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Li J. Long QT syndrome: long story short. Eur Heart J 2022; 43:4976-4977. [PMID: 36254679 DOI: 10.1093/eurheartj/ehac551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Affiliation(s)
- Jin Li
- Department of Cardiology, University Heart Center, University Hospital Zurich, University of Zurich, Raemistrasse 100, 8091 Zurich, Switzerland
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2
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Olgar Y, Durak A, Bitirim CV, Tuncay E, Turan B. Insulin acts as an atypical KCNQ1/KCNE1-current activator and reverses long QT in insulin-resistant aged rats by accelerating the ventricular action potential repolarization through affecting the β 3 -adrenergic receptor signaling pathway. J Cell Physiol 2021; 237:1353-1371. [PMID: 34632595 DOI: 10.1002/jcp.30597] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 09/22/2021] [Accepted: 09/24/2021] [Indexed: 12/13/2022]
Abstract
Insufficient-heart function is associated with myocardial insulin resistance in the elderly, particularly associated with long-QT, in a dependency on dysfunctional KCNQ1/KCNE1-channels. So, we aimed to examine the contribution of alterations in KCNQ1/KCNE1-current (IKs ) to the aging-related remodeling of the heart as well as the role of insulin treatment on IKs in the aged rats. Prolonged late-phase action potential (AP) repolarization of ventricular cardiomyocytes from insulin-resistant 24-month-old rats was significantly reversed by in vitro treatment of insulin or PKG inhibitor (in vivo, as well) via recovery in depressed IKs . Although the protein level of either KCNQ1 or KCNE1 in cardiomyocytes was not affected with aging, PKG level was significantly increased in those cells. The inhibited IKs in β3 -ARs-stimulated cells could be reversed with a PKG inhibitor, indicating the correlation between PKG-activation and β3 -ARs activation. Furthermore, in vivo treatment of aged rats, characterized by β3 -ARs activation, with either insulin or a PKG inhibitor for 2 weeks provided significant recoveries in IKs , prolonged late phases of APs, prolonged QT-intervals, and low heart rates without no effect on insulin resistance. In vivo insulin treatment provided also significant recovery in increased PKG and decreased PIP2 level, without the insulin effect on the KCNQ1 level in β3 -ARs overexpressed cells. The inhibition of IKs in aged-rat cardiomyocytes seems to be associated with activated β3 -ARs dependent remodeling in the interaction between KCNQ1 and KCNE1. Significant recoveries in ventricular-repolarization of insulin-treated aged cardiomyocytes via recovery in IKs strongly emphasize two important issues: (1) IKs can be a novel target in aging-associated remodeling in the heart and insulin may be a cardioprotective agent in the maintenance of normal heart function during the aging process. (2) This study is one of the first to demonstrate insulin's benefits on long-QT in insulin-resistant aged rats by accelerating the ventricular AP repolarization through reversing the depressed IKs via affecting the β3 -ARs signaling pathway and particularly affecting activated PKG.
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Affiliation(s)
- Yusuf Olgar
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Aysegul Durak
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | | | - Erkan Tuncay
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, Ankara, Turkey.,Department of Biophysics, Faculty of Medicine, Lokman Hekim University, Ankara, Turkey
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3
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Marian AJ, Asatryan B, Wehrens XHT. Genetic basis and molecular biology of cardiac arrhythmias in cardiomyopathies. Cardiovasc Res 2021; 116:1600-1619. [PMID: 32348453 DOI: 10.1093/cvr/cvaa116] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 03/09/2020] [Accepted: 04/21/2020] [Indexed: 12/19/2022] Open
Abstract
Cardiac arrhythmias are common, often the first, and sometimes the life-threatening manifestations of hereditary cardiomyopathies. Pathogenic variants in several genes known to cause hereditary cardiac arrhythmias have also been identified in the sporadic cases and small families with cardiomyopathies. These findings suggest a shared genetic aetiology of a subset of hereditary cardiomyopathies and cardiac arrhythmias. The concept of a shared genetic aetiology is in accord with the complex and exquisite interplays that exist between the ion currents and cardiac mechanical function. However, neither the causal role of cardiac arrhythmias genes in cardiomyopathies is well established nor the causal role of cardiomyopathy genes in arrhythmias. On the contrary, secondary changes in ion currents, such as post-translational modifications, are common and contributors to the pathogenesis of arrhythmias in cardiomyopathies through altering biophysical and functional properties of the ion channels. Moreover, structural changes, such as cardiac hypertrophy, dilatation, and fibrosis provide a pro-arrhythmic substrate in hereditary cardiomyopathies. Genetic basis and molecular biology of cardiac arrhythmias in hereditary cardiomyopathies are discussed.
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Affiliation(s)
- Ali J Marian
- Department of Medicine, Center for Cardiovascular Genetics, Institute of Molecular Medicine, University of Texas Health Sciences Center at Houston, 6770 Bertner Street, Suite C900A, Houston, TX 77030, USA
| | - Babken Asatryan
- Department of Cardiology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| | - Xander H T Wehrens
- Department of Biophysics and Molecular Physiology, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX 77030, USA
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Abstract
Conduction disorders and arrhythmias remain difficult to treat and are increasingly prevalent owing to the increasing age and body mass of the general population, because both are risk factors for arrhythmia. Many of the underlying conditions that give rise to arrhythmia - including atrial fibrillation and ventricular arrhythmia, which frequently occur in patients with acute myocardial ischaemia or heart failure - can have an inflammatory component. In the past, inflammation was viewed mostly as an epiphenomenon associated with arrhythmia; however, the recently discovered inflammatory and non-canonical functions of cardiac immune cells indicate that leukocytes can be arrhythmogenic either by altering tissue composition or by interacting with cardiomyocytes; for example, by changing their phenotype or perhaps even by directly interfering with conduction. In this Review, we discuss the electrophysiological properties of leukocytes and how these cells relate to conduction in the heart. Given the thematic parallels, we also summarize the interactions between immune cells and neural systems that influence information transfer, extrapolating findings from the field of neuroscience to the heart and defining common themes. We aim to bridge the knowledge gap between electrophysiology and immunology, to promote conceptual connections between these two fields and to explore promising opportunities for future research.
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Abstract
PURPOSE OF REVIEW The role of autoantibodies in arrhythmogenesis has been the subject of research in recent times. This review focuses on the rapidly expanding field of autoantibody-mediated cardiac arrhythmias. RECENT FINDINGS Since the discovery of cardiac autoantibodies more than three decades ago, a great deal of effort has been devoted to understanding their contribution to arrhythmias. Different cardiac receptors and ion channels were identified as targets for autoantibodies, the binding of which either initiates a signaling cascade or serves as a biomarker of underlying remodeling process. Consequently, the wide spectrum of heart rhythm disturbances may emerge, ranging from atrial to ventricular arrhythmias as well as conduction diseases, irrespective of concomitant structural heart disease or manifest autoimmune disorder. The time has come to acknowledge autoimmune cardiac arrhythmias as a distinct disease entity. Establishing the autoantibody profile of patients will help to develop novel treatment approaches for patients.
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Affiliation(s)
- Jin Li
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012, Bern, Switzerland. .,Department of Cardiology, Lausanne University Hospital, rue du Bugnon 46, 1011, Lausanne, Switzerland.
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6
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Boutjdir M, Lazzerini PE. A Novel Peptide/Antibody-Based Antiarrhythmic Approach to Long QT Syndrome and Beyond. J Am Coll Cardiol 2020; 75:2153-2155. [PMID: 32354383 DOI: 10.1016/j.jacc.2020.03.027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/13/2020] [Accepted: 03/17/2020] [Indexed: 01/08/2023]
Affiliation(s)
- Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, New York, New York; Departments of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Medical Center, New York, New York; Cardiology Division, Department of Medicine, NYU School of Medicine, New York, New York.
| | - Pietro Enea Lazzerini
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
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7
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Maguy A, Kucera JP, Wepfer JP, Forest V, Charpentier F, Li J. KCNQ1 Antibodies for Immunotherapy of Long QT Syndrome Type 2. J Am Coll Cardiol 2020; 75:2140-2152. [DOI: 10.1016/j.jacc.2020.02.067] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 02/04/2020] [Accepted: 02/25/2020] [Indexed: 02/02/2023]
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Abstract
BACKGROUND Cardiac arrest is a tragic event that causes 1 death roughly every 90 seconds worldwide. Survivors generally undergo a workup to identify the cause of arrest. However, 5% to 10% of cardiac arrests remain unexplained. Because cardiac arrhythmias underlie most cardiac arrests and increasing evidence strongly supports the involvement of autoantibodies in arrhythmogenesis, a large-panel autoantibody screening was performed in patients with cardiac arrest. METHODS This is an observational, cross-sectional study of patients from the Montreal Heart Institute hospital cohort, a single-center registry of participants. A peptide microarray was designed to screen for immunoglobulin G targeting epitopes from all known cardiac ion channels with extracellular domains. Plasma samples from 23 patients with unexplained cardiac arrest were compared with those from 22 patients with cardiac arrest cases of ischemic origin and a group of 29 age-, sex-, and body mass index-matched healthy subjects. The false discovery rate, least absolute shrinkage and selection operator logistic regression, and random forest methods were carried out jointly to find significant differential immunoglobulin G responses. RESULTS The autoantibody against the pore domain of the L-type voltage-gated calcium channel was consistently identified as a biomarker of idiopathic cardiac arrest (P=0.002; false discovery rate, 0.007; classification accuracies ≥0.83). Functional studies on human induced pluripotent stem cell-derived cardiomyocytes demonstrated that the anti-L-type voltage-gated calcium channel immunoglobulin G purified from patients with idiopathic cardiac arrest is proarrhythmogenic by reducing the action potential duration through calcium channel inhibition. CONCLUSIONS The present report addresses the concept of autoimmunity and cardiac arrest. Hitherto unknown autoantibodies targeting extracellular sequences of cardiac ion channels were detected. Moreover, the study identified an autoantibody signature specific to patients with cardiac arrest.
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Affiliation(s)
- Ange Maguy
- Institute of Physiology (A.M.), University of Bern, Switzerland
| | - Jean-Claude Tardif
- Montreal Heart Institute, Université de Montréal, QC, Canada (J.C.T., D.B.)
| | - David Busseuil
- Montreal Heart Institute, Université de Montréal, QC, Canada (J.C.T., D.B.)
| | - Camillo Ribi
- Division of Immunology and Allergy (C.R.), Lausanne University Hospital, Switzerland
| | - Jin Li
- Institute of Biochemistry and Molecular Medicine (J.L.), University of Bern, Switzerland.,Department of Cardiology (J.L.), Lausanne University Hospital, Switzerland
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Wu H, Wang Y, Wang G, Qiu Z, Hu X, Zhang H, Yan X, Ke F, Zou A, Wang M, Liao Y, Chen X. A bivalent antihypertensive vaccine targeting L-type calcium channels and angiotensin AT 1 receptors. Br J Pharmacol 2019; 177:402-419. [PMID: 31625597 DOI: 10.1111/bph.14875] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 09/09/2019] [Accepted: 09/15/2019] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND AND PURPOSE Hypertension has been the leading preventable cause of premature death worldwide. The aim of this study was to design a more efficient vaccine against novel targets for the treatment of hypertension. EXPERIMENTAL APPROACH The epitope CE12, derived from the human L-type calcium channel (CaV 1.2), was designed and conjugated with Qβ bacteriophage virus-like particles to test the efficacy in hypertensive animals. Further, the hepatitis B core antigen (HBcAg)-CE12-CQ10 vaccine, a bivalent vaccine based on HBcAg virus-like particles and targeting both human angiotensin AT1 receptors and CaV 1.2 channels, was developed and evaluated in hypertensive rodents. KEY RESULTS The Qβ-CE12 vaccine effectively decreased the BP in hypertensive rodents. A monoclonal antibody against CE12 specifically bound to L-type calcium channels and inhibited channel activity. Injection with monoclonal antibody against CE12 effectively reduced the BP in angiotensin II-induced hypertensive mice. The HBcAg-CE12-CQ10 vaccine showed antihypertensive effects in hypertensive mice and relatively superior antihypertensive effects in spontaneously hypertensive rats and ameliorated L-NAME-induced renal injury. In addition, no obvious immune-mediated damage or electrophysiological adverse effects were detected. CONCLUSION AND IMPLICATIONS Immunotherapy against both AT1 receptors and CaV 1.2 channels decreased the BP in hypertensive rodents effectively and provided protection against hypertensive target organ damage without obvious feedback activation of renin-angiotensin system or induction of dominant antibodies against the carrier protein. Thus, the HBcAg-CE12-CQ10 vaccine may provide a novel and promising therapeutic approach for hypertension.
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Affiliation(s)
- Hailang Wu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yiyi Wang
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gongxin Wang
- Electrophysiological Laboratory, Qingdao Haiwei Biopharma Co. Ltd, Qingdao, China
| | - Zhihua Qiu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiajun Hu
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hongrong Zhang
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaole Yan
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fan Ke
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Anruo Zou
- Electrophysiological Laboratory, Qingdao Haiwei Biopharma Co. Ltd, Qingdao, China
| | - Min Wang
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yuhua Liao
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao Chen
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Institute of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.,Key Lab for Biological Targeted Therapy of Education Ministry and Hubei Province, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Varshneya M, Devenyi RA, Sobie EA. Slow Delayed Rectifier Current Protects Ventricular Myocytes From Arrhythmic Dynamics Across Multiple Species: A Computational Study. Circ Arrhythm Electrophysiol 2019; 11:e006558. [PMID: 30354408 DOI: 10.1161/circep.118.006558] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
BACKGROUND The slow and rapid delayed rectifier K+ currents (IKs and IKr, respectively) are responsible for repolarizing the ventricular action potential (AP) and preventing abnormally long APs that may lead to arrhythmias. Although differences in biophysical properties of the 2 currents have been carefully documented, the respective physiological roles of IKr and IKs are less established. In this study, we sought to understand the individual roles of these currents and quantify how effectively each stabilizes the AP and protects cells against arrhythmias across multiple species. METHODS We compared 10 mathematical models describing ventricular myocytes from human, rabbit, dog, and guinea pig. We examined variability within heterogeneous cell populations, tested the susceptibility of cells to proarrhythmic behavior, and studied how IKs and IKr responded to changes in the AP. RESULTS We found that (1) models with higher baseline IKs exhibited less cell-to-cell variability in AP duration; (2) models with higher baseline IKs were less susceptible to early afterdepolarizations induced by depolarizing perturbations; (3) as AP duration is lengthened, IKs increases more profoundly than IKr, thereby providing negative feedback that resists excessive AP prolongation; and (4) the increase in IKs that occurs during β-adrenergic stimulation is critical for protecting cardiac myocytes from early afterdepolarizations under these conditions. CONCLUSIONS Slow delayed rectifier current is uniformly protective across a variety of cell types. These results suggest that IKs enhancement could potentially be an effective antiarrhythmic strategy.
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Affiliation(s)
- Meera Varshneya
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (M.V., R.A.D., E.A.S.)
| | - Ryan A Devenyi
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (M.V., R.A.D., E.A.S.)
| | - Eric A Sobie
- Department of Pharmacological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY (M.V., R.A.D., E.A.S.)
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11
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Autoimmune and inflammatory K+ channelopathies in cardiac arrhythmias: Clinical evidence and molecular mechanisms. Heart Rhythm 2019; 16:1273-1280. [DOI: 10.1016/j.hrthm.2019.02.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Indexed: 12/30/2022]
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12
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Lethal immunoglobulins: Autoantibodies and sudden cardiac death. Autoimmun Rev 2019; 18:415-425. [DOI: 10.1016/j.autrev.2018.12.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Accepted: 12/13/2018] [Indexed: 02/08/2023]
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13
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Lazzerini PE, Laghi-Pasini F, Boutjdir M, Capecchi PL. Cardioimmunology of arrhythmias: the role of autoimmune and inflammatory cardiac channelopathies. Nat Rev Immunol 2018; 19:63-64. [DOI: 10.1038/s41577-018-0098-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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14
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Lazzerini PE, Capecchi PL, El‐Sherif N, Laghi‐Pasini F, Boutjdir M. Emerging Arrhythmic Risk of Autoimmune and Inflammatory Cardiac Channelopathies. J Am Heart Assoc 2018; 7:e010595. [PMID: 30571503 PMCID: PMC6404431 DOI: 10.1161/jaha.118.010595] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
| | | | - Nabil El‐Sherif
- Veterans Affairs New York Harbor Healthcare SystemState University of New York Downstate Medical CenterNew YorkNY
| | - Franco Laghi‐Pasini
- Department of Medical Sciences, Surgery and NeurosciencesUniversity of SienaItaly
| | - Mohamed Boutjdir
- Veterans Affairs New York Harbor Healthcare SystemState University of New York Downstate Medical CenterNew YorkNY
- New York University School of MedicineNew YorkNY
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15
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Yao H, Ji CC, Cheng YJ, Chen XM, Liu LJ, Fan J, Wu SH. Mutation in KCNE1 associated to early repolarization syndrome by modulation of slowly activating delayed rectifier K + current. Exp Cell Res 2018; 363:315-320. [DOI: 10.1016/j.yexcr.2018.01.030] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 01/11/2018] [Accepted: 01/20/2018] [Indexed: 01/13/2023]
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Fosmo AL, Skraastad ØB. The Kv7 Channel and Cardiovascular Risk Factors. Front Cardiovasc Med 2017; 4:75. [PMID: 29259974 PMCID: PMC5723334 DOI: 10.3389/fcvm.2017.00075] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/21/2017] [Indexed: 12/30/2022] Open
Abstract
Potassium channels play a pivotal role in the regulation of excitability in cells such as neurons, cardiac myocytes, and vascular smooth muscle cells. The KCNQ (Kv7) family of voltage-activated K+ channels hyperpolarizes the cell and stabilizes the membrane potential. Here, we outline how Kv7 channel activity may contribute to the development of the cardiovascular risk factors such as hypertension, diabetes, and obesity. Questions and hypotheses regarding previous and future research have been raised. Alterations in the Kv7 channel may contribute to the development of cardiovascular disease (CVD). Pharmacological modification of Kv7 channels may represent a possible treatment for CVD in the future.
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Affiliation(s)
- Andreas L Fosmo
- Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Øyvind B Skraastad
- Division of Physiology, Department of Molecular Medicine, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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18
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19
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Lazzerini PE, Capecchi PL, Laghi-Pasini F, Boutjdir M. Autoimmune channelopathies as a novel mechanism in cardiac arrhythmias. Nat Rev Cardiol 2017; 14:521-535. [PMID: 28470179 DOI: 10.1038/nrcardio.2017.61] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cardiac arrhythmias confer a considerable burden of morbidity and mortality in industrialized countries. Although coronary artery disease and heart failure are the prevalent causes of cardiac arrest, in 5-15% of patients, structural abnormalities at autopsy are absent. In a proportion of these patients, mutations in genes encoding cardiac ion channels are documented (inherited channelopathies), but, to date, the molecular autopsy is negative in nearly 70% of patients. Emerging evidence indicates that autoimmunity is involved in the pathogenesis of cardiac arrhythmias. In particular, several arrhythmogenic autoantibodies targeting specific calcium, potassium, or sodium channels in the heart have been identified. Experimental and clinical studies demonstrate that these autoantibodies can promote conduction disturbances and life-threatening tachyarrhythmias by inducing substantial electrophysiological changes. In this Review, we propose the term 'autoimmune cardiac channelopathies' to define this novel pathogenic mechanism of cardiac arrhythmias, which could be more frequent and clinically relevant than previously appreciated. Indeed, pathogenic autoantibodies against ion channels are detectable not only in patients with manifest autoimmune disease, but also in apparently healthy individuals, which suggests a causal role in some cases of unexplained arrhythmias and cardiac arrest. Considering this possibility and performing specific testing in patients with 'idiopathic' rhythm disturbances could create novel treatment opportunities.
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Affiliation(s)
- Pietro Enea Lazzerini
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Viale Bracci 16, Siena, 53100, Italy
| | - Pier Leopoldo Capecchi
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Viale Bracci 16, Siena, 53100, Italy
| | - Franco Laghi-Pasini
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Viale Bracci 16, Siena, 53100, Italy
| | - Mohamed Boutjdir
- VA New York Harbor Healthcare System, 800 Poly Place, Brooklyn, New York 11209, USA.,SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York 11203, USA.,NYU School of Medicine, 550 1st Avenue, New York, New York 10016, USA
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Dromedary immune response and specific Kv2.1 antibody generation using a specific immunization approach. Int J Biol Macromol 2016; 93:167-171. [DOI: 10.1016/j.ijbiomac.2016.06.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Revised: 06/10/2016] [Accepted: 06/11/2016] [Indexed: 01/11/2023]
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21
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Fabris F, Yue Y, Qu Y, Chahine M, Sobie E, Lee P, Wieczorek R, Jiang XC, Capecchi PL, Laghi-Pasini F, Lazzerini PE, Boutjdir M. Induction of autoimmune response to the extracellular loop of the HERG channel pore induces QTc prolongation in guinea-pigs. J Physiol 2016; 594:6175-6187. [PMID: 27296897 DOI: 10.1113/jp272151] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 06/01/2016] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Channelopathies of autoimmune origin are novel and are associated with corrected QT (QTc) prolongation and complex ventricular arrhythmias. We have recently demonstrated that anti-SSA/Ro antibodies from patients with autoimmune diseases and with QTc prolongation on the ECG target the human ether-à-go-go-related gene (HERG) K+ channel by inhibiting the corresponding current, IKr , at the pore region. Immunization of guinea-pigs with a peptide (E-pore peptide) corresponding to the extracellular loop region connecting the S5 and S6 segments of the HERG channel induces high titres of antibodies that inhibit IKr , lengthen the action potential and cause QTc prolongation on the surface ECG. In addition, anti-SSA/Ro-positive sera from patients with connective tissue diseases showed high reactivity to the E-pore peptide. The translational impact is the development of a peptide-based approach for the diagnosis and treatment of autoimmune-associated long QT syndrome. ABSTRACT We recently demonstrated that anti-SSA/52 kDa Ro antibodies (Abs) from patients with autoimmune diseases and corrected QT (QTc) prolongation directly target and inhibit the human ether-à-go-go-related gene (HERG) K+ channel at the extracellular pore (E-pore) region, where homology with SSA/52 kDa Ro antigen was demonstrated. We tested the hypothesis that immunization of guinea-pigs with a peptide corresponding to the E-pore region (E-pore peptide) will generate pathogenic inhibitory Abs and cause QTc prolongation. Guinea-pigs were immunized with a 31-amino-acid peptide corresponding to the E-pore region of HERG. On days 10-62 after immunization, ECGs were recorded and blood was sampled for the detection of E-pore peptide Abs. Serum samples from patients with autoimmune diseases were evaluated for reactivity to E-pore peptide by enzyme-linked immunosorbent assay (ELISA), and histology was performed on hearts using Masson's Trichrome. Inhibition of the HERG channel was assessed by electrophysiology and by computational modelling of the human ventricular action potential. The ELISA results revealed the presence of high titres of E-pore peptide Abs and significant QTc prolongation after immunization. High reactivity to E-pore peptide was found using anti-SSA/Ro Ab-positive sera from patients with QTc prolongation. Histological data showed no evidence of fibrosis in immunized hearts. Simulations of simultaneous inhibition of repolarizing currents by anti-SSA/Ro Ab-positive sera showed the predominance of the HERG channel in controlling action potential duration and the QT interval. These results are the first to demonstrate that inhibitory Abs to the HERG E-pore region induce QTc prolongation in immunized guinea-pigs by targeting the HERG channel independently from fibrosis. The reactivity of anti-SSA/Ro Ab-positive sera from patients with connective tissue diseases with the E-pore peptide opens novel pharmacotherapeutic avenues in the diagnosis and management of autoimmune-associated QTc prolongation.
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Affiliation(s)
- Frank Fabris
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, NY, USA.,Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Yuankun Yue
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, NY, USA
| | - Yongxia Qu
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, NY, USA.,Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Mohamed Chahine
- Centre de Recherche de l'Institut Universitaire en Santé Mentale de Québec, Laval University, Quebec City, QC, Canada
| | - Eric Sobie
- Department of Pharmacology & Systems Therapeutics, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Peng Lee
- Pathology Department, VA New York Harbor Healthcare System, New York, NY, USA.,Department of Pathology, New York University School of Medicine, New York, NY, USA
| | - Rosemary Wieczorek
- Pathology Department, VA New York Harbor Healthcare System, New York, NY, USA
| | - Xian-Cheng Jiang
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, NY, USA.,Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Pier-Leopoldo Capecchi
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Franco Laghi-Pasini
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Pietro-Enea Lazzerini
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena, Siena, Italy
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare System, Brooklyn, NY, USA. .,Department of Medicine, State University of New York Downstate Medical Center, Brooklyn, NY, USA. .,Department of Cell Biology, State University of New York Downstate Medical Center, Brooklyn, NY, USA. .,Department of Pharmacology, State University of New York Downstate Medical Center, Brooklyn, NY, USA. .,Department of Medicine, New York University School of Medicine, New York, NY, USA.
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RamaKrishnan AM, Sankaranarayanan K. Understanding autoimmunity: The ion channel perspective. Autoimmun Rev 2016; 15:585-620. [PMID: 26854401 DOI: 10.1016/j.autrev.2016.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2016] [Accepted: 01/29/2016] [Indexed: 12/11/2022]
Abstract
Ion channels are integral membrane proteins that orchestrate the passage of ions across the cell membrane and thus regulate various key physiological processes of the living system. The stringently regulated expression and function of these channels hold a pivotal role in the development and execution of various cellular functions. Malfunction of these channels results in debilitating diseases collectively termed channelopathies. In this review, we highlight the role of these proteins in the immune system with special emphasis on the development of autoimmunity. The role of ion channels in various autoimmune diseases is also listed out. This comprehensive review summarizes the ion channels that could be used as molecular targets in the development of new therapeutics against autoimmune disorders.
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Affiliation(s)
| | - Kavitha Sankaranarayanan
- AU-KBC Research Centre, Madras Institute of Technology, Anna University, Chrompet, Chennai 600 044, India.
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Lazzerini PE, Capecchi PL, Laghi-Pasini F. Long QT Syndrome: An Emerging Role for Inflammation and Immunity. Front Cardiovasc Med 2015; 2:26. [PMID: 26798623 PMCID: PMC4712633 DOI: 10.3389/fcvm.2015.00026] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 05/08/2015] [Indexed: 01/07/2023] Open
Abstract
The long QT syndrome (LQTS), classified as congenital or acquired, is a multi-factorial disorder of myocardial repolarization predisposing to life-threatening ventricular arrhythmias, particularly torsades de pointes. In the latest years, inflammation and immunity have been increasingly recognized as novel factors crucially involved in modulating ventricular repolarization. In the present paper, we critically review the available information on this topic, also analyzing putative mechanisms and potential interplays with the other etiologic factors, either acquired or inherited. Accumulating data indicate inflammatory activation as a potential cause of acquired LQTS. The putative underlying mechanisms are complex but essentially cytokine-mediated, including both direct actions on cardiomyocyte ion channels expression and function, and indirect effects resulting from an increased central nervous system sympathetic drive on the heart. Autoimmunity represents another recently arising cause of acquired LQTS. Indeed, increasing evidence demonstrates that autoantibodies may affect myocardial electric properties by directly cross-reacting with the cardiomyocyte and interfering with specific ion currents as a result of molecular mimicry mechanisms. Intriguingly, recent data suggest that inflammation and immunity may be also involved in modulating the clinical expression of congenital forms of LQTS, possibly triggering or enhancing electrical instability in patients who already are genetically predisposed to arrhythmias. In this view, targeting immuno-inflammatory pathways may in the future represent an attractive therapeutic approach in a number of LQTS patients, thus opening new exciting avenues in antiarrhythmic therapy.
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Affiliation(s)
- Pietro Enea Lazzerini
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena , Siena , Italy
| | - Pier Leopoldo Capecchi
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena , Siena , Italy
| | - Franco Laghi-Pasini
- Department of Medical Sciences, Surgery and Neurosciences, University of Siena , Siena , Italy
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Li J, Maguy A, Duverger JE, Vigneault P, Comtois P, Shi Y, Tardif JC, Thomas D, Nattel S. Induced KCNQ1 autoimmunity accelerates cardiac repolarization in rabbits: potential significance in arrhythmogenesis and antiarrhythmic therapy. Heart Rhythm 2014; 11:2092-100. [PMID: 25087487 DOI: 10.1016/j.hrthm.2014.07.040] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Indexed: 11/15/2022]
Abstract
BACKGROUND Autoantibodies directed against various cardiac receptors have been implicated in cardiomyopathy and heart rhythm disturbances. In a previous study among patients with dilated cardiomyopathy, autoantibodies targeting the cardiac voltage-gated KCNQ1 K(+) channel were associated with shortened corrected QT intervals (QTc). However, the electrophysiologic actions of KCNQ1 autoimmunity have not been assessed experimentally in a direct fashion. OBJECTIVE The purpose of this study was to investigate the cardiac electrophysiologic effects of KCNQ1 autoantibody production induced by vaccination in a rabbit model. METHODS Rabbits were immunized with KCNQ1 channel peptide. ECG recordings were obtained during a 1-month follow-up period. Rabbits then underwent in vivo electrophysiologic study, after which cardiomyocytes were isolated for analysis of slow delayed rectifier current (IKs) and action potential properties via patch-clamp. RESULTS KCNQ1-immunized rabbits exhibited shortening of QTc compared to sham-immunized controls. Reduced ventricular effective refractory periods and increased susceptibility to ventricular tachyarrhythmia induction were noted in KCNQ1-immunized rabbits upon programmed ventricular stimulation. Action potential durations were shortened in cardiomyocytes isolated from KCNQ1-immunized rabbits compared to the sham group. IKs step and tail current densities were enhanced after KCNQ1 immunization. Functional and structural changes of the heart were not observed. The potential therapeutic significance of KCNQ1 immunization was then explored in a dofetilide-induced long QT rabbit model. KCNQ1 immunization prevented dofetilide-induced QTc prolongation and attenuated long QT-related arrhythmias. CONCLUSION Induction of KCNQ1 autoimmunity accelerates cardiac repolarization and increases susceptibility to ventricular tachyarrhythmia induction through IKs enhancement. On the other hand, vaccination against KCNQ1 ameliorates drug-induced QTc prolongation and might be useful therapeutically to enhance repolarization reserve in long QT syndrome.
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Affiliation(s)
- Jin Li
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada; Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Ange Maguy
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada
| | - James Elber Duverger
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada; Institute of Biomedical Engineering and Department of Physiology, University of Montreal; Montreal, Quebec, Canada
| | - Patrick Vigneault
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada
| | - Philippe Comtois
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada; Institute of Biomedical Engineering and Department of Physiology, University of Montreal; Montreal, Quebec, Canada
| | - Yanfen Shi
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada
| | - Jean-Claude Tardif
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada
| | - Dierk Thomas
- Department of Cardiology, University of Heidelberg, Heidelberg, Germany
| | - Stanley Nattel
- Department of Medicine and Research Center, Montreal Heart Institute and Université de Montréal, Montréal, Québec, Canada.
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