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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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2
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Veitch CR, Power AS, Erickson JR. CaMKII Inhibition is a Novel Therapeutic Strategy to Prevent Diabetic Cardiomyopathy. Front Pharmacol 2021; 12:695401. [PMID: 34381362 PMCID: PMC8350113 DOI: 10.3389/fphar.2021.695401] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/14/2021] [Indexed: 11/24/2022] Open
Abstract
Increasing prevalence of diabetes mellitus worldwide has pushed the complex disease state to the foreground of biomedical research, especially concerning its multifaceted impacts on the cardiovascular system. Current therapies for diabetic cardiomyopathy have had a positive impact, but with diabetic patients still suffering from a significantly greater burden of cardiac pathology compared to the general population, the need for novel therapeutic approaches is great. A new therapeutic target, calcium/calmodulin-dependent kinase II (CaMKII), has emerged as a potential treatment option for preventing cardiac dysfunction in the setting of diabetes. Within the last 10 years, new evidence has emerged describing the pathophysiological consequences of CaMKII activation in the diabetic heart, the mechanisms that underlie persistent CaMKII activation, and the protective effects of CaMKII inhibition to prevent diabetic cardiomyopathy. This review will examine recent evidence tying cardiac dysfunction in diabetes to CaMKII activation. It will then discuss the current understanding of the mechanisms by which CaMKII activity is enhanced during diabetes. Finally, it will examine the benefits of CaMKII inhibition to treat diabetic cardiomyopathy, including contractile dysfunction, heart failure with preserved ejection fraction, and arrhythmogenesis. We intend this review to serve as a critical examination of CaMKII inhibition as a therapeutic strategy, including potential drawbacks of this approach.
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Affiliation(s)
- Christopher R Veitch
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Amelia S Power
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
| | - Jeffrey R Erickson
- Department of Physiology and HeartOtago, University of Otago, Dunedin, New Zealand
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3
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Inhibition of Ca 2+-dependent protein kinase C rescues high calcium-induced pro-arrhythmogenic cardiac alternans in rabbit hearts. Pflugers Arch 2021; 473:1315-1327. [PMID: 34145500 DOI: 10.1007/s00424-021-02574-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/22/2021] [Accepted: 05/03/2021] [Indexed: 10/21/2022]
Abstract
Cardiac alternans closely linked to calcium dysregulation is a crucial risk factor for fatal arrhythmia causing especially sudden death. Calcium overload is well-known to activate Ca2+-dependent protein kinase C (PKC); however, the effects of PKC on arrhythmogenic cardiac alternans have not yet been investigated. This study aimed to determine the contributions of PKC activities in cardiac alternans associated with calcium cycling disturbances. In the present study, action potential duration alternans (APD-ALT) induced by high free intracellular calcium ([Ca2+]i) exerted not only in a calcium concentration-dependent manner but also in a frequency-dependent manner. High [Ca2+]i-induced APD-ALT was suppressed by not only BAPTA-AM but also nifedipine. On the other hand, PKC inhibitors BIM and Gö 6976 eliminated high [Ca2+]i-induced APD-ALT, and PKC activator PMA was found to induce APD-ALT at normal [Ca2+]i condition. Furthermore, BIM effectively prevented calcium transient alternans (CaT-ALT) and even CaT disorders caused by calcium overload. Moreover, BIM not only eliminated electrocardiographic T-wave alternans (TWA) caused by calcium dysregulation, but also lowered the incidence of ventricular arrhythmias in isolated hearts. What's more, BIM prevented the expression of PKC α upregulated by calcium overload in high calcium-perfused hearts. We firstly found that pharmacologically inhibiting Ca2+-dependent PKC over-activation suppressed high [Ca2+]i-induced cardiac alternans. This recognition indicates that inhibition of PKC activities may become a therapeutic target for the prevention of pro-arrhythmogenic cardiac alternans associated with calcium dysregulation.
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4
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Cheng KJ, Liang WZ. Influence of a bearing-wastewater phenolic compound (3,4-dimethylphenol, 3,4-DMP) treatment on Ca 2+ homeostasis and its related cytotoxicity in human proximal renal tubular epithelial cells. Hum Exp Toxicol 2021; 40:1899-1908. [PMID: 33906515 DOI: 10.1177/09603271211013453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A lot of phenolic compounds are widespread in industrial effluents and they are considerable environmental pollutants. Being a compound commercially available, the effect of a bearing-wastewater phenolic compound 3,4-dimethylphenol (3,4-DMP) on Ca2+ homeostasis and its related physiology has not been explored in cultured human kidney cell models. The aim of this study was to explore the effect of 3,4-DMP on [Ca2+]i and viability in HK-2 human proximal renal tubular epithelial cells. In terms of Ca2+ signaling, 3,4-DMP (5-100 μM) induced [Ca2+]i rises only in HK-2 cells and Ca2+ removal reduced the signal by 40%. In Ca2+-containing medium, 3,4-DMP-induced Ca2+ entry was inhibited by 20% by a modulator of store-operated Ca2+ channels (2-APB), and by a PKC activator (PMA) and inhibitor (GF109203X). Moreover, 3,4-DMP-induced Mn2+ influx suggesting of Ca2+ entry. In Ca2+-free medium, inhibition of PLC with U73122 abolished 3,4-DMP-induced [Ca2+]i rises. Furthermore, treatment with the endoplasmic reticulum Ca2+ pump inhibitor thapsigargin abolished 3,4-DMP-evoked [Ca2+]i rises. Conversely, treatment with 3,4-DMP abolished thapsigargin-evoked [Ca2+]i rises. Regarding to cell viability, 3,4-DMP (60-140 μM) killed cells in a concentration-dependent fashion in HK-2 cells. Chelation of cytosolic Ca2+ with BAPTA-AM partially reversed cytotoxicity of 3,4-DMP. Collectively, our data suggest that in HK-2 cells, 3,4-DMP-induced [Ca2+]i rises by evoking Ca2+ entry via PKC-sensitive store-operated Ca2+ entry and PLC-dependent Ca2+ release from the endoplasmic reticulum. 3,4-DMP also caused cytotoxicity that was linked to preceding [Ca2+]i rises. Our findings provide new insight into the cytotoxic effects of 3,4-DMP and the possible mechanisms underlying these effects.
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Affiliation(s)
- K-J Cheng
- Department of Nephrology, 210825Kaohsiung Municipal United Hospital, Kaohsiung.,Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung
| | - W-Z Liang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.,Department of Pharmacy and Master Program, College of Pharmacy and Health Care, 63299Tajen University, Pingtung County, Taiwan
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5
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Kudinov A, Darbar D. Deciphering the Electrophysiological Mechanisms for Ibrutinib-Induced Ventricular Arrhythmias. JACC CardioOncol 2020; 2:630-631. [PMID: 34396274 PMCID: PMC8352279 DOI: 10.1016/j.jaccao.2020.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Alex Kudinov
- Division of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Medicine, Jesse Brown Veterans Affairs Medical Center, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Dawood Darbar
- Division of Cardiology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, USA
- Department of Medicine, Jesse Brown Veterans Affairs Medical Center, University of Illinois at Chicago, Chicago, Illinois, USA
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Del-Canto I, Gómez-Cid L, Hernández-Romero I, Guillem MS, Fernández-Santos ME, Atienza F, Such L, Fernández-Avilés F, Chorro FJ, Climent AM. Ranolazine-Mediated Attenuation of Mechanoelectric Feedback in Atrial Myocyte Monolayers. Front Physiol 2020; 11:922. [PMID: 32848863 PMCID: PMC7417656 DOI: 10.3389/fphys.2020.00922] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 07/09/2020] [Indexed: 12/20/2022] Open
Abstract
Background Mechanical stretch increases Na+ inflow into myocytes, related to mechanisms including stretch-activated channels or Na+/H+ exchanger activation, involving Ca2+ increase that leads to changes in electrophysiological properties favoring arrhythmia induction. Ranolazine is an antianginal drug with confirmed beneficial effects against cardiac arrhythmias associated with the augmentation of INaL current and Ca2+ overload. Objective This study investigates the effects of mechanical stretch on activation patterns in atrial cell monolayers and its pharmacological response to ranolazine. Methods Confluent HL-1 cells were cultured in silicone membrane plates and were stretched to 110% of original length. The characteristics of in vitro fibrillation (dominant frequency, regularity index, density of phase singularities, rotor meandering, and rotor curvature) were analyzed using optical mapping in order to study the mechanoelectric response to stretch under control conditions and ranolazine action. Results HL-1 cell stretch increased fibrillatory dominant frequency (3.65 ± 0.69 vs. 4.35 ± 0.74 Hz, p < 0.01) and activation complexity (1.97 ± 0.45 vs. 2.66 ± 0.58 PS/cm2, p < 0.01) under control conditions. These effects were related to stretch-induced changes affecting the reentrant patterns, comprising a decrease in rotor meandering (0.72 ± 0.12 vs. 0.62 ± 0.12 cm/s, p < 0.001) and an increase in wavefront curvature (4.90 ± 0.42 vs. 5.68 ± 0.40 rad/cm, p < 0.001). Ranolazine reduced stretch-induced effects, attenuating the activation rate increment (12.8% vs. 19.7%, p < 0.01) and maintaining activation complexity—both parameters being lower during stretch than under control conditions. Moreover, under baseline conditions, ranolazine slowed and regularized the activation patterns (3.04 ± 0.61 vs. 3.65 ± 0.69 Hz, p < 0.01). Conclusion Ranolazine attenuates the modifications of activation patterns induced by mechanical stretch in atrial myocyte monolayers.
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Affiliation(s)
- Irene Del-Canto
- INCLIVA Health Research Institute, Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares, Valencia, Spain.,Department of Electronic Engineering, Universitat Politècnica de València, Valencia, Spain
| | - Lidia Gómez-Cid
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares, Madrid, Spain
| | | | - María S Guillem
- ITACA Institute, Universitat Politècnica de València, Valencia, Spain
| | - María Eugenia Fernández-Santos
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares, Madrid, Spain
| | - Felipe Atienza
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares, Madrid, Spain
| | - Luis Such
- INCLIVA Health Research Institute, Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares, Valencia, Spain.,Department of Physiology, Universitat de València Estudi General, Valencia, Spain
| | - Francisco Fernández-Avilés
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares, Madrid, Spain
| | - Francisco J Chorro
- INCLIVA Health Research Institute, Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares, Valencia, Spain.,Department of Cardiology, Hospital Clínico Universitario de Valencia, INCLIVA, Valencia, Spain
| | - Andreu M Climent
- Department of Cardiology, Hospital General Universitario Gregorio Marañón, Instituto de Investigación Sanitaria Gregorio Marañón, Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares, Madrid, Spain.,ITACA Institute, Universitat Politècnica de València, Valencia, Spain
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7
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Junho CVC, Panico K, Nakama KK, Sonoda MT, Christoffolete MA, Beserra SS, Roman-Campos D, Carneiro-Ramos MS. Time Course of Gene Expression Profile in Renal Ischemia and Reperfusion Injury in Mice. Transplant Proc 2020; 52:2970-2976. [PMID: 32763007 DOI: 10.1016/j.transproceed.2020.06.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/05/2020] [Accepted: 06/29/2020] [Indexed: 11/17/2022]
Abstract
Ischemic renal failure is an inflammatory disease that can affect various organs, including the heart. The organ responds to the stimulus and undergoes tissue remodeling that can result in cardiac hypertrophy. This study aimed to characterize the cardiac global gene expression profile in renal ischemia/reperfusion (IR) model using microarray technology. To do that, left kidney ischemia was induced in male C57BL/6 mice for 60 minutes, followed by reperfusion (IR) for 5, 8, 15, or 20 days post ischemia (dpi). Total cardiac tissue RNA was extracted and hybridized to chips with 35,000 mouse genes. The GeneChip Mouse Genome 430 2.0 Array Expression chip (Affymetrix) was used, and CEL files generated were processed with DNA-Chip-Analyzer (dCHIP) software. Subsequent analysis considered only differences among groups of at least 1.2-fold (up or down) expression changes. Analyses of the samples indicated positive modulation of 17,413 genes and 405 pathways and negative modulation of 18,287 genes and 300 pathways. A narrower analysis of genes related to inflammation, metabolism, apoptosis, oxidative stress, and channels/ion transport was performance, and it was correlated with IR injury, corroborating previous data from literature. Renal IR induced a global shift in cardiac tissue gene expression; in particular, genes related to the inflammatory system and cardiomyocyte function were changed. The in-depth study of the cell signaling in the present study could stimulate the development of new therapeutic option to ameliorate the outcome of renal-IR-induced heart damage.
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Affiliation(s)
| | - Karine Panico
- Human and Natural Sciences Center (CCNH), Federal University of ABC, Santo André, SP, Brazil
| | - Karina Kaori Nakama
- Human and Natural Sciences Center (CCNH), Federal University of ABC, Santo André, SP, Brazil
| | - Mayra Trentin Sonoda
- Division of Nephrology, Department of Medicine, Kidney Research Centre, Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Samuel Santos Beserra
- Cardiobiology Laboratory, Department of Biophysic, Paulista School of Medicine, University of São Paulo, São Paulo, SP, Brazil
| | - Danilo Roman-Campos
- Cardiobiology Laboratory, Department of Biophysic, Paulista School of Medicine, University of São Paulo, São Paulo, SP, Brazil
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8
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Liu Z, Hu L, Zhang Z, Song L, Zhang P, Cao Z, Ma J. Isoliensinine Eliminates Afterdepolarizations Through Inhibiting Late Sodium Current and L-Type Calcium Current. Cardiovasc Toxicol 2020; 21:67-78. [PMID: 32770463 DOI: 10.1007/s12012-020-09597-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Accepted: 08/01/2020] [Indexed: 12/19/2022]
Abstract
Isoliensinine (IL) extracted from lotus seed has a good therapeutic effect on cardiovascular diseases. However, its effect on ion channels of ventricular myocytes is still unclear. We used whole-cell patch-clamp techniques to detect the effects of IL on transmembrane ion currents and action potential (AP) in isolated rabbit left ventricular myocytes. IL inhibited the transient sodium current (INaT), late sodium current (INaL) enlarged by sea anemone toxin (ATX II) and L-type calcium current (ICaL) in a concentration-dependent manner without affecting inward rectifier potassium current (IK1) and delayed rectifier potassium current (IK). These inhibitory effects are mainly manifested as reduced the AP amplitude (APA) and maximum depolarization velocity (Vmax) and shortened the action potential duration (APD), but had no significant effect on the resting membrane potential (RMP). Moreover, IL significantly eliminated ATX II-induced early afterdepolarizations (EADs) and high extracellular calcium-induced delayed afterdepolarizations (DADs). These results revealed that IL effectively eliminated EADs and DADs through inhibiting INaL and ICaL in ventricular myocytes, which indicates it has potential antiarrhythmic action.
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Affiliation(s)
- Zhipei Liu
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Hongshan District, Wuhan, 430065, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College of Wuhan University of Science and Technology, Wuhan, 430065, China
| | - Liangkun Hu
- Tianyou Hospital Affiliated to Wuhan University of Science and Technology, Wuhan, 430065, China
| | - Zefu Zhang
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Hongshan District, Wuhan, 430065, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College of Wuhan University of Science and Technology, Wuhan, 430065, China
| | - Lv Song
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Hongshan District, Wuhan, 430065, China
| | - Peihua Zhang
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Hongshan District, Wuhan, 430065, China
| | - Zhenzhen Cao
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Hongshan District, Wuhan, 430065, China
| | - Jihua Ma
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Hongshan District, Wuhan, 430065, China. .,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College of Wuhan University of Science and Technology, Wuhan, 430065, China.
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9
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Horváth B, Hézső T, Kiss D, Kistamás K, Magyar J, Nánási PP, Bányász T. Late Sodium Current Inhibitors as Potential Antiarrhythmic Agents. Front Pharmacol 2020; 11:413. [PMID: 32372952 PMCID: PMC7184885 DOI: 10.3389/fphar.2020.00413] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 03/18/2020] [Indexed: 12/19/2022] Open
Abstract
Based on recent findings, an increased late sodium current (INa,late) plays an important pathophysiological role in cardiac diseases, including rhythm disorders. The article first describes what is INa,late and how it functions under physiological circumstances. Next, it shows the wide range of cellular mechanisms that can contribute to an increased INa,late in heart diseases, and also discusses how the upregulated INa,late can play a role in the generation of cardiac arrhythmias. The last part of the article is about INa,late inhibiting drugs as potential antiarrhythmic agents, based on experimental and preclinical data as well as in the light of clinical trials.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - Tamás Hézső
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Dénes Kiss
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Division of Sport Physiology, University of Debrecen, Debrecen, Hungary
| | - Péter P. Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, Debrecen, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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10
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Liu Z, Jia Y, Song L, Tian Y, Zhang P, Zhang P, Cao Z, Ma J. Antiarrhythmic effect of crotonoside by regulating sodium and calcium channels in rabbit ventricular myocytes. Life Sci 2020; 244:117333. [PMID: 31962132 DOI: 10.1016/j.lfs.2020.117333] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Revised: 12/30/2019] [Accepted: 01/13/2020] [Indexed: 12/14/2022]
Abstract
AIMS Detect the antiarrhythmic effect of crotonoside (Cro). MAIN METHODS We used whole-cell patch-clamp techniques to detect the effects of Cro on action potentials (APs) and transmembrane ion currents in isolated rabbit left ventricular myocytes. We also verified the effect of Cro on ventricular arrhythmias caused by aconitine in vivo. KEY FINDINGS Cro reduced the maximum depolarization velocity (Vmax) of APs and shortened the action potential duration (APD) in a concentration-dependent manner, but it had no significant effect on the resting membrane potential (RMP) or action potential amplitude (APA). It also inhibited the peak sodium current (INa) and L-type calcium current (ICaL) in a concentration-dependent manner with half-maximal inhibitory concentrations (IC50) of 192 μmol/L and 159 μmol/L, respectively. However, Cro had no significant effects on the inward rectifier potassium current (IK1) or rapidly activating delayed rectifier potassium current (IKr). Sea anemone toxin II (ATX II) increased the late sodium current (INaL), but Cro abolished this effect. Moreover, Cro significantly abolished ATX II-induced early afterdepolarizations (EADs) and high extracellular Ca2+ concentration (3.6 mmol/L)-induced delayed afterdepolarizations (DADs). We also verified that Cro effectively delayed the onset time and reduced the incidence of ventricular arrhythmias caused by aconitine in vivo. SIGNIFICANCE These results revealed that Cro effectively inhibits INa, INaL, and ICaL in ventricular myocytes. Cro has antiarrhythmic potential and thus deserves further study.
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Affiliation(s)
- Zhipei Liu
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China
| | - Yuzhong Jia
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China
| | - Lv Song
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China
| | - Youjia Tian
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China
| | - Peipei Zhang
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China
| | - Peihua Zhang
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China
| | - Zhenzhen Cao
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China
| | - Jihua Ma
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College of Wuhan University of Science and Technology, Wuhan 430065, China.
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11
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Chadda KR, Fazmin IT, Ahmad S, Valli H, Edling CE, Huang CLH, Jeevaratnam K. Arrhythmogenic mechanisms of obstructive sleep apnea in heart failure patients. Sleep 2019; 41:5054592. [PMID: 30016501 DOI: 10.1093/sleep/zsy136] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 07/13/2018] [Indexed: 01/01/2023] Open
Abstract
Heart failure (HF) affects 23 million people worldwide and results in 300000 annual deaths. It is associated with many comorbidities, such as obstructive sleep apnea (OSA), and risk factors for both conditions overlap. Eleven percent of HF patients have OSA and 7.7% of OSA patients have left ventricular ejection fraction <50% with arrhythmias being a significant comorbidity in HF and OSA patients. Forty percent of HF patients develop atrial fibrillation (AF) and 30%-50% of deaths from cardiac causes in HF patients are from sudden cardiac death. OSA is prevalent in 32%-49% of patients with AF and there is a dose-dependent relationship between OSA severity and resistance to anti-arrhythmic therapies. HF and OSA lead to various downstream arrhythmogenic mechanisms, including metabolic derangement, remodeling, inflammation, and autonomic imbalance. (1) Metabolic derangement and production of reactive oxidative species increase late Na+ currents, decrease outward K+ currents and downregulate connexin-43 and cell-cell coupling. (2) remodeling also features downregulated K+ currents in addition to decreased Na+/K+ ATPase currents, altered Ca2+ homeostasis, and increased density of If current. (3) Chronic inflammation leads to downregulation of both Nav1.5 channels and K+ channels, altered Ca2+ homeostasis and reduced cellular coupling from alterations of connexin expression. (4) Autonomic imbalance causes arrhythmias by evoking triggered activity through increased Ca2+ transients and reduction of excitation wavefront wavelength. Thus, consideration of these multiple pathophysiological pathways (1-4) will enable the development of novel therapeutic strategies that can be targeted against arrhythmias in the context of complex disease, such as the comorbidities of HF and OSA.
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Affiliation(s)
- Karan R Chadda
- Faculty of Health and Medical Science, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Ibrahim T Fazmin
- Faculty of Health and Medical Science, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Shiraz Ahmad
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Haseeb Valli
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
| | - Charlotte E Edling
- Faculty of Health and Medical Science, University of Surrey, Guildford, United Kingdom
| | - Christopher L-H Huang
- Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom.,Department of Biochemistry, Hopkins Building, University of Cambridge, Cambridge, United Kingdom
| | - Kamalan Jeevaratnam
- Faculty of Health and Medical Science, University of Surrey, Guildford, United Kingdom.,Physiological Laboratory, University of Cambridge, Downing Street, Cambridge, United Kingdom
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12
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Huang JH, Chen YC, Lu YY, Lin YK, Chen SA, Chen YJ. Arginine vasopressin modulates electrical activity and calcium homeostasis in pulmonary vein cardiomyocytes. J Biomed Sci 2019; 26:71. [PMID: 31530276 PMCID: PMC6747756 DOI: 10.1186/s12929-019-0564-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 09/10/2019] [Indexed: 02/06/2023] Open
Abstract
Background Atrial fibrillation (AF) frequently coexists with congestive heart failure (HF) and arginine vasopressin (AVP) V1 receptor antagonists are used to treat hyponatremia in HF. However, the role of AVP in HF-induced AF still remains unclear. Pulmonary veins (PVs) are central in the genesis of AF. The purpose of this study was to determine if AVP is directly involved in the regulation of PV electrophysiological properties and calcium (Ca2+) homeostasis as well as the identification of the underlying mechanisms. Methods Patch clamp, confocal microscopy with Fluo-3 fluorescence, and Western blot analyses were used to evaluate the electrophysiological characteristics, Ca2+ homeostasis, and Ca2+ regulatory proteins in isolated rabbit single PV cardiomyocytes incubated with and without AVP (1 μM), OPC 21268 (0.1 μM, AVP V1 antagonist), or OPC 41061 (10 nM, AVP V2 antagonist) for 4–6 h. Results AVP (0.1 and 1 μM)-treated PV cardiomyocytes had a faster beating rate (108 to 152%) than the control cells. AVP (1 μM) treated PV cardiomyocytes had higher late sodium (Na+) and Na+/Ca2+ exchanger (NCX) currents than control PV cardiomyocytes. AVP (1 μM) treated PV cardiomyocytes had smaller Ca2+i transients, and sarcoplasmic reticulum (SR) Ca2+ content as well as higher Ca2+ leak. However, combined AVP (1 μM) and OPC 21268 (0.1 μM) treated PV cardiomyocytes had a slower PV beating rate, larger Ca2+i transients and SR Ca2+ content, smaller late Na+ and NCX currents than AVP (1 μM)-treated PV cardiomyocytes. Western blot experiments showed that AVP (1 μM) treated PV cardiomyocytes had higher expression of NCX and p-CaMKII, and a higher ratio of p-CaMKII/CaMKII. Conclusions AVP increases PV arrhythmogenesis with dysregulated Ca2+ homeostasis through vasopressin V1 signaling.
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Affiliation(s)
- Jen-Hung Huang
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, 111 Hsin-Lung Road, Sec. 3, Taipei, 116, Taiwan.,Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yao-Chang Chen
- Department of Biomedical Engineering, and Institute of Physiology, National Defense Medical Center, Taipei, Taiwan
| | - Yen-Yu Lu
- Division of Cardiology, Department of Internal Medicine, Sijhih Cathay General Hospital, New Taipei City, Taiwan.,School of Medicine, Fu-Jen Catholic University, New Taipei City, Taiwan
| | - Yung-Kuo Lin
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, 111 Hsin-Lung Road, Sec. 3, Taipei, 116, Taiwan.,Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Shih-Ann Chen
- Heart Rhythm Center and Division of Cardiology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yi-Jen Chen
- Division of Cardiovascular Medicine, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, 111 Hsin-Lung Road, Sec. 3, Taipei, 116, Taiwan. .,Graduate Institute of Clinical Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan. .,Cardiovascular Research Center, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan.
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13
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Del Canto I, Santamaría L, Genovés P, Such-Miquel L, Arias-Mutis O, Zarzoso M, Soler C, Parra G, Tormos Á, Alberola A, Such L, Chorro FJ. Effects of the Inhibition of Late Sodium Current by GS967 on Stretch-Induced Changes in Cardiac Electrophysiology. Cardiovasc Drugs Ther 2019; 32:413-425. [PMID: 30173392 DOI: 10.1007/s10557-018-6822-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE Mechanical stretch increases sodium and calcium entry into myocytes and activates the late sodium current. GS967, a triazolopyridine derivative, is a sodium channel blocker with preferential effects on the late sodium current. The present study evaluates whether GS967 inhibits or modulates the arrhythmogenic electrophysiological effects of myocardial stretch. METHODS Atrial and ventricular refractoriness and ventricular fibrillation modifications induced by acute stretch were studied in Langendorff-perfused rabbit hearts (n = 28) using epicardial multiple electrodes and high-resolution mapping techniques under control conditions and during the perfusion of GS967 at different concentrations (0.03, 0.1, and 0.3 μM). RESULTS On comparing ventricular refractoriness, conduction velocity and wavelength obtained before stretch had no significant changes under each GS967 concentration while atrial refractoriness increased under GS967 0.3 μM. Under GS967, the stretch-induced changes were attenuated, and no significant differences were observed between before and during stretch. GS967 0.3 μM diminished the normal stretch-induced changes resulting in longer (less shortened) atrial refractoriness (138 ± 26 ms vs 95 ± 9 ms; p < 0.01), ventricular refractoriness (155 ± 18 ms vs 124 ± 16 ms; p < 0.01) and increments in spectral concentration (23 ± 5% vs 17 ± 2%; p < 0.01), the fifth percentile of ventricular activation intervals (46 ± 8 ms vs 31 ± 3 ms; p < 0.05), and wavelength of ventricular fibrillation (2.5 ±0.5 cm vs 1.7 ± 0.3 cm; p < 0.05) during stretch. The stretch-induced increments in dominant frequency during ventricular fibrillation (control = 38%, 0.03 μM = 33%, 0.1 μM = 33%, 0.3 μM = 14%; p < 0.01) and the stretch-induced increments in arrhythmia complexity index (control = 62%, 0.03μM = 41%, 0.1 μM = 32%, 0.3 μM = 16%; p < 0.05) progressively decreased on increasing the GS967 concentration. CONCLUSIONS GS967 attenuates stretch-induced changes in cardiac electrophysiology.
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Affiliation(s)
- Irene Del Canto
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Electronics, Universitat Politècnica de València, Valencia, Spain
| | - Laura Santamaría
- Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | | | - Luis Such-Miquel
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Physiotherapy, Valencia University - Estudi General, Valencia, Spain
| | | | - Manuel Zarzoso
- Department of Physiotherapy, Valencia University - Estudi General, Valencia, Spain
| | - Carlos Soler
- Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | - Germán Parra
- Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | - Álvaro Tormos
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Electronics, Universitat Politècnica de València, Valencia, Spain
| | - Antonio Alberola
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | - Luis Such
- CIBER CV. Carlos III Health Institute, Madrid, Spain.,Department of Physiology, Valencia University - Estudi General, Valencia, Spain
| | - Francisco J Chorro
- CIBER CV. Carlos III Health Institute, Madrid, Spain. .,Service of Cardiology, Valencia University Clinic Hospital, INCLIVA, Valencia, Spain. .,Department of Medicine, Valencia University - Estudi General, Valencia, Spain. .,Servicio de Cardiología, Hospital Clínico Universitario, Avda. Blasco Ibañez 17, 46010, Valencia, Spain.
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14
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Increase in CO 2 levels by upregulating late sodium current is proarrhythmic in the heart. Heart Rhythm 2019; 16:1098-1106. [PMID: 30710739 DOI: 10.1016/j.hrthm.2019.01.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND Increased CO2 levels in the general circulation and/or in the myocardium are common under pathologic conditions. OBJECTIVE The purpose of this study was to test the hypothesis that an increase in CO2 levels, and not just the subsequent extra- or intracellular acidosis, would augment late sodium current (INa,L) and contribute to arrhythmogenesis in hearts with reduced repolarization reserve. METHODS Monophasic action potential durations at 90% completion of repolarization (MAPD90) from isolated rabbit hearts, INa,L, and extra- (pHo) and intracellular pH (pHi) values from cardiomyocytes using the whole-cell patch-clamp techniques and 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein, acetoxymethyl ester (BCECF-AM), respectively, were measured. RESULTS Increasing CO2 levels from 5% to 10% and 20% and administration of 1 nM sea anemone toxin (ATX)-II increased INa,L and prolonged both epicardial and endocardial MAPD90 (n = 7 and 10, respectively) without causing arrhythmic activities. Compared to 5% CO2, 10% and 20% CO2 decreased pHo and pHi in hearts treated with 1 nM ATX-II, caused greater prolongation of MAPD90, and elicited ventricular tachycardias. Increasing CO2 levels from 5% to 10% and 20% with pHo maintained at 7.4 produced smaller changes in pHi (P <.05) but similar increases in INa,L, prolongation of MAPD90, and incidence of ventricular tachycardias (n = 8). Inhibition of INa,L reversed the increase in INa,L, suppressed MAPD90 prolongations, and ventricular tachycardias induced by 20% CO2. Increased phospho-calmodulin-dependent protein kinase II-δ (CaMKIIδ) and phospho-NaV1.5 protein levels in hearts treated with 20% CO2 was attenuated by eleclazine. CONCLUSION Increased CO2 levels enhance INa,L and are proarrhythmic factors in hearts with reduced repolarization reserve, possibly via mechanisms related to phosphorylation of CaMKIIδ and NaV1.5.
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15
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Hegyi B, Bányász T, Izu LT, Belardinelli L, Bers DM, Chen-Izu Y. β-adrenergic regulation of late Na + current during cardiac action potential is mediated by both PKA and CaMKII. J Mol Cell Cardiol 2018; 123:168-179. [PMID: 30240676 DOI: 10.1016/j.yjmcc.2018.09.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 08/28/2018] [Accepted: 09/16/2018] [Indexed: 12/12/2022]
Abstract
Late Na+ current (INaL) significantly contributes to shaping cardiac action potentials (APs) and increased INaL is associated with cardiac arrhythmias. β-adrenergic receptor (βAR) stimulation and its downstream signaling via protein kinase A (PKA) and Ca2+/calmodulin-dependent protein kinase II (CaMKII) pathways are known to regulate INaL. However, it remains unclear how each of these pathways regulates INaL during the AP under physiological conditions. Here we performed AP-clamp experiments in rabbit ventricular myocytes to delineate the impact of each signaling pathway on INaL at different AP phases to understand the arrhythmogenic potential. During the physiological AP (2 Hz, 37 °C) we found that INaL had a basal level current independent of PKA, but partially dependent on CaMKII. βAR activation (10 nM isoproterenol, ISO) further enhanced INaL via both PKA and CaMKII pathways. However, PKA predominantly increased INaL early during the AP plateau, whereas CaMKII mainly increased INaL later in the plateau and during rapid repolarization. We also tested the role of key signaling pathways through exchange protein activated by cAMP (Epac), nitric oxide synthase (NOS) and reactive oxygen species (ROS). Direct Epac stimulation enhanced INaL similar to the βAR-induced CaMKII effect, while NOS inhibition prevented the βAR-induced CaMKII-dependent INaL enhancement. ROS generated by NADPH oxidase 2 (NOX2) also contributed to the ISO-induced INaL activation early in the AP. Taken together, our data reveal differential modulations of INaL by PKA and CaMKII signaling pathways at different AP phases. This nuanced and comprehensive view on the changes in INaL during AP deepens our understanding of the important role of INaL in reshaping the cardiac AP and arrhythmogenic potential under elevated sympathetic stimulation, which is relevant for designing therapeutic treatment of arrhythmias under pathological conditions.
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Affiliation(s)
- Bence Hegyi
- Department of Pharmacology, University of California, Davis, CA, USA.
| | - Tamás Bányász
- Department of Pharmacology, University of California, Davis, CA, USA; Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Leighton T Izu
- Department of Pharmacology, University of California, Davis, CA, USA
| | | | - Donald M Bers
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Ye Chen-Izu
- Department of Pharmacology, University of California, Davis, CA, USA; Department of Biomedical Engineering, University of California, Davis, CA, USA; Department of Internal Medicine/Cardiology, University of California, Davis, CA, USA.
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16
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Howard T, Greer-Short A, Satroplus T, Patel N, Nassal D, Mohler PJ, Hund TJ. CaMKII-dependent late Na + current increases electrical dispersion and arrhythmia in ischemia-reperfusion. Am J Physiol Heart Circ Physiol 2018; 315:H794-H801. [PMID: 29932771 DOI: 10.1152/ajpheart.00197.2018] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The mechanisms underlying Ca2+/calmodulin-dependent protein kinase II (CaMKII)-induced arrhythmias in ischemia-reperfusion (I/R) are not fully understood. We tested the hypothesis that CaMKII increases late Na+ current ( INa,L) via phosphorylation of Nav1.5 at Ser571 during I/R, thereby increasing arrhythmia susceptibility. To test our hypothesis, we studied isolated, Langendorff-perfused hearts from wild-type (WT) mice and mice expressing Nav channel variants Nav1.5-Ser571E (S571E) and Nav1.5-Ser571A (S571A). WT hearts showed a significant increase in the levels of phosphorylated CaMKII and Nav1.5 at Ser571 [p-Nav1.5(S571)] after 15 min of global ischemia (just before the onset of reperfusion). Optical mapping experiments revealed an increase in action potential duration (APD) and APD dispersion without changes in conduction velocity during I/R in WT and S571E compared with S571A hearts. At the same time, WT and S571E hearts showed an increase in spontaneous arrhythmia events (e.g., premature ventricular contractions) and an increase in the inducibility of reentrant arrhythmias during reperfusion. Pretreatment of WT hearts with the Na+ channel blocker mexiletine (10 μM) normalized APD dispersion and reduced arrhythmia susceptibility during I/R. We conclude that CaMKII-dependent phosphorylation of Nav1.5 is a crucial driver for increased INa,L, arrhythmia triggers, and substrate during I/R. Selective targeting of this CaMKII-dependent pathway may have therapeutic potential for reducing arrhythmias in the setting of I/R. NEW & NOTEWORTHY Ca2+/calmodulin-dependent protein kinase II (CaMKII) phosphorylation of Nav1.5 at Ser571 leads to a prolongation of action potential duration (APD), increased APD dispersion, and increased arrhythmia susceptibility after ischemia-reperfusion in isolated mouse hearts. Genetic ablation of the CaMKII-dependent phosphorylation site Ser571 on Nav1.5 or low-dose mexiletine (to inhibit late Na+ current) reduced APD dispersion, arrhythmia triggers, and ventricular tachycardia inducibility.
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Affiliation(s)
- Taylor Howard
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center , Columbus, Ohio.,Department of Biomedical Engineering, College of Engineering, The Ohio State University , Columbus, Ohio
| | - Amara Greer-Short
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center , Columbus, Ohio.,Department of Biomedical Engineering, College of Engineering, The Ohio State University , Columbus, Ohio
| | - Tony Satroplus
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center , Columbus, Ohio.,Department of Biomedical Engineering, College of Engineering, The Ohio State University , Columbus, Ohio
| | - Nehal Patel
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center , Columbus, Ohio.,Department of Biomedical Engineering, College of Engineering, The Ohio State University , Columbus, Ohio
| | - Drew Nassal
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center , Columbus, Ohio.,Department of Biomedical Engineering, College of Engineering, The Ohio State University , Columbus, Ohio
| | - Peter J Mohler
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center , Columbus, Ohio.,Department of Internal Medicine, The Ohio State University Wexner Medical Center , Columbus, Ohio.,Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center , Columbus, Ohio
| | - Thomas J Hund
- The Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center , Columbus, Ohio.,Department of Biomedical Engineering, College of Engineering, The Ohio State University , Columbus, Ohio.,Department of Internal Medicine, The Ohio State University Wexner Medical Center , Columbus, Ohio
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17
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Manring HR, Dorn LE, Ex-Willey A, Accornero F, Ackermann MA. At the heart of inter- and intracellular signaling: the intercalated disc. Biophys Rev 2018; 10:961-971. [PMID: 29876873 DOI: 10.1007/s12551-018-0430-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2018] [Accepted: 05/22/2018] [Indexed: 12/17/2022] Open
Abstract
Proper cardiac function requires the synchronous mechanical and electrical coupling of individual cardiomyocytes. The intercalated disc (ID) mediates coupling of neighboring myocytes through intercellular signaling. Intercellular communication is highly regulated via intracellular signaling, and signaling pathways originating from the ID control cardiomyocyte remodeling and function. Herein, we present an overview of the inter- and intracellular signaling that occurs at and originates from the intercalated disc in normal physiology and pathophysiology. This review highlights the importance of the intercalated disc as an integrator of signaling events regulating homeostasis and stress responses in the heart and the center of several pathophysiological processes mediating the development of cardiomyopathies.
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Affiliation(s)
- Heather R Manring
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Lisa E Dorn
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Aidan Ex-Willey
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA
| | - Federica Accornero
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA.
| | - Maegen A Ackermann
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH, 43210, USA.
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18
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Song Y, Belardinelli L. Basal late sodium current is a significant contributor to the duration of action potential of guinea pig ventricular myocytes. Physiol Rep 2018; 5:e13295. [PMID: 28554967 PMCID: PMC5449569 DOI: 10.14814/phy2.13295] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 05/01/2017] [Accepted: 05/02/2017] [Indexed: 01/17/2023] Open
Abstract
In cardiac myocytes, an enhancement of late sodium current (INaL) under pathological conditions is known to cause prolongation of action potential duration (APD). This study investigated the contribution of INaL under basal, physiological conditions to the APD Whole-cell INaL and the APD of ventricular myocytes isolated from healthy adult guinea pigs were measured at 36°C. The INaL inhibitor GS967 or TTX was applied to block INaL The amplitude of basal INaL and the APD at 50% repolarization in myocytes stimulated at a frequency of 0.17 Hz were -0.24 ± 0.02 pA/pF and 229 ± 6 msec, respectively. GS967 (0.01-1 μmol/L) concentration dependently reduced the basal INaL by 18 ± 3-82 ± 4%. At the same concentrations, GS967 shortened the APD by 9 ± 2 to 25 ± 1%. Similarly, TTX at 0.1-10 μmol/L decreased the basal INaL by 13 ± 1-94 ± 1% and APD by 8 ± 1-31 ± 2%. There was a close correlation (R2 = 0.958) between the percentage inhibition of INaL and the percentage shortening of APD caused by either GS967 or TTX MTSEA (methanethiosulfonate ethylammonium, 2 mmol/L), a NaV1.5 channel blocker, reduced the INaL by 90 ± 5%, suggesting that the NaV1.5 channel isoform is the major contributor to the basal INaL KN-93 (10 μmol/L) and AIP (2 μmol/L), blockers of CaMKII, moderately reduced the basal INaL Thus, this study provides strong evidence that basal endogenous INaL is a significant contributor to the APD of cardiac myocytes. In addition, the basal INaL of guinea pig ventricular myocytes is mainly generated from NaV1.5 channel isoform and is regulated by CaMKII.
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Affiliation(s)
- Yejia Song
- University of Florida, Gainesville, Florida
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19
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Cao ZZ, Tian YJ, Hao J, Zhang PH, Liu ZP, Jiang WZ, Zeng ML, Zhang PP, Ma JH. Barbaloin inhibits ventricular arrhythmias in rabbits by modulating voltage-gated ion channels. Acta Pharmacol Sin 2018; 39:357-370. [PMID: 29072259 DOI: 10.1038/aps.2017.93] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 06/17/2017] [Indexed: 12/15/2022] Open
Abstract
Barbaloin (10-β-D-glucopyranosyl-1,8-dihydroxy-3-(hydroxymethyl)-9(10H)-anthracenone) is extracted from the aloe plant and has been reported to have anti-inflammatory, antitumor, antibacterial, and other biological activities. Here, we investigated the effects of barbaloin on cardiac electrophysiology, which has not been reported thus far. Cardiac action potentials (APs) and ionic currents were recorded in isolated rabbit ventricular myocytes using whole-cell patch-clamp technique. Additionally, the antiarrhythmic effect of barbaloin was examined in Langendorff-perfused rabbit hearts. In current-clamp recording, application of barbaloin (100 and 200 μmol/L) dose-dependently reduced the action potential duration (APD) and the maximum depolarization velocity (Vmax), and attenuated APD reverse-rate dependence (RRD) in ventricular myocytes. Furthermore, barbaloin (100 and 200 μmol/L) effectively eliminated ATX II-induced early afterdepolarizations (EADs) and Ca2+-induced delayed afterdepolarizations (DADs) in ventricular myocytes. In voltage-clamp recording, barbaloin (10-200 μmol/L) dose-dependently inhibited L-type calcium current (ICa.L) and peak sodium current (INa.P) with IC50 values of 137.06 and 559.80 μmol/L, respectively. Application of barbaloin (100, 200 μmol/L) decreased ATX II-enhanced late sodium current (INa.L) by 36.6%±3.3% and 71.8%±6.5%, respectively. However, barbaloin up to 800 μmol/L did not affect the inward rectifier potassium current (IK1) or the rapidly activated delayed rectifier potassium current (IKr) in ventricular myocytes. In Langendorff-perfused rabbit hearts, barbaloin (200 μmol/L) significantly inhibited aconitine-induced ventricular arrhythmias. These results demonstrate that barbaloin has potential as an antiarrhythmic drug.
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20
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The effect of magnolol on Ca 2+ homeostasis and its related physiology in human oral cancer cells. Arch Oral Biol 2018; 89:49-54. [PMID: 29471192 DOI: 10.1016/j.archoralbio.2018.02.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 02/08/2018] [Accepted: 02/11/2018] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Magnolol, a polyphenol compound from herbal medicines, was shown to alter physiology in various cell models. However, the effect of magnolol on Ca2+ homeostasis and its related physiology in oral cancer cells is unclear. This study examined whether magnolol altered Ca2+ signaling and cell viability in OC2 human oral cancer cells. METHODS Cytosolic Ca2+ concentrations ([Ca2+]i) in suspended cells were measured by using the fluorescent Ca2+-sensitive dye fura-2. Cell viability was examined by 4-[3-[4-lodophenyl]-2-4(4-nitrophenyl)-2H-5-tetrazolio-1,3-benzene disulfonate] water soluble tetrazolium-1 (WST-1) assay. RESULTS Magnolol at concentrations of 20-100 μM induced [Ca2+]i rises. Ca2+ removal reduced the signal by approximately 50%. Magnolol (100 μM) induced Mn2+ influx suggesting of Ca2+ entry. Magnolol-induced Ca2+ entry was partially suppressed by protein kinase C (PKC) regulators, and inhibitors of store-operated Ca2+ channels. In Ca2+-free medium, treatment with the endoplasmic reticulum Ca2+ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) abolished magnolol-evoked [Ca2+]i rises. Conversely, treatment with magnolol abolished BHQ-evoked [Ca2+]i rises. Inhibition of phospholipase C (PLC) with U73122 partially inhibited magnolol-induced [Ca2+]i rises. Magnolol at 20-100 μM decreased cell viability, which was not reversed by pretreatment with the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM). CONCLUSIONS Together, in OC2 cells, magnolol induced [Ca2+]i rises by evoking partially PLC-dependent Ca2+ release from the endoplasmic reticulum and Ca2+ entry via PKC-sensitive store-operated Ca2+ entry. Magnolol also caused Ca2+-independent cell death. Therefore, magnolol-induced cytotoxicity may not be involved in activation mechanisms associated with intracellular Ca2+ mobilization in oral cancer cells.
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21
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Na V Channels: Assaying Biosynthesis, Trafficking, Function. Methods Mol Biol 2017. [PMID: 29264805 DOI: 10.1007/978-1-4939-7553-2_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Integral to the cell surface is channels, pumps, and exchanger proteins that facilitate the movement of ions across the membrane. Ion channels facilitate the passive movement of ions down an electrochemical gradient. Ion pumps actively use energy to actively translocate ions, often against concentration or voltage gradients, while ion exchangers utilize energy to couple the transport of different ion species such that one ion moves down its gradient and the released free energy is used to drive the movement of a different ion against its electrochemical gradient. Some ion pumps and exchangers may be electrogenic, i.e., the ion transport they support is not electrically neutral and generates a current. Functions of these pore-forming membrane proteins include the establishment of membrane potentials, gating of ions flows across the cell membrane to elicit action potentials and other electrical signals, as well as the regulation of cell volumes. The major forms of ion channels include voltage-, ligand-, and signal-gated channels. In this review, we describe mammalian voltage dependent Na (NaV) channels.
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Luo A, Liu Z, Cao Z, Hao J, Wu L, Fu C, Zeng M, Jiang W, Zhang P, Zhao B, Zhao T, Zhao J, Ma J. Wenxin Keli diminishes Ca2+
overload induced by hypoxia/reoxygenation in cardiomyocytes through inhibiting INaL
and ICaL. PACING AND CLINICAL ELECTROPHYSIOLOGY: PACE 2017; 40:1412-1425. [PMID: 28972668 DOI: 10.1111/pace.13206] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 09/11/2017] [Accepted: 09/22/2017] [Indexed: 11/30/2022]
Affiliation(s)
- Antao Luo
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Zhipei Liu
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Zhenzhen Cao
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Jie Hao
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Lin Wu
- Department of Cardiology, First Hospital; Peking University; Beijing China
| | - Chen Fu
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Mengliu Zeng
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Wanzhen Jiang
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Peihua Zhang
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Buchang Zhao
- Buchang Cardio-cerebrovascular Hospital; Xian China
| | - Tao Zhao
- Graduate School; Tianjin University of Traditional Chinese Medicine; Tianjin China
| | - Jing Zhao
- Buchang Cardio-cerebrovascular Hospital; Xian China
| | - Jihua Ma
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
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23
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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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24
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Fu C, Hao J, Zeng M, Song Y, Jiang W, Zhang P, Luo A, Cao Z, Belardinelli L, Ma J. Modulation of late sodium current by Ca2+-calmodulin-dependent protein kinase II, protein kinase C and Ca2+during hypoxia in rabbit ventricular myocytes. Exp Physiol 2017; 102:818-834. [DOI: 10.1113/ep085990] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2016] [Accepted: 04/13/2017] [Indexed: 01/05/2023]
Affiliation(s)
- Chen Fu
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
- Department of Cardiovascular Medicine; Tianyou Hospital, affiliated to Wuhan University of Science and Technology; Wuhan China
| | - Jie Hao
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Mengliu Zeng
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Yejia Song
- Division of Cardiovascular Medicine; University of Florida College of Medicine; Gainesville FL USA
| | - Wanzhen Jiang
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Peihua Zhang
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Antao Luo
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | - Zhenzhen Cao
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
| | | | - Jihua Ma
- Cardio-Electrophysiological Research Laboratory; Medical College of Wuhan University of Science and Technology; Wuhan China
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25
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Fang YC, Chou CT, Liang WZ, Kuo CC, Hsu SS, Wang JL, Jan CR. Effect of tetramethylpyrazine (TMP) on Ca 2+ signal transduction and cell viability in a model of renal tubular cells. J Biochem Mol Toxicol 2017; 31. [PMID: 28658523 DOI: 10.1002/jbt.21952] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 05/29/2017] [Accepted: 06/14/2017] [Indexed: 11/09/2022]
Abstract
Tetramethylpyrazine (TMP) is a compound purified from herb. Its effect on Ca2+ concentrations ([Ca2+ ]i ) in renal cells is unclear. This study examined whether TMP altered Ca2+ signaling in Madin-Darby canine kidney (MDCK) cells. TMP at 100-800 μM induced [Ca2+ ]i rises, which were reduced by Ca2+ removal. TMP induced Mn2+ influx implicating Ca2+ entry. TMP-induced Ca2+ entry was inhibited by 30% by modulators of protein kinase C (PKC) and store-operated Ca2+ channels. Treatment with the endoplasmic reticulum Ca2+ pump inhibitor 2,5-di-tert-butylhydroquinone (BHQ) inhibited 93% of TMP-evoked [Ca2+ ]i rises. Treatment with TMP abolished BHQ-evoked [Ca2+ ]i rises. Inhibition of phospholipase C (PLC) abolished TMP-induced responses. TMP at 200-1000 μM decreased viability, which was not reversed by pretreatment with the Ca2+ chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester. Together, in MDCK cells, TMP induced [Ca2+ ]i rises by evoking PLC-dependent Ca2+ release from endoplasmic reticulum and Ca2+ entry via PKC-sensitive store-operated Ca2+ entry. TMP also caused Ca2+ -independent cell death.
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Affiliation(s)
- Yi-Chien Fang
- Department of Laboratory Medicine, Zuoying Branch of Kaohsiung Armed Forces General Hospital, Kaohsiung, 81345, Taiwan
| | - Chiang-Ting Chou
- Department of Nursing, Division of Basic Medical Sciences, Chang Gung University of Science and Technology, Chia-Yi, 61363, Taiwan.,Chronic Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chia-Yi, 61363, Taiwan
| | - Wei-Zhe Liang
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, 81362, Taiwan
| | - Chun-Chi Kuo
- Department of Nursing, Tzu Hui Institute of Technology, Pingtung, 92641, Taiwan
| | - Shu-Shong Hsu
- Department of Surgery, Kaohsiung Veterans General Hospital, Kaohsiung, 81362, Taiwan
| | - Jue-Long Wang
- Department of Rehabilitation, Kaohsiung Veterans General Hospital Tainan Branch, Tainan, 71051, Taiwan
| | - Chung-Ren Jan
- Department of Medical Education and Research, Kaohsiung Veterans General Hospital, Kaohsiung, 81362, Taiwan
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26
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Jiang W, Zeng M, Cao Z, Liu Z, Hao J, Zhang P, Tian Y, Zhang P, Ma J. Icariin, a Novel Blocker of Sodium and Calcium Channels, Eliminates Early and Delayed Afterdepolarizations, As Well As Triggered Activity, in Rabbit Cardiomyocytes. Front Physiol 2017; 8:342. [PMID: 28611679 PMCID: PMC5447092 DOI: 10.3389/fphys.2017.00342] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/09/2017] [Indexed: 11/13/2022] Open
Abstract
Icariin, a flavonoid monomer from Herba Epimedii, has confirmed pharmacological and biological effects. However, its effects on arrhythmias and cardiac electrophysiology remain unclear. Here we investigate the effects of icariin on ion currents and action potentials (APs) in the rabbit myocardium. Furthermore, the effects of icariin on aconitine-induced arrhythmias were assessed in whole rabbits. Ion currents and APs were recorded in voltage-clamp and current-clamp mode in rabbit left ventricular myocytes (LVMs) and left atrial myocytes (LAMs), respectively. Icariin significantly shortened action potential durations (APDs) at 50 and 90% repolarization (APD50 and APD90) and reduced AP amplitude (APA) and the maximum upstroke velocity (Vmax) of APs in LAMs and LVMs; however, icariin had no effect on resting membrane potential (RMP) in these cells. Icariin decreased the rate-dependence of the APD and completely abolished anemonia toxin II (ATX-II)-induced early afterdepolarizations (EADs). Moreover, icariin significantly suppressed delayed afterdepolarizations (DADs) and triggered activities (TAs) elicited by isoproterenol (ISO, 1 μM) and high extracellular calcium concentrations ([Ca2+]o, 3.6 mM) in LVMs. Icariin also decreased INaT in a concentration-dependent manner in LAMs and LVMs, with IC50 values of 12.28 ± 0.29 μM (n = 8 cells/4 rabbits) and 11.83 ± 0.92 μM (n = 10 cells/6 rabbits; p > 0.05 vs. LAMs), respectively, and reversed ATX-II-induced INaL in a concentration-dependent manner in LVMs. Furthermore, icariin attenuated ICaL in a dose-dependent manner in LVMs. The corresponding IC50 value was 4.78 ± 0.89 μM (n = 8 cells/4 rabbits), indicating that the aforementioned current in LVMs was 2.8-fold more sensitive to icariin than ICaL in LAMs (13.43 ± 2.73 μM; n = 9 cells/5 rabbits). Icariin induced leftward shifts in the steady-state inactivation curves of INaT and ICaL in LAMs and LVMs but did not have a significant effect on their activation processes. Moreover, icariin had no effects on IK1 and IKr in LVMs or Ito and IKur in LAMs. These results revealed for the first time that icariin is a multichannel blocker that affects INaT, INaL and ICaL in the myocardium and that the drug had significant inhibitory effects on aconitine-induced arrhythmias in whole rabbits. Therefore, icariin has potential as a class I and IV antiarrhythmic drug.
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Affiliation(s)
- Wanzhen Jiang
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and TechnologyHubei, China
| | - Mengliu Zeng
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and TechnologyHubei, China
| | - Zhenzhen Cao
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and TechnologyHubei, China
| | - Zhipei Liu
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and TechnologyHubei, China
| | - Jie Hao
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and TechnologyHubei, China
| | - Peipei Zhang
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and TechnologyHubei, China
| | - Youjia Tian
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and TechnologyHubei, China
| | - Peihua Zhang
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and TechnologyHubei, China
| | - Jihua Ma
- Cardio-Electrophysiological Research Laboratory, Medical College, Wuhan University of Science and TechnologyHubei, China
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27
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Wei XH, Yu SD, Ren L, Huang SH, Yang QM, Wang P, Chu YP, Yang W, Ding YS, Huo Y, Wu L. Inhibition of late sodium current suppresses calcium-related ventricular arrhythmias by reducing the phosphorylation of CaMK-II and sodium channel expressions. Sci Rep 2017; 7:981. [PMID: 28428622 PMCID: PMC5430524 DOI: 10.1038/s41598-017-01056-0] [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: 07/21/2016] [Accepted: 03/20/2017] [Indexed: 12/19/2022] Open
Abstract
Cardiac arrhythmias associated with intracellular calcium inhomeostasis are refractory to antiarrhythmic therapy. We hypothesized that late sodium current (I Na) contributed to the calcium-related arrhythmias. Monophasic action potential duration at 90% completion of repolarization (MAPD90) was significantly increased and ventricular arrhythmias were observed in hearts with increased intracellular calcium concentration ([Ca2+]i) by using Bay K 8644, and the increase became greater in hearts treated with a combination of ATX-II and Bay K 8644 compared to Bay K 8644 alone. The prolongations caused by Bay K 8644 and frequent episodes of ventricular tachycardias, both in absence and presence of ATX-II, were significantly attenuated or abolished by late I Na inhibitors TTX and eleclazine. In rabbit ventricular myocytes, Bay K 8644 increased I CaL density, calcium transient and myocyte contraction. TTX and eleclazine decreased the amplitude of late I Na, the reverse use dependence of MAPD90 at slower heart rate, and attenuated the increase of intracellular calcium transient and myocyte contraction. TTX diminished the phosphorylation of CaMKII-δ and Nav 1.5 in hearts treated with Bay K 8644 and ATX-II. In conclusion, late I Na contributes to ventricular arrhythmias and its inhibition is plausible to treat arrhythmias in hearts with increased [Ca2+]i.
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Affiliation(s)
- Xiao-Hong Wei
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Shan-Dong Yu
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Lu Ren
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Si-Hui Huang
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Qiao-Mei Yang
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Ping Wang
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China
| | - Yan-Peng Chu
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Wei Yang
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Yan-Sheng Ding
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China.,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China
| | - Yong Huo
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China. .,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China.
| | - Lin Wu
- Department of Cardiology, Peking University First Hospital, Beijing, 100034, China. .,Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, 100191, China.
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Oxidative Stress-Induced Afterdepolarizations and Protein Kinase C Signaling. Int J Mol Sci 2017; 18:ijms18040688. [PMID: 28358314 PMCID: PMC5412274 DOI: 10.3390/ijms18040688] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/06/2017] [Accepted: 03/14/2017] [Indexed: 12/28/2022] Open
Abstract
Background: Hydrogen peroxide (H2O2)-induced oxidative stress has been demonstrated to induce afterdepolarizations and triggered activities in isolated myocytes, but the underlying mechanisms remain not fully understood. We aimed to explore whether protein kinase C (PKC) activation plays an important role in oxidative stress-induced afterdepolarizations. Methods: Action potentials and ion currents of isolated rabbit cardiomyocytes were recorded using the patch clamp technique. H2O2 (1 mM) was perfused to induce oxidative stress and the specific classical PKC inhibitor, Gö 6983 (1 μM), was applied to test the involvement of PKC. Results: H2O2 perfusion prolonged the action potential duration and induced afterdepolarizations. Pretreatment with Gö 6983 prevented the emergence of H2O2-induced afterdepolarizations. Additional application of Gö 6983 with H2O2 effectively suppressed H2O2-induced afterdepolarizations. H2O2 increased the late sodium current (INa,L) (n = 7, p < 0.01) and the L-type calcium current (ICa,L) (n = 5, p < 0.01), which were significantly reversed by Gö 6983 (p < 0.01). H2O2 also increased the transient outward potassium current (Ito) (n = 6, p < 0.05). However, Gö 6983 showed little effect on H2O2-induced enhancement of Ito. Conclusions: H2O2 induced afterdepolarizations via the activation of PKC and the enhancement of ICa,L and INa,L. These results provide evidence of a link between oxidative stress, PKC activation and afterdepolarizations.
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29
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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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Ranolazine Attenuates the Electrophysiological Effects of Myocardial Stretch in Langendorff-Perfused Rabbit Hearts. Cardiovasc Drugs Ther 2016; 29:231-41. [PMID: 26138210 DOI: 10.1007/s10557-015-6587-4] [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: 10/23/2022]
Abstract
PURPOSE Mechanical stretch is an arrhythmogenic factor found in situations of cardiac overload or dyssynchronic contraction. Ranolazine is an antianginal agent that inhibits the late Na (+) current and has been shown to exert a protective effect against arrhythmias. The present study aims to determine whether ranolazine modifies the electrophysiological responses induced by acute mechanical stretch. METHODS The ventricular fibrillation modifications induced by acute stretch were studied in Langendorff-perfused rabbit hearts using epicardial multiple electrodes under control conditions (n = 9) or during perfusion of the late Na(+) current blocker ranolazine 5 μM (n = 9). Spectral and mapping techniques were used to establish the ventricular fibrillation dominant frequency, the spectral concentration and the complexity of myocardial activation in three situations: baseline, stretch and post-stretch. RESULTS Ranolazine attenuated the increase in ventricular fibrillation dominant frequency produced by stretch (23.0 vs 40.4 %) (control: baseline =13.6 ± 2.6 Hz, stretch = 19.1 ± 3.1 Hz, p < 0.0001; ranolazine: baseline = 1.4 ± 1.8 Hz, stretch =14.0 ± 2.4 Hz, p < 0.05 vs baseline, p < 0.001 vs control). During stretch, ventricular fibrillation was less complex in the ranolazine than in the control series, as evaluated by the lesser percentage of complex maps and the greater spectral concentration of ventricular fibrillation. These changes were associated to an increase in the fifth percentile of VV intervals during ventricular fibrillation (50 ± 8 vs 38 ± 5 ms, p < .01) and in the wavelength of the activation (2.4 ± 0.3 vs 1.9 ± 0.2 cm, p < 0.001) under ranolazine. CONCLUSIONS The late inward Na(+) current inhibitor ranolazine attenuates the electrophysiological effects responsible for the acceleration and increase in complexity of ventricular fibrillation produced by myocardial stretch.
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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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Luo AT, Cao ZZ, Xiang Y, Zhang S, Qian CP, Fu C, Zhang PH, Ma JH. Ketamine attenuates the Na+-dependent Ca2+ overload in rabbit ventricular myocytes in vitro by inhibiting late Na+ and L-type Ca2+ currents. Acta Pharmacol Sin 2015; 36:1327-36. [PMID: 26456586 DOI: 10.1038/aps.2015.75] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 07/02/2015] [Indexed: 12/27/2022] Open
Abstract
AIM Intracellular Ca(2+) ([Ca(2+)]i) overload occurs in myocardial ischemia. An increase in the late sodium current (INaL) causes intracellular Na(+) overload and subsequently [Ca(2+)]i overload via the reverse-mode sodium-calcium exchanger (NCX). Thus, inhibition of INaL is a potential therapeutic target for cardiac diseases associated with [Ca(2+)]i overload. The aim of this study was to investigate the effects of ketamine on Na(+)-dependent Ca(2+) overload in ventricular myocytes in vitro. METHODS Ventricular myocytes were enzymatically isolated from hearts of rabbits. INaL, NCX current (INCX) and L-type Ca(2+) current (ICaL) were recorded using whole-cell patch-clamp technique. Myocyte shortening and [Ca(2+)]i transients were measured simultaneously using a video-based edge detection and dual excitation fluorescence photomultiplier system. RESULTS Ketamine (20, 40, 80 μmol/L) inhibited INaL in a concentration-dependent manner. In the presence of sea anemone toxin II (ATX, 30 nmol/L), INaL was augmented by more than 3-fold, while ketamine concentration-dependently suppressed the ATX-augmented INaL. Ketamine (40 μmol/L) also significantly suppressed hypoxia or H2O2-induced enhancement of INaL. Furthermore, ketamine concentration-dependently attenuated ATX-induced enhancement of reverse-mode INCX. In addition, ketamine (40 μmol/L) inhibited ICaL by 33.4%. In the presence of ATX (3 nmol/L), the rate and amplitude of cell shortening and relaxation, the diastolic [Ca(2+)]i, and the rate and amplitude of [Ca(2+)]i rise and decay were significantly increased, which were reverted to control levels by tetrodotoxin (TTX, 2 μmol/L) or by ketamine (40 μmol/L). CONCLUSION Ketamine protects isolated rabbit ventricular myocytes against [Ca(2+)]i overload by inhibiting INaL and ICaL.
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Glynn P, Musa H, Wu X, Unudurthi SD, Little S, Qian L, Wright PJ, Radwanski PB, Gyorke S, Mohler PJ, Hund TJ. Voltage-Gated Sodium Channel Phosphorylation at Ser571 Regulates Late Current, Arrhythmia, and Cardiac Function In Vivo. Circulation 2015; 132:567-77. [PMID: 26187182 DOI: 10.1161/circulationaha.114.015218] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 06/12/2015] [Indexed: 12/19/2022]
Abstract
BACKGROUND Voltage-gated Na(+) channels (Nav) are essential for myocyte membrane excitability and cardiac function. Nav current (INa) is a large-amplitude, short-duration spike generated by rapid channel activation followed immediately by inactivation. However, even under normal conditions, a small late component of INa (INa,L) persists because of incomplete/failed inactivation of a subpopulation of channels. Notably, INa,L is directly linked with both congenital and acquired disease states. The multifunctional Ca(2+)/calmodulin-dependent kinase II (CaMKII) has been identified as an important activator of INa,L in disease. Several potential CaMKII phosphorylation sites have been discovered, including Ser571 in the Nav1.5 DI-DII linker, but the molecular mechanism underlying CaMKII-dependent regulation of INa,L in vivo remains unknown. METHODS AND RESULTS To determine the in vivo role of Ser571, 2 Scn5a knock-in mouse models were generated expressing either: (1) Nav1.5 with a phosphomimetic mutation at Ser571 (S571E), or (2) Nav1.5 with the phosphorylation site ablated (S571A). Electrophysiology studies revealed that Ser571 regulates INa,L but not other channel properties previously linked to CaMKII. Ser571-mediated increases in INa,L promote abnormal repolarization and intracellular Ca(2+) handling and increase susceptibility to arrhythmia at the cellular and animal level. Importantly, Ser571 is required for maladaptive remodeling and arrhythmias in response to pressure overload. CONCLUSIONS Our data provide the first in vivo evidence for the molecular mechanism underlying CaMKII activation of the pathogenic INa,L. Relevant for improved rational design of potential therapies, our findings demonstrate that Ser571-dependent regulation of Nav1.5 specifically tunes INa,L without altering critical physiological components of the current.
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Affiliation(s)
- Patric Glynn
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Hassan Musa
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Xiangqiong Wu
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Sathya D Unudurthi
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Sean Little
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Lan Qian
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Patrick J Wright
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Przemyslaw B Radwanski
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Sandor Gyorke
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Peter J Mohler
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.)
| | - Thomas J Hund
- From Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (P.G., H.M., X.W., S.D.U., S.L., L.Q., P.J.W., P.B.R., S.G., P.J.M., T.J.H.); Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus (P.G., X.W., S.D.U., L.Q., T.J.H.); Departments of Physiology & Cell Biology (H.M., S.L., P.J.W., P.B.R., S.G., P.J.M.) and Internal Medicine (P.J.M., T.J.H.), The Ohio State University Wexner Medical Center, Columbus; and Division of Pharmacy Practice and Administration, College of Pharmacy, The Ohio State University, Columbus (P.B.R.).
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Regulation of the cardiac Na+ channel NaV1.5 by post-translational modifications. J Mol Cell Cardiol 2015; 82:36-47. [PMID: 25748040 DOI: 10.1016/j.yjmcc.2015.02.013] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 01/28/2015] [Accepted: 02/17/2015] [Indexed: 02/07/2023]
Abstract
The cardiac voltage-gated Na(+) channel, Na(V)1.5, is responsible for the upstroke of the action potential in cardiomyocytes and for efficient propagation of the electrical impulse in the myocardium. Even subtle alterations of Na(V)1.5 function, as caused by mutations in its gene SCN5A, may lead to many different arrhythmic phenotypes in carrier patients. In addition, acquired malfunctions of Na(V)1.5 that are secondary to cardiac disorders such as heart failure and cardiomyopathies, may also play significant roles in arrhythmogenesis. While it is clear that the regulation of Na(V)1.5 protein expression and function tightly depends on genetic mechanisms, recent studies have demonstrated that Na(V)1.5 is the target of various post-translational modifications that are pivotal not only in physiological conditions, but also in disease. In this review, we examine the recent literature demonstrating glycosylation, phosphorylation by Protein Kinases A and C, Ca(2+)/Calmodulin-dependent protein Kinase II, Phosphatidylinositol 3-Kinase, Serum- and Glucocorticoid-inducible Kinases, Fyn and Adenosine Monophosphate-activated Protein Kinase, methylation, acetylation, redox modifications, and ubiquitylation of Na(V)1.5. Modern and sensitive mass spectrometry approaches, applied directly to channel proteins that were purified from native cardiac tissues, have enabled the determination of the precise location of post-translational modification sites, thus providing essential information for understanding the mechanistic details of these regulations. The current challenge is first, to understand the roles of these modifications on the expression and the function of Na(V)1.5, and second, to further identify other chemical modifications. It is postulated that the diversity of phenotypes observed with Na(V)1.5-dependent disorders may partially arise from the complex post-translational modifications of channel protein components.
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Horvath B, Bers DM. The late sodium current in heart failure: pathophysiology and clinical relevance. ESC Heart Fail 2014; 1:26-40. [PMID: 28834665 DOI: 10.1002/ehf2.12003] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 07/13/2014] [Accepted: 07/14/2014] [Indexed: 12/19/2022] Open
Abstract
Large and growing body of data suggest that an increased late sodium current (INa,late ) can have a significant pathophysiological role in heart failure and other heart diseases. The first goal of this article is to describe how INa,late functions under physiological circumstances. The second goal is to show the wide range of cellular mechanisms that can increase INa,late in cardiac disease, and also to describe how the up-regulated INa,late contributes to the pathophysiology of heart failure. The final section of the article discusses the possible use of INa,late -modifying drugs in heart failure, on the basis of experimental and preclinical data.
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Affiliation(s)
- Balazs Horvath
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
- Faculty of Pharmacy, University of Debrecen, Debrecen, Hungary
| | - Donald M Bers
- Department of Pharmacology, School of Medicine, University of California, Davis, CA, USA
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Ma J, Song Y, Shryock JC, Hu L, Wang W, Yan X, Zhang P, Belardinelli L. Ranolazine Attenuates Hypoxia- and Hydrogen Peroxide-induced Increases in Sodium Channel Late Openings in Ventricular Myocytes. J Cardiovasc Pharmacol 2014; 64:60-8. [DOI: 10.1097/fjc.0000000000000090] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Grandi E, Herren AW. CaMKII-dependent regulation of cardiac Na(+) homeostasis. Front Pharmacol 2014; 5:41. [PMID: 24653702 PMCID: PMC3948048 DOI: 10.3389/fphar.2014.00041] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Accepted: 02/21/2014] [Indexed: 01/01/2023] Open
Abstract
Na+ homeostasis is a key regulator of cardiac excitation and contraction. The cardiac voltage-gated Na+ channel, NaV1.5, critically controls cell excitability, and altered channel gating has been implicated in both inherited and acquired arrhythmias. Ca2+/calmodulin-dependent protein kinase II (CaMKII), a serine/threonine kinase important in cardiac physiology and disease, phosphorylates NaV1.5 at multiple sites within the first intracellular linker loop to regulate channel gating. Although CaMKII sites on the channel have been identified (S516, T594, S571), the relative role of each of these phospho-sites in channel gating properties remains unclear, whereby both loss-of-function (reduced availability) and gain-of-function (late Na+ current, INaL) effects have been reported. Our review highlights investigating the complex multi-site phospho-regulation of NaV1.5 gating is crucial to understanding the genesis of acquired arrhythmias in heart failure (HF) and CaMKII activated conditions. In addition, the increased Na+ influx accompanying INaL may also indirectly contribute to arrhythmia by promoting Ca2+ overload. While the precise mechanisms of Na+ loading during HF remain unclear, and quantitative analyses of the contribution of INaL are lacking, disrupted Na+ homeostasis is a consistent feature of HF. Computational and experimental observations suggest that both increased diastolic Na+ influx and action potential prolongation due to systolic INaL contribute to disruption of Ca2+ handling in failing hearts. Furthermore, simulations reveal a synergistic interaction between perturbed Na+ fluxes and CaMKII, and confirm recent experimental findings of an arrhythmogenic feedback loop, whereby CaMKII activation is at once a cause and a consequence of Na+ loading.
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Affiliation(s)
- Eleonora Grandi
- Department of Pharmacology, University of California at Davis Davis, CA, USA
| | - Anthony W Herren
- Department of Pharmacology, University of California at Davis Davis, CA, USA
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Morotti S, Edwards AG, McCulloch AD, Bers DM, Grandi E. A novel computational model of mouse myocyte electrophysiology to assess the synergy between Na+ loading and CaMKII. J Physiol 2014; 592:1181-97. [PMID: 24421356 DOI: 10.1113/jphysiol.2013.266676] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Ca(2+)-calmodulin-dependent protein kinase II (CaMKII) hyperactivity in heart failure causes intracellular Na(+) ([Na(+)]i) loading (at least in part by enhancing the late Na(+) current). This [Na(+)]i gain promotes intracellular Ca(2+) ([Ca(2+)]i) overload by altering the equilibrium of the Na(+)-Ca(2+) exchanger to impair forward-mode (Ca(2+) extrusion), and favour reverse-mode (Ca(2+) influx) exchange. In turn, this Ca(2+) overload would be expected to further activate CaMKII and thereby form a pathological positive feedback loop of ever-increasing CaMKII activity, [Na(+)]i, and [Ca(2+)]i. We developed an ionic model of the mouse ventricular myocyte to interrogate this potentially arrhythmogenic positive feedback in both control conditions and when CaMKIIδC is overexpressed as in genetically engineered mice. In control conditions, simulation of increased [Na(+)]i causes the expected increases in [Ca(2+)]i, CaMKII activity, and target phosphorylation, which degenerate into unstable Ca(2+) handling and electrophysiology at high [Na(+)]i gain. Notably, clamping CaMKII activity to basal levels ameliorates but does not completely offset this outcome, suggesting that the increase in [Ca(2+)]i per se plays an important role. The effect of this CaMKII-Na(+)-Ca(2+)-CaMKII feedback is more striking in CaMKIIδC overexpression, where high [Na(+)]i causes delayed afterdepolarizations, which can be prevented by imposing low [Na(+)]i, or clamping CaMKII phosphorylation of L-type Ca(2+) channels, ryanodine receptors and phospholamban to basal levels. In this setting, Na(+) loading fuels a vicious loop whereby increased CaMKII activation perturbs Ca(2+) and membrane potential homeostasis. High [Na(+)]i is also required to produce instability when CaMKII is further activated by increased Ca(2+) loading due to β-adrenergic activation. Our results support recent experimental findings of a synergistic interaction between perturbed Na(+) fluxes and CaMKII, and suggest that pharmacological inhibition of intracellular Na(+) loading can contribute to normalizing Ca(2+) and membrane potential dynamics in heart failure.
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Affiliation(s)
- S Morotti
- Department of Pharmacology, University of California Davis, 451 Health Sciences Drive, GBSF rm 3502, Davis, CA 95616, USA.
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Wang XJ, Wang LL, Fu C, Zhang PH, Wu Y, Ma JH. Ranolazine Attenuates the Enhanced Reverse Na+-Ca2+ Exchange Current via Inhibiting Hypoxia-Increased Late Sodium Current in Ventricular Myocytes. J Pharmacol Sci 2014; 124:365-73. [DOI: 10.1254/jphs.13202fp] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Abstract
Late I Na is an integral part of the sodium current, which persists long after the fast-inactivating component. The magnitude of the late I Na is relatively small in all species and in all types of cardiomyocytes as compared with the amplitude of the fast sodium current, but it contributes significantly to the shape and duration of the action potential. This late component had been shown to increase in several acquired or congenital conditions, including hypoxia, oxidative stress, and heart failure, or due to mutations in SCN5A, which encodes the α-subunit of the sodium channel, as well as in channel-interacting proteins, including multiple β subunits and anchoring proteins. Patients with enhanced late I Na exhibit the type-3 long QT syndrome (LQT3) characterized by high propensity for the life-threatening ventricular arrhythmias, such as Torsade de Pointes (TdP), as well as for atrial fibrillation. There are several distinct mechanisms of arrhythmogenesis due to abnormal late I Na, including abnormal automaticity, early and delayed after depolarization-induced triggered activity, and dramatic increase of ventricular dispersion of repolarization. Many local anesthetic and antiarrhythmic agents have a higher potency to block late I Na as compared with fast I Na. Several novel compounds, including ranolazine, GS-458967, and F15845, appear to be the most selective inhibitors of cardiac late I Na reported to date. Selective inhibition of late I Na is expected to be an effective strategy for correcting these acquired and congenital channelopathies.
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Luo A, Ma J, Song Y, Qian C, Wu Y, Zhang P, Wang L, Fu C, Cao Z, Shryock JC. Larger late sodium current density as well as greater sensitivities to ATX II and ranolazine in rabbit left atrial than left ventricular myocytes. Am J Physiol Heart Circ Physiol 2013; 306:H455-61. [PMID: 24322614 DOI: 10.1152/ajpheart.00727.2013] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An increase of cardiac late sodium current (INa.L) is arrhythmogenic in atrial and ventricular tissues, but the densities of INa.L and thus the potential relative contributions of this current to sodium ion (Na(+)) influx and arrhythmogenesis in atria and ventricles are unclear. In this study, whole-cell and cell-attached patch-clamp techniques were used to measure INa.L in rabbit left atrial and ventricular myocytes under identical conditions. The density of INa.L was 67% greater in left atrial (0.50 ± 0.09 pA/pF, n = 20) than in left ventricular cells (0.30 ± 0.07 pA/pF, n = 27, P < 0.01) when elicited by step pulses from -120 to -20 mV at a rate of 0.2 Hz. Similar results were obtained using step pulses from -90 to -20 mV. Anemone toxin II (ATX II) increased INa.L with an EC50 value of 14 ± 2 nM and a Hill slope of 1.4 ± 0.1 (n = 9) in atrial myocytes and with an EC50 of 21 ± 5 nM and a Hill slope of 1.2 ± 0.1 (n = 12) in ventricular myocytes. Na(+) channel open probability (but not mean open time) was greater in atrial than in ventricular cells in the absence and presence of ATX II. The INa.L inhibitor ranolazine (3, 6, and 9 μM) reduced INa.L more in atrial than ventricular myocytes in the presence of 40 nM ATX II. In summary, rabbit left atrial myocytes have a greater density of INa.L and higher sensitivities to ATX II and ranolazine than rabbit left ventricular myocytes.
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Affiliation(s)
- Antao Luo
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, China
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Coppini R, Ferrantini C, Mazzoni L, Sartiani L, Olivotto I, Poggesi C, Cerbai E, Mugelli A. Regulation of intracellular Na(+) in health and disease: pathophysiological mechanisms and implications for treatment. Glob Cardiol Sci Pract 2013; 2013:222-42. [PMID: 24689024 PMCID: PMC3963757 DOI: 10.5339/gcsp.2013.30] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Accepted: 09/01/2013] [Indexed: 12/19/2022] Open
Abstract
Transmembrane sodium (Na+) fluxes and intracellular sodium homeostasis are central players in the physiology of the cardiac myocyte, since they are crucial for both cell excitability and for the regulation of the intracellular calcium concentration. Furthermore, Na+ fluxes across the membrane of mitochondria affect the concentration of protons and calcium in the matrix, regulating mitochondrial function. In this review we first analyze the main molecular determinants of sodium fluxes across the sarcolemma and the mitochondrial membrane and describe their role in the physiology of the healthy myocyte. In particular we focus on the interplay between intracellular Ca2+ and Na+. A large part of the review is dedicated to discuss the changes of Na+ fluxes and intracellular Na+ concentration([Na+]i) occurring in cardiac disease; we specifically focus on heart failure and hypertrophic cardiomyopathy, where increased intracellular [Na+]i is an established determinant of myocardial dysfunction. We review experimental evidence attributing the increase of [Na+]i to either decreased Na+ efflux (e.g. via the Na+/K+ pump) or increased Na+ influx into the myocyte (e.g. via Na+ channels). In particular, we focus on the role of the “late sodium current” (INaL), a sustained component of the fast Na+ current of cardiac myocytes, which is abnormally enhanced in cardiac diseases and contributes to both electrical and contractile dysfunction. We analyze the pathophysiological role of INaL enhancement in heart failure and hypertrophic cardiomyopathy and the consequences of its pharmacological modulation, highlighting the clinical implications. The central role of Na+ fluxes and intracellular Na+ physiology and pathophysiology of cardiac myocytes has been highlighted by a large number of recent works. The possibility of modulating Na+ inward fluxes and [Na+]i with specific INaL inhibitors, such as ranolazine, has made Na+a novel suitable target for cardiac therapy, potentially capable of addressing arrhythmogenesis and diastolic dysfunction in severe conditions such as heart failure and hypertrophic cardiomyopathy.
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Affiliation(s)
- Raffaele Coppini
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
| | - Cecilia Ferrantini
- Department of Clinical and Experimental Medicine, division of Physiology, University of Florence, Italy
| | - Luca Mazzoni
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
| | - Laura Sartiani
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
| | - Iacopo Olivotto
- Referral Center for Cardiomyopathies, Careggi University Hospital, Florence, Italy
| | - Corrado Poggesi
- Department of Clinical and Experimental Medicine, division of Physiology, University of Florence, Italy
| | - Elisabetta Cerbai
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
| | - Alessandro Mugelli
- Department NeuroFarBa, Division of Pharmacology, University of Florence, Italy
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Toischer K, Hartmann N, Wagner S, Fischer TH, Herting J, Danner BC, Sag CM, Hund TJ, Mohler PJ, Belardinelli L, Hasenfuss G, Maier LS, Sossalla S. Role of late sodium current as a potential arrhythmogenic mechanism in the progression of pressure-induced heart disease. J Mol Cell Cardiol 2013; 61:111-22. [PMID: 23570977 PMCID: PMC3720777 DOI: 10.1016/j.yjmcc.2013.03.021] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 03/08/2013] [Accepted: 03/29/2013] [Indexed: 12/19/2022]
Abstract
The aim of the study was to determine the characteristics of the late Na current (INaL) and its arrhythmogenic potential in the progression of pressure-induced heart disease. Transverse aortic constriction (TAC) was used to induce pressure overload in mice. After one week the hearts developed isolated hypertrophy with preserved systolic contractility. In patch-clamp experiments both, INaL and the action potential duration (APD90) were unchanged. In contrast, after five weeks animals developed heart failure with prolonged APDs and slowed INaL decay time which could be normalized by addition of the INaL inhibitor ranolazine (Ran) or by the Ca/calmodulin-dependent protein kinase II (CaMKII) inhibitor AIP. Accordingly the APD90 could be significantly abbreviated by Ran, tetrodotoxin and the CaMKII inhibitor AIP. Isoproterenol increased the number of delayed afterdepolarizations (DAD) in myocytes from failing but not sham hearts. Application of either Ran or AIP prevented the occurrence of DADs. Moreover, the incidence of triggered activity was significantly increased in TAC myocytes and was largely prevented by Ran and AIP. Western blot analyses indicate that increased CaMKII activity and a hyperphosphorylation of the Nav1.5 at the CaMKII phosphorylation site (Ser571) paralleled our functional observations five weeks after TAC surgery. In pressure overload-induced heart failure a CaMKII-dependent augmentation of INaL plays a crucial role in the AP prolongation and generation of cellular arrhythmogenic triggers, which cannot be found in early and still compensated hypertrophy. Inhibition of INaL and CaMKII exerts potent antiarrhythmic effects and might therefore be of potential therapeutic interest. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes".
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Affiliation(s)
- Karl Toischer
- Abt. Kardiologie und Pneumologie / Herzzentrum, Georg-August-Universität Göttingen, Germany
| | - Nico Hartmann
- Abt. Kardiologie und Pneumologie / Herzzentrum, Georg-August-Universität Göttingen, Germany
| | - Stefan Wagner
- Abt. Kardiologie und Pneumologie / Herzzentrum, Georg-August-Universität Göttingen, Germany
| | - Thomas H. Fischer
- Abt. Kardiologie und Pneumologie / Herzzentrum, Georg-August-Universität Göttingen, Germany
| | - Jonas Herting
- Abt. Kardiologie und Pneumologie / Herzzentrum, Georg-August-Universität Göttingen, Germany
| | - Bernhard C. Danner
- Abt. Herzund Thoraxchirurgie, Georg-August-Universität Göttingen, Germany
| | - Can M. Sag
- Abt. Kardiologie und Pneumologie / Herzzentrum, Georg-August-Universität Göttingen, Germany
| | - Thomas J. Hund
- Dorothy M. Davis Heart and Lung Research Institute, Dept. of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Peter J. Mohler
- Dorothy M. Davis Heart and Lung Research Institute, Dept. of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH
| | | | - Gerd Hasenfuss
- Abt. Kardiologie und Pneumologie / Herzzentrum, Georg-August-Universität Göttingen, Germany
| | - Lars S. Maier
- Abt. Kardiologie und Pneumologie / Herzzentrum, Georg-August-Universität Göttingen, Germany
| | - Samuel Sossalla
- Abt. Kardiologie und Pneumologie / Herzzentrum, Georg-August-Universität Göttingen, Germany
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44
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Herren AW, Bers DM, Grandi E. Post-translational modifications of the cardiac Na channel: contribution of CaMKII-dependent phosphorylation to acquired arrhythmias. Am J Physiol Heart Circ Physiol 2013; 305:H431-45. [PMID: 23771687 DOI: 10.1152/ajpheart.00306.2013] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The voltage-gated Na channel isoform 1.5 (NaV1.5) is the pore forming α-subunit of the voltage-gated cardiac Na channel, which is responsible for the initiation and propagation of cardiac action potentials. Mutations in the SCN5A gene encoding NaV1.5 have been linked to changes in the Na current leading to a variety of arrhythmogenic phenotypes, and alterations in the NaV1.5 expression level, Na current density, and/or gating have been observed in acquired cardiac disorders, including heart failure. The precise mechanisms underlying these abnormalities have not been fully elucidated. However, several recent studies have made it clear that NaV1.5 forms a macromolecular complex with a number of proteins that modulate its expression levels, localization, and gating and is the target of extensive post-translational modifications, which may also influence all these properties. We review here the molecular aspects of cardiac Na channel regulation and their functional consequences. In particular, we focus on the molecular and functional aspects of Na channel phosphorylation by the Ca/calmodulin-dependent protein kinase II, which is hyperactive in heart failure and has been causally linked to cardiac arrhythmia. Understanding the mechanisms of altered NaV1.5 expression and function is crucial for gaining insight into arrhythmogenesis and developing novel therapeutic strategies.
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Affiliation(s)
- Anthony W Herren
- Department of Pharmacology, University of California Davis, Davis, California
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