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Saito Y, Nakamura K, Yoshida M, Sugiyama H, Akagi S, Miyoshi T, Morita H, Ito H. Enhancement of pacing function by HCN4 overexpression in human pluripotent stem cell-derived cardiomyocytes. Stem Cell Res Ther 2022; 13:141. [PMID: 35365232 PMCID: PMC8973792 DOI: 10.1186/s13287-022-02818-y] [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: 12/27/2021] [Accepted: 03/20/2022] [Indexed: 11/10/2022] Open
Abstract
Background The number of patients with bradyarrhythmia and the number of patients with cardiac pacemakers are increasing with the aging population and the increase in the number of patients with heart diseases. Some patients in whom a cardiac pacemaker has been implanted experience problems such as pacemaker infection and inconvenience due to electromagnetic interference. We have reported that overexpression of HCN channels producing a pacemaker current in mouse embryonic stem cell-derived cardiomyocytes showed enhanced pacing function in vitro and in vivo. The aim of this study was to determine whether HCN4 overexpression in human induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) can strengthen the pacing function of the cells. Methods Human HCN4 was transduced in the AAVS1 locus of human induced pluripotent stem cells by nucleofection and HCN4-overexpressing iPSC-CMs were generated. Gene expression profiles, frequencies of spontaneous contraction and pacing abilities of HCN4-overexpressing and non-overexpressing iPSC-CMs in vitro were compared. Results HCN4-overexpressing iPSC-CMs showed higher spontaneous contraction rates than those of non-overexpressing iPSC-CMs. They responded to an HCN channel blocker and β adrenergic stimulation. The pacing rates against parent iPSC line-derived cardiomyocytes were also higher in HCN4-overexpressing iPSC-CMs than in non-overexpressing iPSC-CMs. Conclusions Overexpression of HCN4 showed enhancement of If current, spontaneous firing and pacing function in iPSC-CMs. These data suggest this transgenic cell line may be useful as a cardiac pacemaker. Supplementary Information The online version contains supplementary material available at 10.1186/s13287-022-02818-y.
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Affiliation(s)
- Yukihiro Saito
- Department of Cardiovascular Medicine, Okayama University Hospital, Okayama, Japan.
| | - Kazufumi Nakamura
- Department of Cardiovascular Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, 700-8558, Kita-ku, Okayama, Japan.
| | - Masashi Yoshida
- Department of Chronic Kidney Disease and Cardiovascular Disease, Dentistry, and Pharmaceutical Science, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Hiroki Sugiyama
- Department of Internal Medicine, Okayama Saiseikai General Hospital, Okayama, Japan
| | - Satoshi Akagi
- Department of Cardiovascular Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, 700-8558, Kita-ku, Okayama, Japan
| | - Toru Miyoshi
- Department of Cardiovascular Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, 700-8558, Kita-ku, Okayama, Japan
| | - Hiroshi Morita
- Department of Cardiovascular Therapeutics, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, Okayama, Japan
| | - Hiroshi Ito
- Department of Cardiovascular Medicine, Dentistry and Pharmaceutical Sciences, Okayama University Graduate School of Medicine, 2-5-1 Shikata-cho, 700-8558, Kita-ku, Okayama, Japan
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2
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Piantoni C, Paina M, Molla D, Liu S, Bertoli G, Jiang H, Wang Y, Wang Y, Wang Y, DiFrancesco D, Barbuti A, Bucchi A, Baruscotti M. Chinese natural compound decreases pacemaking of rabbit cardiac sinoatrial cells by targeting second messenger regulation of f-channels. eLife 2022; 11:75119. [PMID: 35315774 PMCID: PMC8940175 DOI: 10.7554/elife.75119] [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: 10/29/2021] [Accepted: 03/03/2022] [Indexed: 11/13/2022] Open
Abstract
Tongmai Yangxin (TMYX) is a complex compound of the Traditional Chinese Medicine (TCM) used to treat several cardiac rhythm disorders; however, no information regarding its mechanism of action is available. In this study we provide a detailed characterization of the effects of TMYX on the electrical activity of pacemaker cells and unravel its mechanism of action. Single-cell electrophysiology revealed that TMYX elicits a reversible and dose-dependent (2/6 mg/ml) slowing of spontaneous action potentials rate (−20.8/–50.2%) by a selective reduction of the diastolic phase (−50.1/–76.0%). This action is mediated by a negative shift of the If activation curve (−6.7/–11.9 mV) and is caused by a reduction of the cyclic adenosine monophosphate (cAMP)-induced stimulation of pacemaker channels. We provide evidence that TMYX acts by directly antagonizing the cAMP-induced allosteric modulation of the pacemaker channels. Noticeably, this mechanism functionally resembles the pharmacological actions of muscarinic stimulation or β-blockers, but it does not require generalized changes in cytoplasmic cAMP levels thus ensuring a selective action on rate. In agreement with a competitive inhibition mechanism, TMYX exerts its maximal antagonistic action at submaximal cAMP concentrations and then progressively becomes less effective thus ensuring a full contribution of If to pacemaker rate during high metabolic demand and sympathetic stimulation.
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Affiliation(s)
- Chiara Piantoni
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Manuel Paina
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - David Molla
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Sheng Liu
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Giorgia Bertoli
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Hongmei Jiang
- Department of Physiology and Pathophysiology, School of Basic Medical Science, Tianjin Medical University, Tianjin, China
| | - Yanyan Wang
- School of Integrative Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yi Wang
- College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Traditional Chinese Medicine Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Dario DiFrancesco
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Andrea Barbuti
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Annalisa Bucchi
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
| | - Mirko Baruscotti
- Department of Biosciences, The Cell Physiology Lab and "Centro Interuniversitario di Medicina Molecolare e Biofisica Applicata", Università degli Studi di Milano, Milano, Italy
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3
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Depuydt AS, Peigneur S, Tytgat J. Review: HCN Channels in the Heart. Curr Cardiol Rev 2022; 18:e040222200836. [PMID: 35125083 PMCID: PMC9893134 DOI: 10.2174/1573403x18666220204142436] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 12/13/2021] [Accepted: 12/23/2021] [Indexed: 11/22/2022] Open
Abstract
Pacemaker cells are the basis of rhythm in the heart. Cardiovascular diseases, and in particular, arrhythmias are a leading cause of hospital admissions and have been implicated as a cause of sudden death. The prevalence of people with arrhythmias will increase in the next years due to an increase in the ageing population and risk factors. The current therapies are limited, have a lot of side effects, and thus, are not ideal. Pacemaker channels, also called hyperpolarizationactivated cyclic nucleotide-gated (HCN) channels, are the molecular correlate of the hyperpolarization- activated current, called Ih (from hyperpolarization) or If (from funny), that contribute crucially to the pacemaker activity in cardiac nodal cells and impulse generation and transmission in neurons. HCN channels have emerged as interesting targets for the development of drugs, in particular, to lower the heart rate. Nonetheless, their pharmacology is still rather poorly explored in comparison to many other voltage-gated ion channels or ligand-gated ion channels. Ivabradine is the first and currently the only clinically approved compound that specifically targets HCN channels. The therapeutic indication of ivabradine is the symptomatic treatment of chronic stable angina pectoris in patients with coronary artery disease with a normal sinus rhythm. Several other pharmacological agents have been shown to exert an effect on heart rate, although this effect is not always desired. This review is focused on the pacemaking process taking place in the heart and summarizes the current knowledge on HCN channels.
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Affiliation(s)
- Anne-Sophie Depuydt
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
| | - Steve Peigneur
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
| | - Jan Tytgat
- Toxicology and Pharmacology, University of Leuven (KU Leuven), Campus Gasthuisberg, O&N2, PO Box 922, Herestraat 49, 3000Leuven, Belgium
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4
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Oknińska M, Paterek A, Zambrowska Z, Mackiewicz U, Mączewski M. Effect of Ivabradine on Cardiac Ventricular Arrhythmias: Friend or Foe? J Clin Med 2021; 10:4732. [PMID: 34682854 PMCID: PMC8537674 DOI: 10.3390/jcm10204732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 09/24/2021] [Accepted: 10/08/2021] [Indexed: 12/12/2022] Open
Abstract
Life-threatening ventricular arrhythmias, such as ventricular tachycardia and ventricular fibrillation remain an ongoing clinical problem and their prevention and treatment require optimization. Conventional antiarrhythmic drugs are associated with significant proarrhythmic effects that often outweigh their benefits. Another option, the implantable cardioverter defibrillator, though clearly the primary therapy for patients at high risk of ventricular arrhythmias, is costly, invasive, and requires regular monitoring. Thus there is a clear need for new antiarrhythmic treatment strategies. Ivabradine, a heartrate-reducing agent, an inhibitor of HCN channels, may be one of such options. In this review we discuss emerging data from experimental studies that indicate new mechanism of action of this drug and further areas of investigation and potential use of ivabradine as an antiarrhythmic agent. However, clinical evidence is limited, and the jury is still out on effects of ivabradine on cardiac ventricular arrhythmias in the clinical setting.
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Affiliation(s)
| | | | | | | | - Michał Mączewski
- Centre of Postgraduate Medical Education, Department of Clinical Physiology, ul. Marymoncka 99/103, 01-813 Warsaw, Poland; (M.O.); (A.P.); (Z.Z.); (U.M.)
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5
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Effect of ivabradine on cardiac arrhythmias: Antiarrhythmic or proarrhythmic? Heart Rhythm 2021; 18:1230-1238. [PMID: 33737235 DOI: 10.1016/j.hrthm.2021.03.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/09/2021] [Accepted: 03/10/2021] [Indexed: 12/28/2022]
Abstract
Cardiac arrhythmias are a major source of mortality and morbidity. Unfortunately, their treatment remains suboptimal. Major classes of antiarrhythmic drugs pose a significant risk of proarrhythmia, and their side effects often outweigh their benefits. Therefore, implantable devices remain the only truly effective antiarrhythmic therapy, and new strategies of antiarrhythmic treatment are required. Ivabradine is a selective heart rate-reducing agent, an inhibitor of hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels, currently approved for treatment of coronary artery disease and chronic heart failure. In this review, we focus on the clinical and basic science evidence for the antiarrhythmic and proarrhythmic effects of ivabradine. We attempt to dissect the mechanisms behind the effects of ivabradine and indicate the focus of future studies.
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6
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Rivolta I, Binda A, Masi A, DiFrancesco JC. Cardiac and neuronal HCN channelopathies. Pflugers Arch 2020; 472:931-951. [PMID: 32424620 DOI: 10.1007/s00424-020-02384-3] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/21/2020] [Accepted: 04/24/2020] [Indexed: 12/31/2022]
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels are expressed as four different isoforms (HCN1-4) in the heart and in the central and peripheral nervous systems. In the voltage range of activation, HCN channels carry an inward current mediated by Na+ and K+, termed If in the heart and Ih in neurons. Altered function of HCN channels, mainly HCN4, is associated with sinus node dysfunction and other arrhythmias such as atrial fibrillation, ventricular tachycardia, and atrioventricular block. In recent years, several data have also shown that dysfunctional HCN channels, in particular HCN1, but also HCN2 and HCN4, can play a pathogenic role in epilepsy; these include experimental data from animal models, and data collected over genetic mutations of the channels identified and characterized in epileptic patients. In the central nervous system, alteration of the Ih current could predispose to the development of neurodegenerative diseases such as Parkinson's disease; since HCN channels are widely expressed in the peripheral nervous system, their dysfunctional behavior could also be associated with the pathogenesis of neuropathic pain. Given the fundamental role played by the HCN channels in the regulation of the discharge activity of cardiac and neuronal cells, the modulation of their function for therapeutic purposes is under study since it could be useful in various pathological conditions. Here we review the present knowledge of the HCN-related channelopathies in cardiac and neurological diseases, including clinical, genetic, therapeutic, and physiopathological aspects.
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Affiliation(s)
- Ilaria Rivolta
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy
| | - Anna Binda
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy
| | - Alessio Masi
- Department of Neuroscience, Psychology, Drug Research and Child Health (NEUROFARBA), section of Pharmacology and Toxicology, University of Florence, Florence, Italy
| | - Jacopo C DiFrancesco
- School of Medicine and Surgery, Milan Center for Neuroscience (NeuroMI), University of Milano-Bicocca, Monza, Italy. .,Department of Neurology, ASST San Gerardo Hospital, University of Milano-Bicocca, Via Pergolesi, 33, 20900, Monza, MB, Italy.
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7
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Genetically Modified Porcine Mesenchymal Stem Cells by Lentiviral Tbx18 Create a Biological Pacemaker. Stem Cells Int 2019; 2019:3621314. [PMID: 31814832 PMCID: PMC6877911 DOI: 10.1155/2019/3621314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 07/13/2019] [Accepted: 08/24/2019] [Indexed: 11/24/2022] Open
Abstract
Background Tbx18 is a vital transcription factor involved in embryonic sinoatrial node (SAN) formation process but is gradually vanished after birth. Myocardial injection of lentiviral Tbx18 converts cardiomyocytes into pacemaker-like cells morphologically and functionally. In this in vitro and in vivo study, genetical modification of porcine bone mesenchymal stem cells (BMSCs) by recapturing the Tbx18 expression creates a biological pacemaker which was examined. Methods The isolated porcine BMSCs were transfected with lentiviral Tbx18, and the induced pacemaker-like cells were analyzed using real-time polymerase chain reaction and western blotting to investigate the efficiency of transformation. Then, the induced pacemaker-like cells were implanted into the right ventricle of the SAN dysfunction porcine model after the differentiation process. Biological pacemaker activity and ectopic pacing region were tested by an electrocardiograph (ECG) monitor. Results The isolated porcine BMSCs expressed specific surface markers of stem cells; meanwhile, the expression of myocardial markers was upregulated significantly after lentiviral Tbx18 transfection. The porcine SAN dysfunction model was constructed by electrocoagulation using a surgical electrotome. The results showed that the mean heart beat (HR) of BMSCs-Tbx18 was significantly higher than that of BMSCs-GFP. An ectopic pacing region was affirmed into the right ventricle by ECG after implantation of BMSCs-Tbx18. Conclusion It was verified that Lenti-Tbx18 is capable of transducing porcine BMSCs into pacemaker-like cells. Genetically modified porcine BMSCs by lentiviral Tbx18 could create a biological pacemaker. However, further researches in large-scale animals are required to rule out unexpected complications prior to application in clinical practice.
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8
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Yampolsky P, Koenen M, Mosqueira M, Geschwill P, Nauck S, Witzenberger M, Seyler C, Fink T, Kruska M, Bruehl C, Schwoerer AP, Ehmke H, Fink RHA, Draguhn A, Thomas D, Katus HA, Schweizer PA. Augmentation of myocardial I f dysregulates calcium homeostasis and causes adverse cardiac remodeling. Nat Commun 2019; 10:3295. [PMID: 31337768 PMCID: PMC6650438 DOI: 10.1038/s41467-019-11261-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 06/28/2019] [Indexed: 01/18/2023] Open
Abstract
HCN channels underlie the depolarizing funny current (If) that contributes importantly to cardiac pacemaking. If is upregulated in failing and infarcted hearts, but its implication in disease mechanisms remained unresolved. We generated transgenic mice (HCN4tg/wt) to assess functional consequences of HCN4 overexpression-mediated If increase in cardiomyocytes to levels observed in human heart failure. HCN4tg/wt animals exhibit a dilated cardiomyopathy phenotype with increased cellular arrhythmogenicity but unchanged heart rate and conduction parameters. If augmentation induces a diastolic Na+ influx shifting the Na+/Ca2+ exchanger equilibrium towards 'reverse mode' leading to increased [Ca2+]i. Changed Ca2+ homeostasis results in significantly higher systolic [Ca2+]i transients and stimulates apoptosis. Pharmacological inhibition of If prevents the rise of [Ca2+]i and protects from ventricular remodeling. Here we report that augmented myocardial If alters intracellular Ca2+ homeostasis leading to structural cardiac changes and increased arrhythmogenicity. Inhibition of myocardial If per se may constitute a therapeutic mechanism to prevent cardiomyopathy.
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Affiliation(s)
- Pessah Yampolsky
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- Department of Molecular Neurology, Max-Planck-Institute for Medical Research, Jahnstrasse 29, 69120, Heidelberg, Germany
| | - Michael Koenen
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- Department of Molecular Neurology, Max-Planck-Institute for Medical Research, Jahnstrasse 29, 69120, Heidelberg, Germany
| | - Matias Mosqueira
- Division of Medical Biophysics, Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Pascal Geschwill
- Division of Neuro- and Sensory Physiology, Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Sebastian Nauck
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research) partner site Heidelberg/Mannheim, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Monika Witzenberger
- Division of Medical Biophysics, Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Claudia Seyler
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research) partner site Heidelberg/Mannheim, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Thomas Fink
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Mathieu Kruska
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Claus Bruehl
- Division of Neuro- and Sensory Physiology, Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Alexander P Schwoerer
- Department of Cellular and Integrative Physiology, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research) partner site Hamburg/Kiel/Lübeck, Martinistrasse 52, 20246, Hamburg, Germany
| | - Heimo Ehmke
- Department of Cellular and Integrative Physiology, University Medical Centre Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
- DZHK (German Centre for Cardiovascular Research) partner site Hamburg/Kiel/Lübeck, Martinistrasse 52, 20246, Hamburg, Germany
| | - Rainer H A Fink
- Division of Medical Biophysics, Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Andreas Draguhn
- Division of Neuro- and Sensory Physiology, Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Dierk Thomas
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research) partner site Heidelberg/Mannheim, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Centre for Cardiovascular Research) partner site Heidelberg/Mannheim, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Patrick A Schweizer
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
- DZHK (German Centre for Cardiovascular Research) partner site Heidelberg/Mannheim, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
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9
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Lussier Y, Fürst O, Fortea E, Leclerc M, Priolo D, Moeller L, Bichet DG, Blunck R, D'Avanzo N. Disease-linked mutations alter the stoichiometries of HCN-KCNE2 complexes. Sci Rep 2019; 9:9113. [PMID: 31235733 PMCID: PMC6591248 DOI: 10.1038/s41598-019-45592-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 06/11/2019] [Indexed: 12/21/2022] Open
Abstract
The four hyperpolarization-activated cylic-nucleotide gated (HCN) channel isoforms and their auxiliary subunit KCNE2 are important in the regulation of peripheral and central neuronal firing and the heartbeat. Disruption of their normal function has been implicated in cardiac arrhythmias, peripheral pain, and epilepsy. However, molecular details of the HCN-KCNE2 complexes are unknown. Using single-molecule subunit counting, we determined that the number of KCNE2 subunits in complex with the pore-forming subunits of human HCN channels differs with each HCN isoform and is dynamic with respect to concentration. These interactions can be altered by KCNE2 gene-variants with functional implications. The results provide an additional consideration necessary to understand heart rhythm, pain, and epileptic disorders.
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Affiliation(s)
- Yoann Lussier
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Oliver Fürst
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Eva Fortea
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Marc Leclerc
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Dimitri Priolo
- Department of Physics, Université de Montréal, Montréal, Canada
| | - Lena Moeller
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Canada
| | - Daniel G Bichet
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Rikard Blunck
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada.,Department of Physics, Université de Montréal, Montréal, Canada
| | - Nazzareno D'Avanzo
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada. .,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Canada.
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10
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Oshita K, Kozasa Y, Nakagawa Y, Kuwabara Y, Kuwahara K, Nakagawa T, Nakashima N, Hiraki T, Takano M. Overexpression of the HCN2 channel increases the arrhythmogenicity induced by hypokalemia. J Physiol Sci 2019; 69:653-660. [PMID: 31087220 PMCID: PMC6583697 DOI: 10.1007/s12576-019-00684-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 04/30/2019] [Indexed: 12/19/2022]
Abstract
Hypokalemia, an abnormally low level of potassium (K+), is a electrolyte imbalance that commonly occurs in heart failure patients. Hypokalemia is well known to induce lethal ventricular arrhythmia. However, the effects of hypokalemia in failing hearts that have undergone electrophysiological remodeling, i.e., the reactivation of fetal-type ion channels, remain unexplored. We have examined the effect of hypokalemia in the myocytes of transgenic mice overexpressing the hyperpolarization-activated, cyclic nucleotide-sensitive (HCN) channel in the heart (HCN2-Tg mice). Perfusion with a mild hypokalemic solution containing 3 mM K+ induced ectopic ventricular automaticity in 55.0% of HCN2-Tg mouse myocytes. In the remaining HCN2-Tg mouse myocytes, the resting membrane potential (RMP) was more depolarized than that of wild-type myocytes subjected to the same treatment and could also be hyperpolarized by an HCN channel blocker. We conclude that in hypokalemia in our mice model, the HCN2 channel was constitutively activated at the hyperpolarized RMP, thereby destabilizing the electrophysiological activity of ventricular myocytes.
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Affiliation(s)
- Kensuke Oshita
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan.,Department of Anesthesiology, Kurume University School of Medicine, Kurume, Japan
| | - Yuko Kozasa
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan.,Department of Anesthesiology, Kurume University School of Medicine, Kurume, Japan
| | - Yasuaki Nakagawa
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Yoshihiro Kuwabara
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Koichiro Kuwahara
- Department of Cardiovascular Medicine, Shinshu University School of Medicine, Matsumoto, Japan
| | - Taku Nakagawa
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Noriyuki Nakashima
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Teruyuki Hiraki
- Department of Anesthesiology, Kurume University School of Medicine, Kurume, Japan
| | - Makoto Takano
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan.
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Tanguay J, Callahan KM, D'Avanzo N. Characterization of drug binding within the HCN1 channel pore. Sci Rep 2019; 9:465. [PMID: 30679654 PMCID: PMC6345760 DOI: 10.1038/s41598-018-37116-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 11/29/2018] [Indexed: 11/09/2022] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channels mediate rhythmic electrical activity of cardiac pacemaker cells, and in neurons play important roles in setting resting membrane potentials, dendritic integration, neuronal pacemaking, and establishing action potential threshold. Block of HCN channels slows the heart rate and is currently used to treat angina. However, HCN block also provides a promising approach to the treatment of neuronal disorders including epilepsy and neuropathic pain. While several molecules that block HCN channels have been identified, including clonidine and its derivative alinidine, lidocaine, mepivacaine, bupivacaine, ZD7288, ivabradine, zatebradine, and cilobradine, their low affinity and lack of specificity prevents wide-spread use. Different studies suggest that the binding sites of these inhibitors are located in the inner vestibule of HCN channels, but the molecular details of their binding remain unknown. We used computational docking experiments to assess the binding sites and mode of binding of these inhibitors against the recently solved atomic structure of human HCN1 channels, and a homology model of the open pore derived from a closely related CNG channel. We identify a possible hydrophobic groove in the pore cavity that plays an important role in conformationally restricting the location and orientation of drugs bound to the inner vestibule. Our results also help explain the molecular basis of the low-affinity binding of these inhibitors, paving the way for the development of higher affinity molecules.
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Affiliation(s)
- Jérémie Tanguay
- Department of Physics, Université de Montréal, Montréal, Canada
| | - Karen M Callahan
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada
| | - Nazzareno D'Avanzo
- Department of Pharmacology and Physiology, Université de Montréal, Montréal, Canada.
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Liu X, Zhang L, Jin L, Tan Y, Li W, Tang J. HCN2 contributes to oxaliplatin-induced neuropathic pain through activation of the CaMKII/CREB cascade in spinal neurons. Mol Pain 2018; 14:1744806918778490. [PMID: 29806529 PMCID: PMC5974562 DOI: 10.1177/1744806918778490] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Emerging evidence showed that hyperpolarization-activated cation channels (HCN) participate in the development of inflammatory and neuropathic pain. However, the role of HCN2 in oxaliplatin-induced neuropathic pain remains unknown. Here, we found that HCN2 expression was upregulated in a rat model of oxaliplatin-induced neuropathic pain. Intrathecal injection of ZD7288, an HCN specific inhibitor, decreased the HCN2 level, as well as weakened the neuropathic pain behaviors compared to naive rats. Besides, mechanistic studies revealed that the expression of the spinal N-methyl-D-aspartate receptor subunit 2B was increased after oxaliplatin administration and was reduced by ZD7288 administration. The nociceptive behaviors were reversed by NR2B antagonist Ro 25–6981 in HCN2-overexpression rats. Furthermore, the underlying cellular mechanism demonstrated that ZD7288 administration restrained the enhanced activation of the neuronal calcium–calmodulin-dependent kinase II (CaMKII)/cyclic adenosine monophosphate response element-binding protein cascade after oxaliplatin administration. Moreover, pretreatment of CaMKII inhibitor KN-93 suppressed the nociceptive behaviors, as well as NR2B upregulation induced by overexpression of HCN2. In a word, HCN2 is conducive to oxaliplatin-induced neuropathic pain by activating the neuronal CaMKII/CREB cascade.
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Affiliation(s)
- Xiaoyu Liu
- Department of Anesthesiology, Jinling Hospital, Medical School of Nanjing University, Nanjing, P.R. China
| | - Lidong Zhang
- Department of Anesthesiology, Jinling Hospital, Medical School of Nanjing University, Nanjing, P.R. China
| | - Li Jin
- Department of Anesthesiology, Jinling Hospital, Medical School of Nanjing University, Nanjing, P.R. China
| | - Yuanhui Tan
- Department of Anesthesiology, Jinling Hospital, Medical School of Nanjing University, Nanjing, P.R. China
| | - Weiyan Li
- Department of Anesthesiology, Jinling Hospital, Medical School of Nanjing University, Nanjing, P.R. China
- Weiyan Li and Jun Tang, Department of Anesthesiology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu Province 210002, P.R. China. Emails: ;
| | - Jun Tang
- Department of Anesthesiology, Jinling Hospital, Medical School of Nanjing University, Nanjing, P.R. China
- Weiyan Li and Jun Tang, Department of Anesthesiology, Jinling Hospital, Medical School of Nanjing University, 305 East Zhongshan Road, Nanjing, Jiangsu Province 210002, P.R. China. Emails: ;
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Kozasa Y, Nakashima N, Ito M, Ishikawa T, Kimoto H, Ushijima K, Makita N, Takano M. HCN4 pacemaker channels attenuate the parasympathetic response and stabilize the spontaneous firing of the sinoatrial node. J Physiol 2018; 596:809-825. [PMID: 29315578 PMCID: PMC5830425 DOI: 10.1113/jp275303] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 01/02/2018] [Indexed: 01/01/2023] Open
Abstract
Key points The contribution of HCN4 pacemaker channels in the autonomic regulation of the sino‐atrial node (SAN) has been a matter of debate. The transgenic overexpression of HCN4 did not induce tachycardia, but reduced heart rate variability, while the conditional knockdown of HCN4 gave rise to sinus arrhythmia. The response of the SAN to β‐adrenergic stimulation was not affected by overexpression or knockdown of HCN4 channels. When HCN4 channels were knocked down, the parasympathetic response examined by cervical vagus nerve stimulation (CVNS) was enhanced; the CVNS induced complete sinus pause. The overexpression of HCN4 attenuated bradycardia induced by CVNS only during β‐adrenergic stimulation. We concluded that HCN4 pacemaker channels stabilize the spontaneous firing by attenuating the parasympathetic response of the SAN.
Abstract The heart rate is dynamically controlled by the sympathetic and parasympathetic nervous systems that regulate the sinoatrial node (SAN). HCN4 pacemaker channels are the well‐known causative molecule of congenital sick sinus syndrome. Although HCN4 channels are activated by cAMP, the sympathetic response of the SAN was preserved in patients carrying loss‐of‐function mutations of the HCN4 gene. In order to clarify the contribution of HCN4 channels in the autonomic regulation of the SAN, we developed novel gain‐of‐function mutant mice in which the expression level of HCN4 channels could be reversibly changed from zero to ∼3 times that in wild‐type mice, using tetracycline transactivator and the tetracycline responsive element. We recorded telemetric ECGs in freely moving conscious mice and analysed the heart rate variability. We also evaluated the response of the SAN to cervical vagus nerve stimulation (CVNS). The conditional overexpression of HCN4 did not induce tachycardia, but reduced heart rate variability. The HCN4 overexpression also attenuated bradycardia induced by the CVNS only during the β‐adrenergic stimulation. In contrast, the knockdown of HCN4 gave rise to sinus arrhythmia, and enhanced the parasympathetic response; complete sinus pause was induced by the CVNS. In vitro, we compared the effects of acetylcholine on the spontaneous action potentials of single pacemaker cells, and found that similar phenotypic changes were induced by genetic manipulation of HCN4 expression both in the presence and absence of β‐adrenergic stimulation. Our study suggests that HCN4 channels attenuate the vagal response of the SAN, and thereby stabilize the spontaneous firing of the SAN. The contribution of HCN4 pacemaker channels in the autonomic regulation of the sino‐atrial node (SAN) has been a matter of debate. The transgenic overexpression of HCN4 did not induce tachycardia, but reduced heart rate variability, while the conditional knockdown of HCN4 gave rise to sinus arrhythmia. The response of the SAN to β‐adrenergic stimulation was not affected by overexpression or knockdown of HCN4 channels. When HCN4 channels were knocked down, the parasympathetic response examined by cervical vagus nerve stimulation (CVNS) was enhanced; the CVNS induced complete sinus pause. The overexpression of HCN4 attenuated bradycardia induced by CVNS only during β‐adrenergic stimulation. We concluded that HCN4 pacemaker channels stabilize the spontaneous firing by attenuating the parasympathetic response of the SAN.
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Affiliation(s)
- Yuko Kozasa
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan.,Department of Anesthesiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Noriyuki Nakashima
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Masayuki Ito
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, NCNP, Tokyo, 187-8502, Japan
| | - Taisuke Ishikawa
- Department of Molecular Physiology, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-4, Sakamoto, Nagasaki, 852-8523, Japan
| | - Hiroki Kimoto
- Department of Molecular Physiology, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-4, Sakamoto, Nagasaki, 852-8523, Japan
| | - Kazuo Ushijima
- Department of Anesthesiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
| | - Naomasa Makita
- Department of Molecular Physiology, Nagasaki University, Graduate School of Biomedical Sciences, 1-12-4, Sakamoto, Nagasaki, 852-8523, Japan
| | - Makoto Takano
- Department of Physiology, Kurume University School of Medicine, 67 Asahi-Machi, Kurume, 830-0011, Japan
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