1
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Trayanova NA, Lyon A, Shade J, Heijman J. Computational modeling of cardiac electrophysiology and arrhythmogenesis: toward clinical translation. Physiol Rev 2024; 104:1265-1333. [PMID: 38153307 DOI: 10.1152/physrev.00017.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 12/19/2023] [Accepted: 12/21/2023] [Indexed: 12/29/2023] Open
Abstract
The complexity of cardiac electrophysiology, involving dynamic changes in numerous components across multiple spatial (from ion channel to organ) and temporal (from milliseconds to days) scales, makes an intuitive or empirical analysis of cardiac arrhythmogenesis challenging. Multiscale mechanistic computational models of cardiac electrophysiology provide precise control over individual parameters, and their reproducibility enables a thorough assessment of arrhythmia mechanisms. This review provides a comprehensive analysis of models of cardiac electrophysiology and arrhythmias, from the single cell to the organ level, and how they can be leveraged to better understand rhythm disorders in cardiac disease and to improve heart patient care. Key issues related to model development based on experimental data are discussed, and major families of human cardiomyocyte models and their applications are highlighted. An overview of organ-level computational modeling of cardiac electrophysiology and its clinical applications in personalized arrhythmia risk assessment and patient-specific therapy of atrial and ventricular arrhythmias is provided. The advancements presented here highlight how patient-specific computational models of the heart reconstructed from patient data have achieved success in predicting risk of sudden cardiac death and guiding optimal treatments of heart rhythm disorders. Finally, an outlook toward potential future advances, including the combination of mechanistic modeling and machine learning/artificial intelligence, is provided. As the field of cardiology is embarking on a journey toward precision medicine, personalized modeling of the heart is expected to become a key technology to guide pharmaceutical therapy, deployment of devices, and surgical interventions.
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Affiliation(s)
- Natalia A Trayanova
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, Maryland, United States
| | - Aurore Lyon
- Department of Biomedical Engineering, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
- Division of Heart and Lungs, Department of Medical Physiology, University Medical Centre Utrecht, Utrecht, The Netherlands
| | - Julie Shade
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, United States
- Alliance for Cardiovascular Diagnostic and Treatment Innovation, Johns Hopkins University, Baltimore, Maryland, United States
| | - Jordi Heijman
- Department of Cardiology, CARIM School for Cardiovascular Diseases, Maastricht University, Maastricht, The Netherlands
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2
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Zhang Y, Toyoda F, Himeno Y, Noma A, Amano A. Cell-specific models of hiPSC-CMs developed by the gradient-based parameter optimization method fitting two different action potential waveforms. Sci Rep 2024; 14:13086. [PMID: 38849433 PMCID: PMC11161598 DOI: 10.1038/s41598-024-63413-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 05/28/2024] [Indexed: 06/09/2024] Open
Abstract
Parameter optimization (PO) methods to determine the ionic current composition of experimental cardiac action potential (AP) waveform have been developed using a computer model of cardiac membrane excitation. However, it was suggested that fitting a single AP record in the PO method was not always successful in providing a unique answer because of a shortage of information. We found that the PO method worked perfectly if the PO method was applied to a pair of a control AP and a model output AP in which a single ionic current out of six current species, such as IKr, ICaL, INa, IKs, IKur or IbNSC was partially blocked in silico. When the target was replaced by a pair of experimental control and IKr-blocked records of APs generated spontaneously in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs), the simultaneous fitting of the two waveforms by the PO method was hampered to some extent by the irregular slow fluctuations in the Vm recording and/or sporadic alteration in AP configurations in the hiPSC-CMs. This technical problem was largely removed by selecting stable segments of the records for the PO method. Moreover, the PO method was made fail-proof by running iteratively in identifying the optimized parameter set to reconstruct both the control and the IKr-blocked AP waveforms. In the lead potential analysis, the quantitative ionic mechanisms deduced from the optimized parameter set were totally consistent with the qualitative view of ionic mechanisms of AP so far described in physiological literature.
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Affiliation(s)
- Yixin Zhang
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Futoshi Toyoda
- Department of Physiology, Shiga University of Medical Science, Otsu, Japan
- Central Research Laboratory, Shiga University of Medical Science, Otsu, Japan
| | - Yukiko Himeno
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Japan.
- Department of Physiology, Shiga University of Medical Science, Otsu, Japan.
| | - Akinori Noma
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Akira Amano
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Japan
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3
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Pironet A, Vandewiele F, Vennekens R. Exploring the role of TRPM4 in calcium-dependent triggered activity and cardiac arrhythmias. J Physiol 2024; 602:1605-1621. [PMID: 37128952 DOI: 10.1113/jp283831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 04/28/2023] [Indexed: 05/03/2023] Open
Abstract
Cardiac arrhythmias pose a major threat to a patient's health, yet prove to be often difficult to predict, prevent and treat. A key mechanism in the occurrence of arrhythmias is disturbed Ca2+ homeostasis in cardiac muscle cells. As a Ca2+-activated non-selective cation channel, TRPM4 has been linked to Ca2+-induced arrhythmias, potentially contributing to translating an increase in intracellular Ca2+ concentration into membrane depolarisation and an increase in cellular excitability. Indeed, evidence from genetically modified mice, analysis of mutations in human patients and the identification of a TRPM4 blocking compound that can be applied in vivo further underscore this hypothesis. Here, we provide an overview of these data in the context of our current understanding of Ca2+-dependent arrhythmias.
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Affiliation(s)
- Andy Pironet
- Laboratory of Ion Channel Research, VIB Centre for Brain and Disease Research, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Frone Vandewiele
- Laboratory of Ion Channel Research, VIB Centre for Brain and Disease Research, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
| | - Rudi Vennekens
- Laboratory of Ion Channel Research, VIB Centre for Brain and Disease Research, Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium
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4
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Himeno Y, Zhang Y, Enomoto S, Nomura H, Yamamoto N, Kiyokawa S, Ujihara M, Muangkram Y, Noma A, Amano A. Ionic Mechanisms of Propagated Repolarization in a One-Dimensional Strand of Human Ventricular Myocyte Model. Int J Mol Sci 2023; 24:15378. [PMID: 37895058 PMCID: PMC10607672 DOI: 10.3390/ijms242015378] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Accepted: 10/13/2023] [Indexed: 10/29/2023] Open
Abstract
Although repolarization has been suggested to propagate in cardiac tissue both theoretically and experimentally, it has been challenging to estimate how and to what extent the propagation of repolarization contributes to relaxation because repolarization only occurs in the course of membrane excitation in normal hearts. We established a mathematical model of a 1D strand of 600 myocytes stabilized at an equilibrium potential near the plateau potential level by introducing a sustained component of the late sodium current (INaL). By applying a hyperpolarizing stimulus to a small part of the strand, we succeeded in inducing repolarization which propagated along the strand at a velocity of 1~2 cm/s. The ionic mechanisms responsible for repolarization at the myocyte level, i.e., the deactivation of both the INaL and the L-type calcium current (ICaL), and the activation of the rapid component of delayed rectifier potassium current (IKr) and the inward rectifier potassium channel (IK1), were found to be important for the propagation of repolarization in the myocyte strand. Using an analogy with progressive activation of the sodium current (INa) in the propagation of excitation, regenerative activation of the predominant magnitude of IK1 makes the myocytes at the wave front start repolarization in succession through the electrical coupling via gap junction channels.
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Affiliation(s)
- Yukiko Himeno
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan; (Y.Z.); (A.N.); (A.A.)
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5
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Terrar DA. Timing mechanisms to control heart rhythm and initiate arrhythmias: roles for intracellular organelles, signalling pathways and subsarcolemmal Ca 2. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220170. [PMID: 37122228 PMCID: PMC10150226 DOI: 10.1098/rstb.2022.0170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Rhythms of electrical activity in all regions of the heart can be influenced by a variety of intracellular membrane bound organelles. This is true both for normal pacemaker activity and for abnormal rhythms including those caused by early and delayed afterdepolarizations under pathological conditions. The influence of the sarcoplasmic reticulum (SR) on cardiac electrical activity is widely recognized, but other intracellular organelles including lysosomes and mitochondria also contribute. Intracellular organelles can provide a timing mechanism (such as an SR clock driven by cyclic uptake and release of Ca2+, with an important influence of intraluminal Ca2+), and/or can act as a Ca2+ store involved in signalling mechanisms. Ca2+ plays many diverse roles including carrying electric current, driving electrogenic sodium-calcium exchange (NCX) particularly when Ca2+ is extruded across the surface membrane causing depolarization, and activation of enzymes which target organelles and surface membrane proteins. Heart function is also influenced by Ca2+ mobilizing agents (cADP-ribose, nicotinic acid adenine dinucleotide phosphate and inositol trisphosphate) acting on intracellular organelles. Lysosomal Ca2+ release exerts its effects via calcium/calmodulin-dependent protein kinase II to promote SR Ca2+ uptake, and contributes to arrhythmias resulting from excessive beta-adrenoceptor stimulation. A separate arrhythmogenic mechanism involves lysosomes, mitochondria and SR. Interacting intracellular organelles, therefore, have profound effects on heart rhythms and NCX plays a central role. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Affiliation(s)
- Derek A Terrar
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
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Agrawal A, Wang K, Polonchuk L, Cooper J, Hendrix M, Gavaghan DJ, Mirams GR, Clerx M. Models of the cardiac L-type calcium current: A quantitative review. WIREs Mech Dis 2023; 15:e1581. [PMID: 36028219 PMCID: PMC10078428 DOI: 10.1002/wsbm.1581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 06/16/2022] [Accepted: 07/19/2022] [Indexed: 01/31/2023]
Abstract
The L-type calcium current (I CaL ) plays a critical role in cardiac electrophysiology, and models ofI CaL are vital tools to predict arrhythmogenicity of drugs and mutations. Five decades of measuring and modelingI CaL have resulted in several competing theories (encoded in mathematical equations). However, the introduction of new models has not typically been accompanied by a data-driven critical comparison with previous work, so that it is unclear which model is best suited for any particular application. In this review, we describe and compare 73 published mammalianI CaL models and use simulated experiments to show that there is a large variability in their predictions, which is not substantially diminished when grouping by species or other categories. We provide model code for 60 models, list major data sources, and discuss experimental and modeling work that will be required to reduce this huge list of competing theories and ultimately develop a community consensus model ofI CaL . This article is categorized under: Cardiovascular Diseases > Computational Models Cardiovascular Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Aditi Agrawal
- Computational Biology & Health Informatics, Department of Computer ScienceUniversity of OxfordOxfordUK
| | - Ken Wang
- Pharma Research and Early Development, Innovation Center BaselF. Hoffmann‐La Roche Ltd.BaselSwitzerland
| | - Liudmila Polonchuk
- Pharma Research and Early Development, Innovation Center BaselF. Hoffmann‐La Roche Ltd.BaselSwitzerland
| | - Jonathan Cooper
- Centre for Advanced Research ComputingUniversity College LondonLondonUK
| | - Maurice Hendrix
- Centre for Mathematical Medicine & Biology, School of Mathematical SciencesUniversity of NottinghamNottinghamUK
- Digital Research Service, Information SciencesUniversity of NottinghamNottinghamUK
| | - David J. Gavaghan
- Computational Biology & Health Informatics, Department of Computer ScienceUniversity of OxfordOxfordUK
| | - Gary R. Mirams
- Centre for Mathematical Medicine & Biology, School of Mathematical SciencesUniversity of NottinghamNottinghamUK
| | - Michael Clerx
- Centre for Mathematical Medicine & Biology, School of Mathematical SciencesUniversity of NottinghamNottinghamUK
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7
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Kohjitani H, Koda S, Himeno Y, Makiyama T, Yamamoto Y, Yoshinaga D, Wuriyanghai Y, Kashiwa A, Toyoda F, Zhang Y, Amano A, Noma A, Kimura T. Gradient-based parameter optimization method to determine membrane ionic current composition in human induced pluripotent stem cell-derived cardiomyocytes. Sci Rep 2022; 12:19110. [PMID: 36351955 PMCID: PMC9646722 DOI: 10.1038/s41598-022-23398-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 10/31/2022] [Indexed: 11/11/2022] Open
Abstract
Premature cardiac myocytes derived from human induced pluripotent stem cells (hiPSC-CMs) show heterogeneous action potentials (APs), probably due to different expression patterns of membrane ionic currents. We developed a method for determining expression patterns of functional channels in terms of whole-cell ionic conductance (Gx) using individual spontaneous AP configurations. It has been suggested that apparently identical AP configurations can be obtained using different sets of ionic currents in mathematical models of cardiac membrane excitation. If so, the inverse problem of Gx estimation might not be solved. We computationally tested the feasibility of the gradient-based optimization method. For a realistic examination, conventional 'cell-specific models' were prepared by superimposing the model output of AP on each experimental AP recorded by conventional manual adjustment of Gxs of the baseline model. Gxs of 4-6 major ionic currents of the 'cell-specific models' were randomized within a range of ± 5-15% and used as an initial parameter set for the gradient-based automatic Gxs recovery by decreasing the mean square error (MSE) between the target and model output. Plotting all data points of the MSE-Gx relationship during optimization revealed progressive convergence of the randomized population of Gxs to the original value of the cell-specific model with decreasing MSE. The absence of any other local minimum in the global search space was confirmed by mapping the MSE by randomizing Gxs over a range of 0.1-10 times the control. No additional local minimum MSE was obvious in the whole parameter space, in addition to the global minimum of MSE at the default model parameter.
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Affiliation(s)
- Hirohiko Kohjitani
- grid.258799.80000 0004 0372 2033Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Shigeya Koda
- grid.262576.20000 0000 8863 9909Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Yukiko Himeno
- grid.262576.20000 0000 8863 9909Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Takeru Makiyama
- grid.258799.80000 0004 0372 2033Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yuta Yamamoto
- grid.258799.80000 0004 0372 2033Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Daisuke Yoshinaga
- grid.258799.80000 0004 0372 2033Department Pediatrics, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yimin Wuriyanghai
- grid.258799.80000 0004 0372 2033Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Asami Kashiwa
- grid.258799.80000 0004 0372 2033Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Futoshi Toyoda
- grid.410827.80000 0000 9747 6806Department of Physiology, Shiga University of Medical Science, Otsu, Japan
| | - Yixin Zhang
- grid.262576.20000 0000 8863 9909Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Akira Amano
- grid.262576.20000 0000 8863 9909Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Akinori Noma
- grid.262576.20000 0000 8863 9909Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Japan
| | - Takeshi Kimura
- grid.258799.80000 0004 0372 2033Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
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Tsumoto K, Kurata Y. Bifurcations and Proarrhythmic Behaviors in Cardiac Electrical Excitations. Biomolecules 2022; 12:biom12030459. [PMID: 35327651 PMCID: PMC8946197 DOI: 10.3390/biom12030459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Revised: 03/09/2022] [Accepted: 03/14/2022] [Indexed: 12/23/2022] Open
Abstract
The heart is a hierarchical dynamic system consisting of molecules, cells, and tissues, and acts as a pump for blood circulation. The pumping function depends critically on the preceding electrical activity, and disturbances in the pattern of excitation propagation lead to cardiac arrhythmia and pump failure. Excitation phenomena in cardiomyocytes have been modeled as a nonlinear dynamical system. Because of the nonlinearity of excitation phenomena, the system dynamics could be complex, and various analyses have been performed to understand the complex dynamics. Understanding the mechanisms underlying proarrhythmic responses in the heart is crucial for developing new ways to prevent and control cardiac arrhythmias and resulting contractile dysfunction. When the heart changes to a pathological state over time, the action potential (AP) in cardiomyocytes may also change to a different state in shape and duration, often undergoing a qualitative change in behavior. Such a dynamic change is called bifurcation. In this review, we first summarize the contribution of ion channels and transporters to AP formation and our knowledge of ion-transport molecules, then briefly describe bifurcation theory for nonlinear dynamical systems, and finally detail its recent progress, focusing on the research that attempts to understand the developing mechanisms of abnormal excitations in cardiomyocytes from the perspective of bifurcation phenomena.
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9
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Occurrence of early afterdepolarization under healthy or hypertrophic cardiomyopathy conditions in the human ventricular endocardial myocyte: In silico study using 109 torsadogenic or non-torsadogenic compounds. Toxicol Appl Pharmacol 2022; 438:115914. [DOI: 10.1016/j.taap.2022.115914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 01/19/2022] [Accepted: 02/05/2022] [Indexed: 11/18/2022]
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10
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Kir Channel Molecular Physiology, Pharmacology, and Therapeutic Implications. Handb Exp Pharmacol 2021; 267:277-356. [PMID: 34345939 DOI: 10.1007/164_2021_501] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
For the past two decades several scholarly reviews have appeared on the inwardly rectifying potassium (Kir) channels. We would like to highlight two efforts in particular, which have provided comprehensive reviews of the literature up to 2010 (Hibino et al., Physiol Rev 90(1):291-366, 2010; Stanfield et al., Rev Physiol Biochem Pharmacol 145:47-179, 2002). In the past decade, great insights into the 3-D atomic resolution structures of Kir channels have begun to provide the molecular basis for their functional properties. More recently, computational studies are beginning to close the time domain gap between in silico dynamic and patch-clamp functional studies. The pharmacology of these channels has also been expanding and the dynamic structural studies provide hope that we are heading toward successful structure-based drug design for this family of K+ channels. In the present review we focus on placing the physiology and pharmacology of this K+ channel family in the context of atomic resolution structures and in providing a glimpse of the promising future of therapeutic opportunities.
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Corrado C, Avezzù A, Lee AWC, Mendoca Costa C, Roney CH, Strocchi M, Bishop M, Niederer SA. Using cardiac ionic cell models to interpret clinical data. WIREs Mech Dis 2020; 13:e1508. [PMID: 33027553 DOI: 10.1002/wsbm.1508] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/27/2020] [Accepted: 09/04/2020] [Indexed: 01/24/2023]
Abstract
For over 100 years cardiac electrophysiology has been measured in the clinic. The electrical signals that can be measured span from noninvasive ECG and body surface potentials measurements through to detailed invasive measurements of local tissue electrophysiology. These electrophysiological measurements form a crucial component of patient diagnosis and monitoring; however, it remains challenging to quantitatively link changes in clinical electrophysiology measurements to biophysical cellular function. Multi-scale biophysical computational models represent one solution to this problem. These models provide a formal framework for linking cellular function through to emergent whole organ function and routine clinical diagnostic signals. In this review, we describe recent work on the use of computational models to interpret clinical electrophysiology signals. We review the simulation of human cardiac myocyte electrophysiology in the atria and the ventricles and how these models are being used to link organ scale function to patient disease mechanisms and therapy response in patients receiving implanted defibrillators, \cardiac resynchronisation therapy or suffering from atrial fibrillation and ventricular tachycardia. There is a growing use of multi-scale biophysical models to interpret clinical data. This allows cardiologists to link clinical observations with cellular mechanisms to better understand cardiopathophysiology and identify novel treatment strategies. This article is categorized under: Cardiovascular Diseases > Computational Models Cardiovascular Diseases > Biomedical Engineering Cardiovascular Diseases > Molecular and Cellular Physiology.
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12
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Liu CM, Lin FZ, Chen YC, Lin YK, Lu YY, Wu CI, Higa S, Chen SA, Chen YJ. Concurrent increases in post-pacing action potential duration and contractility predict occurrence of ventricular arrhythmia. Pflugers Arch 2020; 472:1783-1791. [PMID: 32794054 DOI: 10.1007/s00424-020-02445-7] [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: 06/30/2020] [Revised: 07/29/2020] [Accepted: 07/31/2020] [Indexed: 12/14/2022]
Abstract
Excitation-contraction coupling from the integration of action potential duration (APD) and muscle contractility plays an important role in arrhythmogenesis. We aimed to determine whether distinctive excitation-contraction coupling contributes to the genesis of ventricular tachycardias (VTs). Action potential (AP) and mechanical activity were simultaneously recorded under electrical pacing (cycle lengths from 1000 to 100 ms) in the tissue model created from isolated rabbit right ventricular outflow tracts treated with NS 5806 (10 μM, transient outward potassium current enhancer), pinacidil (2 μM, ATP-sensitive potassium channel opener), and pilsicainide (5 μM, sodium channel blocker). There were 15 (9.9%) inducible VT episodes (group 1) and 136 (90.1%) non-inducible VT episodes (group 2) in our tissue model. Group 1 had greater post-pacing increases of the first occurrence of AP at 90% repolarization (ΔAPD90, p < 0.001) and contractility (ΔContractility, p = 0.003) compared with group 2. Triggered VT episodes were common (72.7%) in cases with a ΔAPD90 > 15% and a ΔContractility > 270%, but were undetectable in those with a ΔAPD90 < 15% and a ΔContractility < 270%. In those with pacing-induced VTs, KB-R7943 (10 μM, a Na+-Ca2+ exchanger inhibitor, NCX inhibitor) significantly reduced the occurrence of VTs from 100.0 to 20.0% (15/15 to 3/15 episodes, p < 0.001). Concurrent increases in both post-pacing APD and contractility resulted in the occurrence of ventricular arrhythmias. NCX inhibition may be a potential therapeutic strategy for ventricular arrhythmias.
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Affiliation(s)
- Chih-Min Liu
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Feng-Zhi Lin
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, National Defense Medical Center, Taipei, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, 111 Hsin-Lung Road, Sec. 3, Taipei, Taiwan
- Division of Cardiology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yen-Yu Lu
- Division of Cardiology, Sijhih Cathay General Hospital, New Taipei City, Taiwan
| | - Cheng-I Wu
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Satoshi Higa
- Cardiac Electrophysiology and Pacing Laboratory, Division of Cardiovascular Medicine, Makiminato Central Hospital, Okinawa, Japan
| | - Shih-Ann Chen
- Heart Rhythm Center, Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
- Institute of Clinical Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, 111 Hsin-Lung Road, Sec. 3, Taipei, Taiwan.
- Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
- Cardiovacular Research Center, Wan Fang Hospital, Taipei Medical University , Taipei, Taiwan.
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Hwang M, Lim CH, Leem CH, Shim EB. In silico models for evaluating proarrhythmic risk of drugs. APL Bioeng 2020; 4:021502. [PMID: 32548538 PMCID: PMC7274812 DOI: 10.1063/1.5132618] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 04/27/2020] [Indexed: 02/07/2023] Open
Abstract
Safety evaluation of drugs requires examination of the risk of generating Torsade de Pointes (TdP) because it can lead to sudden cardiac death. Until recently, the QT interval in the electrocardiogram (ECG) has been used in the evaluation of TdP risk because the QT interval is known to be associated with the development of TdP. Although TdP risk evaluation based on QT interval has been successful in removing drugs with TdP risk from the market, some safe drugs may have also been affected due to the low specificity of QT interval-based evaluation. For more accurate evaluation of drug safety, the comprehensive in vitro proarrhythmia assay (CiPA) has been proposed by regulatory agencies, industry, and academia. Although the CiPA initiative includes in silico evaluation of cellular action potential as a component, attempts to utilize in silico simulation in drug safety evaluation are expanding, even to simulating human ECG using biophysical three-dimensional models of the heart and torso under the effects of drugs. Here, we review recent developments in the use of in silico models for the evaluation of the proarrhythmic risk of drugs. We review the single cell, one-dimensional, two-dimensional, and three-dimensional models and their applications reported in the literature and discuss the possibility of utilizing ECG simulation in drug safety evaluation.
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Affiliation(s)
- Minki Hwang
- SiliconSapiens Inc., Seoul 06097, South Korea
| | - Chul-Hyun Lim
- Department of Mechanical and Biomedical Engineering, Kangwon National University, Chuncheon 24341, South Korea
| | - Chae Hun Leem
- Department of Physiology, College of Medicine, University of Ulsan, Asan Medical Center, Seoul 05505, South Korea
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14
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Kistamás K, Veress R, Horváth B, Bányász T, Nánási PP, Eisner DA. Calcium Handling Defects and Cardiac Arrhythmia Syndromes. Front Pharmacol 2020; 11:72. [PMID: 32161540 PMCID: PMC7052815 DOI: 10.3389/fphar.2020.00072] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 01/24/2020] [Indexed: 12/13/2022] Open
Abstract
Calcium ions (Ca2+) play a major role in the cardiac excitation-contraction coupling. Intracellular Ca2+ concentration increases during systole and falls in diastole thereby determining cardiac contraction and relaxation. Normal cardiac function also requires perfect organization of the ion currents at the cellular level to drive action potentials and to maintain action potential propagation and electrical homogeneity at the tissue level. Any imbalance in Ca2+ homeostasis of a cardiac myocyte can lead to electrical disturbances. This review aims to discuss cardiac physiology and pathophysiology from the elementary membrane processes that can cause the electrical instability of the ventricular myocytes through intracellular Ca2+ handling maladies to inherited and acquired arrhythmias. Finally, the paper will discuss the current therapeutic approaches targeting cardiac arrhythmias.
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Affiliation(s)
- Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
| | - Roland Veress
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Department of Dental Physiology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - David A Eisner
- Division of Cardiovascular Sciences, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
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Kurata Y, Tsumoto K, Hayashi K, Hisatome I, Kuda Y, Tanida M. Multiple Dynamical Mechanisms of Phase-2 Early Afterdepolarizations in a Human Ventricular Myocyte Model: Involvement of Spontaneous SR Ca 2+ Release. Front Physiol 2020; 10:1545. [PMID: 31998140 PMCID: PMC6965073 DOI: 10.3389/fphys.2019.01545] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 12/05/2019] [Indexed: 12/19/2022] Open
Abstract
Early afterdepolarization (EAD) is known to cause lethal ventricular arrhythmias in long QT syndrome (LQTS). In this study, dynamical mechanisms of EAD formation in human ventricular myocytes (HVMs) were investigated using the mathematical model developed by ten Tusscher and Panfilov (Am J Physiol Heart Circ Physiol 291, 2006). We explored how the rapid (IKr) and slow (IKs) components of delayed-rectifier K+ channel currents, L-type Ca2+ channel current (ICa L), Na+/Ca2+ exchanger current (INCX), and intracellular Ca2+ handling via the sarcoplasmic reticulum (SR) contribute to initiation, termination and modulation of phase-2 EADs during pacing in relation to bifurcation phenomena in non-paced model cells. Parameter-dependent dynamical behaviors of the non-paced model cell were determined by calculating stabilities of equilibrium points (EPs) and limit cycles, and bifurcation points to construct bifurcation diagrams. Action potentials (APs) and EADs during pacing were reproduced by numerical simulations for constructing phase diagrams of the paced model cell dynamics. Results are summarized as follows: (1) A modified version of the ten Tusscher-Panfilov model with accelerated ICaL inactivation could reproduce bradycardia-related EADs in LQTS type 2 and β-adrenergic stimulation-induced EADs in LQTS type 1. (2) Two types of EADs with different initiation mechanisms, ICaL reactivation-dependent and spontaneous SR Ca2+ release-mediated EADs, were detected. (3) Termination of EADs (AP repolarization) during pacing depended on the slow activation of IKs. (4) Spontaneous SR Ca2+ releases occurred at higher Ca2+ uptake rates, attributable to the instability of steady-state intracellular Ca2+ concentrations. Dynamical mechanisms of EAD formation and termination in the paced model cell are closely related to stability changes (bifurcations) in dynamical behaviors of the non-paced model cell, but they are model-dependent. Nevertheless, the modified ten Tusscher-Panfilov model would be useful for systematically investigating possible dynamical mechanisms of EAD-related arrhythmias in LQTS.
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Affiliation(s)
- Yasutaka Kurata
- Department of Physiology II, Kanazawa Medical University, Uchinada, Japan
| | - Kunichika Tsumoto
- Department of Physiology II, Kanazawa Medical University, Uchinada, Japan
| | - Kenshi Hayashi
- Department of Cardiovascular and Internal Medicine, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
| | - Ichiro Hisatome
- Department of Genetic Medicine and Regenerative Therapeutics, Graduate School of Medical Sciences, Tottori University, Yonago, Japan
| | - Yuhichi Kuda
- Department of Physiology II, Kanazawa Medical University, Uchinada, Japan
| | - Mamoru Tanida
- Department of Physiology II, Kanazawa Medical University, Uchinada, Japan
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16
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Umehara S, Tan X, Okamoto Y, Ono K, Noma A, Amano A, Himeno Y. Mechanisms Underlying Spontaneous Action Potential Generation Induced by Catecholamine in Pulmonary Vein Cardiomyocytes: A Simulation Study. Int J Mol Sci 2019; 20:ijms20122913. [PMID: 31207916 PMCID: PMC6628582 DOI: 10.3390/ijms20122913] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 06/11/2019] [Accepted: 06/12/2019] [Indexed: 12/24/2022] Open
Abstract
Cardiomyocytes and myocardial sleeves dissociated from pulmonary veins (PVs) potentially generate ectopic automaticity in response to noradrenaline (NA), and thereby trigger atrial fibrillation. We developed a mathematical model of rat PV cardiomyocytes (PVC) based on experimental data that incorporates the microscopic framework of the local control theory of Ca2+ release from the sarcoplasmic reticulum (SR), which can generate rhythmic Ca2+ release (limit cycle revealed by the bifurcation analysis) when total Ca2+ within the cell increased. Ca2+ overload in SR increased resting Ca2+ efflux through the type II inositol 1,4,5-trisphosphate (IP3) receptors (InsP3R) as well as ryanodine receptors (RyRs), which finally triggered massive Ca2+ release through activation of RyRs via local Ca2+ accumulation in the vicinity of RyRs. The new PVC model exhibited a resting potential of −68 mV. Under NA effects, repetitive Ca2+ release from SR triggered spontaneous action potentials (APs) by evoking transient depolarizations (TDs) through Na+/Ca2+ exchanger (APTDs). Marked and variable latencies initiating APTDs could be explained by the time courses of the α1- and β1-adrenergic influence on the regulation of intracellular Ca2+ content and random occurrences of spontaneous TD activating the first APTD. Positive and negative feedback relations were clarified under APTD generation.
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Affiliation(s)
- Shohei Umehara
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan.
| | - Xiaoqiu Tan
- Institute of Cardiovascular Research, Southwest Medical University, Luzhou 640000, China.
| | - Yosuke Okamoto
- Department of Cell Physiology, Graduate School of Medicine, Akita University, Akita 010-8543, Japan.
| | - Kyoichi Ono
- Department of Cell Physiology, Graduate School of Medicine, Akita University, Akita 010-8543, Japan.
| | - Akinori Noma
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan.
| | - Akira Amano
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan.
| | - Yukiko Himeno
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Shiga 525-8577, Japan.
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Tian G, Sun Y, Liu S, Li C, Chen S, Qiu R, Zhang X, Li Y, Li M, Shang H. Therapeutic Effects of Wenxin Keli in Cardiovascular Diseases: An Experimental and Mechanism Overview. Front Pharmacol 2018; 9:1005. [PMID: 30233380 PMCID: PMC6134428 DOI: 10.3389/fphar.2018.01005] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 08/16/2018] [Indexed: 02/05/2023] Open
Abstract
Cardiovascular diseases (CVDs) are the major public health problem and a leading cause of morbidity and mortality on a global basis. Wenxin Keli (WXKL), a formally classical Chinese patent medicine with obvious efficacy and favorable safety, plays a great role in the management of patients with CVDs. Accumulating evidence from various animal and cell studies has showed that WXKL could protect myocardium and anti-arrhythmia against CVDs. WXKL exhibited its cardioprotective roles by inhibiting inflammatory reaction, decreasing oxidative stress, regulating vasomotor disorders, lowering cell apoptosis, and protection against endothelial injure, myocardial ischemia, cardiac fibrosis, and cardiac hypertrophy. Besides, WXKL could effectively shorten the QRS and Q-T intervals, decrease the incidence of atrial/ventricular fibrillation and the number of ventricular tachycardia episodes, improve the severity of arrhythmias by regulating various ion channels with different potencies, mainly comprising peak sodium current (INa), late sodium current (INaL), transient outward potassium current (Ito), L-type calcium current (ICaL), and pacemaker current (If).
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Affiliation(s)
- Guihua Tian
- Chinese Cochrane Center, West China Hospital, Sichuan University, Chengdu, China
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Yang Sun
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Shuo Liu
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Chengyu Li
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Shiqi Chen
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Ruijin Qiu
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Xiaoyu Zhang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Youping Li
- Chinese Cochrane Center, West China Hospital, Sichuan University, Chengdu, China
| | - Min Li
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
| | - Hongcai Shang
- Key Laboratory of Chinese Internal Medicine of Ministry of Education and Beijing, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing, China
- Institute of Integration of Traditional Chinese and Western Medicine, Guangzhou Medical University, Guangzhou, China
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18
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Muangkram Y, Noma A, Amano A. A new myofilament contraction model with ATP consumption for ventricular cell model. J Physiol Sci 2018; 68:541-554. [PMID: 28770433 PMCID: PMC10717283 DOI: 10.1007/s12576-017-0560-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 07/14/2017] [Indexed: 01/14/2023]
Abstract
A new contraction model of cardiac muscle was developed by combining previously described biochemical and biophysical models. The biochemical component of the new contraction model represents events in the presence of Ca2+-crossbridge attachment and power stroke following inorganic phosphate release, detachment evoked by the replacement of ADP by ATP, ATP hydrolysis, and recovery stroke. The biophysical component focuses on Ca2+ activation and force (F b) development assuming an equivalent crossbridge. The new model faithfully incorporates the major characteristics of the biochemical and biophysical models, such as F b activation by transient Ca2+ ([Ca2+]-F b), [Ca2+]-ATP hydrolysis relations, sarcomere length-F b, and F b recovery after jumps in length under the isometric mode and upon sarcomere shortening after a rapid release of mechanical load under the isotonic mode together with the load-velocity relationship. ATP consumption was obtained for all responses. When incorporated in a ventricular cell model, the contraction model was found to share approximately 60% of the total ATP usage in the cell model.
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Affiliation(s)
- Yuttamol Muangkram
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan
| | - Akinori Noma
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan
| | - Akira Amano
- Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga, 525-8577, Japan.
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19
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Ishihara K. External K + dependence of strong inward rectifier K + channel conductance is caused not by K + but by competitive pore blockade by external Na .. J Gen Physiol 2018; 150:977-989. [PMID: 29907600 PMCID: PMC6028490 DOI: 10.1085/jgp.201711936] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 04/23/2018] [Accepted: 05/21/2018] [Indexed: 11/20/2022] Open
Abstract
Strong inward rectifier K+ (sKir) channels determine the membrane potentials of many types of excitable and nonexcitable cells, most notably the resting potentials of cardiac myocytes. They show little outward current during membrane depolarization (i.e., strong inward rectification) because of the channel blockade by cytoplasmic polyamines, which depends on the deviation of the membrane potential from the K+ equilibrium potential (V - EK) when the extracellular K+ concentration ([K+]out) is changed. Because their open-channel conductance is apparently proportional to the "square root" of [K+]out, increases/decreases in [K+]out enhance/diminish outward currents through sKir channels at membrane potentials near their reversal potential, which also affects, for example, the repolarization and action-potential duration of cardiac myocytes. Despite its importance, however, the mechanism underlying the [K+]out dependence of the open sKir channel conductance has remained elusive. By studying Kir2.1, the canonical member of the sKir channel family, we first show that the outward currents of Kir2.1 are observed under the external K+-free condition when its inward rectification is reduced and that the complete inhibition of the currents at 0 [K+]out results solely from pore blockade caused by the polyamines. Moreover, the noted square-root proportionality of the open sKir channel conductance to [K+]out is mediated by the pore blockade by the external Na+, which is competitive with the external K+ Our results show that external K+ itself does not activate or facilitate K+ permeation through the open sKir channel to mediate the apparent external K+ dependence of its open channel conductance. The paradoxical increase/decrease in outward sKir channel currents during alternations in [K+]out, which is physiologically relevant, is caused by competition from impermeant extracellular Na.
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Affiliation(s)
- Keiko Ishihara
- Department of Physiology, Kurume University School of Medicine, Kurume, Japan
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20
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Hysteretic Dynamics of Multi-Stable Early Afterdepolarisations with Repolarisation Reserve Attenuation: A Potential Dynamical Mechanism for Cardiac Arrhythmias. Sci Rep 2017; 7:10771. [PMID: 28883639 PMCID: PMC5589958 DOI: 10.1038/s41598-017-11355-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 08/23/2017] [Indexed: 02/08/2023] Open
Abstract
Some cardiovascular and non-cardiovascular drugs frequently cause excessive prolongation of the cardiac action potential (AP) and lead to the development of early afterdepolarisations (EADs), which trigger lethal ventricular arrhythmias. Combining computer simulations in APs with numerical calculations based on dynamical system theory, we investigated stability changes of APs observed in a paced human ventricular myocyte model by decreasing and/or increasing the rapid (IKr) and slow (IKs) components of delayed rectifying K+ current. Upon reducing IKr, the APs without EADs (no-EAD response) showed gradual prolongation of AP duration (APD), and were annihilated without AP configuration changes due to the occurrence of saddle-node bifurcations. This annihilation caused a transition to an AP with EADs as a new stable steady state. Furthermore, reducing repolarisation currents (repolarisation reserve attenuation) evoked multi-stable states consisting of APs with different APDs, and caused multiple hysteretic dynamics. Depending on initial ion circumstances within ventricular myocytes, these multi-stable AP states might increase the local/global heterogeneity of AP repolarisations in the ventricle. Thus, the EAD-induced arrhythmias with repolarisation reserve attenuation might be attributed to the APD variability caused by multi-stability in cardiac AP dynamics.
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21
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Li M, Xu X, Yang X, Kwong JSW, Shang H. The cardioprotective and antiarrhythmic effects of Nardostachys chinensis in animal and cell experiments. Altern Ther Health Med 2017; 17:398. [PMID: 28797251 PMCID: PMC5553922 DOI: 10.1186/s12906-017-1910-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Accepted: 08/04/2017] [Indexed: 12/13/2022]
Abstract
Background Cardiovascular disease (CVD) is the leading cause of premature death throughout the world. An estimated 17.5 million people died from CVD in 2012, representing 31% of all global deaths. Nardostachys chinensis (NC), a typical traditional Chinese medicine (TCM), plays a crucial role in the management of patients with CVD, especially for those with cardiac arrhythmia. The purpose of this study was to evaluate the cardioprotective and antiarrhythmic effects of NC in animal and cell experiments. Methods To review the cardioprotective and antiarrhythmic effects of NC, studies of NC on cardiovascular diseases in animal and cell experiments were identified from five databases through April 2016. Two investigators independently conducted the literature search, study selection, and data extraction. Results A total of 16 studies were identified, including five animal experiments and eleven cell experiments. Four studies showed significant effects of NC on myocardial protection by inhibiting myocardial apoptosis, inflammation and oxidative stress. Twelve studies indicated significant beneficial effects of NC in cardiac arrhythmia primarily through the modulation of ion channels (Ik, Ik1, INa, ICa-L, Ito). Conclusion The above findings showed the possible efficacy of NC via its cardioprotective and antiarrhythmic effects, but the results should be interpreted with caution due to the limitations and the deficiencies in the studies.
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22
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Abstract
There has been a significant progress in our understanding of the molecular mechanisms by which calcium (Ca2+) ions mediate various types of cardiac arrhythmias. A growing list of inherited gene defects can cause potentially lethal cardiac arrhythmia syndromes, including catecholaminergic polymorphic ventricular tachycardia, congenital long QT syndrome, and hypertrophic cardiomyopathy. In addition, acquired deficits of multiple Ca2+-handling proteins can contribute to the pathogenesis of arrhythmias in patients with various types of heart disease. In this review article, we will first review the key role of Ca2+ in normal cardiac function-in particular, excitation-contraction coupling and normal electric rhythms. The functional involvement of Ca2+ in distinct arrhythmia mechanisms will be discussed, followed by various inherited arrhythmia syndromes caused by mutations in Ca2+-handling proteins. Finally, we will discuss how changes in the expression of regulation of Ca2+ channels and transporters can cause acquired arrhythmias, and how these mechanisms might be targeted for therapeutic purposes.
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Affiliation(s)
- Andrew P Landstrom
- From the Section of Cardiology, Department of Pediatrics (A.P.L.), Cardiovascular Research Institute (A.P.L., X.H.T.W.), and Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), Center for Space Medicine (X.H.T.W.), Baylor College of Medicine, Houston, TX; and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Dobromir Dobrev
- From the Section of Cardiology, Department of Pediatrics (A.P.L.), Cardiovascular Research Institute (A.P.L., X.H.T.W.), and Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), Center for Space Medicine (X.H.T.W.), Baylor College of Medicine, Houston, TX; and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.)
| | - Xander H T Wehrens
- From the Section of Cardiology, Department of Pediatrics (A.P.L.), Cardiovascular Research Institute (A.P.L., X.H.T.W.), and Departments of Molecular Physiology and Biophysics, Medicine (Cardiology), Center for Space Medicine (X.H.T.W.), Baylor College of Medicine, Houston, TX; and Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Essen, Germany (D.D.).
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23
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Zeng M, Jiang W, Tian Y, Hao J, Cao Z, Liu Z, Fu C, Zhang P, Ma J. Andrographolide inhibits arrhythmias and is cardioprotective in rabbits. Oncotarget 2017; 8:61226-61238. [PMID: 28977859 PMCID: PMC5617419 DOI: 10.18632/oncotarget.18051] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 04/21/2017] [Indexed: 01/01/2023] Open
Abstract
Andrographolide has a protective effect on the cardiovascular system. To study its cardic-electrophysiological effects, action potentials and voltage-gated Na+ (INa), Ca2+ (ICaL), and K+ (IK1, IKr, Ito and IKur) currents were recorded using whole-cell patch clamp and current clamp techniques. Additionally, the effects of andrographolide on aconitine-induced arrhythmias were assessed on electrocardiograms in vivo. We found that andrographolide shortened action potential duration and reduced maximum upstroke velocity in rabbit left ventricular and left atrial myocytes. Andrographolide attenuated rate-dependence of action potential duration, and reduced or abolished delayed afterdepolarizations and triggered activities induced by isoproterenol (1 μM) and high calcium ([Ca2+]o=3.6 mM) in left ventricular myocytes. Andrographolide also concentration-dependently inhibited INa and ICaL, but had no effect on Ito, IKur, IK1, or IKr in rabbit left ventricular and left atrial myocytes. Andrographolide treatment increased the time and dosage thresholds of aconitine-induced arrhythmias, and reduced arrhythmia incidence and mortality in rabbits. Our results indicate that andrographolide inhibits cellular arrhythmias (delayed afterdepolarizations and triggered activities) and aconitine-induced arrhythmias in vivo, and these effects result from INa and ICaL inhibition. Andrographolide may be useful as a class I and IV antiarrhythmic therapeutic.
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Affiliation(s)
- Mengliu Zeng
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Wanzhen Jiang
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Youjia Tian
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Jie Hao
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Zhenzhen Cao
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Zhipei Liu
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Chen Fu
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Peihua Zhang
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Jihua Ma
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
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24
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Kurata Y, Tsumoto K, Hayashi K, Hisatome I, Tanida M, Kuda Y, Shibamoto T. Dynamical mechanisms of phase-2 early afterdepolarizations in human ventricular myocytes: insights from bifurcation analyses of two mathematical models. Am J Physiol Heart Circ Physiol 2016; 312:H106-H127. [PMID: 27836893 DOI: 10.1152/ajpheart.00115.2016] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 11/08/2016] [Accepted: 11/08/2016] [Indexed: 01/16/2023]
Abstract
Early afterdepolarization (EAD) is known as a cause of ventricular arrhythmias in long QT syndromes. We theoretically investigated how the rapid (IKr) and slow (IKs) components of delayed-rectifier K+ channel currents, L-type Ca2+ channel current (ICaL), Na+/Ca2+ exchanger current (INCX), Na+-K+ pump current (INaK), intracellular Ca2+ (Cai) handling via sarcoplasmic reticulum (SR), and intracellular Na+ concentration (Nai) contribute to initiation, termination, and modulation of phase-2 EADs, using two human ventricular myocyte models. Bifurcation structures of dynamical behaviors in model cells were explored by calculating equilibrium points, limit cycles (LCs), and bifurcation points as functions of parameters. EADs were reproduced by numerical simulations. The results are summarized as follows: 1) decreasing IKs and/or IKr or increasing ICaL led to EAD generation, to which mid-myocardial cell models were especially susceptible; the parameter regions of EADs overlapped the regions of stable LCs. 2) Two types of EADs (termination mechanisms), IKs activation-dependent and ICaL inactivation-dependent EADs, were detected; IKs was not necessarily required for EAD formation. 3) Inhibiting INCX suppressed EADs via facilitating Ca2+-dependent ICaL inactivation. 4) Cai dynamics (SR Ca2+ handling) and Nai strongly affected bifurcations and EAD generation in model cells via modulating ICaL, INCX, and INaK Parameter regions of EADs, often overlapping those of stable LCs, shifted depending on Cai and Nai in stationary and dynamic states. 5) Bradycardia-related induction of EADs was mainly due to decreases in Nai at lower pacing rates. This study demonstrates that bifurcation analysis allows us to understand the dynamical mechanisms of EAD formation more profoundly. NEW & NOTEWORTHY We investigated mechanisms of phase-2 early afterdepolarization (EAD) by bifurcation analyses of human ventricular myocyte (HVM) models. EAD formation in paced HVMs basically depended on bifurcation phenomena in non-paced HVMs, but was strongly affected by intracellular ion concentrations in stationary and dynamic states. EAD generation did not necessarily require IKs.
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Affiliation(s)
- Yasutaka Kurata
- Department of Physiology, Kanazawa Medical University, Ishikawa, Japan;
| | - Kunichika Tsumoto
- Department of Pharmacology, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Kenshi Hayashi
- Division of Cardiovascular Medicine, Kanazawa University Graduate School of Medicine, Kanazawa, Japan; and
| | - Ichiro Hisatome
- Department of Genetic Medicine and Regenerative Therapeutics, Tottori University Graduate School of Medical Science, Yonago, Japan
| | - Mamoru Tanida
- Department of Physiology, Kanazawa Medical University, Ishikawa, Japan
| | - Yuhichi Kuda
- Department of Physiology, Kanazawa Medical University, Ishikawa, Japan
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Himeno Y, Asakura K, Cha CY, Memida H, Powell T, Amano A, Noma A. A human ventricular myocyte model with a refined representation of excitation-contraction coupling. Biophys J 2016. [PMID: 26200878 DOI: 10.1016/j.bpj.2015.06.017] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cardiac Ca(2+)-induced Ca(2+) release (CICR) occurs by a regenerative activation of ryanodine receptors (RyRs) within each Ca(2+)-releasing unit, triggered by the activation of L-type Ca(2+) channels (LCCs). CICR is then terminated, most probably by depletion of Ca(2+) in the junctional sarcoplasmic reticulum (SR). Hinch et al. previously developed a tightly coupled LCC-RyR mathematical model, known as the Hinch model, that enables simulations to deal with a variety of functional states of whole-cell populations of a Ca(2+)-releasing unit using a personal computer. In this study, we developed a membrane excitation-contraction model of the human ventricular myocyte, which we call the human ventricular cell (HuVEC) model. This model is a hybrid of the most recent HuVEC models and the Hinch model. We modified the Hinch model to reproduce the regenerative activation and termination of CICR. In particular, we removed the inactivated RyR state and separated the single step of RyR activation by LCCs into triggering and regenerative steps. More importantly, we included the experimental measurement of a transient rise in Ca(2+) concentrations ([Ca(2+)], 10-15 μM) during CICR in the vicinity of Ca(2+)-releasing sites, and thereby calculated the effects of the local Ca(2+) gradient on CICR as well as membrane excitation. This HuVEC model successfully reconstructed both membrane excitation and key properties of CICR. The time course of CICR evoked by an action potential was accounted for by autonomous changes in an instantaneous equilibrium open probability of couplons. This autonomous time course was driven by a core feedback loop including the pivotal local [Ca(2+)], influenced by a time-dependent decay in the SR Ca(2+) content during CICR.
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Affiliation(s)
- Yukiko Himeno
- Biosimulation Research Center, College of Life Sciences, Ritsumeikan University, Shiga, Japan
| | - Keiichi Asakura
- Biosimulation Research Center, College of Life Sciences, Ritsumeikan University, Shiga, Japan; Nippon Shinyaku Co., Ltd., Kyoto, Japan
| | - Chae Young Cha
- Biosimulation Research Center, College of Life Sciences, Ritsumeikan University, Shiga, Japan; Oxford Centre for Diabetes Endocrinology and Metabolism, University of Oxford, Oxford, UK
| | - Hiraku Memida
- Biosimulation Research Center, College of Life Sciences, Ritsumeikan University, Shiga, Japan
| | - Trevor Powell
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - Akira Amano
- Biosimulation Research Center, College of Life Sciences, Ritsumeikan University, Shiga, Japan
| | - Akinori Noma
- Biosimulation Research Center, College of Life Sciences, Ritsumeikan University, Shiga, Japan.
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Effect of α-Allocryptopine on Delayed Afterdepolarizations and Triggered Activities in Mice Cardiomyocytes Treated with Isoproterenol. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:634172. [PMID: 26557861 PMCID: PMC4629026 DOI: 10.1155/2015/634172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 08/07/2015] [Accepted: 08/13/2015] [Indexed: 12/16/2022]
Abstract
Objective. To investigate the effect of α-allocryptopine (ALL) on delayed afterdepolarization (DAD) incidence and triggered activity (TA) in mice administered isoproterenol (ISO). Methods. Mouse ventricular myocytes were isolated. And the cellular electrophysiological properties of ventricular myocytes were investigated. Results. We found that the incidences of DADs and TA in mouse myocytes were increased by ISO treatment. In sharp contrast, triggered arrhythmia events were rarely observed in myocytes with 10 μM ALL treatment. Transient inward current (I ti) was reduced significantly with ALL treatment, which contributed to DAD-related triggered arrhythmia. Compared to Iso-treated group, the L-type calcium current (I Ca,L) densities were decreased after exposure to ALL, along with slower activation, quicker inactivation, and longer time constant of recovery from inactivation kinetics. Conclusion. There is less triggered arrhythmia events in ventricular myocytes treated with ALL. This effect may be associated with the inhibition of I ti and I Ca,L.
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Special issue on "Toward physiome based therapeutics". PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2014; 116:1-2. [PMID: 25454286 DOI: 10.1016/j.pbiomolbio.2014.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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