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Dias LG, Reis CHO, Dos Santos L, Krause Neto W, Lima-Leopoldo AP, Baker JS, Leopoldo AS, Bocalini DS. Strength training improves heart function, collagen and strength in rats with heart failure. J Physiol Sci 2024; 74:10. [PMID: 38365576 PMCID: PMC10873996 DOI: 10.1186/s12576-024-00899-3] [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: 10/28/2023] [Accepted: 01/20/2024] [Indexed: 02/18/2024]
Abstract
BACKGROUND/OBJECTIVES Myocardial infarction (MI) frequently leads to cardiac remodeling and failure with impaired life quality, playing an important role in cardiovascular deaths. Although physical exercise is a well-recognized effective non-pharmacological therapy for cardiovascular diseases, the effects of strength training (ST) on the structural and functional aspects of cardiac remodeling need to be further documented. In this study, we aimed to investigate the role of a linear block ST protocol in the rat model of MI. METHODS AND RESULTS After 6 weeks of MI induction or sham surgery, male adult rats performed ST for the following 12 weeks. The ladder-based ST program was organized in three mesocycles of 4 weeks, with one load increment for each block according to the maximal carrying load test. After 12 weeks, the infarcted-trained rats exhibited an increase in performance, associated with reduced cardiac hypertrophy and pulmonary congestion compared with the untrained group. Despite not changing MI size, the ST program partially prevented cardiac dilatation and ventricular dysfunction assessed by echocardiography and hemodynamics, and interstitial fibrosis evaluated by histology. In addition, isolated cardiac muscles from infarcted-trained rats had improved contractility parameters in a steady state, and in response to calcium or stimuli pauses. CONCLUSIONS The ST in infarcted rats increased the capacity to carry mass, associated with attenuation of cardiac remodeling and pulmonary congestion with improving cardiac function that could be attributed, at least in part, to the improvement of myocardial contractility.
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Affiliation(s)
- Leisiane G Dias
- Experimental Physiology and Biochemistry Laboratory. Physical Education and Sport Center, Federal University of Espirito Santo, Vitoria, Brazil
| | - Carlos H O Reis
- Experimental Physiology and Biochemistry Laboratory. Physical Education and Sport Center, Federal University of Espirito Santo, Vitoria, Brazil
| | - Leonardo Dos Santos
- Department of Physiological Sciences, Health Sciences Center, Federal University of Espirito Santo, Vitoria, Brazil
| | - Walter Krause Neto
- Department of Morphology and Genetics, Federal University of São Paulo, São Paulo, Brazil
| | - Ana Paula Lima-Leopoldo
- Experimental Physiology and Biochemistry Laboratory. Physical Education and Sport Center, Federal University of Espirito Santo, Vitoria, Brazil
| | - Julien S Baker
- Department of Sport, Physical Education and Health, Centre for Health and Exercise Science Research, Hong Kong Baptist University, Kowloon Tong, Hong Kong
| | - André S Leopoldo
- Experimental Physiology and Biochemistry Laboratory. Physical Education and Sport Center, Federal University of Espirito Santo, Vitoria, Brazil
| | - Danilo S Bocalini
- Experimental Physiology and Biochemistry Laboratory. Physical Education and Sport Center, Federal University of Espirito Santo, Vitoria, Brazil.
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2
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Lian H, Qin Z, Wu M, Zuo P, Bai L, Lu M, Li L, Zhang H. Contractility detection of isolated mouse papillary muscle using myotronic Myostation-Intact device. Animal Model Exp Med 2022; 5:445-452. [PMID: 36168142 PMCID: PMC9610137 DOI: 10.1002/ame2.12272] [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: 04/13/2022] [Accepted: 08/29/2022] [Indexed: 11/06/2022] Open
Abstract
Background To understand the relationship between myocardial contractility and external stimuli, detecting ex vivo myocardial contractility is necessary. Methods We elaborated a method for contractility detection of isolated C57 mouse papillary muscle using Myostation‐Intact system under different frequencies, voltages, and calcium concentrations. Results The results indicated that the basal contractility of the papillary muscle was 0.27 ± 0.03 mN at 10 V, 500‐ms pulse duration, and 1 Hz. From 0.1 to 1.0 Hz, contractility decreased with an increase in frequency (0.45 ± 0.11–0.10 ± 0.02 mN). The voltage‐initiated muscle contractility varied from 3 to 6 V, and the contractility gradually increased as the voltage increased from 6 to 10 V (0.14 ± 0.02–0.28 ± 0.03 mN). Moreover, the muscle contractility increased when the calcium concentration was increased from 1.5 to 3 mM (0.45 ± 0.17–1.11 ± 0.05 mN); however, the contractility stopped increasing even when the concentration was increased to 7.5 mM (1.02 ± 0.23 mN). Conclusions Our method guaranteed the survivability of papillary muscle ex vivo and provided instructions for Myostation‐Intact users for isolated muscle contractility investigations.
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Affiliation(s)
- Hong Lian
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Beijing Key Laboratory of Preclinical Research and Evaluation for Cardiovascular Implant Materials, Animal Experimental Center, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Zhuyun Qin
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Adult Surgical Intensive Care Unit, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Mengge Wu
- National Health Commission Key Laboratory of Cardiovascular Regenerative Medicine, Fuwai Central-China Hospital, Central-China Subcenter of National Center for Cardiovascular Diseases, Zhengzhou, China
| | - Peipei Zuo
- National Health Commission Key Laboratory of Cardiovascular Regenerative Medicine, Fuwai Central-China Hospital, Central-China Subcenter of National Center for Cardiovascular Diseases, Zhengzhou, China
| | - Lina Bai
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Minjie Lu
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lulu Li
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Disease, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Adult Surgical Intensive Care Unit, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Haitao Zhang
- Adult Surgical Intensive Care Unit, Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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3
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Critical Evaluation of Current Hypotheses for the Pathogenesis of Hypertrophic Cardiomyopathy. Int J Mol Sci 2022; 23:ijms23042195. [PMID: 35216312 PMCID: PMC8880276 DOI: 10.3390/ijms23042195] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/07/2022] [Accepted: 02/14/2022] [Indexed: 02/04/2023] Open
Abstract
Hereditary hypertrophic cardiomyopathy (HCM), due to mutations in sarcomere proteins, occurs in more than 1/500 individuals and is the leading cause of sudden cardiac death in young people. The clinical course exhibits appreciable variability. However, typically, heart morphology and function are normal at birth, with pathological remodeling developing over years to decades, leading to a phenotype characterized by asymmetric ventricular hypertrophy, scattered fibrosis and myofibrillar/cellular disarray with ultimate mechanical heart failure and/or severe arrhythmias. The identity of the primary mutation-induced changes in sarcomere function and how they trigger debilitating remodeling are poorly understood. Support for the importance of mutation-induced hypercontractility, e.g., increased calcium sensitivity and/or increased power output, has been strengthened in recent years. However, other ideas that mutation-induced hypocontractility or non-uniformities with contractile instabilities, instead, constitute primary triggers cannot yet be discarded. Here, we review evidence for and criticism against the mentioned hypotheses. In this process, we find support for previous ideas that inefficient energy usage and a blunted Frank–Starling mechanism have central roles in pathogenesis, although presumably representing effects secondary to the primary mutation-induced changes. While first trying to reconcile apparently diverging evidence for the different hypotheses in one unified model, we also identify key remaining questions and suggest how experimental systems that are built around isolated primarily expressed proteins could be useful.
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4
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Marston S. Force Measurements From Myofibril to Filament. Front Physiol 2022; 12:817036. [PMID: 35153821 PMCID: PMC8829514 DOI: 10.3389/fphys.2021.817036] [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: 11/17/2021] [Accepted: 12/21/2021] [Indexed: 11/13/2022] Open
Abstract
Contractility, the generation of force and movement by molecular motors, is the hallmark of all muscles, including striated muscle. Contractility can be studied at every level of organization from a whole animal to single molecules. Measurements at sub-cellular level are particularly useful since, in the absence of the excitation-contraction coupling system, the properties of the contractile proteins can be directly investigated; revealing mechanistic details not accessible in intact muscle. Moreover, the conditions can be manipulated with ease, for instance changes in activator Ca2+, small molecule effector concentration or phosphorylation levels and introducing mutations. Subcellular methods can be successfully applied to frozen materials and generally require the smallest amount of tissue, thus greatly increasing the range of possible experiments compared with the study of intact muscle and cells. Whilst measurement of movement at the subcellular level is relatively simple, measurement of force is more challenging. This mini review will describe current methods for measuring force production at the subcellular level including single myofibril and single myofilament techniques.
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5
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Ribitsch I, Baptista PM, Lange-Consiglio A, Melotti L, Patruno M, Jenner F, Schnabl-Feichter E, Dutton LC, Connolly DJ, van Steenbeek FG, Dudhia J, Penning LC. Large Animal Models in Regenerative Medicine and Tissue Engineering: To Do or Not to Do. Front Bioeng Biotechnol 2020; 8:972. [PMID: 32903631 PMCID: PMC7438731 DOI: 10.3389/fbioe.2020.00972] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 07/27/2020] [Indexed: 12/13/2022] Open
Abstract
Rapid developments in Regenerative Medicine and Tissue Engineering has witnessed an increasing drive toward clinical translation of breakthrough technologies. However, the progression of promising preclinical data to achieve successful clinical market authorisation remains a bottleneck. One hurdle for progress to the clinic is the transition from small animal research to advanced preclinical studies in large animals to test safety and efficacy of products. Notwithstanding this, to draw meaningful and reliable conclusions from animal experiments it is critical that the species and disease model of choice is relevant to answer the research question as well as the clinical problem. Selecting the most appropriate animal model requires in-depth knowledge of specific species and breeds to ascertain the adequacy of the model and outcome measures that closely mirror the clinical situation. Traditional reductionist approaches in animal experiments, which often do not sufficiently reflect the studied disease, are still the norm and can result in a disconnect in outcomes observed between animal studies and clinical trials. To address these concerns a reconsideration in approach will be required. This should include a stepwise approach using in vitro and ex vivo experiments as well as in silico modeling to minimize the need for in vivo studies for screening and early development studies, followed by large animal models which more closely resemble human disease. Naturally occurring, or spontaneous diseases in large animals remain a largely untapped resource, and given the similarities in pathophysiology to humans they not only allow for studying new treatment strategies but also disease etiology and prevention. Naturally occurring disease models, particularly for longer lived large animal species, allow for studying disorders at an age when the disease is most prevalent. As these diseases are usually also a concern in the chosen veterinary species they would be beneficiaries of newly developed therapies. Improved awareness of the progress in animal models is mutually beneficial for animals, researchers, human and veterinary patients. In this overview we describe advantages and disadvantages of various animal models including domesticated and companion animals used in regenerative medicine and tissue engineering to provide an informed choice of disease-relevant animal models.
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Affiliation(s)
- Iris Ribitsch
- Veterm, Department for Companion Animals and Horses, University Equine Hospital, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Pedro M. Baptista
- Laboratory of Organ Bioengineering and Regenerative Medicine, Health Research Institute of Aragon (IIS Aragon), Zaragoza, Spain
| | - Anna Lange-Consiglio
- Department of Veterinary Medicine, Università degli Studi di Milano, Milan, Italy
| | - Luca Melotti
- Department of Comparative Biomedicine and Food Science, University of Padua, Padua, Italy
| | - Marco Patruno
- Department of Comparative Biomedicine and Food Science, University of Padua, Padua, Italy
| | - Florien Jenner
- Veterm, Department for Companion Animals and Horses, University Equine Hospital, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Eva Schnabl-Feichter
- Clinical Unit of Small Animal Surgery, Department for Companion Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Luke C. Dutton
- Department of Clinical Sciences and Services, Royal Veterinary College, Hertfordshire, United Kingdom
| | - David J. Connolly
- Clinical Unit of Small Animal Surgery, Department for Companion Animals and Horses, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Frank G. van Steenbeek
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
| | - Jayesh Dudhia
- Department of Clinical Sciences and Services, Royal Veterinary College, Hertfordshire, United Kingdom
| | - Louis C. Penning
- Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Utrecht, Netherlands
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6
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Bhagwan JR, Mosqueira D, Chairez-Cantu K, Mannhardt I, Bodbin SE, Bakar M, Smith JGW, Denning C. Isogenic models of hypertrophic cardiomyopathy unveil differential phenotypes and mechanism-driven therapeutics. J Mol Cell Cardiol 2020; 145:43-53. [PMID: 32531470 PMCID: PMC7487780 DOI: 10.1016/j.yjmcc.2020.06.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/18/2020] [Accepted: 06/05/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Hypertrophic cardiomyopathy (HCM) is a prevalent and complex cardiovascular condition. Despite being strongly associated with genetic alterations, wide variation of disease penetrance, expressivity and hallmarks of progression complicate treatment. We aimed to characterize different human isogenic cellular models of HCM bearing patient-relevant mutations to clarify genetic causation and disease mechanisms, hence facilitating the development of effective therapeutics. METHODS We directly compared the p.β-MHC-R453C and p.ACTC1-E99K HCM-associated mutations in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and their healthy isogenic counterparts, generated using CRISPR/Cas9 genome editing technology. By harnessing several state-of-the-art HCM phenotyping techniques, these mutations were investigated to identify similarities and differences in disease progression and hypertrophic signaling pathways, towards establishing potential targets for pharmacological treatment. CRISPR/Cas9 knock-in of the genetically-encoded calcium indicator R-GECO1.0 to the AAVS1 locus into these disease models resulted in calcium reporter lines. RESULTS Confocal line scan analysis identified calcium transient arrhythmias and intracellular calcium overload in both models. The use of optogenetics and 2D/3D contractility assays revealed opposing phenotypes in the two mutations. Gene expression analysis highlighted upregulation of CALM1, CASQ2 and CAMK2D, and downregulation of IRF8 in p.β-MHC-R453C mutants, whereas the opposite changes were detected in p.ACTC1-E99K mutants. Contrasting profiles of nuclear translocation of NFATc1 and MEF2 between the two HCM models suggest differential hypertrophic signaling pathway activation. Calcium transient abnormalities were rescued with combination of dantrolene and ranolazine, whilst mavacamten reduced the hyper-contractile phenotype of p.ACTC1-E99K hiPSC-CMs. CONCLUSIONS Our data show that hypercontractility and molecular signaling within HCM are not uniform between different gene mutations, suggesting that a 'one-size fits all' treatment underestimates the complexity of the disease. Understanding where the similarities (arrhythmogenesis, bioenergetics) and differences (contractility, molecular profile) lie will allow development of therapeutics that are directed towards common mechanisms or tailored to each disease variant, hence providing effective patient-specific therapy.
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Affiliation(s)
- Jamie R Bhagwan
- Division of Cancer & Stem Cells, Biodiscovery Institute, University of Nottingham, NG7 2RD, UK.
| | - Diogo Mosqueira
- Division of Cancer & Stem Cells, Biodiscovery Institute, University of Nottingham, NG7 2RD, UK.
| | - Karolina Chairez-Cantu
- Division of Cancer & Stem Cells, Biodiscovery Institute, University of Nottingham, NG7 2RD, UK
| | - Ingra Mannhardt
- Department of Experimental Pharmacology and Toxicology, Cardiovascular Research Center, University Medical Center Hamburg-Eppendorf, and DZHK (German Center for Cardiovascular Research), partner site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Sara E Bodbin
- Division of Cancer & Stem Cells, Biodiscovery Institute, University of Nottingham, NG7 2RD, UK
| | - Mine Bakar
- Division of Cancer & Stem Cells, Biodiscovery Institute, University of Nottingham, NG7 2RD, UK
| | - James G W Smith
- Division of Cancer & Stem Cells, Biodiscovery Institute, University of Nottingham, NG7 2RD, UK; Faculty of Medicine and Health Sciences, Norwich Medical School, University of East Anglia,NR4 7UQ, UK
| | - Chris Denning
- Division of Cancer & Stem Cells, Biodiscovery Institute, University of Nottingham, NG7 2RD, UK.
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7
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Teng GZ, Shaikh Z, Liu H, Dawson JF. M-class hypertrophic cardiomyopathy cardiac actin mutations increase calcium sensitivity of regulated thin filaments. Biochem Biophys Res Commun 2019; 519:148-152. [PMID: 31481237 DOI: 10.1016/j.bbrc.2019.08.151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 08/27/2019] [Indexed: 12/22/2022]
Abstract
Hypertrophic cardiomyopathy is a commonly occurring cardiovascular disease resulting primarily from changes in proteins participating in muscle contraction in the heart, including the cardiac actin protein. Changes in cardiac actin located exclusively in the myosin binding site are called M-class variants and include the H88Y, R95C, and E99K substitutions and F90Δ deletion. The prevailing hypothesis for these mutations is that hypertrophic cardiomyopathy is the result of increased calcium sensitivity of contraction in the myocardium. To test this hypothesis, we studied the activity of myosin at varying calcium concentrations in the presence of regulated thin filaments containing M-class cardiac actin variants. We found that all M-class cardiac actin variants exhibit increased calcium sensitivity, with the R95C variant also displaying significant decreases in maximal myosin activity. This work represents the first characterization of all M-class variant proteins and suggests that drugs targeting contraction specifically to treat hypertrophic cardiomyopathy must consider the impact on both calcium sensitivity and maximal myosin activity on overall heart health.
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Affiliation(s)
- Grace Zi Teng
- Department of Molecular & Cellular Biology and Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Zeeshan Shaikh
- Department of Molecular & Cellular Biology and Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Haidun Liu
- Department of Molecular & Cellular Biology and Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - John F Dawson
- Department of Molecular & Cellular Biology and Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, N1G 2W1, Canada.
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8
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Lin YH, Yap J, Ramachandra CJ, Hausenloy DJ. New insights provided by myofibril mechanics in inherited cardiomyopathies. CONDITIONING MEDICINE 2019; 2:213-224. [PMID: 32133438 PMCID: PMC7055865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Cardiomyopathies represent a heterogeneous group of cardiac disorders that perturb cardiac contraction and/or relaxation, and can result in arrhythmias, heart failure, and sudden cardiac death. Based on morphological and functional differences, cardiomyopathies have been classified into hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM), and restrictive cardiomyopathy (RCM). It has been well documented that mutations in genes encoding sarcomeric proteins are associated with the onset of inherited cardiomyopathies. However, correlating patient genotype to the clinical phenotype has been challenging because of the complex genetic backgrounds, environmental influences, and lifestyles of individuals. Thus, "scaling down" the focus to the basic contractile unit of heart muscle using isolated single myofibril function techniques is of great importance and may be used to understand the molecular basis of disease-causing sarcomeric mutations. Single myofibril bundles harvested from diseased human or experimental animal hearts, as well as cultured adult cardiomyocytes or human cardiomyocytes derived from induced pluripotent stem cells, can be used, thereby providing an ideal multi-level, cross-species platform to dissect sarcomeric function in cardiomyopathies. Here, we will review the myofibril function technique, and discuss alterations in myofibril mechanics, which are known to occur in sarcomeric genetic mutations linked to inherited HCM, DCM, and RCM, and describe the therapeutic potential for future target identification.
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Affiliation(s)
- Ying-Hsi Lin
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
- Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Jonathan Yap
- Center for Cardiovascular Research, John A. Burns School of Medicine, University of Hawaii, USA
| | - Chrishan J.A. Ramachandra
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
- Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
| | - Derek J. Hausenloy
- National Heart Research Institute Singapore, National Heart Centre Singapore, Singapore
- Cardiovascular & Metabolic Disorders Program, Duke-National University of Singapore Medical School, Singapore
- Yong Loo Lin School of Medicine, National University Singapore, Singapore
- The Hatter Cardiovascular Institute, University College London, London, UK
- The National Institute of Health Research University College London Hospitals
- Biomedical Research Centre, Research & Development, London, UK
- Tecnologico de Monterrey, Centro de Biotecnologia-FEMSA, Nuevo Leon, Mexico
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Mosqueira D, Smith JGW, Bhagwan JR, Denning C. Modeling Hypertrophic Cardiomyopathy: Mechanistic Insights and Pharmacological Intervention. Trends Mol Med 2019; 25:775-790. [PMID: 31324451 DOI: 10.1016/j.molmed.2019.06.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2019] [Revised: 06/12/2019] [Accepted: 06/18/2019] [Indexed: 02/06/2023]
Abstract
Hypertrophic cardiomyopathy (HCM) is a prevalent and complex cardiovascular disease where cardiac dysfunction often associates with mutations in sarcomeric genes. Various models based on tissue explants, isolated cardiomyocytes, skinned myofibrils, and purified actin/myosin preparations have uncovered disease hallmarks, enabling the development of putative therapeutics, with some reaching clinical trials. Newly developed human pluripotent stem cell (hPSC)-based models could be complementary by overcoming some of the inconsistencies of earlier systems, whilst challenging and/or clarifying previous findings. In this article we compare recent progress in unveiling multiple HCM mechanisms in different models, highlighting similarities and discrepancies. We explore how insight is facilitating the design of new HCM therapeutics, including those that regulate metabolism, contraction and heart rhythm, providing a future perspective for treatment of HCM.
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Affiliation(s)
- Diogo Mosqueira
- Department of Stem Cell Biology, Centre of Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, UK.
| | - James G W Smith
- Faculty of Medicine and Health Sciences, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, UK
| | - Jamie R Bhagwan
- Department of Stem Cell Biology, Centre of Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, UK
| | - Chris Denning
- Department of Stem Cell Biology, Centre of Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, UK
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10
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Smith JGW, Owen T, Bhagwan JR, Mosqueira D, Scott E, Mannhardt I, Patel A, Barriales-Villa R, Monserrat L, Hansen A, Eschenhagen T, Harding SE, Marston S, Denning C. Isogenic Pairs of hiPSC-CMs with Hypertrophic Cardiomyopathy/LVNC-Associated ACTC1 E99K Mutation Unveil Differential Functional Deficits. Stem Cell Reports 2018; 11:1226-1243. [PMID: 30392975 PMCID: PMC6235010 DOI: 10.1016/j.stemcr.2018.10.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 10/04/2018] [Accepted: 10/05/2018] [Indexed: 12/14/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a primary disorder of contractility in heart muscle. To gain mechanistic insight and guide pharmacological rescue, this study models HCM using isogenic pairs of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) carrying the E99K-ACTC1 cardiac actin mutation. In both 3D engineered heart tissues and 2D monolayers, arrhythmogenesis was evident in all E99K-ACTC1 hiPSC-CMs. Aberrant phenotypes were most common in hiPSC-CMs produced from the heterozygote father. Unexpectedly, pathological phenotypes were less evident in E99K-expressing hiPSC-CMs from the two sons. Mechanistic insight from Ca2+ handling expression studies prompted pharmacological rescue experiments, wherein dual dantroline/ranolazine treatment was most effective. Our data are consistent with E99K mutant protein being a central cause of HCM but the three-way interaction between the primary genetic lesion, background (epi)genetics, and donor patient age may influence the pathogenic phenotype. This illustrates the value of isogenic hiPSC-CMs in genotype-phenotype correlations.
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Affiliation(s)
- James G W Smith
- Wolfson Centre for Stem Cells, Tissue Engineering and Modelling, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; Faculty of Medicine and Health Sciences, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7UQ, UK.
| | - Thomas Owen
- National Heart and Lung Institute, Imperial College, London W12 0NN, UK
| | - Jamie R Bhagwan
- Wolfson Centre for Stem Cells, Tissue Engineering and Modelling, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Diogo Mosqueira
- Wolfson Centre for Stem Cells, Tissue Engineering and Modelling, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Elizabeth Scott
- Wolfson Centre for Stem Cells, Tissue Engineering and Modelling, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Ingra Mannhardt
- Institute of Experimental Pharmacology and Toxicology, University Medical Centre, Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Asha Patel
- Wolfson Centre for Stem Cells, Tissue Engineering and Modelling, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; Department of Gene Therapy, National Heart and Lung Institute, Imperial College London SW3 6LR, UK
| | - Roberto Barriales-Villa
- Inherited Cardiovascular Diseases Unit, Cardiology Service, Complexo Hospitalario Universitario A Coruña, Servizo Galego de Saúde (SERGAS), Universidade da Coruña, A Coruña, Spain; Instituto de Investigación Biomédica de A Coruña (INIBIC), A Coruña, Spain
| | - Lorenzo Monserrat
- Instituto de Investigación Biomédica de A Coruña (INIBIC), A Coruña, Spain; Health in Code S.L., Cardiology Department, A Coruña, Spain
| | - Arne Hansen
- Institute of Experimental Pharmacology and Toxicology, University Medical Centre, Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Thomas Eschenhagen
- Institute of Experimental Pharmacology and Toxicology, University Medical Centre, Hamburg-Eppendorf, Hamburg, Germany; DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Hamburg, Germany
| | - Sian E Harding
- National Heart and Lung Institute, Imperial College, London W12 0NN, UK
| | - Steve Marston
- National Heart and Lung Institute, Imperial College, London W12 0NN, UK
| | - Chris Denning
- Wolfson Centre for Stem Cells, Tissue Engineering and Modelling, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK.
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11
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Dvornikov AV, de Tombe PP, Xu X. Phenotyping cardiomyopathy in adult zebrafish. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2018; 138:116-125. [PMID: 29884423 PMCID: PMC6269218 DOI: 10.1016/j.pbiomolbio.2018.05.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Revised: 04/26/2018] [Accepted: 05/29/2018] [Indexed: 12/21/2022]
Abstract
Hypertrophic cardiomyopathy (HCM) is usually manifested by increased myofilament Ca2+ sensitivity, excessive contractility, and impaired relaxation. In contrast, dilated cardiomyopathy (DCM) originates from insufficient sarcomere contractility and reduced cardiac pump function, subsequently resulting in heart failure. The zebrafish has emerged as a new model of human cardiomyopathy with high-throughput screening, which will facilitate the discovery of novel genetic factors and the development of new therapies. Given the small hearts of zebrafish, better phenotyping tools are needed to discern different types of cardiomyopathy, such as HCM and DCM. This article reviews the existing models of cardiomyopathy, available morphologic and functional methods, and current understanding of the different types of cardiomyopathy in adult zebrafish.
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Affiliation(s)
- Alexey V Dvornikov
- Department of Biochemistry and Molecular Biology, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.
| | - Pieter P de Tombe
- University of Illinois at Chicago, Department of Physiology and Biophysics, Chicago, IL, USA; Magdi Yacoub Institute, Cardiac Biophysics Division, Harefield, UK; Imperial College, Heart and Lung Institute, London, UK; Freiburg University, Institute for Experimental Cardiovascular Medicine, Germany
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology, Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN, USA.
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12
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The Molecular Mechanisms of Mutations in Actin and Myosin that Cause Inherited Myopathy. Int J Mol Sci 2018; 19:ijms19072020. [PMID: 29997361 PMCID: PMC6073311 DOI: 10.3390/ijms19072020] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 07/06/2018] [Accepted: 07/08/2018] [Indexed: 12/23/2022] Open
Abstract
The discovery that mutations in myosin and actin genes, together with mutations in the other components of the muscle sarcomere, are responsible for a range of inherited muscle diseases (myopathies) has revolutionized the study of muscle, converting it from a subject of basic science to a relevant subject for clinical study and has been responsible for a great increase of interest in muscle studies. Myopathies are linked to mutations in five of the myosin heavy chain genes, three of the myosin light chain genes, and three of the actin genes. This review aims to determine to what extent we can explain disease phenotype from the mutant genotype. To optimise our chances of finding the right mechanism we must study a myopathy where there are a large number of different mutations that cause a common phenotype and so are likely to have a common mechanism: a corollary to this criterion is that if any mutation causes the disease phenotype but does not correspond to the proposed mechanism, then the whole mechanism is suspect. Using these criteria, we consider two cases where plausible genotype-phenotype mechanisms have been proposed: the actin “A-triad” and the myosin “mesa/IHD” models.
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13
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Despond EA, Dawson JF. Classifying Cardiac Actin Mutations Associated With Hypertrophic Cardiomyopathy. Front Physiol 2018; 9:405. [PMID: 29719515 PMCID: PMC5913282 DOI: 10.3389/fphys.2018.00405] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 04/04/2018] [Indexed: 11/13/2022] Open
Abstract
Mutations in the cardiac actin gene (ACTC1) are associated with the development of hypertrophic cardiomyopathy (HCM). To date, 12 different ACTC1 mutations have been discovered in patients with HCM. Given the high degree of sequence conservation of actin proteins and the range of protein–protein interactions actin participates in, mutations in cardiac actin leading to HCM are particularly interesting. Here, we suggest the classification of ACTC1 mutations based on the location of the resulting amino acid change in actin into three main groups: (1) those affecting only the binding site of the myosin molecular motor, termed M-class mutations, (2) those affecting only the binding site of the tropomyosin (Tm) regulatory protein, designated T-class mutations, and (3) those affecting both the myosin- and Tm-binding sites, called MT-class mutations. To understand the precise pathogenesis of cardiac actin mutations and develop treatments specific to the molecular cause of disease, we need to integrate rapidly growing structural information with studies of regulated actomyosin systems.
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Affiliation(s)
- Evan A Despond
- Department of Molecular and Cellular Biology, Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, Canada
| | - John F Dawson
- Department of Molecular and Cellular Biology, Centre for Cardiovascular Investigations, University of Guelph, Guelph, ON, Canada
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14
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Sheehan A, Messer AE, Papadaki M, Choudhry A, Kren V, Biedermann D, Blagg B, Khandelwal A, Marston SB. Molecular Defects in Cardiac Myofilament Ca 2+-Regulation Due to Cardiomyopathy-Linked Mutations Can Be Reversed by Small Molecules Binding to Troponin. Front Physiol 2018; 9:243. [PMID: 29636697 PMCID: PMC5881522 DOI: 10.3389/fphys.2018.00243] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 03/06/2018] [Indexed: 12/28/2022] Open
Abstract
The inherited cardiomyopathies, hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) are relatively common, potentially life-threatening and currently untreatable. Mutations are often in the contractile proteins of cardiac muscle and cause abnormal Ca2+ regulation via troponin. HCM is usually linked to higher myofilament Ca2+-sensitivity whilst in both HCM and DCM mutant tissue there is often an uncoupling of the relationship between troponin I (TnI) phosphorylation by PKA and modulation of myofilament Ca2+-sensitivity, essential for normal responses to adrenaline. The adrenergic response is blunted, and this may predispose the heart to failure under stress. At present there are no compounds or interventions that can prevent or treat sarcomere cardiomyopathies. There is a need for novel therapies that act at a more fundamental level to affect the disease process. We demonstrated that epigallocatechin-3 gallate (EGCG) was found to be capable of restoring the coupled relationship between Ca2+-sensitivity and TnI phosphorylation in mutant thin filaments to normal in vitro, independent of the mutation (15 mutations tested). We have labeled this property "re-coupling." The action of EGCG in vitro to reverse the abnormality caused by myopathic mutations would appear to be an ideal pharmaceutical profile for treatment of inherited HCM and DCM but EGCG is known to be promiscuous in vivo and is thus unsuitable as a therapeutic drug. We therefore investigated whether other structurally related compounds can re-couple myofilaments without these off-target effects. We used the quantitative in vitro motility assay to screen 40 compounds, related to C-terminal Hsp90 inhibitors, and found 23 that can re-couple mutant myofilaments. There is no correlation between re-couplers and Hsp90 inhibitors. The Ca2+-sensitivity shift due to TnI phosphorylation was restored to 2.2 ± 0.01-fold (n = 19) compared to 2.0 ± 0.24-fold (n = 7) in wild-type thin filaments. Many of these compounds were either pure re-couplers or pure desensitizers, indicating these properties are independent; moreover, re-coupling ability could be lost with small changes of compound structure, indicating the possibility of specificity. Small molecules that can re-couple may have therapeutic potential. HIGHLIGHTS - Inherited cardiomyopathies are common diseases that are currently untreatable at a fundamental level and therefore finding a small molecule treatment is highly desirable.- We have identified a molecular level dysfunction common to nearly all mutations: uncoupling of the relationship between troponin I phosphorylation and modulation of myofilament Ca2+-sensitivity, essential for normal responses to adrenaline.- We have identified a new class of drugs that are capable of both reducing Ca2+-sensitivity and/or recouping the relationship between troponin I phosphorylation and Ca2+-sensitivity.- The re-coupling phenomenon can be explained on the basis of a single mechanism that is testable.- Measurements with a wide range of small molecules of varying structures can indicate the critical molecular features required for recoupling and allows the prediction of other potential re-couplers.
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Affiliation(s)
- Alice Sheehan
- NHLI, Imperial College London, London, United Kingdom
| | | | | | | | - Vladimír Kren
- Laboratory of Biotransformation, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - David Biedermann
- Laboratory of Biotransformation, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Brian Blagg
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, KS, United States
| | - Anuj Khandelwal
- Department of Medicinal Chemistry, The University of Kansas, Lawrence, KS, United States
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15
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Wang L, Bai F, Zhang Q, Song W, Messer A, Kawai M. Development of apical hypertrophic cardiomyopathy with age in a transgenic mouse model carrying the cardiac actin E99K mutation. J Muscle Res Cell Motil 2018; 38:421-435. [PMID: 29582353 DOI: 10.1007/s10974-018-9492-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/12/2018] [Indexed: 10/17/2022]
Abstract
In both humans and mice, the Glu-99-Lys (E99K) mutation in the cardiac actin gene (ACTC) results in little understood apical hypertrophic cardiomyopathy (AHCM). To determine how cross-bridge kinetics change with AHCM development, we applied sinusoidal length perturbations to skinned papillary muscle fibres from 2- and 5-month old E99K transgenic (Tg) and non-transgenic (NTg) mice, and studied tension and its transients. These age groups were chosen because our preliminary studies indicated that AHCM develops with age. Fibres from 5-month old E99K mice showed significant decreases in tension, stiffness, the rate of the medium-speed exponential process and its magnitude compared to non-transgenic control. The nucleotide association constants increased with age, and they were significantly larger in E99K compared to NTg. However, there were no large differences in the rates of the cross-bridge detachment step, the rates of the force generation step, or the phosphate association constant. Our result on force/cross-bridge demonstrates that the decreased active tension of E99K fibres was caused by a decreased amount of force generated per each cross-bridge. The effects were generally less or insignificant at 2 months. A pCa-tension study showed increased Ca2+-sensitivity (pCa50) with age in both the E99K and NTg sample groups, and pCa50 was significantly larger (but only for 0.05-0.06 pCa units) in E99K than in NTg groups. A significant decrease in cooperativity (nH) was observed only in 5-month old E99K mice. We conclude that the AHCM-causing ACTC E99K mutation is associated with progressive alterations in biomechanical parameters, with changes smaller at 2 months but larger at 5 months, correlating with the development of AHCM.
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Affiliation(s)
- Li Wang
- School of Nursing, Medical College, Soochow University, Suzhou, 215006, Jiangsu, China.,Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA, 52242, USA
| | - Fan Bai
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA, 52242, USA
| | - Qing Zhang
- School of Nursing, Medical College, Soochow University, Suzhou, 215006, Jiangsu, China
| | - Weihua Song
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Andrew Messer
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Masataka Kawai
- Department of Anatomy and Cell Biology, University of Iowa, Iowa City, IA, 52242, USA.
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16
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Rowlands CT, Owen T, Lawal S, Cao S, Pandey SS, Yang HY, Song W, Wilkinson R, Alvarez-Laviada A, Gehmlich K, Marston SB, MacLeod KT. Age- and strain-related aberrant Ca 2+ release is associated with sudden cardiac death in the ACTC E99K mouse model of hypertrophic cardiomyopathy. Am J Physiol Heart Circ Physiol 2017; 313:H1213-H1226. [PMID: 28887330 DOI: 10.1152/ajpheart.00244.2017] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Patients with hypertrophic cardiomyopathy, particularly young adults, can die from arrhythmia, but the mechanism underlying abnormal rhythm formation remains unknown. C57Bl6 × CBA/Ca mice carrying a cardiac actin ( ACTC) E99K (Glu99Lys) mutation reproduce many aspects of human hypertrophic cardiomyopathy, including increased myofilament Ca2+ sensitivity and sudden death in a proportion (up to 40%) of young (28-40 day old) animals. We studied the hearts of transgenic (TG; ACTC E99K) mice and their non-TG (NTG) littermates when they were in their vulnerable period (28-40 days old) and when they were adult (8-12 wk old). Ventricular myocytes were isolated from the hearts of TG and NTG mice at these two time points. We also examined the hearts of mice that died suddenly (SCD). SCD animals had approximately four times more collagen compared with age-matched NTG mice, yet myocyte cell size was normal. Young TG mice had double the collagen content of NTG mice. Contraction and Ca2+ transients were greater in cells from young TG mice compared with their NTG littermates but not in cells from adult mice (TG or NTG). Cells from young TG mice had a greater propensity for Ca2+ waves than NTG littermates, and, despite similar sarcoplasmic reticulum Ca2+ content, a proportion of these cells had larger Ca2+ spark mass. We found that the probability of SCD in young TG mice was increased when the mutation was expressed in animals with a CBA/Ca2+ background and almost eliminated in mice bred on a C57Bl6 background. The latter TG mice had normal cellular Ca2+ homeostasis. NEW & NOTEWORTHY Mice with the actin Glu99Lys hypertrophic cardiomyopathy mutation ( ACTC E99K) are prone to sudden cardiac death around 40 days, associated with increased Ca2+ transients, spark mass, and fibrosis. However, adult survivors have normal Ca2+ transients and spark density accompanied by hypertrophy. Penetrance of the sudden cardiac death phenotype depends on the genetic background of the mouse. Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/calcium-regulation-in-e99k-mouse-heart/ .
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Affiliation(s)
- Christina T Rowlands
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Thomas Owen
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Saheed Lawal
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Shuangyi Cao
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Samata S Pandey
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Hsiang-Yu Yang
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Weihua Song
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Ross Wilkinson
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Anita Alvarez-Laviada
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Katja Gehmlich
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Steven B Marston
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
| | - Kenneth T MacLeod
- National Heart & Lung Institute, Imperial Centre for Translational and Experimental Medicine, Imperial College, Hammersmith Hospital , London , United Kingdom
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17
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Messer AE, Chan J, Daley A, Copeland O, Marston SB, Connolly DJ. Investigations into the Sarcomeric Protein and Ca 2+-Regulation Abnormalities Underlying Hypertrophic Cardiomyopathy in Cats ( Felix catus). Front Physiol 2017. [PMID: 28642712 DOI: 10.3389/fphys.2017.00348.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common single gene inherited cardiomyopathy. In cats (Felix catus) HCM is even more prevalent and affects 16% of the outbred population and up to 26% in pedigree breeds such as Maine Coon and Ragdoll. Homozygous MYBPC3 mutations have been identified in these breeds but the mutations in other cats are unknown. At the clinical and physiological level feline HCM is closely analogous to human HCM but little is known about the primary causative mechanism. Most identified HCM causing mutations are in the genes coding for proteins of the sarcomere. We therefore investigated contractile and regulatory proteins in left ventricular tissue from 25 cats, 18 diagnosed with HCM, including a Ragdoll cat with a homozygous MYBPC3 R820W, and 7 non-HCM cats in comparison with human HCM (from septal myectomy) and donor heart tissue. Myofibrillar protein expression was normal except that we observed 20-44% MyBP-C haploinsufficiency in 5 of the HCM cats. Troponin extracted from 8 HCM and 5 non-HCM cat hearts was incorporated into thin filaments and studied by in vitro motility assay. All HCM cat hearts had a higher (2.06 ± 0.13 fold) Ca2+-sensitivity than non-HCM cats and, in all the HCM cats, Ca2+-sensitivity was not modulated by troponin I phosphorylation. We were able to restore modulation of Ca2+-sensitivity by replacing troponin T with wild-type protein or by adding 100 μM Epigallocatechin 3-gallate (EGCG). These fundamental regulatory characteristics closely mimic those seen in human HCM indicating a common molecular mechanism that is independent of the causative mutation. Thus, the HCM cat is a potentially useful large animal model.
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Affiliation(s)
- Andrew E Messer
- Myocardial Function, NHLI, Imperial College LondonLondon, United Kingdom
| | - Jasmine Chan
- The Royal Veterinary CollegeHatfield, United Kingdom
| | - Alex Daley
- The Royal Veterinary CollegeHatfield, United Kingdom
| | - O'Neal Copeland
- Myocardial Function, NHLI, Imperial College LondonLondon, United Kingdom
| | - Steven B Marston
- Myocardial Function, NHLI, Imperial College LondonLondon, United Kingdom
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18
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Messer AE, Chan J, Daley A, Copeland O, Marston SB, Connolly DJ. Investigations into the Sarcomeric Protein and Ca 2+-Regulation Abnormalities Underlying Hypertrophic Cardiomyopathy in Cats ( Felix catus). Front Physiol 2017. [PMID: 28642712 PMCID: PMC5462916 DOI: 10.3389/fphys.2017.00348] [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] [Indexed: 12/27/2022] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is the most common single gene inherited cardiomyopathy. In cats (Felix catus) HCM is even more prevalent and affects 16% of the outbred population and up to 26% in pedigree breeds such as Maine Coon and Ragdoll. Homozygous MYBPC3 mutations have been identified in these breeds but the mutations in other cats are unknown. At the clinical and physiological level feline HCM is closely analogous to human HCM but little is known about the primary causative mechanism. Most identified HCM causing mutations are in the genes coding for proteins of the sarcomere. We therefore investigated contractile and regulatory proteins in left ventricular tissue from 25 cats, 18 diagnosed with HCM, including a Ragdoll cat with a homozygous MYBPC3 R820W, and 7 non-HCM cats in comparison with human HCM (from septal myectomy) and donor heart tissue. Myofibrillar protein expression was normal except that we observed 20–44% MyBP-C haploinsufficiency in 5 of the HCM cats. Troponin extracted from 8 HCM and 5 non-HCM cat hearts was incorporated into thin filaments and studied by in vitro motility assay. All HCM cat hearts had a higher (2.06 ± 0.13 fold) Ca2+-sensitivity than non-HCM cats and, in all the HCM cats, Ca2+-sensitivity was not modulated by troponin I phosphorylation. We were able to restore modulation of Ca2+-sensitivity by replacing troponin T with wild-type protein or by adding 100 μM Epigallocatechin 3-gallate (EGCG). These fundamental regulatory characteristics closely mimic those seen in human HCM indicating a common molecular mechanism that is independent of the causative mutation. Thus, the HCM cat is a potentially useful large animal model.
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Affiliation(s)
- Andrew E Messer
- Myocardial Function, NHLI, Imperial College LondonLondon, United Kingdom
| | - Jasmine Chan
- The Royal Veterinary CollegeHatfield, United Kingdom
| | - Alex Daley
- The Royal Veterinary CollegeHatfield, United Kingdom
| | - O'Neal Copeland
- Myocardial Function, NHLI, Imperial College LondonLondon, United Kingdom
| | - Steven B Marston
- Myocardial Function, NHLI, Imperial College LondonLondon, United Kingdom
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19
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Marston SB. Why Is there a Limit to the Changes in Myofilament Ca 2+-Sensitivity Associated with Myopathy Causing Mutations? Front Physiol 2016; 7:415. [PMID: 27725803 PMCID: PMC5035734 DOI: 10.3389/fphys.2016.00415] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 09/05/2016] [Indexed: 12/15/2022] Open
Abstract
Mutations in striated muscle contractile proteins have been found to be the cause of a number of inherited muscle diseases; in most cases the mechanism proposed for causing the disease is derangement of the thin filament-based Ca2+-regulatory system of the muscle. When considering the results of experiments reported over the last 15 years, one feature has been frequently noted, but rarely discussed: the magnitude of changes in myofilament Ca2+-sensitivity due to myopathy-causing mutations in skeletal or heart muscle seems to be always in the range 1.5-3x EC50. Such consistency suggests it may be related to a fundamental property of muscle regulation; in this article we will investigate whether this observation is true and consider why this should be so. A literature search found 71 independent measurements of HCM mutation-induced change of EC50 ranging from 1.15 to 3.8-fold with a mean of 1.87 ± 0.07 (sem). We also found 11 independent measurements of increased Ca2+-sensitivity due to mutations in skeletal muscle proteins ranging from 1.19 to 2.7-fold with a mean of 2.00 ± 0.16. Investigation of dilated cardiomyopathy-related mutations found 42 independent determinations with a range of EC50 wt/mutant from 0.3 to 2.3. In addition we found 14 measurements of Ca2+-sensitivity changes due skeletal muscle myopathy mutations ranging from 0.39 to 0.63. Thus, our extensive literature search, although not necessarily complete, found that, indeed, the changes in myofilament Ca2+-sensitivity due to disease-causing mutations have a bimodal distribution and that the overall changes in Ca2+-sensitivity are quite small and do not extend beyond a three-fold increase or decrease in Ca2+-sensitivity. We discuss two mechanism that are not necessarily mutually exclusive. Firstly, it could be that the limit is set by the capabilities of the excitation-contraction machinery that supplies activating Ca2+ and that striated muscle cannot work in a way compatible with life outside these limits; or it may be due to a fundamental property of the troponin system and the permitted conformational transitions compatible with efficient regulation.
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Affiliation(s)
- Steven B Marston
- National Heart & Lung Institute, Imperial College London London, UK
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20
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Yu H, Chakravorty S, Song W, Ferenczi MA. Phosphorylation of the regulatory light chain of myosin in striated muscle: methodological perspectives. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2016; 45:779-805. [PMID: 27084718 PMCID: PMC5101276 DOI: 10.1007/s00249-016-1128-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 03/10/2016] [Accepted: 03/23/2016] [Indexed: 12/18/2022]
Abstract
Phosphorylation of the regulatory light chain (RLC) of myosin modulates cellular functions such as muscle contraction, mitosis, and cytokinesis. Phosphorylation defects are implicated in a number of diseases. Here we focus on striated muscle where changes in RLC phosphorylation relate to diseases such as hypertrophic cardiomyopathy and muscular dystrophy, or age-related changes. RLC phosphorylation in smooth muscle and non-muscle cells are covered briefly where relevant. There is much scientific interest in controlling the phosphorylation levels of RLC in vivo and in vitro in order to understand its physiological function in striated muscles. A summary of available and emerging in vivo and in vitro methods is presented. The physiological role of RLC phosphorylation and novel pathways are discussed to highlight the differences between muscle types and to gain insights into disease processes.
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Affiliation(s)
- Haiyang Yu
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Samya Chakravorty
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Weihua Song
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore
| | - Michael A Ferenczi
- Lee Kong Chian School of Medicine, Nanyang Technological University, Experimental Medicine Building, Level 3, 59 Nanyang Drive, Singapore, 636921, Singapore.
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21
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Wilkinson R, Song W, Smoktunowicz N, Marston S. A dilated cardiomyopathy mutation blunts adrenergic response and induces contractile dysfunction under chronic angiotensin II stress. Am J Physiol Heart Circ Physiol 2015; 309:H1936-46. [PMID: 26432839 DOI: 10.1152/ajpheart.00327.2015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 10/02/2015] [Indexed: 11/22/2022]
Abstract
We investigated cardiac contractility in the ACTC E361G transgenic mouse model of dilated cardiomyopathy (DCM). No differences in cardiac dimensions or systolic function were observed in young mice, whereas young adult mice exhibited only mild diastolic abnormalities. Dobutamine had an inotropic and lusitropic effect on the mouse heart. In papillary muscle at 37°C, dobutamine increased relaxation rates [∼50% increase of peak rate of force decline normalized to force (dF/dtmin/F), 25% reduction of time to 90% relaxation (t90) in nontransgenic (NTG) mice], but in the ACTC E361G mouse, dF/dtmin/F was increased 20-30%, and t90 was only reduced 10% at 10 Hz. Pressure-volume measurements showed increases in maximum rate of pressure decline and decreases in time constant of left ventricular pressure decay in the ACTC E361G mouse that were 25-30% of the changes in the NTG mouse, consistent with blunting of the lusitropic response. The inotropic effect of dobutamine was also blunted in ACTC E361G mice, and the dobutamine-stimulated increase in cardiac output (CO) was reduced from 2,100 to 900 μl/min. Mice were treated with high doses of ANG II for 4 wk. The chronic stress treatment evoked systolic dysfunction in ACTC E361G mice but not in NTG. There was a significant reduction in rates of pressure increase and decrease, as well as reduced end-systolic pressure and increased volume. Ejection fraction and CO were reduced in the ACTC E361G mouse, indicating DCM. In vitro DCM-causing mutations uncouple the relationship between Ca(2+) sensitivity and troponin I phosphorylation. We conclude that this leads to the observed, reduced response to β1 agonists and reduced cardiac reserve that predisposes the heart to DCM under conditions of chronic stress.
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Affiliation(s)
- Ross Wilkinson
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Weihua Song
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Natalia Smoktunowicz
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Steven Marston
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
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22
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Vikhorev PG, Song W, Wilkinson R, Copeland O, Messer AE, Ferenczi MA, Marston SB. The dilated cardiomyopathy-causing mutation ACTC E361G in cardiac muscle myofibrils specifically abolishes modulation of Ca(2+) regulation by phosphorylation of troponin I. Biophys J 2015; 107:2369-80. [PMID: 25418306 PMCID: PMC4241448 DOI: 10.1016/j.bpj.2014.10.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 09/25/2014] [Accepted: 10/16/2014] [Indexed: 01/30/2023] Open
Abstract
Phosphorylation of troponin I by protein kinase A (PKA) reduces Ca2+ sensitivity and increases the rate of Ca2+ release from troponin C and the rate of relaxation in cardiac muscle. In vitro experiments indicate that mutations that cause dilated cardiomyopathy (DCM) uncouple this modulation, but this has not been demonstrated in an intact contractile system. Using a Ca2+-jump protocol, we measured the effect of the DCM-causing mutation ACTC E361G on the equilibrium and kinetic parameters of Ca2+ regulation of contractility in single transgenic mouse heart myofibrils. We used propranolol treatment of mice to reduce the level of troponin I and myosin binding protein C (MyBP-C) phosphorylation in their hearts before isolating the myofibrils. In nontransgenic mouse myofibrils, the Ca2+ sensitivity of force was increased, the fast relaxation phase rate constant, kREL, was reduced, and the length of the slow linear phase, tLIN, was increased when the troponin I phosphorylation level was reduced from 1.02 to 0.3 molPi/TnI (EC50 P/unP = 1.8 ± 0.2, p < 0.001). Native myofibrils from ACTC E361G transgenic mice had a 2.4-fold higher Ca2+ sensitivity than nontransgenic mouse myofibrils. Strikingly, the Ca2+ sensitivity and relaxation parameters of ACTC E361G myofibrils did not depend on the troponin I phosphorylation level (EC50 P/unP = 0.88 ± 0.17, p = 0.39). Nevertheless, modulation of the Ca2+ sensitivity of ACTC E361G myofibrils by sarcomere length or EMD57033 was indistinguishable from that of nontransgenic myofibrils. Overall, EC50 measured in different conditions varied over a 7-fold range. The time course of relaxation, as defined by tLIN and kREL, was correlated with EC50 but varied by just 2.7- and 3.3-fold, respectively. Our results confirm that troponin I phosphorylation specifically alters the Ca2+ sensitivity of isometric tension and the time course of relaxation in cardiac muscle myofibrils. Moreover, the DCM-causing mutation ACTC E361G blunts this phosphorylation-dependent response without affecting other parameters of contraction, including length-dependent activation and the response to EMD57033.
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Affiliation(s)
- Petr G Vikhorev
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Weihua Song
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Ross Wilkinson
- National Heart and Lung Institute, Imperial College London, London, UK
| | - O'Neal Copeland
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Andrew E Messer
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Michael A Ferenczi
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Steven B Marston
- National Heart and Lung Institute, Imperial College London, London, UK.
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Bai F, Caster HM, Rubenstein PA, Dawson JF, Kawai M. Using baculovirus/insect cell expressed recombinant actin to study the molecular pathogenesis of HCM caused by actin mutation A331P. J Mol Cell Cardiol 2014; 74:64-75. [PMID: 24793351 DOI: 10.1016/j.yjmcc.2014.04.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 04/21/2014] [Accepted: 04/22/2014] [Indexed: 01/07/2023]
Abstract
Recombinant WT human cardiac actin (WT actin) was expressed using the baculovirus/insect cell expression system, purified, and used to reconstitute the thin-filament of bovine cardiac muscle fibers, together with bovine cardiac tropomyosin (Tm) and troponin (Tn). Effects of [Ca(2+)], [ATP], [phosphate] and [ADP] on tension and tension transients were studied at 25°C by using sinusoidal analysis, and the results were compared with those of native fibers and fibers reconstituted with purified bovine cardiac actin (BVC actin). In actin filament reconstituted fibers (without Tm/Tn), those reconstituted with WT actin showed exactly the same active tension as those reconstituted with purified BVC actin (WT: 0.75±0.06 T0, N=11; BVC: 0.73±0.07 T0, N=12, where T0 is the tension of original fibers before extraction). After Tm/Tn reconstitution, fibers reconstituted with WT actin generated 0.85±0.06 T0 (N=11) compared to 0.98±0.04 T0 (N=12) recovered by those reconstituted with BVC actin. In the presence of Tm/Tn, WT actin reconstituted fibers showed exactly the same Ca(2+) sensitivity as those of the native fibers and BVC actin reconstituted fibers (pCa50: native fibers: 5.69±0.01, N=10; WT: 5.69±0.02, N=11; BVC: 5.68±0.02, N=12). Sinusoidal analysis showed that the cross-bridge kinetics were the same among native fibers, BVC actin reconstituted fibers and WT actin reconstituted fibers, followed by reconstitution of Tm/Tn. These results demonstrate that baculovirus/insect cell expressed actin has no significant differences from tissue purified actin and can be used for thin-filament reconstitution assays. One hypertrophic cardiomyopathy (HCM) causing actin mutant A331P actin was also expressed and studied similarly, and the results were compared to those of the WT actin. In the reconstituted fibers, A331P significantly decreased the tension both in the absence of Tm/Tn (0.55±0.03 T0, N=13) and in their presence (0.65±0.02 T0, N=13) compared to those of the WT (0.75±0.06 T0 and 0.85±0.06 T0, respectively, N=11). A331P also showed decreased pCa50 (5.57±0.03, N=13) compared to that of WT (5.69±0.02, N=11). The cross-bridge kinetics and its distribution were similar between WT and A331P actin reconstituted fibers, indicating that force/cross-bridge was decreased by A331P. In conclusion, A331P causes a weakened cross-bridge force, which leads to a decreased active tension, reduces left-ventricular ejection fraction, and eventually results in the HCM phenotype.
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Affiliation(s)
- Fan Bai
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242-1109, USA.
| | - Hannah M Caster
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242-1109, USA.
| | - Peter A Rubenstein
- Department of Biochemistry, The University of Iowa, Iowa City, IA 52242-1109, USA.
| | - John F Dawson
- Department of Molecular & Cellular Biology, University of Guelph, College of Biological Science, Guelph, Ontario N1G 2 W1, Canada.
| | - Masataka Kawai
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242-1109, USA; Department of Internal Medicine, The University of Iowa, Iowa City, IA 52242-1109, USA.
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