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Pizzo E, Cervantes DO, Ketkar H, Ripa V, Nassal DM, Buck B, Parambath SP, Di Stefano V, Singh K, Thompson CI, Mohler PJ, Hund TJ, Jacobson JT, Jain S, Rota M. Phosphorylation of cardiac sodium channel at Ser571 anticipates manifestations of the aging myopathy. Am J Physiol Heart Circ Physiol 2024; 326:H1424-H1445. [PMID: 38639742 DOI: 10.1152/ajpheart.00325.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 03/12/2024] [Accepted: 04/02/2024] [Indexed: 04/20/2024]
Abstract
Diastolic dysfunction and delayed ventricular repolarization are typically observed in the elderly, but whether these defects are intimately associated with the progressive manifestation of the aging myopathy remains to be determined. In this regard, aging in experimental animals is coupled with increased late Na+ current (INa,L) in cardiomyocytes, raising the possibility that INa,L conditions the modality of electrical recovery and myocardial relaxation of the aged heart. For this purpose, aging male and female wild-type (WT) C57Bl/6 mice were studied together with genetically engineered mice with phosphomimetic (gain of function, GoF) or ablated (loss of function, LoF) mutations of the sodium channel Nav1.5 at Ser571 associated with, respectively, increased and stabilized INa,L. At ∼18 mo of age, WT mice developed prolonged duration of the QT interval of the electrocardiogram and impaired diastolic left ventricular (LV) filling, defects that were reversed by INa,L inhibition. Prolonged repolarization and impaired LV filling occurred prematurely in adult (∼5 mo) GoF mutant mice, whereas these alterations were largely attenuated in aging LoF mutant animals. Ca2+ transient decay and kinetics of myocyte shortening/relengthening were delayed in aged (∼24 mo) WT myocytes, with respect to adult cells. In contrast, delayed Ca2+ transients and contractile dynamics occurred at adult stage in GoF myocytes and further deteriorated in old age. Conversely, myocyte mechanics were minimally affected in aging LoF cells. Collectively, these results document that Nav1.5 phosphorylation at Ser571 and the late Na+ current modulate the modality of myocyte relaxation, constituting the mechanism linking delayed ventricular repolarization and diastolic dysfunction.NEW & NOTEWORTHY We have investigated the impact of the late Na current (INa,L) on cardiac and myocyte function with aging by using genetically engineered animals with enhanced or stabilized INa,L, due to phosphomimetic or phosphoablated mutations of Nav1.5. Our findings support the notion that phosphorylation of Nav1.5 at Ser571 prolongs myocardial repolarization and impairs diastolic function, contributing to the manifestations of the aging myopathy.
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Affiliation(s)
- Emanuele Pizzo
- Department of Physiology, New York Medical College, Valhalla, New York, United States
| | - Daniel O Cervantes
- Department of Physiology, New York Medical College, Valhalla, New York, United States
| | - Harshada Ketkar
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, New York, United States
| | - Valentina Ripa
- Department of Physiology, New York Medical College, Valhalla, New York, United States
| | - Drew M Nassal
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, United States
| | - Benjamin Buck
- Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Sreema P Parambath
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, New York, United States
| | - Valeria Di Stefano
- Department of Physiology, New York Medical College, Valhalla, New York, United States
| | - Kanwardeep Singh
- Department of Physiology, New York Medical College, Valhalla, New York, United States
| | - Carl I Thompson
- Department of Physiology, New York Medical College, Valhalla, New York, United States
| | - Peter J Mohler
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
- Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, United States
- Department of Physiology and Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio, United States
| | - Thomas J Hund
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, United States
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, United States
- Division of Cardiovascular Medicine, Department of Internal Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Jason T Jacobson
- Department of Physiology, New York Medical College, Valhalla, New York, United States
- Department of Cardiology, Westchester Medical Center, Valhalla, New York, United States
| | - Sudhir Jain
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, New York, United States
| | - Marcello Rota
- Department of Physiology, New York Medical College, Valhalla, New York, United States
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2
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Nasilli G, Verkerk AO, O’Reilly M, Yiangou L, Davis RP, Casini S, Remme CA. Chronic Mexiletine Administration Increases Sodium Current in Non-Diseased Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes. Biomedicines 2024; 12:1212. [PMID: 38927420 PMCID: PMC11200762 DOI: 10.3390/biomedicines12061212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Accepted: 05/21/2024] [Indexed: 06/28/2024] Open
Abstract
A sodium current (INa) reduction occurs in the setting of many acquired and inherited conditions and is associated with cardiac conduction slowing and increased arrhythmia risks. The sodium channel blocker mexiletine has been shown to restore the trafficking of mutant sodium channels to the membrane. However, these studies were mostly performed in heterologous expression systems using high mexiletine concentrations. Moreover, the chronic effects on INa in a non-diseased cardiomyocyte environment remain unknown. In this paper, we investigated the chronic and acute effects of a therapeutic dose of mexiletine on INa and the action potential (AP) characteristics in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) of a healthy individual. Control hiPSC-CMs were incubated for 48 h with 10 µM mexiletine or vehicle. Following the wash-out of mexiletine, patch clamp analysis and immunocytochemistry experiments were performed. The incubation of hiPSC-CMs for 48 h with mexiletine (followed by wash-out) induced a significant increase in peak INa of ~75%, without any significant change in the voltage dependence of (in)activation. This was accompanied by a significant increase in AP upstroke velocity, without changes in other AP parameters. The immunocytochemistry experiments showed a significant increase in membrane Nav1.5 fluorescence following a 48 h incubation with mexiletine. The acute re-exposure of hiPSC-CMs to 10 µM mexiletine resulted in a small but significant increase in AP duration, without changes in AP upstroke velocity, peak INa density, or the INa voltage dependence of (in)activation. Importantly, the increase in the peak INa density and resulting AP upstroke velocity induced by chronic mexiletine incubation was not counteracted by the acute re-administration of the drug. In conclusion, the chronic administration of a clinically relevant concentration of mexiletine increases INa density in non-diseased hiPSC-CMs, likely by enhancing the membrane trafficking of sodium channels. Our findings identify mexiletine as a potential therapeutic strategy to enhance and/or restore INa and cardiac conduction.
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Affiliation(s)
- Giovanna Nasilli
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Heart Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands (A.O.V.)
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, 1105 AZ Amsterdam, The Netherlands
| | - Arie O. Verkerk
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Heart Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands (A.O.V.)
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, 1105 AZ Amsterdam, The Netherlands
- Department of Medical Biology, Amsterdam University Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
| | - Molly O’Reilly
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Heart Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands (A.O.V.)
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, 1105 AZ Amsterdam, The Netherlands
| | - Loukia Yiangou
- Department of Anatomy and Embryology, Leiden University Medical Center, Albinusdreef 2, 2300 RC Leiden, The Netherlands
| | - Richard P. Davis
- Department of Anatomy and Embryology, Leiden University Medical Center, Albinusdreef 2, 2300 RC Leiden, The Netherlands
- The Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW), Leiden University Medical Center, Albinusdreef 2, 2300 RC Leiden, The Netherlands
| | - Simona Casini
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Heart Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands (A.O.V.)
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, 1105 AZ Amsterdam, The Netherlands
| | - Carol Ann Remme
- Department of Experimental Cardiology, Amsterdam University Medical Center, University of Amsterdam, Heart Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands (A.O.V.)
- Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, 1105 AZ Amsterdam, The Netherlands
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3
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Arabia G, Bellicini MG, Cersosimo A, Memo M, Mazzarotto F, Inciardi RM, Cerini M, Chen LY, Aboelhassan M, Benzoni P, Mitacchione G, Bontempi L, Curnis A. Ion channel dysfunction and fibrosis in atrial fibrillation: Two sides of the same coin. Pacing Clin Electrophysiol 2024; 47:417-428. [PMID: 38375940 DOI: 10.1111/pace.14944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 01/10/2024] [Accepted: 01/23/2024] [Indexed: 02/21/2024]
Abstract
BACKGROUND Atrial fibrillation (AF) is a common heart rhythm disorder that is associated with an increased risk of stroke and heart failure (HF). Initially, an association between AF and ion channel dysfunction was identified, classifying the pathology as a predominantly electrical disease. More recently it has been recognized that fibrosis and structural atrial remodeling play a driving role in the development of this arrhythmia also in these cases. PURPOSE Understanding the role of fibrosis in genetic determined AF could be important to better comprise the pathophysiology of this arrhythmia and to refine its management also in nongenetic forms. In this review we analyze genetic and epigenetic mechanisms responsible for AF and their link with atrial fibrosis, then we will consider analogies with the pathophysiological mechanism in nongenetic AF, and discuss consequent therapeutic options.
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Affiliation(s)
- Gianmarco Arabia
- Cardiology Department, Spedali Civili Hospital, University of Brescia, Brescia, Italy
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | | | - Angelica Cersosimo
- Cardiology Department, Spedali Civili Hospital, University of Brescia, Brescia, Italy
| | - Maurizio Memo
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Francesco Mazzarotto
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
- National Heart and Lung Institute, Imperial College London (F.M., J. Ware), London, UK
| | | | - Manuel Cerini
- Cardiology Department, Spedali Civili Hospital, University of Brescia, Brescia, Italy
| | - Lin Yee Chen
- University of Minnesota (L.Y.C.), Minneapolis, USA
| | | | - Patrizia Benzoni
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | | | - Luca Bontempi
- Unit of Cardiology, Cardiac Electrophysiology and, Electrostimulation Laboratory, "Bolognini" Hospital of Seriate - ASST Bergamo Est, Bergamo, Italy
| | - Antonio Curnis
- Cardiology Department, Spedali Civili Hospital, University of Brescia, Brescia, Italy
- Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
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4
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Fullerton KE, Clark AP, Krogh-Madsen T, Christini DJ. Optimization of a cardiomyocyte model illuminates role of increased INa,L in repolarization reserve. Am J Physiol Heart Circ Physiol 2024; 326:H334-H345. [PMID: 38038718 DOI: 10.1152/ajpheart.00553.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/15/2023] [Accepted: 11/19/2023] [Indexed: 12/02/2023]
Abstract
Cardiac ion currents may compensate for each other when one is compromised by a congenital or drug-induced defect. Such redundancy contributes to a robust repolarization reserve that can prevent the development of lethal arrhythmias. Most efforts made to describe this phenomenon have quantified contributions by individual ion currents. However, it is important to understand the interplay between all major ion-channel conductances, as repolarization reserve is dependent on the balance between all ion currents in a cardiomyocyte. Here, a genetic algorithm was designed to derive profiles of nine ion-channel conductances that optimize repolarization reserve in a mathematical cardiomyocyte model. Repolarization reserve was quantified using a previously defined metric, repolarization reserve current, i.e., the minimum constant current to prevent normal action potential repolarization in a cell. The optimization improved repolarization reserve current up to 84% compared to baseline in a human adult ventricular myocyte model and increased resistance to arrhythmogenic insult. The optimized conductance profiles were not only characterized by increased repolarizing current conductances but also uncovered a previously unreported behavior by the late sodium current. Simulations demonstrated that upregulated late sodium increased action potential duration, without compromising repolarization reserve current. The finding was generalized to multiple models. Ultimately, this computational approach, in which multiple currents were studied simultaneously, illuminated mechanistic insights into how the metric's magnitude could be increased and allowed for the unexpected role of late sodium to be elucidated.NEW & NOTEWORTHY Genetic algorithms are typically used to fit models or extract desired parameters from data. Here, we use the tool to produce a ventricular cardiomyocyte model with increased repolarization reserve. Since arrhythmia mitigation is dependent on multiple cardiac ion-channel conductances, study using a comprehensive, unbiased, and systems-level approach is important. The use of this optimization strategy allowed us to find robust profiles that illuminated unexpected mechanistic determinants of key ion-channel conductances in repolarization reserve.
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Affiliation(s)
- Kristin E Fullerton
- Physiology, Biophysics and Systems Biology Program, Weill Cornell Graduate School of Medical Sciences, New York, New York, United States
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, New York, United States
| | - Alexander P Clark
- Department of Biomedical Engineering, Cornell University, Ithaca, New York, United States
| | - Trine Krogh-Madsen
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, New York, United States
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, New York, United States
| | - David J Christini
- Department of Physiology and Pharmacology, SUNY Downstate Health Sciences University, Brooklyn, New York, United States
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5
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Marchal GA, Remme CA. Subcellular diversity of Nav1.5 in cardiomyocytes: distinct functions, mechanisms and targets. J Physiol 2023; 601:941-960. [PMID: 36469003 DOI: 10.1113/jp283086] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 11/24/2022] [Indexed: 12/11/2022] Open
Abstract
In cardiomyocytes, the rapid depolarisation of the membrane potential is mediated by the α-subunit of the cardiac voltage-gated Na+ channel (NaV 1.5), encoded by the gene SCN5A. This ion channel allows positively charged Na+ ions to enter the cardiomyocyte, resulting in the fast upstroke of the action potential and is therefore crucial for cardiac excitability and electrical propagation. This essential role is underscored by the fact that dysfunctional NaV 1.5 is associated with high risk for arrhythmias and sudden cardiac death. However, development of therapeutic interventions regulating NaV 1.5 has been limited due to the complexity of NaV 1.5 structure and function and its diverse roles within the cardiomyocyte. In particular, research from the last decade has provided us with increased knowledge on the subcellular distribution of NaV 1.5 as well as the proteins which it interacts with in distinct cardiomyocyte microdomains. We here review these insights, detailing the potential role of NaV 1.5 within subcellular domains as well as its dysfunction in the setting of arrhythmia disorders. We furthermore provide an overview of current knowledge on the pathways involved in (microdomain-specific) trafficking of NaV 1.5, and their potential as novel targets. Unravelling the complexity of NaV 1.5 (dys)function may ultimately facilitate the development of therapeutic strategies aimed at preventing lethal arrhythmias. This is not only of importance for pathophysiological conditions where sodium current is specifically decreased within certain subcellular regions, such as in arrhythmogenic cardiomyopathy and Duchenne muscular dystrophy, but also for other acquired and inherited disorders associated with NaV 1.5.
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Affiliation(s)
- Gerard A Marchal
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands.,National Institute of Optics, National Research Council (CNR-INO), Sesto Fiorentino, Florence, Italy
| | - Carol Ann Remme
- Department of Experimental Cardiology, Heart Centre, Amsterdam Cardiovascular Sciences, Heart Failure & Arrhythmias, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands
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Comollo TW, Zou X, Zhang C, Kesters D, Hof T, Sampson KJ, Kass RS. Exploring mutation specific beta blocker pharmacology of the pathogenic late sodium channel current from patient-specific pluripotent stem cell myocytes derived from long QT syndrome mutation carriers. Channels (Austin) 2022; 16:173-184. [PMID: 35949058 PMCID: PMC9373745 DOI: 10.1080/19336950.2022.2106025] [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] [Indexed: 01/31/2023] Open
Abstract
The congenital long QT syndrome (LQTS), one of the most common cardiac channelopathies, is characterized by delayed ventricular repolarization underlying prolongation of the QT interval of the surface electrocardiogram. LQTS is caused by mutations in genes coding for cardiac ion channels or ion channel-associated proteins. The major therapeutic approach to LQTS management is beta blocker therapy which has been shown to be effective in treatment of LQTS variants caused by mutations in K+ channels. However, this approach has been questioned in the treatment of patients identified as LQTS variant 3(LQT3) patients who carry mutations in SCN5A, the gene coding for the principal cardiac Na+ channel. LQT3 mutations are gain of function mutations that disrupt spontaneous Na+ channel inactivation and promote persistent or late Na+ channel current (INaL) that delays repolarization and underlies QT prolongation. Clinical investigation of patients with the two most common LQT3 mutations, the ΔKPQ and the E1784K mutations, found beta blocker treatment a useful therapeutic approach for managing arrhythmias in this patient population. However, there is little experimental data that reveals the mechanisms underlying these antiarrhythmic actions. Here, we have investigated the effects of the beta blocker propranolol on INaL expressed by ΔKPQ and E1784K channels in induced pluripotent stem cells derived from patients carrying these mutations. Our results indicate that propranolol preferentially inhibits INaL expressed by these channels suggesting that the protective effects of propranolol in treating LQT3 patients is due in part to modulation of INaL.
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Affiliation(s)
- Thomas W. Comollo
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Xinle Zou
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Chuangeng Zhang
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Divya Kesters
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Thomas Hof
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Kevin J. Sampson
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA
| | - Robert S. Kass
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, Vagelos College of Physicians and Surgeons, Columbia, NY, USA,CONTACT Robert S. Kass
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7
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Cervantes DO, Pizzo E, Ketkar H, Parambath SP, Tang S, Cianflone E, Cannata A, Vinukonda G, Jain S, Jacobson JT, Rota M. Scn1b expression in the adult mouse heart modulates Na + influx in myocytes and reveals a mechanistic link between Na + entry and diastolic function. Am J Physiol Heart Circ Physiol 2022; 322:H975-H993. [PMID: 35394857 PMCID: PMC9076421 DOI: 10.1152/ajpheart.00465.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 03/09/2022] [Accepted: 03/23/2022] [Indexed: 11/22/2022]
Abstract
Voltage-gated sodium channels (VGSCs) are macromolecular assemblies composed of a number of proteins regulating channel conductance and properties. VGSCs generate Na+ current (INa) in myocytes and play fundamental roles in excitability and impulse conduction in the heart. Moreover, VGSCs condition mechanical properties of the myocardium, a process that appears to involve the late component of INa. Variants in the gene SCN1B, encoding the VGSC β1- and β1B-subunits, result in inherited neurological disorders and cardiac arrhythmias. But the precise contributions of β1/β1B-subunits and VGSC integrity to the overall function of the adult heart remain to be clarified. For this purpose, adult mice with cardiac-restricted, inducible deletion of Scn1b (conditional knockout, cKO) were studied. Myocytes from cKO mice had increased densities of fast (+20%)- and slow (+140%)-inactivating components of INa, with respect to control cells. By echocardiography and invasive hemodynamics, systolic function was preserved in cKO mice, but diastolic properties and ventricular compliance were compromised, with respect to control animals. Importantly, inhibition of late INa with GS967 normalized left ventricular filling pattern and isovolumic relaxation time in cKO mice. At the cellular level, cKO myocytes presented delayed kinetics of Ca2+ transients and cell mechanics, defects that were corrected by inhibition of INa. Collectively, these results document that VGSC β1/β1B-subunits modulate electrical and mechanical function of the heart by regulating, at least in part, Na+ influx in cardiomyocytes.NEW & NOTEWORTHY We have investigated the consequences of deletion of Scn1b, the gene encoding voltage-gated sodium channel β1-subunits, on myocyte and cardiac function. Our findings support the notion that Scn1b expression controls properties of Na+ influx and Ca2+ cycling in cardiomyocytes affecting the modality of cell contraction and relaxation. These effects at the cellular level condition electrical recovery and diastolic function in vivo, substantiating the multifunctional role of β1-subunits in the physiology of the heart.
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Affiliation(s)
| | - Emanuele Pizzo
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Harshada Ketkar
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, New York
| | - Sreema P Parambath
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, New York
| | - Samantha Tang
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, New York
| | - Eleonora Cianflone
- Department of Physiology, New York Medical College, Valhalla, New York
- Molecular and Cellular Cardiology, Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy
| | - Antonio Cannata
- School of Cardiovascular Medicine and Sciences, King's College London British Heart Foundation Centre of Excellence, London, United Kingdom
| | | | - Sudhir Jain
- Department of Pathology, Microbiology and Immunology, New York Medical College, Valhalla, New York
| | - Jason T Jacobson
- Department of Physiology, New York Medical College, Valhalla, New York
- Department of Cardiology, Westchester Medical Center, Valhalla, New York
| | - Marcello Rota
- Department of Physiology, New York Medical College, Valhalla, New York
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Borowicz-Reutt KK. Effects of Antiarrhythmic Drugs on Antiepileptic Drug Action-A Critical Review of Experimental Findings. Int J Mol Sci 2022; 23:ijms23052891. [PMID: 35270033 PMCID: PMC8911389 DOI: 10.3390/ijms23052891] [Citation(s) in RCA: 2] [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: 02/09/2022] [Revised: 02/28/2022] [Accepted: 03/04/2022] [Indexed: 01/27/2023] Open
Abstract
Severe cardiac arrhythmias developing in the course of seizures increase the risk of SUDEP (sudden unexpected death in epilepsy). Hence, epilepsy patients with pre-existing arrhythmias should receive appropriate pharmacotherapy. Concomitant treatment with antiarrhythmic and antiseizure medications creates, however, the possibility of drug–drug interactions. This is due, among other reasons, to a similar mechanism of action. Both groups of drugs inhibit the conduction of electrical impulses in excitable tissues. The aim of this review was the analysis of such interactions in animal seizure models, including the maximal electroshock (MES) test in mice, a widely accepted screening test for antiepileptic drugs.
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Affiliation(s)
- Kinga K Borowicz-Reutt
- Independent Unit of Experimental Neuropathophysiology, Department of Toxicology, Medical University of Lublin, 20-090 Lublin, Poland
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9
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Horváth B, Szentandrássy N, Almássy J, Dienes C, Kovács ZM, Nánási PP, Banyasz T. Late Sodium Current of the Heart: Where Do We Stand and Where Are We Going? Pharmaceuticals (Basel) 2022; 15:ph15020231. [PMID: 35215342 PMCID: PMC8879921 DOI: 10.3390/ph15020231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 02/05/2023] Open
Abstract
Late sodium current has long been linked to dysrhythmia and contractile malfunction in the heart. Despite the increasing body of accumulating information on the subject, our understanding of its role in normal or pathologic states is not complete. Even though the role of late sodium current in shaping action potential under physiologic circumstances is debated, it’s unquestioned role in arrhythmogenesis keeps it in the focus of research. Transgenic mouse models and isoform-specific pharmacological tools have proved useful in understanding the mechanism of late sodium current in health and disease. This review will outline the mechanism and function of cardiac late sodium current with special focus on the recent advances of the area.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Norbert Szentandrássy
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Department of Basic Medical Sciences, Faculty of Dentistry, University of Debrecen, 4032 Debrecen, Hungary
| | - János Almássy
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Csaba Dienes
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Zsigmond Máté Kovács
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
| | - Péter P. Nánási
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Department of Dental Physiology and Pharmacology, University of Debrecen, 4032 Debrecen, Hungary
| | - Tamas Banyasz
- Department of Physiology, University of Debrecen, 4032 Debrecen, Hungary; (B.H.); (N.S.); (J.A.); (C.D.); (Z.M.K.); (P.P.N.)
- Correspondence: ; Tel.: +36-(52)-255-575; Fax: +36-(52)-255-116
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Ranolazine: An Old Drug with Emerging Potential; Lessons from Pre-Clinical and Clinical Investigations for Possible Repositioning. Pharmaceuticals (Basel) 2021; 15:ph15010031. [PMID: 35056088 PMCID: PMC8777683 DOI: 10.3390/ph15010031] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 02/07/2023] Open
Abstract
Ischemic heart disease is a significant public health problem with high mortality and morbidity. Extensive scientific investigations from basic sciences to clinics revealed multilevel alterations from metabolic imbalance, altered electrophysiology, and defective Ca2+/Na+ homeostasis leading to lethal arrhythmias. Despite the recent identification of numerous molecular targets with potential therapeutic interest, a pragmatic observation on the current pharmacological R&D output confirms the lack of new therapeutic offers to patients. By contrast, from recent trials, molecules initially developed for other fields of application have shown cardiovascular benefits, as illustrated with some anti-diabetic agents, regardless of the presence or absence of diabetes, emphasizing the clear advantage of “old” drug repositioning. Ranolazine is approved as an antianginal agent and has a favorable overall safety profile. This drug, developed initially as a metabolic modulator, was also identified as an inhibitor of the cardiac late Na+ current, although it also blocks other ionic currents, including the hERG/Ikr K+ current. The latter actions have been involved in this drug’s antiarrhythmic effects, both on supraventricular and ventricular arrhythmias (VA). However, despite initial enthusiasm and promising development in the cardiovascular field, ranolazine is only authorized as a second-line treatment in patients with chronic angina pectoris, notwithstanding its antiarrhythmic properties. A plausible reason for this is the apparent difficulty in linking the clinical benefits to the multiple molecular actions of this drug. Here, we review ranolazine’s experimental and clinical knowledge on cardiac metabolism and arrhythmias. We also highlight advances in understanding novel effects on neurons, the vascular system, skeletal muscles, blood sugar control, and cancer, which may open the way to reposition this “old” drug alone or in combination with other medications.
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11
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Philippaert K, Kalyaanamoorthy S, Fatehi M, Long W, Soni S, Byrne NJ, Barr A, Singh J, Wong J, Palechuk T, Schneider C, Darwesh AM, Maayah ZH, Seubert JM, Barakat K, Dyck JR, Light PE. Cardiac Late Sodium Channel Current Is a Molecular Target for the Sodium/Glucose Cotransporter 2 Inhibitor Empagliflozin. Circulation 2021; 143:2188-2204. [PMID: 33832341 PMCID: PMC8154177 DOI: 10.1161/circulationaha.121.053350] [Citation(s) in RCA: 98] [Impact Index Per Article: 32.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 02/25/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND SGLT2 (sodium/glucose cotransporter 2) inhibitors exert robust cardioprotective effects against heart failure in patients with diabetes, and there is intense interest to identify the underlying molecular mechanisms that afford this protection. Because the induction of the late component of the cardiac sodium channel current (late-INa) is involved in the etiology of heart failure, we investigated whether these drugs inhibit late-INa. METHODS Electrophysiological, in silico molecular docking, molecular, calcium imaging, and whole heart perfusion techniques were used to address this question. RESULTS The SGLT2 inhibitor empagliflozin reduced late-INa in cardiomyocytes from mice with heart failure and in cardiac Nav1.5 sodium channels containing the long QT syndrome 3 mutations R1623Q or ΔKPQ. Empagliflozin, dapagliflozin, and canagliflozin are all potent and selective inhibitors of H2O2-induced late-INa (half maximal inhibitory concentration = 0.79, 0.58, and 1.26 µM, respectively) with little effect on peak sodium current. In mouse cardiomyocytes, empagliflozin reduced the incidence of spontaneous calcium transients induced by the late-INa activator veratridine in a similar manner to tetrodotoxin, ranolazine, and lidocaine. The putative binding sites for empagliflozin within Nav1.5 were investigated by simulations of empagliflozin docking to a three-dimensional homology model of human Nav1.5 and point mutagenic approaches. Our results indicate that empagliflozin binds to Nav1.5 in the same region as local anesthetics and ranolazine. In an acute model of myocardial injury, perfusion of isolated mouse hearts with empagliflozin or tetrodotoxin prevented activation of the cardiac NLRP3 (nuclear-binding domain-like receptor 3) inflammasome and improved functional recovery after ischemia. CONCLUSIONS Our results provide evidence that late-INa may be an important molecular target in the heart for the SGLT2 inhibitors, contributing to their unexpected cardioprotective effects.
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Affiliation(s)
- Koenraad Philippaert
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Subha Kalyaanamoorthy
- Faculty of Medicine and Dentistry (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
| | - Mohammad Fatehi
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Wentong Long
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Shubham Soni
- Department of Pediatrics (S.S., N.J.B., Z.H.M., J.R.B.D.), University of Alberta, Edmonton, Canada
| | - Nikole J. Byrne
- Department of Pediatrics (S.S., N.J.B., Z.H.M., J.R.B.D.), University of Alberta, Edmonton, Canada
| | - Amy Barr
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Jyoti Singh
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Jordan Wong
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Taylor Palechuk
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Chloe Schneider
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
| | - Ahmed M. Darwesh
- Faculty of Medicine and Dentistry (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
| | - Zaid H. Maayah
- Department of Pediatrics (S.S., N.J.B., Z.H.M., J.R.B.D.), University of Alberta, Edmonton, Canada
| | - John M. Seubert
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
- Faculty of Medicine and Dentistry (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
| | - Khaled Barakat
- Faculty of Medicine and Dentistry (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Faculty of Pharmacy and Pharmaceutical Sciences (S.K., A.M.D., J.M.S., K.B.), University of Alberta, Edmonton, Canada
- Li Ka Shing Institute of Virology (K.B.), University of Alberta, Edmonton, Canada
| | - Jason R.B. Dyck
- Department of Pediatrics (S.S., N.J.B., Z.H.M., J.R.B.D.), University of Alberta, Edmonton, Canada
| | - Peter E. Light
- Alberta Diabetes Institute (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada.xs
- Department of Pharmacology (K.P., M.F., W.L., A.B., J.S., J.W., T.P., C.S., J.M.S., P.E.L.), University of Alberta, Edmonton, Canada
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12
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Cellular Mechanisms of the Anti-Arrhythmic Effect of Cardiac PDE2 Overexpression. Int J Mol Sci 2021; 22:ijms22094816. [PMID: 34062838 PMCID: PMC8125727 DOI: 10.3390/ijms22094816] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/27/2021] [Accepted: 04/28/2021] [Indexed: 12/11/2022] Open
Abstract
Background: Phosphodiesterases (PDE) critically regulate myocardial cAMP and cGMP levels. PDE2 is stimulated by cGMP to hydrolyze cAMP, mediating a negative crosstalk between both pathways. PDE2 upregulation in heart failure contributes to desensitization to β-adrenergic overstimulation. After isoprenaline (ISO) injections, PDE2 overexpressing mice (PDE2 OE) were protected against ventricular arrhythmia. Here, we investigate the mechanisms underlying the effects of PDE2 OE on susceptibility to arrhythmias. Methods: Cellular arrhythmia, ion currents, and Ca2+-sparks were assessed in ventricular cardiomyocytes from PDE2 OE and WT littermates. Results: Under basal conditions, action potential (AP) morphology were similar in PDE2 OE and WT. ISO stimulation significantly increased the incidence of afterdepolarizations and spontaneous APs in WT, which was markedly reduced in PDE2 OE. The ISO-induced increase in ICaL seen in WT was prevented in PDE2 OE. Moreover, the ISO-induced, Epac- and CaMKII-dependent increase in INaL and Ca2+-spark frequency was blunted in PDE2 OE, while the effect of direct Epac activation was similar in both groups. Finally, PDE2 inhibition facilitated arrhythmic events in ex vivo perfused WT hearts after reperfusion injury. Conclusion: Higher PDE2 abundance protects against ISO-induced cardiac arrhythmia by preventing the Epac- and CaMKII-mediated increases of cellular triggers. Thus, activating myocardial PDE2 may represent a novel intracellular anti-arrhythmic therapeutic strategy in HF.
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13
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Ozturk N, Uslu S, Ozdemir S. Diabetes-induced changes in cardiac voltage-gated ion channels. World J Diabetes 2021; 12:1-18. [PMID: 33520105 PMCID: PMC7807254 DOI: 10.4239/wjd.v12.i1.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/05/2020] [Accepted: 11/13/2020] [Indexed: 02/06/2023] Open
Abstract
Diabetes mellitus affects the heart through various mechanisms such as microvascular defects, metabolic abnormalities, autonomic dysfunction and incompatible immune response. Furthermore, it can also cause functional and structural changes in the myocardium by a disease known as diabetic cardiomyopathy (DCM) in the absence of coronary artery disease. As DCM progresses it causes electrical remodeling of the heart, left ventricular dysfunction and heart failure. Electrophysiological changes in the diabetic heart contribute significantly to the incidence of arrhythmias and sudden cardiac death in diabetes mellitus patients. In recent studies, significant changes in repolarizing K+ currents, Na+ currents and L-type Ca2+ currents along with impaired Ca2+ homeostasis and defective contractile function have been identified in the diabetic heart. In addition, insulin levels and other trophic factors change significantly to maintain the ionic channel expression in diabetic patients. There are many diagnostic tools and management options for DCM, but it is difficult to detect its development and to effectively prevent its progress. In this review, diabetes-associated alterations in voltage-sensitive cardiac ion channels are comprehensively assessed to understand their potential role in the pathophysiology and pathogenesis of DCM.
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Affiliation(s)
- Nihal Ozturk
- Department of Biophysics, Akdeniz University Faculty of Medicine, Antalya 07058, Turkey
| | - Serkan Uslu
- Department of Biophysics, Akdeniz University Faculty of Medicine, Antalya 07058, Turkey
| | - Semir Ozdemir
- Department of Biophysics, Akdeniz University Faculty of Medicine, Antalya 07058, Turkey
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14
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Cano J, Zorio E, Mazzanti A, Arnau MÁ, Trenor B, Priori SG, Saiz J, Romero L. Ranolazine as an Alternative Therapy to Flecainide for SCN5A V411M Long QT Syndrome Type 3 Patients. Front Pharmacol 2020; 11:580481. [PMID: 33519442 PMCID: PMC7845660 DOI: 10.3389/fphar.2020.580481] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 10/16/2020] [Indexed: 12/14/2022] Open
Abstract
The prolongation of the QT interval represents the main feature of the long QT syndrome (LQTS), a life-threatening genetic disease. The heterozygous SCN5A V411M mutation of the human sodium channel leads to a LQTS type 3 with severe proarrhythmic effects due to an increase in the late component of the sodium current (INaL). The two sodium blockers flecainide and ranolazine are equally recommended by the current 2015 ESC guidelines to treat patients with LQTS type 3 and persistently prolonged QT intervals. However, awareness of pro-arrhythmic effects of flecainide in LQTS type 3 patients arose upon the study of the SCN5A E1784K mutation. Regarding SCN5A V411M individuals, flecainide showed good results albeit in a reduced number of patients and no evidence supporting the use of ranolazine has ever been released. Therefore, we ought to compare the effect of ranolazine and flecainide in a SCN5A V411M model using an in-silico modeling and simulation approach. We collected clinical data of four patients. Then, we fitted four Markovian models of the human sodium current (INa) to experimental and clinical data. Two of them correspond to the wild type and the heterozygous SCN5A V411M scenarios, and the other two mimic the effects of flecainide and ranolazine on INa. Next, we inserted them into three isolated cell action potential (AP) models for endocardial, midmyocardial and epicardial cells and in a one-dimensional tissue model. The SCN5A V411M mutation produced a 15.9% APD90 prolongation in the isolated endocardial cell model, which corresponded to a 14.3% of the QT interval prolongation in a one-dimensional strand model, in keeping with clinical observations. Although with different underlying mechanisms, flecainide and ranolazine partially countered this prolongation at the isolated endocardial model by reducing the APD90 by 8.7 and 4.3%, and the QT interval by 7.2 and 3.2%, respectively. While flecainide specifically targeted the mutation-induced increase in peak INaL, ranolazine reduced it during the entire AP. Our simulations also suggest that ranolazine could prevent early afterdepolarizations triggered by the SCN5A V411M mutation during bradycardia, as flecainide. We conclude that ranolazine could be used to treat SCN5A V411M patients, specifically when flecainide is contraindicated.
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Affiliation(s)
- Jordi Cano
- Centro de Investigación e Innovación en Bioingeniería (CI2B), Universitat Politècnica de València, Valencia, España
| | - Esther Zorio
- Unidad de Cardiopatías Familiares y Muerte Súbita, Servicio de Cardiología, Hospital Universitario y Politécnico La Fe, Valencia, España.,Center for Biomedical Network Research on Cardiovascular Diseases (CIBERCV), Madrid, Spain
| | - Andrea Mazzanti
- Molecular Cardiology, IRCCS, Istituti Clinici Scientifici Maugeri, Pavia, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Miguel Ángel Arnau
- Unidad de Cardiopatías Familiares y Muerte Súbita, Servicio de Cardiología, Hospital Universitario y Politécnico La Fe, Valencia, España
| | - Beatriz Trenor
- Centro de Investigación e Innovación en Bioingeniería (CI2B), Universitat Politècnica de València, Valencia, España
| | - Silvia G Priori
- Molecular Cardiology, IRCCS, Istituti Clinici Scientifici Maugeri, Pavia, Italy.,Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Javier Saiz
- Centro de Investigación e Innovación en Bioingeniería (CI2B), Universitat Politècnica de València, Valencia, España
| | - Lucia Romero
- Centro de Investigación e Innovación en Bioingeniería (CI2B), Universitat Politècnica de València, Valencia, España
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15
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Abrams J, Roybal D, Chakouri N, Katchman AN, Weinberg R, Yang L, Chen BX, Zakharov SI, Hennessey JA, Avula UMR, Diaz J, Wang C, Wan EY, Pitt GS, Ben-Johny M, Marx SO. Fibroblast growth factor homologous factors tune arrhythmogenic late NaV1.5 current in calmodulin binding-deficient channels. JCI Insight 2020; 5:141736. [PMID: 32870823 PMCID: PMC7566708 DOI: 10.1172/jci.insight.141736] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 08/26/2020] [Indexed: 12/19/2022] Open
Abstract
The Ca2+-binding protein calmodulin has emerged as a pivotal player in tuning Na+ channel function, although its impact in vivo remains to be resolved. Here, we identify the role of calmodulin and the NaV1.5 interactome in regulating late Na+ current in cardiomyocytes. We created transgenic mice with cardiac-specific expression of human NaV1.5 channels with alanine substitutions for the IQ motif (IQ/AA). The mutations rendered the channels incapable of binding calmodulin to the C-terminus. The IQ/AA transgenic mice exhibited normal ventricular repolarization without arrhythmias and an absence of increased late Na+ current. In comparison, transgenic mice expressing a lidocaine-resistant (F1759A) human NaV1.5 demonstrated increased late Na+ current and prolonged repolarization in cardiomyocytes, with spontaneous arrhythmias. To determine regulatory factors that prevent late Na+ current for the IQ/AA mutant channel, we considered fibroblast growth factor homologous factors (FHFs), which are within the NaV1.5 proteomic subdomain shown by proximity labeling in transgenic mice expressing NaV1.5 conjugated to ascorbate peroxidase. We found that FGF13 diminished late current of the IQ/AA but not F1759A mutant cardiomyocytes, suggesting that endogenous FHFs may serve to prevent late Na+ current in mouse cardiomyocytes. Leveraging endogenous mechanisms may furnish an alternative avenue for developing novel pharmacology that selectively blunts late Na+ current.
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Affiliation(s)
| | | | - Nourdine Chakouri
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | | | | | - Lin Yang
- Division of Cardiology, Department of Medicine
| | | | | | | | | | - Johanna Diaz
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Chaojian Wang
- Division of Cardiology, Department of Medicine, Duke University Medical Center, Durham, North Carolina, USA
| | | | - Geoffrey S. Pitt
- Cardiovascular Research Institute, Weill Cornell Medical College, New York, New York, USA
| | - Manu Ben-Johny
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine
- Department of Pharmacology, and
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16
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Rose P, Schleimer JH, Schreiber S. Modifications of sodium channel voltage dependence induce arrhythmia-favouring dynamics of cardiac action potentials. PLoS One 2020; 15:e0236949. [PMID: 32750067 PMCID: PMC7402508 DOI: 10.1371/journal.pone.0236949] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 07/16/2020] [Indexed: 11/19/2022] Open
Abstract
Heart arrhythmia is a pathological condition where the sequence of electrical impulses in the heart deviates from the normal rhythm. It is often associated with specific channelopathies in cardiac tissue, yet how precisely the changes in ionic channels affect the electrical activity of cardiac cells is still an open question. Even though sodium channel mutations that underlie cardiac syndromes like the Long-Q-T and the Brugada-syndrome are known to affect a number of channel parameters simultaneously, previous studies have predominantly focused on the persistent late component of the sodium current as the causal explanation for an increased risk of heart arrhythmias in these cardiac syndromes. A systematic analysis of the impact of other important sodium channel parameters is currently lacking. Here, we investigate the reduced ten-Tusscher-model for single human epicardium ventricle cells and use mathematical bifurcation analysis to predict the dependence of the cardiac action potential on sodium channel activation and inactivation time-constants and voltage dependence. We show that, specifically, shifts of the voltage dependence of activation and inactivation curve can lead to drastic changes in the action potential dynamics, inducing oscillations of the membrane potential as well as bistability. Our results not only demonstrate a new way to induce multiple co-existing states of excitability (biexcitability) but also emphasize the critical role of the voltage dependence of sodium channel activation and inactivation curves for the induction of heart-arrhythmias.
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Affiliation(s)
- Pia Rose
- Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Jan-Hendrik Schleimer
- Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience, Berlin, Germany
| | - Susanne Schreiber
- Institute for Theoretical Biology, Humboldt-Universität zu Berlin, Berlin, Germany
- Bernstein Center for Computational Neuroscience, Berlin, Germany
- * E-mail:
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17
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Liu X, Gao Q, Feng Z, Tang Y, Zhao X, Chen D, Feng X. Protective Effects of Spermidine and Melatonin on Deltamethrin-Induced Cardiotoxicity and Neurotoxicity in Zebrafish. Cardiovasc Toxicol 2020; 21:29-41. [PMID: 32651933 DOI: 10.1007/s12012-020-09591-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Accepted: 07/03/2020] [Indexed: 02/07/2023]
Abstract
Increased application of the pyrethroid insecticide deltamethrin has adverse effects on the cardiac system and neurobehavior on the non-target organisms, which has raised the public's attention. Because of spermidine and melatonin considered to have cardioprotective and neuroprotective characteristics, zebrafish were utilized as the model organism to explore the protective effects of spermidine and melatonin against deltamethrin-induced toxicity. We tested the neurobehavior of zebrafish larvae through a rest/wake behavior assay, and evaluated the levels of the expression of Scn5lab, gata4, nkx2.5, hcrt, hcrtr, and aanat2 by qRT-PCR. Besides that cmlc2 was evaluated by whole-mount in situ hybridization. Results have shown that compared with control group, 0.025 mg/L deltamethrin could significantly disturb the cardiac development, downregulating the expression of Scn5lab and transcriptional factors gata4 and nkx2.5, disturbing cardiac looping, resulting in defects in cardiac morphology and function. Moreover, deltamethrin could alter the expression levels of rest/wake genes and cause hyperactivity in zebrafish larvae. Besides, compared with deltamethrin group, the exogenous 0.01 mg/L spermidine and 0.232 mg/L melatonin could significantly rescue the adverse effects of deltamethrin on the cardiac system and neurobehavior in zebrafish. This indicated that spermidine and melatonin have neuroprotective and cardioprotective effects against deltamethrin-induced adverse effects in zebrafish.
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Affiliation(s)
- Xingyu Liu
- State Key Laboratory of Medicinal Chemical Biology, The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Qian Gao
- Tianjin Key Laboratory of Molecular Drug Research, College of Pharmacy, Nankai University, Tianjin, 300071, China
| | - Zeyang Feng
- The Institute of Robotics and Automatic Information Systems, College of Artificial Intelligence, Nankai University, Tianjin, 300071, China
| | - Yaqiu Tang
- State Key Laboratory of Medicinal Chemical Biology, The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China
| | - Xin Zhao
- The Institute of Robotics and Automatic Information Systems, College of Artificial Intelligence, Nankai University, Tianjin, 300071, China
| | - Dongyan Chen
- Tianjin Key Laboratory of Molecular Drug Research, College of Pharmacy, Nankai University, Tianjin, 300071, China.
| | - Xizeng Feng
- State Key Laboratory of Medicinal Chemical Biology, The Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Science, Nankai University, Tianjin, 300071, China.
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18
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Matasic DS, Yoon JY, McLendon JM, Mehdi H, Schmidt MS, Greiner AM, Quinones P, Morgan GM, Boudreau RL, Irani K, Brenner C, London B. Modulation of the cardiac sodium channel Na V1.5 peak and late currents by NAD + precursors. J Mol Cell Cardiol 2020; 141:70-81. [PMID: 32209328 PMCID: PMC7234910 DOI: 10.1016/j.yjmcc.2020.01.013] [Citation(s) in RCA: 10] [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: 08/07/2019] [Revised: 12/09/2019] [Accepted: 01/08/2020] [Indexed: 01/02/2023]
Abstract
RATIONALE The cardiac sodium channel NaV1.5, encoded by SCN5A, produces the rapidly inactivating depolarizing current INa that is responsible for the initiation and propagation of the cardiac action potential. Acquired and inherited dysfunction of NaV1.5 results in either decreased peak INa or increased residual late INa (INa,L), leading to tachy/bradyarrhythmias and sudden cardiac death. Previous studies have shown that increased cellular NAD+ and NAD+/NADH ratio increase INa through suppression of mitochondrial reactive oxygen species and PKC-mediated NaV1.5 phosphorylation. In addition, NAD+-dependent deacetylation of NaV1.5 at K1479 by Sirtuin 1 increases NaV1.5 membrane trafficking and INa. The role of NAD+ precursors in modulating INa remains unknown. OBJECTIVE To determine whether and by which mechanisms the NAD+ precursors nicotinamide riboside (NR) and nicotinamide (NAM) affect peak INa and INa,Lin vitro and cardiac electrophysiology in vivo. METHODS AND RESULTS The effects of NAD+ precursors on the NAD+ metabolome and electrophysiology were studied using HEK293 cells expressing wild-type and mutant NaV1.5, rat neonatal cardiomyocytes (RNCMs), and mice. NR increased INa in HEK293 cells expressing NaV1.5 (500 μM: 51 ± 18%, p = .02, 5 mM: 59 ± 22%, p = .03) and RNCMs (500 μM: 60 ± 26%, p = .02, 5 mM: 74 ± 39%, p = .03) while reducing INa,L at the higher concentration (RNCMs, 5 mM: -45 ± 11%, p = .04). NR (5 mM) decreased NaV1.5 K1479 acetylation but increased INa in HEK293 cells expressing a mutant form of NaV1.5 with disruption of the acetylation site (NaV1.5-K1479A). Disruption of the PKC phosphorylation site abolished the effect of NR on INa. Furthermore, NAM (5 mM) had no effect on INa in RNCMs or in HEK293 cells expressing wild-type NaV1.5, but increased INa in HEK293 cells expressing NaV1.5-K1479A. Dietary supplementation with NR for 10-12 weeks decreased QTc in C57BL/6 J mice (0.35% NR: -4.9 ± 2.0%, p = .14; 1.0% NR: -9.5 ± 2.8%, p = .01). CONCLUSIONS NAD+ precursors differentially regulate NaV1.5 via multiple mechanisms. NR increases INa, decreases INa,L, and warrants further investigation as a potential therapy for arrhythmic disorders caused by NaV1.5 deficiency and/or dysfunction.
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Affiliation(s)
- Daniel S Matasic
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Jin-Young Yoon
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Jared M McLendon
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Haider Mehdi
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Mark S Schmidt
- Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Alexander M Greiner
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Pravda Quinones
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Gina M Morgan
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Ryan L Boudreau
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Kaikobad Irani
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Charles Brenner
- Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Department of Biochemistry, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America
| | - Barry London
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America; Department of Molecular Physiology and Biophysics, University of Iowa Carver College of Medicine, Iowa City, IA, United States of America.
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Djamgoz MBA. Hyponatremia and Cancer Progression: Possible Association with Sodium-Transporting Proteins. Bioelectricity 2020; 2:14-20. [PMID: 34471833 DOI: 10.1089/bioe.2019.0035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Hyponatremia, the phenomenon of serum sodium level falling below 135 mmol/L, is seen frequently in cancer patients and has been correlated with poor prognosis. Hyponatremia has classically been attributed to the "syndrome of inappropriate antidiuretic hormone secretion," leading to prolonged fluid retention. However, this is unlikely to be the only mechanism. In this study, we advance the hypothesis that upregulation of various sodium-transporting proteins during the cancer process makes a significant contribution to the pathophysiology of cancer-associated hyponatremia. Such sodium-transporting proteins include voltage-gated sodium channels, especially its hypoxia-promoted persistent current, epithelial sodium channels, and transient receptor potential channels. Thus, hyponatremia follows cancer, whereby drop in blood serum level occurs as a result of uptake of sodium from extracellular fluid by cancer cells. Indeed, the sodium content of cancer cells/tissues is higher than normal. In turn, the rise in the intracellular sodium concentration brings about a range of cellular effects, including extracellular acidification that promotes invasiveness and thus leads to poor prognosis. This perspective offers novel therapies for cancer and the associated hyponatremia.
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Affiliation(s)
- Mustafa B A Djamgoz
- Department of Life Sciences, Neuroscience Solutions to Cancer Research Group, Imperial College London, London, United Kingdom.,Biotechnology Research Centre, Cyprus International University, Lefkosa, North Cyprus
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20
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Struckman HL, Baine S, Thomas J, Mezache L, Mykytyn K, Györke S, Radwański PB, Veeraraghavan R. Super-Resolution Imaging Using a Novel High-Fidelity Antibody Reveals Close Association of the Neuronal Sodium Channel Na V1.6 with Ryanodine Receptors in Cardiac Muscle. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2020; 26:157-165. [PMID: 31931893 PMCID: PMC7061261 DOI: 10.1017/s1431927619015289] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The voltage-gated sodium channel [pore-forming subunit of the neuronal voltage-gated sodium channel (NaV1.6)] has recently been found in cardiac myocytes. Emerging studies indicate a role for NaV1.6 in ionic homeostasis as well as arrhythmogenesis. Little is known about the spatial organization of these channels in cardiac muscle, mainly due to the lack of high-fidelity antibodies. Therefore, we developed and rigorously validated a novel rabbit polyclonal NaV1.6 antibody and undertook super-resolution microscopy studies of NaV1.6 localization in cardiac muscle. We developed and validated a novel rabbit polyclonal antibody against a C-terminal epitope on the neuronal sodium channel 1.6 (NaV1.6). Raw sera showed high affinity in immuno-fluorescence studies, which was improved with affinity purification. The antibody was rigorously validated for specificity via multiple approaches. Lastly, we used this antibody in proximity ligation assay (PLA) and super-resolution STochastic Optical Reconstruction Microscopy (STORM) studies, which revealed enrichment of NaV1.6 in close proximity to ryanodine receptor (RyR2), a key calcium (Ca2+) cycling protein, in cardiac myocytes. In summary, our novel NaV1.6 antibody demonstrates high degrees of specificity and fidelity in multiple preparations. It enabled multimodal microscopic studies and revealed that over half of the NaV1.6 channels in cardiac myocytes are located within 100 nm of ryanodine receptor Ca2+ release channels.
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Affiliation(s)
- Heather L. Struckman
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH, US
| | - Stephen Baine
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, US
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, US
| | - Justin Thomas
- Division of Pharmacy Practice and Sciences, College of Pharmacy, The Ohio State University, Columbus, OH, US
| | - Louisa Mezache
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH, US
| | - Kirk Mykytyn
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, US
| | - Sándor Györke
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, US
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, US
| | - Przemysław B. Radwański
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, US
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, US
- Division of Pharmacy Practice and Sciences, College of Pharmacy, The Ohio State University, Columbus, OH, US
| | - Rengasayee Veeraraghavan
- Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH, US
- Dorothy M. Davis Heart and Lung Research Institute, College of Medicine, The Ohio State University Wexner Medical Center, Columbus, OH, US
- Department of Physiology and Cell Biology, College of Medicine, The Ohio State University, Columbus, OH, US
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21
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Maroni M, Körner J, Schüttler J, Winner B, Lampert A, Eberhardt E. β1 and β3 subunits amplify mechanosensitivity of the cardiac voltage-gated sodium channel Nav1.5. Pflugers Arch 2019; 471:1481-1492. [PMID: 31728700 DOI: 10.1007/s00424-019-02324-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Revised: 09/25/2019] [Accepted: 10/21/2019] [Indexed: 12/19/2022]
Abstract
In cardiomyocytes, electrical activity is coupled to cellular contraction, thus exposing all proteins expressed in the sarcolemma to mechanical stress. The voltage-gated sodium channel Nav1.5 is the main contributor to the rising phase of the action potential in the heart. There is growing evidence that gating and kinetics of Nav1.5 are modulated by mechanical forces and pathogenic variants that affect mechanosensitivity have been linked to arrhythmias. Recently, the sodium channel β1 subunit has been described to stabilise gating against mechanical stress of Nav1.7 expressed in neurons. Here, we tested the effect of β1 and β3 subunits on mechanosensitivity of the cardiac Nav1.5. β1 amplifies stress-induced shifts of V1/2 of steady-state fast inactivation to hyperpolarised potentials (ΔV1/2: 6.2 mV without and 10.7 mV with β1 co-expression). β3, on the other hand, almost doubles stress-induced speeding of time to sodium current transient peak (Δtime to peak at - 30 mV: 0.19 ms without and 0.37 ms with β3 co-expression). Our findings may indicate that in cardiomyocytes, the interdependence of electrical activity and contraction is used as a means of fine tuning cardiac sodium channel function, allowing quicker but more strongly inactivating sodium currents under conditions of increased mechanical stress. This regulation may help to shorten action potential duration during tachycardia, to prevent re-entry phenomena and thus arrhythmias.
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Affiliation(s)
- Michele Maroni
- Department of Anaesthesiology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany.,Department of Stem Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
| | - Jannis Körner
- Institute of Physiology, Medical Faculty, RWTH Aachen University, 52074, Aachen, Germany.,Department of Anaesthesiology, Medical Faculty, RWTH Aachen University, 52074, Aachen, Germany
| | - Jürgen Schüttler
- Department of Anaesthesiology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
| | - Beate Winner
- Department of Stem Cell Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany
| | - Angelika Lampert
- Institute of Physiology, Medical Faculty, RWTH Aachen University, 52074, Aachen, Germany
| | - Esther Eberhardt
- Department of Anaesthesiology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 91054, Erlangen, Germany.
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22
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Neubauer J, Wang Z, Rougier JS, Abriel H, Rieubland C, Bartholdi D, Haas C, Medeiros-Domingo A. Functional characterization of a novel SCN5A variant associated with long QT syndrome and sudden cardiac death. Int J Legal Med 2019; 133:1733-1742. [DOI: 10.1007/s00414-019-02141-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 08/06/2019] [Indexed: 12/14/2022]
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23
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Wu M, Tran PN, Sheng J, Randolph AL, Wu WW. Drug potency on inhibiting late Na + current is sensitive to gating modifier and current region where drug effects were measured. J Pharmacol Toxicol Methods 2019; 100:106605. [PMID: 31255744 DOI: 10.1016/j.vascn.2019.106605] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 06/18/2019] [Accepted: 06/24/2019] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Cardiac late Na+ current (INaL) contributes to ventricular action potential duration. Pathological increase in INaL is arrhythmogenic, and inhibition of INaL offers protection against ventricular repolarization disturbance. Recently, two INaL datasets generated by different laboratories that assessed current inhibition by a panel of clinical drugs as a part of the Comprehensive in vitro Proarrhythmia Assay (CiPA) initiative were published. The results revealed a surprising degree of data variability despite of the use of a standardized voltage protocol. This study investigated whether remaining procedural differences related to experimental methods and data analysis associated with these datasets can produce differences in INaL pharmacology. METHODS Whole cell voltage clamp recordings were performed on cells expressing NaV1.5 α- and β1-subunits to study: 1) the impact of gating modifiers used to augment INaL (ATX-II vs. veratridine), internal solution composition (with vs. without ATP and GTP), and recording temperature (23 °C vs 37 °C) on stability of INaL measured across the duration of a patch clamp experiment; 2) mechanisms of each gating modifier on Na+ channels; and 3) effects of six drugs (lidocaine, mexiletine, chloroquine, ranolazine, ritonavir, and verapamil) on INaL induced by either gating modifier. RESULTS Stability of INaL is affected by the choice of gating modifier, presence of nucleotides in the internal solution, and recording temperature. ATX-II and veratridine produced different changes in Na+ channel gating, inducing mechanistically distinct INaL. Drug potencies on inhibiting INaL were dependent on the choice of gating modifier and current region where drug effects were measured. DISCUSSION INaL pharmacology can be impacted by all experimental factors examined in this study. The effect of gating modifier and current region used to quantify drug inhibition alone led to 30× difference in half inhibitory concentration (IC50) for ritonavir, demonstrating that substantial difference in drug inhibition can be produced. Drug potencies on inhibiting INaL derived from different patch clamp studies may thus not be generalizable. For INaL pharmacology to be useful for in silico modeling or interpreting drug-induced changes in cardiac action potentials or ECG, standardizing INaL experimental procedures including data analysis methods is necessary to minimize data variability.
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Affiliation(s)
- Min Wu
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Center for Drug Evaluation and Research, The US Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, United States of America
| | - Phu N Tran
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Center for Drug Evaluation and Research, The US Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, United States of America
| | - Jiansong Sheng
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Center for Drug Evaluation and Research, The US Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, United States of America
| | - Aaron L Randolph
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Center for Drug Evaluation and Research, The US Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, United States of America
| | - Wendy W Wu
- Division of Applied Regulatory Science, Office of Clinical Pharmacology, Center for Drug Evaluation and Research, The US Food and Drug Administration, 10903 New Hampshire Avenue, Silver Spring, MD 20993, United States of America.
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24
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Ghosh GC, Ghosh RK, Bandyopadhyay D, Chatterjee K, Aneja A. Ranolazine: Multifaceted Role beyond Coronary Artery Disease, a Recent Perspective. Heart Views 2019; 19:88-98. [PMID: 31007857 PMCID: PMC6448470 DOI: 10.4103/heartviews.heartviews_18_18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Ranolazine is a piperazine derivative approved as an antianginal. Primarily used as a second-line antianginal in stable coronary artery disease. Ranolazine blocks the late Na + current and prevents the rise of cytosolic calcium. It decreases myocardial wall tension and improves coronary blood flow. Ranolazine is effective in atrial fibrillation (AF) as an adjunct to electrical or pharmacological cardioversion. It can be used in combination with amiodarone or dronedarone. It has also been used in AF arising after coronary artery bypass grafting surgery. Role of ranolazine is also being evaluated in pulmonary arterial hypertension, diastolic dysfunction, and chemotherapy-induced cardiotoxicity. Ranolazine has some anti-glycemic effect and has shown a reduction of hemoglobin A1c in multiple trials. The antianginal effect of ranolazine has also been seen to be more in patients with diabetes compared to those without diabetes. Ranolazine is being evaluated in patients with the peripheral arterial disease with intermittent claudication and hypertrophic cardiomyopathy. Pilot studies have shown that ranolazine may be beneficial in neurological conditions with myotonia. The evidence-base on the use of ranolazine in various conditions is rapidly increasing with results of further trials eagerly awaited. Accumulating evidence may see ranolazine in routine clinical use for many conditions beyond its traditional role as an antianginal.
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Affiliation(s)
- Gopal Chandra Ghosh
- Department of Cardiology, Christian Medical College, Vellore, Tamil Nadu, India
| | - Raktim Kumar Ghosh
- MetroHealth Medical Center, Case Western Reserve University, Heart and Vascular Institute, Cleveland, OH, USA
| | | | - Krishnarpan Chatterjee
- Department of Cardiology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Ashish Aneja
- MetroHealth Medical Center, Case Western Reserve University, Heart and Vascular Institute, Cleveland, OH, USA
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25
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Fux JE, Mehta A, Moffat J, Spafford JD. Eukaryotic Voltage-Gated Sodium Channels: On Their Origins, Asymmetries, Losses, Diversification and Adaptations. Front Physiol 2018; 9:1406. [PMID: 30519187 PMCID: PMC6259924 DOI: 10.3389/fphys.2018.01406] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 09/14/2018] [Indexed: 12/19/2022] Open
Abstract
The appearance of voltage-gated, sodium-selective channels with rapid gating kinetics was a limiting factor in the evolution of nervous systems. Two rounds of domain duplications generated a common 24 transmembrane segment (4 × 6 TM) template that is shared amongst voltage-gated sodium (Nav1 and Nav2) and calcium channels (Cav1, Cav2, and Cav3) and leak channel (NALCN) plus homologs from yeast, different single-cell protists (heterokont and unikont) and algae (green and brown). A shared architecture in 4 × 6 TM channels include an asymmetrical arrangement of extended extracellular L5/L6 turrets containing a 4-0-2-2 pattern of cysteines, glycosylated residues, a universally short III-IV cytoplasmic linker and often a recognizable, C-terminal PDZ binding motif. Six intron splice junctions are conserved in the first domain, including a rare U12-type of the minor spliceosome provides support for a shared heritage for sodium and calcium channels, and a separate lineage for NALCN. The asymmetrically arranged pores of 4x6 TM channels allows for a changeable ion selectivity by means of a single lysine residue change in the high field strength site of the ion selectivity filter in Domains II or III. Multicellularity and the appearance of systems was an impetus for Nav1 channels to adapt to sodium ion selectivity and fast ion gating. A non-selective, and slowly gating Nav2 channel homolog in single cell eukaryotes, predate the diversification of Nav1 channels from a basal homolog in a common ancestor to extant cnidarians to the nine vertebrate Nav1.x channel genes plus Nax. A close kinship between Nav2 and Nav1 homologs is evident in the sharing of most (twenty) intron splice junctions. Different metazoan groups have lost their Nav1 channel genes altogether, while vertebrates rapidly expanded their gene numbers. The expansion in vertebrate Nav1 channel genes fills unique functional niches and generates overlapping properties contributing to redundancies. Specific nervous system adaptations include cytoplasmic linkers with phosphorylation sites and tethered elements to protein assemblies in First Initial Segments and nodes of Ranvier. Analogous accessory beta subunit appeared alongside Nav1 channels within different animal sub-phyla. Nav1 channels contribute to pace-making as persistent or resurgent currents, the former which is widespread across animals, while the latter is a likely vertebrate adaptation.
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Affiliation(s)
- Julia E Fux
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | - Amrit Mehta
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | - Jack Moffat
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
| | - J David Spafford
- Department of Biology, University of Waterloo, Waterloo, ON, Canada
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26
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Skogestad J, Aronsen JM. Hypokalemia-Induced Arrhythmias and Heart Failure: New Insights and Implications for Therapy. Front Physiol 2018; 9:1500. [PMID: 30464746 PMCID: PMC6234658 DOI: 10.3389/fphys.2018.01500] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 10/05/2018] [Indexed: 12/18/2022] Open
Abstract
Routine use of diuretics and neurohumoral activation make hypokalemia (serum K+ < 3. 5 mM) a prevalent electrolyte disorder among heart failure patients, contributing to the increased risk of ventricular arrhythmias and sudden cardiac death in heart failure. Recent experimental studies have suggested that hypokalemia-induced arrhythmias are initiated by the reduced activity of the Na+/K+-ATPase (NKA), subsequently leading to Ca2+ overload, Ca2+/Calmodulin-dependent kinase II (CaMKII) activation, and development of afterdepolarizations. In this article, we review the current mechanistic evidence of hypokalemia-induced triggered arrhythmias and discuss how molecular changes in heart failure might lower the threshold for these arrhythmias. Finally, we discuss how recent insights into hypokalemia-induced arrhythmias could have potential implications for future antiarrhythmic treatment strategies.
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Affiliation(s)
- Jonas Skogestad
- Division of Cardiovascular and Pulmonary Diseases, Institute of Experimental Medical Research, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - Jan Magnus Aronsen
- Department of Pharmacology, Faculty of Medicine, University of Oslo and Oslo University Hospital, Oslo, Norway.,Bjørknes College, Oslo, Norway
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27
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Chang CJ, Cheng CC, Chen YC, Higa S, Huang JH, Chen SA, Chen YJ. Factor Xa inhibitors differently modulate electrical activities in pulmonary veins and the sinoatrial node. Eur J Pharmacol 2018; 833:462-471. [DOI: 10.1016/j.ejphar.2018.07.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 06/29/2018] [Accepted: 07/02/2018] [Indexed: 02/04/2023]
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28
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Gardill BR, Rivera-Acevedo RE, Tung CC, Okon M, McIntosh LP, Van Petegem F. The voltage-gated sodium channel EF-hands form an interaction with the III-IV linker that is disturbed by disease-causing mutations. Sci Rep 2018; 8:4483. [PMID: 29540853 PMCID: PMC5852250 DOI: 10.1038/s41598-018-22713-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 02/27/2018] [Indexed: 12/20/2022] Open
Abstract
Voltage-gated sodium channels (NaV) are responsible for the rapid depolarization of many excitable cells. They readily inactivate, a process where currents diminish after milliseconds of channel opening. They are also targets for a multitude of disease-causing mutations, many of which have been shown to affect inactivation. A cluster of disease mutations, linked to Long-QT and Brugada syndromes, is located in a C-terminal EF-hand like domain of NaV1.5, the predominant cardiac sodium channel isoform. Previous studies have suggested interactions with the III-IV linker, a cytosolic element directly involved in inactivation. Here we validate and map the interaction interface using isothermal titration calorimetry (ITC) and NMR spectroscopy. We investigated the impact of various disease mutations on the stability of the domain, and found that mutations that cause misfolding of the EF-hand domain result in hyperpolarizing shifts in the steady-state inactivation curve. Conversely, mutations in the III-IV linker that disrupt the interaction with the EF-hand domain also result in large hyperpolarization shifts, supporting the interaction between both elements in intact channels. Disrupting the interaction also causes large late currents, pointing to a dual role of the interaction in reducing the population of channels entering inactivation and in stabilizing the inactivated state.
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Affiliation(s)
- Bernd R Gardill
- Department of Biochemistry and Molecular Biology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Ricardo E Rivera-Acevedo
- Department of Biochemistry and Molecular Biology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
- Department of Anesthesiology, Pharmacology, and Therapeutics, The University of British Columbia, 2176 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Ching-Chieh Tung
- Department of Biochemistry and Molecular Biology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Mark Okon
- Department of Biochemistry and Molecular Biology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
- Department of Chemistry, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Lawrence P McIntosh
- Department of Biochemistry and Molecular Biology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
- Department of Chemistry, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Filip Van Petegem
- Department of Biochemistry and Molecular Biology, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada.
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Banach M, Popławska M, Borowicz-Reutt KK. Amiodarone, a multi-channel blocker, enhances anticonvulsive effect of carbamazepine in the mouse maximal electroshock model. Epilepsy Res 2018; 140:105-110. [PMID: 29329017 DOI: 10.1016/j.eplepsyres.2018.01.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 12/07/2017] [Accepted: 01/03/2018] [Indexed: 12/11/2022]
Abstract
Cardiac arrhythmia may occur in the course of epilepsy. Simultaneous therapy of the two diseases might be complicated by drug interactions since antiarrhythmic and antiepileptic agents share some molecular targets. The aim of this study was to evaluate the influence of amiodarone, an antiarrhythmic drug working as a multi-channel blocker, on the protective activity of four classical antiepileptic drugs in the maximal electroshock test in mice. Amiodarone at doses up to 75 mg/kg did not affect the electroconvulsive threshold in mice. Acute amiodarone at the dose of 75 mg/kg significantly potentiated the anticonvulsive effect of carbamazepine, but not that of valproate, phenytoin or phenobarbital in the maximal electroshock-induced seizures in mice. The antiarrhythmic agent and its combinations with antiepileptic drugs did not impair motor performance or long-term memory in mice, except for the combination of amiodarone and phenobarbital. Brain concentrations of antiepileptic drugs were not changed. Despite favourable impact of amiodarone on the anticonvulsive action of carbamazepine in the maximal electroshock, co-administration of the two drugs should be carefully monitored in clinical conditions. Further studies are necessary to evaluate effects of chronic treatment with amiodarone on seizure activity and the action of antiepileptic drugs.
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Affiliation(s)
- Monika Banach
- Independent Unit of Experimental Neuropathophysiology, Department of Pathophysiology, Medical University of Lublin, Jaczewskiego 8, PL-20-954, Lublin, Poland
| | - Monika Popławska
- Independent Unit of Experimental Neuropathophysiology, Department of Pathophysiology, Medical University of Lublin, Jaczewskiego 8, PL-20-954, Lublin, Poland
| | - Kinga K Borowicz-Reutt
- Independent Unit of Experimental Neuropathophysiology, Department of Pathophysiology, Medical University of Lublin, Jaczewskiego 8, PL-20-954, Lublin, Poland.
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30
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Natesan V. Fundamental role of warburg effect in various pathophysiological processes. ACTA ACUST UNITED AC 2018. [DOI: 10.4103/ijcep.ijcep_55_17] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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31
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ICaL and Ito mediate rate-dependent repolarization in rabbit atrial myocytes. J Physiol Biochem 2017; 74:57-67. [DOI: 10.1007/s13105-017-0603-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 12/04/2017] [Indexed: 01/01/2023]
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32
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Late sodium current associated cardiac electrophysiological and mechanical dysfunction. Pflugers Arch 2017; 470:461-469. [DOI: 10.1007/s00424-017-2079-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Revised: 09/27/2017] [Accepted: 10/09/2017] [Indexed: 12/19/2022]
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33
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Naumenko N, Huusko J, Tuomainen T, Koivumäki JT, Merentie M, Gurzeler E, Alitalo K, Kivelä R, Ylä-Herttuala S, Tavi P. Vascular Endothelial Growth Factor-B Induces a Distinct Electrophysiological Phenotype in Mouse Heart. Front Physiol 2017; 8:373. [PMID: 28620319 PMCID: PMC5450225 DOI: 10.3389/fphys.2017.00373] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 05/18/2017] [Indexed: 12/22/2022] Open
Abstract
Vascular endothelial growth factor B (VEGF-B) is a potent mediator of vascular, metabolic, growth, and stress responses in the heart, but the effects on cardiac muscle and cardiomyocyte function are not known. The purpose of this study was to assess the effects of VEGF-B on the energy metabolism, contractile, and electrophysiological properties of mouse cardiac muscle and cardiac muscle cells. In vivo and ex vivo analysis of cardiac-specific VEGF-B TG mice indicated that the contractile function of the TG hearts was normal. Neither the oxidative metabolism of isolated TG cardiomyocytes nor their energy substrate preference showed any difference to WT cardiomyocytes. Similarly, myocyte Ca2+ signaling showed only minor changes compared to WT myocytes. However, VEGF-B overexpression induced a distinct electrophysiological phenotype characterized by ECG changes such as an increase in QRSp time and decreases in S and R amplitudes. At the level of isolated TG cardiomyocytes, these changes were accompanied with decreased action potential upstroke velocity and increased duration (APD60–70). These changes were partly caused by downregulation of sodium current (INa) due to reduced expression of Nav1.5. Furthermore, TG myocytes had alterations in voltage-gated K+ currents, namely decreased density of transient outward current (Ito) and total K+ current (Ipeak). At the level of transcription, these were accompanied by downregulation of Kv channel-interacting protein 2 (Kcnip2), a known modulatory subunit for Kv4.2/3 channel. Cardiac VEGF-B overexpression induces a distinct electrophysiological phenotype including remodeling of cardiomyocyte ion currents, which in turn induce changes in action potential waveform and ECG.
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Affiliation(s)
- Nikolay Naumenko
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
| | - Jenni Huusko
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
| | - Tomi Tuomainen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
| | - Jussi T Koivumäki
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
| | - Mari Merentie
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
| | - Erika Gurzeler
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
| | - Kari Alitalo
- Wihuri Research Institute and Translational Cancer Biology Program, University of Helsinki, Biomedicum HelsinkiHelsinki, Finland
| | - Riikka Kivelä
- Wihuri Research Institute and Translational Cancer Biology Program, University of Helsinki, Biomedicum HelsinkiHelsinki, Finland
| | - Seppo Ylä-Herttuala
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland.,Heart Center and Gene Therapy Unit, Kuopio University HospitalKuopio, Finland
| | - Pasi Tavi
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern FinlandKuopio, Finland
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34
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Huang H, Pugsley MK, Fermini B, Curtis MJ, Koerner J, Accardi M, Authier S. Cardiac voltage-gated ion channels in safety pharmacology: Review of the landscape leading to the CiPA initiative. J Pharmacol Toxicol Methods 2017; 87:11-23. [PMID: 28408211 DOI: 10.1016/j.vascn.2017.04.002] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 03/27/2017] [Accepted: 04/06/2017] [Indexed: 12/15/2022]
Abstract
Voltage gated ion channels are central in defining the fundamental properties of the ventricular cardiac action potential (AP), and are also involved in the development of drug-induced arrhythmias. Many drugs can inhibit cardiac ion currents, including the Na+ current (INa), L-type Ca2+ current (Ica-L), and K+ currents (Ito, IK1, IKs, and IKr), and thereby affect AP properties in a manner that can trigger or sustain cardiac arrhythmias. Since publication of ICH E14 and S7B over a decade ago, there has been a focus on drug effects on QT prolongation clinically, and on the rapidly activating delayed rectifier current (IKr), nonclinically, for evaluation of proarrhythmic risk. This focus on QT interval prolongation and a single ionic current likely impacted negatively some drugs that lack proarrhythmic liability in humans. To rectify this issue, the Comprehensive in vitro proarrhythmia assay (CiPA) initiative has been proposed to integrate drug effects on multiple cardiac ionic currents with in silico modelling of human ventricular action potentials, and in vitro data obtained from human stem cell-derived ventricular cardiomyocytes to estimate proarrhythmic risk of new drugs with improved accuracy. In this review, we present the physiological functions and the molecular basis of major cardiac ion channels that contribute to the ventricle AP, and discuss the CiPA paradigm in drug development.
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Affiliation(s)
- Hai Huang
- CiToxLAB North America, 445, Armand-Frappier Boul, Laval H7V 4B3, QC, Canada
| | - Michael K Pugsley
- Department of Toxicology, Purdue Pharma L.P., Cranbury, NJ 08512, USA
| | | | - Michael J Curtis
- Cardiovascular Division, Faculty of Life Sciences & Medicine, King's College London, Rayne Institute, St Thomas' Hospital, London SE17EH, UK
| | - John Koerner
- Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, MD 20993, USA
| | - Michael Accardi
- CiToxLAB North America, 445, Armand-Frappier Boul, Laval H7V 4B3, QC, Canada
| | - Simon Authier
- CiToxLAB North America, 445, Armand-Frappier Boul, Laval H7V 4B3, QC, Canada.
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35
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Bezzerides VJ, Zhang A, Xiao L, Simonson B, Khedkar SA, Baba S, Ottaviano F, Lynch S, Hessler K, Rigby AC, Milan D, Das S, Rosenzweig A. Inhibition of serum and glucocorticoid regulated kinase-1 as novel therapy for cardiac arrhythmia disorders. Sci Rep 2017; 7:346. [PMID: 28336914 PMCID: PMC5428512 DOI: 10.1038/s41598-017-00413-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Accepted: 02/27/2017] [Indexed: 12/17/2022] Open
Abstract
Alterations in sodium flux (INa) play an important role in the pathogenesis of cardiac arrhythmias and may also contribute to the development of cardiomyopathies. We have recently demonstrated a critical role for the regulation of the voltage-gated sodium channel NaV1.5 in the heart by the serum and glucocorticoid regulated kinase-1 (SGK1). Activation of SGK1 in the heart causes a marked increase in both the peak and late sodium currents leading to prolongation of the action potential duration and an increased propensity to arrhythmia. Here we show that SGK1 directly regulates NaV1.5 channel function, and genetic inhibition of SGK1 in a zebrafish model of inherited long QT syndrome rescues the long QT phenotype. Using computer-aided drug discovery coupled with in vitro kinase assays, we identified a novel class of SGK1 inhibitors. Our lead SGK1 inhibitor (5377051) selectively inhibits SGK1 in cultured cardiomyocytes, and inhibits phosphorylation of an SGK1-specific target as well as proliferation in the prostate cancer cell line, LNCaP. Finally, 5377051 can reverse SGK1’s effects on NaV1.5 and shorten the action potential duration in induced pluripotent stem cell (iPSC)-derived cardiomyocytes from a patient with a gain-of-function mutation in Nav 1.5 (Long QT3 syndrome). Our data suggests that SGK1 inhibitors warrant further investigation in the treatment of cardiac arrhythmias.
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Affiliation(s)
- Vassilios J Bezzerides
- Beth Israel Deaconess Medical Center, Boston, MA, USA.,Boston Children's Hospital, Department of Cardiology, Boston, MA, USA
| | - Aifeng Zhang
- Beth Israel Deaconess Medical Center, Boston, MA, USA.,Massachusetts General Hospital, Boston, MA, USA
| | - Ling Xiao
- Massachusetts General Hospital, Boston, MA, USA
| | - Bridget Simonson
- Beth Israel Deaconess Medical Center, Boston, MA, USA.,Massachusetts General Hospital, Boston, MA, USA
| | - Santosh A Khedkar
- Beth Israel Deaconess Medical Center, Boston, MA, USA.,ChemBio Discovery Solutions, Lexington, MA, USA
| | - Shiro Baba
- Graduate School of Medicine Kyoto University, Kyoto City, Japan
| | | | | | | | - Alan C Rigby
- Beth Israel Deaconess Medical Center, Boston, MA, USA.,Warp Drive Bio Inc., Cambridge, MA, USA
| | - David Milan
- Massachusetts General Hospital, Boston, MA, USA
| | - Saumya Das
- Beth Israel Deaconess Medical Center, Boston, MA, USA. .,Massachusetts General Hospital, Boston, MA, USA.
| | - Anthony Rosenzweig
- Beth Israel Deaconess Medical Center, Boston, MA, USA.,Massachusetts General Hospital, Boston, MA, USA
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36
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Chadda KR, Jeevaratnam K, Lei M, Huang CLH. Sodium channel biophysics, late sodium current and genetic arrhythmic syndromes. Pflugers Arch 2017; 469:629-641. [PMID: 28265756 PMCID: PMC5438422 DOI: 10.1007/s00424-017-1959-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 02/14/2017] [Indexed: 12/11/2022]
Abstract
Arrhythmias arise from breakdown of orderly action potential (AP) activation, propagation and recovery driven by interactive opening and closing of successive voltage-gated ion channels, in which one or more Na+ current components play critical parts. Early peak, Na+ currents (INa) reflecting channel activation drive the AP upstroke central to cellular activation and its propagation. Sustained late Na+ currents (INa-L) include contributions from a component with a delayed inactivation timecourse influencing AP duration (APD) and refractoriness, potentially causing pro-arrhythmic phenotypes. The magnitude of INa-L can be analysed through overlaps or otherwise in the overall voltage dependences of the steady-state properties and kinetics of activation and inactivation of the Na+ conductance. This was useful in analysing repetitive firing associated with paramyotonia congenita in skeletal muscle. Similarly, genetic cardiac Na+ channel abnormalities increasing INa-L are implicated in triggering phenomena of automaticity, early and delayed afterdepolarisations and arrhythmic substrate. This review illustrates a wide range of situations that may accentuate INa-L. These include (1) overlaps between steady-state activation and inactivation increasing window current, (2) kinetic deficiencies in Na+ channel inactivation leading to bursting phenomena associated with repetitive channel openings and (3) non-equilibrium gating processes causing channel re-opening due to more rapid recoveries from inactivation. All these biophysical possibilities were identified in a selection of abnormal human SCN5A genotypes. The latter presented as a broad range of clinical arrhythmic phenotypes, for which effective therapeutic intervention would require specific identification and targeting of the diverse electrophysiological abnormalities underlying their increased INa-L.
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Affiliation(s)
- Karan R Chadda
- Faculty of Health and Medical Sciences, University of Surrey, VSM Building, Guildford, GU2 7AL, UK
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Sciences, University of Surrey, VSM Building, Guildford, GU2 7AL, UK
- School of Medicine, Perdana University-Royal College of Surgeons Ireland, 43400, Serdang, Selangor Darul Ehsan, Malaysia
| | - Ming Lei
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - Christopher L-H Huang
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK.
- Department of Biochemistry, University of Cambridge, Hopkins Building, Cambridge, CB2 1QW, UK.
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37
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Chiamvimonvat N, Chen-Izu Y, Clancy CE, Deschenes I, Dobrev D, Heijman J, Izu L, Qu Z, Ripplinger CM, Vandenberg JI, Weiss JN, Koren G, Banyasz T, Grandi E, Sanguinetti MC, Bers DM, Nerbonne JM. Potassium currents in the heart: functional roles in repolarization, arrhythmia and therapeutics. J Physiol 2017; 595:2229-2252. [PMID: 27808412 DOI: 10.1113/jp272883] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 10/11/2016] [Indexed: 12/19/2022] Open
Abstract
This is the second of the two White Papers from the fourth UC Davis Cardiovascular Symposium Systems Approach to Understanding Cardiac Excitation-Contraction Coupling and Arrhythmias (3-4 March 2016), a biennial event that brings together leading experts in different fields of cardiovascular research. The theme of the 2016 symposium was 'K+ channels and regulation', and the objectives of the conference were severalfold: (1) to identify current knowledge gaps; (2) to understand what may go wrong in the diseased heart and why; (3) to identify possible novel therapeutic targets; and (4) to further the development of systems biology approaches to decipher the molecular mechanisms and treatment of cardiac arrhythmias. The sessions of the Symposium focusing on the functional roles of the cardiac K+ channel in health and disease, as well as K+ channels as therapeutic targets, were contributed by Ye Chen-Izu, Gideon Koren, James Weiss, David Paterson, David Christini, Dobromir Dobrev, Jordi Heijman, Thomas O'Hara, Crystal Ripplinger, Zhilin Qu, Jamie Vandenberg, Colleen Clancy, Isabelle Deschenes, Leighton Izu, Tamas Banyasz, Andras Varro, Heike Wulff, Eleonora Grandi, Michael Sanguinetti, Donald Bers, Jeanne Nerbonne and Nipavan Chiamvimonvat as speakers and panel discussants. This article summarizes state-of-the-art knowledge and controversies on the functional roles of cardiac K+ channels in normal and diseased heart. We endeavour to integrate current knowledge at multiple scales, from the single cell to the whole organ levels, and from both experimental and computational studies.
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Affiliation(s)
- Nipavan Chiamvimonvat
- Department of Internal Medicine, University of California, Davis, Genome and Biomedical Science Facility, Rm 6315, Davis, CA, 95616, USA.,Department of Veterans Affairs, Northern California Health Care System, Mather, CA, 95655, USA
| | - Ye Chen-Izu
- Department of Internal Medicine, University of California, Davis, Genome and Biomedical Science Facility, Rm 6315, Davis, CA, 95616, USA.,Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA.,Department of Biomedical Engineering, University of California, Davis, Genome and Biomedical Science Facility, Rm 2303, Davis, CA, 95616, USA
| | - Colleen E Clancy
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Isabelle Deschenes
- Department of Physiology and Biophysics, and Biomedical Engineering, Case Western Reserve University, Cleveland, OH, 44109, USA.,Heart and Vascular Research Center, MetroHealth Medical Center, Cleveland, OH, 44109, USA
| | - Dobromir Dobrev
- Institute of Pharmacology, West German Heart and Vascular Center, University Duisburg-Essen, Hufelandstrasse 55, 45122, Essen, Germany
| | - Jordi Heijman
- Department of Cardiology, Cardiovascular Research Institute Maastricht, Faculty of Health, Medicine, and Life Sciences, Maastricht University, Maastricht, The Netherlands
| | - Leighton Izu
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Zhilin Qu
- Division of Cardiology, Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 3645 MRL, Los Angeles, CA, 90095, USA
| | - Crystal M Ripplinger
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Jamie I Vandenberg
- Victor Chang Cardiac Research Institute, 405 Liverpool Street, Darlinghurst, NSW, 2010, Australia
| | - James N Weiss
- Division of Cardiology, Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, 3645 MRL, Los Angeles, CA, 90095, USA
| | - Gideon Koren
- Cardiovascular Research Center, Rhode Island Hospital and the Cardiovascular Institute, The Warren Alpert Medical School of Brown University, Providence, RI, 02903, USA
| | - Tamas Banyasz
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Eleonora Grandi
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Michael C Sanguinetti
- Department of Internal Medicine, University of Utah, Nora Eccles Harrison Cardiovascular Research & Training Institute, Salt Lake City, UT, 84112, USA
| | - Donald M Bers
- Department of Pharmacology, University of California, Davis, Genome and Biomedical Science Facility, Rm 3503, Davis, CA, 95616, USA
| | - Jeanne M Nerbonne
- Departments of Developmental Biology and Internal Medicine, Cardiovascular Division, Washington University Medical School, St Louis, MO, 63110, USA
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38
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Mason FE, Sossalla S. The Significance of the Late Na+ Current for Arrhythmia Induction and the Therapeutic Antiarrhythmic Potential of Ranolazine. J Cardiovasc Pharmacol Ther 2016; 22:40-50. [DOI: 10.1177/1074248416644989] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The purpose of this article is to review the basis of arrhythmogenesis, the functional and clinical role of the late Na current, and its therapeutic inhibition. Under pathological conditions such as ischemia and heart failure this current is abnormally enhanced and influences cellular electrophysiology as a proarrhythmic substrate in myocardial pathology. Ranolazine the only approved late Na current blocker has been demonstrated to produce antiarrhythmic effects in the atria and the ventricle. We summarize recent experimental and clinical studies of ranolazine and other experimental late Na current blockers and discuss the significance of the available data.
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Affiliation(s)
- Fleur E. Mason
- Department of Cardiology and Pneumology, Georg-August-University Göttingen, Göttingen, Germany
| | - Samuel Sossalla
- Department of Cardiology and Pneumology, Georg-August-University Göttingen, Göttingen, Germany
- Department of Internal Medicine III (Cardiology and Angiology), University Hospital Schleswig-Holstein, Kiel, Germany
- German Centre for Cardiovascular Research (DZHK), Göttingen & Kiel, Germany
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39
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DeMarco KR, Clancy CE. Cardiac Na Channels: Structure to Function. CURRENT TOPICS IN MEMBRANES 2016; 78:287-311. [PMID: 27586288 DOI: 10.1016/bs.ctm.2016.05.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Heart rhythms arise from electrical activity generated by precisely timed opening and closing of ion channels in individual cardiac myocytes. Opening of the primary cardiac voltage-gated sodium (NaV1.5) channel initiates cellular depolarization and the propagation of an electrical action potential that promotes coordinated contraction of the heart. The regularity of these contractile waves is critically important since it drives the primary function of the heart: to act as a pump that delivers blood to the brain and vital organs. When electrical activity goes awry during a cardiac arrhythmia, the pump does not function, the brain does not receive oxygenated blood, and death ensues. Perturbations to NaV1.5 may alter the structure, and hence the function, of the ion channel and are associated downstream with a wide variety of cardiac conduction pathologies, such as arrhythmias.
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Affiliation(s)
- K R DeMarco
- University of California, Davis, Davis, CA, United States
| | - C E Clancy
- University of California, Davis, Davis, CA, United States
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40
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Shenasa M, Assadi H, Heidary S, Shenasa H. Ranolazine: Electrophysiologic Effect, Efficacy, and Safety in Patients with Cardiac Arrhythmias. Card Electrophysiol Clin 2016; 8:467-479. [PMID: 27261835 DOI: 10.1016/j.ccep.2016.02.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Ranolazine is currently approved as an antianginal agent in patients with chronic angina (class IIA). Ranolazine exhibits antiarrhythmic effects that are related to its multichannel blocking effect, predominantly inhibition of late sodium (late INa) current and the rapid potassium rectifier current (IKr), as well as ICa, late ICa, and INa-Ca. It also suppresses the early and delayed after depolarizations. Ranolazine is effective in the suppression of atrial and ventricular arrhythmias (off-label use) without significant proarrhythmic effect. Currently, ongoing trials are evaluating the efficacy and safety of ranolazine in patients with cardiac arrhythmias; preliminary results suggest that ranolazine, when used alone or in combination with dronedarone, is safe and effective in reducing atrial fibrillation. Ranolazine is not currently approved by the US Food and Drug Administration as an antiarrhythmic agent.
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Affiliation(s)
- Mohammad Shenasa
- Heart and Rhythm Medical Group, Department of Cardiovascular Services, O'Connor Hospital, 105 North Bascom Avenue, San Jose, CA 95128, USA.
| | - Hamid Assadi
- Heart and Rhythm Medical Group, Department of Cardiovascular Services, O'Connor Hospital, 105 North Bascom Avenue, San Jose, CA 95128, USA
| | - Shahriar Heidary
- Heart and Rhythm Medical Group, Department of Cardiovascular Services, O'Connor Hospital, 105 North Bascom Avenue, San Jose, CA 95128, USA
| | - Hossein Shenasa
- Heart and Rhythm Medical Group, Department of Cardiovascular Services, O'Connor Hospital, 105 North Bascom Avenue, San Jose, CA 95128, USA
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41
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Multi-scale Modeling of the Cardiovascular System: Disease Development, Progression, and Clinical Intervention. Ann Biomed Eng 2016; 44:2642-60. [PMID: 27138523 DOI: 10.1007/s10439-016-1628-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 04/22/2016] [Indexed: 12/19/2022]
Abstract
Cardiovascular diseases (CVDs) are the leading cause of death in the western world. With the current development of clinical diagnostics to more accurately measure the extent and specifics of CVDs, a laudable goal is a better understanding of the structure-function relation in the cardiovascular system. Much of this fundamental understanding comes from the development and study of models that integrate biology, medicine, imaging, and biomechanics. Information from these models provides guidance for developing diagnostics, and implementation of these diagnostics to the clinical setting, in turn, provides data for refining the models. In this review, we introduce multi-scale and multi-physical models for understanding disease development, progression, and designing clinical interventions. We begin with multi-scale models of cardiac electrophysiology and mechanics for diagnosis, clinical decision support, personalized and precision medicine in cardiology with examples in arrhythmia and heart failure. We then introduce computational models of vasculature mechanics and associated mechanical forces for understanding vascular disease progression, designing clinical interventions, and elucidating mechanisms that underlie diverse vascular conditions. We conclude with a discussion of barriers that must be overcome to provide enhanced insights, predictions, and decisions in pre-clinical and clinical applications.
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42
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Haverinen J, Vornanen M. Deltamethrin is toxic to the fish (crucian carp, Carassius carassius) heart. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2016; 129:36-42. [PMID: 27017879 DOI: 10.1016/j.pestbp.2015.10.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 09/08/2015] [Accepted: 10/19/2015] [Indexed: 06/05/2023]
Abstract
Pyrethroids are extensively used for the control of insect pests and disease vectors. Pyrethroids are regarded safe due to their selective toxicity: they are effective against insects but relatively harmless to mammals and birds. Unfortunately, pyrethroids are very toxic to fishes. The high toxicity of pyrethroids to fishes is only partly explained by slow metabolic elimination of pyrethroids, suggesting that some molecular targets in vital organs of the fish body are sensitive to pyrethroids. To this end we tested the effect of deltamethrin (DM) on fish (crucian carp, Carassius carassius) heart function in vitro. In sinoatrial preparations of the crucian carp heart DM (10 μM) caused irregularities in rate and rhythm of atrial beating and strong reductions in force of atrial contraction, thus indicating that DM is arrhythmogenic to the fish heart. Consistent with this, DM (10.0 μM) induced irregularities in electrical activity (surface electrocardiogram) of spontaneous beating hearts in vitro. In isolated ventricular myocytes, DM (0.1-30.0 μM) modified Na(+) current by slowing channel closing and shifting reversal potential and steady-state activation of the current to more negative voltages. Maximally about 48% of the cardiac Na(+) channels were affected by DM with a half-maximal effect occurring at the concentration of 1.3 μM. These findings indicate that DM can be cardiotoxic to the crucian carp and that these effects could be due to DM related changes in Na(+) channel function. These findings indicate that in addition to their neurotoxicity effects pyrethroid could also be cardiotoxic to fishes.
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Affiliation(s)
- Jaakko Haverinen
- University of Eastern Finland, Department of Biology, P.O. Box 111, 80101 Joensuu, Finland.
| | - Matti Vornanen
- University of Eastern Finland, Department of Biology, P.O. Box 111, 80101 Joensuu, Finland
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Abstract
Cardiovascular and neurodegenerative diseases are major health threats in many
developed countries. Recently, target tissues derived from human embryonic stem
(hES) cells and induced pluripotent stem cells (iPSCs), such as cardiomyocytes
(CMs) or neurons, have been actively mobilized for drug screening. Knowledge of
drug toxicity and efficacy obtained using stem cell-derived tissues could
parallel that obtained from human trials. Furthermore, iPSC disease models could
be advantageous in the development of personalized medicine in various parts of
disease sectors. To obtain the maximum benefit from iPSCs in disease modeling,
researchers are now focusing on aging, maturation, and metabolism to
recapitulate the pathological features seen in patients. Compared to pediatric
disease modeling, adult-onset disease modeling with iPSCs requires proper
maturation for full manifestation of pathological features. Herein, the success
of iPSC technology, focusing on patient-specific drug treatment,
maturation-based disease modeling, and alternative approaches to compensate for
the current limitations of patient iPSC modeling, will be further discussed.
[BMB Reports 2015; 48(5): 256-265]
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Affiliation(s)
- Changsung Kim
- Department of Bioscience and Biotechnology, Sejong University, Seoul 143-747, Korea
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Sorrentino A, Signore S, Qanud K, Borghetti G, Meo M, Cannata A, Zhou Y, Wybieralska E, Luciani M, Kannappan R, Zhang E, Matsuda A, Webster A, Cimini M, Kertowidjojo E, D'Alessandro DA, Wunimenghe O, Michler RE, Royer C, Goichberg P, Leri A, Barrett EG, Anversa P, Hintze TH, Rota M. Myocyte repolarization modulates myocardial function in aging dogs. Am J Physiol Heart Circ Physiol 2016; 310:H873-90. [PMID: 26801307 DOI: 10.1152/ajpheart.00682.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 12/24/2015] [Indexed: 12/19/2022]
Abstract
Studies of myocardial aging are complex and the mechanisms involved in the deterioration of ventricular performance and decreased functional reserve of the old heart remain to be properly defined. We have studied a colony of beagle dogs from 3 to 14 yr of age kept under a highly regulated environment to define the effects of aging on the myocardium. Ventricular, myocardial, and myocyte function, together with anatomical and structural properties of the organ and cardiomyocytes, were evaluated. Ventricular hypertrophy was not observed with aging and the structural composition of the myocardium was modestly affected. Alterations in the myocyte compartment were identified in aged dogs, and these factors negatively interfere with the contractile reserve typical of the young heart. The duration of the action potential is prolonged in old cardiomyocytes contributing to the slower electrical recovery of the myocardium. Also, the remodeled repolarization of cardiomyocytes with aging provides inotropic support to the senescent muscle but compromises its contractile reserve, rendering the old heart ineffective under conditions of high hemodynamic demand. The defects in the electrical and mechanical properties of cardiomyocytes with aging suggest that this cell population is an important determinant of the cardiac senescent phenotype. Collectively, the delayed electrical repolarization of aging cardiomyocytes may be viewed as a critical variable of the aging myopathy and its propensity to evolve into ventricular decompensation under stressful conditions.
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Affiliation(s)
- Andrea Sorrentino
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Sergio Signore
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Khaled Qanud
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Giulia Borghetti
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Marianna Meo
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Antonio Cannata
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Yu Zhou
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ewa Wybieralska
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Marco Luciani
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ramaswamy Kannappan
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Eric Zhang
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Alex Matsuda
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Andrew Webster
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Maria Cimini
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | | | | | - Oriyanhan Wunimenghe
- Department of Cardiovascular and Thoracic Surgery, Montefiore Medical Center, Albert Einstein College of Medicine, New York, New York; and
| | - Robert E Michler
- Department of Cardiovascular and Thoracic Surgery, Montefiore Medical Center, Albert Einstein College of Medicine, New York, New York; and
| | | | - Polina Goichberg
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Annarosa Leri
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Edward G Barrett
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico
| | - Piero Anversa
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Thomas H Hintze
- Department of Physiology, New York Medical College, Valhalla, New York
| | - Marcello Rota
- Departments of Anesthesia and Medicine, and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts; Department of Physiology, New York Medical College, Valhalla, New York;
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Chen-Izu Y, Shaw RM, Pitt GS, Yarov-Yarovoy V, Sack JT, Abriel H, Aldrich RW, Belardinelli L, Cannell MB, Catterall WA, Chazin WJ, Chiamvimonvat N, Deschenes I, Grandi E, Hund TJ, Izu LT, Maier LS, Maltsev VA, Marionneau C, Mohler PJ, Rajamani S, Rasmusson RL, Sobie EA, Clancy CE, Bers DM. Na+ channel function, regulation, structure, trafficking and sequestration. J Physiol 2015; 593:1347-60. [PMID: 25772290 DOI: 10.1113/jphysiol.2014.281428] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 11/02/2014] [Indexed: 12/19/2022] Open
Abstract
This paper is the second of a series of three reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation-contraction coupling and arrhythmias: Na(+) channel and Na(+) transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on Na(+) channel function and regulation, Na(+) channel structure and function, and Na(+) channel trafficking, sequestration and complexing.
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Affiliation(s)
- Ye Chen-Izu
- Department of Pharmacology, University of California, Davis, USA; Department of Biomedical Engineering, University of California, Davis, USA; Department of Internal Medicine/Cardiology, University of California, Davis, USA
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Tse G, Yeo JM. Conduction abnormalities and ventricular arrhythmogenesis: The roles of sodium channels and gap junctions. IJC HEART & VASCULATURE 2015; 9:75-82. [PMID: 26839915 PMCID: PMC4695916 DOI: 10.1016/j.ijcha.2015.10.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 10/19/2015] [Indexed: 01/12/2023]
Abstract
Ventricular arrhythmias arise from disruptions in the normal orderly sequence of electrical activation and recovery of the heart. They can be categorized into disorders affecting predominantly cellular depolarization or repolarization, or those involving action potential (AP) conduction. This article briefly discusses the factors causing conduction abnormalities in the form of unidirectional conduction block and reduced conduction velocity (CV). It then examines the roles that sodium channels and gap junctions play in AP conduction. Finally, it synthesizes experimental results to illustrate molecular mechanisms of how abnormalities in these proteins contribute to such conduction abnormalities and hence ventricular arrhythmogenesis, in acquired pathologies such as acute ischaemia and heart failure, as well as inherited arrhythmic syndromes.
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Affiliation(s)
- Gary Tse
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, University of Hong Kong, Hong Kong
| | - Jie Ming Yeo
- School of Medicine, Imperial College London, SW7 2AZ, UK
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Signore S, Sorrentino A, Borghetti G, Cannata A, Meo M, Zhou Y, Kannappan R, Pasqualini F, O'Malley H, Sundman M, Tsigkas N, Zhang E, Arranto C, Mangiaracina C, Isobe K, Sena BF, Kim J, Goichberg P, Nahrendorf M, Isom LL, Leri A, Anversa P, Rota M. Late Na(+) current and protracted electrical recovery are critical determinants of the aging myopathy. Nat Commun 2015; 6:8803. [PMID: 26541940 PMCID: PMC4638135 DOI: 10.1038/ncomms9803] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 10/02/2015] [Indexed: 12/19/2022] Open
Abstract
The aging myopathy manifests itself with diastolic dysfunction and preserved ejection fraction. We raised the possibility that, in a mouse model of physiological aging, defects in electromechanical properties of cardiomyocytes are important determinants of the diastolic characteristics of the myocardium, independently from changes in structural composition of the muscle and collagen framework. Here we show that an increase in the late Na(+) current (INaL) in aging cardiomyocytes prolongs the action potential (AP) and influences temporal kinetics of Ca(2+) cycling and contractility. These alterations increase force development and passive tension. Inhibition of INaL shortens the AP and corrects dynamics of Ca(2+) transient, cell contraction and relaxation. Similarly, repolarization and diastolic tension of the senescent myocardium are partly restored. Thus, INaL offers inotropic support, but negatively interferes with cellular and ventricular compliance, providing a new perspective of the biology of myocardial aging and the aetiology of the defective cardiac performance in the elderly.
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Affiliation(s)
- Sergio Signore
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Andrea Sorrentino
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Giulia Borghetti
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Antonio Cannata
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Marianna Meo
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Yu Zhou
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Ramaswamy Kannappan
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Francesco Pasqualini
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Heather O'Malley
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Mark Sundman
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Nikolaos Tsigkas
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Eric Zhang
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Christian Arranto
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Chiara Mangiaracina
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Kazuya Isobe
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Brena F Sena
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Junghyun Kim
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Polina Goichberg
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Matthias Nahrendorf
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
| | - Lori L Isom
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Annarosa Leri
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Piero Anversa
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
| | - Marcello Rota
- Departments of Anesthesia and Medicine and Division of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, 20 Shattuck Street, Boston, Massachusetts 02115, USA
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48
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Abstract
Despite improvements in the therapy of underlying heart disease, sudden cardiac death is a major cause of death worldwide. Disturbed Na and Ca handling is known to be a major predisposing factor for life-threatening tachyarrhythmias. In cardiomyocytes, many ion channels and transporters, including voltage-gated Na and Ca channels, cardiac ryanodine receptors, Na/Ca-exchanger, and SR Ca-ATPase are involved in this regulation. We have learned a lot about the pathophysiological relevance of disturbed ion channel function from monogenetic disorders. Changes in the gating of a single ion channel and the activity of an ion pump suffice to dramatically increase the propensity for arrhythmias even in structurally normal hearts. Nevertheless, patients with heart failure with acquired dysfunction in many ion channels and transporters exhibit profound dysregulation of Na and Ca handling and Ca/calmodulin-dependent protein kinase and are especially prone to arrhythmias. A deeper understanding of the underlying arrhythmic principles is mandatory if we are to improve their outcome. This review addresses basic tachyarrhythmic mechanisms, the underlying ionic mechanisms and the consequences for ion homeostasis, and the situation in complex diseases like heart failure.
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Affiliation(s)
- Stefan Wagner
- From the Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.W., L.S.M.); and Department of Pharmacology, University of California, Davis, CA (D.M.B.)
| | - Lars S Maier
- From the Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.W., L.S.M.); and Department of Pharmacology, University of California, Davis, CA (D.M.B.).
| | - Donald M Bers
- From the Department of Internal Medicine II, University Hospital Regensburg, Regensburg, Germany (S.W., L.S.M.); and Department of Pharmacology, University of California, Davis, CA (D.M.B.)
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49
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Biet M, Morin N, Lessard-Beaudoin M, Graham RK, Duss S, Gagné J, Sanon NT, Carmant L, Dumaine R. Prolongation of Action Potential Duration and QT Interval During Epilepsy Linked to Increased Contribution of Neuronal Sodium Channels to Cardiac Late Na
+
Current. Circ Arrhythm Electrophysiol 2015; 8:912-20. [DOI: 10.1161/circep.114.002693] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 06/01/2015] [Indexed: 11/16/2022]
Affiliation(s)
- Michael Biet
- From the Département de Pharmacologie et Physiologie, Université de Sherbrooke, Sherbrooke, Canada (M.B., N.M., M.L.-B., R.K.G., R.D.); and Department of Pediatrics, Centre de Recherche du CHU Sainte Justine, Université de Montréal, Montréal, Quebec, Canada (S.D., J.G., N.T.S., L.C.)
| | - Nathalie Morin
- From the Département de Pharmacologie et Physiologie, Université de Sherbrooke, Sherbrooke, Canada (M.B., N.M., M.L.-B., R.K.G., R.D.); and Department of Pediatrics, Centre de Recherche du CHU Sainte Justine, Université de Montréal, Montréal, Quebec, Canada (S.D., J.G., N.T.S., L.C.)
| | - Melissa Lessard-Beaudoin
- From the Département de Pharmacologie et Physiologie, Université de Sherbrooke, Sherbrooke, Canada (M.B., N.M., M.L.-B., R.K.G., R.D.); and Department of Pediatrics, Centre de Recherche du CHU Sainte Justine, Université de Montréal, Montréal, Quebec, Canada (S.D., J.G., N.T.S., L.C.)
| | - Rona K. Graham
- From the Département de Pharmacologie et Physiologie, Université de Sherbrooke, Sherbrooke, Canada (M.B., N.M., M.L.-B., R.K.G., R.D.); and Department of Pediatrics, Centre de Recherche du CHU Sainte Justine, Université de Montréal, Montréal, Quebec, Canada (S.D., J.G., N.T.S., L.C.)
| | - Sandra Duss
- From the Département de Pharmacologie et Physiologie, Université de Sherbrooke, Sherbrooke, Canada (M.B., N.M., M.L.-B., R.K.G., R.D.); and Department of Pediatrics, Centre de Recherche du CHU Sainte Justine, Université de Montréal, Montréal, Quebec, Canada (S.D., J.G., N.T.S., L.C.)
| | - Jonathan Gagné
- From the Département de Pharmacologie et Physiologie, Université de Sherbrooke, Sherbrooke, Canada (M.B., N.M., M.L.-B., R.K.G., R.D.); and Department of Pediatrics, Centre de Recherche du CHU Sainte Justine, Université de Montréal, Montréal, Quebec, Canada (S.D., J.G., N.T.S., L.C.)
| | - Nathalie T. Sanon
- From the Département de Pharmacologie et Physiologie, Université de Sherbrooke, Sherbrooke, Canada (M.B., N.M., M.L.-B., R.K.G., R.D.); and Department of Pediatrics, Centre de Recherche du CHU Sainte Justine, Université de Montréal, Montréal, Quebec, Canada (S.D., J.G., N.T.S., L.C.)
| | - Lionel Carmant
- From the Département de Pharmacologie et Physiologie, Université de Sherbrooke, Sherbrooke, Canada (M.B., N.M., M.L.-B., R.K.G., R.D.); and Department of Pediatrics, Centre de Recherche du CHU Sainte Justine, Université de Montréal, Montréal, Quebec, Canada (S.D., J.G., N.T.S., L.C.)
| | - Robert Dumaine
- From the Département de Pharmacologie et Physiologie, Université de Sherbrooke, Sherbrooke, Canada (M.B., N.M., M.L.-B., R.K.G., R.D.); and Department of Pediatrics, Centre de Recherche du CHU Sainte Justine, Université de Montréal, Montréal, Quebec, Canada (S.D., J.G., N.T.S., L.C.)
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50
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Cavero I, Holzgrefe H. CiPA: Ongoing testing, future qualification procedures, and pending issues. J Pharmacol Toxicol Methods 2015; 76:27-37. [PMID: 26159293 DOI: 10.1016/j.vascn.2015.06.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2015] [Revised: 06/04/2015] [Accepted: 06/25/2015] [Indexed: 01/04/2023]
Abstract
INTRODUCTION The comprehensive in vitro proarrhythmia assay (CiPA) is a nonclinical, mechanism-based paradigm for assessing drug proarrhythmic liability. TOPICS COVERED The first CiPA assay determines effects on cloned human cardiac ion channels. The second investigates whether the latter study-generated metrics engender proarrhythmic markers on a computationally reconstructed human ventricular action potential. The third evaluates conclusions from, and searches possibly missed effects by in silico analysis, in human stem cell-derived cardiomyocytes (hSC-CMs). CiPA ad hoc Expert-Working Groups have proposed patch clamp protocols for seven cardiac ion channels, a modified O'Hara-Rudy model for in silico analysis, detailed procedures for field (MEA) and action potential (VSD) measurements in hSC-CMs, and 29 reference drugs for CiPA assay testing and validation. DISCUSSION CiPA adoption as drug development tool for identifying electrophysiological mechanisms conferring proarrhythmic liability to candidate drugs is a complex, multi-functional task requiring significant time, reflection, and efforts to be fully achieved.
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