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Kataoka N, Imamura T. Unique feature of Brugada syndrome in children. Pacing Clin Electrophysiol 2024; 47:172. [PMID: 38038122 DOI: 10.1111/pace.14893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 11/17/2023] [Indexed: 12/02/2023]
Affiliation(s)
- Naoya Kataoka
- Second Department of Internal Medicine, University of Toyama, Toyama, Japan
| | - Teruhiko Imamura
- Second Department of Internal Medicine, University of Toyama, Toyama, Japan
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2
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Radford D, Chou OHI, Bazoukis G, Letsas K, Liu T, Tse G, Lee S. Electrocardiographic features in SCN5A mutation-positive patients with Brugada and early repolarization syndromes: a systematic review and meta-analysis. INTERNATIONAL JOURNAL OF ARRHYTHMIA 2022. [DOI: 10.1186/s42444-022-00066-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Early repolarization syndrome (ERS) and Brugada syndrome (BrS) are both J-wave syndromes. Both can involve mutations in the SCN5A gene but may exhibit distinct electrocardiographic (ECG) differences. The aim of this systematic review and meta-analysis is to investigate possible differences in ECG markers between SCN5A-positive patients with ERS and BrS.
Methods
PubMed and Embase were searched from their inception to 20 October 2021 for human studies containing the search terms “SCN5A” and “variant” and “early repolarization” or “Brugada”, with no language restrictions. Continuous variables were expressed as mean±standard deviation. PR interval, QRS duration, QTc and heart rate from the included studies were pooled to calculate a mean for each variable amongst BrS and ERS patients. A two-tailed Student’s t test was then performed to for comparisons.
Results
A total of 328 studies were identified. After full-text screening, 12 studies met our inclusion criteria and were included in this present study. One hundred and four ERS patients (mean age 30.86±14.45) and 2000 BrS patients (mean age 36.17±11.39) were studied. Our meta-analysis found that ERS patients had shorter QRS duration (90.40±9.97 vs. 114.79±20.10, P = 0.0001) and shorter corrected QT intervals (QTc) with borderline significance (393.63±40.04 vs. 416.82±37.43, P = 0.052). By contrast, no significant differences in baseline heart rate (65.15±18.78 vs. 76.06±18.78, P = 0.068) or PR intervals (197.40±34.69 vs. 191.88±35.08, P = 0.621) were observed between ERS and BrS patients.
Conclusion
BrS patients with positive SCN5A mutations exhibited prolonged QRS, indicating conduction abnormalities, whereas ERS patients with positive SCN5A mutations showed normal QRS. By contrast, whilst QTc intervals were longer in BrS than in ERS SCN5A positive patients, they were within normal limits. Further studies are needed to examine the implications of these findings for arrhythmic risk stratification.
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3
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Liang S, Zhao J, Wang Q, Yang M, Wang X, Chen S, Chen M, Sun C. Carbon monoxide enhances calcium transients and glucose-stimulated insulin secretion from pancreatic β-cells by activating Phospholipase C signal pathway in diabetic mice. Biochem Biophys Res Commun 2021; 582:1-7. [PMID: 34678590 DOI: 10.1016/j.bbrc.2021.10.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/29/2021] [Accepted: 10/12/2021] [Indexed: 01/31/2023]
Abstract
In early stage of diabetes, insulin secretion from pancreatic β-cells is increased to deal with the elevated blood glucose. Previous studies have reported that islet-produced carbon monoxide (CO) is associated with increased glucose-stimulated insulin secretion from β-cells. However, this compensatory mechanism by which CO may act to enhance β-cell function remain unclear. In this study, we revealed that CO promoted intracellular calcium ([Ca2+]i) elevation and glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells in leptin receptor deficient db/db mice but not in C57 mice. The stimulatory effects of CO on β-cell function in db/db mice was blocked by inhibition of Phospholipase C (PLC) signaling pathway. We further demonstrated that CO triggered [Ca2+]i transients and enhanced GSIS in C57 islets when β-cells overexpressed with PLCγ1 and PLCδ1, but not PLCβ1. On the other hand, reducing PLCγ1 and PLCδ1 expressions in db/db islets dramatically attenuated the stimulatory effects of CO on β-cell function, whereas interfering PLCβ1 expression had no effects on CO-induced β-cell function enhancement. Our findings showing that CO elevated [Ca2+]i and enhanced GSIS by activating PLC signaling through PLCγ1 and PLCδ1 isoforms in db/db pancreatic β-cells may suggest an important mechanism by which CO promotes β-cell function to prevent hyperglycemia. Our study may also provide new insights into the therapy for type II diabetes and offer a potential target for therapeutic applications of CO.
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Affiliation(s)
- Shenghui Liang
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China.
| | - Jia Zhao
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China
| | - Quanyi Wang
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China; Department of Biopharmaceutics, School of Life Science and Technology, China Pharmaceutical University, Nanjing, Jiangsu, 211198, China
| | - Min Yang
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China; The Key Laboratory of Invertebrate Systematics and Application, College of Life Sciences, Hebei University, Baoding, Hebei, 071002, China
| | - Xiaozhi Wang
- Institute of Molecular Medicine, Peking University, Beijing, 100871, China; Department of Cardiology, The First Affiliated Hospital with Nanjing Medical University, Nanjing, Jiangsu, 210029, China
| | - Shuqiu Chen
- Department of Urology, Zhongda Hospital, Southeast University, Nanjing, Jiangsu, 210009, China
| | - Ming Chen
- Department of Urology, Zhongda Hospital, Southeast University, Nanjing, Jiangsu, 210009, China
| | - Chao Sun
- Department of Urology, Zhongda Hospital, Southeast University, Nanjing, Jiangsu, 210009, China.
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Zimik S, Pandit R, Majumder R. Anisotropic shortening in the wavelength of electrical waves promotes onset of electrical turbulence in cardiac tissue: An in silico study. PLoS One 2020; 15:e0230214. [PMID: 32168323 PMCID: PMC7069633 DOI: 10.1371/journal.pone.0230214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 02/24/2020] [Indexed: 12/03/2022] Open
Abstract
Several pathological conditions introduce spatial variations in the electrical properties of cardiac tissue. These variations occur as localized or distributed gradients in ion-channel functionality over extended tissue media. Electrical waves, propagating through such affected tissue, demonstrate distortions, depending on the nature of the ionic gradient in the diseased substrate. If the degree of distortion is large, reentrant activity may develop, in the form of rotating spiral (2d) and scroll (3d) waves of electrical activity. These reentrant waves are associated with the occurrence of lethal cardiac rhythm disorders, known as arrhythmias, such as ventricular tachycardia (VT) and ventricular fibrillation (VF), which are believed to be common precursors of sudden cardiac arrest. By using state-of-the-art mathematical models for generic, and ionically-realistic (human) cardiac tissue, we study the detrimental effects of these ionic gradients on electrical wave propagation. We propose a possible mechanism for the development of instabilities in reentrant wave patterns, in the presence of ionic gradients in cardiac tissue, which may explain how one type of arrhythmia (VT) can degenerate into another (VF). Our proposed mechanism entails anisotropic reduction in the wavelength of the excitation waves because of anisotropic variation in its electrical properties, in particular the action potential duration (APD). We find that the variation in the APD, which we induce by varying ion-channel conductances, imposes a spatial variation in the spiral- or scroll-wave frequency ω. Such gradients in ω induce anisotropic shortening of wavelength of the spiral or scroll arms and eventually leads to instabilitites.
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Affiliation(s)
- Soling Zimik
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, India
| | - Rahul Pandit
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore, India
| | - Rupamanjari Majumder
- Laboratory for Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany
- * E-mail:
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5
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Handa BS, Lawal S, Wright IJ, Li X, Cabello-García J, Mansfield C, Chowdhury RA, Peters NS, Ng FS. Interventricular Differences in Action Potential Duration Restitution Contribute to Dissimilar Ventricular Rhythms in ex vivo Perfused Hearts. Front Cardiovasc Med 2019; 6:34. [PMID: 31001543 PMCID: PMC6456660 DOI: 10.3389/fcvm.2019.00034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 03/13/2019] [Indexed: 01/24/2023] Open
Abstract
Background: Dissimilar ventricular rhythms refer to the occurrence of different ventricular tachyarrhythmias in the right and left ventricles or different rates of the same tachyarrhythmia in the two ventricles. Objective: We investigated the inducibility of dissimilar ventricular rhythms, their underlying mechanisms, and the impact of anti-arrhythmic drugs (lidocaine and amiodarone) on their occurrence. Methods: Ventricular tachyarrhythmias were induced with burst pacing in 28 Langendorff-perfused Sprague Dawley rat hearts (14 control, 8 lidocaine, 6 amiodarone) and bipolar electrograms recorded from the right and left ventricles. Fourteen (6 control, 4 lidocaine, 4 amiodarone) further hearts underwent optical mapping of transmembrane voltage to study interventricular electrophysiological differences and mechanisms of dissimilar rhythms. Results: In control hearts, dissimilar ventricular rhythms developed in 8/14 hearts (57%). In lidocaine treated hearts, there was a lower cycle length threshold for developing dissimilar rhythms, with 8/8 (100%) hearts developing dissimilar rhythms in comparison to 0/6 in the amiodarone group. Dissimilar ventricular tachycardia (VT) rates occurred at longer cycle lengths with lidocaine vs. control (57.1 ± 7.9 vs. 36.6 ± 8.4 ms, p < 0.001). The ratio of LV:RV VT rate was greater in the lidocaine group than control (1.91 ± 0.30 vs. 1.76 ± 0.36, p < 0.001). The gradient of the action potential duration (APD) restitution curve was shallower in the RV compared with LV (Control - LV: 0.12 ± 0.03 vs RV: 0.002 ± 0.03, p = 0.015), leading to LV-to-RV conduction block during VT. Conclusion: Interventricular differences in APD restitution properties likely contribute to the occurrence of dissimilar rhythms. Sodium channel blockade with lidocaine increases the likelihood of dissimilar ventricular rhythms.
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Affiliation(s)
- Balvinder S. Handa
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Saheed Lawal
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Ian J. Wright
- Imperial College Healthcare NHS Trust, London, United Kingdom
| | - Xinyang Li
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | | | - Catherine Mansfield
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Rasheda A. Chowdhury
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Nicholas S. Peters
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Fu Siong Ng
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
- Imperial College Healthcare NHS Trust, London, United Kingdom
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6
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Abstract
Spatiotemporal gene expression during cardiac development is a highly regulated process. Activation of key signaling pathways involved in electrophysiological programming, such as Notch and Wnt signaling, occurs in early cardiovascular development and these pathways are reactivated during pathologic remodeling. Direct targets of these signaling pathways have also been associated with inherited arrhythmias such as Brugada syndrome and arrhythmogenic cardiomyopathy. In addition, evidence is emerging from animal models that reactivation of Notch and Wnt signaling during cardiac pathology may predispose to acquired arrhythmias, underscoring the importance of elucidating the transcriptional and epigenetic effects on cardiac gene regulation. Here, we highlight specific examples where gene expression dictates electrophysiological properties in both normal and diseased hearts.
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Lipovsky CE, Brumback BD, Khandekar A, Rentschler SL. Multi-Scale Assessments of Cardiac Electrophysiology Reveal Regional Heterogeneity in Health and Disease. J Cardiovasc Dev Dis 2018; 5:E16. [PMID: 29517992 PMCID: PMC5872364 DOI: 10.3390/jcdd5010016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 02/27/2018] [Accepted: 03/05/2018] [Indexed: 12/19/2022] Open
Abstract
The left and right ventricles of the four-chambered heart have distinct developmental origins and functions. Chamber-specific developmental programming underlies the differential gene expression of ion channel subunits regulating cardiac electrophysiology that persists into adulthood. Here, we discuss regional specific electrical responses to genetic mutations and cardiac stressors, their clinical correlations, and describe many of the multi-scale techniques commonly used to analyze electrophysiological regional heterogeneity.
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Affiliation(s)
- Catherine E Lipovsky
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, Campus Box 8103, 660 S Euclid Ave, St. Louis, MO 63110, USA.
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
| | - Brittany D Brumback
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, Campus Box 8103, 660 S Euclid Ave, St. Louis, MO 63110, USA.
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, USA.
| | - Aditi Khandekar
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, Campus Box 8103, 660 S Euclid Ave, St. Louis, MO 63110, USA.
| | - Stacey L Rentschler
- Department of Medicine, Cardiovascular Division, Washington University School of Medicine, Campus Box 8103, 660 S Euclid Ave, St. Louis, MO 63110, USA.
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
- Department of Biomedical Engineering, Washington University, St. Louis, MO 63130, USA.
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8
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Sánchez C, Bueno-Orovio A, Pueyo E, Rodríguez B. Atrial Fibrillation Dynamics and Ionic Block Effects in Six Heterogeneous Human 3D Virtual Atria with Distinct Repolarization Dynamics. Front Bioeng Biotechnol 2017; 5:29. [PMID: 28534025 PMCID: PMC5420585 DOI: 10.3389/fbioe.2017.00029] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/18/2017] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) usually manifests as reentrant circuits propagating through the whole atria creating chaotic activation patterns. Little is yet known about how differences in electrophysiological and ionic properties between patients modulate reentrant patterns in AF. The goal of this study is to quantify how variability in action potential duration (APD) at different stages of repolarization determines AF dynamics and their modulation by ionic block using a set of virtual whole-atria human models. Six human whole-atria models are constructed based on the same anatomical structure and fiber orientation, but with different electrophysiological phenotypes. Membrane kinetics for each whole-atria model are selected with distinct APD characteristics at 20, 50, and 90% repolarization, from an experimentally calibrated population of human atrial action potential models, including AF remodeling and acetylcholine parasympathetic effects. Our simulations show that in all whole-atria models, reentrant circuits tend to organize around the pulmonary veins and the right atrial appendage, thus leading to higher dominant frequency (DF) and more organized activation in the left atrium than in the right atrium. Differences in APD in all phases of repolarization (not only APD90) yielded quantitative differences in fibrillation patterns with long APD associated with slower and more regular dynamics. Long APD50 and APD20 were associated with increased interatrial conduction block and interatrial differences in DF and organization index, creating reentry instability and self-termination in some cases. Specific inhibitions of IK1, INaK, or INa reduce DF and organization of the arrhythmia by enlarging wave meandering, reducing the number of secondary wavelets, and promoting interatrial block in all six virtual patients, especially for the phenotypes with short APD at 20, 50, and/or 90% repolarization. This suggests that therapies aiming at prolonging the early phase of repolarization might constitute effective antiarrhythmic strategies for the pharmacological management of AF. In summary, simulations report significant differences in atrial fibrillatory dynamics resulting from differences in APD at all phases of repolarization.
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Affiliation(s)
- Carlos Sánchez
- Biosignal Interpretation and Computational Simulation (BSICoS), I3A and IIS, University of Zaragoza, Zaragoza, Spain.,Defense University Centre (CUD), General Military Academy of Zaragoza (AGM), Zaragoza, Spain
| | | | - Esther Pueyo
- Biosignal Interpretation and Computational Simulation (BSICoS), I3A and IIS, University of Zaragoza, Zaragoza, Spain.,Biomedical Research Networking Center in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza, Spain
| | - Blanca Rodríguez
- Department of Computer Science, University of Oxford, Oxford, UK
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9
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Briot J, Tétreault MP, Bourdin B, Parent L. Inherited Ventricular Arrhythmias: The Role of the Multi-Subunit Structure of the L-Type Calcium Channel Complex. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 966:55-64. [PMID: 28315127 DOI: 10.1007/5584_2016_186] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The normal heartbeat is conditioned by transient increases in the intracellular free Ca2+ concentration. Ca2+ influx in cardiomyocytes is regulated by the activity of the heteromeric L-type voltage-activated CaV1.2 channel. A complex network of interactions between the different proteins forming the ion channel supports the kinetics and the activation gating of the Ca2+ influx. Alterations in the biophysical and biochemical properties or in the biogenesis in any of these proteins can lead to serious disturbances in the cardiac rhythm. The multi-subunit nature of the channel complex is better comprehended by examining the high-resolution three-dimensional structure of the closely related CaV1.1 channel. The architectural map identifies precise interaction loci between the different subunits and paves the way for elucidating the mechanistic basis for the regulation of Ca2+ balance in cardiac myocytes under physiological and pathological conditions.
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Affiliation(s)
- Julie Briot
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Institut Cardiologie de Montréal, Université de Montréal, 5000 Bélanger, Montréal, QC, H1T 1C8, Canada
| | - Marie-Philippe Tétreault
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Institut Cardiologie de Montréal, Université de Montréal, 5000 Bélanger, Montréal, QC, H1T 1C8, Canada
| | - Benoîte Bourdin
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Institut Cardiologie de Montréal, Université de Montréal, 5000 Bélanger, Montréal, QC, H1T 1C8, Canada
| | - Lucie Parent
- Département de Pharmacologie et Physiologie, Faculté de Médecine, Institut Cardiologie de Montréal, Université de Montréal, 5000 Bélanger, Montréal, QC, H1T 1C8, Canada.
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10
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The Effects of Puerarin on Rat Ventricular Myocytes and the Potential Mechanism. Sci Rep 2016; 6:35475. [PMID: 27762288 PMCID: PMC5071873 DOI: 10.1038/srep35475] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 09/28/2016] [Indexed: 12/22/2022] Open
Abstract
Puerarin, a known isoflavone, is commonly found as a Chinese herb medicine. It is widely used in China to treat cardiac diseases such as angina, cardiac infarction and arrhythmia. However, its cardioprotective mechanism remains unclear. In this study, puerarin significantly prolonged ventricular action potential duration (APD) with a dosage dependent manner in the micromolar range on isolated rat ventricular myocytes. However, submicromolar puerarin had no effect on resting membrane potential (RMP), action potential amplitude (APA) and maximal velocity of depolarization (Vmax) of action potential. Only above the concentration of 10 mM, puerarin exhibited more aggressive effect on action potential, and shifted RMP to the positive direction. Millimolar concentrations of puerarin significantly inhibited inward rectified K+ channels in a dosage dependent manner, and exhibited bigger effects upon Kir2.1 vs Kir2.3 in transfected HEK293 cells. As low as micromolar range concentrations of puerarin significantly inhibited Kv7.1 and IKs. These inhibitory effects may due to the direct inhibition of puerarin upon channels not via the PKA-dependent pathway. These results provided direct preclinical evidence that puerarin prolonged APD via its inhibitory effect upon Kv7.1 and IKs, contributing to a better understanding the mechanism of puerarin cardioprotection in the treatment of cardiovascular diseases.
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11
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Rodriguez B, Carusi A, Abi-Gerges N, Ariga R, Britton O, Bub G, Bueno-Orovio A, Burton RAB, Carapella V, Cardone-Noott L, Daniels MJ, Davies MR, Dutta S, Ghetti A, Grau V, Harmer S, Kopljar I, Lambiase P, Lu HR, Lyon A, Minchole A, Muszkiewicz A, Oster J, Paci M, Passini E, Severi S, Taggart P, Tinker A, Valentin JP, Varro A, Wallman M, Zhou X. Human-based approaches to pharmacology and cardiology: an interdisciplinary and intersectorial workshop. Europace 2016; 18:1287-98. [PMID: 26622055 PMCID: PMC5006958 DOI: 10.1093/europace/euv320] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/20/2015] [Indexed: 12/12/2022] Open
Abstract
Both biomedical research and clinical practice rely on complex datasets for the physiological and genetic characterization of human hearts in health and disease. Given the complexity and variety of approaches and recordings, there is now growing recognition of the need to embed computational methods in cardiovascular medicine and science for analysis, integration and prediction. This paper describes a Workshop on Computational Cardiovascular Science that created an international, interdisciplinary and inter-sectorial forum to define the next steps for a human-based approach to disease supported by computational methodologies. The main ideas highlighted were (i) a shift towards human-based methodologies, spurred by advances in new in silico, in vivo, in vitro, and ex vivo techniques and the increasing acknowledgement of the limitations of animal models. (ii) Computational approaches complement, expand, bridge, and integrate in vitro, in vivo, and ex vivo experimental and clinical data and methods, and as such they are an integral part of human-based methodologies in pharmacology and medicine. (iii) The effective implementation of multi- and interdisciplinary approaches, teams, and training combining and integrating computational methods with experimental and clinical approaches across academia, industry, and healthcare settings is a priority. (iv) The human-based cross-disciplinary approach requires experts in specific methodologies and domains, who also have the capacity to communicate and collaborate across disciplines and cross-sector environments. (v) This new translational domain for human-based cardiology and pharmacology requires new partnerships supported financially and institutionally across sectors. Institutional, organizational, and social barriers must be identified, understood and overcome in each specific setting.
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Affiliation(s)
- Blanca Rodriguez
- Department of Computer Science, University of Oxford, Oxford, UK
| | | | - Najah Abi-Gerges
- AnaBios Corporation, San Diego Science Center, San Diego, CA 92109, USA
| | - Rina Ariga
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | - Oliver Britton
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Gil Bub
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | | | - Rebecca A B Burton
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, UK
| | | | | | - Matthew J Daniels
- Radcliffe Department of Medicine, University of Oxford, John Radcliffe Hospital, Oxford, UK
| | | | - Sara Dutta
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Andre Ghetti
- AnaBios Corporation, San Diego Science Center, San Diego, CA 92109, USA
| | - Vicente Grau
- Department of Engineering Science, University of Oxford, Oxford, UK
| | - Stephen Harmer
- William Harvey Heart Centre, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | - Ivan Kopljar
- Discovery Sciences, Dis&Dev Research, Janssen Pharmaceutical NV, Beerse, Belgium
| | - Pier Lambiase
- Institute of Cardiovascular Science, University College London, Bars Heart Centre, London, UK
| | - Hua Rong Lu
- Discovery Sciences, Dis&Dev Research, Janssen Pharmaceutical NV, Beerse, Belgium
| | - Aurore Lyon
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Ana Minchole
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Anna Muszkiewicz
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Julien Oster
- Department of Engineering Science, University of Oxford, Oxford, UK
| | - Michelangelo Paci
- Department of Electronics and Communications Engineering, Tampere University of Technology, BioMediTech, Tampere, Finland
| | - Elisa Passini
- Department of Computer Science, University of Oxford, Oxford, UK
| | - Stefano Severi
- Department of Electrical, Electronic and Information Engineering, University of Bologna, Cesena 47521, Italy
| | - Peter Taggart
- Institute of Cardiovascular Science, University College London, Bars Heart Centre, London, UK
| | - Andy Tinker
- William Harvey Heart Centre, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, Charterhouse Square, London, UK
| | | | | | | | - Xin Zhou
- Department of Computer Science, University of Oxford, Oxford, UK
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12
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Page G, Ratchada P, Miron Y, Steiner G, Ghetti A, Miller PE, Reynolds JA, Wang K, Greiter-Wilke A, Polonchuk L, Traebert M, Gintant GA, Abi-Gerges N. Human ex-vivo action potential model for pro-arrhythmia risk assessment. J Pharmacol Toxicol Methods 2016; 81:183-95. [PMID: 27235787 PMCID: PMC5042841 DOI: 10.1016/j.vascn.2016.05.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 05/03/2016] [Accepted: 05/24/2016] [Indexed: 12/20/2022]
Abstract
While current S7B/E14 guidelines have succeeded in protecting patients from QT-prolonging drugs, the absence of a predictive paradigm identifying pro-arrhythmic risks has limited the development of valuable drug programs. We investigated if a human ex-vivo action potential (AP)-based model could provide a more predictive approach for assessing pro-arrhythmic risk in man. Human ventricular trabeculae from ethically consented organ donors were used to evaluate the effects of dofetilide, d,l-sotalol, quinidine, paracetamol and verapamil on AP duration (APD) and recognized pro-arrhythmia predictors (short-term variability of APD at 90% repolarization (STV(APD90)), triangulation (ADP90-APD30) and incidence of early afterdepolarizations at 1 and 2Hz to quantitatively identify the pro-arrhythmic risk. Each drug was blinded and tested separately with 3 concentrations in triplicate trabeculae from 5 hearts, with one vehicle time control per heart. Electrophysiological stability of the model was not affected by sequential applications of vehicle (0.1% dimethyl sulfoxide). Paracetamol and verapamil did not significantly alter anyone of the AP parameters and were classified as devoid of pro-arrhythmic risk. Dofetilide, d,l-sotalol and quinidine exhibited an increase in the manifestation of pro-arrhythmia markers. The model provided quantitative and actionable activity flags and the relatively low total variability in tissue response allowed for the identification of pro-arrhythmic signals. Power analysis indicated that a total of 6 trabeculae derived from 2 hearts are sufficient to identify drug-induced pro-arrhythmia. Thus, the human ex-vivo AP-based model provides an integrative translational assay assisting in shaping clinical development plans that could be used in conjunction with the new CiPA-proposed approach.
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Affiliation(s)
- Guy Page
- AnaBios Corporation, San Diego, CA 92109, USA
| | | | | | - Guido Steiner
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center, Basel, Switzerland
| | | | | | | | - Ken Wang
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center, Basel, Switzerland
| | - Andrea Greiter-Wilke
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center, Basel, Switzerland
| | - Liudmila Polonchuk
- Roche Pharma Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center, Basel, Switzerland
| | - Martin Traebert
- Novartis Institutes of Biomedical Research, Safety Pharmacology, CH-4057 Basel, Switzerland
| | - Gary A Gintant
- Department of Integrative Pharmacology Integrated Sciences & Technology, AbbVie, North Chicago, IL, USA
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Molina CE, Heijman J, Dobrev D. Differences in Left Versus Right Ventricular Electrophysiological Properties in Cardiac Dysfunction and Arrhythmogenesis. Arrhythm Electrophysiol Rev 2016; 5:14-9. [PMID: 27403288 DOI: 10.15420/aer.2016.8.2] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A wide range of ion channels, transporters, signaling pathways and tissue structure at a microscopic and macroscopic scale regulate the electrophysiological activity of the heart. Each region of the heart has optimised these properties based on its specific role during the cardiac cycle, leading to well-established differences in electrophysiology, Ca(2+) handling and tissue structure between atria and ventricles and between different layers of the ventricular wall. Similarly, the right ventricle (RV) and left ventricle (LV) have different embryological, structural, metabolic and electrophysiological features, but whether interventricular differences promote differential remodeling leading to arrhythmias is not well understood. In this article, we will summarise the available data on intrinsic differences between LV and RV electrophysiology and indicate how these differences affect cardiac function. Furthermore, we will discuss the differential remodeling of both chambers in pathological conditions and its potential impact on arrhythmogenesis.
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Affiliation(s)
- Cristina E Molina
- Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
| | - Jordi Heijman
- Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, Faculty of Medicine, University Duisburg-Essen, Essen, Germany
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14
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Davies MR, Wang K, Mirams GR, Caruso A, Noble D, Walz A, Lavé T, Schuler F, Singer T, Polonchuk L. Recent developments in using mechanistic cardiac modelling for drug safety evaluation. Drug Discov Today 2016; 21:924-38. [PMID: 26891981 PMCID: PMC4909717 DOI: 10.1016/j.drudis.2016.02.003] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 01/13/2016] [Accepted: 02/05/2016] [Indexed: 01/21/2023]
Abstract
Modelling and simulation can streamline decision making in drug safety testing. Computational cardiac electrophysiology is a mature technology with a long heritage. There are many challenges and opportunities in using in silico techniques in future. We discuss how models can be used at different stages of drug discovery. CiPA will combine screening platforms, human cell assays and in silico predictions.
On the tenth anniversary of two key International Conference on Harmonisation (ICH) guidelines relating to cardiac proarrhythmic safety, an initiative aims to consider the implementation of a new paradigm that combines in vitro and in silico technologies to improve risk assessment. The Comprehensive In Vitro Proarrhythmia Assay (CiPA) initiative (co-sponsored by the Cardiac Safety Research Consortium, Health and Environmental Sciences Institute, Safety Pharmacology Society and FDA) is a bold and welcome step in using computational tools for regulatory decision making. This review compares and contrasts the state-of-the-art tools from empirical to mechanistic models of cardiac electrophysiology, and how they can and should be used in combination with experimental tests for compound decision making.
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Affiliation(s)
| | - Ken Wang
- Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, Switzerland
| | - Gary R Mirams
- Computational Biology, Department of Computer Science, University of Oxford, OX1 3QD, UK
| | - Antonello Caruso
- Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, Switzerland
| | - Denis Noble
- Department of Physiology, Anatomy & Genetics, University of Oxford, OX1 3PT, UK
| | - Antje Walz
- Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, Switzerland
| | - Thierry Lavé
- Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, Switzerland
| | - Franz Schuler
- Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, Switzerland
| | - Thomas Singer
- Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, Switzerland
| | - Liudmila Polonchuk
- Roche Pharmaceutical Research and Early Development, Pharmaceutical Sciences, Roche Innovation Center Basel, Switzerland
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15
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16
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Dubois VFS, de Witte WEA, Visser SAG, Danhof M, Della Pasqua O. Assessment of Interspecies Differences in Drug-Induced QTc Interval Prolongation in Cynomolgus Monkeys, Dogs and Humans. Pharm Res 2015; 33:40-51. [PMID: 26553352 PMCID: PMC4689776 DOI: 10.1007/s11095-015-1760-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Accepted: 07/16/2015] [Indexed: 11/30/2022]
Abstract
Background and Purpose The selection of the most suitable animal species and subsequent translation of the concentration-effect relationship to humans are critical steps for accurate assessment of the pro-arrhythmic risk of candidate molecules. The objective of this investigation was to assess quantitatively the differences in the QTc prolonging effects of moxifloxacin between cynomolgus monkeys, dogs and humans. The impact of interspecies differences is also illustrated for a new candidate molecule. Experimental Approach Pharmacokinetic data and ECG recordings from pre-clinical protocols in monkeys and dogs and from a phase I trial in healthy subjects were identified for the purpose of this analysis. A previously established Bayesian model describing the combined effect of heart rate, circadian variation and drug effect on the QT interval was used to describe the pharmacokinetic-pharmacodynamic relationships. The probability of a ≥10 ms increase in QT was derived as measure of the pro-arrhythmic effect. Key Results For moxifloxacin, the concentrations associated with a 50% probability of QT prolongation ≥10 ms (Cp50) varied from 20.3 to 6.4 and 2.6 μM in dogs, monkeys and humans, respectively. For NCE05, these values were 0.4 μM vs 2.0 μM for monkeys and humans, respectively. Conclusions and Implications Our findings reveal significant interspecies differences in the QT-prolonging effect of moxifloxacin. In addition to the dissimilarity in pharmacokinetics across species, it is likely that differences in pharmacodynamics also play an important role. It appears that, regardless of the animal model used, a translation function is needed to predict concentration-effect relationships in humans.
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Affiliation(s)
- V F S Dubois
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - W E A de Witte
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - S A G Visser
- Global DMPK, AstraZeneca R&D, Sodertalje, Sweden
| | - M Danhof
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands
| | - O Della Pasqua
- Leiden Academic Centre for Drug Research, Division of Pharmacology, Leiden University, Leiden, The Netherlands. .,Clinical Pharmacology Modelling & Simulation, GlaxoSmithKline, Stockley Park, Uxbridge, UK. .,Clinical Pharmacology & Therapeutics, University College London, London, UK.
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17
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Finlay MC, Lambiase PD, Ben-Simon R, Taggart P. Effect of mental stress on dynamic electrophysiological properties of the endocardium and epicardium in humans. Heart Rhythm 2015; 13:175-82. [PMID: 26272521 PMCID: PMC4703839 DOI: 10.1016/j.hrthm.2015.08.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Indexed: 01/09/2023]
Abstract
BACKGROUND Striking temporal associations exist between ventricular arrhythmia and acute mental stress, for example, during natural disasters, or defibrillator shocks associated with stressful events. We hypothesized that electrophysiological changes in response to mental stress may be exaggerated at short coupling intervals and hence relevant to arrhythmia initiation. OBJECTIVE The aim of this study was to determine the dynamic response in human electrophysiology during mental stress. METHODS Patients with normal hearts and supraventricular tachycardia underwent electrophysiological studies avoiding sedation. Conditions of relaxation and stress were induced with standardized psychometric protocols (mental arithmetic and anger recall) during decremental S1S2 right ventricular (RV) pacing. Unipolar electrograms were acquired simultaneously from the RV endocardium, left ventricular (LV) endocardium (LV endo), and epicardium (LV epi), and activation-recovery intervals (ARIs) computed. RESULTS Twelve patients ( 9 women; median age 34 years) were studied. During stress, effective refractory period (ERP) reduced from 228 ± 23 to 221 ± 21 ms (P < .001). ARIs reduced during mental stress (P < .001), with greater reductions in LV endocardium than in the epicardium or RV endocardium (LV endo -8 ms; LV epi -5 ms; RV endo -4 ms; P < .001). Mental stress depressed the entire electrical restitution curve, with minimal effect on slope. A substantial reduction in minimal ARIs on the restitution curve in LV endo occurred, commensurate with the reduction in ERP (LV endo ARI 195 ± 31 ms at rest to 182 ± 32 ms during mental stress; P < .001). Dispersion of repolarization increased sharply at coupling intervals approaching ERP during stress but not at rest. CONCLUSION Mental stress induces significant electrophysiological changes. The increase in dispersion of repolarization at short coupling intervals may be relevant to observed phenomena of arousal-associated arrhythmia.
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Affiliation(s)
- Malcolm C Finlay
- University College London, Queen Mary University of London & St Bartholomew's Hospital, London, United Kingdom
| | - Pier D Lambiase
- University College London, Queen Mary University of London & St Bartholomew's Hospital, London, United Kingdom
| | - Ron Ben-Simon
- Barts Heart Centre, St Bartholomew's Hospital, London, United Kingdom
| | - Peter Taggart
- University College London, University College London Hospitals NHS Foundation Trust, London, United Kingdom.
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Bourdin B, Shakeri B, Tétreault MP, Sauvé R, Lesage S, Parent L. Functional characterization of CaVα2δ mutations associated with sudden cardiac death. J Biol Chem 2014; 290:2854-69. [PMID: 25527503 DOI: 10.1074/jbc.m114.597930] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
L-type Ca(2+) channels play a critical role in cardiac rhythmicity. These ion channels are oligomeric complexes formed by the pore-forming CaVα1 with the auxiliary CaVβ and CaVα2δ subunits. CaVα2δ increases the peak current density and improves the voltage-dependent activation gating of CaV1.2 channels without increasing the surface expression of the CaVα1 subunit. The functional impact of genetic variants of CACNA2D1 (the gene encoding for CaVα2δ), associated with shorter repolarization QT intervals (the time interval between the Q and the T waves on the cardiac electrocardiogram), was investigated after recombinant expression of the full complement of L-type CaV1.2 subunits in human embryonic kidney 293 cells. By performing side-by-side high resolution flow cytometry assays and whole-cell patch clamp recordings, we revealed that the surface density of the CaVα2δ wild-type protein correlates with the peak current density. Furthermore, the cell surface density of CaVα2δ mutants S755T, Q917H, and S956T was not significantly different from the cell surface density of the CaVα2δ wild-type protein expressed under the same conditions. In contrast, the cell surface expression of CaVα2δ D550Y, CaVα2δ S709N, and the double mutant D550Y/Q917H was reduced, respectively, by ≈30-33% for the single mutants and by 60% for the latter. The cell surface density of D550Y/Q917H was more significantly impaired than protein stability, suggesting that surface trafficking of CaVα2δ was disrupted by the double mutation. Co-expression with D550Y/Q917H significantly decreased CaV1.2 currents as compared with results obtained with CaVα2δ wild type. It is concluded that D550Y/Q917H reduced inward Ca(2+) currents through a defect in the cell surface trafficking of CaVα2δ. Altogether, our results provide novel insight in the molecular mechanism underlying the modulation of CaV1.2 currents by CaVα2δ.
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Affiliation(s)
- Benoîte Bourdin
- From the Département de Physiologie, Montreal Heart Institute Research Centre, and
| | - Behzad Shakeri
- From the Département de Physiologie, Montreal Heart Institute Research Centre, and
| | | | - Rémy Sauvé
- From the Département de Physiologie, Montreal Heart Institute Research Centre, and
| | - Sylvie Lesage
- Département de Microbiologie, Infectiologie et Immunologie, Centre de Recherche de l'Hôpital Maisonneuve-Rosemont, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Lucie Parent
- From the Département de Physiologie, Montreal Heart Institute Research Centre, and
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Carbon monoxide inhibits inward rectifier potassium channels in cardiomyocytes. Nat Commun 2014; 5:4676. [PMID: 25118981 DOI: 10.1038/ncomms5676] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 07/13/2014] [Indexed: 11/09/2022] Open
Abstract
Reperfusion-induced ventricular fibrillation (VF) severely threatens the lives of post-myocardial infarction patients. Carbon monoxide (CO)--produced by haem oxygenase in cardiomyocytes--has been reported to prevent VF through an unknown mechanism of action. Here, we report that CO prolongs action potential duration (APD) by inhibiting a subset of inward-rectifying potassium (Kir) channels. We show that CO blocks Kir2.2 and Kir2.3 but not Kir2.1 channels in both cardiomyocytes and HEK-293 cells transfected with Kir. CO directly inhibits Kir2.3 by interfering with its interaction with the second messenger phosphatidylinositol (4,5)-bisphosphate (PIP2). As the inhibition of Kir2.2 and Kir2.3 by CO prolongs APD in myocytes, cardiac Kir2.2 and Kir2.3 are promising targets for the prevention of reperfusion-induced VF.
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