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Osten F, Weber N, Wendland M, Holler T, Piep B, Kröhn S, Teske J, Bodenschatz AK, Devadas SB, Menge KS, Chatterjee S, Schwanke K, Kosanke M, Montag J, Thum T, Zweigerdt R, Kraft T, Iorga B, Meissner JD. Myosin expression and contractile function are altered by replating stem cell-derived cardiomyocytes. J Gen Physiol 2023; 155:e202313377. [PMID: 37656049 PMCID: PMC10473967 DOI: 10.1085/jgp.202313377] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/16/2023] [Accepted: 07/19/2023] [Indexed: 09/02/2023] Open
Abstract
Myosin heavy chain (MyHC) is the main determinant of contractile function. Human ventricular cardiomyocytes (CMs) predominantly express the β-isoform. We previously demonstrated that ∼80% of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) express exclusively β-MyHC after long-term culture on laminin-coated glass coverslips. Here, we investigated the impact of enzymatically detaching hESC-CMs after long-term culture and subsequently replating them for characterization of cellular function. We observed that force-related kinetic parameters, as measured in a micromechanical setup, resembled α- rather than β-MyHC-expressing myofibrils, as well as changes in calcium transients. Single-cell immunofluorescence analysis revealed that replating hESC-CMs led to rapid upregulation of α-MyHC, as indicated by increases in exclusively α-MyHC- and in mixed α/β-MyHC-expressing hESC-CMs. A comparable increase in heterogeneity of MyHC isoform expression was also found among individual human induced pluripotent stem cell (hiPSC)-derived CMs after replating. Changes in MyHC isoform expression and cardiomyocyte function induced by replating were reversible in the course of the second week after replating. Gene enrichment analysis based on RNA-sequencing data revealed changes in the expression profile of mechanosensation/-transduction-related genes and pathways, especially integrin-associated signaling. Accordingly, the integrin downstream mediator focal adhesion kinase (FAK) promoted β-MyHC expression on a stiff matrix, further validating gene enrichment analysis. To conclude, detachment and replating induced substantial changes in gene expression, MyHC isoform composition, and function of long-term cultivated human stem cell-derived CMs, thus inducing alterations in mechanosensation/-transduction, that need to be considered, particularly for downstream in vitro assays.
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Affiliation(s)
- Felix Osten
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Natalie Weber
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
- Institute of Molecular and Translational Therapeutic Strategies (IMTTS), Hannover Medical School, Hannover, Germany
| | - Meike Wendland
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Tim Holler
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Birgit Piep
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Simon Kröhn
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Jana Teske
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Alea K. Bodenschatz
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Santoshi Biswanath Devadas
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Kaja S. Menge
- Institute of Molecular and Translational Therapeutic Strategies (IMTTS), Hannover Medical School, Hannover, Germany
| | - Shambhabi Chatterjee
- Institute of Molecular and Translational Therapeutic Strategies (IMTTS), Hannover Medical School, Hannover, Germany
| | - Kristin Schwanke
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Maike Kosanke
- Research Core Unit Genomics, Hannover Medical School, Hannover, Germany
| | - Judith Montag
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Thomas Thum
- Institute of Molecular and Translational Therapeutic Strategies (IMTTS), Hannover Medical School, Hannover, Germany
- REBIRTH Center for Translational Regenerative Therapies, Hannover Medical School, Hannover, Germany
- Fraunhofer Institute for Toxicology and Experimental Medicine, Hannover, Germany
| | - Robert Zweigerdt
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Hannover Medical School, Hannover, Germany
| | - Theresia Kraft
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
| | - Bogdan Iorga
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
- Department of Analytical Chemistry and Physical Chemistry, Faculty of Chemistry, University of Bucharest, Bucharest, Romania
| | - Joachim D. Meissner
- Institute of Molecular and Cell Physiology, Hannover Medical School, Hannover, Germany
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Dewan S, Witayavanitkul N, Kumar M, Mayer BJ, Betancourt L, Cazorla O, de Tombe PP. Depressed myocardial cross-bridge cycling kinetics in a female guinea pig model of diastolic heart failure. J Gen Physiol 2023; 155:e202213288. [PMID: 37102986 PMCID: PMC10140646 DOI: 10.1085/jgp.202213288] [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: 10/28/2022] [Revised: 02/10/2023] [Accepted: 04/17/2023] [Indexed: 04/28/2023] Open
Abstract
Cardiac hypertrophy is associated with diastolic heart failure (DHF), a syndrome in which systolic function is preserved but cardiac filling dynamics are depressed. The molecular mechanisms underlying DHF and the potential role of altered cross-bridge cycling are poorly understood. Accordingly, chronic pressure overload was induced by surgically banding the thoracic ascending aorta (AOB) in ∼400 g female Dunkin Hartley guinea pigs (AOB); Sham-operated age-matched animals served as controls. Guinea pigs were chosen to avoid the confounding impacts of altered myosin heavy chain (MHC) isoform expression seen in other small rodent models. In vivo cardiac function was assessed by echocardiography; cardiac hypertrophy was confirmed by morphometric analysis. AOB resulted in left ventricle (LV) hypertrophy and compromised diastolic function with normal systolic function. Biochemical analysis revealed exclusive expression of β-MHC isoform in both sham control and AOB LVs. Myofilament function was assessed in skinned multicellular preparations, skinned single myocyte fragments, and single myofibrils prepared from frozen (liquid N2) LVs. The rates of force-dependent ATP consumption (tension-cost) and force redevelopment (Ktr), as well as myofibril relaxation time (Timelin) were significantly blunted in AOB, indicating reduced cross-bridge cycling kinetics. Maximum Ca2+ activated force development was significantly reduced in AOB myocytes, while no change in myofilament Ca2+ sensitivity was observed. Our results indicate blunted cross-bridge cycle in a β-MHC small animal DHF model. Reduced cross-bridge cycling kinetics may contribute, at least in part, to the development of DHF in larger mammals, including humans.
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Affiliation(s)
- Sukriti Dewan
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Namthip Witayavanitkul
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Mohit Kumar
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Beth J Mayer
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
| | - Lauren Betancourt
- Phymedexp INSERM, CNRS, University of Montpellier , Montpellier, France
| | - Olivier Cazorla
- Phymedexp INSERM, CNRS, University of Montpellier , Montpellier, France
| | - Pieter P de Tombe
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA
- Phymedexp INSERM, CNRS, University of Montpellier , Montpellier, France
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Sridharan D, Pracha N, Rana SJ, Ahmed S, Dewani AJ, Alvi SB, Mergaye M, Ahmed U, Khan M. Preclinical Large Animal Porcine Models for Cardiac Regeneration and Its Clinical Translation: Role of hiPSC-Derived Cardiomyocytes. Cells 2023; 12:cells12071090. [PMID: 37048163 PMCID: PMC10093073 DOI: 10.3390/cells12071090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/14/2023] Open
Abstract
Myocardial Infarction (MI) occurs due to a blockage in the coronary artery resulting in ischemia and necrosis of cardiomyocytes in the left ventricular heart muscle. The dying cardiac tissue is replaced with fibrous scar tissue, causing a decrease in myocardial contractility and thus affecting the functional capacity of the myocardium. Treatments, such as stent placements, cardiac bypasses, or transplants are beneficial but with many limitations, and may decrease the overall life expectancy due to related complications. In recent years, with the advent of human induced pluripotent stem cells (hiPSCs), newer avenues using cell-based approaches for the treatment of MI have emerged as a potential for cardiac regeneration. While hiPSCs and their derived differentiated cells are promising candidates, their translatability for clinical applications has been hindered due to poor preclinical reproducibility. Various preclinical animal models for MI, ranging from mice to non-human primates, have been adopted in cardiovascular research to mimic MI in humans. Therefore, a comprehensive literature review was essential to elucidate the factors affecting the reproducibility and translatability of large animal models. In this review article, we have discussed different animal models available for studying stem-cell transplantation in cardiovascular applications, mainly focusing on the highly translatable porcine MI model.
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Affiliation(s)
- Divya Sridharan
- Department of Emergency Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Nooruddin Pracha
- Department of Emergency Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Schaza Javed Rana
- Department of Emergency Medicine, The Ohio State University, Columbus, OH 43210, USA
- Department of Internal Medicine, Northeast Georgia Medical Center, Gainesville, GA 30501, USA
| | - Salmman Ahmed
- Department of Emergency Medicine, The Ohio State University, Columbus, OH 43210, USA
- Lake Erie College of Osteopathic Medicine (LECOM), Erie, PA 16509, USA
| | - Anam J Dewani
- Department of Emergency Medicine, The Ohio State University, Columbus, OH 43210, USA
- Department of Chemistry & Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Syed Baseeruddin Alvi
- Department of Emergency Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Muhamad Mergaye
- Department of Emergency Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Uzair Ahmed
- Department of Emergency Medicine, The Ohio State University, Columbus, OH 43210, USA
| | - Mahmood Khan
- Department of Emergency Medicine, The Ohio State University, Columbus, OH 43210, USA
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH 43210, USA
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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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Isola R, Broccia F, Casti A, Loy F, Isola M, Vargiu R. STZ-diabetic rat heart maintains developed tension amplitude by increasing sarcomere length and crossbridge density. Exp Physiol 2021; 106:1572-1586. [PMID: 33977604 PMCID: PMC8362044 DOI: 10.1113/ep089000] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 05/04/2021] [Indexed: 12/21/2022]
Abstract
New Findings What is the central question of this study? In the papillary muscle from type I diabetic rats, does diabetes‐associated altered ventricular function result from changes of acto‐myosin interactions and are these modifications attributable to a possible sarcomere rearrangement? What is the main finding and its importance? For the first time, we showed that type‐I diabetes altered sarcomeric ultrastructure, as seen by transmission electron microscopy, consistent with physiological parameters. The diabetic condition induced slower timing parameters, which is compatible with a diastolic dysfunction. At the sarcomeric level, augmented β‐myosin heavy chain content and increased sarcomere length and crossbridges' number preserve myocardial stroke and could concur to maintain the ejection fraction.
Abstract We investigated whether diabetes‐associated altered ventricular function, in a type I diabetes animal model, results from a modification of acto‐myosin interactions, through the in vitro recording of left papillary muscle mechanical parameters and examination of sarcomere morphology by transmission electron microscopy (TEM). Experiments were performed on streptozotocin‐induced diabetic and age‐matched control female Wistar rats. Mechanical isometric and isotonic indexes and timing parameters were determined. Using Huxley's equations, we calculated mechanics, kinetics and energetics of myosin crossbridges. Sarcomere length and A‐band length were measured on TEM images. Type I and III collagen and β‐myosin heavy chain (MHC) expression were determined by immunoblotting. No variation in resting and developed tension or maximum extent of shortening was evident between groups, but diabetic rats showed lower maximum shortening velocity and prolonged timing parameters. Compared to controls, diabetics also displayed a higher number of crossbridges with lower unitary force. Moreover, no change in type I and III collagen was associated to diabetes, but pathological rats showed a two‐fold enhancement of β‐MHC content and longer sarcomeres and A‐band, detected by ultrastructural morphometry. Overall, these data address whether a preserved systolic function accompanied by an altered diastolic phase results from a recruitment of super‐relaxed myosin heads or the phosphorylation of the regulatory light chain site in myosin. Although the early signs of diabetic cardiomyopathy were well expressed, the striking finding of our study was that, in diabetics, sarcomere modification may be a possible compensatory mechanism that preserves systolic function.
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Affiliation(s)
- Raffaella Isola
- Department of Biomedical Sciences, Division of Cytomorphology, University of Cagliari, Cittadella Universitaria di Monserrato, SP 8, Monserrato, Italy
| | - Francesca Broccia
- Department of Biomedical Sciences, Division of Physiology, University of Cagliari, Cittadella Universitaria di Monserrato, SP 8, Monserrato, Italy
| | - Alberto Casti
- Department of Biomedical Sciences, Division of Cytomorphology, University of Cagliari, Cittadella Universitaria di Monserrato, SP 8, Monserrato, Italy
| | - Francesco Loy
- Department of Biomedical Sciences, Division of Cytomorphology, University of Cagliari, Cittadella Universitaria di Monserrato, SP 8, Monserrato, Italy
| | - Michela Isola
- Department of Biomedical Sciences, Division of Cytomorphology, University of Cagliari, Cittadella Universitaria di Monserrato, SP 8, Monserrato, Italy
| | - Romina Vargiu
- Department of Biomedical Sciences, Division of Physiology, University of Cagliari, Cittadella Universitaria di Monserrato, SP 8, Monserrato, Italy
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Shin HS, Shin HH, Shudo Y. Current Status and Limitations of Myocardial Infarction Large Animal Models in Cardiovascular Translational Research. Front Bioeng Biotechnol 2021; 9:673683. [PMID: 33996785 PMCID: PMC8116580 DOI: 10.3389/fbioe.2021.673683] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 04/06/2021] [Indexed: 01/16/2023] Open
Abstract
Establishing an appropriate disease model that mimics the complexities of human cardiovascular disease is critical for evaluating the clinical efficacy and translation success. The multifaceted and complex nature of human ischemic heart disease is difficult to recapitulate in animal models. This difficulty is often compounded by the methodological biases introduced in animal studies. Considerable variations across animal species, modifications made in surgical procedures, and inadequate randomization, sample size calculation, blinding, and heterogeneity of animal models used often produce preclinical cardiovascular research that looks promising but is irreproducible and not translatable. Moreover, many published papers are not transparent enough for other investigators to verify the feasibility of the studies and the therapeutics' efficacy. Unfortunately, successful translation of these innovative therapies in such a closed and biased research is difficult. This review discusses some challenges in current preclinical myocardial infarction research, focusing on the following three major inhibitors for its successful translation: Inappropriate disease model, frequent modifications to surgical procedures, and insufficient reporting transparency.
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Affiliation(s)
- Hye Sook Shin
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA, United States
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States
| | - Heather Hyeyoon Shin
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA, United States
| | - Yasuhiro Shudo
- Department of Cardiothoracic Surgery, Stanford University School of Medicine, Stanford, CA, United States
- Stanford Cardiovascular Institute, Stanford University School of Medicine, Stanford, CA, United States
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7
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Rodrigues da Silva R, Baptista de Souza Filho O, Bassani JWM, Bassani RA. The ForceLAB simulator: Application to the comparison of current models of cardiomyocyte contraction. Comput Biol Med 2021; 131:104240. [PMID: 33556894 DOI: 10.1016/j.compbiomed.2021.104240] [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: 10/23/2020] [Revised: 01/20/2021] [Accepted: 01/20/2021] [Indexed: 10/22/2022]
Abstract
Mathematical models are useful tools in the study of physiological phenomena. However, due to differences in assumptions and formulations, discrepancy in simulations may occur. Among the models for cardiomyocyte contraction based on Huxley's cross-bridge cycling, those proposed by Negroni and Lascano (NL) and Rice et al. (RWH) are the most frequently used. This study was aimed at developing a computational tool, ForceLAB, which allows implementing different contraction models and modifying several functional parameters. As an application, electrically-stimulated twitches triggered by an equal Ca2+ input and steady-state force x pCa relationship (pCa = -log of the molar free Ca2+ concentration) simulated with the NL and RWH models were compared. The equilibrium Ca2+-troponin C (TnC) dissociation constant (Kd) was modified by changing either the association (kon) or the dissociation (koff) rate constant. With the NL model, raising Kd by either maneuver decreased monotonically twitch amplitude and duration, as expected. With the RWH model, in contrast, the same Kd variation caused increase or decrease of peak force depending on which rate constant was modified. Additionally, force x pCa curves simulated using Ca2+ binding constants estimated in cardiomyocytes bearing wild-type and mutated TnC were compared to curves previously determined in permeabilized fibers. Mutations increased kon and koff, and decreased Kd. Both models produced curves fairly comparable to the experimental ones, although sensitivity to Ca2+ was greater, especially with RWH model. The NL model reproduced slightly better the qualitative changes associated with the mutations. It is expected that this tool can be useful for teaching and investigation.
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Affiliation(s)
- Robson Rodrigues da Silva
- Research and Technology Center, University of Mogi Das Cruzes, Mogi Das Cruzes, SP, Brazil; LabNECC, Center for Biomedical Engineering, University of Campinas, Campinas, SP, Brazil.
| | | | - José Wilson Magalhães Bassani
- LabNECC, Center for Biomedical Engineering, University of Campinas, Campinas, SP, Brazil; Department of Biomedical Engineering, School of Electrical and Computing Engineering, University of Campinas, Campinas, São Paulo, Brazil
| | - Rosana Almada Bassani
- LabNECC, Center for Biomedical Engineering, University of Campinas, Campinas, SP, Brazil
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8
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Species differences in cardiovascular physiology that affect pharmacology and toxicology. CURRENT OPINION IN TOXICOLOGY 2020. [DOI: 10.1016/j.cotox.2020.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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9
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Weber N, Kowalski K, Holler T, Radocaj A, Fischer M, Thiemann S, de la Roche J, Schwanke K, Piep B, Peschel N, Krumm U, Lingk A, Wendland M, Greten S, Schmitto JD, Ismail I, Warnecke G, Zywietz U, Chichkov B, Meißner J, Haverich A, Martin U, Brenner B, Zweigerdt R, Kraft T. Advanced Single-Cell Mapping Reveals that in hESC Cardiomyocytes Contraction Kinetics and Action Potential Are Independent of Myosin Isoform. Stem Cell Reports 2020; 14:788-802. [PMID: 32302556 PMCID: PMC7220955 DOI: 10.1016/j.stemcr.2020.03.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/12/2020] [Accepted: 03/17/2020] [Indexed: 01/14/2023] Open
Abstract
Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) represent an attractive model to investigate CM function and disease mechanisms. One characteristic marker of ventricular specificity of human CMs is expression of the ventricular, slow β-myosin heavy chain (MyHC), as opposed to the atrial, fast α-MyHC. The main aim of this study was to investigate at the single-cell level whether contraction kinetics and electrical activity of hESC-CMs are influenced by the relative expression of α-MyHC versus β-MyHC. For effective assignment of functional parameters to the expression of both MyHC isoforms at protein and mRNA levels in the very same hESC-CMs, we developed a single-cell mapping technique. Surprisingly, α- versus β-MyHC was not related to specific contractile or electrophysiological properties of the same cells. The multiparametric cell-by-cell analysis suggests that in hESC-CMs the expression of genes associated with electrical activity, contraction, calcium handling, and MyHCs is independently regulated.
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Affiliation(s)
- Natalie Weber
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany.
| | - Kathrin Kowalski
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Tim Holler
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Ante Radocaj
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Martin Fischer
- Institute of Neurophysiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Stefan Thiemann
- Institute of Neurophysiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Jeanne de la Roche
- Institute of Neurophysiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Kristin Schwanke
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Birgit Piep
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Neele Peschel
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Uwe Krumm
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Alexander Lingk
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Meike Wendland
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Stephan Greten
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Jan Dieter Schmitto
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Issam Ismail
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Gregor Warnecke
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Urs Zywietz
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany
| | - Boris Chichkov
- Laser Zentrum Hannover e.V., Hollerithallee 8, 30419 Hannover, Germany
| | - Joachim Meißner
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Axel Haverich
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Ulrich Martin
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Bernhard Brenner
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Robert Zweigerdt
- Leibniz Research Laboratories for Biotechnology and Artificial Organs (LEBAO), Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
| | - Theresia Kraft
- Institute of Molecular and Cell Physiology, Hannover Medical School, Carl-Neuberg Straße 1, 30625 Hannover, Germany
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10
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Gregorich ZR, Patel JR, Cai W, Lin Z, Heurer R, Fitzsimons DP, Moss RL, Ge Y. Deletion of Enigma Homologue from the Z-disc slows tension development kinetics in mouse myocardium. J Gen Physiol 2019; 151:670-679. [PMID: 30642915 PMCID: PMC6504290 DOI: 10.1085/jgp.201812214] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 12/20/2018] [Indexed: 12/14/2022] Open
Abstract
Enigma Homologue (ENH) is a component of the Z-disc, a structure that anchors actin filaments in the contractile unit of muscle, the sarcomere. Cardiac-specific ablation of ENH protein expression causes contractile dysfunction that ultimately culminates in dilated cardiomyopathy. However, whether ENH is involved in the regulation of myocardial contractility is unknown. To determine if ENH is required for the mechanical activity of cardiac muscle, we analyze muscle mechanics of isolated trabeculae from the hearts of ENH +/+ and ENH -/- mice. We detected no differences in steady-state mechanical properties but show that when muscle fibers are allowed to relax and then are restretched, the rate at which tension redevelops is depressed in ENH -/- mouse myocardium relative to that in ENH +/+ myocardium. SDS-PAGE analysis demonstrated that the expression of β-myosin heavy chain is increased in ENH -/- mouse myocardium, which could partially, but not completely, account for the depression in tension redevelopment kinetics. Using top-down proteomics analysis, we found that the expression of other thin/thick filament regulatory proteins is unaltered, although the phosphorylation of a cardiac troponin T isoform, cardiac troponin I, and myosin regulatory light chain is decreased in ENH -/- mouse myocardium. Nevertheless, these alterations are very small and thus insufficient to explain slowed tension redevelopment kinetics in ENH -/- mouse myocardium. These data suggest that the ENH protein influences tension redevelopment kinetics in mouse myocardium, possibly by affecting cross-bridge cycling kinetics. Previous studies also indicate that ablation of specific Z-disc proteins in myocardium slows contraction kinetics, which could also be a contributing factor in this study.
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Affiliation(s)
- Zachery R Gregorich
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI.,Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, WI
| | - Jitandrakumar R Patel
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI.,University of Wisconsin-Madison Cardiovascular Research Center, University of Wisconsin-Madison, Madison, WI
| | - Wenxuan Cai
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI.,Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, WI
| | - Ziqing Lin
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI.,Human Proteomics Program, University of Wisconsin-Madison, Madison, WI
| | - Rachel Heurer
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
| | - Daniel P Fitzsimons
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
| | - Richard L Moss
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI .,University of Wisconsin-Madison Cardiovascular Research Center, University of Wisconsin-Madison, Madison, WI.,Human Proteomics Program, University of Wisconsin-Madison, Madison, WI
| | - Ying Ge
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI .,Molecular and Cellular Pharmacology Training Program, University of Wisconsin-Madison, Madison, WI.,University of Wisconsin-Madison Cardiovascular Research Center, University of Wisconsin-Madison, Madison, WI.,Human Proteomics Program, University of Wisconsin-Madison, Madison, WI
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11
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Janssen PML. Myocardial relaxation in human heart failure: Why sarcomere kinetics should be center-stage. Arch Biochem Biophys 2018; 661:145-148. [PMID: 30447209 DOI: 10.1016/j.abb.2018.11.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/12/2018] [Accepted: 11/13/2018] [Indexed: 12/19/2022]
Abstract
Myocardial relaxation is critical for the heart to allow for adequate filling of the ventricles prior to the next contraction. In human heart failure, impairment of myocardial relaxation is a major problem, and impacts most patients suffering from end-stage failure. Furthering our understanding of myocardial relaxation is critical in developing future treatment strategies. This review highlights processes involved in myocardial relaxation, as well as governing processes that modulate myocardial relaxation, with a focus on impairment of myocardium-level relaxation in human end-stage heart failure.
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Affiliation(s)
- Paul M L Janssen
- Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, USA; Department of Internal Medicine, The Ohio State University Wexner Medical Center, USA.
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12
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Bunch TA, Lepak VC, Kanassatega RS, Colson BA. N-terminal extension in cardiac myosin-binding protein C regulates myofilament binding. J Mol Cell Cardiol 2018; 125:140-148. [PMID: 30359561 DOI: 10.1016/j.yjmcc.2018.10.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 08/22/2018] [Accepted: 10/10/2018] [Indexed: 10/28/2022]
Abstract
RATIONALE Mutations in the gene encoding the sarcomeric protein cardiac myosin-binding protein C (cMyBP-C) are a leading cause of hypertrophic cardiomyopathy (HCM). Mouse models targeting cMyBP-C and use of recombinant proteins have been effective in studying its roles in contractile function and disease. Surprisingly, while the N-terminus of cMyBP-C is important to regulate myofilament binding and contains many HCM mutations, an incorrect sequence, lacking the N-terminal 8 amino acids has been used in many studies. OBJECTIVES To determine the N-terminal cMyBP-C sequences in ventricles and investigate the roles of species-specific differences in cMyBP-C on myofilament binding. METHODS AND RESULTS We determined cMyBP-C sequences in mouse and human by inspecting available sequence databases. N-terminal differences were confirmed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Cosedimentation assays with actin or myosin were used to examine binding in mouse, human and chimeric fusion proteins of cMyBP-C. Time-resolved FRET (TR-FRET) with site-directed probes on cMyBP-C was employed to measure structural dynamics. LC-MS/MS supported the sequencing data that mouse cMyBP-C contains an eight-residue N-terminal extension (NTE) not found in human. Cosedimentation assays revealed that cardiac myosin binding was strongly influenced by the presence of the NTE, which reduced binding by 60%. 75% more human C0-C2 than mouse bound to myosin. Actin binding of mouse C0-C2 was not affected by the NTE. 50% more human C0-C2 than mouse bound to actin. TR-FRET indicates that the NTE did not significantly affect structural dynamics across domains C0 and C1. CONCLUSIONS Our functional results are consistent with the idea that cardiac myosin binding of N-terminal cMyBP-C is reduced in the mouse protein due to the presence of the NTE, which is proposed to interfere with myosin regulatory light chain (RLC) binding. The NTE is a critical component of mouse cMyBP-C, and should be considered in extrapolation of studies to cMyBP-C and HCM mechanisms in human.
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Affiliation(s)
- Thomas A Bunch
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States
| | - Victoria C Lepak
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States
| | - Rhye-Samuel Kanassatega
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States
| | - Brett A Colson
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States.
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13
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Papadaki M, Holewinski RJ, Previs SB, Martin TG, Stachowski MJ, Li A, Blair CA, Moravec CS, Van Eyk JE, Campbell KS, Warshaw DM, Kirk JA. Diabetes with heart failure increases methylglyoxal modifications in the sarcomere, which inhibit function. JCI Insight 2018; 3:121264. [PMID: 30333300 DOI: 10.1172/jci.insight.121264] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 09/04/2018] [Indexed: 12/27/2022] Open
Abstract
Patients with diabetes are at significantly higher risk of developing heart failure. Increases in advanced glycation end products are a proposed pathophysiological link, but their impact and mechanism remain incompletely understood. Methylglyoxal (MG) is a glycolysis byproduct, elevated in diabetes, and modifies arginine and lysine residues. We show that left ventricular myofilament from patients with diabetes and heart failure (dbHF) exhibited increased MG modifications compared with nonfailing controls (NF) or heart failure patients without diabetes. In skinned NF human and mouse cardiomyocytes, acute MG treatment depressed both calcium sensitivity and maximal calcium-activated force in a dose-dependent manner. Importantly, dbHF myocytes were resistant to myofilament functional changes from MG treatment, indicating that myofilaments from dbHF patients already had depressed function arising from MG modifications. In human dbHF and MG-treated mice, mass spectrometry identified increased MG modifications on actin and myosin. Cosedimentation and in vitro motility assays indicate that MG modifications on actin and myosin independently depress calcium sensitivity, and mechanistically, the functional consequence requires actin/myosin interaction with thin-filament regulatory proteins. MG modification of the myofilament may represent a critical mechanism by which diabetes induces heart failure, as well as a therapeutic target to avoid the development of or ameliorate heart failure in these patients.
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Affiliation(s)
- Maria Papadaki
- Loyola University Chicago, Department of Cell and Molecular Physiology, Chicago, Illinois, USA
| | | | - Samantha Beck Previs
- University of Vermont, Department of Molecular Physiology and Biophysics, Burlington, Vermont, USA
| | - Thomas G Martin
- Loyola University Chicago, Department of Cell and Molecular Physiology, Chicago, Illinois, USA
| | - Marisa J Stachowski
- Loyola University Chicago, Department of Cell and Molecular Physiology, Chicago, Illinois, USA
| | - Amy Li
- University of Vermont, Department of Molecular Physiology and Biophysics, Burlington, Vermont, USA
| | - Cheavar A Blair
- University of Kentucky, Department of Physiology, Lexington, Kentucky, USA
| | - Christine S Moravec
- The Cleveland Clinic, Department of Molecular Cardiology, Cleveland, Ohio, USA
| | - Jennifer E Van Eyk
- Cedars-Sinai Medical Center, Heart Institute, Los Angeles, California, USA
| | - Kenneth S Campbell
- University of Kentucky, Department of Physiology, Lexington, Kentucky, USA
| | - David M Warshaw
- University of Vermont, Department of Molecular Physiology and Biophysics, Burlington, Vermont, USA
| | - Jonathan A Kirk
- Loyola University Chicago, Department of Cell and Molecular Physiology, Chicago, Illinois, USA
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14
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Nassar SZ, Hassaan PS, Abdelmonsif DA, ElAchy SN. Cardioprotective effect of cerium oxide nanoparticles in monocrotaline rat model of pulmonary hypertension: A possible implication of endothelin-1. Life Sci 2018; 201:89-101. [DOI: 10.1016/j.lfs.2018.03.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2017] [Revised: 03/17/2018] [Accepted: 03/23/2018] [Indexed: 01/03/2023]
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15
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Joumaa V, Fitzowich A, Herzog W. Energy cost of isometric force production after active shortening in skinned muscle fibres. J Exp Biol 2017; 220:1509-1515. [DOI: 10.1242/jeb.117622] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 02/01/2017] [Indexed: 11/20/2022]
Abstract
The steady state isometric force after active shortening of a skeletal muscle is lower than the purely isometric force at the corresponding length. This property of skeletal muscle is known as force depression. The purpose of this study was to investigate whether the energy cost of force production at the steady state after active shortening was reduced compared to the energy cost of force production for a purely isometric contraction performed at the corresponding length (same length, same activation). Experiments were performed in skinned fibres isolated from rabbit psoas muscle. Skinned fibres were actively shortened from an average sarcomere length of 3.0 µm to an average sarcomere length of 2.4 µm. Purely isometric reference contractions were performed at an average sarcomere length of 2.4 µm. Simultaneously with the force measurements, the ATP cost was measured during the last 30 seconds of isometric contractions using an enzyme-coupled assay. Stiffness was calculated during a quick stretch-release cycle of 0.2% fibre length performed once the steady state had been reached after active shortening and during the purely isometric reference contractions. Force and stiffness following active shortening were decreased by 10.0±1.8% and 11.0±2.2%, respectively compared to the isometric reference contractions. Similarly, ATPase activity per second (not normalized to the force) showed a decrease of 15.6±3.0% in the force depressed state compared to the purely isometric reference state. However, ATPase activity per second per unit of force was similar for the isometric contractions following active shortening (28.7±2.4 mM/mN.s.mm3) and the corresponding purely isometric reference contraction (30.9±2.8 mM/mN.s.mm3). Furthermore, the reduction in absolute ATPase activity per second was significantly correlated with force depression and stiffness depression. These results are in accordance with the idea that force depression following active shortening is primarily caused by a decrease in the proportion of attached cross bridges. Furthermore, these findings, along with previously reported results showing a decrease in ATP consumption per unit of force after active muscle stretching, suggest that the mechanisms involved in the steady state force after active muscle shortening and active muscle lengthening are of distinctly different origin.
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Affiliation(s)
- V. Joumaa
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada
| | - A. Fitzowich
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada
| | - W. Herzog
- Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Alberta, Canada
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16
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Cheng W, Zhou R, Liang F, Wei H, Feng Y, Wang Y. Application of Mouse Embryonic Stem Cell Test to Detect Gender-Specific Effect of Chemicals: A Supplementary Tool for Embryotoxicity Prediction. Chem Res Toxicol 2016; 29:1519-33. [PMID: 27445234 DOI: 10.1021/acs.chemrestox.6b00197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Gender effect is an inherent property of chemicals, characterized by variations caused by the chemical-biology interaction. It has widely existed, but the shortage of an appropriate model restricts the study on gender-specific effect. The embryonic stem cell test (EST) has been utilized as an alternative test for developmental toxicity. Despite its numerous improvements, mouse embryonic stem cells with an XX karyotype have not been used in the EST, which restricts the ability of the EST to identify gender-specific effects during high-throughput-screening (HTS) of chemicals to date. To address this, the embryonic stem cell (ESC) SP3 line with an XX karyotype was used to establish a "female" model as a complement to EST. Here, we proposed a "double-objects in unison" (DOU)-EST, which consisted of male ESC and female ESC; a seven-day EST protocol was utilized, and the gender-specific effect of chemicals was determined and discriminated; the replacement of myosin heavy chain (MHC) with myosin light chain (MLC) provided a suitable molecular biomarker in the DOU-EST. New linear discriminant functions were given in the purpose of distinguishing chemicals into three classes, namely, no gender-specific effect, male-susceptive, and female-susceptive. For 15 chemicals in the training set, the concordances of prediction result as no gender effect, male susceptive, and female susceptive were 86.67%, 86.67%, and 93.33%, respectively, the sensitivities were 66.67%, 83.33%, and 83.33%, respectively, and the specificities were 91.67%, 88.89%, and 100%, respectively; the total accuracy of DOU-EST was 86.67%. For three chemicals in the test set, one was incorrectively predicted. The possible reason for misclassification may due to the absence of hormone environment in vitro. Leave-one-out cross-validation (LOOCV) indicated a mean error rate of 18.34%. Taken together, these data suggested a good performance of the proposed DOU-EST. Emerging chemicals with undiscovered gender-specific effects are anticipated to be screened with the DOU-EST.
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Affiliation(s)
- Wei Cheng
- College of Public Health, School of Medicine, Shanghai Jiaotong University , Shanghai 200025, P.R. China
| | - Ren Zhou
- College of Public Health, School of Medicine, Shanghai Jiaotong University , Shanghai 200025, P.R. China
| | - Fan Liang
- College of Public Health, School of Medicine, Shanghai Jiaotong University , Shanghai 200025, P.R. China
| | - Hongying Wei
- College of Public Health, School of Medicine, Shanghai Jiaotong University , Shanghai 200025, P.R. China.,Hongqiao International Institute of Medicine, School of Medicine, Shanghai Jiaotong University , Shanghai 200336, P.R. China
| | - Yan Feng
- College of Public Health, School of Medicine, Shanghai Jiaotong University , Shanghai 200025, P.R. China
| | - Yan Wang
- College of Public Health, School of Medicine, Shanghai Jiaotong University , Shanghai 200025, P.R. China.,Hongqiao International Institute of Medicine, School of Medicine, Shanghai Jiaotong University , Shanghai 200336, P.R. China.,Shanghai Ninth People's Hospital Affiliated to Shanghai Jiaotong University School of Medicine , Shanghai 200011, P.R. China
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17
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Han P, Li W, Yang J, Shang C, Lin CH, Cheng W, Hang CT, Cheng HL, Chen CH, Wong J, Xiong Y, Zhao M, Drakos SG, Ghetti A, Li DY, Bernstein D, Chen HSV, Quertermous T, Chang CP. Epigenetic response to environmental stress: Assembly of BRG1-G9a/GLP-DNMT3 repressive chromatin complex on Myh6 promoter in pathologically stressed hearts. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:1772-81. [PMID: 26952936 DOI: 10.1016/j.bbamcr.2016.03.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 02/07/2023]
Abstract
Chromatin structure is determined by nucleosome positioning, histone modifications, and DNA methylation. How chromatin modifications are coordinately altered under pathological conditions remains elusive. Here we describe a stress-activated mechanism of concerted chromatin modification in the heart. In mice, pathological stress activates cardiomyocytes to express Brg1 (nucleosome-remodeling factor), G9a/Glp (histone methyltransferase), and Dnmt3 (DNA methyltransferase). Once activated, Brg1 recruits G9a and then Dnmt3 to sequentially assemble repressive chromatin-marked by H3K9 and CpG methylation-on a key molecular motor gene (Myh6), thereby silencing Myh6 and impairing cardiac contraction. Disruption of Brg1, G9a or Dnmt3 erases repressive chromatin marks and de-represses Myh6, reducing stress-induced cardiac dysfunction. In human hypertrophic hearts, BRG1-G9a/GLP-DNMT3 complex is also activated; its level correlates with H3K9/CpG methylation, Myh6 repression, and cardiomyopathy. Our studies demonstrate a new mechanism of chromatin assembly in stressed hearts and novel therapeutic targets for restoring Myh6 and ventricular function. The stress-induced Brg1-G9a-Dnmt3 interactions and sequence of repressive chromatin assembly on Myh6 illustrates a molecular mechanism by which the heart epigenetically responds to environmental signals. This article is part of a Special Issue entitled: Cardiomyocyte Biology: Integration of Developmental and Environmental Cues in the Heart edited by Marcus Schaub and Hughes Abriel.
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Affiliation(s)
- Pei Han
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Wei Li
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Jin Yang
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Ching Shang
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Chiou-Hong Lin
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Wei Cheng
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Calvin T Hang
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Hsiu-Ling Cheng
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Chen-Hao Chen
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Johnson Wong
- Del E. Webb Neuroscience, Aging & Stem Cell Research Center, Sanford/Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Yiqin Xiong
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Mingming Zhao
- Division of Cardiovascular Medicine, Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
| | - Stavros G Drakos
- Cardiovascular Department and Utah Artificial Heart Program, Intermountain Medical Center, Salt Lake City, UT 84112, USA
| | - Andrea Ghetti
- AnaBios Corporation, 3030 Bunker Hill St., San Diego, CA 92109, USA
| | - Dean Y Li
- Cardiovascular Department and Utah Artificial Heart Program, Intermountain Medical Center, Salt Lake City, UT 84112, USA
| | - Daniel Bernstein
- Division of Cardiovascular Medicine, Department of Pediatrics, Stanford University, Stanford, CA 94305, USA
| | - Huei-Sheng Vincent Chen
- Del E. Webb Neuroscience, Aging & Stem Cell Research Center, Sanford/Burnham Medical Research Institute, La Jolla, CA 92037, USA
| | - Thomas Quertermous
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA 94305, USA
| | - Ching-Pin Chang
- Krannert Institute of Cardiology and Division of Cardiology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Krannert Institute of Cardiology and Division of Cardiology, Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA; Krannert Institute of Cardiology and Division of Cardiology, Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
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18
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Wang Y, Ajtai K, Kazmierczak K, Szczesna-Cordary D, Burghardt TP. N-Terminus of Cardiac Myosin Essential Light Chain Modulates Myosin Step-Size. Biochemistry 2015; 55:186-98. [PMID: 26671638 DOI: 10.1021/acs.biochem.5b00817] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Muscle myosin cyclically hydrolyzes ATP to translate actin. Ventricular cardiac myosin (βmys) moves actin with three distinct unitary step-sizes resulting from its lever-arm rotation and with step-frequencies that are modulated in a myosin regulation mechanism. The lever-arm associated essential light chain (vELC) binds actin by its 43 residue N-terminal extension. Unitary steps were proposed to involve the vELC N-terminal extension with the 8 nm step engaging the vELC/actin bond facilitating an extra ∼19 degrees of lever-arm rotation while the predominant 5 nm step forgoes vELC/actin binding. A minor 3 nm step is the unlikely conversion of the completed 5 to the 8 nm step. This hypothesis was tested using a 17 residue N-terminal truncated vELC in porcine βmys (Δ17βmys) and a 43 residue N-terminal truncated human vELC expressed in transgenic mouse heart (Δ43αmys). Step-size and step-frequency were measured using the Qdot motility assay. Both Δ17βmys and Δ43αmys had significantly increased 5 nm step-frequency and coincident loss in the 8 nm step-frequency compared to native proteins suggesting the vELC/actin interaction drives step-size preference. Step-size and step-frequency probability densities depend on the relative fraction of truncated vELC and relate linearly to pure myosin species concentrations in a mixture containing native vELC homodimer, two truncated vELCs in the modified homodimer, and one native and one truncated vELC in the heterodimer. Step-size and step-frequency, measured for native homodimer and at two or more known relative fractions of truncated vELC, are surmised for each pure species by using a new analytical method.
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Affiliation(s)
| | | | - Katarzyna Kazmierczak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine , Miami, Florida 33136, United States
| | - Danuta Szczesna-Cordary
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine , Miami, Florida 33136, United States
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19
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Mamidi R, Gresham KS, Li A, dos Remedios CG, Stelzer JE. Molecular effects of the myosin activator omecamtiv mecarbil on contractile properties of skinned myocardium lacking cardiac myosin binding protein-C. J Mol Cell Cardiol 2015; 85:262-72. [PMID: 26100051 DOI: 10.1016/j.yjmcc.2015.06.011] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 05/28/2015] [Accepted: 06/15/2015] [Indexed: 01/03/2023]
Abstract
Decreased expression of cardiac myosin binding protein-C (cMyBP-C) in the myocardium is thought to be a contributing factor to hypertrophic cardiomyopathy in humans, and the initial molecular defect is likely abnormal cross-bridge (XB) function which leads to impaired force generation, decreased contractile performance, and hypertrophy in vivo. The myosin activator omecamtiv mecarbil (OM) is a pharmacological drug that specifically targets the myosin XB and recent evidence suggests that OM induces a significant decrease in the in vivo motility velocity and an increase in the XB duty cycle. Thus, the molecular effects of OM maybe beneficial in improving contractile function in skinned myocardium lacking cMyBP-C because absence of cMyBP-C in the sarcomere accelerates XB kinetics and enhances XB turnover rate, which presumably reduces contractile efficiency. Therefore, parameters of XB function were measured in skinned myocardium lacking cMyBP-C prior to and following OM incubation. We measured ktr, the rate of force redevelopment as an index of XB transition from both the weakly- to strongly-bound state and from the strongly- to weakly-bound states and performed stretch activation experiments to measure the rates of XB detachment (krel) and XB recruitment (kdf) in detergent-skinned ventricular preparations isolated from hearts of wild-type (WT) and cMyBP-C knockout (KO) mice. Samples from donor human hearts were also used to assess the effects of OM in cardiac muscle expressing a slow β-myosin heavy chain (β-MHC). Incubation of skinned myocardium with OM produced large enhancements in steady-state force generation which were most pronounced at low levels of [Ca(2+)] activations, suggesting that OM cooperatively recruits additional XB's into force generating states. Despite a large increase in steady-state force generation following OM incubation, parallel accelerations in XB kinetics as measured by ktr were not observed, and there was a significant OM-induced decrease in krel which was more pronounced in the KO skinned myocardium compared to WT skinned myocardium (58% in WT vs. 76% in KO at pCa 6.1), such that baseline differences in krel between KO and WT skinned myocardium were no longer apparent following OM-incubation. A significant decrease in the kdf was also observed following OM incubation in all groups, which may be related to the increase in the number of cooperatively recruited XB's at low Ca(2+)-activations which slows the overall rate of force generation. Our results indicate that OM may be a useful pharmacological approach to normalize hypercontractile XB kinetics in myocardium with decreased cMyBP-C expression due to its molecular effects on XB behavior.
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Affiliation(s)
- Ranganath Mamidi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Kenneth S Gresham
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA
| | - Amy Li
- Muscle Research Unit, Bosch Institute, University of Sydney, Sydney Australia
| | | | - Julian E Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 44106 USA.
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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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Kolli MB, Manne NDPK, Para R, Nalabotu SK, Nandyala G, Shokuhfar T, He K, Hamlekhan A, Ma JY, Wehner PS, Dornon L, Arvapalli R, Rice KM, Blough ER. Cerium oxide nanoparticles attenuate monocrotaline induced right ventricular hypertrophy following pulmonary arterial hypertension. Biomaterials 2014; 35:9951-9962. [PMID: 25224369 DOI: 10.1016/j.biomaterials.2014.08.037] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Accepted: 08/23/2014] [Indexed: 12/16/2022]
Abstract
Cerium oxide (CeO2) nanoparticles have been posited to exhibit potent anti-oxidant activity which may allow for the use of these materials in biomedical applications. Herein, we investigate whether CeO2 nanoparticle administration can diminish right ventricular (RV) hypertrophy following four weeks of monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH). Male Sprague Dawley rats were randomly divided into three groups: control, MCT only (60 mg/kg), or MCT + CeO2 nanoparticle treatment (60 mg/kg; 0.1 mg/kg). Compared to the control group, the RV weight to body weight ratio was 45% and 22% higher in the MCT and MCT + CeO2 groups, respectively (p < 0.05). Doppler echocardiography demonstrated that CeO2 nanoparticle treatment attenuated monocrotaline-induced changes in pulmonary flow and RV wall thickness. Paralleling these changes in cardiac function, CeO2 nanoparticle treatment also diminished MCT-induced increases in right ventricular (RV) cardiomyocyte cross sectional area, β-myosin heavy chain, fibronectin expression, protein nitrosylation, protein carbonylation and cardiac superoxide levels. These changes with treatment were accompanied by a decrease in the ratio of Bax/Bcl2, diminished caspase-3 activation and reduction in serum inflammatory markers. Taken together, these data suggest that CeO2 nanoparticle administration may attenuate the hypertrophic response of the heart following PAH.
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Affiliation(s)
- Madhukar B Kolli
- Department of Pharmacology, Physiology and Toxicology, Marshall University, Joan C. Edwards School of Medicine, Huntington, WV, United States; Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, United States
| | - Nandini D P K Manne
- Department of Pharmacology, Physiology and Toxicology, Marshall University, Joan C. Edwards School of Medicine, Huntington, WV, United States; Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, United States
| | - Radhakrishna Para
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, United States
| | - Siva K Nalabotu
- Department of Pharmacology, Physiology and Toxicology, Marshall University, Joan C. Edwards School of Medicine, Huntington, WV, United States; Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, United States
| | - Geeta Nandyala
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, United States
| | - Tolou Shokuhfar
- Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, MI, United States
| | - Kun He
- Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, MI, United States; School of Materials Science and Engineering, Shandong University, Ji'nan, China
| | - Azhang Hamlekhan
- Department of Mechanical Engineering and Engineering Mechanics, Michigan Technological University, Houghton, MI, United States
| | - Jane Y Ma
- Health Effects Laboratory Division, NIOSH, Morgantown, WV, United States
| | - Paulette S Wehner
- Department of Cardiology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
| | - Lucy Dornon
- Department of Cardiology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
| | - Ravikumar Arvapalli
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, United States
| | - Kevin M Rice
- Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, United States
| | - Eric R Blough
- Department of Pharmacology, Physiology and Toxicology, Marshall University, Joan C. Edwards School of Medicine, Huntington, WV, United States; Center for Diagnostic Nanosystems, Marshall University, Huntington, WV, United States; Department of Cardiology, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States; Department of Pharmaceutical Sciences and Research, Marshall University, Huntington, WV, United States.
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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: 308] [Impact Index Per Article: 30.8] [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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Mamidi R, Chandra M. Divergent effects of α- and β-myosin heavy chain isoforms on the N terminus of rat cardiac troponin T. ACTA ACUST UNITED AC 2013; 142:413-23. [PMID: 24043862 PMCID: PMC3787779 DOI: 10.1085/jgp.201310971] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Divergent effects of α– and β–myosin heavy chain (MHC) isoforms on contractile behavior arise mainly because of their impact on thin filament cooperativity. The N terminus of cardiac troponin T (cTnT) also modulates thin filament cooperativity. Our hypothesis is that the impact of the N terminus of cTnT on thin filament activation is modulated by a shift from α- to β-MHC isoform. We engineered two recombinant proteins by deleting residues 1–43 and 44–73 in rat cTnT (RcTnT): RcTnT1–43Δ and RcTnT44–73Δ, respectively. Dynamic and steady-state contractile parameters were measured at sarcomere length of 2.3 µm after reconstituting proteins into detergent-skinned muscle fibers from normal (α-MHC) and propylthiouracil-treated (β-MHC) rat hearts. α-MHC attenuated Ca2+-activated maximal tension (∼46%) in RcTnT1–43Δ fibers. In contrast, β-MHC decreased tension only by 19% in RcTnT1–43Δ fibers. Both α- and β-MHC did not affect tension in RcTnT44–73Δ fibers. The instantaneous muscle fiber stiffness measurements corroborated the divergent impact of α- and β-MHC on tension in RcTnT1–43Δ fibers. pCa50 (-log of [Ca2+]free required for half-maximal activation) decreased significantly by 0.13 pCa units in α-MHC + RcTnT1–43Δ fibers but remained unaltered in β-MHC + RcTnT1–43Δ fibers, demonstrating that β-MHC counteracted the attenuating effect of RcTnT1–43Δ on myofilament Ca2+ sensitivity. β-MHC did not alter the sudden stretch–mediated recruitment of new cross-bridges (ER) in RcTnT1–43Δ fibers, but α-MHC attenuated ER by 36% in RcTnT1–43Δ fibers. The divergent impact of α- and β-MHC on how the N terminus of cTnT modulates contractile dynamics has implications for heart disease; alterations in cTnT and MHC are known to occur via changes in isoform expression or mutations.
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Affiliation(s)
- Ranganath Mamidi
- Department of Integrative Physiology and Neuroscience, Washington State University, Pullman, WA 99164
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Andre L, Fauconnier J, Reboul C, Feillet-Coudray C, Meschin P, Farah C, Fouret G, Richard S, Lacampagne A, Cazorla O. Subendocardial increase in reactive oxygen species production affects regional contractile function in ischemic heart failure. Antioxid Redox Signal 2013; 18:1009-20. [PMID: 22978600 DOI: 10.1089/ars.2012.4534] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
AIMS Heart failure (HF) is characterized by regionalized contractile alterations resulting in loss of the transmural contractile gradient across the left ventricular free wall. We tested whether a regional alteration in mitochondrial oxidative metabolism during HF could affect myofilament function through protein kinase A (PKA) signaling. RESULTS Twelve weeks after permanent left coronary artery ligation that induced myocardial infarction (MI), subendocardial (Endo) cardiomyocytes had decreased activity of complex I and IV of the mitochondrial electron transport chain and produced twice more superoxide anions than sham Endo and subepicardial cells. This effect was associated with a reduced antioxidant activity of superoxide dismutase and Catalase only in MI Endo cells. The myofilament contractile properties (Ca(2+) sensitivity and maximal tension), evaluated in skinned cardiomyocytes, were also reduced only in MI Endo myocytes. Conversely, in MI rats treated with the antioxidant N-acetylcysteine (NAC) for 4 weeks, the generation of superoxide anions in Endo cardiomyocytes was normalized and the contractile properties of skinned cardiomyocytes restored. This effect was accompanied by improved in vivo contractility. The beneficial effects of NAC were mediated, at least, in part, through reduction of the PKA activity, which was higher in MI myofilaments, particularly, the PKA-mediated hyperphosphorylation of cardiac Troponin I. INNOVATION The Transmural gradient in the mitochondrial content/activity is lost during HF and mediates reactive oxygen species-dependent contractile dysfunction. CONCLUSIONS Regionalized alterations in redox signaling affect the contractile machinery of sub-Endo myocytes through a PKA-dependent pathway that contributes to the loss of the transmural contractile gradient and impairs global contractility.
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Affiliation(s)
- Lucas Andre
- U1046, INSERM, Université Montpellier 1, Université Montpellier 2, Montpellier, France
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26
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Length-dependent effects on cardiac contractile dynamics are different in cardiac muscle containing α- or β-myosin heavy chain. Arch Biochem Biophys 2012; 535:3-13. [PMID: 23111184 DOI: 10.1016/j.abb.2012.10.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Revised: 10/12/2012] [Accepted: 10/18/2012] [Indexed: 11/20/2022]
Abstract
Actomyosin crossbridges (XBs) are the fundamental source of force generation and pressure development in the myocardium. Faster kinetics are imparted on XBs comprised of the fast, α-myosin heavy chain (MHC) isoform, whereas slower kinetics are imparted on XBs comprised of the slow, β-MHC isoform. Other factors, such as sarcomere length (SL), influence XB formation, presumably acting through allosteric effects on the kinetics that regulate the XB cycle. We sought to determine whether the slower XB kinetics of β-MHC were more sensitive to such length-dependent effects than those of α-MHC. We studied the SL effects on mechanical properties of demembranated muscle fibers from normal and propylthiouracil-treated mouse hearts, which expressed predominantly α-MHC or β-MHC, respectively. Interestingly, XB detachment kinetics were more length-sensitive in β-MHC fibers, as estimated by tension cost and XB detachment rate constant (c), and as inferred by ktr. The nonlinearity in force responses to various-amplitude step-like changes in muscle length was more pronounced in β-MHC fibers. This phenomenon is attributed to a greater cooperative/allosteric mechanism in β-MHC fibers, as estimated by model parameter γ. These data suggest a mechanism whereby greater cooperative/allosteric effects impart an enhanced length-sensitivity of XB cycling kinetics in fibers containing the slower cycling β-MHC.
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Chen PP, Patel JR, Powers PA, Fitzsimons DP, Moss RL. Dissociation of structural and functional phenotypes in cardiac myosin-binding protein C conditional knockout mice. Circulation 2012; 126:1194-205. [PMID: 22829020 DOI: 10.1161/circulationaha.111.089219] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cardiac myosin-binding protein C (cMyBP-C) is a sarcomeric protein that dynamically regulates thick-filament structure and function. In constitutive cMyBP-C knockout (cMyBP-C(-/-)) mice, loss of cMyBP-C has been linked to left ventricular dilation, cardiac hypertrophy, and systolic and diastolic dysfunction, although the pathogenesis of these phenotypes remains unclear. METHODS AND RESULTS We generated cMyBP-C conditional knockout (cMyBP-C-cKO) mice expressing floxed cMyBP-C alleles and a tamoxifen-inducible Cre-recombinase fused to 2 mutated estrogen receptors to study the onset and progression of structural and functional phenotypes caused by the loss of cMyBP-C. In adult cMyBP-C-cKO mice, knockdown of cMyBP-C over a 2-month period resulted in a corresponding impairment of diastolic function and a concomitant abbreviation of systolic ejection, although contractile function was largely preserved. No significant changes in cardiac structure or morphology were immediately evident; however, mild hypertrophy developed after near-complete knockdown of cMyBP-C. In response to pressure overload induced by transaortic constriction, cMyBP-C-cKO mice treated with tamoxifen also developed greater cardiac hypertrophy, left ventricular dilation, and reduced contractile function. CONCLUSIONS These results indicate that myocardial dysfunction is largely caused by the removal of cMyBP-C and occurs before the onset of cytoarchitectural remodeling in tamoxifen-treated cMyBP-C-cKO myocardium. Moreover, near ablation of cMyBP-C in adult myocardium primarily leads to the development of hypertrophic cardiomyopathy in contrast to the dilated phenotype evident in cMyBP-C(-/-) mice, which highlights the importance of additional factors such as loading stress in determining the expression and progression of cMyBP-C-associated cardiomyopathy.
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Affiliation(s)
- Peter P Chen
- Department of Cellular and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, 601 Science Dr, Madison, WI 53711, USA
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Affiliation(s)
- Leslie A Leinwand
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.
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Chen PP, Patel JR, Rybakova IN, Walker JW, Moss RL. Protein kinase A-induced myofilament desensitization to Ca(2+) as a result of phosphorylation of cardiac myosin-binding protein C. ACTA ACUST UNITED AC 2011; 136:615-27. [PMID: 21115695 PMCID: PMC2995154 DOI: 10.1085/jgp.201010448] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In skinned myocardium, cyclic AMP–dependent protein kinase A (PKA)-catalyzed phosphorylation of cardiac myosin–binding protein C (cMyBP-C) and cardiac troponin I (cTnI) is associated with a reduction in the Ca2+ responsiveness of myofilaments and an acceleration in the kinetics of cross-bridge cycling, although the respective contribution of these two proteins remains controversial. To further examine the relative roles that cTnI and cMyBP-C phosphorylation play in altering myocardial function, we determined the Ca2+ sensitivity of force (pCa50) and the activation dependence of the rate of force redevelopment (ktr) in control and PKA-treated mouse myocardium (isolated in the presence of 2,3-butanedione monoxime) expressing: (a) phosphorylatable cTnI and cMyBP-C (wild type [WT]), (b) phosphorylatable cTnI on a cMyBP-C–null background (cMyBP-C−/−), (c) nonphosphorylatable cTnI with serines23/24/43/45 and threonine144 mutated to alanines (cTnIAla5), and (d) nonphosphorylatable cTnI on a cMyBP-C–null background (cTnIAla5/cMyBP-C−/−). Here, PKA treatment decreased pCa50 in WT, cTnIAla5, and cMyBP-C−/− myocardium by 0.13, 0.08, and 0.09 pCa units, respectively, but had no effect in cTnIAla5/cMyBP-C−/− myocardium. In WT and cTnIAla5 myocardium, PKA treatment also increased ktr at submaximal levels of activation; however, PKA treatment did not have an effect on ktr in cMyBP-C−/− or cTnIAla5/cMyBP-C−/− myocardium. In addition, reconstitution of cTnIAla5/cMyBP-C−/− myocardium with recombinant cMyBP-C restored the effects of PKA treatment on pCa50 and ktr reported in cTnIAla5 myocardium. Collectively, these results indicate that the attenuation in myofilament force response to PKA occurs as a result of both cTnI and cMyBP-C phosphorylation, and that the reduction in pCa50 mediated by cMyBP-C phosphorylation most likely arises from an accelerated cross-bridge cycling kinetics partly as a result of an increased rate constant of cross-bridge detachment.
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Affiliation(s)
- Peter P Chen
- Department of Physiology and UW Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, USA. peterchen@wisc.edu
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Pol CJ, Muller A, Zuidwijk MJ, van Deel ED, Kaptein E, Saba A, Marchini M, Zucchi R, Visser TJ, Paulus WJ, Duncker DJ, Simonides WS. Left-ventricular remodeling after myocardial infarction is associated with a cardiomyocyte-specific hypothyroid condition. Endocrinology 2011; 152:669-79. [PMID: 21159857 DOI: 10.1210/en.2010-0431] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Similarities in cardiac gene expression in hypothyroidism and left ventricular (LV) pathological remodeling after myocardial infarction (MI) suggest a role for impaired cardiac thyroid hormone (TH) signaling in the development of heart failure. Increased ventricular activity of the TH-degrading enzyme type 3 deiodinase (D3) is recognized as a potential cause. In the present study, we investigated the cardiac expression and activity of D3 over an 8-wk period after MI in C57Bl/6J mice. Pathological remodeling of the noninfarcted part of the LV was evident from cardiomyocyte hypertrophy, interstitial fibrosis, and impairment of contractility. These changes were maximal and stable from the first week onward, as was the degree of LV dilation. A strong induction of D3 activity was found, which was similarly stable for the period examined. Plasma T(4) levels were transiently decreased at 1 wk after MI, but T(3) levels remained normal. The high D3 activity was associated with increased D3 mRNA expression at 1 but not at 4 and 8 wk after MI. Immunohistochemistry localized D3 protein to cardiomyocytes. In vivo measurement of TH-dependent transcription activity in cardiomyocytes using a luciferase reporter assay indicated a 48% decrease in post-MI mice relative to sham-operated animals, and this was associated with a 50% decrease in LV tissue T(3) concentration. In conclusion, pathological ventricular remodeling after MI in the mouse leads to high and stable induction of D3 activity in cardiomyocytes and a local hypothyroid condition.
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Affiliation(s)
- Christine J Pol
- Laboratory for Physiology, Institute for Cardiovascular Research, Vrije Universiteit University Medical Center, 1081 HV Amsterdam, The Netherlands
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Locher MR, Razumova MV, Stelzer JE, Norman HS, Moss RL. Effects of low-level α-myosin heavy chain expression on contractile kinetics in porcine myocardium. Am J Physiol Heart Circ Physiol 2011; 300:H869-78. [PMID: 21217059 DOI: 10.1152/ajpheart.00452.2010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Myosin heavy chain (MHC) isoforms are principal determinants of work capacity in mammalian ventricular myocardium. The ventricles of large mammals including humans normally express ∼10% α-MHC on a predominantly β-MHC background, while in failing human ventricles α-MHC is virtually eliminated, suggesting that low-level α-MHC expression in normal myocardium can accelerate the kinetics of contraction and augment systolic function. To test this hypothesis in a model similar to human myocardium we determined composite rate constants of cross-bridge attachment (f(app)) and detachment (g(app)) in porcine myocardium expressing either 100% α-MHC or 100% β-MHC in order to predict the MHC isoform-specific effect on twitch kinetics. Right atrial (∼100% α-MHC) and left ventricular (∼100% β-MHC) tissue was used to measure myosin ATPase activity, isometric force, and the rate constant of force redevelopment (k(tr)) in solutions of varying Ca(2+) concentration. The rate of ATP utilization and k(tr) were approximately ninefold higher in atrial compared with ventricular myocardium, while tension cost was approximately eightfold greater in atrial myocardium. From these values, we calculated f(app) to be ∼10-fold higher in α- compared with β-MHC, while g(app) was 8-fold higher in α-MHC. Mathematical modeling of an isometric twitch using these rate constants predicts that the expression of 10% α-MHC increases the maximal rate of rise of force (dF/dt(max)) by 92% compared with 0% α-MHC. These results suggest that low-level expression of α-MHC significantly accelerates myocardial twitch kinetics, thereby enhancing systolic function in large mammalian myocardium.
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Affiliation(s)
- Matthew R Locher
- 1Department of Physiology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin 53711, USA.
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MacDonald JR, Oellermann M, Rynbeck S, Chang G, Ruggiero K, Cooper GJS, Hickey AJR. Transmural differences in respiratory capacity across the rat left ventricle in health, aging, and streptozotocin-induced diabetes mellitus: evidence that mitochondrial dysfunction begins in the subepicardium. Am J Physiol Cell Physiol 2010; 300:C246-55. [PMID: 21084644 DOI: 10.1152/ajpcell.00294.2010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In diabetic cardiomyopathy, ventricular dysfunction occurs in the absence of hypertension or atherosclerosis and is accompanied by altered myocardial substrate utilization and depressed mitochondrial respiration. It is not known if mitochondrial function differs across the left ventricular (LV) wall in diabetes. In the healthy heart, the inner subendocardial region demonstrates higher rates of blood flow, oxygen consumption, and ATP turnover compared with the outer subepicardial region, but published transmural respirometric measurements have not demonstrated differences. We aim to measure mitochondrial function in Wistar rat LV to determine the effects of age, streptozotocin-diabetes, and LV layer. High-resolution respirometry measured indexes of respiration in saponin-skinned fibers dissected from the LV subendocardium and subepicardium of 3-mo-old rats after 1 mo of streptozotocin-induced diabetes and 4-mo-old rats following 2 mo of diabetes. Heart rate and heartbeat duration were measured under isoflurane-anesthesia using a fetal-Doppler, and transmission electron microscopy was employed to observe ultrastructural differences. Heart rate decreased with age and diabetes, whereas heartbeat duration increased with diabetes. While there were no transmural respirational differences in young healthy rat hearts, both myocardial layers showed a respiratory depression with age (30-40%). In 1-mo diabetic rat hearts only subepicardial respiration was depressed, whereas after 2 mo diabetes, respiration in subendocardial and subepicardial layers was depressed and showed elevated leak (state 2) respiration. These data provide evidence that mitochondrial dysfunction is first detectable in the subepicardium of diabetic rat LV, whereas there are measureable changes in LV mitochondria after only 4 mo of aging.
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Affiliation(s)
- J R MacDonald
- University of Auckland, School of Biological Sciences, Private Bag 92019, Auckland Mail Centre, Auckland 1142, New Zealand
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Chen Y, Somji A, Yu X, Stelzer JE. Altered in vivo left ventricular torsion and principal strains in hypothyroid rats. Am J Physiol Heart Circ Physiol 2010; 299:H1577-87. [PMID: 20729398 DOI: 10.1152/ajpheart.00406.2010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The twisting and untwisting motions of the left ventricle (LV) lead to efficient ejection of blood during systole and filling of the ventricle during diastole. Global LV mechanical performance is dependent on the contractile properties of cardiac myocytes; however, it is not known how changes in contractile protein expression affect the pattern and timing of LV rotation. At the myofilament level, contractile performance is largely dependent on the isoforms of myosin heavy chain (MHC) that are expressed. Therefore, in this study, we used MRI to examine the in vivo mechanical consequences of altered MHC isoform expression by comparing the contractile properties of hypothyroid rats, which expressed only the slow β-MHC isoform, and euthyroid rats, which predominantly expressed the fast α-MHC isoform. Unloaded shortening velocity (V(o)) and apparent rate constants of force development (k(tr)) were measured in the skinned ventricular myocardium isolated from euthyroid and hypothyroid hearts. Increased expression of β-MHC reduced LV torsion and fiber strain and delayed the development of peak torsion and strain during systole. Depressed in vivo mechanical performance in hypothyroid rats was related to slowed cross-bridge performance, as indicated by significantly slower V(o) and k(tr), compared with euthyroid rats. Dobutamine infusion in hypothyroid hearts produced smaller increases in torsion and strain and aberrant transmural torsion patterns, suggesting that the myocardial response to β-adrenergic stress is compromised. Thus, increased expression of β-MHC alters the pattern and decreases the magnitude of LV rotation, contributing to reduced mechanical performance during systole, especially in conditions of increased workload.
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Affiliation(s)
- Yong Chen
- Department of Biomedical Engineering, School of Engineering, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Herron TJ, Devaney E, Mundada L, Arden E, Day S, Guerrero-Serna G, Turner I, Westfall M, Metzger JM. Ca2+-independent positive molecular inotropy for failing rabbit and human cardiac muscle by alpha-myosin motor gene transfer. FASEB J 2009; 24:415-24. [PMID: 19801488 DOI: 10.1096/fj.09-140566] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Current inotropic therapies used to increase cardiac contractility of the failing heart center on increasing the amount of calcium available for contraction, but their long-term use is associated with increased mortality due to fatal arrhythmias. Thus, there is a need to develop and explore novel inotropic therapies that can act via calcium-independent mechanisms. The purpose of this study was to determine whether fast alpha-myosin molecular motor gene transfer can confer calcium-independent positive inotropy in slow beta-myosin-dominant rabbit and human failing ventricular myocytes. To this end, we generated a recombinant adenovirus (AdMYH6) to deliver the full-length human alpha-myosin gene to adult rabbit and human cardiac myocytes in vitro. Fast alpha-myosin motor expression was determined by Western blotting and immunocytochemical analysis and confocal imaging. In experiments using electrically stimulated myocytes from ischemic failing hearts, AdMYH6 increased the contractile amplitude of failing human [23.9+/-7.8 nm (n=10) vs. AdMYH6 amplitude 78.4+/-16.5 nm (n=6)] and rabbit myocytes. The intracellular calcium transient amplitude was not altered. Control experiments included the use of a green fluorescent protein or a beta-myosin heavy chain adenovirus. Our data provide evidence for a novel form of calcium-independent positive inotropy in failing cardiac myocytes by fast alpha-myosin motor protein gene transfer.
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Affiliation(s)
- Todd J Herron
- Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, Michigan, USA
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