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Shi R, Reichardt M, Fiegle DJ, Küpfer LK, Czajka T, Sun Z, Salditt T, Dendorfer A, Seidel T, Bruegmann T. Contractility measurements for cardiotoxicity screening with ventricular myocardial slices of pigs. Cardiovasc Res 2023; 119:2469-2481. [PMID: 37934066 PMCID: PMC10651213 DOI: 10.1093/cvr/cvad141] [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: 11/08/2022] [Revised: 05/22/2023] [Accepted: 07/10/2023] [Indexed: 11/08/2023] Open
Abstract
AIMS Cardiotoxicity is one major reason why drugs do not enter or are withdrawn from the market. Thus, approaches are required to predict cardiotoxicity with high specificity and sensitivity. Ideally, such methods should be performed within intact cardiac tissue with high relevance for humans and detect acute and chronic side effects on electrophysiological behaviour, contractility, and tissue structure in an unbiased manner. Herein, we evaluate healthy pig myocardial slices and biomimetic cultivation setups (BMCS) as a new cardiotoxicity screening approach. METHODS AND RESULTS Pig left ventricular samples were cut into slices and spanned into BMCS with continuous electrical pacing and online force recording. Automated stimulation protocols were established to determine the force-frequency relationship (FFR), frequency dependence of contraction duration, effective refractory period (ERP), and pacing threshold. Slices generated 1.3 ± 0.14 mN/mm2 force at 0.5 Hz electrical pacing and showed a positive FFR and a shortening of contraction duration with increasing pacing rates. Approximately 62% of slices were able to contract for at least 6 days while showing stable ERP, contraction duration-frequency relationship, and preserved cardiac structure confirmed by confocal imaging and X-ray diffraction analysis. We used specific blockers of the most important cardiac ion channels to determine which analysis parameters are influenced. To validate our approach, we tested five drug candidates selected from the Comprehensive in vitro Proarrhythmia Assay list as well as acetylsalicylic acid and DMSO as controls in a blinded manner in three independent laboratories. We were able to detect all arrhythmic drugs and their respective mode of action on cardiac tissue including inhibition of Na+, Ca2+, and hERG channels as well as Na+/Ca2+ exchanger. CONCLUSION We systematically evaluate this approach for cardiotoxicity screening, which is of high relevance for humans and can be upscaled to medium-throughput screening. Thus, our approach will improve the predictive value and efficiency of preclinical cardiotoxicity screening.
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Affiliation(s)
- Runzhu Shi
- Institute for Cardiovascular Physiology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Göttingen, Germany
- International Research Training Group 1816, University Medical Center Göttingen, Göttingen, Germany
| | - Marius Reichardt
- Institute for Cardiovascular Physiology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Göttingen, Germany
- Institute for X-ray Physics, University of Göttingen, Göttingen, Germany
| | - Dominik J Fiegle
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Linda K Küpfer
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Titus Czajka
- Institute for X-ray Physics, University of Göttingen, Göttingen, Germany
| | - Zhengwu Sun
- Walter-Brendel-Centre of Experimental Medicine, Hospital of the University Munich, Munich, Germany
| | - Tim Salditt
- Institute for X-ray Physics, University of Göttingen, Göttingen, Germany
- Cluster of Excellence ‘Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells’ (MBExC), University of Göttingen, Göttingen, Germany
| | - Andreas Dendorfer
- Walter-Brendel-Centre of Experimental Medicine, Hospital of the University Munich, Munich, Germany
- German Centre of Cardiovascular Research (DZHK), Munich Heart Alliance, Munich, Germany
| | - Thomas Seidel
- Institute of Cellular and Molecular Physiology, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Tobias Bruegmann
- Institute for Cardiovascular Physiology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Göttingen, Germany
- Cluster of Excellence ‘Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells’ (MBExC), University of Göttingen, Göttingen, Germany
- German Center for Cardiovascular Research (DZHK), Partner site Göttingen, Göttingen, Germany
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2
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Liu J, Nie Y, Chaudhry M, Bai F, Chuang J, Sodhi K, Shapiro JI. The Redox-Sensitive Na/K-ATPase Signaling in Uremic Cardiomyopathy. Int J Mol Sci 2020; 21:ijms21041256. [PMID: 32069992 PMCID: PMC7072896 DOI: 10.3390/ijms21041256] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/10/2020] [Accepted: 02/10/2020] [Indexed: 02/07/2023] Open
Abstract
In recent years, Na/K-ATPase signaling has been implicated in different physiological and pathophysiological conditions, including cardiac hypertrophy and uremic cardiomyopathy. Cardiotonic steroids (CTS), specific ligands of Na/K-ATPase, regulate its enzymatic activity (at higher concentrations) and signaling function (at lower concentrations without significantly affecting its enzymatic activity) and increase reactive oxygen species (ROS) generation. On the other hand, an increase in ROS alone also regulates the Na/K-ATPase enzymatic activity and signaling function. We termed this phenomenon the Na/K-ATPase-mediated oxidant-amplification loop, in which oxidative stress regulates both the Na/K-ATPase activity and signaling. Most recently, we also demonstrated that this amplification loop is involved in the development of uremic cardiomyopathy. This review aims to evaluate the redox-sensitive Na/K-ATPase-mediated oxidant amplification loop and uremic cardiomyopathy.
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Affiliation(s)
- Jiang Liu
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA; (Y.N.); (M.C.); (F.B.)
- Correspondence:
| | - Ying Nie
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA; (Y.N.); (M.C.); (F.B.)
| | - Muhammad Chaudhry
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA; (Y.N.); (M.C.); (F.B.)
| | - Fang Bai
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA; (Y.N.); (M.C.); (F.B.)
| | - Justin Chuang
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA; (J.C.); (K.S.); (J.I.S.)
| | - Komal Sodhi
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA; (J.C.); (K.S.); (J.I.S.)
| | - Joseph I. Shapiro
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25755, USA; (J.C.); (K.S.); (J.I.S.)
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Meraviglia V, Bocchi L, Sacchetto R, Florio MC, Motta BM, Corti C, Weichenberger CX, Savi M, D'Elia Y, Rosato-Siri MD, Suffredini S, Piubelli C, Pompilio G, Pramstaller PP, Domingues FS, Stilli D, Rossini A. HDAC Inhibition Improves the Sarcoendoplasmic Reticulum Ca 2+-ATPase Activity in Cardiac Myocytes. Int J Mol Sci 2018; 19:ijms19020419. [PMID: 29385061 PMCID: PMC5855641 DOI: 10.3390/ijms19020419] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 01/23/2018] [Accepted: 01/29/2018] [Indexed: 02/06/2023] Open
Abstract
SERCA2a is the Ca2+ ATPase playing the major contribution in cardiomyocyte (CM) calcium removal. Its activity can be regulated by both modulatory proteins and several post-translational modifications. The aim of the present work was to investigate whether the function of SERCA2 can be modulated by treating CMs with the histone deacetylase (HDAC) inhibitor suberanilohydroxamic acid (SAHA). The incubation with SAHA (2.5 µM, 90 min) of CMs isolated from rat adult hearts resulted in an increase of SERCA2 acetylation level and improved ATPase activity. This was associated with a significant improvement of calcium transient recovery time and cell contractility. Previous reports have identified K464 as an acetylation site in human SERCA2. Mutants were generated where K464 was substituted with glutamine (Q) or arginine (R), mimicking constitutive acetylation or deacetylation, respectively. The K464Q mutation ameliorated ATPase activity and calcium transient recovery time, thus indicating that constitutive K464 acetylation has a positive impact on human SERCA2a (hSERCA2a) function. In conclusion, SAHA induced deacetylation inhibition had a positive impact on CM calcium handling, that, at least in part, was due to improved SERCA2 activity. This observation can provide the basis for the development of novel pharmacological approaches to ameliorate SERCA2 efficiency.
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Affiliation(s)
- Viviana Meraviglia
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Leonardo Bocchi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
| | - Roberta Sacchetto
- Department of Comparative Biomedicine and Food Science, University of Padova, 35020 Legnaro (Padova), Italy.
| | - Maria Cristina Florio
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Benedetta M Motta
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Corrado Corti
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Christian X Weichenberger
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Monia Savi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
| | - Yuri D'Elia
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Marcelo D Rosato-Siri
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Silvia Suffredini
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Chiara Piubelli
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Giulio Pompilio
- Vascular Biology and Regenerative Medicine Unit, Centro Cardiologico Monzino, IRCCS, 20138 Milano, Italy.
- Dipartimento di Scienze Cliniche e di Comunità, Università degli Studi di Milano, 20122 Milano, Italy.
| | - Peter P Pramstaller
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Francisco S Domingues
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
| | - Donatella Stilli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
| | - Alessandra Rossini
- Institute for Biomedicine, Eurac Research, 39100 Bolzano, Italy (affiliated institute of the University of Lübeck, 23562 Lübeck, Germany).
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Wang X, Liu J, Drummond CA, Shapiro JI. Sodium potassium adenosine triphosphatase (Na/K-ATPase) as a therapeutic target for uremic cardiomyopathy. Expert Opin Ther Targets 2017; 21:531-541. [PMID: 28338377 PMCID: PMC5590225 DOI: 10.1080/14728222.2017.1311864] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 03/23/2017] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Clinically, patients with significant reductions in renal function present with cardiovascular dysfunction typically termed, uremic cardiomyopathy. It is a progressive series of cardiac pathophysiological changes, including left ventricular diastolic dysfunction and hypertrophy (LVH) which sometimes progress to left ventricular dilation (LVD) and systolic dysfunction in the setting of chronic kidney disease (CKD). Uremic cardiomyopathy is almost ubiquitous in patients afflicted with end stage renal disease (ESRD). Areas covered: This article reviews recent epidemiology, pathophysiology of uremic cardiomyopathy and provide a board overview of Na/K-ATPase research with detailed discussion on the mechanisms of Na/K-ATPase/Src/ROS amplification loop. We also present clinical and preclinical evidences as well as molecular mechanism of this amplification loop in the development of uremic cardiomyopathy. A potential therapeutic peptide that targets on this loop is discussed. Expert opinion: Current clinical treatment for uremic cardiomyopathy remains disappointing. Targeting the ROS amplification loop mediated by the Na/K-ATPase signaling function may provide a novel therapeutic target for uremic cardiomyopathy and related diseases. Additional studies of Na/K-ATPase and other strategies that regulate this loop will lead to new therapeutics.
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Affiliation(s)
- Xiaoliang Wang
- a Joan C Edwards School of Medicine at Marshall University , Huntington , WV , United States
- b University of Toledo College of Medicine and Life Sciences , Toledo , OH , United States
| | - Jiang Liu
- a Joan C Edwards School of Medicine at Marshall University , Huntington , WV , United States
| | - Christopher A Drummond
- b University of Toledo College of Medicine and Life Sciences , Toledo , OH , United States
| | - Joseph I Shapiro
- a Joan C Edwards School of Medicine at Marshall University , Huntington , WV , United States
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Srikanthan K, Shapiro JI, Sodhi K. The Role of Na/K-ATPase Signaling in Oxidative Stress Related to Obesity and Cardiovascular Disease. Molecules 2016; 21:molecules21091172. [PMID: 27598118 PMCID: PMC5642908 DOI: 10.3390/molecules21091172] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 08/26/2016] [Accepted: 09/01/2016] [Indexed: 12/16/2022] Open
Abstract
Na/K-ATPase has been extensively studied for its ion pumping function, but, in the past several decades, has been identified as a scaffolding and signaling protein. Initially it was found that cardiotonic steroids (CTS) mediate signal transduction through the Na/K-ATPase and result in the generation of reactive oxygen species (ROS), which are also capable of initiating the signal cascade. However, in recent years, this Na/K-ATPase/ROS amplification loop has demonstrated significance in oxidative stress related disease states, including obesity, atherosclerosis, heart failure, uremic cardiomyopathy, and hypertension. The discovery of this novel oxidative stress signaling pathway, holds significant therapeutic potential for the aforementioned conditions and others that are rooted in ROS.
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Affiliation(s)
- Krithika Srikanthan
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA.
| | - Joseph I Shapiro
- Department of Medicine, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA.
| | - Komal Sodhi
- Department of Surgery, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV 25701, USA.
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6
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Shah PT, Martin R, Yan Y, Shapiro JI, Liu J. Carbonylation Modification Regulates Na/K-ATPase Signaling and Salt Sensitivity: A Review and a Hypothesis. Front Physiol 2016; 7:256. [PMID: 27445847 PMCID: PMC4923243 DOI: 10.3389/fphys.2016.00256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/11/2016] [Indexed: 01/01/2023] Open
Abstract
Na/K-ATPase signaling has been implicated in different physiological and pathophysiological conditions. Accumulating evidence indicates that oxidative stress not only regulates the Na/K-ATPase enzymatic activity, but also regulates its signaling and other functions. While cardiotonic steroids (CTS)-induced increase in reactive oxygen species (ROS) generation is an intermediate step in CTS-mediated Na/K-ATPase signaling, increase in ROS alone also stimulates Na/K-ATPase signaling. Based on literature and our observations, we hypothesize that ROS have biphasic effects on Na/K-ATPase signaling, transcellular sodium transport, and urinary sodium excretion. Oxidative modulation, in particular site specific carbonylation of the Na/K-ATPase α1 subunit, is a critical step in proximal tubular Na/K-ATPase signaling and decreased transcellular sodium transport leading to increases in urinary sodium excretion. However, once this system is overstimulated, the signaling, and associated changes in sodium excretion are blunted. This review aims to evaluate ROS-mediated carbonylation of the Na/K-ATPase, and its potential role in the regulation of pump signaling and sodium reabsorption in the renal proximal tubule (RPT).
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Affiliation(s)
- Preeya T Shah
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Rebecca Martin
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Yanling Yan
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Joseph I Shapiro
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
| | - Jiang Liu
- Department of Pharmacology, Physiology and Toxicology, Joan C. Edwards School of Medicine, Marshall University Huntington, WV, USA
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Sirenko SG, Maltsev VA, Yaniv Y, Bychkov R, Yaeger D, Vinogradova T, Spurgeon HA, Lakatta EG. Electrochemical Na+ and Ca2+ gradients drive coupled-clock regulation of automaticity of isolated rabbit sinoatrial nodal pacemaker cells. Am J Physiol Heart Circ Physiol 2016; 311:H251-67. [PMID: 27208164 DOI: 10.1152/ajpheart.00667.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 05/11/2016] [Indexed: 11/22/2022]
Abstract
Coupling of an intracellular Ca(2+) clock to surface membrane ion channels, i.e., a "membrane clock, " via coupling of electrochemical Na(+) and Ca(2+) gradients (ENa and ECa, respectively) has been theorized to regulate sinoatrial nodal cell (SANC) normal automaticity. To test this hypothesis, we measured responses of [Na(+)]i, [Ca(2+)]i, membrane potential, action potential cycle length (APCL), and rhythm in rabbit SANCs to Na(+)/K(+) pump inhibition by the digitalis glycoside, digoxigenin (DG, 10-20 μmol/l). Initial small but significant increases in [Na(+)]i and [Ca(2+)]i and reductions in ENa and ECa in response to DG led to a small reduction in maximum diastolic potential (MDP), significantly enhanced local diastolic Ca(2+) releases (LCRs), and reduced the average APCL. As [Na(+)]i and [Ca(2+)]i continued to increase at longer times following DG exposure, further significant reductions in MDP, ENa, and ECa occurred; LCRs became significantly reduced, and APCL became progressively and significantly prolonged. This was accompanied by increased APCL variability. We also employed a coupled-clock numerical model to simulate changes in ENa and ECa simultaneously with ion currents not measured experimentally. Numerical modeling predicted that, as the ENa and ECa monotonically reduced over time in response to DG, ion currents (ICaL, ICaT, If, IKr, and IbNa) monotonically decreased. In parallel with the biphasic APCL, diastolic INCX manifested biphasic changes; initial INCX increase attributable to enhanced LCR ensemble Ca(2+) signal was followed by INCX reduction as ENCX (ENCX = 3ENa - 2ECa) decreased. Thus SANC automaticity is tightly regulated by ENa, ECa, and ENCX via a complex interplay of numerous key clock components that regulate SANC clock coupling.
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Affiliation(s)
- Syevda G Sirenko
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Victor A Maltsev
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Yael Yaniv
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland; Biomedical Engineering Faculty, Technion-IIT, Haifa, Israel
| | - Rostislav Bychkov
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland; Universidad Central del Caribe, Santa Juanita, Bayamon Puerto Rico
| | - Daniel Yaeger
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Tatiana Vinogradova
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Harold A Spurgeon
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, National Institutes of Health, National Institute on Aging, Intramural Research Program, Baltimore, Maryland;
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8
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Yan Y, Shapiro JI. The physiological and clinical importance of sodium potassium ATPase in cardiovascular diseases. Curr Opin Pharmacol 2016; 27:43-9. [PMID: 26891193 PMCID: PMC5161351 DOI: 10.1016/j.coph.2016.01.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/14/2016] [Accepted: 01/29/2016] [Indexed: 12/14/2022]
Abstract
The Na/K-ATPase has been extensively studied, but it is only recently that its role as a scaffolding and signaling protein has been identified. It has been identified that cardiotonic steroids (CTS) such as digitalis mediate signal transduction through the Na/K-ATPase in a process found to result in the generation of reactive oxygen species (ROS). As these ROS also appear capable of initiating this signal cascade, a feed forward amplification process has been postulated and subsequently implicated in some disease pathways including uremic cardiomyopathy.
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Affiliation(s)
- Yanling Yan
- Joan C. Edwards School of Medicine, Marshall University, Department of Medicine, USA
| | - Joseph I Shapiro
- Joan C. Edwards School of Medicine, Marshall University, Department of Medicine, USA.
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Kennedy DJ, Shrestha K, Sheehey B, Li XS, Guggilam A, Wu Y, Finucan M, Gabi A, Medert CM, Westfall K, Borowski A, Fedorova O, Bagrov AY, Tang WHW. Elevated Plasma Marinobufagenin, An Endogenous Cardiotonic Steroid, Is Associated With Right Ventricular Dysfunction and Nitrative Stress in Heart Failure. Circ Heart Fail 2015; 8:1068-76. [PMID: 26276886 DOI: 10.1161/circheartfailure.114.001976] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Accepted: 08/05/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Plasma levels of cardiotonic steroids are elevated in volume-expanded states, such as chronic kidney disease, but the role of these natriuretic hormones in subjects with heart failure (HF) is unclear. We sought to determine the prognostic role of the cardiotonic steroids marinobufagenin (MBG) in HF, particularly in relation to long-term outcomes. METHODS AND RESULTS We first measured plasma MBG levels and performed comprehensive clinical, laboratory, and echocardiographic assessment in 245 patients with HF. All-cause mortality, cardiac transplantation, and HF hospitalization were tracked for 5 years. In our study cohort, median (interquartile range) MBG was 583 (383-812) pM. Higher MBG was associated with higher myeloperoxidase (r=0.42, P<0.0001), B-type natriuretic peptide (r=0.25, P=0.001), and asymmetrical dimethylarginine (r=0.32, P<0.001). Elevated levels of MBG were associated with measures of worse right ventricular function (RV s', r=-0.39, P<0.0001) and predicted increased risk of adverse clinical outcomes (MBG≥574 pmol/L: hazard ratio 1.58 [1.10-2.31], P=0.014) even after adjustment for age, sex, diabetes mellitus, and ischemic pathogenesis. In mice, a left anterior descending coronary artery ligation model of HF lead to increases in MBG, whereas infusion of MBG into mice for 4 weeks lead to significant increases in myeloperoxidase, asymmetrical dimethylarginine, and cardiac fibrosis. CONCLUSIONS In the setting of HF, elevated plasma levels of MBG are associated with right ventricular dysfunction and predict worse long-term clinical outcomes in multivariable models adjusting for established clinical and biochemical risk factors. Infusion of MBG seems to directly contribute to increased nitrative stress and cardiac fibrosis.
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Affiliation(s)
- David J Kennedy
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Kevin Shrestha
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Brendan Sheehey
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Xinmin S Li
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Anuradha Guggilam
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Yuping Wu
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Michael Finucan
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Alaa Gabi
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Charles M Medert
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Kristen Westfall
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Allen Borowski
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Olga Fedorova
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - Alexei Y Bagrov
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.)
| | - W H Wilson Tang
- From the Department of Cellular and Molecular Medicine (D.J.K., K.S., B.S., X.S.L., A.G., Y.W., M.F., A.G., C.M.M., K.W., A.B., W.H.W.T.), Center for Cardiovascular Diagnostics and Prevention, Lerner Research Institute (W.H.W.T.), Department of Nephrology and Hypertension, Glickman Urological and Kidney Institute (D.J.K.), and Department of Cardiovascular Medicine, Heart and Vascular Institute (W.H.W.T.), Cleveland Clinic, Cleveland, OH; and Laboratory of Cardiovascular Science, Hypertension Unit, National Institute on Aging, National Institutes of Health, Baltimore, MD (O.F., A.Y.B.).
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10
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The expression of Ubc9 and the intensity of SERCA2a-SUMOylation were reduced in diet-induced obese rats and partially restored by trimetazidine. J Cardiovasc Pharmacol 2015; 65:47-53. [PMID: 25329748 DOI: 10.1097/fjc.0000000000000162] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Reduced expression of sarcoplasmic reticulum calcium-transporting ATPase isoform 2a (SERCA2a) has been shown to play a significant role in the cardiac dysfunction of obese animal models. It was reported recently that SUMOylation enhances the stability and activity of SERCA2a. We hypothesized that SERCA2a-SUMOylation might be involved in obesity-mediated reduction of SERCA2a. METHOD AND RESULTS Trimetazidine (TMZ), the drug that inhibits fatty acid oxidation, was used in diet-induced obese (DIO) rats and palmitic acid (PA)-treated cardiomyocytes. The intensity of SERCA2a-SUMOylation and proteins involved in SERCA2a-SUMOylation were investigated in vivo and in vitro. DIO rats presented cardiac dysfunction, which was alleviated by TMZ treatment. Reductions of SERCA2a protein and the intensity of SERCA2a-SUMOylation were observed in DIO rats and PA-treated cardiomyocytes. These reductions were partially restored by TMZ. However, TMZ itself did not alter the intensity of SERCA2a-SUMOylation in control cardiomyocytes. The variations of protein and messenger RNA levels of Ubiquitin carrier protein 9 are in accordance with the intensity of SERCA2a-SUMOylation. Whereas the other proteins involved in SERCA2a-SUMOylation were not changed by DIO and PA. CONCLUSIONS TMZ alleviates the DIO- and PA-induced reductions of SERCA2a-SUMOylation. Ubiquitin carrier protein 9 is involved in the reductions.
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11
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A role for the sodium pump in H2O2-induced vasorelaxation in porcine isolated coronary arteries. Pharmacol Res 2014; 90:25-35. [PMID: 25258292 DOI: 10.1016/j.phrs.2014.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 09/08/2014] [Accepted: 09/14/2014] [Indexed: 01/17/2023]
Abstract
Hydrogen peroxide (H2O2) has been proposed to act as a factor for endothelium-derived hyperpolarization (EDH) and EDH may act as a 'back up' system to compensate the loss of the NO pathway. Here, the mechanism of action of H2O2 in porcine isolated coronary arteries (PCAs) was investigated. Distal PCAs were mounted in a wire myograph and pre-contracted with U46619 (1nM-50μM), a thromboxane A2-mimetic or KCl (60mM). Concentration-response curves to H2O2(1μM-1mM), bradykinin (0.01nM-1μM), sodium nitroprusside (SNP) (10nM-10μM), verapamil (1nM-10μM), KCl (0-20mM) or Ca(2+)-reintroduction (1μM-10mM) were constructed in the presence of various inhibitors. Activity of the Na(+)/K(+)-pump was measured through rubidium-uptake using atomic absorption spectrophotometry. H2O2 caused concentration-dependent vasorelaxations with a maximum relaxation (Rmax) of 100±16% (mean±SEM), pEC50=4.18±0.20 (n=4) which were significantly inhibited by PEG-catalase at 0.1-1.0mM H2O2 (P<0.05). 10mM TEA significantly inhibited the relaxation up to 100μM H2O2 (P<0.05). 60mM K(+) and 500nM ouabain significantly inhibited H2O2-induced vasorelaxation producing a relaxation of 40.8±8.5% (n=5) and 47.5±8.6% (n=6) respectively at 1mM H2O2 (P<0.0001). H2O2-induced vasorelaxation was unaffected by the removal of endothelium, inhibition of NO, cyclo-oxygenase, gap junctions, SKCa, IKCa, BKCa Kir, KV, KATP or cGMP. 100μM H2O2 had no effects on the KCl-induced vasorelaxation or Ca(2+)-reintroduction contraction. 1mM H2O2 inhibited both KCl-induced vasorelaxation and rubidium-uptake consistent with inhibition of the Na(+)/K(+)-pump activity. We have shown that the vascular actions of H2O2 are sensitive to ouabain and high concentrations of H2O2 are able to modulate the Na(+)/K(+)-pump. This may contribute towards its vascular actions.
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12
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Yan Y, Shapiro AP, Haller S, Katragadda V, Liu L, Tian J, Basrur V, Malhotra D, Xie ZJ, Abraham NG, Shapiro JI, Liu J. Involvement of reactive oxygen species in a feed-forward mechanism of Na/K-ATPase-mediated signaling transduction. J Biol Chem 2013; 288:34249-34258. [PMID: 24121502 DOI: 10.1074/jbc.m113.461020] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Cardiotonic steroids (such as ouabain) signaling through Na/K-ATPase regulate sodium reabsorption in the renal proximal tubule. We report here that reactive oxygen species are required to initiate ouabain-stimulated Na/K-ATPase·c-Src signaling. Pretreatment with the antioxidant N-acetyl-L-cysteine prevented ouabain-stimulated Na/K-ATPase·c-Src signaling, protein carbonylation, redistribution of Na/K-ATPase and sodium/proton exchanger isoform 3, and inhibition of active transepithelial (22)Na(+) transport. Disruption of the Na/K-ATPase·c-Src signaling complex attenuated ouabain-stimulated protein carbonylation. Ouabain-stimulated protein carbonylation is reversed after removal of ouabain, and this reversibility is largely independent of de novo protein synthesis and degradation by either the lysosome or the proteasome pathways. Furthermore, ouabain stimulated direct carbonylation of two amino acid residues in the actuator domain of the Na/K-ATPase α1 subunit. Taken together, the data indicate that carbonylation modification of the Na/K-ATPase α1 subunit is involved in a feed-forward mechanism of regulation of ouabain-mediated renal proximal tubule Na/K-ATPase signal transduction and subsequent sodium transport.
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Affiliation(s)
- Yanling Yan
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine at Marshall University, Huntington, West Virginia 25755; Institute of Biomedical Engineering, Yanshan University, Qinhuangdao 066004, China
| | - Anna P Shapiro
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Steven Haller
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Vinai Katragadda
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Lijun Liu
- Department of Pharmacology, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Jiang Tian
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614; Department of Pharmacology, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Venkatesha Basrur
- Department of Pathology, University of Michigan, Ann Arbor, Michigan 48109
| | - Deepak Malhotra
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Zi-Jian Xie
- Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614; Department of Pharmacology, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Nader G Abraham
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine at Marshall University, Huntington, West Virginia 25755
| | - Joseph I Shapiro
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine at Marshall University, Huntington, West Virginia 25755; Department of Medicine, University of Toledo College of Medicine, Toledo, Ohio 43614
| | - Jiang Liu
- Department of Pharmacology, Physiology and Toxicology, JCE School of Medicine at Marshall University, Huntington, West Virginia 25755.
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13
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Drummond CA, Buddny G, Haller ST, Liu J, Yan Y, Xie Z, Malhotra D, Shapiro JI, Tian J. Gender differences in the development of uremic cardiomyopathy following partial nephrectomy: Role of progesterone. ACTA ACUST UNITED AC 2013; 2. [PMID: 24404431 PMCID: PMC3880896 DOI: 10.4172/2167-1095.1000109] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Gender difference has been suggested as a risk factor for developing cardiovascular and renal diseases in humans and experimental animals. As a major sex hormone, progesterone was reported to compete with cardiotonic steroid binding to Na/K-ATPase. Our previous publication demonstrated that cardiotonic steroids (e.g., marinobufagenin) play an important role in the development of experimental uremic cardiomyopathy. We also observed that the putative mineralocorticoid antagonists, spironolactone and its major metabolite canrenone, antagonize binding of cardiotonic steroids to Na/K-ATPase in a competitive manner and also ameliorate experimental uremic cardiomyopathy induced by partial nephrectomy. In the following studies, we noted that progesterone displayed competitive inhibition of cardiotonic steroid binding to Na/K-ATPase and partially inhibited collagen synthesis induced by marinobufagenin in cultured cardiac fibroblasts. Therefore, we sought to examine whether female rats displayed less uremic cardiomyopathy than male rats when subjected to partial nephrectomy. Although partial nephrectomy caused the induction of smaller increases in blood pressure of female rats, they appeared to be similarly susceptible to cardiac remodeling induced by partial nephrectomy in terms of hypertrophy and fibrosis as age-matched male rats. The possible explanations for our findings are therefore discussed.
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Affiliation(s)
| | - George Buddny
- Department of Medicine, University of Toledo, Ohio, USA
| | | | - Jiang Liu
- Marshall University Joan C. Edwards School of Medicine, Huntington, WV, USA
| | - Yanling Yan
- Marshall University Joan C. Edwards School of Medicine, Huntington, WV, USA
| | - Zijian Xie
- Physiology/Pharmacology, University of Toledo College of Medicine, Toledo, OH, USA
| | | | - Joseph I Shapiro
- Marshall University Joan C. Edwards School of Medicine, Huntington, WV, USA
| | - Jiang Tian
- Department of Medicine, University of Toledo, Ohio, USA
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14
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Brüning CA, Prigol M, Luchese C, Pinton S, Nogueira CW. Diphenyl diselenide ameliorates behavioral and oxidative parameters in an animal model of mania induced by ouabain. Prog Neuropsychopharmacol Biol Psychiatry 2012; 38:168-74. [PMID: 22459096 DOI: 10.1016/j.pnpbp.2012.03.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 03/09/2012] [Accepted: 03/09/2012] [Indexed: 12/28/2022]
Abstract
Bipolar disorder (BD) is a common and severe mood disorder associated with higher rates of suicide and disability. Ouabain, a Na(+)/K(+)-ATPase inhibitor, induces behavioral changes in rats and has been used as a model of mania. The aim of this study was to investigate if diphenyl diselenide [(PhSe)(2)], an organoselenium compound with pharmacological properties, is effective against ouabain-induced hyperactivity and alterations in cerebral oxidative status of rats. Male Wistar rats were treated with a single dose of (PhSe)(2) (50 mg/kg, p.o.) 30 min before i.c.v. injection of ouabain (5 μl, 10(-5) M) or with the mood stabilizer, lithium chloride (LiCl) (45 mg/kg, p.o.), twice a day, for 7 days before the administration of ouabain. Open-field locomotion was quantified after ouabain administration. Thiobarbituric acid reactive substances (TBARS), oxidatively modified proteins, tyrosine nitration, ascorbic acid and non-protein thiols (NPSH) levels and superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) activities were determined in the whole brain. Ouabain increased locomotor activity in the open-field test and pretreatment with (PhSe)(2) or LiCl blocked this effect. In addition, ouabain increased lipid peroxidation and oxidatively modified proteins, demonstrated by a significant increase in TBARS levels and carbonyl content, which were attenuated by pretreatment with (PhSe)(2) or LiCl. The activities of SOD and CAT were increased by ouabain. LiCl was effective on preventing the increases of both enzyme activities, but (PhSe)(2) attenuated the ouabain effect in SOD activity. GPx and GR activities, ascorbic acid, NPSH and tyrosine nitration levels were not altered in all experimental groups. Similarly to LiCl, (PhSe)(2) produced an antimanic-like action, since it was effective against the locomotor hyperactivity elicited by ouabain. The results also indicated that (PhSe)(2) was effective against oxidative stress caused by ouabain in rats.
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Affiliation(s)
- César Augusto Brüning
- Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, CEP 97105-900, RS, Brazil
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15
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The novel antidote Bezoar Bovis prevents the cardiotoxicity of Toad (Bufo bufo gargarizans Canto) Venom in mice. ACTA ACUST UNITED AC 2012; 64:417-23. [DOI: 10.1016/j.etp.2010.10.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2010] [Revised: 10/10/2010] [Accepted: 10/18/2010] [Indexed: 11/29/2022]
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16
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Affiliation(s)
- Bina Joe
- Center for Hypertension and Personalized Medicine, University of Toledo College of Medicine and Life Sciences Toledo, OH (B.J., J.I.S.) ; Department of Physiology/Pharmacology, University of Toledo College of Medicine and Life Sciences Toledo, OH (B.J., J.I.S.)
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17
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Bapat A, Nguyen TP, Lee JH, Sovari AA, Fishbein MC, Weiss JN, Karagueuzian HS. Enhanced sensitivity of aged fibrotic hearts to angiotensin II- and hypokalemia-induced early afterdepolarization-mediated ventricular arrhythmias. Am J Physiol Heart Circ Physiol 2012; 302:H2331-40. [PMID: 22467308 DOI: 10.1152/ajpheart.00094.2012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Unlike young hearts, aged hearts are highly susceptible to early afterdepolarization (EAD)-mediated ventricular fibrillation (VF). This differential may result from age-related structural remodeling (fibrosis) or electrical remodeling of ventricular myocytes or both. We used optical mapping and microelectrode recordings in Langendorff-perfused hearts and patch-clamp recordings in isolated ventricular myocytes from aged (24-26 mo) and young (3-4 mo) rats to assess susceptibility to EADs and VF during either oxidative stress with ANG II (2 μM) or ionic stress with hypokalemia (2.7 mM). ANG II caused EAD-mediated VF in 16 of 19 aged hearts (83%) after 32 ± 7 min but in 0 of 9 young hearts (0%). ANG II-mediated VF was suppressed with KN-93 (Ca(2+)/calmodulin-dependent kinase inhibitor) and the reducing agent N-acetylcysteine. Hypokalemia caused EAD-mediated VF in 11 of 11 aged hearts (100%) after 7.4 ± 0.4 min. In 14 young hearts, however, VF did not occur in 6 hearts (43%) or was delayed in onset (31 ± 22 min, P < 0.05) in 8 hearts (57%). In patch-clamped myocytes, ANG II and hypokalemia (n = 6) induced EADs and triggered activity in both age groups (P = not significant) at a cycle length of >0.5 s. When myocytes of either age group were coupled to a virtual fibroblast using the dynamic patch-clamp technique, EADs arose in both groups at a cycle length of <0.5 s. Aged ventricles had significantly greater fibrosis and reduced connexin43 gap junction density compared with young hearts. The lack of differential age-related sensitivity at the single cell level in EAD susceptibility indicates that increased ventricular fibrosis in the aged heart plays a key role in increasing vulnerability to VF induced by oxidative and ionic stress.
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Affiliation(s)
- Aneesh Bapat
- Translational Arrhythmia Research Section, University of California-Los Angeles Cardiovascular Research Laboratory, USA
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18
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Reactive Oxygen Species Modulation of Na/K-ATPase Regulates Fibrosis and Renal Proximal Tubular Sodium Handling. Int J Nephrol 2012; 2012:381320. [PMID: 22518311 PMCID: PMC3299271 DOI: 10.1155/2012/381320] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Accepted: 11/07/2011] [Indexed: 01/11/2023] Open
Abstract
The Na/K-ATPase is the primary force regulating renal sodium handling and plays a key role in both ion homeostasis and blood pressure regulation. Recently, cardiotonic steroids (CTS)-mediated Na/K-ATPase signaling has been shown to regulate fibrosis, renal proximal tubule (RPT) sodium reabsorption, and experimental Dahl salt-sensitive hypertension in response to a high-salt diet. Reactive oxygen species (ROS) are an important modulator of nephron ion transport. As there is limited knowledge regarding the role of ROS-mediated fibrosis and RPT sodium reabsorption through the Na/K-ATPase, the focus of this review is to examine the possible role of ROS in the regulation of Na/K-ATPase activity, its signaling, fibrosis, and RPT sodium reabsorption.
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19
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Gan XT, Hunter JC, Huang C, Xue J, Rajapurohitam V, Javadov S, Karmazyn M. Ouabain increases iNOS-dependent nitric oxide generation which contributes to the hypertrophic effect of the glycoside: possible role of peroxynitrite formation. Mol Cell Biochem 2011; 363:323-33. [PMID: 22160804 DOI: 10.1007/s11010-011-1185-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 11/24/2011] [Indexed: 12/27/2022]
Abstract
In addition to inotropic effects, cardiac glycosides exert deleterious effects on the heart which limit their use for cardiac therapeutics. In this study, we determined the possible contribution of ouabain-induced iNOS stimulation to the resultant hypertrophic as well as cytotoxic effects of the glycoside on cultured adult rat ventricular myocytes. Myocytes were treated with ouabain (50 μM) for up to 24 h. Ouabain significantly increased gene and protein levels of inducible nitric oxide synthase (iNOS) which was associated with significantly increased release of NO from myocytes as well as increased total release of reactive oxygen species (ROS), superoxide anion (O(2) (-)), and increased peroxynitrite formation as assessed by protein tyrosine nitration. Administration of ouabain was also associated with increased levels of myocyte toxicity as determined by myocyte morphology, trypan blue staining and lactate dehydrogenase (LDH) efflux. The nonspecific NOS inhibitor Nω-nitro-L: -arginine methyl ester and the more selective iNOS inhibitor 1400W both abrogated the increase in LDH release but had no significant effect on either morphology or trypan blue staining. Ouabain also significantly increased both myocyte surface area and expression of atrial natriuretic peptide indicating a hypertrophic response with both parameters being completely prevented by NOS inhibition. The effects of iNOS inhibitors were associated with diminished ouabain tyrosine nitration as well as abrogation of ouabain-induced p38 and ERK phosphorylation. Our study shows that ouabain is a potent inducer of NO formation, iNOS upregulation, and increased production of ROS. Inhibition of ouabain-dependent peroxynitrite formation may contribute to the antihypertrophic effect of iNOS inhibition possibly by preventing downstream MAPK activation.
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MESH Headings
- Animals
- Cardiotonic Agents/toxicity
- Cell Shape/drug effects
- Cells, Cultured
- Dose-Response Relationship, Drug
- Enzyme Induction
- Enzyme Inhibitors/pharmacology
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Hypertrophy, Left Ventricular/chemically induced
- Hypertrophy, Left Ventricular/enzymology
- Hypertrophy, Left Ventricular/pathology
- L-Lactate Dehydrogenase/metabolism
- Male
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/pathology
- Nitric Oxide/metabolism
- Nitric Oxide Synthase Type II/antagonists & inhibitors
- Nitric Oxide Synthase Type II/genetics
- Nitric Oxide Synthase Type II/metabolism
- Ouabain/toxicity
- Peroxynitrous Acid/metabolism
- Phosphorylation
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Signal Transduction/drug effects
- Superoxides/metabolism
- Time Factors
- Tyrosine/analogs & derivatives
- Tyrosine/metabolism
- Up-Regulation
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Xiaohong Tracey Gan
- Department of Physiology & Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5C1, Canada
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20
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Ho HT, Stevens SCW, Terentyeva R, Carnes CA, Terentyev D, Györke S. Arrhythmogenic adverse effects of cardiac glycosides are mediated by redox modification of ryanodine receptors. J Physiol 2011; 589:4697-708. [PMID: 21807619 DOI: 10.1113/jphysiol.2011.210005] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The therapeutic use of cardiac glycosides (CGs), agents commonly used in treating heart failure (HF), is limited by arrhythmic toxicity. The adverse effects of CGs have been attributed to excessive accumulation of intracellular Ca(2+) resulting from inhibition of Na(+)/K(+)-ATPase ion transport activity. However, CGs are also known to increase intracellular reactive oxygen species (ROS), which could contribute to arrhythmogenesis through redox modification of cardiac ryanodine receptors (RyR2s). Here we sought to determine whether modification of RyR2s by ROS contributes to CG-dependent arrhythmogenesis and examine the relevant sources of ROS. In isolated rat ventricular myocytes, the CG digitoxin (DGT) increased the incidence of arrhythmogenic spontaneous Ca(2+) waves, decreased the sarcoplasmic reticulum (SR) Ca(2+) load, and increased both ROS and RyR2 thiol oxidation. Additionally, pretreatment with DGT increased spark frequency in permeabilized myocytes. These effects on Ca(2+) waves and sparks were prevented by the antioxidant N-(2-mercaptopropionyl) glycine (MPG). The CG-dependent increases in ROS, RyR2 oxidation and arrhythmogenic propensity were reversed by inhibitors of NADPH oxidase, mitochondrial ATP-dependent K(+) channels (mito-K(ATP)) or permeability transition pore (PTP), but not by inhibition of xanthine oxidase. These results suggest that the arrhythmogenic adverse effects of CGs involve alterations in RyR2 function caused by oxidative changes in the channel structure by ROS. These CG-dependent effects probably involve release of ROS from mitochondria possibly mediated by NADPH oxidase.
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Affiliation(s)
- Hsiang-Ting Ho
- Davis Heart and Lung Research Institute, The Ohio State University Medical Centre, 473 W. 12th Avenue, Columbus, OH 43210, USA
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Morita N, Lee JH, Bapat A, Fishbein MC, Mandel WJ, Chen PS, Weiss JN, Karagueuzian HS. Glycolytic inhibition causes spontaneous ventricular fibrillation in aged hearts. Am J Physiol Heart Circ Physiol 2011; 301:H180-91. [PMID: 21478408 DOI: 10.1152/ajpheart.00128.2011] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Selective glycolytic inhibition (GI) promotes electromechanical alternans and triggered beats in isolated cardiac myocytes. We sought to determine whether GI promotes triggered activity by early afterdepolarization (EAD) or delayed afterdepolarizations in intact hearts isolated from adult and aged rats. Dual voltage and intracellular calcium ion (Ca(i)(2+)) fluorescent optical maps and single cell glass microelectrode recordings were made from the left ventricular (LV) epicardium of isolated Langendorff-perfused adult (∼4 mo) and aged (∼24 mo) rat hearts. GI was induced by replacing glucose with 10 mM pyruvate in oxygenated Tyrode's. Within 20 min, GI slowed Ca(i)(2+) transient decline rate and shortened action potential duration in both groups. These changes were associated with ventricular fibrillation (VF) in the aged hearts (64 out of 66) but not in adult hearts (0 out of 18; P < 0.001). VF was preceded by a transient period of focal ventricular tachycardia caused by EAD-mediated triggered activity leading to VF within seconds. The VF was suppressed by the ATP-sensitive K (K(ATP)) channel blocker glibenclamide (1 μM) but not (0 out of 7) by mitochondrial K(ATP) block. The Ca-calmodulin-dependent protein kinase II (CaMKII) blocker KN-93 (1 μM) prevented GI-mediated VF (P < 0.05). Block of Na-Ca exchanger (NCX) by SEA0400 (2 μM) prevented GI-mediated VF (3 out of 6), provided significant bradycardia did not occur. Aged hearts had significantly greater LV fibrosis and reduced connexin 43 than adult hearts (P < 0.05). We conclude that in aged fibrotic unlike in adult rat hearts, GI promotes EADs, triggered activity, and VF by activation of K(ATP) channels CaMKII and NCX.
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Affiliation(s)
- Norishige Morita
- Translational Arrhythmia Research Section, Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 675 Charles E. Young Dr. South, MRL 3645 Mail Code: 176022, Los Angeles, CA 90095, USA
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22
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Saini-Chohan HK, Goyal RK, Dhalla NS. Involvement of sarcoplasmic reticulum in changing intracellular calcium due to Na+/K+-ATPase inhibition in cardiomyocytes. Can J Physiol Pharmacol 2010; 88:702-15. [PMID: 20651818 DOI: 10.1139/y10-055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Earlier studies have demonstrated that ouabain-induced increase in [Ca2+]i, as a consequence of sarcolemma (SL) Na+/K+-ATPase inhibition, is associated with activation of both the SL Na+/Ca2+ exchanger and SL Ca2+ channels. In view of the importance of sarcoplasmic reticulum (SR) in the regulation of [Ca2+]i, this study examined the role of SR in ouabain-induced increase in [Ca2+]i in both quiescent and KCl-depolarized cardiomyocytes. For this purpose, adult rat cardiomyocytes were loaded with fura-2 and ouabain-induced changes in [Ca2+]i were monitored upon treatment with or without different agents that are known to influence Ca2+ handling by the intracellular organelles. Ouabain not only increased the basal [Ca2+]i and augmented KCl-induced increase in [Ca2+]i but also produced similar effects on the ATP-induced increase in [Ca2+]i. Treatments of cardiomyocytes with caffeine, ryanodine, or cyclopiazonic acid, which affect SR Ca2+ stores, attenuated the ouabain-induced increase in basal Ca2+ as well as augmentation of the KCl response. Both ryanodine and cyclopiazonic acid produced additional effects, when used in combination with a SL Ca2+ channel inhibitor (verapamil), but not with a Na+/Ca2+ exchange inhibitor (KB-R7943). Inhibitors of Ca2+/calmodulin kinase, protein kinase A, and inositol-3-phosphate receptors were also observed to depress the ouabain-induced increase in [Ca2+]i in cardiomyocytes. On the other hand, mitochondrial Ca2+ transport inhibitors did not exert any effect on the ouabain-induced alterations in [Ca2+]i in cardiomyocytes. Furthermore, ouabain did not show any direct effect on the Ca2+ uptake and Ca2+ release activities of SR or mitochondria. These results suggest an indirect involvement of SR Ca2+ stores in the ouabain-induced increase in [Ca2+]i in cardiomyocytes and indicate the participation of both Ca2+-induced Ca2+ release and regulatory mechanisms in this action.
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Affiliation(s)
- Harjot K Saini-Chohan
- Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, University of Manitoba, Winnipeg, MB R2H 2A6, Canada
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Brocardo PS, Budni J, Pavesi E, Franco JL, Uliano-Silva M, Trevisan R, Terenzi MG, Dafre AL, Rodrigues ALS. Folic acid administration prevents ouabain-induced hyperlocomotion and alterations in oxidative stress markers in the rat brain. Bipolar Disord 2010; 12:414-24. [PMID: 20636639 DOI: 10.1111/j.1399-5618.2010.00827.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
OBJECTIVE Bipolar disorder (BD) is a chronic, prevalent, and highly debilitating psychiatric illness. Folic acid has been shown to have antidepressant-like effects in preclinical and clinical studies and has also been suggested to play a role in BD. The present work investigates the therapeutic value of folic acid supplementation in a preclinical animal model of mania induced by ouabain. METHODS Male Wistar rats were treated twice daily for seven days with folic acid (10, 50, and 100 mg/kg, p.o.) or the mood stabilizer lithium chloride (LiCl) (45 mg/kg, p.o.). One day after the last dose was given, the animals received an i.c.v. injection of ouabain (10 microM), a Na(+),K(+)-ATPase-inhibiting compound. Locomotor activity was assessed in the open-field test. Thiobarbituric acid-reactive substance (TBARS) levels, glutathione peroxidase (GPx), and glutathione reductase (GR) activities were measured in the cerebral cortex and hippocampus. RESULTS Ouabain (10 microM, i.c.v.) significantly increased motor activity in the open-field test, and seven days of pretreatment with folic acid (50 mg/kg, p.o.) or LiCl (45 mg/kg, p.o.) completely prevented this effect. Ouabain treatment elicited lipid peroxidation (increased TBARS levels) and reduced GPx activity in the hippocampus. GR activity was decreased in the cerebral cortex and hippocampus. These effects were prevented by pretreatment with folic acid and LiCl. CONCLUSIONS Our results show that folic acid, similarly to LiCl, produces a clear antimanic action and prevents the neurochemical alterations indicative of oxidative stress in an animal model of mania.
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Affiliation(s)
- Patrícia S Brocardo
- Department of Biochemistry, Centre of Biological Sciences, Federal University of Santa Catarina, Campus Universitario, Trindade, Florianopolis, Santa Catarina, Brazil
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Morita N, Sovari AA, Xie Y, Fishbein MC, Mandel WJ, Garfinkel A, Lin SF, Chen PS, Xie LH, Chen F, Qu Z, Weiss JN, Karagueuzian HS. Increased susceptibility of aged hearts to ventricular fibrillation during oxidative stress. Am J Physiol Heart Circ Physiol 2009; 297:H1594-605. [PMID: 19767530 DOI: 10.1152/ajpheart.00579.2009] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Oxidative stress with hydrogen peroxide (H(2)O(2)) readily promotes early afterdepolarizations (EADs) and triggered activity (TA) in isolated rat and rabbit ventricular myocytes. Here we examined the effects of H(2)O(2) on arrhythmias in intact Langendorff rat and rabbit hearts using dual-membrane voltage and intracellular calcium optical mapping and glass microelectrode recordings. Young adult rat (3-5 mo, N = 25) and rabbit (3-5 mo, N = 6) hearts exhibited no arrhythmias when perfused with H(2)O(2) (0.1-2 mM) for up to 3 h. However, in 33 out of 35 (94%) aged (24-26 mo) rat hearts, 0.1 mM H(2)O(2) caused EAD-mediated TA, leading to ventricular tachycardia (VT) and fibrillation (VF). Aged rabbits (life span, 8-12 yr) were not available, but 4 of 10 middle-aged rabbits (3-5 yr) developed EADs, TA, VT, and VF. These arrhythmias were suppressed by the reducing agent N-acetylcysteine (2 mM) and CaMKII inhibitor KN-93 (1 microM) but not by its inactive form (KN-92, 1 microM). There were no significant differences between action potential duration (APD) or APD restitution slope before or after H(2)O(2) in aged or young adult rat hearts. In histological sections, however, trichrome staining revealed that aged rat hearts exhibited extensive fibrosis, ranging from 10-90%; middle-aged rabbit hearts had less fibrosis (5-35%), whereas young adult rat and rabbit hearts had <4% fibrosis. In aged rat hearts, EADs and TA arose most frequently (70%) from the left ventricular base where fibrosis was intermediate ( approximately 30%). Computer simulations in two-dimensional tissue incorporating variable degrees of fibrosis showed that intermediate (but not mild or severe) fibrosis promoted EADs and TA. We conclude that in aged ventricles exposed to oxidative stress, fibrosis facilitates the ability of cellular EADs to emerge and generate TA, VT, and VF at the tissue level.
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Affiliation(s)
- Norishige Morita
- Translational Arrhythmia Research Laboratory and Cardiovascular Research Laboratory, Division of Cardiology, Department of Medicine, David Geffen School of Medicine at University of California, Los Angeles, USA
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Singh P, Salih M, Tuana BS. Alpha-kinase anchoring protein alphaKAP interacts with SERCA2A to spatially position Ca2+/calmodulin-dependent protein kinase II and modulate phospholamban phosphorylation. J Biol Chem 2009; 284:28212-28221. [PMID: 19671701 DOI: 10.1074/jbc.m109.044990] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The sarco-endoplasmic reticulum calcium ATPase 2a (SERCA2a) is critical for sequestering cytosolic calcium into the sarco-endoplasmic reticulum (SR) and regulating cardiac muscle relaxation. Protein-protein interactions indicated that it exists in complex with Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) and its anchoring protein alphaKAP. Confocal imaging of isolated cardiomyocytes revealed the colocalization of CAMKII and alphaKAP with SERCA2a at the SR. Deletion analysis indicated that SERCA2a and CaMKII bind to different regions in the association domain of alphaKAP but not with each other. Although deletion of the putative N-terminal hydrophobic amino acid stretch in alphaKAP prevented its membrane targeting, it did not influence binding to SERCA2a or CaMKII. Both CaMKIIdelta(C) and the novel CaMKIIbeta(4) isoforms were found to exist in complex with alphaKAP and SERCA2a at the SR and were able to phosphorylate Thr-17 on phospholamban (PLN), an accessory subunit and known regulator of SERCA2a activity. Interestingly, the presence of alphaKAP was also found to significantly modulate the Ca(2+)/calmodulin-dependent phosphorylation of Thr-17 on PLN. These data demonstrate that alphaKAP exhibits a novel interaction with SERCA2a and may serve to spatially position CaMKII isoforms at the SR and to uniquely modulate the phosphorylation of PLN.
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Affiliation(s)
- Puneet Singh
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Maysoon Salih
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Balwant S Tuana
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada.
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Bagrov AY, Shapiro JI, Fedorova OV. Endogenous cardiotonic steroids: physiology, pharmacology, and novel therapeutic targets. Pharmacol Rev 2009; 61:9-38. [PMID: 19325075 PMCID: PMC2763610 DOI: 10.1124/pr.108.000711] [Citation(s) in RCA: 384] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Endogenous cardiotonic steroids (CTS), also called digitalis-like factors, have been postulated to play important roles in health and disease for nearly half a century. Recent discoveries, which include the specific identification of endogenous cardenolide (endogenous ouabain) and bufadienolide (marinobufagenin) CTS in humans along with the delineation of an alternative mechanism by which CTS can signal through the Na(+)/K(+)-ATPase, have increased the interest in this field substantially. Although CTS were first considered important in the regulation of renal sodium transport and arterial pressure, more recent work implicates these hormones in the regulation of cell growth, differentiation, apoptosis, and fibrosis, the modulation of immunity and of carbohydrate metabolism, and the control of various central nervous functions and even behavior. This review focuses on the physiological interactions between CTS and other regulatory systems that may be important in the pathophysiology of essential hypertension, preeclampsia, end-stage renal disease, congestive heart failure, and diabetes mellitus. Based on our increasing understanding of the regulation of CTS as well as the molecular mechanisms of these hormone increases, we also discuss potential therapeutic strategies.
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Affiliation(s)
- Alexei Y Bagrov
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, 5600 Nathan Shock Dr., Baltimore, MD 21224, USA.
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Schoner W, Scheiner-Bobis G. Role of endogenous cardiotonic steroids in sodium homeostasis. Nephrol Dial Transplant 2008; 23:2723-9. [PMID: 18556748 DOI: 10.1093/ndt/gfn325] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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Li Z, Xie Z. The Na/K-ATPase/Src complex and cardiotonic steroid-activated protein kinase cascades. Pflugers Arch 2008; 457:635-44. [DOI: 10.1007/s00424-008-0470-0] [Citation(s) in RCA: 145] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2007] [Revised: 01/24/2008] [Accepted: 01/29/2008] [Indexed: 01/01/2023]
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Li D, Yang C, Chen Y, Tian J, Liu L, Dai Q, Wan X, Xie Z. Identification of a PKCε-dependent regulation of myocardial contraction by epicatechin-3-gallate. Am J Physiol Heart Circ Physiol 2008; 294:H345-53. [DOI: 10.1152/ajpheart.00785.2007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
In this study, the effects of tea catechins and tea theaflavins on myocardial contraction were examined in isolated rat hearts using a Langendorff-perfusion system. We found that both tea catechins and theaflavins had positive inotropic effects on the myocardium. Of the tested chemicals, epicatechin-3-gallate (ECG) and theaflavin-3,3′-digallate (TF4) appear to be the most effective tea catechin and theaflavin, respectively. Further studies of ECG-induced positive inotropy revealed the following insights. First, unlike digitalis drugs, ECG had no effect on intracellular Ca2+ level in cultured adult cardiac myocytes. Second, it activated PKCε, but not PKCα, in the isolated hearts as well as in cultured cells. Neither a phospholipase C (PLC) inhibitor ( U73122) nor the antioxidant N-acetyl cysteine (NAC) affected the ECG-induced activation of PKCε. Third, inhibition of PKCε by either chelerythrine chloride (CHE) or PKCε translocation inhibitor peptide (TIP) caused a partial reduction of ECG-induced increases in myocardial contraction. Moreover, NAC was also effective in reducing the effects of ECG on myocardial contraction. Finally, pretreatment of the heart with both CHE and NAC completely abolished ECG-induced inotropic effects on the heart. Together, these findings indicate that ECG can regulate myocardial contractility via a novel PKCε-dependent signaling pathway.
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Pasdois P, Quinlan CL, Rissa A, Tariosse L, Vinassa B, Costa ADT, Pierre SV, Dos Santos P, Garlid KD. Ouabain protects rat hearts against ischemia-reperfusion injury via pathway involving src kinase, mitoKATP, and ROS. Am J Physiol Heart Circ Physiol 2006; 292:H1470-8. [PMID: 17098831 DOI: 10.1152/ajpheart.00877.2006] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We showed recently that mitochondrial ATP-dependent K(+) channel (mitoK(ATP)) opening is required for the inotropic response to ouabain. Because mitoK(ATP) opening is also required for most forms of cardioprotection, we investigated whether exposure to ouabain was cardioprotective. We also began to map the signaling pathways linking ouabain binding to Na(+)-K(+)-ATPase with the opening of mitoK(ATP). In Langendorff-perfused rat hearts, 10-80 microM ouabain given before the onset of ischemia resulted in cardioprotection against ischemia-reperfusion injury, as documented by an improved recovery of contractile function and a reduction of infarct size. In skinned cardiac fibers, a ouabain-induced protection of mitochondrial outer membrane integrity, adenine nucleotide compartmentation, and energy transfer efficiency was evidenced by a decreased release of cytochrome c and preserved half-saturation constant of respiration for ADP and adenine nucleotide translocase-mitochondrial creatine kinase coupling, respectively. Ouabain-induced positive inotropy was dose dependent over the range studied, whereas ouabain-induced cardioprotection was maximal at the lowest dose tested. Compared with bradykinin (BK)-induced preconditioning, ouabain was equally efficient. However, the two ligands clearly diverge in the intracellular steps leading to mitoK(ATP) opening from their respective receptors. Thus BK-induced cardioprotection was blocked by inhibitors of cGMP-dependent protein kinase (PKG) or guanylyl cyclase (GC), whereas ouabain-induced protection was not blocked by either agent. Interestingly, however, ouabain-induced inotropy appears to require PKG and GC. Thus 5-hydroxydecanoate (a selective mitoK(ATP) inhibitor), N-(2-mercaptopropionyl)glycine (MPG; a reactive oxygen species scavenger), ODQ (a GC inhibitor), PP2 (a src kinase inhibitor), and KT-5823 (a PKG inhibitor) abolished preconditioning by BK and blocked the inotropic response to ouabain. However, only PP2, 5-HD, and MPG blocked ouabain-induced cardioprotection.
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Affiliation(s)
- Philippe Pasdois
- Institut National de la Santé et de la Recherche, Médicale U441, University Victor Segalen-Bordeaux 2, University Hospital of Bordeaux, Bordeaux, France
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