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Stroik D, Gregorich ZR, Raza F, Ge Y, Guo W. Titin: roles in cardiac function and diseases. Front Physiol 2024; 15:1385821. [PMID: 38660537 PMCID: PMC11040099 DOI: 10.3389/fphys.2024.1385821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 03/25/2024] [Indexed: 04/26/2024] Open
Abstract
The giant protein titin is an essential component of muscle sarcomeres. A single titin molecule spans half a sarcomere and mediates diverse functions along its length by virtue of its unique domains. The A-band of titin functions as a molecular blueprint that defines the length of the thick filaments, the I-band constitutes a molecular spring that determines cell-based passive stiffness, and various domains, including the Z-disk, I-band, and M-line, serve as scaffolds for stretch-sensing signaling pathways that mediate mechanotransduction. This review aims to discuss recent insights into titin's functional roles and their relationship to cardiac function. The role of titin in heart diseases, such as dilated cardiomyopathy and heart failure with preserved ejection fraction, as well as its potential as a therapeutic target, is also discussed.
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Affiliation(s)
- Dawson Stroik
- Cellular and Molecular Pathology Program, Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
- Department of Animal and Dairy Sciences, College of Agriculture and Life Science, University of Wisconsin-Madison, Madison, WI, United States
| | - Zachery R. Gregorich
- Department of Animal and Dairy Sciences, College of Agriculture and Life Science, University of Wisconsin-Madison, Madison, WI, United States
| | - Farhan Raza
- Department of Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Ying Ge
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
| | - Wei Guo
- Cellular and Molecular Pathology Program, Department of Pathology and Laboratory Medicine, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, United States
- Department of Animal and Dairy Sciences, College of Agriculture and Life Science, University of Wisconsin-Madison, Madison, WI, United States
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2
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Perrin A, Métay C, Savarese M, Ben Yaou R, Demidov G, Nelson I, Solé G, Péréon Y, Bertini ES, Fattori F, D'Amico A, Ricci F, Ginsberg M, Seferian A, Boespflug-Tanguy O, Servais L, Chapon F, Lagrange E, Gaudon K, Bloch A, Ghanem R, Guyant-Maréchal L, Johari M, Van Goethem C, Fardeau M, Morales RJ, Genetti CA, Marttila M, Koenig M, Beggs AH, Udd B, Bonne G, Cossée M. Titin copy number variations associated with dominant inherited phenotypes. J Med Genet 2024; 61:369-377. [PMID: 37935568 PMCID: PMC10957311 DOI: 10.1136/jmg-2023-109473] [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: 06/22/2023] [Accepted: 10/18/2023] [Indexed: 11/09/2023]
Abstract
BACKGROUND Titinopathies are caused by mutations in the titin gene (TTN). Titin is the largest known human protein; its gene has the longest coding phase with 364 exons. Titinopathies are very complex neuromuscular pathologies due to the variable age of onset of symptoms, the great diversity of pathological and muscular impairment patterns (cardiac, skeletal muscle or mixed) and both autosomal dominant and recessive modes of transmission. Until now, only few CNVs in TTN have been reported without clear genotype-phenotype associations. METHODS Our study includes eight families with dominant titinopathies. We performed next-generation sequencing or comparative genomic hybridisation array analyses and found CNVs in the TTN gene. We characterised these CNVs by RNA sequencing (RNAseq) analyses in six patients' muscles and performed genotype-phenotype inheritance association study by combining the clinical and biological data of these eight families. RESULTS Seven deletion-type CNVs in the TTN gene were identified among these families. Genotype and RNAseq results showed that five deletions do not alter the reading frame and one is out-of-reading frame. The main phenotype identified was distal myopathy associated with contractures. The analysis of morphological, clinical and genetic data and imaging let us draw new genotype-phenotype associations of titinopathies. CONCLUSION Identifying TTN CNVs will further increase diagnostic sensitivity in these complex neuromuscular pathologies. Our cohort of patients enabled us to identify new deletion-type CNVs in the TTN gene, with unexpected autosomal dominant transmission. This is valuable in establishing new genotype-phenotype associations of titinopathies, mainly distal myopathy in most of the patients.
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Affiliation(s)
- Aurélien Perrin
- Laboratoire de Génétique Moléculaire, Centre Hospitalier Universitaire de Montpellier, Montpellier, France
- PhyMedExp, Université de Montpellier, INSERM, CNRS, Montpellier, France
| | - Corinne Métay
- Unité Fonctionnelle de Cardiogénétique et Myogénétique moléculaire et cellulaire, Centre de Génétique Moléculaire et Chromosomique, Groupe Hospitalier La Pitié-Salpêtrière-Charles Foix, Paris, France
- Sorbonne Université, INSERM, Institut de Myologie, Centre de Recherche en Myologie, Paris, France
| | - Marco Savarese
- Tampere Neuromuscular Center, Folkhälsan Research Center, Helsinki, Finland
| | - Rabah Ben Yaou
- Sorbonne Université, INSERM, Institut de Myologie, Centre de Recherche en Myologie, Paris, France
| | - German Demidov
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tubingen, Germany
| | - Isabelle Nelson
- Sorbonne Université, INSERM, Institut de Myologie, Centre de Recherche en Myologie, Paris, France
| | - Guilhem Solé
- CHU de Bordeaux, AOC National Reference Center for Neuromuscular Disorders, Bordeaux, France
| | - Yann Péréon
- Department of Clinical Neurophysiology, Reference Centre for Neuromuscular Diseases AOC, Filnemus, Euro-NMD, CHU Nantes, Nantes Université, Place Alexis-Ricordeau, Nantes, France
| | - Enrico Silvio Bertini
- Unit of Muscular and Neurodegenerative Disorders, Bambino Gesù Children Research Hospital, IRCCS, Rome, Italy
| | - Fabiana Fattori
- Unit of Muscular and Neurodegenerative Disorders, Bambino Gesù Children Research Hospital, IRCCS, Rome, Italy
| | - Adele D'Amico
- Unit of Muscular and Neurodegenerative Disorders, Bambino Gesù Children Research Hospital, IRCCS, Rome, Italy
| | - Federica Ricci
- Division of Child and Adolescent Neuropsychiatry, University of Turin, Turin, Italy
| | - Mira Ginsberg
- Department of Pediatric Neurology, Wolfson Medical Center, Holon, Israel
| | | | - Odile Boespflug-Tanguy
- Institut I-MOTION, Hôpital Armand Trousseau, Paris, France
- UMR 1141, INSERM, NeuroDiderot Université Paris Cité and APHP, Neuropédiatrie, French Reference Center for Leukodystrophies, LEUKOFRANCE, Hôpital Robert Debré, Paris, France
| | - Laurent Servais
- Institut I-MOTION, Hôpital Armand Trousseau, Paris, France
- MDUK Oxford Neuromuscular Centre & NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford, UK
- Neuromuscular Reference Center, Division of Paediatrics, University and Hospital University of Liège, Liège, Belgium
| | - Françoise Chapon
- Département de pathologie, Centre de Compétence des Maladies Neuromusculaires, Centre Hospitalier Universitaire de Caen, Caen, France
| | - Emmeline Lagrange
- Centre de Compétences des Maladies Neuro Musculaires, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble, France
| | - Karen Gaudon
- Unité Fonctionnelle de Cardiogénétique et Myogénétique moléculaire et cellulaire, Centre de Génétique Moléculaire et Chromosomique, Groupe Hospitalier La Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Adrien Bloch
- Unité Fonctionnelle de Cardiogénétique et Myogénétique moléculaire et cellulaire, Centre de Génétique Moléculaire et Chromosomique, Groupe Hospitalier La Pitié-Salpêtrière-Charles Foix, Paris, France
| | - Robin Ghanem
- Unité Fonctionnelle de Cardiogénétique et Myogénétique moléculaire et cellulaire, Centre de Génétique Moléculaire et Chromosomique, Groupe Hospitalier La Pitié-Salpêtrière-Charles Foix, Paris, France
| | | | - Mridul Johari
- Tampere Neuromuscular Center, Folkhälsan Research Center, Helsinki, Finland
- Harry Perkins Institute of Medical Research, Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia
| | - Charles Van Goethem
- Laboratoire de Génétique Moléculaire, Centre Hospitalier Universitaire de Montpellier, Montpellier, France
- Montpellier BioInformatique pour le Diagnostic Clinique (MOBIDIC), Plateau de Médecine Moléculaire et Génomique (PMMG), CHU Montpellier, Montpellier, France
| | - Michel Fardeau
- Sorbonne Université, INSERM, Institut de Myologie, Centre de Recherche en Myologie, Paris, France
| | - Raul Juntas Morales
- Department of Neurology, Hospital Universitario Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Casie A Genetti
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Minttu Marttila
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- HiLIFE Helsinki Institute of Life Science, Tukholmankatu 8, FI-00014, University of Helsinki, Helsinki, Finland
| | - Michel Koenig
- Laboratoire de Génétique Moléculaire, Centre Hospitalier Universitaire de Montpellier, Montpellier, France
- PhyMedExp, Université de Montpellier, INSERM, CNRS, Montpellier, France
| | - Alan H Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Bjarne Udd
- Tampere Neuromuscular Center, Folkhälsan Research Center, Helsinki, Finland
| | - Gisèle Bonne
- Sorbonne Université, INSERM, Institut de Myologie, Centre de Recherche en Myologie, Paris, France
| | - Mireille Cossée
- Laboratoire de Génétique Moléculaire, Centre Hospitalier Universitaire de Montpellier, Montpellier, France
- PhyMedExp, Université de Montpellier, INSERM, CNRS, Montpellier, France
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Jolfayi AG, Kohansal E, Ghasemi S, Naderi N, Hesami M, MozafaryBazargany M, Moghadam MH, Fazelifar AF, Maleki M, Kalayinia S. Exploring TTN variants as genetic insights into cardiomyopathy pathogenesis and potential emerging clues to molecular mechanisms in cardiomyopathies. Sci Rep 2024; 14:5313. [PMID: 38438525 PMCID: PMC10912352 DOI: 10.1038/s41598-024-56154-7] [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: 11/22/2023] [Accepted: 03/01/2024] [Indexed: 03/06/2024] Open
Abstract
The giant protein titin (TTN) is a sarcomeric protein that forms the myofibrillar backbone for the components of the contractile machinery which plays a crucial role in muscle disorders and cardiomyopathies. Diagnosing TTN pathogenic variants has important implications for patient management and genetic counseling. Genetic testing for TTN variants can help identify individuals at risk for developing cardiomyopathies, allowing for early intervention and personalized treatment strategies. Furthermore, identifying TTN variants can inform prognosis and guide therapeutic decisions. Deciphering the intricate genotype-phenotype correlations between TTN variants and their pathologic traits in cardiomyopathies is imperative for gene-based diagnosis, risk assessment, and personalized clinical management. With the increasing use of next-generation sequencing (NGS), a high number of variants in the TTN gene have been detected in patients with cardiomyopathies. However, not all TTN variants detected in cardiomyopathy cohorts can be assumed to be disease-causing. The interpretation of TTN variants remains challenging due to high background population variation. This narrative review aimed to comprehensively summarize current evidence on TTN variants identified in published cardiomyopathy studies and determine which specific variants are likely pathogenic contributors to cardiomyopathy development.
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Affiliation(s)
- Amir Ghaffari Jolfayi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Erfan Kohansal
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Serwa Ghasemi
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Niloofar Naderi
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mahshid Hesami
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | | | - Maryam Hosseini Moghadam
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Amir Farjam Fazelifar
- Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Maleki
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Samira Kalayinia
- Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran.
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4
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Weston TGR, Rees M, Gautel M, Fraternali F. Walking with giants: The challenges of variant impact assessment in the giant sarcomeric protein titin. WIREs Mech Dis 2024; 16:e1638. [PMID: 38155593 DOI: 10.1002/wsbm.1638] [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] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/30/2023]
Abstract
Titin, the so-called "third filament" of the sarcomere, represents a difficult challenge for the determination of damaging genetic variants. A single titin molecule extends across half the length of a sarcomere in striated muscle, fulfilling a variety of vital structural and signaling roles, and has been linked to an equally varied range of myopathies, resulting in a significant burden on individuals and healthcare systems alike. While the consequences of truncating variants of titin are well-documented, the ramifications of the missense variants prevalent in the general population are less so. We here present a compendium of titin missense variants-those that result in a single amino-acid substitution in coding regions-reported to be pathogenic and discuss these in light of the nature of titin and the variant position within the sarcomere and their domain, the structural, pathological, and biophysical characteristics that define them, and the methods used for characterization. Finally, we discuss the current knowledge and integration of the multiple fields that have contributed to our understanding of titin-related pathology and offer suggestions as to how these concurrent methodologies may aid the further development in our understanding of titin and hopefully extend to other, less well-studied giant proteins. This article is categorized under: Cardiovascular Diseases > Genetics/Genomics/Epigenetics Congenital Diseases > Genetics/Genomics/Epigenetics Congenital Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Timir G R Weston
- Randall Centre for Cell & Molecular Biophysics, King's College London, London, UK
| | - Martin Rees
- Randall Centre for Cell & Molecular Biophysics, King's College London, London, UK
| | - Mathias Gautel
- Randall Centre for Cell & Molecular Biophysics, King's College London, London, UK
| | - Franca Fraternali
- Institute of Structural and Molecular Biology, University College London, London, UK
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5
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Lord SO, Dawson PW, Chunthorng-Orn J, Ng J, Baehr LM, Hughes DC, Sridhar P, Knowles T, Bodine SC, Lai YC. Uncovering the mechanisms of MuRF1-induced ubiquitylation and revealing similarities with MuRF2 and MuRF3. Biochem Biophys Rep 2024; 37:101636. [PMID: 38283190 PMCID: PMC10818185 DOI: 10.1016/j.bbrep.2023.101636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/12/2023] [Accepted: 12/29/2023] [Indexed: 01/30/2024] Open
Abstract
MuRF1 (Muscle-specific RING finger protein 1; gene name TRIM63) is a ubiquitin E3 ligase, associated with the progression of muscle atrophy. As a RING (Really Interesting New Gene) type E3 ligase, its unique activity of ubiquitylation is driven by a specific interaction with a UBE2 (ubiquitin conjugating enzyme). Our understanding of MuRF1 function remains unclear as candidate UBE2s have not been fully elucidated. In the present study, we screened human ubiquitin dependent UBE2s in vitro and found that MuRF1 engages in ubiquitylation with UBE2D, UBE2E, UBE2N/V families and UBE2W. MuRF1 can cause mono-ubiquitylation, K48- and K63-linked polyubiquitin chains in a UBE2 dependent manner. Moreover, we identified a two-step UBE2 dependent mechanism whereby MuRF1 is monoubiquitylated by UBE2W which acts as an anchor for UBE2N/V to generate polyubiquitin chains. With the in vitro ubiquitylation assay, we also found that MuRF2 and MuRF3 not only share the same UBE2 partners as MuRF1 but can also directly ubiquitylate the same substrates: Titin (A168-A170), Desmin, and MYLPF (Myosin Light Chain, Phosphorylatable, Fast Skeletal Muscle; also called Myosin Light Regulatory Chain 2). In summary, our work presents new insights into the mechanisms that underpin MuRF1 activity and reveals overlap in MuRF-induced ubiquitylation which could explain their partial redundancy in vivo.
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Affiliation(s)
- Samuel O. Lord
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Peter W.J. Dawson
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
- MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, UK
| | | | - Jimi Ng
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
| | - Leslie M. Baehr
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - David C. Hughes
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Pooja Sridhar
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - Timothy Knowles
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - Sue C. Bodine
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Yu-Chiang Lai
- School of Sport, Exercise and Rehabilitation Sciences, University of Birmingham, Birmingham, UK
- MRC Versus Arthritis Centre for Musculoskeletal Ageing Research, University of Birmingham, Birmingham, UK
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6
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Abou-El-Naga IF, Mogahed NMFH. Immuno-molecular profile for Biomphalaria glabrata/Schistosoma mansoni interaction. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2024; 150:105083. [PMID: 37852455 DOI: 10.1016/j.dci.2023.105083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 10/14/2023] [Accepted: 10/15/2023] [Indexed: 10/20/2023]
Abstract
The complex innate immune defense of Biomphalaria glabrata, the intermediate host of Schistosoma mansoni, governs the successful development of the intramolluscan stages of the parasite. The interaction between the snail and the parasite involves a complex immune molecular crosstalk between several parasite antigens and the snail immune recognition receptors, evoking different signals and effector molecules. This work seeks to discuss the immune-related molecules that influence compatibility in Biomphalaria glabrata/Schistosoma mansoni interaction and the differential expression of these molecules between resistant and susceptible snails. It also includes the current understanding of the immune molecular determinants that govern the compatibility in sympatric and allopatric interactions, and the expression of these molecules after immune priming and the secondary immune response. Herein, the differences in the immune-related molecules in the interaction of other Biomphalaria species with Schistosoma mansoni compared to the Biomphalaria glabrata model snail are highlighted. Understanding the diverse immune molecular determinants in the snail/schistosome interaction can lead to alternative control strategies for schistosomiasis.
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7
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Rees M, Nikoopour R, Alexandrovich A, Pfuhl M, Lopes LR, Akhtar MM, Syrris P, Elliott P, Carr-White G, Gautel M. Structure determination and analysis of titin A-band fibronectin type III domains provides insights for disease-linked variants and protein oligomerisation. J Struct Biol 2023; 215:108009. [PMID: 37549721 PMCID: PMC10862085 DOI: 10.1016/j.jsb.2023.108009] [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: 04/30/2023] [Revised: 07/06/2023] [Accepted: 08/03/2023] [Indexed: 08/09/2023]
Abstract
Titin is the largest protein found in nature and spans half a sarcomere in vertebrate striated muscle. The protein has multiple functions, including in the organisation of the thick filament and acting as a molecular spring during the muscle contraction cycle. Missense variants in titin have been linked to both cardiac and skeletal myopathies. Titin is primarily composed of tandem repeats of immunoglobulin and fibronectin type III (Fn3) domains in a variety of repeat patterns; however, the vast majority of these domains have not had their high-resolution structure determined experimentally. Here, we present the crystal structures of seven wild type titin Fn3 domains and two harbouring rare missense variants reported in hypertrophic cardiomyopathy (HCM) patients. All domains present the typical Fn3 fold, with the domains harbouring variants reported in HCM patients retaining the wild-type conformation. The effect on domain folding and stability were assessed for five rare missense variants found in HCM patients: four caused thermal destabilization of between 7 and 13 °C and one prevented the folding of its domain. The structures also allowed us to locate the positions of residues whose mutations have been linked to congenital myopathies and rationalise how they convey their deleterious effects. We find no evidence of physiological homodimer formation, excluding one hypothesised mechanism as to how titin variants could exert pathological effects.
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Affiliation(s)
- Martin Rees
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom.
| | - Roksana Nikoopour
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom
| | - Alexander Alexandrovich
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom
| | - Mark Pfuhl
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom; School of Cardiovascular Sciences and Medicine, King's College London, United Kingdom
| | - Luis R Lopes
- Institute of Cardiovascular Science, University College London, United Kingdom; Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom
| | - Mohammed M Akhtar
- Institute of Cardiovascular Science, University College London, United Kingdom
| | - Petros Syrris
- Institute of Cardiovascular Science, University College London, United Kingdom
| | - Perry Elliott
- Institute of Cardiovascular Science, University College London, United Kingdom; Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom
| | - Gerry Carr-White
- Guy's and St Thomas' NHS Foundation Trust, London, United Kingdom; School of Biomedical Engineering and Imaging Sciences, Rayne Institute, King's College London, St Thomas' Hospital, London, United Kingdom
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, King's College London BHF Centre of Research Excellence, United Kingdom.
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8
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Lepley LK, Stoneback L, Macpherson PC, Butterfield TA. Eccentric Exercise as a Potent Prescription for Muscle Weakness After Joint Injury. Exerc Sport Sci Rev 2023; 51:109-116. [PMID: 37093645 PMCID: PMC10330137 DOI: 10.1249/jes.0000000000000319] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Lengthening contractions (i.e., eccentric contractions) are capable of uniquely triggering the nervous system and signaling pathways to promote tissue health/growth. This mode of exercise may be particularly potent for patients suffering from muscle weakness after joint injury. Here we provide a novel framework for eccentric exercise as a safe, effective mode of exercise prescription for muscle recovery.
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Affiliation(s)
| | - Luke Stoneback
- School of Kinesiology, University of Michigan, Ann Arbor, MI, USA
| | - Peter C.D. Macpherson
- School of Kinesiology, University of Michigan, Ann Arbor, MI, USA
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, USA
| | - Timothy A. Butterfield
- Department of Athletic Training and Clinical Nutrition, University of Kentucky, Lexington, KY, USA
- Center for Muscle Biology, University of Kentucky, Lexington, KY, USA
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9
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Banga S, Cardoso R, Castellani C, Srivastava S, Watkins J, Lima J. Cardiac MRI as an Imaging Tool in Titin Variant-Related Dilated Cardiomyopathy. CARDIOVASCULAR REVASCULARIZATION MEDICINE 2023; 52:86-93. [PMID: 36934006 DOI: 10.1016/j.carrev.2023.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/05/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023]
Abstract
Dilated Cardiomyopathy is a common myocardial disease characterized by dilation and loss of function of one or both ventricles. A variety of etiologies have been implicated including genetic variation. Advancement in genetic sequencing, and diagnostic imaging allows for detection of genetic mutations in sarcomere protein titin (TTN) and high resolution assessment of cardiac function. This review article discusses the role of cardiac MRI in diagnosing dilated cardiomyopathy in patients with TTN variant related cardiomyopathy.
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Affiliation(s)
- Sandeep Banga
- Division of Cardiology, Michigan State University, Sparrow Hospital, Lansing, MI, USA.
| | | | - Carson Castellani
- Division of Internal Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Shaurya Srivastava
- Division of Internal Medicine, Michigan State University, Lansing, MI, USA
| | - Jennifer Watkins
- Division of Cardiology, Michigan State University, Sparrow Hospital, Lansing, MI, USA
| | - Joao Lima
- Division of Cardiology, Johns Hopkins University, Baltimore, MD, USA
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Gibertini S, Ruggieri A, Cheli M, Maggi L. Protein Aggregates and Aggrephagy in Myopathies. Int J Mol Sci 2023; 24:ijms24098456. [PMID: 37176163 PMCID: PMC10179229 DOI: 10.3390/ijms24098456] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 05/02/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023] Open
Abstract
A number of muscular disorders are hallmarked by the aggregation of misfolded proteins within muscle fibers. A specialized form of macroautophagy, termed aggrephagy, is designated to remove and degrade protein aggregates. This review aims to summarize what has been studied so far about the direct involvement of aggrephagy and the activation of the key players, among others, p62, NBR1, Alfy, Tollip, Optineurin, TAX1BP1 and CCT2 in muscular diseases. In the first part of the review, we describe the aggrephagy pathway with the involved proteins; then, we illustrate the muscular disorder histologically characterized by protein aggregates, highlighting the role of aggrephagy pathway abnormalities in these muscular disorders.
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Affiliation(s)
- Sara Gibertini
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
| | - Alessandra Ruggieri
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
| | - Marta Cheli
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
| | - Lorenzo Maggi
- Neuroimmunology and Neuromuscular Diseases Unit, Fondazione IRCCS Istituto Neurologico "Carlo Besta", 20133 Milan, Italy
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11
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Linke WA. Stretching the story of titin and muscle function. J Biomech 2023; 152:111553. [PMID: 36989971 DOI: 10.1016/j.jbiomech.2023.111553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/29/2023]
Abstract
The discovery of the giant protein titin, also known as connectin, dates almost half a century back. In this review, I recapitulate major advances in the discovery of the titin filaments and the recognition of their properties and function until today. I briefly discuss how our understanding of the layout and interactions of titin in muscle sarcomeres has evolved and review key facts about the titin sequence at the gene (TTN) and protein levels. I also touch upon properties of titin important for the stability of the contractile units and the assembly and maintenance of sarcomeric proteins. The greater part of my discussion centers around the mechanical function of titin in skeletal muscle. I cover milestones of research on titin's role in stretch-dependent passive tension development, recollect the reasons behind the enormous elastic diversity of titin, and provide an update on the molecular mechanisms of titin elasticity, details of which are emerging even now. I reflect on current knowledge of how muscle fibers behave mechanically if titin stiffness is removed and how titin stiffness can be dynamically regulated, such as by posttranslational modifications or calcium binding. Finally, I highlight novel and exciting, but still controversially discussed, insight into the role titin plays in active tension development, such as length-dependent activation and contraction from longer muscle lengths.
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Affiliation(s)
- Wolfgang A Linke
- Institute of Physiology II, University of Münster, Germany; Clinic for Cardiology and Pneumology, University Medical Center Göttingen, Germany; German Centre for Cardiovascular Research, Berlin, Germany.
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12
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Zacharchenko T, Dorendorf T, Locker N, Van Dijk E, Katzemich A, Diederichs K, Bullard B, Mayans O. PK1 from Drosophila obscurin is an inactive pseudokinase with scaffolding properties. Open Biol 2023; 13:220350. [PMID: 37121260 PMCID: PMC10129394 DOI: 10.1098/rsob.220350] [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: 11/25/2022] [Accepted: 03/23/2023] [Indexed: 05/02/2023] Open
Abstract
Obscurins are large filamentous proteins with crucial roles in the assembly, stability and regulation of muscle. Characteristic of these proteins is a tandem of two C-terminal kinase domains, PK1 and PK2, that are separated by a long intrinsically disordered sequence. The significance of this conserved domain arrangement is unknown. Our study of PK1 from Drosophila obscurin shows that this is a pseudokinase with features typical of the CAM-kinase family, but which carries a minimalistic regulatory tail that no longer binds calmodulin or has mechanosensory properties typical of other sarcomeric kinases. PK1 binds ATP with high affinity, but in the absence of magnesium and lacks detectable phosphotransfer activity. It also has a highly diverged active site, strictly conserved across arthropods, that might have evolved to accommodate an unconventional binder. We find that PK1 interacts with PK2, suggesting a functional relation to the latter. These findings lead us to speculate that PK1/PK2 form a pseudokinase/kinase dual system, where PK1 might act as an allosteric regulator of PK2 and where mechanosensing properties, akin to those described for regulatory tails in titin-like kinases, might now reside on the unstructured interkinase segment. We propose that the PK1-interkinase-PK2 region constitutes an integrated functional unit in obscurin proteins.
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Affiliation(s)
- Thomas Zacharchenko
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
| | - Till Dorendorf
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | - Nicolas Locker
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Evert Van Dijk
- Biosynth B.V., Zuidersluisweg 2, 8243 RC Lelystad, The Netherlands
| | | | - Kay Diederichs
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
| | | | - Olga Mayans
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
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13
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Loreau V, Rees R, Chan EH, Taxer W, Gregor K, Mußil B, Pitaval C, Luis NM, Mangeol P, Schnorrer F, Görlich D. A nanobody toolbox to investigate localisation and dynamics of Drosophila titins and other key sarcomeric proteins. eLife 2023; 12:79343. [PMID: 36645120 PMCID: PMC9886281 DOI: 10.7554/elife.79343] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 12/16/2022] [Indexed: 01/17/2023] Open
Abstract
Measuring the positions and dynamics of proteins in intact tissues or whole animals is key to understanding protein function. However, to date, this is challenging, as the accessibility of large antibodies to dense tissues is often limited, and fluorescent proteins inserted close to a domain of interest may affect protein function. These complications apply in particular to muscle sarcomeres, arguably one of the most protein-dense assemblies in nature, which complicates studying sarcomere morphogenesis at molecular resolution. Here, we introduce a toolbox of nanobodies recognising various domains of the two Drosophila titin homologs, Sallimus and Projectin, as well as the key sarcomeric proteins Obscurin, α-Actinin, and Zasp52. We verified the superior labelling qualities of our nanobodies in muscle tissue as compared to antibodies. By applying our toolbox to larval muscles, we found a gigantic Sallimus isoform stretching more than 2 µm to bridge the sarcomeric I-band, while Projectin covers almost the entire myosin filaments in a polar orientation. Transgenic expression of tagged nanobodies confirmed their high affinity-binding without affecting target protein function. Finally, adding a degradation signal to anti-Sallimus nanobodies suggested that it is difficult to fully degrade Sallimus in mature sarcomeres; however, expression of these nanobodies caused developmental lethality. These results may inspire the generation of similar toolboxes for other large protein complexes in Drosophila or mammals.
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Affiliation(s)
- Vincent Loreau
- Turing Centre for Living Systems, Aix-Marseille University, CNRS, IDBMMarseilleFrance
| | - Renate Rees
- Department of Cellular Logistics, Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Eunice HoYee Chan
- Turing Centre for Living Systems, Aix-Marseille University, CNRS, IDBMMarseilleFrance
| | - Waltraud Taxer
- Department of Cellular Logistics, Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Kathrin Gregor
- Department of Cellular Logistics, Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Bianka Mußil
- Department of Cellular Logistics, Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Christophe Pitaval
- Turing Centre for Living Systems, Aix-Marseille University, CNRS, IDBMMarseilleFrance
| | - Nuno Miguel Luis
- Turing Centre for Living Systems, Aix-Marseille University, CNRS, IDBMMarseilleFrance
| | - Pierre Mangeol
- Turing Centre for Living Systems, Aix-Marseille University, CNRS, IDBMMarseilleFrance
| | - Frank Schnorrer
- Turing Centre for Living Systems, Aix-Marseille University, CNRS, IDBMMarseilleFrance
| | - Dirk Görlich
- Department of Cellular Logistics, Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
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14
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Schueder F, Mangeol P, Chan EH, Rees R, Schünemann J, Jungmann R, Görlich D, Schnorrer F. Nanobodies combined with DNA-PAINT super-resolution reveal a staggered titin nanoarchitecture in flight muscles. eLife 2023; 12:79344. [PMID: 36645127 PMCID: PMC9886278 DOI: 10.7554/elife.79344] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 11/22/2022] [Indexed: 01/17/2023] Open
Abstract
Sarcomeres are the force-producing units of all striated muscles. Their nanoarchitecture critically depends on the large titin protein, which in vertebrates spans from the sarcomeric Z-disc to the M-band and hence links actin and myosin filaments stably together. This ensures sarcomeric integrity and determines the length of vertebrate sarcomeres. However, the instructive role of titins for sarcomeric architecture outside of vertebrates is not as well understood. Here, we used a series of nanobodies, the Drosophila titin nanobody toolbox, recognising specific domains of the two Drosophila titin homologs Sallimus and Projectin to determine their precise location in intact flight muscles. By combining nanobodies with DNA-PAINT super-resolution microscopy, we found that, similar to vertebrate titin, Sallimus bridges across the flight muscle I-band, whereas Projectin is located at the beginning of the A-band. Interestingly, the ends of both proteins overlap at the I-band/A-band border, revealing a staggered organisation of the two Drosophila titin homologs. This architecture may help to stably anchor Sallimus at the myosin filament and hence ensure efficient force transduction during flight.
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Affiliation(s)
- Florian Schueder
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian UniversityMunichGermany
- Max Planck Institute of BiochemistryMartinsriedGermany
| | - Pierre Mangeol
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living SystemsMarseilleFrance
| | - Eunice HoYee Chan
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living SystemsMarseilleFrance
| | - Renate Rees
- Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | | | - Ralf Jungmann
- Faculty of Physics and Center for Nanoscience, Ludwig Maximilian UniversityMunichGermany
- Max Planck Institute of BiochemistryMartinsriedGermany
| | - Dirk Görlich
- Max Planck Institute for Multidisciplinary SciencesGöttingenGermany
| | - Frank Schnorrer
- Aix Marseille University, CNRS, IBDM, Turing Centre for Living SystemsMarseilleFrance
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15
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Shariq M, Quadir N, Alam A, Zarin S, Sheikh JA, Sharma N, Samal J, Ahmad U, Kumari I, Hasnain SE, Ehtesham NZ. The exploitation of host autophagy and ubiquitin machinery by Mycobacterium tuberculosis in shaping immune responses and host defense during infection. Autophagy 2023; 19:3-23. [PMID: 35000542 PMCID: PMC9809970 DOI: 10.1080/15548627.2021.2021495] [Citation(s) in RCA: 31] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Intracellular pathogens have evolved various efficient molecular armaments to subvert innate defenses. Cellular ubiquitination, a normal physiological process to maintain homeostasis, is emerging one such exploited mechanism. Ubiquitin (Ub), a small protein modifier, is conjugated to diverse protein substrates to regulate many functions. Structurally diverse linkages of poly-Ub to target proteins allow enormous functional diversity with specificity being governed by evolutionarily conserved enzymes (E3-Ub ligases). The Ub-binding domain (UBD) and LC3-interacting region (LIR) are critical features of macroautophagy/autophagy receptors that recognize Ub-conjugated on protein substrates. Emerging evidence suggests that E3-Ub ligases unexpectedly protect against intracellular pathogens by tagging poly-Ub on their surfaces and targeting them to phagophores. Two E3-Ub ligases, PRKN and SMURF1, provide immunity against Mycobacterium tuberculosis (M. tb). Both enzymes conjugate K63 and K48-linked poly-Ub to M. tb for successful delivery to phagophores. Intriguingly, M. tb exploits virulence factors to effectively dampen host-directed autophagy utilizing diverse mechanisms. Autophagy receptors contain LIR-motifs that interact with conserved Atg8-family proteins to modulate phagophore biogenesis and fusion to the lysosome. Intracellular pathogens have evolved a vast repertoire of virulence effectors to subdue host-immunity via hijacking the host ubiquitination process. This review highlights the xenophagy-mediated clearance of M. tb involving host E3-Ub ligases and counter-strategy of autophagy inhibition by M. tb using virulence factors. The role of Ub-binding receptors and their mode of autophagy regulation is also explained. We also discuss the co-opting and utilization of the host Ub system by M. tb for its survival and virulence.Abbreviations: APC: anaphase promoting complex/cyclosome; ATG5: autophagy related 5; BCG: bacille Calmette-Guerin; C2: Ca2+-binding motif; CALCOCO2: calcium binding and coiled-coil domain 2; CUE: coupling of ubiquitin conjugation to ER degradation domains; DUB: deubiquitinating enzyme; GABARAP: GABA type A receptor-associated protein; HECT: homologous to the E6-AP carboxyl terminus; IBR: in-between-ring fingers; IFN: interferon; IL1B: interleukin 1 beta; KEAP1: kelch like ECH associated protein 1; LAMP1: lysosomal associated membrane protein 1; LGALS: galectin; LIR: LC3-interacting region; MAPK11/p38: mitogen-activated protein kinase 11; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MAP3K7/TAK1: mitogen-activated protein kinase kinase kinase 7; MAPK8/JNK: mitogen-activated protein kinase 8; MHC-II: major histocompatibility complex-II; MTOR: mechanistic target of rapamycin kinase; NBR1: NBR1 autophagy cargo receptor; NFKB1/p50: nuclear factor kappa B subunit 1; OPTN: optineurin; PB1: phox and bem 1; PE/PPE: proline-glutamic acid/proline-proline-glutamic acid; PknG: serine/threonine-protein kinase PknG; PRKN: parkin RBR E3 ubiquitin protein ligase; RBR: RING-in between RING; RING: really interesting new gene; RNF166: RING finger protein 166; ROS: reactive oxygen species; SMURF1: SMAD specific E3 ubiquitin protein ligase 1; SQSTM1: sequestosome 1; STING1: stimulator of interferon response cGAMP interactor 1; TAX1BP1: Tax1 binding protein 1; TBK1: TANK binding kinase 1; TNF: tumor necrosis factor; TRAF6: TNF receptor associated factor 6; Ub: ubiquitin; UBA: ubiquitin-associated; UBAN: ubiquitin-binding domain in ABIN proteins and NEMO; UBD: ubiquitin-binding domain; UBL: ubiquitin-like; ULK1: unc-51 like autophagy activating kinase 1.
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Affiliation(s)
- Mohd Shariq
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology-ICMR, Ansari Nagar West, New Delhi, India
| | - Neha Quadir
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology-ICMR, Ansari Nagar West, New Delhi, India,Department of Molecular Medicine, Jamia Hamdard-Institute of Molecular Medicine, Jamia Hamdard, New Delhi, India
| | - Anwar Alam
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology-ICMR, Ansari Nagar West, New Delhi, India
| | - Sheeba Zarin
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology-ICMR, Ansari Nagar West, New Delhi, India,Department of Molecular Medicine, Jamia Hamdard-Institute of Molecular Medicine, Jamia Hamdard, New Delhi, India
| | - Javaid A. Sheikh
- Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, India
| | - Neha Sharma
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology-ICMR, Ansari Nagar West, New Delhi, India,Department of Molecular Medicine, Jamia Hamdard-Institute of Molecular Medicine, Jamia Hamdard, New Delhi, India
| | - Jasmine Samal
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology-ICMR, Ansari Nagar West, New Delhi, India
| | - Uzair Ahmad
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology-ICMR, Ansari Nagar West, New Delhi, India
| | - Indu Kumari
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology-ICMR, Ansari Nagar West, New Delhi, India
| | - Seyed E. Hasnain
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi (IIT-D), New Delhi, India,Department of Life Science, School of Basic Sciences and Research, Sharda University, Greater Noida, India,Seyed E. Hasnain ; ; Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology, Delhi (IIT-D), Hauz Khas, New Delhi 110 016, India
| | - Nasreen Z. Ehtesham
- Inflammation Biology and Cell Signaling Laboratory, National Institute of Pathology-ICMR, Ansari Nagar West, New Delhi, India,CONTACT Nasreen Z. Ehtesham ; ICMR-National Institute of Pathology, Ansari Nagar West, New Delhi110029, India
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16
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Rasmussen NL, Kournoutis A, Lamark T, Johansen T. NBR1: The archetypal selective autophagy receptor. J Cell Biol 2022; 221:213552. [PMID: 36255390 PMCID: PMC9582228 DOI: 10.1083/jcb.202208092] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 10/03/2022] [Accepted: 10/03/2022] [Indexed: 11/24/2022] Open
Abstract
NBR1 was discovered as an autophagy receptor not long after the first described vertebrate autophagy receptor p62/SQSTM1. Since then, p62 has currently been mentioned in >10,000 papers on PubMed, while NBR1 is mentioned in <350 papers. Nonetheless, evolutionary analysis reveals that NBR1, and likely also selective autophagy, was present already in the last eukaryotic common ancestor (LECA), while p62 appears first in the early Metazoan lineage. Furthermore, yeast-selective autophagy receptors Atg19 and Atg34 represent NBR1 homologs. NBR1 is the main autophagy receptor in plants that do not contain p62, while most animal taxa contain both NBR1 and p62. Mechanistic studies are starting to shed light on the collaboration between mammalian NBR1 and p62 in the autophagic degradation of protein aggregates (aggrephagy). Several domains of NBR1 are involved in cargo recognition, and the list of known substrates for NBR1-mediated selective autophagy is increasing. Lastly, roles of NBR1 in human diseases such as proteinopathies and cancer are emerging.
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Affiliation(s)
- Nikoline Lander Rasmussen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Athanasios Kournoutis
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Trond Lamark
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
| | - Terje Johansen
- Autophagy Research Group, Department of Medical Biology, University of Tromsø-The Arctic University of Norway, Tromsø, Norway
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17
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Marcello M, Cetrangolo V, Savarese M, Udd B. Use of animal models to understand titin physiology and pathology. J Cell Mol Med 2022; 26:5103-5112. [PMID: 36065969 PMCID: PMC9575118 DOI: 10.1111/jcmm.17533] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/24/2022] [Accepted: 08/26/2022] [Indexed: 12/01/2022] Open
Abstract
In recent years, increasing attention has been paid to titin (TTN) and its mutations. Heterozygous TTN truncating variants (TTNtv) increase the risk of a cardiomyopathy. At the same time, TTNtv and few missense variants have been identified in patients with mainly recessive skeletal muscle diseases. The pathogenic mechanisms underlying titin‐related diseases are still partly unknown. Similarly, the titin mechanical and functional role in the muscle contraction are far from being exhaustively clarified. In the last few years, several animal models carrying variants in the titin gene have been developed and characterized to study the structural and mechanical properties of specific titin domains or to mimic patients' mutations. This review describes the main animal models so far characterized, including eight mice models and three fish models (Medaka and Zebrafish) and discusses the useful insights provided by a thorough characterization of the cell‐, tissue‐ and organism‐phenotypes in these models.
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Affiliation(s)
| | | | - Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Finland.,Department of Medical and Clinical Genetics, Medicum, University of Helsinki, Helsinki, Finland.,Department of Neurology, Vaasa Central Hospital, Vaasa, Finland
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18
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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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19
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Deshpande A, Shetty PMV, Frey N, Rangrez AY. SRF: a seriously responsible factor in cardiac development and disease. J Biomed Sci 2022; 29:38. [PMID: 35681202 PMCID: PMC9185982 DOI: 10.1186/s12929-022-00820-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Accepted: 05/27/2022] [Indexed: 11/10/2022] Open
Abstract
The molecular mechanisms that regulate embryogenesis and cardiac development are calibrated by multiple signal transduction pathways within or between different cell lineages via autocrine or paracrine mechanisms of action. The heart is the first functional organ to form during development, which highlights the importance of this organ in later stages of growth. Knowledge of the regulatory mechanisms underlying cardiac development and adult cardiac homeostasis paves the way for discovering therapeutic possibilities for cardiac disease treatment. Serum response factor (SRF) is a major transcription factor that controls both embryonic and adult cardiac development. SRF expression is needed through the duration of development, from the first mesodermal cell in a developing embryo to the last cell damaged by infarction in the myocardium. Precise regulation of SRF expression is critical for mesoderm formation and cardiac crescent formation in the embryo, and altered SRF levels lead to cardiomyopathies in the adult heart, suggesting the vital role played by SRF in cardiac development and disease. This review provides a detailed overview of SRF and its partners in their various functions and discusses the future scope and possible therapeutic potential of SRF in the cardiovascular system.
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Affiliation(s)
- Anushka Deshpande
- Department of Internal Medicine III, Cardiology and Angiology, University Medical Center Schleswig-Holstein, Campus Kiel, Kiel, Germany.,Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner site Hamburg/Kiel/Lübeck, Kiel, Germany
| | - Prithviraj Manohar Vijaya Shetty
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Norbert Frey
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany
| | - Ashraf Yusuf Rangrez
- Department of Cardiology, Angiology and Pneumology, University Hospital Heidelberg, Heidelberg, Germany. .,DZHK (German Centre for Cardiovascular Research), Partner Site Heidelberg/Mannheim, Heidelberg, Germany.
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20
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Bogomolovas J, Gravenhorst P, Mayans O. Production and analysis of titin kinase: Exploiting active/inactive kinase homologs in pseudokinase validation. Methods Enzymol 2022; 667:147-181. [PMID: 35525541 DOI: 10.1016/bs.mie.2022.03.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Protein pseudokinases are key regulators of the eukaryotic cell. Understanding their unconventional molecular mechanisms relies on deciphering their putative potential to perform phosphotransfer, their scaffolding properties and the nature of their regulation. Titin pseudokinase (TK) is the defining member of a family of poorly characterized muscle-specific kinases thought to act as sensors and transducers of mechanical signals in the sarcomere. The functional mechanisms of TK remain obscure due to the challenges posed by its production and analysis. Here, we provide guidelines and tailored research approaches for the study of TK, including profiting from its close structure-function relationship to the catalytically active homolog twitchin kinase (TwcK) from C. elegans. We describe a methodological pipeline to produce recombinant TK and TwcK samples; design, prioritize and validate mutated and truncated variants; assess sample stability and perform activity assays. The strategy is exportable to other pseudokinase members of the TK-like kinase family.
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Affiliation(s)
- Julius Bogomolovas
- School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | | | - Olga Mayans
- Department of Biology, University of Konstanz, Konstanz, Germany.
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21
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TaNBR1, a Novel Wheat NBR1-like Domain Gene Negatively Regulates Drought Stress Tolerance in Transgenic Arabidopsis. Int J Mol Sci 2022; 23:ijms23094519. [PMID: 35562909 PMCID: PMC9105663 DOI: 10.3390/ijms23094519] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/10/2022] [Accepted: 04/13/2022] [Indexed: 02/04/2023] Open
Abstract
Drought stress is an important factor that severely affects crop yield and quality. Autophagy has a crucial role in the responses to abiotic stresses. In this study, we explore TaNBR1 in response to drought stress. Expression of the TaNBR1 gene was strongly induced by NaCl, PEG, and abscisic acid treatments. The TaNBR1 protein is localized in the Golgi apparatus and autophagosome. Transgenic Arabidopsis plants overexpressing TaNBR1 exhibited reduced drought tolerance. When subjected to drought stress, compared to the wild-type (WT) lines, the transgenic overexpressing TaNBR1 plants had a lower seed germination rate, relative water content, proline content, and reduced accumulation of antioxidant enzymes, i.e., superoxide dismutase, peroxidase, and catalase, as well as higher chlorophyll losses, malondialdehyde contents, and water loss. The transgenic plants overexpressing TaNBR1 produced much shorter roots in response to mannitol stress, in comparison to the WT plants, and they exhibited greater sensitivity to abscisic acid treatment. The expression levels of the genes related to stress in the transgenic plants were affected in response to drought stress. Our results indicate that TaNBR1 negatively regulates drought stress responses by affecting the expression of stress-related genes in Arabidopsis.
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22
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de Regt AK, Clark CJ, Asbury CL, Biggins S. Tension can directly suppress Aurora B kinase-triggered release of kinetochore-microtubule attachments. Nat Commun 2022; 13:2152. [PMID: 35443757 PMCID: PMC9021268 DOI: 10.1038/s41467-022-29542-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 03/03/2022] [Indexed: 11/09/2022] Open
Abstract
Chromosome segregation requires sister kinetochores to attach microtubules emanating from opposite spindle poles. Proper attachments come under tension and are stabilized, but defective attachments lacking tension are released, giving another chance for correct attachments to form. This error correction process depends on Aurora B kinase, which phosphorylates kinetochores to destabilize their microtubule attachments. However, the mechanism by which Aurora B distinguishes tense versus relaxed kinetochores remains unclear because it is difficult to detect kinase-triggered detachment and to manipulate kinetochore tension in vivo. To address these challenges, we apply an optical trapping-based assay using soluble Aurora B and reconstituted kinetochore-microtubule attachments. Strikingly, the tension on these attachments suppresses their Aurora B-triggered release, suggesting that tension-dependent changes in the conformation of kinetochores can regulate Aurora B activity or its outcome. Our work uncovers the basis for a key mechano-regulatory event that ensures accurate segregation and may inform studies of other mechanically regulated enzymes.
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Affiliation(s)
- Anna K de Regt
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Cordell J Clark
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of Washington, Seattle, WA, USA.
| | - Sue Biggins
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.
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23
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Lamber EP, Guicheney P, Pinotsis N. The role of the M-band myomesin proteins in muscle integrity and cardiac disease. J Biomed Sci 2022; 29:18. [PMID: 35255917 PMCID: PMC8900313 DOI: 10.1186/s12929-022-00801-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 02/28/2022] [Indexed: 11/30/2022] Open
Abstract
Transversal structural elements in cross-striated muscles, such as the M-band or the Z-disc, anchor and mechanically stabilize the contractile apparatus and its minimal unit—the sarcomere. The ability of proteins to target and interact with these structural sarcomeric elements is an inevitable necessity for the correct assembly and functionality of the myofibrillar apparatus. Specifically, the M-band is a well-recognized mechanical and signaling hub dealing with active forces during contraction, while impairment of its function leads to disease and death. Research on the M-band architecture is focusing on the assembly and interactions of the three major filamentous proteins in the region, mainly the three myomesin proteins including their embryonic heart (EH) isoform, titin and obscurin. These proteins form the basic filamentous network of the M-band, interacting with each other as also with additional proteins in the region that are involved in signaling, energetic or mechanosensitive processes. While myomesin-1, titin and obscurin are found in every muscle, the expression levels of myomesin-2 (also known as M-protein) and myomesin-3 are tissue specific: myomesin-2 is mainly expressed in the cardiac and fast skeletal muscles, while myomesin-3 is mainly expressed in intermediate muscles and specific regions of the cardiac muscle. Furthermore, EH-myomesin apart from its role during embryonic stages, is present in adults with specific cardiac diseases. The current work in structural, molecular, and cellular biology as well as in animal models, provides important details about the assembly of myomesin-1, obscurin and titin, the information however about the myomesin-2 and -3, such as their interactions, localization and structural details remain very limited. Remarkably, an increasing number of reports is linking all three myomesin proteins and particularly myomesin-2 to serious cardiovascular diseases suggesting that this protein family could be more important than originally thought. In this review we will focus on the myomesin protein family, the myomesin interactions and structural differences between isoforms and we will provide the most recent evidence why the structurally and biophysically unexplored myomesin-2 and myomesin-3 are emerging as hot targets for understanding muscle function and disease.
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24
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Attwaters M, Hughes SM. Cellular and molecular pathways controlling muscle size in response to exercise. FEBS J 2022; 289:1428-1456. [PMID: 33755332 DOI: 10.1111/febs.15820] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 02/27/2021] [Accepted: 03/12/2021] [Indexed: 12/14/2022]
Abstract
From the discovery of ATP and motor proteins to synaptic neurotransmitters and growth factor control of cell differentiation, skeletal muscle has provided an extreme model system in which to understand aspects of tissue function. Muscle is one of the few tissues that can undergo both increase and decrease in size during everyday life. Muscle size depends on its contractile activity, but the precise cellular and molecular pathway(s) by which the activity stimulus influences muscle size and strength remain unclear. Four correlates of muscle contraction could, in theory, regulate muscle growth: nerve-derived signals, cytoplasmic calcium dynamics, the rate of ATP consumption and physical force. Here, we summarise the evidence for and against each stimulus and what is known or remains unclear concerning their molecular signal transduction pathways and cellular effects. Skeletal muscle can grow in three ways, by generation of new syncytial fibres, addition of nuclei from muscle stem cells to existing fibres or increase in cytoplasmic volume/nucleus. Evidence suggests the latter two processes contribute to exercise-induced growth. Fibre growth requires increase in sarcolemmal surface area and cytoplasmic volume at different rates. It has long been known that high-force exercise is a particularly effective growth stimulus, but how this stimulus is sensed and drives coordinated growth that is appropriately scaled across organelles remains a mystery.
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Affiliation(s)
- Michael Attwaters
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, UK
| | - Simon M Hughes
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, UK
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25
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Pitsch M, Kant S, Mytzka C, Leube RE, Krusche CA. Autophagy and Endoplasmic Reticulum Stress during Onset and Progression of Arrhythmogenic Cardiomyopathy. Cells 2021; 11:96. [PMID: 35011658 PMCID: PMC8750195 DOI: 10.3390/cells11010096] [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: 11/10/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 11/16/2022] Open
Abstract
Arrhythmogenic cardiomyopathy (AC) is a heritable, potentially lethal disease without a causal therapy. AC is characterized by focal cardiomyocyte death followed by inflammation and progressive formation of connective tissue. The pathomechanisms leading to structural disease onset and progression, however, are not fully elucidated. Recent studies revealed that dysregulation of autophagy and endoplasmic/sarcoplasmic reticulum (ER/SR) stress plays an important role in cardiac pathophysiology. We therefore examined the temporal and spatial expression patterns of autophagy and ER/SR stress indicators in murine AC models by qRT-PCR, immunohistochemistry, in situ hybridization and electron microscopy. Cardiomyocytes overexpressing the autophagy markers LC3 and SQSTM1/p62 and containing prominent autophagic vacuoles were detected next to regions of inflammation and fibrosis during onset and chronic disease progression. mRNAs of the ER stress markers Chop and sXbp1 were elevated in both ventricles at disease onset. During chronic disease progression Chop mRNA was upregulated in right ventricles. In addition, reduced Ryr2 mRNA expression together with often drastically enlarged ER/SR cisternae further indicated SR dysfunction during this disease phase. Our observations support the hypothesis that locally altered autophagy and enhanced ER/SR stress play a role in AC pathogenesis both at the onset and during chronic progression.
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Affiliation(s)
| | | | | | - Rudolf E. Leube
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany; (M.P.); (S.K.); (C.M.)
| | - Claudia A. Krusche
- Institute of Molecular and Cellular Anatomy, RWTH Aachen University, Wendlingweg 2, 52074 Aachen, Germany; (M.P.); (S.K.); (C.M.)
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26
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Solís C, Russell B. Striated muscle proteins are regulated both by mechanical deformation and by chemical post-translational modification. Biophys Rev 2021; 13:679-695. [PMID: 34777614 DOI: 10.1007/s12551-021-00835-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 08/23/2021] [Indexed: 01/09/2023] Open
Abstract
All cells sense force and build their cytoskeleton to optimize function. How is this achieved? Two major systems are involved. The first is that load deforms specific protein structures in a proportional and orientation-dependent manner. The second is post-translational modification of proteins as a consequence of signaling pathway activation. These two processes work together in a complex way so that local subcellular assembly as well as overall cell function are controlled. This review discusses many cell types but focuses on striated muscle. Detailed information is provided on how load deforms the structure of proteins in the focal adhesions and filaments, using α-actinin, vinculin, talin, focal adhesion kinase, LIM domain-containing proteins, filamin, myosin, titin, and telethonin as examples. Second messenger signals arising from external triggers are distributed throughout the cell causing post-translational or chemical modifications of protein structures, with the actin capping protein CapZ and troponin as examples. There are numerous unanswered questions of how mechanical and chemical signals are integrated by muscle proteins to regulate sarcomere structure and function yet to be studied. Therefore, more research is needed to see how external triggers are integrated with local tension generated within the cell. Nonetheless, maintenance of tension in the sarcomere is the essential and dominant mechanism, leading to the well-known phrase in exercise physiology: "use it or lose it."
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Affiliation(s)
- Christopher Solís
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612 USA
| | - Brenda Russell
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL 60612 USA
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27
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Swiatlowska P, Iskratsch T. Tools for studying and modulating (cardiac muscle) cell mechanics and mechanosensing across the scales. Biophys Rev 2021; 13:611-623. [PMID: 34765044 PMCID: PMC8553672 DOI: 10.1007/s12551-021-00837-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 08/24/2021] [Indexed: 12/26/2022] Open
Abstract
Cardiomyocytes generate force for the contraction of the heart to pump blood into the lungs and body. At the same time, they are exquisitely tuned to the mechanical environment and react to e.g. changes in cell and extracellular matrix stiffness or altered stretching due to reduced ejection fraction in heart disease, by adapting their cytoskeleton, force generation and cell mechanics. Both mechanical sensing and cell mechanical adaptations are multiscale processes. Receptor interactions with the extracellular matrix at the nanoscale will lead to clustering of receptors and modification of the cytoskeleton. This in turn alters mechanosensing, force generation, cell and nuclear stiffness and viscoelasticity at the microscale. Further, this affects cell shape, orientation, maturation and tissue integration at the microscale to macroscale. A variety of tools have been developed and adapted to measure cardiomyocyte receptor-ligand interactions and forces or mechanics at the different ranges, resulting in a wealth of new information about cardiomyocyte mechanobiology. Here, we take stock at the different tools for exploring cardiomyocyte mechanosensing and cell mechanics at the different scales from the nanoscale to microscale and macroscale.
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Affiliation(s)
- Pamela Swiatlowska
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
| | - Thomas Iskratsch
- School of Engineering and Materials Science, Queen Mary University of London, London, UK
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28
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Fomin A, Gärtner A, Cyganek L, Tiburcy M, Tuleta I, Wellers L, Folsche L, Hobbach AJ, von Frieling-Salewsky M, Unger A, Hucke A, Koser F, Kassner A, Sielemann K, Streckfuß-Bömeke K, Hasenfuss G, Goedel A, Laugwitz KL, Moretti A, Gummert JF, Dos Remedios CG, Reinecke H, Knöll R, van Heesch S, Hubner N, Zimmermann WH, Milting H, Linke WA. Truncated titin proteins and titin haploinsufficiency are targets for functional recovery in human cardiomyopathy due to TTN mutations. Sci Transl Med 2021; 13:eabd3079. [PMID: 34731013 DOI: 10.1126/scitranslmed.abd3079] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Andrey Fomin
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Göttingen, Germany
| | - Anna Gärtner
- Erich and Hanna Klessmann Institute, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany
| | - Lukas Cyganek
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Göttingen, Germany.,Stem Cell Unit, University Medical Center, 37075 Göttingen, Germany.,Institute of Pharmacology and Toxicology, University Medical Center, 37075 Göttingen, Germany
| | - Malte Tiburcy
- German Centre for Cardiovascular Research, 10785 Berlin, partner site Göttingen, Germany.,Institute of Pharmacology and Toxicology, University Medical Center, 37075 Göttingen, Germany
| | - Izabela Tuleta
- Department of Cardiology I, Coronary, Peripheral Vascular Disease and Heart Failure, 48149 University Hospital Münster, Münster, Germany
| | - Luisa Wellers
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Lina Folsche
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Anastasia J Hobbach
- Department of Cardiology I, Coronary, Peripheral Vascular Disease and Heart Failure, 48149 University Hospital Münster, Münster, Germany
| | | | - Andreas Unger
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Anna Hucke
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Franziska Koser
- Institute of Physiology II, University of Münster, 48149 Münster, Germany
| | - Astrid Kassner
- Erich and Hanna Klessmann Institute, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany
| | - Katharina Sielemann
- Erich and Hanna Klessmann Institute, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany
| | - Katrin Streckfuß-Bömeke
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Göttingen, Germany
| | - Gerd Hasenfuss
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Göttingen, Germany
| | - Alexander Goedel
- First Medical Department, Cardiology, Technical University of Munich, 81675 Munich, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Munich, Germany.,Department of Cell and Molecular Biology, Karolinska Institute, S-17177 Stockholm, Sweden
| | - Karl-Ludwig Laugwitz
- First Medical Department, Cardiology, Technical University of Munich, 81675 Munich, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Munich, Germany.,Munich Heart Alliance, 80802 Munich, Germany
| | - Alessandra Moretti
- First Medical Department, Cardiology, Technical University of Munich, 81675 Munich, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Munich, Germany.,Munich Heart Alliance, 80802 Munich, Germany
| | - Jan F Gummert
- Erich and Hanna Klessmann Institute, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany.,Department of Cardio-Thoracic Surgery, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany
| | | | - Holger Reinecke
- Department of Cardiology I, Coronary, Peripheral Vascular Disease and Heart Failure, 48149 University Hospital Münster, Münster, Germany
| | - Ralph Knöll
- Department of Medicine, Integrated Cardio Metabolic Centre (ICMC), Heart and Vascular Theme, Karolinska Institute, S-17177 Stockholm, Sweden.,Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, 43183 Gothenburg, Sweden
| | - Sebastiaan van Heesch
- Cardiovascular and Metabolic Sciences, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Berlin, Germany.,Princess Máxima Center for Pediatric Oncology, 3584 CT Utrecht, Netherlands
| | - Norbert Hubner
- Cardiovascular and Metabolic Sciences, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Berlin, Germany.,Charité-Universitätsmedizin, 10117 Berlin, Germany.,Berlin Institute of Health, 10178 Berlin, Germany
| | - Wolfram H Zimmermann
- German Centre for Cardiovascular Research, 10785 Berlin, partner site Göttingen, Germany.,Institute of Pharmacology and Toxicology, University Medical Center, 37075 Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells," University of Göttingen, 37073 Göttingen, Germany
| | - Hendrik Milting
- Erich and Hanna Klessmann Institute, Heart and Diabetes Centre NRW, University Hospital of the Ruhr-University Bochum, 32545 Bad Oeynhausen, Germany
| | - Wolfgang A Linke
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany.,German Centre for Cardiovascular Research, 10785 Berlin, partner site Göttingen, Germany.,Institute of Physiology II, University of Münster, 48149 Münster, Germany
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29
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Molecular and cellular basis of genetically inherited skeletal muscle disorders. Nat Rev Mol Cell Biol 2021; 22:713-732. [PMID: 34257452 PMCID: PMC9686310 DOI: 10.1038/s41580-021-00389-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/04/2021] [Indexed: 02/06/2023]
Abstract
Neuromuscular disorders comprise a diverse group of human inborn diseases that arise from defects in the structure and/or function of the muscle tissue - encompassing the muscle cells (myofibres) themselves and their extracellular matrix - or muscle fibre innervation. Since the identification in 1987 of the first genetic lesion associated with a neuromuscular disorder - mutations in dystrophin as an underlying cause of Duchenne muscular dystrophy - the field has made tremendous progress in understanding the genetic basis of these diseases, with pathogenic variants in more than 500 genes now identified as underlying causes of neuromuscular disorders. The subset of neuromuscular disorders that affect skeletal muscle are referred to as myopathies or muscular dystrophies, and are due to variants in genes encoding muscle proteins. Many of these proteins provide structural stability to the myofibres or function in regulating sarcolemmal integrity, whereas others are involved in protein turnover, intracellular trafficking, calcium handling and electrical excitability - processes that ensure myofibre resistance to stress and their primary activity in muscle contraction. In this Review, we discuss how defects in muscle proteins give rise to muscle dysfunction, and ultimately to disease, with a focus on pathologies that are most common, best understood and that provide the most insight into muscle biology.
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30
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Müller E, Salcan S, Bongardt S, Barbosa DM, Krüger M, Kötter S. E3-ligase knock down revealed differential titin degradation by autopagy and the ubiquitin proteasome system. Sci Rep 2021; 11:21134. [PMID: 34702928 PMCID: PMC8548520 DOI: 10.1038/s41598-021-00618-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Accepted: 09/30/2021] [Indexed: 01/09/2023] Open
Abstract
The sarcomere protein titin is a major determinant of cardiomyocyte stiffness and ventricular distensibility. The constant mechanical stress on titin requires well-controlled protein quality control, the exact mechanisms of which have not yet been fully elucidated. Here, we analyzed E3-ligases potentially responsible for cardiac titin ubiquitination and specifically studied the involvement of the autophagosomal system in titin degradation. Pharmacological inhibition of autophagy and the proteasome in cultured primary rat cardiomyocytes significantly elevated titin ubiquitination and increased titin degradation. Using in-vitro pull down assays we identified binding of E3-ligases MuRF1-3, CHIP and Fbx32 to several titin domains. Immunofluorescence analysis showed sarcomeric localization of the E3-ligases. siRNA-mediated knock-down of the E3-ligases MuRF-1, -3 and a combination of CHIP/Fbx32 significantly reduced autophagy-related titin ubiquitination, whereas knock-down of MuRF-2 and -3 reduced proteasome-related titin ubiquitination. We demonstrated that the proteasomal and the autophagosomal-lysosomal system participate in degradation of the titin filament. We found that ubiquitination and degradation of titin are partially regulated by E3-ligases of the MuRF family. We further identified CHIP and Fbx32 as E3-ligases involved in titin ubiquitination.
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Affiliation(s)
- Erik Müller
- Department of Cardiovascular Physiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 22.03 02, 40225, Düsseldorf, Germany
| | - Senem Salcan
- Department of Cardiovascular Physiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 22.03 02, 40225, Düsseldorf, Germany
| | - Sabine Bongardt
- Department of Cardiovascular Physiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 22.03 02, 40225, Düsseldorf, Germany
| | - David Monteiro Barbosa
- Department of Cardiovascular Physiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 22.03 02, 40225, Düsseldorf, Germany
| | - Martina Krüger
- Department of Cardiovascular Physiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 22.03 02, 40225, Düsseldorf, Germany
| | - Sebastian Kötter
- Department of Cardiovascular Physiology, Medical Faculty and University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 22.03 02, 40225, Düsseldorf, Germany.
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31
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Loescher CM, Hobbach AJ, Linke WA. Titin (TTN): from molecule to modifications, mechanics and medical significance. Cardiovasc Res 2021; 118:2903-2918. [PMID: 34662387 PMCID: PMC9648829 DOI: 10.1093/cvr/cvab328] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/13/2021] [Indexed: 12/19/2022] Open
Abstract
The giant sarcomere protein titin is a major determinant of cardiomyocyte stiffness and contributor to cardiac strain sensing. Titin-based forces are highly regulated in health and disease, which aids in the regulation of myocardial function, including cardiac filling and output. Due to the enormous size, complexity, and malleability of the titin molecule, titin properties are also vulnerable to dysregulation, as observed in various cardiac disorders. This review provides an overview of how cardiac titin properties can be changed at a molecular level, including the role isoform diversity and post-translational modifications (acetylation, oxidation, and phosphorylation) play in regulating myocardial stiffness and contractility. We then consider how this regulation becomes unbalanced in heart disease, with an emphasis on changes in titin stiffness and protein quality control. In this context, new insights into the key pathomechanisms of human cardiomyopathy due to a truncation in the titin gene (TTN) are discussed. Along the way, we touch on the potential for titin to be therapeutically targeted to treat acquired or inherited cardiac conditions, such as HFpEF or TTN-truncation cardiomyopathy.
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Affiliation(s)
- Christine M Loescher
- Institute of Physiology II, University Hospital Münster, Robert-Koch-Str. 27B, Münster, 48149 Germany
| | - Anastasia J Hobbach
- Department of Cardiology I, Coronary, Peripheral Vascular Disease and Heart Failure, University Hospital Münster, Münster, Germany
| | - Wolfgang A Linke
- Institute of Physiology II, University Hospital Münster, Robert-Koch-Str. 27B, Münster, 48149 Germany
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32
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Bogomolovas J, Fleming JR, Franke B, Manso B, Simon B, Gasch A, Markovic M, Brunner T, Knöll R, Chen J, Labeit S, Scheffner M, Peter C, Mayans O. Titin kinase ubiquitination aligns autophagy receptors with mechanical signals in the sarcomere. EMBO Rep 2021; 22:e48018. [PMID: 34402565 PMCID: PMC8490993 DOI: 10.15252/embr.201948018] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 07/07/2021] [Accepted: 07/19/2021] [Indexed: 12/13/2022] Open
Abstract
Striated muscle undergoes remodelling in response to mechanical and physiological stress, but little is known about the integration of such varied signals in the myofibril. The interaction of the elastic kinase region from sarcomeric titin (A168-M1) with the autophagy receptors Nbr1/p62 and MuRF E3 ubiquitin ligases is well suited to link mechanosensing with the trophic response of the myofibril. To investigate the mechanisms of signal cross-talk at this titin node, we elucidated its 3D structure, analysed its response to stretch using steered molecular dynamics simulations and explored its functional relation to MuRF1 and Nbr1/p62 using cellular assays. We found that MuRF1-mediated ubiquitination of titin kinase promotes its scaffolding of Nbr1/p62 and that the process can be dynamically down-regulated by the mechanical unfolding of a linker sequence joining titin kinase with the MuRF1 receptor site in titin. We propose that titin ubiquitination is sensitive to the mechanical state of the sarcomere, the regulation of sarcomere targeting by Nbr1/p62 being a functional outcome. We conclude that MuRF1/Titin Kinase/Nbr1/p62 constitutes a distinct assembly that predictably promotes sarcomere breakdown in inactive muscle.
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Affiliation(s)
- Julius Bogomolovas
- Department of MedicineSchool of MedicineUniversity of CaliforniaSan Diego, La JollaCAUSA
- Department of Cognitive and Clinical NeuroscienceCentral Institute of Mental HealthMedical Faculty MannheimHeidelberg UniversityMannheimGermany
- Department of Integrative PathophysiologyMedical Faculty MannheimUniversity of HeidelbergMannheimGermany
| | | | - Barbara Franke
- Department of BiologyUniversity of KonstanzKonstanzGermany
| | - Bruno Manso
- Department of BiologyUniversity of KonstanzKonstanzGermany
| | - Bernd Simon
- Structural and Computational Biology UnitEMBLHeidelbergGermany
| | - Alexander Gasch
- Department of Integrative PathophysiologyMedical Faculty MannheimUniversity of HeidelbergMannheimGermany
| | | | - Thomas Brunner
- Department of BiologyUniversity of KonstanzKonstanzGermany
| | - Ralph Knöll
- Integrated Cardio Metabolic Centre (ICMC)Heart and Vascular ThemeUniversity Hospital, MedHKarolinska InstitutetHuddingeSweden
- Bioscience, CardiovascularRenal & MetabolismBioPharmaceuticalsR&D, AstraZenecaGothenburgSweden
| | - Ju Chen
- Department of MedicineSchool of MedicineUniversity of CaliforniaSan Diego, La JollaCAUSA
| | - Siegfried Labeit
- Department of Integrative PathophysiologyMedical Faculty MannheimUniversity of HeidelbergMannheimGermany
| | | | - Christine Peter
- Department of ChemistryUniversity of KonstanzKonstanzGermany
| | - Olga Mayans
- Department of BiologyUniversity of KonstanzKonstanzGermany
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33
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Zhang J, Liang Y, Bradford WH, Sheikh F. Desmosomes: emerging pathways and non-canonical functions in cardiac arrhythmias and disease. Biophys Rev 2021; 13:697-706. [PMID: 34765046 PMCID: PMC8555023 DOI: 10.1007/s12551-021-00829-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/12/2021] [Indexed: 12/14/2022] Open
Abstract
Desmosomes are critical adhesion structures in cardiomyocytes, with mutation/loss linked to the heritable cardiac disease, arrhythmogenic right ventricular cardiomyopathy (ARVC). Early studies revealed the ability of desmosomal protein loss to trigger ARVC disease features including structural remodeling, arrhythmias, and inflammation; however, the precise mechanisms contributing to diverse disease presentations are not fully understood. Recent mechanistic studies demonstrated the protein degradation component CSN6 is a resident cardiac desmosomal protein which selectively restricts cardiomyocyte desmosomal degradation and disease. This suggests defects in protein degradation can trigger the structural remodeling underlying ARVC. Additionally, a subset of ARVC-related mutations show enhanced vulnerability to calpain-mediated degradation, further supporting the relevance of these mechanisms in disease. Desmosomal gene mutations/loss has been shown to impact arrhythmogenic pathways in the absence of structural disease within ARVC patients and model systems. Studies have shown the involvement of connexins, calcium handling machinery, and sodium channels as early drivers of arrhythmias, suggesting these may be distinct pathways regulating electrical function from the desmosome. Emerging evidence has suggested inflammation may be an early mechanism in disease pathogenesis, as clinical reports have shown an overlap between myocarditis and ARVC. Recent studies focus on the association between desmosomal mutations/loss and inflammatory processes including autoantibodies and signaling pathways as a way to understand the involvement of inflammation in ARVC pathogenesis. A specific focus will be to dissect ongoing fields of investigation to highlight diverse pathogenic pathways associated with desmosomal mutations/loss.
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Affiliation(s)
- Jing Zhang
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Yan Liang
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - William H. Bradford
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
| | - Farah Sheikh
- Department of Medicine, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093 USA
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Porto D, Matsunaga Y, Franke B, Williams RM, Qadota H, Mayans O, Benian GM, Lu H. Conformational changes in twitchin kinase in vivo revealed by FRET imaging of freely moving C. elegans. eLife 2021; 10:e66862. [PMID: 34569929 PMCID: PMC8523150 DOI: 10.7554/elife.66862] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Accepted: 09/24/2021] [Indexed: 02/07/2023] Open
Abstract
The force-induced unfolding and refolding of proteins is speculated to be a key mechanism in the sensing and transduction of mechanical signals in the living cell. Yet, little evidence has been gathered for its existence in vivo. Prominently, stretch-induced unfolding is postulated to be the activation mechanism of the twitchin/titin family of autoinhibited sarcomeric kinases linked to the mechanical stress response of muscle. To test the occurrence of mechanical kinase activation in living working muscle, we generated transgenic Caenorhabditis elegans expressing twitchin containing FRET moieties flanking the kinase domain and developed a quantitative technique for extracting FRET signals in freely moving C. elegans, using tracking and simultaneous imaging of animals in three channels (donor fluorescence, acceptor fluorescence, and transmitted light). Computer vision algorithms were used to extract fluorescence signals and muscle contraction states in each frame, in order to obtain fluorescence and body curvature measurements with spatial and temporal precision in vivo. The data revealed statistically significant periodic changes in FRET signals during muscle activity, consistent with a periodic change in the conformation of twitchin kinase. We conclude that stretch-unfolding of twitchin kinase occurs in the active muscle, whereby mechanical activity titrates the signaling pathway of this cytoskeletal kinase. We anticipate that the methods we have developed here could be applied to obtaining in vivo evidence for force-induced conformational changes or elastic behavior of other proteins not only in C. elegans but in other animals in which there is optical transparency (e.g., zebrafish).
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Affiliation(s)
- Daniel Porto
- Interdisciplinary Bioengineering Program, Georgia Institute of TechnologyAtlantaUnited States
| | - Yohei Matsunaga
- Department of Pathology, Emory UniversityAtlantaUnited States
| | - Barbara Franke
- Department of Biology, University of KonstanzKonstanzGermany
| | - Rhys M Williams
- Department of Biology, University of KonstanzKonstanzGermany
| | - Hiroshi Qadota
- Department of Pathology, Emory UniversityAtlantaUnited States
| | - Olga Mayans
- Department of Biology, University of KonstanzKonstanzGermany
| | - Guy M Benian
- Department of Pathology, Emory UniversityAtlantaUnited States
| | - Hang Lu
- Interdisciplinary Bioengineering Program, Georgia Institute of TechnologyAtlantaUnited States
- School of Chemical & Biomolecular Engineering, Georgia Institute of TechnologyAtlantaUnited States
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Huang K, Duan HQ, Li QX, Luo YB, Bi FF, Yang H. Clinicopathological features of titinopathy from a Chinese neuromuscular center. Neuropathology 2021; 41:349-356. [PMID: 34553419 DOI: 10.1111/neup.12761] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/14/2022]
Abstract
Titin, one of the largest proteins in humans, is a major component of muscle sarcomeres. Pathogenic variants in the titin gene (TTN) have been reported to cause a range of skeletal muscle diseases, collectively known as titinopathy. Titinopathy is a heterogeneous group of disabling diseases characterized by muscle weakness. In our study, we aimed to establish the clinicopathological-genetic spectrum of titinopathy from a single neuromuscular center. Three patients were diagnosed as having definite titinopathy, and additional three patients were diagnosed as having possible titinopathy according to the diagnostic criteria. All the patients showed initial symptoms from age one to 40 years. Physical examination revealed that five patients had muscle weakness, and that one patient experienced behavioral changes. Muscle biopsy specimens obtained from all six patients demonstrated multiple myopathological changes, including increased fiber size variation, muscle fiber hypertrophy or atrophy, formation of centralized cell nuclei, necklace cytoplasmic bodies, and formation of rimmed vacuoles and cores. Genetic testing revealed 11 different TTN alterations, including missense (6/11), nonsense (2/11), frameshift (2/11), and splicing (1/11) mutations. Our study provides further evidence that TTN mutations are more likely to be responsible for an increasing proportion of various myopathies, such as hereditary myopathy with early respiratory failure (HMERF), core myopathy, and distal myopathy with rimmed vacuoles, than currently recognized mutations. Our findings expand the clinical, pathohistological and genetic spectrum of titinopathy.
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Affiliation(s)
- Kun Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Hui-Qian Duan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qiu-Xiang Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yue-Bei Luo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Fang-Fang Bi
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
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Lövenich L, Dreissen G, Hoffmann C, Konrad J, Springer R, Höhfeld J, Merkel R, Hoffmann B. Strain induced mechanoresponse depends on cell contractility and BAG3-mediated autophagy. Mol Biol Cell 2021; 32:ar9. [PMID: 34379447 PMCID: PMC8684750 DOI: 10.1091/mbc.e21-05-0254] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Basically all mammalian tissues are constantly exposed to a variety of environmental mechanical signals. Depending on the signal strength, mechanics intervenes in a multitude of cellular processes and is thus capable to induce simple cellular adaptations but also complex differentiation processes and even apoptosis. The underlying recognition typically depends on mechanosensitive proteins, which most often sense the mechanical signal for the induction of a cellular signaling cascade by changing their protein conformation. However, the fate of mechanosensors after mechanical stress application is still poorly understood and it remains unclear whether protein degradation pathways affect the mechanosensitivity of cells. Here, we show that cyclic stretch induces autophagosome formation in a time-dependent manner. Formation depends on the cochaperone BAG3 and thus likely involves BAG3-mediated chaperone-assisted selective autophagy. Furthermore, we demonstrate that strain-induced cell reorientation is clearly delayed upon inhibition of autophagy, suggesting a bidirectional crosstalk between mechanotransduction and autophagic degradation. The strength of the observed delay depends on stable adhesion structures and stress fiber formation in a RhoA-dependent manner.
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Affiliation(s)
- Lukas Lövenich
- Forschungszentrum Jülich, Institute of Biological Information Processing, IBI-2: Mechanobiology, 52428 Jülich, Germany
| | - Georg Dreissen
- Forschungszentrum Jülich, Institute of Biological Information Processing, IBI-2: Mechanobiology, 52428 Jülich, Germany
| | - Christina Hoffmann
- Forschungszentrum Jülich, Institute of Biological Information Processing, IBI-2: Mechanobiology, 52428 Jülich, Germany
| | - Jens Konrad
- Forschungszentrum Jülich, Institute of Biological Information Processing, IBI-2: Mechanobiology, 52428 Jülich, Germany
| | - Ronald Springer
- Forschungszentrum Jülich, Institute of Biological Information Processing, IBI-2: Mechanobiology, 52428 Jülich, Germany
| | - Jörg Höhfeld
- Institute for Cell Biology, University of Bonn, 53121 Bonn, Germany
| | - Rudolf Merkel
- Forschungszentrum Jülich, Institute of Biological Information Processing, IBI-2: Mechanobiology, 52428 Jülich, Germany
| | - Bernd Hoffmann
- Forschungszentrum Jülich, Institute of Biological Information Processing, IBI-2: Mechanobiology, 52428 Jülich, Germany
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Why exercise builds muscles: titin mechanosensing controls skeletal muscle growth under load. Biophys J 2021; 120:3649-3663. [PMID: 34389312 PMCID: PMC8456289 DOI: 10.1016/j.bpj.2021.07.023] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 04/29/2021] [Accepted: 07/23/2021] [Indexed: 12/22/2022] Open
Abstract
Muscles sense internally generated and externally applied forces, responding to these in a coordinated hierarchical manner at different timescales. The center of the basic unit of the muscle, the sarcomeric M-band, is perfectly placed to sense the different types of load to which the muscle is subjected. In particular, the kinase domain of titin (TK) located at the M-band is a known candidate for mechanical signaling. Here, we develop a quantitative mathematical model that describes the kinetics of TK-based mechanosensitive signaling and predicts trophic changes in response to exercise and rehabilitation regimes. First, we build the kinetic model for TK conformational changes under force: opening, phosphorylation, signaling, and autoinhibition. We find that TK opens as a metastable mechanosensitive switch, which naturally produces a much greater signal after high-load resistance exercise than an equally energetically costly endurance effort. Next, for the model to be stable and give coherent predictions, in particular for the lag after the onset of an exercise regime, we have to account for the associated kinetics of phosphate (carried by ATP) and for the nonlinear dependence of protein synthesis rates on muscle fiber size. We suggest that the latter effect may occur via the steric inhibition of ribosome diffusion through the sieve-like myofilament lattice. The full model yields a steady-state solution (homeostasis) for muscle cross-sectional area and tension and, a quantitatively plausible hypertrophic response to training, as well as atrophy after an extended reduction in tension.
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Höhfeld J, Benzing T, Bloch W, Fürst DO, Gehlert S, Hesse M, Hoffmann B, Hoppe T, Huesgen PF, Köhn M, Kolanus W, Merkel R, Niessen CM, Pokrzywa W, Rinschen MM, Wachten D, Warscheid B. Maintaining proteostasis under mechanical stress. EMBO Rep 2021; 22:e52507. [PMID: 34309183 PMCID: PMC8339670 DOI: 10.15252/embr.202152507] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 06/28/2021] [Accepted: 07/01/2021] [Indexed: 12/11/2022] Open
Abstract
Cell survival, tissue integrity and organismal health depend on the ability to maintain functional protein networks even under conditions that threaten protein integrity. Protection against such stress conditions involves the adaptation of folding and degradation machineries, which help to preserve the protein network by facilitating the refolding or disposal of damaged proteins. In multicellular organisms, cells are permanently exposed to stress resulting from mechanical forces. Yet, for long time mechanical stress was not recognized as a primary stressor that perturbs protein structure and threatens proteome integrity. The identification and characterization of protein folding and degradation systems, which handle force-unfolded proteins, marks a turning point in this regard. It has become apparent that mechanical stress protection operates during cell differentiation, adhesion and migration and is essential for maintaining tissues such as skeletal muscle, heart and kidney as well as the immune system. Here, we provide an overview of recent advances in our understanding of mechanical stress protection.
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Affiliation(s)
- Jörg Höhfeld
- Institute for Cell BiologyRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Thomas Benzing
- Department II of Internal Medicine and Center for Molecular Medicine Cologne (CMMC)University of CologneCologneGermany
| | - Wilhelm Bloch
- Institute of Cardiovascular Research and Sports MedicineGerman Sport UniversityCologneGermany
| | - Dieter O Fürst
- Institute for Cell BiologyRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Sebastian Gehlert
- Institute of Cardiovascular Research and Sports MedicineGerman Sport UniversityCologneGermany
- Department for the Biosciences of SportsInstitute of Sports ScienceUniversity of HildesheimHildesheimGermany
| | - Michael Hesse
- Institute of Physiology I, Life & Brain CenterMedical FacultyRheinische Friedrich‐Wilhelms UniversityBonnGermany
| | - Bernd Hoffmann
- Institute of Biological Information Processing, IBI‐2: MechanobiologyForschungszentrum JülichJülichGermany
| | - Thorsten Hoppe
- Institute for GeneticsCologne Excellence Cluster on Cellular Stress Responses in Aging‐Associated Diseases (CECAD) and CMMCUniversity of CologneCologneGermany
| | - Pitter F Huesgen
- Central Institute for Engineering, Electronics and Analytics, ZEA3Forschungszentrum JülichJülichGermany
- CECADUniversity of CologneCologneGermany
| | - Maja Köhn
- Institute of Biology IIIFaculty of Biology, and Signalling Research Centres BIOSS and CIBSSAlbert‐Ludwigs‐University FreiburgFreiburgGermany
| | - Waldemar Kolanus
- LIMES‐InstituteRheinische Friedrich‐Wilhelms University BonnBonnGermany
| | - Rudolf Merkel
- Institute of Biological Information Processing, IBI‐2: MechanobiologyForschungszentrum JülichJülichGermany
| | - Carien M Niessen
- Department of Dermatology and CECADUniversity of CologneCologneGermany
| | | | - Markus M Rinschen
- Department of Biomedicine and Aarhus Institute of Advanced StudiesAarhus UniversityAarhusDenmark
- Department of MedicineUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Dagmar Wachten
- Institute of Innate ImmunityUniversity Hospital BonnBonnGermany
| | - Bettina Warscheid
- Institute of Biology IIFaculty of Biology, and Signalling Research Centres BIOSS and CIBSSAlbert‐Ludwigs‐University FreiburgFreiburgGermany
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Lieber RL, Binder-Markey B. Biochemical and structural basis of the passive mechanical properties of whole skeletal muscle. J Physiol 2021; 599:3809-3823. [PMID: 34101193 PMCID: PMC8364503 DOI: 10.1113/jp280867] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 05/06/2021] [Indexed: 01/18/2023] Open
Abstract
Passive mechanical properties of whole skeletal muscle are not as well understood as active mechanical properties. Both the structural basis for passive mechanical properties and the properties themselves are challenging to determine because it is not clear which structures within skeletal muscle actually bear passive loads and there are not established standards by which to make mechanical measurements. Evidence suggests that titin bears the majority of the passive load within the single muscle cell. However, at larger scales, such as fascicles and muscles, there is emerging evidence that the extracellular matrix bears the major part of the load. Complicating the ability to quantify and compare across size scales, muscles and species, definitions of muscle passive properties such as stress, strain, modulus and stiffness can be made relative to many reference parameters. These uncertainties make a full understanding of whole muscle passive mechanical properties and modelling these properties very difficult. Future studies defining the specific load bearing structures and their composition and organization are required to fully understand passive mechanics of the whole muscle and develop therapies to treat disorders in which passive muscle properties are altered such as muscular dystrophy, traumatic laceration, and contracture due to upper motor neuron lesion as seen in spinal cord injury, stroke and cerebral palsy.
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Affiliation(s)
- Richard L. Lieber
- Shirley Ryan AbilityLab
- Departments of Physical Medicine and Rehabilitation and
Biomedical Engineering, Northwestern University, Chicago, IL, USA
- Edward Hines V.A. Medical Center, Hines, IL USA
| | - Ben Binder-Markey
- Department of Physical Therapy and Rehabilitation Sciences
and School of Biomedical Engineering, Sciences and Health Systems, Drexel
University, Philadelphia, PA USA
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40
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Liang Y, Lyon RC, Pellman J, Bradford WH, Lange S, Bogomolovas J, Dalton ND, Gu Y, Bobar M, Lee MH, Iwakuma T, Nigam V, Asimaki A, Scheinman M, Peterson KL, Sheikh F. Desmosomal COP9 regulates proteome degradation in arrhythmogenic right ventricular dysplasia/cardiomyopathy. J Clin Invest 2021; 131:137689. [PMID: 33857019 PMCID: PMC8159691 DOI: 10.1172/jci137689] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/14/2021] [Indexed: 12/28/2022] Open
Abstract
Dysregulated protein degradative pathways are increasingly recognized as mediators of human disease. This mechanism may have particular relevance to desmosomal proteins that play critical structural roles in both tissue architecture and cell-cell communication, as destabilization/breakdown of the desmosomal proteome is a hallmark of genetic-based desmosomal-targeted diseases, such as the cardiac disease arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). However, no information exists on whether there are resident proteins that regulate desmosomal proteome homeostasis. Here, we uncovered a cardiac constitutive photomorphogenesis 9 (COP9) desmosomal resident protein complex, composed of subunit 6 of the COP9 signalosome (CSN6), that enzymatically restricted neddylation and targeted desmosomal proteome degradation. CSN6 binding, localization, levels, and function were affected in hearts of classic mouse and human models of ARVD/C affected by desmosomal loss and mutations, respectively. Loss of desmosomal proteome degradation control due to junctional reduction/loss of CSN6 and human desmosomal mutations destabilizing junctional CSN6 were also sufficient to trigger ARVD/C in mice. We identified a desmosomal resident regulatory complex that restricted desmosomal proteome degradation and disease.
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Affiliation(s)
- Yan Liang
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Robert C. Lyon
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Jason Pellman
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - William H. Bradford
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Stephan Lange
- Department of Medicine, University of California San Diego, La Jolla, California, USA
- Institute of Medicine, Department of Molecular and Clinical Medicine and Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
| | - Julius Bogomolovas
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Nancy D. Dalton
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Yusu Gu
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Marcus Bobar
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Mong-Hong Lee
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Tomoo Iwakuma
- Department of Cancer Biology, University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Vishal Nigam
- Department of Pediatrics, University of California San Diego, La Jolla, California, USA
- Department of Pediatrics, Seattle Children’s Research Institute and University of Washington, Seattle, Washington, USA
| | - Angeliki Asimaki
- Cardiology Clinical Academic Group, St. George’s University of London, London, United Kingdom
| | - Melvin Scheinman
- Department of Medicine, Cardiac Electrophysiology Section, University of California San Francisco, San Francisco, California, USA
| | - Kirk L. Peterson
- Department of Medicine, University of California San Diego, La Jolla, California, USA
| | - Farah Sheikh
- Department of Medicine, University of California San Diego, La Jolla, California, USA
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Abstract
PURPOSE OF REVIEW The last few years have confirmed previous assumptions of an enormous impact of the titin gene (TTN) on the occurrence of muscle disease, cardiomyopathy, or both together. The reason for this rather late understanding of its importance is because of the huge size which prevented sequencing of the whole gene by the previous Sanger technique in the individual cases. An update of the advances in diagnosing titinopathies is the main focus of this review. RECENT FINDINGS High throughput methods are now widely available for TTN sequencing and a corresponding explosion of different types of identified titinopathies is observed and published in the literature, although final confirmation is lacking in many cases with recessive missense variants. SUMMARY The implications of these findings for clinical practice are easy to understand: patients with previously undiagnosed muscle disease can now have a correct diagnosis and subsequently receive a likely prognosis, can have accurate genetic counseling for the whole family and early treatment for predictable complications from the heart and respiratory muscles. In addition not to forget, they can avoid wrong diagnoses leading to wrong treatments.
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Shenkman BS, Tsaturyan AK, Vikhlyantsev IM, Kozlovskaya IB, Grigoriev AI. Molecular Mechanisms of Muscle Tone Impairment under Conditions of Real and Simulated Space Flight. Acta Naturae 2021; 13:85-97. [PMID: 34377559 PMCID: PMC8327152 DOI: 10.32607/actanaturae.10953] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 08/04/2020] [Indexed: 01/08/2023] Open
Abstract
Kozlovskaya et al. [1] and Grigoriev et al. [2] showed that enormous loss of muscle stiffness (atonia) develops in humans under true (space flight) and simulated microgravity conditions as early as after the first days of exposure. This phenomenon is attributed to the inactivation of slow motor units and called reflectory atonia. However, a lot of evidence indicating that even isolated muscle or a single fiber possesses substantial stiffness was published at the end of the 20th century. This intrinsic stiffness is determined by the active component, i.e. the ability to form actin-myosin cross-bridges during muscle stretch and contraction, as well as by cytoskeletal and extracellular matrix proteins, capable of resisting muscle stretch. The main facts on intrinsic muscle stiffness under conditions of gravitational unloading are considered in this review. The data obtained in studies of humans under dry immersion and rodent hindlimb suspension is analyzed. The results and hypotheses regarding reduced probability of cross-bridge formation in an atrophying muscle due to increased interfilament spacing are described. The evidence of cytoskeletal protein (titin, nebulin, etc.) degradation during gravitational unloading is also discussed. The possible mechanisms underlying structural changes in skeletal muscle collagen and its role in reducing intrinsic muscle stiffness are presented. The molecular mechanisms of changes in intrinsic stiffness during space flight and simulated microgravity are reviewed.
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Affiliation(s)
- B. S. Shenkman
- State Scientific Center of Russian Federation – Institute of Biomedical Problems, Moscow, 123007 Russia
| | - A. K. Tsaturyan
- Lomonosov Moscow State University Research Institute of Mechanics, Moscow, 119192 Russia
| | - I. M. Vikhlyantsev
- Institute of Experimental and Theoretical Biophysics, Moscow Region, Pushchino, 142290 Russia
| | - I. B. Kozlovskaya
- State Scientific Center of Russian Federation – Institute of Biomedical Problems, Moscow, 123007 Russia
| | - A. I. Grigoriev
- State Scientific Center of Russian Federation – Institute of Biomedical Problems, Moscow, 123007 Russia
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Solís C, Solaro RJ. Novel insights into sarcomere regulatory systems control of cardiac thin filament activation. J Gen Physiol 2021; 153:211903. [PMID: 33740037 PMCID: PMC7988513 DOI: 10.1085/jgp.202012777] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/23/2021] [Indexed: 12/11/2022] Open
Abstract
Our review focuses on sarcomere regulatory mechanisms with a discussion of cardiac-specific modifications to the three-state model of thin filament activation from a blocked to closed to open state. We discuss modulation of these thin filament transitions by Ca2+, by crossbridge interactions, and by thick filament–associated proteins, cardiac myosin–binding protein C (cMyBP-C), cardiac regulatory light chain (cRLC), and titin. Emerging evidence supports the idea that the cooperative activation of the thin filaments despite a single Ca2+ triggering regulatory site on troponin C (cTnC) cannot be considered in isolation of other functional domains of the sarcomere. We discuss long- and short-range interactions among these domains with the regulatory units of thin filaments, including proteins at the barbed end at the Z-disc and the pointed end near the M-band. Important to these discussions is the ever-increasing understanding of the role of cMyBP-C, cRLC, and titin filaments. Detailed knowledge of these control processes is critical to the understanding of mechanisms sustaining physiological cardiac state with varying hemodynamic load, to better defining genetic and acquired cardiac disorders, and to developing targets for therapies at the level of the sarcomeres.
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Affiliation(s)
- Christopher Solís
- University of Illinois at Chicago, College of Medicine, Department of Physiology and Biophysics and Center for Cardiovascular Research, Chicago, IL
| | - R John Solaro
- University of Illinois at Chicago, College of Medicine, Department of Physiology and Biophysics and Center for Cardiovascular Research, Chicago, IL
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44
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Fleming JR, Rani A, Kraft J, Zenker S, Börgeson E, Lange S. Exploring Obscurin and SPEG Kinase Biology. J Clin Med 2021; 10:jcm10050984. [PMID: 33801198 PMCID: PMC7957886 DOI: 10.3390/jcm10050984] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 02/10/2021] [Accepted: 02/18/2021] [Indexed: 12/15/2022] Open
Abstract
Three members of the obscurin protein family that contain tandem kinase domains with important signaling functions for cardiac and striated muscles are the giant protein obscurin, its obscurin-associated kinase splice isoform, and the striated muscle enriched protein kinase (SPEG). While there is increasing evidence for the specific roles that each individual kinase domain plays in cross-striated muscles, their biology and regulation remains enigmatic. Our present study focuses on kinase domain 1 and the adjacent low sequence complexity inter-kinase domain linker in obscurin and SPEG. Using Phos-tag gels, we show that the linker in obscurin contains several phosphorylation sites, while the same region in SPEG remained unphosphorylated. Our homology modeling, mutational analysis and molecular docking demonstrate that kinase 1 in obscurin harbors all key amino acids important for its catalytic function and that actions of this domain result in autophosphorylation of the protein. Our bioinformatics analyses also assign a list of putative substrates for kinase domain 1 in obscurin and SPEG, based on the known and our newly proposed phosphorylation sites in muscle proteins, including obscurin itself.
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Affiliation(s)
- Jennifer R. Fleming
- Department of Biology, University of Konstanz, 78457 Konstanz, Germany
- Correspondence: (J.R.F.); (E.B.); (S.L.)
| | - Alankrita Rani
- Centre for Molecular and Translational Medicine, The Wallenberg Laboratory and Wallenberg, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; (A.R.); (J.K.)
| | - Jamie Kraft
- Centre for Molecular and Translational Medicine, The Wallenberg Laboratory and Wallenberg, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; (A.R.); (J.K.)
| | - Sanja Zenker
- Department of Medicine, University of California, San Diego, CA 92093, USA;
| | - Emma Börgeson
- Centre for Molecular and Translational Medicine, The Wallenberg Laboratory and Wallenberg, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; (A.R.); (J.K.)
- Department of Clinical Physiology, Sahlgrenska University Hospital, 41345 Gothenburg, Sweden
- Correspondence: (J.R.F.); (E.B.); (S.L.)
| | - Stephan Lange
- Centre for Molecular and Translational Medicine, The Wallenberg Laboratory and Wallenberg, Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden; (A.R.); (J.K.)
- Department of Medicine, University of California, San Diego, CA 92093, USA;
- Correspondence: (J.R.F.); (E.B.); (S.L.)
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45
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Schiaffino S, Reggiani C, Akimoto T, Blaauw B. Molecular Mechanisms of Skeletal Muscle Hypertrophy. J Neuromuscul Dis 2021; 8:169-183. [PMID: 33216041 PMCID: PMC8075408 DOI: 10.3233/jnd-200568] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Skeletal muscle hypertrophy can be induced by hormones and growth factors acting directly as positive regulators of muscle growth or indirectly by neutralizing negative regulators, and by mechanical signals mediating the effect of resistance exercise. Muscle growth during hypertrophy is controlled at the translational level, through the stimulation of protein synthesis, and at the transcriptional level, through the activation of ribosomal RNAs and muscle-specific genes. mTORC1 has a central role in the regulation of both protein synthesis and ribosomal biogenesis. Several transcription factors and co-activators, including MEF2, SRF, PGC-1α4, and YAP promote the growth of the myofibers. Satellite cell proliferation and fusion is involved in some but not all muscle hypertrophy models.
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Affiliation(s)
| | - Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Italy.,Science and Research Centre Koper, Institute for Kinesiology Research, Koper, Slovenia
| | | | - Bert Blaauw
- Venetian Institute of Molecular Medicine, Padova, Italy.,Department of Biomedical Sciences, University of Padova, Italy
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46
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Rees M, Nikoopour R, Fukuzawa A, Kho AL, Fernandez-Garcia MA, Wraige E, Bodi I, Deshpande C, Özdemir Ö, Daimagüler HS, Pfuhl M, Holt M, Brandmeier B, Grover S, Fluss J, Longman C, Farrugia ME, Matthews E, Hanna M, Muntoni F, Sarkozy A, Phadke R, Quinlivan R, Oates EC, Schröder R, Thiel C, Reimann J, Voermans N, Erasmus C, Kamsteeg EJ, Konersman C, Grosmann C, McKee S, Tirupathi S, Moore SA, Wilichowski E, Hobbiebrunken E, Dekomien G, Richard I, Van den Bergh P, Domínguez-González C, Cirak S, Ferreiro A, Jungbluth H, Gautel M. Making sense of missense variants in TTN-related congenital myopathies. Acta Neuropathol 2021; 141:431-453. [PMID: 33449170 PMCID: PMC7882473 DOI: 10.1007/s00401-020-02257-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 12/20/2020] [Accepted: 12/20/2020] [Indexed: 12/15/2022]
Abstract
Mutations in the sarcomeric protein titin, encoded by TTN, are emerging as a common cause of myopathies. The diagnosis of a TTN-related myopathy is, however, often not straightforward due to clinico-pathological overlap with other myopathies and the prevalence of TTN variants in control populations. Here, we present a combined clinico-pathological, genetic and biophysical approach to the diagnosis of TTN-related myopathies and the pathogenicity ascertainment of TTN missense variants. We identified 30 patients with a primary TTN-related congenital myopathy (CM) and two truncating variants, or one truncating and one missense TTN variant, or homozygous for one TTN missense variant. We found that TTN-related myopathies show considerable overlap with other myopathies but are strongly suggested by a combination of certain clinico-pathological features. Presentation was typically at birth with the clinical course characterized by variable progression of weakness, contractures, scoliosis and respiratory symptoms but sparing of extraocular muscles. Cardiac involvement depended on the variant position. Our biophysical analyses demonstrated that missense mutations associated with CMs are strongly destabilizing and exert their effect when expressed on a truncating background or in homozygosity. We hypothesise that destabilizing TTN missense mutations phenocopy truncating variants and are a key pathogenic feature of recessive titinopathies that might be amenable to therapeutic intervention.
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Affiliation(s)
- Martin Rees
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Roksana Nikoopour
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Atsushi Fukuzawa
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Ay Lin Kho
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Miguel A Fernandez-Garcia
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK
| | - Elizabeth Wraige
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK
| | - Istvan Bodi
- Department of Clinical Neuropathology, King's College Hospital, London, UK
| | | | - Özkan Özdemir
- Centre for Molecular Medicine, University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Hülya-Sevcan Daimagüler
- Centre for Molecular Medicine, University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Mark Pfuhl
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
- School of Cardiovascular Medicine and Sciences, King's College London BHF Centre of Research Excellence, London, UK
| | - Mark Holt
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
- School of Cardiovascular Medicine and Sciences, King's College London BHF Centre of Research Excellence, London, UK
| | - Birgit Brandmeier
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Sarah Grover
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
| | - Joël Fluss
- Pediatric Neurology Unit, Paediatrics Subspecialties Service, Geneva Children's Hospital, Geneva, Switzerland
| | - Cheryl Longman
- West of Scotland Regional Genetics Service, Laboratory Medicine Building, Queen Elizabeth University Hospital, Glasgow, UK
| | | | - Emma Matthews
- MRC Neuromuscular Centre, National Hospital for Neurology and Neurosurgery, Queen's Square, London, UK
| | - Michael Hanna
- MRC Neuromuscular Centre, National Hospital for Neurology and Neurosurgery, Queen's Square, London, UK
| | - Francesco Muntoni
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
- NIHR Great Ormond Street Hospital Biomedical Research Centre, Great Ormond Street Institute of Child Health, University College London, Great Ormond Street Hospital Trust, London, UK
| | - Anna Sarkozy
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
| | - Rahul Phadke
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
| | - Ros Quinlivan
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
| | - Emily C Oates
- Dubowitz Neuromuscular Centre, Great Ormond Street Hospital for Children, London, UK
- School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sidney, Australia
- Kids Neuroscience Centre, Kids Research, The Children's Hospital at Westmead, Sydney, NSW, Australia
| | - Rolf Schröder
- Institute of Neuropathology, University Hospital Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Christian Thiel
- Department of Genetics, University of Erlangen, Erlangen, Germany
| | - Jens Reimann
- Muscle Laboratory, Department of Neurology, University of Bonn Medical Centre, Bonn, Germany
| | - Nicol Voermans
- Department of Neurology, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, The Netherlands
| | - Corrie Erasmus
- Department of Paediatric Neurology, Radboud University, Nijmegen, The Netherlands
| | - Erik-Jan Kamsteeg
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Chaminda Konersman
- UCSD, Rady Children's Hospital, and VA San Diego Healthcare System, San Diego, USA
| | | | - Shane McKee
- Northern Ireland Regional Genetics Service, Belfast City Hospital, Belfast, UK
| | - Sandya Tirupathi
- Department of Paediatric Neurology, Royal Belfast Hospital for Sick Children, Belfast, UK
| | - Steven A Moore
- Department of Pathology, The University of Iowa, Iowa City, IA, USA
| | | | - Elke Hobbiebrunken
- Department of Paediatric Neurology, University of Göttingen, Göttingen, Germany
| | | | - Isabelle Richard
- Genethon and UMR_S951, INSERM, Université Evry, Université Paris Saclay, Evry, 91002, Evry, France
| | - Peter Van den Bergh
- Neuromuscular Reference Centre, Department of Neurology, University Hospital Saint-Luc, Brussels, Belgium
| | | | - Sebahattin Cirak
- Centre for Molecular Medicine, University of Cologne, Cologne, Germany
- Department of Pediatrics, University Hospital Cologne and Faculty of Medicine, University of Cologne, Cologne, Germany
- Centre for Rare Diseases (ZSEK), University of Cologne, Cologne, Germany
| | - Ana Ferreiro
- Basic and Translational Myology Laboratory, Université de Paris, Paris, France
- Centre de Référence Des Maladies Neuromusculaires, APHP, Institut of Myology, GHU Pitié Salpêtrière- Charles Foix, Paris, France
| | - Heinz Jungbluth
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK
- Department of Paediatric Neurology, Evelina Children's Hospital, Guy's & St Thomas' NHS Foundation Trust, London, UK
- Department of Clinical and Basic Neuroscience, IoPPN, King's College London, London, UK
| | - Mathias Gautel
- Randall Centre for Cell and Molecular Biophysics, Muscle Biophysics, King's College London BHF Centre of Research Excellence, London, UK.
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47
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Santiago CF, Huttner IG, Fatkin D. Mechanisms of TTNtv-Related Dilated Cardiomyopathy: Insights from Zebrafish Models. J Cardiovasc Dev Dis 2021; 8:jcdd8020010. [PMID: 33504111 PMCID: PMC7912658 DOI: 10.3390/jcdd8020010] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 12/15/2022] Open
Abstract
Dilated cardiomyopathy (DCM) is a common heart muscle disorder characterized by ventricular dilation and contractile dysfunction that is associated with significant morbidity and mortality. New insights into disease mechanisms and strategies for treatment and prevention are urgently needed. Truncating variants in the TTN gene, which encodes the giant sarcomeric protein titin (TTNtv), are the most common genetic cause of DCM, but exactly how TTNtv promote cardiomyocyte dysfunction is not known. Although rodent models have been widely used to investigate titin biology, they have had limited utility for TTNtv-related DCM. In recent years, zebrafish (Danio rerio) have emerged as a powerful alternative model system for studying titin function in the healthy and diseased heart. Optically transparent embryonic zebrafish models have demonstrated key roles of titin in sarcomere assembly and cardiac development. The increasing availability of sophisticated imaging tools for assessment of heart function in adult zebrafish has revolutionized the field and opened new opportunities for modelling human genetic disorders. Genetically modified zebrafish that carry a human A-band TTNtv have now been generated and shown to spontaneously develop DCM with age. This zebrafish model will be a valuable resource for elucidating the phenotype modifying effects of genetic and environmental factors, and for exploring new drug therapies.
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Affiliation(s)
- Celine F. Santiago
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; (C.F.S.); (I.G.H.)
- St. Vincent’s Clinical School, Faculty of Medicine, UNSW Sydney, Kensington, NSW 2052, Australia
| | - Inken G. Huttner
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; (C.F.S.); (I.G.H.)
- St. Vincent’s Clinical School, Faculty of Medicine, UNSW Sydney, Kensington, NSW 2052, Australia
| | - Diane Fatkin
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; (C.F.S.); (I.G.H.)
- St. Vincent’s Clinical School, Faculty of Medicine, UNSW Sydney, Kensington, NSW 2052, Australia
- Cardiology Department, St. Vincent’s Hospital, Darlinghurst, NSW 2010, Australia
- Correspondence:
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48
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Nikooie R, Moflehi D, Zand S. Lactate regulates autophagy through ROS-mediated activation of ERK1/2/m-TOR/p-70S6K pathway in skeletal muscle. J Cell Commun Signal 2021; 15:107-123. [PMID: 33398722 DOI: 10.1007/s12079-020-00599-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 11/26/2020] [Indexed: 12/09/2022] Open
Abstract
The role of autophagy and lysosomal degradation pathway in the regulation of skeletal muscle metabolism was previously studied. However, underlying molecular mechanisms are poorly understood. L-lactate which is utilized as an energetic substrate by skeletal muscle can also augment genes expression related to metabolism and up-regulate those being responsive to reactive oxygen species (ROS). Since ROS is the most important regulator of autophagy in skeletal muscle, we tested if there is a link between cellular lactate metabolism and autophagy in differentiated C2C12 myotubes and the gastrocnemius muscle of male wistar rats. C2C12 mouse skeletal muscle was exposed to 2, 6, 10, and 20 mM lactate and evaluated for lactate autophagic effects. Lactate dose-dependently increased autophagy and augmented ROS generation in differentiated C2C12 myotubes. The autophagic effect of lactate deterred in N-acetylcysteine presence (NAC, a ROS scavenger) indicated lactate regulates autophagy with ROS participation. Lactate-induced up-regulation of extracellular signal-regulated kinase 1/2 (ERK1/2) through ROS was required to regulate the autophagy by lactate. Further analysis about ERK1/2 up- and downstream indicated that lactate regulates autophagy through ROS-mediated the activation of ERK1/2/mTOR/p70S6K pathway in skeletal muscle. The in vitro effects of lactate on autophagy also occurred in the gastrocnemius muscle of male Wistar rats. In conclusion, we provided the lactate-associated regulation evidence of autophagy in skeletal muscle by activating ROS-mediated ERK1/2/mTOR/p70S6K pathway. Since the increase in cellular lactate concentration is a hallmark of energy deficiency, the results provide insight into a skeletal muscle mechanism to fulfill its enhanced energy requirement.
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Affiliation(s)
- Rohollah Nikooie
- Department of Exercise physiology, Faculty of Physical Education and Sport Sciences, Shahid Bahonar University of Kerman, Kerman, Iran. .,Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.
| | - Daruosh Moflehi
- Department of Exercise physiology, Faculty of Physical Education and Sport Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
| | - Samira Zand
- Department of Exercise physiology, Faculty of Physical Education and Sport Sciences, Shahid Bahonar University of Kerman, Kerman, Iran
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49
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Korb MK, Kimonis VE, Mozaffar T. Multisystem proteinopathy: Where myopathy and motor neuron disease converge. Muscle Nerve 2020; 63:442-454. [PMID: 33145792 DOI: 10.1002/mus.27097] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 10/08/2020] [Accepted: 10/18/2020] [Indexed: 12/12/2022]
Abstract
Multisystem proteinopathy (MSP) is a pleiotropic group of inherited disorders that cause neurodegeneration, myopathy, and bone disease, and share common pathophysiology. Originally referred to as inclusion body myopathy associated with Paget disease of bone and frontotemporal dementia (IBMPFD), attributed to mutations in the gene encoding valosin-containing protein (VCP), it has more recently been discovered that there are several other genes responsible for similar clinical and pathological phenotypes with muscle, brain, nerve, and bone involvement, in various combinations. These include heterogeneous nuclear ribonucleoprotein A2B1 and A1 (hnRNPA2B1, hnRNPA1), sequestosome 1 (SQSTM1), matrin 3 (MATR3), T-cell restricted intracellular antigen 1 (TIA1), and optineurin (OPTN), all of which share disruption of RNA stress granule function and autophagic degradation. This review will discuss each of the genes implicated in MSP, exploring the molecular pathogenesis, clinical features, current standards of care, and future directions for this diverse yet mechanistically linked spectrum of disorders.
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Affiliation(s)
- Manisha K Korb
- Departments of Neurology, University of California Irvine, Orange, California, USA
| | - Virginia E Kimonis
- Departments of Pediatrics, University of California Irvine, Orange, California, USA
| | - Tahseen Mozaffar
- Departments of Neurology, University of California Irvine, Orange, California, USA.,Departments of Orthopedic Surgery, University of California Irvine, Orange, California, USA.,Departments of Pathology & Laboratory Medicine, University of California Irvine, Orange, California, USA
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50
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Woo H, Choi B, Eom K. Ligand-binding alters the mechanical stability of muscle protein titin domains. J Biomol Struct Dyn 2020; 38:4938-4946. [DOI: 10.1080/07391102.2019.1688686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- Hwanyoung Woo
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon, Republic of Korea
| | - Bumjoon Choi
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon, Republic of Korea
| | - Kilho Eom
- Biomechanics Laboratory, College of Sport Science, Sungkyunkwan University (SKKU), Suwon, Republic of Korea
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