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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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2
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Moura J, Sousa AP, Samões R, Carneiro P, Neves E, Silva AM, Santos E. Anti-titin antibodies in a cohort of myasthenia gravis patients. J Thorac Dis 2024; 16:973-978. [PMID: 38505076 PMCID: PMC10944723 DOI: 10.21037/jtd-23-94] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 01/18/2024] [Indexed: 03/21/2024]
Abstract
Background Anti-titin antibodies have been previously associated with thymoma-associated myasthenia gravis (MG) and a more clinically severe form of MG. While currently only serving as a disease biomarker, its possible utility as an indicator of underlying thymus malignancy may be of value in clinical practice. Methods Data was retrospectively collected and analyzed from 2013 to 2022 using an institutional record of MG patients. Anti-titin antibodies were assessed using Line Blot immunoassay. Results From 130 MG cases, 32 (24.6%) were anti-titin positive. Anti-titin positive cases were associated with older age of disease onset [median (IQR): 63.0 (44.3-70.8) vs. 35.5 (24.8-60.8) years] (P<0.01). Thymectomy was performed in 46 (35.4%) MG patients, 12 of which anti-titin positive (26.1%). Thymectomy samples from anti-titin positive patients comprised 10 (83.3%) cases of thymoma and 2 (16.7%) cases of thymus hyperplasia. There was a tendency towards anti-titin positive patients having more thymoma while anti-titin negative displayed more hyperplasia (P<0.01). Anti-titin positivity correlated with thymoma in patients with age of onset bellow 50 years (P=0.028). Anti-titin positivity was significantly associated with generalized MG in the late-onset group (P=0.005). Conclusions The presence of anti-titin antibodies appears to correlate with underlying thymoma in early-onset MG cases and with generalized MG in late-onset cases. Prospective studies are needed to further study this association.
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Affiliation(s)
- João Moura
- Department of Neurology, Centro Hospitalar Universitário de Santo António, Porto, Portugal
| | - Ana Paula Sousa
- Department of Neurophysiology, Centro Hospitalar Universitário de Santo António, Porto, Portugal
| | - Raquel Samões
- Department of Neurology, Centro Hospitalar Universitário de Santo António, Porto, Portugal
- Unit of Multidisciplinary Research in Biomedicine (UMIB), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal
| | - Paula Carneiro
- Department of Immunology, Centro Hospitalar Universitário de Santo António, Porto, Portugal
| | - Esmeralda Neves
- Department of Immunology, Centro Hospitalar Universitário de Santo António, Porto, Portugal
| | - Ana Martins Silva
- Department of Neurology, Centro Hospitalar Universitário de Santo António, Porto, Portugal
- Unit of Multidisciplinary Research in Biomedicine (UMIB), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal
| | - Ernestina Santos
- Department of Neurology, Centro Hospitalar Universitário de Santo António, Porto, Portugal
- Unit of Multidisciplinary Research in Biomedicine (UMIB), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), University of Porto, Porto, Portugal
- Laboratory for Integrative and Translational Research in Population Health (ITR), Porto, Portugal
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Abbasi Yeganeh F, Rastegarpouyani H, Li J, Taylor KA. Structure of the Drosophila melanogaster Flight Muscle Myosin Filament at 4.7 Å Resolution Reveals New Details of Non-Myosin Proteins. Int J Mol Sci 2023; 24:14936. [PMID: 37834384 PMCID: PMC10573858 DOI: 10.3390/ijms241914936] [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] [Received: 09/03/2023] [Revised: 09/29/2023] [Accepted: 10/01/2023] [Indexed: 10/15/2023] Open
Abstract
Striated muscle thick filaments are composed of myosin II and several non-myosin proteins which define the filament length and modify its function. Myosin II has a globular N-terminal motor domain comprising its catalytic and actin-binding activities and a long α-helical, coiled tail that forms the dense filament backbone. Myosin alone polymerizes into filaments of irregular length, but striated muscle thick filaments have defined lengths that, with thin filaments, define the sarcomere structure. The motor domain structure and function are well understood, but the myosin filament backbone is not. Here we report on the structure of the flight muscle thick filaments from Drosophila melanogaster at 4.7 Å resolution, which eliminates previous ambiguities in non-myosin densities. The full proximal S2 region is resolved, as are the connecting densities between the Ig domains of stretchin-klp. The proteins, flightin, and myofilin are resolved in sufficient detail to build an atomic model based on an AlphaFold prediction. Our results suggest a method by which flightin and myofilin cooperate to define the structure of the thick filament and explains a key myosin mutation that affects flightin incorporation. Drosophila is a genetic model organism for which our results can define strategies for functional testing.
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Affiliation(s)
- Fatemeh Abbasi Yeganeh
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA; (F.A.Y.); (H.R.); (J.L.)
| | - Hosna Rastegarpouyani
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA; (F.A.Y.); (H.R.); (J.L.)
- Department of Biological Science, Florida State University, Tallahassee, FL 32306-4380, USA
| | - Jiawei Li
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA; (F.A.Y.); (H.R.); (J.L.)
| | - Kenneth A. Taylor
- Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306-4380, USA; (F.A.Y.); (H.R.); (J.L.)
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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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5
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Effect of titin phosphorylation on degradation of titin from skeletal muscles. FOOD SCIENCE AND HUMAN WELLNESS 2023. [DOI: 10.1016/j.fshw.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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6
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Prodanovic M, Wang Y, Mijailovich SM, Irving T. Using Multiscale Simulations as a Tool to Interpret Equatorial X-ray Fiber Diffraction Patterns from Skeletal Muscle. Int J Mol Sci 2023; 24:8474. [PMID: 37239821 PMCID: PMC10218096 DOI: 10.3390/ijms24108474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
Synchrotron small-angle X-ray diffraction is the method of choice for nm-scale structural studies of striated muscle under physiological conditions and on millisecond time scales. The lack of generally applicable computational tools for modeling X-ray diffraction patterns from intact muscles has been a significant barrier to exploiting the full potential of this technique. Here, we report a novel "forward problem" approach using the spatially explicit computational simulation platform MUSICO to predict equatorial small-angle X-ray diffraction patterns and the force output simultaneously from resting and isometrically contracting rat skeletal muscle that can be compared to experimental data. The simulation generates families of thick-thin filament repeating units, each with their individually predicted occupancies of different populations of active and inactive myosin heads that can be used to generate 2D-projected electron density models based on known Protein Data Bank structures. We show how, by adjusting only a few selected parameters, we can achieve a good correspondence between experimental and predicted X-ray intensities. The developments presented here demonstrate the feasibility of combining X-ray diffraction and spatially explicit modeling to form a powerful hypothesis-generating tool that can be used to motivate experiments that can reveal emergent properties of muscle.
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Affiliation(s)
- Momcilo Prodanovic
- Institute for Information Technologies, University of Kragujevac, 34000 Kragujevac, Serbia;
- FilamenTech, Inc., Newton, MA 02458, USA;
| | - Yiwei Wang
- Department of Applied Mathematics, Illinois Institute of Technology, Chicago, IL 60616, USA;
- Department of Biology, Illinois Institute of Technology, Chicago, IL 60616, USA
- Department of Mathematics, University of California, Riverside, CA 92521, USA
| | | | - Thomas Irving
- Department of Biology, Illinois Institute of Technology, Chicago, IL 60616, USA
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Alkhunaizi E, Martin N, Jelin AC, Rosner M, Bailey DJ, Steiner LA, Lakhani S, Ji W, Katzman PJ, Forster KR, Jarinova O, Shannon P, Chitayat D. Fetal akinesia deformation sequence syndrome associated with recessive TTN variants. Am J Med Genet A 2023; 191:760-769. [PMID: 36495114 PMCID: PMC9928776 DOI: 10.1002/ajmg.a.63071] [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] [Received: 06/14/2022] [Revised: 10/12/2022] [Accepted: 11/12/2022] [Indexed: 12/14/2022]
Abstract
Arthrogryposis multiplex congenita (AMC) [also known as multiple joints contracture or Fetal Akinesia Deformation Sequence (FADS)] is etiologically a heterogeneous condition with an estimated incidence of approximately 1 in 3000 live births and much higher incidence when prenatally diagnosed cases are included. The condition can be acquired or secondary to fetal exposures and can also be caused by a variety of single-gene disorders affecting the brain, spinal cord, peripheral nerves, neuromuscular junction, muscle, and a variety of disorders affecting the connective tissues (Niles et al., Prenatal Diagnosis, 2019; 39:720-731). The introduction of next-generation gene sequencing uncovered many genes and causative variants of AMC but also identified genes that cause both dominant and recessive inherited conditions with the variability of clinical manifestations depending on the genes and variants. Molecular diagnosis in these cases is not only important for prognostication but also for the determination of recurrence risk and for providing reproductive options including preimplantation and prenatal diagnosis. TTN, the largest known gene in the human genome, has been known to be associated with autosomal dominant dilated cardiomyopathy. However, homozygote and compound heterozygote pathogenic variants with recessive inheritance have rarely been reported. We report the effect of recessive variants located within the fetal IC and/or N2BA isoforms in association with severe FADS in three families. All parents were healthy obligate carriers and none of them had cardiac or skeletal muscle abnormalities. This report solidifies FADS as an alternative phenotypic presentation associated with homozygote/compound heterozygous pathogenic variants in the TTN.
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Affiliation(s)
- Ebba Alkhunaizi
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Nicole Martin
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Angie C. Jelin
- Department of Gynecology and Obstetrics and Department of Genetic Medicine, Johns Hopkins Hospital, Baltimore, Maryland, USA
| | - Mara Rosner
- Department of Gynecology and Obstetrics, Center for Fetal Therapy, Johns Hopkins Hospital, Baltimore, Maryland, USA
| | - Diana J. Bailey
- Department of Pediatrics, University of Rochester, Rochester, New York, USA
| | - Laurie A. Steiner
- Department of Pediatrics, University of Rochester, Rochester, New York, USA
| | - Saquib Lakhani
- Department of Pediatrics, Pediatric Genomics Discovery Program, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Weizhen Ji
- Department of Pediatrics, Pediatric Genomics Discovery Program, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Philip J. Katzman
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, New York, USA
| | - Katherine R. Forster
- Department of Gynecology and Obstetrics, Center for Fetal Therapy, Johns Hopkins Hospital, Baltimore, Maryland, USA
- Division of Maternal Fetal Medicine, Sibley Memorial Hospital, Johns Hopkins Medicine, Washington, Washington, USA
| | - Olga Jarinova
- Department of Pathology and Laboratory Medicine, CHEO Genetics Diagnostic Laboratory, University of Ottawa, Ottawa, Ontario, Canada
| | - Patrick Shannon
- Department of Pathology and Laboratory Medicine, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
| | - David Chitayat
- Division of Clinical and Metabolic Genetics, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
- The Prenatal Diagnosis and Medical Genetics Program, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, Toronto, Ontario, Canada
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8
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Harding D, Chong MHA, Lahoti N, Bigogno CM, Prema R, Mohiddin SA, Marelli-Berg F. Dilated cardiomyopathy and chronic cardiac inflammation: Pathogenesis, diagnosis and therapy. J Intern Med 2023; 293:23-47. [PMID: 36030368 DOI: 10.1111/joim.13556] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Dilated cardiomyopathy (DCM) is typically defined by left ventricular dilation and systolic dysfunction in the absence of a clear precipitant. Idiopathic disease is common; up to 50% of patients with DCM have no cause found despite imaging, genetic and biopsy assessments. Treatment remains focused on managing symptoms, reducing the risk of sudden cardiac death and ameliorating the structural and electrical complications of disease progression. In the absence of aetiology-specific treatments, the condition remains associated with a poor prognosis; mortality is approximately 40% at 10 years. The role of immune-mediated inflammatory injury in the development and progression of DCM was first proposed over 30 years ago. Despite the subsequent failures of three large clinical trials of immunosuppressive treatment (ATTACH, RENEWAL and the Myocarditis Treatment Trial), evidence for an abnormal adaptive immune response in DCM remains significant. In this review, we summarise and discuss available evidence supporting immune dysfunction in DCM, with a specific focus on cellular immunity. We also highlight current clinical and experimental treatments. We propose that the success of future immunosuppressive treatment trials in DCM will be dependent on the deep immunophenotyping of patients, to identify those with active inflammation and/or an abnormal immune response who are most likely to respond to therapy.
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Affiliation(s)
- Daniel Harding
- Centre for Biochemical Pharmacology, William Harvey Research Institute, London, UK
| | - Ming H A Chong
- Barts and The London School of Medicine and Dentistry, London, UK
| | - Nishant Lahoti
- Conquest Hospital, East Sussex Healthcare NHS Trust, St Leonards-on-Sea, UK
| | - Carola M Bigogno
- Barts and The London School of Medicine and Dentistry, London, UK
| | - Roshni Prema
- University Hospital, University Hospitals Coventry and Warwickshire NHS Trust, Coventry, UK
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9
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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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10
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Abstract
Symmetry of the face is one of the most important features for the perception of attractiveness. Asymmetry of the face means that the right and left sides of the face are not identical. Subclinical facial asymmetry is very common in the general population. Most people have some slight facial asymmetry, and this is the normal biological situation in humans. Abnormalities from soft tissue, dental, and skeletal elements lead to facial asymmetry. Asymmetry has many causal factors, and its aetiology includes both congenital and acquired conditions. Neurological facial asymmetry is scarcely addressed in the dental literature. In this narrative review, we focus on the most common neurological causes of facial asymmetry. From a neurological point of view, facial asymmetry can result from disturbances of the cranial nerves, developmental disorders, or myopathies. In the broad range of differential diagnostics of facial asymmetry, neurological abnormalities should be taken into consideration. The treatment must be related to the underlying cause. Complete knowledge of the aetiological factors and the character of the asymmetry plays a crucial role in formulating a treatment plan.
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Villalobos Lizardi JC, Baranger J, Nguyen MB, Asnacios A, Malik A, Lumens J, Mertens L, Friedberg MK, Simmons CA, Pernot M, Villemain O. A guide for assessment of myocardial stiffness in health and disease. NATURE CARDIOVASCULAR RESEARCH 2022; 1:8-22. [PMID: 39196108 DOI: 10.1038/s44161-021-00007-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/10/2021] [Indexed: 08/29/2024]
Abstract
Myocardial stiffness is an intrinsic property of the myocardium that influences both diastolic and systolic cardiac function. Myocardial stiffness represents the resistance of this tissue to being deformed and depends on intracellular components of the cardiomyocyte, particularly the cytoskeleton, and on extracellular components, such as collagen fibers. Myocardial disease is associated with changes in myocardial stiffness, and its assessment is a key diagnostic marker of acute or chronic pathological myocardial disease with the potential to guide therapeutic decision-making. In this Review, we appraise the different techniques that can be used to estimate myocardial stiffness, evaluate their advantages and disadvantages, and discuss potential clinical applications.
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Affiliation(s)
- José Carlos Villalobos Lizardi
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Jerome Baranger
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Minh B Nguyen
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Atef Asnacios
- Laboratoire Matière et Systèmes Complexes, CNRS UMR 7057, Université de Paris, Paris, France
| | - Aimen Malik
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Joost Lumens
- Department of Biomedical Engineering, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands
| | - Luc Mertens
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Mark K Friedberg
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Craig A Simmons
- Institute of Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Mathieu Pernot
- Physics for Medicine Paris, INSERM U1273, ESPCI Paris, CNRS UMR 8063, PSL Research University, Paris, France
| | - Olivier Villemain
- Division of Cardiology, Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
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12
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Hassoun R, Budde H, Zhazykbayeva S, Herwig M, Sieme M, Delalat S, Mostafi N, Gömöri K, Tangos M, Jarkas M, Pabel S, Bruckmüller S, Skrygan M, Lódi M, Jaquet K, Sequeira V, Gambichler T, Remedios CD, Kovács Á, Mannherz HG, Mügge A, Sossalla S, Hamdani N. Stress activated signalling impaired protein quality control pathways in human hypertrophic cardiomyopathy. Int J Cardiol 2021; 344:160-169. [PMID: 34517018 DOI: 10.1016/j.ijcard.2021.09.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Revised: 08/30/2021] [Accepted: 09/06/2021] [Indexed: 01/09/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is a complex myocardial disorder with no well-established disease-modifying therapy so far. Our study aimed to investigate how autophagy, oxidative stress, inflammation, stress signalling pathways, and apoptosis are hallmark of HCM and their contribution to the cardiac dysfunction. Demembranated cardiomyocytes from patients with HCM display increased titin-based stiffness (Fpassive), which was corrected upon antioxidant treatment. Titin as a main determinant of Fpassive was S-glutathionylated and highly ubiquitinated in HCM patients. This was associated with a shift in the balance of reduced and oxidized forms of glutathione (GSH and GSSG, respectively). Both heat shock proteins (HSP27 and α-ß crystalline) were upregulated and S-glutathionylated in HCM. Administration of HSPs in vitro significantly reduced HCM cardiomyocyte stiffness. High levels of the phosphorylated monomeric superoxide anion-generating endothelial nitric oxide synthase (eNOS), decreased nitric oxide (NO) bioavailability, decreased soluble guanylyl cyclase (sGC) activity, and high levels of 3-nitrotyrosine were observed in HCM. Many regulators of signal transduction pathways that are involved in autophagy, apoptosis, cardiac contractility, and growth including the mitogen-activated protein kinase (MAPK), protein kinase B (AKT), glycogen synthase kinase 3ß (GSK-3ß), mammalian target of rapamycin (mTOR), forkhead box O transcription factor (FOXO), c-Jun N-terminal protein kinase (JNK), and extracellular-signal-regulated kinase (ERK1/2) were modified in HCM. The apoptotic factors cathepsin, procaspase 3, procaspase 9 and caspase 12, but not caspase 9, were elevated in HCM hearts and associated with increased proinflammatory cytokines (Interleukin 6 (IL-6), interleukin 18 (IL-18), intercellular cell adhesion molecule-1 (ICAM1), vascular cell adhesion molecule-1 (VCAM1), the Toll-like receptors 2 (TLR2) and the Toll-like receptors 4 (TLR4)) and oxidative stress (3-nitrotyrosine and hydrogen peroxide (H2O2)). Here we reveal stress signalling and impaired PQS as potential mechanisms underlying the HCM phenotype. Our data suggest that reducing oxidative stress can be a viable therapeutic approach to attenuating the severity of cardiac dysfunction in heart failure and potentially in HCM and prevent its progression.
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Affiliation(s)
- Roua Hassoun
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Heidi Budde
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Saltanat Zhazykbayeva
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Melissa Herwig
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Marcel Sieme
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Simin Delalat
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Nusratul Mostafi
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Kamilla Gömöri
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Melina Tangos
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Muhammad Jarkas
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Steffen Pabel
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany.
| | - Stefanie Bruckmüller
- Department of Dermatology, Skin Cancer Center, Ruhr University Bochum, Bochum, Germany.
| | - Marina Skrygan
- Department of Dermatology, Skin Cancer Center, Ruhr University Bochum, Bochum, Germany.
| | - Mária Lódi
- Department of Neuroanatomy and Molecular Brain Research, Ruhr University Bochum, Medical Faculty, Bochum, Germany.
| | - Kornelia Jaquet
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Vasco Sequeira
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Germany.
| | - Thilo Gambichler
- Department of Dermatology, Skin Cancer Center, Ruhr University Bochum, Bochum, Germany.
| | - Cris Dos Remedios
- Molecular Biophysics, Victor Chang Cardiac Research Institute, Faculty of Medicine and Health, Darlinghurst, Australia.
| | - Árpád Kovács
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Hans Georg Mannherz
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Anatomy and Molecular Embryology, Ruhr University, Bochum, Germany.
| | - Andreas Mügge
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
| | - Samuel Sossalla
- Department of Internal Medicine II, University Medical Center Regensburg, Regensburg, Germany; Clinic for Cardiology & Pneumology, Georg-August University Goettingen, and DZHK (German Centre for Cardiovascular Research), partner site Goettingen, Germany.
| | - Nazha Hamdani
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, Bochum, Germany; Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, Bochum, Germany.
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The Sarcomeric Spring Protein Titin: Biophysical Properties, Molecular Mechanisms, and Genetic Mutations Associated with Heart Failure and Cardiomyopathy. Curr Cardiol Rep 2021; 23:121. [PMID: 34269900 DOI: 10.1007/s11886-021-01550-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/07/2021] [Indexed: 01/06/2023]
Abstract
PURPOSE OF REVIEW The giant protein titin forms the "elastic" filament of the sarcomere, essential for the mechanical compliance of the heart muscle. Titin serves a biological spring, and therefore structural modifications of titin affect function of the myocardium and are associated with heart failure and cardiomyopathy. RECENT FINDINGS In this review, we discuss the current understanding of titin's biophysical properties and how modifications contribute to cardiac function and heart failure. In addition, we review the most recent data on the clinical impact and phenotype heterogeneity of TTN truncating variants, including diseases involving striated muscles, and prospects for future therapies. Because of the giant structure of the titin protein and the complexity of its function, titin's role in health and disease is not yet completely understood. Future research efforts need to focus on novel therapeutic approaches able to modulate titin transcriptional and post-translational modification.
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Li X, Zhang D, Ren C, Bai Y, Ijaz M, Hou C, Chen L. Effects of protein posttranslational modifications on meat quality: A review. Compr Rev Food Sci Food Saf 2020; 20:289-331. [PMID: 33443799 DOI: 10.1111/1541-4337.12668] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/14/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023]
Abstract
Meat quality plays an important role in the purchase decision of consumers, affecting producers and retailers. The formation mechanisms determining meat quality are intricate, as several endogenous and exogenous factors contribute during antemortem and postmortem periods. Abundant research has been performed on meat quality; however, unexpected variation in meat quality remains an issue in the meat industry. Protein posttranslational modifications (PTMs) regulate structures and functions of proteins in living tissues, and recent reports confirmed their importance in meat quality. The objective of this review was to provide a summary of the research on the effects of PTMs on meat quality. The effects of four common PTMs, namely, protein phosphorylation, acetylation, S-nitrosylation, and ubiquitination, on meat quality were discussed, with emphasis on the effects of protein phosphorylation on meat tenderness, color, and water holding capacity. The mechanisms and factors that may affect the function of protein phosphorylation are also discussed. The current research confirms that meat quality traits are regulated by multiple PTMs. Cross talk between different PTMs and interactions of PTMs with postmortem biochemical processes need to be explored to improve our understanding on factors affecting meat quality.
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Affiliation(s)
- Xin Li
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Dequan Zhang
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Chi Ren
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yuqiang Bai
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Muawuz Ijaz
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Chengli Hou
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Li Chen
- Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
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15
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Huang C, Hou C, Ijaz M, Yan T, Li X, Li Y, Zhang D. Proteomics discovery of protein biomarkers linked to meat quality traits in post-mortem muscles: Current trends and future prospects: A review. Trends Food Sci Technol 2020. [DOI: 10.1016/j.tifs.2020.09.030] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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16
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Chian FM, Kaur L, Astruc T, Vénien A, Stübler AS, Aganovic K, Loison O, Hodgkinson S, Boland M. Shockwave processing of beef brisket in conjunction with sous vide cooking: Effects on protein structural characteristics and muscle microstructure. Food Chem 2020; 343:128500. [PMID: 33221107 DOI: 10.1016/j.foodchem.2020.128500] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 10/06/2020] [Accepted: 10/26/2020] [Indexed: 11/17/2022]
Abstract
We studied the effect of shockwave processing and subsequent sous vide cooking on meat proteins (molecular size and thermal stability) and muscle structures (molecular, micro- and ultrastructure). Beef briskets were subjected to shockwave (11 kJ/pulse) and were sous vide-cooked at 60 °C for 12 h. Shockwave processing alone decreased the enthalpy and thermal denaturation temperature of the connective tissue proteins (second peak in the DSC thermogram, p < 0.05) compared to the control raw samples, while the protein gel electrophoresis profile remained unaffected. It led to disorganisation of the sarcomere structure and also modified the protein secondary structure. More severe muscle fibre coagulation and denaturation were observed in the shockwave-treated cooked meat compared to the cooked control. The results show that shockwave processing, with and without sous vide cooking, promotes structural changes in meat, and thus may have the potential to improve the organoleptic quality of the tough meat cuts.
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Affiliation(s)
- Feng Ming Chian
- Riddet Institute, Massey University, Palmerston North 4442, New Zealand; School of Food and Advanced Technology, Massey University, Palmerston North 4442, New Zealand.
| | - Lovedeep Kaur
- Riddet Institute, Massey University, Palmerston North 4442, New Zealand; School of Food and Advanced Technology, Massey University, Palmerston North 4442, New Zealand.
| | | | - Annie Vénien
- INRAE, QuaPA, F-63122 Saint-Genès-Champanelle, France.
| | - Anna-Sophie Stübler
- German Institute of Food Technologies DIL e.V., Prof.-von-Klitzing Str. 7, 49610 Quakenbrueck, Germany.
| | - Kemal Aganovic
- German Institute of Food Technologies DIL e.V., Prof.-von-Klitzing Str. 7, 49610 Quakenbrueck, Germany.
| | | | - Suzanne Hodgkinson
- Riddet Institute, Massey University, Palmerston North 4442, New Zealand.
| | - Mike Boland
- Riddet Institute, Massey University, Palmerston North 4442, New Zealand.
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17
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Rich KA, Moscarello T, Siskind C, Brock G, Tan CA, Vatta M, Winder TL, Elsheikh B, Vicini L, Tucker B, Palettas M, Hershberger RE, Kissel JT, Morales A, Roggenbuck J. Novel heterozygous truncating titin variants affecting the A-band are associated with cardiomyopathy and myopathy/muscular dystrophy. Mol Genet Genomic Med 2020; 8:e1460. [PMID: 32815318 PMCID: PMC7549586 DOI: 10.1002/mgg3.1460] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/10/2020] [Accepted: 07/31/2020] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Variants in TTN are frequently identified in the genetic evaluation of skeletal myopathy or cardiomyopathy. However, due to the high frequency of TTN variants in the general population, incomplete penetrance, and limited understanding of the spectrum of disease, interpretation of TTN variants is often difficult for laboratories and clinicians. Currently, cardiomyopathy is associated with heterozygous A-band TTN variants, whereas skeletal myopathy is largely associated with homozygous or compound heterozygous TTN variants. Recent reports show pathogenic variants in TTN may result in a broader phenotypic spectrum than previously recognized. METHODS Here we report the results of a multisite study that characterized the phenotypes of probands with variants in TTN. We investigated TTN genotype-phenotype correlations in probands with skeletal myopathy and/or cardiomyopathy. Probands with TTN truncating variants (TTNtv) or pathogenic missense variants were ascertained from two academic medical centers. Variants were identified via clinical genetic testing and reviewed according to the American College of Medical Genetics criteria. Clinical and family history data were documented via retrospective chart review. Family studies were performed for probands with atypical phenotypes. RESULTS Forty-nine probands were identified with TTNtv or pathogenic missense variants. Probands were classified by clinical presentation: cardiac (n = 30), skeletal muscle (n = 12), or both (cardioskeletal, n = 7). Within the cardioskeletal group, 5/7 probands had heterozygous TTNtv predicted to affect the distal (3') end of the A-band. All cardioskeletal probands had onset of proximal-predominant muscle weakness before diagnosis of cardiovascular disease, five pedigrees support dominant transmission. CONCLUSION Although heterozygous TTNtv in the A-band is known to cause dilated cardiomyopathy, we present evidence that these variants may in some cases cause a novel, dominant skeletal myopathy with a limb-girdle pattern of weakness. These findings emphasize the importance of multidisciplinary care for patients with A-band TTNtv who may be at risk for multisystem disease.
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Affiliation(s)
- Kelly A Rich
- The Ohio State University Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Tia Moscarello
- Stanford Center for Inherited Cardiovascular Disease, Stanford University, Stanford, CA, USA
| | - Carly Siskind
- Stanford Health Care, Stanford University, Stanford, CA, USA
| | - Guy Brock
- The Ohio State University Center for Biostatistics, The Ohio State University, Columbus, OH, USA
| | | | | | | | - Bakri Elsheikh
- The Ohio State University Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Leah Vicini
- The Ohio State University Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Brianna Tucker
- Stanford Center for Inherited Cardiovascular Disease, Stanford University, Stanford, CA, USA
| | - Marilly Palettas
- The Ohio State University Center for Biostatistics, The Ohio State University, Columbus, OH, USA
| | - Ray E Hershberger
- The Ohio State University Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - John T Kissel
- The Ohio State University Wexner Medical Center, The Ohio State University, Columbus, OH, USA
| | - Ana Morales
- The Ohio State University Wexner Medical Center, The Ohio State University, Columbus, OH, USA.,Invitae Corporation, San Francisco, CA, USA
| | - Jennifer Roggenbuck
- The Ohio State University Wexner Medical Center, The Ohio State University, Columbus, OH, USA
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Sarcomeric Gene Variants and Their Role with Left Ventricular Dysfunction in Background of Coronary Artery Disease. Biomolecules 2020; 10:biom10030442. [PMID: 32178433 PMCID: PMC7175236 DOI: 10.3390/biom10030442] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 03/11/2020] [Indexed: 12/18/2022] Open
Abstract
: Cardiovascular diseases are one of the leading causes of death in developing countries, generally originating as coronary artery disease (CAD) or hypertension. In later stages, many CAD patients develop left ventricle dysfunction (LVD). Left ventricular ejection fraction (LVEF) is the most prevalent prognostic factor in CAD patients. LVD is a complex multifactorial condition in which the left ventricle of the heart becomes functionally impaired. Various genetic studies have correlated LVD with dilated cardiomyopathy (DCM). In recent years, enormous progress has been made in identifying the genetic causes of cardiac diseases, which has further led to a greater understanding of molecular mechanisms underlying each disease. This progress has increased the probability of establishing a specific genetic diagnosis, and thus providing new opportunities for practitioners, patients, and families to utilize this genetic information. A large number of mutations in sarcomeric genes have been discovered in cardiomyopathies. In this review, we will explore the role of the sarcomeric genes in LVD in CAD patients, which is a major cause of cardiac failure and results in heart failure.
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Abstract
Cell-cell fusion is indispensable for creating life and building syncytial tissues and organs. Ever since the discovery of cell-cell fusion, how cells join together to form zygotes and multinucleated syncytia has remained a fundamental question in cell and developmental biology. In the past two decades, Drosophila myoblast fusion has been used as a powerful genetic model to unravel mechanisms underlying cell-cell fusion in vivo. Many evolutionarily conserved fusion-promoting factors have been identified and so has a surprising and conserved cellular mechanism. In this review, we revisit key findings in Drosophila myoblast fusion and highlight the critical roles of cellular invasion and resistance in driving cell membrane fusion.
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Affiliation(s)
- Donghoon M Lee
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
| | - Elizabeth H Chen
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA;
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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20
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Adipose Tissue Quality in Aging: How Structural and Functional Aspects of Adipose Tissue Impact Skeletal Muscle Quality. Nutrients 2019; 11:nu11112553. [PMID: 31652734 PMCID: PMC6893709 DOI: 10.3390/nu11112553] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 10/19/2019] [Accepted: 10/21/2019] [Indexed: 12/20/2022] Open
Abstract
The interplay between adipose tissue and skeletal muscle and the impact on mobility and aging remain enigmatic. The progressive decline in mobility promoted by aging has been previously attributed to the loss of skeletal mass and function and more recently linked to changes in body fat composition and quantity. Regardless of body size, visceral and intermuscular adipose depots increase with aging and are associated with adverse health outcomes. However, the quality of adipose tissue, in particular abdominal subcutaneous as it is the largest depot, likely plays a significant role in aging outcomes, such as mobility decline, though its communication with other tissues such as skeletal muscle. In this review, we discuss the age-associated development of a pro-inflammatory profile, cellular senescence, and metabolic inflexibility in abdominal subcutaneous adipose tissue. Collectively, these facets of adipose tissue quality influence its secretory profile and crosstalk with skeletal muscle and likely contribute to the development of muscle atrophy and disability. Therefore, the identification of the key structural and functional components of adipose tissue quality—including necrosis, senescence, inflammation, self-renewal, metabolic flexibility—and adipose tissue-secreted proteins that influence mobility via direct effects on skeletal muscle are necessary to prevent morbidity/mortality in the aging population.
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21
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Koser F, Loescher C, Linke WA. Posttranslational modifications of titin from cardiac muscle: how, where, and what for? FEBS J 2019; 286:2240-2260. [PMID: 30989819 PMCID: PMC6850032 DOI: 10.1111/febs.14854] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/27/2019] [Accepted: 04/13/2019] [Indexed: 12/11/2022]
Abstract
Titin is a giant elastic protein expressed in the contractile units of striated muscle cells, including the sarcomeres of cardiomyocytes. The last decade has seen enormous progress in our understanding of how titin molecular elasticity is modulated in a dynamic manner to help cardiac sarcomeres adjust to the varying hemodynamic demands on the heart. Crucial events mediating the rapid modulation of cardiac titin stiffness are post‐translational modifications (PTMs) of titin. In this review, we first recollect what is known from earlier and recent work on the molecular mechanisms of titin extensibility and force generation. The main goal then is to provide a comprehensive overview of current insight into the relationship between titin PTMs and cardiomyocyte stiffness, notably the effect of oxidation and phosphorylation of titin spring segments on titin stiffness. A synopsis is given of which type of oxidative titin modification can cause which effect on titin stiffness. A large part of the review then covers the mechanically relevant phosphorylation sites in titin, their location along the elastic segment, and the protein kinases and phosphatases known to target these sites. We also include a detailed coverage of the complex changes in phosphorylation at specific titin residues, which have been reported in both animal models of heart disease and in human heart failure, and their correlation with titin‐based stiffness alterations. Knowledge of the relationship between titin PTMs and titin elasticity can be exploited in the search for therapeutic approaches aimed at softening the pathologically stiffened myocardium in heart failure patients.
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22
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Rees DJ, Hanifi A, Obille A, Alexander R, Sone ED. Fingerprinting of Proteins that Mediate Quagga Mussel Adhesion using a De Novo Assembled Foot Transcriptome. Sci Rep 2019; 9:6305. [PMID: 31004089 PMCID: PMC6474901 DOI: 10.1038/s41598-019-41976-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 03/15/2019] [Indexed: 12/20/2022] Open
Abstract
The European freshwater mollusk Dreissena bugensis (quagga mussel), an invasive species to North America, adheres to surfaces underwater via the byssus: a non-living protein 'anchor'. In spite of its importance as a biofouling species, the sequence of the majority of byssal proteins responsible for adhesion are not known, and little genomic data is available. To determine protein sequence information, we utilized next-generation RNA sequencing and de novo assembly to construct a cDNA library of the quagga mussel foot transcriptome, which contains over 200,000 transcripts. Quagga mussel byssal proteins were extracted from freshly induced secretions and analyzed using LC-MS/MS; peptide spectra were matched to the transcriptome to fingerprint the entire protein primary sequences. We present the full sequences of fourteen novel quagga mussel byssal proteins, named Dreissena bugensis foot proteins 4 to 17 (Dbfp4-Dbfp17), and new sequence data for two previously observed byssal proteins Dbfp1 and Dbfp2. Theoretical masses of the newly discovered proteins range from 4.3 kDa to 21.6 kDa. These protein sequences are unique but contain features similar to glue proteins from other species, including a high degree of polymorphism, proteins with repeated peptide motifs, disordered protein structure, and block structures.
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Affiliation(s)
- David J Rees
- Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Arash Hanifi
- Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Angelico Obille
- Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Robert Alexander
- Department of Materials Science & Engineering, University of Toronto, Toronto, ON, Canada
| | - Eli D Sone
- Institute of Biomaterials & Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
- Department of Materials Science & Engineering, University of Toronto, Toronto, ON, Canada.
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada.
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23
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Li CJ, Chen CS, Yiang GT, Tsai APY, Liao WT, Wu MY. Advanced Evolution of Pathogenesis Concepts in Cardiomyopathies. J Clin Med 2019; 8:jcm8040520. [PMID: 30995779 PMCID: PMC6518034 DOI: 10.3390/jcm8040520] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/12/2019] [Accepted: 04/12/2019] [Indexed: 12/15/2022] Open
Abstract
Cardiomyopathy is a group of heterogeneous cardiac diseases that impair systolic and diastolic function, and can induce chronic heart failure and sudden cardiac death. Cardiomyopathy is prevalent in the general population, with high morbidity and mortality rates, and contributes to nearly 20% of sudden cardiac deaths in younger individuals. Genetic mutations associated with cardiomyopathy play a key role in disease formation, especially the mutation of sarcomere encoding genes and ATP kinase genes, such as titin, lamin A/C, myosin heavy chain 7, and troponin T1. Pathogenesis of cardiomyopathy occurs by multiple complex steps involving several pathways, including the Ras-Raf-mitogen-activated protein kinase-extracellular signal-activated kinase pathway, G-protein signaling, mechanotransduction pathway, and protein kinase B/phosphoinositide 3-kinase signaling. Excess biomechanical stress induces apoptosis signaling in cardiomyocytes, leading to cell loss, which can induce myocardial fibrosis and remodeling. The clinical features and pathophysiology of cardiomyopathy are discussed. Although several basic and clinical studies have investigated the mechanism of cardiomyopathy, the detailed pathophysiology remains unclear. This review summarizes current concepts and focuses on the molecular mechanisms of cardiomyopathy, especially in the signaling from mutation to clinical phenotype, with the aim of informing the development of therapeutic interventions.
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Affiliation(s)
- Chia-Jung Li
- Department of Obstetrics and Gynecology, Kaohsiung Veterans General Hospital, Kaohsiung 813, Taiwan.
| | - Chien-Sheng Chen
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
| | - Giou-Teng Yiang
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
| | - Andy Po-Yi Tsai
- Department of Medical Research, Buddhist Tzu Chi General Hospital, Hualien 970, Taiwan.
| | - Wan-Ting Liao
- Institute of Medicine, Chung Shan Medical University, Taichung 402, Taiwan.
- Chinese Medicine Department, Show Chwan Memorial Hospital, Changhua 500, Taiwan.
| | - Meng-Yu Wu
- Department of Emergency Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, New Taipei 231, Taiwan.
- Department of Emergency Medicine, School of Medicine, Tzu Chi University, Hualien 970, Taiwan.
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24
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Mijailovich SM, Stojanovic B, Nedic D, Svicevic M, Geeves MA, Irving TC, Granzier HL. Nebulin and titin modulate cross-bridge cycling and length-dependent calcium sensitivity. J Gen Physiol 2019; 151:680-704. [PMID: 30948421 PMCID: PMC6504291 DOI: 10.1085/jgp.201812165] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 01/15/2019] [Accepted: 03/03/2019] [Indexed: 12/13/2022] Open
Abstract
Various mutations in the structural proteins nebulin and titin that are present in human disease are known to affect the contractility of striated muscle. Loss of nebulin is associated with reduced actin filament length and impairment of myosin binding to actin, whereas titin is thought to regulate muscle passive elasticity and is likely involved in length-dependent activation. Here, we sought to assess the modulation of muscle function by these sarcomeric proteins by using the computational platform muscle simulation code (MUSICO) to quantitatively separate the effects of structural changes, kinetics of cross-bridge cycling, and calcium sensitivity of the thin filaments. The simulations show that variation in thin filament length cannot by itself account for experimental observations of the contractility in nebulin-deficient muscle, but instead must be accompanied by a decreased myosin binding rate. Additionally, to match the observed calcium sensitivity, the rate of TnI detachment from actin needed to be increased. Simulations for cardiac muscle provided quantitative estimates of the effects of different titin-based passive elasticities on muscle force and activation in response to changes in sarcomere length and interfilament lattice spacing. Predicted force-pCa relations showed a decrease in both active tension and sensitivity to calcium with a decrease in passive tension and sarcomere length. We conclude that this behavior is caused by partial redistribution of the muscle load between active muscle force and titin-dependent passive force, and also by redistribution of stretch along the thin filament, which together modulate the release of TnI from actin. These data help advance understanding of how nebulin and titin mutations affect muscle function.
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Affiliation(s)
- Srboljub M Mijailovich
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA .,Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL
| | - Boban Stojanovic
- University of Kragujevac, Faculty of Science, Kragujevac, Serbia
| | - Djordje Nedic
- University of Kragujevac, Faculty of Science, Kragujevac, Serbia
| | - Marina Svicevic
- University of Kragujevac, Faculty of Science, Kragujevac, Serbia
| | - Michael A Geeves
- Department of Biosciences, University of Kent, Canterbury, Kent, UK
| | - Thomas C Irving
- Department of Biological Sciences, Illinois Institute of Technology, Chicago, IL
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25
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Deracinois B, Camoin L, Lambert M, Boyer JB, Dupont E, Bastide B, Cieniewski-Bernard C. O-GlcNAcylation site mapping by (azide-alkyne) click chemistry and mass spectrometry following intensive fractionation of skeletal muscle cells proteins. J Proteomics 2018; 186:83-97. [DOI: 10.1016/j.jprot.2018.07.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 06/13/2018] [Accepted: 07/03/2018] [Indexed: 12/22/2022]
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Rahim MAA, Rahim ZHA, Ahmad WAWAN, Bakri MM, Ismail MD, Hashim OH. Inverse changes in plasma tetranectin and titin levels in patients with type 2 diabetes mellitus: a potential predictor of acute myocardial infarction? Acta Pharmacol Sin 2018; 39:1197-1207. [PMID: 29417940 PMCID: PMC6289394 DOI: 10.1038/aps.2017.141] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 10/10/2017] [Indexed: 01/05/2023] Open
Abstract
An early intervention using biomarkers to predict acute myocardial infarction (AMI) will effectively reduce global heart attack incidence, particularly among high-risk patients with type 2 diabetes mellitus (T2DM). This study attempted to identify potential biomarkers by detecting changes in the levels of plasma proteins in T2DM patients following onset of AMI in comparison with those without AMI. Volunteer T2DM patients without AMI (control; n=10) and T2DM patients with AMI (n=10) were recruited. Plasma samples from these patients were evaluated via two-dimensional gel electrophoresis (2DE) to screen for proteins with level changes between the two groups. The abundance of spots on gel images was analyzed using Progenesis SameSpots and subjected to false discovery rate (FDR) analysis. Protein spots with statistically significant changes of at least 1.5 fold were selected for mass spectrometry (MS) analysis. Due to strong cardiac connections, tetranectin and titin were evaluated by enzymelinked immunosorbent assay (ELISA). The adjusted P-values and fold changes between the two groups resulted in identification of 34 protein spots with significantly altered abundance. Upon MS analysis, 17 plasma proteins were identified: tetranectin, titin, clusterin, haptoglobin, myosin-13, zinc fnger protein 445, DNA repair protein RAD50, serum albumin, apolipoprotein A-IV, caspase-6, aminoacyl tRNA synthase complex-interacting multifunctional protein 1, serotransferrin, retinol-binding protein 4, transthyretin, alpha-1-antitrypsin, apolipoprotein A-I and serum amyloid A. Comparable patterns of changes in tetranectin and titin between the control and AMI groups were confirmed using ELISA. In summary, tetranectin and titin in plasma appeared to be closely associated with the onset of AMI among T2DM patients and can be used as potential biomarkers for prediction of a cardiac event, though this requires validation in a prospective cohort study.
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Joumaa V, Bertrand F, Liu S, Poscente S, Herzog W. Does partial titin degradation affect sarcomere length nonuniformities and force in active and passive myofibrils? Am J Physiol Cell Physiol 2018; 315:C310-C318. [PMID: 29768046 DOI: 10.1152/ajpcell.00183.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The aim of this study was to determine the role of titin in preventing the development of sarcomere length nonuniformities following activation and after active and passive stretch by determining the effect of partial titin degradation on sarcomere length nonuniformities and force in passive and active myofibrils. Selective partial titin degradation was performed using a low dose of trypsin. Myofibrils were set at a sarcomere length of 2.4 µm and then passively stretched to sarcomere lengths of 3.4 and 4.4 µm. In the active condition, myofibrils were set at a sarcomere length of 2.8 µm, activated, and actively stretched by 1 µm/sarcomere. The extent of sarcomere length nonuniformities was calculated for each sarcomere as the absolute difference between sarcomere length and the mean sarcomere length of the myofibril. Our main finding is that partial titin degradation does not increase sarcomere length nonuniformities after passive stretch and activation compared with when titin is intact but increases the extent of sarcomere length nonuniformities after active stretch. Furthermore, when titin was partially degraded, active and passive stresses were substantially reduced. These results suggest that titin plays a crucial role in actively stretched myofibrils and is likely involved in active and passive force production.
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Affiliation(s)
- V Joumaa
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, AB, Canada
| | - F Bertrand
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, AB, Canada
| | - S Liu
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, AB, Canada
| | - S Poscente
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, AB, Canada
| | - W Herzog
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, AB, Canada
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Wang L, Geist J, Grogan A, Hu LYR, Kontrogianni-Konstantopoulos A. Thick Filament Protein Network, Functions, and Disease Association. Compr Physiol 2018; 8:631-709. [PMID: 29687901 PMCID: PMC6404781 DOI: 10.1002/cphy.c170023] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Sarcomeres consist of highly ordered arrays of thick myosin and thin actin filaments along with accessory proteins. Thick filaments occupy the center of sarcomeres where they partially overlap with thin filaments. The sliding of thick filaments past thin filaments is a highly regulated process that occurs in an ATP-dependent manner driving muscle contraction. In addition to myosin that makes up the backbone of the thick filament, four other proteins which are intimately bound to the thick filament, myosin binding protein-C, titin, myomesin, and obscurin play important structural and regulatory roles. Consistent with this, mutations in the respective genes have been associated with idiopathic and congenital forms of skeletal and cardiac myopathies. In this review, we aim to summarize our current knowledge on the molecular structure, subcellular localization, interacting partners, function, modulation via posttranslational modifications, and disease involvement of these five major proteins that comprise the thick filament of striated muscle cells. © 2018 American Physiological Society. Compr Physiol 8:631-709, 2018.
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Affiliation(s)
- Li Wang
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Janelle Geist
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Alyssa Grogan
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
| | - Li-Yen R. Hu
- Department of Biochemistry and Molecular Biology, University of Maryland, Baltimore, Maryland, USA
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29
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Carlisle C, Prill K, Pilgrim D. Chaperones and the Proteasome System: Regulating the Construction and Demolition of Striated Muscle. Int J Mol Sci 2017; 19:E32. [PMID: 29271938 PMCID: PMC5795982 DOI: 10.3390/ijms19010032] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2017] [Revised: 11/28/2017] [Accepted: 12/18/2017] [Indexed: 12/21/2022] Open
Abstract
Protein folding factors (chaperones) are required for many diverse cellular functions. In striated muscle, chaperones are required for contractile protein function, as well as the larger scale assembly of the basic unit of muscle, the sarcomere. The sarcomere is complex and composed of hundreds of proteins and the number of proteins and processes recognized to be regulated by chaperones has increased dramatically over the past decade. Research in the past ten years has begun to discover and characterize the chaperones involved in the assembly of the sarcomere at a rapid rate. Because of the dynamic nature of muscle, wear and tear damage is inevitable. Several systems, including chaperones and the ubiquitin proteasome system (UPS), have evolved to regulate protein turnover. Much of our knowledge of muscle development focuses on the formation of the sarcomere but recent work has begun to elucidate the requirement and role of chaperones and the UPS in sarcomere maintenance and disease. This review will cover the roles of chaperones in sarcomere assembly, the importance of chaperone homeostasis and the cooperation of chaperones and the UPS in sarcomere integrity and disease.
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Affiliation(s)
- Casey Carlisle
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
| | - Kendal Prill
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
| | - Dave Pilgrim
- Department of Biological Sciences, University of Alberta, Edmonton, AB T6G 2E9, Canada.
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Irving M. Regulation of Contraction by the Thick Filaments in Skeletal Muscle. Biophys J 2017; 113:2579-2594. [PMID: 29262355 PMCID: PMC5770512 DOI: 10.1016/j.bpj.2017.09.037] [Citation(s) in RCA: 113] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 09/27/2017] [Accepted: 09/29/2017] [Indexed: 11/23/2022] Open
Abstract
Contraction of skeletal muscle cells is initiated by a well-known signaling pathway. An action potential in a motor nerve triggers an action potential in a muscle cell membrane, a transient increase of intracellular calcium concentration, binding of calcium to troponin in the actin-containing thin filaments, and a structural change in the thin filaments that allows myosin motors from the thick filaments to bind to actin and generate force. This calcium/thin filament mediated pathway provides the "START" signal for contraction, but it is argued that the functional response of the muscle cell, including the speed of its contraction and relaxation, adaptation to the external load, and the metabolic cost of contraction is largely determined by additional mechanisms. This review considers the role of the thick filaments in those mechanisms, and puts forward a paradigm for the control of contraction in skeletal muscle in which both the thick and thin filaments have a regulatory function. The OFF state of the thick filament is characterized by helical packing of most of the myosin head or motor domains on the thick filament surface in a conformation that makes them unavailable for actin binding or ATP hydrolysis, although a small fraction of the myosin heads are constitutively ON. The availability of the majority fraction of the myosin heads for contraction is controlled in part by the external load on the muscle, so that these heads only attach to actin and hydrolyze ATP when they are required. This phenomenon seems to be the major determinant of the well-known force-velocity relationship of muscle, and controls the metabolic cost of contraction. The regulatory state of the thick filament also seems to control the dynamics of both muscle activation and relaxation.
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Affiliation(s)
- Malcolm Irving
- Randall Centre for Cell and Molecular Biophysics and BHF Centre of Research Excellence, King's College London, London, United Kingdom.
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31
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Abstract
Dilated cardiomyopathy (DCM) affects approximately 1 in 250 individuals and is the leading indication for heart transplantation. DCM is often familial, and the most common genetic predisposition is a truncating variation in the giant sarcomeric protein, titin, which occurs in up to 15% of ambulant patients with DCM and 25% of end-stage or familial cases. In this article, we review the evidence for the role of titin truncation in the pathogenesis of DCM and our understanding of the molecular mechanisms and pathophysiological consequences of variation in the gene encoding titin (TTN). Such variation is common in the general population (up to 1% of individuals), and we consider key features that discriminate variants with disease-causing potential from those that are benign. We summarize strategies for clinical interpretation of genetic variants for use in the diagnosis of patients and the evaluation of their relatives. Finally, we consider the contemporary and potential future role for genetic stratification in cardiomyopathy and in the general population, evaluating titin variation as a predictor of outcome and treatment response for precision medicine.
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Affiliation(s)
- James S Ware
- National Heart and Lung Institute, Imperial College London, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK.,Medical Research College (MRC) London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK
| | - Stuart A Cook
- National Heart and Lung Institute, Imperial College London, Royal Brompton Hospital, Sydney Street, London SW3 6NP, UK.,Medical Research College (MRC) London Institute of Medical Sciences, Du Cane Road, London W12 0NN, UK.,Duke-National University of Singapore (Duke-NUS) Medical School and National Heart Centre Singapore, 8 College Road, 169857, Singapore
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32
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Sublethal effects of imidacloprid on targeting muscle and ribosomal protein related genes in the honey bee Apis mellifera L. Sci Rep 2017; 7:15943. [PMID: 29162882 PMCID: PMC5698328 DOI: 10.1038/s41598-017-16245-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 11/07/2017] [Indexed: 11/20/2022] Open
Abstract
A sublethal concentration of imidacloprid can cause chronic toxicity in bees and can impact the behavior of honey bees. The nectar- and water-collecting, and climbing abilities of bees are crucial to the survival of the bees and the execution of responsibilities in bee colonies. Besides behavioral impact, data on the molecular mechanisms underlying the toxicity of imidacloprid, especially by the way of RNA-seq at the transcriptomic level, are limited. We treated Apis mellifera L. with sublethal concentrations of imidacloprid (0.1, 1 and 10 ppb) and determined the effect on behaviors and the transcriptomic changes. The sublethal concentrations of imidacloprid had a limited impact on the survival and syrup consumption of bees, but caused a significant increase in water consumption. Moreover, the climbing ability was significantly impaired by 10 ppb imidacloprid at 8 d. In the RNA-seq analysis, gene ontology (GO) term enrichment indicated a significant down-regulation of muscle-related genes, which might contribute to the impairment in climbing ability of bees. The enriched GO terms were attributed to the up-regulated ribosomal protein genes. Considering the ribosomal and extra-ribosomal functions of the ribosomal proteins, we hypothesized that imidacloprid also causes cell dysfunction. Our findings further enhance the understanding of imidacloprid sublethal toxicity.
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33
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Muscle structure, sarcomere length and influences on meat quality: A review. Meat Sci 2017; 132:139-152. [PMID: 28552497 DOI: 10.1016/j.meatsci.2017.04.261] [Citation(s) in RCA: 154] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 04/26/2017] [Accepted: 04/28/2017] [Indexed: 11/20/2022]
Abstract
The basic contractile unit of muscle, the sarcomere, will contract as the muscle goes into rigor post-mortem. Depending on the conditions, such as the rate of pH decline, the cooling rate and the mechanical restraints on the muscles, this longitudinal shortening will result in various post-mortem sarcomere lengths as well as lateral differences in the distances between the myosin and actin filaments. This shortening is underlying the phenomena described as rigor contraction, thaw rigor, cold shortening and heat shortening. The shortening in combination with the molecular architecture of the sarcomere as defined by the myosin filaments and their S-1 and S-2 units, the interaction with the actin filaments, and the boundaries formed by the Z-disks will subsequently influence basic meat quality traits including tenderness and water-holding capacity. Biochemical reactions from proteolysis and glycogen metabolism interrelate with the sarcomere length in a complex manner. The sarcomere length is also influencing the eating quality of cooked meat and the water-holding in meat products.
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34
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Smart N, Riegler J, Turtle CW, Lygate CA, McAndrew DJ, Gehmlich K, Dubé KN, Price AN, Muthurangu V, Taylor AM, Lythgoe MF, Redwood C, Riley PR. Aberrant developmental titin splicing and dysregulated sarcomere length in Thymosin β4 knockout mice. J Mol Cell Cardiol 2017; 102:94-107. [PMID: 27914791 PMCID: PMC5319848 DOI: 10.1016/j.yjmcc.2016.10.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/20/2016] [Accepted: 10/22/2016] [Indexed: 02/07/2023]
Abstract
Sarcomere assembly is a highly orchestrated and dynamic process which adapts, during perinatal development, to accommodate growth of the heart. Sarcomeric components, including titin, undergo an isoform transition to adjust ventricular filling. Many sarcomeric genes have been implicated in congenital cardiomyopathies, such that understanding developmental sarcomere transitions will inform the aetiology and treatment. We sought to determine whether Thymosin β4 (Tβ4), a peptide that regulates the availability of actin monomers for polymerization in non-muscle cells, plays a role in sarcomere assembly during cardiac morphogenesis and influences adult cardiac function. In Tβ4 null mice, immunofluorescence-based sarcomere analyses revealed shortened thin filament, sarcomere and titin spring length in cardiomyocytes, associated with precocious up-regulation of the short titin isoforms during the postnatal splicing transition. By magnetic resonance imaging, this manifested as diminished stroke volume and limited contractile reserve in adult mice. Extrapolating to an in vitro cardiomyocyte model, the altered postnatal splicing was corrected with addition of synthetic Tβ4, whereby normal sarcomere length was restored. Our data suggest that Tβ4 is required for setting correct sarcomere length and for appropriate splicing of titin, not only in the heart but also in skeletal muscle. Distinguishing between thin filament extension and titin splicing as the primary defect is challenging, as these events are intimately linked. The regulation of titin splicing is a previously unrecognised role of Tβ4 and gives preliminary insight into a mechanism by which titin isoforms may be manipulated to correct cardiac dysfunction.
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Affiliation(s)
- Nicola Smart
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK.
| | - Johannes Riegler
- Centre for Advanced Biomedical Imaging, Department of Medicine, University College London (UCL), London, UK
| | - Cameron W Turtle
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Craig A Lygate
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Debra J McAndrew
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Katja Gehmlich
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | | | - Anthony N Price
- Centre for Advanced Biomedical Imaging, Department of Medicine, University College London (UCL), London, UK
| | - Vivek Muthurangu
- Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, UK
| | - Andrew M Taylor
- Centre for Cardiovascular Imaging, UCL Institute of Cardiovascular Science, London, UK
| | - Mark F Lythgoe
- Centre for Advanced Biomedical Imaging, Department of Medicine, University College London (UCL), London, UK
| | - Charles Redwood
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Paul R Riley
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
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35
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Smooth muscle titin forms in vitro amyloid aggregates. Biosci Rep 2016; 36:BSR20160066. [PMID: 27129292 PMCID: PMC5293577 DOI: 10.1042/bsr20160066] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2016] [Accepted: 04/01/2016] [Indexed: 01/07/2023] Open
Abstract
Amyloids are insoluble fibrous protein aggregates, and their accumulation is associated with amyloidosis and many neurodegenerative diseases, including Alzheimer's disease. In the present study, we report that smooth muscle titin (SMT; 500 kDa) from chicken gizzard forms amyloid aggregates in vitro. This conclusion is supported by EM data, fluorescence analysis using thioflavin T (ThT), Congo red (CR) spectroscopy and X-ray diffraction. Our dynamic light scattering (DLS) data show that titin forms in vitro amyloid aggregates with a hydrodynamic radius (Rh) of approximately 700–4500 nm. The initial titin aggregates with Rh approximately 700 nm were observed beyond first 20 min its aggregation that shows a high rate of amyloid formation by this protein. We also showed using confocal microscopy the cytotoxic effect of SMT amyloid aggregates on smooth muscle cells from bovine aorta. This effect involves the disorganization of the actin cytoskeleton and result is cell damage. Cumulatively, our results indicate that titin may be involved in generation of amyloidosis in smooth muscles.
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36
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Krüger M, Kötter S. Titin, a Central Mediator for Hypertrophic Signaling, Exercise-Induced Mechanosignaling and Skeletal Muscle Remodeling. Front Physiol 2016; 7:76. [PMID: 26973541 PMCID: PMC4771757 DOI: 10.3389/fphys.2016.00076] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 02/15/2016] [Indexed: 01/09/2023] Open
Abstract
Titin is a giant scaffold protein with multiple functions in striated muscle physiology. Due to the elastic I-band domains and the filament-like integration in the half-sarcomere titin is an important factor for sarcomere assembly and serves as an adaptable molecular spring that determines myofilament distensibility. Protein-interactions e.g., with muscle ankyrin repeat proteins or muscle LIM-protein link titin to hypertrophic signaling and via p62 and Muscle Ring Finger proteins to mechanisms that control protein quality control. This review summarizes our current knowledge on titin as a central node for exercise-induced mechanosignaling and remodeling and further highlights the pathophysiological implications.
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Affiliation(s)
- Martina Krüger
- Institute of Cardiovascular Physiology, Heinrich Heine University Düsseldorf Düsseldorf, Germany
| | - Sebastian Kötter
- Institute of Cardiovascular Physiology, Heinrich Heine University Düsseldorf Düsseldorf, Germany
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37
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Caldwell TA, Sumner I, Wright NT. Mechanical dissociation of the M-band titin/obscurin complex is directionally dependent. FEBS Lett 2015; 589:1735-9. [PMID: 26001486 DOI: 10.1016/j.febslet.2015.05.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/08/2015] [Accepted: 05/11/2015] [Indexed: 11/29/2022]
Abstract
Titin and obscurin, two giant muscle proteins, bind to each other in an antiparallel Ig-Ig fashion at the M-band. This interaction must be able to withstand the mechanical strain that the M-band typically experiences and remain intact. The mechanical force on these domains is likely exerted along one of two axes: a longitudinal axis, resulting in a 'shearing' force, or a lateral axis, resulting in a 'peeling' force. Here we present molecular dynamics data suggesting that these forces result in distinct unraveling pathways of the titin/obscurin complex and that peeling the domains apart requires less work and force.
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Affiliation(s)
- Tracy A Caldwell
- Department of Chemistry and Biochemistry, James Madison University, 901 Carrier Dr., Harrisonburg, VA 22807, United States
| | - Isaiah Sumner
- Department of Chemistry and Biochemistry, James Madison University, 901 Carrier Dr., Harrisonburg, VA 22807, United States
| | - Nathan T Wright
- Department of Chemistry and Biochemistry, James Madison University, 901 Carrier Dr., Harrisonburg, VA 22807, United States.
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38
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Ortega JO, Lindstedt SL, Nelson FE, Jubrias SA, Kushmerick MJ, Conley KE. Muscle force, work and cost: a novel technique to revisit the Fenn effect. ACTA ACUST UNITED AC 2015; 218:2075-82. [PMID: 25964423 DOI: 10.1242/jeb.114512] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 04/29/2015] [Indexed: 11/20/2022]
Abstract
Muscle produces force by forming cross-bridges, using energy released from ATP. While the magnitude and duration of force production primarily determine the energy requirement, nearly a century ago Fenn observed that muscle shortening or lengthening influenced energetic cost of contraction. When work is done by the muscle, the energy cost is increased and when work is done on the muscle the energy cost is reduced. However, the magnitude of the 'Fenn effect' and its mirror ('negative Fenn effect') have not been quantitatively resolved. We describe a new technique coupling magnetic resonance spectroscopy with an in vivo force clamp that can directly quantify the Fenn effect [E=I+W, energy liberated (E) equals the energy cost of isometric force production (I) plus the work done (W)] and the negative Fenn effect (E=I-W) for one muscle, the first dorsal interosseous (FDI). ATP cost was measured during a series of contractions, each of which occurred at a constant force and for a constant duration, thus constant force-time integral (FTI). In all subjects, as the FTI increased with load, there was a proportional linear increase in energy cost. In addition, the cost of producing force greatly increased when the muscle shortened, and was slightly reduced during lengthening contraction. These results, though limited to a single muscle, contraction velocity and muscle length change, do quantitatively support the Fenn effect. We speculate that they also suggest that an elastic element within the FDI muscle functions to preserve the force generated within the cross-bridges.
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Affiliation(s)
- Justus O Ortega
- Department of Kinesiology & Recreation Administration, Humboldt State University, Arcata, CA 95521, USA Department of Radiology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Stan L Lindstedt
- Department of Biological Sciences, Northern Arizona University, South Beaver Street, Flagstaff, AZ 86001, USA
| | - Frank E Nelson
- Department of Radiology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Sharon A Jubrias
- Department of Radiology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Martin J Kushmerick
- Department of Radiology, University of Washington Medical Center, Seattle, WA 98195, USA
| | - Kevin E Conley
- Department of Radiology, University of Washington Medical Center, Seattle, WA 98195, USA Department of Physiology & Biophysics, University of Washington Medical Center, Seattle, WA 98195, USA Department of Bioengineering, University of Washington Medical Center, Seattle, WA 98105, USA
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39
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Rudloff MW, Woosley AN, Wright NT. Biophysical characterization of naturally occurring titin M10 mutations. Protein Sci 2015; 24:946-55. [PMID: 25739468 DOI: 10.1002/pro.2670] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 02/17/2015] [Accepted: 02/18/2015] [Indexed: 12/15/2022]
Abstract
The giant proteins titin and obscurin are important for sarcomeric organization, stretch response, and sarcomerogenesis in myofibrils. The extreme C-terminus of titin (the M10 domain) binds to the N-terminus of obscurin (the Ig1 domain) in the M-band. The high-resolution structure of human M10 has been solved, along with M10 bound to one of its two known molecular targets, the Ig1 domain of obscurin-like. Multiple M10 mutations are linked to limb-girdle muscular dystrophy type 2J (LGMD2J) and tibial muscular dystrophy (TMD). The effect of the M10 mutations on protein structure and function has not been thoroughly characterized. We have engineered all four of the naturally occurring human M10 missense mutants and biophysically characterized them in vitro. Two of the four mutated constructs are severely misfolded, and cannot bind to the obscurin Ig1 domain. One mutation, H66P, is folded at room temperature but unfolds at 37°C, rendering it binding incompetent. The I57N mutation shows no significant structural, dynamic, or binding differences from the wild-type domain. We suggest that this mutation is not directly responsible for muscle wasting disease, but is instead merely a silent mutation found in symptomatic patients. Understanding the biophysical basis of muscle wasting disease can help streamline potential future treatments.
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Affiliation(s)
- Michael W Rudloff
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| | - Alec N Woosley
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
| | - Nathan T Wright
- Department of Chemistry and Biochemistry, James Madison University, Harrisonburg, Virginia, 22807
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40
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Gallego M, Mora L, Aristoy MC, Toldrá F. Titin-derived peptides as processing time markers in dry-cured ham. Food Chem 2015; 167:326-39. [DOI: 10.1016/j.foodchem.2014.06.088] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 04/29/2014] [Accepted: 06/20/2014] [Indexed: 10/25/2022]
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41
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Chen SF, Rao LY, Wei TZ, Xu MG, Dong ZL. Expression patterns of sarcomeric α-actin, α-actinin and UCP2 in the myocardium of Kunming mice after exposure to c-terminal polypeptide of cardiotrophin-1. ACTA ACUST UNITED AC 2014; 34:796-800. [PMID: 25480572 DOI: 10.1007/s11596-014-1355-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 07/01/2014] [Indexed: 11/24/2022]
Abstract
Cardiotrophin-1 (CT-1) activates a distinct form of cardiac muscle cell hypertrophy in which the sarcomeric units are assembled in series. The aim of the study was to determine the expression pattern of sarcomeric contractile protein α-actin, specialized cytoskeletal protein α-actinin and mitochondrial uncoupling protein-2 (UCP2) in myocardial remodeling induced by chronic exposure to CT-1. Kunming mice were intraperitoneally injected with carboxy-terminal polypeptide (CP) of CT-1 (CT-1-CP, 500 μg·kg(-1)· day(-1)) for 1, 2, 3 and 4 week (s), respectively (4 groups obtained according to the injection time, n=10 each, with 5 males and 5 females in each group). Those injected with physiological saline for 4 weeks served as controls (n=10, with 5 males and 5 females). The heart tissues of mice were harvested at 1, 2, 3 or 4 week (s). Immunohistochemistry (IHC) and Western blotting (WB) were used to detect the distribution and expression of sarcomeric α-actin, α-actinin and mitochondrial UCP2 in myocardial tissues. IHC showed that α-actin was mainly distributed around the nuclei of cardiomyocytes, α-actinin concentrated around the striae and UCP2 scattered rather evenly in the plasma. The expression of α-actin was slightly greater than that of α-actinin and UCP2 in the control group (IHC: χ(2)=6.125; WB: F=0.249, P>0.05) and it gradually decreased after exposure to CT-1-CP. There was no significant difference in the expression of α-actin between the control group and the CT-1-CP-treated groups (χ (2)=7.386, P>0.05). But Western blotting revealed significant difference in the expression of α-actin between the control group and the 4-week CT-1-CP-treated group (F=2.912; q=4.203, P<0.05). Moreover, it was found that the expression of α-actinin increased stepwise with the exposure time in CT-1-CP-treated groups and differed significantly between CT-1-CP-treated groups and the control group (ICH: χ (2)=21.977; WB: F=50.388; P<0.01). The expression of UCP2 was initially increased (WB: control group vs. 1- or 2-week group, q values: 5.603 and 9.995, respectively, P<0.01) and then decreased (WB: control group vs. 3-week group, q=4.742, P<0.01; control group vs. 4-week group, q=0.558, P>0.05). It was suggested that long-term exposure to CT-1-CP could lead to the alteration in the expression of sarcomeric α-actin, α-actinin and mitochondrial UCP2. The different expressions of sarcomeric structure proteins and mitochondrial UCP2 may be involved in myocardial remodeling.
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Affiliation(s)
- Shu-Fen Chen
- Central Clinical Laboratory, Affiliated Hospital of Hainan Medical University, Haikou, 570102, China
| | - Li-Ya Rao
- Department of Cardiology Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China.
| | - Tao-Zhi Wei
- Department of Cardiology Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430022, China
| | - Min-Guang Xu
- Department of Physiology, Hainan Medical University, Haikou, 571101, China
| | - Zhan-Ling Dong
- Department of Physiology, Hainan Medical University, Haikou, 571101, China
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Recovery of Tilapia (Oreochromis niloticus) Protein Isolate by High-Intensity Ultrasound-Aided Alkaline Isoelectric Solubilization/Precipitation Process. FOOD BIOPROCESS TECH 2014. [DOI: 10.1007/s11947-014-1431-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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43
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Ribeiro EDA, Pinotsis N, Ghisleni A, Salmazo A, Konarev PV, Kostan J, Sjöblom B, Schreiner C, Polyansky AA, Gkougkoulia EA, Holt MR, Aachmann FL, Zagrović B, Bordignon E, Pirker KF, Svergun DI, Gautel M, Djinović-Carugo K. The structure and regulation of human muscle α-actinin. Cell 2014; 159:1447-60. [PMID: 25433700 PMCID: PMC4259493 DOI: 10.1016/j.cell.2014.10.056] [Citation(s) in RCA: 144] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Revised: 10/01/2014] [Accepted: 10/24/2014] [Indexed: 11/29/2022]
Abstract
The spectrin superfamily of proteins plays key roles in assembling the actin cytoskeleton in various cell types, crosslinks actin filaments, and acts as scaffolds for the assembly of large protein complexes involved in structural integrity and mechanosensation, as well as cell signaling. α-actinins in particular are the major actin crosslinkers in muscle Z-disks, focal adhesions, and actin stress fibers. We report a complete high-resolution structure of the 200 kDa α-actinin-2 dimer from striated muscle and explore its functional implications on the biochemical and cellular level. The structure provides insight into the phosphoinositide-based mechanism controlling its interaction with sarcomeric proteins such as titin, lays a foundation for studying the impact of pathogenic mutations at molecular resolution, and is likely to be broadly relevant for the regulation of spectrin-like proteins. Structure of human α-actinin-2 in an autoinhibited closed conformation Facilitation of PIP2-induced allosteric modulation for opening and titin binding Essentiality of structural flexibility for crosslinking antiparallel F-actin Relevance for the intramolecular pseudoligand regulation mechanism of the spectrin family
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Affiliation(s)
- Euripedes de Almeida Ribeiro
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Nikos Pinotsis
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Andrea Ghisleni
- British Heart Foundation Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK
| | - Anita Salmazo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Petr V Konarev
- European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
| | - Julius Kostan
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Björn Sjöblom
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Claudia Schreiner
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Anton A Polyansky
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria; M.M. Shemyakin and Yu.A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
| | - Eirini A Gkougkoulia
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Mark R Holt
- British Heart Foundation Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK
| | - Finn L Aachmann
- Department of Biotechnology, Norwegian University of Science and Technology, Sem Sælands vei 6/8, 7491 Trondheim, Norway
| | - Bojan Zagrović
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria
| | - Enrica Bordignon
- Laboratory of Physical Chemistry, ETH Zurich, Vladimir-Prelog-Weg 2, 8093 Zurich, Switzerland; Fachbereich Physik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Katharina F Pirker
- Division of Biochemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria
| | - Dmitri I Svergun
- European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
| | - Mathias Gautel
- British Heart Foundation Centre of Research Excellence, Randall Division for Cell and Molecular Biophysics and Cardiovascular Division, King's College London, London SE1 1UL, UK.
| | - Kristina Djinović-Carugo
- Department of Structural and Computational Biology, Max F. Perutz Laboratories, University of Vienna, Campus Vienna Biocenter 5, 1030 Vienna, Austria; Department of Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, 1000 Ljubljana, Slovenia.
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Abstract
The giant protein titin forms a unique filament network in cardiomyocytes, which engages in both mechanical and signaling functions of the heart. TTN, which encodes titin, is also a major human disease gene. In this review, we cover the roles of cardiac titin in normal and failing hearts, with a special emphasis on the contribution of titin to diastolic stiffness. We provide an update on disease-associated titin mutations in cardiac and skeletal muscles and summarize what is known about the impact of protein-protein interactions on titin properties and functions. We discuss the importance of titin-isoform shifts and titin phosphorylation, as well as titin modifications related to oxidative stress, in adjusting the diastolic stiffness of the healthy and the failing heart. Along the way we distinguish among titin alterations in systolic and in diastolic heart failure and ponder the evidence for titin stiffness as a potential target for pharmacological intervention in heart disease.
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Affiliation(s)
- Wolfgang A Linke
- From the Department of Cardiovascular Physiology, Ruhr University Bochum, Bochum, Germany
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Kononova O, Jones L, Barsegov V. Order statistics inference for describing topological coupling and mechanical symmetry breaking in multidomain proteins. J Chem Phys 2014; 139:121913. [PMID: 24089725 DOI: 10.1063/1.4816104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Cooperativity is a hallmark of proteins, many of which show a modular architecture comprising discrete structural domains. Detecting and describing dynamic couplings between structural regions is difficult in view of the many-body nature of protein-protein interactions. By utilizing the GPU-based computational acceleration, we carried out simulations of the protein forced unfolding for the dimer WW - WW of the all-β-sheet WW domains used as a model multidomain protein. We found that while the physically non-interacting identical protein domains (WW) show nearly symmetric mechanical properties at low tension, reflected, e.g., in the similarity of their distributions of unfolding times, these properties become distinctly different when tension is increased. Moreover, the uncorrelated unfolding transitions at a low pulling force become increasingly more correlated (dependent) at higher forces. Hence, the applied force not only breaks "the mechanical symmetry" but also couples the physically non-interacting protein domains forming a multi-domain protein. We call this effect "the topological coupling." We developed a new theory, inspired by order statistics, to characterize protein-protein interactions in multi-domain proteins. The method utilizes the squared-Gaussian model, but it can also be used in conjunction with other parametric models for the distribution of unfolding times. The formalism can be taken to the single-molecule experimental lab to probe mechanical cooperativity and domain communication in multi-domain proteins.
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Affiliation(s)
- Olga Kononova
- Department of Chemistry, University of Massachusetts, Lowell, Massachusetts 01854, USA
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Kiss B, Kellermayer MSZ. Stretching desmin filaments with receding meniscus reveals large axial tensile strength. J Struct Biol 2014; 186:472-80. [PMID: 24746912 DOI: 10.1016/j.jsb.2014.04.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 04/06/2014] [Accepted: 04/08/2014] [Indexed: 11/25/2022]
Abstract
Desmin forms the intermediate filament system of muscle cells where it plays important role in maintaining mechanical integrity and elasticity. Although the importance of intermediate-filament elasticity in cellular mechanics is being increasingly recognized, the molecular basis of desmin's elasticity is not fully understood. We explored desmin elasticity by molecular combing with forces calculated to be as large as 4nN. Average filament contour length increased 1.55-fold axial on average. Molecular combing together with EGTA-treatment caused the fragmentation of the filament into short, 60 to 120-nm-long and 4-nm-wide structures. The fragments display a surface periodicity of 38nm, suggesting that they are composed of laterally attached desmin dimers. The axis of the fragments may deviate significantly from that of the overstretched filament, indicating that they have a large orientational freedom in spite of being axially interconnected. The emergence of protofibril fragments thus suggests that the interconnecting head or tail domains of coiled-coil desmin dimers are load-bearing elements during axial stretch.
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Affiliation(s)
- Balázs Kiss
- Department of Biophysics and Radiation Biology, MTA-SE Molecular Biophysics Research Group, Semmelweis University, 1094 Budapest, Tűzoltó u. 37-47, Hungary.
| | - Miklós S Z Kellermayer
- Department of Biophysics and Radiation Biology, MTA-SE Molecular Biophysics Research Group, Semmelweis University, 1094 Budapest, Tűzoltó u. 37-47, Hungary
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47
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Greaser ML, Pleitner JM. Titin isoform size is not correlated with thin filament length in rat skeletal muscle. Front Physiol 2014; 5:35. [PMID: 24550844 PMCID: PMC3910082 DOI: 10.3389/fphys.2014.00035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 01/16/2014] [Indexed: 01/17/2023] Open
Abstract
The mechanisms controlling thin filament length (TFL) in muscle remain controversial. It was recently reported that TFL was related to titin size, and that the latter might be involved in TFL determination. Titin plays several crucial roles in the sarcomere, but its function as it pertains to the thin filament has not been explored. We tested this relationship using several muscles from wild type rats and from a mutant rat model (Greaser et al., 2008) which results in increased titin size. Myofibrils were isolated from skeletal muscles [extensor digitorum longus (EDL), external oblique (EO), gastrocnemius (GAS), longissimus dorsi (LD), psoas major (PM), and tibialis anterior(TA)] using both adult wild type (WT) and homozygous mutant (HM) rats (n = 6 each). Phalloidin and antibodies against tropomodulin-4 (Tmod-4) and nebulin's N-terminus were used to determine TFL. The WT rats studied express skeletal muscle titin sizes ranging from 3.2 to 3.7 MDa, while the HM rats express a giant titin isoform sized at 3.8 MDa. No differences in phalloidin based TFL, nebulin distance, or Tmod distance were observed across genotypes. However, the HM rats demonstrated a significantly increased (p < 0.01) rest sarcomere length relative to the WT phenotype. It appears that the increased titin size, predominantly observed in HM rats' middle Ig domain, allows for increased extensibility. The data indicates that, although titin performs many sarcomeric functions, its correlation with TFL and structure could not be demonstrated in the rat.
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Affiliation(s)
- Marion L Greaser
- Muscle Biology Laboratory, Animal Sciences, University of Wisconsin-Madison Madison, WI, USA
| | - Jonathan M Pleitner
- Muscle Biology Laboratory, Animal Sciences, University of Wisconsin-Madison Madison, WI, USA
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48
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Gritsyna YV, Salmov NN, Vikhlyantsev IM, Ulanova AD, Sharapov MG, Teplova VV, Podlubnaya ZA. Changes in gene expression and titin (connectin) content in striated muscles of chronically alcoholized rats. Mol Biol 2013. [DOI: 10.1134/s0026893313060058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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49
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Al-Khayat HA. Three-dimensional structure of the human myosin thick filament: clinical implications. Glob Cardiol Sci Pract 2013; 2013:280-302. [PMID: 24689030 PMCID: PMC3963759 DOI: 10.5339/gcsp.2013.36] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 10/11/2013] [Indexed: 11/27/2022] Open
Abstract
High resolution information about the three-dimensional (3D) structure of myosin filaments has always been hard to obtain. Solving the 3D structure of myosin filaments is very important because mutations in human cardiac muscle myosin and its associated proteins (e.g. titin and myosin binding protein C) are known to be associated with a number of familial human cardiomyopathies (e.g. hypertrophic cardiomyopathy and dilated cardiomyopathy). In order to understand how normal heart muscle works and how it fails, as well as the effects of the known mutations on muscle contractility, it is essential to properly understand myosin filament 3D structure and properties in both healthy and diseased hearts. The aim of this review is firstly to provide a general overview of the 3D structure of myosin thick filaments, as studied so far in both vertebrates and invertebrate striated muscles. Knowledge of this 3D structure is the starting point from which myosin filaments isolated from human cardiomyopathic samples, with known mutations in either myosin or its associated proteins (titin or C-protein), can be studied in detail. This should, in turn, enable us to relate the structure of myosin thick filament to its function and to understanding the disease process. A long term objective of this research would be to assist the design of possible therapeutic solutions to genetic myosin-related human cardiomyopathies.
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Affiliation(s)
- Hind A Al-Khayat
- Qatar Cardiovascular Research Centre, Qatar Foundation, PO Box 5825, Doha, Qatar
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50
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Vikhlyantsev IM, Podlubnaya ZA. New titin (connectin) isoforms and their functional role in striated muscles of mammals: facts and suppositions. BIOCHEMISTRY (MOSCOW) 2013; 77:1515-35. [PMID: 23379526 DOI: 10.1134/s0006297912130093] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
This review summarizes results of our studies on titin isoform composition in vertebrate striated muscles under normal conditions, during hibernation, real and simulated microgravity, and under pathological conditions (stiff-person syndrome, post-apoplectic spasticity, dilated cardiomyopathy, cardiac hypertrophy). Experimental evidence for the existence in mammalian striated muscles of higher molecular weight isoforms of titin (NT-isoforms) in addition to the known N2A-, N2BA-, and N2B-titin isoforms was obtained. Comparative studies of changes in titin isoform composition and structure-functional properties of human and animal striated muscles during adaptive and pathological processes led to a conclusion about the key role of NT-isoforms of titin in maintenance of sarcomere structure and contractile function of these muscles.
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Affiliation(s)
- I M Vikhlyantsev
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia.
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