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Cazzato F, Coll M, Grassi S, Fernàndez-Falgueras A, Nogué-Navarro L, Iglesias A, Castellà J, Oliva A, Brugada R. Investigating cardiac genetic background in sudden infant death syndrome (SIDS). Int J Legal Med 2024:10.1007/s00414-024-03264-6. [PMID: 38849547 DOI: 10.1007/s00414-024-03264-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 05/30/2024] [Indexed: 06/09/2024]
Abstract
Sudden infant death syndrome (SIDS) is still the leading cause of death for newborns in developed countries. The pathophysiological mechanisms have not been fully clarified, but in some of SIDS cases variants of genes associated with inherited cardiac conditions are found. In this study, an analysis of SCD-related genes was performed to determine the prevalence of rare pathogenic (P) or likely pathogenic (LP) variants that could provide an unambiguous explanation for the fatal event. A cohort of 76 SIDS cases underwent Next-Generation Sequencing (NGS) analysis with a custom panel of SCD-related genes. Rare variants were classified according to the guidelines provided by the American College of Medical Genetics and Genomics (ACMG) and the specifications of the ClinGen association. Post-mortem genetic testing identified 50 (65.8%) carriers of at least one variant in SCD genes. 104 rare genetic variants were found, 65.4% in genes encoding structural proteins. Only 4 out of 76 cases (5.3%) hosted at least a P or LP variant found in genes with structural or structural/arrhythmogenic functions (SLC22A5, SCN5A, MYL3and TTN). 99 variants were classified as of uncertain significance (VUS). The difference in the distribution of variants between gene groups by function was not statistically significant (chi square, p = 0,219). Despite this, most of the variants concerned structural genes that were supposed to have a close interaction with ion channels, thus providing an explanation for the arrhythmic event. Segregation analysis, reclassification of VUS variants and identification of new associated genes could clarify the implications of the current findings.
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Affiliation(s)
- Francesca Cazzato
- Department of Health Surveillance and Bioethics, Section of Legal Medicine, Fondazione Policlinico A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
| | - Mònica Coll
- Cardiovascular Genetics Centre, University of Girona-IDIBGI, 17190, Salt, Spain
| | - Simone Grassi
- Department of Health Sciences, Section of Forensic Medical Sciences, University of Florence, Largo Brambilla 3, 50134, Florence, Italy.
| | | | - Laia Nogué-Navarro
- Faculty of Medicine, University of Vic-Central University of Catalonia (UVic-UCC), Vic 08500, Can Baumann, Spain
| | - Anna Iglesias
- Cardiovascular Genetics Centre, University of Girona-IDIBGI, 17190, Salt, Spain
| | - Josep Castellà
- Forensic Pathology Service, Institut Medicina Legal Ciències Mèdiques Catalunya, Barcelona, Spain
| | - Antonio Oliva
- Department of Health Surveillance and Bioethics, Section of Legal Medicine, Fondazione Policlinico A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, 00168, Rome, Italy
| | - Ramon Brugada
- Cardiovascular Genetics Centre, University of Girona-IDIBGI, 17190, Salt, Spain
- Cardiology Department, Hospital Universitari Doctor Josep Trueta, 17003, Girona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), 28029, Madrid, Spain
- Medical Science Department, School of Medicine, University of Girona, 17003, Girona, Spain
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2
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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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3
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Weston TGR, Rees M, Gautel M, Fraternali F. Walking with giants: The challenges of variant impact assessment in the giant sarcomeric protein titin. WIREs Mech Dis 2024; 16:e1638. [PMID: 38155593 DOI: 10.1002/wsbm.1638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 12/01/2023] [Accepted: 12/04/2023] [Indexed: 12/30/2023]
Abstract
Titin, the so-called "third filament" of the sarcomere, represents a difficult challenge for the determination of damaging genetic variants. A single titin molecule extends across half the length of a sarcomere in striated muscle, fulfilling a variety of vital structural and signaling roles, and has been linked to an equally varied range of myopathies, resulting in a significant burden on individuals and healthcare systems alike. While the consequences of truncating variants of titin are well-documented, the ramifications of the missense variants prevalent in the general population are less so. We here present a compendium of titin missense variants-those that result in a single amino-acid substitution in coding regions-reported to be pathogenic and discuss these in light of the nature of titin and the variant position within the sarcomere and their domain, the structural, pathological, and biophysical characteristics that define them, and the methods used for characterization. Finally, we discuss the current knowledge and integration of the multiple fields that have contributed to our understanding of titin-related pathology and offer suggestions as to how these concurrent methodologies may aid the further development in our understanding of titin and hopefully extend to other, less well-studied giant proteins. This article is categorized under: Cardiovascular Diseases > Genetics/Genomics/Epigenetics Congenital Diseases > Genetics/Genomics/Epigenetics Congenital Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Timir G R Weston
- Randall Centre for Cell & Molecular Biophysics, King's College London, London, UK
| | - Martin Rees
- Randall Centre for Cell & Molecular Biophysics, King's College London, London, UK
| | - Mathias Gautel
- Randall Centre for Cell & Molecular Biophysics, King's College London, London, UK
| | - Franca Fraternali
- Institute of Structural and Molecular Biology, University College London, London, UK
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4
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Dratch L, Bardakjian TM, Johnson K, Babaian N, Gonzalez-Alegre P, Elman L, Quinn C, Guo MH, Scherer SS, Amado DA. The Importance of Offering Exome or Genome Sequencing in Adult Neuromuscular Clinics. BIOLOGY 2024; 13:93. [PMID: 38392311 PMCID: PMC10886886 DOI: 10.3390/biology13020093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 01/29/2024] [Accepted: 01/30/2024] [Indexed: 02/24/2024]
Abstract
Advances in gene-specific therapeutics for patients with neuromuscular disorders (NMDs) have brought increased attention to the importance of genetic diagnosis. Genetic testing practices vary among adult neuromuscular clinics, with multi-gene panel testing currently being the most common approach; follow-up testing using broad-based methods, such as exome or genome sequencing, is less consistently offered. Here, we use five case examples to illustrate the unique ability of broad-based testing to improve diagnostic yield, resulting in identification of SORD-neuropathy, HADHB-related disease, ATXN2-ALS, MECP2 related progressive gait decline and spasticity, and DNMT1-related cerebellar ataxia, deafness, narcolepsy, and hereditary sensory neuropathy type 1E. We describe in each case the technological advantages that enabled identification of the causal gene, and the resultant clinical and personal implications for the patient, demonstrating the importance of offering exome or genome sequencing to adults with NMDs.
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Affiliation(s)
- Laynie Dratch
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tanya M Bardakjian
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Sarepta Therapeutics Inc., Cambridge, MA 02142, USA
| | - Kelsey Johnson
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nareen Babaian
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Pedro Gonzalez-Alegre
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
- Spark Therapeutics, Inc., Philadelphia, PA 19104, USA
| | - Lauren Elman
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Colin Quinn
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael H Guo
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Steven S Scherer
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Defne A Amado
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
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5
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Qi T, Zhang J, Zhang K, Zhang W, Song Y, Lian K, Kan C, Han F, Hou N, Sun X. Unraveling the role of the FHL family in cardiac diseases: Mechanisms, implications, and future directions. Biochem Biophys Res Commun 2024; 694:149468. [PMID: 38183876 DOI: 10.1016/j.bbrc.2024.149468] [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: 11/07/2023] [Revised: 12/23/2023] [Accepted: 01/02/2024] [Indexed: 01/08/2024]
Abstract
Heart diseases are a major cause of morbidity and mortality worldwide. Understanding the molecular mechanisms underlying these diseases is essential for the development of effective diagnostic and therapeutic strategies. The FHL family consists of five members: FHL1, FHL2, FHL3, FHL4, and FHL5/Act. These members exhibit different expression patterns in various tissues including the heart. FHL family proteins are implicated in cardiac remodeling, regulation of metabolic enzymes, and cardiac biomechanical stress perception. A large number of studies have explored the link between FHL family proteins and cardiac disease, skeletal muscle disease, and ovarian metabolism, but a comprehensive and in-depth understanding of the specific molecular mechanisms targeting FHL on cardiac disease is lacking. The aim of this review is to explore the structure and function of FHL family members, to comprehensively elucidate the mechanisms by which they regulate the heart, and to explore in depth the changes in FHL family members observed in different cardiac disorders, as well as the effects of mutations in FHL proteins on heart health.
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Affiliation(s)
- Tongbing Qi
- Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Clinical Research Center, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China
| | - Jingwen Zhang
- Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Clinical Research Center, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China
| | - Kexin Zhang
- Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Clinical Research Center, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China
| | - Wenqiang Zhang
- Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Clinical Research Center, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Department of Pathology, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China
| | - Yixin Song
- Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Clinical Research Center, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China
| | - Kexin Lian
- Department of Nephrology, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China
| | - Chengxia Kan
- Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Clinical Research Center, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China
| | - Fang Han
- Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Clinical Research Center, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Department of Pathology, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China
| | - Ningning Hou
- Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China.
| | - Xiaodong Sun
- Department of Endocrinology and Metabolism, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China; Clinical Research Center, Affiliated Hospital of Weifang Medical University, Weifang, 261031, China.
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6
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Aboonabi A, McCauley MD. Myofilament dysfunction in diastolic heart failure. Heart Fail Rev 2024; 29:79-93. [PMID: 37837495 PMCID: PMC10904515 DOI: 10.1007/s10741-023-10352-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/18/2023] [Indexed: 10/16/2023]
Abstract
Diastolic heart failure (DHF), in which impaired ventricular filling leads to typical heart failure symptoms, represents over 50% of all heart failure cases and is linked with risk factors, including metabolic syndrome, hypertension, diabetes, and aging. A substantial proportion of patients with this disorder maintain normal left ventricular systolic function, as assessed by ejection fraction. Despite the high prevalence of DHF, no effective therapeutic agents are available to treat this condition, partially because the molecular mechanisms of diastolic dysfunction remain poorly understood. As such, by focusing on the underlying molecular and cellular processes contributing to DHF can yield new insights that can represent an exciting new avenue and propose a novel therapeutic approach for DHF treatment. This review discusses new developments from basic and clinical/translational research to highlight current knowledge gaps, help define molecular determinants of diastolic dysfunction, and clarify new targets for treatment.
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Affiliation(s)
- Anahita Aboonabi
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago, 840 S. Wood St., 920S (MC 715), Chicago, IL, 60612, USA.
- Jesse Brown VA Medical Center, Chicago, IL, USA.
| | - Mark D McCauley
- Division of Cardiology, Department of Medicine, College of Medicine, University of Illinois at Chicago, 840 S. Wood St., 920S (MC 715), Chicago, IL, 60612, USA.
- Jesse Brown VA Medical Center, Chicago, IL, USA.
- Department of Physiology and Biophysics and the Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.
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7
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Banga S, Cardoso R, Castellani C, Srivastava S, Watkins J, Lima J. Cardiac MRI as an Imaging Tool in Titin Variant-Related Dilated Cardiomyopathy. CARDIOVASCULAR REVASCULARIZATION MEDICINE 2023; 52:86-93. [PMID: 36934006 DOI: 10.1016/j.carrev.2023.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 02/05/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023]
Abstract
Dilated Cardiomyopathy is a common myocardial disease characterized by dilation and loss of function of one or both ventricles. A variety of etiologies have been implicated including genetic variation. Advancement in genetic sequencing, and diagnostic imaging allows for detection of genetic mutations in sarcomere protein titin (TTN) and high resolution assessment of cardiac function. This review article discusses the role of cardiac MRI in diagnosing dilated cardiomyopathy in patients with TTN variant related cardiomyopathy.
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Affiliation(s)
- Sandeep Banga
- Division of Cardiology, Michigan State University, Sparrow Hospital, Lansing, MI, USA.
| | | | - Carson Castellani
- Division of Internal Medicine, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Shaurya Srivastava
- Division of Internal Medicine, Michigan State University, Lansing, MI, USA
| | - Jennifer Watkins
- Division of Cardiology, Michigan State University, Sparrow Hospital, Lansing, MI, USA
| | - Joao Lima
- Division of Cardiology, Johns Hopkins University, Baltimore, MD, USA
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8
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Xu Y, Ma Q, Ren J, Chen L, Guo W, Feng K, Zeng Z, Huang T, Cai Y. Using Machine Learning Methods in Identifying Genes Associated with COVID-19 in Cardiomyocytes and Cardiac Vascular Endothelial Cells. Life (Basel) 2023; 13:life13041011. [PMID: 37109540 PMCID: PMC10146712 DOI: 10.3390/life13041011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/02/2023] [Accepted: 04/08/2023] [Indexed: 04/29/2023] Open
Abstract
Corona Virus Disease 2019 (COVID-19) not only causes respiratory system damage, but also imposes strain on the cardiovascular system. Vascular endothelial cells and cardiomyocytes play an important role in cardiac function. The aberrant expression of genes in vascular endothelial cells and cardiomyocytes can lead to cardiovascular diseases. In this study, we sought to explain the influence of respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on the gene expression levels of vascular endothelial cells and cardiomyocytes. We designed an advanced machine learning-based workflow to analyze the gene expression profile data of vascular endothelial cells and cardiomyocytes from patients with COVID-19 and healthy controls. An incremental feature selection method with a decision tree was used in building efficient classifiers and summarizing quantitative classification genes and rules. Some key genes, such as MALAT1, MT-CO1, and CD36, were extracted, which exert important effects on cardiac function, from the gene expression matrix of 104,182 cardiomyocytes, including 12,007 cells from patients with COVID-19 and 92,175 cells from healthy controls, and 22,438 vascular endothelial cells, including 10,812 cells from patients with COVID-19 and 11,626 cells from healthy controls. The findings reported in this study may provide insights into the effect of COVID-19 on cardiac cells and further explain the pathogenesis of COVID-19, and they may facilitate the identification of potential therapeutic targets.
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Affiliation(s)
- Yaochen Xu
- Department of Mathematics, School of Sciences, Shanghai University, Shanghai 200444, China
| | - Qinglan Ma
- School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Jingxin Ren
- School of Life Sciences, Shanghai University, Shanghai 200444, China
| | - Lei Chen
- College of Information Engineering, Shanghai Maritime University, Shanghai 201306, China
| | - Wei Guo
- Key Laboratory of Stem Cell Biology, Shanghai Jiao Tong University School of Medicine (SJTUSM) & Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS), Shanghai 200030, China
| | - Kaiyan Feng
- Department of Computer Science, Guangdong AIB Polytechnic College, Guangzhou 510507, China
| | - Zhenbing Zeng
- Department of Mathematics, School of Sciences, Shanghai University, Shanghai 200444, China
| | - Tao Huang
- Bio-Med Big Data Center, CAS Key Laboratory of Computational Biology, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
- CAS Key Laboratory of Tissue Microenvironment and Tumor, Shanghai Institute of Nutrition and Health, University of Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Yudong Cai
- Department of Mathematics, School of Sciences, Shanghai University, Shanghai 200444, China
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9
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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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10
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Noureddine M, Gehmlich K. Structural and signaling proteins in the Z-disk and their role in cardiomyopathies. Front Physiol 2023; 14:1143858. [PMID: 36935760 PMCID: PMC10017460 DOI: 10.3389/fphys.2023.1143858] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/21/2023] [Indexed: 03/06/2023] Open
Abstract
The sarcomere is the smallest functional unit of muscle contraction. It is delineated by a protein-rich structure known as the Z-disk, alternating with M-bands. The Z-disk anchors the actin-rich thin filaments and plays a crucial role in maintaining the mechanical stability of the cardiac muscle. A multitude of proteins interact with each other at the Z-disk and they regulate the mechanical properties of the thin filaments. Over the past 2 decades, the role of the Z-disk in cardiac muscle contraction has been assessed widely, however, the impact of genetic variants in Z-disk proteins has still not been fully elucidated. This review discusses the various Z-disk proteins (alpha-actinin, filamin C, titin, muscle LIM protein, telethonin, myopalladin, nebulette, and nexilin) and Z-disk-associated proteins (desmin, and obscurin) and their role in cardiac structural stability and intracellular signaling. This review further explores how genetic variants of Z-disk proteins are linked to inherited cardiac conditions termed cardiomyopathies.
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Affiliation(s)
- Maya Noureddine
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Katja Gehmlich
- Institute of Cardiovascular Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford, United Kingdom
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11
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Wang Y, Zhang C, Ji C, Jin W, He X, Yu S, Guo R. Molecular subtypes based on cuproptosis-related genes and immune profiles in lung adenocarcinoma. Front Genet 2022; 13:1006938. [PMID: 36313439 PMCID: PMC9597639 DOI: 10.3389/fgene.2022.1006938] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 09/29/2022] [Indexed: 07/21/2024] Open
Abstract
Background: Recent studies have identified several molecular subtypes of lung adenocarcinoma (LUAD) that have different prognoses to help predict the efficacy of immunotherapy. However, the prognostic prediction is less than satisfactory. Alterations in intracellular copper levels may affect the tumor immune microenvironment and are linked to cancer progression. Previous studies have identified some genes related to cuproptosis. The characteristics of the cuproptosis molecular subtypes have not been thoroughly studied in LUAD. Methods: The transcriptomic data and clinical information of 632 LUAD patients were used to investigate the LUAD molecular subtypes that are associated with the cuproptosis-related genes (CRGs), the tumor immune microenvironment, and stemness. The cuproptosis score was constructed using univariate Cox regression and the minor absolute shrinkage and selection operator (LASSO) to quantify the prognostic characteristics. Results: Three different molecular subtypes related to cuproptosis, with different prognoses, were identified in LUAD. Cluster A had the highest cuproptosis score and the worst prognosis. Patients in the high cuproptosis score group had a higher somatic mutation frequency and stemness scores. Patients in the low cuproptosis score group had more immune infiltration and better prognosis. Conclusion: Molecular subtypes of LUAD based on CRGs reflect the differences in LUAD patients. The cuproptosis score can be used as a promising biomarker, which is of great significance to distinguish the relationship between cuproptosis and the immune microenvironment. The cuproptosis signature based on the cuproptosis score and clinical characteristics of individual patients will be useful for guiding immunotherapy in LUAD.
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Affiliation(s)
- Yufei Wang
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, Zhejiang, China
| | - Chen Zhang
- Jiangsu Province Hospital and Nanjing Medical University First Affiliated Hospital, Nanjing, Jiangsu, China
| | - Chengyue Ji
- Jiangsu Province Hospital and Nanjing Medical University First Affiliated Hospital, Nanjing, Jiangsu, China
| | - Wenli Jin
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, Zhejiang, China
| | - Xin He
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining, Zhejiang, China
| | - Shunzhi Yu
- Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Renhua Guo
- Jiangsu Province Hospital and Nanjing Medical University First Affiliated Hospital, Nanjing, Jiangsu, China
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12
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Averdunk L, Donkervoort S, Horn D, Waldmüller S, Syeda S, Neuhaus SB, Chao KR, van Riesen A, Gauck D, Haack T, Japp AS, Lee U, Bönnemann CG, Mayatepek E, Distelmaier F. Recognizable Pattern of Arthrogryposis and Congenital Myopathy Caused by the Recurrent TTN Metatranscript-only c.39974-11T > G Splice Variant. Neuropediatrics 2022; 53:309-320. [PMID: 35605965 DOI: 10.1055/a-1859-0800] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
INTRODUCTION Arthrogryposis is characterized by the presence of multiple contractures at birth and can be caused by pathogenic variants in TTN (Titin). Exons and variants that are not expressed in one of the three major isoforms of titin are referred to as "metatranscript-only" and have been considered to be only expressed during fetal development. Recently, the metatranscript-only variant (c.39974-11T > G) in TTN with a second truncating TTN variant has been linked to arthrogryposis multiplex congenita and myopathy. METHODS Via exome sequencing we identified the TTN c.39974-11T > G splice variant in trans with one of three truncating variants (p.Arg8922*, p.Lys32998Asnfs*63, p.Tyr10345*) in five individuals from three families. Clinical presentation and muscle ultrasound as well as MRI images were analyzed. RESULTS All five patients presented with generalized muscular hypotonia, reduced muscle bulk, and congenital contractures most prominently affecting the upper limbs and distal joints. Muscular hypotonia persisted and contractures improved over time. One individual, the recipient twin in the setting of twin-to-twin transfusion syndrome, died from severe cardiac hypertrophy 1 day after birth. Ultrasound and MRI imaging studies revealed a recognizable pattern of muscle involvement with striking fibrofatty involvement of the hamstrings and calves, and relative sparing of the femoral adductors and anterior segment of the thighs. CONCLUSION The recurrent TTN c.39974-11T > G variant consistently causes congenital arthrogryposis and persisting myopathy providing evidence that the metatranscript-only 213 to 217 exons impact muscle elasticity during early development and beyond. There is a recognizable pattern of muscle involvement, which is distinct from other myopathies and provides valuable clues for diagnostic work-up.
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Affiliation(s)
- Luisa Averdunk
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, University Hospital, Düsseldorf, Germany
| | - Sandra Donkervoort
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States
| | - Denise Horn
- Institute of Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Stephan Waldmüller
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Safoora Syeda
- Institute of Medical Genetics and Human Genetics, Charité-Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Sarah B Neuhaus
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States
| | - Katherine R Chao
- Center for Mendelian Genomics, Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts, United States
| | - Anne van Riesen
- Center for Chronically Sick Children, Charité - Universitätsmedizin Berlin, Berlin, Germany.,Department of Pediatric Neurology, University Medical Center Göttingen, Göttingen, Germany
| | - Darja Gauck
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Tobias Haack
- Institute of Medical Genetics and Applied Genomics, University of Tuebingen, Tuebingen, Germany
| | - Anna S Japp
- Institute of Pathology, University Hospital Düsseldorf, Düsseldorf, Germany
| | - Unaa Lee
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, University Hospital, Düsseldorf, Germany
| | - Carsten G Bönnemann
- Neuromuscular and Neurogenetic Disorders of Childhood Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, United States
| | - Ertan Mayatepek
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, University Hospital, Düsseldorf, Germany
| | - Felix Distelmaier
- Department of General Pediatrics, Neonatology and Pediatric Cardiology, Medical Faculty, Heinrich-Heine-University, University Hospital, Düsseldorf, Germany
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Array Comparative Genomic Hybridisation and Droplet Digital PCR Uncover Recurrent Copy Number Variation of the TTN Segmental Duplication Region. Genes (Basel) 2022; 13:genes13050905. [PMID: 35627290 PMCID: PMC9142044 DOI: 10.3390/genes13050905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/13/2022] [Accepted: 05/17/2022] [Indexed: 02/04/2023] Open
Abstract
Intragenic segmental duplication regions are potential hotspots for recurrent copy number variation and possible pathogenic aberrations. Two large sarcomeric genes, nebulin and titin, both contain such segmental duplication regions. Using our custom Comparative Genomic Hybridisation array, we have previously shown that a gain or loss of more than one copy of the repeated block of the nebulin triplicate region constitutes a recessive pathogenic mutation. Using targeted array-CGH, similar copy number variants can be detected in the segmental duplication region of titin. Due to the limitations of the array-CGH methodology and the repetitiveness of the region, the exact copy numbers of the blocks could not be determined. Therefore, we developed complementary custom Droplet Digital PCR assays for the titin segmental duplication region to confirm true variation. Our combined methods show that the titin segmental duplication region is subject to recurrent copy number variation. Gains and losses were detected in samples from healthy individuals as well as in samples from patients with different muscle disorders. The copy number variation observed in our cohort is likely benign, but pathogenic copy number variants in the segmental duplication region of titin cannot be excluded. Further investigations are needed, however, this region should no longer be neglected in genetic analyses.
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Barbosa-Gouveia S, Vázquez-Mosquera ME, González-Vioque E, Hermida-Ameijeiras Á, Sánchez-Pintos P, de Castro MJ, León SR, Gil-Fournier B, Domínguez-González C, Camacho Salas A, Negrão L, Fineza I, Laranjeira F, Couce ML. Rapid Molecular Diagnosis of Genetically Inherited Neuromuscular Disorders Using Next-Generation Sequencing Technologies. J Clin Med 2022; 11:jcm11102750. [PMID: 35628876 PMCID: PMC9143479 DOI: 10.3390/jcm11102750] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/13/2022] [Accepted: 05/09/2022] [Indexed: 02/07/2023] Open
Abstract
Neuromuscular diseases are genetically highly heterogeneous, and differential diagnosis can be challenging. Over a 3-year period, we prospectively analyzed 268 pediatric and adult patients with a suspected diagnosis of inherited neuromuscular disorder (INMD) using comprehensive gene-panel analysis and next-generation sequencing. The rate of diagnosis increased exponentially with the addition of genes to successive versions of the INMD panel, from 31% for the first iteration (278 genes) to 40% for the last (324 genes). The global mean diagnostic rate was 36% (97/268 patients), with a diagnostic turnaround time of 4–6 weeks. Most diagnoses corresponded to muscular dystrophies/myopathies (68.37%) and peripheral nerve diseases (22.45%). The most common causative genes, TTN, RYR1, and ANO5, accounted for almost 30% of the diagnosed cases. Finally, we evaluated the utility of the differential diagnosis tool Phenomizer, which established a correlation between the phenotype and molecular findings in 21% of the diagnosed patients. In summary, comprehensive gene-panel analysis of all genes implicated in neuromuscular diseases facilitates a rapid diagnosis and provides a high diagnostic yield.
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Affiliation(s)
- Sofia Barbosa-Gouveia
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Paediatrics, Santiago de Compostela University Clinical Hospital, 15704 Santiago de Compostela, Spain; (M.E.V.-M.); (Á.H.-A.); (P.S.-P.); (M.J.d.C.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IDIS-Health Research Institute of Santiago de Compostela, Santiago de Compostela University Clinical Hospital, European Reference Network for Hereditary Metabolic Disorders (MetabERN), 15704 Santiago de Compostela, Spain
- Correspondence: (S.B.-G.); (M.L.C.); Tel.: +34-981-950-151 (M.L.C.)
| | - Maria Eugenia Vázquez-Mosquera
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Paediatrics, Santiago de Compostela University Clinical Hospital, 15704 Santiago de Compostela, Spain; (M.E.V.-M.); (Á.H.-A.); (P.S.-P.); (M.J.d.C.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IDIS-Health Research Institute of Santiago de Compostela, Santiago de Compostela University Clinical Hospital, European Reference Network for Hereditary Metabolic Disorders (MetabERN), 15704 Santiago de Compostela, Spain
| | - Emiliano González-Vioque
- Department of Clinical Biochemistry, Puerta de Hierro-Majadahonda University Hospital, 28222 Majadahonda, Spain;
| | - Álvaro Hermida-Ameijeiras
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Paediatrics, Santiago de Compostela University Clinical Hospital, 15704 Santiago de Compostela, Spain; (M.E.V.-M.); (Á.H.-A.); (P.S.-P.); (M.J.d.C.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IDIS-Health Research Institute of Santiago de Compostela, Santiago de Compostela University Clinical Hospital, European Reference Network for Hereditary Metabolic Disorders (MetabERN), 15704 Santiago de Compostela, Spain
| | - Paula Sánchez-Pintos
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Paediatrics, Santiago de Compostela University Clinical Hospital, 15704 Santiago de Compostela, Spain; (M.E.V.-M.); (Á.H.-A.); (P.S.-P.); (M.J.d.C.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IDIS-Health Research Institute of Santiago de Compostela, Santiago de Compostela University Clinical Hospital, European Reference Network for Hereditary Metabolic Disorders (MetabERN), 15704 Santiago de Compostela, Spain
| | - Maria José de Castro
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Paediatrics, Santiago de Compostela University Clinical Hospital, 15704 Santiago de Compostela, Spain; (M.E.V.-M.); (Á.H.-A.); (P.S.-P.); (M.J.d.C.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IDIS-Health Research Institute of Santiago de Compostela, Santiago de Compostela University Clinical Hospital, European Reference Network for Hereditary Metabolic Disorders (MetabERN), 15704 Santiago de Compostela, Spain
| | - Soraya Ramiro León
- Genetics Department, Hospital Universitario de Getafe, 28905 Madrid, Spain; (S.R.L.); (B.G.-F.)
| | - Belén Gil-Fournier
- Genetics Department, Hospital Universitario de Getafe, 28905 Madrid, Spain; (S.R.L.); (B.G.-F.)
| | - Cristina Domínguez-González
- Neuromuscular Unit, Imas12 Research Institute, Hospital Universitario 12 de Octubre, 28041 Madrid, Spain;
- Center for Biomedical Network Research On Rare Diseases (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Ana Camacho Salas
- Pediatric Neurology Unit, Hospital Universitario 12 de Octubre, Complutense University of Madrid, 28041 Madrid, Spain;
| | - Luis Negrão
- Neuromuscular Diseases Unit, Neurology Service, Centro Hospitalar e Universitário de Coimbra, 3000-075 Coimbra, Portugal;
| | - Isabel Fineza
- Pediatric Neurology Department, Child Developmental Center, Hospital Pediátrico, Centro Hospitalar e Universitário de Coimbra Coimbra Portugal, 3000-075 Coimbra, Portugal;
| | - Francisco Laranjeira
- Biochemical Genetics Unit, Centro de Genética Médica Doutor Jacinto Magalhães, 4050-466 Porto, Portugal;
| | - Maria Luz Couce
- Unit of Diagnosis and Treatment of Congenital Metabolic Diseases, Department of Paediatrics, Santiago de Compostela University Clinical Hospital, 15704 Santiago de Compostela, Spain; (M.E.V.-M.); (Á.H.-A.); (P.S.-P.); (M.J.d.C.)
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), IDIS-Health Research Institute of Santiago de Compostela, Santiago de Compostela University Clinical Hospital, European Reference Network for Hereditary Metabolic Disorders (MetabERN), 15704 Santiago de Compostela, Spain
- Correspondence: (S.B.-G.); (M.L.C.); Tel.: +34-981-950-151 (M.L.C.)
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15
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Navarro AM, Orti F, Martínez-Pérez E, Alonso M, Simonetti FL, Iserte JA, Marino-Buslje C. DisPhaseDB: an integrative database of diseases related variations in liquid-liquid phase separation proteins. Comput Struct Biotechnol J 2022; 20:2551-2557. [PMID: 35685370 PMCID: PMC9156858 DOI: 10.1016/j.csbj.2022.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/03/2022] [Accepted: 05/03/2022] [Indexed: 11/29/2022] Open
Abstract
Phase separation proteins involved in membraneless organelles are increasingly implicated in several complex human diseases. DisPhaseDB integrates ten repositories for analyzing clinically relevant mutations in phase separation proteins. Contains over a million disease-related mutations mapped onto the protein sequences along with extensive metadata. It is a comprehensive meta-database, implemented in an user-friendly web with visualization tools and downloadable datasets. DisPhaseDB will contribute deciphering still not fully understood human disease mechanisms under the lens of phase separation.
Motivation Proteins involved in liquid–liquid phase separation (LLPS) and membraneless organelles (MLOs) are recognized to be decisive for many biological processes and also responsible for several diseases. The recent explosion of research in the area still lacks tools for the analysis and data integration among different repositories. Currently, there is not a comprehensive and dedicated database that collects all disease-related variations in combination with the protein location, biological role in the MLO, and all the metadata available for each protein and disease. Disease-related protein variants and additional features are dispersed and the user has to navigate many databases, with a different focus, formats, and often not user friendly. Results We present DisPhaseDB, a database dedicated to disease-related variants of liquid–liquid phase separation proteins. It integrates 10 databases, contains 5,741 proteins, 1,660,059 variants, and 4,051 disease terms. It also offers intuitive navigation and an informative display. It constitutes a pivotal starting point for further analysis, encouraging the development of new computational tools. The database is freely available at http://disphasedb.leloir.org.ar.
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16
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In vivo identification and validation of novel potential predictors for human cardiovascular diseases. PLoS One 2021; 16:e0261572. [PMID: 34919578 PMCID: PMC8682894 DOI: 10.1371/journal.pone.0261572] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 12/03/2021] [Indexed: 12/30/2022] Open
Abstract
Genetics crucially contributes to cardiovascular diseases (CVDs), the global leading cause of death. Since the majority of CVDs can be prevented by early intervention there is a high demand for the identification of predictive causative genes. While genome wide association studies (GWAS) correlate genes and CVDs after diagnosis and provide a valuable resource for such causative candidate genes, often preferentially those with previously known or suspected function are addressed further. To tackle the unaddressed blind spot of understudied genes, we particularly focused on the validation of human heart phenotype-associated GWAS candidates with little or no apparent connection to cardiac function. Building on the conservation of basic heart function and underlying genetics from fish to human we combined CRISPR/Cas9 genome editing of the orthologs of human GWAS candidates in isogenic medaka with automated high-throughput heart rate analysis. Our functional analyses of understudied human candidates uncovered a prominent fraction of heart rate associated genes from adult human patients impacting on the heart rate in embryonic medaka already in the injected generation. Following this pipeline, we identified 16 GWAS candidates with potential diagnostic and predictive power for human CVDs.
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17
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Soetkamp D, Gallet R, Parker SJ, Holewinski R, Venkatraman V, Peck K, Goldhaber JI, Marbán E, Van Eyk JE. Myofilament Phosphorylation in Stem Cell Treated Diastolic Heart Failure. Circ Res 2021; 129:1125-1140. [PMID: 34641704 DOI: 10.1161/circresaha.119.316311] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
RATIONALE Phosphorylation of sarcomeric proteins has been implicated in heart failure with preserved ejection fraction (HFpEF); such changes may contribute to diastolic dysfunction by altering contractility, cardiac stiffness, Ca2+-sensitivity, and mechanosensing. Treatment with cardiosphere-derived cells (CDCs) restores normal diastolic function, attenuates fibrosis and inflammation, and improves survival in a rat HFpEF model. OBJECTIVE Phosphorylation changes that underlie HFpEF and those reversed by CDC therapy, with a focus on the sarcomeric subproteome were analyzed. METHODS AND RESULTS Dahl salt-sensitive rats fed a high-salt diet, with echocardiographically verified diastolic dysfunction, were randomly assigned to either intracoronary CDCs or placebo. Dahl salt-sensitive rats receiving low salt diet served as controls. Protein and phosphorylated Ser, Thr, and Tyr residues from left ventricular tissue were quantified by mass spectrometry. HFpEF hearts exhibited extensive hyperphosphorylation with 98% of the 529 significantly changed phospho-sites increased compared with control. Of those, 39% were located within the sarcomeric subproteome, with a large group of proteins located or associated with the Z-disk. CDC treatment partially reverted the hyperphosphorylation, with 85% of the significantly altered 76 residues hypophosphorylated. Bioinformatic upstream analysis of the differentially phosphorylated protein residues revealed PKC as the dominant putative regulatory kinase. PKC isoform analysis indicated increases in PKC α, β, and δ concentration, whereas CDC treatment led to a reversion of PKCβ. Use of PKC isoform specific inhibition and overexpression of various PKC isoforms strongly suggests that PKCβ is the dominant kinase involved in hyperphosphorylation in HFpEF and is altered with CDC treatment. CONCLUSIONS Increased protein phosphorylation at the Z-disk is associated with diastolic dysfunction, with PKC isoforms driving most quantified phosphorylation changes. Because CDCs reverse the key abnormalities in HFpEF and selectively reverse PKCβ upregulation, PKCβ merits being classified as a potential therapeutic target in HFpEF, a disease notoriously refractory to medical intervention.
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Affiliation(s)
- Daniel Soetkamp
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Romain Gallet
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | - Sarah J Parker
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | | | | | - Kiel Peck
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
| | | | - Eduardo Marbán
- Smidt Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA
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18
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van der Pijl RJ, Domenighetti AA, Sheikh F, Ehler E, Ottenheijm CAC, Lange S. The titin N2B and N2A regions: biomechanical and metabolic signaling hubs in cross-striated muscles. Biophys Rev 2021; 13:653-677. [PMID: 34745373 PMCID: PMC8553726 DOI: 10.1007/s12551-021-00836-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 08/23/2021] [Indexed: 02/07/2023] Open
Abstract
Muscle specific signaling has been shown to originate from myofilaments and their associated cellular structures, including the sarcomeres, costameres or the cardiac intercalated disc. Two signaling hubs that play important biomechanical roles for cardiac and/or skeletal muscle physiology are the N2B and N2A regions in the giant protein titin. Prominent proteins associated with these regions in titin are chaperones Hsp90 and αB-crystallin, members of the four-and-a-half LIM (FHL) and muscle ankyrin repeat protein (Ankrd) families, as well as thin filament-associated proteins, such as myopalladin. This review highlights biological roles and properties of the titin N2B and N2A regions in health and disease. Special emphasis is placed on functions of Ankrd and FHL proteins as mechanosensors that modulate muscle-specific signaling and muscle growth. This region of the sarcomere also emerged as a hotspot for the modulation of passive muscle mechanics through altered titin phosphorylation and splicing, as well as tethering mechanisms that link titin to the thin filament system.
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Affiliation(s)
| | - Andrea A. Domenighetti
- Shirley Ryan AbilityLab, Chicago, IL USA
- Department of Physical Medicine and Rehabilitation, Northwestern University, Chicago, IL USA
| | - Farah Sheikh
- Division of Cardiology, School of Medicine, UC San Diego, La Jolla, CA USA
| | - Elisabeth Ehler
- Randall Centre for Cell and Molecular Biophysics, School of Cardiovascular Medicine and Sciences, King’s College London, London, UK
| | - Coen A. C. Ottenheijm
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ USA
- Department of Physiology, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - Stephan Lange
- Division of Cardiology, School of Medicine, UC San Diego, La Jolla, CA USA
- Department of Molecular and Clinical Medicine, University of Gothenburg, Gothenburg, Sweden
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Zuo J, Zhan D, Xia J, Li H. Single-Molecule Force Spectroscopy Studies of Missense Titin Mutations That Are Likely Causing Cardiomyopathy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:12128-12137. [PMID: 34618459 PMCID: PMC9150697 DOI: 10.1021/acs.langmuir.1c02006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/20/2021] [Indexed: 06/13/2023]
Abstract
The giant muscle protein titin plays important roles in heart function. Mutations in titin have emerged as a major cause of familial cardiomyopathy. Missense mutations have been identified in cardiomyopathy patients; however, it is challenging to distinguish disease-causing mutations from benign ones. Given the importance of titin mechanics in heart function, it is critically important to elucidate the mechano-phenotypes of cardiomyopathy-causing mutations found in the elastic I-band part of cardiac titin. Using single-molecule atomic force microscopy (AFM) and equilibrium chemical denaturation, we investigated the mechanical and thermodynamic effects of two missense mutations, R57C-I94 and S22P-I84, found in the elastic I-band part of cardiac titin that were predicted to be likely causing cardiomyopathy by bioinformatics analysis. Our AFM results showed that mutation R57C had a significant destabilization effect on the I94 module. R57C reduced the mechanical unfolding force of I94 by ∼30-40 pN, accelerated the unfolding kinetics, and decelerated the folding. These effects collectively increased the unfolding propensity of I94, likely resulting in altered titin elasticity. In comparison, S22P led to only modest destabilization of I84, with a decrease in unfolding force by ∼10 pN. It is unlikely that such a modest destabilization would lead to a change in titin elasticity. These results will serve as the first step toward elucidating mechano-phenotypes of cardiomyopathy-causing mutations in the elastic I-band.
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Emig R, Zgierski-Johnston CM, Timmermann V, Taberner AJ, Nash MP, Kohl P, Peyronnet R. Passive myocardial mechanical properties: meaning, measurement, models. Biophys Rev 2021; 13:587-610. [PMID: 34765043 PMCID: PMC8555034 DOI: 10.1007/s12551-021-00838-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 08/26/2021] [Indexed: 02/06/2023] Open
Abstract
Passive mechanical tissue properties are major determinants of myocardial contraction and relaxation and, thus, shape cardiac function. Tightly regulated, dynamically adapting throughout life, and affecting a host of cellular functions, passive tissue mechanics also contribute to cardiac dysfunction. Development of treatments and early identification of diseases requires better spatio-temporal characterisation of tissue mechanical properties and their underlying mechanisms. With this understanding, key regulators may be identified, providing pathways with potential to control and limit pathological development. Methodologies and models used to assess and mimic tissue mechanical properties are diverse, and available data are in part mutually contradictory. In this review, we define important concepts useful for characterising passive mechanical tissue properties, and compare a variety of in vitro and in vivo techniques that allow one to assess tissue mechanics. We give definitions of key terms, and summarise insight into determinants of myocardial stiffness in situ. We then provide an overview of common experimental models utilised to assess the role of environmental stiffness and composition, and its effects on cardiac cell and tissue function. Finally, promising future directions are outlined.
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Affiliation(s)
- Ramona Emig
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Callum M. Zgierski-Johnston
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Viviane Timmermann
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Andrew J. Taberner
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
| | - Martyn P. Nash
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
- Department of Engineering Science, The University of Auckland, Auckland, New Zealand
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- Faculty of Engineering, University of Freiburg, Freiburg, Germany
| | - Rémi Peyronnet
- Institute for Experimental Cardiovascular Medicine, University Heart Center Freiburg, Bad Krozingen, Freiburg, Germany
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
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21
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Jia J, Li J, Qu H, Li M, Zhang S, Hao J, Gao X, Meng X, Sun Y, Hakonarson H, Zeng X, Xia Q, Li J. New insights into hallux valgus by whole exome sequencing study. Exp Biol Med (Maywood) 2021; 246:1607-1616. [PMID: 33926255 PMCID: PMC8326439 DOI: 10.1177/15353702211008641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/13/2021] [Indexed: 11/16/2022] Open
Abstract
The traditional view is that the occurrence and development of hallux valgus (HV) are mainly due to environmental factors. Recent studies have suggested the large contribution of genetic heritability to HV, but it remains elusive about the genetic variants underlying the development of HV. To gain knowledge about the molecular mechanisms of HV pathogenesis by genetic approach, whole exome sequencing studies were performed in 10 individuals (7 affected by HV and 3 unaffected) from three independent families. Specific mutations were found to be related to the pathogenesis of HV and conform to the laws of inheritance. A total of 36 genes with functional candidate single nucleotide variants were identified. Genetic predisposition plays an important role in the development of HV. Interestingly, some of these genes are related to chronic arthritis, such as the complement encoding gene C7, or are related to long toe or long fingers, such as TTN, COL6A3, LARS, FIG4, and CBS. This study identified rare potentially pathogenic mutations represented by genes related to digital anomalies and chronic arthritis underlying the familial types of HV, which acquired new insights into the genetic and physiological foundations of HV, thereby might improve accurate prevention and drug development for HV.
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Affiliation(s)
- Jun Jia
- Department of Surgery of Foot and Ankle, Tianjin Hospital,
Tianjin 300211, China
| | - Junyi Li
- Department of Cell Biology, the Province and Ministry
Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of
Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Huiqi Qu
- Center for Applied Genomics, Children’s Hospital of
Philadelphia, Philadelphia, PA 19104-4399, USA
| | - Mengyu Li
- Department of Cell Biology, the Province and Ministry
Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of
Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Sipeng Zhang
- Department of Cell Biology, the Province and Ministry
Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of
Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Jun Hao
- Tianjin University of Traditional Chinese Medicine, Tianjin
301617, China
| | - Xinyi Gao
- Department of Cell Biology, the Province and Ministry
Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of
Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Xinyi Meng
- Department of Cell Biology, the Province and Ministry
Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of
Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Yan Sun
- Department of Cell Biology, the Province and Ministry
Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of
Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Hakon Hakonarson
- Center for Applied Genomics, Children’s Hospital of
Philadelphia, Philadelphia, PA 19104-4399, USA
- Division of Human Genetics, Children’s Hospital of Philadelphia,
Philadelphia, PA 19104-4399, USA
- Department of Pediatrics, Perelman School of Medicine,
University of Pennsylvania, Philadelphia, PA 19104-6243, USA
| | - Xiantie Zeng
- Department of Surgery of Foot and Ankle, Tianjin Hospital,
Tianjin 300211, China
| | - Qianghua Xia
- Department of Cell Biology, the Province and Ministry
Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of
Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Jin Li
- Department of Cell Biology, the Province and Ministry
Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of
Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
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22
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Association of SNPs in AKIRIN2, TTN, EDG1 and MYBPC1 genes with growth and carcass traits in Qinchuan cattle. ANNALS OF ANIMAL SCIENCE 2021. [DOI: 10.2478/aoas-2021-0025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Growth and carcass traits are the main breeding objectives in beef cattle. The aim of this study was to confirm genetic effects of the c.*188G>A SNP of AKIRIN2, the g.231054C>T SNP of TTN, the g.1471620G>T SNP of EDG1 and the g.70014208A>G SNP of MYBPC1 on growth and carcass traits in Chinese Qinchuan (QC) cattle, as well as to compare the frequencies of the well-characterized alleles of these SNPs among six Chinese cattle populations, three Japanese cattle populations, two European cattle populations and one Korean cattle population. In this study, a total of 665 cattle samples were genotyped using MassARRAY and PCR-RFLP. Association analysis explored effects of four SNPs on growth and carcass traits including body length, wither height, hip height, hip width, rump length, chest depth, chest circumference, back fat thickness, ultrasound longissimus muscle area and ultrasound longissimus muscle depth in QC (P<0.05 to P<0.001). The well-characterized A (c.*188G>A), T (g.231054C>T) and T (g.1471620G>T) alleles in Japanese Black cattle were significantly higher than Chinese cattle breeds, on the contrary, the G allele (g.70014208A>G) was markedly higher in Chinese cattle breeds than other cattle breeds. These results suggest that the four SNPs might be useful as a molecular marker for growth-related traits in Chinese QC cattle.
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Abstract
PURPOSE OF REVIEW The last few years have confirmed previous assumptions of an enormous impact of the titin gene (TTN) on the occurrence of muscle disease, cardiomyopathy, or both together. The reason for this rather late understanding of its importance is because of the huge size which prevented sequencing of the whole gene by the previous Sanger technique in the individual cases. An update of the advances in diagnosing titinopathies is the main focus of this review. RECENT FINDINGS High throughput methods are now widely available for TTN sequencing and a corresponding explosion of different types of identified titinopathies is observed and published in the literature, although final confirmation is lacking in many cases with recessive missense variants. SUMMARY The implications of these findings for clinical practice are easy to understand: patients with previously undiagnosed muscle disease can now have a correct diagnosis and subsequently receive a likely prognosis, can have accurate genetic counseling for the whole family and early treatment for predictable complications from the heart and respiratory muscles. In addition not to forget, they can avoid wrong diagnoses leading to wrong treatments.
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24
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Tanabe Y, Shimizu K, Sagayama H, Fujii N, Takahashi H. Urinary N-terminal fragment of titin: A surrogate marker of serum creatine kinase activity after exercise-induced severe muscle damage. J Sports Sci 2021; 39:1437-1444. [PMID: 33722155 DOI: 10.1080/02640414.2021.1876329] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We aimed to evaluate whether changes in the noninvasively assessed urinary N-terminal fragment of titin (U-titin) concentration may be associated with those of serum creatine kinase (CK) activity, transverse relaxation time (T2), maximal voluntary contraction (MVC) torque, range of motion (ROM), and muscle soreness, following high-intensity eccentric exercise. Twenty-eight healthy young men performed 30 maximal isokinetic (120°/s) eccentric elbow flexor contractions using an isokinetic dynamometer. U-titin concentration, serum CK activity, T2, MVC torque, ROM, and muscle soreness were measured before and after a maximum of 4 days. Both U-titin concentration and serum CK activity increased post-exercise in a similar manner, though the former elevated slightly earlier (p < 0.05). The peak values of log U-titin concentration following eccentric exercise were strongly correlated with those of log serum CK activity (r = 0.90, p < 0.05) and T2 (r = 0.84, p < 0.05). There were moderate correlations between peak values of U-titin concentration and those of MVC torque (r = 0.69, p < 0.05) and ROM decline rate (r = 0.45, p < 0.05). These results suggest that in healthy young men, the non-invasive marker, U-titin, may be used as a serum CK surrogate following exercise-induced severe muscle damage.
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Affiliation(s)
- Yoko Tanabe
- Department of Sport Research, Japan Institute of Sports Sciences, Tokyo, Japan.,Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
| | - Kazuhiro Shimizu
- Department of Sport Research, Japan Institute of Sports Sciences, Tokyo, Japan
| | - Hiroyuki Sagayama
- Department of Sport Research, Japan Institute of Sports Sciences, Tokyo, Japan.,Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
| | - Naoto Fujii
- Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
| | - Hideyuki Takahashi
- Department of Sport Research, Japan Institute of Sports Sciences, Tokyo, Japan.,Faculty of Health and Sport Sciences, University of Tsukuba, Ibaraki, Japan
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25
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Hirayama-Yamada K, Inagaki N, Hayashi T, Kimura A. A Novel Titin Truncation Variant Linked to Familial Dilated Cardiomyopathy Found in a Japanese Family and Its Functional Analysis in Genome-Edited Model Cells. Int Heart J 2021; 62:359-366. [PMID: 33678800 DOI: 10.1536/ihj.20-664] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Dilated cardiomyopathy (DCM) is a common cause of heart failure. TTN, which encodes titin protein, is a representative causative gene of DCM, and is presented mainly as a truncation variant. However, TTN truncation variants are also found in healthy individuals, and it is therefore important to evaluate the pathogenicity of each variant. In this study, we analyzed 67 cardiomyopathy-associated genes in a male Japanese patient who was hospitalized for recurrent severe heart failure and identified a novel truncation variant, TTN Ser17456Arg fs*14. This TTN truncation variant was located in the A-band region. Moreover, the patient's mother with heart failure harbored the same variant, whereas the father and brother without heart failure did not harbor the variant. To examine the functional changes associated with the truncation variant, H9c2 cells were subjected to genome editing to generate cells with a homologous truncation variant. The cells were differentiated using all-trans-retinoic acid, and the mRNA expression of skeletal actin and cardiac actin were found to be increased and decreased, respectively, consistent with known changes in patients with DCM or heart failure. In contrast, another cell with the titin truncation variant used as a control showed no changes in heart failure-related genes. In summary, we found a novel TTN truncation variant in familial DCM patients and confirmed its functional changes using a relatively simple cell model. The novel truncation variant was identified as a pathogenic and disease-causing mutation.
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Affiliation(s)
- Kayoko Hirayama-Yamada
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University (TMDU)
| | - Natsuko Inagaki
- Department of Cardiology, Tokyo Medical University.,Department of Clinical Genetics Center, Tokyo Medical University
| | - Takeharu Hayashi
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University (TMDU).,Laboratory for Integrated Research Projects on Intractable Diseases, Medical Research Institute, Tokyo Medical and Dental University (TMDU).,Department of Physiology, Tokai University School of Medicine
| | - Akinori Kimura
- Department of Molecular Pathogenesis, Medical Research Institute, Tokyo Medical and Dental University (TMDU).,Laboratory for Integrated Research Projects on Intractable Diseases, Medical Research Institute, Tokyo Medical and Dental University (TMDU).,Research Core, Tokyo Medical and Dental University (TMDU)
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26
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Savarese M, Sarparanta J, Vihola A, Jonson PH, Johari M, Rusanen S, Hackman P, Udd B. Panorama of the distal myopathies. ACTA MYOLOGICA : MYOPATHIES AND CARDIOMYOPATHIES : OFFICIAL JOURNAL OF THE MEDITERRANEAN SOCIETY OF MYOLOGY 2020; 39:245-265. [PMID: 33458580 PMCID: PMC7783427 DOI: 10.36185/2532-1900-028] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 11/11/2020] [Indexed: 12/15/2022]
Abstract
Distal myopathies are genetic primary muscle disorders with a prominent weakness at onset in hands and/or feet. The age of onset (from early childhood to adulthood), the distribution of muscle weakness (upper versus lower limbs) and the histological findings (ranging from nonspecific myopathic changes to myofibrillar disarrays and rimmed vacuoles) are extremely variable. However, despite being characterized by a wide clinical and genetic heterogeneity, the distal myopathies are a category of muscular dystrophies: genetic diseases with progressive loss of muscle fibers. Myopathic congenital arthrogryposis is also a form of distal myopathy usually caused by focal amyoplasia. Massive parallel sequencing has further expanded the long list of genes associated with a distal myopathy, and contributed identifying as distal myopathy-causative rare variants in genes more often related with other skeletal or cardiac muscle diseases. Currently, almost 20 genes (ACTN2, CAV3, CRYAB, DNAJB6, DNM2, FLNC, HNRNPA1, HSPB8, KHLH9, LDB3, MATR3, MB, MYOT, PLIN4, TIA1, VCP, NOTCH2NLC, LRP12, GIPS1) have been associated with an autosomal dominant form of distal myopathy. Pathogenic changes in four genes (ADSSL, ANO5, DYSF, GNE) cause an autosomal recessive form; and disease-causing variants in five genes (DES, MYH7, NEB, RYR1 and TTN) result either in a dominant or in a recessive distal myopathy. Finally, a digenic mechanism, underlying a Welander-like form of distal myopathy, has been recently elucidated. Rare pathogenic mutations in SQSTM1, previously identified with a bone disease (Paget disease), unexpectedly cause a distal myopathy when combined with a common polymorphism in TIA1. The present review aims at describing the genetic basis of distal myopathy and at summarizing the clinical features of the different forms described so far.
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Affiliation(s)
- Marco Savarese
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Jaakko Sarparanta
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Anna Vihola
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Neuromuscular Research Center, Department of Genetics, Fimlab Laboratories, Tampere, Finland
| | - Per Harald Jonson
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Mridul Johari
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Salla Rusanen
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Peter Hackman
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
| | - Bjarne Udd
- Folkhälsan Research Center, Helsinki, Finland
- Department of Medical Genetics, Medicum, University of Helsinki, Helsinki, Finland
- Department of Neurology, Vaasa Central Hospital, Vaasa, Finland
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27
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T-tubule remodeling in human hypertrophic cardiomyopathy. J Muscle Res Cell Motil 2020; 42:305-322. [PMID: 33222034 PMCID: PMC8332592 DOI: 10.1007/s10974-020-09591-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 10/22/2020] [Indexed: 11/17/2022]
Abstract
The highly organized transverse T-tubule membrane system represents the ultrastructural substrate for excitation–contraction coupling in ventricular myocytes. While the architecture and function of T-tubules have been well described in animal models, there is limited morpho-functional data on T-tubules in human myocardium. Hypertrophic cardiomyopathy (HCM) is a primary disease of the heart muscle, characterized by different clinical presentations at the various stages of its progression. Most HCM patients, indeed, show a compensated hypertrophic disease (“non-failing hypertrophic phase”), with preserved left ventricular function, and only a small subset of individuals evolves into heart failure (“end stage HCM”). In terms of T-tubule remodeling, the “end-stage” disease does not differ from other forms of heart failure. In this review we aim to recapitulate the main structural features of T-tubules during the “non-failing hypertrophic stage” of human HCM by revisiting data obtained from human myectomy samples. Moreover, by comparing pathological changes observed in myectomy samples with those introduced by acute (experimentally induced) detubulation, we discuss the role of T-tubular disruption as a part of the complex excitation–contraction coupling remodeling process that occurs during disease progression. Lastly, we highlight how T-tubule morpho-functional changes may be related to patient genotype and we discuss the possibility of a primitive remodeling of the T-tubule system in rare HCM forms associated with genes coding for proteins implicated in T-tubule structural integrity, formation and maintenance.
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28
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The effect of calcium binding on the unfolding force of mutated and healthy titin I10 domain: A steered molecular dynamics simulation study. J Mol Graph Model 2020; 96:107534. [DOI: 10.1016/j.jmgm.2020.107534] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 12/03/2019] [Accepted: 01/08/2020] [Indexed: 01/03/2023]
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29
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Genetic Dissection of Hypertrophic Cardiomyopathy with Myocardial RNA-Seq. Int J Mol Sci 2020; 21:ijms21093040. [PMID: 32344918 PMCID: PMC7246737 DOI: 10.3390/ijms21093040] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/20/2020] [Accepted: 04/24/2020] [Indexed: 01/13/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is an inherited disorder of the myocardium, and pathogenic mutations in the sarcomere genes myosin heavy chain 7 (MYH7) and myosin-binding protein C (MYBPC3) explain 60%–70% of observed clinical cases. The heterogeneity of phenotypes observed in HCM patients, however, suggests that novel causative genes or genetic modifiers likely exist. Here, we systemically evaluated RNA-seq data from 28 HCM patients and 9 healthy controls with pathogenic variant identification, differential expression analysis, and gene co-expression and protein–protein interaction network analyses. We identified 43 potential pathogenic variants in 19 genes in 24 HCM patients. Genes with more than one variant included the following: MYBPC3, TTN, MYH7, PSEN2, and LDB3. A total of 2538 protein-coding genes, six microRNAs (miRNAs), and 1617 long noncoding RNAs (lncRNAs) were identified differentially expressed between the groups, including several well-characterized cardiomyopathy-related genes (ANKRD1, FHL2, TGFB3, miR-30d, and miR-154). Gene enrichment analysis revealed that those genes are significantly involved in heart development and physiology. Furthermore, we highlighted four subnetworks: mtDNA-subnetwork, DSP-subnetwork, MYH7-subnetwork, and MYBPC3-subnetwork, which could play significant roles in the progression of HCM. Our findings further illustrate that HCM is a complex disease, which results from mutations in multiple protein-coding genes, modulation by non-coding RNAs and perturbations in gene networks.
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30
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Sarcomeric Gene Variants and Their Role with Left Ventricular Dysfunction in Background of Coronary Artery Disease. Biomolecules 2020; 10:biom10030442. [PMID: 32178433 PMCID: PMC7175236 DOI: 10.3390/biom10030442] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 03/11/2020] [Indexed: 12/18/2022] Open
Abstract
: Cardiovascular diseases are one of the leading causes of death in developing countries, generally originating as coronary artery disease (CAD) or hypertension. In later stages, many CAD patients develop left ventricle dysfunction (LVD). Left ventricular ejection fraction (LVEF) is the most prevalent prognostic factor in CAD patients. LVD is a complex multifactorial condition in which the left ventricle of the heart becomes functionally impaired. Various genetic studies have correlated LVD with dilated cardiomyopathy (DCM). In recent years, enormous progress has been made in identifying the genetic causes of cardiac diseases, which has further led to a greater understanding of molecular mechanisms underlying each disease. This progress has increased the probability of establishing a specific genetic diagnosis, and thus providing new opportunities for practitioners, patients, and families to utilize this genetic information. A large number of mutations in sarcomeric genes have been discovered in cardiomyopathies. In this review, we will explore the role of the sarcomeric genes in LVD in CAD patients, which is a major cause of cardiac failure and results in heart failure.
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31
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Zhang W, Shen D, Li Y, Zhong H, Wang X, Cui XW, Shi CM, Ji CB, Guo XR, Chen L. A novel peptide RIFV suppresses human adipocyte differentiation through the inhibition of C/EBP-β expression. Nutr Metab (Lond) 2020; 16:88. [PMID: 31889968 PMCID: PMC6929371 DOI: 10.1186/s12986-019-0414-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 12/12/2019] [Indexed: 01/12/2023] Open
Abstract
Background Obesity is a global epidemic disease that increases the risk of metabolic syndrome. However, therapeutic drugs for obesity are still scarce. In recent years, peptides have been identified as new biological regulators. RIFV (R-I-F-V-P-I-K-G-R-P-A-P), a novel active peptide from our peptide database. Methods We performed oil red O staining and triglyceride measurement to analyze the influence of RIFV on white preadipocytes differentiation. Then the effects of RIFV on cell proliferation, apoptosis and cell cycle were determined by using CCK-8 assay and flow cytometry. The mRNA and protein levels of adipogenesis-related genes were respectively detected by qRT-PCR and western blot. Rescue experiment was conducted to confirm whether RIFV could regulate adipocytes differentiation via targeting C/EBP-β. Finally, the luciferase reporter gene assay was performed to verify the regulation of RIFV on C/EBP-β gene. Results RIFV was revealed to inhibit the differentiation of human white adipocytes without affecting their proliferation. Additionally, RIFV could also suppress the differentiation of mouse primary white preadipocytes isolated from inguinal fat tissues. Furthermore, RIFV may have an inhibitory effect on adipogenesis by inhibiting the regulation of the adipogenic gene C/EBP-β. Conclusions Our results indicated that RIFV may be a novel essential regulator of adipocyte differentiation and represents a therapeutic strategy for obesity and related complications.
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Affiliation(s)
- Wen Zhang
- 1Department of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, 210029 China.,2Department of Internal Medicine, Nantong Maternal and Child Health Care Hospital, Affiliated to Nantong University, Nantong, China
| | - Dan Shen
- 1Department of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Yun Li
- 1Department of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Hong Zhong
- 1Department of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Xing Wang
- 1Department of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Xian-Wei Cui
- 1Department of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Chun-Mei Shi
- 1Department of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Chen-Bo Ji
- 1Department of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Xi-Rong Guo
- 3Hongqiao International Institute of Medicine, Tongren Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Ling Chen
- 1Department of Pediatrics, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University, Nanjing, 210029 China
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32
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Higashikuse Y, Mittal N, Arimura T, Yoon SH, Oda M, Enomoto H, Kaneda R, Hattori F, Suzuki T, Kawakami A, Gasch A, Furukawa T, Labeit S, Fukuda K, Kimura A, Makino S. Perturbation of the titin/MURF1 signaling complex is associated with hypertrophic cardiomyopathy in a fish model and in human patients. Dis Model Mech 2019; 12:dmm.041103. [PMID: 31628103 PMCID: PMC6899042 DOI: 10.1242/dmm.041103] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 09/25/2019] [Indexed: 11/24/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a hereditary disease characterized by cardiac hypertrophy with diastolic dysfunction. Gene mutations causing HCM have been found in about half of HCM patients, while the genetic etiology and pathogenesis remain unknown for many cases of HCM. To identify novel mechanisms underlying HCM pathogenesis, we generated a cardiovascular-mutant medaka fish, non-spring heart (nsh), which showed diastolic dysfunction and hypertrophic myocardium. The nsh homozygotes had fewer myofibrils, disrupted sarcomeres and expressed pathologically stiffer titin isoforms. In addition, the nsh heterozygotes showed M-line disassembly that is similar to the pathological changes found in HCM. Positional cloning revealed a missense mutation in an immunoglobulin (Ig) domain located in the M-line–A-band transition zone of titin. Screening of mutations in 96 unrelated patients with familial HCM, who had no previously implicated mutations in known sarcomeric gene candidates, identified two mutations in Ig domains close to the M-line region of titin. In vitro studies revealed that the mutations found both in medaka fish and in familial HCM increased binding of titin to muscle-specific ring finger protein 1 (MURF1) and enhanced titin degradation by ubiquitination. These findings implicate an impaired interaction between titin and MURF1 as a novel mechanism underlying the pathogenesis of HCM. Summary: The authors identified and characterized a medaka mutation in titin that leads to a phenotype similar to hypertrophic cardiomyopathy. Similar mutations were also observed in human patients.
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Affiliation(s)
- Yuta Higashikuse
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan.,Division of Basic Biological Sciences, Faculty of Pharmacy, Keio University, Tokyo 105-8512, Japan
| | - Nishant Mittal
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan
| | - Takuro Arimura
- Laboratory of Genome Diversity, Graduate School of Biomedical Science, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Sung Han Yoon
- Department of Interventional Cardiology, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, AHSP A9229, Los Angeles, CA 90048, USA
| | - Mayumi Oda
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hirokazu Enomoto
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan
| | - Ruri Kaneda
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan
| | - Fumiyuki Hattori
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan
| | - Takeshi Suzuki
- Division of Basic Biological Sciences, Faculty of Pharmacy, Keio University, Tokyo 105-8512, Japan
| | - Atsushi Kawakami
- Department of Biological Information, Tokyo Institute of Technology, Yokohama 226-8501, Japan
| | - Alexander Gasch
- Department of Integrative Pathophysiology, Medical Faculty Mannheim, Mannheim 68167, Germany
| | - Tetsushi Furukawa
- Department of Bio-informational Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Siegfried Labeit
- Department of Integrative Pathophysiology, Medical Faculty Mannheim, Mannheim 68167, Germany
| | - Keiichi Fukuda
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan
| | - Akinori Kimura
- Laboratory of Genome Diversity, Graduate School of Biomedical Science, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Shinji Makino
- Department of Cardiology, Keio University School of Medicine, 35-Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan .,Keio University Health Centre, 35-Shinanomachi Shinjuku-ku, Tokyo 160-8582, Japan
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Reichart D, Magnussen C, Zeller T, Blankenberg S. Dilated cardiomyopathy: from epidemiologic to genetic phenotypes: A translational review of current literature. J Intern Med 2019; 286:362-372. [PMID: 31132311 DOI: 10.1111/joim.12944] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Dilated cardiomyopathy (DCM) is characterized by left ventricular dilatation and, consecutively, contractile dysfunction. The causes of DCM are heterogeneous. DCM often results from myocarditis, exposure to alcohol, drugs or other toxins and metabolic or endocrine disturbances. In about 35% of patients, genetic mutations can be identified that usually involve genes responsible for cytoskeletal, sarcomere and nuclear envelope proteins. Due to its heterogeneity, a detailed diagnostic work-up is necessary to identify the specific underlying cause and exclude other conditions with phenotype overlap. Patients with DCM show typical systolic heart failure symptoms, but, with progress of the disease, diastolic dysfunction is present as well. Depending on the underlying pathology, DCM patients also become apparent through arrhythmias, thromboembolic events or cardiogenic shock. Disease progression and prognosis are mostly driven by disease severity and reverse remodelling within the heart. The worst prognosis is seen in patients with lowest ejection fractions or severe diastolic dysfunction, leading to terminal heart failure with subsequent need for left ventricular assist device implantation or heart transplantation. Guideline-based heart failure medication and device therapy reduces the frequency of heart failure hospitalizations and improves survival.
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Affiliation(s)
- D Reichart
- From the, University Heart Center Hamburg, Hamburg, Germany
| | - C Magnussen
- From the, University Heart Center Hamburg, Hamburg, Germany
| | - T Zeller
- From the, University Heart Center Hamburg, Hamburg, Germany
| | - S Blankenberg
- From the, University Heart Center Hamburg, Hamburg, Germany
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34
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Brodehl A, Ebbinghaus H, Deutsch MA, Gummert J, Gärtner A, Ratnavadivel S, Milting H. Human Induced Pluripotent Stem-Cell-Derived Cardiomyocytes as Models for Genetic Cardiomyopathies. Int J Mol Sci 2019; 20:ijms20184381. [PMID: 31489928 PMCID: PMC6770343 DOI: 10.3390/ijms20184381] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 08/29/2019] [Accepted: 09/03/2019] [Indexed: 12/17/2022] Open
Abstract
In the last few decades, many pathogenic or likely pathogenic genetic mutations in over hundred different genes have been described for non-ischemic, genetic cardiomyopathies. However, the functional knowledge about most of these mutations is still limited because the generation of adequate animal models is time-consuming and challenging. Therefore, human induced pluripotent stem cells (iPSCs) carrying specific cardiomyopathy-associated mutations are a promising alternative. Since the original discovery that pluripotency can be artificially induced by the expression of different transcription factors, various patient-specific-induced pluripotent stem cell lines have been generated to model non-ischemic, genetic cardiomyopathies in vitro. In this review, we describe the genetic landscape of non-ischemic, genetic cardiomyopathies and give an overview about different human iPSC lines, which have been developed for the disease modeling of inherited cardiomyopathies. We summarize different methods and protocols for the general differentiation of human iPSCs into cardiomyocytes. In addition, we describe methods and technologies to investigate functionally human iPSC-derived cardiomyocytes. Furthermore, we summarize novel genome editing approaches for the genetic manipulation of human iPSCs. This review provides an overview about the genetic landscape of inherited cardiomyopathies with a focus on iPSC technology, which might be of interest for clinicians and basic scientists interested in genetic cardiomyopathies.
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Affiliation(s)
- Andreas Brodehl
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Hans Ebbinghaus
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Marcus-André Deutsch
- Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, University Hospital Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Jan Gummert
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
- Department of Thoracic and Cardiovascular Surgery, Heart and Diabetes Center NRW, University Hospital Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Anna Gärtner
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Sandra Ratnavadivel
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
| | - Hendrik Milting
- Erich and Hanna Klessmann Institute, Heart and Diabetes Center NRW, University Hospital of the Ruhr-University Bochum, Georgstrasse 11, D-32545 Bad Oeynhausen, Germany.
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35
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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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36
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Müller D, Hagenah D, Biswanath S, Coffee M, Kampmann A, Zweigerdt R, Heisterkamp A, Kalies SMK. Femtosecond laser-based nanosurgery reveals the endogenous regeneration of single Z-discs including physiological consequences for cardiomyocytes. Sci Rep 2019; 9:3625. [PMID: 30842507 PMCID: PMC6403391 DOI: 10.1038/s41598-019-40308-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 02/13/2019] [Indexed: 11/24/2022] Open
Abstract
A highly organized cytoskeleton architecture is the basis for continuous and controlled contraction in cardiomyocytes (CMs). Abnormalities in cytoskeletal elements, like the Z-disc, are linked to several diseases. It is challenging to reveal the mechanisms of CM failure, endogenous repair, or mechanical homeostasis on the scale of single cytoskeletal elements. Here, we used a femtosecond (fs) laser to ablate single Z-discs in human pluripotent stem cells (hPSC) -derived CMs (hPSC-CM) and neonatal rat CMs. We show, that CM viability was unaffected by the loss of a single Z-disc. Furthermore, more than 40% of neonatal rat and 68% of hPSC-CMs recovered the Z-disc loss within 24 h. Significant differences to control cells, after the Z-disc loss, in terms of cell perimeter, x- and y-expansion and calcium homeostasis were not found. Only 14 days in vitro old hPSC-CMs reacted with a significant decrease in cell area, x- and y-expansion 24 h past nanosurgery. This demonstrates that CMs can compensate the loss of a single Z-disc and recover a regular sarcomeric pattern during spontaneous contraction. It also highlights the significant potential of fs laser-based nanosurgery to physically micro manipulate CMs to investigate cytoskeletal functions and organization of single elements.
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Affiliation(s)
- Dominik Müller
- Institute of Quantum Optics, Leibniz University Hannover, Hannover, Germany. .,REBIRTH-Cluster of Excellence, Hannover Medical School, Hannover, Germany. .,Lower Saxony Centre for Biomedical Engineering, Implant Research and Development (NIFE), Hannover, Germany.
| | - Dorian Hagenah
- Institute of Quantum Optics, Leibniz University Hannover, Hannover, Germany.,REBIRTH-Cluster of Excellence, Hannover Medical School, Hannover, Germany.,Lower Saxony Centre for Biomedical Engineering, Implant Research and Development (NIFE), Hannover, Germany
| | - Santoshi Biswanath
- REBIRTH-Cluster of Excellence, Hannover Medical School, Hannover, Germany.,Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplantation and Vascular Surgery (HTTG), Hannover Medical, School, Hannover, Germany
| | - Michelle Coffee
- REBIRTH-Cluster of Excellence, Hannover Medical School, Hannover, Germany.,Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplantation and Vascular Surgery (HTTG), Hannover Medical, School, Hannover, Germany
| | - Andreas Kampmann
- Lower Saxony Centre for Biomedical Engineering, Implant Research and Development (NIFE), Hannover, Germany.,Clinic for Cranio-Maxillo-Facial Surgery, Hannover Medical School, Hannover, Germany
| | - Robert Zweigerdt
- REBIRTH-Cluster of Excellence, Hannover Medical School, Hannover, Germany.,Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiac, Thoracic, Transplantation and Vascular Surgery (HTTG), Hannover Medical, School, Hannover, Germany
| | - Alexander Heisterkamp
- Institute of Quantum Optics, Leibniz University Hannover, Hannover, Germany.,REBIRTH-Cluster of Excellence, Hannover Medical School, Hannover, Germany.,Lower Saxony Centre for Biomedical Engineering, Implant Research and Development (NIFE), Hannover, Germany
| | - Stefan M K Kalies
- Institute of Quantum Optics, Leibniz University Hannover, Hannover, Germany.,REBIRTH-Cluster of Excellence, Hannover Medical School, Hannover, Germany.,Lower Saxony Centre for Biomedical Engineering, Implant Research and Development (NIFE), Hannover, Germany
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37
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A missense variant in the titin gene in Doberman pinscher dogs with familial dilated cardiomyopathy and sudden cardiac death. Hum Genet 2019; 138:515-524. [DOI: 10.1007/s00439-019-01973-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Accepted: 01/04/2019] [Indexed: 12/30/2022]
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38
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Laitano O, Sheikh LH, Mattingly AJ, Murray KO, Ferreira LF, Clanton TL. Osmolality Selectively Offsets the Impact of Hyperthermia on Mouse Skeletal Muscle in vitro. Front Physiol 2018; 9:1496. [PMID: 30429796 PMCID: PMC6220237 DOI: 10.3389/fphys.2018.01496] [Citation(s) in RCA: 6] [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: 07/10/2018] [Accepted: 10/03/2018] [Indexed: 11/24/2022] Open
Abstract
Hyperthermia and dehydration can occur during exercise in hot environments. Nevertheless, whether elevations in extracellular osmolality contributes to the increased skeletal muscle tension, sarcolemmal injury, and oxidative stress reported in warm climates remains unknown. We simulated osmotic and heat stress, in vitro, in mouse limb muscles with different fiber compositions. Extensor digitorum longus (EDL) and soleus (SOL) were dissected from 36 male C57BL6J and mounted at optimal length in tissue baths containing oxygenated buffer. Muscles were stimulated with non-fatiguing twitches for 30 min. Four experimental conditions were tested: isotonic-normothermia (285 mOsm•kg-1 and 35°C), hypertonic-normothermia (300 mOsm•kg-1 and 35°C), isotonic-hyperthermia (285 mOsm•kg-1 and 41°C), and hypertonic-hyperthermia (300 mOsm•kg-1 and 41°C). Passive tension was recorded continuously. The integrity of the sarcolemma was determined using a cell-impermeable fluorescent dye and immunoblots were used for detection of protein carbonyls. In EDL muscles, isotonic and hypertonic-hyperthermia increased resting tension (P < 0.001). Whereas isotonic-hyperthermia increased sarcolemmal injury in EDL (P < 0.001), this effect was absent in hypertonic-hyperthermia. Similarly, isotonic-hyperthermia elevated protein carbonyls (P = 0.018), a response not observed with hypertonic-hyperthermia. In SOL muscles, isotonic-hyperthermia also increases resting tension (P < 0.001); however, these effects were eliminated in hypertonic-hyperthermia. Unlike EDL, there were no effects of hyperthermia and/or hyperosmolality on sarcolemmal injury or protein carbonyls. Osmolality selectively modifies skeletal muscle response to hyperthermia in this model. Fast-glycolytic muscle appears particularly vulnerable to isotonic-hyperthermia, resulting in elevated muscle tension, sarcolemmal injury and protein oxidation; whereas slow-oxidative muscle exhibits increased tension but no injury or protein oxidation under the conditions and duration tested.
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Affiliation(s)
- Orlando Laitano
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States
- Colegiado de Educação Física, Federal University of Vale do São Francisco, Petrolina, Brazil
| | - Laila H. Sheikh
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States
| | - Alex J. Mattingly
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States
| | - Kevin O. Murray
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States
| | - Leonardo F. Ferreira
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States
| | - Thomas L. Clanton
- Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States
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39
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Translating emerging molecular genetic insights into clinical practice in inherited cardiomyopathies. J Mol Med (Berl) 2018; 96:993-1024. [PMID: 30128729 DOI: 10.1007/s00109-018-1685-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 07/22/2018] [Accepted: 08/08/2018] [Indexed: 12/19/2022]
Abstract
Cardiomyopathies are primarily genetic disorders of the myocardium associated with higher risk of life-threatening cardiac arrhythmias, heart failure, and sudden cardiac death. The evolving knowledge in genomic medicine during the last decade has reshaped our understanding of cardiomyopathies as diseases of multifactorial nature and complex pathophysiology. Genetic testing in cardiomyopathies has subsequently grown from primarily a research tool into an essential clinical evaluation piece with important clinical implications for patients and their families. The purpose of this review is to provide with a contemporary insight into the implications of genetic testing in diagnosis, therapy, and prognosis of patients with inherited cardiomyopathies. Here, we summarize the contemporary knowledge on genotype-phenotype correlations in inherited cardiomyopathies and highlight the recent significant achievements in the field of translational cardiovascular genetics.
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40
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Ye L, Su L, Wang C, Loo S, Tee G, Tan S, Khin SW, Ko S, Su B, Cook SA. Truncations of the titin Z-disc predispose to a heart failure with preserved ejection phenotype in the context of pressure overload. PLoS One 2018; 13:e0201498. [PMID: 30063764 PMCID: PMC6067738 DOI: 10.1371/journal.pone.0201498] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 07/15/2018] [Indexed: 01/02/2023] Open
Abstract
Titin (TTN) Truncating variants (TTNtv) in the A-band of TTN predispose the mouse heart to systolic dysfunction when subjected to pressure-loading. However, the effects of TTNtv of the Z-disc are largely unexplored. A rat model of pressure-loaded heart is developed by trans-aortic constriction (TAC). Rats with TTNtv of the Z-disc were randomly assigned to TAC (Z-TAC) or sham-surgery (Z-Sham) and wildtype (WT) littermates served as controls (WT-TAC or WT-Sham). Left ventricular (LV) function was assessed by echocardiography. Pressure volume (PV) loops, histology and molecular profiling were performed eight months after surgery. Pressure-load by TAC increased LV mass in all cases when compared with Sham animals. Notably, systolic function was preserved in TAC animals throughout the study period, which was confirmed by terminal PV loops. Diastolic function was impaired in Z-disc TTNtv rats at baseline as compared to WT and became impaired further after TAC (dp/dtmin, mmHg/s): Z-TAC = -3435±763, WT-TAC = -6497±1299 (p<0.01). Z-TAC animals had greater cardiac fibrosis, with elevated collagen content and decreased vascular density as compared to WT-TAC animals associated with enhanced apoptosis of myocyte and non-myocyte populations. In the context of pressure overload, Z-disc TTNtv is associated with cardiac fibrosis, diastolic dysfunction, and capillary rarefaction in the absence of overt systolic dysfunction.
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Affiliation(s)
- Lei Ye
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
- * E-mail:
| | - Liping Su
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Chenxu Wang
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Szejie Loo
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Guizhen Tee
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Shihua Tan
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Sandar Win Khin
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Shijie Ko
- Duke-National University of Singapore Medical School, Singapore, Singapore
| | - Boyang Su
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
| | - Stuart A. Cook
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore, Singapore
- Duke-National University of Singapore Medical School, Singapore, Singapore
- National Heart and Lung Institute, Imperial College, London, United Kingdom
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41
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Four and a half LIM domain protein signaling and cardiomyopathy. Biophys Rev 2018; 10:1073-1085. [PMID: 29926425 DOI: 10.1007/s12551-018-0434-3] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 06/06/2018] [Indexed: 01/10/2023] Open
Abstract
Four and a half LIM domain (FHL) protein family members, FHL1 and FHL2, are multifunctional proteins that are enriched in cardiac muscle. Although they both localize within the cardiomyocyte sarcomere (titin N2B), they have been shown to have important yet unique functions within the context of cardiac hypertrophy and disease. Studies in FHL1-deficient mice have primarily uncovered mitogen-activated protein kinase (MAPK) scaffolding functions for FHL1 as part of a novel biomechanical stretch sensor within the cardiomyocyte sarcomere, which acts as a positive regulator of pressure overload-mediated cardiac hypertrophy. New data have highlighted a novel role for the serine/threonine protein phosphatase (PP5) as a deactivator of the FHL1-based biomechanical stretch sensor, which has implications in not only cardiac hypertrophy but also heart failure. In contrast, studies in FHL2-deficient mice have primarily uncovered an opposing role for FHL2 as a negative regulator of adrenergic-mediated signaling and cardiac hypertrophy, further suggesting unique functions targeted by FHL proteins in the "stressed" cardiomyocyte. In this review, we provide current knowledge of the role of FHL1 and FHL2 in cardiac muscle as it relates to their actions in cardiac hypertrophy and cardiomyopathy. A specific focus will be to dissect the pathways and protein-protein interactions that underlie FHLs' signaling role in cardiac hypertrophy as well as provide a comprehensive list of FHL mutations linked to cardiac disease, using evidence gained from genetic mouse models and human genetic studies.
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42
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Ehsan M, Jiang H, L Thomson K, Gehmlich K. When signalling goes wrong: pathogenic variants in structural and signalling proteins causing cardiomyopathies. J Muscle Res Cell Motil 2017; 38:303-316. [PMID: 29119312 PMCID: PMC5742121 DOI: 10.1007/s10974-017-9487-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/28/2017] [Indexed: 12/20/2022]
Abstract
Cardiomyopathies are a diverse group of cardiac disorders with distinct phenotypes, depending on the proteins and pathways affected. A substantial proportion of cardiomyopathies are inherited and those will be the focus of this review article. With the wide application of high-throughput sequencing in the practice of clinical genetics, the roles of novel genes in cardiomyopathies are recognised. Here, we focus on a subgroup of cardiomyopathy genes [TTN, FHL1, CSRP3, FLNC and PLN, coding for Titin, Four and a Half LIM domain 1, Muscle LIM Protein, Filamin C and Phospholamban, respectively], which, despite their diverse biological functions, all have important signalling functions in the heart, suggesting that disturbances in signalling networks can contribute to cardiomyopathies.
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Affiliation(s)
- Mehroz Ehsan
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, UK
| | - He Jiang
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, UK
| | - Kate L Thomson
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, UK
| | - Katja Gehmlich
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence, University of Oxford, Oxford, UK.
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Should Identifying a Titin Truncating Variant Change the Management of Patients With Dilated Cardiomyopathy? J Am Coll Cardiol 2017; 70:2275-2277. [DOI: 10.1016/j.jacc.2017.09.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 09/12/2017] [Indexed: 10/18/2022]
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44
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Shim SH, Kim JY, Sung SR, Park JE, Shin YJ, Shim SH, Cha DH. Prenatally diagnosed TTN mutation with repeated bilateral club foot by whole exome sequencing. BIOCHIP JOURNAL 2017. [DOI: 10.1007/s13206-017-1309-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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45
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Magi S, Lariccia V, Maiolino M, Amoroso S, Gratteri S. Sudden cardiac death: focus on the genetics of channelopathies and cardiomyopathies. J Biomed Sci 2017; 24:56. [PMID: 28810874 PMCID: PMC5556354 DOI: 10.1186/s12929-017-0364-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 08/09/2017] [Indexed: 01/22/2023] Open
Abstract
Sudden cardiac death (SCD) describes a natural and unexpected death from cardiac causes occurring within a short period of time (generally within 1 h of symptom onset) in the absence of any other potentially lethal condition. Most SCD-related diseases have a genetic basis; in particular congenital cardiac channelopathies and cardiomyopathies have been described as leading causes of SCD. Congenital cardiac channelopathies are primary electric disorders caused by mutations affecting genes encoding cardiac ion channels or associated proteins, whereas cardiomyopathies are related to mutations in genes encoding several categories of proteins, including those of sarcomeres, desmosomes, the cytoskeleton, and the nuclear envelope. The purpose of this review is to provide a general overview of the main genetic variants that have been linked to the major congenital cardiac channelopathies and cardiomyopathies. Functional alterations of the related proteins are also described.
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Affiliation(s)
- Simona Magi
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy.
| | - Vincenzo Lariccia
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
| | - Marta Maiolino
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
| | - Salvatore Amoroso
- Department of Biomedical Sciences and Public Health, School of Medicine, University "Politecnica delle Marche", Via Tronto 10/A, 60126, Ancona, Italy
| | - Santo Gratteri
- Department of Health Sciences, University "Magna Graecia", 88100, Catanzaro, Italy
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Abstract
Cardiomyopathies represent a heterogeneous group of diseases that negatively affect heart function. Primary cardiomyopathies specifically target the myocardium, and may arise from genetic [hypertrophic cardiomyopathy (HCM), arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D), mitochondrial cardiomyopathy] or genetic and acquired [dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM)] etiology. Modern genomics has identified mutations that are common in these populations, while in vitro and in vivo experimentation with these mutations have provided invaluable insight into the molecular mechanisms native to these diseases. For example, increased myosin heavy chain (MHC) binding and ATP utilization lead to the hypercontractile sarcomere in HCM, while abnormal protein–protein interaction and impaired Ca2+ flux underlie the relaxed sarcomere of DCM. Furthermore, expanded access to genetic testing has facilitated identification of potential risk factors that appear through inheritance and manifest sometimes only in the advanced stages of the disease. In this review, we discuss the genetic and molecular abnormalities unique to and shared between these primary cardiomyopathies and discuss some of the important advances made using more traditional basic science experimentation.
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Genetic epidemiology of titin-truncating variants in the etiology of dilated cardiomyopathy. Biophys Rev 2017; 9:207-223. [PMID: 28510119 PMCID: PMC5498329 DOI: 10.1007/s12551-017-0265-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 04/10/2017] [Indexed: 02/07/2023] Open
Abstract
Heart failure (HF) is a complex clinical syndrome defined by the inability of the heart to pump enough blood to meet the body's metabolic demands. Major causes of HF are cardiomyopathies (diseases of the myocardium associated with mechanical and/or electrical dysfunction), among which the most common form is dilated cardiomyopathy (DCM). DCM is defined by ventricular chamber enlargement and systolic dysfunction with normal left ventricular wall thickness, which leads to progressive HF. Over 60 genes are linked to the etiology of DCM. Titin (TTN) is the largest known protein in biology, spanning half the cardiac sarcomere and, as such, is a basic structural and functional unit of striated muscles. It is essential for heart development as well as mechanical and regulatory functions of the sarcomere. Next-generation sequencing (NGS) in clinical DCM cohorts implicated truncating variants in titin (TTNtv) as major disease alleles, accounting for more than 25% of familial DCM cases, but these variants have also been identified in 2-3% of the general population, where these TTNtv blur diagnostic and clinical utility. Taking into account the published TTNtv and their association to DCM, it becomes clear that TTNtv harm the heart with position-dependent occurrence, being more harmful when present in the A-band TTN, presumably with dominant negative/gain-of-function mechanisms. However, these insights are challenged by the depiction of position-independent toxicity of TTNtv acting via haploinsufficient alleles, which are sufficient to induce cardiac pathology upon stress. In the current review, we provide an overview of TTN and discuss studies investigating various TTN mutations. We also present an overview of different mechanisms postulated or experimentally validated in the pathogenicity of TTNtv. DCM-causing genes are also discussed with respect to non-truncating mutations in the etiology of DCM. One way of understanding pathogenic variants is probably to understand the context in which they may or may not affect protein-protein interactions, changes in cell signaling, and substrate specificity. In this regard, we also provide a brief overview of TTN interactions in situ. Quantitative models in the risk assessment of TTNtv are also discussed. In summary, we highlight the importance of gene-environment interactions in the etiology of DCM and further mechanistic studies used to delineate the pathways which could be targeted in the management of DCM.
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48
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Dalin MG, Engström PG, Ivarsson EG, Unneberg P, Light S, Schaufelberger M, Gilljam T, Andersson B, Bergo MO. Massive parallel sequencing questions the pathogenic role of missense variants in dilated cardiomyopathy. Int J Cardiol 2017; 228:742-748. [DOI: 10.1016/j.ijcard.2016.11.066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 11/05/2016] [Indexed: 01/13/2023]
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Franaszczyk M, Chmielewski P, Truszkowska G, Stawinski P, Michalak E, Rydzanicz M, Sobieszczanska-Malek M, Pollak A, Szczygieł J, Kosinska J, Parulski A, Stoklosa T, Tarnowska A, Machnicki MM, Foss-Nieradko B, Szperl M, Sioma A, Kusmierczyk M, Grzybowski J, Zielinski T, Ploski R, Bilinska ZT. Titin Truncating Variants in Dilated Cardiomyopathy - Prevalence and Genotype-Phenotype Correlations. PLoS One 2017; 12:e0169007. [PMID: 28045975 PMCID: PMC5207678 DOI: 10.1371/journal.pone.0169007] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Accepted: 12/09/2016] [Indexed: 11/18/2022] Open
Abstract
TTN gene truncating variants are common in dilated cardiomyopathy (DCM), although data on their clinical significance is still limited. We sought to examine the frequency of truncating variants in TTN in patients with DCM, including familial DCM (FDCM), and to look for genotype-phenotype correlations. Clinical cardiovascular data, family histories and blood samples were collected from 72 DCM probands, mean age of 34 years, 45.8% FDCM. DNA samples were examined by next generation sequencing (NGS) with a focus on the TTN gene. Truncating mutations were followed up by segregation study among family members. We identified 16 TTN truncating variants (TTN trunc) in 17 probands (23.6% of all cases, 30.3% of FDCM, 17.9% of sporadic DCM). During mean 63 months from diagnosis, there was no difference in adverse cardiac events between probands with and without TTN truncating mutations. Among relatives 29 mutation carriers were identified, nine were definitely affected (31%), eight probably affected (27.6%) one possibly affected (3.4%) and eleven were not affected (37.9%). When relatives with all affected statuses were combined, disease penetrance was still incomplete (62.1%) even after exclusion of unaffected relatives under 40 (82%) and was higher in males versus females. In all mutation carriers, during follow-up, 17.4% had major adverse cardiac events, and prognosis was significantly worse in men than in women. In conclusion, TTN truncating variants were observed in nearly one fourth of young DCM patient population, in vast majority without conduction system disease. Incomplete penetrance suggests possible influence of other genetic and/or environmental factors on the course of cardiotitinopathy. Counseling should take into account sex and incomplete penetrance.
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Affiliation(s)
- Maria Franaszczyk
- Department of Medical Biology, Molecular Biology Laboratory, Institute of Cardiology, Warsaw, Poland
| | - Przemyslaw Chmielewski
- Unit for Screening Studies in Inherited Cardiovascular Diseases, Institute of Cardiology, Warsaw, Poland
| | - Grazyna Truszkowska
- Department of Medical Biology, Molecular Biology Laboratory, Institute of Cardiology, Warsaw, Poland
| | - Piotr Stawinski
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Kajetany/Warsaw, Poland
| | - Ewa Michalak
- Unit for Screening Studies in Inherited Cardiovascular Diseases, Institute of Cardiology, Warsaw, Poland
| | | | | | - Agnieszka Pollak
- Department of Genetics, Institute of Physiology and Pathology of Hearing, Kajetany/Warsaw, Poland
| | - Justyna Szczygieł
- Department of Cardiomyopathies, Institute of Cardiology, Warsaw, Poland
| | - Joanna Kosinska
- Department of Medical; Genetics, Medical University of Warsaw, Warsaw, Poland
| | - Adam Parulski
- Department of Cardiac Surgery and Transplantology, Institute of Cardiology, Warsaw, Poland
| | - Tomasz Stoklosa
- Department of Immunology, Center for Biostructure Research, Medical University of Warsaw, Warsaw, Poland
| | - Agnieszka Tarnowska
- Department of Heart Failure and Transplantology, Institute of Cardiology, Warsaw, Poland
| | - Marcin M. Machnicki
- Department of Immunology, Center for Biostructure Research, Medical University of Warsaw, Warsaw, Poland
- Postgraduate School of Molecular Medicine, Medical University of Warsaw, Warsaw, Poland
| | - Bogna Foss-Nieradko
- Unit for Screening Studies in Inherited Cardiovascular Diseases, Institute of Cardiology, Warsaw, Poland
| | - Malgorzata Szperl
- Department of Medical Biology, Molecular Biology Laboratory, Institute of Cardiology, Warsaw, Poland
| | - Agnieszka Sioma
- Department of Cardiomyopathies, Institute of Cardiology, Warsaw, Poland
| | - Mariusz Kusmierczyk
- Department of Cardiac Surgery and Transplantology, Institute of Cardiology, Warsaw, Poland
| | - Jacek Grzybowski
- Department of Cardiomyopathies, Institute of Cardiology, Warsaw, Poland
| | - Tomasz Zielinski
- Department of Heart Failure and Transplantology, Institute of Cardiology, Warsaw, Poland
| | - Rafal Ploski
- Department of Medical; Genetics, Medical University of Warsaw, Warsaw, Poland
- * E-mail: (RP); (ZTB)
| | - Zofia T. Bilinska
- Unit for Screening Studies in Inherited Cardiovascular Diseases, Institute of Cardiology, Warsaw, Poland
- * E-mail: (RP); (ZTB)
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50
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Jansweijer JA, Nieuwhof K, Russo F, Hoorntje ET, Jongbloed JDH, Lekanne Deprez RH, Postma AV, Bronk M, van Rijsingen IAW, de Haij S, Biagini E, van Haelst PL, van Wijngaarden J, van den Berg MP, Wilde AAM, Mannens MMAM, de Boer RA, van Spaendonck-Zwarts KY, van Tintelen JP, Pinto YM. Truncating titin mutations are associated with a mild and treatable form of dilated cardiomyopathy. Eur J Heart Fail 2016; 19:512-521. [PMID: 27813223 DOI: 10.1002/ejhf.673] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Revised: 09/02/2016] [Accepted: 09/05/2016] [Indexed: 11/09/2022] Open
Abstract
AIMS Truncating titin mutations (tTTN) occur in 25% of dilated cardiomyopathy (DCM) cases, but the phenotype and severity of disease they cause have not yet been systematically studied. We studied whether tTTN variants are associated with a clinically distinguishable form of DCM. METHODS AND RESULTS We compared clinical data on DCM probands and relatives with a tTTN mutation (n = 45, n = 73), LMNA mutation (n = 28, n = 29), and probands who tested negative for both genes [idiopathic DCM (iDCM); n = 60]. Median follow-up was at least 2.5 years in each group. TTN subjects presented with DCM at higher age than LMNA subjects (probands 47.9 vs. 40.4 years, P = 0.004; relatives 59.8 vs. 47.0 years, P = 0.01), less often developed LVEF <35% [probands hazard ratio (HR) 0.38, P = 0.002], had higher age of death (probands 70.4 vs. 59.4 years, P < 0.001; relatives 74.1 vs. 58.4 years, P = 0.008), and had better composite outcome (malignant ventricular arrhythmia, heart transplantation, or death; probands HR 0.09, P < 0.001; relatives HR 0.21, P = 0.02) than LMNA subjects and iDCM subjects (HR 0.36, P = 0.07). An LVEF increase of at least 10% occurred in 46.9% of TTN subjects after initiation of standard heart failure treatment, while this only occurred in 6.5% of LMNA subjects (P < 0.001) and 18.5% of iDCM subjects (P = 0.02). This was confirmed in families with co-segregation, in which the 10% point LVEF increase occurred in 55.6% of subjects (P = 0.003 vs. LMNA, P = 0.079 vs. iDCM). CONCLUSIONS This study shows that tTTN-associated DCM is less severe at presentation and more amenable to standard therapy than LMNA mutation-induced DCM or iDCM.
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Affiliation(s)
- Joeri A Jansweijer
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Karin Nieuwhof
- Department of Clinical Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Francesco Russo
- Department of Clinical Genetics, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Edgar T Hoorntje
- Department of Clinical Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Jan D H Jongbloed
- Department of Clinical Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Ronald H Lekanne Deprez
- Department of Clinical Genetics, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Alex V Postma
- Department of Anatomy, Embryology and Physiology, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Marieke Bronk
- Department of Clinical Genetics, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Ingrid A W van Rijsingen
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Simone de Haij
- Department of Clinical Genetics, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Elena Biagini
- Department of Cardiology, S. Orsola-Malpighi Hospital, Bologna University, Italy
| | | | | | - Maarten P van den Berg
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Arthur A M Wilde
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Marcel M A M Mannens
- Department of Clinical Genetics, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Rudolf A de Boer
- Department of Cardiology, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Karin Y van Spaendonck-Zwarts
- Department of Clinical Genetics, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - J Peter van Tintelen
- Department of Clinical Genetics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.,Department of Clinical Genetics, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
| | - Yigal M Pinto
- AMC Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center Amsterdam, University of Amsterdam, Amsterdam, The Netherlands
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