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Jin X, Meletiou A, Chung J, Tilunaite A, Demydenko K, Dries E, Puertas RD, Amoni M, Tomar A, Claus P, Soeller C, Rajagopal V, Sipido K, Roderick HL. InsP 3R-RyR channel crosstalk augments sarcoplasmic reticulum Ca 2+ release and arrhythmogenic activity in post-MI pig cardiomyocytes. J Mol Cell Cardiol 2023; 179:47-59. [PMID: 37003353 DOI: 10.1016/j.yjmcc.2023.03.015] [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: 11/17/2022] [Revised: 03/08/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023]
Abstract
Ca2+ transients (CaT) underlying cardiomyocyte (CM) contraction require efficient Ca2+ coupling between sarcolemmal Ca2+ channels and sarcoplasmic reticulum (SR) ryanodine receptor Ca2+ channels (RyR) for their generation; reduced coupling in disease contributes to diminished CaT and arrhythmogenic Ca2+ events. SR Ca2+ release also occurs via inositol 1,4,5-trisphosphate receptors (InsP3R) in CM. While this pathway contributes negligeably to Ca2+ handling in healthy CM, rodent studies support a role in altered Ca2+ dynamics and arrhythmogenic Ca2+ release involving InsP3R crosstalk with RyRs in disease. Whether this mechanism persists in larger mammals with lower T-tubular density and coupling of RyRs is not fully resolved. We have recently shown an arrhythmogenic action of InsP3-induced Ca2+ release (IICR) in end stage human heart failure, often associated with underlying ischemic heart disease (IHD). How IICR contributes to early stages of disease is however not determined but highly relevant. To access this stage, we chose a porcine model of IHD, which shows substantial remodelling of the area adjacent to the infarct. In cells from this region, IICR preferentially augmented Ca2+ release from non-coupled RyR clusters that otherwise showed delayed activation during the CaT. IICR in turn synchronised Ca2+ release during the CaT but also induced arrhythmogenic delayed afterdepolarizations and action potentials. Nanoscale imaging identified co-clustering of InsP3Rs and RyRs, thereby allowing Ca2+-mediated channel crosstalk. Mathematical modelling supported and further delineated this mechanism of enhanced InsP3R-RyRs coupling in MI. Our findings highlight the role of InsP3R-RyR channel crosstalk in Ca2+ release and arrhythmia during post-MI remodelling.
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Affiliation(s)
- Xin Jin
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Anna Meletiou
- Department of Physiology, University of Bern, Bern, Switzerland
| | - Joshua Chung
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium; Cell Structure and Mechanobiology Group, Department of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Australia
| | - Agne Tilunaite
- Cell Structure and Mechanobiology Group, Department of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Australia; Systems Biology Laboratory, School of Mathematics and Statistics, and Department of Biomedical Engineering, University of Melbourne, Australia
| | - Kateryna Demydenko
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Eef Dries
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Rosa Doñate Puertas
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Matthew Amoni
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Ashutosh Tomar
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - Piet Claus
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | | | - Vijay Rajagopal
- Cell Structure and Mechanobiology Group, Department of Biomedical Engineering, Melbourne School of Engineering, University of Melbourne, Australia
| | - Karin Sipido
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium
| | - H Llewelyn Roderick
- KU Leuven, Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, B-3000 Leuven, Belgium.
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Jin X, Amoni M, Gilbert G, Dries E, Doñate Puertas R, Tomar A, Nagaraju CK, Pradhan A, Yule DI, Martens T, Menten R, Vanden Berghe P, Rega F, Sipido K, Roderick HL. InsP 3R-RyR Ca 2+ channel crosstalk facilitates arrhythmias in the failing human ventricle. Basic Res Cardiol 2022; 117:60. [PMID: 36378362 DOI: 10.1007/s00395-022-00967-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/13/2022] [Accepted: 10/31/2022] [Indexed: 11/16/2022]
Abstract
Dysregulated intracellular Ca2+ handling involving altered Ca2+ release from intracellular stores via RyR channels underlies both arrhythmias and reduced function in heart failure (HF). Mechanisms linking RyR dysregulation and disease are not fully established. Studies in animals support a role for InsP3 receptor Ca2+ channels (InsP3R) in pathological alterations in cardiomyocyte Ca2+ handling but whether these findings translate to the divergent physiology of human cardiomyocytes during heart failure is not determined. Using electrophysiological and Ca2+ recordings in human ventricular cardiomyocytes, we uncovered that Ca2+ release via InsP3Rs facilitated Ca2+ release from RyR and induced arrhythmogenic delayed after depolarisations and action potentials. InsP3R-RyR crosstalk was particularly increased in HF at RyR clusters isolated from the T-tubular network. Reduced SERCA activity in HF further facilitated the action of InsP3. Nanoscale imaging revealed co-localisation of InsP3Rs with RyRs in the dyad, which was increased in HF, providing a mechanism for augmented Ca2+ channel crosstalk. Notably, arrhythmogenic activity dependent on InsP3Rs was increased in tissue wedges from failing hearts perfused with AngII to promote InsP3 generation. These data indicate a central role for InsP3R-RyR Ca2+ signalling crosstalk in the pro-arrhythmic action of GPCR agonists elevated in HF and the potential for their therapeutic targeting.
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Affiliation(s)
- Xin Jin
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium.,Department of Internal Medicine, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Matthew Amoni
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Guillaume Gilbert
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Eef Dries
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Rosa Doñate Puertas
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Ashutosh Tomar
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Chandan K Nagaraju
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Ankit Pradhan
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - David I Yule
- Department of Pharmacology and Physiology, Medical Center School of Medicine and Dentistry, University of Rochester, 601 Elmwood Avenue, Box 711, Rochester, NY, 14642, USA
| | - Tobie Martens
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, 3000, Leuven, Belgium.,Cell and Tissue Imaging Cluster (CIC), KU Leuven, 3000, Leuven, Belgium
| | - Roxane Menten
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - Pieter Vanden Berghe
- Laboratory for Enteric NeuroScience (LENS), Translational Research Center for Gastrointestinal Disorders (TARGID), KU Leuven, 3000, Leuven, Belgium.,Cell and Tissue Imaging Cluster (CIC), KU Leuven, 3000, Leuven, Belgium
| | - Filip Rega
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium.,Department of Cardiology and Department of Cardiac Surgery, University Hospitals Leuven, Leuven, Belgium
| | - Karin Sipido
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium
| | - H Llewelyn Roderick
- Department of Cardiovascular Sciences, Laboratory of Experimental Cardiology, KU Leuven, 3000, Leuven, Belgium.
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Coscarella IL, Landim-Vieira M, Pinto JR, Chelko SP. Arrhythmogenic Cardiomyopathy: Exercise Pitfalls, Role of Connexin-43, and Moving beyond Antiarrhythmics. Int J Mol Sci 2022; 23:ijms23158753. [PMID: 35955883 PMCID: PMC9369094 DOI: 10.3390/ijms23158753] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 07/28/2022] [Accepted: 08/03/2022] [Indexed: 12/11/2022] Open
Abstract
Arrhythmogenic Cardiomyopathy (ACM), a Mendelian disorder that can affect both left and right ventricles, is most often associated with pathogenic desmosomal variants that can lead to fibrofatty replacement of the myocardium, a pathological hallmark of this disease. Current therapies are aimed to prevent the worsening of disease phenotypes and sudden cardiac death (SCD). Despite the use of implantable cardioverter defibrillators (ICDs) there is no present therapy that would mitigate the loss in electrical signal and propagation by these fibrofatty barriers. Recent studies have shown the influence of forced vs. voluntary exercise in a variety of healthy and diseased mice; more specifically, that exercised mice show increased Connexin-43 (Cx43) expression levels. Fascinatingly, increased Cx43 expression ameliorated the abnormal electrical signal conduction in the myocardium of diseased mice. These findings point to a major translational pitfall in current therapeutics for ACM patients, who are advised to completely cease exercising and already demonstrate reduced Cx43 levels at the myocyte intercalated disc. Considering cardiac dysfunction in ACM arises from the loss of cardiomyocytes and electrical signal conduction abnormalities, an increase in Cx43 expression-promoted by low to moderate intensity exercise and/or gene therapy-could very well improve cardiac function in ACM patients.
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Affiliation(s)
- Isabella Leite Coscarella
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32303, USA
| | - Maicon Landim-Vieira
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32303, USA
| | - José Renato Pinto
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32303, USA
| | - Stephen P. Chelko
- Department of Biomedical Sciences, Florida State University College of Medicine, Tallahassee, FL 32303, USA
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21215, USA
- Correspondence: ; Tel.: +1-850-644-2215
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Ronchi C, Badone B, Bernardi J, Zaza A. Action Potential Prolongation, β-Adrenergic Stimulation, and Angiotensin II as Co-factors in Sarcoplasmic Reticulum Instability. Front Physiol 2019; 9:1893. [PMID: 30687114 PMCID: PMC6333690 DOI: 10.3389/fphys.2018.01893] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 12/14/2018] [Indexed: 12/26/2022] Open
Abstract
Introduction: Increases in action potential duration (APD), genetic or acquired, and arrhythmias are often associated; nonetheless, the relationship between the two phenomena is inconstant, suggesting coexisting factors. β-adrenergic activation increases sarcoplasmic reticulum (SR) Ca2+-content; angiotensin II (ATII) may increase cytosolic Ca2+ and ROS production, all actions stimulating RyRs opening. Here we test how APD interacts with β-adrenergic and AT-receptor stimulation in facilitating spontaneous Ca2+ release events (SCR). Methods: Under “action potential (AP) clamp”, guinea-pig cardiomyocytes (CMs) were driven with long (200 ms), normal (150 ms), and short (100 ms) AP waveforms at a CL of 500 ms; in a subset of CMs, all the 3 waveforms could be tested within the same cell. SCR were detected as inward current transients (ITI) following repolarization; ITI incidence and repetition within the same cycle were measured under increasing isoprenaline concentration ([ISO]) alone, or plus 100 nM ATII (30 min incubation+superfusion). Results: ITI incidence and repetition increased with [ISO]; at longer APs the [ISO]-response curve was shifted upward and ITI coupling interval was reduced. ATII increased ITI incidence more at low [ISO] and under normal (as compared to long) APs. Efficacy of AP shortening in suppressing ITI decreased in ATII-treated myocytes and at higher [ISO]. Conclusions: AP prolongation sensitized the SR to the destabilizing actions of ISO and ATII. Summation of ISO, ATII and AP duration effects had a “saturating” effect on SCR incidence, thus suggesting convergence on a common factor (RyRs stability) “reset” by the occurrence of spontaneous Ca2+ release events.
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Affiliation(s)
- Carlotta Ronchi
- Laboratory of Cardiac Cellular Physiology, Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Beatrice Badone
- Laboratory of Cardiac Cellular Physiology, Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Joyce Bernardi
- Laboratory of Cardiac Cellular Physiology, Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Antonio Zaza
- Laboratory of Cardiac Cellular Physiology, Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
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Schiemann R, Lammers K, Janz M, Lohmann J, Paululat A, Meyer H. Identification and In Vivo Characterisation of Cardioactive Peptides in Drosophila melanogaster. Int J Mol Sci 2018; 20:ijms20010002. [PMID: 30577424 PMCID: PMC6337577 DOI: 10.3390/ijms20010002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 11/22/2018] [Indexed: 12/23/2022] Open
Abstract
Neuropeptides and peptide hormones serve as critical regulators of numerous biological processes, including development, growth, reproduction, physiology, and behaviour. In mammals, peptidergic regulatory systems are complex and often involve multiple peptides that act at different levels and relay to different receptors. To improve the mechanistic understanding of such complex systems, invertebrate models in which evolutionarily conserved peptides and receptors regulate similar biological processes but in a less complex manner have emerged as highly valuable. Drosophila melanogaster represents a favoured model for the characterisation of novel peptidergic signalling events and for evaluating the relevance of those events in vivo. In the present study, we analysed a set of neuropeptides and peptide hormones for their ability to modulate cardiac function in semi-intact larval Drosophila melanogaster. We identified numerous peptides that significantly affected heart parameters such as heart rate, systolic and diastolic interval, rhythmicity, and contractility. Thus, peptidergic regulation of the Drosophila heart is not restricted to chronotropic adaptation but also includes inotropic modulation. By specifically interfering with the expression of corresponding peptides in transgenic animals, we assessed the in vivo relevance of the respective peptidergic regulation. Based on the functional conservation of certain peptides throughout the animal kingdom, the identified cardiomodulatory activities may be relevant not only to proper heart function in Drosophila, but also to corresponding processes in vertebrates, including humans.
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Affiliation(s)
- Ronja Schiemann
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Kay Lammers
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Maren Janz
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Jana Lohmann
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Achim Paululat
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
| | - Heiko Meyer
- Department of Zoology and Developmental Biology, University of Osnabrück, Barbarastraße 11, 49076 Osnabrück, Germany.
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Single therapeutic and supratherapeutic doses of sacubitril/valsartan (LCZ696) do not affect cardiac repolarization. Eur J Clin Pharmacol 2016; 72:917-24. [PMID: 27083930 PMCID: PMC4942489 DOI: 10.1007/s00228-016-2062-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/10/2016] [Indexed: 12/11/2022]
Abstract
Purpose Sacubitril/valsartan (LCZ696) is a first-in-class angiotensin receptor neprilysin inhibitor (ARNI) indicated to reduce the risk of cardiovascular death and hospitalization for heart failure in patients with chronic heart failure (NYHA class II–IV) and reduced ejection fraction. This study was aimed to evaluate the effect of single oral therapeutic (400 mg) and supratherapeutic (1200 mg) doses of LCZ696 on cardiac repolarization. Method This randomized double-blind crossover study in healthy male subjects compared the effect of therapeutic and supratherapeutic doses of LCZ696 with placebo and moxifloxacin 400 mg (open-label treatment) as positive control. The primary assessment was mean baseline- and placebo-corrected QTcF (∆∆QTcF; Fridericia correction). Additional assessments included the ∆∆QTcB (Bazett’s correction), PR interval, QRS duration, heart rate (HR), LCZ696 pharmacokinetics, pharmacokinetic/pharmacodynamic relationships, and safety. Results Of the 84 subjects enrolled, 81 completed the study. The maximum upper bound of the two-sided 90 % confidence interval for ∆∆QTcF for LCZ696 400 mg and 1200 mg were <10 ms, and assay sensitivity was confirmed with moxifloxacin. No relevant treatment-emergent changes were observed in any of the ECG-derived parameters with LCZ696 or placebo, and the incidence of adverse events was comparable among the treatment groups. Conclusion Single therapeutic and supratherapeutic doses of LCZ696 did not affect cardiac repolarization as defined by the E14 ICH guidelines. Electronic supplementary material The online version of this article (doi:10.1007/s00228-016-2062-9) contains supplementary material, which is available to authorized users.
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Modulation of the QT interval duration in hypertension with antihypertensive treatment. Hypertens Res 2015; 38:447-54. [DOI: 10.1038/hr.2015.30] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 10/27/2014] [Accepted: 11/12/2014] [Indexed: 11/08/2022]
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Matus M, Kucerova D, Kruzliak P, Adameova A, Doka G, Turcekova K, Kmecova J, Kyselovic J, Krenek P, Kirchhefer U, Mueller FU, Boknik P, Klimas J. Upregulation of SERCA2a following short-term ACE inhibition (by enalaprilat) alters contractile performance and arrhythmogenicity of healthy myocardium in rat. Mol Cell Biochem 2015; 403:199-208. [PMID: 25663023 DOI: 10.1007/s11010-015-2350-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2014] [Accepted: 01/30/2015] [Indexed: 12/12/2022]
Abstract
Chronic angiotensin-converting enzyme inhibitor (ACEIs) treatment can suppress arrhythmogenesis. To examine whether the effect is more immediate and independent of suppression of pathological remodelling, we tested the antiarrhythmic effect of short-term ACE inhibition in healthy normotensive rats. Wistar rats were administered with enalaprilat (ENA, i.p., 5 mg/kg every 12 h) or vehicle (CON) for 2 weeks. Intraarterial blood pressure in situ was measured in A. carotis. Cellular shortening was measured in isolated, electrically paced cardiomyocytes. Standard 12-lead electrocardiography was performed, and hearts of anaesthetized open-chest rats were subjected to 6-min ischemia followed by 10-min reperfusion to examine susceptibility to ventricular arrhythmias. Expressions of calcium-regulating proteins (SERCA2a, cardiac sarco/endoplasmic reticulum Ca(2+)-ATPase; CSQ, calsequestrin; TRD, triadin; PLB, phospholamban; Thr(17)-PLB-phosphorylated PLB at threonine-17, FKBP12.6, FK506-binding protein, Cav1.2-voltage-dependent L-type calcium channel alpha 1C subunit) were measured by Western blot; mRNA levels of L-type calcium channel (Cacna1c), ryanodine receptor (Ryr2) and potassium channels Kcnh2 and Kcnq1 were measured by qRT-PCR. ENA decreased intraarterial systolic as well as diastolic blood pressure (by 20%, and by 31%, respectively, for both P < 0.05) but enhanced shortening of cardiomyocytes at basal conditions (by 34%, P < 0.05) and under beta-adrenergic stimulation (by 73%, P < 0.05). Enalaprilat shortened QTc interval duration (CON 78 ± 1 ms vs. ENA 72 ± 2 ms; P < 0.05) and significantly decreased the total duration of ventricular fibrillations (VF) and the number of VF episodes (P < 0.05). Reduction in arrhythmogenesis was associated with a pronounced upregulation of SERCA2a (CON 100 ± 20 vs. ENA 304 ± 13; P < 0.05) and complete absence of basal Ca(2+)/calmodulin-dependent phosphorylation of PLB at Thr(17). Short-term ACEI treatment can provide protection against I/R injury-induced ventricular arrhythmias in healthy myocardium, and this effect is associated with increased SERCA2a expression.
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MESH Headings
- Angiotensin-Converting Enzyme Inhibitors/pharmacology
- Animals
- Arrhythmias, Cardiac/complications
- Arrhythmias, Cardiac/diagnostic imaging
- Arrhythmias, Cardiac/physiopathology
- Blotting, Western
- Calcium Channels, L-Type/genetics
- Calcium Channels, L-Type/metabolism
- Cell Separation
- Electrolytes/blood
- Enalaprilat/administration & dosage
- Enalaprilat/pharmacology
- Heart Ventricles/drug effects
- Heart Ventricles/pathology
- Heart Ventricles/physiopathology
- Isoproterenol/pharmacology
- Male
- Myocardial Contraction/drug effects
- Myocardium/enzymology
- Myocardium/pathology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Organ Size/drug effects
- Potassium Channels/genetics
- Potassium Channels/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats, Wistar
- Reperfusion Injury/complications
- Reperfusion Injury/pathology
- Reperfusion Injury/physiopathology
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
- Ultrasonography
- Up-Regulation/drug effects
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Affiliation(s)
- Marek Matus
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Bratislava, Slovak Republic
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Aldi S, Marino A, Tomita K, Corti F, Anand R, Olson KE, Marcus AJ, Levi R. E-NTPDase1/CD39 modulates renin release from heart mast cells during ischemia/reperfusion: a novel cardioprotective role. FASEB J 2014; 29:61-9. [PMID: 25318477 DOI: 10.1096/fj.14-261867] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Ischemia/reperfusion (I/R) elicits renin release from cardiac mast cells (MC), thus activating a local renin-angiotensin system (RAS), culminating in ventricular fibrillation. We hypothesized that in I/R, neurogenic ATP could degranulate juxtaposed MC and that ecto-nucleoside triphosphate diphosphohydrolase 1/CD39 (CD39) on MC membrane could modulate ATP-induced renin release. We report that pharmacological inhibition of CD39 in a cultured human mastocytoma cell line (HMC-1) and murine bone marrow-derived MC with ARL67156 (100 µM) increased ATP-induced renin release (≥2-fold), whereas purinergic P2X7 receptors (P2X7R) blockade with A740003 (3 µM) prevented it. Likewise, CD39 RNA silencing in HMC-1 increased ATP-induced renin release (≥2-fold), whereas CD39 overexpression prevented it. Acetaldehyde, an I/R product (300 µM), elicited an 80% increase in ATP release from HMC-1, in turn, causing an autocrine 20% increase in renin release. This effect was inhibited or potentiated when CD39 was overexpressed or silenced, respectively. Moreover, P2X7R silencing prevented ATP- and acetaldehyde-induced renin release. I/R-induced RAS activation in ex vivo murine hearts, characterized by renin and norepinephrine overflow and ventricular fibrillation, was potentiated (∼2-fold) by CD39 inhibition, an effect prevented by P2X7R blockade. Our data indicate that by regulating ATP availability at the MC surface, CD39 modulates local renin release and thus, RAS activation, ultimately exerting a cardioprotective effect.
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Affiliation(s)
| | | | | | | | - Ranjini Anand
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, New York, USA; and Thrombosis Research Laboratory, Veterans Affairs New York Harbor Healthcare System, New York, New York, USA
| | - Kim E Olson
- Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, New York, USA; and Thrombosis Research Laboratory, Veterans Affairs New York Harbor Healthcare System, New York, New York, USA
| | - Aaron J Marcus
- Pathology and Laboratory Medicine and Division of Hematology and Medical Oncology, Department of Medicine, Weill Cornell Medical College, New York, New York, USA; and Thrombosis Research Laboratory, Veterans Affairs New York Harbor Healthcare System, New York, New York, USA
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Doménech M, Berruezo A, Molina I, Mont L, Coca A. La presión arterial ambulatoria nocturna se asocia al remodelado auricular y la activación neurohormonal en pacientes con fibrilación auricular idiopática. Rev Esp Cardiol 2013. [DOI: 10.1016/j.recesp.2012.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Nighttime ambulatory blood pressure is associated with atrial remodelling and neurohormonal activation in patients with idiopathic atrial fibrillation. ACTA ACUST UNITED AC 2013; 66:458-63. [PMID: 24776048 DOI: 10.1016/j.rec.2012.11.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 11/28/2012] [Indexed: 11/20/2022]
Abstract
INTRODUCTION AND OBJECTIVES Hypertension is a risk factor for atrial fibrillation. Activation of the renin-angiotensin-system seems to be involved in atrial enlargement, with release of atrial and brain natriuretic peptides. The aim of this study was to evaluate the relationship between ambulatory blood pressure and levels of natriuretic peptides, with left atrial size in normotensives with idiopathic atrial fibrillation. METHODS This was a cross-sectional study in patients with idiopathic atrial fibrillation. The following measurements were recorded during the course of the study: office and 24-h ambulatory blood pressure, atrial and brain natriuretic peptides, plasma renin, aldosterone, and angiotensin-converting enzyme. RESULTS Forty-eight patients (mean age 55 [10] years; 70.6% male) were included in the study. Mean office sitting blood pressure values were 132.49 (14.9)/80.96 (9.2) mmHg. Mean 24-h ambulatory systolic and diastolic blood pressure values were 121.10 (8.3)/72.11 (6.8) mmHg (daytime, 126.8 [9.7]/77.58 [7.9] mmHg; nighttime, 114.56 [11.6]/68.6 [8.8] mmHg). A clear trend towards increased left atrial size with higher ambulatory blood pressure values was noted, which was statistically significant for nighttime values (r=0.34; P=.020 for systolic and r=0.51; p=.0001 for diastolic). A significant correlation between atrial natriuretic peptide and nighttime systolic (r=0.297; P=.047) and diastolic (r=0.312; P=.037) blood pressure was observed. Significant correlations were also observed between left atrial size and atrial natriuretic peptide levels (r=0.577; p<.0001) and brain natriuretic peptide levels (r=0.379; P=.012). CONCLUSIONS Nighttime blood pressure is associated with left atrial size and the release of natriuretic peptides in normotensive patients with idiopathic atrial fibrillation.
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Blanco RR, Austin H, Vest RN, Valadri R, Li W, Lassegue B, Song Q, London B, Dudley SC, Bloom HL, Searles CD, Zafari AM. Angiotensin receptor type 1 single nucleotide polymorphism 1166A/C is associated with malignant arrhythmias and altered circulating miR-155 levels in patients with chronic heart failure. J Card Fail 2012; 18:717-23. [PMID: 22939041 DOI: 10.1016/j.cardfail.2012.06.531] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 06/12/2012] [Accepted: 06/21/2012] [Indexed: 01/22/2023]
Abstract
BACKGROUND Sudden cardiac death (SCD) from ventricular tachyarrhythmias accounts for approximately 450,000 annual deaths in the United States; many of these cases involve patients with chronic heart failure (HF). Prediction of which HF patients are most susceptible to SCD is difficult, and it is uncertain whether gene polymorphisms associated with HF outcomes are also linked to arrhythmic risk. METHODS We evaluated 485 patients with chronic HF to see whether the angiotensin receptor type 1 (AT1R) 1166A/C or angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphisms were associated with a higher rate of ventricular arrhythmias requiring implantable cardioverter defibrillator (ICD) therapies over a 5-year period. We assessed the correlation between polymorphisms and antitachycardia pacing (ATP) and/or ICD shocks. RESULTS Patients with AT1R-1166CC genotype had an increased rate of all events: ATP plus ICD shocks (P = .02). There was no association between ACE I/D genotype and ICD therapies. Furthermore, circulating levels of microRNA-155 (miR-155), a microRNA known to posttranscriptionally regulate AT1R expression, were significantly decreased in the CC compared with the AC and AA genotypes and were associated with ICD events. CONCLUSION Our study suggests that the AT1R-1166CC genotype is associated with increased ICD therapies in patients with chronic HF, and the level of circulating miR-155 may be a potential marker for arrhythmic risk. Although these findings are novel, they will need replication and validation in larger cohorts of chronic HF patients.
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Affiliation(s)
- Raul R Blanco
- Emory University School of Medicine, Atlanta, GA, USA
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Reid AC, Brazin JA, Morrey C, Silver RB, Levi R. Targeting cardiac mast cells: pharmacological modulation of the local renin-angiotensin system. Curr Pharm Des 2012; 17:3744-52. [PMID: 22103845 DOI: 10.2174/138161211798357908] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 07/12/2011] [Accepted: 09/07/2011] [Indexed: 11/22/2022]
Abstract
Enhanced production of angiotensin II and excessive release of norepinephrine in the ischemic heart are major causes of arrhythmias and sudden cardiac death. Mast cell-dependent mechanisms are pivotal in the local formation of angiotensin II and modulation of norepinephrine release in cardiac pathophysiology. Cardiac mast cells increase in number in myocardial ischemia and are located in close proximity to sympathetic neurons expressing angiotensin AT1- and histamine H3-receptors. Once activated, cardiac mast cells release a host of potent pro-inflammatory and pro-fibrotic cytokines, chemokines, preformed mediators (e.g., histamine) and proteases (e.g., renin). In myocardial ischemia, angiotensin II (formed locally from mast cell-derived renin) and histamine (also released from local mast cells) respectively activate AT1- and H3-receptors on sympathetic nerve endings. Stimulation of angiotensin AT1-receptors is arrhythmogenic whereas H3-receptor activation is cardioprotective. It is likely that in ischemia/reperfusion the balance may be tipped toward the deleterious effects of mast cell renin, as demonstrated in mast cell-deficient mice, lacking mast cell renin and histamine in the heart. In these mice, no ventricular fibrillation occurs at reperfusion following ischemia, as opposed to wild-type hearts which all fibrillate. Preventing mast cell degranulation in the heart and inhibiting the activation of a local renin-angiotensin system, hence abolishing its detrimental effects on cardiac rhythmicity, appears to be more significant than the loss of histamine-induced cardioprotection. This suggests that therapeutic targets in the treatment of myocardial ischemia, and potentially congestive heart failure and hypertension, should include prevention of mast cell degranulation, mast cell renin inhibition, local ACE inhibition, ANG II antagonism and H3-receptor activation.
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Affiliation(s)
- Alicia C Reid
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA
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14
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Direct action of angiotensin II on the conduction through papillary muscle preparations of rat heart immediately after reoxygenation. J Arrhythm 2012. [DOI: 10.1016/j.joa.2012.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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15
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Dartsch T, Fischer R, Gapelyuk A, Weiergraeber M, Ladage D, Schneider T, Schirdewan A, Reuter H, Mueller-Ehmsen J, Zobel C. Aldosterone induces electrical remodeling independent of hypertension. Int J Cardiol 2011; 164:170-8. [PMID: 21764470 DOI: 10.1016/j.ijcard.2011.06.100] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2010] [Revised: 05/17/2011] [Accepted: 06/18/2011] [Indexed: 12/26/2022]
Abstract
BACKGROUND Treatment of heart failure patients with aldosterone antagonists has been shown to reduce the occurrence of sudden cardiac death. Therefore we aimed at determining the consequences of chronic exposure to aldosterone and the aldosterone antagonists eplerenone and spironolactone on the electrophysiological properties of the heart in a rat model. METHODS AND RESULTS Male Wistar rats were chronically treated (4weeks) with aldosterone (ALD) via an osmotic minipump. Spironolactone (SPI) or eplerenone (EPL) was administered with the rat chow. ALD treated animals developed left ventricular hypertrophy, prolonged QT-intervals, a higher rate of ventricular premature beats and non-sustained ventricular tachycardia despite normal blood pressure values. Spironolactone and eplerenone were both able to inhibit the alterations. Left-ventricular mRNA expressions of Kv4.2 and Kv4.3 (Ito), Kv1.5 (IKur), Kir2.1 and Kir2.3 (IK1) and of Cav1.2 (L-type Ca(2+) channel) were significantly down-regulated in ALD. Correspondingly, the protein expressions of subunits Kv1.5, Kir2.3 and Cav1.2 were significantly decreased. A diminished calcineurin activity and mRNA expression of the Aß subunit of calcineurin were found in ALD, which was insensitive to aldosterone antagonists. CONCLUSIONS Chronic aldosterone-overload induces blood pressure independent structural and electrical remodeling of the myocardium resulting in an increased risk for malignant ventricular arrhythmias.
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Affiliation(s)
- Theresa Dartsch
- Department of Internal Medicine III, University of Cologne, Cologne, Germany
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16
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Zhao Z, Fefelova N, Shanmugam M, Bishara P, Babu GJ, Xie LH. Angiotensin II induces afterdepolarizations via reactive oxygen species and calmodulin kinase II signaling. J Mol Cell Cardiol 2010; 50:128-36. [PMID: 21059353 DOI: 10.1016/j.yjmcc.2010.11.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 10/02/2010] [Accepted: 11/01/2010] [Indexed: 12/13/2022]
Abstract
Renin-angiotensin system inhibitors significantly reduce the incidence of arrhythmias. However, the underlying mechanism(s) is not well understood. We aim to test the hypothesis that angiotensin II (Ang II) induces early afterdepolarizations (EADs) and triggered activities (TAs) via the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase-ROS-calmodulin kinase II (CaMKII) pathway. ROS production was analyzed in the isolated rabbit myocytes loaded with ROS dye. Ang II (1-2 μM) increased ROS fluorescence in myocytes, which was abolished by Ang II type 1 receptor blocker losartan, NADPH oxidase inhibitor apocynin, and antioxidant MnTMPyP, respectively. Action potentials were recorded using the perforated patch-clamp technique. EADs emerged in 27 out of 41 (66%) cells at 15.8 ± 1.6 min after Ang II (1-2 μM) perfusion. Ang II-induced EADs were eliminated by losartan, apocynin, or trolox. The CaMKII inhibitor KN-93 (n=6) and inhibitory peptide (AIP) (n=4) also suppressed Ang II-induced EADs, whereas the inactive analogue KN-92 did not. Nifedipine, a blocker of L-type Ca current (I(Ca)(2+)(,L)), or ranolazine, an inhibitor of late Na current (I(Na)(+)), abolished Ang II-induced EADs. The effects of Ang II on major membrane currents were evaluated using voltage clamp. While Ang II at same concentrations had no significant effect on total outward K(+) current, it enhanced I(Ca.L) and late I(Na), which were attenuated by losartan, apocynin, trolox, or KN-93. We conclude that Ang II induces EADs via intracellular ROS production through NADPH oxidase, activation of CaMKII, and enhancement of I(Ca,L) and late I(Na). These results provide evidence supporting a link between renin-angiotensin system and cardiac arrhythmias.
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Affiliation(s)
- Zhenghang Zhao
- Department of Cell Biology and Molecular Medicine, UMDNJ-New Jersey Medical School, Newark, NJ 07101, USA
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Ghelfi E, Wellenius GA, Lawrence J, Millet E, Gonzalez-Flecha B. Cardiac oxidative stress and dysfunction by fine concentrated ambient particles (CAPs) are mediated by angiotensin-II. Inhal Toxicol 2010; 22:963-72. [PMID: 20718632 PMCID: PMC3771644 DOI: 10.3109/08958378.2010.503322] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Inhalation exposure to fine concentrated ambient particles (CAPs) increases cardiac oxidants by mechanisms involving modulation of the sympathovagal tone on the heart. Angiotensin-II is a potent vasoconstrictor and a sympatho-excitatory peptide involved in the regulation of blood pressure. We hypothesized that increases in angiotensin-II after fine particulate matter (PM) exposure could be involved in the development of cardiac oxidative stress. Adult rats were treated with an angiotensin-converting enzyme (ACE) inhibitor (benazepril), or an angiotensin receptor blocker (ARB; valsartan) before exposure to fine PM aerosols or filtered air. Exposures were carried out for 5 hours in the chamber of the Harvard fine particle concentrator (fine PM mass concentration: 440 +/- 80 microg/m(3)). At the end of the exposure the animals were tested for in situ chemiluminescence (CL) of the heart, thiobarbituric acid reactive substances (TBARS) and for plasma levels of angiotensin-II. Also, continuous electrocardiogram (ECG) measurements were collected on a subgroup of exposed animals. PM exposure was associated with statistically significant increases in plasma angiotensin concentrations. Pre-treatment with the ACE inhibitor effectively lowered angiotensin concentration, whereas ARB treatment led to increases in angiotensin above the PM-only level. PM exposure also led to significant increases in heart oxidative stress (CL, TBARS), and a shortening of the T-end to T-peak interval on the ECG that were prevented by treatment with both the ACE inhibitor and ARB. These results show that ambient fine particles can increase plasma levels of angiotensin-II and suggest a role of the renin-angiotensin system in the development of particle-related acute cardiac events.
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Affiliation(s)
- Elisa Ghelfi
- Harvard School of Public Health, Department of Environmental Health
| | | | - Joy Lawrence
- Harvard School of Public Health, Department of Environmental Health
| | - Emil Millet
- Harvard School of Public Health, Department of Environmental Health
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18
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Matavel A, Lopes CMB. PKC activation and PIP(2) depletion underlie biphasic regulation of IKs by Gq-coupled receptors. J Mol Cell Cardiol 2009; 46:704-12. [PMID: 19233191 DOI: 10.1016/j.yjmcc.2009.02.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 01/21/2009] [Accepted: 02/03/2009] [Indexed: 10/24/2022]
Abstract
KCNQ1 is co-assembled with KCNE1 subunits in the heart to form the cardiac delayed rectifier K(+) current (IKs), which is one of the main currents responsible for myocyte repolarization. The most commonly inherited form of cardiac arrhythmias, long-QT syndrome type 1 (LQT1), is due to mutations on KCNQ1. Gq-coupled receptors (GqPCRs) are known to mediate positive inotropism in human ventricular myocardium. The mechanism of IKs current modulation by GqPCRs remains incompletely understood. Here we studied the molecular mechanisms underlying Gq regulation of the IKs channel. Heterologously expressed IKs (human KCNQ1/KCNE1 subunits) was measured in Xenopus oocytes, expressed together with GqPCRs. Our data from several GqPCRs shows that IKs is regulated in a biphasic manner, showing both an activation and an inhibition phase. Receptor-mediated inhibition phase was irreversible when recycling of agonist-sensitive pools of phosphatidylinositol-4,5-bisphosphate (PIP2) was blocked by the lipid kinase inhibitor wortmannin. In addition, stimulation of PIP(2) production, by overexpression of phosphatidylinositol-4-phosphate-5-kinase (PIP5-kinase), decreased receptor-mediated inhibition. The receptor-mediated activation phase was inhibited by the PKC inhibitor calphostin C and by a mutation in a putative PKC phosphorylation site in the KCNE1 subunit. Our results indicate that the depletion of membrane PIP(2) underlies receptor-mediated inhibition of IKs and that phosphorylation by PKC of the KCNE1 subunit underlies the GqPCR-mediated channel activation.
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Affiliation(s)
- Alessandra Matavel
- Cardiovascular Research Institute, Department of Medicine, University of Rochester, 601 Elmwood Ave, Box: CVRI, Rochester, NY 14642, USA
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Makkar KM, Sanoski CA, Spinler SA. Role of Angiotensin-Converting Enzyme Inhibitors, Angiotensin II Receptor Blockers, and Aldosterone Antagonists in the Prevention of Atrial and Ventricular Arrhythmias. Pharmacotherapy 2009; 29:31-48. [DOI: 10.1592/phco.29.1.31] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Iravanian S, Dudley SC. The renin-angiotensin-aldosterone system (RAAS) and cardiac arrhythmias. Heart Rhythm 2008; 5:S12-7. [PMID: 18456194 DOI: 10.1016/j.hrthm.2008.02.025] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Indexed: 12/19/2022]
Abstract
The role of the renin-angiotensin-aldosterone system (RAAS) in many cardiovascular disorders, including hypertension, cardiac hypertrophy, and atherosclerosis, is well established, whereas its relationship with cardiac arrhythmias is a new area of investigation. Atrial fibrillation and malignant ventricular tachyarrhythmias, especially in the setting of cardiac hypertrophy or failure, seem to be examples of RAAS-related arrhythmias because treatment with RAAS modulators, including angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor blockers, reduces the incidence of these arrhythmias. RAAS has a multitude of electrophysiological effects and can potentially cause arrhythmia through a variety of mechanisms. We review new experimental results that suggest that RAAS has proarrhythmic effects on membrane and sarcoplasmic reticulum ion channels and that increased oxidative stress is likely contributing to the increased arrhythmic incidence. A summary of ongoing clinical trials that will address the clinical usefulness of RAAS modulators for prevention or treatment of arrhythmias is presented.
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Affiliation(s)
- Shahriar Iravanian
- Division of Cardiology, Department of Medicine, Emory University, Atlanta, Georgia, USA
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Abstract
Cardiac mast cells proliferate in cardiovascular diseases. In myocardial ischemia, mast cell mediators contribute to coronary vasoconstriction, arrhythmias, leukocyte recruitment, and tissue injury and repair. Arrhythmic dysfunction, coronary vasoconstriction, and contractile failure are also characteristic of cardiac anaphylaxis. In coronary atherosclerosis, mast cell mediators facilitate cholesterol accumulation and plaque destabilization. In cardiac failure, mast cell chymase causes myocyte apoptosis and fibroblast proliferation, leading to ventricular dysfunction. Chymase and tryptase also contribute to fibrosis in cardiomyopathies and myocarditis. In addition, mast cell tumor necrosis factor-alpha promotes myocardial remodeling. Cardiac remodeling and hypertrophy in end-stage hypertension are also induced by mast cell mediators and proteases. We recently discovered that cardiac mast cells contain and release renin, which initiates local angiotensin formation. Angiotensin causes coronary vasoconstriction, arrhythmias, fibrosis, apoptosis, and endothelin release, all demonstrated mechanisms of mast-cell-associated cardiac disease. The effects of angiotensin are further amplified by the release of norepinephrine from cardiac sympathetic nerves. Our discovery of renin in cardiac mast cells and its release in pathophysiological conditions uncovers an important new pathway in the development of mast-cell-associated heart diseases. Several steps in this novel pathway may constitute future therapeutic targets.
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Affiliation(s)
- Alicia C Reid
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY 10021, USA
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