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Hartmann N, Knierim M, Maurer W, Dybkova N, Zeman F, Hasenfuß G, Sossalla S, Streckfuss-Bömeke K. Na V1.8 as Proarrhythmic Target in a Ventricular Cardiac Stem Cell Model. Int J Mol Sci 2024; 25:6144. [PMID: 38892333 PMCID: PMC11172914 DOI: 10.3390/ijms25116144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 05/25/2024] [Accepted: 05/30/2024] [Indexed: 06/21/2024] Open
Abstract
The sodium channel NaV1.8, encoded by the SCN10A gene, has recently emerged as a potential regulator of cardiac electrophysiology. We have previously shown that NaV1.8 contributes to arrhythmogenesis by inducing a persistent Na+ current (late Na+ current, INaL) in human atrial and ventricular cardiomyocytes (CM). We now aim to further investigate the contribution of NaV1.8 to human ventricular arrhythmogenesis at the CM-specific level using pharmacological inhibition as well as a genetic knockout (KO) of SCN10A in induced pluripotent stem cell CM (iPSC-CM). In functional voltage-clamp experiments, we demonstrate that INaL was significantly reduced in ventricular SCN10A-KO iPSC-CM and in control CM after a specific pharmacological inhibition of NaV1.8. In contrast, we did not find any effects on ventricular APD90. The frequency of spontaneous sarcoplasmic reticulum Ca2+ sparks and waves were reduced in SCN10A-KO iPSC-CM and control cells following the pharmacological inhibition of NaV1.8. We further analyzed potential triggers of arrhythmias and found reduced delayed afterdepolarizations (DAD) in SCN10A-KO iPSC-CM and after the specific inhibition of NaV1.8 in control cells. In conclusion, we show that NaV1.8-induced INaL primarily impacts arrhythmogenesis at a subcellular level, with minimal effects on systolic cellular Ca2+ release. The inhibition or knockout of NaV1.8 diminishes proarrhythmic triggers in ventricular CM. In conjunction with our previously published results, this work confirms NaV1.8 as a proarrhythmic target that may be useful in an anti-arrhythmic therapeutic strategy.
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Affiliation(s)
- Nico Hartmann
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen and Rhein Main, 61231 Bad Nauheim, Germany
| | - Maria Knierim
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen and Rhein Main, 61231 Bad Nauheim, Germany
- Clinic for Cardio-Thoracic and Vascular Surgery, University Medical Center, 37075 Göttingen, Germany
| | - Wiebke Maurer
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen and Rhein Main, 61231 Bad Nauheim, Germany
| | - Nataliya Dybkova
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen and Rhein Main, 61231 Bad Nauheim, Germany
| | - Florian Zeman
- Center for Clinicial Trials, University of Regensburg, 93042 Regensburg, Germany
| | - Gerd Hasenfuß
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen and Rhein Main, 61231 Bad Nauheim, Germany
| | - Samuel Sossalla
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen and Rhein Main, 61231 Bad Nauheim, Germany
- Medical Clinic I, Cardiology and Angiology, Giessen and Department of Cardiology at Kerckhoff Heart and Lung Center, Justus-Liebig-University, 61231 Bad Nauheim, Germany
| | - Katrin Streckfuss-Bömeke
- Clinic for Cardiology and Pneumology, University Medical Center, 37075 Göttingen, Germany
- DZHK (German Center for Cardiovascular Research), Partner Site Göttingen and Rhein Main, 61231 Bad Nauheim, Germany
- Institute of Pharmacology and Toxicology, University of Würzburg, 97078 Würzburg, Germany
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Lei M, Salvage SC, Jackson AP, Huang CLH. Cardiac arrhythmogenesis: roles of ion channels and their functional modification. Front Physiol 2024; 15:1342761. [PMID: 38505707 PMCID: PMC10949183 DOI: 10.3389/fphys.2024.1342761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/22/2024] [Indexed: 03/21/2024] Open
Abstract
Cardiac arrhythmias cause significant morbidity and mortality and pose a major public health problem. They arise from disruptions in the normally orderly propagation of cardiac electrophysiological activation and recovery through successive cardiomyocytes in the heart. They reflect abnormalities in automaticity, initiation, conduction, or recovery in cardiomyocyte excitation. The latter properties are dependent on surface membrane electrophysiological mechanisms underlying the cardiac action potential. Their disruption results from spatial or temporal instabilities and heterogeneities in the generation and propagation of cellular excitation. These arise from abnormal function in their underlying surface membrane, ion channels, and transporters, as well as the interactions between them. The latter, in turn, form common regulatory targets for the hierarchical network of diverse signaling mechanisms reviewed here. In addition to direct molecular-level pharmacological or physiological actions on these surface membrane biomolecules, accessory, adhesion, signal transduction, and cytoskeletal anchoring proteins modify both their properties and localization. At the cellular level of excitation-contraction coupling processes, Ca2+ homeostatic and phosphorylation processes affect channel activity and membrane excitability directly or through intermediate signaling. Systems-level autonomic cellular signaling exerts both acute channel and longer-term actions on channel expression. Further upstream intermediaries from metabolic changes modulate the channels both themselves and through modifying Ca2+ homeostasis. Finally, longer-term organ-level inflammatory and structural changes, such as fibrotic and hypertrophic remodeling, similarly can influence all these physiological processes with potential pro-arrhythmic consequences. These normal physiological processes may target either individual or groups of ionic channel species and alter with particular pathological conditions. They are also potentially alterable by direct pharmacological action, or effects on longer-term targets modifying protein or cofactor structure, expression, or localization. Their participating specific biomolecules, often clarified in experimental genetically modified models, thus constitute potential therapeutic targets. The insights clarified by the physiological and pharmacological framework outlined here provide a basis for a recent modernized drug classification. Together, they offer a translational framework for current drug understanding. This would facilitate future mechanistically directed therapeutic advances, for which a number of examples are considered here. The latter are potentially useful for treating cardiac, in particular arrhythmic, disease.
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Affiliation(s)
- Ming Lei
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Samantha C. Salvage
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Antony P. Jackson
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Christopher L.-H. Huang
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom
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Huang Y, Wang LL, Liu ZB, Chen C, Ren X, Luo AT, Ma JH, Antzelevitch C, Barajas-Martínez H, Hu D. Underlying mechanism of atrial fibrillation-associated Nppa-I137T mutation and cardiac effect of potential drug therapy. Heart Rhythm 2024; 21:184-196. [PMID: 37924963 DOI: 10.1016/j.hrthm.2023.10.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 10/16/2023] [Accepted: 10/27/2023] [Indexed: 11/06/2023]
Abstract
BACKGROUND More than a hundred genetic loci have been associated with atrial fibrillation (AF). But the exact mechanism remains unclear and the treatment needs to be improved. OBJECTIVE This study aimed to investigate the mechanism and potential treatment of NPPA mutation-associated AF. METHODS Nppa knock-in (KI, p.I137T) rats were generated, and cardiac function was evaluated. Blood pressure was recorded using a tail-cuff system. The expression levels were measured using real-time polymerase chain reaction, enzyme-linked immunosorbent assay or Western blot analysis, and RNA-sequence analysis. Programmed electrical stimulation, patch clamp, and multielectrode array were used to record the electrophysical characteristics. RESULTS Mutant rats displayed downregulated expression of atrial natriuretic peptide but elevated blood pressure and enlarged left atrial end-diastolic diameter. Further, gene topology analysis suggested that the majority of differently expressed genes in Nppa KI rats were related to inflammation, electrical remodeling, and structural remodeling. The expression levels of C-C chemokine ligand 5 and galectin-3 involved in remodeling were higher, while there were declined levels of Nav1.5, Cav1.2, and connexin 40. AF was more easily induced in KI rats. Electrical remodeling included abbreviated action potentials, effective refractory period, increased late sodium current, and reduced calcium current, giving rise to conduction abnormalities. These electrophysiological changes could be reversed by the late sodium current blocker ranolazine and the Nav1.8 blocker A-803467. CONCLUSION Our findings suggest that structural remodeling related to inflammation and fibrosis and electrical remodeling involved in late sodium current underly the major effects of the Nppa (p.I137T) variant to induce AF, which can be attenuated by the late sodium current blocker and Nav1.8 blocker.
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Affiliation(s)
- Yan Huang
- Department of Cardiology and Cardiovascular Research Institute, Renmin Hospital of Wuhan University, Wuhan, Hubei, China; Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China
| | - Ling-Ling Wang
- Department of Cardiology and Cardiovascular Research Institute, Renmin Hospital of Wuhan University, Wuhan, Hubei, China; Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China
| | - Zhe-Bo Liu
- Department of Cardiology and Cardiovascular Research Institute, Renmin Hospital of Wuhan University, Wuhan, Hubei, China; Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China
| | - Cheng Chen
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xiang Ren
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology and Center for Human Genome Research, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - An-Tao Luo
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Ji-Hua Ma
- Cardio-Electrophysiological Research Laboratory, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China; Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College of Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Charles Antzelevitch
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania; Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Hector Barajas-Martínez
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania; Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Dan Hu
- Department of Cardiology and Cardiovascular Research Institute, Renmin Hospital of Wuhan University, Wuhan, Hubei, China; Hubei Key Laboratory of Cardiology, Wuhan, Hubei, China.
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Zhu X, Lv M, Cheng T, Zhou Y, Yuan G, Chu Y, Luan Y, Song Q, Hu Y. Bibliometric analysis of atrial fibrillation and ion channels. Heart Rhythm 2024:S1547-5271(24)00086-9. [PMID: 38280618 DOI: 10.1016/j.hrthm.2024.01.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 01/29/2024]
Abstract
Atrial fibrillation (AF) is a common clinical malignant arrhythmia with an increasing global incidence. Ion channel dysfunction is an important mechanism in the development of AF. In this study, we used bibliometrics to analyze the studies of ion channels and AF, aiming to provide inspiration and reference for researchers. A total of 3179 literature citations were obtained from Web of Science core databases. Analysis software included Excel 2019, VOSviewer 1.6.16, and CiteSpace 5.7.R2. This field of research has been growing since 1985. The most active country is the United States. The University of Montreal is the most important research institution. The journal Cardiovascular Research has published the largest number of articles in this field. Stanley Nattel and Dobromir Dobrev are the most frequently cited authors. The most cited literature was published in Nature and Science. Cardiac electrophysiology, gene expression, pathogenesis of AF, and AF prevention and treatment are the hot topics for this field research. Cardiac fibrillation and catheter ablation may be future research hotspots in this field.
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Affiliation(s)
- Xueping Zhu
- Guang 'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Meng Lv
- Guang 'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Tao Cheng
- Graduate School of Beijing University of Chinese Medicine, Beijing, China
| | - Yan Zhou
- Graduate School of Beijing University of Chinese Medicine, Beijing, China
| | - Guozhen Yuan
- Guang 'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yuguang Chu
- Guang 'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yujie Luan
- Graduate School of Beijing University of Chinese Medicine, Beijing, China
| | - Qingqiao Song
- Guang 'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
| | - Yuanhui Hu
- Guang 'anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, China.
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Burashnikov A, Di Diego JM, Patocskai B, Echt DS, Belardinelli L, Antzelevitch C. Effect of Flecainide and Ibutilide Alone and in Combination to Terminate and Prevent Recurrence of Atrial Fibrillation. Circ Arrhythm Electrophysiol 2024; 17:e012454. [PMID: 38146652 DOI: 10.1161/circep.123.012454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 11/30/2023] [Indexed: 12/27/2023]
Abstract
BACKGROUND There is a need for improved approaches to rhythm control therapy of atrial fibrillation (AF). METHODS The effectiveness of flecainide (1.5 µmol/L) and ibutilide (20 nmol/L), alone and in combination, to cardiovert and prevent AF recurrence was studied in canine-isolated coronary-perfused right atrioventricular preparations. We also examined the safety of the combination of flecainide (1.5 µmol/L) and ibutilide (50 nmol/L) using canine left ventricular wedge preparations. RESULTS Sustained AF (>1 hour) was inducible in 100%, 60%, 20%, and 0% of atria in the presence of acetylcholine alone, acetylcholine+ibutilide, acetylcholine+flecainide, and acetylcholine+ibutilide+flecainide, respectively. When used alone, flecainide and ibutilide cardioverted sustained AF in 40% and 20% of atria, respectively, but in 100% of atria when used in combination. Ibutilide prolonged atrial and ventricular effective refractory period by 15% and 8%, respectively, at a cycle length of 500 ms (P<0.05 for both). Flecainide increased the effective refractory period in atria by 27% (P<0.01) but by only 2% in the ventricles. The combination of the 2 drugs lengthened the effective refractory period by 42% in atria (P<0.01) but by only 7% (P<0.05) in the ventricles. In left ventricular wedges, ibutilide prolonged QT and Tpeak-Tend intervals by 25 and 55%, respectively (P<0.05 for both; cycle length, 2000 ms). The addition of flecainide (1.5 µmol/L) partially reversed these effects (P<0.05 for both parameters versus ibutilide alone). Torsades de Pointes score was relatively high with ibutilide alone and low with the drug combination. CONCLUSIONS In our experimental model, a combination of flecainide and ibutilide significantly improves cardioversion and prevents the recurrence of AF compared with monotherapies with little to no risk for the development of long-QT-mediated ventricular proarrhythmia.
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Affiliation(s)
- Alexander Burashnikov
- Lankenau Institute for Medical Research, Wynnewood, PA (A.B., J.M.D.D., B.P., C.A.)
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA (A.B., C.A.)
| | - José M Di Diego
- Lankenau Institute for Medical Research, Wynnewood, PA (A.B., J.M.D.D., B.P., C.A.)
| | - Bence Patocskai
- Lankenau Institute for Medical Research, Wynnewood, PA (A.B., J.M.D.D., B.P., C.A.)
| | - Debra S Echt
- InCarda Therapeutics, Inc, Newark, CA (D.S.E., L.B.)
| | | | - Charles Antzelevitch
- Lankenau Institute for Medical Research, Wynnewood, PA (A.B., J.M.D.D., B.P., C.A.)
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA (A.B., C.A.)
- Lankenau Heart Institute, Main Line Health System, Wynnewood, PA (C.A.)
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Li W, Wu CX, Hou JW, Sun J, Wang QS, Zhang PP, Yu Y, Yang M, Chen M, Mo BF, Wang YP, Li YG. Higher Sodium Channel Excitability in Cardiac Purkinje Fibers: Implications for Multifocal Ectopic Purkinje-Related Premature Contractions. JACC Clin Electrophysiol 2023; 9:2477-2490. [PMID: 37831033 DOI: 10.1016/j.jacep.2023.08.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2023] [Revised: 07/24/2023] [Accepted: 08/22/2023] [Indexed: 10/14/2023]
Abstract
BACKGROUND Multifocal ectopic Purkinje-related premature contractions (MEPPCs) are associated with SCN5A variants. However, it is not well understood why Purkinje fibers, but not ventricular myocardium, play a predominant role in arrhythmogenesis. OBJECTIVES This study sought to explore the underlying mechanisms of MEPPC. METHODS Whole-cell patch-clamp and molecular biology techniques were used in the present study. RESULTS Clinical data from one patient with R814W variant showed MEPPC syndrome, which is well responsive to amiodarone. Compared with canine ventricular myocytes, Purkinje cells (PCs) had significantly larger sodium current (INa), leftward shift of INa activation and inactivation curves, suggesting higher sodium channel excitability in PCs. Real-time polymerase chain reaction and Western blot analysis showed that the mRNA and protein expression of NaVβ1 and NaVβ3 was higher in canine Purkinje fibers than in ventricular myocardium. INa in heterologous Chinese hamster ovary cell expression system co-expressing NaV1.5 and NaVβ1/NaVβ3 exhibited similar biophysical properties of INa in PCs. R814W variant shifted INa activation in a hyperdepolarized direction, caused a larger window current, and generated an outward-gating pore current at depolarized voltages. Coexpression of NaVβ1/NaVβ3 with Nav1.5-R814W further left-shifted INa activation and caused an even larger window current and gating pore current, suggesting higher susceptibility of Purkinje fibers to R814W variant. Amiodarone inhibited INa, shifted its inactivation to more negative voltages, and significantly decreased the window current. CONCLUSIONS A higher expression of β1 and β3 subunits contributes to higher sodium channel excitability in cardiac Purkinje fibers, making them more susceptible to MEPPC.
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Affiliation(s)
- Wei Li
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Chun-Xuan Wu
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian-Wen Hou
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian Sun
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qun-Shan Wang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Peng-Pai Zhang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi Yu
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mei Yang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Mu Chen
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bin-Feng Mo
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yue-Peng Wang
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yi-Gang Li
- Department of Cardiology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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7
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Chapotte-Baldacci CA, Pierre M, Djemai M, Pouliot V, Chahine M. Biophysical properties of Na V1.5 channels from atrial-like and ventricular-like cardiomyocytes derived from human induced pluripotent stem cells. Sci Rep 2023; 13:20685. [PMID: 38001331 PMCID: PMC10673932 DOI: 10.1038/s41598-023-47310-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 11/12/2023] [Indexed: 11/26/2023] Open
Abstract
Generating atrial-like cardiomyocytes derived from human induced pluripotent stem cells (hiPSCs) is crucial for modeling and treating atrial-related diseases, such as atrial arrythmias including atrial fibrillations. However, it is essential to obtain a comprehensive understanding of the electrophysiological properties of these cells. The objective of the present study was to investigate the molecular, electrical, and biophysical properties of several ion channels, especially NaV1.5 channels, in atrial hiPSC cardiomyocytes. Atrial cardiomyocytes were obtained by the differentiation of hiPSCs treated with retinoic acid (RA). The quality of the atrial specification was assessed by qPCR, immunocytofluorescence, and western blotting. The electrophysiological properties of action potentials (APs), Ca2+ dynamics, K+ and Na+ currents were investigated using patch-clamp and optical mapping approaches. We evaluated mRNA transcript and protein expressions to show that atrial cardiomyocytes expressed higher atrial- and sinoatrial-specific markers (MYL7, CACNA1D) and lower ventricular-specific markers (MYL2, CACNA1C, GJA1) than ventricular cardiomyocytes. The amplitude, duration, and steady-state phase of APs in atrial cardiomyocytes decreased, and had a shape similar to that of mature atrial cardiomyocytes. Interestingly, NaV1.5 channels in atrial cardiomyocytes exhibited lower mRNA transcripts and protein expression, which could explain the lower current densities recorded by patch-clamp. Moreover, Na+ currents exhibited differences in activation and inactivation parameters. These differences could be explained by an increase in SCN2B regulatory subunit expression and a decrease in SCN1B and SCN4B regulatory subunit expressions. Our results show that a RA treatment made it possible to obtain atrial cardiomyocytes and investigate differences in NaV1.5 channel properties between ventricular- and atrial-like cells.
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Affiliation(s)
- Charles-Albert Chapotte-Baldacci
- Department of Medicine, Laval University, Quebec City, QC, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - Marion Pierre
- Department of Medicine, Laval University, Quebec City, QC, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - Mohammed Djemai
- Department of Medicine, Laval University, Quebec City, QC, Canada
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - Valérie Pouliot
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada
| | - Mohamed Chahine
- CERVO Brain Research Centre, 2601, chemin de la Canardière, Quebec City, QC, G1J 2G3, Canada.
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8
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Burashnikov A, Antzelevitch C. Mild elevation of extracellular potassium greatly potentiates the effect of sodium channel block to cardiovert atrial fibrillation: The Lankenau approach. Heart Rhythm 2023; 20:1257-1264. [PMID: 37169158 DOI: 10.1016/j.hrthm.2023.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 05/03/2023] [Accepted: 05/03/2023] [Indexed: 05/13/2023]
Abstract
BACKGROUND Cardioversion of atrial fibrillation (AF) is a common clinical necessity, and there is a need for more effective and safe options for acute cardioversion of AF. OBJECTIVE The purpose of this study was to test the hypothesis that the efficacy and time course of AF cardioversion by sodium channel current (INa) block can be improved by mild elevation of extracellular potassium ([K+]0). METHODS Using a canine acetylcholine (ACh)-mediated AF model (isolated coronary-perfused right atrial preparations with a rim of right ventricle), we evaluated the ability of flecainide to suppress AF in the presence of [K+]0 ranging from 3 to 8 mM. RESULTS At [K+]0 of 4 mM (baseline), persistent AF (>1 hour) was induced in 5 of 5 atria in the presence of 0.5 μM ACh. Flecainide alone (1.5 μM) cardioverted 3 of 6 atria at 4 mM [K+]0, 1 of 6 atria at 3 mM [K+]0, 5 of 5 atria at 5 mM and 6 mM [K+]0, and 4 of 4 atria at 8 mM [K+]0. In the absence of flecainide, an increase in [K+]0 from 4 mM to 5, 6, and 8 mM terminated AF in 0 of 5, 2 of 6, and 4 of 4 atria, respectively. The time to conversion was also abbreviated by elevation of [K+]0. After AF termination with flecainide plus elevated [K+]0, AF was either not inducible or brief (<100 seconds). Combined flecainide and elevated [K+]0 (6 mM) caused an atrial preferential depression of excitability. CONCLUSION Our findings suggest that a combination of INa block accompanied by mild elevation of serum potassium may be a novel approach to more effectively, rapidly, and safely cardiovert AF and prevent its recurrence in the short term.
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Affiliation(s)
- Alexander Burashnikov
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania; Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania.
| | - Charles Antzelevitch
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania; Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania; Lankenau Heart Institute, Main Line Health System, Wynnewood, Pennsylvania
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9
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Hu D, Barajas-Martinez H, Zhang ZH, Duan HY, Zhao QY, Bao MW, Du YM, Burashnikov A, Monasky MM, Pappone C, Huang CX, Antzelevitch C, Jiang H. Advances in basic and translational research in atrial fibrillation. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220174. [PMID: 37122214 PMCID: PMC10150218 DOI: 10.1098/rstb.2022.0174] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/08/2023] [Indexed: 05/02/2023] Open
Abstract
Atrial fibrillation (AF) is a very common cardiac arrhythmia with an estimated prevalence of 33.5 million patients globally. It is associated with an increased risk of death, stroke and peripheral embolism. Although genetic studies have identified a growing number of genes associated with AF, the definitive impact of these genetic findings is yet to be established. Several mechanisms, including electrical, structural and neural remodelling of atrial tissue, have been proposed to contribute to the development of AF. Despite over a century of exploration, the molecular and cellular mechanisms underlying AF have not been fully established. Current antiarrhythmic drugs are associated with a significant rate of adverse events and management of AF using ablation is not optimal, especially in cases of persistent AF. This review discusses recent advances in our understanding and management of AF, including new concepts of epidemiology, genetics and pathophysiological mechanisms. We review the current status of antiarrhythmic drug therapy for AF, new potential agents, as well as mechanism-based AF ablation. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Affiliation(s)
- Dan Hu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, People's Republic of China
- Cardiovascular Research Institute of Wuhan University, Wuhan 430060, People's Republic of China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, People's Republic of China
| | - Hector Barajas-Martinez
- Lankenau Institute for Medical Research, and Lankenau Heart Institute, Wynnwood, PA 19096, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19104, USA
| | - Zhong-He Zhang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, People's Republic of China
- Cardiovascular Research Institute of Wuhan University, Wuhan 430060, People's Republic of China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, People's Republic of China
| | - Hong-Yi Duan
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, People's Republic of China
- Cardiovascular Research Institute of Wuhan University, Wuhan 430060, People's Republic of China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, People's Republic of China
| | - Qing-Yan Zhao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, People's Republic of China
- Cardiovascular Research Institute of Wuhan University, Wuhan 430060, People's Republic of China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, People's Republic of China
| | - Ming-Wei Bao
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, People's Republic of China
- Cardiovascular Research Institute of Wuhan University, Wuhan 430060, People's Republic of China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, People's Republic of China
| | - Yi-Mei Du
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China
| | - Alexander Burashnikov
- Lankenau Institute for Medical Research, and Lankenau Heart Institute, Wynnwood, PA 19096, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19104, USA
| | - Michelle M. Monasky
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan 20097, Italy
| | - Carlo Pappone
- Arrhythmology Department, IRCCS Policlinico San Donato, San Donato Milanese, Milan 20097, Italy
- Vita-Salute San Raffaele University, Milan 20132, Italy
- Institute of Molecular and Translational Cardiology (IMTC), San Donato Milanese, Milan 20097, Italy
| | - Cong-Xin Huang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, People's Republic of China
- Cardiovascular Research Institute of Wuhan University, Wuhan 430060, People's Republic of China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, People's Republic of China
| | - Charles Antzelevitch
- Lankenau Institute for Medical Research, and Lankenau Heart Institute, Wynnwood, PA 19096, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19104, USA
| | - Hong Jiang
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, People's Republic of China
- Cardiovascular Research Institute of Wuhan University, Wuhan 430060, People's Republic of China
- Hubei Key Laboratory of Cardiology, Wuhan 430060, People's Republic of China
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10
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Resting membrane potential is less negative in trabeculae from right atrial appendages of women, but action potential duration does not shorten with age. J Mol Cell Cardiol 2023; 176:1-10. [PMID: 36681268 DOI: 10.1016/j.yjmcc.2023.01.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 01/11/2023] [Accepted: 01/14/2023] [Indexed: 01/19/2023]
Abstract
AIMS The incidence of atrial fibrillation (AF) increases with age. Women have a lower risk. Little is known on the impact of age, sex and clinical variables on action potentials (AP) recorded in right atrial tissue obtained during open heart surgery from patients in sinus rhythm (SR) and in longstanding AF. We here investigated whether age or sex have an impact on the shape of AP recorded in vitro from right atrial tissue. METHODS We performed multivariable analysis of individual AP data from trabeculae obtained during heart surgery of patients in SR (n = 320) or in longstanding AF (n = 201). AP were recorded by sharp microelectrodes at 37 °C at 1 Hz. Impact of clinical variables were modeled using a multivariable mixed model regression. RESULTS In SR, AP duration at 90% repolarization (APD90) increased with age. Lower ejection fraction and higher body mass index were associated with smaller action potential amplitude (APA) and maximum upstroke velocity (Vmax). The use of beta-blockers was associated with larger APD90. In tissues from women, resting membrane potential was less negative and APA as well as Vmax were smaller. Besides shorter APD20 in elderly patients, effects of age and sex on atrial AP were lost in AF. CONCLUSION The higher probability to develop AF at advanced age cannot be explained by a shortening in APD90. Less negative RMP and lower upstroke velocity might contribute to lower incidence of AF in women, which may be of clinical relevance.
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11
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Teixeira-Fonseca JL, de Lima Conceição MR, Leal-Silva P, Roman-Campos D. Ranolazine exerts atrial antiarrhythmic effects in a rat model of monocrotaline-induced pulmonary hypertension. Basic Clin Pharmacol Toxicol 2023; 132:359-368. [PMID: 36799082 DOI: 10.1111/bcpt.13845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023]
Abstract
Atrial arrhythmias are a hallmark of heart diseases. The antiarrhythmic drug ranolazine with multichannel blocker properties is a promising agent to treat atrial arrhythmias. We therefore used the rat model of monocrotaline-induced pulmonary-hypertension to assess whether ranolazine can reduce the incidence of ex vivo atrial arrhythmias in isolated right atrium. Four-week-old Wistar rats were injected with 50 mg/kg of monocrotaline, and isolated right atrium function was studied 14 days later. The heart developed right atrium and right ventricular hypertrophy, and the ECG showed an increased P wave duration and QT interval, which are markers of the disease. Moreover, monocrotaline injection caused enhanced chronotropism and faster kinetics of contraction and relaxation in isolated right atrium. Additionally, in a concentration-dependent manner, ranolazine showed chronotropic and ionotropic effects upon isolated right atrium, with higher potency in the control when compared with experimental model. Using a burst pacing protocol, the isolated right atrium from the monocrotaline-treated animals was more susceptible to develop arrhythmias, and ranolazine was able to attenuate the phenotype. Thus, we concluded that the rat model of monocrotaline-induced pulmonary-hypertension develops right atrium remodelling, which increased the susceptibility to present ex vivo atrial arrhythmias, and the antiarrhythmic drug ranolazine ameliorated the phenotype.
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Affiliation(s)
- Jorge Lucas Teixeira-Fonseca
- Laboratory of Cardiobiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Michael Ramon de Lima Conceição
- Laboratory of Cardiobiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Polyana Leal-Silva
- Laboratory of Cardiobiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo, Sao Paulo, Brazil
| | - Danilo Roman-Campos
- Laboratory of Cardiobiology, Department of Biophysics, Paulista School of Medicine, Federal University of Sao Paulo, Sao Paulo, Brazil
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12
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Soltani D, Azizi B, Rahimi R, Talasaz AH, Rezaeizadeh H, Vasheghani-Farahani A. Mechanism-based targeting of cardiac arrhythmias by phytochemicals and medicinal herbs: A comprehensive review of preclinical and clinical evidence. Front Cardiovasc Med 2022; 9:990063. [PMID: 36247473 PMCID: PMC9559844 DOI: 10.3389/fcvm.2022.990063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2022] [Accepted: 09/14/2022] [Indexed: 11/13/2022] Open
Abstract
Cardiac arrhythmias, characterized by an irregular heartbeat, are associated with high mortality and morbidity. Because of the narrow therapeutic window of antiarrhythmic drugs (AADs), the management of arrhythmia is still challenging. Therefore, searching for new safe, and effective therapeutic options is unavoidable. In this study, the antiarrhythmic effects of medicinal plants and their active constituents were systematically reviewed to introduce some possible candidates for mechanism-based targeting of cardiac arrhythmias. PubMed, Embase, and Cochrane library were searched from inception to June 2021 to find the plant extracts, phytochemicals, and multi-component herbal preparations with antiarrhythmic activities. From 7337 identified results, 57 original studies consisting of 49 preclinical and eight clinical studies were finally included. Three plant extracts, eight multi-component herbal preparations, and 26 phytochemicals were found to have antiarrhythmic effects mostly mediated by affecting K+ channels, followed by modulating Ca2+ channels, upstream target pathways, Nav channels, gap junction channels, and autonomic receptors. The most investigated medicinal plants were Rhodiola crenulata and Vitis vinifera. Resveratrol, Oxymatrine, and Curcumin were the most studied phytochemicals found to have multiple mechanisms of antiarrhythmic action. This review emphasized the importance of research on the cardioprotective effect of medicinal plants and their bioactive compounds to guide the future development of new AADs. The most prevalent limitation of the studies was their unqualified methodology. Thus, future well-designed experimental and clinical studies are necessary to provide more reliable evidence.
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Affiliation(s)
- Danesh Soltani
- Cardiac Primary Prevention Research Center (CPPRC), Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
- Tehran Heart Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Bayan Azizi
- Cardiac Primary Prevention Research Center (CPPRC), Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
- Tehran Heart Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Roja Rahimi
- Department of Traditional Pharmacy, School of Persian Medicine, Tehran University of Medical Sciences, Tehran, Iran
- Evidence-Based Evaluation of Cost-Effectiveness and Clinical Outcomes, The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran
- *Correspondence: Roja Rahimi,
| | - Azita H. Talasaz
- Tehran Heart Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA, United States
| | - Hossein Rezaeizadeh
- Department of Persian Medicine, School of Traditional Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Vasheghani-Farahani
- Cardiac Primary Prevention Research Center (CPPRC), Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
- Tehran Heart Center, Cardiovascular Diseases Research Institute, Tehran University of Medical Sciences, Tehran, Iran
- Ali Vasheghani-Farahani,
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13
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Abramochkin DV, Filatova TS, Pustovit KB, Voronina YA, Kuzmin VS, Vornanen M. Ionic currents underlying different patterns of electrical activity in working cardiac myocytes of mammals and non-mammalian vertebrates. Comp Biochem Physiol A Mol Integr Physiol 2022; 268:111204. [PMID: 35346823 DOI: 10.1016/j.cbpa.2022.111204] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 03/21/2022] [Accepted: 03/22/2022] [Indexed: 12/19/2022]
Abstract
The orderly contraction of the vertebrate heart is determined by generation and propagation of cardiac action potentials (APs). APs are generated by the integrated activity of time- and voltage-dependent ionic channels which carry inward Na+ and Ca2+ currents, and outward K+ currents. This review compares atrial and ventricular APs and underlying ion currents between different taxa of vertebrates. We have collected literature data and attempted to find common electrophysiological features for two or more vertebrate groups, show differences between taxa and cardiac chambers, and indicate gaps in the existing data. Although electrical excitability of the heart in all vertebrates is based on the same superfamily of channels, there is a vast variability of AP waveforms between atrial and ventricular myocytes, between different species of the same vertebrate class and between endothermic and ectothermic animals. The wide variability of AP shapes is related to species-specific differences in animal size, heart rate, stage of ontogenetic development, excitation-contraction coupling, temperature and oxygen availability. Some of the differences between taxa are related to evolutionary development of genomes, which appear e.g. in the expression of different Na+ and K+ channel orthologues in cardiomyocytes of vertebrates. There is a wonderful variability of AP shapes and underlying ion currents with which electrical excitability of vertebrate heart can be generated depending on the intrinsic and extrinsic conditions of animal body. This multitude of ionic mechanisms provides excellent material for studying how the function of the vertebrate heart can adapt or acclimate to prevailing physiological and environmental conditions.
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Affiliation(s)
- Denis V Abramochkin
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia.
| | - Tatiana S Filatova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
| | - Ksenia B Pustovit
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
| | - Yana A Voronina
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia; Laboratory of Cardiac Electrophysiology, National Medical Research Center for Cardiology, 3(rd) Cherepkovskaya str., 15A, Moscow, Russia
| | - Vladislav S Kuzmin
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia; Department of Physiology, Pirogov Russian National Research Medical University, Ostrovityanova str., 1, Moscow, Russia
| | - Matti Vornanen
- Department of Environmental and Biological Sciences, University of Eastern Finland, Joensuu, Finland
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14
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O' Brien S, Holmes AP, Johnson DM, Kabir SN, O' Shea C, O' Reilly M, Avezzu A, Reyat JS, Hall AW, Apicella C, Ellinor PT, Niederer S, Tucker NR, Fabritz L, Kirchhof P, Pavlovic D. Increased atrial effectiveness of flecainide conferred by altered biophysical properties of sodium channels. J Mol Cell Cardiol 2022; 166:23-35. [PMID: 35114252 DOI: 10.1016/j.yjmcc.2022.01.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/13/2022] [Accepted: 01/26/2022] [Indexed: 11/25/2022]
Abstract
Atrial fibrillation (AF) affects over 1% of the population and is a leading cause of stroke and heart failure in the elderly. A feared side effect of sodium channel blocker therapy, ventricular pro-arrhythmia, appears to be relatively rare in patients with AF. The biophysical reasons for this relative safety of sodium blockers are not known. Our data demonstrates intrinsic differences between atrial and ventricular cardiac voltage-gated sodium currents (INa), leading to reduced maximum upstroke velocity of action potential and slower conduction, in left atria compared to ventricle. Reduced atrial INa is only detected at physiological membrane potentials and is driven by alterations in sodium channel biophysical properties and not by NaV1.5 protein expression. Flecainide displayed greater inhibition of atrial INa, greater reduction of maximum upstroke velocity of action potential, and slowed conduction in atrial cells and tissue. Our work highlights differences in biophysical properties of sodium channels in left atria and ventricles and their response to flecainide. These differences can explain the relative safety of sodium channel blocker therapy in patients with atrial fibrillation.
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Affiliation(s)
- Sian O' Brien
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Andrew P Holmes
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; School of Biomedical Sciences, Institute of Clinical Sciences, University of Birmingham, Birmingham, UK
| | - Daniel M Johnson
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; School of Life, Health and Chemical Sciences, The Open University, Walton Hall, Milton Keynes, UK
| | - S Nashitha Kabir
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Christopher O' Shea
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Molly O' Reilly
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Adelisa Avezzu
- School of Biomedical Engineering & Imaging Sciences, Kings' College London, London, UK
| | - Jasmeet S Reyat
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Amelia W Hall
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Clara Apicella
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK
| | - Patrick T Ellinor
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Steven Niederer
- School of Biomedical Engineering & Imaging Sciences, Kings' College London, London, UK
| | - Nathan R Tucker
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA 02129, USA; Cardiovascular Disease Initiative, The Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Larissa Fabritz
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; University Center of Cardiovascular Science, University Heart and Vascular Center UKE, Hamburg, Germany; Department of Cardiology, University Heart and Vascular Center UKE, Hamburg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Paulus Kirchhof
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK; Department of Cardiology, University Heart and Vascular Center UKE, Hamburg, Germany; German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck, Germany
| | - Davor Pavlovic
- Institute of Cardiovascular Science, University of Birmingham, Birmingham, UK.
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15
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Pioner JM, Vitale G, Gentile F, Scellini B, Piroddi N, Cerbai E, Olivotto I, Tardiff J, Coppini R, Tesi C, Poggesi C, Ferrantini C. Genotype-Driven Pathogenesis of Atrial Fibrillation in Hypertrophic Cardiomyopathy: The Case of Different TNNT2 Mutations. Front Physiol 2022; 13:864547. [PMID: 35514357 PMCID: PMC9062294 DOI: 10.3389/fphys.2022.864547] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/28/2022] [Indexed: 11/25/2022] Open
Abstract
Atrial dilation and atrial fibrillation (AF) are common in Hypertrophic CardioMyopathy (HCM) patients and associated with a worsening of prognosis. The pathogenesis of atrial myopathy in HCM remains poorly investigated and no specific association with genotype has been identified. By re-analysis of our cohort of thin-filament HCM patients (Coppini et al. 2014) AF was identified in 10% of patients with sporadic mutations in the cardiac Troponin T gene (TNNT2), while AF occurrence was much higher (25-75%) in patients carrying specific "hot-spot" TNNT2 mutations. To determine the molecular basis of arrhythmia occurrence, two HCM mouse models expressing human TNNT2 variants (a "hot-spot" one, R92Q, and a "sporadic" one, E163R) were selected according to the different pathophysiological pathways previously demonstrated in ventricular tissue. Echocardiography studies showed a significant left atrial dilation in both models, but more pronounced in the R92Q. In E163R atrial trabeculae, in line with what previously observed in ventricular preparations, the energy cost of tension generation was markedly increased. However, no changes of twitch amplitude and kinetics were observed, and there was no atrial arrhythmic propensity. R92Q atrial trabeculae, instead, displayed normal ATP consumption but markedly increased myofilament calcium sensitivity, as previously observed in ventricular preparations. This was associated with reduced inotropic reserve and slower kinetics of twitch contractions and, importantly, with an increased occurrence of spontaneous beats and triggered contractions that represent an intrinsic arrhythmogenic mechanism promoting AF. The association of specific TNNT2 mutations with AF occurrence depends on the mutation-driven pathomechanism (i.e., increased atrial myofilament calcium sensitivity rather than increased myofilament tension cost) and may influence the individual response to treatment.
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Affiliation(s)
| | - Giulia Vitale
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Francesca Gentile
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Beatrice Scellini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Nicoletta Piroddi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | | | - Iacopo Olivotto
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Jil Tardiff
- Department of Medicine and Biomedical Engineering, University of Arizona, Tucson, AZ, United States
| | | | - Chiara Tesi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Corrado Poggesi
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
| | - Cecilia Ferrantini
- Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy
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16
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Cowan LM, Strege PR, Rusinova R, Andersen OS, Farrugia G, Beyder A. Capsaicin as an amphipathic modulator of Na V1.5 mechanosensitivity. Channels (Austin) 2022; 16:9-26. [PMID: 35412435 PMCID: PMC9009938 DOI: 10.1080/19336950.2022.2026015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
SCN5A-encoded NaV1.5 is a voltage-gated Na+ channel that drives the electrical excitability of cardiac myocytes and contributes to slow waves of the human gastrointestinal smooth muscle cells. NaV1.5 is mechanosensitive: mechanical force modulates several facets of NaV1.5’s voltage-gated function, and some NaV1.5 channelopathies are associated with abnormal NaV1.5 mechanosensitivity (MS). A class of membrane-active drugs, known as amphiphiles, therapeutically target NaV1.5’s voltage-gated function and produce off-target effects including alteration of MS. Amphiphiles may provide a novel option for therapeutic modulation of NaV1.5’s mechanosensitive operation. To more selectively target NaV1.5 MS, we searched for a membrane-partitioning amphipathic agent that would inhibit MS with minimal closed-state inhibition of voltage-gated currents. Among the amphiphiles tested, we selected capsaicin for further study. We used two methods to assess the effects of capsaicin on NaV1.5 MS: (1) membrane suction in cell-attached macroscopic patches and (2) fluid shear stress on whole cells. We tested the effect of capsaicin on NaV1.5 MS by examining macro-patch and whole-cell Na+ current parameters with and without force. Capsaicin abolished the pressure- and shear-mediated peak current increase and acceleration; and the mechanosensitive shifts in the voltage-dependence of activation (shear) and inactivation (pressure and shear). Exploring the recovery from inactivation and use-dependent entry into inactivation, we found divergent stimulus-dependent effects that could potentiate or mitigate the effect of capsaicin, suggesting that mechanical stimuli may differentially modulate NaV1.5 MS. We conclude that selective modulation of NaV1.5 MS makes capsaicin a promising candidate for therapeutic interventions targeting MS.
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Affiliation(s)
- Luke M Cowan
- Division of Gastroenterology and Hepatology, Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, MN, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Mn, USA
| | - Peter R Strege
- Division of Gastroenterology and Hepatology, Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, MN, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Mn, USA
| | - Radda Rusinova
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY, USA
| | - Olaf S Andersen
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY, USA
| | - Gianrico Farrugia
- Division of Gastroenterology and Hepatology, Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, MN, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Mn, USA
| | - Arthur Beyder
- Division of Gastroenterology and Hepatology, Enteric Neuroscience Program (ENSP), Mayo Clinic, Rochester, MN, USA.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Mn, USA
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17
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Acacetin as a Potential Protective Compound against Cardiovascular Diseases. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2022; 2022:6265198. [PMID: 35280514 PMCID: PMC8906942 DOI: 10.1155/2022/6265198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Accepted: 02/08/2022] [Indexed: 12/19/2022]
Abstract
Acacetin (5,7-dihydroxy-4′-methoxyflavone) is the major bioactive component of the traditional Chinese medicine “Snow lotus”. As a natural flavonoid compound, it has been shown to have good pharmacological effects such as anti-inflammatory, anticancer, and anti-obesity. Among them, its prominent role in cardiovascular diseases (CVD) has received extensive attention from scholars in recent years. In this review, the protective effects of acacetin on a variety of cardiovascular diseases, as well as the existing problems and prospects, are discussed and summarized. This review also highlights the great potential of acacetin, a natural-derived Chinese medicine, as a cardiovascular agent candidate.
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18
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Ranolazine: An Old Drug with Emerging Potential; Lessons from Pre-Clinical and Clinical Investigations for Possible Repositioning. Pharmaceuticals (Basel) 2021; 15:ph15010031. [PMID: 35056088 PMCID: PMC8777683 DOI: 10.3390/ph15010031] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 02/07/2023] Open
Abstract
Ischemic heart disease is a significant public health problem with high mortality and morbidity. Extensive scientific investigations from basic sciences to clinics revealed multilevel alterations from metabolic imbalance, altered electrophysiology, and defective Ca2+/Na+ homeostasis leading to lethal arrhythmias. Despite the recent identification of numerous molecular targets with potential therapeutic interest, a pragmatic observation on the current pharmacological R&D output confirms the lack of new therapeutic offers to patients. By contrast, from recent trials, molecules initially developed for other fields of application have shown cardiovascular benefits, as illustrated with some anti-diabetic agents, regardless of the presence or absence of diabetes, emphasizing the clear advantage of “old” drug repositioning. Ranolazine is approved as an antianginal agent and has a favorable overall safety profile. This drug, developed initially as a metabolic modulator, was also identified as an inhibitor of the cardiac late Na+ current, although it also blocks other ionic currents, including the hERG/Ikr K+ current. The latter actions have been involved in this drug’s antiarrhythmic effects, both on supraventricular and ventricular arrhythmias (VA). However, despite initial enthusiasm and promising development in the cardiovascular field, ranolazine is only authorized as a second-line treatment in patients with chronic angina pectoris, notwithstanding its antiarrhythmic properties. A plausible reason for this is the apparent difficulty in linking the clinical benefits to the multiple molecular actions of this drug. Here, we review ranolazine’s experimental and clinical knowledge on cardiac metabolism and arrhythmias. We also highlight advances in understanding novel effects on neurons, the vascular system, skeletal muscles, blood sugar control, and cancer, which may open the way to reposition this “old” drug alone or in combination with other medications.
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19
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Kaplan AD, Joca HC, Boyman L, Greiser M. Calcium Signaling Silencing in Atrial Fibrillation: Implications for Atrial Sodium Homeostasis. Int J Mol Sci 2021; 22:10513. [PMID: 34638854 PMCID: PMC8508839 DOI: 10.3390/ijms221910513] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 12/19/2022] Open
Abstract
Atrial fibrillation (AF) is the most common type of cardiac arrhythmia, affecting more than 33 million people worldwide. Despite important advances in therapy, AF's incidence remains high, and treatment often results in recurrence of the arrhythmia. A better understanding of the cellular and molecular changes that (1) trigger AF and (2) occur after the onset of AF will help to identify novel therapeutic targets. Over the past 20 years, a large body of research has shown that intracellular Ca2+ handling is dramatically altered in AF. While some of these changes are arrhythmogenic, other changes counteract cellular arrhythmogenic mechanisms (Calcium Signaling Silencing). The intracellular Na+ concentration ([Na+])i is a key regulator of intracellular Ca2+ handling in cardiac myocytes. Despite its importance in the regulation of intracellular Ca2+ handling, little is known about [Na+]i, its regulation, and how it might be changed in AF. Previous work suggests that there might be increases in the late component of the atrial Na+ current (INa,L) in AF, suggesting that [Na+]i levels might be high in AF. Indeed, a pharmacological blockade of INa,L has been suggested as a treatment for AF. Here, we review calcium signaling silencing and changes in intracellular Na+ homeostasis during AF. We summarize the proposed arrhythmogenic mechanisms associated with increases in INa,L during AF and discuss the evidence from clinical trials that have tested the pharmacological INa,L blocker ranolazine in the treatment of AF.
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Affiliation(s)
- Aaron D. Kaplan
- Center for Biomedical Engineering and Technology, Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.D.K.); (H.C.J.); (L.B.)
- Division of Cardiovascular Medicine, Department of Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Humberto C. Joca
- Center for Biomedical Engineering and Technology, Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.D.K.); (H.C.J.); (L.B.)
| | - Liron Boyman
- Center for Biomedical Engineering and Technology, Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.D.K.); (H.C.J.); (L.B.)
| | - Maura Greiser
- Center for Biomedical Engineering and Technology, Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; (A.D.K.); (H.C.J.); (L.B.)
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20
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Tsikala K, Sudunagunta S, Paňero MM, Bode EF. ECG of the Month. J Am Vet Med Assoc 2021; 259:605-608. [PMID: 34448606 DOI: 10.2460/javma.259.6.605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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21
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Liu X, Duan X, Fan H, Wang H, Jiang X, Fang Y, Tang Q, Xiao J, Li Q. 8-hydroxypinoresinol-4-O-β-D-glucoside from Valeriana officinalis L. Is a Novel Kv1.5 Channel Blocker. JOURNAL OF ETHNOPHARMACOLOGY 2021; 276:114168. [PMID: 33932511 DOI: 10.1016/j.jep.2021.114168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 04/23/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
ETHNOPHARMACOLOGY RELEVANCE In folkloric medicine of many cultures, one of the medical uses of Valeriana officinalis Linn is to treat heart-related disease. Recently, it was shown that the ethanol extracts from V. officinalis could effectively prevent auricular fibrillation, and 8-hydroxypinoresinol-4-O-β-D-glucoside (HPG) from the extracts is one of the two active compounds showing antiarrhythmia activities. AIM OF THE STUDY The human Kv1.5 channel (hKv1.5) has potential antiarrhythmia activities, and this study arms at investigating the current blocking effects of HPG on hKv1.5 channel. MATERIAL AND METHODS HPG was obtained from V. officinalis extracts, and hKv1.5 channels were expressed in HEK 293 cells. HPG was perfused while recording the current through hKv1.5 channels. Patch-clamp recording techniques were used to study the effects of HPG at various concentrations (10 μM, 30 μM, and 50 μM) on hKv1.5 channels. RESULTS The present study demonstrated that HPG inhibited hKv1.5 channel current in a concentration-dependent manner; the higher the concentration, the greater is the inhibition at each depolarization potential. During washout, the channels did not full recover indicating that the un-coupling between HPG and hKv1.5 channels is a slow process. CONCLUSION HPG may be an effective and safe active ingredient for AF having translational potential.
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Affiliation(s)
- Xingxing Liu
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Liberty Rd., Wuhan, Hubei, 430022, China
| | - Xueyun Duan
- Pharmaceutical Department, Hubei Provincial Hospital of Traditional Chinese Medicine, Wuhan, 430061, Hubei Province, China
| | - Heng Fan
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Liberty Rd., Wuhan, Hubei, 430022, China
| | - Hongfei Wang
- Department of Cardiac Surgery, Department of Integrated Traditional Chinese Medicine and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Liberty Rd., Wuhan, Hubei, 430022, China
| | - Xionggang Jiang
- Department of Cardiac Surgery, Department of Integrated Traditional Chinese Medicine and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Liberty Rd., Wuhan, Hubei, 430022, China
| | - Ying Fang
- Hubei University of Chinese Medicine, 16 Huangjiahu W Rd, Hongshan, Wuhan, Hubei, 430065, China
| | - Qing Tang
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Liberty Rd., Wuhan, Hubei, 430022, China
| | - Jun Xiao
- The Macrohard Institute of Health, 231 North Ave, Battle Creek, MI, 49017, USA.
| | - Qian Li
- The Macrohard Institute of Health, 231 North Ave, Battle Creek, MI, 49017, USA; The American Academy of Tradition Chinese Medicine Inc., 1925 W County Rd B2, Roseville, MN, 55113, USA.
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22
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Zhu W, Wang W, Angsutararux P, Mellor RL, Isom LL, Nerbonne JM, Silva JR. Modulation of the effects of class Ib antiarrhythmics on cardiac NaV1.5-encoded channels by accessory NaVβ subunits. JCI Insight 2021; 6:e143092. [PMID: 34156986 PMCID: PMC8410097 DOI: 10.1172/jci.insight.143092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 06/17/2021] [Indexed: 01/28/2023] Open
Abstract
Native myocardial voltage-gated sodium (NaV) channels function in macromolecular complexes comprising a pore-forming (α) subunit and multiple accessory proteins. Here, we investigated the impact of accessory NaVβ1 and NaVβ3 subunits on the functional effects of 2 well-known class Ib antiarrhythmics, lidocaine and ranolazine, on the predominant NaV channel α subunit, NaV1.5, expressed in the mammalian heart. We showed that both drugs stabilized the activated conformation of the voltage sensor of domain-III (DIII-VSD) in NaV1.5. In the presence of NaVβ1, the effect of lidocaine on the DIII-VSD was enhanced, whereas the effect of ranolazine was abolished. Mutating the main class Ib drug-binding site, F1760, affected but did not abolish the modulation of drug block by NaVβ1/β3. Recordings from adult mouse ventricular myocytes demonstrated that loss of Scn1b (NaVβ1) differentially affected the potencies of lidocaine and ranolazine. In vivo experiments revealed distinct ECG responses to i.p. injection of ranolazine or lidocaine in WT and Scn1b-null animals, suggesting that NaVβ1 modulated drug responses at the whole-heart level. In the human heart, we found that SCN1B transcript expression was 3 times higher in the atria than ventricles, differences that could, in combination with inherited or acquired cardiovascular disease, dramatically affect patient response to class Ib antiarrhythmic therapies.
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Affiliation(s)
- Wandi Zhu
- Department of Biomedical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri, USA.,Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Wei Wang
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Paweorn Angsutararux
- Department of Biomedical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Rebecca L Mellor
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Lori L Isom
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Jeanne M Nerbonne
- Department of Internal Medicine, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA.,Department of Developmental Biology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA
| | - Jonathan R Silva
- Department of Biomedical Engineering, McKelvey School of Engineering, Washington University in St. Louis, St. Louis, Missouri, USA
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23
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Investigational Anti-Atrial Fibrillation Pharmacology and Mechanisms by Which Antiarrhythmics Terminate the Arrhythmia: Where Are We in 2020? J Cardiovasc Pharmacol 2021; 76:492-505. [PMID: 33165131 PMCID: PMC7641178 DOI: 10.1097/fjc.0000000000000892] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Antiarrhythmic drugs remain the mainstay therapy for patients with atrial fibrillation (AF). A major disadvantage of the currently available anti-AF agents is the risk of induction of ventricular proarrhythmias. Aiming to reduce this risk, several atrial-specific or -selective ion channel block approaches have been introduced for AF suppression, but only the atrial-selective inhibition of the sodium channel has been demonstrated to be valid in both experimental and clinical studies. Among the other pharmacological anti-AF approaches, “upstream therapy” has been prominent but largely disappointing, and pulmonary delivery of anti-AF drugs seems to be promising. Major contradictions exist in the literature about the electrophysiological mechanisms of AF (ie, reentry or focal?) and the mechanisms by which anti-AF drugs terminate AF, making the search for novel anti-AF approaches largely empirical. Drug-induced termination of AF may or may not be associated with prolongation of the atrial effective refractory period. Anti-AF drug research has been largely based on the “suppress reentry” ideology; however, results of the AF mapping studies increasingly indicate that nonreentrant mechanism(s) plays an important role in the maintenance of AF. Also, the analysis of anti-AF drug-induced electrophysiological alterations during AF, conducted in the current study, leans toward the focal source as the prime mechanism of AF maintenance. More effort should be placed on the investigation of pharmacological suppression of the focal mechanisms.
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24
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Mashayekhi-Sardoo H, Mohammadpour AH, Mehri S, Kamali H, Sahebkar A, Imenshahidi M. Diabetes mellitus aggravates ranolazine-induced ECG changes in rats. J Interv Card Electrophysiol 2021; 63:379-388. [PMID: 34155553 DOI: 10.1007/s10840-021-01016-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 05/30/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE Diabetes mellitus (DM) is known to affect the pharmacokinetics of drugs. In this study, we evaluated the effect of DM on the liver content of CYP 3A2 enzyme. We also explored the ECG changes after administration of ranolazine in non-DM and DM rats. METHODS First phase: 24 male Wistar rats were separated into 4 groups. The control group (n = 6) received normal saline and the DM groups (n = 18) were treated with a single dose (55 mg/kg) of streptozocin (STZ; i.p. injection), then were held for 10, 20, and 30 days, respectively. After study duration for each group, the liver CYP 3A2 protein content was determined using western blotting. Second phase: 48 male Wistar rats were classified into two groups of non-DM and DM; and each group was divided into 4 subgroups (n: 6). Experimental groups received oral doses of 20, 40, and 80 mg/kg ranolazine. DM and non-DM control groups received normal saline. Treatment lasted for 28 days, and then the ECG was recorded. RESULTS Experimental DM induced by STZ caused a significant decrement in liver CYP3A2 protein content of rats on days 10 and 20 (P < 0.01), and 30 (P < 0.05) compared to the control animals. Significant increases in QT and corrected QT (QTc) intervals (P < 0.01), and bradycardia (P < 0.01) without any significant effect on PR and QRS intervals were observed in DM in comparison with non-DM groups after ranolazine treatment. CONCLUSIONS In summary, DM induction in animals resulted in CYP 3A2 inhibition and the prolongation of QT and QTc interval as well as bradycardia after ranolazine treatment.
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Affiliation(s)
- Habibeh Mashayekhi-Sardoo
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amir Hooshang Mohammadpour
- Department of Clinical Pharmacy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.,Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Soghra Mehri
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hossein Kamali
- Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Pharmaceutics, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Mohsen Imenshahidi
- Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran. .,Pharmaceutical Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
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25
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Ton AT, Nguyen W, Sweat K, Miron Y, Hernandez E, Wong T, Geft V, Macias A, Espinoza A, Truong K, Rasoul L, Stafford A, Cotta T, Mai C, Indersmitten T, Page G, Miller PE, Ghetti A, Abi-Gerges N. Arrhythmogenic and antiarrhythmic actions of late sustained sodium current in the adult human heart. Sci Rep 2021; 11:12014. [PMID: 34103608 PMCID: PMC8187365 DOI: 10.1038/s41598-021-91528-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/27/2021] [Indexed: 12/19/2022] Open
Abstract
Late sodium current (late INa) inhibition has been proposed to suppress the incidence of arrhythmias generated by pathological states or induced by drugs. However, the role of late INa in the human heart is still poorly understood. We therefore investigated the role of this conductance in arrhythmias using adult primary cardiomyocytes and tissues from donor hearts. Potentiation of late INa with ATX-II (anemonia sulcata toxin II) and E-4031 (selective blocker of the hERG channel) slowed the kinetics of action potential repolarization, impaired Ca2+ homeostasis, increased contractility, and increased the manifestation of arrhythmia markers. These effects could be reversed by late INa inhibitors, ranolazine and GS-967. We also report that atrial tissues from donor hearts affected by atrial fibrillation exhibit arrhythmia markers in the absence of drug treatment and inhibition of late INa with GS-967 leads to a significant reduction in arrhythmic behaviour. These findings reveal a critical role for the late INa in cardiac arrhythmias and suggest that inhibition of this conductance could provide an effective therapeutic strategy. Finally, this study highlights the utility of human ex-vivo heart models for advancing cardiac translational sciences.
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Affiliation(s)
- Anh Tuan Ton
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - William Nguyen
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Katrina Sweat
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Yannick Miron
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Eduardo Hernandez
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Tiara Wong
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Valentyna Geft
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Andrew Macias
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Ana Espinoza
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Ky Truong
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Lana Rasoul
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Alexa Stafford
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Tamara Cotta
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Christina Mai
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Tim Indersmitten
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Guy Page
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Paul E Miller
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Andre Ghetti
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Najah Abi-Gerges
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA.
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26
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Role of Ranolazine in the Prevention and Treatment of Atrial Fibrillation in Patients with Left Ventricular Systolic Dysfunction: A Meta-Analysis of Randomized Clinical Trials. Diseases 2021; 9:diseases9020031. [PMID: 33923428 PMCID: PMC8167551 DOI: 10.3390/diseases9020031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/13/2021] [Accepted: 04/14/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Ranolazine has the potential to prevent atrial fibrillation (AF) and plays a role in rhythm control strategy for atrial fibrillation in various clinical settings. However, data on the use of ranolazine in patients with left ventricular (LV) systolic dysfunction are limited. The aims of this meta-analysis of randomized clinical trials are to investigate the efficacy and safety of ranolazine in AF patients with LV systolic dysfunction. PubMed and the Cochrane Database of Systematic Reviews were searched until July 2020. The efficacy outcomes included the incidence of new-onset AF, the rate of sinus rhythm restoration, and the time until sinus rhythm restoration. Safety endpoints were at death, and any adverse events were reported in the enrolled studies. We initially identified 204 studies and finally retrieved 5 RCTs. Three studies were analyzed in the meta-analysis. Among AF patients with LV systolic dysfunction, our meta-analysis showed that the combination of ranolazine to amiodarone significantly increased the sinus rhythm restoration rate compared to amiodarone alone (risk ratio (RR) 2.87, 95% confidence interval (CI) 2.48-3.32). Moreover, the time to sinus rhythm restoration was 2.46 h shorter in the ranolazine added to amiodarone group (95% CI: 2.27-2.64). No significant adverse events and proarrhythmias in the ranolazine group were identified. In conclusion, in AF patients with LV systolic dysfunction, ranolazine as an add-on therapy to amiodarone potentiates and accelerates the conversion of AF to sinus rhythm. Moreover, ranolazine shows good safety profiles. Further studies to investigate the effectiveness of ranolazine in the prevention of new-onset AF among patients with LV systolic dysfunction are needed.
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27
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Verkerk AO, Marchal GA, Zegers JG, Kawasaki M, Driessen AHG, Remme CA, de Groot JR, Wilders R. Patch-Clamp Recordings of Action Potentials From Human Atrial Myocytes: Optimization Through Dynamic Clamp. Front Pharmacol 2021; 12:649414. [PMID: 33912059 PMCID: PMC8072333 DOI: 10.3389/fphar.2021.649414] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/18/2021] [Indexed: 11/29/2022] Open
Abstract
Introduction: Atrial fibrillation (AF) is the most common cardiac arrhythmia. Consequently, novel therapies are being developed. Ultimately, the impact of compounds on the action potential (AP) needs to be tested in freshly isolated human atrial myocytes. However, the frequent depolarized state of these cells upon isolation seriously hampers reliable AP recordings. Purpose: We assessed whether AP recordings from single human atrial myocytes could be improved by providing these cells with a proper inward rectifier K+ current (IK1), and consequently with a regular, non-depolarized resting membrane potential (RMP), through “dynamic clamp”. Methods: Single myocytes were enzymatically isolated from left atrial appendage tissue obtained from patients with paroxysmal AF undergoing minimally invasive surgical ablation. APs were elicited at 1 Hz and measured using perforated patch-clamp methodology, injecting a synthetic IK1 to generate a regular RMP. The injected IK1 had strong or moderate rectification. For comparison, a regular RMP was forced through injection of a constant outward current. A wide variety of ion channel blockers was tested to assess their modulatory effects on AP characteristics. Results: Without any current injection, RMPs ranged from −9.6 to −86.2 mV in 58 cells. In depolarized cells (RMP positive to −60 mV), RMP could be set at −80 mV using IK1 or constant current injection and APs could be evoked upon stimulation. AP duration differed significantly between current injection methods (p < 0.05) and was shortest with constant current injection and longest with injection of IK1 with strong rectification. With moderate rectification, AP duration at 90% repolarization (APD90) was similar to myocytes with regular non-depolarized RMP, suggesting that a synthetic IK1 with moderate rectification is the most appropriate for human atrial myocytes. Importantly, APs evoked using each injection method were still sensitive to all drugs tested (lidocaine, nifedipine, E-4031, low dose 4-aminopyridine, barium, and apamin), suggesting that the major ionic currents of the atrial cells remained functional. However, certain drug effects were quantitatively dependent on the current injection approach used. Conclusion: Injection of a synthetic IK1 with moderate rectification facilitates detailed AP measurements in human atrial myocytes. Therefore, dynamic clamp represents a promising tool for testing novel antiarrhythmic drugs.
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Affiliation(s)
- Arie O Verkerk
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.,Department of Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Gerard A Marchal
- Department of Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Jan G Zegers
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Makiri Kawasaki
- Department of Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Antoine H G Driessen
- Department of Cardiothoracic Surgery, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Carol Ann Remme
- Department of Experimental Cardiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Joris R de Groot
- Department of Cardiology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Ronald Wilders
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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28
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The Small Conductance Calcium-Activated Potassium Channel Inhibitors NS8593 and UCL1684 Prevent the Development of Atrial Fibrillation Through Atrial-Selective Inhibition of Sodium Channel Activity. J Cardiovasc Pharmacol 2021; 76:164-172. [PMID: 32453071 DOI: 10.1097/fjc.0000000000000855] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The mechanisms underlying atrial-selective prolongation of effective refractory period (ERP) and suppression of atrial fibrillation (AF) by NS8593 and UCL1684, small conductance calcium-activated potassium (SK) channel blockers, are poorly defined. The purpose of the study was to confirm the effectiveness of these agents to suppress AF and to probe the underlying mechanisms. Transmembrane action potentials and pseudoelectrocardiograms were recorded from canine isolated coronary-perfused canine atrial and ventricular wedge preparations. Patch clamp techniques were used to record sodium channel current (INa) in atrial and ventricular myocytes and human embryonic kidney cells. In both atria and ventricles, NS8593 (3-10 µM) and UCL1684 (0.5 µM) did not significantly alter action potential duration, suggesting little to no SK channel inhibition. Both agents caused atrial-selective: (1) prolongation of ERP secondary to development of postrepolarization refractoriness, (2) reduction of Vmax, and (3) increase of diastolic threshold of excitation (all are sodium-mediated parameters). NS8593 and UCL1684 significantly reduced INa density in human embryonic kidney cells as well as in atrial but not in ventricular myocytes at physiologically relevant holding potentials. NS8593 caused a shift of steady-state inactivation to negative potentials in atrial but not ventricular cells. NS8593 and UCL1684 prevented induction of acetylcholine-mediated AF in 6/6 and 8/8 preparations, respectively. This anti-AF effect was associated with strong rate-dependent depression of excitability. The SK channel blockers, NS8593 and UCL1684, are effective in preventing the development of AF due to potent atrial-selective inhibition of INa, causing atrial-selective prolongation of ERP secondary to induction of postrepolarization refractoriness.
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29
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Burashnikov A. Depolarization of the atrial resting membrane potential as an approach to enhance the anti-atrial fibrillation efficacy of sodium channel blockers. Heart Rhythm 2021; 18:1221-1222. [PMID: 33785461 DOI: 10.1016/j.hrthm.2021.03.039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 03/25/2021] [Indexed: 10/21/2022]
Affiliation(s)
- Alexander Burashnikov
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania, and Sidney Kimmel College of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania.
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30
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Are atrial human pluripotent stem cell-derived cardiomyocytes ready to identify drugs that beat atrial fibrillation? Nat Commun 2021; 12:1725. [PMID: 33741918 PMCID: PMC7979815 DOI: 10.1038/s41467-021-21949-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 02/04/2021] [Indexed: 01/27/2023] Open
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31
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Aidonidis I, Simopoulos V, Dipla K, Hatziefthimiou A, Stamatiou R, Skoularigis I, Molyvdas PA. Effects of Ranolazine and its Combination with Amiodarone on Rapid Pacing-induced Reentrant Atrial Tachycardia in Rabbits. J Innov Card Rhythm Manag 2021; 12:4421-4427. [PMID: 33777481 PMCID: PMC7987427 DOI: 10.19102/icrm.2021.120304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 10/21/2020] [Indexed: 11/21/2022] Open
Abstract
Ranolazine (RAN) has previously been shown to lower the onset of cholinergic atrial fibrillation in intact animals; however, its efficacy in the setting of atrial tachycardia (AT) is unknown. The purpose of this study was to investigate the effects of RAN alone or in combination with amiodarone (AMIO) on rapid pacing-evoked right AT in rabbit hearts. Right atrial monophasic action potentials (MAPs) were recorded in 11 anesthetized rabbits, using combination MAP pacing catheters. Vulnerability to AT was tested by employing consecutive trains of rapid burst pacing prior to and after 2.4 mg/kg of RAN alone delivered intravenously and then in combination with 3 mg/kg of AMIO as a 15-minute infusion. Primary endpoints were postdrug AT reproducibility as well as cycle length (CL) and tachycardia duration. MAP duration at 75% repolarization and the effective refractory period (ERP) were assessed during programmed pacing to calculate the atrial postrepolarization refractoriness (aPRR = ERP – MAPD75%). AT was elicited in eight out of 11 rabbits; only these animals were included for further investigation. RAN did not abolish the inducibility of AT in any experiment; however, it prolonged its CL (baseline vs. RAN: 120 ± 16 ms vs. 138 ± 18 ms; p = 0.053). Supplemental AMIO further increased the AT CL (baseline vs. RAN + AMIO: 120 ± 16 ms vs. 152 ± 23 ms; p = 0.006), without affecting arrhythmia reinducibility. Slowing of the tachycardia after RAN or RAN + AMIO was associated with spontaneous termination of the arrhythmia. RAN prolonged the aPRR significantly, while AMIO in addition to RAN potentiated this effect. Neither RAN alone nor its combination with AMIO abolished the elicitation of AT in this model. However, both agents synergistically prolonged the aPRR, resulting in the slowing of AT and promoting spontaneous termination of the arrhythmia.
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Affiliation(s)
- Isaac Aidonidis
- Department of Physiology, University of Thessaly, School of Medicine, Larissa, Greece
| | - Vassileios Simopoulos
- Department of Cardiac and Thoracic Surgery, University Hospital of Larissa, School of Medicine, University of Thessaly, Thessaly, Greece
| | - Konstantina Dipla
- Department of Sport Sciences at Serres, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | | | - Rodopi Stamatiou
- Department of Physiology, University of Thessaly, School of Medicine, Larissa, Greece
| | - Ioannis Skoularigis
- Department of Cardiology, University Hospital of Larissa Medical School, University of Thessaly, Larissa, Greece
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Chukwunyere U, Sehirli AO, Abacioglu N. COVID-19-related arrhythmias and the possible effects of ranolazine. Med Hypotheses 2021; 149:110545. [PMID: 33636586 PMCID: PMC7890340 DOI: 10.1016/j.mehy.2021.110545] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/03/2021] [Accepted: 02/12/2021] [Indexed: 12/30/2022]
Abstract
The COVID-19 pandemic has become a burden to the global healthcare community. Despite the severity of the complications associated with COVID-19, no antiviral agent is yet available for the treatment of this disease. Several studies have reported arrhythmias as one of the numerous manifestations associated with COVID-19 infection. Clinicians use different therapeutic agents in the management of COVID-19 patients with arrhythmias, apart from ranolazine; however, some of these drugs are administered with caution because of their significant side effects. In this study, we reviewed the potential antiarrhythmic effects of ranolazine in the management of cardiac arrhythmias associated with COVID-19. Ranolazine is a second-line drug approved for the treatment of chronic stable angina pectoris. Previous studies have shown that ranolazine produces its beneficial cardiac effects without any significant impact on the body’s hemodynamics; hence, blood pressure is not altered. Due to its reduced side effects, ranolazine may be more effective than other drugs in producing the desired relief from COVID-19 related arrhythmias, since it produces its antiarrhythmic effect by modulating sodium, potassium and calcium channels, and suppressing cytokine expression.
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Affiliation(s)
- Ugochukwu Chukwunyere
- Department of Pharmacology, Faculty of Pharmacy, Near East University, Nicosia, Cyprus.
| | - Ahmet Ozer Sehirli
- Department of Pharmacology, Faculty of Dentistry, Near East University, Nicosia, Cyprus
| | - Nurettin Abacioglu
- Department of Pharmacology, Faculty of Pharmacy, Near East University, Nicosia, Cyprus; Department of Pharmacology, Faculty of Pharmacy, Kyrenia University, Kyrenia, Cyprus
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Dewal RS, Greer-Short A, Lane C, Nirengi S, Manzano PA, Hernández-Saavedra D, Wright KR, Nassal D, Baer LA, Mohler PJ, Hund TJ, Stanford KI. Phospho-ablation of cardiac sodium channel Na v1.5 mitigates susceptibility to atrial fibrillation and improves glucose homeostasis under conditions of diet-induced obesity. Int J Obes (Lond) 2021; 45:795-807. [PMID: 33500550 PMCID: PMC8005377 DOI: 10.1038/s41366-021-00742-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 11/19/2020] [Accepted: 01/04/2021] [Indexed: 01/30/2023]
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common sustained arrhythmia, with growing evidence identifying obesity as an important risk factor for the development of AF. Although defective atrial myocyte excitability due to stress-induced remodeling of ion channels is commonly observed in the setting of AF, little is known about the mechanistic link between obesity and AF. Recent studies have identified increased cardiac late sodium current (INa,L) downstream of calmodulin-dependent kinase II (CaMKII) activation as an important driver of AF susceptibility. METHODS Here, we investigated a possible role for CaMKII-dependent INa,L in obesity-induced AF using wild-type (WT) and whole-body knock-in mice that ablates phosphorylation of the Nav1.5 sodium channel and prevents augmentation of the late sodium current (S571A; SA mice). RESULTS A high-fat diet (HFD) increased susceptibility to arrhythmias in WT mice, while SA mice were protected from this effect. Unexpectedly, SA mice had improved glucose homeostasis and decreased body weight compared to WT mice. However, SA mice also had reduced food consumption compared to WT mice. Controlling for food consumption through pair feeding of WT and SA mice abrogated differences in weight gain and AF inducibility, but not atrial fibrosis, premature atrial contractions or metabolic capacity. CONCLUSIONS These data demonstrate a novel role for CaMKII-dependent regulation of Nav1.5 in mediating susceptibility to arrhythmias and whole-body metabolism under conditions of diet-induced obesity.
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Affiliation(s)
- Revati S. Dewal
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Center for Diabetes and Metabolism Research Center, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Amara Greer-Short
- grid.261331.40000 0001 2285 7943Department of Biomedical Engineering, The Ohio State University, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Cemantha Lane
- grid.261331.40000 0001 2285 7943Department of Biomedical Engineering, The Ohio State University, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Shinsuke Nirengi
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Center for Diabetes and Metabolism Research Center, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Pedro Acosta Manzano
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Center for Diabetes and Metabolism Research Center, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Diego Hernández-Saavedra
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Center for Diabetes and Metabolism Research Center, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Katherine R. Wright
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Center for Diabetes and Metabolism Research Center, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Drew Nassal
- grid.261331.40000 0001 2285 7943Department of Biomedical Engineering, The Ohio State University, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Lisa A. Baer
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Center for Diabetes and Metabolism Research Center, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Peter J. Mohler
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Thomas J. Hund
- grid.261331.40000 0001 2285 7943Department of Biomedical Engineering, The Ohio State University, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH USA
| | - Kristin I. Stanford
- grid.412332.50000 0001 1545 0811Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Center for Diabetes and Metabolism Research Center, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, OH USA ,grid.412332.50000 0001 1545 0811Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH USA
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Ghovanloo MR, Atallah J, Escudero CA, Ruben PC. Biophysical Characterization of a Novel SCN5A Mutation Associated With an Atypical Phenotype of Atrial and Ventricular Arrhythmias and Sudden Death. Front Physiol 2020; 11:610436. [PMID: 33414724 PMCID: PMC7783455 DOI: 10.3389/fphys.2020.610436] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Background Sudden cardiac death (SCD) is an unexpected death that occurs within an hour of the onset of symptoms. Hereditary primary electrical disorders account for up to 1/3 of all SCD cases in younger individuals and include conditions such as catecholaminergic polymorphic ventricular tachycardia (CPVT). These disorders are caused by mutations in the genes encoding cardiac ion channels, hence they are known as cardiac channelopathies. We identified a novel variant, T1857I, in the C-terminus of Nav1.5 (SCN5A) linked to a family with a CPVT-like phenotype characterized by atrial tachy-arrhythmias and polymorphic ventricular ectopy occurring at rest and with adrenergic stimulation, and a strong family history of SCD. Objective Our goal was to functionally characterize the novel Nav1.5 variant and determine a possible link between channel gating and clinical phenotype. Methods We first used electrocardiogram recordings to visualize the patient cardiac electrical properties. Then, we performed voltage-clamp of transiently transfected CHO cells. Lastly, we used the ventricular/atrial models to visualize gating defects on cardiac excitability. Results Voltage-dependences of both activation and inactivation were right-shifted, the overlap between activation and inactivation predicted increased window currents, the recovery from fast inactivation was slowed, there was no significant difference in late currents, and there was no difference in use-dependent inactivation. The O’Hara-Rudy model suggests ventricular after depolarizations and atrial Grandi-based model suggests a slight prolongation of atrial action potential duration. Conclusion We conclude that T1857I likely causes a net gain-of-function in Nav1.5 gating, which may in turn lead to ventricular after depolarization, predisposing carriers to tachy-arrhythmias.
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Affiliation(s)
- Mohammad-Reza Ghovanloo
- Department of Biomedical Physiology and Kinesiology, Faculty of Science, Simon Fraser University, Burnaby, BC, Canada
| | - Joseph Atallah
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Carolina A Escudero
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Peter C Ruben
- Department of Biomedical Physiology and Kinesiology, Faculty of Science, Simon Fraser University, Burnaby, BC, Canada
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da Rocha AM, Creech J, Thonn E, Mironov S, Herron TJ. Detection of Drug-Induced Torsades de Pointes Arrhythmia Mechanisms Using hiPSC-CM Syncytial Monolayers in a High-Throughput Screening Voltage Sensitive Dye Assay. Toxicol Sci 2020; 173:402-415. [PMID: 31764978 DOI: 10.1093/toxsci/kfz235] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
We validated 3 distinct hiPSC-CM cell lines-each of different purity and a voltage sensitive dye (VSD)-based high-throughput proarrhythmia screening assay as a noncore site in the recently completed CiPA Myocyte Phase II Validation Study. Blinded validation was performed using 12 drugs linked to low, intermediate, or high risk for causing Torsades de Pointes (TdP). Commercially sourced hiPSC-CMs were obtained either from Cellular Dynamics International (CDI, Madison, Wisconsin, iCell Cardiomyoyctes2) or Takara Bio (CLS, Cellartis Cardiomyocytes). A third hiPSC-CM cell line (MCH, Michigan) was generated in house. Each cell type had distinct baseline electrophysiological function (spontaneous beat rate, action potential duration, and conduction velocity) and drug responsiveness. Use of VSD and optical mapping enabled the detection of conduction slowing of sodium channel blockers (quinidine, disopyramide, and mexiletine) and drug-induced TdP-like activation patterns (rotors) for some high- and intermediate-risk compounds. Low-risk compounds did not induce rotors in any cell type tested. These results further validate the utility of hiPSC-CMs for predictive proarrhythmia screening and the utility of VSD technology to detect drug-induced APD prolongation, arrhythmias (rotors), and conduction slowing. Importantly, results indicate that different ratios of cardiomyocytes and noncardiomyocytes have important impact on drug response that may be considered during risk assessment of new drugs. Finally, we present the first blinded CiPA hiPSC-CM validation results to simultaneously detect drug-induced conduction slowing, action potential duration prolongation, action potential triangulation, and drug-induced rotors in a proarrhythmia assay.
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Affiliation(s)
- Andre Monteiro da Rocha
- Frankel Cardiovascular Regeneration Core Laboratory, Ann Arbor, MI.,Center for Arrhythmia Research-Department of Internal Medicine, University of Michigan, Ann Arbor, MI.,CARTOX, LLC-Cardiotoxicity Department, New Hudson, MI 48165
| | - Jeffery Creech
- Frankel Cardiovascular Regeneration Core Laboratory, Ann Arbor, MI.,Center for Arrhythmia Research-Department of Internal Medicine, University of Michigan, Ann Arbor, MI.,CARTOX, LLC-Cardiotoxicity Department, New Hudson, MI 48165
| | - Ethan Thonn
- Frankel Cardiovascular Regeneration Core Laboratory, Ann Arbor, MI
| | - Sergey Mironov
- Center for Arrhythmia Research-Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Todd J Herron
- Frankel Cardiovascular Regeneration Core Laboratory, Ann Arbor, MI.,Center for Arrhythmia Research-Department of Internal Medicine, University of Michigan, Ann Arbor, MI.,CARTOX, LLC-Cardiotoxicity Department, New Hudson, MI 48165
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Electrophysiological effects of ranolazine in a goat model of lone atrial fibrillation. Heart Rhythm 2020; 18:615-622. [PMID: 33232809 DOI: 10.1016/j.hrthm.2020.11.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 11/14/2020] [Accepted: 11/17/2020] [Indexed: 11/22/2022]
Abstract
BACKGROUND There is still an unmet need for pharmacologic treatment of atrial fibrillation (AF) with few effects on ventricular electrophysiology. Ranolazine is an antiarrhythmic drug reported to have strong atrial selectivity. OBJECTIVE The purpose of this study was to investigate the electrophysiological effects of ranolazine in atria with AF-induced electrical remodeling in a model of lone AF in awake goats. METHODS Electrode patches were implanted on the atrial epicardium of 8 Dutch milk goats. Experiments were performed at baseline and after 2 and 14 days of electrically maintained AF. Several electrophysiological parameters and AF episode duration were measured during infusion of vehicle and different doses of ranolazine (target plasma levels 4, 8, and 16 μM, respectively). RESULTS The highest dose of ranolazine significantly prolonged atrial effective refractory period and decreased atrial conduction velocity at baseline and after 2 days of AF. After 2 weeks of AF, ranolazine prolonged the p5 and p50 of AF cycle length distribution in a dose-dependent manner but was not effective in restoring sinus rhythm. No adverse ventricular arrhythmic events (eg, premature ventricular beats or signs of hemodynamic instability) were observed during infusion of ranolazine at any point in the study. CONCLUSION The lowest investigated dose of ranolazine, which is expected to block both late INa and atrial peak INa, had no effect on the investigated electrophysiological parameters. The highest dose affected both atrial and ventricular electrophysiological parameters at different stages of AF-induced remodeling but was not efficacious in cardioverting AF to sinus rhythm in a goat model of lone AF.
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Geng M, Lin A, Nguyen TP. Revisiting Antiarrhythmic Drug Therapy for Atrial Fibrillation: Reviewing Lessons Learned and Redefining Therapeutic Paradigms. Front Pharmacol 2020; 11:581837. [PMID: 33240090 PMCID: PMC7680856 DOI: 10.3389/fphar.2020.581837] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 09/17/2020] [Indexed: 12/12/2022] Open
Abstract
Since the clinical use of digitalis as the first pharmacological therapy for atrial fibrillation (AF) 235 years ago in 1785, antiarrhythmic drug therapy has advanced considerably and become a cornerstone of AF clinical management. Yet, a preventive or curative panacea for sustained AF does not exist despite the rise of AF global prevalence to epidemiological proportions. While multiple elevated risk factors for AF have been established, the natural history and etiology of AF remain incompletely understood. In the present article, the first section selectively highlights some disappointing shortcomings and current efforts in antiarrhythmic drug therapy to uncover reasons why AF is such a clinical challenge. The second section discusses some modern takes on the natural history of AF as a relentless, progressive fibro-inflammatory "atriomyopathy." The final section emphasizes the need to redefine therapeutic strategies on par with new insights of AF pathophysiology.
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Affiliation(s)
| | | | - Thao P. Nguyen
- Division of Cardiology, Department of Medicine, The Cardiovascular Research Laboratory, David Geffen School of Medicine at UCLA, Los Angeles, CA, United States
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38
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Abstract
Pharmacologic management of atrial fibrillation (AF) is a pressing problem. This arrhythmia afflicts >5 million individuals in the United States and prevalence is estimated to rise to 12 million by 2050. Although the pill-in-the-pocket regimen for self-administered AF cardioversion introduced over a decade ago has proven useful, significant drawbacks exist. Among these are the relatively long latency of effects in the range of hours along with potential for hypotension and other adverse effects. This experience prompted development of a new strategy for increasing plasma concentrations of antiarrhythmic drugs rapidly and for a limited time, namely, pulmonary delivery. In preclinical studies in Yorkshire pigs, intratracheal administration of flecainide was shown to cause a rapid, reproducible increase in plasma drug levels. Moreover, pulmonary delivery of flecainide converted AF to normal sinus rhythm by prolonging atrial depolarization, which slows intra-atrial conduction and seems to be directly correlated with efficacy in converting AF. The rapid rise in plasma flecainide levels optimizes its anti-AF effects while minimizing adverse influences on ventricular depolarization and contractility. A more concentrated and soluble formulation of flecainide using a novel cyclodextrin complex excipient reduced net drug delivery for AF conversion when compared to the acetate formulation. Inhalation of the beta-adrenergic blocking agent metoprolol slows ventricular rate and can also terminate AF. In human subjects, oral inhalation of flecainide acetate with a hand-held, breath-actuated nebulizer results in signature prolongation of the QRS complex without serious adverse events. Thus, pulmonary delivery is a promising advance in pharmacologic approach to management of AF.
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Herruzo-Rojas MS, Martín-Toro MA, Carrillo-Bailén M. Ranolazina en cardiopatía isquémica crónica: un factor protector frente a la fibrilación auricular de novo. REVISTA COLOMBIANA DE CARDIOLOGÍA 2020. [DOI: 10.1016/j.rccar.2018.10.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
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Caves RE, Carpenter A, Choisy SC, Clennell B, Cheng H, McNiff C, Mann B, Milnes JT, Hancox JC, James AF. Inhibition of voltage-gated Na + currents by eleclazine in rat atrial and ventricular myocytes. Heart Rhythm O2 2020; 1:206-214. [PMID: 32864638 PMCID: PMC7442036 DOI: 10.1016/j.hroo.2020.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Background Atrial-ventricular differences in voltage-gated Na+ currents might be exploited for atrial-selective antiarrhythmic drug action for the suppression of atrial fibrillation without risk of ventricular tachyarrhythmia. Eleclazine (GS-6615) is a putative antiarrhythmic drug with properties similar to the prototypical atrial-selective Na+ channel blocker ranolazine that has been shown to be safe and well tolerated in patients. Objective The present study investigated atrial-ventricular differences in the biophysical properties and inhibition by eleclazine of voltage-gated Na+ currents. Methods The fast and late components of whole-cell voltage-gated Na+ currents (respectively, INa and INaL) were recorded at room temperature (∼22°C) from rat isolated atrial and ventricular myocytes. Results Atrial INa activated at command potentials ∼5.5 mV more negative and inactivated at conditioning potentials ∼7 mV more negative than ventricular INa. There was no difference between atrial and ventricular myocytes in the eleclazine inhibition of INaL activated by 3 nM ATX-II (IC50s ∼200 nM). Eleclazine (10 μM) inhibited INa in atrial and ventricular myocytes in a use-dependent manner consistent with preferential activated state block. Eleclazine produced voltage-dependent instantaneous inhibition in atrial and ventricular myocytes; it caused a negative shift in voltage of half-maximal inactivation and slowed the recovery of INa from inactivation in both cell types. Conclusions Differences exist between rat atrial and ventricular myocytes in the biophysical properties of INa. The more negative voltage dependence of INa activation/inactivation in atrial myocytes underlies differences between the 2 cell types in the voltage dependence of instantaneous inhibition by eleclazine. Eleclazine warrants further investigation as an atrial-selective antiarrhythmic drug.
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Affiliation(s)
- Rachel E Caves
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Alexander Carpenter
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Stéphanie C Choisy
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Ben Clennell
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Hongwei Cheng
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Cameron McNiff
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Brendan Mann
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | | | - Jules C Hancox
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Andrew F James
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, United Kingdom
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Ni H, Fogli Iseppe A, Giles WR, Narayan SM, Zhang H, Edwards AG, Morotti S, Grandi E. Populations of in silico myocytes and tissues reveal synergy of multiatrial-predominant K + -current block in atrial fibrillation. Br J Pharmacol 2020; 177:4497-4515. [PMID: 32667679 DOI: 10.1111/bph.15198] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 06/22/2020] [Accepted: 07/03/2020] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND AND PURPOSE Pharmacotherapy of atrial fibrillation (AF), the most common cardiac arrhythmia, remains unsatisfactory due to low efficacy and safety concerns. New therapeutic strategies target atrial-predominant ion-channels and involve multichannel block (poly)therapy. As AF is characterized by rapid and irregular atrial activations, compounds displaying potent antiarrhythmic effects at fast and minimal effects at slow rates are desirable. We present a novel systems pharmacology framework to quantitatively evaluate synergistic anti-AF effects of combined block of multiple atrial-predominant K+ currents (ultra-rapid delayed rectifier K+ current, IKur , small conductance Ca2+ -activated K+ current, IKCa , K2P 3.1 2-pore-domain K+ current, IK2P ) in AF. EXPERIMENTAL APPROACH We constructed experimentally calibrated populations of virtual atrial myocyte models in normal sinus rhythm and AF-remodelled conditions using two distinct, well-established atrial models. Sensitivity analyses on our atrial populations was used to investigate the rate dependence of action potential duration (APD) changes due to blocking IKur , IK2P or IKCa and interactions caused by blocking of these currents in modulating APD. Block was simulated in both single myocytes and one-dimensional tissue strands to confirm insights from the sensitivity analyses and examine anti-arrhythmic effects of multi-atrial-predominant K+ current block in single cells and coupled tissue. KEY RESULTS In both virtual atrial myocytes and tissues, multiple atrial-predominant K+ -current block promoted favourable positive rate-dependent APD prolongation and displayed positive rate-dependent synergy, that is, increasing synergistic antiarrhythmic effects at fast pacing versus slow rates. CONCLUSION AND IMPLICATIONS Simultaneous block of multiple atrial-predominant K+ currents may be a valuable antiarrhythmic pharmacotherapeutic strategy for AF.
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Affiliation(s)
- Haibo Ni
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Alex Fogli Iseppe
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Wayne R Giles
- Faculties of Kinesiology and Medicine, University of Calgary, Calgary, Alberta, Canada
| | - Sanjiv M Narayan
- Division of Cardiology, Cardiovascular Institute, Stanford University, Stanford, CA, USA
| | - Henggui Zhang
- Biological Physics Group, School of Physics and Astronomy, The University of Manchester, Manchester, UK
| | - Andrew G Edwards
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Stefano Morotti
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Eleonora Grandi
- Department of Pharmacology, University of California, Davis, CA, USA
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Zhu W, Li T, Silva JR, Chen J. Conservation and divergence in NaChBac and Na V1.7 pharmacology reveals novel drug interaction mechanisms. Sci Rep 2020; 10:10730. [PMID: 32612253 PMCID: PMC7329812 DOI: 10.1038/s41598-020-67761-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 05/13/2020] [Indexed: 01/16/2023] Open
Abstract
Voltage-gated Na+ (NaV) channels regulate homeostasis in bacteria and control membrane electrical excitability in mammals. Compared to their mammalian counterparts, bacterial NaV channels possess a simpler, fourfold symmetric structure and have facilitated studies of the structural basis of channel gating. However, the pharmacology of bacterial NaV remains largely unexplored. Here we systematically screened 39 NaV modulators on a bacterial channel (NaChBac) and characterized a selection of compounds on NaChBac and a mammalian channel (human NaV1.7). We found that while many compounds interact with both channels, they exhibit distinct functional effects. For example, the local anesthetics ambroxol and lidocaine block both NaV1.7 and NaChBac but affect activation and inactivation of the two channels to different extents. The voltage-sensing domain targeting toxin BDS-I increases NaV1.7 but decreases NaChBac peak currents. The pore binding toxins aconitine and veratridine block peak currents of NaV1.7 and shift activation (aconitine) and inactivation (veratridine) respectively. In NaChBac, they block the peak current by binding to the pore residue F224. Nonetheless, aconitine has no effect on activation or inactivation, while veratridine only modulates activation of NaChBac. The conservation and divergence in the pharmacology of bacterial and mammalian NaV channels provide insights into the molecular basis of channel gating and will facilitate organism-specific drug discovery.
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Affiliation(s)
- Wandi Zhu
- Biochemical and Cellular Pharmacology, Genentech Inc., 103 DNA Way, South San Francisco, CA, USA. .,Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA.
| | - Tianbo Li
- Biochemical and Cellular Pharmacology, Genentech Inc., 103 DNA Way, South San Francisco, CA, USA
| | - Jonathan R Silva
- Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Jun Chen
- Biochemical and Cellular Pharmacology, Genentech Inc., 103 DNA Way, South San Francisco, CA, USA.
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44
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Isaac E, Cooper SM, Jones SA, Loubani M. Do age-associated changes of voltage-gated sodium channel isoforms expressed in the mammalian heart predispose the elderly to atrial fibrillation? World J Cardiol 2020; 12:123-135. [PMID: 32431783 PMCID: PMC7215965 DOI: 10.4330/wjc.v12.i4.123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 01/18/2020] [Accepted: 03/15/2020] [Indexed: 02/06/2023] Open
Abstract
Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide. The prevalence of the disease increases with age, strongly implying an age-related process underlying the pathology. At a time when people are living longer than ever before, an exponential increase in disease prevalence is predicted worldwide. Hence unraveling the underlying mechanics of the disease is paramount for the development of innovative treatment and prevention strategies. The role of voltage-gated sodium channels is fundamental in cardiac electrophysiology and may provide novel insights into the arrhythmogenesis of AF. Nav1.5 is the predominant cardiac isoform, responsible for the action potential upstroke. Recent studies have demonstrated that Nav1.8 (an isoform predominantly expressed within the peripheral nervous system) is responsible for cellular arrhythmogenesis through the enhancement of pro-arrhythmogenic currents. Animal studies have shown a decline in Nav1.5 leading to a diminished action potential upstroke during phase 0. Furthermore, the study of human tissue demonstrates an inverse expression of sodium channel isoforms; reduction of Nav1.5 and increase of Nav1.8 in both heart failure and ventricular hypertrophy. This strongly suggests that the expression of voltage-gated sodium channels play a crucial role in the development of arrhythmias in the diseased heart. Targeting aberrant sodium currents has led to novel therapeutic approaches in tackling AF and continues to be an area of emerging research. This review will explore how voltage-gated sodium channels may predispose the elderly heart to AF through the examination of laboratory and clinical based evidence.
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Affiliation(s)
- Emmanuel Isaac
- Department of Cardiothoracic Surgery, Hull University Teaching Hospitals, Cottingham HU16 5JQ, United Kingdom
| | - Stephanie M Cooper
- Department of Biomedical Sciences, University of Hull, Hull HU6 7RX, United Kingdom
| | - Sandra A Jones
- Department of Biomedical Sciences, University of Hull, Hull HU6 7RX, United Kingdom
| | - Mahmoud Loubani
- Department of Cardiothoracic Surgery, Hull University Teaching Hospitals, Cottingham HU16 5JQ, United Kingdom
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45
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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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Lebek S, Pichler K, Reuthner K, Trum M, Tafelmeier M, Mustroph J, Camboni D, Rupprecht L, Schmid C, Maier LS, Arzt M, Wagner S. Enhanced CaMKII-Dependent Late I
Na
Induces Atrial Proarrhythmic Activity in Patients With Sleep-Disordered Breathing. Circ Res 2020; 126:603-615. [DOI: 10.1161/circresaha.119.315755] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Rationale:
Sleep-disordered breathing (SDB) is frequently associated with atrial arrhythmias. Increased CaMKII (Ca/calmodulin-dependent protein kinase II) activity has been previously implicated in atrial arrhythmogenesis.
Objective:
We hypothesized that CaMKII-dependent dysregulation of Na current (I
Na
) may contribute to atrial proarrhythmic activity in patients with SDB.
Methods and Results:
We prospectively enrolled 113 patients undergoing elective coronary artery bypass grafting for cross-sectional study and collected right atrial appendage biopsies. The presence of SDB (defined as apnea-hypopnea index ≥15/h) was assessed with a portable SDB monitor the night before surgery. Compared with 56 patients without SDB, patients with SDB (57) showed a significantly increased level of activated CaMKII. Patch clamp was used to measure I
Na
. There was a significantly enhanced late I
Na
, but reduced peak I
Na
due to enhanced steady-state inactivation in atrial myocytes of patients with SDB consistent with significantly increased CaMKII-dependent cardiac Na channel phosphorylation (Na
V
1.5, at serine 571, Western blotting). These gating changes could be fully reversed by acute CaMKII inhibition (AIP [autocamtide-2 related inhibitory peptide]). As a consequence, we observed significantly more cellular afterdepolarizations and more severe premature atrial contractions in atrial trabeculae of patients with SDB, which could be blocked by either AIP or KN93 (N-[2-[[[(E)-3-(4-chlorophenyl)prop-2-enyl]-methylamino]methyl]phenyl]-N-(2-hydroxyethyl)-4-methoxybenzenesulfonamide). In multivariable linear regression models incorporating age, sex, body mass index, existing atrial fibrillation, existing heart failure, diabetes mellitus, and creatinine levels, apnea-hypopnea index was independently associated with increased CaMKII activity, enhanced late I
Na
and correlated with premature atrial contraction severity.
Conclusions:
In atrial myocardium of patients with SDB, increased CaMKII-dependent phosphorylation of Na
V
1.5 results in dysregulation of I
Na
with proarrhythmic activity that was independent from preexisting comorbidities. Inhibition of CaMKII may be useful for prevention or treatment of arrhythmias in SDB.
Clinical Trial Registration:
URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT02877745.
Visual Overview:
An online visual overview is available for this article.
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Affiliation(s)
- Simon Lebek
- From the Department of Internal Medicine II (S.L., K.P., K.R., M. Trum, M. Tafelmeier, J.M., L.S.M., M.A., S.W.), University Hospital Regensburg, Germany
| | - Konstantin Pichler
- From the Department of Internal Medicine II (S.L., K.P., K.R., M. Trum, M. Tafelmeier, J.M., L.S.M., M.A., S.W.), University Hospital Regensburg, Germany
| | - Kathrin Reuthner
- From the Department of Internal Medicine II (S.L., K.P., K.R., M. Trum, M. Tafelmeier, J.M., L.S.M., M.A., S.W.), University Hospital Regensburg, Germany
| | - Maximillian Trum
- From the Department of Internal Medicine II (S.L., K.P., K.R., M. Trum, M. Tafelmeier, J.M., L.S.M., M.A., S.W.), University Hospital Regensburg, Germany
| | - Maria Tafelmeier
- From the Department of Internal Medicine II (S.L., K.P., K.R., M. Trum, M. Tafelmeier, J.M., L.S.M., M.A., S.W.), University Hospital Regensburg, Germany
| | - Julian Mustroph
- From the Department of Internal Medicine II (S.L., K.P., K.R., M. Trum, M. Tafelmeier, J.M., L.S.M., M.A., S.W.), University Hospital Regensburg, Germany
| | - Daniele Camboni
- Department of Cardiothoracic Surgery (D.C., L.R., C.S.), University Hospital Regensburg, Germany
| | - Leopold Rupprecht
- Department of Cardiothoracic Surgery (D.C., L.R., C.S.), University Hospital Regensburg, Germany
| | - Christof Schmid
- Department of Cardiothoracic Surgery (D.C., L.R., C.S.), University Hospital Regensburg, Germany
| | - Lars S. Maier
- From the Department of Internal Medicine II (S.L., K.P., K.R., M. Trum, M. Tafelmeier, J.M., L.S.M., M.A., S.W.), University Hospital Regensburg, Germany
| | - Michael Arzt
- From the Department of Internal Medicine II (S.L., K.P., K.R., M. Trum, M. Tafelmeier, J.M., L.S.M., M.A., S.W.), University Hospital Regensburg, Germany
| | - Stefan Wagner
- From the Department of Internal Medicine II (S.L., K.P., K.R., M. Trum, M. Tafelmeier, J.M., L.S.M., M.A., S.W.), University Hospital Regensburg, Germany
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Wenxin Keli Regulates Mitochondrial Oxidative Stress and Homeostasis and Improves Atrial Remodeling in Diabetic Rats. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:2468031. [PMID: 32104528 PMCID: PMC7040409 DOI: 10.1155/2020/2468031] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 01/07/2020] [Accepted: 01/25/2020] [Indexed: 12/13/2022]
Abstract
Mitochondrial dysfunction and oxidative stress play an important role in the pathogenesis of both atrial fibrillation (AF) and diabetes mellitus (DM). Wenxin Keli (WXKL), an antiarrhythmic traditional Chinese medicine, has been shown to prevent cardiac arrhythmias through modulation of cardiac ion channels. This study tested the hypothesis that WXKL can improve atrial remodeling in diabetic rats by restoring mitochondrial function. Primary atrial fibroblasts of neonatal SD rats were divided into four groups: control, hydrogen peroxide (H2O2), H2O2+WXKL 1 g/L, and H2O2+WXKL 3 g/L groups. Intracellular mitochondrial membrane potential (MMP), reactive oxygen species (ROS), and mitochondrial oxygen consumption were measured. SD male rats were randomly divided into three groups: control, DM, and DM+WXKL groups. Rats in the DM+WXKL group were treated with daily gavage of WXKL at 3 g/kg. After eight weeks, echocardiography, hemodynamic examination, histology, electrophysiology study, mitochondrial respiratory function, and western blots were assessed. H2O2 treatment led to increased ROS and decreased intracellular MMP and mitochondrial oxygen consumption in primary atrial fibroblasts. WXKL improved the above changes. DM rats showed increased atrial fibrosis, greater left atrial diameter, lower atrial conduction velocity, higher conduction heterogeneity, higher AF inducibility, and lower mitochondrial protein expression, and all these abnormal changes except for left atrial diameter were improved in the DM+WXKL group. WXKL improves atrial remodeling by regulating mitochondrial function and homeostasis and reducing mitochondrial ROS in diabetic rats.
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48
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Ratte A, Wiedmann F, Kraft M, Katus HA, Schmidt C. Antiarrhythmic Properties of Ranolazine: Inhibition of Atrial Fibrillation Associated TASK-1 Potassium Channels. Front Pharmacol 2019; 10:1367. [PMID: 32038227 PMCID: PMC6988797 DOI: 10.3389/fphar.2019.01367] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2019] [Accepted: 10/28/2019] [Indexed: 12/03/2022] Open
Abstract
Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and one of the major causes of cardiovascular morbidity and mortality. Despite good progress within the past years, safe and effective treatment of AF remains an unmet clinical need. The anti-anginal agent ranolazine has been shown to exhibit antiarrhythmic properties via mainly late INa and IKr blockade. This results in prolongation of the atrial action potential duration (APD) and effective refractory period (ERP) with lower effect on ventricular electrophysiology. Furthermore, ranolazine has been shown to be effective in the treatment of AF. TASK-1 is a two-pore domain potassium (K2P) channel that shows nearly atrial specific expression within the human heart and has been found to be upregulated in AF, resulting in shortening the atrial APD in patients suffering from AF. We hypothesized that inhibition TASK-1 contributes to the observed electrophysiological and clinical effects of ranolazine. Methods: We used Xenopus laevis oocytes and CHO-cells as heterologous expression systems for the study of TASK-1 inhibition by ranolazine and molecular drug docking simulations to investigate the ranolazine binding site and binding characteristics. Results: Ranolazine acts as an inhibitor of TASK-1 potassium channels that inhibits TASK-1 currents with an IC50 of 30.6 ± 3.7 µM in mammalian cells and 198.4 ± 1.1 µM in X. laevis oocytes. TASK-1 inhibition by ranolazine is not frequency dependent but shows voltage dependency with a higher inhibitory potency at more depolarized membrane potentials. Ranolazine binds within the central cavity of the TASK-1 inner pore, at the bottom of the selectivity filter. Conclusions: In this study, we show that ranolazine inhibits TASK-1 channels. We suggest that inhibition of TASK-1 may contribute to the observed antiarrhythmic effects of Ranolazine. This puts forward ranolazine as a prototype drug for the treatment of atrial arrhythmia because of its combined efficacy on atrial electrophysiology and lower risk for ventricular side effects.
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Affiliation(s)
- Antonius Ratte
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Centre for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Felix Wiedmann
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Centre for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Manuel Kraft
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Centre for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Hugo A Katus
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Centre for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany.,DZHK (German Centre for Cardiovascular Research), partner site Heidelberg/Mannheim, University of Heidelberg, Heidelberg, Germany.,HCR, Heidelberg Centre for Heart Rhythm Disorders, University of Heidelberg, Heidelberg, Germany
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49
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Greer-Short A, Musa H, Alsina KM, Ni L, Word TA, Reynolds JO, Gratz D, Lane C, El-Refaey M, Unudurthi S, Skaf M, Li N, Fedorov VV, Wehrens XHT, Mohler PJ, Hund TJ. Calmodulin kinase II regulates atrial myocyte late sodium current, calcium handling, and atrial arrhythmia. Heart Rhythm 2019; 17:503-511. [PMID: 31622781 DOI: 10.1016/j.hrthm.2019.10.016] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Indexed: 12/19/2022]
Abstract
BACKGROUND Atrial fibrillation (AF) is the most common type of arrhythmia. Abnormal atrial myocyte Ca2+ handling promotes aberrant membrane excitability and remodeling that are important for atrial arrhythmogenesis. The sequence of molecular events leading to loss of normal atrial myocyte Ca2+ homeostasis is not established. Late Na+ current (INa,L) is increased in atrial myocytes from AF patients together with an increase in activity of Ca2+/calmodulin-dependent kinase II (CaMKII). OBJECTIVE The purpose of this study was to determine whether CaMKII-dependent phosphorylation at Ser571 on NaV1.5 increases atrial INa,L, leading to aberrant atrial Ca2+ cycling, altered electrophysiology, and increased AF risk. METHODS Atrial myocyte electrophysiology, Ca2+ handling, and arrhythmia susceptibility were studied in wild-type and Scn5a knock-in mice expressing phosphomimetic (S571E) or phosphoresistant (S571A) NaV1.5 at Ser571. RESULTS Atrial myocytes from S571E but not S571A mice displayed an increase in INa,L and action potential duration, and with adrenergic stress have increased delayed afterdepolarizations. Frequency of Ca2+ sparks and waves was increased in S571E atrial myocytes compared to wild type. S571E mice showed an increase in atrial events induced by adrenergic stress and AF inducibility in vivo. Isolated S571E atria were more susceptible to spontaneous atrial events, which were abrogated by inhibiting sarcoplasmic reticulum Ca2+ release, CaMKII, or the Na+/Ca2+ exchanger. Expression of phospho-NaV1.5 at Ser571 and autophosphorylated CaMKII were increased in atrial samples from human AF patients. CONCLUSION This study identified CaMKII-dependent regulation of NaV1.5 as an important upstream event in Ca2+ handling defects and abnormal impulse generation in the setting of AF.
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Affiliation(s)
- Amara Greer-Short
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio
| | - Hassan Musa
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Katherina M Alsina
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Li Ni
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Tarah A Word
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Julia O Reynolds
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Daniel Gratz
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio
| | - Cemantha Lane
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio
| | - Mona El-Refaey
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Sathya Unudurthi
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio
| | - Michel Skaf
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Ning Li
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Physiology & Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio
| | - Vadim V Fedorov
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Physiology & Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio
| | - Xander H T Wehrens
- Cardiovascular Research Institute, Departments of Molecular Physiology & Biophysics, Medicine (Cardiology), Pediatrics (Cardiology), and Neuroscience, Center for Space Medicine, Baylor College of Medicine, Houston, Texas
| | - Peter J Mohler
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Physiology & Cell Biology, The Ohio State University College of Medicine, Columbus, Ohio; Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, Ohio
| | - Thomas J Hund
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio; Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio; Department of Internal Medicine, The Ohio State University College of Medicine, Columbus, Ohio.
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50
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Ramirez RJ, Takemoto Y, Martins RP, Filgueiras-Rama D, Ennis SR, Mironov S, Bhushal S, Deo M, Rajamani S, Berenfeld O, Belardinelli L, Jalife J, Pandit SV. Mechanisms by Which Ranolazine Terminates Paroxysmal but Not Persistent Atrial Fibrillation. Circ Arrhythm Electrophysiol 2019; 12:e005557. [PMID: 31594392 DOI: 10.1161/circep.117.005557] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
BACKGROUND Ranolazine inhibits Na+ current (INa), but whether it can convert atrial fibrillation (AF) to sinus rhythm remains unclear. We investigated antiarrhythmic mechanisms of ranolazine in sheep models of paroxysmal (PxAF) and persistent AF (PsAF). METHODS PxAF was maintained during acute stretch (N=8), and PsAF was induced by long-term atrial tachypacing (N=9). Isolated, Langendorff-perfused sheep hearts were optically mapped. RESULTS In PxAF ranolazine (10 μmol/L) reduced dominant frequency from 8.3±0.4 to 6.2±0.5 Hz (P<0.01) before converting to sinus rhythm, decreased singularity point density from 0.070±0.007 to 0.039±0.005 cm-2 s-1 (P<0.001) in left atrial epicardium (LAepi), and prolonged AF cycle length (AFCL); rotor duration, tip trajectory, and variance of AFCL were unaltered. In PsAF, ranolazine reduced dominant frequency (8.3±0.5 to 6.5±0.4 Hz; P<0.01), prolonged AFCL, increased the variance of AFCL, had no effect on singularity point density (0.048±0.011 to 0.042±0.016 cm-2 s-1; P=ns) and failed to convert AF to sinus rhythm. Doubling the ranolazine concentration (20 μmol/L) or supplementing with dofetilide (1 μmol/L) failed to convert PsAF to sinus rhythm. In computer simulations of rotors, reducing INa decreased dominant frequency, increased tip meandering and produced vortex shedding on wave interaction with unexcitable regions. CONCLUSIONS PxAF and PsAF respond differently to ranolazine. Cardioversion in the former can be attributed partly to decreased dominant frequency and singularity point density, and prolongation of AFCL. In the latter, increased dispersion of AFCL and likely vortex shedding contributes to rotor formation, compensating for any rotor loss, and may underlie the inefficacy of ranolazine to terminate PsAF.
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Affiliation(s)
- Rafael J Ramirez
- Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.)
| | - Yoshio Takemoto
- Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.)
| | - Raphaël P Martins
- Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.)
| | - David Filgueiras-Rama
- Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.).,Fundación Centro Nacional de Investigaciones Cardiovasculares, Carlos III (CNIC; D.F.-R., J.J.).,Centros de Investigación Biomédica en Red (CIBER) for Cardiovascular Diseases, Madrid, Spain (D.F.-R., J.J.)
| | - Steven R Ennis
- Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.)
| | - Sergey Mironov
- Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.)
| | - Sandesh Bhushal
- Department of Engineering, Norfolk State University, VA (S.B., M.D.)
| | - Makarand Deo
- Department of Engineering, Norfolk State University, VA (S.B., M.D.)
| | - Sridharan Rajamani
- Gilead Sciences, Foster City, CA (S.R., L.B.).,Currently: Amgen Inc, San Francisco, CA (S.R.)
| | - Omer Berenfeld
- Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.)
| | | | - José Jalife
- Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.).,Fundación Centro Nacional de Investigaciones Cardiovasculares, Carlos III (CNIC; D.F.-R., J.J.).,Centros de Investigación Biomédica en Red (CIBER) for Cardiovascular Diseases, Madrid, Spain (D.F.-R., J.J.)
| | - Sandeep V Pandit
- Center for Arrhythmia Research, Department of Internal Medicine-Cardiology, University of Michigan, Ann Arbor (R.J.R., Y.T., R.P.M., D.F.-R., S.R.E., S.M., O.B., J.J., S.V.P.)
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