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Amesz JH, Langmuur SJJ, Epskamp N, Bogers AJJC, de Groot NMS, Manintveld OC, Taverne YJHJ. Acute Biomechanical Effects of Empagliflozin on Living Isolated Human Heart Failure Myocardium. Cardiovasc Drugs Ther 2024; 38:659-666. [PMID: 36780068 PMCID: PMC11266265 DOI: 10.1007/s10557-023-07434-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/20/2023] [Indexed: 02/14/2023]
Abstract
PURPOSE Multiple randomized controlled trials have presented SGLT2 inhibitors (SGLT2i) as novel pharmacological therapy for patients with heart failure, resulting in reductions in hospitalization for heart failure and mortality. Given the absence of SGLT2 receptors in the heart, mechanisms of direct cardioprotective effects of SGLT2i are complex and remain to be investigated. In this study, we evaluated the direct biomechanical effects of SGLT2i empagliflozin on isolated myocardium from end-stage heart failure patients. METHODS Ventricular tissue biopsies obtained from 7 patients undergoing heart transplantation or ventricular assist device implantation surgery were cut into 27 living myocardial slices (LMS) and mounted in custom-made cultivation chambers with mechanical preload and electrical stimulation, resulting in cardiac contractions. These 300 µm thick LMS were subjected to 10 µM empagliflozin and with continuous recording of biomechanical parameters. RESULTS Empagliflozin did not affect the maximum contraction force of the slices, however, increased total contraction duration by 13% (p = 0.002) which was determined by prolonged time to peak and time to relaxation (p = 0.009 and p = 0.003, respectively). CONCLUSION The addition of empagliflozin to LMS from end-stage heart failure patients cultured in a biomimetic system improves contraction and relaxation kinetics by increasing total contraction duration without diminishing maximum force production. Therefore, we present convincing evidence that SGLT2i can directly act on the myocardium in absence of systemic influences from other organ systems.
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Affiliation(s)
- Jorik H Amesz
- Translational Cardiothoracic Surgery Research Lab, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Dr. Molewaterplein 40, 3015GD, Rotterdam, the Netherlands
- Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Sanne J J Langmuur
- Translational Cardiothoracic Surgery Research Lab, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Dr. Molewaterplein 40, 3015GD, Rotterdam, the Netherlands
- Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Nina Epskamp
- Translational Cardiothoracic Surgery Research Lab, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Dr. Molewaterplein 40, 3015GD, Rotterdam, the Netherlands
| | - Ad J J C Bogers
- Translational Cardiothoracic Surgery Research Lab, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Dr. Molewaterplein 40, 3015GD, Rotterdam, the Netherlands
| | - Natasja M S de Groot
- Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, the Netherlands
- Department of Cardiology, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Olivier C Manintveld
- Department of Cardiology, Erasmus University Medical Center, Rotterdam, the Netherlands
- Erasmus MC Transplant Institute, Erasmus University Medical Center, Rotterdam, the Netherlands
| | - Yannick J H J Taverne
- Translational Cardiothoracic Surgery Research Lab, Department of Cardiothoracic Surgery, Erasmus University Medical Center, Dr. Molewaterplein 40, 3015GD, Rotterdam, the Netherlands.
- Lowlands Institute for Bioelectric Medicine, Department of Cardiology, Erasmus University Medical Center, Rotterdam, the Netherlands.
- Erasmus MC Transplant Institute, Erasmus University Medical Center, Rotterdam, the Netherlands.
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Mertens J, De Lange WJ, Farrell ET, Harbaugh EC, Gauchan A, Fitzsimons DP, Moss RL, Ralphe JC. The W792R HCM missense mutation in the C6 domain of cardiac myosin binding protein-C increases contractility in neonatal mouse myocardium. J Mol Cell Cardiol 2024:S0022-2828(24)00123-8. [PMID: 39059462 DOI: 10.1016/j.yjmcc.2024.07.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Revised: 07/22/2024] [Accepted: 07/23/2024] [Indexed: 07/28/2024]
Abstract
Missense mutations in cardiac myosin binding protein C (cMyBP-C) are known to cause hypertrophic cardiomyopathy (HCM). The W792R mutation in the C6 domain of cMyBP-C causes severe, early onset HCM in humans, yet its impact on the function of cMyBP-C and the mechanism through which it causes disease remain unknown. To fully characterize the effect of the W792R mutation on cardiac morphology and function in vivo, we generated a murine knock-in model. We crossed heterozygous W792RWR mice to produce homozygous mutant W792RRR, heterozygous W792RWR, and control W792RWW mice. W792RRR mice present with cardiac hypertrophy, myofibrillar disarray and fibrosis by postnatal day 10 (PND10), and do not survive past PND21. Full-length cMyBP-C is present at similar levels in W792RWW, W792RWR and W792RRR mice and is properly incorporated into the sarcomere. Heterozygous W792RWR mice displayed normal heart morphology and contractility. Permeabilized myocardium from PND10 W792RRR mice showed increased Ca2+ sensitivity, accelerated cross-bridge cycling kinetics, decreased cooperativity in the activation of force, and increased expression of hypertrophy-related genes. In silico modeling suggests that the W792R mutation destabilizes the fold of the C6 domain and increases torsion in the C5-C7 region, possibly impacting regulatory interactions of cMyBP-C with myosin and actin. Based on the data presented here, we propose a model in which mutant W792R cMyBP-C preferentially forms Ca2+ sensitizing interactions with actin, rather than inhibitory interactions with myosin. The W792R-cMyBP-C mouse model provides mechanistic insights into the pathology of this mutation and may provide a mechanism by which other central domain missense mutations in cMyBP-C may alter contractility, leading to HCM.
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Affiliation(s)
- Jasmine Mertens
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America; UW Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America
| | - Willem J De Lange
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America; UW Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America
| | - Emily T Farrell
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America; UW Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America
| | - Ella C Harbaugh
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America; UW Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America
| | - Angeela Gauchan
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America; UW Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America
| | - Daniel P Fitzsimons
- UW Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America; Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America
| | - Richard L Moss
- UW Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America; Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America
| | - J Carter Ralphe
- Department of Pediatrics, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America; UW Cardiovascular Research Center, University of Wisconsin School of Medicine and Public Health, Madison, WI 53706, United States of America.
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3
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Desai DA, Baby A, Ananthamohan K, Green LC, Arif M, Duncan BC, Kumar M, Singh RR, Koch SE, Natesan S, Rubinstein J, Jegga AG, Sadayappan S. Roles of cMyBP-C phosphorylation on cardiac contractile dysfunction in db/db mice. JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY PLUS 2024; 8:100075. [PMID: 38957358 PMCID: PMC11218625 DOI: 10.1016/j.jmccpl.2024.100075] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Type 2 diabetes mellitus (T2DM) is a metabolic disease and comorbidity associated with several conditions, including cardiac dysfunction leading to heart failure with preserved ejection fraction (HFpEF), in turn resulting in T2DM-induced cardiomyopathy (T2DM-CM). However, the molecular mechanisms underlying the development of T2DM-CM are poorly understood. It is hypothesized that molecular alterations in myopathic genes induced by diabetes promote the development of HFpEF, whereas cardiac myosin inhibitors can rescue the resultant T2DM-mediated cardiomyopathy. To test this hypothesis, a Leptin receptor-deficient db/db homozygous (Lepr db/db) mouse model was used to define the pathogenesis of T2DM-CM. Echocardiographic studies at 4 and 6 months revealed that Lepr db/db hearts started developing cardiac dysfunction by four months, and left ventricular hypertrophy with diastolic dysfunction was evident at 6 months. RNA-seq data analysis, followed by functional enrichment, revealed the differential regulation of genes related to cardiac dysfunction in Lepr db/db heart tissues. Strikingly, the level of cardiac myosin binding protein-C phosphorylation was significantly increased in Lepr db/db mouse hearts. Finally, using isolated skinned papillary muscles and freshly isolated cardiomyocytes, CAMZYOS ® (mavacamten, MYK-461), a prescription heart medicine used for symptomatic obstructive hypertrophic cardiomyopathy treatment, was tested for its ability to rescue T2DM-CM. Compared with controls, MYK-461 significantly reduced force generation in papillary muscle fibers and cardiomyocyte contractility in the db/db group. This line of evidence shows that 1) T2DM-CM is associated with hyperphosphorylation of cardiac myosin binding protein-C and 2) MYK-461 significantly lessened disease progression in vitro, suggesting its promise as a treatment for HFpEF.
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Affiliation(s)
- Darshini A. Desai
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Akhil Baby
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
- Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai 625021, India
| | - Kalyani Ananthamohan
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Lisa C. Green
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Mohammed Arif
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Brittany C. Duncan
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Mohit Kumar
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Rohit R. Singh
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Sheryl E. Koch
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Sankar Natesan
- Department of Genetic Engineering, School of Biotechnology, Madurai Kamaraj University, Madurai 625021, India
| | - Jack Rubinstein
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
| | - Anil G. Jegga
- Division of Biomedical Informatics, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
- Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati, OH, USA
| | - Sakthivel Sadayappan
- Center for Cardiovascular Research, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA
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McNamara JW, Song T, Alam P, Binek A, Singh RR, Nieman ML, Koch SE, Ivey MJ, Lynch TL, Rubinstein J, Jin JP, Lorenz JN, Van Eyk JE, Kanisicak O, Sadayappan S. Fast skeletal myosin binding protein-C expression exacerbates dysfunction in heart failure. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.30.591979. [PMID: 38746225 PMCID: PMC11092637 DOI: 10.1101/2024.04.30.591979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
During heart failure, gene and protein expression profiles undergo extensive compensatory and pathological remodeling. We previously observed that fast skeletal myosin binding protein-C (fMyBP-C) is upregulated in diseased mouse hearts. While fMyBP-C shares significant homology with its cardiac paralog, cardiac myosin binding protein-C (cMyBP-C), there are key differences that may affect cardiac function. However, it is unknown if the expression of fMyBP-C expression in the heart is a pathological or compensatory response. We aim to elucidate the cardiac consequence of either increased or knockout of fMyBP-C expression. To determine the sufficiency of fMyBP-C to cause cardiac dysfunction, we generated cardiac-specific fMyBP-C over-expression mice. These mice were further crossed into a cMyBP-C null model to assess the effect of fMyBP-C in the heart in the complete absence of cMyBP-C. Finally, fMyBP-C null mice underwent transverse aortic constriction (TAC) to define the requirement of fMyBP-C during heart failure development. We confirmed the upregulation of fMyBP-C in several models of cardiac disease, including the use of lineage tracing. Low levels of fMyBP-C caused mild cardiac remodeling and sarcomere dysfunction. Exclusive expression of fMyBP-C in a heart failure model further exacerbated cardiac pathology. Following 8 weeks of TAC, fMyBP-C null mice demonstrated greater protection against heart failure development. Mechanistically, this may be due to the differential regulation of the myosin super-relaxed state. These findings suggest that the elevated expression of fMyBP-C in diseased hearts is a pathological response. Targeted therapies to prevent upregulation of fMyBP-C may prove beneficial in the treatment of heart failure. Significance Statement Recently, the sarcomere - the machinery that controls heart and muscle contraction - has emerged as a central target for development of cardiac therapeutics. However, there remains much to understand about how the sarcomere is modified in response to disease. We recently discovered that a protein normally expressed in skeletal muscle, is present in the heart in certain settings of heart disease. How this skeletal muscle protein affects the function of the heart remained unknown. Using genetically engineered mouse models to modulate expression of this skeletal muscle protein, we determined that expression of this skeletal muscle protein in the heart negatively affects cardiac performance. Importantly, deletion of this protein from the heart could improve heart function suggesting a possible therapeutic avenue.
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5
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Wijnker PJM, Dinani R, van der Laan NC, Algül S, Knollmann BC, Verkerk AO, Remme CA, Zuurbier CJ, Kuster DWD, van der Velden J. Hypertrophic cardiomyopathy dysfunction mimicked in human engineered heart tissue and improved by sodium-glucose cotransporter 2 inhibitors. Cardiovasc Res 2024; 120:301-317. [PMID: 38240646 PMCID: PMC10939456 DOI: 10.1093/cvr/cvae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 11/15/2023] [Accepted: 11/29/2023] [Indexed: 03/16/2024] Open
Abstract
AIMS Hypertrophic cardiomyopathy (HCM) is the most common inherited cardiomyopathy, often caused by pathogenic sarcomere mutations. Early characteristics of HCM are diastolic dysfunction and hypercontractility. Treatment to prevent mutation-induced cardiac dysfunction is lacking. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a group of antidiabetic drugs that recently showed beneficial cardiovascular outcomes in patients with acquired forms of heart failure. We here studied if SGLT2i represent a potential therapy to correct cardiomyocyte dysfunction induced by an HCM sarcomere mutation. METHODS AND RESULTS Contractility was measured of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) harbouring an HCM mutation cultured in 2D and in 3D engineered heart tissue (EHT). Mutations in the gene encoding β-myosin heavy chain (MYH7-R403Q) or cardiac troponin T (TNNT2-R92Q) were investigated. In 2D, intracellular [Ca2+], action potential and ion currents were determined. HCM mutations in hiPSC-CMs impaired relaxation or increased force, mimicking early features observed in human HCM. SGLT2i enhance the relaxation of hiPSC-CMs, to a larger extent in HCM compared to control hiPSC-CMs. Moreover, SGLT2i-effects on relaxation in R403Q EHT increased with culture duration, i.e. hiPSC-CMs maturation. Canagliflozin's effects on relaxation were more pronounced than empagliflozin and dapagliflozin. SGLT2i acutely altered Ca2+ handling in HCM hiPSC-CMs. Analyses of SGLT2i-mediated mechanisms that may underlie enhanced relaxation in mutant hiPSC-CMs excluded SGLT2, Na+/H+ exchanger, peak and late Nav1.5 currents, and L-type Ca2+ current, but indicate an important role for the Na+/Ca2+ exchanger. Indeed, electrophysiological measurements in mutant hiPSC-CM indicate that SGLT2i altered Na+/Ca2+ exchange current. CONCLUSION SGLT2i (canagliflozin > dapagliflozin > empagliflozin) acutely enhance relaxation in human EHT, especially in HCM and upon prolonged culture. SGLT2i may represent a potential therapy to correct early cardiac dysfunction in HCM.
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Affiliation(s)
- Paul J M Wijnker
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Rafeeh Dinani
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Nico C van der Laan
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Sila Algül
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Bjorn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Arie O Verkerk
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
- Experimental Cardiology, Amsterdam UMC, Academic Medical Centre, Amsterdam, The Netherlands
| | - Carol Ann Remme
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
- Experimental Cardiology, Amsterdam UMC, Academic Medical Centre, Amsterdam, The Netherlands
| | - Coert J Zuurbier
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
- Laboratory for Experimental Intensive Care and Anesthesiology (L.E.I.C.A.), Department of Anesthesiology, Amsterdam UMC, Academic Medical Centre, Amsterdam, The Netherlands
| | - Diederik W D Kuster
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
| | - Jolanda van der Velden
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, De Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, De Boelelaan 1108, 1081 HZ Amsterdam, The Netherlands
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6
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Janssens JV, Raaijmakers AJA, Weeks KL, Bell JR, Mellor KM, Curl CL, Delbridge LMD. The cardiomyocyte origins of diastolic dysfunction: cellular components of myocardial "stiffness". Am J Physiol Heart Circ Physiol 2024; 326:H584-H598. [PMID: 38180448 DOI: 10.1152/ajpheart.00334.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 12/07/2023] [Accepted: 12/21/2023] [Indexed: 01/06/2024]
Abstract
The impaired ability of the heart to relax and stretch to accommodate venous return is generally understood to represent a state of "diastolic dysfunction" and often described using the all-purpose noun "stiffness." Despite the now common qualitative usage of this term in fields of cardiac patho/physiology, the specific quantitative concept of stiffness as a molecular and biophysical entity with real practical interpretation in healthy and diseased hearts is sometimes obscure. The focus of this review is to characterize the concept of cardiomyocyte stiffness and to develop interpretation of "stiffness" attributes at the cellular and molecular levels. Here, we consider "stiffness"-related terminology interpretation and make links between cardiomyocyte stiffness and aspects of functional and structural cardiac performance. We discuss cross bridge-derived stiffness sources, considering the contributions of diastolic myofilament activation and impaired relaxation. This includes commentary relating to the role of cardiomyocyte Ca2+ flux and Ca2+ levels in diastole, the troponin-tropomyosin complex role as a Ca2+ effector in diastole, the myosin ADP dissociation rate as a modulator of cross bridge attachment and regulation of cross-bridge attachment by myosin binding protein C. We also discuss non-cross bridge-derived stiffness sources, including the titin sarcomeric spring protein, microtubule and intermediate filaments, and cytoskeletal extracellular matrix interactions. As the prevalence of conditions involving diastolic heart failure has escalated, a more sophisticated understanding of the molecular, cellular, and tissue determinants of cardiomyocyte stiffness offers potential to develop imaging and molecular intervention tools.
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Affiliation(s)
- Johannes V Janssens
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Antonia J A Raaijmakers
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Kate L Weeks
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria, Australia
- Baker Department of Cardiometabolic Health, University of Melbourne, Melbourne, Victoria, Australia
- Department of Diabetes, Monash University, Parkville, Victoria, Australia
| | - James R Bell
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Microbiology, Anatomy, Physiology and Pharmacology, La Trobe University, Melbourne, Victoria, Australia
| | - Kimberley M Mellor
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria, Australia
- Department of Physiology, University of Auckland, Auckland, New Zealand
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Claire L Curl
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Lea M D Delbridge
- Department of Anatomy and Physiology, University of Melbourne, Melbourne, Victoria, Australia
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7
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Doh CY, Schmidt AV, Chinthalapudi K, Stelzer JE. Bringing into focus the central domains C3-C6 of myosin binding protein C. Front Physiol 2024; 15:1370539. [PMID: 38487262 PMCID: PMC10937550 DOI: 10.3389/fphys.2024.1370539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Accepted: 02/19/2024] [Indexed: 03/17/2024] Open
Abstract
Myosin binding protein C (MyBPC) is a multi-domain protein with each region having a distinct functional role in muscle contraction. The central domains of MyBPC have often been overlooked due to their unclear roles. However, recent research shows promise in understanding their potential structural and regulatory functions. Understanding the central region of MyBPC is important because it may have specialized function that can be used as drug targets or for disease-specific therapies. In this review, we provide a brief overview of the evolution of our understanding of the central domains of MyBPC in regard to its domain structures, arrangement and dynamics, interaction partners, hypothesized functions, disease-causing mutations, and post-translational modifications. We highlight key research studies that have helped advance our understanding of the central region. Lastly, we discuss gaps in our current understanding and potential avenues to further research and discovery.
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Affiliation(s)
- Chang Yoon Doh
- Department of Medicine, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Alexandra V. Schmidt
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
| | - Krishna Chinthalapudi
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart & Lung Research Institute, College of Medicine, The Ohio State University, Columbus, OH, United States
| | - Julian E. Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, United States
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8
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Mastos C, Xu X, Keen AC, Halls ML. Signalling of Adrenoceptors: Canonical Pathways and New Paradigms. Handb Exp Pharmacol 2024. [PMID: 38227198 DOI: 10.1007/164_2023_704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2024]
Abstract
The concept of G protein-coupled receptors initially arose from studies of the β-adrenoceptor, adenylyl cyclase, and cAMP signalling pathway. Since then both canonical G protein-coupled receptor signalling pathways and emerging paradigms in receptor signalling have been defined by experiments focused on adrenoceptors. Here, we discuss the evidence for G protein coupling specificity of the nine adrenoceptor subtypes. We summarise the ability of each of the adrenoceptors to activate proximal signalling mediators including cAMP, calcium, mitogen-activated protein kinases, and protein kinase C pathways. Finally, we highlight the importance of precise spatial and temporal control of adrenoceptor signalling that is controlled by the localisation of receptors at intracellular membranes and in larger protein complexes.
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Affiliation(s)
- Chantel Mastos
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Xiaomeng Xu
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Alastair C Keen
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Michelle L Halls
- Drug Discovery Biology Theme, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia.
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9
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Wong FL, Bunch TA, Lepak VC, Steedman AL, Colson BA. Cardiac myosin-binding protein C N-terminal interactions with myosin and actin filaments: Opposite effects of phosphorylation and M-domain mutations. J Mol Cell Cardiol 2024; 186:125-137. [PMID: 38008210 PMCID: PMC10872421 DOI: 10.1016/j.yjmcc.2023.11.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 10/26/2023] [Accepted: 11/17/2023] [Indexed: 11/28/2023]
Abstract
N-terminal cardiac myosin-binding protein C (cMyBP-C) domains (C0-C2) bind to thick (myosin) and thin (actin) filaments to coordinate contraction and relaxation of the heart. These interactions are regulated by phosphorylation of the M-domain situated between domains C1 and C2. In cardiomyopathies and heart failure, phosphorylation of cMyBP-C is significantly altered. We aimed to investigate how cMyBP-C interacts with myosin and actin. We developed complementary, high-throughput, C0-C2 FRET-based binding assays for myosin and actin to characterize the effects due to 5 HCM-linked variants or functional mutations in unphosphorylated and phosphorylated C0-C2. The assays indicated that phosphorylation decreases binding to both myosin and actin, whereas the HCM mutations in M-domain generally increase binding. The effects of mutations were greatest in phosphorylated C0-C2, and some mutations had a larger effect on actin than myosin binding. Phosphorylation also altered the spatial relationship of the probes on C0-C2 and actin. The magnitude of these structural changes was dependent on C0-C2 probe location (C0, C1, or M-domain). We conclude that binding can differ between myosin and actin due to phosphorylation or mutations. Additionally, these variables can change the mode of binding, affecting which of the interactions in cMyBP-C N-terminal domains with myosin or actin take place. The opposite effects of phosphorylation and M-domain mutations is consistent with the idea that cMyBP-C phosphorylation is critical for normal cardiac function. The precision of these assays is indicative of their usefulness in high-throughput screening of drug libraries for targeting cMyBP-C as therapy.
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Affiliation(s)
- Fiona L Wong
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States
| | - 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
| | - Allison L Steedman
- 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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10
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Ananthamohan K, Stelzer JE, Sadayappan S. Hypertrophic cardiomyopathy in MYBPC3 carriers in aging. THE JOURNAL OF CARDIOVASCULAR AGING 2024; 4:9. [PMID: 38406555 PMCID: PMC10883298 DOI: 10.20517/jca.2023.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Hypertrophic cardiomyopathy (HCM) is characterized by abnormal thickening of the myocardium, leading to arrhythmias, heart failure, and elevated risk of sudden cardiac death, particularly among the young. This inherited disease is predominantly caused by mutations in sarcomeric genes, among which those in the cardiac myosin binding protein-C3 (MYBPC3) gene are major contributors. HCM associated with MYBPC3 mutations usually presents in the elderly and ranges from asymptomatic to symptomatic forms, affecting numerous cardiac functions and presenting significant health risks with a spectrum of clinical manifestations. Regulation of MYBPC3 expression involves various transcriptional and translational mechanisms, yet the destiny of mutant MYBPC3 mRNA and protein in late-onset HCM remains unclear. Pathogenesis related to MYBPC3 mutations includes nonsense-mediated decay, alternative splicing, and ubiquitin-proteasome system events, leading to allelic imbalance and haploinsufficiency. Aging further exacerbates the severity of HCM in carriers of MYBPC3 mutations. Advancements in high-throughput omics techniques have identified crucial molecular events and regulatory disruptions in cardiomyocytes expressing MYBPC3 variants. This review assesses the pathogenic mechanisms that promote late-onset HCM through the lens of transcriptional, post-transcriptional, and post-translational modulation of MYBPC3, underscoring its significance in HCM across carriers. The review also evaluates the influence of aging on these processes and MYBPC3 levels during HCM pathogenesis in the elderly. While pinpointing targets for novel medical interventions to conserve cardiac function remains challenging, the emergence of personalized omics offers promising avenues for future HCM treatments, particularly for late-onset cases.
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Affiliation(s)
- Kalyani Ananthamohan
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH 45267, USA
| | - Julian E. Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH 45267, USA
| | - Sakthivel Sadayappan
- Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH 45267, USA
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11
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Stern JA, Rivas VN, Kaplan JL, Ueda Y, Oldach MS, Ontiveros ES, Kooiker KB, van Dijk SJ, Harris SP. Hypertrophic cardiomyopathy in purpose-bred cats with the A31P mutation in cardiac myosin binding protein-C. Sci Rep 2023; 13:10319. [PMID: 37365215 PMCID: PMC10293195 DOI: 10.1038/s41598-023-36932-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Accepted: 06/13/2023] [Indexed: 06/28/2023] Open
Abstract
We sought to establish a large animal model of inherited hypertrophic cardiomyopathy (HCM) with sufficient disease severity and early penetrance for identification of novel therapeutic strategies. HCM is the most common inherited cardiac disorder affecting 1 in 250-500 people, yet few therapies for its treatment or prevention are available. A research colony of purpose-bred cats carrying the A31P mutation in MYBPC3 was founded using sperm from a single heterozygous male cat. Cardiac function in four generations was assessed by periodic echocardiography and measurement of blood biomarkers. Results showed that HCM penetrance was age-dependent, and that penetrance occurred earlier and was more severe in successive generations, especially in homozygotes. Homozygosity was also associated with progression from preclinical to clinical disease. A31P homozygous cats represent a heritable model of HCM with early disease penetrance and a severe phenotype necessary for interventional studies aimed at altering disease progression. The occurrence of a more severe phenotype in later generations of cats, and the occasional occurrence of HCM in wildtype cats suggests the presence of at least one gene modifier or a second causal variant in this research colony that exacerbates the HCM phenotype when inherited in combination with the A31P mutation.
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Affiliation(s)
- Joshua A Stern
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1038 William Moore Dr, Raleigh, NC, 27606, USA
| | - Victor N Rivas
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1038 William Moore Dr, Raleigh, NC, 27606, USA
| | - Joanna L Kaplan
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Yu Ueda
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, 1038 William Moore Dr, Raleigh, NC, 27606, USA
| | - Maureen S Oldach
- VCA Sacramento Veterinary Referral Center, 9801 Old Winery Place, Sacramento, CA, 95827, USA
| | - Eric S Ontiveros
- Rady Children's Institute for Genomic Medicine, 7910 Frost Street, San Diego, CA, 92123, USA
| | - Kristina B Kooiker
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, 98109, USA
| | - Sabine J van Dijk
- Department of Neurobiology, Physiology, and Behavior, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Samantha P Harris
- Department of Neurobiology, Physiology, and Behavior, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA.
- Department of Physiology, College of Medicine-Tucson, University of Arizona, 313 Medical Research Building, 1656 E Mabel St., Tucson, AZ, 85724, USA.
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12
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Dominic KL, Choi J, Holmes JB, Singh M, Majcher MJ, Stelzer JE. The contribution of N-terminal truncated cMyBPC to in vivo cardiac function. J Gen Physiol 2023; 155:e202213318. [PMID: 37067542 PMCID: PMC10114924 DOI: 10.1085/jgp.202213318] [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: 12/15/2022] [Revised: 02/13/2023] [Accepted: 03/24/2023] [Indexed: 04/18/2023] Open
Abstract
Cardiac myosin binding protein C (cMyBPC) is an 11-domain sarcomeric protein (C0-C10) integral to cardiac muscle regulation. In vitro studies have demonstrated potential functional roles for regions beyond the N-terminus. However, the in vivo contributions of these domains are mostly unknown. Therefore, we examined the in vivo consequences of expression of N-terminal truncated cMyBPC (C3C10). Neonatal cMyBPC-/- mice were injected with AAV9-full length (FL), C3C10 cMyBPC, or saline, and echocardiography was performed 6 wk after injection. We then isolated skinned myocardium from virus-treated hearts and performed mechanical experiments. Our results show that expression of C3C10 cMyBPC in cMyBPC-/- mice resulted in a 28% increase in systolic ejection fraction compared to saline-injected cMyBPC-/- mice and a 25% decrease in left ventricle mass-to-body weight ratio. However, unlike expression of FL cMyBPC, there was no prolongation of ejection time compared to saline-injected mice. In vitro mechanical experiments demonstrated that functional improvements in cMyBPC-/- mice expressing C3C10 were primarily due to a 35% reduction in the rate of cross-bridge recruitment at submaximal Ca2+ concentrations when compared to hearts from saline-injected cMyBPC-/- mice. However, unlike the expression of FL cMyBPC, there was no change in the rate of cross-bridge detachment when compared to saline-injected mice. Our data demonstrate that regions of cMyBPC beyond the N-terminus are important for in vivo cardiac function, and have divergent effects on cross-bridge behavior. Elucidating the molecular mechanisms of cMyBPC region-specific function could allow for development of targeted approaches to manipulate specific aspects of cardiac contractile function.
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Affiliation(s)
- Katherine L. Dominic
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Joohee Choi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Joshua B. Holmes
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Mandeep Singh
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Michael J. Majcher
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Julian E. Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
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13
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Feng HZ, Huang X, Jin JP. N-terminal truncated cardiac troponin I enhances Frank-Starling response by increasing myofilament sensitivity to resting tension. J Gen Physiol 2023; 155:e202012821. [PMID: 36880803 PMCID: PMC10005897 DOI: 10.1085/jgp.202012821] [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: 11/11/2020] [Revised: 12/09/2022] [Accepted: 12/29/2022] [Indexed: 03/08/2023] Open
Abstract
Cardiac troponin I (cTnI) of higher vertebrates has evolved with an N-terminal extension, of which deletion via restrictive proteolysis occurs as a compensatory adaptation in chronic heart failure to increase ventricular relaxation and stroke volume. Here, we demonstrate in a transgenic mouse model expressing solely N-terminal truncated cTnI (cTnI-ND) in the heart with deletion of the endogenous cTnI gene. Functional studies using ex vivo working hearts showed an extended Frank-Starling response to preload with reduced left ventricular end diastolic pressure. The enhanced Frank-Starling response effectively increases systolic ventricular pressure development and stroke volume. A novel finding is that cTnI-ND increases left ventricular relaxation velocity and stroke volume without increasing the end diastolic volume. Consistently, the optimal resting sarcomere length (SL) for maximum force development in cTnI-ND cardiac muscle was not different from wild-type (WT) control. Despite the removal of the protein kinase A (PKA) phosphorylation sites in cTnI, β-adrenergic stimulation remains effective on augmenting the enhanced Frank-Starling response of cTnI-ND hearts. Force-pCa relationship studies using skinned preparations found that while cTnI-ND cardiac muscle shows a resting SL-resting tension relationship similar to WT control, cTnI-ND significantly increases myofibril Ca2+ sensitivity to resting tension. The results demonstrate that restrictive N-terminal deletion of cTnI enhances Frank-Starling response by increasing myofilament sensitivity to resting tension rather than directly depending on SL. This novel function of cTnI regulation suggests a myofilament approach to utilizing Frank-Starling mechanism for the treatment of heart failure, especially diastolic failure where ventricular filling is limited.
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Affiliation(s)
- Han-Zhong Feng
- Department of Physiology and Biophysics, University of Illinois at Chicago School of Medicine, Chicago, IL, USA
| | - Xupei Huang
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Jian-Ping Jin
- Department of Physiology and Biophysics, University of Illinois at Chicago School of Medicine, Chicago, IL, USA
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14
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Rosas PC, Solaro RJ. Implications of S-glutathionylation of sarcomere proteins in cardiac disorders, therapies, and diagnosis. Front Cardiovasc Med 2023; 9:1060716. [PMID: 36762302 PMCID: PMC9902711 DOI: 10.3389/fcvm.2022.1060716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Accepted: 12/29/2022] [Indexed: 01/25/2023] Open
Abstract
The discovery that cardiac sarcomere proteins are substrates for S-glutathionylation and that this post-translational modification correlates strongly with diastolic dysfunction led to new concepts regarding how levels of oxidative stress affect the heartbeat. Major sarcomere proteins for which there is evidence of S-glutathionylation include cardiac myosin binding protein C (cMyBP-C), actin, cardiac troponin I (cTnI) and titin. Our hypothesis is that these S-glutathionylated proteins are significant factors in acquired and familial disorders of the heart; and, when released into the serum, provide novel biomarkers. We consider the molecular mechanisms for these effects in the context of recent revelations of how these proteins control cardiac dynamics in close collaboration with Ca2+ fluxes. These revelations were made using powerful approaches and technologies that were focused on thin filaments, thick filaments, and titin filaments. Here we integrate their regulatory processes in the sarcomere as modulated mainly by neuro-humoral control of phosphorylation inasmuch evidence indicates that S-glutathionylation and protein phosphorylation, promoting increased dynamics and modifying the Frank-Starling relation, may be mutually exclusive. Earlier studies demonstrated that in addition to cTnI as a well-established biomarker for cardiac disorders, serum levels of cMyBP-C are also a biomarker for cardiac disorders. We describe recent studies approaching the question of whether serum levels of S-glutathionylated-cMyBP-C could be employed as an important clinical tool in patient stratification, early diagnosis in at risk patients before HFpEF, determination of progression, effectiveness of therapeutic approaches, and as a guide in developing future therapies.
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Affiliation(s)
- Paola C. Rosas
- Department of Pharmacy Practice, College of Pharmacy, Chicago, IL, United States
| | - R. John Solaro
- Department of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, United States
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15
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De Lorenzi AB, Kaplinsky E, Zambrano MR, Chaume LT, Rosas JM. Emerging concepts in heart failure management and treatment: focus on SGLT2 inhibitors in heart failure with preserved ejection fraction. Drugs Context 2023; 12:dic-2022-7-1. [PMID: 36660013 PMCID: PMC9828870 DOI: 10.7573/dic.2022-7-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2022] [Accepted: 11/08/2022] [Indexed: 01/04/2023] Open
Abstract
The role of sodium-glucose cotransporter 2 inhibitors (SLTG2i), developed initially as glucose-lowering agents, has represented a novelty in patients with heart failure (HF) and reduced ejection fraction (HFrEF) since dapagliflozin (DAPA-HF study) and empagliflozin (EMPEROR-Reduced study) were able to reduce morbidity and mortality in this setting regardless of the presence or absence of diabetes. In previous large clinical trials (EMPA-REG OUTCOME study, CANVAS, DECLARE-TIMI 58), SGLT2i have been shown to attenuate HF progression expressed by reducing the risk of HF hospitalizations in patients with type 2 diabetes mellitus mostly without HF at baseline. This benefit was then corroborated with positive results in HF outcomes (cardiovascular mortality and HF hospitalizations) in patients with HF with preserved ejection fraction (HFpEF) in the EMPEROR-Preserved (empagliflozin) and DELIVER (dapagliflozin) trials. Several biological mechanisms apart from the glycosuria are attributed to these agents in this last context, including anti-inflammatory effects, reduction of fibrosis and apoptosis, improvement of myocardial metabolism, mitochondrial function optimization, and oxidative stress protection. Moreover, SGLT2i can also improve ventricular loading conditions by forcing diuresis and natriuresis, and by enhancing vascular and renal function. In addition, SGLT2i can reduce myocardial passive stiffness (diastolic function) by enforcing the phosphorylation of myofilament modulatory proteins. This article provided an overview of the main pathophysiological characteristics of HFpEF and of the diverse mechanisms of action of SGLT2i in this setting. The supporting clinical evidence of SGLT2i in HFpEF (EMPEROR-Preserved and DELIVER trials) is also reviewed. This article is part of the Emerging concepts in heart failure management and treatment Special Issue: https://www.drugsincontext.com/special_issues/emerging-concepts-in-heart-failure-management-and-treatment.
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Affiliation(s)
| | - Edgardo Kaplinsky
- Cardiology Unit, Medicine Department, Hospital Municipal de Badalona, Spain
| | | | - Laia Tomás Chaume
- Unitat de Cardiología, Hospital General de Granollers, Barcelona, Spain
| | - Joan Monell Rosas
- Unitat de Cardiología, Hospital General de Granollers, Barcelona, Spain
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16
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Solís C, Thompson WC, Peña JR, McDermott-Roe C, Langa P, Warren CM, Chrzanowska M, Wolska BM, Solaro RJ, Pieter Detombe, Goldspink PH. Mechano-growth factor E-domain modulates cardiac contractile function through 14-3-3 protein interactomes. Front Physiol 2022; 13:1028345. [PMID: 36467694 PMCID: PMC9709209 DOI: 10.3389/fphys.2022.1028345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 10/31/2022] [Indexed: 11/18/2022] Open
Abstract
In the heart, alternative splicing of the igf-I gene produces two isoforms: IGF-IEa and IGF-IEc, (Mechano-growth factor, MGF). The sequence divergence between their E-domain regions suggests differential isoform function. To define the biological actions of MGF's E-domain, we performed in silico analysis of the unique C-terminal sequence and identified a phosphorylation consensus site residing within a putative 14-3-3 binding motif. To test the functional significance of Ser 18 phosphorylation, phospho-mimetic (S/E18) and phospho-null (S/A18) peptides were delivered to mice at different doses for 2 weeks. Cardiovascular function was measured using echocardiography and a pressure-volume catheter. At the lowest (2.25 mg/kg/day) and highest (9 mg/kg/day) doses, the peptides produced a depression in systolic and diastolic parameters. However, at 4.5 mg/kg/day the peptides produced opposing effects on cardiac function. Fractional shortening analysis also showed a similar trend, but with no significant change in cardiac geometry. Microarray analysis discovered 21 genes (FDR p < 0.01), that were expressed accordant with the opposing effects on contractile function at 4.5 mg/kg/day, with the nuclear receptor subfamily 4 group A member 2 (Nr4a2) identified as a potential target of peptide regulation. Testing the regulation of the Nr4a family, showed the E-domain peptides modulate Nr4a gene expression following membrane depolarization with KCl in vitro. To determine the potential role of 14-3-3 proteins, we examined 14-3-3 isoform expression and distribution. 14-3-3γ localized to the myofilaments in neonatal cardiac myocytes, the cardiac myocytes and myofilament extracts from the adult heart. Thermal shift analysis of recombinant 14-3-3γ protein showed the S/A18 peptide destabilized 14-3-3γ folding. Also, the S/A18 peptide significantly inhibited 14-3-3γ's ability to interact with myosin binding protein C (MYPC3) and phospholamban (PLN) in heart lysates from dobutamine injected mice. Conversely, the S/E18 peptide showed no effect on 14-3-3γ stability, did not inhibit 14-3-3γ's interaction with PLN but did inhibit the interaction with MYPC3. Replacing the glutamic acid with a phosphate group on Ser 18 (pSer18), significantly increased 14-3-3γ protein stability. We conclude that the state of Ser 18 phosphorylation within the 14-3-3 binding motif of MGF's E-domain, modulates protein-protein interactions within the 14-3-3γ interactome, which includes proteins involved in the regulation of contractile function.
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Affiliation(s)
- Christopher Solís
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States
| | - Walter C. Thompson
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States
| | - James R. Peña
- Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Christopher McDermott-Roe
- Department of Medicine, and Department of Genetics, Perelman School of Medicine, Cardiovascular Institute, University of Pennsylvania, Philadelphia, PA, United States
| | - Paulina Langa
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Chad M. Warren
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Magdalena Chrzanowska
- Blood Research Institute, Versiti, Department of Pharmacology and Toxicology, Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Beata M. Wolska
- Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States,Department of Medicine, Division of Cardiology, University of Illinois at Chicago, Chicago, IL, United States
| | - R. John Solaro
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States
| | - Pieter Detombe
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Phymedexp, Université de Montpellier, Inserm, CNRS, Montpellier, France
| | - Paul H. Goldspink
- Department of Physiology and Biophysics, University of Illinois Chicago, Chicago, IL, United States,Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, United States,*Correspondence: Paul H. Goldspink,
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17
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Kanassatega RS, Bunch TA, Lepak VC, Wang C, Colson BA. Human cardiac myosin-binding protein C phosphorylation- and mutation-dependent structural dynamics monitored by time-resolved FRET. J Mol Cell Cardiol 2022; 166:116-126. [PMID: 35227736 PMCID: PMC9067379 DOI: 10.1016/j.yjmcc.2022.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/31/2022] [Accepted: 02/21/2022] [Indexed: 11/27/2022]
Abstract
Cardiac myosin-binding protein C (cMyBP-C) is a thick filament-associated protein of the sarcomere and a potential therapeutic target for treating contractile dysfunction in heart failure. Mimicking the structural dynamics of phosphorylated cMyBP-C by small-molecule drug binding could lead to therapies that modulate cMyBP-C conformational states, and thereby function, to improve contractility. We have developed a human cMyBP-C biosensor capable of detecting intramolecular structural changes due to phosphorylation and mutation. Using site-directed mutagenesis and time-resolved fluorescence resonance energy transfer (TR-FRET), we substituted cysteines in cMyBP-C N-terminal domains C0 through C2 (C0-C2) for thiol-reactive fluorescent probe labeling to examine C0-C2 structure. We identified a cysteine pair that upon donor-acceptor labeling reports phosphorylation-sensitive structural changes between the C1 domain and the tri-helix bundle of the M-domain that links C1 to C2. Phosphorylation reduced FRET efficiency by ~18%, corresponding to a ~11% increase in the distance between probes and a ~30% increase in disorder between them. The magnitude and precision of phosphorylation-mediated TR-FRET changes, as quantified by the Z'-factor, demonstrate the assay's potential for structure-based high-throughput screening of compounds for cMyBP-C-targeted therapies to improve cardiac performance in heart failure. Additionally, by probing C1's spatial positioning relative to the tri-helix bundle, these findings provide new molecular insight into the structural dynamics of phosphoregulation as well as mutations in cMyBP-C. Biosensor sensitivity to disease-relevant mutations in C0-C2 was demonstrated by examination of the hypertrophic cardiomyopathy mutation R282W. The results presented here support a screening platform to identify small molecules that regulate N-terminal cMyBP-C conformational states.
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Affiliation(s)
- Rhye-Samuel Kanassatega
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America
| | - Thomas A Bunch
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America
| | - Victoria C Lepak
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America
| | - Christopher Wang
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America
| | - Brett A Colson
- Department of Cellular and Molecular Medicine, University of Arizona, Tucson, AZ 85724, United States of America.
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18
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Hou L, Kumar M, Anand P, Chen Y, El-Bizri N, Pickens CJ, Seganish WM, Sadayappan S, Swaminath G. Modulation of myosin by cardiac myosin binding protein-C peptides improves cardiac contractility in ex-vivo experimental heart failure models. Sci Rep 2022; 12:4337. [PMID: 35288601 PMCID: PMC8921245 DOI: 10.1038/s41598-022-08169-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 03/03/2022] [Indexed: 01/23/2023] Open
Abstract
Cardiac myosin binding protein-C (cMyBP-C) is an important regulator of sarcomeric function. Reduced phosphorylation of cMyBP-C has been linked to compromised contractility in heart failure patients. Here, we used previously published cMyBP-C peptides 302A and 302S, surrogates of the regulatory phosphorylation site serine 302, as a tool to determine the effects of modulating the dephosphorylation state of cMyBP-C on cardiac contraction and relaxation in experimental heart failure (HF) models in vitro. Both peptides increased the contractility of papillary muscle fibers isolated from a mouse model expressing cMyBP-C phospho-ablation (cMyBP-CAAA) constitutively. Peptide 302A, in particular, could also improve the force redevelopment rate (ktr) in papillary muscle fibers from cMyBP-CAAA (nonphosphorylated alanines) mice. Consistent with the above findings, both peptides increased ATPase rates in myofibrils isolated from rats with myocardial infarction (MI), but not from sham rats. Furthermore, in the cMyBP-CAAA mouse model, both peptides improved ATPase hydrolysis rates. These changes were not observed in non-transgenic (NTG) mice or sham rats, indicating the specific effects of these peptides in regulating the dephosphorylation state of cMyBP-C under the pathological conditions of HF. Taken together, these studies demonstrate that modulation of cMyBP-C dephosphorylation state can be a therapeutic approach to improve myosin function, sarcomere contractility and relaxation after an adverse cardiac event. Therefore, targeting cMyBP-C could potentially improve overall cardiac performance as a complement to standard-care drugs in HF patients.
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Affiliation(s)
- Luqia Hou
- Cardiometabolic Department, Merck & Co., Inc., 213 East Grand Ave., South San Francisco, CA, 94080, USA
| | - Mohit Kumar
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Priti Anand
- Cardiometabolic Department, Merck & Co., Inc., 213 East Grand Ave., South San Francisco, CA, 94080, USA
| | - Yinhong Chen
- Cardiometabolic Department, Merck & Co., Inc., 213 East Grand Ave., South San Francisco, CA, 94080, USA
| | - Nesrine El-Bizri
- Cardiometabolic Department, Merck & Co., Inc., 213 East Grand Ave., South San Francisco, CA, 94080, USA
| | - Chad J Pickens
- Analytical R&D, Merck & Co., Inc., South San Francisco, CA, 94080, USA
| | - W Michael Seganish
- Discovery Chemistry, Merck & Co., Inc., South San Francisco, CA, 94080, USA
| | - Sakthivel Sadayappan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, Cincinnati, OH, 45267, USA
| | - Gayathri Swaminath
- Cardiometabolic Department, Merck & Co., Inc., 213 East Grand Ave., South San Francisco, CA, 94080, USA.
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19
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Abstract
Each heartbeat is initiated by the action potential, an electrical signal that depolarizes the plasma membrane and activates a cycle of calcium influx via voltage-gated calcium channels, calcium release via ryanodine receptors, and calcium reuptake and efflux via calcium-ATPase pumps and sodium-calcium exchangers. Agonists of the sympathetic nervous system bind to adrenergic receptors in cardiomyocytes, which, via cascading signal transduction pathways and protein kinase A (PKA), increase the heart rate (chronotropy), the strength of myocardial contraction (inotropy), and the rate of myocardial relaxation (lusitropy). These effects correlate with increased intracellular concentration of calcium, which is required for the augmentation of cardiomyocyte contraction. Despite extensive investigations, the molecular mechanisms underlying sympathetic nervous system regulation of calcium influx in cardiomyocytes have remained elusive over the last 40 years. Recent studies have uncovered the mechanisms underlying this fundamental biologic process, namely that PKA phosphorylates a calcium channel inhibitor, Rad, thereby releasing inhibition and increasing calcium influx. Here, we describe an updated model for how signals from adrenergic agonists are transduced to stimulate calcium influx and contractility in the heart.
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Affiliation(s)
- Arianne Papa
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Jared Kushner
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA;
| | - Steven O Marx
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA;
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
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20
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Shah AS, Sadayappan S, Urbina EM. Lipids: a Potential Molecular Pathway Towards Diastolic Dysfunction in Youth-Onset Type 2 Diabetes. Curr Atheroscler Rep 2022; 24:109-117. [PMID: 35080716 PMCID: PMC8930525 DOI: 10.1007/s11883-022-00989-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/18/2021] [Indexed: 02/03/2023]
Abstract
PURPOSE OF THE REVIEW Obesity and type 2 diabetes (T2D) with onset in youth are emerging public health concerns. Youth with obesity and T2D are at risk for the development of heart failure with preserved ejection fraction (HFpEF) due to diabetes-related cardiomyopathy with evidence of precursor stages, namely diastolic dysfunction, present in youth. We review the literature regarding diastolic dysfunction in youth with obesity and T2D; discuss the potential mechanisms including the role of lipids, contractile proteins and their post-translational modifications, and conclude with studies to guide future treatments. RECENT FINDINGS The diabetes milieu namely hyperglycemia, hyperinsulinemia, and lipotoxicity favor development of diastolic dysfunction and HFpEF. Recent studies show HFpEF is associated with slow left ventricular relaxation and sarcomere stiffness induced by reduced calcium (Ca2+) and β-adrenergic responses. There are currently no effective therapies available for treating HFpEF. Targeting the sarcomere is an area of ongoing research.
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Affiliation(s)
- Amy S. Shah
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children’s Hospital Medical Center and The University of Cincinnati, 3333 Burnet Ave ML 7012, Cincinnati, OH, 45229, USA
| | - Sakthivel Sadayappan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, Cincinnati, Ohio, USA
| | - Elaine M. Urbina
- Department of Pediatrics, Division of Endocrinology, Cincinnati Children’s Hospital Medical Center and The University of Cincinnati, 3333 Burnet Ave ML 7012, Cincinnati, OH, 45229, USA,The Heart Institute, Cincinnati Children’s Hospital, and the University of Cincinnati, Cincinnati, Ohio, USA
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21
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Zhou G, Chen J, Wu C, Jiang P, Wang Y, Zhang Y, Jiang Y, Li X. Deciphering the Protein, Modular Connections and Precision Medicine for Heart Failure With Preserved Ejection Fraction and Hypertension Based on TMT Quantitative Proteomics and Molecular Docking. Front Physiol 2021; 12:607089. [PMID: 34721049 PMCID: PMC8552070 DOI: 10.3389/fphys.2021.607089] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 09/23/2021] [Indexed: 12/16/2022] Open
Abstract
Background: Exploring the potential biological relationships between heart failure with preserved ejection fraction (HFpEF) and concomitant diseases has been the focus of many studies for the establishment of personalized therapies. Hypertension (HTN) is the most common concomitant disease in HFpEF patients, but the functional connections between HFpEF and HTN are still not fully understood and effective treatment strategies are still lacking. Methods: In this study, tandem mass tag (TMT) quantitative proteomics was used to identify disease-related proteins and construct disease-related networks. Furthermore, functional enrichment analysis of overlapping network modules was used to determine the functional similarities between HFpEF and HTN. Molecular docking and module analyses were combined to identify therapeutic targets for HFpEF and HTN. Results: Seven common differentially expressed proteins (co-DEPs) and eight overlapping modules were identified in HFpEF and HTN. The common biological processes between HFpEF and HTN were mainly related to energy metabolism. Myocardial contraction, energy metabolism, apoptosis, oxidative stress, immune response, and cardiac hypertrophy were all closely associated with HFpEF and HTN. Epinephrine, sulfadimethoxine, chloroform, and prednisolone acetate were best matched with the co-DEPs by molecular docking analyses. Conclusion: Myocardial contraction, energy metabolism, apoptosis, oxidative stress, immune response, and cardiac hypertrophy were the main functional connections between HFpEF and HTN. Epinephrine, sulfadimethoxine, chloroform, and prednisolone acetate could potentially be effective for the treatment of HTN and HFpEF.
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Affiliation(s)
- Guofeng Zhou
- First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Jiye Chen
- First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Chuanhong Wu
- The Biomedical Sciences Institute of Qingdao University (Qingdao Branch of SJTU Bio-X Institutes), Qingdao University, Qingdao, China
| | - Ping Jiang
- First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yongcheng Wang
- Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yongjian Zhang
- First Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Yuehua Jiang
- Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
| | - Xiao Li
- Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, China
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22
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Capote AE, Batra A, Warren CM, Chowdhury SAK, Wolska BM, Solaro RJ, Rosas PC. B-arrestin-2 Signaling Is Important to Preserve Cardiac Function During Aging. Front Physiol 2021; 12:696852. [PMID: 34512376 PMCID: PMC8430342 DOI: 10.3389/fphys.2021.696852] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Accepted: 07/26/2021] [Indexed: 12/25/2022] Open
Abstract
Experiments reported here tested the hypothesis that β-arrestin-2 is an important element in the preservation of cardiac function during aging. We tested this hypothesis by aging β-arrestin-2 knock-out (KO) mice, and wild-type equivalent (WT) to 12-16months. We developed the rationale for these experiments on the basis that angiotensin II (ang II) signaling at ang II receptor type 1 (AT1R), which is a G-protein coupled receptor (GPCR) promotes both G-protein signaling as well as β-arrestin-2 signaling. β-arrestin-2 participates in GPCR desensitization, internalization, but also acts as a scaffold for adaptive signal transduction that may occur independently or in parallel to G-protein signaling. We have previously reported that biased ligands acting at the AT1R promote β-arrestin-2 signaling increasing cardiac contractility and reducing maladaptations in a mouse model of dilated cardiomyopathy. Although there is evidence that ang II induces maladaptive senescence in the cardiovascular system, a role for β-arrestin-2 signaling has not been studied in aging. By echocardiography, we found that compared to controls aged KO mice exhibited enlarged left atria and left ventricular diameters as well as depressed contractility parameters with preserved ejection fraction. Aged KO also exhibited depressed relaxation parameters when compared to WT controls at the same age. Moreover, cardiac dysfunction in aged KO mice was correlated with alterations in the phosphorylation of myofilament proteins, such as cardiac myosin binding protein-C, and myosin regulatory light chain. Our evidence provides novel insights into a role for β-arrestin-2 as an important signaling mechanism that preserves cardiac function during aging.
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Affiliation(s)
- Andrielle E. Capote
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Ashley Batra
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Chad M. Warren
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Shamim A. K. Chowdhury
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Beata M. Wolska
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
- Department of Medicine, Division of Cardiology, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - R. John Solaro
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
| | - Paola C. Rosas
- Department of Physiology & Biophysics, Center for Cardiovascular Research, University of Illinois at Chicago, Chicago, IL, United States
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23
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Kwon HK, Choi H, Park SG, Park WJ, Kim, DH, Park ZY. Integrated Quantitative Phosphoproteomics and Cell-based Functional Screening Reveals Specific Pathological Cardiac Hypertrophy-related Phosphorylation Sites. Mol Cells 2021; 44:500-516. [PMID: 34158421 PMCID: PMC8334354 DOI: 10.14348/molcells.2021.4002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 01/07/2019] [Indexed: 12/29/2022] Open
Abstract
Cardiac hypertrophic signaling cascades resulting in heart failure diseases are mediated by protein phosphorylation. Recent developments in mass spectrometry-based phosphoproteomics have led to the identification of thousands of differentially phosphorylated proteins and their phosphorylation sites. However, functional studies of these differentially phosphorylated proteins have not been conducted in a large-scale or high-throughput manner due to a lack of methods capable of revealing the functional relevance of each phosphorylation site. In this study, an integrated approach combining quantitative phosphoproteomics and cell-based functional screening using phosphorylation competition peptides was developed. A pathological cardiac hypertrophy model, junctate-1 transgenic mice and control mice, were analyzed using label-free quantitative phosphoproteomics to identify differentially phosphorylated proteins and sites. A cell-based functional assay system measuring hypertrophic cell growth of neonatal rat ventricle cardiomyocytes (NRVMs) following phenylephrine treatment was applied, and changes in phosphorylation of individual differentially phosphorylated sites were induced by incorporation of phosphorylation competition peptides conjugated with cell-penetrating peptides. Cell-based functional screening against 18 selected phosphorylation sites identified three phosphorylation sites (Ser-98, Ser-179 of Ldb3, and Ser-1146 of palladin) displaying near-complete inhibition of cardiac hypertrophic growth of NRVMs. Changes in phosphorylation levels of Ser-98 and Ser-179 in Ldb3 were further confirmed in NRVMs and other pathological/physiological hypertrophy models, including transverse aortic constriction and swimming models, using site-specific phospho-antibodies. Our integrated approach can be used to identify functionally important phosphorylation sites among differentially phosphorylated sites, and unlike conventional approaches, it is easily applicable for large-scale and/or high-throughput analyses.
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Affiliation(s)
- Hye Kyeong Kwon
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Hyunwoo Choi
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Sung-Gyoo Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Woo Jin Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Do Han Kim,
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Zee-Yong Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
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24
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Caporizzo MA, Prosser BL. Need for Speed: The Importance of Physiological Strain Rates in Determining Myocardial Stiffness. Front Physiol 2021; 12:696694. [PMID: 34393820 PMCID: PMC8361601 DOI: 10.3389/fphys.2021.696694] [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: 04/17/2021] [Accepted: 07/06/2021] [Indexed: 01/07/2023] Open
Abstract
The heart is viscoelastic, meaning its compliance is inversely proportional to the speed at which it stretches. During diastolic filling, the left ventricle rapidly expands at rates where viscoelastic forces impact ventricular compliance. In heart disease, myocardial viscoelasticity is often increased and can directly impede diastolic filling to reduce cardiac output. Thus, treatments that reduce myocardial viscoelasticity may provide benefit in heart failure, particularly for patients with diastolic heart failure. Yet, many experimental techniques either cannot or do not characterize myocardial viscoelasticity, and our understanding of the molecular regulators of viscoelasticity and its impact on cardiac performance is lacking. Much of this may stem from a reliance on techniques that either do not interrogate viscoelasticity (i.e., use non-physiological rates of strain) or techniques that compromise elements that contribute to viscoelasticity (i.e., skinned or permeabilized muscle preparations that compromise cytoskeletal integrity). Clinically, cardiac viscoelastic characterization is challenging, requiring the addition of strain-rate modulation during invasive hemodynamics. Despite these challenges, data continues to emerge demonstrating a meaningful contribution of viscoelasticity to cardiac physiology and pathology, and thus innovative approaches to characterize viscoelasticity stand to illuminate fundamental properties of myocardial mechanics and facilitate the development of novel therapeutic strategies.
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Affiliation(s)
- Matthew A Caporizzo
- Department of Physiology, Perelman School of Medicine, The University of Pennsylvania, Philadelphia, PA, United States
| | - Benjamin L Prosser
- Department of Physiology, Perelman School of Medicine, The University of Pennsylvania, Philadelphia, PA, United States
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25
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Hanft LM, Fitzsimons DP, Hacker TA, Moss RL, McDonald KS. Cardiac MyBP-C phosphorylation regulates the Frank-Starling relationship in murine hearts. J Gen Physiol 2021; 153:e202012770. [PMID: 33646280 PMCID: PMC7927661 DOI: 10.1085/jgp.202012770] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 01/04/2021] [Accepted: 01/26/2021] [Indexed: 01/08/2023] Open
Abstract
The Frank-Starling relationship establishes that elevated end-diastolic volume progressively increases ventricular pressure and stroke volume in healthy hearts. The relationship is modulated by a number of physiological inputs and is often depressed in human heart failure. Emerging evidence suggests that cardiac myosin-binding protein-C (cMyBP-C) contributes to the Frank-Starling relationship. We measured contractile properties at multiple levels of structural organization to determine the role of cMyBP-C and its phosphorylation in regulating (1) the sarcomere length dependence of power in cardiac myofilaments and (2) the Frank-Starling relationship in vivo. We compared transgenic mice expressing wild-type cMyBP-C on the null background, which have ∼50% phosphorylated cMyBP-C (Controls), to transgenic mice lacking cMyBP-C (KO) and to mice expressing cMyBP-C that have serine-273, -282, and -302 mutated to aspartate (cMyBP-C t3SD) or alanine (cMyBP-C t3SA) on the null background to mimic either constitutive PKA phosphorylation or nonphosphorylated cMyBP-C, respectively. We observed a continuum of length dependence of power output in myocyte preparations. Sarcomere length dependence of power progressively increased with a rank ordering of cMyBP-C KO = cMyBP-C t3SA < Control < cMyBP-C t3SD. Length dependence of myofilament power translated, at least in part, to hearts, whereby Frank-Starling relationships were steepest in cMyBP-C t3SD mice. The results support the hypothesis that cMyBP-C and its phosphorylation state tune sarcomere length dependence of myofibrillar power, and these regulatory processes translate across spatial levels of myocardial organization to control beat-to-beat ventricular performance.
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Affiliation(s)
- Laurin M. Hanft
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO
| | - Daniel P. Fitzsimons
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
| | - Timothy A. Hacker
- Department of Medicine, University of Wisconsin-Madison, Madison, WI
| | - Richard L. Moss
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI
| | - Kerry S. McDonald
- Department of Medical Pharmacology and Physiology, University of Missouri, Columbia, MO
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26
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Tan W, Li X, Zheng S, Li X, Zhang X, Pyle WG, Chen H, Wu J, Sun H, Zou Y, Backx PH, Yang FH. A Porcine Model of Heart Failure With Preserved Ejection Fraction Induced by Chronic Pressure Overload Characterized by Cardiac Fibrosis and Remodeling. Front Cardiovasc Med 2021; 8:677727. [PMID: 34150870 PMCID: PMC8206269 DOI: 10.3389/fcvm.2021.677727] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/10/2021] [Indexed: 12/17/2022] Open
Abstract
Heart failure is induced by multiple pathological mechanisms, and current therapies are ineffective against heart failure with preserved ejection fraction (HFpEF). As there are limited animal models of HFpEF, its underlying mechanisms have not yet been elucidated. Here, we employed the descending aortic constriction (DAC) technique to induce chronic pressure overload in the left ventricles of Tibetan minipigs for 12 weeks. Cardiac function, pathological and cellular changes, fibrotic signaling activation, and gene expression profiles were explored. The left ventricles developed concentric hypertrophy from weeks 4 to 6 and transition to dilation starting in week 10. Notably, the left ventricular ejection fraction was maintained at >50% in the DAC group during the 12-week period. Pathological examination, biochemical analyses, and gene profile analysis revealed evidence of inflammation, fibrosis, cell death, and myofilament dephosphorylation in the myocardium of HFpEF model animals, together with gene expression shifts promoting cardiac remodeling and downregulating metabolic pathways. Furthermore, we noted the activation of several signaling proteins that impact cardiac fibrosis and remodeling, including transforming growth factor-β/SMAD family members 2/3, type I/III/V collagens, phosphatidylinositol 3-kinase, extracellular signal-regulated kinase, matrix metalloproteinases 2 and 9, tissue inhibitor of metalloproteinases 1 and 2, interleukins 6 and 1β, and inhibitor of κBα/nuclear factor-κB. Our findings demonstrate that this chronic pressure overload-induced porcine HFpEF model is a powerful tool to elucidate the mechanisms of this disease and translate preclinical findings.
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Affiliation(s)
- Weijiang Tan
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Xiang Li
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Shuang Zheng
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Xiaohui Li
- Department of Cardiovascular Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Xiaoshen Zhang
- Department of Cardiovascular Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - W Glen Pyle
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada
| | - Honghua Chen
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China
| | - Jian Wu
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Huan Sun
- Cardiology Department, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Yunzeng Zou
- Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai, China
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Feng Hua Yang
- Guangdong Provincial Key Laboratory of Laboratory Animals, Guangdong Laboratory Animals Monitoring Institute, Guangzhou, China.,Department of Cardiovascular Surgery, The First Affiliated Hospital, Jinan University, Guangzhou, China
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27
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Bunch TA, Guhathakurta P, Lepak VC, Thompson AR, Kanassatega RS, Wilson A, Thomas DD, Colson BA. Cardiac myosin-binding protein C interaction with actin is inhibited by compounds identified in a high-throughput fluorescence lifetime screen. J Biol Chem 2021; 297:100840. [PMID: 34052227 PMCID: PMC8233204 DOI: 10.1016/j.jbc.2021.100840] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/19/2021] [Accepted: 05/26/2021] [Indexed: 11/26/2022] Open
Abstract
Cardiac myosin-binding protein C (cMyBP-C) interacts with actin and myosin to modulate cardiac muscle contractility. These interactions are disfavored by cMyBP-C phosphorylation. Heart failure patients often display decreased cMyBP-C phosphorylation, and phosphorylation in model systems has been shown to be cardioprotective against heart failure. Therefore, cMyBP-C is a potential target for heart failure drugs that mimic phosphorylation or perturb its interactions with actin/myosin. Here we have used a novel fluorescence lifetime-based assay to identify small-molecule inhibitors of actin-cMyBP-C binding. Actin was labeled with a fluorescent dye (Alexa Fluor 568, AF568) near its cMyBP-C binding sites; when combined with the cMyBP-C N-terminal fragment, C0-C2, the fluorescence lifetime of AF568-actin decreases. Using this reduction in lifetime as a readout of actin binding, a high-throughput screen of a 1280-compound library identified three reproducible hit compounds (suramin, NF023, and aurintricarboxylic acid) that reduced C0-C2 binding to actin in the micromolar range. Binding of phosphorylated C0-C2 was also blocked by these compounds. That they specifically block binding was confirmed by an actin-C0-C2 time-resolved FRET (TR-FRET) binding assay. Isothermal titration calorimetry (ITC) and transient phosphorescence anisotropy (TPA) confirmed that these compounds bind to cMyBP-C, but not to actin. TPA results were also consistent with these compounds inhibiting C0-C2 binding to actin. We conclude that the actin-cMyBP-C fluorescence lifetime assay permits detection of pharmacologically active compounds that affect cMyBP-C-actin binding. We now have, for the first time, a validated high-throughput screen focused on cMyBP-C, a regulator of cardiac muscle contractility and known key factor in heart failure.
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Affiliation(s)
- Thomas A Bunch
- Department of Cellular & Molecular Medicine, University of Arizona, Tucson Arizona, USA
| | - Piyali Guhathakurta
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Victoria C Lepak
- Department of Cellular & Molecular Medicine, University of Arizona, Tucson Arizona, USA
| | - Andrew R Thompson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | | | - Anna Wilson
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota, USA
| | - Brett A Colson
- Department of Cellular & Molecular Medicine, University of Arizona, Tucson Arizona, USA.
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28
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Tanner BCW, Previs MJ, Wang Y, Robbins J, Palmer BM. Cardiac myosin binding protein-C phosphorylation accelerates β-cardiac myosin detachment rate in mouse myocardium. Am J Physiol Heart Circ Physiol 2021; 320:H1822-H1835. [PMID: 33666504 PMCID: PMC8163640 DOI: 10.1152/ajpheart.00673.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 02/08/2021] [Accepted: 03/01/2021] [Indexed: 11/22/2022]
Abstract
Cardiac myosin binding protein-C (cMyBP-C) is a thick filament protein that influences sarcomere stiffness and modulates cardiac contraction-relaxation through its phosphorylation. Phosphorylation of cMyBP-C and ablation of cMyBP-C have been shown to increase the rate of MgADP release in the acto-myosin cross-bridge cycle in the intact sarcomere. The influence of cMyBP-C on Pi-dependent myosin kinetics has not yet been examined. We investigated the effect of cMyBP-C, and its phosphorylation, on myosin kinetics in demembranated papillary muscle strips bearing the β-cardiac myosin isoform from nontransgenic and homozygous transgenic mice lacking cMyBP-C. We used quick stretch and stochastic length-perturbation analysis to characterize rates of myosin detachment and force development over 0-12 mM Pi and at maximal (pCa 4.8) and near-half maximal (pCa 5.75) Ca2+ activation. Protein kinase A (PKA) treatment was applied to half the strips to probe the effect of cMyBP-C phosphorylation on Pi sensitivity of myosin kinetics. Increasing Pi increased myosin cross-bridge detachment rate similarly for muscles with and without cMyBP-C, although these rates were higher in muscle without cMyBP-C. Treating myocardial strips with PKA accelerated detachment rate when cMyBP-C was present over all Pi, but not when cMyBP-C was absent. The rate of force development increased with Pi in all muscles. However, Pi sensitivity of the rate force development was reduced when cMyBP-C was present versus absent, suggesting that cMyBP-C inhibits Pi-dependent reversal of the power stroke or stabilizes cross-bridge attachment to enhance the probability of completing the power stroke. These results support a functional role for cMyBP-C in slowing myosin detachment rate, possibly through a direct interaction with myosin or by altering strain-dependent myosin detachment via cMyBP-C-dependent stiffness of the thick filament and myofilament lattice. PKA treatment reduces the role for cMyBP-C to slow myosin detachment and thus effectively accelerates β-myosin detachment in the intact myofilament lattice.NEW & NOTEWORTHY Length perturbation analysis was used to demonstrate that β-cardiac myosin characteristic rates of detachment and recruitment in the intact myofilament lattice are accelerated by Pi, phosphorylation of cMyBP-C, and the absence of cMyBP-C. The results suggest that cMyBP-C normally slows myosin detachment, including Pi-dependent detachment, and that this inhibition is released with phosphorylation or absence of cMyBP-C.
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Affiliation(s)
- Bertrand C W Tanner
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
| | - Michael J Previs
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
| | - Yuan Wang
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
| | - Jeffrey Robbins
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio
| | - Bradley M Palmer
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont
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29
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Joshi A, Rienks M, Theofilatos K, Mayr M. Systems biology in cardiovascular disease: a multiomics approach. Nat Rev Cardiol 2021; 18:313-330. [PMID: 33340009 DOI: 10.1038/s41569-020-00477-1] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/02/2020] [Indexed: 12/13/2022]
Abstract
Omics techniques generate large, multidimensional data that are amenable to analysis by new informatics approaches alongside conventional statistical methods. Systems theories, including network analysis and machine learning, are well placed for analysing these data but must be applied with an understanding of the relevant biological and computational theories. Through applying these techniques to omics data, systems biology addresses the problems posed by the complex organization of biological processes. In this Review, we describe the techniques and sources of omics data, outline network theory, and highlight exemplars of novel approaches that combine gene regulatory and co-expression networks, proteomics, metabolomics, lipidomics and phenomics with informatics techniques to provide new insights into cardiovascular disease. The use of systems approaches will become necessary to integrate data from more than one omic technique. Although understanding the interactions between different omics data requires increasingly complex concepts and methods, we argue that hypothesis-driven investigations and independent validation must still accompany these novel systems biology approaches to realize their full potential.
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Affiliation(s)
- Abhishek Joshi
- King's British Heart Foundation Centre, King's College London, London, UK
- Bart's Heart Centre, St. Bartholomew's Hospital, London, UK
| | - Marieke Rienks
- King's British Heart Foundation Centre, King's College London, London, UK
| | | | - Manuel Mayr
- King's British Heart Foundation Centre, King's College London, London, UK.
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30
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Solís C, Solaro RJ. Novel insights into sarcomere regulatory systems control of cardiac thin filament activation. J Gen Physiol 2021; 153:211903. [PMID: 33740037 PMCID: PMC7988513 DOI: 10.1085/jgp.202012777] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 02/23/2021] [Indexed: 12/11/2022] Open
Abstract
Our review focuses on sarcomere regulatory mechanisms with a discussion of cardiac-specific modifications to the three-state model of thin filament activation from a blocked to closed to open state. We discuss modulation of these thin filament transitions by Ca2+, by crossbridge interactions, and by thick filament–associated proteins, cardiac myosin–binding protein C (cMyBP-C), cardiac regulatory light chain (cRLC), and titin. Emerging evidence supports the idea that the cooperative activation of the thin filaments despite a single Ca2+ triggering regulatory site on troponin C (cTnC) cannot be considered in isolation of other functional domains of the sarcomere. We discuss long- and short-range interactions among these domains with the regulatory units of thin filaments, including proteins at the barbed end at the Z-disc and the pointed end near the M-band. Important to these discussions is the ever-increasing understanding of the role of cMyBP-C, cRLC, and titin filaments. Detailed knowledge of these control processes is critical to the understanding of mechanisms sustaining physiological cardiac state with varying hemodynamic load, to better defining genetic and acquired cardiac disorders, and to developing targets for therapies at the level of the sarcomeres.
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Affiliation(s)
- Christopher Solís
- University of Illinois at Chicago, College of Medicine, Department of Physiology and Biophysics and Center for Cardiovascular Research, Chicago, IL
| | - R John Solaro
- University of Illinois at Chicago, College of Medicine, Department of Physiology and Biophysics and Center for Cardiovascular Research, Chicago, IL
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Mamidi R, Holmes JB, Doh CY, Dominic KL, Madugula N, Stelzer JE. cMyBPC phosphorylation modulates the effect of omecamtiv mecarbil on myocardial force generation. J Gen Physiol 2021; 153:211867. [PMID: 33688929 PMCID: PMC7953254 DOI: 10.1085/jgp.202012816] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/27/2021] [Indexed: 01/15/2023] Open
Abstract
Omecamtiv mecarbil (OM), a direct myosin motor activator, is currently being tested as a therapeutic replacement for conventional inotropes in heart failure (HF) patients. It is known that HF patients exhibit dysregulated β-adrenergic signaling and decreased cardiac myosin-binding protein C (cMyBPC) phosphorylation, a critical modulator of myocardial force generation. However, the functional effects of OM in conditions of altered cMyBPC phosphorylation have not been established. Here, we tested the effects of OM on force generation and cross-bridge (XB) kinetics using murine myocardial preparations isolated from wild-type (WT) hearts and from hearts expressing S273A, S282A, and S302A substitutions (SA) in the M domain, between the C1 and C2 domains of cMyBPC, which cannot be phosphorylated. At submaximal Ca2+ activations, OM-mediated force enhancements were less pronounced in SA than in WT myocardial preparations. Additionally, SA myocardial preparations lacked the dose-dependent increases in force that were observed in WT myocardial preparations. Following OM incubation, the basal differences in the rate of XB detachment (krel) between WT and SA myocardial preparations were abolished, suggesting that OM differentially affects the XB behavior when cMyBPC phosphorylation is reduced. Similarly, in myocardial preparations pretreated with protein kinase A to phosphorylate cMyBPC, incubation with OM significantly slowed krel in both the WT and SA myocardial preparations. Collectively, our data suggest there is a strong interplay between the effects of OM and XB behavior, such that it effectively uncouples the sarcomere from cMyBPC phosphorylation levels. Our findings imply that OM may significantly alter the in vivo cardiac response to β-adrenergic stimulation.
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Affiliation(s)
- Ranganath Mamidi
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH
| | - Joshua B Holmes
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH
| | - Chang Yoon Doh
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH
| | - Katherine L Dominic
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH
| | - Nikhil Madugula
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH
| | - Julian E Stelzer
- Department of Physiology and Biophysics, School of Medicine, Case Western Reserve University, Cleveland, OH
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Giles J, Fitzsimons DP, Patel JR, Knudtsen C, Neuville Z, Moss RL. cMyBP-C phosphorylation modulates the time-dependent slowing of unloaded shortening in murine skinned myocardium. J Gen Physiol 2021; 153:e202012782. [PMID: 33566084 PMCID: PMC7879488 DOI: 10.1085/jgp.202012782] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/14/2021] [Indexed: 11/20/2022] Open
Abstract
In myocardium, phosphorylation of cardiac myosin-binding protein-C (cMyBP-C) is thought to modulate the cooperative activation of the thin filament by binding to myosin and/or actin, thereby regulating the probability of cross-bridge binding to actin. At low levels of Ca2+ activation, unloaded shortening velocity (Vo) in permeabilized cardiac muscle is comprised of an initial high-velocity phase and a subsequent low-velocity phase. The velocities in these phases scale with the level of activation, culminating in a single high-velocity phase (Vmax) at saturating Ca2+. To test the idea that cMyBP-C phosphorylation contributes to the activation dependence of Vo, we measured Vo before and following treatment with protein kinase A (PKA) in skinned trabecula isolated from mice expressing either wild-type cMyBP-C (tWT), nonphosphorylatable cMyBP-C (t3SA), or phosphomimetic cMyBP-C (t3SD). During maximal Ca2+ activation, Vmax was monophasic and not significantly different between the three groups. Although biphasic shortening was observed in all three groups at half-maximal activation under control conditions, the high- and low-velocity phases were faster in the t3SD myocardium compared with values obtained in either tWT or t3SA myocardium. Treatment with PKA significantly accelerated both the high- and low-velocity phases in tWT myocardium but had no effect on Vo in either the t3SD or t3SA myocardium. These results can be explained in terms of a model in which the level of cMyBP-C phosphorylation modulates the extent and rate of cooperative spread of myosin binding to actin.
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Affiliation(s)
- Jasmine Giles
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, and the University of Wisconsin Cardiovascular Research Center, Madison, WI
| | - Daniel P. Fitzsimons
- Department of Animal, Veterinary and Food Sciences, College of Agricultural and Life Sciences, University of Idaho, Moscow, ID
| | - Jitandrakumar R. Patel
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, and the University of Wisconsin Cardiovascular Research Center, Madison, WI
| | - Chloe Knudtsen
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, and the University of Wisconsin Cardiovascular Research Center, Madison, WI
| | - Zander Neuville
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, and the University of Wisconsin Cardiovascular Research Center, Madison, WI
| | - Richard L. Moss
- Department of Cell and Regenerative Biology, University of Wisconsin School of Medicine and Public Health, and the University of Wisconsin Cardiovascular Research Center, Madison, WI
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Rahmanseresht S, Lee KH, O’Leary TS, McNamara JW, Sadayappan S, Robbins J, Warshaw DM, Craig R, Previs MJ. The N terminus of myosin-binding protein C extends toward actin filaments in intact cardiac muscle. J Gen Physiol 2021; 153:e202012726. [PMID: 33528507 PMCID: PMC7852460 DOI: 10.1085/jgp.202012726] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/23/2020] [Accepted: 12/03/2020] [Indexed: 12/31/2022] Open
Abstract
Myosin and actin filaments are highly organized within muscle sarcomeres. Myosin-binding protein C (MyBP-C) is a flexible, rod-like protein located within the C-zone of the sarcomere. The C-terminal domain of MyBP-C is tethered to the myosin filament backbone, and the N-terminal domains are postulated to interact with actin and/or the myosin head to modulate filament sliding. To define where the N-terminal domains of MyBP-C are localized in the sarcomere of active and relaxed mouse myocardium, the relative positions of the N terminus of MyBP-C and actin were imaged in fixed muscle samples using super-resolution fluorescence microscopy. The resolution of the imaging was enhanced by particle averaging. The images demonstrate that the position of the N terminus of MyBP-C is biased toward the actin filaments in both active and relaxed muscle preparations. Comparison of the experimental images with images generated in silico, accounting for known binding partner interactions, suggests that the N-terminal domains of MyBP-C may bind to actin and possibly the myosin head but only when the myosin head is in the proximity of an actin filament. These physiologically relevant images help define the molecular mechanism by which the N-terminal domains of MyBP-C may search for, and capture, molecular binding partners to tune cardiac contractility.
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Affiliation(s)
- Sheema Rahmanseresht
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT
| | - Kyoung H. Lee
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Thomas S. O’Leary
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT
| | - James W. McNamara
- Heart, Lung and Vascular Institute, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH
| | - Sakthivel Sadayappan
- Heart, Lung and Vascular Institute, Department of Internal Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH
| | - Jeffrey Robbins
- Department of Pediatrics and the Heart Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH
| | - David M. Warshaw
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT
| | - Roger Craig
- Division of Cell Biology and Imaging, Department of Radiology, University of Massachusetts Medical School, Worcester, MA
| | - Michael J. Previs
- Department of Molecular Physiology and Biophysics, Cardiovascular Research Institute, University of Vermont, Burlington, VT
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Liu Y, Chen J, Fontes SK, Bautista EN, Cheng Z. Physiological And Pathological Roles Of Protein Kinase A In The Heart. Cardiovasc Res 2021; 118:386-398. [PMID: 33483740 DOI: 10.1093/cvr/cvab008] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 11/30/2020] [Accepted: 01/08/2021] [Indexed: 12/21/2022] Open
Abstract
Protein kinase A (PKA) is a central regulator of cardiac performance and morphology. Myocardial PKA activation is induced by a variety of hormones, neurotransmitters and stress signals, most notably catecholamines secreted by the sympathetic nervous system. Catecholamines bind β-adrenergic receptors to stimulate cAMP-dependent PKA activation in cardiomyocytes. Elevated PKA activity enhances Ca2+ cycling and increases cardiac muscle contractility. Dynamic control of PKA is essential for cardiac homeostasis, as dysregulation of PKA signaling is associated with a broad range of heart diseases. Specifically, abnormal PKA activation or inactivation contributes to the pathogenesis of myocardial ischemia, hypertrophy, heart failure, as well as diabetic, takotsubo, or anthracycline cardiomyopathies. PKA may also determine sex-dependent differences in contractile function and heart disease predisposition. Here, we describe the recent advances regarding the roles of PKA in cardiac physiology and pathology, highlighting previous study limitations and future research directions. Moreover, we discuss the therapeutic strategies and molecular mechanisms associated with cardiac PKA biology. In summary, PKA could serve as a promising drug target for cardioprotection. Depending on disease types and mechanisms, therapeutic intervention may require either inhibition or activation of PKA. Therefore, specific PKA inhibitors or activators may represent valuable drug candidates for the treatment of heart diseases.
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Affiliation(s)
- Yuening Liu
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Jingrui Chen
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Shayne K Fontes
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Erika N Bautista
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
| | - Zhaokang Cheng
- Department of Pharmaceutical Sciences, Washington State University, PBS 423, 412 E. Spokane Falls Blvd, ., Spokane, WA, 99202-2131, USA
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Richards DA, Aronovitz MJ, Liu P, Martin GL, Tam K, Pande S, Karas RH, Bloomfield DM, Mendelsohn ME, Blanton RM. CRD-733, a Novel PDE9 (Phosphodiesterase 9) Inhibitor, Reverses Pressure Overload-Induced Heart Failure. Circ Heart Fail 2021; 14:e007300. [PMID: 33464954 DOI: 10.1161/circheartfailure.120.007300] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Augmentation of NP (natriuretic peptide) receptor and cyclic guanosine monophosphate (cGMP) signaling has emerged as a therapeutic strategy in heart failure (HF). cGMP-specific PDE9 (phosphodiesterase 9) inhibition increases cGMP signaling and attenuates stress-induced hypertrophic heart disease in preclinical studies. A novel cGMP-specific PDE9 inhibitor, CRD-733, is currently being advanced in human clinical studies. Here, we explore the effects of chronic PDE9 inhibition with CRD-733 in the mouse transverse aortic constriction pressure overload HF model. METHODS Adult male C57BL/6J mice were subjected to transverse aortic constriction and developed significant left ventricular (LV) hypertrophy after 7 days (P<0.001). Mice then received daily treatment with CRD-733 (600 mg/kg per day; n=10) or vehicle (n=17), alongside sham-operated controls (n=10). RESULTS CRD-733 treatment reversed existing LV hypertrophy compared with vehicle (P<0.001), significantly improved LV ejection fraction (P=0.009), and attenuated left atrial dilation (P<0.001), as assessed by serial echocardiography. CRD-733 prevented elevations in LV end diastolic pressures (P=0.037) compared with vehicle, while lung weights, a surrogate for pulmonary edema, were reduced to sham levels. Chronic CRD-733 treatment increased plasma cGMP levels compared with vehicle (P<0.001), alongside increased phosphorylation of Ser273 of cardiac myosin binding protein-C, a cGMP-dependent protein kinase I phosphorylation site. CONCLUSIONS The PDE9 inhibitor, CRD-733, improves key hallmarks of HF including LV hypertrophy, LV dysfunction, left atrial dilation, and pulmonary edema after pressure overload in the mouse transverse aortic constriction HF model. Additionally, elevated plasma cGMP may be used as a biomarker of target engagement. These findings support future investigation into the therapeutic potential of CRD-733 in human HF.
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Affiliation(s)
- Daniel A Richards
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA (D.A.R., M.J.A., G.L.M., K.T., S.P., R.H.K., R.M.B.)
| | - Mark J Aronovitz
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA (D.A.R., M.J.A., G.L.M., K.T., S.P., R.H.K., R.M.B.)
| | - Peiwen Liu
- Graduate School of Biomedical Sciences, Tufts University, Boston, MA (P.L., R.M.B.)
| | - Gregory L Martin
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA (D.A.R., M.J.A., G.L.M., K.T., S.P., R.H.K., R.M.B.)
| | - Kelly Tam
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA (D.A.R., M.J.A., G.L.M., K.T., S.P., R.H.K., R.M.B.)
| | - Suchita Pande
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA (D.A.R., M.J.A., G.L.M., K.T., S.P., R.H.K., R.M.B.)
| | - Richard H Karas
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA (D.A.R., M.J.A., G.L.M., K.T., S.P., R.H.K., R.M.B.)
| | | | | | - Robert M Blanton
- Molecular Cardiology Research Institute, Tufts Medical Center, Boston, MA (D.A.R., M.J.A., G.L.M., K.T., S.P., R.H.K., R.M.B.).,Graduate School of Biomedical Sciences, Tufts University, Boston, MA (P.L., R.M.B.)
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Abstract
The 3',5'-cyclic guanosine monophosphate (cGMP)-dependent protein kinase type I (cGKI aka PKGI) is a major cardiac effector acting downstream of nitric oxide (NO)-sensitive soluble guanylyl cyclase and natriuretic peptides (NPs), which signal through transmembrane guanylyl cyclases. Consistent with the wide distribution of the cGMP-generating guanylyl cyclases, cGKI, which usually elicits its cellular effects by direct phosphorylation of its targets, is present in multiple cardiac cell types including cardiomyocytes (CMs). Although numerous targets of cGMP/cGKI in heart were identified in the past, neither their exact patho-/physiological functions nor cell-type specific roles are clear. Herein, we inform about the current knowledge on the signal transduction downstream of CM cGKI. We believe that better insights into the specific actions of cGMP and cGKI in these cells will help to guide future studies in the search for predictive biomarkers for the response to pharmacological cGMP pathway modulation. In addition, targets downstream of cGMP/cGKI may be exploited for refined and optimized diagnostic and therapeutic strategies in different types of heart disease and their causes. Importantly, key functions of these proteins and particularly sites of regulatory phosphorylation by cGKI should, at least in principle, remain intact, although upstream signaling through the second messenger cGMP is impaired or dysregulated in a stressed or diseased heart state.
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Jokerst S, Nizmutdinov D, Edgar C, Kaspick AM, Tong CW, Dostal DE. Preparation of Neonatal Rat Papillary Muscles for Contractile Studies. Methods Mol Biol 2021; 2319:31-44. [PMID: 34331240 DOI: 10.1007/978-1-0716-1480-8_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Isolated cardiac tissue allows investigators to study mechanisms underlying normal and pathological conditions, which would otherwise be difficult or impossible to perform in vivo. In contrast to ventricular muscle strip preparations, papillary muscles can be prepared without severely damaging the muscle tissue. In this preparation, the isolated papillary muscle is fixed in an environmentally controlled organ bath chamber and electrically stimulated. The evoked twitch force is recorded using a pressure transducer, and parameters such as twitch force amplitude and twitch kinetics are analyzed. A variety of experimental protocols can be performed to investigate the calcium- and frequency-dependent contractility as well as dose-response curves of contractile agents, as well as simulation of pathologic conditions such as acute cardiac ischemia. Mouse papillary muscle preparations have long been the mainstay for studying interactions between intracellular calcium regulation and contractile responses under a number of simulated pathophysiological conditions. These studies are often used to complement in vitro studies performed using isolated neonatal rat cardiac myocytes. In this procedure, we describe how neonatal rat papillary muscles can also be prepared for use in contractile studies.
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Affiliation(s)
- Steven Jokerst
- Department of Medical Physiology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Damir Nizmutdinov
- Department of Medical Physiology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Charley Edgar
- Department of Medical Physiology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - April M Kaspick
- Department of Medical Physiology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - Carl W Tong
- Department of Medical Physiology, College of Medicine, Texas A&M University, Bryan, TX, USA
| | - David E Dostal
- Department of Medical Physiology, College of Medicine, Texas A&M University, Bryan, TX, USA.
- Central Texas Veterans Health Care System, Department of Internal Medicine, Dell Medical School, The University of Texas at Austin, Austin, TX, USA.
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Michel LYM, Farah C, Balligand JL. The Beta3 Adrenergic Receptor in Healthy and Pathological Cardiovascular Tissues. Cells 2020; 9:cells9122584. [PMID: 33276630 PMCID: PMC7761574 DOI: 10.3390/cells9122584] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/27/2020] [Accepted: 11/30/2020] [Indexed: 12/15/2022] Open
Abstract
The third isotype of beta-adrenoreceptors (β3-AR) has recently come (back) into focus after the observation of its expression in white and beige human adipocytes and its implication in metabolic regulation. This coincides with the recent development and marketing of agonists at the human receptor with superior specificity. Twenty years ago, however, we and others described the expression of β3-AR in human myocardium and its regulation of contractility and cardiac remodeling. Subsequent work from many laboratories has since expanded the characterization of β3-AR involvement in many aspects of cardiovascular physio(patho)logy, justifying the present effort to update current paradigms under the light of the most recent evidence.
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Affiliation(s)
- Lauriane Y. M. Michel
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Experimentale et Clinique (IREC), Université Catholique de Louvain, B1.57.04, 57 Avenue Hippocrate, 1200 Brussels, Belgium; (L.Y.M.M.); (C.F.)
| | - Charlotte Farah
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Experimentale et Clinique (IREC), Université Catholique de Louvain, B1.57.04, 57 Avenue Hippocrate, 1200 Brussels, Belgium; (L.Y.M.M.); (C.F.)
| | - Jean-Luc Balligand
- Pole of Pharmacology and Therapeutics (FATH), Institut de Recherche Experimentale et Clinique (IREC), Université Catholique de Louvain, B1.57.04, 57 Avenue Hippocrate, 1200 Brussels, Belgium; (L.Y.M.M.); (C.F.)
- Department of Medicine, Cliniques Universitaires Saint-Luc, Université Catholique de Louvain, 10 Avenue Hippocrate, 1200 Brussels, Belgium
- Correspondence: ; Tel.: +32-27645262
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Abstract
Cyclic GMP (cGMP) represents a classic intracellular second messenger molecule. Over the past 2 decades, important discoveries have identified that cGMP signaling becomes deranged in heart failure (HF) and that cGMP and its main kinase effector, protein kinase G, generally oppose the biological abnormalities contributing to HF, in experimental studies. These findings have influenced the design of clinical trials of cGMP-augmenting drugs in HF patients. At present, the trial results of cGMP-augmenting therapies in HF remain mixed. As detailed in this review, strong evidence now exists that protein kinase G opposes pathologic cardiac remodeling through regulation of diverse biological processes and myocardial substrates. Potential reasons for the failures of cGMP-augmenting drugs in HF may be related to biological mechanisms opposing cGMP or because of certain features of clinical trials, all of which are discussed.
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Lau E, Han Y, Williams DR, Thomas CT, Shrestha R, Wu JC, Lam MPY. Splice-Junction-Based Mapping of Alternative Isoforms in the Human Proteome. Cell Rep 2020; 29:3751-3765.e5. [PMID: 31825849 PMCID: PMC6961840 DOI: 10.1016/j.celrep.2019.11.026] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 09/24/2019] [Accepted: 11/06/2019] [Indexed: 12/18/2022] Open
Abstract
The protein-level translational status and function of many alternative splicing events remain poorly understood. We use an RNA sequencing (RNA-seq)-guided proteomics method to identify protein alternative splicing isoforms in the human proteome by constructing tissue-specific protein databases that prioritize transcript splice junction pairs with high translational potential. Using the custom databases to reanalyze ~80 million mass spectra in public proteomics datasets, we identify more than 1,500 noncanonical protein isoforms across 12 human tissues, including ~400 sequences undocumented on TrEMBL and RefSeq databases. We apply the method to original quantitative mass spectrometry experiments and observe widespread isoform regulation during human induced pluripotent stem cell cardiomyocyte differentiation. On a proteome scale, alternative isoform regions overlap frequently with disordered sequences and post-translational modification sites, suggesting that alternative splicing may regulate protein function through modulating intrinsically disordered regions. The described approach may help elucidate functional consequences of alternative splicing and expand the scope of proteomics investigations in various systems. The translation and function of many alternative splicing events await confirmation at the protein level. Lau et al. use an integrated proteotranscriptomics approach to identify non-canonical and undocumented isoforms from 12 organs in the human proteome. Alternative isoforms interfere with functional sequence features and are differentially regulated during iPSC cardiomyocyte differentiation.
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Affiliation(s)
- Edward Lau
- Stanford Cardiovascular Institute, Department of Medicine, Stanford University, Palo Alto, CA, USA
| | - Yu Han
- Consortium for Fibrosis Research and Translation, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA; Departments of Medicine-Cardiology and Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA
| | - Damon R Williams
- Stanford Cardiovascular Institute, Department of Medicine, Stanford University, Palo Alto, CA, USA
| | - Cody T Thomas
- Departments of Medicine-Cardiology and Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA
| | - Rajani Shrestha
- Stanford Cardiovascular Institute, Department of Medicine, Stanford University, Palo Alto, CA, USA
| | - Joseph C Wu
- Stanford Cardiovascular Institute, Department of Medicine, Stanford University, Palo Alto, CA, USA; Department of Radiology, School of Medicine, Stanford University, Palo Alto, CA, USA
| | - Maggie P Y Lam
- Consortium for Fibrosis Research and Translation, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA; Departments of Medicine-Cardiology and Biochemistry and Molecular Genetics, Anschutz Medical Campus, University of Colorado, Aurora, CO, USA.
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Li J, Mamidi R, Doh CY, Holmes JB, Bharambe N, Ramachandran R, Stelzer JE. AAV9 gene transfer of cMyBPC N-terminal domains ameliorates cardiomyopathy in cMyBPC-deficient mice. JCI Insight 2020; 5:130182. [PMID: 32750038 PMCID: PMC7526450 DOI: 10.1172/jci.insight.130182] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 07/29/2020] [Indexed: 01/05/2023] Open
Abstract
Decreased cardiac myosin-binding protein C (cMyBPC) expression due to inheritable mutations is thought to contribute to the hypertrophic cardiomyopathy (HCM) phenotype, suggesting that increasing cMyBPC content is of therapeutic benefit. In vitro assays show that cMyBPC N-terminal domains (NTDs) contain structural elements necessary and sufficient to modulate actomyosin interactions, but it is unknown if they can regulate in vivo myocardial function. To test whether NTDs can recapitulate the effects of full-length (FL) cMyBPC in rescuing cardiac function in a cMyBPC-null mouse model of HCM, we assessed the efficacy of AAV9 gene transfer of a cMyBPC NTD that contained domains C0C2 and compared its therapeutic potential with AAV9-FL gene replacement. AAV9 vectors were administered systemically at neonatal day 1, when early-onset disease phenotypes begin to manifest. A comprehensive analysis of in vivo and in vitro function was performed following cMyBPC gene transfer. Our results show that a systemic injection of AAV9-C0C2 significantly improved cardiac function (e.g., 52.24 ± 1.69 ejection fraction in the C0C2-treated group compared with 40.07 ± 1.97 in the control cMyBPC–/– group, P < 0.05) and reduced the histopathologic signs of cardiomyopathy. Furthermore, C0C2 significantly slowed and normalized the accelerated cross-bridge kinetics found in cMyBPC–/– control myocardium, as evidenced by a 32.41% decrease in the rate of cross-bridge detachment (krel). Results indicate that C0C2 can rescue biomechanical defects of cMyBPC deficiency and that the NTD may be a target region for therapeutic myofilament kinetic manipulation. Cardiac function improves following AAV9-mediated delivery of the C0C2 domains of cardiac myosin-binding protein C in a mouse model of hypertrophic cardiomyopathy.
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Arif M, Nabavizadeh P, Song T, Desai D, Singh R, Bazrafshan S, Kumar M, Wang Y, Gilbert RJ, Dhandapany PS, Becker RC, Kranias EG, Sadayappan S. Genetic, clinical, molecular, and pathogenic aspects of the South Asian-specific polymorphic MYBPC3 Δ25bp variant. Biophys Rev 2020; 12:1065-1084. [PMID: 32656747 PMCID: PMC7429610 DOI: 10.1007/s12551-020-00725-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 07/03/2020] [Indexed: 02/06/2023] Open
Abstract
Hypertrophic cardiomyopathy (HCM) is a cardiac genetic disease characterized by ventricular enlargement, diastolic dysfunction, and increased risk for sudden cardiac death. Sarcomeric genetic defects are the predominant known cause of HCM. In particular, mutations in the myosin-binding protein C gene (MYBPC3) are associated with ~ 40% of all HCM cases in which a genetic basis has been established. A decade ago, our group reported a 25-base pair deletion in intron 32 of MYBPC3 (MYBPC3Δ25bp) that is uniquely prevalent in South Asians and is associated with autosomal dominant cardiomyopathy. Although our studies suggest that this deletion results in left ventricular dysfunction, cardiomyopathies, and heart failure, the precise mechanism by which this variant predisposes to heart disease remains unclear. Increasingly appreciated, however, is the contribution of secondary risk factors, additional mutations, and lifestyle choices in augmenting or modifying the HCM phenotype in MYBPC3Δ25bp carriers. Therefore, the goal of this review article is to summarize the current research dedicated to understanding the molecular pathophysiology of HCM in South Asians with the MYBPC3Δ25bp variant. An emphasis is to review the latest techniques currently applied to explore the MYBPC3Δ25bp pathogenesis and to provide a foundation for developing new diagnostic strategies and advances in therapeutics.
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Affiliation(s)
- Mohammed Arif
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA.
| | - Pooneh Nabavizadeh
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Taejeong Song
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Darshini Desai
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Rohit Singh
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Sholeh Bazrafshan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Mohit Kumar
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Yigang Wang
- Department of Pathology and Laboratory Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH, 45267, USA
| | - Richard J Gilbert
- Research Service, Providence VA Medical Center, Providence, RI, 02908, USA
| | - Perundurai S Dhandapany
- Centre for Cardiovascular Biology and Disease, Institute for Stem Cell Biology and Regenerative Medicine (inStem), Bangalore, India
- The Knight Cardiovascular Institute, Oregon Health and Science University, Portland, OR, USA
- Department of Medicine, Oregon Health and Science University, Portland, OR, USA
- Department of Molecular and Medical Genetics, Oregon Health and Science University, Portland, OR, USA
| | - Richard C Becker
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
| | - Evangelia G Kranias
- Department of Pharmacology and Systems Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH, 45267, USA
| | - Sakthivel Sadayappan
- Division of Cardiovascular Health and Disease, Department of Internal Medicine, Heart, Lung and Vascular Institute, University of Cincinnati, College of Medicine, 231 Albert Sabin Way, Cincinnati, OH, 45267-0575, USA
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Chiao YA, Zhang H, Sweetwyne M, Whitson J, Ting YS, Basisty N, Pino LK, Quarles E, Nguyen NH, Campbell MD, Zhang T, Gaffrey MJ, Merrihew G, Wang L, Yue Y, Duan D, Granzier HL, Szeto HH, Qian WJ, Marcinek D, MacCoss MJ, Rabinovitch P. Late-life restoration of mitochondrial function reverses cardiac dysfunction in old mice. eLife 2020; 9:e55513. [PMID: 32648542 PMCID: PMC7377906 DOI: 10.7554/elife.55513] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 07/07/2020] [Indexed: 12/26/2022] Open
Abstract
Diastolic dysfunction is a prominent feature of cardiac aging in both mice and humans. We show here that 8-week treatment of old mice with the mitochondrial targeted peptide SS-31 (elamipretide) can substantially reverse this deficit. SS-31 normalized the increase in proton leak and reduced mitochondrial ROS in cardiomyocytes from old mice, accompanied by reduced protein oxidation and a shift towards a more reduced protein thiol redox state in old hearts. Improved diastolic function was concordant with increased phosphorylation of cMyBP-C Ser282 but was independent of titin isoform shift. Late-life viral expression of mitochondrial-targeted catalase (mCAT) produced similar functional benefits in old mice and SS-31 did not improve cardiac function of old mCAT mice, implicating normalizing mitochondrial oxidative stress as an overlapping mechanism. These results demonstrate that pre-existing cardiac aging phenotypes can be reversed by targeting mitochondrial dysfunction and implicate mitochondrial energetics and redox signaling as therapeutic targets for cardiac aging.
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Affiliation(s)
- Ying Ann Chiao
- Department of Pathology, University of WashingtonSeattleUnited States
- Aging and Metabolism Program, Oklahoma Medical Research FoundationOklahoma CityUnited States
| | - Huiliang Zhang
- Department of Pathology, University of WashingtonSeattleUnited States
| | - Mariya Sweetwyne
- Department of Pathology, University of WashingtonSeattleUnited States
| | - Jeremy Whitson
- Department of Pathology, University of WashingtonSeattleUnited States
| | - Ying Sonia Ting
- Department of Genome Science, University of WashingtonSeattleUnited States
| | | | - Lindsay K Pino
- Department of Genome Science, University of WashingtonSeattleUnited States
| | - Ellen Quarles
- Department of Pathology, University of WashingtonSeattleUnited States
| | - Ngoc-Han Nguyen
- Department of Pathology, University of WashingtonSeattleUnited States
| | | | - Tong Zhang
- Biological Sciences Division, Pacific Northwest National LaboratoryRichlandUnited States
| | - Matthew J Gaffrey
- Biological Sciences Division, Pacific Northwest National LaboratoryRichlandUnited States
| | - Gennifer Merrihew
- Department of Genome Science, University of WashingtonSeattleUnited States
| | - Lu Wang
- Department of Environmental and Occupational Health Sciences, University of WashingtonSeattleUnited States
| | - Yongping Yue
- Department of Molecular Microbiology and Immunology, School of Medicine, University of MissouriColumbiaUnited States
| | - Dongsheng Duan
- Department of Molecular Microbiology and Immunology, School of Medicine, University of MissouriColumbiaUnited States
| | - Henk L Granzier
- Department of Cellular and Molecular Medicine, University of ArizonaTucsonUnited States
| | | | - Wei-Jun Qian
- Biological Sciences Division, Pacific Northwest National LaboratoryRichlandUnited States
| | - David Marcinek
- Department of Radiology, University of WashingtonSeattleUnited States
| | - Michael J MacCoss
- Department of Genome Science, University of WashingtonSeattleUnited States
| | - Peter Rabinovitch
- Department of Pathology, University of WashingtonSeattleUnited States
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Kumar M, Haghighi K, Kranias EG, Sadayappan S. Phosphorylation of cardiac myosin-binding protein-C contributes to calcium homeostasis. J Biol Chem 2020; 295:11275-11291. [PMID: 32554466 DOI: 10.1074/jbc.ra120.013296] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 06/17/2020] [Indexed: 12/13/2022] Open
Abstract
Cardiac myosin-binding protein-C (cMyBP-C) is highly phosphorylated under basal conditions. However, its phosphorylation level is decreased in individuals with heart failure. The necessity of cMyBP-C phosphorylation for proper contractile function is well-established, but the physiological and pathological consequences of decreased cMyBP-C phosphorylation in the heart are not clear. Herein, using intact adult cardiomyocytes from mouse models expressing phospho-ablated (AAA) and phosphomimetic (DDD) cMyBP-C as well as controls, we found that cMyBP-C dephosphorylation is sufficient to reduce contractile parameters and calcium kinetics associated with prolonged decay time of the calcium transient and increased diastolic calcium levels. Isoproterenol stimulation reversed the depressive contractile and Ca2+-kinetic parameters. Moreover, caffeine-induced calcium release yielded no difference between AAA/DDD and controls in calcium content of the sarcoplasmic reticulum. On the other hand, sodium-calcium exchanger function and phosphorylation levels of calcium-handling proteins were significantly decreased in AAA hearts compared with controls. Stress conditions caused increases in both spontaneous aftercontractions in AAA cardiomyocytes and the incidence of arrhythmias in vivo compared with the controls. Treatment with omecamtiv mecarbil, a positive cardiac inotropic drug, rescued the contractile deficit in AAA cardiomyocytes, but not the calcium-handling abnormalities. These findings indicate a cascade effect whereby cMyBP-C dephosphorylation causes contractile defects, which then lead to calcium-cycling abnormalities, resulting in aftercontractions and increased incidence of cardiac arrhythmias under stress conditions. We conclude that improvement of contractile deficits alone without improving calcium handling may be insufficient for effective management of heart failure.
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Affiliation(s)
- Mohit Kumar
- Heart, Lung, and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA.,Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Kobra Haghighi
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Evangelia G Kranias
- Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, USA
| | - Sakthivel Sadayappan
- Heart, Lung, and Vascular Institute, Division of Cardiovascular Health and Disease, Department of Internal Medicine, University of Cincinnati, Cincinnati, Ohio, USA .,Department of Pharmacology and Systems Physiology, University of Cincinnati, Cincinnati, Ohio, USA
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Reil JC, Reil GH, Kovács Á, Sequeira V, Waddingham MT, Lodi M, Herwig M, Ghaderi S, Kreusser MM, Papp Z, Voigt N, Dobrev D, Meyhöfer S, Langer HF, Maier LS, Linz D, Mügge A, Hohl M, Steendijk P, Hamdani N. CaMKII activity contributes to homeometric autoregulation of the heart: A novel mechanism for the Anrep effect. J Physiol 2020; 598:3129-3153. [PMID: 32394454 DOI: 10.1113/jp279607] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 05/04/2020] [Indexed: 01/14/2023] Open
Abstract
KEY POINTS The Anrep effect represents the alteration of left ventricular (LV) contractility to acutely enhanced afterload in a few seconds, thereby preserving stroke volume (SV) at constant preload. As a result of the missing preload stretch in our model, the Anrep effect differs from the slow force response and has a different mechanism. The Anrep effect demonstrated two different phases. First, the sudden increased afterload was momentary equilibrated by the enhanced LV contractility as a result of higher power strokes of strongly-bound myosin cross-bridges. Second, the slightly delayed recovery of SV is perhaps dependent on Ca2+ /calmodulin-dependent protein kinase II activation caused by oxidation and myofilament phosphorylation (cardiac myosin-binding protein-C, myosin light chain 2), maximizing the recruitment of available strongly-bound myosin cross-bridges. Short-lived oxidative stress might present a new facet of subcellular signalling with respect to cardiovascular regulation. Relevance for human physiology was demonstrated by echocardiography disclosing the Anrep effect in humans during handgrip exercise. ABSTRACT The present study investigated whether oxidative stress and Ca2+ /calmodulin-dependent protein kinase II (CaMKII) activity are involved in triggering the Anrep effect. LV pressure-volume (PV) analyses of isolated, preload controlled working hearts were performed at two afterload levels (60 and 100 mmHg) in C57BL/6N wild-type (WT) and CaMKII-double knockout mice (DKOCaMKII ). In snap-frozen WT hearts, force-pCa relationship, H2 O2 generation, CaMKII oxidation and phosphorylation of myofilament and Ca2+ handling proteins were assessed. Acutely raised afterload showed significantly increased wall stress, H2 O2 generation and LV contractility in the PV diagram with an initial decrease and recovery of stroke volume, whereas end-diastolic pressure and volume, as well as heart rate, remained constant. Afterload induced increase in LV contractility was blunted in DKOCaMKII -hearts. Force development of single WT cardiomyocytes was greater with elevated afterload at submaximal Ca2+ concentration and associated with increases in CaMKII oxidation and phosphorylation of cardiac-myosin binding protein-C, myosin light chain and Ca2+ handling proteins. CaMKII activity is involved in the regulation of the Anrep effect and associates with stimulation of oxidative stress, presumably starting a cascade of CaMKII oxidation with downstream phosphorylation of myofilament and Ca2+ handling proteins. These mechanisms improve LV inotropy and preserve stroke volume within few seconds.
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Affiliation(s)
- Jan-Christian Reil
- Klinik für Innere Medizin II, Kardiologie, Angiologie und Internistische Intensivmedizin, Universitäres Herzzentrum Lübeck, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Gert-Hinrich Reil
- Klinik für Kardiologie, Klinikum Oldenburg, Innere Medizin I, Oldenburg, Germany
| | - Árpád Kovács
- Institute of Physiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University of Bochum, Bochum, Germany.,Molecular and Experimental Cardiology, Ruhr Universität Bochum, Bochum, Germany
| | - Vasco Sequeira
- Comprehensive Heart Failure Center (CHFC), University Clinic Würzburg, Germany
| | - Mark T Waddingham
- Department of Physiology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Cardiovascular Sciences, Amsterdam, The Netherlands
| | - Maria Lodi
- Institute of Physiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University of Bochum, Bochum, Germany.,Molecular and Experimental Cardiology, Ruhr Universität Bochum, Bochum, Germany
| | - Melissa Herwig
- Institute of Physiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University of Bochum, Bochum, Germany.,Molecular and Experimental Cardiology, Ruhr Universität Bochum, Bochum, Germany
| | - Shahrooz Ghaderi
- Institute of Physiology, Ruhr University Bochum, Bochum, Germany
| | - Michael M Kreusser
- Departments of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Zoltán Papp
- Division of Clinical Physiology, Department of Cardiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Niels Voigt
- Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany.,Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Georg-August University Göttingen, Göttingen, Germany.,DZHK (German Center for Cardiovascular Research), partner site Göttingen, Göttingen, Germany
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
| | - Svenja Meyhöfer
- Institute for Endocrinology & Diabetes, University of Lübeck, Lübeck, Germany and German Center for Diabetes Research, Neuherberg, Germany
| | - Harald F Langer
- Klinik für Innere Medizin II, Kardiologie, Angiologie und Internistische Intensivmedizin, Universitäres Herzzentrum Lübeck, Universitätsklinikum Schleswig-Holstein, Campus Lübeck, Lübeck, Germany
| | - Lars S Maier
- Klinik und Poliklinik für innere Medizin II, Universitätsklinikum Regensburg, Regensburg, Germany
| | - Dominik Linz
- Klinik für Innere Medizin III (Kardiologie, Angiologie, Internistische Intensivmedizin), Universitätsklinikum des Saarlandes, Homburg/Saar, Germany
| | - Andreas Mügge
- Department of Cardiology, St. Josef-Hospital, Ruhr University of Bochum, Bochum, Germany.,Molecular and Experimental Cardiology, Ruhr Universität Bochum, Bochum, Germany
| | - Mathias Hohl
- Klinik für Innere Medizin III (Kardiologie, Angiologie, Internistische Intensivmedizin), Universitätsklinikum des Saarlandes, Homburg/Saar, Germany
| | - Paul Steendijk
- Departments of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Nazha Hamdani
- Institute of Physiology, Ruhr University Bochum, Bochum, Germany.,Department of Cardiology, St. Josef-Hospital, Ruhr University of Bochum, Bochum, Germany.,Molecular and Experimental Cardiology, Ruhr Universität Bochum, Bochum, Germany.,Department Clinical Pharmacology, Ruhr University of Bochum, Bochum, Germany
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46
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Methawasin M, Strom J, Borkowski T, Hourani Z, Runyan R, Smith JE, Granzier H. Phosphodiesterase 9a Inhibition in Mouse Models of Diastolic Dysfunction. Circ Heart Fail 2020; 13:e006609. [PMID: 32418479 DOI: 10.1161/circheartfailure.119.006609] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Low myocardial cGMP-PKG (cyclic guanosine monophosphate-protein kinase G) activity has been associated with increased cardiomyocyte diastolic stiffness in heart failure with preserved ejection fraction. Cyclic guanosine monophosphate is mainly hydrolyzed by PDE (phosphodiesterases) 5a and 9a. Importantly, PDE9a expression has been reported to be upregulated in human heart failure with preserved ejection fraction myocardium and chronic administration of a PDE9a inhibitor reverses preestablished cardiac hypertrophy and systolic dysfunction in mice subjected to transverse aortic constriction (TAC). We hypothesized that inhibiting PDE9a activity ameliorates diastolic dysfunction. METHODS To examine the effect of chronic PDE9a inhibition, 2 diastolic dysfunction mouse models were studied: (1) TAC-deoxycorticosterone acetate and (2) Leprdb/db. PDE9a inhibitor (5 and 8 mg/kg per day) was administered to the mice via subcutaneously implanted osmotic minipumps for 28 days. The effect of acute PDE9a inhibition was investigated in intact cardiomyocytes isolated from TAC-deoxycorticosterone acetate mice. Atrial natriuretic peptide together with PDE9a inhibitor were administered to the isolated intact cardiomyocytes through the cell perfusate. RESULTS For acute inhibition, no cellular stiffness reduction was found, whereas chronic PDE9a inhibition resulted in reduced left ventricular chamber stiffness in TAC-deoxycorticosterone acetate, but not in Leprdb/db mice. Passive cardiomyocyte stiffness was reduced by chronic PDE9a inhibition, with no differences in myocardial fibrosis or cardiac morphometry. PDE9a inhibition increased the ventricular-arterial coupling ratio, reflecting impaired systolic function. CONCLUSIONS Chronic PDE9a inhibition lowers left ventricular chamber stiffness in TAC-deoxycorticosterone acetate mice. However, the usefulness of PDE9a inhibition to treat high-diastolic stiffness may be limited as the required PDE9a inhibitor dose also impairs systolic function, observed as a decline in ventricular-arterial coordination, in this model.
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Affiliation(s)
- Mei Methawasin
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - Joshua Strom
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - Tomasz Borkowski
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - Zaynab Hourani
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - Ray Runyan
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - John E Smith
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
| | - Henk Granzier
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, University of Arizona, Tucson, AZ
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47
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Jiao L, Machuki JO, Wu Q, Shi M, Fu L, Adekunle AO, Tao X, Xu C, Hu X, Yin Z, Sun H. Estrogen and calcium handling proteins: new discoveries and mechanisms in cardiovascular diseases. Am J Physiol Heart Circ Physiol 2020; 318:H820-H829. [PMID: 32083972 DOI: 10.1152/ajpheart.00734.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Estrogen deficiency is considered to be an important factor leading to cardiovascular diseases (CVDs). Indeed, the prevalence of CVDs in postmenopausal women exceeds that of premenopausal women and men of the same age. Recent research findings provide evidence that estrogen plays a pivotal role in the regulation of calcium homeostasis and therefore fine-tunes normal cardiomyocyte contraction and relaxation processes. Disruption of calcium homeostasis is closely associated with the pathological mechanism of CVDs. Thus, this paper maps out and summarizes the effects and mechanisms of estrogen on calcium handling proteins in cardiac myocytes, including L-type Ca2+ channel, the sarcoplasmic reticulum Ca2+ release channel named ryanodine receptor, sarco(endo)plasmic reticulum Ca2+-ATPase, and sodium-calcium exchanger. In so doing, we provide theoretical and experimental evidence for the successful design of estrogen-based prevention and treatment therapies for CVDs.
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Affiliation(s)
- Lijuan Jiao
- Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | | | - Qi Wu
- Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Mingjin Shi
- Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Lu Fu
- Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | | | - Xi Tao
- Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Chenxi Xu
- Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xide Hu
- Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Zeyuan Yin
- Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Hong Sun
- Department of Physiology, Xuzhou Medical University, Xuzhou, Jiangsu, China
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48
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Napierski NC, Granger K, Langlais PR, Moran HR, Strom J, Touma K, Harris SP. A Novel "Cut and Paste" Method for In Situ Replacement of cMyBP-C Reveals a New Role for cMyBP-C in the Regulation of Contractile Oscillations. Circ Res 2020; 126:737-749. [PMID: 32078438 DOI: 10.1161/circresaha.119.315760] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE cMyBP-C (cardiac myosin-binding protein-C) is a critical regulator of heart contraction, but the mechanisms by which cMyBP-C affects actin and myosin are only partly understood. A primary obstacle is that cMyBP-C localization on thick filaments may be a key factor defining its interactions, but most in vitro studies cannot duplicate the unique spatial arrangement of cMyBP-C within the sarcomere. OBJECTIVE The goal of this study was to validate a novel hybrid genetic/protein engineering approach for rapid manipulation of cMyBP-C in sarcomeres in situ. METHODS AND RESULTS We designed a novel cut and paste approach for removal and replacement of cMyBP-C N'-terminal domains (C0-C7) in detergent-permeabilized cardiomyocytes from gene-edited Spy-C mice. Spy-C mice express a TEVp (tobacco etch virus protease) cleavage site and a SpyTag (st) between cMyBP-C domains C7 and C8. A cut is achieved using TEVp which cleaves cMyBP-C to create a soluble N'-terminal γC0C7 (endogenous [genetically encoded] N'-terminal domains C0 to C7 of cardiac myosin binding protein-C) fragment and an insoluble C'-terminal SpyTag-C8-C10 fragment that remains associated with thick filaments. Paste of new recombinant (r)C0C7 domains is achieved by a covalent bond formed between SpyCatcher (-sc; encoded at the C'-termini of recombinant proteins) and SpyTag. Results show that loss of γC0C7 reduced myofilament Ca2+ sensitivity and increased cross-bridge cycling (ktr) at submaximal [Ca2+]. Acute loss of γC0C7 also induced auto-oscillatory contractions at submaximal [Ca2+]. Ligation of rC0C7 (exogenous [recombinant] N'-terminal domains C0 to C7 of cardiac myosin binding protein-C)-sc returned pCa50 and ktr to control values and abolished oscillations, but phosphorylated (p)-rC0C7-sc did not completely rescue these effects. CONCLUSIONS We describe a robust new approach for acute removal and replacement of cMyBP-C in situ. The method revealed a novel role for cMyBP-C N'-terminal domains to damp sarcomere-driven contractile waves (so-called spontaneous oscillatory contractions). Because phosphorylated (p)-rC0C7-sc was less effective at damping contractile oscillations, results suggest that spontaneous oscillatory contractions may contribute to enhanced contractility in response to inotropic stimuli.
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Affiliation(s)
- Nathaniel C Napierski
- From the Department of Cellular and Molecular Medicine (N.C.N., K.G., H.R.M, J.S., S.P.H.), University of Arizona College of Medicine, Tucson
| | - Kevin Granger
- From the Department of Cellular and Molecular Medicine (N.C.N., K.G., H.R.M, J.S., S.P.H.), University of Arizona College of Medicine, Tucson
| | - Paul R Langlais
- Division of Endocrinology, Department of Medicine (P.R.L.), University of Arizona College of Medicine, Tucson
| | - Hannah R Moran
- From the Department of Cellular and Molecular Medicine (N.C.N., K.G., H.R.M, J.S., S.P.H.), University of Arizona College of Medicine, Tucson
| | - Joshua Strom
- From the Department of Cellular and Molecular Medicine (N.C.N., K.G., H.R.M, J.S., S.P.H.), University of Arizona College of Medicine, Tucson
| | | | - Samantha P Harris
- From the Department of Cellular and Molecular Medicine (N.C.N., K.G., H.R.M, J.S., S.P.H.), University of Arizona College of Medicine, Tucson
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49
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Defining decreased protein succinylation of failing human cardiac myofibrils in ischemic cardiomyopathy. J Mol Cell Cardiol 2019; 138:304-317. [PMID: 31836543 DOI: 10.1016/j.yjmcc.2019.11.159] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 11/23/2019] [Accepted: 11/27/2019] [Indexed: 12/20/2022]
Abstract
Succinylation is a post-translational modification of protein lysine residues with succinyl groups derived from succinyl CoA. Succinylation is considered a significant post-translational modification with the potential to impact protein function which is highly conserved across numerous species. The role of succinylation in the heart, especially in heart failure and myofibril mechanics, remains largely unexplored. Mechanical parameters were measured in myofibrils isolated from failing hearts of ischemic cardiomyopathy patients and non-failing donor controls. We employed mass spectrometry to quantify differential protein expression in myofibrils from failing ischemic cardiomyopathy hearts compared to non-failing hearts. In addition, we combined peptide enrichment by immunoprecipitation with liquid chromatography tandem mass spectrometry to quantitatively analyze succinylated lysine residues in these myofibrils. Several key parameters of sarcomeric mechanical interactions were altered in myofibrils isolated from failing ischemic cardiomyopathy hearts, including lower resting tension and a faster rate of activation. Of the 100 differentially expressed proteins, 46 showed increased expression in ischemic heart failure, while 54 demonstrated decreased expression in ischemic heart failure. Our quantitative succinylome analysis identified a total of 572 unique succinylated lysine sites located on 181 proteins, with 307 significantly changed succinylation events. We found that 297 succinyl-Lys demonstrated decreased succinylation on 104 proteins, while 10 residues demonstrated increased succinylation on 4 proteins. Investigating succinyl CoA generation, enzyme activity assays demonstrated that α-ketoglutarate dehydrogenase and succinate dehydrogenase activities were significantly decreased in ischemic heart failure. An activity assay for succinyl CoA synthetase demonstrated a significant increase in ischemic heart failure. Taken together, our findings support the hypothesis that succinyl CoA production is decreased and succinyl CoA turnover is increased in ischemic heart failure, potentially resulting in an overall decrease in the mitochondrial succinyl CoA pool, which may contribute to decreased myofibril protein succinylation in heart failure.
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Rosas PC, Warren CM, Creed HA, Trzeciakowski JP, Solaro RJ, Tong CW. Cardiac Myosin Binding Protein-C Phosphorylation Mitigates Age-Related Cardiac Dysfunction: Hope for Better Aging? JACC Basic Transl Sci 2019; 4:817-830. [PMID: 31998850 PMCID: PMC6978553 DOI: 10.1016/j.jacbts.2019.06.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 06/14/2019] [Accepted: 06/19/2019] [Indexed: 12/29/2022]
Abstract
Cardiac myosin binding protein-C (cMyBP-C) phosphorylation prevents aging-related cardiac dysfunction. We tested this hypothesis by aging genetic mouse models of hypophosphorylated cMyBP-C, wild-type equivalent, and phosphorylated-mimetic cMyBP-C for 18 to 20 months. Phosphorylated-mimetic cMyBP-C mice exhibited better survival, better preservation of systolic and diastolic functions, and unchanging wall thickness. Wild-type equivalent mice showed decreasing cMyBP-C phosphorylation along with worsening cardiac function and hypertrophy approaching those found in hypophosphorylated cMyBP-C mice. Intact papillary muscle experiments suggested that cMyBP-C phosphorylation increased cross-bridge detachment rates as the underlying mechanism. Thus, phosphorylating cMyBP-C is a novel mechanism with potential to treat aging-related cardiac dysfunction.
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Key Words
- 3SA, mutated 3 serines to 3 alanines to mimic hypophosphorylated cardiac myosin binding protein-C (S273A, S282A, and S302A)
- 3SD, mutated 3 serines to 3 aspartic acids to mimic phosphorylated cMyBP-C (S273D, S282D, and S302D)
- ANOVA, analysis of variance
- EF, ejection fraction
- HF, heart failure
- HFpEF, heart failure with preserved ejection fraction
- HOP, hydroxyproline
- LV, left ventricular
- aging
- cMyBP-C, cardiac myosin binding protein-C
- cTnI, cardiac troponin I
- cardiac myosin binding protein-C
- dyastolic dysfunction
- heart failure
- phosphorylation
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Affiliation(s)
- Paola C. Rosas
- Department of Physiology and Biophysics, Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Chad M. Warren
- Department of Physiology and Biophysics, Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Heidi A. Creed
- Department of Medical Physiology, Texas A and M University Health Science Center, College of Medicine, College Station, Texas
| | - Jerome P. Trzeciakowski
- Department of Medical Physiology, Texas A and M University Health Science Center, College of Medicine, College Station, Texas
| | - R. John Solaro
- Department of Physiology and Biophysics, Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Carl W. Tong
- Department of Medical Physiology, Texas A and M University Health Science Center, College of Medicine, College Station, Texas
- Catholic Health Initiatives-St. Joseph Health, Bryan, Texas
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