive muscle weakness. Besides EBS-MD, PLEC mutations lead to EBS with nail dystrophy, EBS-MD with a myasthenic syndrome, EBS with pyloric atresia, limb-girdle muscular dystrophy type R17, or EBS-Ogna. In this review, we focus on the clinical and pathological manifestations caused by PLEC mutations on skeletal and cardiac muscle. Skeletal muscle biopsies from EBS-MD patients and plectin-deficient mice revealed severe dystrophic features with variation in fiber size, degenerative myofibrillar changes, mitochondrial alterations, and pathological desmin-positive protein aggregates. Ultrastructurally, PLEC mutations lead to a disorganization of myofibrils and sarcomeres, Z- and I-band alterations, autophagic vacuoles and cytoplasmic bodies, and misplaced and degenerating mitochondria. We also summarize a variety of genetically manipulated mouse and cell models, which are either plectin-deficient or that specifically lack a skeletal muscle-expressed plectin isoform. These models are powerful tools to study functional and molecular consequences of PLEC defects and their downstream effects on the skeletal muscle organization.
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Affiliation(s)
| | | | - Lilli Winter
- Center for Anatomy and Cell Biology, Neuromuscular Research Department, Medical University of Vienna, 1090 Vienna, Austria; (M.M.Z.); (M.K.)
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10
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GNE Myopathy as a Myofibrillar Myopathy: Potential Important Disease Mechanism Implied by Muscle Biopsy. J Clin Neuromuscul Dis 2021; 22:90-96. [PMID: 33214394 DOI: 10.1097/cnd.0000000000000317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
We report a case of 2 sisters in their 20s with genetically confirmed UDP-N-acetylglucoasmine 2-epimerase/N-acetylmannosamine kinase myopathy along with muscle biopsy findings. Both patients described slowly progressive signs of distal-predominant weakness since adolescence that had been dismissed as "clumsiness." Exam and electrodiagnostic testing suggested a predominately distal myopathy. Muscle biopsy of the left tibialis anterior revealed rimmed vacuoles and, interestingly, also had characteristic features of a myofibrillar myopathy. Genetic testing confirmed a diagnosis of autosomal recessive GNE myopathy in both patients. GNE myopathy has not typically been considered a myofibrillar myopathy, but this case raises possibilities worthy of further exploration. It is possible that the unique combination of pathogenic alleles in GNE reported here has led to a novel form of GNE myopathy with muscle biopsy showing characteristic features of GNE myopathy and myofibrillar myopathy. The other possibility is that myofibrillar myopathy may be a more common feature of GNE myopathies than classically described.
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11
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Nicolau S, Milone M, Liewluck T. Guidelines for genetic testing of muscle and neuromuscular junction disorders. Muscle Nerve 2021; 64:255-269. [PMID: 34133031 DOI: 10.1002/mus.27337] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 05/28/2021] [Indexed: 12/24/2022]
Abstract
Despite recent advances in the understanding of inherited muscle and neuromuscular junction diseases, as well as the advent of a wide range of genetic tests, patients continue to face delays in diagnosis of sometimes treatable disorders. These guidelines outline an approach to genetic testing in such disorders. Initially, a patient's phenotype is evaluated to identify myopathies requiring directed testing, including myotonic dystrophies, facioscapulohumeral muscular dystrophy, oculopharyngeal muscular dystrophy, mitochondrial myopathies, dystrophinopathies, and oculopharyngodistal myopathy. Initial investigation in the remaining patients is generally a comprehensive gene panel by next-generation sequencing. Broad panels have a higher diagnostic yield and can be cost-effective. Due to extensive phenotypic overlap and treatment implications, genes responsible for congenital myasthenic syndromes should be included when evaluating myopathy patients. For patients whose initial genetic testing is negative or inconclusive, phenotypic re-evaluation is warranted, along with consideration of genes and variants not included initially, as well as their acquired mimickers.
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Affiliation(s)
- Stefan Nicolau
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Teerin Liewluck
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
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12
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Eggers B, Schork K, Turewicz M, Barkovits K, Eisenacher M, Schröder R, Clemen CS, Marcus K. Advanced Fiber Type-Specific Protein Profiles Derived from Adult Murine Skeletal Muscle. Proteomes 2021; 9:proteomes9020028. [PMID: 34201234 PMCID: PMC8293376 DOI: 10.3390/proteomes9020028] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 02/07/2023] Open
Abstract
Skeletal muscle is a heterogeneous tissue consisting of blood vessels, connective tissue, and muscle fibers. The last are highly adaptive and can change their molecular composition depending on external and internal factors, such as exercise, age, and disease. Thus, examination of the skeletal muscles at the fiber type level is essential to detect potential alterations. Therefore, we established a protocol in which myosin heavy chain isoform immunolabeled muscle fibers were laser microdissected and separately investigated by mass spectrometry to develop advanced proteomic profiles of all murine skeletal muscle fiber types. All data are available via ProteomeXchange with the identifier PXD025359. Our in-depth mass spectrometric analysis revealed unique fiber type protein profiles, confirming fiber type-specific metabolic properties and revealing a more versatile function of type IIx fibers. Furthermore, we found that multiple myopathy-associated proteins were enriched in type I and IIa fibers. To further optimize the assignment of fiber types based on the protein profile, we developed a hypothesis-free machine-learning approach, identified a discriminative peptide panel, and confirmed our panel using a public data set.
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Affiliation(s)
- Britta Eggers
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
- Correspondence: (B.E.); (K.M.)
| | - Karin Schork
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
| | - Michael Turewicz
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
| | - Katalin Barkovits
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
| | - Martin Eisenacher
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
| | - Rolf Schröder
- Institute of Neuropathology, University Hospital Erlangen, Friedrich-Alexander University Erlangen-Nürnberg, 91054 Erlangen, Germany;
| | - Christoph S. Clemen
- German Aerospace Center, Institute of Aerospace Medicine, 51147 Cologne, Germany;
- Center for Physiology and Pathophysiology, Institute of Vegetative Physiology, Medical Faculty, University of Cologne, 50931 Cologne, Germany
| | - Katrin Marcus
- Medizinisches Proteom-Center, Medical Faculty, Ruhr-University Bochum, 44801 Bochum, Germany; (K.S.); (M.T.); (K.B.); (M.E.)
- Medical Proteome Analysis, Center for Protein Diagnostics (PRODI), Ruhr-University Bochum, 44801 Bochum, Germany
- Correspondence: (B.E.); (K.M.)
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Liewluck T. A Window Into the Myofibrillar Myopathy Proteome. Neurol Genet 2021; 7:e587. [PMID: 34084941 PMCID: PMC8170776 DOI: 10.1212/nxg.0000000000000587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Teerin Liewluck
- Division of Neuromuscular Medicine and Muscle Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN
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14
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Kley RA, Leber Y, Schrank B, Zhuge H, Orfanos Z, Kostan J, Onipe A, Sellung D, Güttsches AK, Eggers B, Jacobsen F, Kress W, Marcus K, Djinovic-Carugo K, van der Ven PFM, Fürst DO, Vorgerd M. FLNC-Associated Myofibrillar Myopathy: New Clinical, Functional, and Proteomic Data. NEUROLOGY-GENETICS 2021; 7:e590. [PMID: 34235269 PMCID: PMC8237399 DOI: 10.1212/nxg.0000000000000590] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 12/28/2020] [Indexed: 11/15/2022]
Abstract
Objective To determine whether a new indel mutation in the dimerization domain of filamin C (FLNc) causes a hereditary myopathy with protein aggregation in muscle fibers, we clinically and molecularly studied a German family with autosomal dominant myofibrillar myopathy (MFM). Methods We performed mutational analysis in 3 generations, muscle histopathology, and proteomic studies of IM protein aggregates. Functional consequences of the FLNC mutation were investigated with interaction and transfection studies and biophysics molecular analysis. Results Eight patients revealed clinical features of slowly progressive proximal weakness associated with a heterozygous c.8025_8030delCAAGACinsA (p.K2676Pfs*3) mutation in FLNC. Two patients exhibited a mild cardiomyopathy. MRI of skeletal muscle revealed lipomatous changes typical for MFM with FLNC mutations. Muscle biopsies showed characteristic MFM findings with protein aggregation and lesion formation. The proteomic profile of aggregates was specific for MFM-filaminopathy and indicated activation of the ubiquitin-proteasome system (UPS) and autophagic pathways. Functional studies revealed that mutant FLNc is misfolded, unstable, and incapable of forming homodimers and heterodimers with wild-type FLNc. Conclusions This new MFM-filaminopathy family confirms that expression of mutant FLNC leads to an adult-onset muscle phenotype with intracellular protein accumulation. Mutant FLNc protein is biochemically compromised and leads to dysregulation of protein quality control mechanisms. Proteomic analysis of MFM protein aggregates is a potent method to identify disease-relevant proteins, differentiate MFM subtypes, evaluate the relevance of gene variants, and identify novel MFM candidate genes.
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Affiliation(s)
- Rudolf Andre Kley
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Yvonne Leber
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Bertold Schrank
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Heidi Zhuge
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Zacharias Orfanos
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Julius Kostan
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Adekunle Onipe
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Dominik Sellung
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Anne Katrin Güttsches
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Britta Eggers
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Frank Jacobsen
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Wolfram Kress
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Katrin Marcus
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Kristina Djinovic-Carugo
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Peter F M van der Ven
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Dieter O Fürst
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Matthias Vorgerd
- Department of Neurology (R.A.K., H.Z., D.S., A.K.G., F.J., M.V.), Heimer Institute for Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany; Department of Neurology and Clinical Neurophysiology (R.A.K.), St. Marien-Hospital Borken, Borken, Germany; Department of Molecular Cell Biology (Y.L., Z.O., P.F.M.V., D.O.F.), Institute for Cell Biology, University of Bonn, Bonn, Germany; Department of Neurology (B.S.), DKD HELIOS Klinik Wiesbaden, Wiesbaden, Germany; Department of Structural and Computational Biology (J.K., A.O., K.D.-C.), Max Perutz Laboratories, University of Vienna, Vienna, Austria; Medizinisches Proteom-Center (B.E., K.M.), Ruhr-University Bochum, Bochum, Germany; Institute of Human Genetics (W.K.), University of Würzburg, Würzburg, Germany; and Department of Biochemistry (K.D.-C.), Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
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15
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Schänzer A, Schumann E, Zengeler D, Gulatz L, Maroli G, Ahting U, Sprengel A, Gräf S, Hahn A, Jux C, Acker T, Fürst DO, Rupp S, Schuld J, van der Ven PFM. The p.Ala2430Val mutation in filamin C causes a "hypertrophic myofibrillar cardiomyopathy". J Muscle Res Cell Motil 2021; 42:381-397. [PMID: 33710525 DOI: 10.1007/s10974-021-09601-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 02/26/2021] [Indexed: 10/21/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) often leads to heart failure. Mutations in sarcomeric proteins are most frequently the cause of HCM but in many patients the gene defect is not known. Here we report on a young man who was diagnosed with HCM shortly after birth. Whole exome sequencing revealed a mutation in the FLNC gene (c.7289C > T; p.Ala2430Val) that was previously shown to cause aggregation of the mutant protein in transfected cells. Myocardial tissue from patients with this mutation has not been analyzed before and thus, the underlying etiology is not well understood. Myocardial tissue of our patient obtained during myectomy at the age of 23 years was analyzed in detail by histochemistry, immunofluorescence staining, electron microscopy and western blot analysis. Cardiac histology showed a pathology typical for myofibrillar myopathy with myofibril disarray and abnormal protein aggregates containing BAG3, desmin, HSPB5 and filamin C. Analysis of sarcomeric and intercalated disc proteins showed focally reduced expression of the gap junction protein connexin43 and Xin-positive sarcomeric lesions in the cardiomyocytes of our patient. In addition, autophagy pathways were altered with upregulation of LC3-II, WIPI1 and HSPB5, 6, 7 and 8. We conclude that the p.Ala2430Val mutation in FLNC most probably is associated with HCM characterized by abnormal intercalated discs, disarray of myofibrils and aggregates containing Z-disc proteins similar to myofibrillar myopathy, which supports the pathological effect of the mutation.
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Affiliation(s)
- Anne Schänzer
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany.
| | - Elisabeth Schumann
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Diana Zengeler
- Center for Genomics and Transcriptomics (CeGat) GmbH, Tübingen, Germany
| | - Lisann Gulatz
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Giovanni Maroli
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Uwe Ahting
- Institute of Human Genetics, Technical University of Munich (TUM), Munich, Germany
| | - Anke Sprengel
- Pediatric Heart Center, Justus Liebig University, Giessen, Germany
| | - Sabine Gräf
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Andreas Hahn
- Department of Child Neurology, Justus Liebig University, Giessen, Germany
| | - Christian Jux
- Pediatric Heart Center, Justus Liebig University, Giessen, Germany
| | - Till Acker
- Institute of Neuropathology, Justus Liebig University, Arndstr.16, 35392, Giessen, Germany
| | - Dieter O Fürst
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Stefan Rupp
- Pediatric Heart Center, Justus Liebig University, Giessen, Germany
| | - Julia Schuld
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
| | - Peter F M van der Ven
- Department of Molecular Cell Biology, Institute for Cell Biology, University of Bonn, Bonn, Germany
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16
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Bouman K, Küsters B, De Winter JM, Gillet C, Van Kleef ESB, Eshuis L, Brochier G, Madelaine A, Labasse C, Boulogne C, Van Engelen BGM, Ottenheijm CAC, Romero NB, Voermans NC, Malfatti E. NEM6, KBTBD13-Related Congenital Myopathy: Myopathological Analysis in 18 Dutch Patients Reveals Ring Rods Fibers, Cores, Nuclear Clumps, and Granulo-Filamentous Protein Material. J Neuropathol Exp Neurol 2021; 80:366-376. [PMID: 33693846 DOI: 10.1093/jnen/nlab012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Nemaline myopathy type 6 (NEM6), KBTBD13-related congenital myopathy is caused by mutated KBTBD13 protein that interacts improperly with thin filaments/actin, provoking impaired muscle-relaxation kinetics. We describe muscle morphology in 18 Dutch NEM6 patients and correlate it with clinical phenotype and pathophysiological mechanisms. Rods were found in in 85% of biopsies by light microscopy, and 89% by electron microscopy. A peculiar ring disposition of rods resulting in ring-rods fiber was observed. Cores were found in 79% of NEM6 biopsies by light microscopy, and 83% by electron microscopy. Electron microscopy also disclosed granulofilamentous protein material in 9 biopsies. Fiber type 1 predominance and prominent nuclear internalization were found. Rods were immunoreactive for α-actinin and myotilin. Areas surrounding the rods showed titin overexpression suggesting derangement of the surrounding sarcomeres. NEM6 myopathology hallmarks are prominent cores, rods including ring-rods fibers, nuclear clumps, and granulofilamentous protein material. This material might represent the histopathologic epiphenomenon of altered interaction between mutated KBTBD13 protein and thin filaments. We claim to classify KBTBD13-related congenital myopathy as rod-core myopathy.
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Affiliation(s)
- Karlijn Bouman
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands.,U1179 UVSQ-INSERM Handicap Neuromusculaire: Physiologie, Biothérapie et Pharmacologie appliquées, UFR Simone Veil-Santé, Université Versailles-Saint-Quentin-en-Yvelines, Paris-Saclay, France
| | - Benno Küsters
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Josine M De Winter
- Department of Physiology, Amsterdam University Medical Center, VUmc, The Netherlands
| | - Cynthia Gillet
- Cytometry/Electronic Microscopy/Light Microscopy Facility, Imagerie-Gif, Institute for Integrative Biology of the Cell I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Esmee S B Van Kleef
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lilian Eshuis
- Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Guy Brochier
- Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Angeline Madelaine
- Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Clémence Labasse
- Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France
| | - Claire Boulogne
- Cytometry/Electronic Microscopy/Light Microscopy Facility, Imagerie-Gif, Institute for Integrative Biology of the Cell I2BC), CEA, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Baziel G M Van Engelen
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Coen A C Ottenheijm
- Department of Physiology, Amsterdam University Medical Center, VUmc, The Netherlands
| | - Norma B Romero
- Unité de Morphologie Neuromusculaire, Institut de Myologie, Groupe Hospitalier Universitaire La Pitié-Salpêtrière, Paris, France.,Université Sorbonne, INSERM UMRS974, Center for Research in Myology, Centre de référence de Pathologie Neuromusculaire Paris-Est, GHU Pitié-Salpêtrière, Paris, France
| | - Nicol C Voermans
- From the Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Edoardo Malfatti
- U1179 UVSQ-INSERM Handicap Neuromusculaire: Physiologie, Biothérapie et Pharmacologie appliquées, UFR Simone Veil-Santé, Université Versailles-Saint-Quentin-en-Yvelines, Paris-Saclay, France.,APHP, Department of Neurology, Raymond Poincaré Hospital, Centre de Référence de Pathologie Neuromusculaire Nord-Est-Ile-de-France, Garches, France
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17
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Qian FY, Guo YD, Zu J, Zhang JH, Zheng YM, Abdoulaye IA, Pan ZH, Xie CM, Gao HC, Zhang ZJ. A novel recessive mutation affecting DNAJB6a causes myofibrillar myopathy. Acta Neuropathol Commun 2021; 9:23. [PMID: 33557929 PMCID: PMC7869515 DOI: 10.1186/s40478-020-01046-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 10/02/2020] [Indexed: 11/10/2022] Open
Abstract
Mutations in the DNAJB6 gene have been identified as rare causes of myofibrillar myopathies. However, the underlying pathophysiologica mechanisms remain elusive. DNAJB6 has two known isoforms, including the nuclear isoform DNAJB6a and the cytoplasmic isoform DNAJB6b, which was thought to be the pathogenic isoform. Here, we report a novel recessive mutation c.695_699del (p. Val 232 Gly fs*7) in the DNAJB6 gene, associated with an apparently recessively inherited late onset distal myofibrillar myopathy in a Chinese family. Notably, the novel mutation localizes to exon 9 and uniquely encodes DNAJB6a. We further identified that this mutation decreases the mRNA and protein levels of DNAJB6a and results in an age-dependent recessive toxic effect on skeletal muscle in knock-in mice. Moreover, the mutant DNAJB6a showed a dose-dependent anti-aggregation effect on polyglutamine-containing proteins in vitro. Taking together, these findings reveal the pathogenic role of DNAJB6a insufficiency in myofibrillar myopathies and expand upon the molecular spectrum of DNAJB6 mutations.
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18
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Fonseca AC, Almeida AG, Santos MO, Ferro JM. Neurological complications of cardiomyopathies. HANDBOOK OF CLINICAL NEUROLOGY 2021; 177:91-109. [PMID: 33632460 DOI: 10.1016/b978-0-12-819814-8.00001-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/28/2023]
Abstract
There is a multifaceted relationship between the cardiomyopathies and a wide spectrum of neurological disorders. Severe acute neurological events, such as a status epilepticus and aneurysmal subarachnoid hemorrhage, may result in an acute cardiomyopathy the likes of Takotsubo cardiomyopathy. Conversely, the cardiomyopathies may result in a wide array of neurological disorders. Diagnosis of a cardiomyopathy may have already been established at the time of the index neurological event, or the neurological event may have prompted subsequent cardiac investigations, which ultimately lead to the diagnosis of a cardiomyopathy. The cardiomyopathies belong to one of the many phenotypes of complex genetic diseases or syndromes, which may also involve the central or peripheral nervous systems. A number of exogenous agents or risk factors such as diphtheria, alcohol, and several viruses may result in secondary cardiomyopathies accompanied by several neurological manifestations. A variety of neuromuscular disorders, such as myotonic dystrophy or amyloidosis, may demonstrate cardiac involvement during their clinical course. Furthermore, a number of genetic cardiomyopathies phenotypically incorporate during their clinical evolution, a gamut of neurological manifestations, usually neuromuscular in nature. Likewise, neurological complications may be the result of diagnostic procedures or medications for the cardiomyopathies and vice versa. Neurological manifestations of the cardiomyopathies are broad and include, among others, transient ischemic attacks, ischemic strokes, intracranial hemorrhages, syncope, muscle weakness and atrophy, myotonia, cramps, ataxia, seizures, intellectual developmental disorder, cognitive impairment, dementia, oculomotor palsies, deafness, retinal involvement, and headaches.
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Affiliation(s)
- Ana Catarina Fonseca
- Neurology Service, Hospital Santa Maria, Centro Hospitalar Lisboa Norte and Faculty of Medicine, University of Lisbon, Lisbon, Portugal
| | - Ana G Almeida
- Cardiology Service, Hospital Santa Maria, Centro Hospitalar Lisboa Norte and Faculty of Medicine, University of Lisbon, Lisbon, Portugal
| | - Miguel Oliveira Santos
- Neurology Service, Hospital Santa Maria, Centro Hospitalar Lisboa Norte and Faculty of Medicine, University of Lisbon, Lisbon, Portugal
| | - José M Ferro
- Neurology Service, Hospital Santa Maria, Centro Hospitalar Lisboa Norte and Faculty of Medicine, University of Lisbon, Lisbon, Portugal.
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19
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Czajkowski ER, Cisneros M, Garcia BS, Shen J, Cripps RM. The Drosophila CG1674 gene encodes a synaptopodin 2-like related protein that localizes to the Z-disc and is required for normal flight muscle development and function. Dev Dyn 2021; 250:99-110. [PMID: 32893414 PMCID: PMC7902442 DOI: 10.1002/dvdy.250] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Revised: 08/12/2020] [Accepted: 09/01/2020] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND To identify novel myofibrillar components of the Drosophila flight muscles, we carried out a proteomic analysis of chemically demembranated flight muscle myofibrils, and characterized the knockdown phenotype of a novel gene identified in the screen, CG1674. RESULTS The CG1674 protein has some similarity to vertebrate synaptopodin 2-like, and when expressed as a FLAG-tagged fusion protein, it was localized during development to the Z-disc and cytoplasm. Knockdown of CG1674 expression affected the function of multiple muscle types, and defective flight in adults was accompanied by large actin-rich structures in the flight muscles that resembled overgrown Z-discs. Localization of CG1674 to the Z-disc depended predominantly upon presence of the Z-disc component alpha-actinin, but also depended upon other Z-disc components, including Mask, Zasp52, and Sals. We also observed re-localization of FLAG-CG1674 to the nucleus in Alpha-actinin and sals knockdown animals. CONCLUSIONS These studies identify and characterize a previously unreported myofibrillar component of Drosophila muscle that is necessary for proper myofibril assembly during development.
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Affiliation(s)
| | - Marilyn Cisneros
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Bianca S. Garcia
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
| | - Jim Shen
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
| | - Richard M. Cripps
- Department of Biology, University of New Mexico, Albuquerque, NM 87131, USA
- Department of Biology, San Diego State University, San Diego, CA 92182, USA
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20
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246th ENMC International Workshop: Protein aggregate myopathies 24-26 May 2019, Hoofddorp, The Netherlands. Neuromuscul Disord 2020; 31:158-166. [PMID: 33303357 DOI: 10.1016/j.nmd.2020.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 11/05/2020] [Indexed: 12/30/2022]
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21
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Luo YB, Peng Y, Lu Y, Li Q, Duan H, Bi F, Yang H. Expanding the Clinico-Genetic Spectrum of Myofibrillar Myopathy: Experience From a Chinese Neuromuscular Center. Front Neurol 2020; 11:1014. [PMID: 33041974 PMCID: PMC7522348 DOI: 10.3389/fneur.2020.01014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 07/31/2020] [Indexed: 12/14/2022] Open
Abstract
Background: Myofibrillar myopathy is a group of hereditary neuromuscular disorders characterized by dissolution of myofibrils and abnormal intracellular accumulation of Z disc-related proteins. We aimed to characterize the clinical, physiological, pathohistological, and genetic features of Chinese myofibrillar myopathy patients from a single neuromuscular center. Methods: A total of 18 patients were enrolled. Demographic and clinical data were collected. Laboratory investigations, electromyography, and cardiac evaluation was performed. Routine and immunohistochemistry stainings against desmin, αB-crystallin, and BAG3 of muscle specimen were carried out. Finally, next-generation sequencing panel array for genes associated with hereditary neuromuscular disorders were performed. Results: Twelve pathogenic variants in DES, BAG3, FLNC, FHL1, and TTN were identified, of which seven were novel mutations. The novel DES c.1256C>T substitution is a high frequency mutation. The combined recessively/dominantly transmitted c.19993G>T and c.107545delG mutations in TTN gene cause a limb girdle muscular dystrophy phenotype with the classical myofibrillar myopathy histological changes. Conclusions: We report for the first time that hereditary myopathy with early respiratory failure patient can have peripheral nerve and severe spine involvement. The mutation in Ig-like domain 16 of FLNC is associated with the limb girdle type of filaminopathy, and the mutation in Ig-like domain 18 with distal myopathy type. These findings expand the phenotypic and genotypic correlation spectrum of myofibrillar myopathy.
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Affiliation(s)
- Yue-Bei Luo
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Yuyao Peng
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Yuling Lu
- Department of Neurology, the First Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Qiuxiang Li
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Huiqian Duan
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Fangfang Bi
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South Hospital, Changsha, China
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22
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A family with adult-onset myofibrillar myopathy with BAG3 mutation (P470S) presenting with axonal polyneuropathy. Neuromuscul Disord 2020; 30:727-731. [PMID: 32859500 DOI: 10.1016/j.nmd.2020.07.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 06/05/2020] [Accepted: 07/28/2020] [Indexed: 11/22/2022]
Abstract
We report a family with adult-onset myofibrillar myopathy with BAG3 mutation who presented peroneal weakness and axonal polyneuropathy, mimicking axonal Charcot-Marie-Tooth disease. The male proband noticed difficulty in tiptoeing at age 34. At age 42, the examination showed muscle weakness and atrophy in distal lower extremities with diminished patellar and Achilles tendon reflexes. Thermal and vibration sensations were also impaired in both feet. The serum CK level was 659 U/L. On muscle imaging, predominant semitendinosus muscle atrophy coexisted with atrophies in the quadriceps, gastrocnemius and lumbar paraspinal muscles. The muscle biopsy showed myofibrillar myopathy with fiber type grouping. His 68-year-old mother also had suffered from distal leg weakness and sensory impairment since her forties. A heterozygous mutation in BAG3 (P470S) was identified in both patients. Clinical features of myofibrillar myopathy with axonal polyneuropathy were consistent with BAG3-related myopathy. Our patients showed remarkably mild presentations without cardiomyopathy, unlike the majorities of previously reported cases.
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23
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Bengoechea R, Findlay AR, Bhadra AK, Shao H, Stein KC, Pittman SK, Daw JA, Gestwicki JE, True HL, Weihl CC. Inhibition of DNAJ-HSP70 interaction improves strength in muscular dystrophy. J Clin Invest 2020; 130:4470-4485. [PMID: 32427588 PMCID: PMC7410071 DOI: 10.1172/jci136167] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Accepted: 05/14/2020] [Indexed: 12/12/2022] Open
Abstract
Dominant mutations in the HSP70 cochaperone DNAJB6 cause a late-onset muscle disease termed limb-girdle muscular dystrophy type D1 (LGMDD1), which is characterized by protein aggregation and vacuolar myopathology. Disease mutations reside within the G/F domain of DNAJB6, but the molecular mechanisms underlying dysfunction are not well understood. Using yeast, cell culture, and mouse models of LGMDD1, we found that the toxicity associated with disease-associated DNAJB6 required its interaction with HSP70 and that abrogating this interaction genetically or with small molecules was protective. In skeletal muscle, DNAJB6 localizes to the Z-disc with HSP70. Whereas HSP70 normally diffused rapidly between the Z-disc and sarcoplasm, the rate of diffusion of HSP70 in LGMDD1 mouse muscle was diminished, probably because it had an unusual affinity for the Z-disc and mutant DNAJB6. Treating LGMDD1 mice with a small-molecule inhibitor of the DNAJ-HSP70 complex remobilized HSP70, improved strength, and corrected myopathology. These data support a model in which LGMDD1 mutations in DNAJB6 are a gain-of-function disease that is, counterintuitively, mediated via HSP70 binding. Thus, therapeutic approaches targeting HSP70-DNAJB6 may be effective in treating this inherited muscular dystrophy.
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Affiliation(s)
| | | | - Ankan K. Bhadra
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Hao Shao
- Institute for Neurodegenerative Diseases, UCSF, San Francisco, California, USA
| | - Kevin C. Stein
- Department of Biology, Stanford University, Stanford, California, USA
| | | | | | - Jason E. Gestwicki
- Institute for Neurodegenerative Diseases, UCSF, San Francisco, California, USA
| | - Heather L. True
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri, USA
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24
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25
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Aoki R, Kokubun N, Komagamine T, Ishii Y, Nishino I, Hirata K. [Selective muscular atrophy in a family with hereditary myopathy with early respiratory failure]. Rinsho Shinkeigaku 2020; 60:334-339. [PMID: 32307395 DOI: 10.5692/clinicalneurol.cn-001380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Hereditary myopathy with early respiratory failure (HMERF) with heterozygous mutations in the titin gene (TTN) is characterized by respiratory failure developing from the early phase of limb weakness or gait disturbance. Here, we describe a characteristic distribution of muscle involvement in three members of a HMERF family with a TTN mutation. Despite the differences in severity exhibited among the father, daughter and son, the systemic imaging studies showed a similar pattern among these individuals. The semitendinosus and fibularis longus muscles were selectively affected, as described previously. In addition, we found marked atrophy in the sternocleidomastoid and psoas major muscles, regardless of the disease severity. The atrophy in selective trunk muscles observed in routine CT scans can be useful for the differential diagnosis of hereditary myopathies with heart and respiratory failure.
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Affiliation(s)
- Reika Aoki
- Department of Neurology, Dokkyo Medical University
| | | | | | - Yuko Ishii
- Department of Neurology, Dokkyo Medical University
| | - Ichizo Nishino
- Department of Neuromuscular Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP)
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26
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Brooks D, Naeem F, Stetsiv M, Goetting SC, Bawa S, Green N, Clark C, Bashirullah A, Geisbrecht ER. Drosophila NUAK functions with Starvin/BAG3 in autophagic protein turnover. PLoS Genet 2020; 16:e1008700. [PMID: 32320396 PMCID: PMC7176095 DOI: 10.1371/journal.pgen.1008700] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 02/28/2020] [Indexed: 11/18/2022] Open
Abstract
The inability to remove protein aggregates in post-mitotic cells such as muscles or neurons is a cellular hallmark of aging cells and is a key factor in the initiation and progression of protein misfolding diseases. While protein aggregate disorders share common features, the molecular level events that culminate in abnormal protein accumulation cannot be explained by a single mechanism. Here we show that loss of the serine/threonine kinase NUAK causes cellular degeneration resulting from the incomplete clearance of protein aggregates in Drosophila larval muscles. In NUAK mutant muscles, regions that lack the myofibrillar proteins F-actin and Myosin heavy chain (MHC) instead contain damaged organelles and the accumulation of select proteins, including Filamin (Fil) and CryAB. NUAK biochemically and genetically interacts with Drosophila Starvin (Stv), the ortholog of mammalian Bcl-2-associated athanogene 3 (BAG3). Consistent with a known role for the co-chaperone BAG3 and the Heat shock cognate 71 kDa (HSC70)/HSPA8 ATPase in the autophagic clearance of proteins, RNA interference (RNAi) of Drosophila Stv, Hsc70-4, or autophagy-related 8a (Atg8a) all exhibit muscle degeneration and muscle contraction defects that phenocopy NUAK mutants. We further demonstrate that Fil is a target of NUAK kinase activity and abnormally accumulates upon loss of the BAG3-Hsc70-4 complex. In addition, Ubiquitin (Ub), ref(2)p/p62, and Atg8a are increased in regions of protein aggregation, consistent with a block in autophagy upon loss of NUAK. Collectively, our results establish a novel role for NUAK with the Stv-Hsc70-4 complex in the autophagic clearance of proteins that may eventually lead to treatment options for protein aggregate diseases.
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Affiliation(s)
- David Brooks
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States of America
| | - Fawwaz Naeem
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States of America
| | - Marta Stetsiv
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States of America
| | - Samantha C Goetting
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States of America
| | - Simranjot Bawa
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States of America
| | - Nicole Green
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States of America
| | - Cheryl Clark
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States of America
| | - Arash Bashirullah
- Division of Pharmaceutical Sciences, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Erika R Geisbrecht
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States of America
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27
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Widespread remodeling of proteome solubility in response to different protein homeostasis stresses. Proc Natl Acad Sci U S A 2020; 117:2422-2431. [PMID: 31964829 DOI: 10.1073/pnas.1912897117] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The accumulation of protein deposits in neurodegenerative diseases has been hypothesized to depend on a metastable subproteome vulnerable to aggregation. To investigate this phenomenon and the mechanisms that regulate it, we measured the solubility of the proteome in the mouse Neuro2a cell line under six different protein homeostasis stresses: 1) Huntington's disease proteotoxicity, 2) Hsp70, 3) Hsp90, 4) proteasome, 5) endoplasmic reticulum (ER)-mediated folding inhibition, and 6) oxidative stress. Overall, we found that about one-fifth of the proteome changed solubility with almost all of the increases in insolubility were counteracted by increases in solubility of other proteins. Each stress directed a highly specific pattern of change, which reflected the remodeling of protein complexes involved in adaptation to perturbation, most notably, stress granule (SG) proteins, which responded differently to different stresses. These results indicate that the protein homeostasis system is organized in a modular manner and aggregation patterns were not correlated with protein folding stability (ΔG). Instead, distinct cellular mechanisms regulate assembly patterns of multiple classes of protein complexes under different stress conditions.
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28
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Abstract
PURPOSE OF REVIEW This article reviews the clinical, laboratory, and histopathologic features of sporadic inclusion body myositis (IBM) and explores its pathogenic overlap with inherited myopathies that have IBM-like pathology. RECENT FINDINGS Sporadic IBM is the most common acquired muscle disease in patients older than 50 years of age and is becoming more prevalent because of the increasing age of the population, the emerging development of more inclusive diagnostic criteria, and the advent of a diagnostic autoantibody. No effective therapy is known, and the pathogenic mechanism remains unclear. Some pathogenic insight can be gleaned from other myopathies with pathologic similarities or hereditary inclusion body myopathies. Although clinically distinct from sporadic IBM, preclinical models of hereditary inclusion body myopathy have offered an opportunity to move some therapies toward clinical development. SUMMARY Patients with sporadic IBM experience significant morbidity, and the disease is associated with a large unmet medical need. As therapies are developed, improved diagnosis will be essential. Early diagnosis relies on awareness, clinical history, physical examination, laboratory features, and appropriate muscle biopsy processing. Future research is needed to understand the natural history, identify genetic risk factors, and validate biomarkers to track disease progression. These steps are essential as we move toward therapeutic interventions.
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29
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Ciryam P, Antalek M, Cid F, Tartaglia GG, Dobson CM, Guettsches AK, Eggers B, Vorgerd M, Marcus K, Kley RA, Morimoto RI, Vendruscolo M, Weihl CC. A metastable subproteome underlies inclusion formation in muscle proteinopathies. Acta Neuropathol Commun 2019; 7:197. [PMID: 31796104 PMCID: PMC6891963 DOI: 10.1186/s40478-019-0853-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2019] [Accepted: 11/21/2019] [Indexed: 01/20/2023] Open
Abstract
Protein aggregation is a pathological feature of neurodegenerative disorders. We previously demonstrated that protein inclusions in the brain are composed of supersaturated proteins, which are abundant and aggregation-prone, and form a metastable subproteome. It is not yet clear, however, whether this phenomenon is also associated with non-neuronal protein conformational disorders. To respond to this question, we analyzed proteomic datasets from biopsies of patients with genetic and acquired protein aggregate myopathy (PAM) by quantifying the changes in composition, concentration and aggregation propensity of proteins in the fibers containing inclusions and those surrounding them. We found that a metastable subproteome is present in skeletal muscle from healthy patients. The expression of this subproteome escalate as proteomic samples are taken more proximal to the pathologic inclusion, eventually exceeding its solubility limits and aggregating. While most supersaturated proteins decrease or maintain steady abundance across healthy fibers and inclusion-containing fibers, proteins within the metastable subproteome rise in abundance, suggesting that they escape regulation. Taken together, our results show in the context of a human conformational disorder that the supersaturation of a metastable subproteome underlies widespread aggregation and correlates with the histopathological state of the tissue.
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Affiliation(s)
- Prajwal Ciryam
- Department of Neurology, Vagelos College of Physicians & Surgeons, Columbia University, New York, NY, USA
| | - Matthew Antalek
- Rice Institute for Biomedical Research, Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Fernando Cid
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Gian Gaetano Tartaglia
- Centre for Genomic Regulation, The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Christopher M Dobson
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Anne-Katrin Guettsches
- Department of Neurology, Heimer Institute of Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Britta Eggers
- Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany
| | - Matthias Vorgerd
- Department of Neurology, Heimer Institute of Muscle Research, University Hospital Bergmannsheil, Ruhr-University Bochum, Bochum, Germany
| | - Katrin Marcus
- Medizinisches Proteom-Center, Ruhr-University Bochum, Bochum, Germany
| | - Rudolf A Kley
- Department of Neurology, St. Marien Hospital Borken, University of Witten/Herdecke, Borken, Germany
| | - Richard I Morimoto
- Rice Institute for Biomedical Research, Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Michele Vendruscolo
- Centre for Misfolding Diseases, Department of Chemistry, University of Cambridge, Cambridge, UK
| | - Conrad C Weihl
- Department of Neurology and Hope Center for Neurological Disease, Washington University School of Medicine, Saint Louis, MO, USA.
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González-Morales N, Xiao YS, Schilling MA, Marescal O, Liao KA, Schöck F. Myofibril diameter is set by a finely tuned mechanism of protein oligomerization in Drosophila. eLife 2019; 8:50496. [PMID: 31746737 PMCID: PMC6910826 DOI: 10.7554/elife.50496] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 11/18/2019] [Indexed: 11/13/2022] Open
Abstract
Myofibrils are huge cytoskeletal assemblies embedded in the cytosol of muscle cells. They consist of arrays of sarcomeres, the smallest contractile unit of muscles. Within a muscle type, myofibril diameter is highly invariant and contributes to its physiological properties, yet little is known about the underlying mechanisms setting myofibril diameter. Here we show that the PDZ and LIM domain protein Zasp, a structural component of Z-discs, mediates Z-disc and thereby myofibril growth through protein oligomerization. Oligomerization is induced by an interaction of its ZM domain with LIM domains. Oligomerization is terminated upon upregulation of shorter Zasp isoforms which lack LIM domains at later developmental stages. The balance between these two isoforms, which we call growing and blocking isoforms sets the stereotyped diameter of myofibrils. If blocking isoforms dominate, myofibrils become smaller. If growing isoforms dominate, myofibrils and Z-discs enlarge, eventually resulting in large pathological aggregates that disrupt muscle function.
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Affiliation(s)
| | - Yu Shu Xiao
- Department of Biology, McGill University, Montreal, Canada
| | | | | | - Kuo An Liao
- Department of Biology, McGill University, Montreal, Canada
| | - Frieder Schöck
- Department of Biology, McGill University, Montreal, Canada
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31
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Desmin forms toxic, seeding-competent amyloid aggregates that persist in muscle fibers. Proc Natl Acad Sci U S A 2019; 116:16835-16840. [PMID: 31371504 PMCID: PMC6708308 DOI: 10.1073/pnas.1908263116] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Protein aggregation and the deposition of amyloid is a common feature in neurodegeneration, but can also be seen in degenerative muscle diseases known as myofibrillar myopathies (MFMs). Hallmark pathology in MFM patient muscle is myofibrillar disarray, aggregation of the muscle-specific intermediate filament, desmin, and amyloid. In some cases, a missense mutation in desmin leads to its destabilization and aggregation. The present study demonstrates that similar to neurodegenerative proteins, desmin can form amyloid and template the amyloidogenic conversion of unaggregated desmin protein. This desmin-derived amyloid is toxic to myocytes and persists when introduced into skeletal muscle, in contrast to unaggregated desmin. These data demonstrate that desmin itself can form amyloid and expand the mechanism of proteinopathies to skeletal muscle. Desmin-associated myofibrillar myopathy (MFM) has pathologic similarities to neurodegeneration-associated protein aggregate diseases. Desmin is an abundant muscle-specific intermediate filament, and disease mutations lead to its aggregation in cells, animals, and patients. We reasoned that similar to neurodegeneration-associated proteins, desmin itself may form amyloid. Desmin peptides corresponding to putative amyloidogenic regions formed seeding-competent amyloid fibrils. Amyloid formation was increased when disease-associated mutations were made within the peptide, and this conversion was inhibited by the anti-amyloid compound epigallocatechin-gallate. Moreover, a purified desmin fragment (aa 117 to 348) containing both amyloidogenic regions formed amyloid fibrils under physiologic conditions. Desmin fragment-derived amyloid coaggregated with full-length desmin and was able to template its conversion into fibrils in vitro. Desmin amyloids were cytotoxic to myotubes and disrupted their myofibril organization compared with desmin monomer or other nondesmin amyloids. Finally, desmin fragment amyloid persisted when introduced into mouse skeletal muscle. These data suggest that desmin forms seeding-competent amyloid that is toxic to myofibers. Moreover, small molecules known to interfere with amyloid formation and propagation may have therapeutic potential in MFM.
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Zhang J, Liu J, Wu J, Li W, Chen Z, Yang L. Progression of the role of CRYAB in signaling pathways and cancers. Onco Targets Ther 2019; 12:4129-4139. [PMID: 31239701 PMCID: PMC6553995 DOI: 10.2147/ott.s201799] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 04/07/2019] [Indexed: 01/18/2023] Open
Abstract
CRYAB is a member of the small heat shock protein family, first discovered in the lens of the eye, and involved in various diseases, such as eye and heart diseases and even cancers, for example, breast cancer, lung cancer, prostate cancer, and ovarian cancer. In addition, CRYAB proteins are involved in a variety of signaling pathways including apoptosis, inflammation, and oxidative stress. This review summarizes the recent progress concerning the role of CRYAB in signaling pathways and diseases. Therefore, the role of CRYAB in signaling pathways and cancers is urgently needed. This article reviews the regulation of CRYAB in the apoptotic inflammatory signaling pathway and its role in cancers progression and as a key role in anti-cancer therapy targeting CRYAB in an effort to improve outcomes for patients with metastatic disease.
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Affiliation(s)
- JunFei Zhang
- Department of Emergency Medical, General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750000, People's Republic of China
| | - Jia Liu
- Department of Emergency Medical, General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750000, People's Republic of China
| | - JiaLi Wu
- Department of Emergency Medical, General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750000, People's Republic of China
| | - WenFeng Li
- Department of Emergency Medical, General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750000, People's Republic of China
| | - ZhongWei Chen
- Department of Emergency Medical, General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750000, People's Republic of China
| | - LiShan Yang
- Department of Emergency Medical, General Hospital of Ningxia Medical University, Yinchuan, Ningxia 750000, People's Republic of China
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Anagnostou E, Vasilakou I, Papadopoulos C, Zambelis T, Papadimas G. Motor unit potential changes in myofibrillar myopathy. J Neurol Sci 2019; 400:110-112. [DOI: 10.1016/j.jns.2019.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 03/15/2019] [Accepted: 03/19/2019] [Indexed: 11/17/2022]
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Murphy S, Dowling P, Zweyer M, Swandulla D, Ohlendieck K. Proteomic profiling of giant skeletal muscle proteins. Expert Rev Proteomics 2019; 16:241-256. [DOI: 10.1080/14789450.2019.1575205] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Sandra Murphy
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Ireland
- Newcastle Fibrosis Research Group, Institute of Cellular Medicine, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Ireland
| | - Margit Zweyer
- Institute of Physiology II, University of Bonn, Bonn, Germany
| | | | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, Maynooth, Ireland
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35
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Milone M, Liewluck T. The unfolding spectrum of inherited distal myopathies. Muscle Nerve 2018; 59:283-294. [PMID: 30171629 DOI: 10.1002/mus.26332] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 08/26/2018] [Accepted: 08/28/2018] [Indexed: 12/30/2022]
Abstract
Distal myopathies are a group of rare muscle diseases characterized by distal weakness at onset. Although acquired myopathies can occasionally present with distal weakness, the majority of distal myopathies have a genetic etiology. Their age of onset varies from early-childhood to late-adulthood while the predominant muscle weakness can affect calf, ankle dorsiflexor, or distal upper limb muscles. A spectrum of muscle pathological changes, varying from nonspecific myopathic changes to rimmed vacuoles to myofibrillar pathology to nuclei centralization, have been noted. Likewise, the underlying molecular defect is heterogeneous. In addition, there is emerging evidence that distal myopathies can result from defective proteins encoded by genes causative of neurogenic disorders, be manifestation of multisystem proteinopathies or the result of the altered interplay between different genes. In this review, we provide an overview on the clinical, electrophysiological, pathological, and molecular aspects of distal myopathies, focusing on the most recent developments in the field. Muscle Nerve 59:283-294, 2019.
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Affiliation(s)
| | - Teerin Liewluck
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
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36
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Ding J, Cong YF, Liu B, Miao J, Wang L. Aberrant Protein Turn-Over Associated With Myofibrillar Disorganization in FHL1 Knockout Mice. Front Genet 2018; 9:273. [PMID: 30083183 PMCID: PMC6065255 DOI: 10.3389/fgene.2018.00273] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/04/2018] [Indexed: 12/12/2022] Open
Abstract
Mutations in the FHL1 gene, and FHL1 protein deletion, are associated with rare hereditary myopathies and cardiomyopathies. FHL1-null mice develop age-dependent myopathy and increased autophagic activity. However, the molecular pathway involved in contractile function and increased autophagic activity in the FHL1-null mouse has not yet been fully elucidated. In this study, FHL1 protein was knocked out in mice using Transcription Activator-like Effector Nucleases (TALENs) and the IRS1-FOXO1/mTOR signaling pathway was investigated in skeletal muscles and heart. TALEN constructs caused targeted mutations in 30% of newborn mice; these mutations caused a deletion of 1–13 base pairs which blocked synthesis of the full-length FHL1 protein. Furthermore, 2.5-month old FHL1-null male mice were not prone to global muscular fatigue when compared with WT littermates, but histological analysis and ultrastructural analysis by transmission electron microscopy confirmed the presence of myofibrillar disorganization and the accumulation of autophagosome or autolysosome-like structures in FHL1-null mice. Moreover, autophagy and mitophagy were both activated in FHL1 KO mice and the degradation of autophagic lysosomes was impeded. Enhanced autophagic activity in FHL1 KO mice was induced by FOXO1 up-regulation and protein synthesis was increased via mTOR. The cytoskeletal proteins, MYBPC2 and LDB3, were involved in the formation of pathological changes in FHL1 KO mice. Markers of early differentiation (MEF2C and MYOD1) and terminal differentiation (total MYH) were both up-regulated in tibialis anterior (TA) muscles in FHL1 KO mice. The number of type I and type II fibers increased in FHL1-null TA muscles, but the number of type| | b, and type | | d fibers were both reduced in FHL1-null TA muscles. The results obtained from the heart were consistent with those from the skeletal muscle and indicated autophagic activation by FOXO1 and an increase in protein synthesis via mTOR also occurred in the heart tissue of FHL1 knockout mice. In conclusion, aberrant protein turn-over associated with myofibrillar disorganization in FHL1 knockout mice. the up-regulation of FOXO1 was associated with enhanced autophagic activity and pathological changes in the muscle fibers of FHL1 KO mice. These results indicated that autophagy activated by FOXO1 is a promising therapeutic target for hereditary myopathies and cardiomyopathies induced by FHL1.
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Affiliation(s)
- Jingjing Ding
- Medical Research Center of Shengjing Hospital, China Medical University, Shenyang, China
| | - Yan Fei Cong
- Medical Research Center of Shengjing Hospital, China Medical University, Shenyang, China
| | - Bo Liu
- Medical Research Center of Shengjing Hospital, China Medical University, Shenyang, China
| | - Jianing Miao
- Medical Research Center of Shengjing Hospital, China Medical University, Shenyang, China
| | - Lili Wang
- Medical Research Center of Shengjing Hospital, China Medical University, Shenyang, China
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Hutt DM, Mishra SK, Roth DM, Larsen MB, Angles F, Frizzell RA, Balch WE. Silencing of the Hsp70-specific nucleotide-exchange factor BAG3 corrects the F508del-CFTR variant by restoring autophagy. J Biol Chem 2018; 293:13682-13695. [PMID: 29986884 DOI: 10.1074/jbc.ra118.002607] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 07/05/2018] [Indexed: 01/11/2023] Open
Abstract
The protein chaperones heat shock protein 70 (Hsp70) and Hsp90 are required for de novo folding of proteins and protect against misfolding-related cellular stresses by directing misfolded or slowly folding proteins to the ubiquitin/proteasome system (UPS) or autophagy/lysosomal degradation pathways. Here, we examined the role of the Bcl2-associated athanogene (BAG) family of Hsp70-specific nucleotide-exchange factors in the biogenesis and functional correction of genetic variants of the cystic fibrosis transmembrane conductance regulator (CFTR) whose mutations cause cystic fibrosis (CF). We show that siRNA-mediated silencing of BAG1 and -3, two BAG members linked to the clearance of misfolded proteins via the UPS and autophagy pathways, respectively, leads to functional correction of F508del-CFTR and other disease-associated CFTR variants. BAG3 silencing was the most effective, leading to improved F508del-CFTR stability, trafficking, and restoration of cell-surface function, both alone and in combination with the FDA-approved CFTR corrector, VX-809. We also found that the BAG3 silencing-mediated correction of F508del-CFTR restores the autophagy pathway, which is defective in F508del-CFTR-expressing cells, likely because of the maladaptive stress response in CF pathophysiology. These results highlight the potential therapeutic benefits of targeting the cellular chaperone system to improve the functional folding of CFTR variants contributing to CF and possibly other protein-misfolding-associated diseases.
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Affiliation(s)
- Darren M Hutt
- From the Department of Molecular Medicine, Skaggs Institute for Chemical Biology, Scripps Research, La Jolla, California 92037 and
| | - Sanjay Kumar Mishra
- the Departments of Pediatrics and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Daniela Martino Roth
- From the Department of Molecular Medicine, Skaggs Institute for Chemical Biology, Scripps Research, La Jolla, California 92037 and
| | - Mads Breum Larsen
- the Departments of Pediatrics and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - Frédéric Angles
- From the Department of Molecular Medicine, Skaggs Institute for Chemical Biology, Scripps Research, La Jolla, California 92037 and
| | - Raymond A Frizzell
- the Departments of Pediatrics and Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15224
| | - William E Balch
- From the Department of Molecular Medicine, Skaggs Institute for Chemical Biology, Scripps Research, La Jolla, California 92037 and
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38
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Jungbluth H. Myopathology in times of modern imaging. Neuropathol Appl Neurobiol 2018; 43:24-43. [PMID: 28111795 DOI: 10.1111/nan.12385] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Revised: 01/17/2017] [Accepted: 01/23/2017] [Indexed: 12/14/2022]
Abstract
Over the last two decades, muscle (magnetic resonance) imaging has become an important complementary tool in the diagnosis and differential diagnosis of inherited neuromuscular disorders, particularly in conditions where the pattern of selective muscle involvement is often more predictive of the underlying genetic background than associated clinical and histopathological features. Following an overview of different imaging modalities, the present review will give a concise introduction to systematic image analysis and interpretation in genetic neuromuscular disorders. The pattern of selective muscle involvement will be presented in detail in conditions such as the congenital or myofibrillar myopathies where muscle imaging is particularly useful to inform the (differential) diagnosis, and in disorders such as Duchenne or fascioscapulohumeral muscular dystrophy where the diagnosis is usually made on clinical grounds but where detailed knowledge of disease progression on the muscle imaging level may inform better understanding of the natural history. Utilizing the group of the congenital myopathies as an example, selected case studies will illustrate how muscle MRI can be used to inform the diagnostic process in the clinico-pathological context. Future developments, in particular, concerning the increasing use of whole-body MRI protocols and novel quantitative fat assessments techniques potentially relevant as an outcome measure, will be briefly outlined.
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Affiliation(s)
- H Jungbluth
- Department of Paediatric Neurology, Neuromuscular Service, Evelina's Children Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, London, UK.,Randall Division of Cell and Molecular Biophysics, Muscle Signalling Section, London, UK.,Department of Clinical and Basic Neuroscience, IoPPN, King's College, London, UK
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39
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Schänzer A, Rupp S, Gräf S, Zengeler D, Jux C, Akintürk H, Gulatz L, Mazhari N, Acker T, Van Coster R, Garvalov BK, Hahn A. Dysregulated autophagy in restrictive cardiomyopathy due to Pro209Leu mutation in BAG3. Mol Genet Metab 2018; 123:388-399. [PMID: 29338979 DOI: 10.1016/j.ymgme.2018.01.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 01/02/2018] [Accepted: 01/02/2018] [Indexed: 12/13/2022]
Abstract
Myofibrillary myopathies (MFM) are hereditary myopathies histologically characterized by degeneration of myofibrils and aggregation of proteins in striated muscle. Cardiomyopathy is common in MFM but the pathophysiological mechanisms are not well understood. The BAG3-Pro209Leu mutation is associated with early onset MFM and severe restrictive cardiomyopathy (RCM), often necessitating heart transplantation during childhood. We report on a young male patient with a BAG3-Pro209Leu mutation who underwent heart transplantation at eight years of age. Detailed morphological analyses of the explanted heart tissue showed intracytoplasmic inclusions, aggregation of BAG3 and desmin, disintegration of myofibers and Z-disk alterations. The presence of undegraded autophagosomes, seen by electron microscopy, as well as increased levels of p62, LC3-I and WIPI1, detected by immunohistochemistry and western blot analyses, indicated a dysregulation of autophagy. Parkin and PINK1, proteins involved in mitophagy, were slightly increased whereas mitochondrial OXPHOS activities were not altered. These findings indicate that altered autophagy plays a role in the pathogenesis and rapid progression of RCM in MFM caused by the BAG3-Pro209Leu mutation, which could have implications for future therapeutic strategies.
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Affiliation(s)
- A Schänzer
- Institute of Neuropathology, Justus Liebig University Giessen, 35392 Giessen, Germany.
| | - S Rupp
- Pediatric Heart Center, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - S Gräf
- Institute of Neuropathology, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - D Zengeler
- Center for Genomics and Transcriptomics (CeGat) GmbH, 72076 Tübingen, Germany
| | - C Jux
- Pediatric Heart Center, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - H Akintürk
- Pediatric Heart Center, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - L Gulatz
- Institute of Neuropathology, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - N Mazhari
- Pediatric Heart Center, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - T Acker
- Institute of Neuropathology, Justus Liebig University Giessen, 35392 Giessen, Germany
| | - R Van Coster
- Division of Child Neurology, Department of Pediatrics, University Hospital Gent, 9000 Gent, Belgium
| | - B K Garvalov
- Institute of Neuropathology, Justus Liebig University Giessen, 35392 Giessen, Germany; Department of Microvascular Biology and Pathobiology, Centre for Biomedicine and Medical Technology Mannheim (CBTM), Medical Faculty Mannheim, University of Heidelberg, 68167 Mannheim, Germany
| | - A Hahn
- Department of Child Neurology, Justus Liebig University Giessen, 35392 Giessen, Germany
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40
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Liewluck T, Milone M. Untangling the complexity of limb-girdle muscular dystrophies. Muscle Nerve 2018; 58:167-177. [PMID: 29350766 DOI: 10.1002/mus.26077] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/16/2018] [Indexed: 12/16/2022]
Abstract
The limb-girdle muscular dystrophies (LGMDs) are a group of genetically heterogeneous, autosomal inherited muscular dystrophies with a childhood to adult onset, manifesting with hip- and shoulder-girdle muscle weakness. When the term LGMD was first conceptualized in 1954, it was thought to be a single entity. Currently, there are 8 autosomal dominant (LGMD1A-1H) and 26 autosomal recessive (LGMD2A-2Z) variants according to the Online Mendelian Inheritance in Man database. In addition, there are other genetically identified muscular dystrophies with an LGMD phenotype not yet classified as LGMD. This highlights the entanglement of LGMDs, which represents an area in continuous expansion. Herein we aim to simplify the complexity of LGMDs by subgrouping them on the basis of the underlying defective protein and impaired function. Muscle Nerve 58: 167-177, 2018.
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Affiliation(s)
- Teerin Liewluck
- Department of Neurology, Mayo Clinic, 200 First Street SW Rochester, Minnesota, 55905, USA
| | - Margherita Milone
- Department of Neurology, Mayo Clinic, 200 First Street SW Rochester, Minnesota, 55905, USA
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41
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The MTM1-UBQLN2-HSP complex mediates degradation of misfolded intermediate filaments in skeletal muscle. Nat Cell Biol 2018; 20:198-210. [PMID: 29358706 DOI: 10.1038/s41556-017-0024-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 12/06/2017] [Indexed: 12/14/2022]
Abstract
The ubiquitin proteasome system and autophagy are major protein turnover mechanisms in muscle cells, which ensure stemness and muscle fibre maintenance. Muscle cells contain a high proportion of cytoskeletal proteins, which are prone to misfolding and aggregation; pathological processes that are observed in several neuromuscular diseases called proteinopathies. Despite advances in deciphering the mechanisms underlying misfolding and aggregation, little is known about how muscle cells manage cytoskeletal degradation. Here, we describe a process by which muscle cells degrade the misfolded intermediate filament proteins desmin and vimentin by the proteasome. This relies on the MTM1-UBQLN2 complex to recognize and guide these misfolded proteins to the proteasome and occurs prior to aggregate formation. Thus, our data highlight a safeguarding function of the MTM1-UBQLN2 complex that ensures cytoskeletal integrity to avoid proteotoxic aggregate formation.
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Bouhy D, Juneja M, Katona I, Holmgren A, Asselbergh B, De Winter V, Hochepied T, Goossens S, Haigh JJ, Libert C, Ceuterick-de Groote C, Irobi J, Weis J, Timmerman V. A knock-in/knock-out mouse model of HSPB8-associated distal hereditary motor neuropathy and myopathy reveals toxic gain-of-function of mutant Hspb8. Acta Neuropathol 2018; 135:131-148. [PMID: 28780615 PMCID: PMC5756276 DOI: 10.1007/s00401-017-1756-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 07/20/2017] [Accepted: 07/25/2017] [Indexed: 12/14/2022]
Abstract
Mutations in the small heat shock protein B8 gene (HSPB8/HSP22) have been associated with distal hereditary motor neuropathy, Charcot-Marie-Tooth disease, and recently distal myopathy. It is so far not clear how mutant HSPB8 induces the neuronal and muscular phenotypes and if a common pathogenesis lies behind these diseases. Growing evidence points towards a role of HSPB8 in chaperone-associated autophagy, which has been shown to be a determinant for the clearance of poly-glutamine aggregates in neurodegenerative diseases but also for the maintenance of skeletal muscle myofibrils. To test this hypothesis and better dissect the pathomechanism of mutant HSPB8, we generated a new transgenic mouse model leading to the expression of the mutant protein (knock-in lines) or the loss-of-function (functional knock-out lines) of the endogenous protein Hspb8. While the homozygous knock-in mice developed motor deficits associated with degeneration of peripheral nerves and severe muscle atrophy corroborating patient data, homozygous knock-out mice had locomotor performances equivalent to those of wild-type animals. The distal skeletal muscles of the post-symptomatic homozygous knock-in displayed Z-disk disorganisation, granulofilamentous material accumulation along with Hspb8, αB-crystallin (HSPB5/CRYAB), and desmin aggregates. The presence of the aggregates correlated with reduced markers of effective autophagy. The sciatic nerve of the homozygous knock-in mice was characterized by low autophagy potential in pre-symptomatic and Hspb8 aggregates in post-symptomatic animals. On the other hand, the sciatic nerve of the homozygous knock-out mice presented a normal morphology and their distal muscle displayed accumulation of abnormal mitochondria but intact myofiber and Z-line organisation. Our data, therefore, suggest that toxic gain-of-function of mutant Hspb8 aggregates is a major contributor to the peripheral neuropathy and the myopathy. In addition, mutant Hspb8 induces impairments in autophagy that may aggravate the phenotype.
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Affiliation(s)
- Delphine Bouhy
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences and Institute Born Bunge, University of Antwerp, Universiteitsplein 1, 2610, Antwerpen, Belgium
| | - Manisha Juneja
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences and Institute Born Bunge, University of Antwerp, Universiteitsplein 1, 2610, Antwerpen, Belgium
| | - Istvan Katona
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Anne Holmgren
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences and Institute Born Bunge, University of Antwerp, Universiteitsplein 1, 2610, Antwerpen, Belgium
| | - Bob Asselbergh
- VIB Center for Molecular Neurology, University of Antwerp, Antwerpen, Belgium
| | - Vicky De Winter
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences and Institute Born Bunge, University of Antwerp, Universiteitsplein 1, 2610, Antwerpen, Belgium
| | - Tino Hochepied
- Transgenic Mouse Core Facility, VIB Inflammation Research Center, Gent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Gent, Belgium
| | - Steven Goossens
- Department of Biomedical Molecular Biology, Ghent University, Gent, Belgium
- Cancer Research Institute Ghent (CRIG), Ghent University, Gent, Belgium
- VIB Inflammation Research Center, Ghent University, Gent, Belgium
| | - Jody J Haigh
- Department of Biomedical Molecular Biology, Ghent University, Gent, Belgium
- Mammalian Functional Genetics Laboratory, Division of Blood Cancers, Australian Centre for Blood Diseases, Monash University, Melbourne, VIC, 3004, Australia
| | - Claude Libert
- VIB Inflammation Research Center, Ghent University, Gent, Belgium
| | - Chantal Ceuterick-de Groote
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge and Translational Neurosciences, University of Antwerp, Antwerpen, Belgium
| | - Joy Irobi
- Neurofunctional Genomics, Biomedical Research Institute (BIOMED), Hasselt University/Transnational University Limburg, School of Life Sciences, Diepenbeek, Belgium
| | - Joachim Weis
- Institute of Neuropathology, RWTH Aachen University Hospital, Aachen, Germany
| | - Vincent Timmerman
- Peripheral Neuropathy Research Group, Department of Biomedical Sciences and Institute Born Bunge, University of Antwerp, Universiteitsplein 1, 2610, Antwerpen, Belgium.
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43
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Dhawan PS, Liewluck T, Knapik J, Milone M. Myofibrillar myopathy due to dominant LMNA mutations: A report of 2 cases. Muscle Nerve 2017; 57:E124-E126. [PMID: 29211919 DOI: 10.1002/mus.26036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 11/27/2017] [Accepted: 12/05/2017] [Indexed: 11/07/2022]
Affiliation(s)
- Priya S Dhawan
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Teerin Liewluck
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Joseph Knapik
- Department of Neurology and Rehabilitation, Saint Mary's Regional Medical Center, Enid, Oklahoma, USA
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Unger A, Beckendorf L, Böhme P, Kley R, von Frieling-Salewsky M, Lochmüller H, Schröder R, Fürst DO, Vorgerd M, Linke WA. Translocation of molecular chaperones to the titin springs is common in skeletal myopathy patients and affects sarcomere function. Acta Neuropathol Commun 2017; 5:72. [PMID: 28915917 PMCID: PMC5603016 DOI: 10.1186/s40478-017-0474-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Accepted: 09/09/2017] [Indexed: 12/16/2022] Open
Abstract
Myopathies encompass a wide variety of acquired and hereditary disorders. The pathomechanisms include structural and functional changes affecting, e.g., myofiber metabolism and contractile properties. In this study, we observed increased passive tension (PT) of skinned myofibers from patients with myofibrillar myopathy (MFM) caused by FLNC mutations (MFM-filaminopathy) and limb-girdle muscular dystrophy type-2A due to CAPN3 mutations (LGMD2A), compared to healthy control myofibers. Because the giant protein titin determines myofiber PT, we measured its molecular size and the titin-to-myosin ratio, but found no differences between myopathies and controls. All-titin phosphorylation and site-specific phosphorylation in the PEVK region were reduced in myopathy, which would be predicted to lower PT. Electron microscopy revealed extensive ultrastructural changes in myofibers of various hereditary myopathies and also suggested massive binding of proteins to the sarcomeric I-band region, presumably heat shock proteins (HSPs), which can translocate to elastic titin under stress conditions. Correlative immunofluorescence and immunoelectron microscopy showed that two small HSPs (HSP27 and αB-crystallin) and the ATP-dependent chaperone HSP90 translocated to the titin springs in myopathy. The small HSPs, but not HSP90, were upregulated in myopathic versus control muscles. The titin-binding pattern of chaperones was regularly observed in Duchenne muscular dystrophy (DMD), LGMD2A, MFM-filaminopathy, MFM-myotilinopathy, titinopathy, and inclusion body myopathy due to mutations in valosin-containing protein, but not in acquired sporadic inclusion body myositis. The three HSPs also associated with elastic titin in mouse models of DMD and MFM-filaminopathy. Mechanical measurements on skinned human myofibers incubated with exogenous small HSPs suggested that the elevated PT seen in myopathy is caused, in part, by chaperone-binding to the titin springs. Whereas this interaction may be protective in that it prevents sarcomeric protein aggregation, it also has detrimental effects on sarcomere function. Thus, we identified a novel pathological phenomenon common to many hereditary muscle disorders, which involves sarcomeric alterations.
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Sharma S, Conover GM, Elliott JL, Der Perng M, Herrmann H, Quinlan RA. αB-crystallin is a sensor for assembly intermediates and for the subunit topology of desmin intermediate filaments. Cell Stress Chaperones 2017; 22:613-626. [PMID: 28470624 PMCID: PMC5465037 DOI: 10.1007/s12192-017-0788-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Revised: 03/07/2017] [Accepted: 03/16/2017] [Indexed: 12/04/2022] Open
Abstract
Mutations in the small heat shock protein chaperone CRYAB (αB-crystallin/HSPB5) and the intermediate filament protein desmin, phenocopy each other causing cardiomyopathies. Whilst the binding sites for desmin on CRYAB have been determined, desmin epitopes responsible for CRYAB binding and also the parameters that determine CRYAB binding to desmin filaments are unknown. Using a combination of co-sedimentation centrifugation, viscometric assays and electron microscopy of negatively stained filaments to analyse the in vitro assembly of desmin filaments, we show that the binding of CRYAB to desmin is subject to its assembly status, to the subunit organization within filaments formed and to the integrity of the C-terminal tail domain of desmin. Our in vitro studies using a rapid assembly protocol, C-terminally truncated desmin and two disease-causing mutants (I451M and R454W) suggest that CRYAB is a sensor for the surface topology of the desmin filament. Our data also suggest that CRYAB performs an assembly chaperone role because the assembling filaments have different CRYAB-binding properties during the maturation process. We suggest that the capability of CRYAB to distinguish between filaments with different surface topologies due either to mutation (R454W) or assembly protocol is important to understanding the pathomechanism(s) of desmin-CRYAB myopathies.
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Affiliation(s)
- Sarika Sharma
- Division of Molecular Genetics, German Cancer Research Center, Heidelberg, Germany
| | - Gloria M Conover
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
| | - Jayne L Elliott
- Department of Biosciences and the Biophysical Sciences Institute, University of Durham, Durham, UK
| | - Ming Der Perng
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Harald Herrmann
- Division of Molecular Genetics, German Cancer Research Center, Heidelberg, Germany
- Institute of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Roy A Quinlan
- Department of Biosciences and the Biophysical Sciences Institute, University of Durham, Durham, UK.
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Klimek C, Kathage B, Wördehoff J, Höhfeld J. BAG3-mediated proteostasis at a glance. J Cell Sci 2017; 130:2781-2788. [DOI: 10.1242/jcs.203679] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
ABSTRACT
Cellular and organismal survival depend on the ability to maintain the proteome, even under conditions that threaten protein integrity. BCL2-associated athanogene 3 (BAG3) is essential for protein homeostasis (proteostasis) in stressed cells. Owing to its multi-domain structure, it engages in diverse processes that are crucial for proteome maintenance. BAG3 promotes the activity of molecular chaperones, sequesters and concentrates misfolded proteins, initiates autophagic disposal, and balances transcription, translation and degradation. In this Cell Science at a Glance article and the accompanying poster, we discuss the functions of this multi-functional proteostasis tool with a focus on mechanical stress protection and describe the importance of BAG3 for human physiology and pathophysiology.
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Affiliation(s)
- Christina Klimek
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, D-53121 Bonn, Germany
| | - Barbara Kathage
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, D-53121 Bonn, Germany
| | - Judith Wördehoff
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, D-53121 Bonn, Germany
| | - Jörg Höhfeld
- Institute for Cell Biology, University of Bonn, Ulrich-Haberland-Str. 61a, D-53121 Bonn, Germany
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A novel dominant D109A CRYAB mutation in a family with myofibrillar myopathy affects αB-crystallin structure. BBA CLINICAL 2016; 7:1-7. [PMID: 27904835 PMCID: PMC5124346 DOI: 10.1016/j.bbacli.2016.11.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 11/09/2016] [Accepted: 11/10/2016] [Indexed: 11/21/2022]
Abstract
Myofibrillar myopathy (MFM) is a group of inherited muscular disorders characterized by myofibrils dissolution and abnormal accumulation of degradation products. So far causative mutations have been identified in nine genes encoding Z-disk proteins, including αB-crystallin (CRYAB), a small heat shock protein (also called HSPB5). Here, we report a case study of a 63-year-old Polish female with a progressive lower limb weakness and muscle biopsy suggesting a myofibrillar myopathy, and extra-muscular multisystemic involvement, including cataract and cardiomiopathy. Five members of the proband's family presented similar symptoms. Whole exome sequencing followed by bioinformatic analysis revealed a novel D109A mutation in CRYAB associated with the disease. Molecular modeling in accordance with muscle biopsy microscopic analyses predicted that D109A mutation influence both structure and function of CRYAB due to decreased stability of oligomers leading to aggregate formation. In consequence disrupted sarcomere cytoskeleton organization might lead to muscle pathology. We also suggest that mutated RQDE sequence of CRYAB could impair CRYAB chaperone-like activity and promote aggregation of lens crystallins.
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