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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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Paasche A, Wiedmann F, Kraft M, Seibertz F, Herlt V, Blochberger PL, Jávorszky N, Beck M, Weirauch L, Seeger T, Blank A, Haefeli WE, Arif R, Meyer AL, Warnecke G, Karck M, Voigt N, Frey N, Schmidt C. Acute antiarrhythmic effects of SGLT2 inhibitors-dapagliflozin lowers the excitability of atrial cardiomyocytes. Basic Res Cardiol 2024; 119:93-112. [PMID: 38170280 PMCID: PMC10837223 DOI: 10.1007/s00395-023-01022-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2023] [Revised: 11/08/2023] [Accepted: 11/24/2023] [Indexed: 01/05/2024]
Abstract
In recent years, SGLT2 inhibitors have become an integral part of heart failure therapy, and several mechanisms contributing to cardiorenal protection have been identified. In this study, we place special emphasis on the atria and investigate acute electrophysiological effects of dapagliflozin to assess the antiarrhythmic potential of SGLT2 inhibitors. Direct electrophysiological effects of dapagliflozin were investigated in patch clamp experiments on isolated atrial cardiomyocytes. Acute treatment with elevated-dose dapagliflozin caused a significant reduction of the action potential inducibility, the amplitude and maximum upstroke velocity. The inhibitory effects were reproduced in human induced pluripotent stem cell-derived cardiomyocytes, and were more pronounced in atrial compared to ventricular cells. Hypothesizing that dapagliflozin directly affects the depolarization phase of atrial action potentials, we examined fast inward sodium currents in human atrial cardiomyocytes and found a significant decrease of peak sodium current densities by dapagliflozin, accompanied by a moderate inhibition of the transient outward potassium current. Translating these findings into a porcine large animal model, acute elevated-dose dapagliflozin treatment caused an atrial-dominant reduction of myocardial conduction velocity in vivo. This could be utilized for both, acute cardioversion of paroxysmal atrial fibrillation episodes and rhythm control of persistent atrial fibrillation. In this study, we show that dapagliflozin alters the excitability of atrial cardiomyocytes by direct inhibition of peak sodium currents. In vivo, dapagliflozin exerts antiarrhythmic effects, revealing a potential new additional role of SGLT2 inhibitors in the treatment of atrial arrhythmias.
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Affiliation(s)
- Amelie Paasche
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Felix Wiedmann
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Manuel Kraft
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Fitzwilliam Seibertz
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert Koch Strasse 42a, 37075, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research) Partner Site Göttingen, Robert Koch Strasse 42a, 37075, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Robert Koch Strasse 40, 37075, Göttingen, Germany
| | - Valerie Herlt
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Pablo L Blochberger
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Natasa Jávorszky
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Moritz Beck
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Leo Weirauch
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Timon Seeger
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
| | - Antje Blank
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Walter E Haefeli
- Department of Clinical Pharmacology and Pharmacoepidemiology, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Rawa Arif
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Anna L Meyer
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Gregor Warnecke
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Matthias Karck
- Department of Cardiac Surgery, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Niels Voigt
- Institute of Pharmacology and Toxicology, University Medical Center Göttingen, Robert Koch Strasse 42a, 37075, Göttingen, Germany
- DZHK (German Center for Cardiovascular Research) Partner Site Göttingen, Robert Koch Strasse 42a, 37075, Göttingen, Germany
- Cluster of Excellence "Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Robert Koch Strasse 40, 37075, Göttingen, Germany
| | - Norbert Frey
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany
| | - Constanze Schmidt
- Department of Cardiology, Medical University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
- DZHK (German Center for Cardiovascular Research), Partner site Heidelberg/Mannheim, University of Heidelberg, Im Neuenheimer Feld 669, 69120, Heidelberg, Germany.
- HCR, Heidelberg Center for Heart Rhythm Disorders, University Hospital Heidelberg, Im Neuenheimer Feld 410, 69120, Heidelberg, Germany.
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Sauer J, Marksteiner J, Lilliu E, Hackl B, Todt H, Kubista H, Dostal C, Podesser BK, Kiss A, Koenig X, Hilber K. Empagliflozin treatment rescues abnormally reduced Na + currents in ventricular cardiomyocytes from dystrophin-deficient mdx mice. Am J Physiol Heart Circ Physiol 2024; 326:H418-H425. [PMID: 38099845 PMCID: PMC11219046 DOI: 10.1152/ajpheart.00729.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/07/2023] [Accepted: 12/12/2023] [Indexed: 01/23/2024]
Abstract
Cardiac arrhythmias significantly contribute to mortality in Duchenne muscular dystrophy (DMD), a severe muscle illness caused by mutations in the gene encoding for the intracellular protein dystrophin. A major source for arrhythmia vulnerability in patients with DMD is impaired ventricular impulse conduction, which predisposes for ventricular asynchrony, decreased cardiac output, and the development of reentrant circuits. Using the dystrophin-deficient mdx mouse model for human DMD, we previously reported that the lack of dystrophin causes a significant loss of peak Na+ current (INa) in ventricular cardiomyocytes. This finding provided a mechanistic explanation for ventricular conduction defects and concomitant arrhythmias in the dystrophic heart. In the present study, we explored the hypothesis that empagliflozin (EMPA), an inhibitor of sodium/glucose cotransporter 2 in clinical use to treat type II diabetes and nondiabetic heart failure, rescues peak INa loss in dystrophin-deficient ventricular cardiomyocytes. We found that INa of cardiomyocytes derived from mdx mice, which had received clinically relevant doses of EMPA for 4 wk, was restored to wild-type level. Moreover, incubation of isolated mdx ventricular cardiomyocytes with 1 µM EMPA for 24 h significantly increased their peak INa. This effect was independent of Na+-H+ exchanger 1 inhibition by the drug. Our findings imply that EMPA treatment can rescue abnormally reduced peak INa of dystrophin-deficient ventricular cardiomyocytes. Long-term EMPA administration may diminish arrhythmia vulnerability in patients with DMD.NEW & NOTEWORTHY Dystrophin deficiency in cardiomyocytes leads to abnormally reduced Na+ currents. These can be rescued by long-term empagliflozin treatment.
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Affiliation(s)
- Jakob Sauer
- Department of Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Jessica Marksteiner
- Department of Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Elena Lilliu
- Department of Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Benjamin Hackl
- Department of Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Hannes Todt
- Department of Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Helmut Kubista
- Department of Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Christopher Dostal
- Center for Biomedical Research and Translational Surgery, Medical University of Vienna, Vienna, Austria
| | - Bruno K Podesser
- Center for Biomedical Research and Translational Surgery, Medical University of Vienna, Vienna, Austria
| | - Attila Kiss
- Center for Biomedical Research and Translational Surgery, Medical University of Vienna, Vienna, Austria
| | - Xaver Koenig
- Department of Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Karlheinz Hilber
- Department of Neurophysiology and Pharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
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Porta-Sánchez A, Mazzanti A, Tarifa C, Kukavica D, Trancuccio A, Mohsin M, Zanfrini E, Perota A, Duchi R, Hernandez-Lopez K, Jáuregui-Abularach ME, Pergola V, Fernandez E, Bongianino R, Tavazzani E, Gambelli P, Memmi M, Scacchi S, Pavarino LF, Franzone PC, Lentini G, Filgueiras-Rama D, Galli C, Santiago DJ, Priori SG. Unexpected impairment of INa underpins reentrant arrhythmias in a knock-in swine model of Timothy syndrome. NATURE CARDIOVASCULAR RESEARCH 2023; 2:1291-1309. [PMID: 38665938 PMCID: PMC11041658 DOI: 10.1038/s44161-023-00393-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 11/15/2023] [Indexed: 04/28/2024]
Abstract
Timothy syndrome 1 (TS1) is a multi-organ form of long QT syndrome associated with life-threatening cardiac arrhythmias, the organ-level dynamics of which remain unclear. In this study, we developed and characterized a novel porcine model of TS1 carrying the causative p.Gly406Arg mutation in CACNA1C, known to impair CaV1.2 channel inactivation. Our model fully recapitulated the human disease with prolonged QT interval and arrhythmic mortality. Electroanatomical mapping revealed the presence of a functional substrate vulnerable to reentry, stemming from an unforeseen constitutional slowing of cardiac activation. This signature substrate of TS1 was reliably identified using the reentry vulnerability index, which, we further demonstrate, can be used as a benchmark for assessing treatment efficacy, as shown by testing of multiple clinical and preclinical anti-arrhythmic compounds. Notably, in vitro experiments showed that TS1 cardiomyocytes display Ca2+ overload and decreased peak INa current, providing a rationale for the arrhythmogenic slowing of impulse propagation in vivo.
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Affiliation(s)
- Andreu Porta-Sánchez
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Andrea Mazzanti
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Carmen Tarifa
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Deni Kukavica
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Alessandro Trancuccio
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Muhammad Mohsin
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
| | | | | | | | - Kevin Hernandez-Lopez
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | | | - Valerio Pergola
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy
| | - Eugenio Fernandez
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Rossana Bongianino
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
| | - Elisa Tavazzani
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
| | - Patrick Gambelli
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
| | - Mirella Memmi
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
| | - Simone Scacchi
- Department of Mathematics, University of Milan, Milano, Italy
| | | | - Piero Colli Franzone
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
- AVANTEA, Cremona, Italy
- Department of Advanced Biomedical Sciences, University of Naples Federico II, Naples, Italy
- Department of Mathematics, University of Milan, Milano, Italy
- Department of Mathematics, University of Pavia, Pavia, Italy
- Department of Pharmacology, University of Bari, Bari, Italy
- Cardiovascular Institute, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares, Madrid, Spain
| | | | - David Filgueiras-Rama
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Cardiovascular Institute, Instituto de Investigación Sanitaria del Hospital Clínico San Carlos (IdISSC), Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares, Madrid, Spain
| | | | - Demetrio Julián Santiago
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
| | - Silvia G. Priori
- Novel Arrhythmogenic Mechanism Program, Centro Nacional de Investigaciones Cardiovasculares (CNIC), Madrid, Spain
- Molecular Cardiology, IRCCS Istituti Clinici Scientifici Maugeri, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
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Zhang W, Dong E, Zhang J, Zhang Y. CaMKII, 'jack of all trades' in inflammation during cardiac ischemia/reperfusion injury. J Mol Cell Cardiol 2023; 184:48-60. [PMID: 37813179 DOI: 10.1016/j.yjmcc.2023.10.003] [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: 06/23/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 10/11/2023]
Abstract
Myocardial infarction and revascularization cause cardiac ischemia/reperfusion (I/R) injury featuring cardiomyocyte death and inflammation. The Ca2+/calmodulin dependent protein kinase II (CaMKII) family are serine/ threonine protein kinases that are involved in I/R injury. CaMKII exists in four different isoforms, α, β, γ, and δ. In the heart, CaMKII-δ is the predominant isoform,with multiple splicing variants, such as δB, δC and δ9. During I/R, elevated intracellular Ca2+ concentrations and reactive oxygen species activate CaMKII. In this review, we summarized the regulation and function of CaMKII in multiple cell types including cardiomyocytes, endothelial cells, and macrophages during I/R. We conclude that CaMKII mediates inflammation in the microenvironment of the myocardium, resulting in cell dysfunction, elevated inflammation, and cell death. However, different CaMKII-δ variants exhibit distinct or even opposite functions. Therefore, reagents/approaches that selectively target specific CaMKII isoforms and variants are needed for evaluating and counteracting the exact role of CaMKII in I/R injury and developing effective treatments against I/R injury.
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Affiliation(s)
- Wenjia Zhang
- State Key Laboratory of Vascular Homeostasis and Remodeling, Institute of Cardiovascular Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China
| | - Erdan Dong
- Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China; Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing 100191, China; Haihe Laboratory of Cell Ecosystem, Beijing 100191, China
| | - Junxia Zhang
- Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China; Department of Cardiology and Institute of Vascular Medicine, Peking University Third Hospital, State Key Laboratory of Vascular Homeostasis and Remodeling, Peking University, NHC Key Laboratory of Cardiovascular Molecular Biology and Regulatory Peptides, Beijing 100191, China; Haihe Laboratory of Cell Ecosystem, Beijing 100191, China.
| | - Yan Zhang
- State Key Laboratory of Vascular Homeostasis and Remodeling, Institute of Cardiovascular Sciences, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China; Beijing Key Laboratory of Cardiovascular Receptors Research, Beijing 100191, China.
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MacLeod KT. Changes in cellular Ca 2+ and Na + regulation during the progression towards heart failure. J Physiol 2023; 601:905-921. [PMID: 35946572 PMCID: PMC10952717 DOI: 10.1113/jp283082] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 08/02/2022] [Indexed: 11/08/2022] Open
Abstract
In adapting to disease and loss of tissue, the heart shows great phenotypic plasticity that involves changes to its structure, composition and electrophysiology. Together with parallel whole body cardiovascular adaptations, the initial decline in cardiac function resulting from the insult is compensated. However, in the long term, the heart muscle begins to fail and patients with this condition have a very poor prognosis, with many dying from disturbances of rhythm. The surviving myocytes of these hearts gain Na+ , which is positively inotropic because of alterations to Ca2+ fluxes mediated by the Na+ /Ca2+ exchange, but compromises Ca2+ -dependent energy metabolism in mitochondria. Uptake of Ca2+ into the sarcoplasmic reticulum (SR) is reduced because of diminished function of SR Ca2+ ATPases. The result of increased Ca2+ influx and reduced SR Ca2+ uptake is an increase in the diastolic cytosolic Ca2+ concentration, which promotes spontaneous SR Ca2+ release and induces delayed afterdepolarisations. Action potential duration prolongs because of increased late Na+ current and changes in expression and function of other ion channels and transporters increasing the probability of the formation of early afterdepolarisations. There is a reduction in T-tubule density and so the normal spatial arrangements required for efficient excitation-contraction coupling are compromised and lead to temporal delays in Ca2+ release from the SR. Therefore, the structural and electrophysiological responses that occur to provide compensation do so at the expense of (1) increasing the likelihood of arrhythmogenesis; (2) activating hypertrophic, apoptotic and Ca2+ signalling pathways; and (3) decreasing the efficiency of SR Ca2+ release.
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Affiliation(s)
- Kenneth T. MacLeod
- National Heart & Lung InstituteImperial Centre for Translational and Experimental MedicineImperial CollegeHammersmith HospitalLondonUK
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Saadeh K, Nantha Kumar N, Fazmin IT, Edling CE, Jeevaratnam K. Anti-malarial drugs: Mechanisms underlying their proarrhythmic effects. Br J Pharmacol 2022; 179:5237-5258. [PMID: 36165125 PMCID: PMC9828855 DOI: 10.1111/bph.15959] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/06/2022] [Accepted: 04/28/2022] [Indexed: 01/12/2023] Open
Abstract
Malaria remains the leading cause of parasitic death in the world. Artemisinin resistance is an emerging threat indicating an imminent need for novel combination therapy. Given the key role of mass drug administration, it is pivotal that the safety of anti-malarial drugs is investigated thoroughly prior to widespread use. Cardiotoxicity, most prominently arrhythmic risk, has been a concern for anti-malarial drugs. We clarify the likely underlying mechanisms by which anti-malarial drugs predispose to arrhythmias. These relate to disruption of (1) action potential upstroke due to effects on the sodium currents, (2) action potential repolarisation due to effects on the potassium currents, (3) cellular calcium homeostasis, (4) mitochondrial function and reactive oxygen species production and (5) cardiac fibrosis. Together, these alterations promote arrhythmic triggers and substrates. Understanding these mechanisms is essential to assess the safety of these drugs, stratify patients based on arrhythmic risk and guide future anti-malarial drug development.
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Affiliation(s)
- Khalil Saadeh
- Faculty of Health and Medical SciencesUniversity of SurreyGuildfordUK,School of Clinical Medicine, Addenbrooke's HospitalUniversity of CambridgeCambridgeUK
| | | | - Ibrahim Talal Fazmin
- Faculty of Health and Medical SciencesUniversity of SurreyGuildfordUK,School of Clinical Medicine, Addenbrooke's HospitalUniversity of CambridgeCambridgeUK
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8
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Zou T, Chen Q, Chen C, Liu G, Ling Y, Pang Y, Xu Y, Cheng K, Zhu W, Wang RX, Qian LL, Ge J. Moricizine prevents atrial fibrillation by late sodium current inhibition in atrial myocytes. J Thorac Dis 2022; 14:2187-2200. [PMID: 35813708 PMCID: PMC9264100 DOI: 10.21037/jtd-22-534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 05/18/2022] [Indexed: 11/25/2022]
Abstract
Background Enhanced late sodium current (INaL) is reportedly related to an increased risk of atrial fibrillation (AF). Moricizine, as a widely used anti-arrhythmia drug for suppressing ventricular tachycardia, has also been shown to prevent paroxysmal AF. However, the mechanism of its therapeutic effect remains poorly understood. Methods Angiotensin II (Ang II) was induced in C57Bl/6 mice (male wild-type) for 4 weeks to increase the susceptibility of AF, and acetylcholine-calcium chloride was used to induce AF. The whole-cell patch-clamp technique was used to detect INaL from isolated atrial myocytes. The expression of proteins in atrial of mice and HL-1 cells were examined by Western-blot. Results The results showed that moricizine significantly inhibited Ang II-mediated atrial enlargement and reduced AF vulnerability. We found that the densities of INaL were enhanced in Ang II-treated left and right atrial cardiomyocytes. Simultaneously, the Ang II-induced increase in INaL currents density was alleviated by the administration of moricizine, and no alteration in Nav1.5 expression was observed. In normal isolated atrial myocytes, moricizine significantly reduced Sea anemone toxin II (ATX II)-enhanced INaL density with a reduction of peak sodium currents. In addition, moricizine reduced the Ang II-induced upregulation of phosphorylated calcium/calmodulin-dependent protein kinase-II (p-CaMKII) in both the left and right atria. In HL-1 cells, moricizine also reduced the upregulation of p-CaMKII with Ang II and ATX II intervention, respectively. Conclusions Our results indicate that Ang II enhances the INaL via activation of CaMKII. Moricizine inhibits INaL and reduces CaMKII activation, which may be one of the mechanisms of moricizine suppression of AF.
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Affiliation(s)
- Tian Zou
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
| | - Qingxing Chen
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
| | - Chaofeng Chen
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
| | - Guijian Liu
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
| | - Yunlong Ling
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
| | - Yang Pang
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
| | - Ye Xu
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
| | - Kuan Cheng
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
| | - Wenqing Zhu
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
| | - Ru-Xing Wang
- Department of Cardiology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, China
| | - Ling-Ling Qian
- Department of Cardiology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, China
| | - Junbo Ge
- Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Disease, Shanghai, China
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Premont A, Balthes S, Marr CM, Jeevaratnam K. Fundamentals of arrhythmogenic mechanisms and treatment strategies for equine atrial fibrillation. Equine Vet J 2021; 54:262-282. [PMID: 34564902 DOI: 10.1111/evj.13518] [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: 12/21/2020] [Revised: 09/13/2021] [Accepted: 09/16/2021] [Indexed: 11/26/2022]
Abstract
Atrial fibrillation (AF) is the most common pathological arrhythmia in horses. Although it is not usually a life-threatening condition on its own, it can cause poor performance and make the horse unsafe to ride. It is a complex multifactorial disease influenced by both genetic and environmental factors including exercise training, comorbidities or ageing. The interactions between all these factors in horses are still not completely understood and the pathophysiology of AF remains poorly defined. Exciting progress has been recently made in equine cardiac electrophysiology in terms of diagnosis and documentation methods such as cardiac mapping, implantable electrocardiogram (ECG) recording devices or computer-based ECG analysis that will hopefully improve our understanding of this disease. The available pharmaceutical and electrophysiological treatments have good efficacy and lead to a good prognosis for AF, but recurrence is a frequent issue that veterinarians have to face. This review aims to summarise our current understanding of equine cardiac electrophysiology and pathophysiology of equine AF while providing an overview of the mechanism of action for currently available treatments for equine AF.
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Affiliation(s)
- Antoine Premont
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Samantha Balthes
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, UK
| | - Celia M Marr
- Rossdales Equine Hospital and Diagnostic Centre, Newmarket, UK
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10
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Non-Coding RNAs in the Cardiac Action Potential and Their Impact on Arrhythmogenic Cardiac Diseases. HEARTS 2021. [DOI: 10.3390/hearts2030026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Cardiac arrhythmias are prevalent among humans across all age ranges, affecting millions of people worldwide. While cardiac arrhythmias vary widely in their clinical presentation, they possess shared complex electrophysiologic properties at cellular level that have not been fully studied. Over the last decade, our current understanding of the functional roles of non-coding RNAs have progressively increased. microRNAs represent the most studied type of small ncRNAs and it has been demonstrated that miRNAs play essential roles in multiple biological contexts, including normal development and diseases. In this review, we provide a comprehensive analysis of the functional contribution of non-coding RNAs, primarily microRNAs, to the normal configuration of the cardiac action potential, as well as their association to distinct types of arrhythmogenic cardiac diseases.
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11
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Dries E, Bardi I, Nunez-Toldra R, Meijlink B, Terracciano CM. CaMKII inhibition reduces arrhythmogenic Ca2+ events in subendocardial cryoinjured rat living myocardial slices. J Gen Physiol 2021; 153:212078. [PMID: 33956073 PMCID: PMC8105719 DOI: 10.1085/jgp.202012737] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 04/13/2021] [Indexed: 01/08/2023] Open
Abstract
Spontaneous Ca2+ release (SCR) can cause triggered activity and initiate arrhythmias. Intrinsic transmural heterogeneities in Ca2+ handling and their propensity to disease remodeling may differentially modulate SCR throughout the left ventricular (LV) wall and cause transmural differences in arrhythmia susceptibility. Here, we aimed to dissect the effect of cardiac injury on SCR in different regions in the intact LV myocardium using cryoinjury on rat living myocardial slices (LMS). We studied SCR under proarrhythmic conditions using a fluorescent Ca2+ indicator and high-resolution imaging in LMS from the subendocardium (ENDO) and subepicardium (EPI). Cryoinjury caused structural remodeling, with loss in T-tubule density and an increased time of Ca2+ transients to peak after injury. In ENDO LMS, the Ca2+ transient amplitude and decay phase were reduced, while these were not affected in EPI LMS after cryoinjury. The frequency of spontaneous whole-slice contractions increased in ENDO LMS without affecting EPI LMS after injury. Cryoinjury caused an increase in foci that generates SCR in both ENDO and EPI LMS. In ENDO LMS, SCRs were more closely distributed and had reduced latencies after cryoinjury, whereas this was not affected in EPI LMS. Inhibition of CaMKII reduced the number, distribution, and latencies of SCR, as well as whole-slice contractions in ENDO LMS, but not in EPI LMS after cryoinjury. Furthermore, CaMKII inhibition did not affect the excitation–contraction coupling in cryoinjured ENDO or EPI LMS. In conclusion, we demonstrate increased arrhythmogenic susceptibility in the injured ENDO. Our findings show involvement of CaMKII and highlight the need for region-specific targeting in cardiac therapies.
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Affiliation(s)
- Eef Dries
- National Heart and Lung Institute, Imperial College London, London, UK.,Lab of Experimental Cardiology, Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium
| | - Ifigeneia Bardi
- National Heart and Lung Institute, Imperial College London, London, UK
| | | | - Bram Meijlink
- National Heart and Lung Institute, Imperial College London, London, UK
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