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Strom J, Bull M, Gohlke J, Saripalli C, Methawasin M, Gotthardt M, Granzier H. Titin's cardiac-specific N2B element is critical to mechanotransduction during volume overload of the heart. J Mol Cell Cardiol 2024; 191:40-49. [PMID: 38604403 PMCID: PMC11229416 DOI: 10.1016/j.yjmcc.2024.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Revised: 03/09/2024] [Accepted: 04/08/2024] [Indexed: 04/13/2024]
Abstract
The heart has the ability to detect and respond to changes in mechanical load through a process called mechanotransduction. In this study, we focused on investigating the role of the cardiac-specific N2B element within the spring region of titin, which has been proposed to function as a mechanosensor. To assess its significance, we conducted experiments using N2B knockout (KO) mice and wildtype (WT) mice, subjecting them to three different conditions: 1) cardiac pressure overload induced by transverse aortic constriction (TAC), 2) volume overload caused by aortocaval fistula (ACF), and 3) exercise-induced hypertrophy through swimming. Under conditions of pressure overload (TAC), both genotypes exhibited similar hypertrophic responses. In contrast, WT mice displayed robust left ventricular hypertrophy after one week of volume overload (ACF), while the KO mice failed to undergo hypertrophy and experienced a high mortality rate. Similarly, swim exercise-induced hypertrophy was significantly reduced in the KO mice. RNA-Seq analysis revealed an abnormal β-adrenergic response to volume overload in the KO mice, as well as a diminished response to isoproterenol-induced hypertrophy. Because it is known that the N2B element interacts with the four-and-a-half LIM domains 1 and 2 (FHL1 and FHL2) proteins, both of which have been associated with mechanotransduction, we evaluated these proteins. Interestingly, while volume-overload resulted in FHL1 protein expression levels that were comparable between KO and WT mice, FHL2 protein levels were reduced by over 90% in the KO mice compared to WT. This suggests that in response to volume overload, FHL2 might act as a signaling mediator between the N2B element and downstream signaling pathways. Overall, our study highlights the importance of the N2B element in mechanosensing during volume overload, both in physiological and pathological settings.
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Affiliation(s)
- Joshua Strom
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, United States of America; Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721, United States of America
| | - Mathew Bull
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, United States of America; Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721, United States of America
| | - Jochen Gohlke
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, United States of America; Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721, United States of America
| | - Chandra Saripalli
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, United States of America; Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721, United States of America
| | - Mei Methawasin
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, United States of America; Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ 85721, United States of America
| | - Michael Gotthardt
- Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany; Department of Cardiology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, United States of America.
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Sun Y, Liu X, Huang W, Le S, Yan J. Structural domain in the Titin N2B-us region binds to FHL2 in a force-activation dependent manner. Nat Commun 2024; 15:4496. [PMID: 38802383 DOI: 10.1038/s41467-024-48828-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/15/2024] [Indexed: 05/29/2024] Open
Abstract
Titin N2B unique sequence (N2B-us) is a 572 amino acid sequence that acts as an elastic spring to regulate muscle passive elasticity. It is thought to lack stable tertiary structures and is a force-bearing region that is regulated by mechanical stretching. In this study, the conformation of N2B-us and its interaction with four-and-a-half LIM domain protein 2 (FHL2) are investigated using AlphaFold2 predictions and single-molecule experimental validation. Surprisingly, a stable alpha/beta structural domain is predicted and confirmed in N2B-us that can be mechanically unfolded at forces of a few piconewtons. Additionally, more than twenty FHL2 LIM domain binding sites are predicted to spread throughout N2B-us. Single-molecule manipulation experiments reveals the force-dependent binding of FHL2 to the N2B-us structural domain. These findings provide insights into the mechano-sensing functions of N2B-us and its interactions with FHL2.
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Affiliation(s)
- Yuze Sun
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore
| | - Xuyao Liu
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Wenmao Huang
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Shimin Le
- Department of Physics, National University of Singapore, Singapore, Singapore
| | - Jie Yan
- Mechanobiology Institute, National University of Singapore, Singapore, Singapore.
- Department of Physics, National University of Singapore, Singapore, Singapore.
- Centre for Biological Imaging Sciences, National University of Singapore, Singapore, Singapore.
- Joint School of National University of Singapore and Tianjin University, International Campus of Tianjin University, Binhai New City, Fuzhou, China.
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3
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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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Linke WA. Stretching the story of titin and muscle function. J Biomech 2023; 152:111553. [PMID: 36989971 DOI: 10.1016/j.jbiomech.2023.111553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 03/14/2023] [Indexed: 03/29/2023]
Abstract
The discovery of the giant protein titin, also known as connectin, dates almost half a century back. In this review, I recapitulate major advances in the discovery of the titin filaments and the recognition of their properties and function until today. I briefly discuss how our understanding of the layout and interactions of titin in muscle sarcomeres has evolved and review key facts about the titin sequence at the gene (TTN) and protein levels. I also touch upon properties of titin important for the stability of the contractile units and the assembly and maintenance of sarcomeric proteins. The greater part of my discussion centers around the mechanical function of titin in skeletal muscle. I cover milestones of research on titin's role in stretch-dependent passive tension development, recollect the reasons behind the enormous elastic diversity of titin, and provide an update on the molecular mechanisms of titin elasticity, details of which are emerging even now. I reflect on current knowledge of how muscle fibers behave mechanically if titin stiffness is removed and how titin stiffness can be dynamically regulated, such as by posttranslational modifications or calcium binding. Finally, I highlight novel and exciting, but still controversially discussed, insight into the role titin plays in active tension development, such as length-dependent activation and contraction from longer muscle lengths.
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Affiliation(s)
- Wolfgang A Linke
- Institute of Physiology II, University of Münster, Germany; Clinic for Cardiology and Pneumology, University Medical Center Göttingen, Germany; German Centre for Cardiovascular Research, Berlin, Germany.
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A Novel Nonsense Pathogenic TTN Variant Identified in a Patient with Severe Dilated Cardiomyopathy. Curr Issues Mol Biol 2023; 45:2422-2430. [PMID: 36975527 PMCID: PMC10047881 DOI: 10.3390/cimb45030157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 03/10/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023] Open
Abstract
Both genetic and environmental factors contribute to the development of dilated cardiomyopathy. Among the genes involved, TTN mutations, including truncated variants, explain 25% of DCM cases. We performed genetic counseling and analysis on a 57-year-old woman diagnosed with severe DCM and presenting relevant acquired risk factors for DCM (hypertension, diabetes, smoking habit, and/or previous alcohol and cocaine abuse) and with a family history of both DCM and sudden cardiac death. The left ventricular systolic function, as assessed by standard echocardiography, was 20%. The genetic analysis performed using TruSight Cardio panel, including 174 genes related to cardiac genetic diseases, revealed a novel nonsense TTN variant (TTN:c.103591A > T, p.Lys34531*), falling within the M-band region of the titin protein. This region is known for its important role in maintaining the structure of the sarcomere and in promoting sarcomerogenesis. The identified variant was classified as likely pathogenic based on ACMG criteria. The current results support the need of genetic analysis in the presence of a family history, even when relevant acquired risk factors for DCM may have contributed to the severity of the disease.
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Hessel AL, Ma W, Mazara N, Rice PE, Nissen D, Gong H, Kuehn M, Irving T, Linke WA. Titin force in muscle cells alters lattice order, thick and thin filament protein formation. Proc Natl Acad Sci U S A 2022; 119:e2209441119. [PMID: 36409887 PMCID: PMC9860331 DOI: 10.1073/pnas.2209441119] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 10/25/2022] [Indexed: 11/22/2022] Open
Abstract
Skeletal muscle force production is increased at longer compared to shorter muscle lengths because of length-dependent priming of thick filament proteins in the contractile unit before contraction. Using small-angle X-ray diffraction in combination with a mouse model that specifically cleaves the stretch-sensitive titin protein, we found that titin cleavage diminished the length-dependent priming of the thick filament. Strikingly, a titin-sensitive, length-dependent priming was also present in thin filaments, which seems only possible via bridge proteins between thick and thin filaments in resting muscle, potentially myosin-binding protein C. We further show that these bridges can be forcibly ruptured via high-speed stretches. Our results advance a paradigm shift to the fundamental regulation of length-dependent priming, with titin as the key driver.
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Affiliation(s)
- Anthony L. Hessel
- Institute of Physiology II, University of Muenster, Muenster, 48149Germany
| | - Weikang Ma
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL 60616
| | - Nicole Mazara
- School of Kinesiology, University of British Columbia, Vancouver, CanadaV6T 1Z1
| | - Paige E. Rice
- Department of Biological Sciences, Northern Arizona University, FlagstaffAZ 86011
| | - Devin Nissen
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL 60616
| | - Henry Gong
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL 60616
| | - Michel Kuehn
- Institute of Physiology II, University of Muenster, Muenster, 48149Germany
| | - Thomas Irving
- BioCAT, Department of Biology, Illinois Institute of Technology, Chicago, IL 60616
| | - Wolfgang A. Linke
- Institute of Physiology II, University of Muenster, Muenster, 48149Germany
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Bacova BS, Andelova K, Sykora M, Egan Benova T, Barancik M, Kurahara LH, Tribulova N. Does Myocardial Atrophy Represent Anti-Arrhythmic Phenotype? Biomedicines 2022; 10:2819. [PMID: 36359339 PMCID: PMC9687767 DOI: 10.3390/biomedicines10112819] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/30/2023] Open
Abstract
This review focuses on cardiac atrophy resulting from mechanical or metabolic unloading due to various conditions, describing some mechanisms and discussing possible strategies or interventions to prevent, attenuate or reverse myocardial atrophy. An improved awareness of these conditions and an increased focus on the identification of mechanisms and therapeutic targets may facilitate the development of the effective treatment or reversion for cardiac atrophy. It appears that a decrement in the left ventricular mass itself may be the central component in cardiac deconditioning, which avoids the occurrence of life-threatening arrhythmias. The depressed myocardial contractility of atrophied myocardium along with the upregulation of electrical coupling protein, connexin43, the maintenance of its topology, and enhanced PKCƐ signalling may be involved in the anti-arrhythmic phenotype. Meanwhile, persistent myocardial atrophy accompanied by oxidative stress and inflammation, as well as extracellular matrix fibrosis, may lead to severe cardiac dysfunction, and heart failure. Data in the literature suggest that the prevention of heart failure via the attenuation or reversion of myocardial atrophy is possible, although this requires further research.
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Affiliation(s)
| | - Katarina Andelova
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
| | - Matus Sykora
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
| | - Tamara Egan Benova
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
| | - Miroslav Barancik
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
| | - Lin Hai Kurahara
- Department of Cardiovascular Physiology, Faculty of Medicine, Kagawa University, Miki-cho 761-0793, Japan
| | - Narcis Tribulova
- Centre of Experimental Medicine, Slovak Academy of Sciences, 84104 Bratislava, Slovakia
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8
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Germain P, Delalande A, Pichon C. Role of Muscle LIM Protein in Mechanotransduction Process. Int J Mol Sci 2022; 23:ijms23179785. [PMID: 36077180 PMCID: PMC9456170 DOI: 10.3390/ijms23179785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 08/14/2022] [Accepted: 08/26/2022] [Indexed: 11/25/2022] Open
Abstract
The induction of protein synthesis is crucial to counteract the deconditioning of neuromuscular system and its atrophy. In the past, hormones and cytokines acting as growth factors involved in the intracellular events of these processes have been identified, while the implications of signaling pathways associated with the anabolism/catabolism ratio in reference to the molecular mechanism of skeletal muscle hypertrophy have been recently identified. Among them, the mechanotransduction resulting from a mechanical stress applied to the cell appears increasingly interesting as a potential pathway for therapeutic intervention. At present, there is an open question regarding the type of stress to apply in order to induce anabolic events or the type of mechanical strain with respect to the possible mechanosensing and mechanotransduction processes involved in muscle cells protein synthesis. This review is focused on the muscle LIM protein (MLP), a structural and mechanosensing protein with a LIM domain, which is expressed in the sarcomere and costamere of striated muscle cells. It acts as a transcriptional cofactor during cell proliferation after its nuclear translocation during the anabolic process of differentiation and rebuilding. Moreover, we discuss the possible opportunity of stimulating this mechanotransduction process to counteract the muscle atrophy induced by anabolic versus catabolic disorders coming from the environment, aging or myopathies.
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Affiliation(s)
- Philippe Germain
- UFR Sciences and Techniques, University of Orleans, 45067 Orleans, France
- Center for Molecular Biophysics, CNRS Orleans, 45071 Orleans, France
| | - Anthony Delalande
- UFR Sciences and Techniques, University of Orleans, 45067 Orleans, France
- Center for Molecular Biophysics, CNRS Orleans, 45071 Orleans, France
| | - Chantal Pichon
- UFR Sciences and Techniques, University of Orleans, 45067 Orleans, France
- Center for Molecular Biophysics, CNRS Orleans, 45071 Orleans, France
- Institut Universitaire de France, 1 Rue Descartes, 75231 Paris, France
- Correspondence:
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Abstract
PURPOSE OF REVIEW Truncating TTN variants (TTNtv) are the most common genetic cause of dilated cardiomyopathy (DCM), but the underlying mechanisms are incompletely understood and effective therapeutic strategies are lacking. Here we review recent data that shed new light on the functional consequences of TTNtv and how these effects may vary with mutation location. RECENT FINDINGS Whether TTNtv act by haploinsufficiency or dominant negative effects has been hotly debated. New evidence now implicates both mechanisms in TTNtv-related DCM, showing reduced titin content and persistent truncated titin that may be incorporated into protein aggregates. The extent to which aggregate formation and protein quality control defects differ with TTNtv location and contribute to contractile dysfunction is unresolved. TTNtv-associated DCM has a complex etiology that involves varying combinations of wild-type titin deficiency and dominant negative effects of truncated mutant titin. Therapeutic strategies to improve protein handling may be beneficial in some cases.
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Shmelev ME, Titov SI, Belousov AS, Farniev VM, Zhmenia VM, Lanskikh DV, Penkova AO, Kumeiko VV. Cell and Tissue Nanomechanics: From Early Development to Carcinogenesis. Biomedicines 2022; 10:biomedicines10020345. [PMID: 35203554 PMCID: PMC8961777 DOI: 10.3390/biomedicines10020345] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 01/22/2022] [Accepted: 01/27/2022] [Indexed: 02/04/2023] Open
Abstract
Cell and tissue nanomechanics, being inspired by progress in high-resolution physical mapping, has recently burst into biomedical research, discovering not only new characteristics of normal and diseased tissues, but also unveiling previously unknown mechanisms of pathological processes. Some parallels can be drawn between early development and carcinogenesis. Early embryogenesis, up to the blastocyst stage, requires a soft microenvironment and internal mechanical signals induced by the contractility of the cortical actomyosin cytoskeleton, stimulating quick cell divisions. During further development from the blastocyst implantation to placenta formation, decidua stiffness is increased ten-fold when compared to non-pregnant endometrium. Organogenesis is mediated by mechanosignaling inspired by intercellular junction formation with the involvement of mechanotransduction from the extracellular matrix (ECM). Carcinogenesis dramatically changes the mechanical properties of cells and their microenvironment, generally reproducing the structural properties and molecular organization of embryonic tissues, but with a higher stiffness of the ECM and higher cellular softness and fluidity. These changes are associated with the complete rearrangement of the entire tissue skeleton involving the ECM, cytoskeleton, and the nuclear scaffold, all integrated with each other in a joint network. The important changes occur in the cancer stem-cell niche responsible for tumor promotion and metastatic growth. We expect that the promising concept based on the natural selection of cancer cells fixing the most invasive phenotypes and genotypes by reciprocal regulation through ECM-mediated nanomechanical feedback loop can be exploited to create new therapeutic strategies for cancer treatment.
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Affiliation(s)
- Mikhail E. Shmelev
- Institute of Life Sciences and Biomedicine, Far Eastern Federal University, 690922 Vladivostok, Russia; (M.E.S.); (S.I.T.); (A.S.B.); (V.M.F.); (V.M.Z.); (D.V.L.); (A.O.P.)
| | - Sergei I. Titov
- Institute of Life Sciences and Biomedicine, Far Eastern Federal University, 690922 Vladivostok, Russia; (M.E.S.); (S.I.T.); (A.S.B.); (V.M.F.); (V.M.Z.); (D.V.L.); (A.O.P.)
| | - Andrei S. Belousov
- Institute of Life Sciences and Biomedicine, Far Eastern Federal University, 690922 Vladivostok, Russia; (M.E.S.); (S.I.T.); (A.S.B.); (V.M.F.); (V.M.Z.); (D.V.L.); (A.O.P.)
| | - Vladislav M. Farniev
- Institute of Life Sciences and Biomedicine, Far Eastern Federal University, 690922 Vladivostok, Russia; (M.E.S.); (S.I.T.); (A.S.B.); (V.M.F.); (V.M.Z.); (D.V.L.); (A.O.P.)
| | - Valeriia M. Zhmenia
- Institute of Life Sciences and Biomedicine, Far Eastern Federal University, 690922 Vladivostok, Russia; (M.E.S.); (S.I.T.); (A.S.B.); (V.M.F.); (V.M.Z.); (D.V.L.); (A.O.P.)
| | - Daria V. Lanskikh
- Institute of Life Sciences and Biomedicine, Far Eastern Federal University, 690922 Vladivostok, Russia; (M.E.S.); (S.I.T.); (A.S.B.); (V.M.F.); (V.M.Z.); (D.V.L.); (A.O.P.)
| | - Alina O. Penkova
- Institute of Life Sciences and Biomedicine, Far Eastern Federal University, 690922 Vladivostok, Russia; (M.E.S.); (S.I.T.); (A.S.B.); (V.M.F.); (V.M.Z.); (D.V.L.); (A.O.P.)
| | - Vadim V. Kumeiko
- Institute of Life Sciences and Biomedicine, Far Eastern Federal University, 690922 Vladivostok, Russia; (M.E.S.); (S.I.T.); (A.S.B.); (V.M.F.); (V.M.Z.); (D.V.L.); (A.O.P.)
- A.V. Zhirmunsky National Scientific Center of Marine Biology, Far Eastern Branch, Russian Academy of Sciences, 690041 Vladivostok, Russia
- Correspondence: ; Tel.: +7-9-02-555-1821
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12
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Radke MH, Badillo-Lisakowski V, Britto-Borges T, Kubli DA, Jüttner R, Parakkat P, Carballo JL, Hüttemeister J, Liss M, Hansen A, Dieterich C, Mullick AE, Gotthardt M. Therapeutic inhibition of RBM20 improves diastolic function in a murine heart failure model and human engineered heart tissue. Sci Transl Med 2021; 13:eabe8952. [PMID: 34851694 DOI: 10.1126/scitranslmed.abe8952] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Michael H Radke
- Department of Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.,German Center for Cardiovascular Research (DZHK), partner site Berlin, 10785 Berlin, Germany
| | - Victor Badillo-Lisakowski
- Department of Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.,German Center for Cardiovascular Research (DZHK), partner site Berlin, 10785 Berlin, Germany.,Humboldt-Universität zu Berlin, 10099 Berlin, Germany
| | - Thiago Britto-Borges
- Section of Bioinformatics and Systems Cardiology, Klaus Tschira Institute for Integrative Computational Cardiology and Department of Internal Medicine III, University Hospital Heidelberg, 69120 Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), partner site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | | | - René Jüttner
- Department of Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany
| | - Pragati Parakkat
- Department of Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.,German Center for Cardiovascular Research (DZHK), partner site Berlin, 10785 Berlin, Germany.,Department of Cardiology, Charité Universitätsmedizin Berlin, 10115 Berlin, Germany
| | - Jacobo Lopez Carballo
- Department of Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.,Department of Cardiology, Charité Universitätsmedizin Berlin, 10115 Berlin, Germany
| | - Judith Hüttemeister
- Department of Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.,German Center for Cardiovascular Research (DZHK), partner site Berlin, 10785 Berlin, Germany
| | - Martin Liss
- Department of Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.,German Center for Cardiovascular Research (DZHK), partner site Berlin, 10785 Berlin, Germany
| | - Arne Hansen
- Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany.,German Center for Cardiovascular Research (DZHK), partner site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Christoph Dieterich
- Section of Bioinformatics and Systems Cardiology, Klaus Tschira Institute for Integrative Computational Cardiology and Department of Internal Medicine III, University Hospital Heidelberg, 69120 Heidelberg, Germany.,German Center for Cardiovascular Research (DZHK), partner site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | | | - Michael Gotthardt
- Department of Neuromuscular and Cardiovascular Cell Biology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, 13125 Berlin, Germany.,German Center for Cardiovascular Research (DZHK), partner site Berlin, 10785 Berlin, Germany.,Department of Cardiology, Charité Universitätsmedizin Berlin, 10115 Berlin, Germany
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13
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Hassoun R, Budde H, Mügge A, Hamdani N. Cardiomyocyte Dysfunction in Inherited Cardiomyopathies. Int J Mol Sci 2021; 22:11154. [PMID: 34681814 PMCID: PMC8541428 DOI: 10.3390/ijms222011154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/08/2021] [Accepted: 10/13/2021] [Indexed: 01/10/2023] Open
Abstract
Inherited cardiomyopathies form a heterogenous group of disorders that affect the structure and function of the heart. Defects in the genes encoding sarcomeric proteins are associated with various perturbations that induce contractile dysfunction and promote disease development. In this review we aimed to outline the functional consequences of the major inherited cardiomyopathies in terms of myocardial contraction and kinetics, and to highlight the structural and functional alterations in some sarcomeric variants that have been demonstrated to be involved in the pathogenesis of the inherited cardiomyopathies. A particular focus was made on mutation-induced alterations in cardiomyocyte mechanics. Since no disease-specific treatments for familial cardiomyopathies exist, several novel agents have been developed to modulate sarcomere contractility. Understanding the molecular basis of the disease opens new avenues for the development of new therapies. Furthermore, the earlier the awareness of the genetic defect, the better the clinical prognostication would be for patients and the better the prevention of development of the disease.
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Affiliation(s)
- Roua Hassoun
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, 44801 Bochum, Germany
- Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, 44801 Bochum, Germany
| | - Heidi Budde
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, 44801 Bochum, Germany
- Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, 44801 Bochum, Germany
| | - Andreas Mügge
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, 44801 Bochum, Germany
- Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, 44801 Bochum, Germany
| | - Nazha Hamdani
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Ruhr University Bochum, 44801 Bochum, Germany
- Department of Cardiology, St. Josef-Hospital and Bergmannsheil, Ruhr University Bochum, 44801 Bochum, Germany
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14
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Kelly C, Gage MJ. Protein Unfolding: Denaturant vs. Force. Biomedicines 2021; 9:biomedicines9101395. [PMID: 34680512 PMCID: PMC8533514 DOI: 10.3390/biomedicines9101395] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/20/2021] [Accepted: 09/28/2021] [Indexed: 11/16/2022] Open
Abstract
While protein refolding has been studied for over 50 years since the pioneering work of Christian Anfinsen, there have been a limited number of studies correlating results between chemical, thermal, and mechanical unfolding. The limited knowledge of the relationship between these processes makes it challenging to compare results between studies if different refolding methods were applied. Our current work compares the energetic barriers and folding rates derived from chemical, thermal, and mechanical experiments using an immunoglobulin-like domain from the muscle protein titin as a model system. This domain, I83, has high solubility and low stability relative to other Ig domains in titin, though its stability can be modulated by calcium. Our experiments demonstrated that the free energy of refolding was equivalent with all three techniques, but the refolding rates exhibited differences, with mechanical refolding having slightly faster rates. This suggests that results from equilibrium-based measurements can be compared directly but care should be given comparing refolding kinetics derived from refolding experiments that used different unfolding methods.
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Affiliation(s)
- Colleen Kelly
- Department of Chemistry, University of Massachusetts Lowell, Lowell, MA 01854, USA;
| | - Matthew J. Gage
- Department of Chemistry, University of Massachusetts Lowell, Lowell, MA 01854, USA;
- UMass Movement Center (UMOVE), University of Massachusetts Lowell, Lowell, MA 01854, USA
- Correspondence:
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15
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Bogomolovas J, Fleming JR, Franke B, Manso B, Simon B, Gasch A, Markovic M, Brunner T, Knöll R, Chen J, Labeit S, Scheffner M, Peter C, Mayans O. Titin kinase ubiquitination aligns autophagy receptors with mechanical signals in the sarcomere. EMBO Rep 2021; 22:e48018. [PMID: 34402565 PMCID: PMC8490993 DOI: 10.15252/embr.201948018] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 07/07/2021] [Accepted: 07/19/2021] [Indexed: 12/13/2022] Open
Abstract
Striated muscle undergoes remodelling in response to mechanical and physiological stress, but little is known about the integration of such varied signals in the myofibril. The interaction of the elastic kinase region from sarcomeric titin (A168-M1) with the autophagy receptors Nbr1/p62 and MuRF E3 ubiquitin ligases is well suited to link mechanosensing with the trophic response of the myofibril. To investigate the mechanisms of signal cross-talk at this titin node, we elucidated its 3D structure, analysed its response to stretch using steered molecular dynamics simulations and explored its functional relation to MuRF1 and Nbr1/p62 using cellular assays. We found that MuRF1-mediated ubiquitination of titin kinase promotes its scaffolding of Nbr1/p62 and that the process can be dynamically down-regulated by the mechanical unfolding of a linker sequence joining titin kinase with the MuRF1 receptor site in titin. We propose that titin ubiquitination is sensitive to the mechanical state of the sarcomere, the regulation of sarcomere targeting by Nbr1/p62 being a functional outcome. We conclude that MuRF1/Titin Kinase/Nbr1/p62 constitutes a distinct assembly that predictably promotes sarcomere breakdown in inactive muscle.
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Affiliation(s)
- Julius Bogomolovas
- Department of MedicineSchool of MedicineUniversity of CaliforniaSan Diego, La JollaCAUSA
- Department of Cognitive and Clinical NeuroscienceCentral Institute of Mental HealthMedical Faculty MannheimHeidelberg UniversityMannheimGermany
- Department of Integrative PathophysiologyMedical Faculty MannheimUniversity of HeidelbergMannheimGermany
| | | | - Barbara Franke
- Department of BiologyUniversity of KonstanzKonstanzGermany
| | - Bruno Manso
- Department of BiologyUniversity of KonstanzKonstanzGermany
| | - Bernd Simon
- Structural and Computational Biology UnitEMBLHeidelbergGermany
| | - Alexander Gasch
- Department of Integrative PathophysiologyMedical Faculty MannheimUniversity of HeidelbergMannheimGermany
| | | | - Thomas Brunner
- Department of BiologyUniversity of KonstanzKonstanzGermany
| | - Ralph Knöll
- Integrated Cardio Metabolic Centre (ICMC)Heart and Vascular ThemeUniversity Hospital, MedHKarolinska InstitutetHuddingeSweden
- Bioscience, CardiovascularRenal & MetabolismBioPharmaceuticalsR&D, AstraZenecaGothenburgSweden
| | - Ju Chen
- Department of MedicineSchool of MedicineUniversity of CaliforniaSan Diego, La JollaCAUSA
| | - Siegfried Labeit
- Department of Integrative PathophysiologyMedical Faculty MannheimUniversity of HeidelbergMannheimGermany
| | | | - Christine Peter
- Department of ChemistryUniversity of KonstanzKonstanzGermany
| | - Olga Mayans
- Department of BiologyUniversity of KonstanzKonstanzGermany
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16
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Huang K, Duan HQ, Li QX, Luo YB, Bi FF, Yang H. Clinicopathological features of titinopathy from a Chinese neuromuscular center. Neuropathology 2021; 41:349-356. [PMID: 34553419 DOI: 10.1111/neup.12761] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/17/2021] [Accepted: 05/18/2021] [Indexed: 12/14/2022]
Abstract
Titin, one of the largest proteins in humans, is a major component of muscle sarcomeres. Pathogenic variants in the titin gene (TTN) have been reported to cause a range of skeletal muscle diseases, collectively known as titinopathy. Titinopathy is a heterogeneous group of disabling diseases characterized by muscle weakness. In our study, we aimed to establish the clinicopathological-genetic spectrum of titinopathy from a single neuromuscular center. Three patients were diagnosed as having definite titinopathy, and additional three patients were diagnosed as having possible titinopathy according to the diagnostic criteria. All the patients showed initial symptoms from age one to 40 years. Physical examination revealed that five patients had muscle weakness, and that one patient experienced behavioral changes. Muscle biopsy specimens obtained from all six patients demonstrated multiple myopathological changes, including increased fiber size variation, muscle fiber hypertrophy or atrophy, formation of centralized cell nuclei, necklace cytoplasmic bodies, and formation of rimmed vacuoles and cores. Genetic testing revealed 11 different TTN alterations, including missense (6/11), nonsense (2/11), frameshift (2/11), and splicing (1/11) mutations. Our study provides further evidence that TTN mutations are more likely to be responsible for an increasing proportion of various myopathies, such as hereditary myopathy with early respiratory failure (HMERF), core myopathy, and distal myopathy with rimmed vacuoles, than currently recognized mutations. Our findings expand the clinical, pathohistological and genetic spectrum of titinopathy.
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Affiliation(s)
- Kun Huang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Hui-Qian Duan
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Qiu-Xiang Li
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Yue-Bei Luo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Fang-Fang Bi
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Huan Yang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
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17
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Biquand A, Spinozzi S, Tonino P, Cosette J, Strom J, Elbeck Z, Knöll R, Granzier H, Lostal W, Richard I. Titin M-line insertion sequence 7 is required for proper cardiac function in mice. J Cell Sci 2021; 134:271843. [PMID: 34401916 DOI: 10.1242/jcs.258684] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 08/06/2021] [Indexed: 11/20/2022] Open
Abstract
Titin is a giant sarcomeric protein that is involved in a large number of functions, with a primary role in skeletal and cardiac sarcomere organization and stiffness. The titin gene (TTN) is subject to various alternative splicing events, but in the region that is present at the M-line, the only exon that can be spliced out is Mex5, which encodes for the insertion sequence 7 (is7). Interestingly, in the heart, the majority of titin isoforms are Mex5+, suggesting a cardiac role for is7. Here, we performed comprehensive functional, histological, transcriptomic, microscopic and molecular analyses of a mouse model lacking the Ttn Mex5 exon (ΔMex5), and revealed that the absence of the is7 is causative for dilated cardiomyopathy. ΔMex5 mice showed altered cardiac function accompanied by increased fibrosis and ultrastructural alterations. Abnormal expression of excitation-contraction coupling proteins was also observed. The results reported here confirm the importance of the C-terminal region of titin in cardiac function and are the first to suggest a possible relationship between the is7 and excitation-contraction coupling. Finally, these findings give important insights for the identification of new targets in the treatment of titinopathies.
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Affiliation(s)
- Ariane Biquand
- Genethon, 91000 Evry, France.,Université Paris-Saclay, Univ Evry, Inserm, Généthon, Integrare research unit UMR_S951, 91000 Evry-Courcouronnes, France
| | - Simone Spinozzi
- Genethon, 91000 Evry, France.,Université Paris-Saclay, Univ Evry, Inserm, Généthon, Integrare research unit UMR_S951, 91000 Evry-Courcouronnes, France
| | - Paola Tonino
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | | | - Joshua Strom
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Zaher Elbeck
- Department of Medicine, Integrated Cardio Metabolic Centre (ICMC), Heart and Vascular Theme, Karolinska Institutet, 141 57 Huddinge, Sweden
| | - Ralph Knöll
- Department of Medicine, Integrated Cardio Metabolic Centre (ICMC), Heart and Vascular Theme, Karolinska Institutet, 141 57 Huddinge, Sweden.,Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, 431 50 Gothenburg, Sweden
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - William Lostal
- Genethon, 91000 Evry, France.,Université Paris-Saclay, Univ Evry, Inserm, Généthon, Integrare research unit UMR_S951, 91000 Evry-Courcouronnes, France
| | - Isabelle Richard
- Genethon, 91000 Evry, France.,Université Paris-Saclay, Univ Evry, Inserm, Généthon, Integrare research unit UMR_S951, 91000 Evry-Courcouronnes, France
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18
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Alegre-Cebollada J. Protein nanomechanics in biological context. Biophys Rev 2021; 13:435-454. [PMID: 34466164 PMCID: PMC8355295 DOI: 10.1007/s12551-021-00822-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Accepted: 07/05/2021] [Indexed: 12/20/2022] Open
Abstract
How proteins respond to pulling forces, or protein nanomechanics, is a key contributor to the form and function of biological systems. Indeed, the conventional view that proteins are able to diffuse in solution does not apply to the many polypeptides that are anchored to rigid supramolecular structures. These tethered proteins typically have important mechanical roles that enable cells to generate, sense, and transduce mechanical forces. To fully comprehend the interplay between mechanical forces and biology, we must understand how protein nanomechanics emerge in living matter. This endeavor is definitely challenging and only recently has it started to appear tractable. Here, I introduce the main in vitro single-molecule biophysics methods that have been instrumental to investigate protein nanomechanics over the last 2 decades. Then, I present the contemporary view on how mechanical force shapes the free energy of tethered proteins, as well as the effect of biological factors such as post-translational modifications and mutations. To illustrate the contribution of protein nanomechanics to biological function, I review current knowledge on the mechanobiology of selected muscle and cell adhesion proteins including titin, talin, and bacterial pilins. Finally, I discuss emerging methods to modulate protein nanomechanics in living matter, for instance by inducing specific mechanical loss-of-function (mLOF). By interrogating biological systems in a causative manner, these new tools can contribute to further place protein nanomechanics in a biological context.
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19
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Xiao L, Li C, Sun Y, Chen Y, Wei H, Hu D, Yu T, Li X, Jin L, Shi L, Marian AJ, Wang DW. Clinical Significance of Variants in the TTN Gene in a Large Cohort of Patients With Sporadic Dilated Cardiomyopathy. Front Cardiovasc Med 2021; 8:657689. [PMID: 33996946 PMCID: PMC8120103 DOI: 10.3389/fcvm.2021.657689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 03/05/2021] [Indexed: 12/11/2022] Open
Abstract
Background: Mutations in the TTN gene are the most common causes of dilated cardiomyopathy (DCM). The clinical significance of TTN gene variants remains inadequately understood. Methods: Whole-exome sequencing and phenotypic characterisation were performed, and patients were followed up for a median of 44 months. Results: We analyzed the association of the TTN variants with the clinical outcomes in a prospective study of 1,041 patients with sporadic DCM. TTN truncating variants (tTTN) were detected in 120 (11.5%) patients as compared with 2.4/10,000 East Asian populations in the Genome Aggregation Database (GnomAD; p < 0.0001). Pathogenic TTN missense variants were also enriched in DCM as compared with the GnomAD populations (27.6 vs. 5.9%, p < 0.0001). DCM patients with tTTN had a lower left ventricular ejection fraction (28.89 ± 8.72 vs. 31.81 ± 9.97, p = 0.002) and a lower frequency of the left bundle branch block (3.3 vs. 11.3%, p = 0.011) than those without or with mutations in other known causal genes (OCG). However, tTTN were not associated with the composite primary endpoint of cardiac death and heart transplantation during the follow-up period [adjusted hazard ratio (HR): 0.912; 95% confidence interval: 0.464–1.793; p = 0.790]. There was also no sex-dependent effect. Concomitant tTTN and pathogenic variants in OCG were present in only eight DCM patients and did not affect the outcome. Conclusion: The phenotype of DCM caused by tTTN, major causes of sporadic DCM, is not distinctly different from those caused by other causal genes for DCM.
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Affiliation(s)
- Lei Xiao
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Chenze Li
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Yang Sun
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Yanghui Chen
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Haoran Wei
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Dong Hu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Ting Yu
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Xianqing Li
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, China
| | - Li Jin
- Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China
| | - Leming Shi
- Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China
| | - Ali J Marian
- Center for Cardiovascular Genetics, Houston, TX, United States
| | - Dao Wen Wang
- Division of Cardiology, Department of Internal Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Hubei Key Laboratory of Genetics and Molecular Mechanism of Cardiologic Disorders, Huazhong University of Science and Technology, Wuhan, China.,Collaborative Innovation Center for Genetics and Development, School of Life Sciences, Fudan University, Shanghai, China
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20
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Hang C, Song Y, Li Y, Zhang S, Chang Y, Bai R, Saleem A, Jiang M, Lu W, Lan F, Cui M. Knockout of MYOM1 in human cardiomyocytes leads to myocardial atrophy via impairing calcium homeostasis. J Cell Mol Med 2021; 25:1661-1676. [PMID: 33452765 PMCID: PMC7875908 DOI: 10.1111/jcmm.16268] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 12/14/2020] [Accepted: 12/22/2020] [Indexed: 12/27/2022] Open
Abstract
Myomesin-1 (encoded by MYOM1 gene) is expressed in almost all cross-striated muscles, whose family (together with myomesin-2 and myomesin-3) helps to cross-link adjacent myosin to form the M-line in myofibrils. However, little is known about its biological function, causal relationship and mechanisms underlying the MYOM1-related myopathies (especially in the heart). Regrettably, there is no MYMO1 knockout model for its study so far. A better and further understanding of MYOM1 biology is urgently needed. Here, we used CRISPR/Cas9 gene-editing technology to establish an MYOM1 knockout human embryonic stem cell line (MYOM1-/- hESC), which was then differentiated into myomesin-1 deficient cardiomyocytes (MYOM1-/- hESC-CMs) in vitro. We found that myomesin-1 plays an important role in sarcomere assembly, contractility regulation and cardiomyocytes development. Moreover, myomesin-1-deficient hESC-CMs can recapitulate myocardial atrophy phenotype in vitro. Based on this model, not only the biological function of MYOM1, but also the aetiology, pathogenesis, and potential treatments of myocardial atrophy caused by myomesin-1 deficiency can be studied.
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Affiliation(s)
- Chengwen Hang
- Department of CardiologyPeking University Third HospitalBeijingChina
| | - Yuanxiu Song
- Department of CardiologyPeking University Third HospitalBeijingChina
| | - Ya’nan Li
- Beijing Lab for Cardiovascular Precision MedicineAnzhen HospitalCapital Medical UniversityBeijingChina
| | - Siyao Zhang
- Beijing Lab for Cardiovascular Precision MedicineAnzhen HospitalCapital Medical UniversityBeijingChina
| | - Yun Chang
- Beijing Lab for Cardiovascular Precision MedicineAnzhen HospitalCapital Medical UniversityBeijingChina
| | - Rui Bai
- Beijing Lab for Cardiovascular Precision MedicineAnzhen HospitalCapital Medical UniversityBeijingChina
| | - Amina Saleem
- Beijing Lab for Cardiovascular Precision MedicineAnzhen HospitalCapital Medical UniversityBeijingChina
| | - Mengqi Jiang
- Department of CardiologyPeking University Third HospitalBeijingChina
| | - Wenjing Lu
- Beijing Lab for Cardiovascular Precision MedicineAnzhen HospitalCapital Medical UniversityBeijingChina
| | - Feng Lan
- Beijing Lab for Cardiovascular Precision MedicineAnzhen HospitalCapital Medical UniversityBeijingChina
| | - Ming Cui
- Department of CardiologyPeking University Third HospitalBeijingChina
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21
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Santiago CF, Huttner IG, Fatkin D. Mechanisms of TTNtv-Related Dilated Cardiomyopathy: Insights from Zebrafish Models. J Cardiovasc Dev Dis 2021; 8:jcdd8020010. [PMID: 33504111 PMCID: PMC7912658 DOI: 10.3390/jcdd8020010] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 12/15/2022] Open
Abstract
Dilated cardiomyopathy (DCM) is a common heart muscle disorder characterized by ventricular dilation and contractile dysfunction that is associated with significant morbidity and mortality. New insights into disease mechanisms and strategies for treatment and prevention are urgently needed. Truncating variants in the TTN gene, which encodes the giant sarcomeric protein titin (TTNtv), are the most common genetic cause of DCM, but exactly how TTNtv promote cardiomyocyte dysfunction is not known. Although rodent models have been widely used to investigate titin biology, they have had limited utility for TTNtv-related DCM. In recent years, zebrafish (Danio rerio) have emerged as a powerful alternative model system for studying titin function in the healthy and diseased heart. Optically transparent embryonic zebrafish models have demonstrated key roles of titin in sarcomere assembly and cardiac development. The increasing availability of sophisticated imaging tools for assessment of heart function in adult zebrafish has revolutionized the field and opened new opportunities for modelling human genetic disorders. Genetically modified zebrafish that carry a human A-band TTNtv have now been generated and shown to spontaneously develop DCM with age. This zebrafish model will be a valuable resource for elucidating the phenotype modifying effects of genetic and environmental factors, and for exploring new drug therapies.
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Affiliation(s)
- Celine F. Santiago
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; (C.F.S.); (I.G.H.)
- St. Vincent’s Clinical School, Faculty of Medicine, UNSW Sydney, Kensington, NSW 2052, Australia
| | - Inken G. Huttner
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; (C.F.S.); (I.G.H.)
- St. Vincent’s Clinical School, Faculty of Medicine, UNSW Sydney, Kensington, NSW 2052, Australia
| | - Diane Fatkin
- Molecular Cardiology and Biophysics Division, Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; (C.F.S.); (I.G.H.)
- St. Vincent’s Clinical School, Faculty of Medicine, UNSW Sydney, Kensington, NSW 2052, Australia
- Cardiology Department, St. Vincent’s Hospital, Darlinghurst, NSW 2010, Australia
- Correspondence:
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22
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Understanding the common mechanisms of heart and skeletal muscle wasting in cancer cachexia. Oncogenesis 2021; 10:1. [PMID: 33419963 PMCID: PMC7794402 DOI: 10.1038/s41389-020-00288-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/26/2020] [Accepted: 11/02/2020] [Indexed: 12/12/2022] Open
Abstract
Cachexia is a severe complication of cancer that adversely affects the course of the disease, with currently no effective treatments. It is characterized by a progressive atrophy of skeletal muscle and adipose tissue, resulting in weight loss, a reduced quality of life, and a shortened life expectancy. Although the cachectic condition primarily affects the skeletal muscle, a tissue that accounts for ~40% of total body weight, cachexia is considered a multi-organ disease that involves different tissues and organs, among which the cardiac muscle stands out for its relevance. Patients with cancer often experience severe cardiac abnormalities and manifest symptoms that are indicative of chronic heart failure, including fatigue, shortness of breath, and impaired exercise tolerance. Furthermore, cardiovascular complications are among the major causes of death in cancer patients who experienced cachexia. The lack of effective treatments for cancer cachexia underscores the need to improve our understanding of the underlying mechanisms. Increasing evidence links the wasting of the cardiac and skeletal muscles to metabolic alterations, primarily increased energy expenditure, and to increased proteolysis, ensuing from activation of the major proteolytic machineries of the cell, including ubiquitin-dependent proteolysis and autophagy. This review aims at providing an overview of the key mechanisms of cancer cachexia, with a major focus on those that are shared by the skeletal and cardiac muscles.
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23
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Zheng Y, Lang Y, Qi Z, Gao W, Hu X, Li T. PIK3R1, SPNB2, and CRYAB as Potential Biomarkers for Patients with Diabetes and Developing Acute Myocardial Infarction. Int J Endocrinol 2021; 2021:2267736. [PMID: 34887920 PMCID: PMC8651423 DOI: 10.1155/2021/2267736] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 10/20/2021] [Accepted: 11/12/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Young patients with type 2 diabetes mellitus (DM) and acute myocardial infarction (AMI) have high long-term all-cause and cardiovascular mortality rates. We aimed to investigate the differentially expressed genes (DEGs) that might be potential targets for DM patients with AMI. METHODS Gene datasets GSE775, GSE19322, and GSE97494 were meta-analyzed to obtain DEGs of the left ventricle myocardium in infarcted mice. Gene datasets including GSE3313, GSE10617, and GSE136948 were meta-analyzed to identify DEGs in diabetes mice. A Venn diagram was used to obtain the overlapping DEGs. KEGG and GO pathway analyses were performed, and hub genes were obtained. Pivotal miRNAs were predicted and validated using the miRNA dataset in GSE114695. To investigate the cardiac function of the screened genes, a MI mouse model was constructed; echocardiogram, qPCR, and ELISA of hub genes were performed; ELISA of hub genes in human blood samples was also utilized. RESULTS A total of 67 DEGs were identified, which may be potential biomarkers for patients with DM and AMI. GO and KEGG pathway analyses were performed, which were mainly enriched in response to organic cyclic compound and PI3K-Akt signaling pathway. The expression of PIK3R1 and SPNB2 increased in the MI group and was negatively correlated to left ventricular ejection fraction (LVEF), whereas that of CRYAB decreased and was positively correlated to LVEF. Patients with high CRYAB expression demonstrated a short hospital stay and the area under the curves of the three protein levels before and after treatment were 0.964, 0.982, and 0.918, suggesting that PIK3R1, SPNB2, and CRYAB may be diagnostic and prognostic biomarkers for the diabetes patients with AMI. CONCLUSION The screened hub genes, PIK3R1, SPNB2, and CRYAB, were validated as credible molecular biomarkers and may provide a novel therapy for diabetic cardiac diseases with increased proteotoxic stress.
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Affiliation(s)
- Yue Zheng
- School of Medicine, Nankai University, Tianjin 300071, China
- Nankai University Affiliated Third Center Hospital, No. 83, Jintang Road, Hedong District, Tianjin 300170, China
- The Third Central Clinical College of Tianjin Medical University, Tianjin 300170, China
- The Third Central Hospital of Tianjin, 83 Jintang Road, Hedong District, Tianjin 300170, China
- Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases, Tianjin, China
| | - Yuheng Lang
- The Third Central Clinical College of Tianjin Medical University, Tianjin 300170, China
- The Third Central Hospital of Tianjin, 83 Jintang Road, Hedong District, Tianjin 300170, China
- Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases, Tianjin, China
- Institute of Hepatobiliary Disease, Tianjin, China
| | - Zhenchang Qi
- The Third Central Clinical College of Tianjin Medical University, Tianjin 300170, China
- The Third Central Hospital of Tianjin, 83 Jintang Road, Hedong District, Tianjin 300170, China
- Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases, Tianjin, China
- Institute of Hepatobiliary Disease, Tianjin, China
| | - Wenqing Gao
- The Third Central Clinical College of Tianjin Medical University, Tianjin 300170, China
- The Third Central Hospital of Tianjin, 83 Jintang Road, Hedong District, Tianjin 300170, China
- Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases, Tianjin, China
- Institute of Hepatobiliary Disease, Tianjin, China
| | - Xiaomin Hu
- Nankai University Affiliated Third Center Hospital, No. 83, Jintang Road, Hedong District, Tianjin 300170, China
- The Third Central Clinical College of Tianjin Medical University, Tianjin 300170, China
- The Third Central Hospital of Tianjin, 83 Jintang Road, Hedong District, Tianjin 300170, China
- Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases, Tianjin, China
- Institute of Hepatobiliary Disease, Tianjin, China
| | - Tong Li
- School of Medicine, Nankai University, Tianjin 300071, China
- Nankai University Affiliated Third Center Hospital, No. 83, Jintang Road, Hedong District, Tianjin 300170, China
- The Third Central Clinical College of Tianjin Medical University, Tianjin 300170, China
- The Third Central Hospital of Tianjin, 83 Jintang Road, Hedong District, Tianjin 300170, China
- Tianjin Key Laboratory of Extracorporeal Life Support for Critical Diseases, Tianjin, China
- Institute of Hepatobiliary Disease, Tianjin, China
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24
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Li Y, Hessel AL, Unger A, Ing D, Recker J, Koser F, Freundt JK, Linke WA. Graded titin cleavage progressively reduces tension and uncovers the source of A-band stability in contracting muscle. eLife 2020; 9:64107. [PMID: 33357376 PMCID: PMC7781594 DOI: 10.7554/elife.64107] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 12/23/2020] [Indexed: 12/11/2022] Open
Abstract
The giant muscle protein titin is a major contributor to passive force; however, its role in active force generation is unresolved. Here, we use a novel titin-cleavage (TC) mouse model that allows specific and rapid cutting of elastic titin to quantify how titin-based forces define myocyte ultrastructure and mechanics. We show that under mechanical strain, as TC doubles from heterozygous to homozygous TC muscles, Z-disks become increasingly out of register while passive and active forces are reduced. Interactions of elastic titin with sarcomeric actin filaments are revealed. Strikingly, when titin-cleaved muscles contract, myosin-containing A-bands become split and adjacent myosin filaments move in opposite directions while also shedding myosins. This establishes intact titin filaments as critical force-transmission networks, buffering the forces observed by myosin filaments during contraction. To perform this function, elastic titin must change stiffness or extensible length, unveiling its fundamental role as an activation-dependent spring in contracting muscle.
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Affiliation(s)
- Yong Li
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Anthony L Hessel
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Andreas Unger
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - David Ing
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Jannik Recker
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Franziska Koser
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Johanna K Freundt
- Institute of Physiology II, University of Muenster, Muenster, Germany
| | - Wolfgang A Linke
- Institute of Physiology II, University of Muenster, Muenster, Germany
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25
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Müller T, Boileau E, Talyan S, Kehr D, Varadi K, Busch M, Most P, Krijgsveld J, Dieterich C. Updated and enhanced pig cardiac transcriptome based on long-read RNA sequencing and proteomics. J Mol Cell Cardiol 2020; 150:23-31. [PMID: 33049256 DOI: 10.1016/j.yjmcc.2020.10.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 09/29/2020] [Accepted: 10/05/2020] [Indexed: 12/14/2022]
Abstract
Clinically translatable large animal models have become indispensable for cardiovascular research, clinically relevant proof of concept studies and for novel therapeutic interventions. In particular, the pig has emerged as an essential cardiovascular disease model, because its heart, circulatory system, and blood supply are anatomically and functionally similar to that of humans. Currently, molecular and omics-based studies in the pig are hampered by the incompleteness of the genome and the lack of diversity of the corresponding transcriptome annotation. Here, we employed Nanopore long-read sequencing and in-depth proteomics on top of Illumina RNA-seq to enhance the pig cardiac transcriptome annotation. We assembled 15,926 transcripts, stratified into coding and non-coding, and validated our results by complementary mass spectrometry. A manual review of several gene loci, which are associated with cardiac function, corroborated the utility of our enhanced annotation. All our data are available for download and are provided as tracks for integration in genome browsers. We deem this resource as highly valuable for molecular research in an increasingly relevant large animal model.
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Affiliation(s)
- Torsten Müller
- German Cancer Research Center (DKFZ), Functional and Structural Genomics, Im Neuenheimer Feld 581, 69120 Heidelberg, Germany; Heidelberg University, Medical Faculty, Im Neuenheimer Feld 672, 69120 Heidelberg, Germany
| | - Etienne Boileau
- Section of Bioinformatics and Systems Cardiology, Klaus Tschira Institute for Integrative Computational Cardiology, University Hospital Heidelberg, Heidelberg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Sweta Talyan
- Section of Bioinformatics and Systems Cardiology, Klaus Tschira Institute for Integrative Computational Cardiology, University Hospital Heidelberg, Heidelberg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany
| | - Dorothea Kehr
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Division of Molecular and Translational Cardiology, Department of Internal Medicine III, Heidelberg University Hospital, INF 410, 69120 Heidelberg, Germany
| | - Karl Varadi
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Division of Molecular and Translational Cardiology, Department of Internal Medicine III, Heidelberg University Hospital, INF 410, 69120 Heidelberg, Germany
| | - Martin Busch
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Division of Molecular and Translational Cardiology, Department of Internal Medicine III, Heidelberg University Hospital, INF 410, 69120 Heidelberg, Germany
| | - Patrick Most
- German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany; Division of Molecular and Translational Cardiology, Department of Internal Medicine III, Heidelberg University Hospital, INF 410, 69120 Heidelberg, Germany; Center for Translational Medicine, Jefferson University, 1020 Locust Street, Philadelphia, PA 19107, USA
| | - Jeroen Krijgsveld
- German Cancer Research Center (DKFZ), Functional and Structural Genomics, Im Neuenheimer Feld 581, 69120 Heidelberg, Germany; Heidelberg University, Medical Faculty, Im Neuenheimer Feld 672, 69120 Heidelberg, Germany
| | - Christoph Dieterich
- Section of Bioinformatics and Systems Cardiology, Klaus Tschira Institute for Integrative Computational Cardiology, University Hospital Heidelberg, Heidelberg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, 69120 Heidelberg, Germany.
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26
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Swist S, Unger A, Li Y, Vöge A, von Frieling-Salewsky M, Skärlén Å, Cacciani N, Braun T, Larsson L, Linke WA. Maintenance of sarcomeric integrity in adult muscle cells crucially depends on Z-disc anchored titin. Nat Commun 2020; 11:4479. [PMID: 32900999 PMCID: PMC7478974 DOI: 10.1038/s41467-020-18131-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Accepted: 08/04/2020] [Indexed: 12/14/2022] Open
Abstract
The giant protein titin is thought to be required for sarcomeric integrity in mature myocytes, but direct evidence for this hypothesis is limited. Here, we describe a mouse model in which Z-disc-anchored TTN is depleted in adult skeletal muscles. Inactivation of TTN causes sarcomere disassembly and Z-disc deformations, force impairment, myocyte de-stiffening, upregulation of TTN-binding mechanosensitive proteins and activation of protein quality-control pathways, concomitant with preferential loss of thick-filament proteins. Interestingly, expression of the myosin-bound Cronos-isoform of TTN, generated from an alternative promoter not affected by the targeting strategy, does not prevent deterioration of sarcomere formation and maintenance. Finally, we demonstrate that loss of Z-disc-anchored TTN recapitulates muscle remodeling in critical illness ‘myosinopathy’ patients, characterized by TTN-depletion and loss of thick filaments. We conclude that full-length TTN is required to integrate Z-disc and A-band proteins into the mature sarcomere, a function that is lost when TTN expression is pathologically lowered. Titin is considered an integrator of muscle cell proteins but direct evidence is limited. Here, titin is inactivated in adult mouse muscles, which causes sarcomere disassembly, protein mis-expression and force impairment, recapitulating key alterations in critical illness myopathy patient muscles.
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Affiliation(s)
- Sandra Swist
- Department of Systems Physiology, Ruhr University Bochum, D-44780, Bochum, Germany.
| | - Andreas Unger
- Institute of Physiology II, University of Munster, D-48149, Munster, Germany
| | - Yong Li
- Institute of Physiology II, University of Munster, D-48149, Munster, Germany
| | - Anja Vöge
- Department of Systems Physiology, Ruhr University Bochum, D-44780, Bochum, Germany
| | | | - Åsa Skärlén
- Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institute, SE-171 77, Stockholm, Sweden
| | - Nicola Cacciani
- Department of Physiology and Pharmacology, Karolinska Institute, SE-171 77, Stockholm, Sweden
| | - Thomas Braun
- Department of Cardiac Development and Remodeling, Max Planck Institute for Heart and Lung Research, D-61231, Bad Nauheim, Germany
| | - Lars Larsson
- Department of Physiology and Pharmacology, Karolinska Institute, SE-171 77, Stockholm, Sweden
| | - Wolfgang A Linke
- Institute of Physiology II, University of Munster, D-48149, Munster, Germany.
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27
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Zhang J, Huang X, Wang X, Gao Y, Liu L, Li Z, Chen X, Zeng J, Ye Z, Li G. Identification of potential crucial genes in atrial fibrillation: a bioinformatic analysis. BMC Med Genomics 2020; 13:104. [PMID: 32682418 PMCID: PMC7368672 DOI: 10.1186/s12920-020-00754-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/10/2020] [Indexed: 11/10/2022] Open
Abstract
Background Atrial fibrillation (AF) is at least partially heritable, affecting 2–3% of the population in Europe and the USA. However, a substantial proportion of heritability is still lacking. In the present study, we aim to identify potential crucial genes associated with AF through bioinformatic analyses of public datasets. Methods Microarray data sets of GSE115574, GSE31821, GSE79768, GSE41177 and GSE14975 from the Gene Expression Omnibus (GEO) database were retrieved. After merging all microarray data and adjusting batch effect, differentially expressed genes (DEGs) were identified. Functional enrichment analyses based on Gene Ontology (GO) resource, Kyoto Encyclopedia of Genes and Genomes (KEGG) resource, Gene Set Enrichment Analysis (GSEA), Reactome Pathway Database and Disease Ontology (DO) were carried out. Protein-protein interaction (PPI) network was constructed using the STRING database. Combined with aforementioned significant bioinformatics information, potential crucial genes were subsequently selected. The comparative toxicogenomics database (CTD) was used to explore the interaction between potential crucial genes and AF. Result We identified 27 of DEGs with gene expression fold change (FC) ≥ 1.5 or ≤ 2/3 (|log2 FC| ≥ 0.58) and 5 with FC ≥ 2 or ≤ 0.5 (|log2 FC| ≥ 1) of AF patients compared with sinus rhythm controls. The most significantly enriched pathway was regulation of insulin-like growth factor transport and uptake by insulin-like growth factor binding proteins. IGFBP2, C1orf105, FHL2, CHGB, ATP1B4, IGFBP3, SLC26A9, CXCR4 and HTR2B were considered the potential crucial genes. CTD showed CXCR4, IGFBP2, IGFBP3 and FHL2 had higher scores with AF. Conclusions The 9 potential crucial genes, especially CXCR4, IGFBP2, IGFBP3 and FHL2, may be associated with risk of AF. Our study provided new insights of AF into genetics, molecular pathogenesis and new therapeutic targets.
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Affiliation(s)
- Junguo Zhang
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, Guangdong, China
| | - Xin Huang
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, Guangdong, China
| | - Xiaojie Wang
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, Guangdong, China
| | - Yanhui Gao
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, 510317, Guangdong, China
| | - Li Liu
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, 510317, Guangdong, China
| | - Ziyi Li
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, Guangdong, China
| | - Xuejiao Chen
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, Guangdong, China
| | - Jie Zeng
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, Guangdong, China
| | - Zebing Ye
- Department of Cardiology, Guangdong Second Provincial General Hospital, Guangzhou, 510317, Guangdong, China.
| | - Guowei Li
- Center for Clinical Epidemiology and Methodology (CCEM), Guangdong Second Provincial General Hospital, Guangzhou, 510317, Guangdong, China. .,Department of Health research methods, Evidence, and Impact (HEI), McMaster University, 1280 Main St West, Hamilton, ON, L8S 4L8, Canada.
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28
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Deconstructing sarcomeric structure-function relations in titin-BioID knock-in mice. Nat Commun 2020; 11:3133. [PMID: 32561764 PMCID: PMC7305127 DOI: 10.1038/s41467-020-16929-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 05/27/2020] [Indexed: 12/04/2022] Open
Abstract
Proximity proteomics has greatly advanced the analysis of native protein complexes and subcellular structures in culture, but has not been amenable to study development and disease in vivo. Here, we have generated a knock-in mouse with the biotin ligase (BioID) inserted at titin’s Z-disc region to identify protein networks that connect the sarcomere to signal transduction and metabolism. Our census of the sarcomeric proteome from neonatal to adult heart and quadriceps reveals how perinatal signaling, protein homeostasis and the shift to adult energy metabolism shape the properties of striated muscle cells. Mapping biotinylation sites to sarcomere structures refines our understanding of myofilament dynamics and supports the hypothesis that myosin filaments penetrate Z-discs to dampen contraction. Extending this proof of concept study to BioID fusion proteins generated with Crispr/CAS9 in animal models recapitulating human pathology will facilitate the future analysis of molecular machines and signaling hubs in physiological, pharmacological, and disease context. Titin determines the elasticity of the sarcomere and integrates into both the Z-disc and the M-band. Here, the authors generate a BioID mouse to study the titin interactome at the Z-disc region in neonatal and adult heart and skeletal muscle.
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29
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van der Pijl RJ, Hudson B, Granzier-Nakajima T, Li F, Knottnerus AM, Smith J, Chung CS, Gotthardt M, Granzier HL, Ottenheijm CAC. Deleting Titin's C-Terminal PEVK Exons Increases Passive Stiffness, Alters Splicing, and Induces Cross-Sectional and Longitudinal Hypertrophy in Skeletal Muscle. Front Physiol 2020; 11:494. [PMID: 32547410 PMCID: PMC7274174 DOI: 10.3389/fphys.2020.00494] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 04/23/2020] [Indexed: 12/13/2022] Open
Abstract
The Proline, Glutamate, Valine and Lysine-rich (PEVK) region of titin constitutes an entropic spring that provides passive tension to striated muscle. To study the functional and structural repercussions of a small reduction in the size of the PEVK region, we investigated skeletal muscles of a mouse with the constitutively expressed C-terminal PEVK exons 219-225 deleted, the TtnΔ219-225 model (MGI: TtnTM 2.1Mgot ). Based on this deletion, passive tension in skeletal muscle was predicted to be increased by ∼17% (sarcomere length 3.0 μm). In contrast, measured passive tension (sarcomere length 3.0 μm) in both soleus and EDL muscles was increased 53 ± 11% and 62 ± 4%, respectively. This unexpected increase was due to changes in titin, not to alterations in the extracellular matrix, and is likely caused by co-expression of two titin isoforms in TtnΔ219-225 muscles: a larger isoform that represents the TtnΔ219-225 N2A titin and a smaller isoform, referred to as N2A2. N2A2 represents a splicing adaption with reduced expression of spring element exons, as determined by titin exon microarray analysis. Maximal tetanic tension was increased in TtnΔ219-225 soleus muscle (WT 240 ± 9; TtnΔ219-225 276 ± 17 mN/mm2), but was reduced in EDL muscle (WT 315 ± 9; TtnΔ219-225 280 ± 14 mN/mm2). The changes in active tension coincided with a switch toward slow fiber types and, unexpectedly, faster kinetics of tension generation and relaxation. Functional overload (FO; ablation) and hindlimb suspension (HS; unloading) experiments were also conducted. TtnΔ219-225 mice showed increases in both longitudinal hypertrophy (increased number of sarcomeres in series) and cross-sectional hypertrophy (increased number of sarcomeres in parallel) in response to FO and attenuated cross-sectional atrophy in response to HS. In summary, slow- and fast-twitch muscles in a mouse model devoid of titin's PEVK exons 219-225 have high passive tension, due in part to alterations elsewhere in splicing of titin's spring region, increased kinetics of tension generation and relaxation, and altered trophic responses to both functional overload and unloading. This implicates titin's C-terminal PEVK region in regulating passive and active muscle mechanics and muscle plasticity.
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Affiliation(s)
- Robbert J van der Pijl
- Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States.,Department of Physiology, Amsterdam UMC, Amsterdam, Netherlands
| | - Brian Hudson
- Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States
| | | | - Frank Li
- Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States
| | - Anne M Knottnerus
- Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States
| | - John Smith
- Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States
| | - Charles S Chung
- Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States.,Department of Physiology, Wayne State University, Detroit, MI, United States
| | - Michael Gotthardt
- Max-Delbruck-Center for Molecular Medicine, Berlin, Germany.,Cardiology, Virchow Klinikum, Charité University Medicine, Berlin, Germany
| | - Henk L Granzier
- Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States
| | - Coen A C Ottenheijm
- Cellular and Molecular Medicine, University of Arizona, Tucson, AZ, United States.,Department of Physiology, Amsterdam UMC, Amsterdam, Netherlands
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30
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Azad A, Poloni G, Sontayananon N, Jiang H, Gehmlich K. The giant titin: how to evaluate its role in cardiomyopathies. J Muscle Res Cell Motil 2019; 40:159-167. [PMID: 31147888 PMCID: PMC6726704 DOI: 10.1007/s10974-019-09518-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/28/2019] [Indexed: 01/02/2023]
Abstract
Titin, the largest protein known, has attracted a lot of interest in the cardiovascular field in recent years, since the discovery that truncating variants in titin are commonly found in patients with dilated cardiomyopathy. This review will discuss the contribution of variants in titin to inherited cardiac conditions (cardiomyopathies) and how model systems, such as animals and cellular systems, can help to provide insights into underlying disease mechanisms. It will also give an outlook onto exciting technological developments, such as in the field of CRISPR, which may facilitate future research on titin variants and their contributions to cardiomyopathies.
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Affiliation(s)
- Amar Azad
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, OX3 9DU, UK
- Swansea University Medical School, Swansea, SA2 8PP, UK
| | - Giulia Poloni
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, OX3 9DU, UK
| | - Naeramit Sontayananon
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, OX3 9DU, UK
| | - He Jiang
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, OX3 9DU, UK
| | - Katja Gehmlich
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, OX3 9DU, UK.
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
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31
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Kellermayer D, Smith JE, Granzier H. Titin mutations and muscle disease. Pflugers Arch 2019; 471:673-682. [PMID: 30919088 DOI: 10.1007/s00424-019-02272-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Accepted: 03/11/2019] [Indexed: 12/12/2022]
Abstract
The introduction of next-generation sequencing technology has revealed that mutations in the gene that encodes titin (TTN) are linked to multiple skeletal and cardiac myopathies. The most prominent of these myopathies is dilated cardiomyopathy (DCM). Over 60 genes are linked to the etiology of DCM, but by far, the leading cause of DCM is mutations in TTN with truncating variants in TTN (TTNtvs) associated with familial DCM in ∼ 20% of the cases. Titin is a large (3-4 MDa) and abundant protein that forms the third myofilament type of striated muscle where it spans half the sarcomere, from the Z-disk to the M-line. The underlying mechanisms by which titin mutations induce disease are poorly understood and targeted therapies are not available. Here, we review what is known about TTN mutations in muscle disease, with a major focus on DCM. We highlight that exon skipping might provide a possible therapeutic avenue to address diseases that arise from TTNtvs.
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Affiliation(s)
- Dalma Kellermayer
- Department of Cellular and Molecular Medicine, University of Arizona, MRB 325. 1656 E Mabel Street, Tucson, AZ, 85724-5217, USA.,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ, 85721, USA
| | - John E Smith
- Department of Cellular and Molecular Medicine, University of Arizona, MRB 325. 1656 E Mabel Street, Tucson, AZ, 85724-5217, USA.,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ, 85721, USA
| | - Henk Granzier
- Department of Cellular and Molecular Medicine, University of Arizona, MRB 325. 1656 E Mabel Street, Tucson, AZ, 85724-5217, USA. .,Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ, 85721, USA.
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