1
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Gerzen O, Potoskueva I, Votinova V, Sergeeva K, Tyganov S, Tzybina A, Shenkman BS, Nikitina L. Mechanical interaction of myosin and native thin filament in the disused rat soleus muscle. LIFE SCIENCES IN SPACE RESEARCH 2024; 41:80-85. [PMID: 38670656 DOI: 10.1016/j.lssr.2024.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2023] [Revised: 01/22/2024] [Accepted: 01/31/2024] [Indexed: 04/28/2024]
Abstract
The disuse of skeletal limb muscles occurs in a variety of conditions, yet our comprehension of the molecular mechanisms involved in adaptation to disuse remains incomplete. We studied the mechanical characteristics of actin-myosin interaction using an in vitro motility assay and isoform composition of myosin heavy and light chains by dint of SDS-PAGE in soleus muscle of both control and hindlimb-unloaded rats. 14 days of hindlimb unloading led to the increased maximum sliding velocity of actin, reconstituted, and native thin filaments over rat soleus muscle myosin by 24 %, 19 %, and 20 %, respectively. The calcium sensitivity of the "pCa-velocity" relationship decreased. There was a 26 % increase in fast myosin heavy chain IIa (MHC IIa), a 22 % increase in fast myosin light chain 2 (MLC 2f), and a 13 % increase in fast MLC 1f content. The content of MLC 1s/v, typical for slow skeletal muscles and cardiac ventricles did not change. At the same time, MLC 1s, typical only for slow skeletal muscles, disappeared. The maximum velocity of soleus muscle native thin filaments was 24 % higher compared to control ones sliding over the same rabbit myosin. Therefore, both myosin and native thin filament kinetics could influence the mechanical characteristics of the soleus muscle. Additionally, the MLC 1s and MLC 1s/v ratio may contribute to the mechanical characteristics of slow skeletal muscle, along with MHC, MLC 2, and MLC 1 slow/fast isoforms ratio.
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Affiliation(s)
- Oksana Gerzen
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia; Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia.
| | - Iulia Potoskueva
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
| | - Veronika Votinova
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
| | - Ksenia Sergeeva
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Sergey Tyganov
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Alena Tzybina
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
| | - Boris S Shenkman
- Institute of Biomedical Problems, Russian Academy of Sciences, Moscow, Russia
| | - Larisa Nikitina
- Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
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2
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Jones TLM, Woulfe KC. Considering impact of age and sex on cardiac cytoskeletal components. Am J Physiol Heart Circ Physiol 2024; 326:H470-H478. [PMID: 38133622 DOI: 10.1152/ajpheart.00619.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/08/2023] [Accepted: 12/21/2023] [Indexed: 12/23/2023]
Abstract
The cardiac cytoskeletal components are integral to cardiomyocyte function and are responsible for contraction, sustaining cell structure, and providing scaffolding to direct signaling. Cytoskeletal components have been implicated in cardiac pathology; however, less attention has been paid to age-related modifications of cardiac cytoskeletal components and how these contribute to dysfunction with increased age. Moreover, significant sex differences in cardiac aging have been identified, but we still lack a complete understanding to the mechanisms behind these differences. This review summarizes what is known about how key cardiomyocyte cytoskeletal components are modified because of age, as well as reported sex-specific differences. Thorough consideration of both age and sex as integral players in cytoskeletal function may reveal potential avenues for more personalized therapeutics.
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Affiliation(s)
- Timothy L M Jones
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
| | - Kathleen C Woulfe
- Division of Cardiology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States
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3
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Bedada FB, Thompson BR, Mikkila JL, Chan SSK, Choi SH, Toso EA, Kyba M, Metzger JM. Inducing positive inotropy in human iPSC-derived cardiac muscle by gene editing-based activation of the cardiac α-myosin heavy chain. Sci Rep 2024; 14:3915. [PMID: 38365813 PMCID: PMC10873390 DOI: 10.1038/s41598-024-53395-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 01/31/2024] [Indexed: 02/18/2024] Open
Abstract
Human induced pluripotent stem cells and their differentiation into cardiac myocytes (hiPSC-CMs) provides a unique and valuable platform for studies of cardiac muscle structure-function. This includes studies centered on disease etiology, drug development, and for potential clinical applications in heart regeneration/repair. Ultimately, for these applications to achieve success, a thorough assessment and physiological advancement of the structure and function of hiPSC-CMs is required. HiPSC-CMs are well noted for their immature and sub-physiological cardiac muscle state, and this represents a major hurdle for the field. To address this roadblock, we have developed a hiPSC-CMs (β-MHC dominant) experimental platform focused on directed physiological enhancement of the sarcomere, the functional unit of cardiac muscle. We focus here on the myosin heavy chain (MyHC) protein isoform profile, the molecular motor of the heart, which is essential to cardiac physiological performance. We hypothesized that inducing increased expression of α-MyHC in β-MyHC dominant hiPSC-CMs would enhance contractile performance of hiPSC-CMs. To test this hypothesis, we used gene editing with an inducible α-MyHC expression cassette into isogeneic hiPSC-CMs, and separately by gene transfer, and then investigated the direct effects of increased α-MyHC expression on hiPSC-CMs contractility and relaxation function. Data show improved cardiac functional parameters in hiPSC-CMs induced with α-MyHC. Positive inotropy and relaxation was evident in comparison to β-MyHC dominant isogenic controls both at baseline and during pacing induced stress. This approach should facilitate studies of hiPSC-CMs disease modeling and drug screening, as well as advancing fundamental aspects of cardiac function parameters for the optimization of future cardiac regeneration, repair and re-muscularization applications.
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Affiliation(s)
- Fikru B Bedada
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA
- Present Address: Department of Clinical Laboratory Sciences, College of Nursing and Allied Health Sciences, Howard University, Washington, DC, USA
| | - Brian R Thompson
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA
| | - Jennifer L Mikkila
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA
| | - Sunny S-K Chan
- Lillehei Heart Institute, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA
| | - Si Ho Choi
- Lillehei Heart Institute, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA
| | - Erik A Toso
- Lillehei Heart Institute, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA
| | - Michael Kyba
- Lillehei Heart Institute, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA
| | - Joseph M Metzger
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA.
- Lillehei Heart Institute, University of Minnesota Medical School, 6-125 Jackson Hall, 321 Church Street SE, Minneapolis, MN, 55455, USA.
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4
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Hau HTA, Kelu JJ, Ochala J, Hughes SM. Slow myosin heavy chain 1 is required for slow myofibril and muscle fibre growth but not for myofibril initiation. Dev Biol 2023; 499:47-58. [PMID: 37121308 PMCID: PMC10713478 DOI: 10.1016/j.ydbio.2023.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/31/2023] [Accepted: 04/04/2023] [Indexed: 05/02/2023]
Abstract
Slow myosin heavy chain 1 (Smyhc1) is the major sarcomeric myosin driving early contraction by slow skeletal muscle fibres in zebrafish. New mutant alleles lacking a functional smyhc1 gene move poorly, but recover motility as the later-formed fast muscle fibres of the segmental myotomes mature, and are adult viable. By motility analysis and inhibiting fast muscle contraction pharmacologically, we show that a slow muscle motility defect persists in mutants until about 1 month of age. Breeding onto a genetic background marking slow muscle fibres with EGFP revealed that mutant slow fibres undergo terminal differentiation, migration and fibre formation indistinguishable from wild type but fail to generate large myofibrils and maintain cellular orientation and attachments. In mutants, initial myofibrillar structures with 1.67 μm periodic actin bands fail to mature into the 1.96 μm sarcomeres observed in wild type, despite the presence of alternative myosin heavy chain molecules. The poorly-contractile mutant slow muscle cells generate numerous cytoplasmic organelles, but fail to grow and bundle myofibrils or to increase in cytoplasmic volume despite passive movements imposed by fast muscle. The data show that both slow myofibril maturation and cellular volume increase depend on the function of a specific myosin isoform and suggest that appropriate force production regulates muscle fibre growth.
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Affiliation(s)
- Hoi-Ting A Hau
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, SE1 1UL, UK; Centre for Human & Applied Physiological Sciences, School of Basic and Medical Biosciences, King's College London, SE1 1UL, UK
| | - Jeffrey J Kelu
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, SE1 1UL, UK
| | - Julien Ochala
- Centre for Human & Applied Physiological Sciences, School of Basic and Medical Biosciences, King's College London, SE1 1UL, UK
| | - Simon M Hughes
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, SE1 1UL, UK.
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5
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Mantzouratou P, Malaxianaki E, Cerullo D, Lavecchia AM, Pantos C, Xinaris C, Mourouzis I. Thyroid Hormone and Heart Failure: Charting Known Pathways for Cardiac Repair/Regeneration. Biomedicines 2023; 11:975. [PMID: 36979954 PMCID: PMC10046827 DOI: 10.3390/biomedicines11030975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/17/2023] [Accepted: 03/20/2023] [Indexed: 03/30/2023] Open
Abstract
Heart failure affects more than 64 million people worldwide, having a serious impact on their survival and quality of life. Exploring its pathophysiology and molecular bases is an urgent need in order to develop new therapeutic approaches. Thyroid hormone signaling, evolutionarily conserved, controls fundamental biological processes and has a crucial role in development and metabolism. Its active form is L-triiodothyronine, which not only regulates important gene expression by binding to its nuclear receptors, but also has nongenomic actions, controlling crucial intracellular signalings. Stressful stimuli, such as acute myocardial infarction, lead to changes in thyroid hormone signaling, and especially in the relation of the thyroid hormone and its nuclear receptor, which are associated with the reactivation of fetal development programmes, with structural remodeling and phenotypical changes in the cardiomyocytes. The recapitulation of fetal-like features of the signaling may be partially an incomplete effort of the myocardium to recapitulate its developmental program and enable cardiomyocytes to proliferate and finally to regenerate. In this review, we will discuss the experimental and clinical evidence about the role of the thyroid hormone in the recovery of the myocardium in the setting of heart failure with reduced and preserved ejection fraction and its future therapeutic implications.
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Affiliation(s)
| | | | - Domenico Cerullo
- Centro Anna Maria Astori, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 24126 Bergamo, Italy
| | - Angelo Michele Lavecchia
- Centro Anna Maria Astori, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 24126 Bergamo, Italy
| | | | - Christodoulos Xinaris
- Centro Anna Maria Astori, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, 24126 Bergamo, Italy
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6
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Hu T, Kalyanaraman H, Pilz RB, Casteel DE. Phosphatase regulatory subunit MYPT2 knock-out partially compensates for the cardiac dysfunction in mice caused by lack of myosin light chain kinase 3. J Biol Chem 2023; 299:104584. [PMID: 36889588 PMCID: PMC10124902 DOI: 10.1016/j.jbc.2023.104584] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 02/26/2023] [Accepted: 02/27/2023] [Indexed: 03/08/2023] Open
Abstract
Cardiac contraction is modulated by the phosphorylation state of myosin regulatory light chain 2 (MLC-2v). The level of MLC-2v phosphorylation is dependent on the opposing activities of MLC kinases and phosphatases. The predominant MLC phosphatase found in cardiac myocytes contains Myosin Phosphatase Targeting Subunit 2 (MYPT2). Overexpression of MYPT2 in cardiac myocytes results in a decreased level of MLC phosphorylation, reduced left ventricular contraction and induction of hypertrophy; however, the effect of knocking out MYPT2 on cardiac function is unknown. We obtained heterozygous mice containing a MYPT2 null allele from the Mutant Mouse Resource Center. These mice were produced in a C57BL/6N background which lack MLCK3, the main regulatory light chain kinase in cardiac myocytes. We found that mice null for MYPT2 were viable and had no obvious phenotypic abnormality when compared to wild-type mice. Additionally, we determined that wild-type C57BL/6N mice had a low basal level of MLC-2v phosphorylation which was significantly increased when MYPT2 was absent. At 12-weeks, MYPT2 knock-out mice had smaller hearts and showed down-regulation of genes involved in cardiac remodeling. Using cardiac echo, we found that 24-week-old male MYPT2 knock-out mice had decreased heart size with increased fractional shortening compared to their MYPT2 wild-type littermates. Collectively, these studies highlight the important role that MYPT2 plays in cardiac function in vivo and demonstrate that its deletion can partially compensate for the lack of MLCK3.
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Affiliation(s)
- Tingfei Hu
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Hema Kalyanaraman
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Renate B Pilz
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093
| | - Darren E Casteel
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093.
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7
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Gerzen OP, Votinova VO, Potoskueva IK, Nabiev SR, Nikitina LV. Characteristics of Actin—Myosin Interaction in Different Regions of Rat Heart. J EVOL BIOCHEM PHYS+ 2022. [DOI: 10.1134/s0022093022070110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
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8
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Gerzen OP, Nabiev SR, Klinova SV, Minigalieva IA, Sutunkova MP, Katsnelson BA, Nikitina LV. Molecular mechanisms of mechanical function changes of the rat myocardium under subchronic lead exposure. Food Chem Toxicol 2022; 169:113444. [PMID: 36179994 DOI: 10.1016/j.fct.2022.113444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/10/2022] [Accepted: 09/21/2022] [Indexed: 11/26/2022]
Abstract
A moderate degree of lead intoxication was observed in male rats after repeated intraperitoneal injections with two doses of lead acetate three times a week during 5 (12.5 mg of Pb per kg body mass) and 6 (6.01 mg of Pb per kg body mass) weeks. Using an in vitro motility assay, we investigated the impact of this intoxication on the characteristics of actin-myosin interaction and its regulation in the atria, right, and left ventricles. Both lead doses exposure decreased the maximum sliding velocity of reconstituted thin filaments over myosin and fraction of motile filaments in all heart chambers, caused the myosin isoforms shift towards slower β-myosin heavy chains in ventricles and decreased regulatory light chain phosphorylation in atria. No statistically significant difference was found in force and calcium regulation of actin-myosin interaction. A dose-dependent effect of lead on myosin functional characteristics was found in all heart chambers, but the degree of this effect varied depending on the heart chamber.
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Affiliation(s)
- Oksana P Gerzen
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia.
| | - Salavat R Nabiev
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
| | - Svetlana V Klinova
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia
| | - Ilzira A Minigalieva
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia
| | - Marina P Sutunkova
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia
| | - Boris A Katsnelson
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia
| | - Larisa V Nikitina
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
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9
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Hsieh J, Becklin KL, Givens S, Komosa ER, Lloréns JEA, Kamdar F, Moriarity BS, Webber BR, Singh BN, Ogle BM. Myosin Heavy Chain Converter Domain Mutations Drive Early-Stage Changes in Extracellular Matrix Dynamics in Hypertrophic Cardiomyopathy. Front Cell Dev Biol 2022; 10:894635. [PMID: 35784482 PMCID: PMC9245526 DOI: 10.3389/fcell.2022.894635] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Accepted: 05/24/2022] [Indexed: 11/24/2022] Open
Abstract
More than 60% of hypertrophic cardiomyopathy (HCM)-causing mutations are found in the gene loci encoding cardiac myosin-associated proteins including myosin heavy chain (MHC) and myosin binding protein C (MyBP-C). Moreover, patients with more than one independent HCM mutation may be at increased risk for more severe disease expression and adverse outcomes. However detailed mechanistic understanding, especially at early stages of disease progression, is limited. To identify early-stage HCM triggers, we generated single (MYH7 c.2167C > T [R723C] with a known pathogenic significance in the MHC converter domain) and double (MYH7 c.2167C > T [R723C]; MYH6 c.2173C > T [R725C] with unknown significance) myosin gene mutations in human induced pluripotent stem cells (hiPSCs) using a base-editing strategy. Cardiomyocytes (CMs) derived from hiPSCs with either single or double mutation exhibited phenotypic characteristics consistent with later-stage HCM including hypertrophy, multinucleation, altered calcium handling, metabolism, and arrhythmia. We then probed mutant CMs at time points prior to the detection of known HCM characteristics. We found MYH7/MYH6 dual mutation dysregulated extracellular matrix (ECM) remodeling, altered integrin expression, and interrupted cell-ECM adhesion by limiting the formation of focal adhesions. These results point to a new phenotypic feature of early-stage HCM and reveal novel therapeutic avenues aimed to delay or prohibit disease onset.
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Affiliation(s)
- Jeanne Hsieh
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Kelsie L. Becklin
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States
| | - Sophie Givens
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Elizabeth R. Komosa
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
| | - Juan E. Abrahante Lloréns
- University of Minnesota Informatics Institute (UMII), University of Minnesota, Minneapolis, MN, United States
| | - Forum Kamdar
- Department of Medicine, University of Minnesota, Minneapolis, MN, United States
| | - Branden S. Moriarity
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States
| | - Beau R. Webber
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States
| | - Bhairab N. Singh
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States
- Stem Cell Institute, University of Minnesota, Minneapolis, MN, United States
- *Correspondence: Bhairab N. Singh, ; Brenda M. Ogle,
| | - Brenda M. Ogle
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States
- Department of Pediatrics, University of Minnesota, Minneapolis, MN, United States
- Stem Cell Institute, University of Minnesota, Minneapolis, MN, United States
- *Correspondence: Bhairab N. Singh, ; Brenda M. Ogle,
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10
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Prodanovic M, Geeves MA, Poggesi C, Regnier M, Mijailovich SM. Effect of Myosin Isoforms on Cardiac Muscle Twitch of Mice, Rats and Humans. Int J Mol Sci 2022; 23:1135. [PMID: 35163054 PMCID: PMC8835009 DOI: 10.3390/ijms23031135] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/16/2022] [Accepted: 01/18/2022] [Indexed: 02/04/2023] Open
Abstract
To understand how pathology-induced changes in contractile protein isoforms modulate cardiac muscle function, it is necessary to quantify the temporal-mechanical properties of contractions that occur under various conditions. Pathological responses are much easier to study in animal model systems than in humans, but extrapolation between species presents numerous challenges. Employing computational approaches can help elucidate relationships that are difficult to test experimentally by translating the observations from rats and mice, as model organisms, to the human heart. Here, we use the spatially explicit MUSICO platform to model twitch contractions from rodent and human trabeculae collected in a single laboratory. This approach allowed us to identify the variations in kinetic characteristics of α- and β-myosin isoforms across species and to quantify their effect on cardiac muscle contractile responses. The simulations showed how the twitch transient varied with the ratio of the two myosin isoforms. Particularly, the rate of tension rise was proportional to the fraction of α-myosin present, while the β-isoform dominated the rate of relaxation unless α-myosin was >50%. Moreover, both the myosin isoform and the Ca2+ transient contributed to the twitch tension transient, allowing two levels of regulation of twitch contraction.
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Affiliation(s)
- Momcilo Prodanovic
- Institute for Information Technologies, University of Kragujevac, 34000 Kragujevac, Serbia;
- Bioengineering Research and Development Center (BioIRC), 34000 Kragujevac, Serbia
- FilamenTech, Inc., Newtown, MA 02458, USA
| | - Michael A. Geeves
- Department of Biosciences, University of Kent, Canterbury CT2 7NJ, Kent, UK;
| | - Corrado Poggesi
- Department of Experimental & Clinical Medicine, University of Florence, 20134 Florence, Italy;
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA;
| | - Srboljub M. Mijailovich
- FilamenTech, Inc., Newtown, MA 02458, USA
- Department of Biology, Illinois Institute of Technology, Chicago, IL 60616, USA
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11
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Chuang C, Collibee S, Ashcraft L, Wang W, Vander Wal M, Wang X, Hwee DT, Wu Y, Wang J, Chin ER, Cremin P, Zamora J, Hartman J, Schaletzky J, Wehri E, Robertson LA, Malik FI, Morgan BP. Discovery of Aficamten (CK-274), a Next-Generation Cardiac Myosin Inhibitor for the Treatment of Hypertrophic Cardiomyopathy. J Med Chem 2021; 64:14142-14152. [PMID: 34606259 DOI: 10.1021/acs.jmedchem.1c01290] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hypercontractility of the cardiac sarcomere may be essential for the underlying pathological hypertrophy and fibrosis in genetic hypertrophic cardiomyopathies. Aficamten (CK-274) is a novel cardiac myosin inhibitor that was discovered from the optimization of indoline compound 1. The important advancement of the optimization was discovery of an Indane analogue (12) with a less restrictive structure-activity relationship that allowed for the rapid improvement of drug-like properties. Aficamten was designed to provide a predicted human half-life (t1/2) appropriate for once a day (qd) dosing, to reach steady state within two weeks, to have no substantial cytochrome P450 induction or inhibition, and to have a wide therapeutic window in vivo with a clear pharmacokinetic/pharmacodynamic relationship. In a phase I clinical trial, aficamten demonstrated a human t1/2 similar to predictions and was able to reach steady state concentration within the desired two-week window.
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Affiliation(s)
- Chihyuan Chuang
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Scott Collibee
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Luke Ashcraft
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Wenyue Wang
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Mark Vander Wal
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Xiaolin Wang
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Darren T Hwee
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Yangsong Wu
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Jingying Wang
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Eva R Chin
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Peadar Cremin
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Jeanelle Zamora
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - James Hartman
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Julia Schaletzky
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Eddie Wehri
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Laura A Robertson
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Fady I Malik
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
| | - Bradley P Morgan
- Cytokinetics, Inc., 280 East Grand Avenue, South San Francisco, California 94080, United States
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12
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Gerzen OP, Nabiev SR, Nikitina LV. Influence of Chronic Lead Intoxication on Functional Characteristics and Isoform Composition of Left Ventricular Myosin in the Rat Heart. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s002209302104013x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Zhang J, Chou OHI, Tse YL, Ng KM, Tse HF. Application of Patient-Specific iPSCs for Modelling and Treatment of X-Linked Cardiomyopathies. Int J Mol Sci 2021; 22:ijms22158132. [PMID: 34360897 PMCID: PMC8347533 DOI: 10.3390/ijms22158132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 07/22/2021] [Accepted: 07/24/2021] [Indexed: 12/11/2022] Open
Abstract
Inherited cardiomyopathies are among the major causes of heart failure and associated with significant mortality and morbidity. Currently, over 70 genes have been linked to the etiology of various forms of cardiomyopathy, some of which are X-linked. Due to the lack of appropriate cell and animal models, it has been difficult to model these X-linked cardiomyopathies. With the advancement of induced pluripotent stem cell (iPSC) technology, the ability to generate iPSC lines from patients with X-linked cardiomyopathy has facilitated in vitro modelling and drug testing for the condition. Nonetheless, due to the mosaicism of the X-chromosome inactivation, disease phenotypes of X-linked cardiomyopathy in heterozygous females are also usually more heterogeneous, with a broad spectrum of presentation. Recent advancements in iPSC procedures have enabled the isolation of cells with different lyonisation to generate isogenic disease and control cell lines. In this review, we will summarise the current strategies and examples of using an iPSC-based model to study different types of X-linked cardiomyopathy. The potential application of isogenic iPSC lines derived from a female patient with heterozygous Danon disease and drug screening will be demonstrated by our preliminary data. The limitations of an iPSC-derived cardiomyocyte-based platform will also be addressed.
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Affiliation(s)
- Jennifer Zhang
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (J.Z.); (O.H.-I.C.); (Y.-L.T.)
| | - Oscar Hou-In Chou
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (J.Z.); (O.H.-I.C.); (Y.-L.T.)
| | - Yiu-Lam Tse
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (J.Z.); (O.H.-I.C.); (Y.-L.T.)
| | - Kwong-Man Ng
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (J.Z.); (O.H.-I.C.); (Y.-L.T.)
- Correspondence: (K.-M.N.); (H.-F.T.); Tel.: +852-3917-9955 (K.-M.N.); +852-2255-3598 (H.-F.T.)
| | - Hung-Fat Tse
- Cardiology Division, Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; (J.Z.); (O.H.-I.C.); (Y.-L.T.)
- Centre of Translational Stem Cell Biology, Hong Kong Science and Technology Park, Hong Kong, China
- Correspondence: (K.-M.N.); (H.-F.T.); Tel.: +852-3917-9955 (K.-M.N.); +852-2255-3598 (H.-F.T.)
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14
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Pertici I, Taft MH, Greve JN, Fedorov R, Caremani M, Manstein DJ. Allosteric modulation of cardiac myosin mechanics and kinetics by the conjugated omega-7,9 trans-fat rumenic acid. J Physiol 2021; 599:3639-3661. [PMID: 33942907 DOI: 10.1113/jp281563] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 04/28/2021] [Indexed: 01/23/2023] Open
Abstract
KEY POINTS Direct binding of rumenic acid to the cardiac myosin-2 motor domain increases the release rate for orthophosphate and increases the Ca2+ responsiveness of cardiac muscle at low load. Physiological cellular concentrations of rumenic acid affect the ATP turnover rates of the super-relaxed and disordered relaxed states of β-cardiac myosin, leading to a net increase in myocardial metabolic load. In Ca2+ -activated trabeculae, rumenic acid exerts a direct inhibitory effect on the force-generating mechanism without affecting the number of force-generating motors. In the presence of saturating actin concentrations rumenic acid binds to the β-cardiac myosin-2 motor domain with an EC50 of 200 nM. Molecular docking studies provide information about the binding site, the mode of binding, and associated allosteric communication pathways. Free rumenic acid may exceed thresholds in cardiomyocytes above which contractile efficiency is reduced and interference with small molecule therapeutics, targeting cardiac myosin, occurs. ABSTRACT Based on experiments using purified myosin motor domains, reconstituted actomyosin complexes and rat heart ventricular trabeculae, we demonstrate direct binding of rumenic acid, the cis-delta-9-trans-delta-11 isomer of conjugated linoleic acid, to an allosteric site located in motor domain of mammalian cardiac myosin-2 isoforms. In the case of porcine β-cardiac myosin, the EC50 for rumenic acid varies from 10.5 μM in the absence of actin to 200 nM in the presence of saturating concentrations of actin. Saturating concentrations of rumenic acid increase the maximum turnover of basal and actin-activated ATPase activity of β-cardiac myosin approximately 2-fold but decrease the force output per motor by 23% during isometric contraction. The increase in ATP turnover is linked to an acceleration of the release of the hydrolysis product orthophosphate. In the presence of 5 μM rumenic acid, the difference in the rate of ATP turnover by the super-relaxed and disordered relaxed states of cardiac myosin increases from 4-fold to 20-fold. The equilibrium between the two functional myosin states is not affected by rumenic acid. Calcium responsiveness is increased under zero-load conditions but unchanged under load. Molecular docking studies provide information about the rumenic acid binding site, the mode of binding, and associated allosteric communication pathways. They show how the isoform-specific replacement of residues in the binding cleft induces a different mode of rumenic acid binding in the case of non-muscle myosin-2C and blocks binding to skeletal muscle and smooth muscle myosin-2 isoforms.
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Affiliation(s)
- Irene Pertici
- PhysioLab, University of Florence, Florence, 50019, Italy.,Institute for Biophysical Chemistry, OE4350, Medizinische Hochschule Hannover, Hannover, 30625, Germany
| | - Manuel H Taft
- Institute for Biophysical Chemistry, OE4350, Medizinische Hochschule Hannover, Hannover, 30625, Germany
| | - Johannes N Greve
- Institute for Biophysical Chemistry, OE4350, Medizinische Hochschule Hannover, Hannover, 30625, Germany
| | - Roman Fedorov
- Division of Structural Biochemistry, OE8830, Medizinische Hochschule Hannover, Hannover, 30625, Germany.,RESiST, Cluster of Excellence 2155, Medizinische Hochschule Hannover, Hannover, 30625, Germany
| | - Marco Caremani
- PhysioLab, University of Florence, Florence, 50019, Italy
| | - Dietmar J Manstein
- Institute for Biophysical Chemistry, OE4350, Medizinische Hochschule Hannover, Hannover, 30625, Germany.,Division of Structural Biochemistry, OE8830, Medizinische Hochschule Hannover, Hannover, 30625, Germany.,RESiST, Cluster of Excellence 2155, Medizinische Hochschule Hannover, Hannover, 30625, Germany
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15
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Tanner BCW, Previs MJ, Wang Y, Robbins J, Palmer BM. Cardiac myosin binding protein-C phosphorylation accelerates β-cardiac myosin detachment rate in mouse myocardium. Am J Physiol Heart Circ Physiol 2021; 320:H1822-H1835. [PMID: 33666504 PMCID: PMC8163640 DOI: 10.1152/ajpheart.00673.2020] [Citation(s) in RCA: 4] [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: 08/17/2020] [Revised: 02/08/2021] [Accepted: 03/01/2021] [Indexed: 11/22/2022]
Abstract
Cardiac myosin binding protein-C (cMyBP-C) is a thick filament protein that influences sarcomere stiffness and modulates cardiac contraction-relaxation through its phosphorylation. Phosphorylation of cMyBP-C and ablation of cMyBP-C have been shown to increase the rate of MgADP release in the acto-myosin cross-bridge cycle in the intact sarcomere. The influence of cMyBP-C on Pi-dependent myosin kinetics has not yet been examined. We investigated the effect of cMyBP-C, and its phosphorylation, on myosin kinetics in demembranated papillary muscle strips bearing the β-cardiac myosin isoform from nontransgenic and homozygous transgenic mice lacking cMyBP-C. We used quick stretch and stochastic length-perturbation analysis to characterize rates of myosin detachment and force development over 0-12 mM Pi and at maximal (pCa 4.8) and near-half maximal (pCa 5.75) Ca2+ activation. Protein kinase A (PKA) treatment was applied to half the strips to probe the effect of cMyBP-C phosphorylation on Pi sensitivity of myosin kinetics. Increasing Pi increased myosin cross-bridge detachment rate similarly for muscles with and without cMyBP-C, although these rates were higher in muscle without cMyBP-C. Treating myocardial strips with PKA accelerated detachment rate when cMyBP-C was present over all Pi, but not when cMyBP-C was absent. The rate of force development increased with Pi in all muscles. However, Pi sensitivity of the rate force development was reduced when cMyBP-C was present versus absent, suggesting that cMyBP-C inhibits Pi-dependent reversal of the power stroke or stabilizes cross-bridge attachment to enhance the probability of completing the power stroke. These results support a functional role for cMyBP-C in slowing myosin detachment rate, possibly through a direct interaction with myosin or by altering strain-dependent myosin detachment via cMyBP-C-dependent stiffness of the thick filament and myofilament lattice. PKA treatment reduces the role for cMyBP-C to slow myosin detachment and thus effectively accelerates β-myosin detachment in the intact myofilament lattice.NEW & NOTEWORTHY Length perturbation analysis was used to demonstrate that β-cardiac myosin characteristic rates of detachment and recruitment in the intact myofilament lattice are accelerated by Pi, phosphorylation of cMyBP-C, and the absence of cMyBP-C. The results suggest that cMyBP-C normally slows myosin detachment, including Pi-dependent detachment, and that this inhibition is released with phosphorylation or absence of cMyBP-C.
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Affiliation(s)
- Bertrand C W Tanner
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
| | - Michael J Previs
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
| | - Yuan Wang
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
| | - Jeffrey Robbins
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Bradley M Palmer
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
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16
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Rasicci DV, Kirkland O, Moonschi FH, Wood NB, Szczesna-Cordary D, Previs MJ, Wenk JF, Campbell KS, Yengo CM. Impact of regulatory light chain mutation K104E on the ATPase and motor properties of cardiac myosin. J Gen Physiol 2021; 153:212025. [PMID: 33891674 PMCID: PMC8077168 DOI: 10.1085/jgp.202012811] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 03/19/2021] [Indexed: 12/11/2022] Open
Abstract
Mutations in the cardiac myosin regulatory light chain (RLC, MYL2 gene) are known to cause inherited cardiomyopathies with variable phenotypes. In this study, we investigated the impact of a mutation in the RLC (K104E) that is associated with hypertrophic cardiomyopathy (HCM). Previously in a mouse model of K104E, older animals were found to develop cardiac hypertrophy, fibrosis, and diastolic dysfunction, suggesting a slow development of HCM. However, variable penetrance of the mutation in human populations suggests that the impact of K104E may be subtle. Therefore, we generated human cardiac myosin subfragment-1 (M2β-S1) and exchanged on either the wild type (WT) or K104E human ventricular RLC in order to assess the impact of the mutation on the mechanochemical properties of cardiac myosin. The maximum actin-activated ATPase activity and actin sliding velocities in the in vitro motility assay were similar in M2β-S1 WT and K104E, as were the detachment kinetic parameters, including the rate of ATP-induced dissociation and the ADP release rate constant. We also examined the mechanical performance of α-cardiac myosin extracted from transgenic (Tg) mice expressing human wild type RLC (Tg WT) or mutant RLC (Tg K104E). We found that α-cardiac myosin from Tg K104E animals demonstrated enhanced actin sliding velocities in the motility assay compared with its Tg WT counterpart. Furthermore, the degree of incorporation of the mutant RLC into α-cardiac myosin in the transgenic animals was significantly reduced compared with wild type. Therefore, we conclude that the impact of the K104E mutation depends on either the length or the isoform of the myosin heavy chain backbone and that the mutation may disrupt RLC interactions with the myosin lever arm domain.
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Affiliation(s)
- David V Rasicci
- Pennsylvania State University College of Medicine, Hershey, PA
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17
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Klinova SV, Katsnelson BA, Minigalieva IA, Gerzen OP, Balakin AA, Lisin RV, Butova KA, Nabiev SR, Lookin ON, Katsnelson LB, Privalova LI, Kuznetsov DA, Shur VY, Shishkina EV, Makeev OH, Valamina IE, Panov VG, Sutunkova MP, Nikitina LV, Protsenko YL. Cardioinotropic Effects in Subchronic Intoxication of Rats with Lead and/or Cadmium Oxide Nanoparticles. Int J Mol Sci 2021; 22:ijms22073466. [PMID: 33801669 PMCID: PMC8036427 DOI: 10.3390/ijms22073466] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/23/2021] [Accepted: 03/24/2021] [Indexed: 01/31/2023] Open
Abstract
Subchronic intoxication was induced in outbred male rats by repeated intraperitoneal injections with lead oxide (PbO) and/or cadmium oxide (CdO) nanoparticles (NPs) 3 times a week during 6 weeks for the purpose of examining its effects on the contractile characteristics of isolated right ventricle trabeculae and papillary muscles in isometric and afterload contractions. Isolated and combined intoxication with these NPs was observed to reduce the mechanical work produced by both types of myocardial preparation. Using the in vitro motility assay, we showed that the sliding velocity of regulated thin filaments drops under both isolated and combined intoxication with CdO–NP and PbO–NP. These results correlate with a shift in the expression of myosin heavy chain (MHC) isoforms towards slowly cycling β–MHC. The type of CdO–NP + PbO–NP combined cardiotoxicity depends on the effect of the toxic impact, the extent of this effect, the ratio of toxicant doses, and the degree of stretching of cardiomyocytes and muscle type studied. Some indices of combined Pb–NP and CdO–NP cardiotoxicity and general toxicity (genotoxicity included) became fully or partly normalized if intoxication developed against background administration of a bioprotective complex.
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Affiliation(s)
- Svetlana V. Klinova
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, 620014 Yekaterinburg, Russia; (S.V.K.); (I.A.M.); (L.I.P.); (V.G.P.); (M.P.S.)
| | - Boris A. Katsnelson
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, 620014 Yekaterinburg, Russia; (S.V.K.); (I.A.M.); (L.I.P.); (V.G.P.); (M.P.S.)
- Correspondence: ; Tel.: +7-343-253-04-21; Fax: +7-343-3717-740; Cell: +7-922-126-30-90
| | - Ilzira A. Minigalieva
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, 620014 Yekaterinburg, Russia; (S.V.K.); (I.A.M.); (L.I.P.); (V.G.P.); (M.P.S.)
| | - Oksana P. Gerzen
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
| | - Alexander A. Balakin
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
| | - Ruslan V. Lisin
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
| | - Ksenia A. Butova
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
| | - Salavat R. Nabiev
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
| | - Oleg N. Lookin
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
| | - Leonid B. Katsnelson
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
| | - Larisa I. Privalova
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, 620014 Yekaterinburg, Russia; (S.V.K.); (I.A.M.); (L.I.P.); (V.G.P.); (M.P.S.)
| | - Daniil A. Kuznetsov
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
| | - Vladimir Ya. Shur
- School of Natural Sciences and Mathematics, The Ural Federal University, 620002 Ekaterinburg, Russia; (V.Y.S.); (E.V.S.)
| | - Ekaterina V. Shishkina
- School of Natural Sciences and Mathematics, The Ural Federal University, 620002 Ekaterinburg, Russia; (V.Y.S.); (E.V.S.)
| | - Oleg H. Makeev
- The Central Research Laboratory, The Ural State Medical University, 620014 Yekaterinburg, Russia; (O.H.M.); (I.E.V.)
| | - Irene E. Valamina
- The Central Research Laboratory, The Ural State Medical University, 620014 Yekaterinburg, Russia; (O.H.M.); (I.E.V.)
| | - Vladimir G. Panov
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, 620014 Yekaterinburg, Russia; (S.V.K.); (I.A.M.); (L.I.P.); (V.G.P.); (M.P.S.)
- Institute of Industrial Ecology, The Urals Branch of the Russian Academy of Sciences, 620049 Ekaterinburg, Russia
| | - Marina P. Sutunkova
- Yekaterinburg Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, 620014 Yekaterinburg, Russia; (S.V.K.); (I.A.M.); (L.I.P.); (V.G.P.); (M.P.S.)
| | - Larisa V. Nikitina
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
| | - Yuri L. Protsenko
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, 620049 Yekaterinburg, Russia; (O.P.G.); (A.A.B.); (R.V.L.); (K.A.B.); (S.R.N.); (O.N.L.); (L.B.K.); (D.A.K.); (L.V.N.); (Y.L.P.)
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18
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Mijailovich SM, Prodanovic M, Poggesi C, Powers JD, Davis J, Geeves MA, Regnier M. The effect of variable troponin C mutation thin filament incorporation on cardiac muscle twitch contractions. J Mol Cell Cardiol 2021; 155:112-124. [PMID: 33636222 DOI: 10.1016/j.yjmcc.2021.02.009] [Citation(s) in RCA: 4] [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: 12/11/2020] [Revised: 02/17/2021] [Accepted: 02/19/2021] [Indexed: 11/19/2022]
Abstract
One of the complexities of understanding the pathology of familial forms of cardiac diseases is the level of mutation incorporation in sarcomeres. Computational models of the sarcomere that are spatially explicit offer an approach to study aspects of mutational incorporation into myofilaments that are more challenging to get at experimentally. We studied two well characterized mutations of cardiac TnC, L48Q and I61Q, that decrease or increase the release rate of Ca2+ from cTnC, k-Ca, resulting in HCM and DCM respectively [1]. Expression of these mutations in transgenic mice was used to provide experimental data for incorporation of 30 and 50% (respectively) into sarcomeres. Here we demonstrate that fixed length twitch contractions of trabeculae from mice containing mutant differ from WT; L48Q trabeculae have slower relaxation while I61Q trabeculae have markedly reduced peak tension. Using our multiscale modelling approach [2] we were able to describe the tension transients of WT mouse myocardium. Tension transients for the mutant cTnCs were simulated with changes in k-Ca, measured experimentally for each cTnC mutant in whole troponin complex, a change in the affinity of cTnC for cTnI, and a reduction in the number of detached crossbridges available for binding. A major advantage of the multiscale explicit 3-D model is that it predicts the effects of variable mutation incorporation, and the effects of variations in mutation distribution within thin filaments in sarcomeres. Such effects are currently impossible to explore experimentally. We explored random and clustered distributions of mutant cTnCs in thin filaments, as well as distributions of individual thin filaments with only WT or mutant cTnCs present. The effects of variable amounts of incorporation and non-random distribution of mutant cTnCs are more marked for I61Q than L48Q cTnC. We conclude that this approach can be effective for study on mutations in multiple proteins of the sarcomere. SUMMARY: A challenge in experimental studies of diseases is accounting for the effect of variable mutation incorporation into myofilaments. Here we use a spatially explicit computational approach, informed by experimental data from transgenic mice expressing one of two mutations in cardiac Troponin C that increase or decrease calcium sensitivity. We demonstrate that the model can accurately describe twitch contractions for the data and go on to explore the effect of variable mutant incorporation and localization on simulated cardiac muscle twitches.
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Affiliation(s)
| | - Momcilo Prodanovic
- Bioengineering Research and Development Center (BioIRC), Kragujevac 34000, Serbia; Faculty of Engineering, University of Kragujevac, Kragujevac 34000, Serbia
| | - Corrado Poggesi
- Department of Experimental & Clinical Medicine, University of Florence, Florence 50134, Italy
| | - Joseph D Powers
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA; Dept. of Bioengineering, University of California, San Diego, CA 92093, USA
| | - Jennifer Davis
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
| | - Michael A Geeves
- Dept. of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK
| | - Michael Regnier
- Department of Bioengineering, University of Washington, Seattle, WA 98105, USA
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19
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Greenberg MJ, Tardiff JC. Complexity in genetic cardiomyopathies and new approaches for mechanism-based precision medicine. J Gen Physiol 2021; 153:211741. [PMID: 33512404 PMCID: PMC7852459 DOI: 10.1085/jgp.202012662] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Accepted: 01/07/2021] [Indexed: 12/11/2022] Open
Abstract
Genetic cardiomyopathies have been studied for decades, and it has become increasingly clear that these progressive diseases are more complex than originally thought. These complexities can be seen both in the molecular etiologies of these disorders and in the clinical phenotypes observed in patients. While these disorders can be caused by mutations in cardiac genes, including ones encoding sarcomeric proteins, the disease presentation varies depending on the patient mutation, where mutations even within the same gene can cause divergent phenotypes. Moreover, it is challenging to connect the mutation-induced molecular insult that drives the disease pathogenesis with the various compensatory and maladaptive pathways that are activated during the course of the subsequent progressive, pathogenic cardiac remodeling. These inherent complexities have frustrated our ability to understand and develop broadly effective treatments for these disorders. It has been proposed that it might be possible to improve patient outcomes by adopting a precision medicine approach. Here, we lay out a practical framework for such an approach, where patient subpopulations are binned based on common underlying biophysical mechanisms that drive the molecular disease pathogenesis, and we propose that this function-based approach will enable the development of targeted therapeutics that ameliorate these effects. We highlight several mutations to illustrate the need for mechanistic molecular experiments that span organizational and temporal scales, and we describe recent advances in the development of novel therapeutics based on functional targets. Finally, we describe many of the outstanding questions for the field and how fundamental mechanistic studies, informed by our more nuanced understanding of the clinical disorders, will play a central role in realizing the potential of precision medicine for genetic cardiomyopathies.
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Affiliation(s)
- Michael J Greenberg
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO
| | - Jil C Tardiff
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ.,Department of Medicine, University of Arizona, Tucson, AZ
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20
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Alpha and beta myosin isoforms and human atrial and ventricular contraction. Cell Mol Life Sci 2021; 78:7309-7337. [PMID: 34704115 PMCID: PMC8629898 DOI: 10.1007/s00018-021-03971-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 10/03/2021] [Accepted: 10/08/2021] [Indexed: 01/15/2023]
Abstract
Human atrial and ventricular contractions have distinct mechanical characteristics including speed of contraction, volume of blood delivered and the range of pressure generated. Notably, the ventricle expresses predominantly β-cardiac myosin while the atrium expresses mostly the α-isoform. In recent years exploration of the properties of pure α- & β-myosin isoforms have been possible in solution, in isolated myocytes and myofibrils. This allows us to consider the extent to which the atrial vs ventricular mechanical characteristics are defined by the myosin isoform expressed, and how the isoform properties are matched to their physiological roles. To do this we Outline the essential feature of atrial and ventricular contraction; Explore the molecular structural and functional characteristics of the two myosin isoforms; Describe the contractile behaviour of myocytes and myofibrils expressing a single myosin isoform; Finally we outline the outstanding problems in defining the differences between the atria and ventricles. This allowed us consider what features of contraction can and cannot be ascribed to the myosin isoforms present in the atria and ventricles.
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21
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Resveratrol attenuates angiotensin II-induced cellular hypertrophy through the inhibition of CYP1B1 and the cardiotoxic mid-chain HETE metabolites. Mol Cell Biochem 2020; 471:165-176. [PMID: 32533462 PMCID: PMC7291180 DOI: 10.1007/s11010-020-03777-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/31/2020] [Indexed: 02/06/2023]
Abstract
Several reports demonstrated the direct contribution of cytochrome P450 1B1 (CYP1B1) enzyme and its associated cardiotoxic mid-chain, hydroxyeicosatetraenoic acid (HETEs) metabolites in the development of cardiac hypertrophy. Resveratrol is commercially available polyphenol that exerts beneficial effects in wide array of cardiovascular diseases including cardiac hypertrophy, myocardial infarction and heart failure. Nevertheless, the underlying mechanisms responsible for these effects are not fully elucidated. Since resveratrol is a well-known CYP1B1 inhibitor, the purpose of this study is to test whether resveratrol attenuates angiotensin II (Ang II)-induced cellular hypertrophy through inhibition of CYP1B1/mid-chain HETEs mechanism. RL-14 and H9c2 cells were treated with vehicle or 10 μM Ang II in the absence and presence of 2, 10 or 50 μM resveratrol for 24 h. Thereafter, the level of mid-chain HETEs was determined using liquid chromatography–mass spectrometry (LC/MS). Hypertrophic markers and CYP1B1 gene expression and protein levels were measured using real-time PCR and Western blot analysis, respectively. Our results demonstrated that resveratrol, at concentrations of 10 and 50 μM, was able to attenuate Ang-II-induced cellular hypertrophy as evidenced by substantial inhibition of hypertrophic markers, β-myosin heavy chain (MHC)/α-MHC and atrial natriuretic peptide. Ang II significantly induced the protein expression of CYP1B1 and increased the metabolite formation rate of its associated mid-chain HETEs. Interestingly, the protective effect of resveratrol was associated with a significant decrease of CYP1B1 protein expression and mid-chain HETEs. Our results provided the first evidence that resveratrol protects against Ang II-induced cellular hypertrophy, at least in part, through CYP1B1/mid-chain HETEs-dependent mechanism.
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Williams JL, Paudyal A, Awad S, Nicholson J, Grzesik D, Botta J, Meimaridou E, Maharaj AV, Stewart M, Tinker A, Cox RD, Metherell LA. Mylk3 null C57BL/6N mice develop cardiomyopathy, whereas Nnt null C57BL/6J mice do not. Life Sci Alliance 2020; 3:3/4/e201900593. [PMID: 32213617 PMCID: PMC7103425 DOI: 10.26508/lsa.201900593] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/10/2020] [Accepted: 03/10/2020] [Indexed: 12/30/2022] Open
Abstract
The C57BL/6J and C57BL/6N mice have well-documented phenotypic and genotypic differences, including the infamous nicotinamide nucleotide transhydrogenase (Nnt) null mutation in the C57BL/6J substrain, which has been linked to cardiovascular traits in mice and cardiomyopathy in humans. To assess whether Nnt loss alone causes a cardiovascular phenotype, we investigated the C57BL/6N, C57BL/6J mice and a C57BL/6J-BAC transgenic rescuing NNT expression, at 3, 12, and 18 mo. We identified a modest dilated cardiomyopathy in the C57BL/6N mice, absent in the two B6J substrains. Immunofluorescent staining of cardiomyocytes revealed eccentric hypertrophy in these mice, with defects in sarcomere organisation. RNAseq analysis identified differential expression of a number of cardiac remodelling genes commonly associated with cardiac disease segregating with the phenotype. Variant calling from RNAseq data identified a myosin light chain kinase 3 (Mylk3) mutation in C57BL/6N mice, which abolishes MYLK3 protein expression. These results indicate the C57BL/6J Nnt-null mice do not develop cardiomyopathy; however, we identified a null mutation in Mylk3 as a credible cause of the cardiomyopathy phenotype in the C57BL/6N.
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Affiliation(s)
- Jack L Williams
- Centre for Endocrinology, William Harvey Research Institute, Charterhouse Square, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Anju Paudyal
- Medical Research Council Harwell Institute, Mary Lyon Centre, Harwell Campus, Oxfordshire, UK
| | - Sherine Awad
- Centre for Endocrinology, William Harvey Research Institute, Charterhouse Square, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - James Nicholson
- Centre for Endocrinology, William Harvey Research Institute, Charterhouse Square, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Dominika Grzesik
- Centre for Endocrinology, William Harvey Research Institute, Charterhouse Square, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Joaquin Botta
- Centre for Endocrinology, William Harvey Research Institute, Charterhouse Square, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Eirini Meimaridou
- School of Human Sciences, London Metropolitan University, London, UK
| | - Avinaash V Maharaj
- Centre for Endocrinology, William Harvey Research Institute, Charterhouse Square, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Michelle Stewart
- Medical Research Council Harwell Institute, Mary Lyon Centre, Harwell Campus, Oxfordshire, UK
| | - Andrew Tinker
- William Harvey Heart Centre, William Harvey Research Institute, Charterhouse Square, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - Roger D Cox
- Medical Research Council Harwell Institute, Mammalian Genetics Unit, Harwell Campus, Oxfordshire, UK
| | - Lou A Metherell
- Centre for Endocrinology, William Harvey Research Institute, Charterhouse Square, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK
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Study of the Expression Transition of Cardiac Myosin Using Polarization-Dependent SHG Microscopy. Biophys J 2020; 118:1058-1066. [PMID: 31995740 DOI: 10.1016/j.bpj.2019.12.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Revised: 12/20/2019] [Accepted: 12/27/2019] [Indexed: 02/04/2023] Open
Abstract
Detection of the transition between the two myosin isoforms α- and β-myosin in living cardiomyocytes is essential for understanding cardiac physiology and pathology. In this study, the differences in symmetry of polarization spectra obtained from α- and β-myosin in various mammalian ventricles and propylthiouracil-treated rats are explored through polarization-dependent second harmonic generation microscopy. Here, we report for the, to our knowledge, first time that α- and β-myosin, as protein crystals, possess different symmetries: the former has C6 symmetry, and the latter has C3v. A single-sarcomere line scan further demonstrated that the differences in polarization-spectrum symmetry between α- and β-myosin came from their head regions: the head and neck domains of α- and β-myosin account for the differences in symmetry. In addition, the dynamic transition of the polarization spectrum from C6 to C3v line profile was observed in a cell culture in which norepinephrine induced an α- to β-myosin transition.
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Johnson CA, Walklate J, Svicevic M, Mijailovich SM, Vera C, Karabina A, Leinwand LA, Geeves MA. The ATPase cycle of human muscle myosin II isoforms: Adaptation of a single mechanochemical cycle for different physiological roles. J Biol Chem 2019; 294:14267-14278. [PMID: 31387944 DOI: 10.1074/jbc.ra119.009825] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 07/28/2019] [Indexed: 01/03/2023] Open
Abstract
Striated muscle myosins are encoded by a large gene family in all mammals, including humans. These isoforms define several of the key characteristics of the different striated muscle fiber types, including maximum shortening velocity. We have previously used recombinant isoforms of the motor domains of seven different human myosin isoforms to define the actin·myosin cross-bridge cycle in solution. Here, we present data on an eighth isoform, the perinatal, which has not previously been characterized. The perinatal is distinct from the embryonic isoform, appearing to have features in common with the adult fast-muscle isoforms, including weak affinity of ADP for actin·myosin and fast ADP release. We go on to use a recently developed modeling approach, MUSICO, to explore how well the experimentally defined cross-bridge cycles for each isoform in solution can predict the characteristics of muscle fiber contraction, including duty ratio, shortening velocity, ATP economy, and load dependence of these parameters. The work shows that the parameters of the cross-bridge cycle predict many of the major characteristics of each muscle fiber type and raises the question of what sequence changes are responsible for these characteristics.
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Affiliation(s)
- Chloe A Johnson
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, United Kingdom
| | - Jonathan Walklate
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, United Kingdom
| | - Marina Svicevic
- Faculty of Science, University of Kragujevac, Kragujevac 34000, Serbia
| | | | - Carlos Vera
- BioFrontiers Institute and Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Anastasia Karabina
- BioFrontiers Institute and Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Leslie A Leinwand
- BioFrontiers Institute and Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80309
| | - Michael A Geeves
- School of Biosciences, University of Kent, Canterbury CT2 7NJ, United Kingdom
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25
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Protsenko YL, Katsnelson BA, Klinova SV, Lookin ON, Balakin AA, Nikitina LV, Gerzen OP, Nabiev SR, Minigalieva IA, Privalova LI, Gurvich VB, Sutunkova MP, Katsnelson LB. Further analysis of rat myocardium contractility changes associated with a subchronic lead intoxication. Food Chem Toxicol 2019; 125:233-241. [PMID: 30634013 DOI: 10.1016/j.fct.2018.12.054] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/06/2018] [Accepted: 12/29/2018] [Indexed: 10/27/2022]
Abstract
A moderate subchronic lead intoxication was observed in male rats after repeated intraperitoneal injections of lead acetate. Right ventricular trabeculae and papillary muscles were isolated for in vitro studying of the contraction-relaxation cycle under isotonic and physiological loading. The contractile function of the myocardium was also assessed by measuring the velocity of thin filament movement over myosin. Lead intoxication led in papillary muscles to a decrease in the maximal rate of isotonic shortening for all afterloads and a decrease in the thin filament sliding velocity. Papillary muscles from lead-exposed rats displayed marked changes in most of the main characteristics of afterload contraction-relaxation cycles, but in trabeculae these changes were less pronounced. The reported changes were attenuated to some extent in rats treated with a Ca-containing bioprotector. The amount of work produced by both types of heart muscle preparations was not changed by lead. Only in papillary muscles the load-dependent relaxation index was significantly increased in the lead-treated groups. Thus subchronic lead intoxication affects the peak rate of force development and relaxation properties of cardiac muscle contracting in isotonic/physiological regimes rather than the total amount of mechanical work, which may reflect adaptive changes in the myocardial function under decreased contractility.
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Affiliation(s)
- Yuri L Protsenko
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
| | - Boris A Katsnelson
- The Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia.
| | - Svetlana V Klinova
- The Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia
| | - Oleg N Lookin
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia; Ural Federal University, Ekaterinburg, Russia
| | - Alexander A Balakin
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
| | - Larisa V Nikitina
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
| | - Oksana P Gerzen
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
| | - Salavat R Nabiev
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia
| | - Ilzira A Minigalieva
- The Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia
| | - Larisa I Privalova
- The Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia
| | - Vladimir B Gurvich
- The Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia
| | - Marina P Sutunkova
- The Medical Research Center for Prophylaxis and Health Protection in Industrial Workers, Ekaterinburg, Russia
| | - Leonid B Katsnelson
- Institute of Immunology and Physiology of the Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia; Ural Federal University, Ekaterinburg, Russia
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Reiser PJ. Current understanding of conventional and novel co-expression patterns of mammalian sarcomeric myosin heavy chains and light chains. Arch Biochem Biophys 2018; 662:129-133. [PMID: 30528779 DOI: 10.1016/j.abb.2018.12.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/31/2018] [Accepted: 12/04/2018] [Indexed: 10/27/2022]
Abstract
A central tenet of muscle physiology that has accrued from several decades of intense investigations is that myosin, and the vast set of isoforms that constitute its six subunits, is a major regulator of contractile properties of smooth, cardiac and skeletal muscle. Two frequent questions are (1) how many myosin heavy chain (MyHC) isoforms and myosin light chain (MLC) isoforms are expressed in mammalian striated muscles and (2) which isoforms of MyHC and MLC are expressed, at the protein level, with each other - that is, what patterns of co-expression exist in single striated muscle fibers? The answer to the former question is straightforward: eleven MyHC isoforms and nine MLC isoforms, are expressed in a developmentally-regulated and muscle-specific manner. The answer to the latter question, on the other hand, is not clear-cut. The observed number of MyHC and MLC isoform combinations among single fibers is far less than the total number of potential permutations, indicating strict regulation of expression in individual muscle cells. This article provides a review of the current and still evolving understanding of the complexity of muscle fiber types defined on the basis of expression patterns of MyHC and MLC isoforms that constitute an intact functioning molecule.
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Affiliation(s)
- Peter J Reiser
- Division of Biosciences, College of Dentistry, The Ohio State University, 305 West 12th Avenue, Columbus, OH, 43210, USA.
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27
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Hypertrophic cardiomyopathy R403Q mutation in rabbit β-myosin reduces contractile function at the molecular and myofibrillar levels. Proc Natl Acad Sci U S A 2018; 115:11238-11243. [PMID: 30322937 DOI: 10.1073/pnas.1802967115] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
In 1990, the Seidmans showed that a single point mutation, R403Q, in the human β-myosin heavy chain (MHC) of heart muscle caused a particularly malignant form of familial hypertrophic cardiomyopathy (HCM) [Geisterfer-Lowrance AA, et al. (1990) Cell 62:999-1006.]. Since then, more than 300 mutations in the β-MHC have been reported, and yet there remains a poor understanding of how a single missense mutation in the MYH7 gene can lead to heart disease. Previous studies with a transgenic mouse model showed that the myosin phenotype depended on whether the mutation was in an α- or β-MHC backbone. This led to the generation of a transgenic rabbit model with the R403Q mutation in a β-MHC backbone. We find that the in vitro motility of heterodimeric R403Q myosin is markedly reduced, whereas the actin-activated ATPase activity of R403Q subfragment-1 is about the same as myosin from a nontransgenic littermate. Single myofibrils isolated from the ventricles of R403Q transgenic rabbits and analyzed by atomic force microscopy showed reduced rates of force development and relaxation, and achieved a significantly lower steady-state level of isometric force compared with nontransgenic myofibrils. Myofibrils isolated from the soleus gave similar results. The force-velocity relationship determined for R403Q ventricular myofibrils showed a decrease in the velocity of shortening under load, resulting in a diminished power output. We conclude that independent of whether experiments are performed with isolated molecules or with ordered molecules in the native thick filament of a myofibril, there is a loss-of-function induced by the R403Q mutation in β-cardiac myosin.
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28
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Wu X, Pan B, Liu L, Zhao W, Zhu J, Huang X, Tian J. In utero exposure to PM2.5 during gestation caused adult cardiac hypertrophy through histone acetylation modification. J Cell Biochem 2018; 120:4375-4384. [PMID: 30269375 DOI: 10.1002/jcb.27723] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/29/2018] [Indexed: 01/27/2023]
Affiliation(s)
- Xiaoqi Wu
- Heart Centre, Children’s Hospital of Chongqing Medical University Chongqing China
- Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education Chongqing China
- Key Laboratory of Pediatrics Chongqing China
- Chongqing International Science and Technology Cooperation Center for Child Development and Disorders Chongqing China
| | - Bo Pan
- Heart Centre, Children’s Hospital of Chongqing Medical University Chongqing China
- Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education Chongqing China
- Key Laboratory of Pediatrics Chongqing China
- Chongqing International Science and Technology Cooperation Center for Child Development and Disorders Chongqing China
| | - Lingjuan Liu
- Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education Chongqing China
- Key Laboratory of Pediatrics Chongqing China
- Chongqing International Science and Technology Cooperation Center for Child Development and Disorders Chongqing China
| | - Weian Zhao
- Heart Centre, Children’s Hospital of Chongqing Medical University Chongqing China
- Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education Chongqing China
- Key Laboratory of Pediatrics Chongqing China
- Chongqing International Science and Technology Cooperation Center for Child Development and Disorders Chongqing China
| | - Jing Zhu
- Key Laboratory of Developmental Disease in Childhood (Chongqing Medical University), Ministry of Education Chongqing China
- Key Laboratory of Pediatrics Chongqing China
- Chongqing International Science and Technology Cooperation Center for Child Development and Disorders Chongqing China
| | - Xupei Huang
- Department of Biomedical Science Charlie E. Schmidt College of Medicine, Florida Atlantic University Boca Raton Florida
| | - Jie Tian
- Heart Centre, Children’s Hospital of Chongqing Medical University Chongqing China
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29
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Greenberg MJ, Daily NJ, Wang A, Conway MK, Wakatsuki T. Genetic and Tissue Engineering Approaches to Modeling the Mechanics of Human Heart Failure for Drug Discovery. Front Cardiovasc Med 2018; 5:120. [PMID: 30283789 PMCID: PMC6156537 DOI: 10.3389/fcvm.2018.00120] [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: 05/30/2018] [Accepted: 08/13/2018] [Indexed: 12/14/2022] Open
Abstract
Heart failure is the leading cause of death in the western world and as such, there is a great need for new therapies. Heart failure has a variable presentation in patients and a complex etiology; however, it is fundamentally a condition that affects the mechanics of cardiac contraction, preventing the heart from generating sufficient cardiac output under normal operating pressures. One of the major issues hindering the development of new therapies has been difficulties in developing appropriate in vitro model systems of human heart failure that recapitulate the essential changes in cardiac mechanics seen in the disease. Recent advances in stem cell technologies, genetic engineering, and tissue engineering have the potential to revolutionize our ability to model and study heart failure in vitro. Here, we review how these technologies are being applied to develop personalized models of heart failure and discover novel therapeutics.
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Affiliation(s)
- Michael J Greenberg
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, MO, United States
| | | | - Ann Wang
- InvivoSciences Inc., Madison, WI, United States
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30
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Pinzauti F, Pertici I, Reconditi M, Narayanan T, Stienen GJM, Piazzesi G, Lombardi V, Linari M, Caremani M. The force and stiffness of myosin motors in the isometric twitch of a cardiac trabecula and the effect of the extracellular calcium concentration. J Physiol 2018; 596:2581-2596. [PMID: 29714038 PMCID: PMC6023834 DOI: 10.1113/jp275579] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 04/13/2018] [Indexed: 01/22/2023] Open
Abstract
KEY POINTS Fast sarcomere-level mechanics in intact trabeculae, which allows the definition of the mechano-kinetic properties of cardiac myosin in situ, is a fundamental tool not only for understanding the molecular mechanisms of heart performance and regulation, but also for investigating the mechanisms of the cardiomyopathy-causing mutations in the myosin and testing small molecules for therapeutic interventions. The approach has been applied to measure the stiffness and force of the myosin motor and the fraction of motors attached during isometric twitches of electrically paced trabeculae under different extracellular Ca2+ concentrations. Although the average force of the cardiac myosin motor (∼6 pN) is similar to that of the fast myosin isoform of skeletal muscle, the stiffness (1.07 pN nm-1 ) is 2- to 3-fold smaller. The increase in the twitch force developed in the presence of larger extracellular Ca2+ concentrations is fully accounted for by a proportional increase in the number of attached motors. ABSTRACT The mechano-kinetic properties of the cardiac myosin were studied in situ, in trabeculae dissected from the right ventricle of the rat heart, by measuring the stiffness of the half-sarcomere both at the twitch force peak (Tp ) of an electrically paced intact trabecula at different extracellular Ca2+ concentrations ([Ca2+ ]o ), and in the same trabecula after skinning and induction of rigor. Taking into account the contribution of filament compliance to half-sarcomere compliance and the lattice geometry, we found that the stiffness of the cardiac myosin motor is 1.07 ± 0.09 pN nm-1 , which is slightly larger than that of the slow myosin isoform of skeletal muscle (0.6-0.8 pN nm-1 ) and 2- to 3-fold smaller than that of the fast skeletal muscle isoform. The increase in Tp from 61 ± 4 kPa to 93 ± 9 kPa, induced by raising [Ca2+ ]o from 1 to 2.5 mm at sarcomere length ∼2.2 μm, is accompanied by an increase of the half-sarcomere stiffness that is explained by an increase of the fraction of actin-attached motors from 0.08 ± 0.01 to 0.12 ± 0.02, proportional to Tp . Consequently, each myosin motor bears an average force of 6.14 ± 0.52 pN independently of Tp and [Ca2+ ]o . The application of fast sarcomere-level mechanics to intact trabeculae to define the mechano-kinetic properties of the cardiac myosin in situ represents a powerful tool for investigating cardiomyopathy-causing mutations in the myosin motor and testing specific therapeutic interventions.
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Affiliation(s)
| | | | | | | | - Ger J. M. Stienen
- Department of PhysiologyVU University Medical CenterAmsterdamThe Netherlands
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31
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Shchepkin DV, Nikitina LV, Bershitsky SY, Kopylova GV. The isoforms of α-actin and myosin affect the Ca 2+ regulation of the actin-myosin interaction in the heart. Biochem Biophys Res Commun 2017. [PMID: 28623140 DOI: 10.1016/j.bbrc.2017.06.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Myocardium of mammals contains a wide range of isoforms of proteins that provides contractile function of the heart. These are two isoforms of ventricular and two of atrial myosin, α- and β-tropomyosin, and two isoforms of α-actin: cardiac and skeletal. We believe that the difference in the amino acid sequence of α-actin can affect the calcium regulation of the actin-myosin interaction. To test this hypothesis, we investigated effects of the isoforms of α-actin, cardiac and skeletal, and the isoforms of cardiac myosin on the calcium regulation of the actin-myosin interaction in an in vitro motility assay using reconstructed regulated thin filaments. The results show that isoforms of α-actin and the ratio of α/β-chains of Tpm differently affect the calcium regulation of the actin-myosin interaction in myocardium in dependence on cardiac myosin isoforms.
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Affiliation(s)
- Daniil V Shchepkin
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg 620049, Russia
| | - Larisa V Nikitina
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg 620049, Russia
| | - Sergey Y Bershitsky
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg 620049, Russia
| | - Galina V Kopylova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg 620049, Russia.
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32
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Distensibility index of the inferior vena cava in experimental acute respiratory distress syndrome. Respir Physiol Neurobiol 2016; 237:7-12. [PMID: 28017906 DOI: 10.1016/j.resp.2016.12.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 12/16/2016] [Accepted: 12/21/2016] [Indexed: 01/23/2023]
Abstract
We determined the accuracy of distensibility index of inferior vena cava (dIVC) for evaluation of fluid responsiveness in rats with acute respiratory distress syndrome (ARDS) and validated this index for use in rat models. In protocol 1, E. coli lipopolysaccharide was administered in Wistar rats (n=7). After 24h, animals were mechanically ventilated, and stroke volume (SV) and dIVC quantified after blood drainage and subsequent volume expansion (albumin 20%). A receiver operating characteristic (ROC) curve was plotted to determine the optimal dIVC cutoff. In protocol 2, rats (n=10) were divided into fluid-responders (SV increase >5%) and nonresponders (SV increase <5%). The dIVC cutoff obtained from protocol 1 was 25%. Fluid responders had a 2.5 relative risk of low dIVC (<25%). The sensitivity, specificity, positive predictive, and negative predictive values for dIVC were 74%, 62%, 59%, and 76%, respectively. In conclusion, a dIVC threshold <25% was associated with positive response after volume expansion and could be used to titrate fluids in endotoxin-induced ARDS.
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Nikitina LV, Kopylova GV, Shchepkin DV, Nabiev SR, Bershitsky SY. Investigations of Molecular Mechanisms of Actin-Myosin Interactions in Cardiac Muscle. BIOCHEMISTRY (MOSCOW) 2016; 80:1748-63. [PMID: 26878579 DOI: 10.1134/s0006297915130106] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The functional characteristics of cardiac muscle depend on the composition of protein isoforms in the cardiomyocyte contractile machinery. In the ventricular myocardium of mammals, several isoforms of contractile and regulatory proteins are expressed - two isoforms of myosin (V1 and V3) and three isoforms of tropomyosin chains (α, β, and κ). Expression of protein isoforms depends on the animal species, its age and hormonal status, and this can change with pathologies of the myocardium. Mutations in these proteins can lead to cardiomyopathies. The functional significance of the protein isoform composition has been studied mainly on intact hearts or on isolated preparations of myocardium, which could not provide a clear comprehension of the role of each particular isoform. Present-day experimental techniques such as an optical trap and in vitro motility assay make it possible to investigate the phenomena of interactions of contractile and regulatory proteins on the molecular level, thus avoiding effects associated with properties of a whole muscle or muscle tissue. These methods enable free combining of the isoforms to test the molecular mechanisms of their participation in the actin-myosin interaction. Using the optical trap and the in vitro motility assay, we have studied functional characteristics of the cardiac myosin isoforms, molecular mechanisms of the calcium-dependent regulation of actin-myosin interaction, and the role of myosin and tropomyosin isoforms in the cooperativity mechanisms in myocardium. The knowledge of molecular mechanisms underlying myocardial contractility and its regulation is necessary for comprehension of cardiac muscle functioning, its disorders in pathologies, and for development of approaches for their correction.
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Affiliation(s)
- L V Nikitina
- Institute of Immunology and Physiology, Ural Division of the Russian Academy of Sciences, Ekaterinburg, 620041, Russia.
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Kopylova G, Nabiev S, Nikitina L, Shchepkin D, Bershitsky S. The properties of the actin-myosin interaction in the heart muscle depend on the isoforms of myosin but not of α-actin. Biochem Biophys Res Commun 2016; 476:648-653. [PMID: 27264951 DOI: 10.1016/j.bbrc.2016.06.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 06/02/2016] [Indexed: 11/27/2022]
Abstract
In myocardium of mammals there are two isoforms of myosin heavy chains, α and β. In ventricle, together with ventricular isoforms of light chains they form two isomyosins: V1 and V3, homodimers of α- and β-heavy chains, respectively. In atria, α- and β-heavy chains together with atrial light chains form A1 (αα) and A2 (ββ) isomyosins. Besides in myocardium two isoforms of α-actin, skeletal and cardiac, are expressed. We assume that the differences in the amino acid sequence of cardiac and skeletal actin may affect its interaction with myosin. To test this hypothesis, we investigated characteristics of actin-myosin interactions of cardiac and skeletal isoforms of α-actin with the isoforms of cardiac myosin using an optical trap technique and an in vitro motility assay. It was found that the mechanical and kinetic characteristics of the interactions of the isoforms of cardiac myosin with actin depend on the isoforms of myosin not α-actin.
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Affiliation(s)
- G Kopylova
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia.
| | - S Nabiev
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - L Nikitina
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - D Shchepkin
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - S Bershitsky
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
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Mohamed RMSM, Morimoto S, Ibrahim IAAEH, Zhan DY, Du CK, Arioka M, Yoshihara T, Takahashi-Yanaga F, Sasaguri T. GSK-3β heterozygous knockout is cardioprotective in a knockin mouse model of familial dilated cardiomyopathy. Am J Physiol Heart Circ Physiol 2016; 310:H1808-15. [PMID: 27106044 DOI: 10.1152/ajpheart.00771.2015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 04/18/2016] [Indexed: 11/22/2022]
Abstract
Glycogen synthase kinase-3β (GSK-3β) plays a central role in both cardiac physiology and pathology. Herein we want to clarify the role of GSK-3β in familial dilated cardiomyopathy. We generated a mouse model carrying a heterozygous knockout mutation of GSK-3β (GSK-3β(+/-) KO), together with a ΔK210 knockin mutation in cardiac troponin T (ΔK210 cTnT KI), which was proved to be one of the genetic causes of familial dilated cardiomyopathy (DCM). GSK-3β(+/-) KO prevented the slow and rapid deterioration in left ventricular systolic function accompanying heart failure (HF) in DCM mice with heterozygous and homozygous ΔK210 cTnT KI mutations, respectively. GSK-3β(+/-) KO also prevented cardiac enlargement, myocardial fibrosis, and cardiomyocyte apoptosis and markedly reduced the expression of cardiac β-myosin heavy chain isoform, indicative of HF, in DCM mice with homozygous ΔK210 cTnT KI mutation. GSK-3β(+/-) KO also extended the life span of these DCM mice. This study suggests that the inhibition of GSK-3β is cardioprotective in familial DCM associated with ΔK210 cTnT mutation.
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Affiliation(s)
- Rasha M S M Mohamed
- Department of Clinical Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; Department of Clinical Pharmacology, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Sachio Morimoto
- Department of Clinical Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan;
| | - Islam A A E-H Ibrahim
- Department of Pharmacology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt; and
| | - Dong-Yun Zhan
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Cheng-Kun Du
- Department of Cardiac Physiology, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan
| | - Masaki Arioka
- Department of Clinical Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Tatsuya Yoshihara
- Department of Clinical Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Fumi Takahashi-Yanaga
- Department of Clinical Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Toshiyuki Sasaguri
- Department of Clinical Pharmacology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
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36
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Caremani M, Pinzauti F, Reconditi M, Piazzesi G, Stienen GJM, Lombardi V, Linari M. Size and speed of the working stroke of cardiac myosin in situ. Proc Natl Acad Sci U S A 2016; 113:3675-80. [PMID: 26984499 PMCID: PMC4822625 DOI: 10.1073/pnas.1525057113] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The power in the myocardium sarcomere is generated by two bipolar arrays of the motor protein cardiac myosin II extending from the thick filament and pulling the thin, actin-containing filaments from the opposite sides of the sarcomere. Despite the interest in the definition of myosin-based cardiomyopathies, no study has yet been able to determine the mechanokinetic properties of this motor protein in situ. Sarcomere-level mechanics recorded by a striation follower is used in electrically stimulated intact ventricular trabeculae from the rat heart to determine the isotonic velocity transient following a stepwise reduction in force from the isometric peak force TP to a value T(0.8-0.2 TP). The size and the speed of the early rapid shortening (the isotonic working stroke) increase by reducing T from ∼3 nm per half-sarcomere (hs) and 1,000 s(-1) at high load to ∼8 nm⋅hs(-1) and 6,000 s(-1) at low load. Increases in sarcomere length (1.9-2.2 μm) and external [Ca(2+)]o (1-2.5 mM), which produce an increase of TP, do not affect the dependence on T, normalized for TP, of the size and speed of the working stroke. Thus, length- and Ca(2+)-dependent increase of TP and power in the heart can solely be explained by modulation of the number of myosin motors, an emergent property of their array arrangement. The motor working stroke is similar to that of skeletal muscle myosin, whereas its speed is about three times slower. A new powerful tool for investigations and therapies of myosin-based cardiomyopathies is now within our reach.
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Affiliation(s)
- Marco Caremani
- Laboratory of Physiology, Department of Biology, Università di Firenze, 50019 Sesto Fiorentino, Florence, Italy
| | - Francesca Pinzauti
- Laboratory of Physiology, Department of Biology, Università di Firenze, 50019 Sesto Fiorentino, Florence, Italy
| | - Massimo Reconditi
- Laboratory of Physiology, Department of Biology, Università di Firenze, 50019 Sesto Fiorentino, Florence, Italy
| | - Gabriella Piazzesi
- Laboratory of Physiology, Department of Biology, Università di Firenze, 50019 Sesto Fiorentino, Florence, Italy
| | - Ger J M Stienen
- Department of Physiology, Institute for Cardiovascular Research, VU University Medical Center, 1081 HV Amsterdam, The Netherlands; Department of Physics and Astronomy, Faculty of Science, VU University, 1081 HV Amsterdam, The Netherlands
| | - Vincenzo Lombardi
- Laboratory of Physiology, Department of Biology, Università di Firenze, 50019 Sesto Fiorentino, Florence, Italy;
| | - Marco Linari
- Laboratory of Physiology, Department of Biology, Università di Firenze, 50019 Sesto Fiorentino, Florence, Italy
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Vermillion KL, Jagtap P, Johnson JE, Griffin TJ, Andrews MT. Characterizing Cardiac Molecular Mechanisms of Mammalian Hibernation via Quantitative Proteogenomics. J Proteome Res 2015; 14:4792-804. [DOI: 10.1021/acs.jproteome.5b00575] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Katie L. Vermillion
- Department
of Biology, University of Minnesota Duluth, 1035 Kirby Drive, Duluth, Minnesota 55812, United States
| | - Pratik Jagtap
- Center
for Mass Spectrometry and Proteomics, University of Minnesota, 1479 Gortner
Avenue, St. Paul, Minnesota 55108, United States
- Department
of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 321 Church St SE, Minneapolis, Minnesota 55455, United States
| | - James E. Johnson
- Minnesota Supercomputing Institute, 512 Walter Library 117 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Timothy J. Griffin
- Center
for Mass Spectrometry and Proteomics, University of Minnesota, 1479 Gortner
Avenue, St. Paul, Minnesota 55108, United States
- Department
of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, 321 Church St SE, Minneapolis, Minnesota 55455, United States
| | - Matthew T. Andrews
- Department
of Biology, University of Minnesota Duluth, 1035 Kirby Drive, Duluth, Minnesota 55812, United States
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Karabina A, Kazmierczak K, Szczesna-Cordary D, Moore JR. Myosin regulatory light chain phosphorylation enhances cardiac β-myosin in vitro motility under load. Arch Biochem Biophys 2015; 580:14-21. [PMID: 26116789 PMCID: PMC4790447 DOI: 10.1016/j.abb.2015.06.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 05/27/2015] [Accepted: 06/21/2015] [Indexed: 12/15/2022]
Abstract
Familial hypertrophic cardiomyopathy (HCM) is characterized by left ventricular hypertrophy and myofibrillar disarray, and often results in sudden cardiac death. Two HCM mutations, N47K and R58Q, are located in the myosin regulatory light chain (RLC). The RLC mechanically stabilizes the myosin lever arm, which is crucial to myosin's ability to transmit contractile force. The N47K and R58Q mutations have previously been shown to reduce actin filament velocity under load, stemming from a more compliant lever arm (Greenberg, 2010). In contrast, RLC phosphorylation was shown to impart stiffness to the myosin lever arm (Greenberg, 2009). We hypothesized that phosphorylation of the mutant HCM-RLC may mitigate distinct mutation-induced structural and functional abnormalities. In vitro motility assays were utilized to investigate the effects of RLC phosphorylation on the HCM-RLC mutant phenotype in the presence of an α-actinin frictional load. Porcine cardiac β-myosin was depleted of its native RLC and reconstituted with mutant or wild-type human RLC in phosphorylated or non-phosphorylated form. Consistent with previous findings, in the presence of load, myosin bearing the HCM mutations reduced actin sliding velocity compared to WT resulting in 31-41% reductions in force production. Myosin containing phosphorylated RLC (WT or mutant) increased sliding velocity and also restored mutant myosin force production to near WT unphosphorylated values. These results point to RLC phosphorylation as a general mechanism to increase force production of the individual myosin motor and as a potential target to ameliorate the HCM-induced phenotype at the molecular level.
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Affiliation(s)
- Anastasia Karabina
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA, USA
| | - Katarzyna Kazmierczak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Danuta Szczesna-Cordary
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Jeffrey R Moore
- Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA, USA.
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Aksel T, Choe Yu E, Sutton S, Ruppel KM, Spudich JA. Ensemble force changes that result from human cardiac myosin mutations and a small-molecule effector. Cell Rep 2015; 11:910-920. [PMID: 25937279 PMCID: PMC4431957 DOI: 10.1016/j.celrep.2015.04.006] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Revised: 03/19/2015] [Accepted: 04/01/2015] [Indexed: 11/24/2022] Open
Abstract
Cardiomyopathies due to mutations in human β-cardiac myosin are a significant cause of heart failure, sudden death, and arrhythmia. To understand the underlying molecular basis of changes in the contractile system's force production due to such mutations and search for potential drugs that restore force generation, an in vitro assay is necessary to evaluate cardiac myosin's ensemble force using purified proteins. Here, we characterize the ensemble force of human α- and β-cardiac myosin isoforms and those of β-cardiac myosins carrying left ventricular non-compaction (M531R) and dilated cardiomyopathy (S532P) mutations using a utrophin-based loaded in vitro motility assay and new filament-tracking software. Our results show that human α- and β-cardiac myosin, as well as the mutants, show opposite mechanical and enzymatic phenotypes with respect to each other. We also show that omecamtiv mecarbil, a previously discovered cardiac-specific myosin activator, increases β-cardiac myosin force generation.
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Affiliation(s)
- Tural Aksel
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Elizabeth Choe Yu
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA; Cancer Biology Program, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Shirley Sutton
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kathleen M Ruppel
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA; Department of Pediatrics (Cardiology), Stanford University School of Medicine, Stanford, CA 94305, USA.
| | - James A Spudich
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305, USA.
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40
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Qi Y, Zhu Q, Zhang K, Thomas C, Wu Y, Kumar R, Baker KM, Xu Z, Chen S, Guo S. Activation of Foxo1 by insulin resistance promotes cardiac dysfunction and β-myosin heavy chain gene expression. Circ Heart Fail 2014; 8:198-208. [PMID: 25477432 DOI: 10.1161/circheartfailure.114.001457] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND Heart failure is a leading cause of morbidity and mortality in the USA and is closely associated with diabetes mellitus. The molecular link between diabetes mellitus and heart failure is incompletely understood. We recently demonstrated that insulin receptor substrates 1, 2 (IRS1, 2) are key components of insulin signaling and loss of IRS1 and IRS2 mediates insulin resistance, resulting in metabolic dysregulation and heart failure, which is associated with downstream Akt inactivation and in turn activation of the forkhead transcription factor Foxo1. METHODS AND RESULTS To determine the role of Foxo1 in control of heart failure in insulin resistance and diabetes mellitus, we generated mice lacking Foxo1 gene specifically in the heart. Mice lacking both IRS1 and IRS2 in adult hearts exhibited severe heart failure and a remarkable increase in the β-isoform of myosin heavy chain (β-MHC) gene expression, whereas deletion of cardiac Foxo1 gene largely prevented the heart failure and resulted in a decrease in β-MHC expression. The effect of Foxo1 deficiency on rescuing cardiac dysfunction was also observed in db/db mice and high-fat diet mice. Using cultures of primary ventricular cardiomyocytes, we found that Foxo1 interacts with the promoter region of β-MHC and stimulates gene expression, mediating an effect of insulin that suppresses β-MHC expression. CONCLUSIONS Our study suggests that Foxo1 has important roles in promoting diabetic cardiomyopathy and controls β-MHC expression in the development of cardiac dysfunction. Targeting Foxo1 and its regulation will provide novel strategies in preventing metabolic and myocardial dysfunction and influencing MHC plasticity in diabetes mellitus.
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Affiliation(s)
- Yajuan Qi
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Qinglei Zhu
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Kebin Zhang
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Candice Thomas
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Yuxin Wu
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Rajesh Kumar
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Kenneth M Baker
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Zihui Xu
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Shouwen Chen
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.)
| | - Shaodong Guo
- From the Division of Molecular Cardiology, Department of Medicine, College of Medicine, Texas A&M University Health Science Center, Baylor Scott & White Health, Central Texas Veterans Health Care System, Temple (Y.Q., Q.Z., K.Z., C.T., Y.W., R.K., K.M.B., Z.X., S.C., S.G.); and Department of Pharmacology, Hebei United University, Tangshan, China (Y.Q.).
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Reiser PJ, Moravec CS. Sex differences in myosin heavy chain isoforms of human failing and nonfailing atria. Am J Physiol Heart Circ Physiol 2014; 307:H265-72. [DOI: 10.1152/ajpheart.00810.2013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Mammalian hearts express two myosin heavy chain (MHC) isoforms, which drive contractions with different kinetics and power-generating ability. The expression of the isoform that is associated with more rapid contraction kinetics and greater power output, MHC-α, is downregulated, with a concurrent increase in the relative amount of the slower isoform, MHC-β, during the progression to experimentally induced or disease-related heart failure. This change in protein expression has been well studied in right and left ventricles in heart failure models and in humans with failure. Relatively little quantitative data exists regarding MHC isoform expression shifts in human failing atria. We previously reported significant increases in the relative amount of MHC-β in the human failing left atrium. The results of that study suggested that there might be a sex-related difference in the level of MHC-β in the left atrium, but the number of female subjects was insufficient for statistical analysis. The objective of this study was to test whether there is, in fact, a sex-related difference in the level of MHC-β in the right and left atria of humans with cardiomyopathy. The results indicate that significant differences exist in atrial MHC isoform expression between men and women who are in failure. The results also revealed an unexpected twofold greater amount of MHC-β in the nonfailing left atrium of women, compared with men. The observed sex-related differences in MHC isoform expression could impact ventricular diastolic filling during normal daily activities, as well as during physiologically stressful events.
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Affiliation(s)
- Peter J. Reiser
- Division of Biosciences, College of Dentistry, Ohio State University, Columbus, Ohio; and
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Milani-Nejad N, Janssen PML. Small and large animal models in cardiac contraction research: advantages and disadvantages. Pharmacol Ther 2014; 141:235-49. [PMID: 24140081 PMCID: PMC3947198 DOI: 10.1016/j.pharmthera.2013.10.007] [Citation(s) in RCA: 295] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2013] [Accepted: 08/15/2013] [Indexed: 12/22/2022]
Abstract
The mammalian heart is responsible for not only pumping blood throughout the body but also adjusting this pumping activity quickly depending upon sudden changes in the metabolic demands of the body. For the most part, the human heart is capable of performing its duties without complications; however, throughout many decades of use, at some point this system encounters problems. Research into the heart's activities during healthy states and during adverse impacts that occur in disease states is necessary in order to strategize novel treatment options to ultimately prolong and improve patients' lives. Animal models are an important aspect of cardiac research where a variety of cardiac processes and therapeutic targets can be studied. However, there are differences between the heart of a human being and an animal and depending on the specific animal, these differences can become more pronounced and in certain cases limiting. There is no ideal animal model available for cardiac research, the use of each animal model is accompanied with its own set of advantages and disadvantages. In this review, we will discuss these advantages and disadvantages of commonly used laboratory animals including mouse, rat, rabbit, canine, swine, and sheep. Since the goal of cardiac research is to enhance our understanding of human health and disease and help improve clinical outcomes, we will also discuss the role of human cardiac tissue in cardiac research. This review will focus on the cardiac ventricular contractile and relaxation kinetics of humans and animal models in order to illustrate these differences.
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Affiliation(s)
- Nima Milani-Nejad
- Department of Physiology and Cell Biology and D. Davis Heart Lung Institute, College of Medicine, The Ohio State University, OH, USA
| | - Paul M L Janssen
- Department of Physiology and Cell Biology and D. Davis Heart Lung Institute, College of Medicine, The Ohio State University, OH, USA.
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Nelson OL, Rourke BC. Increase in cardiac myosin heavy-chain (MyHC) alpha protein isoform in hibernating ground squirrels, with echocardiographic visualization of ventricular wall hypertrophy and prolonged contraction. ACTA ACUST UNITED AC 2013; 216:4678-90. [PMID: 24072796 DOI: 10.1242/jeb.088773] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Deep hibernators such as golden-mantled ground squirrels (Callospermophilus lateralis) have multiple challenges to cardiac function during low temperature torpor and subsequent arousals. As heart rates fall from over 300 beats min(-1) to less than 10, chamber dilation and reduced cardiac output could lead to congestive myopathy. We performed echocardiography on a cohort of individuals prior to and after several months of hibernation. The left ventricular chamber exhibited eccentric and concentric hypertrophy during hibernation and thus calculated ventricular mass was ~30% greater. Ventricular ejection fraction was mildly reduced during hibernation but stroke volumes were greater due to the eccentric hypertrophy and dramatically increased diastolic filling volumes. Globally, the systolic phase in hibernation was ~9.5 times longer, and the diastolic phase was 28× longer. Left atrial ejection generally was not observed during hibernation. Atrial ejection returned weakly during early arousal. Strain echocardiography assessed the velocity and total movement distance of contraction and relaxation for regional ventricular segments in active and early arousal states. Myocardial systolic strain during early arousal was significantly greater than the active state, indicating greater total contractile movement. This mirrored the increased ventricular ejection fraction noted with early arousal. However, strain rates were slower during early arousal than during the active period, particularly systolic strain, which was 33% of active, compared with the rate of diastolic strain, which was 67% of active. As heart rate rose during the arousal period, myocardial velocities and strain rates also increased; this was matched closely by cardiac output. Curiously, though heart rates were only 26% of active heart rates during early arousal, the cardiac output was nearly 40% of the active state, suggesting an efficient pumping system. We further analyzed proportions of cardiac myosin heavy-chain (MyHC) isoforms in a separate cohort of squirrels over 5 months, including time points before hibernation, during hibernation and just prior to emergence. Hibernating individuals were maintained in both a 4°C cold room and a 20°C warm room. Measured by SDS-PAGE, relative percentages of cardiac MyHC alpha were increased during hibernation, at both hibernacula temperatures. A potential increase in contractile speed, and power, from more abundant MyHC alpha may aid force generation at low temperature and at low heart rates. Unlike many models of cardiomyopathies where the alpha isoform is replaced by the beta isoform in order to reduce oxygen consumption, ground squirrels demonstrate a potential cardioprotective mechanism to maintain cardiac output during torpor.
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Affiliation(s)
- O Lynne Nelson
- College of Veterinary Medicine, Washington State University, Pullman, WA 99164, USA
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Lowey S, Bretton V, Gulick J, Robbins J, Trybus KM. Transgenic mouse α- and β-cardiac myosins containing the R403Q mutation show isoform-dependent transient kinetic differences. J Biol Chem 2013; 288:14780-7. [PMID: 23580644 DOI: 10.1074/jbc.m113.450668] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Familial hypertrophic cardiomyopathy (FHC) is a major cause of sudden cardiac death in young athletes. The discovery in 1990 that a point mutation at residue 403 (R403Q) in the β-myosin heavy chain (MHC) caused a severe form of FHC was the first of many demonstrations linking FHC to mutations in muscle proteins. A mouse model for FHC has been widely used to study the mechanochemical properties of mutated cardiac myosin, but mouse hearts express α-MHC, whereas the ventricles of larger mammals express predominantly β-MHC. To address the role of the isoform backbone on function, we generated a transgenic mouse in which the endogenous α-MHC was partially replaced with transgenically encoded β-MHC or α-MHC. A His6 tag was cloned at the N terminus, along with R403Q, to facilitate isolation of myosin subfragment 1 (S1). Stopped flow kinetics were used to measure the equilibrium constants and rates of nucleotide binding and release for the mouse S1 isoforms bound to actin. For the wild-type isoforms, we found that the affinity of MgADP for α-S1 (100 μM) is ~ 4-fold weaker than for β-S1 (25 μM). Correspondingly, the MgADP release rate for α-S1 (350 s(-1)) is ~3-fold greater than for β-S1 (120 s(-1)). Introducing the R403Q mutation caused only a minor reduction in kinetics for β-S1, but R403Q in α-S1 caused the ADP release rate to increase by 20% (430 s(-1)). These transient kinetic studies on mouse cardiac myosins provide strong evidence that the functional impact of an FHC mutation on myosin depends on the isoform backbone.
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Affiliation(s)
- Susan Lowey
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405, USA.
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Deacon JC, Bloemink MJ, Rezavandi H, Geeves MA, Leinwand LA. Erratum to: Identification of functional differences between recombinant human α and β cardiac myosin motors. Cell Mol Life Sci 2012; 69:4239-55. [PMID: 23001010 PMCID: PMC3685716 DOI: 10.1007/s00018-012-1111-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The myosin isoform composition of the heart is dynamic in health and disease and has been shown to affect contractile velocity and force generation. While different mammalian species express different proportions of α and β myosin heavy chain, healthy human heart ventricles express these isoforms in a ratio of about 1:9 (α:β) while failing human ventricles express no detectable α-myosin. We report here fast-kinetic analysis of recombinant human α and β myosin heavy chain motor domains. This represents the first such analysis of any human muscle myosin motor and the first of α-myosin from any species. Our findings reveal substantial isoform differences in individual kinetic parameters, overall contractile character, and predicted cycle times. For these parameters, α-subfragment 1 (S1) is far more similar to adult fast skeletal muscle myosin isoforms than to the slow β isoform despite 91% sequence identity between the motor domains of α- and β-myosin. Among the features that differentiate α- from β-S1: the ATP hydrolysis step of α-S1 is ~ten-fold faster than β-S1, α-S1 exhibits ~five-fold weaker actin affinity than β-S1, and actin·α-S1 exhibits rapid ADP release, which is >ten-fold faster than ADP release for β-S1. Overall, the cycle times are ten-fold faster for α-S1 but the portion of time each myosin spends tightly bound to actin (the duty ratio) is similar. Sequence analysis points to regions that might underlie the basis for this finding.
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Affiliation(s)
- John C. Deacon
- Department of Molecular, Cellular and Developmental Biology and Biofrontiers Institute, University of Colorado, MCDB, UCB 347, Boulder, CO 80309 USA
| | | | - Heresh Rezavandi
- School of Biosciences, University of Kent, Canterbury, CT2 7NJ UK
| | | | - Leslie A. Leinwand
- Department of Molecular, Cellular and Developmental Biology and Biofrontiers Institute, University of Colorado, MCDB, UCB 347, Boulder, CO 80309 USA
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Wang Y, Tanner BCW, Lombardo AT, Tremble SM, Maughan DW, Vanburen P, Lewinter MM, Robbins J, Palmer BM. Cardiac myosin isoforms exhibit differential rates of MgADP release and MgATP binding detected by myocardial viscoelasticity. J Mol Cell Cardiol 2012; 54:1-8. [PMID: 23123290 DOI: 10.1016/j.yjmcc.2012.10.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2012] [Revised: 10/05/2012] [Accepted: 10/22/2012] [Indexed: 01/26/2023]
Abstract
We measured myosin crossbridge detachment rate and the rates of MgADP release and MgATP binding in mouse and rat myocardial strips bearing one of the two cardiac myosin heavy chain (MyHC) isoforms. Mice and rats were fed an iodine-deficient, propylthiouracil diet resulting in ~100% expression of β-MyHC in the ventricles. Ventricles of control animals expressed ~100% α-MyHC. Chemically-skinned myocardial strips prepared from papillary muscle were subjected to sinusoidal length perturbation analysis at maximum calcium activation pCa 4.8 and 17°C. Frequency characteristics of myocardial viscoelasticity were used to calculate crossbridge detachment rate over 0.01 to 5mM [MgATP]. The rate of MgADP release, equivalent to the asymptotic value of crossbridge detachment rate at high MgATP, was highest in mouse α-MyHC (111.4±6.2s(-1)) followed by rat α-MyHC (65.0±7.3s(-1)), mouse β-MyHC (24.3±1.8s(-1)) and rat β-MyHC (15.5±0.8s(-1)). The rate of MgATP binding was highest in mouse α-MyHC (325±32 mM(-1) s(-1)) then mouse β-MyHC (152±23 mM(-1) s(-1)), rat α-MyHC (108±10 mM(-1) s(-1)) and rat β-MyHC (55±6 mM(-1) s(-1)). Because the events of MgADP release and MgATP binding occur in a post power-stroke state of the myosin crossbridge, we infer that MgATP release and MgATP binding must be regulated by isoform- and species-specific structural differences located outside the nucleotide binding pocket, which is identical in sequence for these four myosins. We postulate that differences in the stiffness profile of the entire myosin molecule, including the thick filament and the myosin-actin interface, are primarily responsible for determining the strain on the nucleotide binding pocket and the subsequent differences in the rates of nucleotide release and binding observed among the four myosins examined here.
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Affiliation(s)
- Yuan Wang
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA
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Biondi O, Lopes P, Desseille C, Branchu J, Chali F, Ben Salah A, Pariset C, Chanoine C, Charbonnier F. Physical exercise reduces cardiac defects in type 2 spinal muscular atrophy-like mice. J Physiol 2012; 590:5907-25. [PMID: 22930275 DOI: 10.1113/jphysiol.2012.238196] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Spinal muscular atrophy (SMA), the leading genetic cause of death in infants worldwide, is due to the misexpression of the survival of motor neuron protein, causing death of motor neurons. Several clinical symptoms suggested that, in addition to motor neurons, the autonomic nervous systems could be implicated in the cardiac function alterations observed in patienst with SMA. These alterations were also found in a severe SMA mouse model, including bradycardia and a reduction of sympathetic innervation, both associated with autonomic imbalance. In the present study, we investigate the extent of autonomic dysfunction and the effects of a running-based exercise on the altered cardiorespiratory function in type 2 SMA-like mice. We observed that the SMA induced: (1) a dramatic alteration of intrinsic cardiac conduction associated with bradycardia; (2) a severe cardiomyopathy associated with extensive ventricular fibrosis; and (3) a delay in cardiac muscle maturation associated with contractile protein expression defects. Furthermore, our data indicate that the sympathetic system is not only functioning, but also likely contributes to alleviate the bradycardia and the arrhythmia in SMA-like mice. Moreover, physical exercise provides many benefits, including the reduction of cardiac protein expression defect, the reduction of fibrosis, the increase in cardiac electrical conduction velocity, and the drastic reduction in bradycardia and arrhythmias resulting in the partial restoration of the cardiac function in these mice. Thus, modulating the cardiorespiratory function in SMA could represent a new target for improving supportive care and for developing new pharmacological and non-pharmacological interventions that would most certainly include physical exercise.
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Affiliation(s)
- Olivier Biondi
- Universite Paris Descartes - CESEM UMR 8194, 45 rue des Saints Peres, Paris 75006, France.
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He H, Hoyer K, Tao H, Rice R, Jimenez J, Tardiff JC, Ingwall JS. Myosin-driven rescue of contractile reserve and energetics in mouse hearts bearing familial hypertrophic cardiomyopathy-associated mutant troponin T is mutation-specific. J Physiol 2012; 590:5371-88. [PMID: 22907055 DOI: 10.1113/jphysiol.2012.234252] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The thin filament protein troponin T (TnT) is a regulator of sarcomere function. Whole heart energetics and contractile reserve are compromised in transgenic mice bearing missense mutations at R92 within the tropomyosin-binding domain of cTnT, despite being distal to the ATP hydrolysis domain of myosin. These mutations are associated with familial hypertrophic cardiomyopathy (FHC). Here we test the hypothesis that genetically replacing murine αα-MyHC with murine ββ-MyHC in hearts bearing the R92Q cTnT mutation, a particularly lethal FHC-associated mutation, leads to sufficiently large perturbations in sarcomere function to rescue whole heart energetics and decrease the cost of contraction. By comparing R92Q cTnT and R92L cTnT mutant hearts, we also test whether any rescue is mutation-specific. We defined the energetic state of the isolated perfused heart using (31)P-NMR spectroscopy while simultaneously measuring contractile performance at four work states. We found that the cost of increasing contraction in intact mouse hearts with R92Q cTnT depends on the type of myosin present in the thick filament. We also found that the salutary effect of this manoeuvre is mutation-specific, demonstrating the major regulatory role of cTnT on sarcomere function at the whole heart level.
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Affiliation(s)
- Huamei He
- NMR Laboratory for Physiological Chemistry, Division of Cardiovascular Medicine, Department of Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA 02115, USA
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Zarain-Herzberg A, Estrada-Avilés R, Fragoso-Medina J. Regulation of sarco(endo)plasmic reticulum Ca2+-ATPase and calsequestrin gene expression in the heart. Can J Physiol Pharmacol 2012; 90:1017-28. [DOI: 10.1139/y2012-057] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The precise control of Ca2+levels during the contraction–relaxation cycle in cardiac myocytes is extremely important for normal beat-to-beat contractile activity. The sarcoplasmic reticulum (SR) plays a key role controlling calcium concentration in the cytosol. The SR Ca2+-ATPase (SERCA2) transports Ca2+inside the SR lumen during relaxation of the cardiac myocyte. Calsequestrin (Casq2) is the main protein in the SR lumen, functioning as a Ca2+buffer and participating in Ca2+release by interacting with the ryanodine receptor 2 (RyR2) Ca2+-release channel. Alterations in normal Ca2+handling significantly contribute to the contractile dysfunction observed in cardiac hypertrophy and in heart failure. Transcriptional regulation of the SERCA2 gene has been extensively studied and some of the mechanisms regulating its expression have been elucidated. Overexpression of Sp1 factor in cardiac hypertrophy downregulates SERCA2 gene expression and increased levels of thyroid hormone up-regulates its transcription. Other hormones such norepinephrine, angiotensin II, endothelin-1, parathyroid hormone, prostaglandin-F2α, as well the cytokines tumor necrosis factor-α and interleukin-6 also downregulate SERCA2 expression. Calcium acting through the calcineurin–NFAT (nuclear factor of activated T cells) pathway has been suggested to regulate SERCA2 and CASQ2 gene expression. This review focuses on the current knowledge regarding transcriptional regulation of SERCA2 and CASQ2 genes in the normal and pathologic heart.
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Affiliation(s)
- Angel Zarain-Herzberg
- Department of Biochemistry, School of Medicine, National Autonomous University of México, D.F. 04510, Mexico
| | - Rafael Estrada-Avilés
- Department of Biochemistry, School of Medicine, National Autonomous University of México, D.F. 04510, Mexico
| | - Jorge Fragoso-Medina
- Department of Biochemistry, School of Medicine, National Autonomous University of México, D.F. 04510, Mexico
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Nakagawa Y, Inoue H, Shinone K, Ikemura M, Nata M. Molecular biological analysis of cardiac effect of high temperature in rats. Leg Med (Tokyo) 2012; 14:63-8. [DOI: 10.1016/j.legalmed.2011.12.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 12/02/2011] [Accepted: 12/07/2011] [Indexed: 11/17/2022]
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