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Smith E, Krishnamoorthy D, Burke-Martindale C, Weissler-Snir A. Guilt and Reproductive Decision-Making in Patients With Inherited Cardiac Diseases. J Am Heart Assoc 2024; 13:e032696. [PMID: 38591262 DOI: 10.1161/jaha.123.032696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 01/10/2024] [Indexed: 04/10/2024]
Affiliation(s)
- Emily Smith
- Hartford HealthCare Heart & Vascular Institute Hartford CT USA
| | | | | | - Adaya Weissler-Snir
- Hartford HealthCare Heart & Vascular Institute Hartford CT USA
- Department of Medicine University of Connecticut Farmington CT USA
- Department of Cardiology Icahn School of Medicine at Mount Sinai New York NY USA
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2
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Yang L, Liu Z, Sun J, Chen Z, Gao F, Guo Y. Adenine base editor-based correction of the cardiac pathogenic Lmna c.1621C > T mutation in murine hearts. J Cell Mol Med 2024; 28:e18145. [PMID: 38332517 PMCID: PMC10853587 DOI: 10.1111/jcmm.18145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 12/21/2023] [Accepted: 01/13/2024] [Indexed: 02/10/2024] Open
Abstract
Base editors are emerging as powerful tools to correct single-nucleotide variants and treat genetic diseases. In particular, the adenine base editors (ABEs) exhibit robust and accurate adenine-to-guanidine editing capacity and have entered the clinical stage for cardiovascular therapy. Despite the tremendous progress using ABEs to treat heart diseases, a standard technical route toward successful ABE-based therapy remains to be fully established. In this study, we harnessed adeno-associated virus (AAV) and a mouse model carrying the cardiomyopathy-causing Lmna c.1621C > T mutation to demonstrate key steps and concerns in designing a cardiac ABE experiment in vivo. We found DeepABE as a reliable deep-learning-based model to predict ABE editing outcomes in the heart. Screening of sgRNAs for a Cas9 mutant with relieved protospacer adjacent motif (PAM) allowed the reduction of bystander editing. The ABE editing efficiency can be significantly enhanced by modifying the TadA and Cas9 variants, which are core components of ABEs. The ABE systems can be delivered into the heart via either dual AAV or all-in-one AAV vectors. Together, this study showcased crucial technical considerations in designing an ABE system for the heart and pointed out major challenges in further improvement of this new technology for gene therapy.
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Affiliation(s)
- Luzi Yang
- School of Basic Medical SciencesPeking University Health Science CenterBeijingChina
- Peking University Institute of Cardiovascular SciencesBeijingChina
| | - Zhanzhao Liu
- School of Basic Medical SciencesPeking University Health Science CenterBeijingChina
- Peking University Institute of Cardiovascular SciencesBeijingChina
| | - Jinhuan Sun
- School of Basic Medical SciencesPeking University Health Science CenterBeijingChina
- Peking University Institute of Cardiovascular SciencesBeijingChina
| | - Zhan Chen
- School of Basic Medical SciencesPeking University Health Science CenterBeijingChina
- Peking University Institute of Cardiovascular SciencesBeijingChina
| | - Fei Gao
- Department of Cardiology, Beijing Anzhen HospitalCapital Medical UniversityBeijingChina
| | - Yuxuan Guo
- School of Basic Medical SciencesPeking University Health Science CenterBeijingChina
- Peking University Institute of Cardiovascular SciencesBeijingChina
- State Key Laboratory of Vascular Homeostasis and RemodelingPeking UniversityBeijingChina
- Beijing Key Laboratory of Cardiovascular Receptors ResearchBeijingChina
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3
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Zeppenfeld K, Kimura Y, Ebert M. Mapping and Ablation of Ventricular Tachycardia in Inherited Left Ventricular Cardiomyopathies. JACC Clin Electrophysiol 2023:S2405-500X(23)00816-2. [PMID: 38127011 DOI: 10.1016/j.jacep.2023.10.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 10/12/2023] [Accepted: 10/23/2023] [Indexed: 12/23/2023]
Abstract
Advances in the field of human genetics have led to an accumulating understanding of the genetic basis of distinct nonischemic cardiomyopathies associated with ventricular tachycardias (VTs) and sudden cardiac death. To date, there is an increasing proportion of patients with inherited cardiomyopathies requiring catheter ablation for VTs. This review provides an overview of disease-causing gene mutations frequently encountered and relevant for clinical electrophysiologists. Available data on VT ablation in patients with an inherited etiology and a phenotype of a nondilated left ventricular cardiomyopathy, dilated cardiomyopathy, or hypertrophic cardiomyopathy are summarized. VTs amenable to catheter ablation are related to nonischemic fibrosis. Recent insights into genotype-phenotype relations of subtype and location of fibrosis have important implications for treatment planning. Current strategies to delineate nonischemic fibrosis and related arrhythmogenic substrates using multimodal imaging, image integration, and electroanatomical mapping are provided. The ablation approach depends on substrate location and extension. Related procedural aspects including patient-tailored (enhanced) ablation strategies and outcomes are outlined. Challenging substrates for VT and the underlying inherited etiologies with a high risk for rapid progressive heart failure contribute to poor outcomes after catheter ablation. Electroanatomical data obtained during ablation may allow the identification of patients at particular risk who need to be considered for early work-up for left ventricular assist device implantation or heart transplantation.
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Affiliation(s)
- Katja Zeppenfeld
- Department of Cardiology, Heart-Lung-Center, Leiden University Medical Center, Leiden, the Netherlands; Willem Einthoven Center of Arrhythmia Research and Management, Leiden, the Netherlands, and Aarhus, Denmark.
| | - Yoshitaka Kimura
- Department of Cardiology, Heart-Lung-Center, Leiden University Medical Center, Leiden, the Netherlands; Willem Einthoven Center of Arrhythmia Research and Management, Leiden, the Netherlands, and Aarhus, Denmark
| | - Micaela Ebert
- Department of Cardiology, Heart-Lung-Center, Leiden University Medical Center, Leiden, the Netherlands; Division of Electrophysiology, Department of Internal Medicine and Cardiology, Heart Center Dresden, Technische Universität Dresden, Dresden, Germany
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4
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Chou C, Vemon HJ, Jefferies JL, Chin MT. Editorial: Molecular pathogenesis and novel treatments for inherited cardiomyopathies. Front Cardiovasc Med 2023; 10:1282852. [PMID: 37745121 PMCID: PMC10512058 DOI: 10.3389/fcvm.2023.1282852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 08/28/2023] [Indexed: 09/26/2023] Open
Affiliation(s)
- Chun Chou
- Department of Medicine, Tufts University School of Medicine, Boston, MA, United States
| | - Hilary J. Vemon
- Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - John L. Jefferies
- Division of Cardiology, Department of Medicine, University of Tennessee Health Sciences Center, Memphis, TN, United States
| | - Michael T. Chin
- Department of Medicine, Tufts University School of Medicine, Boston, MA, United States
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA, United States
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5
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Zhang Y, Zhang K, Prakosa A, James C, Zimmerman SL, Carrick R, Sung E, Gasperetti A, Tichnell C, Murray B, Calkins H, Trayanova N. Predicting Ventricular Tachycardia Circuits in Patients with Arrhythmogenic Right Ventricular Cardiomyopathy using Genotype-specific Heart Digital Twins. medRxiv 2023:2023.05.31.23290587. [PMID: 37398074 PMCID: PMC10312861 DOI: 10.1101/2023.05.31.23290587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic cardiac disease that leads to ventricular tachycardia (VT), a life-threatening heart rhythm disorder. Treating ARVC remains challenging due to the complex underlying arrhythmogenic mechanisms, which involve structural and electrophysiological (EP) remodeling. Here, we developed a novel genotype-specific heart digital twin (Geno-DT) approach to investigate the role of pathophysiological remodeling in sustaining VT reentrant circuits and to predict the VT circuits in ARVC patients of different genotypes. This approach integrates the patient's disease-induced structural remodeling reconstructed from contrast-enhanced magnetic-resonance imaging and genotype-specific cellular EP properties. In our retrospective study of 16 ARVC patients with two genotypes: plakophilin-2 (PKP2, n = 8) and gene-elusive (GE, n = 8), we found that Geno-DT accurately and non-invasively predicted the VT circuit locations for both genotypes (with 100%, 94%, 96% sensitivity, specificity, and accuracy for GE patient group, and 86%, 90%, 89% sensitivity, specificity, and accuracy for PKP2 patient group), when compared to VT circuit locations identified during clinical EP studies. Moreover, our results revealed that the underlying VT mechanisms differ among ARVC genotypes. We determined that in GE patients, fibrotic remodeling is the primary contributor to VT circuits, while in PKP2 patients, slowed conduction velocity and altered restitution properties of cardiac tissue, in addition to the structural substrate, are directly responsible for the formation of VT circuits. Our novel Geno-DT approach has the potential to augment therapeutic precision in the clinical setting and lead to more personalized treatment strategies in ARVC.
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Affiliation(s)
- Yingnan Zhang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
| | - Kelly Zhang
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
| | - Adityo Prakosa
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
| | - Cynthia James
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Stefan L Zimmerman
- Department of Radiology and Radiological Science, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Richard Carrick
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Eric Sung
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
| | - Alessio Gasperetti
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Crystal Tichnell
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Brittney Murray
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Hugh Calkins
- Division of Cardiology, Department of Medicine, Johns Hopkins Hospital, Baltimore, MD, USA
| | - Natalia Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, USA
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, MD, USA
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Mansoori GA, Mahmeed WA, Wani S, Salih BT, Ansari TE, Farook F, Farooq Z, Khair H, Zaręba K, Dhahouri NA, Raj A, Foo RS, Ali BR, Jasmi FA, Akawi N. Introducing and Implementing Genetic Assessment in Cardio-Obstetrics Clinical Practice: Clinical and Genetic Workup of Patients with Cardiomyopathy. Int J Mol Sci 2023; 24:ijms24119119. [PMID: 37298070 DOI: 10.3390/ijms24119119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 06/12/2023] Open
Abstract
Cardiovascular disease (CVD) during pregnancy varies significantly worldwide, influenced by factors such as access to healthcare, delayed diagnosis, causes, and risk factors. Our study sought to explore the spectrum of CVD present in pregnant women in the United Arab Emirates to better understand this population's unique needs and challenges. Central to our study is an emphasis on the importance of implementing a multidisciplinary approach that involves the collaboration of obstetricians, cardiologists, geneticists, and other healthcare professionals to ensure that patients receive comprehensive and coordinated care. This approach can also help identify high-risk patients and implement preventive measures to reduce the occurrence of adverse maternal outcomes. Furthermore, increasing awareness among women about the risk of CVD during pregnancy and obtaining detailed family histories can help in the early identification and management of these conditions. Genetic testing and family screening can also aid in identifying inherited CVD that can be passed down through families. To illustrate the significance of such an approach, we provide a comprehensive analysis of five women's cases from our retrospective study of 800 women. The findings from our study emphasize the importance of addressing maternal cardiac health in pregnancy and the need for targeted interventions and improvements in the existing healthcare system to reduce adverse maternal outcomes.
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Affiliation(s)
- Ghadeera Al Mansoori
- Department of Cardiology, Sheikh Shakhbout Medical City, Abu Dhabi 11001, United Arab Emirates
| | - Wael Al Mahmeed
- Heart, Vascular & Thoracic Institute, Cleveland Clinic, Abu Dhabi 112412, United Arab Emirates
| | - Saleema Wani
- Department of Obstetrics & Gynecology, Corniche Hospital, Abu Dhabi 3788, United Arab Emirates
| | - Bashir Taha Salih
- Department of Obstetrics & Gynecology, Corniche Hospital, Abu Dhabi 3788, United Arab Emirates
| | - Tarek El Ansari
- Department of Obstetrics & Gynecology, Corniche Hospital, Abu Dhabi 3788, United Arab Emirates
| | - Fathima Farook
- Department of Obstetrics & Gynecology, Corniche Hospital, Abu Dhabi 3788, United Arab Emirates
| | - Zenab Farooq
- College of Medicine and Health Sciences, Khalifa University, Abu Dhabi 127788, United Arab Emirates
| | - Howaida Khair
- Department of Obstetrics & Gynecology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates
| | - Kornelia Zaręba
- Department of Obstetrics & Gynecology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates
| | - Nahid Al Dhahouri
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates
| | - Anjana Raj
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates
| | - Roger S Foo
- Cardiovascular Research Institute, National University Healthcare Systems, Singapore 117599, Singapore
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore 138672, Singapore
| | - Bassam R Ali
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates
| | - Fatma Al Jasmi
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates
| | - Nadia Akawi
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain 15551, United Arab Emirates
- Division of Cardiovascular Medicine, University of Oxford, Oxford OX3 9DU, UK
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7
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Zech ATL, Prondzynski M, Singh SR, Pietsch N, Orthey E, Alizoti E, Busch J, Madsen A, Behrens CS, Meyer-Jens M, Mearini G, Lemoine MD, Krämer E, Mosqueira D, Virdi S, Indenbirken D, Depke M, Salazar MG, Völker U, Braren I, Pu WT, Eschenhagen T, Hammer E, Schlossarek S, Carrier L. ACTN2 Mutant Causes Proteopathy in Human iPSC-Derived Cardiomyocytes. Cells 2022; 11:cells11172745. [PMID: 36078153 PMCID: PMC9454684 DOI: 10.3390/cells11172745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 08/24/2022] [Accepted: 08/29/2022] [Indexed: 11/28/2022] Open
Abstract
Genetic variants in α-actinin-2 (ACTN2) are associated with several forms of (cardio)myopathy. We previously reported a heterozygous missense (c.740C>T) ACTN2 gene variant, associated with hypertrophic cardiomyopathy, and characterized by an electro-mechanical phenotype in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs). Here, we created with CRISPR/Cas9 genetic tools two heterozygous functional knock-out hiPSC lines with a second wild-type (ACTN2wt) and missense ACTN2 (ACTN2mut) allele, respectively. We evaluated their impact on cardiomyocyte structure and function, using a combination of different technologies, including immunofluorescence and live cell imaging, RNA-seq, and mass spectrometry. This study showed that ACTN2mut presents a higher percentage of multinucleation, protein aggregation, hypertrophy, myofibrillar disarray, and activation of both the ubiquitin-proteasome system and the autophagy-lysosomal pathway as compared to ACTN2wt in 2D-cultured hiPSC-CMs. Furthermore, the expression of ACTN2mut was associated with a marked reduction of sarcomere-associated protein levels in 2D-cultured hiPSC-CMs and force impairment in engineered heart tissues. In conclusion, our study highlights the activation of proteolytic systems in ACTN2mut hiPSC-CMs likely to cope with ACTN2 aggregation and therefore directs towards proteopathy as an additional cellular pathology caused by this ACTN2 variant, which may contribute to human ACTN2-associated cardiomyopathies.
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Affiliation(s)
- Antonia T. L. Zech
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Maksymilian Prondzynski
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
- Department of Cardiology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sonia R. Singh
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Niels Pietsch
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Ellen Orthey
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Erda Alizoti
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Josefine Busch
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Alexandra Madsen
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Charlotta S. Behrens
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Moritz Meyer-Jens
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Giulia Mearini
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Marc D. Lemoine
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
- Department of Cardiology, University Heart and Vascular Center, 20246 Hamburg, Germany
| | - Elisabeth Krämer
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Diogo Mosqueira
- Biodiscovery Institute, University of Nottingham, Nottingham NG7 2RD, UK
| | - Sanamjeet Virdi
- Heinrich-Pette-Institute, Leibniz Institute of Virology, 20246 Hamburg, Germany
| | - Daniela Indenbirken
- Heinrich-Pette-Institute, Leibniz Institute of Virology, 20246 Hamburg, Germany
| | - Maren Depke
- Department for Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Manuela Gesell Salazar
- Department for Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
| | - Uwe Völker
- Department for Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, 17475 Greifswald, Germany
| | - Ingke Braren
- Vector Facility, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
| | - William T. Pu
- Department of Cardiology, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Thomas Eschenhagen
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Elke Hammer
- Department for Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, University Medicine Greifswald, 17475 Greifswald, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Greifswald, 17475 Greifswald, Germany
| | - Saskia Schlossarek
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
| | - Lucie Carrier
- Institute of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, 20246 Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, 20246 Hamburg, Germany
- Correspondence: ; Tel.: +49-40-7410-57208
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Abstract
Background Inherited cardiomyopathies (ICs) are relatively rare. General cardiologists have little experience in diagnosing and managing these conditions. International societies have recognized the need for dedicated IC clinics. However, only few reports on such clinics are available. Methods and Results Clinical data of patients referred to our clinic during its first 2 years for a personal or family history of (possible) IC were analyzed. A total of 207 patients from 196 families were seen; 13% of probands had their diagnosis changed. Diagnosis was most commonly altered in patients referred for possible arrhythmogenic dominant right ventricular cardiomyopathy (62.5%). A total of 90% of probands had genetic testing, of whom 27.3% harbored a likely pathogenic or pathogenic variant. Of patients with confirmed hypertrophic cardiomyopathy, 31 (28.7%) were treated for left ventricular outflow tract obstruction, including septal reduction in 13. Patients with either hypertrophic cardiomyopathy or left ventricular noncompaction and a history of atrial fibrillation were started on oral anticoagulation. Oral anticoagulation was also discussed with all patients with hypertrophic cardiomyopathy and apical aneurysm. Patients with a definite diagnosis of arrhythmogenic dominant right ventricular cardiomyopathy were started on β‐blockers and given restrictive exercise prescriptions. A total of 17 patients with hypertrophic cardiomyopathy and 5 patients with likely pathogenic or likely variants in arrhythmogenic genes received primary prevention implantable cardioverter‐defibrillators. No implantable cardioverter‐defibrillators were warranted for arrhythmogenic dominant right ventricular cardiomyopathy. A total of 76 family members from 24 families had cascade screening, 32 of whom carried the familial variant. A total of 21 members from 13 gene‐elusive families were evaluated by clinical screening, 3 of whom had positive screening. Conclusions Specialized IC clinics may improve diagnosis, management, and outcomes of patients with (possible) IC and their family members.
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Affiliation(s)
- Emily Smith
- Hartford HealthCare, Heart and Vascular Institute Hartford CT
| | - Paul D Thompson
- Hartford HealthCare, Heart and Vascular Institute Hartford CT.,Department of Medicine University of Connecticut Farmington CT
| | | | - Adaya Weissler-Snir
- Hartford HealthCare, Heart and Vascular Institute Hartford CT.,Department of Medicine University of Connecticut Farmington CT
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10
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Dabner L, Pieles GE, Steward CG, Hamilton-Shield JP, Ness AR, Rogers CA, Bucciarelli-Ducci C, Greenwood R, Ellis L, Sheehan K, Reeves BC. Treatment of Barth Syndrome by Cardiolipin Manipulation (CARDIOMAN) With Bezafibrate: Protocol for a Randomized Placebo-Controlled Pilot Trial Conducted in the Nationally Commissioned Barth Syndrome Service. JMIR Res Protoc 2021; 10:e22533. [PMID: 34057417 PMCID: PMC8204243 DOI: 10.2196/22533] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 12/14/2022] Open
Abstract
Background Barth syndrome is a rare, life-threatening, X-linked recessive genetic disease that predominantly affects young males and is caused by abnormal mitochondrial lipid metabolism. Currently, there is no definitive treatment for Barth syndrome other than interventions to ameliorate acute symptoms, such as heart failure, cardiac arrhythmias, neutropenia, and severe muscle fatigue. Previous mechanistic studies have identified the lipid-lowering drug bezafibrate as a promising potential treatment; however, to date, no human trials have been performed in this population. Objective The aim of this study is to determine whether bezafibrate (and resveratrol in vitro) will increase mitochondrial biogenesis and potentially modify the cellular ratio of monolysocardiolipin (MLCL) to tetralinoleoyl-cardiolipin (L4-CL), ameliorating the disease phenotype in those living with the disease. Methods The CARDIOMAN (Cardiolipin Manipulation) study is a UK single-center, double-blinded, randomized, placebo-controlled crossover study investigating the efficacy of bezafibrate in participants with Barth syndrome. Treatment was administered in two 15-week phases with a minimum washout period of 1 month between the phases where no treatment was administered. The primary outcome is peak oxygen consumption (VO2 peak). Secondary outcomes include MLCL/L4-CL ratio and CL profile in blood cells, amino acid expression, phosphocreatine to adenosine triphosphate ratio in cardiac muscle and skeletal muscle oxidative function on phosphorus-31 magnetic resonance spectroscopy, quality of life using the Pediatric Quality of Life Inventory questionnaire, absolute neutrophil count, cardiac function and rhythm profiles at rest and during exercise, and mitochondrial organization and function assessments. Outcomes were assessed at baseline and during the final week of each treatment phase. Results A total of 12 patients were scheduled to participate across three consecutive research clinics between March and April 2019. In total, 11 participants were recruited, and the follow-up was completed in January 2020. Data analysis is ongoing, with publication expected in 2021. Conclusions This trial was approved by the United Kingdom National Research Ethics Service Committee and the Medicines and Healthcare products Regulatory Agency. The feasibility of the CARDIOMAN study will help to inform the future conduct of randomized controlled trials in rare disease populations as well as testing the efficacy of bezafibrate as a potential treatment for the disease and advancing the mechanistic understanding of Barth syndrome. Trial Registration International Standard Randomized Controlled Trial Number (ISRCTN): 58006579; https://www.isrctn.com/ISRCTN58006579 International Registered Report Identifier (IRRID) DERR1-10.2196/22533
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Affiliation(s)
- Lucy Dabner
- Bristol Trials Centre (Clinical Trials and Evaluation Unit), Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Guido E Pieles
- Bristol Congenital Heart Centre, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, United Kingdom.,National Institute of Health Research (NIHR) Biomedical Research Centre (Cardiovascular theme), University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol, Bristol, United Kingdom
| | - Colin G Steward
- School of Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom
| | - Julian P Hamilton-Shield
- NIHR Biomedical Research Centre (Nutrition theme), University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol, Bristol, United Kingdom
| | - Andrew R Ness
- NIHR Biomedical Research Centre (Nutrition theme), University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol, Bristol, United Kingdom.,Bristol Dental School, University of Bristol, Bristol, United Kingdom
| | - Chris A Rogers
- Bristol Trials Centre (Clinical Trials and Evaluation Unit), Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Chiara Bucciarelli-Ducci
- National Institute of Health Research (NIHR) Biomedical Research Centre (Cardiovascular theme), University Hospitals Bristol and Weston NHS Foundation Trust and University of Bristol, Bristol, United Kingdom.,Bristol Heart Institute, University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, United Kingdom
| | - Rosemary Greenwood
- Research Design Service South West, National Institute for Health Research, Bristol, United Kingdom
| | - Lucy Ellis
- Bristol Trials Centre (Clinical Trials and Evaluation Unit), Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Karen Sheehan
- University Hospitals Bristol and Weston NHS Foundation Trust, Bristol, United Kingdom
| | - Barnaby C Reeves
- Bristol Trials Centre (Clinical Trials and Evaluation Unit), Bristol Medical School, University of Bristol, Bristol, United Kingdom
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11
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Jiang X, Chen Y, Liu X, Ye L, Yu M, Shen Z, Lei W, Hu S. Uncovering Inherited Cardiomyopathy With Human Induced Pluripotent Stem Cells. Front Cell Dev Biol 2021; 9:672039. [PMID: 34079803 PMCID: PMC8166268 DOI: 10.3389/fcell.2021.672039] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 04/06/2021] [Indexed: 11/13/2022] Open
Abstract
In the past decades, researchers discovered the contribution of genetic defects to the pathogenesis of primary cardiomyopathy and tried to explain the pathogenesis of these diseases by establishing a variety of disease models. Although human heart tissues and primary cardiomyocytes have advantages in modeling human heart diseases, they are difficult to obtain and culture in vitro. Defects developed in genetically modified animal models are notably different from human diseases at the molecular level. The advent of human induced pluripotent stem cells (hiPSCs) provides an unprecedented opportunity to further investigate the pathogenic mechanisms of inherited cardiomyopathies in vitro using patient-specific hiPSC-derived cardiomyocytes. In this review, we will make a summary of recent advances in in vitro inherited cardiomyopathy modeling using hiPSCs.
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Affiliation(s)
- Xue Jiang
- Department of Cardiovascular Surgery of The First Affiliated Hospital & Institute for Cardiovascular Science, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Medical College, Soochow University, Suzhou, China
| | - Yihuan Chen
- Department of Cardiovascular Surgery of The First Affiliated Hospital & Institute for Cardiovascular Science, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Medical College, Soochow University, Suzhou, China
| | - Xiaofeng Liu
- The Affiliated Haian Hospital of Nantong University, Nantong, China
| | - Lingqun Ye
- Department of Cardiovascular Surgery of The First Affiliated Hospital & Institute for Cardiovascular Science, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Medical College, Soochow University, Suzhou, China
| | - Miao Yu
- Department of Cardiovascular Surgery of The First Affiliated Hospital & Institute for Cardiovascular Science, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Medical College, Soochow University, Suzhou, China
| | - Zhenya Shen
- Department of Cardiovascular Surgery of The First Affiliated Hospital & Institute for Cardiovascular Science, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Medical College, Soochow University, Suzhou, China
| | - Wei Lei
- Department of Cardiovascular Surgery of The First Affiliated Hospital & Institute for Cardiovascular Science, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Medical College, Soochow University, Suzhou, China
| | - Shijun Hu
- Department of Cardiovascular Surgery of The First Affiliated Hospital & Institute for Cardiovascular Science, Collaborative Innovation Center of Hematology, State Key Laboratory of Radiation Medicine and Protection, Medical College, Soochow University, Suzhou, China
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12
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Ebert M, Wijnmaalen AP, de Riva M, Trines SA, Androulakis AFA, Glashan CA, Schalij MJ, Peter van Tintelen J, Jongbloed JDH, Zeppenfeld K. Prevalence and Prognostic Impact of Pathogenic Variants in Patients With Dilated Cardiomyopathy Referred for Ventricular Tachycardia Ablation. JACC Clin Electrophysiol 2020; 6:1103-14. [PMID: 32972544 DOI: 10.1016/j.jacep.2020.04.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 04/13/2020] [Accepted: 04/20/2020] [Indexed: 11/21/2022]
Abstract
OBJECTIVES This study aimed to assess the frequency of (likely) pathogenic variants (LP/Pv) among dilated cardiomyopathy (DCM) ventricular tachycardia (VT) patients referred for CA and their impact on procedural outcome and long-term prognosis. BACKGROUND The prevalence of genetic variants associated with monomorphic VT among DCM is unknown. METHODS Ninety-eight consecutive patients (age 56 ± 15 years; 84% men, left ventricular ejection fraction [LVEF] 39 ± 12%) referred for DCM-VT ablation were included. Patients underwent electroanatomical mapping and testing of ≥55 cardiomyopathy-related genes. Mapping data were analyzed for low-voltage areas and abnormal potentials. LP/Pv-positive (LP/Pv+) patients were compared with LP/Pv-negative (LP/Pv-) patients and followed for VT recurrence and mortality. RESULTS In 37 (38%) patients, LP/Pv were identified, most frequently LMNA (n = 11 of 37, [30%]), TTN (n = 6 of 37, [16%]), PLN (n = 6 of 37, [16%]), SCN5A (n = 3 of 37, [8%]), RBM20 (n = 2 of 37, [5%]) and DSP (n = 2 of 37, [5%]). LP/Pv+ carriers had lower LVEF (35 ± 13% vs. LP/Pv-: 42 ± 11%; p = 0.005) and were less often men (n = 27 [73%] vs. n = 55 [90%]; p = 0.03). After a median follow-up of 2.4 years (interquartile range: 0.9 to 4.4 years), 63 (64%) patients had VT recurrence (LP/Pv+: 30 of 37 [81%] vs. LP/Pv-: 33 of 61 [54%]; p = 0.007). Twenty-eight patients (29%) died (LP/Pv+: 19 of 37 [51%] vs. LP/Pv-: 9 of 61 [15%]; p < 0.001). The cumulative 2-year VT-free survival was 41% in the total cohort (LP/Pv+: 16% vs. LP/Pv-: 54%; p = 0.001). The presence of LP/Pv (hazard ratio: 1.9; 95% confidence interval: 1.1 to 3.4; p = 0.02) and unipolar low-voltage area size/cm2 increase (hazard ratio: 2.5; 95% confidence interval: 1.6 to 4.0; p < 0.001) were associated with a decreased 2-year VT-free survival. CONCLUSIONS In patients with DCM-VT, a genetic cause is frequently identified. LP/Pv+ patients have a lower LVEF and more extensive VT substrates, which, in combination with disease progression, may contribute to the poor prognosis. Genetic testing in patients with DCM-VT should therefore be recommended.
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13
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Rovina D, Castiglioni E, Niro F, Mallia S, Pompilio G, Gowran A. "Betwixt Mine Eye and Heart a League Is Took": The Progress of Induced Pluripotent Stem-Cell-Based Models of Dystrophin-Associated Cardiomyopathy. Int J Mol Sci 2020; 21:E6997. [PMID: 32977524 DOI: 10.3390/ijms21196997] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/17/2020] [Accepted: 09/21/2020] [Indexed: 12/19/2022] Open
Abstract
The ultimate goal of precision disease modeling is to artificially recreate the disease of affected people in a highly controllable and adaptable external environment. This field has rapidly advanced which is evident from the application of patient-specific pluripotent stem-cell-derived precision therapies in numerous clinical trials aimed at a diverse set of diseases such as macular degeneration, heart disease, spinal cord injury, graft-versus-host disease, and muscular dystrophy. Despite the existence of semi-adequate treatments for tempering skeletal muscle degeneration in dystrophic patients, nonischemic cardiomyopathy remains one of the primary causes of death. Therefore, cardiovascular cells derived from muscular dystrophy patients' induced pluripotent stem cells are well suited to mimic dystrophin-associated cardiomyopathy and hold great promise for the development of future fully effective therapies. The purpose of this article is to convey the realities of employing precision disease models of dystrophin-associated cardiomyopathy. This is achieved by discussing, as suggested in the title echoing William Shakespeare's words, the settlements (or "leagues") made by researchers to manage the constraints ("betwixt mine eye and heart") distancing them from achieving a perfect precision disease model.
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14
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Moharem-Elgamal S, Sammut E, Stuart G. Genetic Counseling in Inherited Cardiomyopathies. JACC Case Rep 2020; 2:392-395. [PMID: 34317249 PMCID: PMC8311730 DOI: 10.1016/j.jaccas.2020.02.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Affiliation(s)
- Sarah Moharem-Elgamal
- Department of Cardiology, Bristol Heart Institute,- Bristol, United Kingdom
- University of Bristol, Bristol, United Kingdom
- National Heart Institute, Giza, Egypt
| | - Eva Sammut
- Department of Cardiology, Bristol Heart Institute,- Bristol, United Kingdom
- University of Bristol, Bristol, United Kingdom
| | - Graham Stuart
- Department of Cardiology, Bristol Heart Institute,- Bristol, United Kingdom
- University of Bristol, Bristol, United Kingdom
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15
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Teekakirikul P, Zhu W, Huang HC, Fung E. Hypertrophic Cardiomyopathy: An Overview of Genetics and Management. Biomolecules 2019; 9:biom9120878. [PMID: 31888115 PMCID: PMC6995589 DOI: 10.3390/biom9120878] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 12/12/2019] [Accepted: 12/12/2019] [Indexed: 12/31/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a genetically heterogeneous cardiac muscle disorder with a diverse natural history, characterized by unexplained left ventricular hypertrophy (LVH), with histopathological hallmarks including myocyte enlargement, myocyte disarray and myocardial fibrosis. Although these features can cause significant cardiac symptoms, many young individuals with HCM are asymptomatic or mildly symptomatic. Sudden cardiac death (SCD) may occur as the initial clinical manifestation. Over the past few decades, HCM has been considered a disease of sarcomere, and typically as an autosomal dominant disease with variable expressivity and incomplete penetrance. Important insights into the genetic landscape of HCM have enhanced our understanding of the molecular pathogenesis, empowered gene-based diagnostic testing to identify at-risk individuals, and offered potential targets for the development of therapeutic agents. This article reviews the current knowledge on the clinical genetics and management of HCM.
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Affiliation(s)
- Polakit Teekakirikul
- Division of Cardiology, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Centre for Cardiovascular Genomics and Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Correspondence: (P.T.); (E.F.); Tel.: +852-3505-3139 (P.T.); +852-3505-3140 (E.F.)
| | - Wenjuan Zhu
- Centre for Cardiovascular Genomics and Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Division of Medical Sciences, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
| | - Helen C. Huang
- Department of Medicine (Cardiology), University of California, Los Angeles, CA 90095, USA
| | - Erik Fung
- Division of Cardiology, Department of Medicine and Therapeutics, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Lui Che Woo Institute of Innovative Medicine, The Chinese University of Hong Kong, Hong Kong, China
- Laboratory for Heart Failure + Circulation Research, Li Ka Shing Institute of Health Sciences, Prince of Wales Hospital and Gerald Choa Cardiac Research Centre, The Chinese University of Hong Kong, Hong Kong, China
- Correspondence: (P.T.); (E.F.); Tel.: +852-3505-3139 (P.T.); +852-3505-3140 (E.F.)
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Abstract
Hypertrophic cardiomyopathy (HCM) is a genetically heterogeneous cardiac muscle disorder with a diverse natural history, characterized by unexplained left ventricular hypertrophy (LVH), with histopathological hallmarks including myocyte enlargement, myocyte disarray and myocardial fibrosis. Although these features can cause significant cardiac symptoms, many young individuals with HCM are asymptomatic or mildly symptomatic. Sudden cardiac death (SCD) may occur as the initial clinical manifestation. Over the past few decades, HCM has been considered a disease of sarcomere, and typically as an autosomal dominant disease with variable expressivity and incomplete penetrance. Important insights into the genetic landscape of HCM have enhanced our understanding of the molecular pathogenesis, empowered gene-based diagnostic testing to identify at-risk individuals, and offered potential targets for the development of therapeutic agents. This article reviews the current knowledge on the clinical genetics and management of HCM.
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17
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Abstract
Cardiac fibrosis is a common phenomenon in different types of heart diseases, such as ischemic heart disease, inherited cardiomyopathy mutations, diabetes, and ageing and is associated with morbidity and mortality. Increased accumulation of extracellular matrix (ECM) that impacts cardiac function, is the underlying cause of fibrotic heart disease. There are four different types of cardiac fibrosis, including, reactive interstitial fibrosis, replacement fibrosis, infiltrative interstitial fibrosis and endomyocardial fibrosis. They are involved in the activation and transformation of cardiac fibroblasts to myofibroblasts, which participate in ECM production and fibrotic process and several inflammatory pathways. Besides the ECM proteins, myofibroblasts also express smooth muscle α-actin, SM22 and caldesmon and other markers related to fibrotic process. Most commonly employed techniques to assess myocardial fibrosis include stress echocardiography, cardiac magnetic resonance imaging and positron emission tomography. Because of the involvement of renin-angiotensin-II-aldosterone system, transforming growth factor-β signaling and activin-linked kinase 5 in the mechanisms of cardiac fibrosis, these pathways and the involved proteins are useful as therapeutic targets. However, because of the importance of these pathways in many other physiological functions, their therapeutic targeting needs to be approached with caution.
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Affiliation(s)
- Jing Tian
- Department of Cardiology, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| | - Xinjiang An
- Department of Cardiology, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221002, P.R. China
| | - Ling Niu
- Department of Cardiology, Xuzhou Children's Hospital, Xuzhou, Jiangsu 221002, P.R. China
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18
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Davis J, Wen H, Edwards T, Metzger JM. Allele and species dependent contractile defects by restrictive and hypertrophic cardiomyopathy-linked troponin I mutants. J Mol Cell Cardiol 2008; 44:891-904. [PMID: 18423659 PMCID: PMC2443058 DOI: 10.1016/j.yjmcc.2008.02.274] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Revised: 02/13/2008] [Accepted: 02/16/2008] [Indexed: 11/15/2022]
Abstract
Restrictive cardiomyopathy (RCM) is a debilitating disease characterized by impaired ventricular filling, reduced ventricular volumes, and severe diastolic dysfunction. Hypertrophic cardiomyopathy (HCM) is characterized by ventricular hypertrophy and heightened risk of premature sudden cardiac death. These cardiomyopathies can result from mutations in the same gene that encodes for cardiac troponin I (cTnI). Acute genetic engineering of adult rat cardiac myocytes was used to ascertain whether primary physiologic outcomes could distinguish between RCM and HCM alleles at the cellular level. Co-transduction of cardiac myocytes with wild-type (WT) cTnI and RCM/HCM linked mutants in cTnI's inhibitory region (IR) demonstrated that WT cTnI preferentially incorporated into the sarcomere over IR mutants. The cTnI IR mutants exhibited minor effects in single myocyte Ca(2+)-activated tension assays yet prolonged relaxation and Ca(2+) decay. In comparison RCM cTnI mutants in the helix-4/C-terminal region demonstrated a) hyper-sensitivity to Ca(2+) under loaded conditions, b) slowed myocyte mechanical relaxation and Ca(2+) transient decay, c) frequency-dependent Ca(2+)-independent diastolic tone, d) heightened myofilament incorporation and e) irreversible cellular contractile defects with acute diltiazem administration. For species comparison, a subset of cTnI mutants were tested in isolated adult rabbit cardiac myocytes. Here, RCM and HCM mutant cTnIs exerted similar effects of slowed myocyte relaxation and Ca(2+) transient decay but did not show variable phenotypes by cTnI region. This study highlights cellular contractile defects by cardiomyopathy mutant cTnIs that are allele and species dependent. The species dependent results in particular raise important issues toward elucidating a unifying mechanistic pathway underlying the inherited cardiomyopathies.
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Affiliation(s)
- Jennifer Davis
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, USA
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19
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Abstract
Dilated cardiomyopathy recently has been recognized in juvenile Portuguese Water Dogs. The purpose of this study was to evaluate unaffected and affected puppies by physical examination, electrocardiogram (ECG), echocardiogram, specific biochemical assays, and ultrastructure to document disease progression and to develop a method of early detection. Results of segregation analysis were consistent with autosomal recessive inheritance. Of 124 puppies evaluated clinically and echocardiographically, 10 were affected. No significant differences were found between unaffected and affected puppies for blood and myocardial carnitine or taurine concentrations, serum chemical variables, results of ophthalmological examinations, ECGs, or measurement of urine metabolites. Ultrastructural examination of myocardium from affected dogs revealed myofibrillar atrophy and small regions of myofibrillar degeneration, most prominently at the region of the intercalated discs. Only echocardiography allowed detection of affected puppies before clinical signs became evident. Echocardiography revealed a significant difference in the shortening fraction, E point to septal separation, and the end systolic and diastolic left ventricular internal diameters. Affected puppies were detected 1-4 weeks before the development of acute congestive heart failure.
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Affiliation(s)
- Margaret M Sleeper
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia 19104-6010, USA.
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